Pecam1, also known as platelet endothelial cell adhesion molecule-1 or CD31, is a member of the immunoglobulin superfamily. It is expressed in monocytes, neutrophils, macrophages, immune cells, and endothelial cells. Pecam1 is crucial for the development and maturation of B lymphocytes, and its function is important for lymphatic vasculature formation [2]. It also plays a role in angiogenesis, vascular permeability, and immune response [3].

Based on data sets associated with bone metastases, Pecam1 was selected as a hub-gene. Its expression was found to decrease in bone metastatic tumor tissues. Knocking down Pecam1 expression in lymphocytes from bone marrow-nailed blood promoted osteoclast differentiation, and the treated osteoclast culture medium significantly promoted tumor cell proliferation and migration, suggesting it may be a biomarker for bone metastases diagnosis and treatment [1]. In pulpitis, PECAM1 combines with CXCR4 to trigger inflammatory cell infiltration and pulpitis progression through activating the NF-κB signaling pathway. Down-regulation of PECAM1 suppressed inflammation and apoptosis in lipopolysaccharide-induced human dental pulp fibroblasts [4].

In conclusion, Pecam1 is essential for lymphocyte development, lymphatic vasculature formation, and has functions in angiogenesis, vascular permeability, and immune response. Studies on Pecam1, including those with gene knockdown models, have revealed its potential roles in diseases such as bone metastases and pulpitis, providing insights into disease mechanisms and potential diagnostic and treatment targets.

References:

1. Liang, Zhuo-Tao, Li, Jia-Ke, Li, Jiong, Guo, Chao-Feng, Zhang, Hong-Qi. 2023. PECAM1 plays a role in the pathogenesis and treatment of bone metastases. In Frontiers in genetics, 14, 1151651. doi:10.3389/fgene.2023.1151651. https://pubmed.ncbi.nlm.nih.gov/37007939/

2. Michelini, S, Amato, B, Kenanoglu, S, Basha, S H, Bertelli, M. . Rare PECAM1 variants in three families with lymphedema. In Lymphology, 53, 141-151. doi:. https://pubmed.ncbi.nlm.nih.gov/33350288/

3. Hu, Donghua, Zhang, Lu, Yang, Fan, Li, Deqiang, Cai, Chen-Leng. 2020. Generation of Pecam1 endothelial specific dual reporter mouse model. In Genesis (New York, N.Y. : 2000), 58, e23384. doi:10.1002/dvg.23384. https://pubmed.ncbi.nlm.nih.gov/32618127/

4. Liu, Yonghong, Zhang, Zhiyong, Li, Wenjing, Tian, Songbo. 2020. PECAM1 Combines With CXCR4 to Trigger Inflammatory Cell Infiltration and Pulpitis Progression Through Activating the NF-κB Signaling Pathway. In Frontiers in cell and developmental biology, 8, 593653. doi:10.3389/fcell.2020.593653. https://pubmed.ncbi.nlm.nih.gov/33425898/