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Kulthinee S, Tasanarong A, Franco M, Navar LG. Interaction of Angiotensin II AT1 Receptors with Purinergic P2X Receptors in Regulating Renal Afferent Arterioles in Angiotensin II-Dependent Hypertension. Int J Mol Sci 2023; 24:11413. [PMID: 37511174 PMCID: PMC10380633 DOI: 10.3390/ijms241411413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 07/09/2023] [Indexed: 07/30/2023] Open
Abstract
In angiotensin II (Ang II)-dependent hypertension, Ang II activates angiotensin II type 1 receptors (AT1R) on renal vascular smooth muscle cells, leading to renal vasoconstriction with eventual glomerular and tubular injury and interstitial inflammation. While afferent arteriolar vasoconstriction is initiated by the increased intrarenal levels of Ang II activating AT1R, the progressive increases in arterial pressure stimulate the paracrine secretion of adenosine triphosphate (ATP), leading to the purinergic P2X receptor (P2XR)-mediated constriction of afferent arterioles. Thus, the afferent arteriolar tone is maintained by two powerful systems eliciting the co-existing activation of P2XR and AT1R. This raises the conundrum of how the AT1R and P2XR can both be responsible for most of the increased renal afferent vascular resistance existing in angiotensin-dependent hypertension. Its resolution implies that AT1R and P2XR share common receptor or post receptor signaling mechanisms which converge to maintain renal vasoconstriction in Ang II-dependent hypertension. In this review, we briefly discuss (1) the regulation of renal afferent arterioles in Ang II-dependent hypertension, (2) the interaction of AT1R and P2XR activation in regulating renal afferent arterioles in a setting of hypertension, (3) mechanisms regulating ATP release and effect of angiotensin II on ATP release, and (4) the possible intracellular pathways involved in AT1R and P2XR interactions. Emerging evidence supports the hypothesis that P2X1R, P2X7R, and AT1R actions converge at receptor or post-receptor signaling pathways but that P2XR exerts a dominant influence abrogating the actions of AT1R on renal afferent arterioles in Ang II-dependent hypertension. This finding raises clinical implications for the design of therapeutic interventions that will prevent the impairment of kidney function and subsequent tissue injury.
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Affiliation(s)
- Supaporn Kulthinee
- Department of Physiology, Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Adis Tasanarong
- Chulabhorn International College of Medicine, Thammasat University, Klong Luang 12120, Thailand
| | - Martha Franco
- Department of Cardio-Renal Physiopathology, Instituto Nacional de Cardiología "Ignacio Chávez", Mexico City 14080, Mexico
| | - Luis Gabriel Navar
- Department of Physiology, Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, LA 70112, USA
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Liu Q, Wu J, Lai S, Li G. MiR-665 Participates in the Protective Effect of Dexmedetomidine in Ischemic Stroke by ROCK2/NF-κB Axis. Neurochem Res 2022; 47:2064-2075. [PMID: 35538293 DOI: 10.1007/s11064-022-03597-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 03/24/2022] [Accepted: 04/01/2022] [Indexed: 12/29/2022]
Abstract
Ischemic stroke is a grievous intimidation to the healthiness of sufferers. Previous studies have reported that dexmedetomidine (DEX) has a protective effect on a variety of organs. This paper aimed to explore the regulatory mechanism of DEX in ischemic stroke through miR-665/ROCK2 axis. The mice model of ischemic stroke was constructed by middle cerebral artery occlusion (MCAO). The cell model of ischemic stroke was constructed by oxygen-glucose deprivation (OGD). Cell viability and apoptosis were assessed by CCK-8 assay and flow cytometry. The expression of cytokines was detected by ELISA. Lactate dehydrogenase (LDH) concentration was evaluated by LDH kit. The cerebral infarct volume of MCAO mice was detected by TTC staining, and the apoptosis of brain cells was detected by TUNEL staining. The target relationship between ROCK2 and miR-665 was analyzed by dual-luciferase reporter