The research team, led by Yihong Sun and Jianxin Jia, set out to answer a question that has lingered around this traditional medicinal plant for years. Cistanche glycosides, a family of phenylethanoid-rich compounds derived from a parasitic desert flower long used in Chinese medicine, had already shown antioxidant and neuroprotective effects in earlier studies, including work suggesting they could improve cognition in sleep-deprived animals. What remained unknown was whether the compound acts through this specific signaling cascade, and, crucially, whether the pathway is truly required for the benefits rather than merely changing in parallel with them.

To find out, the researchers built a rigorous experimental system. Sixty male Sprague Dawley rats were randomly assigned to six groups of ten: a normal control group, a platform control group, a sleep deprivation model group, a group receiving 50 mg/kg of the glycosides by daily gavage, a combined control-plus-glycoside group, and a group treated with the prescription sedative estazolam as a comparator. Sleep deprivation was induced with a modified multiple platform water environment method: rats stood on small platforms in shallow water for twelve hours each day over 21 consecutive days, a setup that fragments sleep without immersing the animals and that reliably produces the hallmark cognitive consequences of chronic sleep loss.

The behavioral consequences of that regimen were stark. In the Morris water maze, a standard test of spatial learning and memory in which rats must locate a hidden platform in murky water, sleep-deprived animals took significantly longer to find the platform and, when the platform was removed on the final day, crossed the target location far less often and spent less time in the target quadrant than controls. Electroencephalogram recordings, obtained from electrodes surgically implanted in the skull and neck muscles, confirmed that the model succeeded: deprived rats showed markedly increased wake time and reduced non-REM, REM, and total sleep time. Serum analysis told a parallel biochemical story, with elevated malondialdehyde, a marker of oxidative lipid damage, alongside sharply reduced activities of the antioxidant enzymes superoxide dismutase and glutathione peroxidase.

Under the microscope, the damage extended into the hippocampus, the brain’s memory hub. Nissl staining revealed that pyramidal neurons in the CA1 region of sleep-deprived rats were disorganized, shrunken, and depleted of Nissl bodies, the dense clusters of protein-making machinery that signal healthy neurons. Transmission electron microscopy went deeper still, showing mitochondria with blurred membrane boundaries, ruptured cristae, and vacuolation, the cellular equivalent of power plants falling apart. Western blot analysis then connected these structural injuries to a molecular collapse: protein levels of SIRT1, PGC-1α, and Nrf2, along with the synaptic proteins synaptophysin, PSD-95, and the neurotrophic factor BDNF, were all significantly downregulated in the deprived hippocampus.

Glycoside treatment turned this picture around. Rats receiving the compound showed shortened escape latencies, more platform crossings, and more time in the target quadrant, and they recovered a more normal sleep architecture with increased REM and NREM proportions. Their antioxidant enzyme activities rebounded, malondialdehyde levels fell, hippocampal neurons regained their organized structure and Nissl bodies, and mitochondrial morphology improved. At the molecular level, the full signaling axis, SIRT1, PGC-1α, and Nrf2, together with synaptophysin, PSD-95, and BDNF, was significantly upregulated compared with untreated sleep-deprived animals. Notably, the glycosides performed on par with estazolam across these measures, suggesting the natural extract matches a conventional sleep drug without operating through sedation alone.

The most decisive evidence came from a second cohort of forty rats in which the researchers introduced EX527, a pharmacological inhibitor that specifically blocks SIRT1. When EX527 was co-administered with the glycosides, the protective effects vanished. Treated animals again showed prolonged escape latencies, fewer platform crossings, disordered CA1 neurons, damaged mitochondria, and suppressed expression of the pathway and synaptic proteins. Statistically, the performance of the inhibitor group was indistinguishable from that of untreated sleep-deprived rats. In other words, switching off SIRT1 abolished everything the plant compound had accomplished, providing causal proof that the SIRT1/PGC-1α/Nrf2 axis is the mechanism of action rather than a bystander.

Understanding why this matters requires a look at how the pathway works. SIRT1 is an NAD+-dependent deacetylase, a longevity-linked enzyme that senses cellular energy state and removes acetyl groups from target proteins. One of its key targets is PGC-1α, the master regulator of mitochondrial biogenesis. When SIRT1 deacetylates PGC-1α, the coactivator drives Nrf2 into the nucleus, where it switches on a battery of antioxidant genes that neutralize the free radicals accumulating in stressed neurons. Sleep deprivation suppresses this entire cascade, leaving mitochondria damaged and synapses vulnerable. The new study demonstrates that glycosides of Cistanche restore the axis from its upstream gatekeeper down to its synaptic outputs, extending earlier work showing that hydrogen sulfide can protect the hippocampus by upregulating SIRT1 in sleep-deprived animals.

The authors are candid about the study’s boundaries. Only young adult male rats were tested, leaving questions about whether the findings generalize to females or aged animals. A single dose of the extract was used, so no dose-response relationship has been established. Because glycosides of Cistanche are a multi-component botanical extract, the specific constituent responsible for SIRT1 activation remains unidentified, and more rigorous phytochemical standardization will be needed before clinical translation. The researchers also note that other mechanisms, such as direct activation of Nrf2 or anti-inflammatory actions, cannot be entirely excluded, and sleep architecture was measured only in a two-hour window after deprivation sessions.

Even with those caveats, the convergence of behavioral, histological, ultrastructural, and molecular evidence, capped by pharmacological reversal, makes a compelling case. For shift workers, students, and the billions of adults who sleep less than the recommended seven to nine hours, the prospect of a natural compound that shields the sleep-deprived brain is tantalizing. The findings do not suggest that pills can substitute for sleep, but they do identify a concrete molecular target for future neuroprotective drugs aimed at the cognitive toll of sleep disorders, and they lend modern mechanistic rigor to a desert plant that traditional medicine has prized for centuries.

