Waed Abdel Khalek1,2, Chloé Rafael1,2,3,4,5, Irmine Loisel-Ferreira1,2, Ilektra Kouranti1,2, Eric Clauser1,2, Juliette Hadchouel6,2,3,4, Xavier Jeunemaitre6,2,7. 1. Institut National de la Santé et de la Recherche Médicale U970, Paris Cardiovascular Research Center, Paris, France. 2. Faculty of Medicine, University Paris-Descartes, Sorbonne Paris Cité, Paris, France. 3. Institut National de la Santé et de la Recherche Médicale UMR_S1155, Tenon Hospital, Paris, France. 4. Faculty of Medicine, University Pierre and Marie Curie, Paris, France. 5. Faculty of Sciences, University Paris-Diderot, Sorbonne Paris Cité, Paris, France; and. 6. Institut National de la Santé et de la Recherche Médicale U970, Paris Cardiovascular Research Center, Paris, France; juliette.hadchouel@inserm.fr xavier.jeunemaitre@inserm.fr. 7. Department of Genetics, Hôpital Européen Georges Pompidou, Assistance Publique - Hôpitaux de Paris, Paris, France.
Abstract
BACKGROUND: Mutations in four genes, WNK lysine deficient protein kinase 1 and 4 (WNK1 and WNK4), kelch like family member 3 (KLHL3), or Cullin 3 (CUL3), can result in familial hyperkalemic hypertension (FHHt), a rare Mendelian form of human arterial hypertension. Although all mutations result in an increased abundance of WNK1 or WNK4, all FHHt-causing CUL3 mutations, resulting in the skipping of exon 9, lead to a more severe phenotype. METHODS: We created and compared two mouse models, one expressing the mutant Cul3 protein ubiquitously (pgk-Cul3∆9) and the other specifically in vascular smooth muscle cells (SM22-Cul3∆9). We conducted pharmacologic investigations on isolated aortas and generated stable and inducible HEK293 cell lines that overexpress the wild-type Cul3 or mutant Cul3 (Cul3∆9) protein. RESULTS: As expected, pgk-Cul3∆9 mice showed marked hypertension with significant hyperkalemia, hyperchloremia and low renin. BP increased significantly in SM22-Cul3∆9 mice, independent of any measurable effect on renal transport. Only pgk-Cul3∆9 mice displayed increased expression of the sodium chloride cotransporter and phosphorylation by the WNK-SPAK kinases. Both models showed altered reactivity of isolated aortas to phenylephrine and acetylcholine, as well as marked acute BP sensitivity to the calcium channel blocker amlodipine. Aortas from SM22-Cul3∆9 mice showed increased expression of RhoA, a key molecule involved in regulation of vascular tone, compared with aortas from control mice. We also observed increased RhoA abundance and t 1/2 in Cul3∆9-expressing cells, caused by decreased ubiquitination. CONCLUSIONS: Mutations in Cul3 cause severe hypertension by affecting both renal and vascular function, the latter being associated with activation of RhoA.
BACKGROUND: Mutations in four genes, WNK lysine deficient protein kinase 1 and 4 (WNK1 and WNK4), kelch like family member 3 (KLHL3), or Cullin 3 (CUL3), can result in familial hyperkalemic hypertension (FHHt), a rare Mendelian form of human arterial hypertension. Although all mutations result in an increased abundance of WNK1 or WNK4, all FHHt-causing CUL3 mutations, resulting in the skipping of exon 9, lead to a more severe phenotype. METHODS: We created and compared two mouse models, one expressing the mutant Cul3 protein ubiquitously (pgk-Cul3∆9) and the other specifically in vascular smooth muscle cells (SM22-Cul3∆9). We conducted pharmacologic investigations on isolated aortas and generated stable and inducible HEK293 cell lines that overexpress the wild-type Cul3 or mutant Cul3 (Cul3∆9) protein. RESULTS: As expected, pgk-Cul3∆9 mice showed marked hypertension with significant hyperkalemia, hyperchloremia and low renin. BP increased significantly in SM22-Cul3∆9 mice, independent of any measurable effect on renal transport. Only pgk-Cul3∆9 mice displayed increased expression of the sodium chloride cotransporter and phosphorylation by the WNK-SPAK kinases. Both models showed altered reactivity of isolated aortas to phenylephrine and acetylcholine, as well as marked acute BP sensitivity to the calcium channel blocker amlodipine. Aortas from SM22-Cul3∆9 mice showed increased expression of RhoA, a key molecule involved in regulation of vascular tone, compared with aortas from control mice. We also observed increased RhoA abundance and t 1/2 in Cul3∆9-expressing cells, caused by decreased ubiquitination. CONCLUSIONS: Mutations in Cul3 cause severe hypertension by affecting both renal and vascular function, the latter being associated with activation of RhoA.
Authors: Larry N Agbor; Anand R Nair; Jing Wu; Ko-Ting Lu; Deborah R Davis; Henry L Keen; Frederick W Quelle; James A McCormick; Jeffrey D Singer; Curt D Sigmund Journal: JCI Insight Date: 2019-06-11
Authors: Yujiro Maeoka; Mohammed Z Ferdaus; Ryan J Cornelius; Avika Sharma; Xiao-Tong Su; Lauren N Miller; Joshua A Robertson; Susan B Gurley; Chao-Ling Yang; David H Ellison; James A McCormick Journal: J Am Soc Nephrol Date: 2022-01-21 Impact factor: 14.978