ALS is a progressive neurodegenerative disease in which upper and lower motor neurons gradually deteriorate, leading to muscle weakness, paralysis and, ultimately, respiratory failure. Its causes are diverse, but several damaging processes repeatedly appear across disease forms. Misfolded proteins accumulate inside neurons, mitochondria become dysfunctional, inflammatory signals rise and reactive oxygen species damage cellular structures. Autophagy—the system cells use to capture and degrade damaged proteins and organelles—also becomes impaired as disease advances. These processes reinforce one another: oxidative injury can disrupt autophagy, while inefficient autophagy allows damaged mitochondria and toxic protein aggregates to persist. The researchers focused on the Keap1–Nrf2–ARE pathway because it sits at the intersection of antioxidant protection and cellular quality control.

Nrf2 is a transcription factor that normally remains restrained in the cytoplasm by the protein Keap1 and its associated Cul3 ubiquitin-ligase machinery. Under stress, Nrf2 can escape degradation, enter the nucleus and bind antioxidant response elements, or AREs, in DNA. This activates genes such as HMOX1, NQO1 and GPX1, which help neutralize reactive molecules and maintain redox balance. Nrf2 also influences autophagy-related proteins, including LC3 and p62. The study’s central hypothesis was that stimulating this pathway could address both oxidative stress and autophagic failure rather than treating either process in isolation.

JP1 is a chemically modified oligopeptide derived from the JWA protein, also known as ARL6IP5, which has previously been linked to protection against oxidative injury, DNA damage and inflammation. The peptide sequence is Ac-FPGSDRFGGGG-RGD-NH₂, with an RGD motif designed to recognize integrin αVβ3. Its termini are acetylated and amidated, and the peptide includes a phosphorylated serine. Integrin αVβ3 is a cell-surface receptor involved in adhesion and signaling and has been associated with stress responses in motor neurons. Previous work in cancer and eye-disease models suggested that JP1 can cross biological barriers and interact with αVβ3. In the new study, molecular docking predicted a favorable interaction between JP1 and the integrin, with a calculated binding energy of −7.46 kilocalories per mole, although computational docking alone cannot establish a definitive biological binding mechanism.

The investigators tested JP1 in male SOD1-G93A mice, a widely used model of familial ALS that develops progressive motor impairment, spinal motor-neuron loss, oxidative stress and shortened lifespan. Treatment began at postnatal day 70, before severe symptoms emerged, and continued through disease progression. The animals received daily intraperitoneal injections of 50, 150 or 300 milligrams of JP1 per kilogram of body weight. The middle dose produced the clearest benefit. Mice treated with 150 milligrams per kilogram showed delayed disease onset, better performance on rotarod, grip-strength, pole and gait tests, and longer survival than untreated ALS-model animals. Their average survival increased from approximately 148 days in the model group to about 160 days with JP1. Lower and higher doses did not produce comparable improvements, indicating that the response was not simply proportional to dose.

The treatment did not prevent the animals from losing weight, an important detail because weight loss in ALS can reflect muscle wasting, impaired feeding and broader metabolic dysfunction. This suggests that JP1 primarily protected motor neurons and related pathways rather than correcting every systemic feature of the disease. The researchers reported no detectable deterioration in standard liver or kidney function markers. They also observed lower blood levels of creatine kinase and CK-MB, enzymes associated with muscle injury, along with increased systemic superoxide dismutase activity. These findings point toward reduced muscle damage and improved antioxidant capacity, but the safety assessment was limited to a small animal study and a restricted set of biochemical measurements.

At the cellular level, JP1 appeared to reverse a late-stage collapse in autophagy. In untreated SOD1-G93A mice, autophagic activity was higher at around 90 days but declined at symptomatic and end-stage time points. At 120 days, JP1 increased LC3B-associated autophagic structures and reduced p62, a protein that accumulates when cargo degradation is inefficient. Electron microscopy showed more autophagosomes, fewer abnormal mitochondria, less mitochondrial swelling and better-preserved cristae in treated mice. These observations are consistent with improved autophagic and mitophagic activity, although measurements based on LC3B and p62 can reflect changes in production or degradation. A direct flux assay using lysosomal inhibitors would provide stronger evidence that the entire autophagy pathway, rather than only the abundance of individual markers, was restored.