Subject of Research: Neuroprotective effects of Cistanche glycosides on sleep deprivation-induced cognitive dysfunction via the SIRT1/PGC-1α/Nrf2 pathway

Article Title: Glycosides of Cistanche improve cognitive dysfunction in sleep-deprived model rats by activating the SIRT1/PGC-1α/Nrf2 signaling pathway

Article References: Li, Q., Zhao, S., Huo, J., Wang, Y., Sun, Y., & Jia, J. (2026). Glycosides of Cistanche improve cognitive dysfunction in sleep-deprived model rats by activating the SIRT1/PGC-1α/Nrf2 signaling pathway. Frontiers in Molecular Neuroscience, 19, Article 1945359. https://doi.org/10.3389/fnmol.2026.1945359

Image Credits: AI Generated

DOI: 10.3389/fnmol.2026.1945359

Keywords: sleep deprivation, Cistanche glycosides, SIRT1, PGC-1α, Nrf2, oxidative stress, hippocampus, synaptic plasticity, mitochondria, Morris water maze, EX527, neuroprotection

The logistics of a motor neuron are staggering. These cells extend axons that can stretch up to a meter in the human body, and their distant terminals need a constant supply of fresh mitochondria, the organelles that generate the chemical energy ATP required for synaptic transmission and cellular survival. Moving mitochondria along the axon is an energy-intensive process in itself, and when that transport falters, the far reaches of the neuron are starved of power while damaged organelles pile up. Disrupted axonal transport has been implicated in ALS for years, and previous work had established that C9ORF72 motor neurons show cell-autonomous defects in mitochondrial motility and function. What remained unknown was whether the astrocytes surrounding those neurons—cells already known to contribute to non-cell-autonomous neurodegeneration through mechanisms such as reduced glutamate uptake and impaired lactate shuttling—also influence this transport machinery.

To find out, the team built a rigorous human stem-cell platform. They used induced pluripotent stem cell lines derived from three patients carrying the C9ORF72 repeat expansion, together with isogenic gene-corrected controls created through CRISPR–Cas9 editing, in which the mutation was removed. From these lines they generated highly enriched spinal cord-patterned astrocytes, more than ninety percent of which expressed the canonical astrocyte markers glial fibrillary acidic protein and S100B, as well as motor neuron cultures of which roughly half to sixty percent were ISL1/2-positive motor neurons. The mutant astrocytes carried hallmark C9ORF72 pathologies, including RNA foci and dipeptide repeat proteins, yet showed no differences in glutamate uptake or calcium wave propagation, meaning any effects on transport could not be attributed to those well-known astrocyte dysfunctions.

The central experiment was elegantly simple. The researchers selectively labeled motor neurons with a fluorescent mitochondrial marker, mito-DsRed2, and then imaged mitochondrial movement along a hundred-micrometer stretch of the proximal axon using live-cell time-lapse microscopy, generating kymographs from which they extracted two established metrics: the percentage of mitochondria that were motile and their average velocity. When genetically normal motor neurons were grown in physical contact with C9ORF72-mutant astrocytes, both measures dropped significantly compared with motor neurons cultured alone. Strikingly, when the same control neurons were paired with gene-corrected astrocytes, the deficit vanished entirely. Even more remarkable, mutant motor neurons cocultured with corrected astrocytes recovered both transport parameters to wild-type levels. In these mixed cultures, the phenotype of the neuron’s mitochondrial traffic was dictated not by the neuron’s own genome but by the genotype of its astrocyte neighbors.

Contact, it turned out, was essential. When the team treated control motor neurons with conditioned medium harvested from mutant astrocytes, mitochondrial motility was unaffected, indicating that secreted factors alone could not reproduce the damage; direct physical interaction between the two cell types was required. The specificity of the defect was equally revealing. Tracking HcT-labeled signaling endosomes, another vital axonal cargo, showed no transport changes in any coculture combination. The astrocyte effect was therefore cargo-specific, targeting mitochondria rather than causing a global collapse of axonal transport. The authors suggest this selectivity reflects distinct energetic dependencies: signaling endosomes fuel their movement with locally generated glycolytic ATP, whereas mitochondrial motility depends on membrane potential and calcium-regulated adaptors such as Miro, directly coupling transport to the bioenergetic state of the organelle itself.

That coupling became the thread the researchers followed next. Using Seahorse extracellular flux analysis, they measured oxygen consumption rates as a proxy for mitochondrial respiration. Because motor neuron cultures respire at nearly eightfold the rate of astrocytes alone, changes in coculture readings could be confidently attributed to the neurons. The results were unambiguous: coculture with astrocytes of either genotype boosted basal and maximal respiration relative to neuron monocultures, but pairing neurons with mutant astrocytes significantly reduced both parameters compared with pairing them with corrected astrocytes. A complementary assay using the potentiometric dye MitoTracker Red CMXRos confirmed that the steady-state mitochondrial membrane potential of motor neurons—mutant or normal—fell in the presence of mutant astrocytes and recovered with corrected astrocytes. The astrocyte genotype was directly modulating the bioenergetic health of neurons it touched.

The root of the problem lay within the astrocytes themselves. Isolated C9ORF72-mutant astrocytes showed significantly reduced basal, ATP-linked and maximal respiration compared with their gene-corrected counterparts, along with diminished glycolytic capacity, lactate production and glucose utilization. RNA sequencing, however, revealed no genotype-driven astrocyte reactivity, making a gain-of-toxic-function inflammatory mechanism unlikely. Intriguingly, when the team measured intracellular lactate in motor neurons using a genetically encoded FRET biosensor called Laconic, they found no significant differences across coculture conditions, suggesting that disrupted oxidative metabolism within astrocytes, rather than altered lactate transfer to neurons, mediates the transport deficit. The astrocytes were not failing to deliver fuel; they were failing in a way that somehow drains the neurons’ own power plants.

The therapeutic implication emerged from a rescue experiment targeting the master regulator of mitochondrial biogenesis. The team overexpressed three key metabolic genes in mutant astrocytes via lentiviral delivery: PPARGC1A (encoding PGC-1α), PPARGC1B (PGC-1β) and TFAM. PGC-1β proved toxic to the astrocytes, and TFAM, consistent with prior reports that it does not drive mitochondrial biogenesis, conferred no benefit. PGC-1α, by contrast, upregulated transcripts of the mitochondrial electron transport chain, including MT-CO2, MT-ND2, MT-CO3, MT-ND4 and MT-ATP6, and produced a trend toward increased respiration. When mutant astrocytes overexpressing PGC-1α were cocultured with motor neurons—mutant or corrected—mitochondrial motility and velocity were restored. Boosting the metabolic engine of the astrocyte alone was sufficient to repair the transport machinery inside genetically distinct neurons.

The findings reframe how scientists think about non-cell-autonomous degeneration in ALS. Rather than astrocytes poisoning neurons through inflammatory or excitotoxic signals, this work describes a bioenergetically coupled mechanism in which the metabolic competence of glia sets the ceiling for mitochondrial dynamics in neurons. The result also resonates with earlier animal work in SOD1 models of ALS, where PGC-1α activation preserved mitochondrial function and delayed disease progression, hinting that metabolic rescue of glia could be a broadly applicable strategy. The authors caution that much remains to be defined, including whether direct mitochondrial exchange, metabolite or lipid transfer, vesicular signaling or other modes of metabolic coupling connect astrocytic energy status to neuronal mitochondrial behavior, and whether similar mechanisms operate across other ALS genotypes and in sporadic disease, which accounts for roughly ninety percent of cases.

