Logic-based modeling of inflammatory macrophage cross talk with glomerular endothelial cells in diabetic kidney disease.

Diabetic kidney disease is a complication in one out of three patients with diabetes. Aberrant glucose metabolism in diabetes leads to structural and functional damage in glomerular tissue and a systemic inflammatory immune response. Complex cellular signaling is at the core of metabolic and functional derangement. Unfortunately, the mechanism underlying the role of inflammation in glomerular endothelial cell dysfunction during diabetic kidney disease is not fully understood. Mathematical models in systems biology allow the integration of experimental evidence and cellular signaling networks to understand mechanisms involved in disease progression. This study developed a logic-based ordinary differential equations model to study inflammatory cross talk between macrophages and glomerular endothelial cells during diabetic kidney disease progression using a protein signaling network stimulated with glucose and lipopolysaccharide. This modeling approach reduced the biological parameters needed to study signaling networks. The model was fitted to and validated against available biochemical data from in vitro experiments. The model identified mechanisms for dysregulated signaling in macrophages and glomerular endothelial cells during diabetic kidney disease. In addition, the influence of signaling interactions on glomerular endothelial cell morphology through selective knockdown and downregulation was investigated. Simulation results showed that partial knockdown of VEGF receptor 1, PLC-γ, adherens junction proteins, and calcium partially improved intercellular junction integrity between glomerular endothelial cells. These findings contribute to understanding of signaling and molecular perturbations that affect glomerular endothelial cells in the early stage of diabetic kidney disease. This work provides a novel analysis of signaling cross talk between macrophages and glomerular endothelial cells in the early stage of diabetic kidney disease. A logic-based mathematical modeling approach identified vital signaling molecules and interactions that regulate glucose-mediated inflammation in glomerular endothelial cells and cause endothelial dysfunction in the diabetic kidney. Simulated interactions among vascular endothelial growth factor receptor 1, nitric oxide, and calcium significantly affected the intercellular junction proteins between glomerular endothelial cells.