News Desk , United States, 10/17/2021 / Top Wire News /
It’s a well-known fact that obesity is quite closely linked to the development of several diseases and ailments in humans such as heart disease, diabetes, etc. Although, it’s still not understood how different body organs deteriorate and lose functionality due to chronic obesity. A group of medical researchers from Tokyo Medical and Dental University recently published an article in Nature, in which they used mouse model experiments to examine how a high-fat diet or genetically induced obesity affects hair thinning and hair loss.
The authors discovered in their experiments that obesity leads to depletion of hair follicle stem cells (HFSCs) through the induction of certain inflammatory signals, blocking hair follicle regeneration and ultimately leading to loss of hair follicles.
Normally, HFSCs self-renew in every hair follicle cycle as this is part of the process that allows our hairs to grow back continuously. As humans age, HFSCs fail to renew themselves thus leading to fewer HFSCs and hair thinning. It has been known that obese people have a higher risk of androgenic alopecia, there was not much information about whether obesity accelerates hair thinning, how and the molecular mechanisms behind such change were largely unknown.
Hironobu Morinaga lead author of the study says that “High-fat diet feeding accelerates hair thinning by depleting HFSCs that replenish mature cells that grow hair, especially in old mice.” He further adds “We compared the gene expression in HFSCs between HFD-fed mice and standard diet-fed mice and traced the fate of those HFSCs after their activation and found that those HFSCs in HFD-fed obese mice change their fate into the skin surface corneocytes or sebocytes that secrete sebum upon their activation. Those mice show the faster hair loss and smaller hair follicles along with depletion of HFSCs.”
Emi K. Nishimura, senior author of the study added further that “The gene expression in HFSCs from the high-fat-fed mice indicated the activation of inflammatory cytokine signaling within HFSCs. The inflammatory signals in HFSCs strikingly repress Sonic hedgehog signaling that plays a crucial role in hair follicle regeneration in HFSCs.”
The researchers have confirmed the activation of the Sonic hedgehog signaling pathway in this process can rescue the depletion of HFSCs. Nishimura says that this could prevent the hair loss brought on by the high-fat diet.
This study has provided interesting new insights into the specific cellular fate changes and tissue dysfunction that can occur following a high-fat diet or genetically induced obesity and may lead to future prevention and treatment of hair thinning as well as for the understanding of obesity-related diseases.