Aging of Human Adult Stem Cells.

With the continuous development of stem cell research in recent years, it is realized that stem cell aging may be the core issue of organ aging. As an important approach and main content of regenerative medicine, the stem cell research brings great hope to overcome difficult diseases and improve the quality of life for human beings and become the key to solve this issue. Based on this research, the varying characteristics of stem cells in aging could be recognized; the role of stem cells in the organ aging and regeneration will be revealed; the function of stem cells will be controllable and regulatable in tissues and organs; the stem cells from tissues and organs with rapid or slow cell renewal (e.g., liver and neuron) could be continuously observed from the levels of cellular molecules and dynamic complex. With the assistance of systematical research approaches, the function and mechanism studies can be conducted via multi-perspectives and levels during the different stages of organ aging and regeneration. All of the abovementioned requires great efforts to thoroughly understand the basic rule and the way of stem cell regulation in organ aging and regeneration. Final to the end, the dream of antiaging, efficient repair, and organ remodeling could be realized and also can meet the major needs of population health and disease treatment in our country, meaningfully to contribute benefits for the health of human beings.

Age-Invariant Genes: Multi-Tissue Identification and Characterization of Murine Reference Genes.

Studies of the aging transcriptome focus on genes that change with age. But what can we learn from age-invariant genes-those that remain unchanged throughout the aging process? These genes also have a practical application: they serve as reference genes (often called housekeeping genes) in expression studies. Reference genes have mostly been identified and validated in young organisms, and no systematic investigation has been done across the lifespan. Here, we build upon a common pipeline for identifying reference genes in RNA-seq datasets to identify age-invariant genes across seventeen C57BL/6 mouse tissues (brain, lung, bone marrow, muscle, white blood cells, heart, small intestine, kidney, liver, pancreas, skin, brown, gonadal, marrow, and subcutaneous adipose tissue) spanning 1 to 21+ months of age. We identify 9 pan-tissue age-invariant genes and many tissue-specific age-invariant genes. These genes are stable across the lifespan and are validated in independent bulk RNA-seq datasets and RT-qPCR. We find age-invariant genes have shorter transcripts on average and are enriched for CpG islands. Interestingly, pathway enrichment analysis for age-invariant genes identifies an overrepresentation of molecular functions associated with some, but not all, hallmarks of aging. Thus, though hallmarks of aging typically involve changes in cell maintenance mechanisms, select genes associated with these hallmarks resist fluctuations in expression with age. Finally, our analysis concludes no classical reference gene is appropriate for aging studies in all tissues. Instead, we provide tissue-specific and pan-tissue genes for assays utilizing reference gene normalization (i.e., RT-qPCR) that can be applied to animals across the lifespan.

[Skin aging-cellular senescence : What is the future?] / Hautalterung ­ zelluläre Seneszenz : Wohin geht die Reise?

BACKGROUND: Cellular senescence is the main cause of skin and organ aging and is associated with a wide range of aging-related diseases. OBJECTIVES: To understand which senolytics, senomorphics, and cell-based therapies have been developed to alleviate and even rejuvenate skin aging and reduce cellular senescence. METHODS: Basic literature for the mode of action of senolytics and senomorphics and their clinical perspectives in daily routine are discussed. RESULTS: Various causes lead to mitochondrial dysfunction and the activation of pro-aging signaling pathways, which eventually lead to cellular senescence with degradation of structural proteins of the dermal connective tissue and severe suppression of regenerative stem cell niches of the skin. CONCLUSIONS: Depletion of senescent cells suppress skin aging and enforce rejuvenation of skin and other organs and their function. The removal of senescent cells by cells of the native immune system is severely disturbed during aging. Selected senolytics and senomorphics are approved and are already on the market.

Distinct biological ages of organs and systems identified from a multi-omics study.

Biological age (BA) has been proposed to evaluate the aging status instead of chronological age (CA). Our study shows evidence that there might be multiple "clocks" within the whole-body system: systemic aging drivers/clocks overlaid with organ/tissue-specific counterparts. We utilize multi-omics data, including clinical tests, immune repertoire, targeted metabolomic molecules, gut microbiomes, physical fitness examinations, and facial skin examinations, to estimate the BA of different organs (e.g., liver, kidney) and systems (immune and metabolic system). The aging rates of organs/systems are diverse. People's aging patterns are different. We also demonstrate several applications of organs/systems BA in two independent datasets. Mortality predictions are compared among organs' BA in the dataset of the United States National Health and Nutrition Examination Survey. Polygenic risk score of BAs constructed in the Chinese Longitudinal Healthy Longevity Survey cohort can predict the possibility of becoming centenarian.

Clinical manifestations and gene analysis of Hutchinson-Gilford progeria syndrome: A case report.

BACKGROUND: This case report describes a child with Hutchinson-Gilford progeria syndrome (HGPS, OMIM: 176670) caused by LMNA (OMIM: 150330) gene mutation, and we have previously analyzed the clinical manifestations and imaging characteristics of this case. After 1-year treatment and follow-up, we focus on analyzing the changes in the clinical manifestations and genetic diagnosis of the patient. CASE SUMMARY: In April 2020, a 2-year-old boy with HGPS was found to have an abnormal appearance, and growth and development lagged behind those of children of the same age. The child's weight did not increase normally, the veins of the head were clearly visible, and he had shallow skin color and sparse yellow hair. Peripheral blood DNA samples obtained from the patient and his parents were sequenced using high-throughput whole-exosome sequencing, which was verified by Sanger sequencing. The results showed that there was a synonymous heterozygous mutation of C.1824 C>T (P. G608G) in the LMNA gene. CONCLUSION: Mutation of the LMNA gene provides a molecular basis for diagnosis of HGPS and genetic counseling of the family.

The Role of Rapamycin in Healthspan Extension via the Delay of Organ Aging.

Aging can not only shorten a healthy lifespan, but can also lead to multi-organ dysfunction and failure. Anti-aging is a complex and worldwide conundrum for eliminating the various pathologies of senility. The past decade has seen great progress in the understanding of the aging-associated signaling pathways and their application for developing anti-aging approaches. Currently, some drugs can improve quality of life. The activation of mammalian target of rapamycin (mTOR) signaling is one of the core and detrimental mechanisms related to aging; rapamycin can reduce the rate of aging, improve age-related diseases by inhibiting the mTOR pathway, and prolong lifespan and healthspan effectively. However, the current evidence for rapamycin in lifespan extension and organ aging is fragmented and scattered. In this review, we summarize the efficacy and safety of rapamycin in prolonging a healthy lifespan by systematically alleviating aging in multiple organ systems, i.e., the nervous, urinary, digestive, circulatory, motor, respiratory, endocrine, reproductive, integumentary and immune systems, to provide a theoretical basis for the future clinical application of rapamycin in anti-aging.