Assessing Dihydrotestosterone-Induced Skin Alterations in C57BL/6 Mice: Implications for Androgenetic Alopecia through High-Resolution Ultrasound Imaging

Abstract

Background: There are different types of hair loss known as alopecia. Various methods for treating Androgenetic alopecia (AGA) are being investigated in the preclinical stage using C57BL/6 mice affected by this condition.

Objective: The purpose of the study was to evaluate the effects of dihydrotestosterone (DHT) on the skin layers of male C57BL/6 mice, simulating a model of AGA using high-resolution ultrasound imaging.

Methods: Seven-week-old male C57BL/6 mice were selected for the study. To induce AGA, three of the mice received intraperitoneal injections of DHT at a dosage of 1 mg per day for five consecutive days, a known method for provoking hair loss via androgenic pathways. High-resolution ultrasound imaging at 40 and 75 MHz frequencies allowed detailed observation of skin layer changes due to DHT administration. Shear modulus and Young modulus were extracted using a dynamic loading throughout ultrasonography with 40 MHz frequency. Both control and AGA-affected groups were evaluated through structural imaging and were compared with histopathological results. Tissues were stained with Hematoxylin-Eosin (H&E) and so Trichrome Mason

Results: Ultrasound imaging revealed that the epidermis thickness was 0.22 mm in the control group compared to 0.31 mm in the AGA group at 40 MHz. At 75 MHz, these measurements were 0.10 mm for the control group and 0.20 mm for the AGA group. The dermis thickness measurements showed 0.30 mm in the control group and 0.70 mm in the AGA group at 40 MHz, while at 75 MHz, the thicknesses were 0.40 mm for the control group and 0.70 mm for the AGA group. H&E staining results aligned with these ultrasound findings, confirming increased epidermal and dermal thicknesses in the AGA group. Elasticity metrics indicated a shear modulus of 1.19 kPa for the AGA group and 6.70 kPa for the control group, while Young’s modulus demonstrated values of 6.47 kPa for the control group and 22.69 kPa for the AGA group. Further corroboration of altered tissue elasticity was provided by Trichrome staining, indicating significant changes in skin structure.

Conclusion: The administration of DHT in the C57BL/6 mice model leads to notable structural changes in skin layers, evidenced by an increased thickness of both the epidermis and dermis, along with diminished mechanical properties of skin elasticity.