Inducing Somatic Pkd1 Mutations in Vivo in a Mouse Model of Autosomal-Dominant Polycystic Kidney Disease
Abstract
Polycystic kidney disease (PKD) is one of the most common life-threatening genetic diseases, affecting an estimated 12.5 million people worldwide. It occurs in humans and other animals, and it is characterized by the appearance of multiple cysts, or tubule dilations in one or both kidneys. With age, it is common to develop a few renal cysts that do not affect renal function; however, in PKD patients, the number and size of cysts impairs renal function and leads to chronic kidney disease. Someone in early-stage kidney disease may not feel sick or notice symptoms as they occur. However, as kidney failure progresses and the organs fail to filter blood properly, waste accumulates in the body and symptoms become noticeable. There is no cure for PKD, and patients are treated to ameliorate the symptoms caused by the growth of the cysts. Eventually, the cysts grow so large that surgery to remove one or both kidneys may be needed and patients then require dialysis or a kidney transplant. Understanding how the cysts develop and grow is the first step towards developing therapies to prevent the progression of the disease. Mutations that cause the disease have been identified, and the vast majority of patients have mutations in a gene named PKD1. Human cells have two copies of the PKD1 gene, and PKD patients have mutations in only one copy of the PKD1 gene while the other copy is normal. It is believed that, in the kidneys of patients, the cysts develop when cells randomly mutate the remaining normal copy of PKD1, completely loosing PKD1 function. This is considered a two-hit model, because a second mutation seems to be required for the development of the disease; the first mutation is inherited from a parent and the second mutation happens randomly in a few kidney cells. While there is indirect data supporting this two-hit model, we do not know if, how, or when a second mutation in PKD1 triggers the development of cysts. In order to answer these questions, we propose to generate a mouse model with one inherited mutation in the Pkd1 gene in which we can induce a second mutation in only a few cells in the kidney, hence simulating the two-hit model. At the same time that the mutation is induced, we will label those cells with a fluorescent protein, so we can follow what happens to a renal cell after the second mutation in Pkd1 occurs. Then we will analyze how those cells behave after the mutation: Do they grow more? Do they move more? Do they lose their normal appearance? Do they have the right proteins? And when after the mutation takes place, do these changes happen? The answers to these questions will help us understand how the cysts develop and grow and, consequently, we will be better poised to design therapies to prevent the progression of the disease in humans.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 04, 2016
- Source ID
- W81XWH1510237
Entities
People
- Cristina Cebrian Ligero
Organizations
- United States Army
- University of Michigan