In severe acute pancreatitis (SAP), inflammatory factors promote the expression of matrix metalloproteinases (MMPs) and heparinases, which degrade syndecan-1 (SDC-1) and HS, while oxidative stress disrupts HA-CD44 binding, leading to increased capillary leakage and neutrophil adhesion. The gene discussed is SDC1; the disease is acute pancreatitis.