Characterizing gene expression changes within the human hair follicle bulb driven by hepatocyte growth factor secreted by perifollicular fat

Dermal white adipose tissue (dWAT) has been linked to modulation of murine hair follicle growth and cycling, however no studies have characterized its effects upon human hair growth. Since HGF was detected as a dWAT secretion product in HF-dWAT co-culture, the aim of this study was to characterize changes in gene expression in human dissected hair follicles vs. follicles cultured with surrounding dermal fat treated with/without a neutralizing antibody to HGF. To this end, the hair matrix and pre-cortex in each condition was isolated using laser-capture microdissection and microarray was carried out on the amplified cDNA. We identified 593 genes differentially modulated owing to the dWAT-derived HGF i.e. 301 up-regulated genes and 292 down-regulated genes in the presence of dWAT-secreted HGF and vice versa when HGF is neutralized. Full-length human scalp hair follicles were cultured for 24hr in William's E media in the following conditions: 1) dissected of epidermis and surrounding dermis and adiposse tissue (HF) 2) with 3-5 rows of surrounding dermal adipocytes (HF+dWAT) and 3) HF+dWAT+ neutralizing antibody to human hepatocyte growth factor. Two male donors and two female donors were used. Laser-capture microdissection was carried out on the pre-cortex and hair matrix of each hair follicle, collecting the tissue in RLT buffer with 1% β-mercaptoethanol; RNA extraction was followed by amplification during complementary DNA. This was labelled with a Cy3 probe followed by labelled genomic DNA purification; lastly, a single-channel microarray (Agilent) was performed using Single-channel SurePrint G3 Human Gene Expression 8x60k v2 microarrays.