AIM: Angiotensin Ⅱ(Ang Ⅱ) produces reactive oxygen species (ROS), thus contributing to the development of cardiac hypertrophy and subsequent heart failure, and stimulates the expression of monocyte chemoattractant protein-1 (MCP-1). In addition, Toll-like receptor 4 (TLR4) is involved in the upregulation of MCP-1. In order to clarify whether TLR4 is involved in the onset of cardiac dysfunction caused by Ang Ⅱ stimulation, we investigated the effects of TLR4 on oxidative stress, the MCP-1 expression and cardiac dysfunction in mice with Ang Ⅱ-induced hypertension. METHODS: TLR4-deficient (Tlr4(lps-d)) and wild-type (WT) mice were randomized into groups treated with Ang Ⅱ, norepinephrine (NE) or a subdepressor dose of the Ang Ⅱreceptor blocker irbesartan (IRB) and Ang Ⅱ for two weeks. RESULTS: Ang Ⅱ and NE similarly increased systolic blood pressure in all drug-treated groups compared to that observed in the control group among both WT and Tlr4(lps-d) mice (p＜0.05). In the WT mice, Ang Ⅱ induced cardiac hypertrophy as well as vascular remodeling and perivascular fibrosis of the intramyocardial arteries and monocyte/macrophage infiltration in the heart (p＜0.05). Furthermore, Ang Ⅱ treatment decreased the left ventricular diastolic function and resulted in a greater left ventricular end-systolic dimension (p＜0.05) in addition to producing a five-fold increase in the NADPH oxidase activity, ROS content and MCP-1 expression (p＜0.05). In contrast, the Tlr4(lps-d) mice showed little effects of Ang Ⅱ on these indices. In the WT mice, IRB treatment reversed these changes compared to that seen in the mice treated with Ang Ⅱ alone. NE produced little effect on any of the indices in either the WT or Tlr4(lps-d) mice. CONCLUSIONS: TLR4 may be involved in the processes underlying the increased oxidative stress, selectively activated MCP-1 expression and cardiac hypertrophy and dysfunction seen in cases of Ang Ⅱ- induced hypertension.
AIM: Angiotensin Ⅱ(Ang Ⅱ) produces reactive oxygen species (ROS), thus contributing to the development of cardiac hypertrophy and subsequent heart failure, and stimulates the expression of monocyte chemoattractant protein-1 (MCP-1). In addition, Toll-like receptor 4 (TLR4) is involved in the upregulation of MCP-1. In order to clarify whether TLR4 is involved in the onset of cardiac dysfunction caused by Ang Ⅱ stimulation, we investigated the effects of TLR4 on oxidative stress, the MCP-1 expression and cardiac dysfunction in mice with Ang Ⅱ-induced hypertension. METHODS:TLR4-deficient (Tlr4(lps-d)) and wild-type (WT) mice were randomized into groups treated with Ang Ⅱ, norepinephrine (NE) or a subdepressor dose of the Ang Ⅱreceptor blocker irbesartan (IRB) and Ang Ⅱ for two weeks. RESULTS:Ang Ⅱ and NE similarly increased systolic blood pressure in all drug-treated groups compared to that observed in the control group among both WT and Tlr4(lps-d) mice (p＜0.05). In the WT mice, Ang Ⅱ induced cardiac hypertrophy as well as vascular remodeling and perivascular fibrosis of the intramyocardial arteries and monocyte/macrophage infiltration in the heart (p＜0.05). Furthermore, Ang Ⅱ treatment decreased the left ventricular diastolic function and resulted in a greater left ventricular end-systolic dimension (p＜0.05) in addition to producing a five-fold increase in the NADPH oxidase activity, ROS content and MCP-1 expression (p＜0.05). In contrast, the Tlr4(lps-d) mice showed little effects of Ang Ⅱ on these indices. In the WT mice, IRB treatment reversed these changes compared to that seen in the mice treated with Ang Ⅱ alone. NE produced little effect on any of the indices in either the WT or Tlr4(lps-d) mice. CONCLUSIONS:TLR4 may be involved in the processes underlying the increased oxidative stress, selectively activated MCP-1 expression and cardiac hypertrophy and dysfunction seen in cases of Ang Ⅱ- induced hypertension.
Authors: Joel Schilling; Ling Lai; Nandakumar Sambandam; Courtney E Dey; Teresa C Leone; Daniel P Kelly Journal: Circ Heart Fail Date: 2011-05-10 Impact factor: 8.790
Authors: A Poltorak; X He; I Smirnova; M Y Liu; C Van Huffel; X Du; D Birdwell; E Alejos; M Silva; C Galanos; M Freudenberg; P Ricciardi-Castagnoli; B Layton; B Beutler Journal: Science Date: 1998-12-11 Impact factor: 47.728
Authors: Mălina Suciu-Petrescu; Anamaria Truta; Mihai Domnutiu Suciu; Adrian Pavel Trifa; Denisa Petrescu; Horia Ștefan Roșianu; Octavia Sabin; Daciana Elena Popa; Antonia Eugenia Macarie; Ștefan Cristian Vesa; Anca Dana Buzoianu Journal: Exp Ther Med Date: 2021-04-28 Impact factor: 2.447
Authors: Steven J Forrester; George W Booz; Curt D Sigmund; Thomas M Coffman; Tatsuo Kawai; Victor Rizzo; Rosario Scalia; Satoru Eguchi Journal: Physiol Rev Date: 2018-07-01 Impact factor: 37.312
Authors: Madhu V Singh; Michael Z Cicha; Sarah Nunez; David K Meyerholz; Mark W Chapleau; François M Abboud Journal: Am J Physiol Heart Circ Physiol Date: 2019-02-22 Impact factor: 4.733
Authors: Scott M Brown; Cassandra E Smith; Alex I Meuth; Maloree Khan; Annayya R Aroor; Hannah M Cleeton; Gerald A Meininger; James R Sowers; Vincent G DeMarco; Bysani Chandrasekar; Ravi Nistala; Shawn B Bender Journal: Endocrinology Date: 2017-10-01 Impact factor: 4.736