Calhex231 Alleviates High Glucose-Induced Myocardial Fibrosis via Inhibiting Itch-Ubiquitin Proteasome Pathway in Vitro.

Abstract

Diabetic cardiomyopathy (DCM) is a major complication of diabetes, and features myocardial fibrosis as its main pathological feature. Calcium sensing receptor (CaSR) is a G protein-coupled receptor, which involves in myocardial fibrosis by regulation of calcium homeostasis. Calhex231, the CaSR inhibitor, is not clear whether it regulates myocardial fibrosis in DCM. In the present study, type 1 diabetic (T1D) rats and primary neonatal rat cardiac fibroblasts were used to observe the role of Calhex231. In vivo experiments showed that in the T1D group, contractile dysfunction and the deposition of collagen I and III were obvious after 12 weeks. In vitro experiments, we found that high glucose (HG) could increase the expression of CaSR, α-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1) collagen I/III, matrix metalloproteinase-2 (MMP-2), MMP9, along with cardiac fibroblast migration and proliferation. We further demonstrated that CaSR activation increased intracellular Ca2+ concentration and upregulated the expression of Itch (atrophin-1 interacting protein 4), which resulted in increasing the ubiquitination levels of Smad7 and upregulating the expression of p-Smad2, p-Smad3. However, treatment with Calhex231 clearly inhibited the above-mentioned changes. Collectively these results suggest that Calhex231 could inhibit Itch-ubiquitin proteasome and TGF-β1/Smads pathways, and then depress the proliferation of cardiac fibroblasts, along with the reduction deposition of collagen, alleviate glucose-induced myocardial fibrosis. Our findings indicate an important new mechanism for myocardial fibrosis, and suggest Calhex231 would be a new therapeutic agent for the treatment of DCM.

• Authors: Hui Yuan, Jiyu Xu, Xiaoyi Xu, Tielei Gao, Yuehong Wang, Yuqi Fan, Jing Hu, Yiying Shao, Bingbing Zhao, Hongzhu Li, Jian Sun, Changqing Xu
• Journal: Biological & pharmaceutical bulletin (Biol Pharm Bull) Vol. 42 Issue 8 Pg. 1337-1344 (Aug 01 2019) ISSN: 1347-5215 [Electronic] Japan
• PMID: 31167987 (Publication Type: Journal Article)

Chemical References

• Benzamides
• Collagen Type I
• Collagen Type III
• Cyclohexylamines
• Itch protein, rat
• N(1)-(4-chlorobenzoyl)-N(2)-(1-(1-naphthyl)ethyl)-1,2-diaminocyclohexane
• Receptors, Calcium-Sensing
• Smad2 Protein
• Smad2 protein, rat
• Smad3 Protein
• Smad3 protein, rat
• Smad7 Protein
• Smad7 protein, rat
• Tgfb1 protein, rat
• Transforming Growth Factor beta1
• Ubiquitins
• extracellular calcium cation-sensing receptor, rat
• Ubiquitin-Protein Ligases
• Matrix Metalloproteinase 2
• Matrix Metalloproteinase 9
• Proteasome Endopeptidase Complex
• Glucose
• Calcium

Topics

• Animals
• Benzamides (pharmacology)
• Calcium (metabolism)
• Cell Movement (drug effects)
• Cell Proliferation (drug effects)
• Collagen Type I (metabolism)
• Collagen Type III (metabolism)
• Cyclohexylamines (pharmacology)
• Diabetes Mellitus, Type 1 (chemically induced, metabolism, pathology)
• Diabetic Cardiomyopathies (chemically induced, metabolism, pathology)
• Fibroblasts (drug effects, metabolism)
• Fibrosis (drug therapy, metabolism)
• Glucose (metabolism)
• Heart
• Male
• Matrix Metalloproteinase 2 (metabolism)
• Matrix Metalloproteinase 9 (metabolism)
• Models, Animal
• Myocardium (metabolism, pathology)
• Primary Cell Culture
• Proteasome Endopeptidase Complex (metabolism)
• Rats
• Rats, Wistar
• Receptors, Calcium-Sensing (antagonists & inhibitors)
• Signal Transduction
• Smad2 Protein (metabolism)
• Smad3 Protein (metabolism)
• Smad7 Protein (metabolism)
• Transforming Growth Factor beta1 (metabolism)
• Ubiquitin-Protein Ligases (metabolism)
• Ubiquitins (metabolism)