A Novel Nude Mice Model for Studying the Pathogenesis of Keloid

Keloid is a common fibroproliferative disorder, often manifesting symptoms such as itching and pain. Given the unique characteristics of keloids, their occurrence is primarily limited to humans, posing difficulties for spontaneous keloid development in animals. Consequently, the creation of animal models has somewhat impeded the comprehensive investigation of keloids.

The aim is to develop a keloid mouse model that mimics the formation process of human keloids, enabling researchers to gain a deeper understanding of their pathophysiological mechanisms and to explore effective therapeutic approaches.

Human keloid fibroblasts were isolated, cultured, and subcutaneously injected with Matrigel into nude mice at four concentrations (1 × 10⁶, 3 × 10⁶, 5 × 10⁶, and 7 × 10⁶ cells). Subcutaneous nodules were transplanted into additional mice to validate stability. Histological and immunohistochemical analyses were performed to assess morphological and molecular features.

Keloid-like nodules formed in a cell density-dependent manner, with the highest concentration group (7 × 10⁶ cells) achieving nodule formation in 39.6 ± 3.2 days, significantly faster than lower concentrations (p < 0.001). The transplantation success rate reached 80%, with nodules exhibiting dense collagen deposition (72.7% ± 3.8%), CD34-positive microvessels (23.1 ± 2.2 vessels/field), and α-SMA expression (11.29% ± 3.7%), closely mirroring human keloid histopathology.

The combination of human keloid fibroblasts and Matrigel provides a simple and rational approach for constructing a nude mouse model, offering a reliable animal model for experimental and clinical research on the pathogenesis and treatment strategies of keloids.