Hypertrophic scar is a pathological lesion during the repair of skin wound, involving fibroblast, extracellular matrix and cytokines. The prevention and treatment of hypertrophic scar has been a clinical problem, but its exact mechanism is still unclear. The renin angiotensin system (RAS) in the skin is proved to directly involve in wound healing and hypertrophic scar formation. After local RAS activating during wound repair, the expression of angiotensinogen Ⅱ (Ang Ⅱ) and angiotensin converting enzyme (ACE) have increased. They can lead to pathological scarring by stimulating the proliferation of fibroblasts in the skin, affecting collagen metabolism, promoting skin fibrosis and angiogenesis. This review will focus on the role of Ang Ⅱ and ACE in hypertrophic scar formation, which will help to further understand the mechanism of scar formation, and summarize the potential application of RAS antagonists in hypertrophic scar prevention and treatment, so as to provide a new direction for the prevention and treatment of hypertrophic scar.

Hypertrophic scar is a pathological lesion during the repair of skin wound, involving fibroblast, extracellular matrix and cytokines. The prevention and treatment of hypertrophic scar has been a clinical problem, but its exact mechanism is still unclear. The renin angiotensin system (RAS) in the skin is proved to directly involve in wound healing and hypertrophic scar formation. After local RAS activating during wound repair, the expression of angiotensinogen Ⅱ (Ang Ⅱ) and angiotensin converting enzyme (ACE) have increased. They can lead to pathological scarring by stimulating the proliferation of fibroblasts in the skin, affecting collagen metabolism, promoting skin fibrosis and angiogenesis. This review will focus on the role of Ang Ⅱ and ACE in hypertrophic scar formation, which will help to further understand the mechanism of scar formation, and summarize the potential application of RAS antagonists in hypertrophic scar prevention and treatment, so as to provide a new direction for the prevention and treatment of hypertrophic scar.

Objective    To explore the short-term efficacy and safety of pembrolizumab combined with chemotherapy in the neoadjuvant treatment of non-small cell lung cancer. Methods    The clinical data of 11 male patients with non-small cell lung cancer who underwent pembrolizumab combined with neoadjuvant chemotherapy in the Department of Thoracic Surgery, the First Affiliated Hospital of Xi'an Jiaotong University from December 2019 to June 2021 were retrospectively analyzed. The average age of the patients was 52.0-79.0 (62.0±6.9) years. The imaging data and pathological changes before and after neoadjuvant treatment were compared, and adverse reactions during neoadjuvant treatment were recorded. Objective remission rate (ORR) and main pathological remission rate (MPR) and pathological complete remission rate (pCR) were the main observation endpoints. Results    After preoperative neoadjuvant therapy with pembrolizumab combined with platinum or paclitaxel, all patients successfully underwent thoracoscopic radical resection of lung cancer. The ORR was 72.7%, and the MPR was 81.8%. Among them, 45.5% of patients achieved pCR. The main adverse reactions were hypoalbuminemia, decreased appetite and nausea. The mortality rate within 30 days after surgery was 0, and no tumor metastasis was observed. Conclusion    Pembrolizumab combined with neoadjuvant chemotherapy is safe and feasible to treat non-small cell lung cancer, and the short-term efficacy is beneficial.