Obesity accelerates hair thinning through a stem cell-centric convergence mechanism
Morinaga H., Mohri Y., Grachtchouk, M., et al. Obesity accelerates hair thinning by a stem cell-centric convergence mechanism. Nature (2021). https://doi.org/10.1038/s41586-021-03624-x
Commentary
This study has been conducted to investigate the relationship between obesity and hair. It is generally known that obesity increases susceptibility to many age-related diseases, but its effects on organ dysfunction are not well understood.
Hair loss is caused by age-related miniaturization of hair follicles (mini epithelial organs that grow hair) and depletion of hair follicle stem cells (HFSCs). And stress induced by consuming a high-fat diet (HFD) has been reported to accelerate hair thinning by targeting HFSCs.
The results, which were produced by time-series gene expression analysis, showed that when young mice were treated with HFD for four consecutive days, reactive oxygen species were produced in excess, and activated HFSCs were directed toward epidermal keratinization. However, the pool of HFSCs did not decrease.
Integrated analysis using stem cell fate tracking, epigenetics, and reverse genetics showed that additional administration of HFD induced activation of fat droplets and NF-κB within HFSCs via autocrine and/or paracrine IL-1R signaling.
These integrated factors are described to converge to a marked inhibition of sonic hedgehog (SHH) signaling in HFSCs. They say that this action explains the further depletion of lipid-laden HFSCs through their aberrant differentiation, which induces follicle miniaturization and eventual hair loss. Conversely, since transgenic or pharmacological activation of SHH rescues HFD-induced hair loss, these data collectively indicate that obesity-induced stem cell inflammatory signaling strongly suppresses organ regeneration signaling and accelerates mini-organ miniaturization, suggesting the importance of prevention of organ dysfunction This suggests the importance of preventing organ dysfunction.
However, since the experiments are not conducted on human subjects, we cannot say that these results can be adapted right now. However, it is necessary to keep in mind that the effects of high-fat diets have been reported in many cases, so it is necessary to refrain from consuming them.