assay. DEX contributed cell viability from 42 to 66% (1 μM) and restrained cell apoptosis from 26 to 18% in HT22 cells treated with OGD (P < 0.01). Meanwhile, DEX decreased the expression of cytokines and LDH concentration from 184 to 126% (P < 0.001). Moreover, the expression of miR-665 enhanced 2.9 times (P < 0.05) and the expression of ROCK2 (P < 0.05) and NF-κB p65 (P < 0.01) reduced 1.8 times and 2.2 times after DEX treatment in OGD induced HT22. And miR-665 knockdown attenuated the effect of DEX on inflammation damage (the levels of TNF-α, IL-1β and IL-6 increased 1.36 times, 1.31 times, 1.43 time, respectively, and IL-10 decreased 1.68 times) and apoptosis from 17 to 25% (P < 0.01). MiR-665 directly targeted ROCK2 and regulated ROCK2 and NF-κB p65 expression (P < 0.01). Furthermore, ROCK2 overexpression inhibited the protective effect of DEX in HT22 induced by OGD (P < 0.001), while miR-665 overexpression reversed the regulatory of ROCK2 (P < 0.01). In vivo, DEX decreased cerebral infarction volume and inhibited apoptosis of brain cell (P < 0.001). DEX has a protective effect in ischemic stroke by promoting miR-665 expression to downregulate ROCK2/NF-κB axis, suggesting DEX has a beneficial effect on ischemic stroke and miR-665 is a conceivable target for the therapeutics and diagnosis of ischemic stroke.
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Affiliation(s)
- QiongHua Liu
- Department of Anesthesiology, Nanchang Hongdu Hospital of Traditional Chinese Medicine, Nanchang, 330000, Jiangxi, People's Republic of China
| | - JianE Wu
- Department of Anesthesiology, Nanchang Hongdu Hospital of Traditional Chinese Medicine, Nanchang, 330000, Jiangxi, People's Republic of China
| | - ShangShu Lai
- Department of Anesthesiology, Nanchang Hongdu Hospital of Traditional Chinese Medicine, Nanchang, 330000, Jiangxi, People's Republic of China
| | - Gan Li
- Department of Anesthesiology, The First Affiliated Hospital of Nanchang University, No.17, Yongwai Zhengjie, Donghu District, Nanchang, 330006, Jiangxi, People's Republic of China.
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Kulthinee S, Shao W, Franco M, Navar LG. Purinergic P2X 1 receptor, purinergic P2X 7 receptor, and angiotensin II type 1 receptor interactions in the regulation of renal afferent arterioles in angiotensin II-dependent hypertension. Am J Physiol Renal Physiol 2020; 318:F1400-F1408. [PMID: 32308022 DOI: 10.1152/ajprenal.00602.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
In ANG II-dependent hypertension, ANG II activates ANG II type 1 receptors (AT1Rs), elevating blood pressure and increasing renal afferent arteriolar resistance (AAR). The increased arterial pressure augments interstitial ATP concentrations activating purinergic P2X receptors (P2XRs) also increasing AAR. Interestingly, P2X1R and P2X7R inhibition reduces AAR to the normal range, raising the conundrum regarding the apparent disappearance of AT1R influence. To evaluate the interactions between P2XRs and AT1Rs in mediating the increased AAR elicited by chronic ANG II infusions, experiments using the isolated blood perfused juxtamedullary nephron preparation allowed visualization of afferent arteriolar diameters (AAD). Normotensive and ANG II-infused hypertensive rats showed AAD responses to increases in renal perfusion pressure from 100 to 140 mmHg by decreasing AAD by 26 ± 10% and 19 ± 4%. Superfusion with the inhibitor P2X1Ri (NF4490; 1 μM) increased AAD. In normotensive kidneys, superfusion with ANG II (1 nM) decreased AAD by 16 ± 4% and decreased further by 19 ± 5% with an increase in renal perfusion pressure. Treatment with P2X1Ri increased AAD by 30 ± 6% to values higher than those at 100 mmHg plus ANG II. In hypertensive kidneys, the inhibitor AT1Ri (SML1394; 1 μM) increased AAD by 10 ± 7%. In contrast, treatment with P2X1Ri increased AAD by 21 ± 14%; combination with P2X1Ri plus P2X7Ri (A438079; 1 μM) increased AAD further by 25 ± 8%. The results indicate that P2X1R, P2X7R, and AT1R actions converge at receptor or postreceptor signaling pathways, but P2XR exerts a dominant influence abrogating the actions of AT1Rs on AAR in ANG II-dependent hypertension.
