scholarly journals Angiotensin II-Induced Vasoconstriction via Rho Kinase Activation in Pressure-Overloaded Rat Thoracic Aortas

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1076
Author(s):  
Yuka Terada ◽  
Katsutoshi Yayama

Angiotensin II (Ang II) induces vasoconstriction through myosin light chain (MLC) kinase activation and MLC phosphatase inactivation via phosphorylation of myosin phosphatase targeting subunit 1 (MYPT1) by Rho kinase. However, the detailed mechanism underlying Rho kinase activation by Ang II is still unknown. We investigated the mechanism of Ang II-induced vasoconstriction mediated by Rho kinase in pressure-overloaded rat thoracic aortas. Pressure-overloaded rats were produced by coarctation of the suprarenal abdominal aorta in four-week-old male Wistar rats. The contractile response to Ang II was significantly enhanced in the pressure-overloaded rats. Ang II-induced vasoconstriction was attenuated by inhibitors of Rho kinase, extracellular signal-regulated kinase 1 and 2 (Erk1/2), and epidermal growth factor receptor (EGFR) in both the sham-operated and pressure-overloaded rats. The Ang II-induced vasoconstriction was attenuated by a Janus kinase 2 (JAK2) inhibitor in only the pressure-overloaded rats. The protein levels of MYPT1 and JAK2 increased only in the pressure-overloaded rat thoracic aortas. These results suggested that Ang II-induced contraction is mediated by Rho kinase activation via EGFR, Erk1/2, and JAK2 in pressure-overloaded rat thoracic aortas. Moreover, Ang II-induced contraction was enhanced in pressure-overloaded rats probably because the protein levels of MYPT1 and JAK2 increased in the thoracic aortas.

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 25 ◽  
Author(s):  
Yi Zhang ◽  
Hui Liu ◽  
Wenjing Jia ◽  
Jiayu Qi ◽  
Wentao Zhang ◽  
...  

Angiotensin II (Ang II) participates in the pathogenesis of liver injury. Our previous publications reported that myeloid differentiation protein 2 (MD2) mediates Ang II-induced cardiac and kidney inflammation by directly binding to Ang II. Thus, we hypothesize that MD2 is critical to Ang II-induced liver injury. Subcutaneous injections of Ang II for 8 weeks were adopted to build the liver injury model. With a specific MD2 inhibitor L6H21 and MD2 knockout mice, we reported that MD2 inhibition and knockout significantly mitigate liver inflammation and fibrosis in mice injected with Ang II. To be more specific, the functional and pathological damages induced by Ang II were mitigated by L6H21 or MD2 knockout. MD2 knockout or L6H21 administration inhibited the Ang II-induced upregulation of fibrosis markers, inflammatory cytokines, and adhesion molecules in gene or protein levels. The activation of NF-κB and Extracellular signal-regulated kinases (ERK) induced by Ang II was also reversed by L6H21 treatment or MD2 deficiency. Note that the co-immunoprecipitation study showed that L6H21 downregulated the ANG II-induced toll-like receptor 4 (TLR4)/MD2 complex in liver tissues while having no effects on MD2 expression. Our results reported the critical role of MD2 in the progress of liver injury and suggested that MD2 is a potential therapeutic target for liver injury.


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Catherina A Cuevas ◽  
Alexis A Gonzalez ◽  
Nivaldo C Inestrosa ◽  
Carlos P Vio ◽  
Minolfa C Prieto

