Comparison of the heat shock response in ethnically and ecologically different human populations.

Abstract

In response to heat shock or other metabolic insults, an increased expression of different heat shock proteins (hsps) and, in particular, members of the hsp7O family is observed in human cells. Using two-dimensional electrophoresis, we compared the pattern of hsp7O synthesis in human fibroblast cell lines isolated from two contrasting groups of individuals. The first group was represented by native Turkmen living in the hot desert of Middle Asia; the second group consisted of Russians living in moderate climatic regions of European Russia. This analysis has shown that fibroblasts isolated from Turkmen after severe heat shock exhibited intensive synthesis of all hsps in parallel with synthesis of many other cellular proteins, while only trace synthesis of hsps was observed in the second group (Russians). Surprisingly, Northern analysis of RNA synthesis failed to reveal any differences between the two groups after heat shock treatment. When survival of fibroblasts after severe heat shock treatment was assessed by colony formation assay, the cells of the first group exhibited significantly higher survival rates.All organisms studied to date respond to an elevation of 5°C or more above their normal physiological temperature with the rapid synthesis of a highly conserved group of proteins [heat shock proteins (hsps)]. It is a widely held assumption that the purpose of the heat shock response is to protect organisms from the toxic effects of heat and other forms of stress (1, 2). hsps and, in particular, members of the hsp70 family have been implicated as essential components of protein maturation and transport (3, 4). These proteins have been shown to participate as molecular chaperones, facilitating the early events of protein synthesis, protein folding, and perhaps higher-ordered protein assembly (5,6 MATERIALS AND METHODSTissue Culture Cells of Different Origin. Diploid skin fibroblasts of two different human groups were used in the investigation. The first group was represented by Turkmen aborigines, a tribe with a certain level of inbreeding inhabiting for many generations (about 2500 years) the extremely hot and dry deserts of Middle Asia. The second group consists of Russians living in moderate climatic regions of European parts of the former U.S.S.R. Fibroblast cultures from 7-10 volunteers were compared in both groups.Heat Shock and Protein Purification. Fibroblasts used in all experiments were maintained at 37°C for 10-15 passages. The cells were cultured in Eagle's medium supplemented with 5% fetal calf serum and 5% fetal bovine serum. Each individual culture was subdivided into four flasks and heat shocked at 42.5°C in a circulating water bath for 2, 4, and 6 h. The fourth flask (control) was kept at 37°C in parallel with cells undergoing heat shock treatment, and the control cells were harvested at the end of the heat shock experiment. After heat shock, the cells were rinsed with balanced Hanks' salt medium and labeled for 1 h at 37°C in the same salt solution containing 14C-labeled amino acids ...

Association of Met439Thr Substitution in Heat Shock Protein 70 Gene with Postoperative Atrial Fibrillation and Serum HSP70 Protein Levels

“…Lyashko et al [46] have particularly shown ethnic differences in the heat shock response in human populations. In the present study, we have selected a Caucasian cohort of patients to keep the effect of the population admixture to minimum.…”

Heat Acclimation, Epigenetics, and Cytoprotection Memory

“…In 1997 in his review on "Heat shock proteins and heat adaptation of the whole organism," Moseley (147) At the time, only two studies focused on this aspect: Research on acclimating goby fish-(Gilichthys mirabilis) demonstrated that the threshold for the HSP 90 kDa and 70 kDa shifts upward following the transition from cold acclimation to warm acclimation (39,40), and was accompanied by an increase in levels of these HSPs. Additionally, a number of publications reported that (i) poikilotherms, evolutionary adapted to a hot environment, have higher levels of HSP70 when inhabiting hot environments compared to their counterparts living in comfort habitats (ii) a similar phenomenon was seen when comparing human fibroblasts from populations from different climates (129). The first study on HSPs in heat acclimating homeotherms was that of Horowitz (80), demonstrating that LTHA rats have profoundly greater HSP72 kDa reserves, respond faster to heat stress and that LTHA confers ischemic tolerance.…”

Hsp70 Induction and hsp70 Gene polymorphisms as Indicators of acclimatization under hyperthermic conditions

“…There is evidence that heat-tolerant species, e.g. lizards (Zatsepina et al, 2000) and Turkmen (Lyashko et al, 1994) living in desert environments and rats heat-acclimated for 30 days (Maloyan et al, 1999) have adapted to high ambient temperatures by maintaining a higher level of Hsp70 and having an increased threshold temperature for induction of HSP, and in certain cases also showed faster kinetics of induction. However, the acquisition of thermotolerance through a short period in hot, humid environments combined with exercise cannot be compared to the evolutionary adaptation of living in hot desert climates.…”