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Affiliation(s)
- Supaporn Kulthinee
- Department of Physiology and Hypertension and Renal Center of Excellence, Tulane University Health Science Center, New Orleans, Louisiana.,Chulabhorn International College of Medicine, Thammasat University, Pathum Thani, Thailand
| | - Weijian Shao
- Department of Physiology and Hypertension and Renal Center of Excellence, Tulane University Health Science Center, New Orleans, Louisiana
| | - Martha Franco
- Department of Cardio-Renal Physiopathology, Instituto Nacional de Cardiología "Ignacio Chávez," México City, México
| | - L Gabriel Navar
- Department of Physiology and Hypertension and Renal Center of Excellence, Tulane University Health Science Center, New Orleans, Louisiana
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Role of a RhoA/ROCK-Dependent Pathway on Renal Connexin43 Regulation in the Angiotensin II-Induced Renal Damage. Int J Mol Sci 2019; 20:ijms20184408. [PMID: 31500276 PMCID: PMC6770162 DOI: 10.3390/ijms20184408] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 09/03/2019] [Accepted: 09/03/2019] [Indexed: 12/21/2022] Open
Abstract
In various models of chronic kidney disease, the amount and localization of Cx43 in the nephron is known to increase, but the intracellular pathways that regulate these changes have not been identified. Therefore, we proposed that: "In the model of renal damage induced by infusion of angiotensin II (AngII), a RhoA/ROCK-dependent pathway, is activated and regulates the abundance of renal Cx43". In rats, we evaluated: 1) the time-point where the renal damage induced by AngII is no longer reversible; and 2) the involvement of a RhoA/ROCK-dependent pathway and its relationship with the amount of Cx43 in this irreversible stage. Systolic blood pressure (SBP) and renal function (urinary protein/urinary creatinine: Uprot/UCrea) were evaluated as systemic and organ outcomes, respectively. In kidney tissue, we also evaluated: 1) oxidative stress (amount of thiobarbituric acid reactive species), 2) inflammation (immunoperoxidase detection of the inflammatory markers ED-1 and IL-1β), 3) fibrosis (immune detection of type III collagen; Col III) and 4) activity of RhoA/ROCK (amount of phosphorylated MYPT1; p-MYPT1). The ratio Uprot/UCrea, SBP, oxidative stress, inflammation, amount of Cx43 and p-MYPT1 remained high 2 weeks after suspending AngII treatment in rats treated for 4 weeks with AngII. These responses were not observed in rats treated with AngII for less than 4 weeks, in which all measurements returned spontaneously close to the control values after suspending AngII treatment. Rats treated with AngII for 6 weeks and co-treated for the last 4 weeks with Fasudil, an inhibitor of ROCK, showed high SBP but did not present renal damage or increased amount of renal Cx43. Therefore, renal damage induced by AngII correlates with the activation of RhoA/ROCK and the increase in Cx43 amounts and can be prevented by inhibitors of this pathway.