For a disease with no cure and only modestly effective therapies, the identification of an actionable, astrocyte-centered node is significant. If pharmacological activation of the PGC-1α pathway in glia can correct non-cell-autonomous mitochondrial dysfunction in C9ORF72-ALS, it opens a therapeutic window that does not require correcting the mutation inside every neuron. The study, funded in part by the Medical Research Council, the UK Dementia Research Institute and the My Name’5 Doddie Foundation among others, demonstrates with unusual clarity that in neurodegeneration, the health of a neuron may depend as much on the metabolic company it keeps as on its own genes—a lesson that could reshape drug discovery for ALS well beyond the C9ORF72 mutation that first revealed it.

Subject of Research: Non-cell-autonomous regulation of axonal mitochondrial transport by C9ORF72-mutant astrocytes in amyotrophic lateral sclerosis

Article Title: Astrocytes regulate axonal mitochondrial transport deficits in C9ORF72 amyotrophic lateral sclerosis motor neurons

Article References: Stavrou, M., Heffernan, Á. B., Carter, R. N., Dando, O., Jiwaji, Z., Burr, K., Nanda, J., Villarroel-Campos, D., Masoud Abdelhafid, A., Cholewa-Waclaw, J., Soong, D., Story, D., Schiavo, G., Hardingham, G. E., Chandran, S., & Selvaraj, B. T. (2026). Astrocytes regulate axonal mitochondrial transport deficits in C9ORF72 amyotrophic lateral sclerosis motor neurons. Nature Neuroscience. https://doi.org/10.1038/s41593-026-02464-0

Image Credits: AI Generated

DOI: 10.1038/s41593-026-02464-0

Keywords: amyotrophic lateral sclerosis, C9ORF72, astrocytes, motor neurons, mitochondrial transport, axonal transport, mitochondrial bioenergetics, PGC-1α, induced pluripotent stem cells, non-cell-autonomous neurodegeneration, CRISPR gene correction, live-cell imaging

Exosomes are tiny extracellular vesicles, typically measuring between 30 and 150 nanometers, that cells use to shuttle proteins, lipids, and genetic material to one another. In the tumor microenvironment, they have emerged as important messengers of intercellular communication, and in the case of tumor-associated macrophages, they appear to function as vehicles of immune suppression. The Shanghai-led team wanted to understand precisely how these vesicles metabolically reprogram CD8-positive T cells. Metabolic reprogramming has become a central theme in tumor immunology because it is now clear that the functional state of an immune cell is inseparable from the fuel it burns and the way its mitochondria operate. An exhausted T cell is not merely a cell that has received too many inhibitory signals; it is a cell whose internal power plants have been fundamentally altered.

To model the peritoneal environment of ovarian cancer in the laboratory, the researchers induced M2-type macrophages from the mouse macrophage cell line RAW264.7 by exposing them to the cytokines interleukin-4 and interleukin-13. M2 macrophages are the immunosuppressive, wound-healing variety that tumors preferentially recruit, in contrast to the inflammatory M1 type that helps marshal anti-tumor responses. From these cells the team isolated exosomes using a commercial exosome isolation kit, and then co-cultured the resulting vesicles, which they called TAMs-Exo, with CD8-positive T cells harvested from mouse spleens. They found that these exosomes carry high levels of PD-L1 and are efficiently taken up by the T cells. Once inside, the vesicles significantly impaired three critical dimensions of T-cell function: cytotoxicity, the capacity to kill target cells; proliferation, the ability to expand in numbers after encountering a tumor; and the secretion of effector molecules, including the inflammatory messenger interferon-gamma and the cell-killing enzyme granzyme B.

The mechanistic heart of the paper lies in what happened to the T cells’ mitochondria after exposure to TAMs-Exo. The researchers systematically assessed mitochondrial function using a battery of assays: Western blotting to track protein expression, JC-1 staining to measure mitochondrial membrane potential, ATP assays to quantify cellular energy charge, and assays for reactive oxygen species and lipid peroxidation to gauge oxidative damage. They also directly measured the rate of fatty acid oxidation, the metabolic pathway by which cells break down fatty acids in mitochondria to generate energy. What they observed was a paradoxical combination. On one hand, the exosomes activated the PGC-1α/PPARα/CPT1A axis, a transcriptional program that upregulates the machinery of fatty acid oxidation. On the other hand, the cells showed a collapse in mitochondrial membrane potential, depletion of ATP, and accumulation of reactive oxygen species and lipid peroxides, which are hallmarks of mitochondrial dysfunction.

PGC-1α, or peroxisome proliferator-activated receptor gamma coactivator 1-alpha, is a master regulator of mitochondrial biogenesis and oxidative metabolism. It works in concert with PPARα, a nuclear receptor that controls the expression of genes involved in fatty acid catabolism, including CPT1A, the rate-limiting enzyme that shuttles fatty acids into mitochondria for oxidation. In a healthy context, this axis helps cells adapt to energy demands by tuning oxidative capacity. But the new findings suggest that when this axis is pathologically overactivated in CD8-positive T cells, the result is not enhanced fitness but a kind of metabolic overload. The cells are driven to burn fatty acids at an abnormally high rate even as their mitochondria lose the membrane potential needed to sustain efficient oxidative phosphorylation, leaving them energy-starved and drowning in oxidative byproducts. The researchers interpret this as a compensatory response that ultimately deepens the damage rather than repairing it.

To establish that PD-L1 carried on the exosomes is the causal agent rather than a mere passenger, the team performed two complementary experiments. First, they stimulated CD8-positive T cells with recombinant PD-L1 protein and found that it mimicked the effects of the macrophage-derived exosomes, reproducing the activation of the PGC-1α/PPARα axis, the shift toward excessive fatty acid oxidation, and the resulting mitochondrial dysfunction. Second, they used short hairpin RNA to knock down PD-L1 expression in the macrophages before isolating exosomes, and found that exosomes depleted of PD-L1 lost much of their ability to induce T-cell dysfunction. In a further test of the metabolic mechanism, treatment with etomoxir, a pharmacological inhibitor of fatty acid oxidation, significantly reversed the T-cell impairment caused by the exosomes. Together, these results argue that exosomal PD-L1 is not simply an inhibitory checkpoint molecule delivered from the outside but a trigger that rewrites the metabolic identity of the recipient T cell from within.

