| 1. |
- Popov, Sergej, et al.
(författare)
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Salt-inducible kinase 1 influences Na+,K+-ATPase activity in vascular smooth muscle cells and associates with variations in blood pressure
- 2011
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Ingår i: Journal of Hypertension. - : Lippincott Williams & Wilkins. - 0263-6352 .- 1473-5598. ; 29:12, s. 2395-2403
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES:Essential hypertension is a complex condition whose cause involves the interaction of multiple genetic and environmental factors such as salt intake. Salt-inducible kinase 1 (SIK1) is a sucrose-nonfermenting-like kinase isoform that belongs to the AMPK (5' adenosine monophosphate-activated protein kinase) family. SIK1 activity is increased by high salt intake and plays an essential role in regulating the plasma membrane Na(+),K(+)-ATPase. The objective of this study was to examine whether SIK1 is present in vascular smooth muscle cells (VSMCs) and endothelial cells, whether it affects VSMC Na(+),K(+)-ATPase activity and whether human SIK1 (hSIK1) represents a potential candidate for blood pressure regulation.METHODS:Localization of SIK1 was performed using immunohistochemistry, mRNA and western blot. Functional assays (Na(+),K(+)-ATPase activity) were performed in VSMCs derived from rat aorta. Genotype-phenotype association studies were performed in three Swedish and one Japanese population-based cohorts.RESULTS:SIK1 was localized in human VSMCs and endothelial cells, as well as a cell line derived from rat aorta. A nonsynonymous single nucleotide polymorphism in the hSIK1 gene exon 3 (C→T, rs3746951) results in the amino acid change (15)Gly→Ser in the SIK1 protein. SIK1-(15)Ser was found to increase plasma membrane Na(+),K(+)-ATPase activity in cultured VSMC line from rat aorta. Genotype-phenotype association studies in three Swedish and one Japanese population-based cohorts suggested that T allele (coding for (15)Ser) was associated with lower blood pressure (P = 0.005 for SBP and P = 0.002 for DBP) and with a decrease in left ventricular mass (P = 0.048).CONCLUSION:The hSIK1 appears to be of potential relevance within VSMC function and blood pressure regulation.
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| 2. |
- Sato-Hashimoto, Miho, et al.
(författare)
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Microglial SIRP alpha regulates the emergence of CD11c(+) microglia and demyelination damage in white matter
- 2019
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Ingår i: eLIFE. - : eLIFE Sciences Publications. - 2050-084X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- A characteristic subset of microglia expressing CD11c appears in response to brain damage. However, the functional role of CD11c(+) microglia, as well as the mechanism of its induction, are poorly understood. Here we report that the genetic ablation of signal regulatory protein alpha (SIRP alpha), a membrane protein, induced the emergence of CD11c(+) microglia in the brain white matter. Mice lacking CD47, a physiological ligand of SIRP alpha, and microglia-specific SIRP alpha-knockout mice exhibited the same phenotype, suggesting that an interaction between microglial SIRP alpha and CD47 on neighbouring cells suppressed the emergence of CD11c(+) microglia. A lack of SIRP alpha did not cause detectable damage to the white matter, but resulted in the increased expression of genes whose expression is characteristic of the repair phase after demyelination. In addition, cuprizone-induced demyelination was alleviated by the microglia-specific ablation of SIRP alpha. Thus, microglial SIRP alpha suppresses the induction of CD11c(+) microglia that have the potential to accelerate the repair of damaged white matter.
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| 3. |
- Yoshimoto, Takanobu, et al.
