BACKGROUND: Androgenetic alopecia (AGA) is a common androgen-induced progressive disorder; the pathways of which are regulated by local genetic codes and hormonal control. Meanwhile, it is unclear whether an altered proliferation or increased apoptosis could contribute to its pathogenesis. AIMS: To evaluate the role of some apoptosis regulatory markers and follicular proliferation in the pathogenesis of AGA. PATIENTS/ METHODS: Thirty biopsies were taken from the frontal (bald) area and occipital (hair-bearing) area of 15 male patients with AGA, as well as five specimens from the frontal area of five age-matched controls. The biopsies were stained with apoptosis regulatory markers (Bcl-2, p53, Bax & Fas) and PCNA (proliferating cell nuclear antigen), as well as TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling) staining for the detection of DNA fragmentation in apoptotic cells. RESULTS: Bcl-2 expression was localized to epidermal basal layer and follicular dermal papilla with highly significant correlation with PCNA expression (P < 0.001). Perifollicular lymphocytic infiltrate of the bald area showed significant expression of Bcl-2. However, pro-apoptotic Bax and Fas were expressed in the epidermis and not in the hair follicles which does not show any apoptotic keratinocytes by TUNEL staining. CONCLUSION: The low proliferation rate in the bald area of patients, together with persistent perifollicular inflammatory infiltrate as evidenced by the anti-apoptotic Bcl-2 expression in dermal lymphocytes, would result in follicular miniaturization and fibrosis.
BACKGROUND: Androgenetic alopecia (AGA) is a common androgen-induced progressive disorder; the pathways of which are regulated by local genetic codes and hormonal control. Meanwhile, it is unclear whether an altered proliferation or increased apoptosis could contribute to its pathogenesis. AIMS: To evaluate the role of some apoptosis regulatory markers and follicular proliferation in the pathogenesis of AGA. PATIENTS/ METHODS: Thirty biopsies were taken from the frontal (bald) area and occipital (hair-bearing) area of 15 male patients with AGA, as well as five specimens from the frontal area of five age-matched controls. The biopsies were stained with apoptosis regulatory markers (Bcl-2, p53, Bax & Fas) and PCNA (proliferating cell nuclear antigen), as well as TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling) staining for the detection of DNA fragmentation in apoptotic cells. RESULTS:Bcl-2 expression was localized to epidermal basal layer and follicular dermal papilla with highly significant correlation with PCNA expression (P < 0.001). Perifollicular lymphocytic infiltrate of the bald area showed significant expression of Bcl-2. However, pro-apoptotic Bax and Fas were expressed in the epidermis and not in the hair follicles which does not show any apoptotic keratinocytes by TUNEL staining. CONCLUSION: The low proliferation rate in the bald area of patients, together with persistent perifollicular inflammatory infiltrate as evidenced by the anti-apoptotic Bcl-2 expression in dermal lymphocytes, would result in follicular miniaturization and fibrosis.