While arterial tone is generally determined by the phosphorylation of Ser in myosin light chain (p-MLC2), Thr/Ser diphosphorylation of MLC2 (pp-MLC2) has been suggested to hinder the relaxation of smooth muscle. In a dual-wire myography of rodent pulmonary artery (PA) and mesenteric artery (MA), we noticed significantly slower relaxation in PA than in MA after 80 mM KCl-induced condition (80K-contraction). Thus, we investigated the MLC2 phosphorylation and the expression levels of its regulatory enzymes; soluble guanylate cyclase (sGC), Rho-A dependent kinase (ROCK) and myosin light chain phosphatase target regulatory subunit (MYPT1). Immunoblotting showed higher sGC-α and ROCK2 in PA than MA, while sGC-β and MYPT1 levels were higher in MA than in PA. Interestingly, the level of pp-MLC2 was higher in PA than in MA without stimulation. In the 80K-contraction state, the levels of p-MLC2 and pp-MLC2 were commonly increased. Treatment with the ROCK inhibitor (Y27632, 10 μM) reversed the higher pp-MLC2 in PA. In the myography study, pharmacological inhibition of sGC (ODQ, 10 μM) slowed relaxation during washout, which was more pronounced in PA than in MA. The simultaneous treatment of Y27632 and ODQ reversed the impaired relaxation in PA and MA. Although treatment of PA with Y27632 alone could increase the rate of relaxation, it was still slower than that of MA without Y27632 treatment. Taken together, we suggest that the higher ROCK and lower MYPT in PA would have induced the higher level of MLC2 phosphorylation, which is responsible for the characteristic slow relaxation in PA.
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http://dx.doi.org/10.4196/kjpp.2024.28.1.49 | DOI Listing |
NPJ Regen Med
December 2024
Key Laboratory of Regenerative Medicine of Ministry of Education, Institute of Aging and Regenerative Medicine, Department of Developmental & Regenerative Biology, College of Life Science and Technology, Department of Cardiology, The Affiliated Guangdong Second Provincial General Hospital, Jinan University, Guangzhou, 510632, China.
Cardiomyocyte proliferation in adult Xenopus tropicalis during heart regeneration has remained largely contentious due to the absence of genetic evidence. Here, we generated a transgenic reporter line Tg(mlc2:H2C) expressing mCherry specifically in cardiomyocyte nuclei driven by the promoter of myosin light chain 2 (mlc2). Using the reporter line, we found that traditional whole-cell staining is not a rigorous way to identify cardiomyocytes in adult Xenopus tropicalis when using a cryosection with common thickness (5 μm) which leading to a high error, but this deviation could be reduced by increasing section thickness.
View Article and Find Full Text PDFThe study is designed to observe the mechanism of Tongfu Xiefei Guanchang Solution(TFXF) in the treatment of acute lung injury(ALI) in rats by improving intestinal barrier and intestinal flora structure via p38 mitogen-activated protein kinase(p38 MAPK)/myosin light chain kinase(MLCK) signaling pathway. Sixty SPF-grade Wistar rats were randomly divided into the control(CON) group, lipopolysaccharide(LPS) group(7.5 mg·kg~(-1)), LPS + dexamethasone(DEX) group(3.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
October 2024
the First Dongguan Affiliated Hospital of Guangdong Medical University Dongguan 523710, China the Second Clinical Medical College, Guangdong Medical University Dongguan 523808, China.
This study aims to elucidate the mechanism of Huangqin Decoction(HQD) in treating ulcerative colitis(UC) by investigating the relationship between tryptophan metabolism and intestinal barriers. In the in vivo experiments, 3% dextran sulfate sodium(DSS) was used to induce a mouse model of acute colitis, with mesalazine as a positive control. The therapeutic effect of HQD on mice with UC was evaluated according to body weight, disease activity index(DAI), colon length, and pathological changes.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
September 2024
Key Laboratory of Traditional Chinese Medicine for Prevention and Control of Regional High Incidence Diseases in Ningxia,Ministry of Education, Ningxia Medical University Yinchuan 750004, China.
Based on transcriptomics technology, this study investigated the molecular mechanisms of Xiangsha Liujunzi Decoction in treating chronic atrophic gastritis(CAG), which were confirmed through experimental validation. The CAG rat model was built by the MNNG composite multi-factor method, followed by a 90-day administration of Xiangsha Liujunzi Decoction. The study measured the rat body mass and 3-hour food intake in each group and observed the pathological changes in gastric tissue using HE staining.
View Article and Find Full Text PDFMicrobiol Spectr
December 2024
Department of Gastrointestinal, Colorectal and Anal Surgery, China-Japan Union Hospital of Jilin University, changchun, China.
Phillyrin (PHY), also known as forsythin, is an active constituent isolated from the fruit of (Thunb.) Vahl (Oleaceae). It exhibits anti-inflammatory, anti-viral, and antioxidant properties.
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