Importantly, the team extended their findings beyond the culture dish. They established an ID8 intraperitoneal metastasis mouse model, a widely used system in which murine ovarian cancer cells are introduced into the peritoneal cavity to recapitulate the pattern of spread seen in human epithelial ovarian cancer. In this model, administration of TAMs-Exo promoted the formation of ascites, the fluid accumulation characteristic of advanced ovarian cancer, and increased the number of peritoneal metastatic nodules. When the researchers examined the CD8-positive T cells recovered from the peritoneal cavity of these mice, they found the same molecular signatures observed in vitro: abnormal activation of the PGC-1α/PPARα axis and evidence of mitochondrial dysfunction. This convergence between the cell culture data and the in vivo observations strengthens the case that the exosome-mediated metabolic reprogramming is not an artifact of laboratory conditions but a process that operates in living tissue.

The clinical significance of these findings is considerable. Ovarian cancer is among the most lethal gynecologic malignancies, and its propensity to spread across the peritoneal lining rather than through the bloodstream makes peritoneal metastasis the dominant pattern of disease progression. Immune checkpoint inhibitors, which have transformed the treatment of many cancers by releasing PD-1/PD-L1-mediated brakes on T cells, have shown limited benefit in ovarian cancer, and the reasons have remained incompletely understood. This study suggests one contributing mechanism: even if a patient’s T cells are liberated from inhibitory signaling at their own PD-1 receptors, they may remain metabolically crippled by exosomes shed from tumor-associated macrophages. In other words, the checkpoint problem may be only the visible surface of a deeper metabolic problem that standard immunotherapy does not address.

The authors propose that targeting what they describe as a metabolic checkpoint may offer a new combination strategy for overcoming immunotherapy resistance in ovarian cancer. In practice, this could mean blocking exosomal PD-L1 to prevent the vesicles from reprogramming T cells in the first place, or inhibiting excessive fatty acid oxidation flux with agents such as etomoxir-like compounds to relieve the mitochondrial strain imposed on the killer cells. The research was supported by the National Natural Science Foundation of China under grant number 81974440, and all animal experiments were approved by the Renji Hospital Animal Experiment Ethics Committee of Shanghai Jiaotong University School of Medicine. Much work remains before such strategies can be translated to patients, including the development of clinically viable approaches to intercept macrophage-derived exosomes and the validation of these mechanisms in human tumor samples. Nevertheless, by tracing a direct line from macrophage vesicles through a defined transcriptional axis to mitochondrial collapse and tumor spread, the study adds a compelling new layer to the growing recognition that the battle against cancer is fought as much in the metabolism of immune cells as in their receptors.

Subject of Research: How exosomal PD-L1 from tumor-associated macrophages metabolically reprograms CD8-positive T cells to promote peritoneal metastasis in epithelial ovarian cancer

Article Title: TAMs-derived exosomal PD-L1 drives mitochondrial dysfunction and aberrant fatty acid oxidation via PGC-1α/PPARα axis to promote peritoneal metastasis in epithelial ovarian cancer

Article References: Ma, J., Wang, Q., Cen, Q., Zhu, J., & Zhou, J. (2026). TAMs-derived exosomal PD-L1 drives mitochondrial dysfunction and aberrant fatty acid oxidation via PGC-1α/PPARα axis to promote peritoneal metastasis in epithelial ovarian cancer. Journal of Ovarian Research. https://doi.org/10.1186/s13048-026-02277-6

Image Credits: AI Generated

DOI: 10.1186/s13048-026-02277-6

Keywords: ovarian cancer, tumor-associated macrophages, exosomes, PD-L1, CD8 T cells, mitochondrial dysfunction, fatty acid oxidation, PGC-1α, PPARα, metabolic reprogramming, peritoneal metastasis, tumor microenvironment

The logic behind the trial rests on one of biology’s most fundamental cofactors: nicotinamide adenine dinucleotide, or NAD+. This molecule sits at the heart of cellular energy metabolism, shuttling electrons during the reactions that ultimately generate adenosine triphosphate, the chemical currency that powers everything from muscle contraction to neural signaling. In mitochondrial disorders, the oxidative phosphorylation system that performs this energy conversion is defective, and NAD+ availability is thought to become limiting. Boosting NAD+ has previously improved mitochondrial function in a range of animal and cellular models of impaired oxidative metabolism, but until now the strategy had never been tested in human patients.

Nicotinamide riboside is a form of vitamin B3 that acts as a precursor to NAD+. When cells take it up, enzymatic pathways convert it into NAD+, raising the intracellular pool of this critical cofactor. Among its downstream effects is the activation of SIRT1, an NAD+-dependent enzyme that in turn activates PGC-1α, the master regulator of mitochondrial biogenesis. In principle, this cascade should coax cells to build more mitochondria and to express more mitochondrial genes, compensating for the respiratory chain defects that define these diseases. The Cambridge team, led by Katherine Schon and Patrick Chinnery, set out to determine whether this theoretical chain of events actually unfolds in living human muscle.

The study was deliberately small but unusually deep in its measurements. Eight participants took part: three carried single large-scale mitochondrial DNA deletions, a common cause of chronic progressive external ophthalmoplegia, and five carried the m.3243 A>G or A>T pathogenic variants, which underlie conditions such as MELAS syndrome and a spectrum of neurological and muscular disease. Each participant received 1,250 to 2,000 milligrams of nicotinamide riboside per day for four weeks. Before and after treatment, the researchers measured clinical outcomes including the timed up and go test, the six-minute walk test, grip strength and quality of life questionnaires. They also tracked blood biomarkers GDF15 and FGF21, used phosphorus-31 magnetic resonance spectroscopy to assess mitochondrial function in vivo, and took quadriceps muscle biopsies for an exhaustive molecular workup.

The biopsies were where the study’s most striking findings emerged. Muscle histopathology revealed that in the three participants with single large-scale deletions, the percentage of cytochrome c oxidase deficient fibers and ragged-red fibers, the classic cellular signatures of mitochondrial dysfunction, decreased after treatment. Respiratory chain complex I and complex IV activities increased, and levels of the mtDNA deletions themselves fell. These changes were not observed in the five participants carrying the m.3243 variants, a divergence that turned out to be one of the most scientifically interesting aspects of the trial. It suggests that the two major classes of heteroplasmic mtDNA disease may respond differently to NAD+ boosting, and that the specific genetic diagnosis may determine who benefits.