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Kohagura K, Arima H, Miyasato H, Chang TH, Yamazato M, Kobori H, Nishiyama A, Iseki K, Ohya Y. Add-On Effect of Angiotensin Receptor Blockade (Candesartan) on Clinical Remission in Active IgA Nephropathy Patients Treated with Steroid Pulse Therapy and Tonsillectomy: a Randomized, Parallel-Group Comparison Trial. Kidney Blood Press Res 2018; 43:780-792. [PMID: 29794482 PMCID: PMC6019550 DOI: 10.1159/000489914] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 05/09/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Angiotensin receptor blockers (ARBs) may be beneficial for clinical remission during conventional therapy with tonsillectomy and steroid pulse (TSP) for active IgA nephropathy. METHODS Seventy-seven patients with active IgA nephropathy were randomly assigned to the control arm with conventional regimen (TSP followed by oral prednisolone) (n = 37) or the ARB arm with conventional regimen plus ARB candesartan for the first 6 months (n = 40). Patients not achieving proteinuria remission at 12 months in either arm were administered candesartan, which was titrated until the 24-month follow-up. The primary endpoints were remission of proteinuria (< 0.3 g/gCr) and hematuria at 12 months. RESULTS Baseline proteinuria (g/g Cr) were comparable between the control and ARB arm (1.02 vs. 0.97, P = 0.97). Similarly, cumulative remission rates at 6, 12, and 24 months were comparable between the control and ARB arms (37.8% vs. 35% [P = 0.80], 48.7% vs. 38.5% [P = 0.37], 71.4% vs. 51.3% [P = 0.08]). Proteinuria, which was slightly worse in the control arm than in the ARB arm at 6 months, was comparable afterwards (0.20 vs. 0.23 g/g Cr at 12 months; 0.12 vs. 0.13 g/g Cr at 24 months). Significant reductions observed in urinary angiotensinogen were almost comparable between the two treatment arms at both 6 and 12 months. CONCLUSION Early candesartan treatment combined with TSP may not benefit clinical remission regardless of the blood pressure. ARB titration later during the treatment might provide benefit for patients with active IgA nephropathy.
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Affiliation(s)
- Kentaro Kohagura
- Dialysis Unit, University of the Ryukyus Hospital, Okinawa, Japan,
- Department of Cardiovascular Medicine, Nephrology and Neurology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan,
| | - Hisatomi Arima
- Department of Preventive Medicine and Public Health, Fukuoka University, Fukuoka, Japan
| | | | | | | | - Hiroyuki Kobori
- Departments of Pharmacology and Nephrology, School of Medicine, International University of Health and Welfare, Narita, Japan
| | - Akira Nishiyama
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | | | - Yusuke Ohya
- Department of Cardiovascular Medicine, Nephrology and Neurology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
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Angiotensin II-Induced Mesangial Cell Damaged Is Preceded by Cell Membrane Permeabilization Due to Upregulation of Non-Selective Channels. Int J Mol Sci 2018; 19:ijms19040957. [PMID: 29570626 PMCID: PMC5979336 DOI: 10.3390/ijms19040957] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 03/20/2018] [Accepted: 03/20/2018] [Indexed: 02/07/2023] Open
Abstract
Connexin43 (Cx43), pannexin1 (Panx1) and P2X7 receptor (P2X7R) are expressed in kidneys and are known to constitute a feedforward mechanism leading to inflammation in other tissues. However, the possible functional relationship between these membrane channels and their role in damaged renal cells remain unknown. In the present work, we found that MES-13 cells, from a cell line derived from mesangial cells, stimulated with angiotensin II (AngII) developed oxidative stress (OS, thiobarbituric acid reactive species (TBARS) and generated pro-inflammatory cytokines (ELISA; IL-1β and TNF-α). The membrane permeability increased progressively several hours before the latter outcome, which was a response prevented by Losartan, indicating the involvement of AT1 receptors. Western blot analysis showed that the amount of phosphorylated MYPT (a substrate of RhoA/ROCK) and Cx43 increased progressively and in parallel in cells treated with AngII, a response followed by an increase in the amount in Panx1 and P2X7R. Greater membrane permeability was partially explained by opening of Cx43 hemichannels (Cx43 HCs) and Panx1 channels (Panx1 Chs), as well as P2X7Rs activation by extracellular ATP, which was presumably released via Cx HCs and Panx1 Chs. Additionally, inhibition of RhoA/ROCK blocked the progressive increase in membrane permeability, and the remaining response was explained by the other non-selective channels. The rise of activity in the RhoA/ROCK-dependent pathway, as well as in Cx HCs, P2X7R, and to a minor extent in Panx1 Chs led to higher amounts of TBARS and pro-inflammatory cytokines. We propose that AngII-induced mesangial cell damage could be effectively inhibited by concomitantly inhibiting the RhoA/ROCK-dependent pathway and one or more non-selective channel(s) activated through this pathway.
