Project description:To study the effects of aldosterone on miRNA in the kidney cortical collecting duct, polarized mpkCCDc14 cell were treated with aldosterone or vehicle. A putative target for miR-466g was identified, the effect of modulating miR-466g levels on SGK1 levels was examined
Project description:Murine inner medullary collecting duct cells were treated for 1 hour with vehicle (control) or aldosterone. Total RNA was isolated and used as template to generate the eventual cRNA target. The experiment was repeated a total of three times. Six cRNA samples, three control and three treated, were generated and used in a total of six hybridizations. The mineralocorticoid aldosterone is a major regulator of Na+ and acid-base balance and control of blood pressure. Although the long-term effects of aldosterone have been extensively studied, the early aldosterone-responsive genes remain largely unknown. Using DNA array technology, we have characterized changes in gene expression after 1 h of exposure to aldosterone in a mouse inner medullary collecting duct cell line, mIMCD-3. Results from three independent microarray experiments revealed that the expression of many transcripts was affected by aldosterone treatment. Northern blot analysis confirmed the upregulation of four distinct transcripts identified by the microarray analysis, namely, the serum and glucose-regulated kinase sgk, connective tissue growth factor, period homolog, and preproendothelin. Immunoblot analysis for preproendothelin demonstrated increased protein expression. Following the levels of the four transcripts over time showed that each had a unique pattern of expression, suggesting that the cellular response to aldosterone is complex. The results presented here represent a novel list of early aldosterone-responsive transcripts and provide new avenues for elucidating the mechanism of acute aldosterone action in the kidney.
Project description:Aldosterone is arguably the single most important hormone implicated in the control of blood pressure and extracellular fluid volume in mammals. It acts primarily by increasing the rate of transepithelial sodium transport in the kidney tubules. Several monogenetic defects resulting in hypertension have now been attributed to abnormalities in sodium handling within the aldosterone-sensitive distal nephron, where the epithelial sodium channel, ENaC, constitutes the rate-limiting step of sodium transport. To date, the transcription-dependent aldosterone-signaling pathway between receptor and membrane transport effectors, remains incompletely understood. The broad aim of our study is to explore these intracellular signaling pathways that are critical to the functioning of sodium channels. Microarray analysis in an aldosterone-responsive kidney cortical collecting duct cell line (mpkCCDc14), allowed us to identify many potential aldosterone-regulated transcripts. The present study describes the identification, and possible physiological relevance of various aldosterone-regulated transcripts. The results of this study promise to extend our understanding of the molecular basis of aldosterone-regulated sodium transport in kidney epithelia, and provide approaches for regulating this process in disease states such as congestive heart failure and hypertension. Keywords: hormone effect
Project description:Murine inner medullary collecting duct cells were treated for 1 hour with vehicle (control) or aldosterone. Total RNA was isolated and used as template to generate the eventual cRNA target. The experiment was repeated a total of three times. Six cRNA samples, three control and three treated, were generated and used in a total of six hybridizations. The mineralocorticoid aldosterone is a major regulator of Na+ and acid-base balance and control of blood pressure. Although the long-term effects of aldosterone have been extensively studied, the early aldosterone-responsive genes remain largely unknown. Using DNA array technology, we have characterized changes in gene expression after 1 h of exposure to aldosterone in a mouse inner medullary collecting duct cell line, mIMCD-3. Results from three independent microarray experiments revealed that the expression of many transcripts was affected by aldosterone treatment. Northern blot analysis confirmed the upregulation of four distinct transcripts identified by the microarray analysis, namely, the serum and glucose-regulated kinase sgk, connective tissue growth factor, period homolog, and preproendothelin. Immunoblot analysis for preproendothelin demonstrated increased protein expression. Following the levels of the four transcripts over time showed that each had a unique pattern of expression, suggesting that the cellular response to aldosterone is complex. The results presented here represent a novel list of early aldosterone-responsive transcripts and provide new avenues for elucidating the mechanism of acute aldosterone action in the kidney. Keywords: other
Project description:The affect of aldosterone on the miRNA landscape in mIMCD-3 cells was determined In the study presented here, the affect of aldosterone was examined on the miRNA content in a murine inner medullary collecting duct cell line
Project description:The appropriate regulation of the epithelial sodium channel (ENaC) in the aldosterone-sensitive distal nephron is required for sodium homeostasis and thereby for the long-term regulation of arterial blood pressure. A unique feature of ENaC is its activation by proteolytic cleavage. However, the relevant proteases involved in proteolytic ENaC activation in the kidney remain elusive. Here, we examined a potential role of transmembrane serine protease 2 (TMPRSS2). A mouse cortical collecting duct cell line (mCCDcl1) was used as a model system. We performed RNA-Seq transcriptome analysis of mCCDcl1 cells, which confirmed coexpression of Tmprss2 and all three ENaC subunits (Scnn1a, Scnn1b, Scnn1g) in this cell line. Importantly, high baseline expression of TMPRSS2 was detected in these cells without a stimulatory effect of aldosterone on its function or transcription. TMPRSS2 knockout in mCCDcl1 cells compromised γ-ENaC cleavage and reduced baseline and aldosterone-stimulated transepithelial short-circuit currents, which could be rescued by chymotrypsin. A compensatory transcriptional upregulation of other proteases was not observed. From these findings we conclude that TMPRSS2 is likely to contribute to proteolytic ENaC activation in the kidney.