Alzheimer’s disease affects an estimated 7.2 million Americans aged 65 and older, a figure expected to climb to 13.8 million by 2060. Despite decades of research into amyloid accumulation, tau pathology, oxidative stress, mitochondrial dysfunction, and chronic inflammation, the aging-related mechanisms that drive the disease remain incompletely understood. The new study homes in on the brain renin-angiotensin system, a hormonal signaling network best known for blood pressure regulation but increasingly implicated in cognition, inflammation, and vascular health within the brain.

Within this system, angiotensin II acts on two principal receptor subtypes: the type 1 receptor and the type 2 receptor. Hyperactivation of the type 1 receptor has been linked to inflammation, oxidative damage, mitochondrial decline, and impaired autophagy in the brain. The type 2 receptor, by contrast, belongs to the protective arm of the system, promoting nitric oxide release, vasodilation, neurite outgrowth, and anti-inflammatory effects. Animal studies have shown that activating the type 2 receptor reduces cortical and hippocampal amyloid plaques and protects against cognitive impairment, but the downstream signaling pathways responsible remained murky.

That is where ATIP enters the picture. ATIP proteins, encoded by the MTUS1 gene through alternative splicing, bind directly to the type 2 receptor and help localize it to the cell membrane, mediating some of its functions. Expression of ATIP variants is highest in the central nervous system, and prior work has shown that upon receptor activation, ATIP forms a complex with the tyrosine phosphatase SHP-1 that translocates to the nucleus and triggers neural differentiation and protection. Given these properties, the research team hypothesized that ATIP might be a key factor connecting the protective angiotensin axis to amyloid pathology.

To test the idea, the investigators analyzed postmortem frontal cortex samples from the Rush Memory and Aging Project, an ongoing cohort study in which participants agree to annual clinical evaluations and brain donation. The sample comprised 60 older adults diagnosed with Alzheimer’s disease, evenly split between those who had used angiotensin receptor blockers, a class of blood pressure drugs that selectively blocks the type 1 receptor, and those who had not. Participants using ACE inhibitors were excluded to avoid confounding effects on renin-angiotensin signaling, and the two groups were matched for age and sex, with a mean age of roughly 90 years.

The methodological centerpiece of the study was TOMAHAQ, short for triggered by offset, multiplexed, accurate mass, high resolution, and absolute quantification. This targeted mass spectrometry technique, which combines tandem mass tags with trigger-peptide detection and sequential MS3 fragmentation, allows highly specific quantification of low-abundance proteins across many samples in a single run. Using this platform, the team successfully quantified an ATIP peptide sequence, ANLKNPQIMYLEQELESLK, in 12 of the 60 participants, and quantified the type 2 receptor peptide GNSTLATTSK in 58 participants. Amyloid-beta and tau burdens were measured by the Rush Alzheimer’s Disease Center using immunohistochemistry and image analysis across eight brain regions.

The results were striking. ATIP levels showed a significant negative correlation with amyloid-beta load in the midfrontal gyrus, where the peptides were quantified, and with amyloid scores averaged across all eight brain regions. The correlation was strong, with a Spearman coefficient of −0.837 for the midfrontal region and −0.872 for the overall score. Critically, the association endured after statistical adjustment for age and angiotensin receptor blocker use, two potential confounders. When the researchers examined users and non-users of the drugs separately, the inverse correlation persisted in both groups and appeared even more pronounced among the drug users.

Not every question was resolved. The study found no significant correlation between ATIP and type 2 receptor protein levels, and no association between ATIP and tau tangle densities. The authors offer several possible explanations: the type 2 receptor is expressed at very low levels in the adult brain and declines further with age, making accurate quantification difficult; receptor protein abundance may not track receptor activity; and ATIP may exert biological effects independent of the receptor, as suggested by mouse studies in which ATIP’s anti-inflammatory benefits persisted even when the receptor was pharmacologically blocked. Detection of the ATIP peptide itself was limited to 12 of 60 samples, reflecting the technical challenge of measuring scarce proteins in postmortem tissue, although participants with and without detectable ATIP did not differ significantly in amyloid burden.

