Adiponectin is a hormone that is primarily secreted by white adipose tissue. High levels of adiponectin in the blood circulation are observed in diseases including fibrosis and diabetes. However, it positively influences skin function and it has anti-aging effects on skin cells.
Interestingly, adiponectin exists in different forms, as globular fragment or in various full-length forms. The individual contributions of these adiponectin forms for the production of melanin, and hence skin pigmentation, remain poorly understood. It is known that full-length adiponectin suppresses the expression of pigmentation genes whereas globular adiponectin stimulates melanin production.
In this study, the authors tried to understand 1) how the different forms of adiponectin influence pigmentation and growth in human hair follicles (HFs) and 2) how adiponectin affects HF biology when produced by white adipose tissue.
Therefore, a synthetic form of full-length adiponectin was given to human HFs and cell growth and pigmentation were analyzed. It turned out that the time frame of treatment was too short to induce detectable effects on HF function. Changes in mRNA content precede the production of proteins, which are necessary to induce alterations in cell function. Therefore mRNA levels were examined in cells of the HF under adiponectin treatment. Interestingly, adiponectin caused lower mRNA levels of genes involved in hair pigmentation and growth.
In the second part the authors were interested if the white adipose tissue surrounding the HF could be the producer of adiponectin in the human skin. To test this they cultured HFs together with white adipose tissue and blocked the function of adiponectin in the same setting. This resulted in 1) an increased HF cell growth and pigmentation and 2) fewer and less activated melanocytes, the main cells producing melanin. These observations show that the white adipose tissue is indeed secreting adiponectin which in turn regulates HF function. Furthermore they emphasize the complex role of adiponectin in human HF biology. Thus, it has to be taken into account that adiponectin is no simple hair growth promoter but that its different forms most likely determine diverse impacts on HF biology.
This study was performed by the team of our CEO, Prof. Ralf Paus, located in Manchester and the described observations highlight the delicate and complex nature of hair and skin biology research. Therefore it is also interesting for our research at Monasterium Laboratory since the applied methods lie also within our expertise and we are confident to perform comparable studies to further comprehend skin and hair function.
Keywords: Adiponectin, hair pigmentation, hair growth, dermal adipose tissue, melanin.
Read the full story here:
Adiponectin negatively regulates pigmentation, Wnt/β-catenin and HGF/c-Met signalling within human scalp hair follicles ex vivo - PubMed (nih.gov)
Nicu C, Jackson J, Shahmalak A, Pople J, Ansell D, Paus R.
"Adiponectin negatively regulates pigmentation, Wnt/β-catenin and HGF/c-Met signalling within human scalp hair follicles ex vivo"
Arch dermatol Res, 2021. doi: 10.1007/s00403-021-02291-2