Unbiased transcriptomic and integrated multi-omic analysis across all eight participants provided the mechanistic confirmation the researchers were seeking. The data showed a clear signature of mitochondrial biogenesis: activation of the SIRT1/PGC-1α axis, increased expression of mitochondrial genes, enhanced levels of NAD-related metabolites, and coordinated shifts in the abundance of mitochondrial proteins. In other words, the drug did exactly what the preclinical models predicted it would do in human tissue. This is a rare and valuable outcome in experimental medicine, where promising animal results frequently fail to translate. The multi-omic integration, combining transcriptomics, proteomics and metabolomics, demonstrated that the molecular response was coherent across multiple layers of biology rather than a scattered artifact.

On the clinical side, the results were more modest but still encouraging. Nicotinamide riboside proved bioavailable and well tolerated across the dose range, with no significant safety concerns reported. Overall, participants improved on the timed up and go test, a measure of mobility that captures the integrated function of muscle, balance and the nervous system. The other clinical measures, including the six-minute walk test and grip strength, did not show consistent improvement, which is unsurprising given the short four-week treatment period and the small number of participants. Mitochondrial disease progresses over years, and remodeling muscle biochemistry in a month is unlikely to translate immediately into measurable gains in endurance or strength.

The authors conclude that nicotinamide riboside has the potential to become the first small-molecule precision treatment for heteroplasmic mtDNA disorders, guided by the specific genetic diagnosis. That framing matters. Rather than a one-size-fits-all therapy, the data point toward a stratified approach in which patients with single large-scale deletions might be prioritized, while those with m.3243 variants may require different strategies or combination therapies. The finding that deletion levels themselves decreased in the deletion group is particularly provocative, because heteroplasmy level, the proportion of defective mitochondrial genomes within a cell, is a key determinant of disease severity. If NAD+ boosting can shift the balance toward healthier mitochondrial genomes, it would represent a genuinely disease-modifying mechanism rather than mere symptomatic support.

Important caveats remain. The study enrolled only eight participants, had no placebo control arm, and lasted just four weeks, so the clinical improvements cannot be definitively attributed to the drug, and the molecular findings require replication in larger, longer, randomized trials. The trial was prospectively registered on ClinicalTrials.gov as NCT03432871, and the researchers are candid that this is an experimental medicine study designed to establish mechanism and feasibility rather than to secure regulatory approval. Nevertheless, the field has waited a long time for any therapy that targets the root cause of these disorders, and the combination of human pharmacodynamics, histological improvement and multi-omic mechanistic evidence represents a genuine step forward.

For patients and families affected by mitochondrial disease, the study offers something that has been in short supply: a plausible path from bench to bedside. Nicotinamide riboside is already widely available as a dietary supplement, which raises both opportunities and risks, since self-dosing without medical supervision cannot replicate the monitored, genetically stratified approach the trial describes. The Cambridge team’s work, funded by a broad coalition including the Medical Research Council, the NIHR Cambridge Biomedical Research Centre, LifeArc’s Centre to Treat Mitochondrial Diseases and international partners, now sets the stage for properly powered efficacy trials. If those trials confirm what this first glimpse suggests, a vitamin B3 derivative could become the first approved precision medicine for a group of diseases that have, until now, been managed only with supportive care.

Subject of Research: Nicotinamide riboside treatment for heteroplasmic mitochondrial DNA disorders

Article Title: Effects of nicotinamide riboside in mitochondrial DNA disease

Article References: Schon, K. R., Sleigh, A., Golder, Z., Berghella, A., Tiet, M. Y., Lyons, C., Bozhilova, L. V., Nie, Y., Harrison, E., Seikus, C., Yu-Wai-Man, P., Quaegebeur, A., Roos, A., Hentschel, A., Biggs, H., Zeviani, M., Viscomi, C., van den Ameele, J., Horvath, R., & Chinnery, P. F. (2026). Effects of nicotinamide riboside in mitochondrial DNA disease. Genome Medicine. https://doi.org/10.1186/s13073-026-01764-1

Image Credits: AI Generated

DOI: 10.1186/s13073-026-01764-1

Keywords: mitochondrial disease, mitochondrial DNA, nicotinamide riboside, NAD+, mitochondrial biogenesis, mtDNA deletions, m.3243A>G, SIRT1, PGC-1α, experimental medicine, Genome Medicine, precision medicine

The motivation comes from a growing recognition that skin diseases are not uniform across depth. Using spatial transcriptomics, the research team mapped bleomycin-induced fibrotic skin and found sharply stratified pathology. In the subcutaneous layer, the adipocyte marker Fabp4 progressively declined, reflecting fat loss and metabolic dysfunction. In the dermis, the senescence marker Cdkn1a steadily rose, pointing to an accumulation of aged, inflammation-secreting fibroblasts. Histological examination of clinical specimens from patients with localized scleroderma confirmed the same architecture: disorganized dermal collagen and fibrotic replacement of the subdermal adipose compartment. Immunofluorescence co-staining revealed senescent fibroblasts clustered in the dermis and adipocyte-to-myofibroblast transition, known as AMT, in the subcutis.

These findings suggest that the dermis and subcutis follow separate pathogenic programs, with the dermis driven by inflammation and cellular senescence and the fat layer driven by metabolic failure and fibrotic remodeling. Conventional delivery approaches cannot respect that geography. Subcutaneous injections and electroporation tend to leave mRNA stranded in the superficial dermis, while standard microneedle patches struggle to reach beyond the upper skin compartments. The stratum corneum, the skin’s tough outer barrier, remains a formidable obstacle for nucleic acid therapeutics, and controlling delivery depth has been an persistent challenge in cutaneous mRNA medicine.

The new platform builds on the team’s earlier threaded microneedle technology, in which continuous spiral grooves are etched into a stainless-steel needle roughly 4 millimeters long with an outer diameter of 230 micrometers. The grooves serve as protective channels that guide nanoformulated cargo along the insertion tract, reducing shear stress and tissue damage while enabling layer-resolved deposition. In prior work, the platform delivered neurotrophic factors for nerve repair and penetrated cartilage’s subchondral region for joint repair. For the skin application, the distal 1.5 millimeters of the threaded region carries the therapeutic payload.

The two therapeutic modules were engineered with complementary release behaviors. The first is SRT1720@HA, a hyaluronic acid hydrogel loaded with SRT1720, a SIRT1 agonist chosen after spatial transcriptomic analysis identified SIRT1 as a target in the epidermal and superficial dermal regions. Rheological testing confirmed a stable viscoelastic network, and in vitro release experiments showed roughly 80 percent cumulative SRT1720 release over 96 hours. The second module is PGC1α@LNP, lipid nanoparticles encapsulating messenger RNA encoding PGC-1α, a master regulator of mitochondrial metabolism identified as a target in the dermal-subcutaneous transitional zone. The nanoparticles measured about 108 nanometers in diameter, achieved an encapsulation efficiency of 92.6 percent, and released approximately 65 percent of their mRNA payload over 96 hours. Confocal imaging demonstrated time-dependent endosomal escape, and the formulation survived lyophilization and one month of storage without losing its ability to drive PGC1α expression in cells.