The proposed signaling mechanism began with increased ERK phosphorylation after JP1 treatment. The researchers reported lower cytoplasmic Keap1 protein and reduced Cul3, together with greater accumulation of Nrf2 in the nucleus. This was accompanied by increased expression of the Nrf2-responsive antioxidant proteins HO-1 and NQO1, higher spinal-cord superoxide dismutase activity and lower levels of malondialdehyde, a marker of lipid peroxidation. JP1 also increased GPX1 expression and reduced NOS2, which encodes a source of nitric oxide-related oxidative stress. Interestingly, JP1 changed Keap1 and Cul3 protein abundance without significantly altering their messenger RNA levels, suggesting post-transcriptional regulation or changes in protein stability.

To test whether Nrf2 was necessary for the protective response, the researchers administered ML385, a pharmacological Nrf2 inhibitor, to a separate group of ALS-model mice. ML385 alone accelerated disease onset, worsened motor performance and shortened survival. When given together with JP1, it largely eliminated the peptide’s benefits: survival, motor behavior, autophagy markers, mitochondrial structure, antioxidant responses and motor-neuron preservation returned toward the untreated ALS-model profile. JP1-treated animals also showed fewer TUNEL-positive apoptotic cells, more surviving motor neurons in Nissl-stained spinal cord sections and a more favorable balance between the pro-apoptotic gene Bax and the anti-apoptotic gene Bcl-2. These reversal experiments support a central role for Nrf2, but they do not exclude contributions from other pathways affected by ML385 or JP1.

The study further linked JP1 treatment to selective changes in inflammatory signaling. ALS-model mice had elevated spinal-cord levels of interleukin-1 beta, interleukin-6, tumor necrosis factor alpha, CCL2 and CCL3. JP1 reduced interleukin-1 beta, CCL2 and CCL3 while increasing the anti-inflammatory cytokine interleukin-10, but it did not significantly change interleukin-6 or tumor necrosis factor alpha. The authors interpret this as a selective immunomodulatory effect rather than broad immune suppression. Transcriptomic and proteomic analyses of spinal cord tissue also showed that JP1-treated mice shifted toward a wild-type molecular profile, with enrichment of antioxidant and autophagy-related pathways. However, the multiomics experiment included only three animals per group, making it useful for generating mechanistic clues but insufficient for definitive conclusions about biological variability.

The researchers also examined JWA expression in human ALS datasets and found that its messenger RNA levels were lower in patients than in healthy controls. Higher expression was associated with limb-onset disease compared with bulbar-onset disease, and patients in a high-expression group had a more favorable survival pattern. In SOD1-G93A mice, JWA expression decreased as disease progressed. These observations suggest that JWA could become a biomarker or therapeutic target, but the human analyses were based on existing transcriptomic datasets, including blood and small tissue cohorts, rather than prospective clinical samples. They cannot establish that reduced JWA causes ALS progression or that restoring its activity would benefit patients.

JP1 therefore emerges from the study as a promising candidate for further investigation, not as an established ALS treatment. The compound’s apparent ability to reach spinal motor neurons, activate Nrf2 and coordinate antioxidant defense with autophagic clearance addresses several interconnected mechanisms of neurodegeneration. Yet important questions remain about its pharmacokinetics, long-term toxicity, optimal delivery, interaction with existing ALS therapies and effectiveness in models carrying mutations such as C9orf72 or FUS. The authors also acknowledge that the structural basis of JP1 binding to αVβ3 remains unresolved. Larger, independently replicated animal studies, rigorous autophagy-flux experiments and clinical-grade safety testing will be necessary before the peptide can be considered for human trials.

Subject of Research: JP1 peptide as a potential treatment for amyotrophic lateral sclerosis through modulation of oxidative stress, autophagy and motor-neuron survival.

Article Title: JP1 peptide modulates oxidative stress and autophagy via Keap1-Nrf2-ARE in ALS model mice.

Article References: Zhang Y, Liu Y, Shi S, et al. “JP1 peptide modulates oxidative stress and autophagy via Keap1-Nrf2-ARE in ALS model mice.” BMC Medicine. 2026;24:460.