The prorenin receptor (PRR) is upregulated in the kidney by high angiotensin II (Ang II) states such as those that occur with AngII-dependent hypertension and low salt diet. The PRR is an accessory protein of the vacuolar H-ATPase, which facilitates Wnt/β-catenin signaling. The Wnt/β-catenin pathway is involved in fibrosis processes. In the present study, we aimed to determine whether the stimulation of PRR in mouse collecting duct M-1 cells induces fibrotic genes independently of Ang II, and if this effect is mediated by activation of Wnt/β-catenin. Both Ang II (10 -7 M) and human recombinant prorenin (hRPr; 2,5 x 10 -8 M) treatments (8 and 16 hours) increased mRNA and protein levels of fibronectin and collagen I (1.5±0.08 and 1.5 ± 0.1 fold change, respectibely; p<0.05); however, the effects of hRPr were elicited earlier. Likewise, Ang II and hRPr stimulated the Wnt target genes, cyclin D1 and c-myc (cyclin D1: 2±0.2 for both; c-myc: 1.4 ± 0.03 and 1.2± 0.002 fold change for Ang II and hRPr, respectively; p<0.001). Ang II type 1 receptor (AT1R) blockade with candesartan (10 -7 M) completely prevented the Ang II-dependent stimulation but not the effects of hRPr on Wnt signaling genes. Upregulation of fibronectin and collagen I genes by Ang II or hRP at 16 h was prevented by Wnt signaling inhibition with Pyrvinium Pamoate (10 -7 M). The data indicate that in M-1 cells, activation of AT1R and PRR stimulate the synthesis of fibrotic genes via Wnt signaling by independent mechanisms.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Ying Wu ◽  
Zhen Li ◽  
Sining Wang ◽  
Aiyuan Xiu ◽  
Chunqing Zhang

Aim. Carvedilol is a nonselective beta-blocker used to reduce portal hypertension. This study investigated the effects and potential mechanisms of carvedilol in angiotensin II- (Ang II-) induced hepatic stellate cell (HSC) proliferation and contraction. Methods. The effect of carvedilol on HSC proliferation was measured by Cell Counting Kit-8 (CCK-8). Cell cycle progression and apoptosis in HSCs were determined by flow cytometry. A collagen gel assay was used to confirm HSC contraction. The extent of liver fibrosis in mice was evaluated by hematoxylin-eosin (H&E) and Sirius Red staining. Western blot analyses were performed to detect the expression of collagen I, collagen III, α-smooth muscle actin (α-SMA), Ang II type I receptor (AT1R), RhoA, Rho-kinase 2 (ROCK2), and others. Results. The results showed that carvedilol inhibited HSC proliferation and arrested the cell cycle at the G0/G1 phase in a dose-dependent manner. Carvedilol also modulated Bcl-2 family proteins and increased apoptosis in Ang II-treated HSCs. Furthermore, carvedilol inhibited HSC contraction induced by Ang II, an effect that was associated with AT1R-mediated RhoA/ROCK2 pathway interference. In addition, carvedilol reduced α-SMA expression and collagen deposition and attenuated liver fibrosis in carbon tetrachloride (CCl4)-treated mice. The in vivo data further confirmed that carvedilol inhibited the expression of angiotensin-converting enzyme (ACE), AT1R, RhoA, and ROCK2. Conclusions. The results indicated that carvedilol dose-dependently inhibited Ang II-induced HSC proliferation by impeding cell cycle progression, thus alleviating hepatic fibrosis. Furthermore, carvedilol could inhibit Ang II-induced HSC contraction by interfering with the AT1R-mediated RhoA/ROCK2 pathway.


1996 ◽  
Vol 271 (2) ◽  
pp. H595-H601 ◽  
Author(s):  
M. Okuda ◽  
Y. Kawahara ◽  
M. Yokoyama

Angiotensin II (ANG II), a potent growth-promoting factor of vascular smooth muscle cells (VSMC), induces activation of mitogen-activated protein (MAP) kinases and subsequent expression of the c-fos protooncogene in VSMC. However, it remains obscure whether ANG II induces activation of the ras protooncogene product (Ras), and if it does, whether Ras is involved in signaling from the ANG II receptor to the MAP kinase pathway in VSMC. In cultured VSMC, ANG II activated Ras comparably to epidermal growth factor. ANG II-induced Ras activation was detectable within 1 min and maximal at 2–5 min. The ANG II type 1 (AT1) receptor antagonist, CV-11974, completely inhibited this reaction. Pertussis toxin treatment of VSMC inhibited ANG II-induced Ras activation by approximately 70% but had no effect on ANG II-induced MAP kinase activation and c-fos expression. These results indicate that ANG II activates Ras via AT1 receptors, which are predominantly linked to a G protein of the Gi subfamily in VSMC1 and suggest that Ras activation may not be a prerequisite for ANG II-induced MAP kinase activation and c-fos expression in this cell type.