When the two modules were combined on a single threaded needle, fluorescence tracing in simulated skin and in living mice revealed a striking spatial division of labor. The hydrogel coating, sitting on the needle’s exterior, was preferentially wiped off during insertion and retained in the dermis, much like a conventional coated needle. The groove-embedded nanoparticles, protected from premature displacement, were carried along the full insertion tract and deposited from the dermis into the subcutaneous layer, particularly during rotational manipulation. Each microneedle carried roughly 44 nanograms of encapsulated PGC1α mRNA and about 15 nanograms of SRT1720, quantified by batch weighing and liquid chromatography-tandem mass spectrometry.

Safety and localization data supported the design. CCK-8 assays, EdU proliferation tests, and live-dead staining showed that both carriers were well tolerated by L929 fibroblasts and differentiated 3T3-L1 adipocytes across the tested concentration ranges. After microneedle application, exogenous PGC1α mRNA was detected only in treated dorsal skin, declining over time, while SRT1720 remained below the limit of quantification in plasma, lymph nodes, liver, and spleen. The system delivered its payloads locally with no measurable systemic exposure.

In cell models, each module addressed its layer-specific pathology. In senescent fibroblasts, SRT1720@HA reduced β-galactosidase positivity, restored migratory capacity in scratch assays, and dampened expression of senescence markers CDKN2A and CDKN1A along with SASP cytokines including IL-6 and IL-1β. In an AMT model where TGF-β1 pushed adipocytes toward a myofibroblast-like state, PGC1α@LNP preserved lipid droplets, upregulated adipocyte genes such as PPARγ, Perilipin, and Adiponectin, and downregulated fibrotic markers including α-SMA and Col1a1 at both the RNA and protein levels.

The decisive test came in bleomycin-induced skin fibrosis mice treated every other day for two weeks. All microneedle-based interventions improved fibrotic features, but the dual-loaded system performed best, markedly reducing dermal thickness, collagen deposition, and elastic fiber destruction. Layer-specific mechanisms were confirmed by immunostaining: the hydrogel module cut the proportion of senescent dermal fibroblasts, while the nanoparticle module suppressed AMT in the subcutaneous fat, and only the combination achieved both. Transcriptomic sequencing showed that combined treatment silenced p53 signaling, inflammatory genes, and matrix-remodeling pathways while reactivating lipid biosynthesis, mitochondrial electron transport, and PPAR-dependent metabolic programs.

The authors caution that the mouse model does not fully recapitulate human fibrosis, that dose-matched free-drug controls are still needed to separate cargo effects from the platform itself, and that long-term durability and recurrence after treatment cessation remain open questions. Even so, the study demonstrates a versatile blueprint for layer-specific intervention in skin disease, one that could extend beyond fibrosis to any condition whose pathology is written differently in the dermis than in the fat beneath it.

Subject of Research: Layer-specific dermal and subcutaneous drug and mRNA delivery using a modular LNP-hydrogel threaded microneedle platform for treating skin fibrosis

Article Title: Layer‐Specific Dermal and Subcutaneous Delivery via Modular LNP–Hydrogel‐Integrated Threaded Microneedles

Article References: Xie, F., Zhang, Y., Ling, S., Huang, Y., Wei, Y., Fu, R., He, J., Liu, B., Zhou, L., Huo, K., Wang, Y., Li, Q., Du, Y., Cui, W., & Xie, Y. (2026). Layer‐Specific Dermal and Subcutaneous Delivery via Modular LNP–Hydrogel‐Integrated Threaded Microneedles. Advanced Science, Article e77624. https://doi.org/10.1002/advs.77624

Image Credits: AI Generated

DOI: 10.1002/advs.77624

Keywords: microneedles, mRNA therapy, lipid nanoparticles, skin fibrosis, spatial transcriptomics, SIRT1, PGC-1α, hydrogel, senescence, adipocyte-to-myofibroblast transition, drug delivery, Advanced Science

The story begins in the muscle fiber itself. During exercise, a transcriptional co-activator called PGC-1α, the master regulator of mitochondrial biogenesis, is activated in skeletal muscle through well-characterized energy-sensing pathways, including AMPK and SIRT1. PGC-1α drives expression of fibronectin domain-containing protein 5, or FNDC5, a membrane protein that is subsequently cleaved to release irisin into the circulation. This PGC-1α/FNDC5/irisin cascade was first described by Bruce Spiegelman’s group in 2012, when irisin was identified as the myokine responsible for driving brown-fat-like thermogenesis in white adipose tissue. Since then, studies have shown that irisin release scales with exercise intensity, occurs independently of age or fitness level, and can be detected in human cerebrospinal fluid by tandem mass spectrometry, a finding that strongly suggests the hormone does not remain confined to the periphery.

How, then, does a peptide secreted by leg muscles influence neurons deep inside the hippocampus? The review highlights recent work pointing to the blood–brain barrier as the critical checkpoint. Endothelial cells lining the brain’s vasculature express integrin receptors, and the αVβ5 integrin in particular has been identified as a binding partner for irisin. Research published in Molecular Neurobiology in 2025 demonstrated that the endothelial αV/β5 integrin signaling pathway plays a critical role in promoting irisin-induced expression of brain-derived neurotrophic factor, or BDNF, in the hippocampus. In other words, circulating irisin appears to engage integrin receptors on the barrier’s endothelial surface, triggering intracellular signaling that ultimately raises BDNF levels in brain tissue. Structural studies have shown that irisin forms a distinctive fibronectin type III dimer with a novel intersubunit beta-sheet, and more recent work indicates that irisin acts through its integrin receptor in a two-step process involving extracellular Hsp90α, adding molecular texture to how the hormone is recognized at the cell surface.