Image Credits: AI Generated

DOI: 10.1186/s12916-026-05119-w

Keywords: Amyotrophic lateral sclerosis; ALS; JP1 peptide; JWA; ARL6IP5; Keap1; Nrf2; ARE; oxidative stress; autophagy; mitophagy; motor neurons; integrin αVβ3; SOD1-G93A mice.

The study, recently published in Acta Neuropathologica Communications, goes beyond previous understandings of autophagy in ALS by focusing specifically on CMA, a selective mechanism by which cells degrade aberrant or damaged proteins. Unlike macroautophagy, which broadly targets cellular debris, CMA identifies and degrades specific protein cargos, a function essential to maintaining neuronal homeostasis. In ALS, where toxic aggregates of the RNA-binding protein TDP-43 accumulate abnormally in motor neurons, the failure of such precision clearance mechanisms could be a driver of cellular degeneration.

To delve into these molecular intricacies, researchers obtained post-mortem spinal cord tissues from ALS patients enrolled in clinical trials and from age-matched healthy donors. Employing advanced immunohistochemistry and immunofluorescence techniques, they quantified levels of LAMP2A, a lysosomal membrane receptor pivotal for substrate translocation in CMA. Strikingly, motor neurons from ALS patients exhibited a pronounced reduction in LAMP2A expression and activity compared to controls, pointing to a compromised CMA pathway as a consistent hallmark in the diseased state.

ALS predominantly affects motor neurons, specialized nerve cells responsible for initiating muscle contractions. In the majority of ALS cases, these neurons harbor cytoplasmic aggregates of TDP-43, a protein normally residing in the nucleus and involved in RNA metabolism. The aberrant cytoplasmic localization of TDP-43 is toxic, disrupting cellular function and viability. The researchers propose that a decline in CMA preferentially impairs the degradation of such proteins, facilitating their pathological accumulation. This observation challenges prior assumptions that generalized autophagy declines were solely responsible, highlighting CMA’s unique and indispensable role.

Professor Salvador Martínez, the laboratory director overseeing this research, emphasized that restoring CMA function may be pivotal for motor neuron survival. “Motor neurons require exceptionally high CMA activity to maintain proteostasis. When this system falters, as observed in ALS, these neurons become especially vulnerable, leading to the progressive neurodegeneration characteristic of the disease,” he explained. This insight underscores the therapeutic potential of pharmacologically or genetically modulating CMA to augment its protein-clearance capacity.

One of the most compelling aspects of this investigation is the direct demonstration of CMA dysfunction in human neuronal tissue, a feat rarely achievable in animal models. This human-centric approach affirms the biological relevance of CMA alterations and enhances translational prospects. The detailed cellular analyses reveal that the malfunction is not an incidental side effect but a targeted failure of protein clearance pathways specific to motor neuron populations impacted by ALS.

The scientific team’s multidisciplinary collaboration included experts from the UMH Sports Research Centre and the Pascual Parrilla Murcia Institute for Biosanitary Research, reflecting the integrated efforts required to tackle a disease of such complexity. They point out that this work was only feasible thanks to the invaluable donations of neural tissue by ALS patients and their families. Such altruistic contributions provide irreplaceable biological material essential for unraveling ALS mechanisms and testing novel hypotheses.

Mechanistically, chaperone-mediated autophagy involves the recognition of substrate proteins by cytosolic chaperones, which then transport these targets to lysosomal membranes bearing LAMP2A receptors. Following binding, substrates translocate into the lysosome for degradation, thus preventing toxic protein build-up. The discovery that LAMP2A expression is diminished in ALS motor neurons suggests that this critical gateway is impaired, obstructing the selective removal of pathological proteins like TDP-43 and potentially amplifying neurotoxicity.

This study’s findings pave the way for exploring CMA-enhancing therapies that could restore cellular balance in ALS-affected neurons. By developing small-molecule activators or gene therapies aimed at increasing LAMP2A levels or stabilizing chaperone function, researchers aim to reverse toxic protein accumulation. Although in the early stages, such strategies could transform the current landscape of ALS treatment, which remains largely supportive without disease-modifying options.

