PubMed HealthSearch

PubMed · 8736697

Age-associated decrease in inositol 1,4,5-trisphosphate and diacylglycerol generation by 1,25(OH)2-vitamin D3 in rat intestine.

Abstract

The hormonal form of vitamin D3, 1,25(OH)2-vitamin D3(1,25[OH]2D3), stimulates the breakdown of membrane phosphoinositides, generating inositol-1,4,5-trisphosphate (IP3) and diacylglycerol (DAG) in a variety of cell systems. Several studies suggest that alterations in the receptor-mediated phosphoinositide cascade are involved in the pathophysiology of aging. Therefore, the formation of IP3 and DAG were determined under basal conditions and after stimulation with physiological concentrations of 1,25(OH)2D3 in duodenum from young (3-mo-old) and aged (24-mo-old) rats. The hormone induced a transient and biphasic formation of IP3 and DAG. Values obtained in young rats peaking at 15 s (51% and 42% above basal levels for IP3 and DAG, respectively) and at 3 min (90% and 74% above basal levels for IP3 and DAG, respectively) were significantly decreased in duodenum from senescent animals (IP3: +20% and DAG: +18% above basal level at 15 s; and IP3: +18% and DAG: +29% above basal level at 3 min). The 1,25(OH)2D3-induced generation of DAG in both young and aged duodenum was effectively inhibited in the presence of neomycin, a phospholipase C (PLC) inhibitor, and was dependent on extracellular Ca2+. After the biphasic response, the levels of DAG generated by the hormone (10 min stimulation) remained elevated; the elevation occurred in the absence of IP3 production; and the elevated levels were not abolished by neomycin, implying that phospholipids other than phosphoinositides are the source of DAG. This 1,25(OH)2D3-dependent late phase of DAG generation was also diminished in aged animals. The precise molecular basis and the physiological significance of decreased liberation of IP3 and DAG by 1,25(OH)2D3 in the aged rat duodenum remains to be determined.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A R de Boland, M M Facchinetti, G Balogh, V Massheimer, R L Boland. 1996. Age-associated decrease in inositol 1,4,5-trisphosphate and diacylglycerol generation by 1,25(OH)2-vitamin D3 in rat intestine.. https://doi.org/10.1016/0898-6568(95)02048-9

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

KEEP EXPLORING

Related citations

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

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&#x2009;=&#x2009;42; 51.62&#x2009;&#xb1;&#x2009;7.33 years; &#x2265;10 years of training and competition in running) and UMA (n&#x2009;=&#x2009;15; 47.73&#x2009;&#xb1;&#x2009;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&#x2009;&#xb1;&#x2009;4.53 vs. 6.08&#x2009;&#xb1;&#x2009;2.11 ng/mL; p&#x2009;<&#x2009;0.0001), as well as of SOD, CAT, and GSH (p&#x2009;<&#x2009;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&#x2009;=&#x2009;0.279; p&#x2009;=&#x2009;0.031), CAT (r&#x2009;=&#x2009;0.485; p&#x2009;<&#x2009;0.001), GSH (r&#x2009;=&#x2009;0.476; p&#x2009;<&#x2009;0.001) and CAT/8-OHdG (r&#x2009;=&#x2009;0.430; p&#x2009;=&#x2009;0.032), and negatively correlated with TBARS (r&#x2009;=&#x2009;-&#x2009;0.518; p&#x2009;<&#x2009;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

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&#x2011;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