PIK3CA as a therapeutic target for patients with proliferative glomerulonephritis

Proliferative glomerulonephritis is a severe kidney condition often associated with advanced renal failure. Unfortunately, there is a significant lack of effective treatment options for these disorders. Here, following the identification of a somatic PIK3CA gain-of-function mutation in glomerular epithelial cells of a patient, we demonstrate using multiple genetically engineered mouse models, single cell RNA sequencing and spatial transcriptomics the crucial role played by this pathway in proliferative glomerulonephritis development by promoting podocyte proliferation, dedifferentiation and inflammation. In addition, we show that alpelisib, a clinically approved pharmacological PI3Ka inhibitor, improves glomerular lesions and kidney function in different models of collapsing glomerulopathy and lupus nephritis by targeting podocytes. But surprisingly, we uncovered that pharmacological inhibition of PI3Ka affects B and T lymphocyte population in lupus nephritis mouse models with decrease in the production of proinflammatory cytokines, autoantibodies and complement deposition, all of which are characteristic features of PI3Kd inhibition. These findings were further confirmed in human lymphocytes isolated from patients with active lupus nephritis. In conclusion, we demonstrate the major role played by PI3Ka in proliferative glomerular lesion and show for the first time that alpelisib holds promise as a therapeutic approach that acts on both, glomerular epithelial cells and immune system.