The researchers also underscore the necessity of further investigations to elucidate how CMA dysfunction interacts with other cellular degradation pathways and contributes to the complex ALS pathology. Synergistic therapeutic strategies combining CMA enhancement with modulation of other proteostatic mechanisms may hold the key to achieving meaningful clinical benefits. This integrative view deepens understanding of motor neuron biology under stress and neurodegenerative demands.

Funding for this pivotal work came from several prestigious sources, including the Spanish State Research Agency’s Severo Ochoa Excellence Programme, the Ministry of Science, Innovation and Universities, the Generalitat Valenciana’s Prometeo Programme, and the Instituto de Salud Carlos III’s Advanced Therapies Network (TERAV). Additionally, support from the Next Generation EU initiative and UMH’s Gregoria Ramos Gil Chair on ALS was instrumental in facilitating comprehensive research efforts.

In conclusion, this landmark study reveals that chaperone-mediated autophagy is critically impaired in spinal motor neurons affected by ALS, contributing to the accumulation of neurotoxic TDP-43 aggregates. This deficiency emerges as a compelling molecular target to develop therapeutic approaches capable of preserving motor neuron integrity and delaying disease progression. As scientists decode the complex interplay of cellular clearance systems, new hope arises for patients facing the relentless challenges of ALS.

Subject of Research: Human tissue samples
Article Title: Chaperone mediated autophagy is deficient in spinal motoneurons of ALS patients with TDP-43 proteinopathy
News Publication Date: 4-Feb-2026
Web References: http://dx.doi.org/10.1186/s40478-026-02238-6
Image Credits: Instituto de Neurociencias UMH CSIC
Keywords: Amyotrophic lateral sclerosis, ALS, motor neurons, TDP-43, chaperone-mediated autophagy, CMA, protein aggregation, neurodegeneration, LAMP2A, autophagy regulation, neurobiology

ALS, characterized by progressive motor neuron degeneration leading to muscle paralysis and eventual respiratory failure, has long been a challenge for researchers seeking to unravel its precise cellular and molecular mechanisms. Although the loss of motor neurons has been clearly established as the core pathological hallmark, the early events that precede overt neuronal death remain elusive. This study shifts the focus to the neuromuscular junction—the specialized synapse connecting motor neurons to muscle fibers—where the initial disruptions in communication and connection appear to set the stage for subsequent neurodegeneration.

The CCL2-CCR2 axis, traditionally recognized for its role in immune cell recruitment and inflammatory responses, emerges here as a central player in neuromuscular pathology. The researchers demonstrated that CCL2, a chemokine ligand, and its receptor CCR2 are aberrantly upregulated in motor neurons and surrounding glial cells in ALS models. This overexpression correlates with pronounced neuromuscular denervation, a process wherein motor nerve terminals withdraw from muscle fibers, leading to functional synapse loss.

Utilizing advanced mouse models genetically engineered to mimic human ALS, the team meticulously mapped the spatial and temporal dynamics of CCL2-CCR2 expression across disease progression. Early pre-symptomatic stages revealed subtle increases in CCL2 secretion, which were amplified as symptoms manifested. Importantly, pharmacological blockade of CCR2 signaling notably attenuated neuromuscular denervation and preserved muscle function, suggesting that this pathway’s activity is not merely correlative but causal in disease development.

A crucial innovation in this work was the deployment of high-resolution imaging techniques to observe neuromuscular junction architecture in vivo. By employing fluorescence microscopy combined with sophisticated neuronal tracing methods, the investigators documented the stepwise disassembly of nerve terminals concurrent with CCL2-CCR2 activation. These visuals not only confirmed biochemical findings but also provided compelling evidence for synaptic vulnerability as an early disease event.

The study further elucidated downstream mechanisms triggered by CCL2-CCR2 signaling. Activation of this axis instigated a cascade involving inflammatory mediators and microglial recruitment, establishing a neuroinflammatory milieu within the spinal cord microenvironment. This inflammation exacerbates synaptic stripping, reinforcing a vicious cycle that accelerates motor neuron degeneration. By dissecting this interplay between chemokine signaling and neuroimmune crosstalk, the research offers a holistic view of ALS pathology beyond mere neuronal demise.