2020 ◽  
Vol 21 (8) ◽  
pp. 2919
Author(s):  
Chia-Liang Lin ◽  
Tung-Wei Hung ◽  
Tsung-Ho Ying ◽  
Chi-Jui Lin ◽  
Yi-Hsien Hsieh ◽  
...  

Renal cell carcinoma (RCC) is the most common adult kidney cancer, and accounts for 85% of all cases of kidney cancers worldwide. Praeruptorin B (Pra-B) is a bioactive constituent of Peucedanum praeruptorum Dunn and exhibits several pharmacological activities, including potent antitumor effects. However, the anti-RCC effects of Pra-B and their underlying mechanisms are unclear; therefore, we explored the effects of Pra-B on RCC cells in this study. We found that Pra-B nonsignificantly influenced the cell viability of human RCC cell lines 786-O and ACHN at a dose of less than 30 μM for 24 h treatment. Further study revealed that Pra-B potently inhibited the migration and invasion of 786-O and ACHN cells, as well as downregulated the mRNA and protein expression of cathepsin C (CTSC) and cathepsin V (CTSV) of 786-O and ACHN cells. Mechanistically, Pra-B also reduced the protein levels of phospho (p)-epidermal growth factor receptor (EGFR), p-mitogen-activated protein kinase kinase (MEK), and p-extracellular signal-regulated kinases (ERK) in RCC cells. In addition, Pra-B treatment inhibited the effect of EGF on the upregulation of EGFR–MEK–ERK, CTSC and CTSV expression, cellular migration, and invasion of 786-O cells. Our findings are the first to demonstrate that Pra-B can reduce the migration and invasion ability of human RCC cells through suppressing the EGFR-MEK-ERK signaling pathway and subsequently downregulating CTSC and CTSV. This evidence suggests that Pra-B can be developed as an effective antimetastatic agent for the treatment of RCC.


Endocrinology ◽  
2003 ◽  
Vol 144 (10) ◽  
pp. 4586-4596 ◽  
Author(s):  
Vivian C. Calegari ◽  
Rosangela M. N. Bezerra ◽  
Márcio A. Torsoni ◽  
Adriana S. Torsoni ◽  
Kleber G. Franchini ◽  
...  

Angiotensin II (Ang II) exerts a potent growth stimulus on the heart and vascular wall. Activation of the Janus kinase/signal transducer and activator of transcription (JAK/STAT) intracellular signaling pathway by Ang II mediates at least some of the mitogenic responses to this hormone. In other signaling systems that use the JAK/STAT pathway, proteins of the suppressor of cytokine signaling (SOCS) family participate in signal regulation. In the present study it is demonstrated that SOCS3 is constitutively expressed at a low level in rat heart and neonatal rat ventricular myocytes. Ang II at a physiological concentration enhances the expression of SOCS3 mRNA and protein, mainly via AT1 receptors. After induction, SOCS3 associates with JAK2 and impairs further activation of the JAK2/STAT1 pathway. Pretreatment of rats with a specific phosphorthioate antisense oligonucleotide to SOCS3, reverses the desensitization to angiotensin signaling, as detected by a fall in c-Jun expression after repetitive infusions of the hormone. Thus, SOCS3 is induced by Ang II in rat heart and neonatal rat ventricular myocytes and participates in the modulation of the signal generated by this hormone.


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