mRNA Therapy for Alport Syndrome

Alport syndrome is caused by mutations in the type IV collagen genes <i>COL4A3, COL4A4,</i> and <i>COL4A5</i> which are expressed in podocytes in the glomerulus of the kidney. Mutation of these genes disrupts blood filtration by the kidney leading to proteinuria and kidney failure. There is no cure for Alport Syndrome. Current therapies do not treat the genetic cause of the disease, but instead aim to delay the disease by reducing blood pressure in the kidney. Here we tested the ability of mRNA therapy to treat the disease. Mice with X-linked Alport syndrome (XLAS) due to mutation of <i>Col4A5</i> were treated intravenously with lipid nanoparticles (LNPs) carrying three mRNAs encoding <i>COL4A3, COL4A4,</i> and <i>COL4A5</i> to produce trimeric collagen IV repair proteins. This intravenous mRNA therapy significantly reduced proteinuria and blood urea nitrogen. Protection against the syndrome was maintained provided that LNP-mRNA injections were continued. However, efficacy was lost when therapy was terminated. These data provide proof of principle to apply a genetic mRNA therapy to halt progression of Alport syndrome in a mouse model of XLAS. These data also demonstrate that damage to the kidney filtration barrier can be leveraged to deliver large molecular therapies to podocytes and other cells within the kidney to treat Alport syndrome and other kidney genetic diseases.