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Guan Z, Wang F, Cui X, Inscho EW. Mechanisms of sphingosine-1-phosphate-mediated vasoconstriction of rat afferent arterioles. Acta Physiol (Oxf) 2018. [PMID: 28640982 DOI: 10.1111/apha.12913] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
AIM Sphingosine-1-phosphate (S1P) influences resistance vessel function and is implicated in renal pathological processes. Previous studies revealed that S1P evoked potent vasoconstriction of the pre-glomerular microvasculature, but the underlying mechanisms remain incompletely defined. We postulated that S1P-mediated pre-glomerular microvascular vasoconstriction involves activation of voltage-dependent L-type calcium channels (L-VDCC) and the rho/rho kinase pathway. METHODS Afferent arteriolar reactivity was assessed in vitro using the blood-perfused rat juxtamedullary nephron preparation, and diameter was measured during exposure to physiological and pharmacological agents. RESULTS Exogenous S1P (10-9 -10-5 mol L-1 ) evoked concentration-dependent vasoconstriction of afferent arterioles. Superfusion with nifedipine, a L-VDCC blocker, increased arteriolar diameter by 39 ± 18% of baseline and significantly attenuated the S1P-induced vasoconstriction. Superfusion with the rho kinase inhibitor, Y-27632, increased diameter by 60 ± 12% of baseline and also significantly blunted vasoconstriction by S1P. Combined nifedipine and Y-27632 treatment significantly inhibited S1P-induced vasoconstriction over the entire concentration range tested. In contrast, depletion of intracellular Ca2+ stores with the Ca2+ -ATPase inhibitors, thapsigargin or cyclopiazonic acid, did not alter the S1P-mediated vasoconstrictor profile. Scavenging reactive oxygen species (ROS) or inhibition of nicotinamide adenine dinucleotide phosphate oxidase activity significantly attenuated S1P-mediated vasoconstriction. CONCLUSION Exogenous S1P elicits potent vasoconstriction of rat afferent arterioles. These data also demonstrate that S1P-mediated pre-glomerular vasoconstriction involves activation of L-VDCC, the rho/rho kinase pathway and ROS. Mobilization of Ca2+ from intracellular stores is not required for S1P-mediated vasoconstriction. These studies reveal a potential role for S1P in the modulation of renal microvascular tone.
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Affiliation(s)
- Z. Guan
- Division of Nephrology; Department of Medicine; University of Alabama at Birmingham; Birmingham AL USA
| | - F. Wang
- Department of Biostatistics; Ryals School of Public Health; University of Alabama at Birmingham; Birmingham AL USA
| | - X. Cui
- Department of Biostatistics; Ryals School of Public Health; University of Alabama at Birmingham; Birmingham AL USA
| | - E. W. Inscho
- Division of Nephrology; Department of Medicine; University of Alabama at Birmingham; Birmingham AL USA
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Kim YY, Kim YJ, Cho KM, Kim SH, Park KE, Kang BC, Jung KC, Kim MS, Ku SY. The expression profile of angiotensin system on thawed murine ovaries. Tissue Eng Regen Med 2016; 13:724-731. [PMID: 30603453 PMCID: PMC6170859 DOI: 10.1007/s13770-016-0009-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 03/02/2016] [Accepted: 03/11/2016] [Indexed: 01/21/2023] Open
Abstract
Freezing and thawing is one of the most widely used tissue engineering techniques for the preservation of ovaries. Many cells and tissues demonstrate changes in functional gene expression after thawing. Several studies have reported the important roles of angiotensin (AT) system during the ovarian follicular growth. AT system consists of ATII, and ATII receptors type I (ATII-RI) and type II (ATII-RII). However, little is known whether frozen-thawed ovaries show any alteration of AT system member gene expression when treated with survival-enhancing factors. We aimed to investigate whether mass freezing and thawing with or without the use of Rho-associated kinase (ROCK) inhibitors up- or down-regulate the expression of ATII, ATII-RI, and ATII-RII genes on frozen-thawed ovarian tissues. Significant changes in the expression of ATII, ATII-RI, and ATII-RII genes were observed on thawed ovaries when compared to fresh control. The treatment with ROCK inhibitors did not significantly alter their expression. In conclusion, freezing and thawing of ovarian tissue may affect the mRNA expression levels of intra-ovarian AT system genes, and modulation of ROCK inhibitor activity may not regulate AT system on the frozenthawed ovarian tissue.
