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Updated: Jul 30, 2026

Assessment of Mitochondrial Functions and Cell Viability in Renal Cells Overexpressing Protein Kinase C Isozymes
Published on: January 7, 2013
PAX2 suppresses apoptosis in renal collecting duct cells
E Torban1, M R Eccles, J Favor
1Department of Pediatrics and Experimental Medicine, McGill University, Montreal, Quebec, Canada.
Abstract:
PAX2 is a transcription factor belonging to the evolutionarily conserved paired box family and is required during development of the central nervous system and genitourinary axis. Mutations in the PAX2 gene cause a rare autosomal dominant renal-coloboma syndrome, characterized by optic nerve colobomas and renal hypoplasia. Recent analysis of a spontaneous PAX2 mutant mouse model (1Neu) revealed that the major cause of renal hypoplasia is reduced branching of the ureteric bud (UB) and fewer nephrons. We have observed that this abnormality is associated with a striking increase in the number of UB cells undergoing programmed cell death during nephrogenesis. To ascertain whether apoptosis is directly linked to the level of PAX2 expression, we have studied the role of PAX2 in cultured renal cells. We show that mIMCD-3 cells, a murine collecting duct cell line with high endogenous PAX2 expression, undergo apoptosis when transfected with anti-sense PAX2. In contrast, HEK293 cells expressing exogenous PAX2 are protected against apoptotic death induced by caspase-2. PAX2 has no effect on proliferation of embryonic kidney or in cultured kidney cells. Our observations imply a direct role for PAX2 in survival of ureteric bud cells.
Insights
The transcription factor PAX2 (paired box gene 2) is crucial for kidney development. Reduced PAX2 levels increase ureteric bud cell death, leading to renal hypoplasia and fewer nephrons.
Area of Science:
- Developmental Biology
- Genetics
- Cell Biology
Background:
- PAX2 (paired box gene 2) is a key transcription factor in central nervous system and genitourinary axis development.
- Mutations in PAX2 cause renal-coloboma syndrome, featuring optic nerve colobomas and renal hypoplasia.
- PAX2 mutant mice exhibit reduced ureteric bud branching and nephron formation, linked to increased apoptosis.
Purpose of the Study:
- To investigate the direct role of PAX2 in regulating ureteric bud (UB) cell survival during nephrogenesis.
- To determine if apoptosis is directly correlated with PAX2 expression levels in renal cells.
Main Methods:
- Studied PAX2's role in cultured renal cells, including mIMCD-3 (murine collecting duct) and HEK293 cells.
- Utilized anti-sense PAX2 transfection in mIMCD-3 cells to assess apoptosis.
- Investigated the effect of exogenous PAX2 expression in HEK293 cells on caspase-2-induced apoptosis.
- Assessed PAX2's impact on proliferation in embryonic kidney and cultured kidney cells.
Main Results:
- High endogenous PAX2 expression in mIMCD-3 cells correlated with resistance to apoptosis; anti-sense PAX2 transfection induced apoptosis.
- Exogenous PAX2 expression in HEK293 cells conferred protection against caspase-2-induced apoptosis.
- PAX2 did not influence the proliferation of embryonic kidney or cultured kidney cells.
Conclusions:
- PAX2 plays a direct role in promoting the survival of ureteric bud cells during kidney development.
- This finding clarifies the mechanism underlying renal hypoplasia in PAX2-related disorders.
- PAX2 is essential for preventing excessive apoptosis in developing renal structures.
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