A pig model exploring the postnatal hair follicle cycle

Area of Science:

• Dermatology
• Developmental Biology
• Animal Models

Background:

• The hair follicle (HF) is a complex micro-organ crucial for skin regeneration.
• Dysregulation of the HF cycle is implicated in various hair disorders, including hair loss.
• Pigs are recognized as valuable biomedical models, yet data on their HF cycle remain limited.

Purpose of the Study:

• To classify the distinct stages of the first hair follicle cycle in pigs.
• To evaluate the suitability of pigs as a preclinical model for human hair follicle research.

Main Methods:

• Skin samples from Yorkshire pigs at various postnatal days were analyzed.
• Histological examination (H&E staining) and immunofluorescence staining were performed.
• Quantitative PCR (q-PCR) and Western blotting were used to assess gene and protein expression.

Main Results:

• The pig HF cycle was delineated into anagen (until P45), catagen (P45-P85), telogen (P85-P100), and a subsequent anagen phase (>P100).
• Expression patterns of key genes (e.g., AE15, CD34, Versican, Ki67) were identified across different HF cycle stages.
• Morphological and molecular data indicate shared characteristics between pig and human HF cycles.

Conclusions:

• The pig hair follicle cycle has been successfully classified, establishing key developmental time points.
• The observed similarities in morphology and marker gene expression support the pig as a relevant model for human hair research.