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Affiliation(s)
- Yoon Young Kim
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea
| | - Yong Jin Kim
- Department of Obstetrics and Gynecology, Korea University Guro Hospital, Seoul, Korea
| | - Kyung Mee Cho
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea
| | - Soo Hyun Kim
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea
| | - Kyung Eui Park
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea
| | - Byeong-Cheol Kang
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Kyung Cheon Jung
- Department of Pathology, Seoul National University College of Medicine, Seoul, Korea
| | - Moon Suk Kim
- Department of Molecular Science, Ajou University, Suwon, Korea
| | - Seung-Yup Ku
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea
- Department of Obstetrics and Gynecology, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, 03080 Seoul, Korea
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Hu HJ, Jiang ZS, Zhou SH, Liu QM. Hydrogen sulfide suppresses angiotensin II-stimulated endothelin-1 generation and subsequent cytotoxicity-induced endoplasmic reticulum stress in endothelial cells via NF-κB. Mol Med Rep 2016; 14:4729-4740. [DOI: 10.3892/mmr.2016.5827] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2015] [Accepted: 08/09/2016] [Indexed: 11/06/2022] Open
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Zhuo JL, Kobori H, Li XC, Satou R, Katsurada A, Navar LG. Augmentation of angiotensinogen expression in the proximal tubule by intracellular angiotensin II via AT1a/MAPK/NF-кB signaling pathways. Am J Physiol Renal Physiol 2016; 310:F1103-12. [PMID: 26864937 PMCID: PMC4889322 DOI: 10.1152/ajprenal.00350.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 02/02/2016] [Indexed: 11/22/2022] Open
Abstract
Long-term angiotensin II (ANG II) infusion significantly increases ANG II levels in the kidney through two major mechanisms: AT1 receptor-mediated augmentation of angiotensinogen (AGT) expression and uptake of circulating ANG II by the proximal tubules. However, it is not known whether intracellular ANG II stimulates AGT expression in the proximal tubule. In the present study, we overexpressed an intracellular cyan fluorescent ANG II fusion protein (Ad-sglt2-ECFP/ANG II) selectively in the proximal tubule of rats and mice using the sodium and glucose cotransporter 2 (sglt2) promoter. AGT mRNA and protein expression in the renal cortex and 24-h urinary AGT excretion were determined 4 wk following overexpression of ECFP/ANG II in the proximal tubule. Systolic blood pressure was significantly increased with a small antinatriuretic effect in rats and mice with proximal tubule-selective expression of ECFP/ANG II (P < 0.01). AGT mRNA and protein expression in the cortex were increased by >1.5-fold and 61 ± 16% (P < 0.05), whereas urinary AGT excretion was increased from 48.7 ± 5.7 (n = 13) to 102 ± 13.5 (n = 13) ng/24 h (P < 0.05). However, plasma AGT, renin activity, and ANG II levels remained unaltered by ECFP/ANG II. The increased AGT mRNA and protein expressions in the cortex by ECFP/ANG II were blocked in AT1a-knockout (KO) mice. Studies in cultured mouse proximal tubule cells demonstrated involvement of AT1a receptor/MAP kinases/NF-кB signaling pathways. These results indicate that intracellular ANG II stimulates AGT expression in the proximal tubules, leading to increased AGT formation and secretion into the tubular fluid, which contributes to ANG II-dependent hypertension.