The researchers caution that the study is exploratory, cross-sectional, and small, and that correlational findings cannot establish causality. Postmortem tissue also captures only a snapshot of dynamic processes occurring during life, and the lack of a cognitively normal control group leaves open whether low ATIP detection is specific to Alzheimer’s disease. Still, the strengths are notable: this is the first direct measurement of ATIP in human Alzheimer’s brain tissue, the design controlled for key demographic factors and drug exposure, and the observed inverse correlation was strong and robust to adjustment. If replicated in larger and more diverse cohorts with longitudinal designs and functional models, ATIP could emerge as a novel target for understanding, and potentially modulating, the amyloid pathology that lies at the heart of Alzheimer’s disease.

Subject of Research: The association between frontal cortex ATIP protein levels and amyloid-beta burden in postmortem brains of older adults with Alzheimer's disease

Article Title: Higher Frontal Cortex Angiotensin Type 2 Receptor‐Interacting Protein (ATIP) Levels Are Associated With a Lower Amyloid‐Beta Burden in Postmortem Brains of Older Adults With Alzheimer's Disease

Article References: Cosarderelioglu, C., Kreimer, S., Plaza‐Rodriguez, A. I., Iglesias, P. A., Talbot, C. C., Jr., Siragy, H. M., Ubaida‐Mohien, C., Grodstein, F., Ferrucci, L., Bennett, D. A., Walston, J., & Abadir, P. (2026). Higher Frontal Cortex Angiotensin Type 2 Receptor‐Interacting Protein ( ATIP ) Levels Are Associated With a Lower Amyloid‐Beta Burden in Postmortem Brains of Older Adults With Alzheimer's Disease. Aging Cell, 25(9), Article e70686. https://doi.org/10.1111/acel.70686

Image Credits: AI Generated

DOI: 10.1111/acel.70686

Keywords: Alzheimer's disease, ATIP, angiotensin II type 2 receptor, amyloid-beta, brain renin-angiotensin system, postmortem brain, TOMAHAQ mass spectrometry, angiotensin receptor blockers, tau pathology, neurodegeneration, aging, MTUS1 gene

The opioid epidemic continues to claim thousands of lives annually, with the complexity of addiction challenging researchers and medical professionals alike. Traditional genetic studies have explored inherited DNA variants associated with addiction, but these do not fully account for the dynamic regulatory mechanisms that influence gene expression without altering the underlying DNA sequence. Epigenetics—the study of chemical modifications to DNA and histone proteins that regulate gene activity—offers a promising avenue for capturing the interplay of environmental influences and genetic predisposition over a person’s lifetime.

Heredia-Negrón and colleagues sought to decode this complex epigenetic landscape by analyzing postmortem brain samples from individuals diagnosed with OUD. By focusing on the frontal cortex, a region intimately involved in decision-making, reward processing, and impulse control, the researchers aimed to pinpoint epigenetic markers that not only correlate with opioid exposure but also distinguish between affected and unaffected brains. This meticulous examination involved mapping DNA methylation patterns, a principal epigenetic mechanism where methyl groups attached to cytosine bases influence gene expression.

To synthesize these findings into a practical tool, the team developed epigenetic risk scores (ERS), a quantitative metric summarizing the cumulative effect of multiple methylation sites across the genome associated with OUD. Unlike single-marker studies, ERS encapsulates the multifaceted nature of epigenetic regulation, offering a composite indicator that reflects the overall epigenomic footprint linked to opioid use. This innovative scoring system was rigorously validated, illustrating robust predictive capabilities that could identify individuals at elevated risk for opioid dependence, even prior to overt clinical manifestations.

One of the most striking aspects of this research lies in its potential clinical translation. The authors highlight that epigenetic markers, unlike static genetic mutations, are inherently dynamic and responsive to environmental factors such as stress, trauma, and drug exposure. This plasticity implies that ERS not only serve as biomarkers of vulnerability but might also provide insights into the biological pathways modulated during addiction development, opening avenues for targeted therapeutic intervention that could reverse maladaptive epigenomic changes.

Moreover, the use of human postmortem samples grants incontrovertible authenticity to these findings, overcoming limitations associated with animal models and peripheral tissue assessments that may not fully capture brain-specific epigenetic alterations. This direct investigation into human brain tissue underscores the validity and relevance of the observed epigenetic modifications, enhancing confidence in the applicability of the ERS framework for clinical and research purposes.

