Biology subjects

Ariceta, G.

Publications and source records attributed to Ariceta, G..

3 recordsLinked to original sources

bioRxiv2025

TMEM9 and SEC22B interact with ClC-5 to shape renal proximal tubule function and Dent's Disease type I pathogenesis

Cl-/H+ antiporter ClC-5 is a key regulator of renal proximal tubule function, primarily by controlling endosomal acidification. Loss-of-function mutations in ClC-5 cause Dents Disease type 1 (DD1), a rare renal tubulopathy that progresses to kidney failure with varying severity. To understand the specific mechanisms linking ClC-5 loss-of-function with DD1 phenotypic heterogeneity, three ClC-5 pathogenic mutations (I524K, E527D and V523{Delta}) were investigated using renal proximal tubule epithelial cell lines. We have identified distinct intracellular retention patterns of these ClC-5 mutants, all leading to altered endolysosomal pH and disrupted secretory pathway organization. Through an interactome analysis, we have uncovered several ClC-5 partners including TMEM9, which interacted with all ClC-5 forms. TMEM9 knockdown (KD) recapitulated key DD1 characteristics, like defective endocytosis and epithelial dedifferentiation, but paradoxically enhanced endosomal acidification. The secretory pathway was also altered in cells lacking TMEM9 (e.g. enlarged endosomes, and fragmented Golgi apparatus). A similar phenotype was observed in cells depleted of SEC22B; an R-SNARE that we have found to specifically interact with wild-type ClC-5, but not the mutants. Notably, its deletion impaired ClC-5 trafficking, causing its retention at the Golgi and endosomes. Altogether, our findings highlight the relevance of TMEM9 and SEC22B in ClC-5 function, suggesting them as DD1 pathophysiology modifiers.

cell biology↗

bioRxiv2023

Renal Cl-/H+ antiporter ClC-5 regulates collagen production and release in Dent Disease models

Mutations in the Cl-/H+ antiporter ClC-5 cause Dents Disease 1 (DD1), a rare primary tubulopathy that eventually progresses to renal failure. In fact, even with normal kidney function, DD1 patients present renal tubulointerstitial fibrosis. However, the link between ClC-5 loss-of-function and renal fibrosis remains unclear. Here, we have shown that DD1 mice models lacking ClC-5 present higher renal collagen deposition and fibrosis. Accordingly, deletion of ClC-5 in human renal proximal tubule epithelial cells (CLCN5 KD) recapitulates this effect. We have demonstrated that CLCN5 KD causes an increase of collagen I (Col I) and IV (Col IV) intracellular levels by promoting their transcription through {beta}-catenin pathway and impairing their lysosomal-mediated degradation. In addition, CLCN5 KD cells release more Col I and IV at the extracellular space that form fibres with altered properties and resistance to removal compared to control cells. Altogether, we describe a new regulatory mechanism for collagens production and release by ClC-5, which is altered in DD1 and provides a better understanding of disease progression to renal fibrosis. SIGNIFICANCE STATEMENTRenal fibrosis is a common pathologic process occurring as consequence of chronic kidney injury and leading to renal dysfunction. Dents Disease is a rare renal pathology that progresses to chronic kidney disease and tubulointerstitial fibrosis. Interestingly, it is caused by mutations in a single gene called CLCN5, therefore it can help understanding the cellular mechanisms of renal fibrosis. Using cellular and mice models of the disease, we describe a mechanism linking CLCN5 function, cell differentiation and regulation of collagen levels, major component of extracellular matrix and important player for renal fibrosis development. In conclusion, our results provide a link between CLCN5 and altered collagen deposition, which could be relevant for other renal Fanconi syndrome related diseases also progressing to fibrosis.

cell biology↗

bioRxiv2020

Global gene-expression analysis reveals the molecular processes underlying ClC-5 loss-of-function in novel Dent Disease 1 cellular models

Dent disease 1 (DD1) is a rare X-linked renal proximal tubulopathy characterized by low molecular weight proteinuria (LMWP) and variable degree of hypercalciuria, nephrocalcinosis and/or nephrolithiasis with progression to chronic kidney disease (CKD). Although loss-of-function mutations in the gene CLCN5 encoding the electrogenic Cl-/H+ antiporter ClC-5, which impair endocytic uptake in proximal tubule cells, cause the disease, there is poor genotype-phenotype correlation and their contribution to proximal tubule dysfunction remains unclear. Here, in order to discover the mechanisms leading to proximal tubule dysfunction due to ClC-5 loss-of-function, we have generated and characterized new human cellular models of DD1 by silencing CLCN5 and introducing the ClC-5 pathogenic mutants V523del, E527D and I524K into the human proximal tubule-derived cell line RPTEC/TERT1. Depletion of CLCN5 or expression of mutant ClC-5 impairs albumin endocytosis, increases substrate adhesion and decreases collective migration, which correlates with a less differentiated epithelial phenotype. Interestingly, although all conditions compromised the endocytic capacity in a similar way, their impact on gene expression profiles was different. Our DNA microarray studies show that ClC-5 silencing or mutant re-introduction alter pathways related to nephron development, anion homeostasis, organic acid transport, extracellular matrix organization and cell migration, compared to control cells. Cells carrying the V523del ClC-5 mutation show the largest differences in gene expression vs WT cells, which is in agreement with the more aggressive clinical phenotype observed in some DD1 patients. Overall, this work emphasizes the use of human proximal tubule derived cell models to identify the molecular processes underlying ClC-5 deficiency.

pathology↗