Late-onset dietary restriction compensates for age-related increase in oxidative stress and alterations of HSP 70 and synapsin1 protein levels in male Wistar rats

Abstract

Numerous reports implicate increased oxidative stress in the functional and structural changes occurring in the brain and other organs as a part of the normal aging process. Dietary restriction (DR) has long been shown to be life-prolonging intervention in several species. This study was aimed to assess the potential efficacy of late-onset short term DR when initiated in 21 months old male wistar rats for 3 months on the antioxidant defense system and lipid peroxidation, cellular stress response protein HSP 70 and synaptic marker protein synapsin 1 in discrete brain regions such as cortex, hypothalamus, and hippocampus as well as liver, kidney and heart from 24 month old rats. Age-associated decline in activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione, and elevated levels of lipid peroxidation was observed in brain and peripheral organ as well as increased expression of HSP 70 and reduction in synapsin 1 was observed in brain studied. Late-onset short term DR was effective in partially restoring the antioxidant status and in decreasing lipid peroxidation level as well as enhancing the expression of HSP 70 and synapsin 1 in aged rats. Late onset short term DR also prevented age-related neurodegeneration as revealed by Fluoro-Jade B staining in hippocampus and cortex regions of rat brain. Thus our current results suggest that DR initiated even in old age has the potential to improve age related decline in body functions.

Reproduction reduces HSP70 expression capacity in Argopecten purpuratus scallops subject to hypoxia and heat stress

“…Therefore, the effect of the energetic restriction may be even higher than observed in this study. Our results and the previous examples show that HSP synthesis and activity are energetically costly; however, the processes of degrading a misfolded protein and re-synthesizing another cost one thousand times more (Sharma et al 2010). Therefore, this cellular stress response is considered a key physiological adaptation (Sharma et al 2010, Morris et al 2013).…”

“…Stress proteins play an important role in energydependent processes, such as protein translocation into cellular organelles (Beckmann et al 1990) and the binding and release of denatured proteins and short peptides to HSP70 (McKay et al 1994, Mayer & Bukau 2005. Recently, it was observed that under in vitro conditions, one Hsp70 molecule consumed 5 ATPs to unfold a single misfolded protein into an intermediate that, upon chaperone dissociation, spontaneously refolded to its native state (Sharma et al 2010). Thus, ATP is considered indispensable for correct HSP70 functioning (Morimoto 1993, Currie et al 1999.…”

“…Therefore, HSPs not only increase the organism's capacity to tolerate stress conditions but also enhance the efficiency of protein synthesis. However, gene expression and protein synthesis processes, as well as the chaperoning activity of these proteins, generate high cellular demands for energy in terms of ATP (Hofmann & Somero 1995, Somero 2002, Sharma et al 2010. Therefore, we propose that upon exposure to a stress factor, the observed level of induced HSP70 may reflect not only the level of molecular damage, but also the capacity to express this protein, which could be energetically limited or affected by the physiological status of the animals.…”

Aging and Diets Regulate the Rat Anterior Pituitary and Hypothalamic Transcriptome

“…LTMCR was shown to prevent age-related decrease of Hsp70 mRNA levels in the rat liver [58] and alveolar macrophages [59] following heat shock. Moreover, HSP70 is increased in the hippocampus and cerebral cortex of calorie-restricted old rats [60]. We also observed beneficial effects of LTMCR on genes encoding enzymes related to antioxidant defenses.…”

Age-related changes of malondialdehyde, body weight and organ weight in male mice

“…Aging decreases the activities of superoxide dismutase, catalase and glutathione and increased lipid peroxidation and 70 kilodalton heat shock protein (Hsp70) levels in the brain and also in peripheral organs such as the liver, kidneys and heart. (6) One of the markers of oxidative stress is malondialdehyde (MDA), which is a product of lipid peroxidation with mutagenic, cytotoxic, and carcinogenic properties, due to its inhibitory effect on antioxidant enzymes. Therefore, increased MDA concentration is frequently used as one of markers of disordered homeostasis and aging.…”