Introduction

• Claudin-5 (CLDN5) is a protein embedded in cell membranes crucial for preserving the integrity of barriers such as the blood-brain barrier (BBB).
• Regulates the passage of molecules by forming selective barriers known as tight junctions within endothelial tissues.

Molecular Structure and Organization

• Four transmembrane domains
• Two extracellular loops
• N-terminal and C-terminal cytoplasmic domains
• PDZ-binding motif at the C-terminus
• Approximately 23 kDa molecular weight
• Key structural elements:
• Highly conserved amino acid sequences
• Specific protein-protein interaction domains
• Unique barrier-forming capabilities
• Post-translational modification sites

Expression Patterns and Regulation

• Primary expression sites:
• Brain endothelial cells
• Blood vessel endothelium
• Choroid plexus epithelium
• Retinal vessels
• Lung endothelium
• Regulatory mechanisms:
• Transcriptional control
• Post-translational modifications
• Environmental factors
• Inflammatory mediators
• Metabolic signals

Barrier Function and Physiological Role

• Core responsibilities:
• Formation of tight junction strands
• Regulation of paracellular permeability
• Ion selectivity
• Maintenance of brain homeostasis
• Protection against toxic substances
• Barrier properties:
• Size-selective molecular sieving
• Charge-selective ion transport
• Dynamic response to physiological needs
• Adaptation to cellular stress

Clinical Implications and Disease Association

• Claudin-5 dysfunction is implicated in various disorders:
• Neurological Diseases: Multiple sclerosis, Alzheimer's disease, Stroke pathology, Brain tumors, Cerebral edema
• Vascular Disorders: Diabetic retinopathy, Cardiovascular disease, Inflammatory conditions, Hypertension complications

Therapeutic Potential and Research Directions

• Current research explores multiple therapeutic approaches:
• Drug Delivery: BBB modulation for therapeutic access, Targeted drug delivery systems, Novel pharmaceutical carriers, Time-controlled barrier opening
• Disease Management: Protection of barrier integrity, Prevention of BBB breakdown, Treatment of neurological conditions, Management of vascular disorders

Research frontiers: Development of specific modulators, Design of barrier-penetrating therapeutics, Creation of diagnostic tools, Understanding regulation mechanisms

Suitable ELISA Kits

• Claudin-5 ELISA Kit