Human umbilical cord mesenchymal stem cells attenuates heatstroke injury in rats

Abstract

Heatstroke reactions include hyperthermia, systemic inflammation, and multiple organ dysfunctions including brain ischemia and hypotension. We aimed to test whether human umbilical cord mesenchymal stem cells (hUC‐MSC) obtained from Meridigen Biotech company improves outcomes of heatstroke in rats. Adult male Sprague‐Dawley rats, under general anesthesia, were subjected to heat stress (42°C for 98 min) to induce heatstroke. Both the cerebral blood flow and the cellular levels of ischemia indicators in the hypothalamus were monitored during the entire experimentation. The serum levels of both lipid peroxidation and activated inflammation were determined by biochemical analyses. Heatstroke rats with vehicle treatment displayed (1) hyperthermia; (2) hypotension and bradycardia; (3) brain ischemia (e.g., decreased cerebral blood flow and increased hypothalamic levels of both glutamate and lactate/pyruvate); (4) systemic inflammation (e.g., increased serum levels of tumor necrosis factor‐alpha and interleukin‐6); and (5) lipid peroxidation (e.g., increased serum levels of malondialdehyde). Survival observations provide supportive evidence. hUC‐MSCs (1×106/ ml/ kg of body weight), but not vehicle (ml/ kg), when administered intravenously at 24 hours before heatstroke, significantly attenuated these heatstroke reactions. Mesenchymal stem cells derived from human umbilical cord promoted survival in rats after heatstroke, likely due to the ability of the cells to produce anti‐hyperthermia, anti‐hypotension, anti‐lipid peroxidation, and anti‐inflammation.