Excessive production of mitochondrial reactive oxygen species (mROS) is strongly associated with mitochondrial and cellular oxidative damage, aging, and degenerative diseases. However, mROS also induces pathways of protection of mitochondria that slow aging, inhibit cell death, and increase lifespan. Recent studies show that the activation of the mitochondrial permeability transition pore (mPTP...

Aging is accompanied by a decline in tissue function, regeneration, and repair. A large part of this decline is caused by the deterioration of tissue stem cell function. Understanding the mechanisms that drive stem cell aging and how to counteract them is a critical step for enhancing tissue repair and maintenance during aging. Emerging evidence indicates that epigenetic modifiers and metabolis...

Reproductive aging in the male Brown Norway (BN) rat is characterized by decreased Leydig cell steroidogenesis associated with seminiferous tubule dysfunction. This could be a result of a combination of a primary testicular defect and a secondary hypothalamic pituitary dysfunction. In the present study, we determined in the BN rat whether germ cell loss occurred via apoptosis. We then defined t...

A mechanistic understanding of aging has yet to be described; this paper puts forth a new theory that has the potential to explain aging in all sexually reproductive life forms. The theory also puts forth a new definition of aging - any change in an organism over time. This definition includes not only the changes associated with the loss of function (i.e. senescence, the commonly accepted defi...

The aging of tissue-specific stem cell and progenitor cell compartments is believed to be central to the decline of tissue and organ integrity and function in the elderly. Here, we examine evidence linking stem cell dysfunction to the pathophysiological conditions accompanying aging, focusing on the mechanisms underlying stem cell decline and their contribution to disease pathogenesis.

Aging affects endogenous stem cells in terms of functionality and numbers. In particular, during aging, the stemness property can decrease because of enhanced apoptotic cell death and senescence. In addition, aging and aging-related co-morbidities affect the paracrine activity of stem cells and the efficiency of their transplantation. Collectively, this leads to a reduction of the capacity of o...

background: aging population and prevalence of diseases like cancer among them have affected general health of the elderly, so that one of the influential factors on health components of elderly patients with cancer is death anxiety, which has important consequences in them. methods: in this cross-sectional (descriptive correlational) study, 130 elderly patients with cancer undergoing chemother...

The study of age-related changes in the physiology, biochemistry, and molecular biology of isolated skin cell populations in culture has greatly expanded the understanding of the fundamental aspects of skin aging. In modern biogerontology, the terms ‘‘cellular aging,’’ ‘‘cell senescence,’’ or ‘‘replicative senescence’’ most commonly imply the study of normal diploid cells in culture, which duri...

For the purpose of studying the aging changes of macromolecular synthesis in the colonic cells of experimental animals, we studied 10 groups of aging mice during aging from fetal day 19 to postnatal month 24. They were injected with 3 H-uridine, a precursor for RNA synthesis, sacrificed and the colonic tissues were taken out, fixed and processed for light and electron microscopic radioautograph...