Cellular metabolic rates and oxidative stress profiles in primary fibroblast cells isolated from virgin females, reproductively experienced females, and male Sprague-Dawley rats

Abstract

Life‐history theory posits that differences in reproductive strategies may dictate lifespans of organisms. Animals that have higher investments in reproduction in terms of litter size and frequency of litters tend to have shorter lifespans. The accumulation of oxidative stress damage has been proposed to be a cost of reproduction and a mediator of life‐histories among animals, however, the implications of reproduction on oxidative stress still remain unclear. We tested physiological consequences of reproduction on metabolism and oxidative stress of Sprague‐Dawley Rats (Rattus norvegicus) with various reproductive experiences at the cell level. We grew primary dermal fibroblasts from Sprague‐Dawley rats which have the potential of having large litters frequently. Cells were isolated from virgin females, primiparous females, multiparous females, and reproductively‐experienced males. We measured basal oxygen consumption (OCR), proton leak, ATP production, spare respiratory capacity, coupling efficiency and glycolysis using a Seahorse XF96 oxygen flux analyzer. Additionally, we measured rates of RS (reactive species) production, reduced glutathione (GSH), mitochondrial content, and lipid peroxidation (LPO) damage to quantify oxidative stress. There were no significant differences in any OCR or glycolytic parameters across any of our groups. However, reproductively‐experienced females had significantly lower rates of LPO damage as compared with virgin females and males, as well as nonsignificant decreases in GSH concentration. Decreases in LPO damage and GSH indicate that reproductively‐experienced females potentially use their endogenous antioxidant system to combat delirious effects of increased metabolism during reproduction. Our results suggest that reproduction may, in fact, have a protective effect in females.

Variations in cellular unfolded protein response, respiratory capacity, and stress tolerance in skin and lung fibroblasts of deer mice (Peromyscus maniculatus)

“…This pattern of differential resistance suggests that cells’ responses to various forms of cytotoxic stress are regulated and coordinated differently. This finding corroborates with findings from other studies looking at cellular stress resistance and aging, where studies often find cells from longer-lived animals more resistant to one form of cellular stress but not another (Salmon et al 2009; Harper et al 2011; Miller et al 2011; Winward, J. D., Ragan, C. M., & Jimenez 2018).…”

“…Respiration rates were normalized to cell protein content. We measured basal respiration, proton leak, FCCP-induced maximal respiration, non-mitochondrial respiration, spare respiratory capacity, ATP production, and coupling efficiency following Winward, J. D., Ragan, C. M., & Jimenez (2018). Spare respiratory capacity, which indicates the cell’s capacity to respond to periods of high ATP demand, is calculated by subtracting basal respiration from FCCP-induced maximal respiration.…”