Potential role of insulin-like growth factor 1 and growth hormone in acneiform eruptions: evidence from a rat model of acromegaly.

BACKGROUND

Acne, a chronic inflammatory disease, is influenced by insulin-like growth factor 1 (IGF-1). Acromegaly, characterized by excessive growth hormone (GH) and IGF-1, is associated with a higher prevalence of acne, though the underlying mechanisms remain unclear.

OBJECTIVE

This study aims to explore the underlying mechanisms why patients with acromegaly are more susceptible to acne, especially refractory acne.

METHODS

An acromegaly rat model was established via biweekly long-acting recombinant human GH (rhGH) injections for eight weeks. Serum levels of GH, IGF-1, and glucose were measured, and skin pathology was examined. Immunohistochemistry, transcriptomics, and proteomics were performed to explore molecular pathways, with RT-qPCR and western blot validation.

RESULTS

Serum GH and IGF-1 levels significantly increased from week 3 and remained elevated throughout the study in the rhGH-treated group. Acneiform lesions, including epidermal hyperkeratosis, sebaceous gland hyperplasia, and dermal thickening, were observed. Immunohistochemical analysis revealed upregulation of IGF-1, IGF-1R, SREBP1, and IL-1β. Transcriptomic and proteomic analyses identified 1,112 differentially expressed genes and 440 differentially expressed proteins, underscoring the activation of inflammation, extracellular matrix (ECM) remodeling, epithelial-mesenchymal transition (EMT), and cell proliferation through PI3K/Akt pathways. Significant upregulation of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase 1 (TIMP-1) was observed in both transcriptomic and proteomic analyses.

CONCLUSION

Chronic GH stimulation leads to persistent IGF-1 elevation, promoting acne by increasing IGF-1R expression and disrupting ECM remodeling via PI3K/Akt-regulated MMPs and TIMP-1. These findings help clarify the link between acromegaly and acne and provide mechanistic insights into the role of IGF-1 in acne pathogenesis.