scholarly journals Cardiac MyD88 Mediates Inflammatory Injury and Adverse Remodeling in Diabetes

Author(s):  
Wu Luo ◽  
Gaojun Wu ◽  
Xiaojun Chen ◽  
Qiuyan Zhang ◽  
Chunpeng Zou ◽  
...  

Abstract Background: Hyperglycemia-associated inflammation contributes to adverse remodeling and fibrosis in diabetic heart. MyD88 is an adapter protein of many Toll-like receptors (TLRs) and is recruited to TLRs to initiate inflammatory signalling pathway in endotoxin-activated innate immunity. However, the role of MyD88 in diabetic cardiomyopathy is unknown. Methods: For genetic deficiency, cardiomyocyte-specific MyD88 knockout and littermate control mice were induced type 1 diabetes (T1D) by intraperitoneal injection of 50 mg/kg/day streptozotocin for five days consecutive and then fed for 4 moths. For pharmacological inhibition, MyD88 inhibitor LM8 were administered daily for 8 weeks by oral gavage in T1D and T2D (db/db) mice. The effect of genetic and pharmacological inhibition MyD88 to myocardial injure which were induced by 33 mM glucose in vivo.Results: In this study, we first found that MyD88 expression was increased in cardiomyocytes of diabetic mouse hearts. Cardiomyocyte-specific MyD88 knockout protected mice against hyperglycemia-induced cardiac inflammation, injury, hypertrophy, and fibrosis in T1D model. In cultured cardiomyocytes, MyD88 inhibition either by siRNA or by small-molecular inhibitor LM8 markedly blocked TLR4-MyD88 complex formation, reduced pro-inflammatory MAPKs/NF-κB cascade activation and decreased pro-inflammatory cytokine expression under high glucose condition. Moreover, pharmacologic inhibition of MyD88 by LM8 showed significantly anti-inflammatory, anti-hypertrophic and anti-fibrotic effects in the hearts of both T1D and T2D mice. These beneficial effects of MyD88 inhibition were correlated to the reduced activation of TLR4-MyD88-MAPKs/NF-κB signaling pathways in the hearts.Conclusion: Taken together, MyD88 in cardiomyocytes mediates diabetes-induced cardiac inflammatory injuries and genetic or pharmacologic inhibition of MyD88 shows significantly cardioprotective effects, indicating MyD88 as a potential therapeutic target for diabetic cardiomyopathy.

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Dezhong Wang ◽  
Yuan Yin ◽  
Shuyi Wang ◽  
Tianyang Zhao ◽  
Fanghua Gong ◽  
...  

AbstractAs a classically known mitogen, fibroblast growth factor 1 (FGF1) has been found to exert other pleiotropic functions such as metabolic regulation and myocardial protection. Here, we show that serum levels of FGF1 were decreased and positively correlated with fraction shortening in diabetic cardiomyopathy (DCM) patients, indicating that FGF1 is a potential therapeutic target for DCM. We found that treatment with a FGF1 variant (FGF1∆HBS) with reduced proliferative potency prevented diabetes-induced cardiac injury and remodeling and restored cardiac function. RNA-Seq results obtained from the cardiac tissues of db/db mice showed significant increase in the expression levels of anti-oxidative genes and decrease of Nur77 by FGF1∆HBS treatment. Both in vivo and in vitro studies indicate that FGF1∆HBS exerted these beneficial effects by markedly reducing mitochondrial fragmentation, reactive oxygen species (ROS) generation and cytochrome c leakage and enhancing mitochondrial respiration rate and β-oxidation in a 5’ AMP-activated protein kinase (AMPK)/Nur77-dependent manner, all of which were not observed in the AMPK null mice. The favorable metabolic activity and reduced proliferative properties of FGF1∆HBS testify to its promising potential for use in the treatment of DCM and other metabolic disorders.


2020 ◽  
Author(s):  
Pengbo Sun ◽  
Yipei Ding ◽  
Jingyi Luo ◽  
Jin Zhong ◽  
Weidong Xie

Abstract BackgroundLipotoxicity plays an important role in the development of diabetic cardiomyopathy and heart failure (HF). Canagliflozin (CAN), a marketed sodium-glucose co-transporter 2 inhibitor, has significant beneficial effects on HF. However, the potential pharmacological mechanism is still unknown.MethodsIn this study, we evaluated the protective effects and mechanism of CAN in the hearts of a C57BL/6J diabetic mouse model induced by a high-fat diet/streptozotocin (HFD/STZ) for 12 weeks in vivo and using HL-1 cells (a type of mouse cardiomyocyte line) induced by palmitic acid (PA) in vitro.ResultsCAN could significantly alleviate lipid accumulation and inflammatory responses in the hearts of the HFD/STZ-induced diabetic mice. Furthermore, CAN significantly attenuated the inflammatory injury induced by PA in the HL-1 cells. In addition, CAN bound to the mammalian target of rapamycin (mTOR) and significantly inhibited mTOR phosphorylation and hypoxia inducible factor-1α (HIF-1α) expression.ConclusionCAN attenuated lipotoxicity in cardiomyocytes and protected diabetic mouse hearts by targeting the mTOR/HIF-1α pathway.


