Extract:

Instead of just fixing worn-out joints with metal and plastic, NITRO (Novel Innovations for Tissue Regeneration in Osteoarthritis) teams are working to regrow real, living tissue, returning joints to their healthy state and eliminating evidence of disease.

In two years, NITRO teams hit aggressive preclinical milestones, regenerating both cartilage and bone in osteoarthritic animal models. They are now working to complete the IND-enabling studies required to secure FDA concurrence to begin first-in-human clinical trials next year.

Led by ARPA-H Program Manager Ross Uhrich, DMD, MBA, NITRO teams are reshaping regenerative medicine across all stages of the OA continuum with new approaches in the program’s three technical areas: targeted bone regeneration, targeted cartilage regeneration, and total knee implants composed of living human tissue.

A fundamental question in physiology is understanding how tissues adapt and alter their cellular composition in response to dietary cues. The mammalian small intestine is maintained by rapidly renewing LGR5^(+) intestinal stem cells (ISCs) that respond to macronutrient changes such as fasting regimens and obesogenic diets, yet how specific amino acids control ISC function during homeostasis and injury remains unclear. Here we demonstrate that dietary cysteine, a semi-essential amino acid, enhances ISC-mediated intestinal regeneration following injury. Cysteine contributes to coenzyme A (CoA) biosynthesis in intestinal epithelial cells, which promotes expansion of intraepithelial CD8αβ^(+) T cells and their production of interleukin-22 (IL-22). This enhanced IL-22 signalling directly augments ISC reparative capacity after injury. The mechanistic involvement of the pathway in driving the effects of cysteine is demonstrated by several findings: CoA supplementation recapitulates cysteine effects, epithelial-specific loss of the cystine transporter SLC7A11 blocks the response, and mice with CD8αβ^(+) T cells lacking IL-22 or a depletion of CD8αβ^(+) T cells fail to show enhanced regeneration despite cysteine treatment. These findings highlight how coupled cysteine metabolism between ISCs and CD8^(+) T cells augments intestinal stemness, providing a dietary approach that exploits ISC and immune cell crosstalk for ameliorating intestinal damage.

https://www.nature.com/articles/s41586-025-09589-5

Sarcopenia and the age-related decline in muscular strength and regenerative capacity contribute directly to loss of autonomy, greater risk for hospitalization and healthcare utilization. One contributing cellular phenotype associated with skeletal muscle aging is a loss in the function and number of resident muscle stem cells (MuSCs) or satellite cells. MuSC activation leads to dramatic changes in cellular architecture and metabolic reprogramming, including both mitochondrial biogenesis and increased glycolysis. Despite these changes to increase energy production, high energy demands may not be fully met during periods of MuSC activation. Here we used in vitro and in vivo approaches in mice to demonstrate the function of glutaminase for age-related changes in MuSC function. By combining fluorescence-activated cell sorting (FACS) isolation with metabolomics and stable isotope tracing, we show an age-related decline in reductive (counterclockwise) flux of glutamine through the tricarboxylic acid (TCA) cycle, a pathway by which MuSCs build cellular fatty acid stores as necessary biomass for MuSC function.

https://www.nature.com/articles/s43587-026-01120-3

Martin Borch-Jensen writes a detailed analysis on the lack of the right datasets, which would hinder even highly advanced AI from producing breakthroughs in human longevity. AI's success in language and knowledge work cannot simply transfer to longevity research because biological data at the physiological and organismal layers where age-related diseases actually live is scarce, hard to generate, and slow to verify. Unlike protein folding or code, there are few corpora of highly-detailed longitudinal measurements; they also lack causal, task-relevant data for conditions like Alzheimer's or heart failure. What's more, clinical trial feedback loops take years. To unlock AI's potential in longevity, we need to deliberately generate the right kinds of data now: rich, multi-layer, longitudinal human studies which can be paired with faster experimental loops for causal hypothesis testing in the future. Because this data takes years to mature regardless of how quickly AI improves, the time to start is immediately.

Apparently the study was only done in 20 people but it's still encouraging.

Abstract

Metabolic disorders have been recognized as a major contributor to the occurrence and progression of osteoarthritis (OA). Identifying novel therapeutic agents to ameliorate the progression of OA with metabolic disorder is crucial. In this study, we demonstrate that ... a glucagon-like peptide-1 receptor (GLP-1R) agonist, exhibits strong chondroprotective effects in an OA mouse model with obesity, as evidenced by reduced pathological changes, including cartilage degeneration, osteophyte formation, synovial lesion, and pain sensitivity. A randomized pilot clinical study (ChiCTR2200066291) further supports these findings. By designing a precise diet-controlled setting to rule out the effect of appetite suppression and weight loss induced by SG, we demonstrate a weight loss-independent mechanism. Through regulating the "GLP-1R-AMPK-PFKFB3" axis, the SG reprograms chondrocyte metabolism profile from glycolysis to oxidative phosphorylation under inflammatory conditions, resulting in cartilage restoration.

Standard preventive measures including the recombinant shingles vaccine, annual influenza vaccination, COVID-19 vaccination to prevent severe infection, and prompt antiviral treatment of clinically relevant herpesvirus reactivations should be part of medical guidance for brain health.

I found this article fascinating — not because it’s science fiction anymore, but because it raises questions we may realistically face within our lifetime.

Researchers continue making major advances in gene editing and embryo research, potentially opening the door to preventing inherited diseases before birth. But once that door opens, where do we draw the line between “treatment” and “enhancement”?

If technology eventually allowed parents to reduce the risk of severe disease in an embryo, would you support it?

What about increasing intelligence, athletic ability, or modifying physical traits?

Would you personally do it for your own future child?

Curious where people think the ethical boundary should be.

Interesting review on GLP-1s and neuroprotection/dementia. Obviously, some of the longevity benefits have to be mediated through the caloric restriction dynamics of being on these medications. The dementia data is kind of a mixed bag.

The case for its neuroprotective benefit seems to largely come from epidemiological studies. A "retrospective cohort of over 295,000 patients found GLP-1 use associated with about a 70% lower risk of incident dementia versus non-use." The other data points come from 3 randomized cardiovascular trials, which showed a 53% lower dementia rate in patients randomized to GLP-1s versus placebo. So, it's a pretty big signal there from epidemiological studies. Would you get the same from other caloric restriction measures? I don't know, but caloric restriction is hard to adhere to for long periods of time.

From a mechanism angle, once again, it theoretically comes down to the distribution of glp-1 receptors, and in this case, GLP-1 receptors in the brain. "GLP-1 receptors are expressed on up to 70% of cerebral aterioles," according to the article. The implication is that glp-1s improve cerebral blood flow, which fits a vascular hypometabolism hypothesis of Alzheimers that some forms of dementia are at least partially driven by a chronic failure of blood flow and energy delivery to the brain. This is the case where the purported benefits are independent of caloric restriction and the weight loss effects of these meds.

The case against would be the recent EVOKE trial. Specifically, oral semaglutide seemed to fail the endpoint of the trial of slowing down cognitive decline. Maybe the oral delivery wasn't strong enough? thoughts here? It would be interesting to see the trial replicated with injectable sema or tirzepatide, to see if it has higher brain penetration, and to see if that is at least one variable that led to the poor outcome.

I want to support longevity research, but I’m not sure where my donations would have the greatest impact. Any suggestions would be greatly appreciated. Thanks!