Once inside or at the brain’s doorstep, irisin’s principal downstream effector is BDNF, a neurotrophin long regarded as a cornerstone of synaptic plasticity, learning, and memory. The canonical 2013 study by Christiane Wrann and colleagues showed that exercise induces hippocampal BDNF through the PGC-1α/FNDC5 pathway, and subsequent genetic work established irisin as a critical regulator of cognitive function in mice. BDNF exerts its effects by binding the tropomyosin receptor kinase B, TrkB, a receptor tyrosine kinase that activates intracellular cascades including MAPK/ERK, PI3K/Akt, and PLCγ. Through these pathways, BDNF promotes dendritic growth, spine formation, long-term potentiation, and the activity of CaMKII, the central molecular organizer of synaptic plasticity. It also modulates NMDA receptor-dependent signaling through scaffolding proteins such as Girdin, linking neurotrophin support directly to the glutamatergic machinery of memory.

What makes the new review particularly compelling is its systematic mapping of BDNF’s protective actions onto each of the core pathological hallmarks of Alzheimer’s disease. First, BDNF enhances neuroplasticity, countering the synapse loss that correlates most strongly with cognitive decline. Second, it reduces amyloid-beta burden: exercise and BDNF have been shown to lower amyloid-beta production by enhancing alpha-secretase processing of the amyloid precursor protein, and irisin itself was recently shown to reduce amyloid-beta by inducing the release of the degrading enzyme neprilysin from astrocytes following downregulation of ERK–STAT3 signaling. Third, BDNF signaling restrains tau hyperphosphorylation, in part through modulation of glycogen synthase kinase 3, the kinase whose dysregulation drives pathological tau accumulation. Fourth, the axis dampens neuroinflammation, with aerobic exercise shown to attenuate glial activation and inflammatory signaling in experimental models. In a landmark 2019 study in Nature Medicine, exercise-linked FNDC5/irisin rescued synaptic plasticity and memory defects in Alzheimer’s mouse models, and a 2018 Science paper demonstrated that combined adult neurogenesis and BDNF can mimic exercise effects on cognition in an Alzheimer’s mouse model.

The review does not, however, paint an unconditionally rosy picture. It emphasizes that Alzheimer’s pathology feeds back negatively on the very axis that protects against it. Oxidative stress and mitochondrial dysfunction, both central features of the diseased brain, impair PGC-1α activity, suppress FNDC5 and BDNF expression, and weaken TrkB signaling, thereby creating a vicious cycle in which neurodegeneration erodes the endogenous defense system that would otherwise restrain it. Amyloid-beta oligomers, for instance, interfere with nuclear calcium signals and neuroprotective gene expression in hippocampal neurons, while mitochondrial damage in neural progenitors compromises the energy supply needed to sustain trophic signaling. This bidirectional framing, in which peripheral activation supports central protection but central pathology undermines the axis, transforms the irisin–BDNF system from a simple one-way messenger route into a dynamic feedback circuit whose integrity may itself determine disease trajectory.

From this molecular map, the authors derive a three-tiered translational strategy. Upstream, exercise remains the most physiological intervention, and the review notes that high-intensity exercise elicits greater irisin responses than low-intensity exercise under comparable energy expenditure, informing prescription design. Midstream, the barrier itself becomes a target: engineered blood–brain barrier-crossing peptides, such as those recently described in materials science literature, could enhance delivery of irisin-mimetic or BDNF-boosting agents into the central nervous system. Downstream, small-molecule TrkB agonists offer a way to bypass the hormone entirely. The flavonoid 7,8-dihydroxyflavone, a selective TrkB agonist discovered in 2010, has been shown to prevent synaptic loss and memory deficits in a mouse model of Alzheimer’s disease, and newer agonists such as R13 have demonstrated neuroprotective effects on mitochondrial function in 5×FAD mice. Together, these three intervention points, muscle, barrier, and receptor, define a pipeline for translating the muscle–brain dialogue into clinical practice.

The clinical stakes are enormous. Alzheimer’s disease and related dementias affect tens of millions of people worldwide, and the Global Burden of Disease study projects that prevalence will more than triple by mid-century as populations age. Existing amyloid-targeting therapies provide only modest benefit and come at high cost, which has intensified interest in mechanisms that act upstream or in parallel with amyloid. The irisin–BDNF axis is attractive precisely because it is multi-target: a single physiological signal simultaneously supports plasticity, curbs amyloid, restrains tau pathology, and calms inflammation. It is also supported by converging evidence across disorders, with recent work showing neuroprotective effects of irisin in mouse models of multiple sclerosis, cerebral ischemia, and Parkinson’s disease, suggesting the axis is a general-purpose mediator of exercise-induced brain resilience rather than an Alzheimer’s-specific curiosity.

Important caveats remain. Human irisin biology has historically been complicated by antibody reliability and the low abundance of the hormone, and the precise contribution of peripherally secreted versus centrally produced irisin to hippocampal BDNF induction is still being resolved. Whether boosting the axis in humans will slow cognitive decline in established disease, or only in preclinical stages, awaits intervention trials. Nevertheless, by assembling the complete molecular cascade, from PGC-1α activation in exercising muscle, through FNDC5 cleavage and integrin-mediated barrier engagement, to BDNF release and TrkB signaling in the hippocampus, the review provides a testable framework. It suggests that the old advice to keep moving is not merely generic wellness guidance but a quantifiable molecular prescription, and that pharmacologically reproducing the muscle–brain dialogue may one day offer a preventive strategy against one of medicine’s most feared diseases.

Subject of Research: The irisin–BDNF molecular axis mediating exercise-induced muscle–brain communication and neuroprotection in Alzheimer's disease

Article Title: Irisin-BDNF axis mediates muscle-brain communication: a complete molecular cascade and potential bidirectional feedback from peripheral activation to central protection

Article References: Duan, X., Chen, Z., Tong, X., Li, X., Liu, Z., Yang, Y., Liu, X., & Liu, W. (2026). Irisin-BDNF axis mediates muscle-brain communication: a complete molecular cascade and potential bidirectional feedback from peripheral activation to central protection. Biogerontology, 27(5), Article 162. https://doi.org/10.1007/s10522-026-10510-4

Image Credits: AI Generated

DOI: 10.1007/s10522-026-10510-4

Keywords: irisin, BDNF, Alzheimer's disease, FNDC5, PGC-1α, TrkB, blood-brain barrier, myokine, exercise, neuroprotection, synaptic plasticity, muscle-brain axis

The research team, led by Shuning Liu and Chang Liu of Beijing Sport University together with collaborators from Lanzhou University, Wuhan Sports University and other institutions, set out to determine whether syringaresinol could activate a well-known signaling circuit that connects muscle and fat tissue. This circuit runs through SIRT1, a NAD-dependent deacetylase enzyme long associated with calorie restriction and mitochondrial health, which in turn activates PGC-1α, the master regulator of mitochondrial biogenesis. PGC-1α then promotes expression of FNDC5, the membrane protein whose cleaved extracellular fragment is the hormone irisin. Irisin released into the bloodstream acts on adipose tissue, encouraging white fat cells to adopt brown-fat-like characteristics—producing heat, burning calories, and reshaping systemic energy balance.

