Claudin1 is a key protein component of tight junctions, specialized cell-cell adhesion structures that regulate paracellular permeability and maintain epithelial and endothelial barrier integrity. As a member of the claudin family, it consists of four transmembrane domains and plays a critical role in controlling the selective transport of ions and molecules across tissues. Claudin1 is widely expressed in epithelial and endothelial tissues, including the skin, liver, and kidneys, and its dysregulation has been linked to various pathologies such as cancer, inflammatory skin disorders, and hepatitis C virus (HCV) infection.
Antibodies targeting Claudin1 are essential tools for studying its localization, expression levels, and functional roles in both physiological and diseased states. In cancer research, Claudin1 antibodies help investigate its dual role as a tumor suppressor or promoter, depending on the tissue context, with altered expression observed in hepatocellular carcinoma, breast cancer, and colorectal cancer. In dermatology, these antibodies are used to explore skin barrier defects in conditions like atopic dermatitis and psoriasis. Additionally, Claudin1 antibodies have been pivotal in elucidating its role as a coreceptor for HCV entry into hepatocytes.
Commercially available Claudin1 antibodies are typically validated for applications like Western blotting, immunohistochemistry, and immunofluorescence. However, variability in antibody specificity due to differences in clonal sources or epitope recognition necessitates careful validation for experimental reproducibility. Research using these antibodies continues to advance therapeutic strategies, including Claudin1-targeted drugs for cancer and barrier-related diseases.