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Affiliation(s)
- Jia L Zhuo
- Laboratory of Receptor and Signal Transduction, Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi; and
| | - H Kobori
- Department of Physiology and Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, Louisiana
| | - Xiao C Li
- Laboratory of Receptor and Signal Transduction, Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi; and
| | - R Satou
- Department of Physiology and Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, Louisiana
| | - A Katsurada
- Department of Physiology and Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, Louisiana
| | - L Gabriel Navar
- Department of Physiology and Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, Louisiana
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Sun J, Luo J, Ruan Y, Xiu L, Fang B, Zhang H, Wang M, Chen H. Free Fatty Acids Activate Renin-Angiotensin System in 3T3-L1 Adipocytes through Nuclear Factor-kappa B Pathway. J Diabetes Res 2016; 2016:1587594. [PMID: 26881238 PMCID: PMC4736205 DOI: 10.1155/2016/1587594] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 10/20/2015] [Indexed: 01/22/2023] Open
Abstract
The activity of a local renin-angiotensin system (RAS) in the adipose tissue is closely associated with obesity-related diseases. However, the mechanism of RAS activation in adipose tissue is still unknown. In the current study, we found that palmitic acid (PA), one kind of free fatty acid, induced the activity of RAS in 3T3-L1 adipocytes. In the presence of fetuin A (Fet A), PA upregulated the expression of angiotensinogen (AGT) and angiotensin type 1 receptor (AT1R) and stimulated the secretion of angiotensin II (ANG II) in 3T3-L1 adipocytes. Moreover, the activation of RAS in 3T3-L1 adipocytes was blocked when we blocked Toll-like receptor 4 (TLR4) signaling pathway using TAK242 or NF-κB signaling pathway using BAY117082. Together, our results have identified critical molecular mechanisms linking PA/TLR4/NF-κB signaling pathway to the activity of the local renin-angiotensin system in adipose tissue.
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Affiliation(s)
- Jia Sun
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jinhua Luo
- Department of Geratology, The Affiliated Hospital of Guangdong Medical College, Guangdong Medical College, Zhanjiang, Guangdong, China
| | - Yuting Ruan
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Liangchang Xiu
- Department of Epidemiology and Medical Statistics, School of Public Health, Guangdong Medical College, Dongguan, Guangdong, China
| | - Bimei Fang
- Second Clinical School of Medicine, Southern Medical University, Guangzhou, China
| | - Hua Zhang
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Ming Wang
- Nephrology Center of Integrated Traditional Chinese and Western Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- *Ming Wang: and
| | - Hong Chen
- Department of Endocrinology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- *Hong Chen:
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Abstract
Experimental models of hypertension and patients with inappropriately increased renin formation due to a stenotic kidney, arteriosclerotic narrowing of the renal arterioles or a rare juxtaglomerular cell tumor have shown a progressive augmentation of the intrarenal/intratubular renin-angiotensin system (RAS). The increased intrarenal angiotensin II (Ang II) elicits renal vasoconstriction and enhanced tubular sodium reabsorption in proximal and distal nephron segments. The enhanced intrarenal Ang II levels are due to both increased Ang II type 1 (AT1) receptor mediated Ang II uptake and AT1 receptor dependent stimulation of renal angiotensinogen (AGT) mRNA and augmented AGT production. The increased AGT formation and secretion into the proximal tubular lumen leads to local formation of Ang II, which stimulates proximal transporters such as the sodium/hydrogen exchanger. Enhanced AGT production also leads to spillover of AGT into the distal nephron segments as reflected by AGT in the urine, which provides an index of intrarenal RAS activity. There is also increased Ang II concentration in distal nephron with stimulation of distal sodium transport. Increased urinary excretion of AGT has been demonstrated in patients with hypertension, type 1 and type 2 diabetes mellitus, and several types of chronic kidney diseases indicating an upregulation of intrarenal RAS activity.
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Affiliation(s)
- Ryousuke Satou
- Department of Physiology and the Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Weijian Shao
- Department of Physiology and the Hypertension and Renal Center of Excellence, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - L Gabriel Navar
- Department of Physiology, Tulane University Health Sciences Center, SL39, 1430 Tulane Avenue, New Orleans, LA 70112, USA
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Yang YC, Wang XD, Huang K, Wang L, Jiang ZL, Qi YX. Temporal phosphoproteomics to investigate the mechanotransduction of vascular smooth muscle cells in response to cyclic stretch. J Biomech 2014; 47:3622-9. [DOI: 10.1016/j.jbiomech.2014.10.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 09/27/2014] [Accepted: 10/05/2014] [Indexed: 12/28/2022]
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