The effect of leptin and adipose tissue on the growth of hair follicles

  • 楊 朝鈞

Student thesis: Doctoral Thesis


The hair follicles and intradermal adipose tissue are close to each other either anatomically or functionally Evidences and new nomenclature indicate intradermal adipose tissue as the adipose tissue above panniculus carnosus The intradermal adipose tissue hosts the lower half of hair follicles in growth phase (anagen) The thickness of intradermal adipose tissue changes according to hair cycle propagation However the interaction between the two tissues in the cellular or molecular level is still largely unknown This PhD theses focused on both the clinical and biological implications that adipose tissue might have on hair growth Leptin receptor is expressed specifically over the bulge area where the hair epithelial stem cells reside either in mouse vibrissa and pelage follicles and human scalp hair follicles Leptin mRNA in the dermal adipose tissue is differentially expressed in different hair cycle stages with lowest level in early anagen phase (growth phase) and highest level in telogen phase (resting phase) In vitro organ culture of vibrissa follicles from mice reveled that adipose-derived leptin inhibits the lengthening of anagen hair shafts In db/db mice the onset of second anagen was delayed and the hair wave propagation didn’t cover the whole back skin The above findings suggest that leptin might modulate hair cycle propagation via the regulation on hair epithelial stem cells Clinically a cross-sectional study was conducted to determine the association between body adiposity as indexed by body mass index (BMI) and alopecia severity in men with androgenetic alopecia (AGA) 189 male patients were enrolled with a mean age of 30 8 years The subjects with severe alopecia (grade V-VII) had higher BMI than subjects with mild to moderate alopecia (grade I-IV) (25 1 vs 22 8 kg/m2 p=0 01) After multivariate adjustments the risk for having severe alopecia was higher in the overweight or obese (BMI ?24 kg/m2) subjects with male pattern AGA (odds ratio=3 52 p
Date of Award2015 Jan 26
Original languageEnglish
SupervisorLynn Ling-Huei Huang (Supervisor)

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