The mechanisms of progression of chronic kidney disease (CKD) are poorly understood. Epidemiologic studies suggest a strong genetic component, but the genes that contribute to the onset and progression of CKD are largely unknown. Here, we applied an experimental model of CKD (75% excision of total renal mass) to six different strains of mice and found that only the FVB/N strain developed renal lesions. We performed a genome-scan analysis in mice generated by back-crossing resistant and sensitive strains; we identified a major susceptibility locus (Ckdp1) on chromosome 6, which corresponds to regions on human chromosome 2 and 3 that link with CKD progression. In silico analysis revealed that the locus includes the gene encoding the EGF receptor (EGFR) ligand TGF-␣. TGF-␣ protein levels markedly increased after nephron reduction exclusively in FVB/N mice, and this increase preceded the development of renal lesions. Furthermore, pharmacologic inhibition of EGFR prevented the development of renal lesions in the sensitive FVB/N strain. These data suggest that variable TGF-␣ expression may explain, in part, the genetic susceptibility to CKD progression. EGFR inhibition may be a therapeutic strategy to counteract the genetic predisposition to CKD. Human chronic kidney diseases (CKD), regardless of their etiology, are characterized by progressive destruction of the renal parenchyma and loss of functional nephrons, leading to ESRD. Approximately 13% of adults suffer from CKD in industrialized countries and the incidence of ESRD increases by 6% to 8% per year. Therefore, understanding the pathophysiology of CKD is a key challenge for public health.The mechanisms of CKD progression are poorly understood. Although clinical studies point to the important role of environmental factors in the biologic processes leading to renal deterioration, epidemiologic studies have underscored the importance of genetic components. Indeed, it has been observed that the evolution of CKD varies considerably among individual patients exposed to the same risk factors. Only a proportion of patients with diabetes or hypertension develop renal failure, and this occurs independently of glycemic control or hypertension. 1,2 However, the propensity to develop ESRD differs among ethnic groups 3-7 and it shows familial clustering. [7][8][9][10] Similarly, the rate of progression of primary hereditary kidney diseases can vary among members of the same family, [11][12][13] suggesting that genes unrelated to the disease

The molecular networks that control the progression of chronic kidney diseases (CKD) are poorly defined. We have recently shown that the susceptibility to development of renal lesions after nephron reduction is controlled by a locus on mouse chromosome 6 and requires epidermal growth factor receptor (EGFR) activation. Here, we identified microphthalmia-associated transcription factor A (MITF-A), a bHLH-Zip transcription factor, as a modifier of CKD progression. Sequence analysis revealed a strain-specific mutation in the 5′ UTR that decreases MITF-A protein synthesis in lesion-prone friend virus B NIH (FVB/N) mice. More importantly, we dissected the molecular pathway by which MITF-A modulates CKD progression. MITF-A interacts with histone deacetylases to repress the transcription of TGF-α, a ligand of EGFR, and antagonizes transactivation by its related partner, transcription factor E3 (TFE3). Consistent with the key role of this network in CKD, Tgfa gene inactivation protected FVB/N mice from renal deterioration after nephron reduction. These data are relevant to human CKD, as we found that the TFE3/MITF-A ratio was increased in patients with damaged kidneys. Our study uncovers a novel transcriptional network and unveils novel potential prognostic and therapeutic targets for preventing human CKD progression.