Heat-induced extracellular HSP72 release is blunted in elderly diabetic people compared with healthy middle-aged and older adults, but it is partially restored by resistance training

Coronavirus infection (SARS-CoV-2) in obesity and diabetes comorbidities: is heat shock response determinant for the disease complications?

“…Different strategies have been used to increase the HSR and raise the levels of HSP72 in patients with inflammatory-related diseases-such as cardiovascular, metabolic and neurodegenerative diseases [17]. Among the alternatives, several data have shown the efficacy of exercise training [15], heat therapy (hot water immersion, sauna or hot tub) [51], pharmacological agents (such as BGP-15, a hydroxylamine derivative) [52], and finally, the rational use of antipyretics for fever control.…”

“…However, with this strategy, only baseline levels can be measured, leading, sometimes, to divergent results. For this reason, we suggest the use a "heat stress test" to determine the real chaperone machinery capacity of the cells to express HSP72 (and release, in the case of peripheral blood mononuclear cells) in response to a heat challenge [15].…”

“…Extracellular HSP72 is receiving more attention since its regulatory role on immune cells are still under discussion. This protein can be released by different cells and stress conditions such as acute exercise and heat [ 15 ] and is involved in several conditions such as insulin resistance and acute lymphoblastic leukemia [ 28 ]. The effects of eHSP72 are still under debate since pro and anti-inflammatory results were described.…”

“…Hampered insulin signalling will lead to a deficient ability to induce HSR and the resolution of inflammation. Obese, insulin resistant individuals, and elderly people (with insulin resistance) have been found to have lower levels of HSP70 [ 15 , 33 , 34 ]. Not surprisingly, obesity-related, chronic inflammatory states show depressed HSR [ 15 , 35 , 36 ].…”

“…This molecular pathway is required for physiological adjustments in proteostasis and normal stress adaptation [ 14 ]. Recent evidence has shown that the HSR pathway, an important inflammation resolution pathway, is reduced in patients with metabolic disease [ 15 ]. Consequently, appropriate resolution of inflammation is impaired, allowing its amplification and propagation through all tissues, which, in patients with SARS-CoV-2 substantially increases the rate of complications [ 15 – 17 ].…”