The technological rigor of this study is underscored by advanced epigenomic profiling techniques. Whole-genome bisulfite sequencing was employed to achieve base-resolution maps of DNA methylation, allowing a comprehensive assessment of epigenetic variation. Sophisticated bioinformatics pipelines integrated these data with clinical phenotypes, ensuring a robust, data-driven construction of the ERS. This methodological sophistication sets a new standard for neuroepigenetic research in addiction biology.

Furthermore, the study sheds light on several key gene regions implicated in opioid signaling, neural plasticity, and stress-response pathways. Differential methylation in these loci suggests epigenetic dysregulation contributes to altered neurocircuitry underlying the compulsive behaviors characteristic of OUD. Such mechanistic insights deepen our understanding of addiction pathophysiology, reinforcing the concept that epigenetic modifications are not mere bystanders but active players in disease progression.

Importantly, the researchers acknowledge the challenge of disentangling cause and effect in epigenetic studies. While altered methylation patterns are observed in OUD brains, it remains critical to determine whether these changes precede addiction onset or result from chronic opioid exposure. The ERS approach provides a framework to longitudinally explore these dynamics in larger cohorts, potentially enabling early detection and intervention strategies.

The implications extend beyond opioid addiction. The methodological advances in constructing and validating epigenetic risk scores pave the way for analogous investigations into other psychiatric and substance use disorders. Through this lens, epigenetics emerges as a vital bridge connecting environmental, psychological, and molecular factors, ultimately shaping individual disease susceptibility and resilience profiles.

In sum, the study by Heredia-Negrón and colleagues represents a seminal leap forward in addiction neuroscience. By harnessing the power of human brain epigenomics to build predictive risk scores, they offer a powerful new toolkit for unraveling the complexity of opioid use disorder. This cutting-edge research not only highlights the biological intricacies of addiction but also underscores the transformative potential of integrating epigenetic biomarkers into clinical practice, heralding a new era in precision medicine and public health strategies against the opioid epidemic.

As the opioid crisis continues to evolve, so too must our scientific approaches. This innovative application of epigenetic risk scoring may soon lead to enhanced screening capabilities, enabling healthcare providers to identify at-risk individuals before addiction takes hold. Beyond that, a deeper mechanistic understanding gleaned from these epigenetic signatures will inform the development of novel therapeutics designed to modify the epigenome itself, thereby mitigating addiction risk and promoting recovery.

Ultimately, this study epitomizes the convergence of genetics, epigenetics, neurobiology, and psychiatry in addressing one of the most pressing public health challenges of our time. It stands as a testament to the power of interdisciplinary research and the promise of personalized medicine guided by the intimate molecular stories encoded in our brains. As researchers continue to map the epigenetic topography of addiction, the prospect of transforming addiction science from reactive treatment to proactive prevention comes tantalizingly closer to reality.

Subject of Research: Epigenetic risk scoring for opioid use disorder using human postmortem brain data

Article Title: Building epigenetic risk scores of opioid use disorder: Insights from human postmortem brain data

Article References:
Heredia-Negrón, F., Nagamatsu, S.T., Carrasquillo-Carrion, K. et al. Building epigenetic risk scores of opioid use disorder: Insights from human postmortem brain data. Transl Psychiatry (2026). https://doi.org/10.1038/s41398-025-03792-8

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41398-025-03792-8

CTE, historically recognized through postmortem diagnosis marked by tau protein aggregation around blood vessels deep within the brain’s convolutions, may now be forewarned by subtler yet significant neuronal and vascular changes. The research team, leveraging tools developed through the NIH’s BRAIN Initiative®, employed sophisticated gene expression profiling and single-cell imaging techniques, elucidating cellular pathways previously inaccessible. This technical advancement allowed the scientists to detect a striking 56% reduction in specific neuronal subpopulations situated in regions vulnerable to biomechanical stress during head impacts, even in cases where tau pathology was absent.

The substantial neuronal loss challenges the traditional framework, indicating that axonal and cellular compromise occurs significantly earlier than detectable tau accumulation. Moreover, this neuronal attrition correlates closely with the duration of exposure to repetitive head impacts, underscoring a dose-dependent trajectory of brain injury seldom characterized in young cohorts. This discovery not only deepens insights into the insidious onset of neurodegeneration but also suggests potential biomarkers for presymptomatic diagnosis.