(författare)
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Angiotensin Converting Enzyme Inhibitor Normalizes Vascular Natriuretic Peptide Type A Receptor Gene Expression via Bradykinin-Dependent Mechanism in Hypertensive Rats
- 1996
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier. - 0006-291X .- 1090-2104. ; 218:1, s. 50-53
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Tidskriftsartikel (refereegranskat)abstract
- We previously demonstrated that angiotensin converting enzyme (ACE) inhibitor normalizes the up-regulated gene expression of vascular natriuretic peptide type A (NP-A) receptor in hypertensive rats. To elucidate the mechanism, we examined the effect of angiotensin II receptor (AT1) antagonist (TCV-116) and bradykinin receptor (B2) antagonist (Hoe 140) on the NP-A receptor mRNA level in the aorta of genetically hypertensive rats (SHR-SP/Izm) using ribonuclease protection assay. The effect of ACE inhibitor on the NP-A receptor mRNA level was completely abolished by a concomitant administration of Hoe 140, while TCV-116 did not show any significant effect on the NP-A receptor mRNA level. These results suggest that bradykinin plays an important role in the regulation of the vascular NP-A receptor gene expression.
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| 4. |
- Yoshimoto, Takanoubu, et al.
(författare)
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Angiotensin II-dependent down-regulation of vascular natriuretic peptide type C receptor gene expression in hypertensive rats
- 1996
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Ingår i: Endocrinology. - : Oxford University Press. - 0013-7227 .- 1945-7170. ; 137:3, s. 1102-1107
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Tidskriftsartikel (refereegranskat)abstract
- Biological actions of natriuretic peptide (NP) are determined by the condition of the receptor as well as that of the hormone. Although we previously demonstrated in hypertensive rats the up-regulation of NP-A receptor that mediates various biological actions of NPs, the pathophysiologic significance of NP-C receptor, another subtype thought to be related to clearance of NPs and possibly to biological actions, remains unknown. In the present study, we determined NP-C receptor messenger RNA (mRNA) level in the aortic tissue of stroke-prone spontaneously hypertensive rats (SHR-SP/Izm) and in cultured aortic smooth muscle cells by ribonuclease protection assay. The aortic NP-C receptor mRNA level in SHR-SP/Izm was significantly lower than that in the control WKY/Izm. Oral administration of an angiotensin (Ang) II receptor (AT1) antagonist, TCV-116, but not a calcium channel blocker, manidipine, reversed the down-regulated NP-C receptor mRNA in SHR-SP/Izm to the level in WKY/Izm, whereas the latter was more potent in decreasing the blood pressure. In cultured aortic smooth muscle cells, the NP-C receptor was the predominant subtype. Ang II decreased the NP-C receptor mRNA level in a dose-dependent manner, but this effect was reversed by an AT1 antagonist, CV-11974. Neither the NP-A nor NP-B receptor mRNA level was altered by Ang II. These findings indicate that vascular NP-C receptor is down- regulated via Ang-II-mediated mechanism in SHR-SP/Izm. The phenomenon, together with the up-regulation of the NP-A receptor, may play an important role in counteracting hypertension by enhancing the action of NPs.
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| 5. |
- Yoshimoto, Takanobu, et al.
(författare)
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Differential Gene Expression of Vascular Natriuretic Peptide Receptor Subtype in Artery and Vein
- 1995
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier. - 0006-291X .- 1090-2104. ; 216:2, s. 535-539
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Tidskriftsartikel (refereegranskat)abstract
- Although the vasorelaxation by natriuretic peptide (NP) is much less potent in the vein than in the artery, mechanism underlying the phenomenon remains unknown. Since NP receptor consists of three subtypes with different functions, we determined the mRNA level of each NP receptor subtype in the artery and vein by ribonuclease protection assay. In the aorta, NP-A receptor related to the biological action of NP was the predominant form. By contrast, NP-C receptor related mainly to the clearance of NP was the predominant form in the inferior vena cava: NP-C mRNA level was about two fold higher than in the aorta, while both NP-A and NP-B receptor mRNA levels were about half of that in the aorta. These results provide the molecular basis for the different biological response to NP in the artery and vein. Differential gene expression of NP receptor subtype could be an important determinant of the biological actions of NP.
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| 6. |
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