Plasma antioxidants and human aging: a study on healthy elderly Tunisian population

Oxidative stress, antioxidants, hormesis and calorie restriction: The current perspective in the biology of aging

Aging, in a large measure, has long been defined as the resultant of oxidative stress acting on the cells. The cellular machinery eventually malfunctions at the basic level by the damage from the processes of oxidation and the system starts slowing down because of intrinsic eroding. To understand the initial destruction at the cellular level spreading outward to affect tissues, organs and the organism, the relationship between molecular damage and oxidative stress is required to understand. Retarding the aging process is a matter of cumulatively decreasing the rate of oxidative damage to the cellular machinery. Along with the genetic reasons, the decrease of oxidative stress is somehow a matter of lifestyle and importantly of diet. In the current review, the theories of aging and the understanding of various levels of molecular damage by oxidative stress have been emphasized. A broader understanding of mechanisms of aging have been elaborated in terms of effects of oxidative at molecular, mitochondrial, cellular and organ levels. The antioxidants supplementation, hormesis and calorie restriction as the prominent anti-aging strategies have also been discussed. The relevance and the efficacy of the antiaging strategies at system level have also been presented.

Social Support, Retirement Resources, and the Gendered Experiences of Aging for Tunisian Older Adults

Cultural context plays an important role in the experience of aging. The country of Tunisia is of particular interest because limited studies on aging have been done in the past decade. The study examined data collected from Tunisian older adults in an attempt to gain additional information about their experience aging in this culture. The purpose of this study was to identify key information tied to social policy factors that have the potential to impact older adults living in Tunisia. From June to July 2017, semi-structured interviews were completed with 60 older adults covering topics about family history, daily activities, health and health satisfaction, retirement benefits and satisfaction, medical coverage, social support, service availability, feelings of growing older, as well as advice provided to younger adults. Findings include gender differences in retirement resources and benefits, sources of support, and older adults' self-reported desires for the future. This work adds to the growing body of literature concerning differences in global aging and provides greater awareness of aging in the distinctive context of Tunisia. Additional work should seek to deepen the investigation of the various social policies that impact the Tunisian older adult.

Aging in Tunisia

Owing in part to its diversity of citizenship, Tunisia has a rich history of economic and social changes-including some of the same age-based demographic changes witnessed globally. Faced with an increasing older population and fewer young adults available to provide support, the government of Tunisia has implemented policies for the older population. These new governmental policies are intended to provide limited funds for older adults to supplement financial assistance provided by their families. Yet, even with a demographic transition occurring, recent published research on the aging Tunisian adult is limited at best. Policy change and research that improve the well-being of Tunisia's aging population must be based on adequate data. Thus, understanding the state of aging in Tunisia provides policymakers and researchers more complete information to use in decision making. Further studies should address more aspects of the Tunisian aging experience and add data that are more contemporary.

Mitochondrial peptidase IMMP2L mutation causes early onset of age-associated disorders and impairs adult stem cell self-renewal

Mitochondrial reactive oxygen species (ROS) are proposed to play a central role in aging and age-associated disorders, although direct in vivo evidence is lacking. We recently generated a mouse mutant with mutated inner mitochondrial membrane peptidase 2-like (Immp2l) gene, which impairs the signal peptide sequence processing of mitochondrial proteins cytochrome c1 and glycerol phosphate dehydrogenase 2. The mitochondria from mutant mice generate elevated levels of superoxide ion and cause impaired fertility in both sexes. Here, we design experiments to examine the effects of excessive mitochondrial ROS generation on health span. We show that Immp2l mutation increases oxidative stress in multiple organs such as the brain and the kidney, although expression of superoxide dismutases in these tissues of the mutants is also increased. The mutants show multiple aging-associated phenotypes, including wasting, sarcopenia, loss of subcutaneous fat, kyphosis, and ataxia, with female mutants showing earlier onset and more severe age-associated disorders than male mutants. The loss of body weight and fat was unrelated to food intake. Adipose-derived stromal cells (ADSC) from mutant mice showed impaired proliferation capability, formed significantly less and smaller colonies in colony formation assays, although they retained adipogenic differentiation capability in vitro. This functional impairment was accompanied by increased levels of oxidative stress. Our data showed that mitochondrial ROS is the driving force of accelerated aging and suggested that ROS damage to adult stem cells could be one of the mechanisms for age-associated disorders.