2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Yan-Jun Song ◽  
Chong-Bin Zhong ◽  
Wei Wu

Diabetic cardiomyopathy (DCM) is a common cardiovascular complication of diabetic mellitus that is characterized by diastolic disorder in the early stage and clinical heart failure in the later stage. Presently, DCM is considered one of the major causes of death in diabetic patients. Resveratrol (RSV), a naturally occurring stilbene, is widely reported as a cardioprotective substance in many heart diseases. Thus far, the specific roles of RSV in DCM prevention and treatment have attracted great attention. Here, we discuss the roles of RSV in DCM by focusing its downstream targets from both in vivo and in vitro studies. Among such targets, Sirtuins 1/3 and AMP-activated kinase have been identified as key mediators that induce cardioprotection during hyperglycemia. In addition, many other signaling molecules (e.g., forkhead box-O3a and extracellular regulated protein kinases) are also regulated in the presence of RSV and exert beneficial effects such as opposing oxidative stress, inflammation, and apoptosis in cardiomyocytes exposed to high-glucose conditions. The beneficial potential of an RSV/stem cell cotherapy is also reviewed as a promising therapeutic strategy for preventing the development of DCM.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Anikó Posa ◽  
Renáta Szabó ◽  
Krisztina Kupai ◽  
Anikó Magyariné Berkó ◽  
Médea Veszelka ◽  
...  

Estrogens and raloxifene (RAL) have beneficial effects on certain cardiovascular indices in postmenopausal women characterized by estrogen deficiency. Heme oxygenase (HO) activity is increased by 17β-estradiol (E2) and RAL in estrogen-deficient rat resulting in vasorelaxation mediated by carbon monoxide. We determined the expressions of HO in cardiac and aortic tissues after ovariectomy (OVX) and subsequent RAL or E2treatment. We investigated the effects of pharmacological inhibition of HO enzyme on the arginine vasopressin- (AVP-) induced blood pressure in vivo, the epinephrine- and phentolamine-induced electrocardiogram ST segment changes in vivo, and the myeloperoxidase (MPO) enzyme activity. When compared with intact females, OVX decreased the HO-1 and HO-2 expression, aggravated the electrocardiogram signs of heart ischemia and the blood pressure response to AVP, and increased the cardiac MPO. E2and RAL are largely protected against these negative impacts induced by OVX. The pharmacological inhibition of HO in E2- or RAL-treated OVX animals, however, restored the cardiovascular status close to that observed in nontreated OVX animals. The decreased expression of HO enzymes and the changes in blood pressure ischemia susceptibility and inflammatory state in OVX rat can be reverted by the administration of E2or RAL partly through its antioxidant and anti-inflammatory roles.


Diabetes ◽  
1988 ◽  
Vol 37 (7) ◽  
pp. 936-942 ◽  
Author(s):  
N. Afzal ◽  
P. K. Ganguly ◽  
K. S. Dhalla ◽  
G. N. Pierce ◽  
P. K. Singal ◽  
...  

2018 ◽  
Vol 15 (6) ◽  
pp. 531-543 ◽  
Author(s):  
Dominik Szwajgier ◽  
Ewa Baranowska-Wojcik ◽  
Kamila Borowiec

Numerous authors have provided evidence regarding the beneficial effects of phenolic acids and their derivatives against Alzheimer's disease (AD). In this review, the role of phenolic acids as inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) is discussed, including the structure-activity relationship. In addition, the inhibitory effect of phenolic acids on the formation of amyloid β-peptide (Aβ) fibrils is presented. We also cover the in vitro, ex vivo, and in vivo studies concerning the prevention and treatment of the cognitive enhancement.


Author(s):  
Yuanyuan Wang ◽  
Shanqi Guo ◽  
Yingjie Jia ◽  
Xiaoyu Yu ◽  
Ruiyu Mou ◽  
...  

ABSTRACT Prostate cancer (PCa) is one of the important factors of cancer deaths especially in the western countries. Hispidulin (4′,5,7-trihydroxy-6-methoxyflavone) is a phenolic flavonoid compound proved to possess anticancer properties, but its effects on PCa are left to be released. The aims of this study were to investigate the effects and the relative mechanisms of Hispidulin on PCa development. Hispidulin administration inhibited proliferation, invasion, and migration, while accelerated apoptosis in Du145 and VCaP cells, which was accompanied by PPARγ activation and autophagy enhancement. The beneficial effects of Hispidulin could be diminished by PPARγ inhibition. Besides, Hispidulin administration suppressed PCa tumorigenicity in Xenograft models, indicating the anticancer properties in vivo. Therefore, our work revealed that the anticancer properties of Hispidulin might be conferred by its activation on PPARγ and autophagy.


Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2305
Author(s):  
Wan-Ju Yeh ◽  
Jung Ko ◽  
Wei-Yi Cheng ◽  
Hsin-Yi Yang

High blood pressure is a crucial risk factor for many cardiovascular diseases, and a diet rich in whole-grain foods may modulate blood pressure. This study investigated the effects of dehulled adlay consumption on blood pressure in vivo. We initially fed spontaneous hypertensive rats diets without (SHR group) or with 12 or 24% dehulled adlay (SHR + LA and SHR + HA groups), and discovered that it could limit blood pressure increases over a 12-week experimental period. Although we found no significant changes in plasma, heart, and kidney angiotensin-converting enzyme activities, both adlay-consuming groups had lower endothelin-1 and creatinine concentrations than the SHR group; the SHR + HA group also had lower aspartate aminotransferase and uric acid levels than the SHR group did. We later recruited 23 participants with overweight and obesity, and they consumed 60 g of dehulled adlay daily for a six-week experimental period. At the end of the study, we observed a significant decrease in the group’s systolic blood pressure (SBP), and the change in SBP was even more evident in participants with high baseline SBP. In conclusion, our results suggested that daily intake of dehulled adlay had beneficial effects in blood-pressure management. Future studies may further clarify the possible underlying mechanisms for the consuming of dehulled adlay as a beneficial dietary approach for people at risk of hypertension.


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