- Jackson, Kristy, Marques, Francine, Watson, Anna, Palma-Rigo, Keisia, Nguyen-Huu, Thu-Phuc, Morris, Brian, Charchar, Fadi, Davern, Pamela, Head, Geoffrey
- Authors: Jackson, Kristy , Marques, Francine , Watson, Anna , Palma-Rigo, Keisia , Nguyen-Huu, Thu-Phuc , Morris, Brian , Charchar, Fadi , Davern, Pamela , Head, Geoffrey
- Date: 2013
- Type: Text , Journal article
- Relation: Hypertension Vol. 62 , no. 4 (2013), p. 775-781
- Full Text: false
- Reviewed:
- Description: Genetically hypertensive mice (BPH/2J) are hypertensive because of an exaggerated contribution of the sympathetic nervous system to blood pressure. We hypothesize that an additional contribution to elevated blood pressure is via sympathetically mediated activation of the intrarenal renin-angiotensin system. Our aim was to determine the contribution of the renin-angiotensin system and sympathetic nervous system to hypertension in BPH/2J mice. BPH/2J and normotensive BPN/3J mice were preimplanted with radiotelemetry devices to measure blood pressure. Depressor responses to ganglion blocker pentolinium (5 mg/kg i.p.) in mice pretreated with the angiotensin-converting enzyme inhibitor enalaprilat (1.5 mg/kg i.p.) revealed a 2-fold greater sympathetic contribution to blood pressure in BPH/2J mice during the active and inactive period. However, the depressor response to enalaprilat was 4-fold greater in BPH/2J compared with BPN/3J mice, but only during the active period (P=0.01). This was associated with 1.6-fold higher renal renin messenger RNA (mRNA; P=0.02) and 0.8-fold lower abundance of micro-RNA-181a (P=0.03), identified previously as regulating human renin mRNA. Renin mRNA levels correlated positively with depressor responses to pentolinium (r=0.99; P=0.001), and BPH/2J mice had greater renal sympathetic innervation density as identified by tyrosine hydroxylase staining of cortical tubules. Although there is a major sympathetic contribution to hypertension in BPH/2J mice, the renin-angiotensin system also contributes, doing so to a greater extent during the active period and less during the inactive period. This is the opposite of the normal renin-angiotensin system circadian pattern. We suggest that renal hyperinnervation and enhanced sympathetically induced renin synthesis mediated by lower micro-RNA-181a contributes to hypertension in BPH/2J mice.
Deficiency of MicroRNA-181a results in transcriptome-wide cell-specific changes in the kidney and increases blood pressure
- Paterson, Madeleine, Jackson, Kristy, Dona, Malathi, Farrugia, Gabriella, Visniauskas, Bruna, Watson, Anna, Johnson, Chad, Prieto, Minolfa, Evans, Roger, Charchar, Fadi, Pinto, Alexander, Marques, Francine, Head, Geoffrey
- Authors: Paterson, Madeleine , Jackson, Kristy , Dona, Malathi , Farrugia, Gabriella , Visniauskas, Bruna , Watson, Anna , Johnson, Chad , Prieto, Minolfa , Evans, Roger , Charchar, Fadi , Pinto, Alexander , Marques, Francine , Head, Geoffrey
- Date: 2021
- Type: Text , Journal article
- Relation: Hypertension Vol. 78, no. 5 (Nov 2021), p. 1322-1334
- Full Text:
- Reviewed:
- Description: MicroRNA miR-181a is downregulated in the kidneys of hypertensive patients and hypertensive mice. In vitro, miR-181a is a posttranslational inhibitor of renin expression, but pleiotropic mechanisms by which miR-181a may influence blood pressure (BP) are unknown. Here, we determined whether deletion of miR-181a/b-1 in vivo changes BP and the molecular mechanisms involved at the single-cell level. We developed a KO (knockout) mouse model lacking miR-181a/b-1 genes using CRISPR/Cas9 technology. Radiotelemetry probes were implanted in 12-week-old C57BL/6J WT (wild type) and miR-181a/b-1 KO mice. Systolic and diastolic BP were 4- to 5-mm Hg higher in KO compared with WT mice over 24 hours (P<0.01). Compared with WT mice, renal renin was higher in the juxtaglomerular cells of KO mice. BP was similar in WT mice on a high- (3.1%) versus low- (0.3%) sodium diet (+0.4 +/- 0.8 mm Hg), but KO mice showed salt sensitivity (+3.3 +/- 0.8 mm Hg; P<0.001). Since microRNAs can target several mRNAs simultaneously, we performed single-nuclei RNA sequencing in 6699 renal cells. We identified 12 distinct types of renal cells, all of which had genes that were dysregulated. This included genes involved in renal fibrosis and inflammation such as Stat4, Col4a1, Cd81, Flt3l, Cxcl16, and Smad4. We observed upregulation of pathways related to the immune system, inflammatory response, reactive oxygen species, and nerve development, consistent with higher tyrosine hydroxylase in the kidney. In conclusion, downregulation of the miR-181a gene led to increased BP and salt sensitivity in mice. This is likely due to an increase in renin expression in juxtaglomerular cells, as well as microRNA-driven pleiotropic effects impacting renal pathways associated with hypertension.
- Authors: Paterson, Madeleine , Jackson, Kristy , Dona, Malathi , Farrugia, Gabriella , Visniauskas, Bruna , Watson, Anna , Johnson, Chad , Prieto, Minolfa , Evans, Roger , Charchar, Fadi , Pinto, Alexander , Marques, Francine , Head, Geoffrey
- Date: 2021
- Type: Text , Journal article
- Relation: Hypertension Vol. 78, no. 5 (Nov 2021), p. 1322-1334
- Full Text:
- Reviewed:
- Description: MicroRNA miR-181a is downregulated in the kidneys of hypertensive patients and hypertensive mice. In vitro, miR-181a is a posttranslational inhibitor of renin expression, but pleiotropic mechanisms by which miR-181a may influence blood pressure (BP) are unknown. Here, we determined whether deletion of miR-181a/b-1 in vivo changes BP and the molecular mechanisms involved at the single-cell level. We developed a KO (knockout) mouse model lacking miR-181a/b-1 genes using CRISPR/Cas9 technology. Radiotelemetry probes were implanted in 12-week-old C57BL/6J WT (wild type) and miR-181a/b-1 KO mice. Systolic and diastolic BP were 4- to 5-mm Hg higher in KO compared with WT mice over 24 hours (P<0.01). Compared with WT mice, renal renin was higher in the juxtaglomerular cells of KO mice. BP was similar in WT mice on a high- (3.1%) versus low- (0.3%) sodium diet (+0.4 +/- 0.8 mm Hg), but KO mice showed salt sensitivity (+3.3 +/- 0.8 mm Hg; P<0.001). Since microRNAs can target several mRNAs simultaneously, we performed single-nuclei RNA sequencing in 6699 renal cells. We identified 12 distinct types of renal cells, all of which had genes that were dysregulated. This included genes involved in renal fibrosis and inflammation such as Stat4, Col4a1, Cd81, Flt3l, Cxcl16, and Smad4. We observed upregulation of pathways related to the immune system, inflammatory response, reactive oxygen species, and nerve development, consistent with higher tyrosine hydroxylase in the kidney. In conclusion, downregulation of the miR-181a gene led to increased BP and salt sensitivity in mice. This is likely due to an increase in renin expression in juxtaglomerular cells, as well as microRNA-driven pleiotropic effects impacting renal pathways associated with hypertension.
- «
- ‹
- 1
- ›
- »