ABSTRACT
We explored the involvement of orphan nuclear receptor 4 A1 (NR4A1) in myocardial fibrosis mediated by transforming growth factor-beta1 (TGF-ß1) and its response to cytosporone B (Csn-B). We developed a diabetic cardiomyopathy mouse model by administering a high-fat diet in conjunction with a low-dose streptozotocin injection. Our analysis involved monitoring alterations in blood glucose and lipid levels, cardiac function and structure, as well as profibrotic factors such as α smooth muscle actin (α-SMA), collagen I, collagen III, TGF-ß1, connective tissue growth factor, and fibronectin. These assessments were conducted using biochemical techniques, Doppler ultrasound, histopathology, and real-time quantitative polymerase chain reaction. Cardiac fibroblasts (CFs) were extracted from suckling mice and cultivated in a high-glucose medium to simulate diabetes-induced myocardial fibrosis in vitro. These CFs were then subjected to coculture experiments with TGF-ß1 or Csn-B. The proliferation and migration of CFs were assessed using cell counting kit 8 (CCK-8) assays and Transwell assays, respectively. Western blotting and immunofluorescence assays were employed to evaluate the expression levels of NR4A1, p-NR4A1, and α-SMA in CFs treated with TGF-ß1 after NR4A1 knockdown or Csn-B administration, respectively. In diabetic heart tissue, the expression of p-NR4A1 was notably elevated. Furthermore, CFs exhibited enhanced proliferative capabilities and increased p-NR4A1 expression following high glucose exposure. Interestingly, NR4A1 knockdown resulted in a significant increase in the expression of fibrosis-related proteins in CFs following treatment with TGF-ß1. Moreover, our observations revealed a marked decrease in p-NR4A1 levels and a reduction in the expression of fibrosis-related proteins after Csn-B treatment. In diabetic mice treated with Csn-B, we noted diminished NR4A1 phosphorylation and a mitigation of myocardial fibrosis. We concluded that in the mouse model, Csn-B played a pivotal role in inhibiting diabetes-induced myocardial fibrosis by activating NR4A1.
Subject(s)
Diabetes Mellitus, Experimental , Phenylacetates , Transforming Growth Factor beta1 , Animals , Mice , Collagen/metabolism , Diabetes Mellitus, Experimental/metabolism , Disease Models, Animal , Fibroblasts/metabolism , Fibrosis , Glucose/metabolism , Orphan Nuclear Receptors/metabolismABSTRACT
The effects of tetrandrine (TET) on the contractile responses of rat aortic rings and perfused rat mesenteric arteries to phenylephrine (PE) were investigated. TET inhibited the maximal contraction to PE in a concentration-dependent manner. TET significantly inhibited the transient contraction in Ca(2+)-free medium presumably due to release of intracellular Ca2+ after activation of alpha 1-adrenoceptors. However, it caused a stronger inhibition of the sustained contraction in Ca(2+)-containing medium presumably the result of Ca2+ influx. TET has no inhibitory effect on caffeine-induced transient contraction. Radioligand receptor binding study using isolated dog aortic muscle membranes indicated that TET inhibited the binding of 3H-prazosin in a competitive manner, hence showing that TET interacted directly with the alpha 1-adrenoceptors. Thus, TET affected PE-induced aortic contractions by multiple mechanisms, inhibiting interaction of PE with alpha 1-adrenoceptors and interfering with PE-induced responses involving both Ca2+ entry and release.
Subject(s)
Alkaloids/pharmacology , Benzylisoquinolines , Calcium Channel Blockers/pharmacology , Drugs, Chinese Herbal , Muscle, Smooth, Vascular/drug effects , Receptors, Adrenergic, alpha-1/drug effects , Animals , Aorta/drug effects , Aorta/metabolism , Aorta/physiology , Culture Media , Dogs , In Vitro Techniques , Male , Muscle Contraction/drug effects , Muscle, Smooth, Vascular/metabolism , Muscle, Smooth, Vascular/physiology , Phenylephrine/antagonists & inhibitors , Phenylephrine/pharmacology , Prazosin/antagonists & inhibitors , Prazosin/metabolism , Protein Binding , Radioligand Assay , Rats , Rats, Sprague-Dawley , Receptors, Adrenergic, alpha-1/metabolismABSTRACT
PIP: It was found from experiments in animals that HFMC hydrogel compound injected into the vas-deferens becomes a hydrogen molecule-releasing sediment, which changes the PH balance inside the vas deferens and can kill the sperm and achieve contraception. HFMC hydrogel can either dissolve in time or through an injection of DMSO solution, and fertility will resume subsequently. For the purpose of further developing HFMC hydrogel into a safe and effective contraceptive method, biological compatibility tests were conducted on mice, rats, and rabbits in the Occupation Disease Research Institute, Sichuan Province, China. No deaths or abnormal effects were found in toxicological tests, which suggested that the in vivo and in vitro administration of HFMC hydrogel is safe; the cell growth was found to be associated with the concentration of the compound. Injection of the compound caused local skin irritation without affecting the blood cell count. The skin irritation gradually recovered as the compound dissolved. The pathological observations on rats and rabbits showed no abnormal changes in the reproductive organs, and no damage of vas deferens was observed from micrography and electron micrography. The micronucleus rate of the polychromatic erythrocyte in the bone marrow of mice was not increased. The results of the investigation showed that HFMC hydrogel is a possible male contraceptive method. No abnormality or mutation was induced during the observation period of the study. Further studies on chronic toxicological effects and secondary toxicological effects need to be done. Other methods for studying its safety should also be explored.^ieng
