Age-associated decrease in proportion and antigen expression of CD8+/CD4+ thymocytes in BALB/c mice.

M el Demellawy; R el Ridi

doi:10.1016/0047-6374(92)90115-t

Home/Archive/PubMed

PubMed · 1349934

Age-associated decrease in proportion and antigen expression of CD8+/CD4+ thymocytes in BALB/c mice.

M el Demellawy·R el Ridi

View original source ↗Export metadata ↓

Abstract

We studied the distribution of Thy-1.2+, CD8+ and CD4+ thymocytes in 3-, 6.5-, 12- and 18-month-old inbred BALB/c mice by staining cells with specific monoclonal antibodies (mAb) using indirect membrane immunofluorescence. The percentages of Thy-1.2+, CD8+, and CD4+ thymocytes did not vary with age until 12 months, but they exhibited at 18 months a highly significant decline. Staining thymocytes with mAb CD8 and CD4 alone or in a mixture allowed us to show that the age-related decline in proportions of CD8+ and CD4+ thymic cells is associated with the double positive (CD8+/CD4+, immature) subset. Most importantly, we observed a progressive age-related decrease in ratio of bright/dull Thy-1.2+, CD8+ and CD4+ thymocytes. The CD8+ and CD4+ thymocytes that did not adhere to peanut agglutinin (PNA-, which is supposed to represent the mature single positive subset) did not show any age-related change in the proportion of bright and dull cells. Therefore, we concluded that the double positive (CD8+/CD4+, immature, PNA+) thymocytes display reduced expression of CD8 and CD4 antigens with aging. The implications of these findings to the fundamental mechanisms of immunosenescence are discussed.

Explore related subjects

Aging Animals Antigens, Surface CD4 Antigens CD4-CD8 Ratio CD8 Antigens Female Lectins Male Membrane Glycoproteins Mice Mice, Inbred BALB C Peanut Agglutinin T-Lymphocyte Subsets Thy-1 Antigens Journal Article Research Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

M el Demellawy, R el Ridi. 1992-03-01. Age-associated decrease in proportion and antigen expression of CD8+/CD4+ thymocytes in BALB/c mice.. https://doi.org/10.1016/0047-6374(92)90115-t

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

An open benchmark and language models for AI in aging biology.

Over the past two decades, human aging has been characterized across DNA methylation, transcriptomic, proteomic, and clinical modalities, yet no benchmark evaluates whether AI systems can interpret these heterogeneous data types in the context of aging biology. We introduce LongevityBench, an open suite of 17 tasks spanning five biodata domains, and use it to assess 18 frontier AI systems from six developer teams. Despite recent advances in AI, no single model dominates all tasks, with omics-based age prediction being the hardest task regardless of scale. To test whether these gaps can be closed without frontier-scale resources, we fine-tuned a family of five multitask Longevity-LLMs on domain-specific aging data. The compact (0.6B-9B parameters) Longevity-LLMs matched or exceeded far larger frontier systems on LongevityBench, showing that general-purpose language models can be adapted to structured-omics tasks. We publicly release the benchmark, models, and Longevity Claw, an agentic research interface for aging researchers.

Aging↗

PubMed2026

Association between sirtuin 1 and markers of oxidative stress in master athletes.

BACKGROUND: Lifelong training in master athletes confers protective effects, promoting higher sirtuin levels and enhanced antioxidant capacity. Although Sirtuin 1 (SIRT1) is well studied, no previous study has examined the relationship between circulating SIRT1 levels and antioxidant defense variables in master athletes. PURPOSE: To compare and analyze the relationships between circulating levels of SIRT1 and variables related to antioxidant defense in master athletes (MA) and untrained middle-aged individuals (UMA). METHODS: Male MA (n = 42; 51.62 ± 7.33 years; ≥10 years of training and competition in running) and UMA (n = 15; 47.73 ± 8.52 years) were evaluated. Venous blood samples were collected for biochemical analyses of SIRT1, antioxidant enzymes, TBARS and F2-isoprostanes, 8-OHdG, and redox balance indexes. RESULTS: MA showed higher levels of SIRT1 (18.22 ± 4.53 vs. 6.08 ± 2.11 ng/mL; p < 0.0001), as well as of SOD, CAT, and GSH (p < 0.001), indicating a more favorable antioxidant profile. After adjustment for body fat percentage, differences in SOD, CAT, GSH and TBARS, remained significant. SIRT1 was positively correlated with SOD (r = 0.279; p = 0.031), CAT (r = 0.485; p < 0.001), GSH (r = 0.476; p < 0.001) and CAT/8-OHdG (r = 0.430; p = 0.032), and negatively correlated with TBARS (r = - 0.518; p < 0.001). CONCLUSION: Master athletes exhibited higher circulating SIRT1 concentrations and a more favorable systemic redox profile than untrained individuals, with SIRT1 being associated with markers of antioxidant defense, lipid peroxidation, and redox balance.

Aging↗

PubMed2026

Decoding SUMOylation as a metabolic stress sensor in aging and age-related disorders: Mechanisms, tissue specificity and therapeutic potential.

SUMOylation is a reversible post-translational modification increasingly recognized for its role in coordinating cellular responses to metabolic stress during aging. Emerging evidence indicates that it functions beyond a conventional modification, representing an adaptive stress‑responsive regulatory network that integrates metabolic, oxidative, inflammatory, and proteotoxic signals. Rather than acting on isolated pathways, this network finely tunes mitochondrial function, proteostasis, genome maintenance, immune balance, and epigenetic regulation. Accumulating evidence indicates that SUMO-dependent regulation exhibits remarkable tissue specificity, supporting mitochondrial adaptation and contractile integrity in skeletal muscle, shaping lipid and glucose metabolism in the liver, modulating proteotoxic stress and neuronal resilience in the brain, and contributing to immune cell differentiation and chronic low-grade inflammation during aging. In this review, we summarize current mechanistic insights into SUMO signaling across aging-relevant tissues, with particular emphasis on its functional interplay with other post-translational modifications, including ubiquitination and acetylation. We discuss how SUMOylation operates as a shared regulatory layer while enabling context-dependent outcomes that underlie diverse aging phenotypes and age-related disorders. Finally, we evaluate emerging translational approaches-ranging from pharmacological modulation of SUMO enzymes to lifestyle interventions such as caloric restriction and exercise-that highlight both the opportunities and challenges of targeting SUMO-regulated stress responses in aging. Together, this synthesis provides a framework for understanding how SUMOylation links metabolic stress to tissue-specific aging trajectories and therapeutic potential.

Aging↗