Moreover, transcriptomic analyses of affected motor neurons revealed that CCL2-CCR2 activation disrupts cytoskeletal integrity and synaptic vesicle trafficking. These intracellular perturbations compromise axonal transport, a process essential for maintaining neuromuscular junction stability and nutrient exchange between nerve and muscle. The work ties molecular deficits directly to functional synapse failure, bridging the gap between cellular dysfunction and clinical symptoms.

Importantly, the team demonstrated that the modulation of CCL2-CCR2 is therapeutically feasible. Using monoclonal antibodies targeting CCR2, treatment delayed disease onset and improved survival rates in ALS model mice. This highlights the translational potential of these findings, positioning CCR2 antagonists as promising candidates for clinical trials aimed at halting or reversing early synaptic damage in ALS patients.

Complementing the in vivo studies, in vitro experiments with cultured motor neurons exposed to exogenous CCL2 confirmed the chemokine’s deleterious effects on neuronal health and synapse maintenance. These experiments also showed that blocking CCR2 restored motor neuron viability, directly linking receptor activity with cellular integrity. The dual approach of in vivo and in vitro validation strengthens the evidence base and assures the robustness of the conclusions.

This discovery also reframes how neuroinflammation is viewed in ALS. While inflammatory responses have been implicated previously, the identification of a specific chemokine axis driving synaptic degeneration underscores a targeted mechanism rather than a broad unspecific immune activation. This specificity opens possibilities for precision medicine approaches where targeted blockade of chemokine receptors could mitigate neurodegeneration without compromising systemic immune functions.

The impact of this research transcends ALS alone. Since the CCL2-CCR2 axis is implicated in various neurodegenerative and inflammatory conditions, these insights could influence therapeutic strategies in diseases where synapse loss is a hallmark, such as multiple sclerosis and certain forms of peripheral neuropathy. Elucidating common molecular drivers of synaptic pathology could pave the way for unified treatment paradigms across neurological disorders.

Beyond molecular science, this study advances our understanding of synaptic homeostasis and neuron-glia interactions in health and disease. It highlights the delicate balance maintained at the neuromuscular junction and the devastating consequences when chemokine signaling is dysregulated. This knowledge enriches the broader neurobiology field, informing future research into synaptic resilience and repair mechanisms.

The publication also offers hope to the ALS community, which has long awaited breakthroughs that can alter the grim prognosis associated with this disease. By identifying a modifiable molecular target acting at early disease stages, the findings suggest potential diagnostic markers and therapeutic windows previously unrecognized. Early intervention in ALS, guided by biomarkers of CCL2-CCR2 activity, could revolutionize patient care.

Nógrádi and colleagues emphasize that while the blockade of CCR2 signaling offers promise, comprehensive clinical studies will be required to translate these preclinical successes into humans. Differences in immune system complexity, chemokine dynamics, and disease heterogeneity pose challenges that future research must address. Nonetheless, this work lays a solid foundation for such endeavors.

In conclusion, the elucidation of the CCL2-CCR2 chemokine axis as a driver of neuromuscular denervation in ALS represents a major leap forward in both basic neurobiology and clinical neurodegeneration research. This meticulously executed study blends genetic, pharmacological, imaging, and transcriptomic approaches to unravel a mechanistic pathway with profound implications. Its findings set the stage for new therapeutic interventions aimed at preserving neuromuscular connectivity, ultimately aspiring to halt or even reverse the progression of ALS.

As neuroscience continues to unravel the complexities of neurodegenerative diseases, the identification of targeted molecular drivers such as the CCL2-CCR2 axis offers a beacon of hope. The prospect of modulating inflammation-induced synaptic loss transforms ALS from an inexorable, untreatable illness into a condition where early and precise intervention could alter the trajectory of suffering. This work stands as a testament to the power of integrative biomedical research in tackling humanity’s most challenging diseases.

Subject of Research: Neurodegeneration; Amyotrophic Lateral Sclerosis; Neuromuscular Junction Pathology; Chemokine Signaling

Article Title: The CCL2-CCR2 axis drives neuromuscular denervation in amyotrophic lateral sclerosis

Article References:
Nógrádi, B., Molnár, K., Kristóf, R. et al. The CCL2-CCR2 axis drives neuromuscular denervation in amyotrophic lateral sclerosis. Nat Commun 16, 7053 (2025). https://doi.org/10.1038/s41467-025-62351-3

Image Credits: AI Generated