In the laboratory phase of the study, the team used differentiated C2C12 myotubes, the standard cell model for mature skeletal muscle, and treated them with syringaresinol alongside two chemical reference compounds: SRT1720, a potent SIRT1 activator, and EX-527, a selective SIRT1 inhibitor. The results were striking. Myotubes exposed to syringaresinol showed increased irisin-related readouts, elevated ATP content, and higher citrate synthase activity, a classic indicator of enhanced mitochondrial oxidative capacity. At the molecular level, the compound produced transcriptional changes consistent with SIRT1/PGC-1α/FNDC5 activation and increased the abundance of both SIRT1 and PGC-1α proteins, placing syringaresinol squarely in the same mechanistic territory as established metabolic interventions.

The critical question was whether these effects genuinely depended on SIRT1. The inhibitor experiments provided the answer: when EX-527 blocked SIRT1 activity, the syringaresinol-driven responses in the myotubes were substantially attenuated. This pharmacological loss-of-function evidence supports the conclusion that SIRT1 signaling sits upstream of the observed changes and is required for syringaresinol to exert its influence on irisin production and mitochondrial markers in muscle cells. It is a level of mechanistic rigor that many plant-compound studies lack, and it gives the findings considerably more weight than simple correlation would allow.

But cell culture only goes so far, and the team therefore moved to a living system. Mice fed a high-fat diet—the standard model of diet-induced obesity—received syringaresinol by oral gavage at either a low or a high dose for 18 weeks, a substantial intervention period that allowed metabolic adaptations to fully develop. Over those weeks, the treated animals gained significantly less body weight than their untreated high-fat-diet counterparts. Crucially, food intake did not differ significantly between groups, which means the anti-obesity effect could not be explained by reduced appetite or caloric restriction. Something else was happening to the animals’ energy economy.

That something else appears to be a combination of circulating irisin and fat-tissue remodeling. Plasma measurements revealed that syringaresinol-treated mice had elevated levels of circulating irisin, consistent with the muscle-cell findings. The compound also improved lipid profiles, lowering the LDL-C/HDL-C ratio—a marker of cardiometabolic risk. In inguinal white adipose tissue, the subcutaneous fat depot most amenable to browning, expression of PGC-1α, uncoupling protein 1 (Ucp1), and Pparγ all increased. Ucp1 is the molecular signature of thermogenically active brown and beige fat: it short-circuits the mitochondrial proton gradient to generate heat instead of ATP, effectively burning calories as warmth. Its upregulation in white fat depots is the hallmark of the browning process that irisin was originally discovered to induce.

The original discovery of irisin in 2012 by Bruce Spiegelman’s group demonstrated that a PGC-1α-dependent myokine released from exercising muscle could drive brown-fat-like development in white fat and stimulate thermogenesis, and the field has since been searching for safe, practical ways to amplify this axis in people who cannot simply exercise their way out of metabolic disease. Recombinant irisin has been shown to induce weight loss in obese mice by increasing energy consumption and thermogenesis, and irisin has been linked to improved fatty acid oxidation and glucose utilization through AMPK signaling. Syringaresinol now emerges as a candidate nutritional tool for tapping into that same axis, working through the upstream SIRT1 node that is also targeted by compounds such as resveratrol and, more recently, by other dietary polyphenols like sesamol.

Syringaresinol itself is no newcomer to scientific attention. Prior studies have reported that it modulates gut microbiota and delays immunosenescence in middle-aged mice, protects against type 1 diabetic cardiomyopathy by reducing inflammation and oxidative stress, attenuates osteoarthritis through the NF-κB pathway, and even shows promise in models of cognitive decline and Alzheimer’s-related pathology. Toxicological testing of syringaresinol and its enterolignan metabolites has been carried out, and a comprehensive 2025 review has catalogued its plant sources, pharmacological activities, and pharmacokinetic characteristics. The new study adds weight management and the muscle–adipose endocrine axis to this expanding portfolio, positioning the compound as a multi-target nutritional agent rather than a single-action drug.

The researchers are appropriately careful about the limits of their evidence. In the published paper, they note that while the findings support syringaresinol as a candidate nutritional modulator of muscle–adipose metabolic communication, causal mediation of the in vivo effects by SIRT1, FNDC5, or irisin requires further pathway-specific validation. In other words, the mouse study shows correlations—less weight gain, more irisin, more Ucp1—but does not yet prove, through knockout models or receptor blockade, that irisin is the indispensable messenger carrying the benefit from muscle to fat. Human trials, which would represent the ultimate test, remain on the horizon. Still, the convergence of in vitro pharmacology, live-animal outcomes, and a mechanistic framework anchored in one of the most extensively studied metabolic pathways gives the work unusual coherence.

For a field wrestling with rising obesity rates and the modest long-term success of lifestyle interventions alone, the appeal of a plant-derived molecule that amplifies an exercise-like hormonal signal is obvious. Syringaresinol is found in common plant foods, has a documented safety profile, and now demonstrates the ability to switch on the SIRT1–PGC-1α–FNDC5/irisin axis in both cells and living animals under obesogenic conditions. If future work confirms causality and translates to humans, the compound—or optimized derivatives of it—could become part of a nutritional strategy that works with the body’s own thermogenic machinery rather than against appetite. For now, the message is more measured but still compelling: a molecule hidden in plants may teach muscle to talk to fat in a language that favors staying lean.

Subject of Research: Activation of the skeletal muscle SIRT1–FNDC5/irisin axis by the plant lignan syringaresinol and its effects on diet-induced obesity

Article Title: Syringaresinol activates the skeletal muscle SIRT1–FNDC5/irisin axis to enhance weight management

Article References: Liu, S., Zhao, F., Azhati, S., Shan, W., Tao, B., Zhong, W., Wei, Y., Jiang, W., Zhao, K., & Liu, C. (2026). Syringaresinol activates the skeletal muscle SIRT1–FNDC5/irisin axis to enhance weight management. 3 Biotech, 16(10), Article 424. https://doi.org/10.1007/s13205-026-05027-z

Image Credits: AI Generated

DOI: 10.1007/s13205-026-05027-z

Keywords: syringaresinol, irisin, SIRT1, PGC-1α, FNDC5, skeletal muscle, adipose tissue browning, obesity, mitochondrial biogenesis, high-fat diet, lignan, weight management