Concomitantly, the study observed a pronounced activation of microglia, the brain’s resident immune cells, which mount inflammatory responses upon injury or disease. These immune cells displayed increasing activation with extended years of contact sport participation, signifying a chronic inflammatory state potentially driving or exacerbating neuronal damage. The persistent neuroinflammation observed could be a key mechanistic link between repetitive mechanical stress and subsequent neurodegenerative cascades.

Alongside neuronal and immune alterations, the research unveiled notable molecular changes within cerebral vasculature. Detailed gene expression patterns indicated heightened immune surveillance activity, likely a response to localized hypoxia or ischemia induced by damaged vascular integrity. Structural modifications such as vasculature thickening and angiogenic growth were also documented, painting a complex picture of vascular remodeling in response to chronic trauma. The intricate crosstalk identified between activated microglia and endothelial cells suggests a novel cellular communication axis that might modulate the transition from acute injury to chronic neurodegeneration.

By directing focus onto younger athletes, this investigation diverges from conventional studies predominantly concerned with advanced CTE in older individuals. It exposes early cellular signatures that herald the path toward devastating brain disease years before clinical symptoms or typical pathological markers emerge. Such findings emphasize the necessity for earlier detection and intervention strategies aimed at mitigating long-term cognitive decline related to contact sports.

Dr. Walter Koroshetz, director of NIH’s National Institute of Neurological Disorders and Stroke (NINDS), highlighted the significance of these early brain changes as potential targets for novel diagnostics or therapeutics, envisioning a future where CTE is identifiable well before irreversible damage ensues. Parallelly, Richard Hodes, director of the National Institute on Aging (NIA), underscored how elucidating these early events could inform protective measures for young athletes and ultimately reduce dementia risk later in life.

This pioneering work forms a foundation for translational applications, advocating for the development of sensitive biomarkers, possibly rooted in molecular, imaging, or immunological signatures, which could revolutionize monitoring of athletes at risk. Furthermore, it propels research into pharmaceutical or lifestyle interventions that might disrupt or slow degenerative processes triggered by repetitive head impacts.

The implications of these findings extend beyond sports medicine into broader neurological research, advising policymakers, clinicians, and researchers on the paramount importance of early brain health surveillance in populations exposed to repetitive concussive and sub-concussive forces. Through cross-disciplinary collaboration and technological innovation, there exists a tangible path toward reshaping clinical paradigms surrounding traumatic brain injury and its neurodegenerative sequelae.

In conclusion, this compelling study catalyzes a paradigm shift from postmortem diagnosis of established CTE to a proactive understanding of early neural deterioration. It signals an urgent call to action within the medical and sports communities to prioritize brain injury prevention, optimized protective equipment, and routine monitoring protocols for athletes. As research progresses, the vision of intercepting and arresting the progression of CTE before devastating symptoms manifest appears increasingly attainable.

This investigation, meticulously funded by the NIH’s NINDS and NIA through a series of competitive grants, embodies a summit of modern neuroscientific inquiry. Its integration of high-resolution single-cell analyses with rigorous clinical data exemplifies how innovative technologies can elucidate complex neuropathological processes, offering hope for the millions of athletes worldwide who face the invisible threat of repeated head trauma.

Subject of Research: Neuropathological effects of repetitive head trauma in young athletes, focusing on early neuronal loss, microglial activation, and vascular molecular changes preceding chronic traumatic encephalopathy.

Article Title: Repeated head trauma causes neuron loss and inflammation in young athletes

News Publication Date: 17-Sep-2025

Web References:

• NIH’s National Institute of Neurological Disorders and Stroke (NINDS): https://www.ninds.nih.gov/
• National Institute on Aging (NIA): https://www.nia.nih.gov/
• National Institutes of Health (NIH): https://www.nih.gov/

References:
Butler MLMD, Pervaiz N, Breen K, et al. Repeated head trauma causes neuron loss and inflammation in young athletes. Nature (2025). DOI: 10.1038/s41586-025-09534-6

Keywords: Neurodegeneration, Chronic Traumatic Encephalopathy, Tau Protein, Neuronal Loss, Microglia Activation, Brain Injury, Head Trauma, Sports Neurology, Blood-brain Barrier, Neuroinflammation, Cerebral Vasculature, Molecular Neuroscience