Mitochondrial Uncoupling: A Key Contributor to Reduced Cardiac Efficiency in Diabetes

Physiology ◽  
2006 ◽  
Vol 21 (4) ◽  
pp. 250-258 ◽  
Author(s):  
Sihem Boudina ◽  
E. Dale Abel
Keyword(s):  
Cardiac Dysfunction ◽  
Myocardial Oxygen Consumption ◽  
Potential Role ◽  
Cardiac Metabolism ◽  
Acid Oxidation ◽  
Cardiac Efficiency ◽  
Mitochondrial Uncoupling ◽  
Obesity And Diabetes ◽  
Underlying Mechanisms

Cardiovascular disease is the primary cause of death in individuals with obesity and diabetes. However, the underlying mechanisms for cardiac dysfunction are partially understood. Studies have suggested that altered cardiac metabolism may play a role. The diabetic heart is characterized by increased fatty acid oxidation, increased myocardial oxygen consumption, and reduced cardiac efficiency. Here, we review possible mechanisms for reduced cardiac efficiency in obesity and diabetes by focusing on the potential role of mitochondrial uncoupling.

The role of Akkermansia muciniphila in obesity, diabetes and atherosclerosis

2021 ◽  
Vol 70 (10) ◽  
Author(s):  
Alka Hasani ◽  
Saba Ebrahimzadeh ◽  
Fatemeh Hemmati ◽  
Aytak Khabbaz ◽  
Akbar Hasani ◽  
...  
Keyword(s):  
Type Species ◽  
Anaerobic Bacteria ◽  
Regulatory System ◽  
Content Type ◽  
Akkermansia Muciniphila ◽  
Link Type ◽  
Animal Trials ◽  
Obesity And Diabetes ◽  
Underlying Mechanisms

Alteration in the composition of the gut microbiota can lead to a number of chronic clinical diseases. Akkermansia muciniphila is an anaerobic bacteria constituting 3–5% of the gut microbial community in healthy adults. This bacterium is responsible for degenerating mucin in the gut; its scarcity leads to diverse clinical disorders. In this review, we focus on the role of A. muciniphila in diabetes, obesity and atherosclerosis, as well as the use of this bacterium as a next-generation probiotic. In regard to obesity and diabetes, human and animal trials have shown that A. muciniphila controls the essential regulatory system of glucose and energy metabolism. However, the underlying mechanisms by which A. muciniphila alleviates the complications of obesity, diabetes and atherosclerosis are unclear. At the same time, its abundance suggests improved metabolic disorders, such as metabolic endotoxemia, adiposity insulin resistance and glucose tolerance. The role of A. muciniphila is implicated in declining aortic lesions and atherosclerosis. Well-characterized virulence factors, antigens and cell wall extracts of A. muciniphila may act as effector molecules in these diseases. These molecules may provide novel mechanisms and strategies by which this bacterium could be used as a probiotic for the treatment of obesity, diabetes and atherosclerosis.

Abstract 87: Loss of Mir-155 Attenuates Sepsis Induced Cardiac Dysfunction

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Hui Wang ◽  
Yihua Bei ◽  
Jing Shi ◽  
Wei Sun ◽  
Peipei Huang ◽  
...  
Keyword(s):  
Cardiac Dysfunction ◽  
Foam Cell ◽  
Cardiac Metabolism ◽  
Significant Inhibition ◽  
Gene Expressions ◽  
Over Expression ◽  
Pathological Cardiac Hypertrophy ◽  
Lps Treatment ◽  
Fractional Shortening

Objective: Sepsis induced cardiac dysfunction is featured by inflammation and metabolic repression. miR-155 is a typical multifunctional miRNA and loss of miR-155 has been shown to protect the heart from pathological cardiac hypertrophy while increased miR-155 could promote the formation of foam cell in atherogenesis. However, the role of miR-155 in sepsis induced cardiac dysfunction is unclear. Methods: E.coli lipopolysaccharide (LPS) (5mg/kg) was administered to C57BL/6 mice to create a sepsis-induced cardiac dysfunction model. Cardiac function was assessed by echocardiography 5-6 h post-LPS administration. Heart tissues were collected within 7-9 h after LPS treatment for the analysis of gene expressions. Tail vein injection of miR-155 antagomir (80mg/kg/d) or miR-155 agomirs (30mg/kg/d) for 3 consecutive days were used to decrease or increase miR-155 expressions in heart. Results: LPS induced a reduction of 15% in fractional shortening (%FS) and 25% in ejection fraction (%EF). Expression of miR-155 was increased by 2 fold in sepsis-induced cardiac dysfunction mouse model. Over-expression of miR-155 agomirs led to a decrease of 5% in FS and 10% in EF as compared to scramble controls. Aggravation of LPS induced cardiac dysfunction by miR-155 agomir was not associated with alteration in inflammation or cardiac metabolism. However, miR-155 agomir increased LPS- induced myocardium apoptosis and also elevated the ratio of Bax/Bcl-2 at the protein level. Intravenous injection of cholesterol-modified antisense oligonucleorides antagomirs of miR-155 markedly rescued the LPS induced heart failure and apoptosis. Western bloting indicated that miR-155 overexpression in vivo led to a significant inhibition of Pea15a while miR-155 knock-down caused a significant upregulation of Pea15a, indicating that Pea15a was a potential target gene of miR-155. Interestingly, plasma miR-155 levels were also found to be significantly increased in critically ill patients with sepsis compared to healthy controls. Conclusion: This study demonstrates that miR-155 regulates sepsis induced cardiac dysfunction and Pea15a is a potential targer gene of miR-155. Loss of miR-155 represents a novel therapeutic method for sepsis induced cardiac dysfunction

scholarly journals Emerging impact of the long noncoding RNA MIR22HG on proliferation and apoptosis in multiple human cancers

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Le Zhang ◽  
Cuixia Li ◽  
Xiulan Su
Keyword(s):  
Chromatin Remodeling ◽  
Noncoding Rna ◽  
Potential Role ◽  
Immune Escape ◽  
Prognostic Biomarker ◽  
Cellular Processes ◽  
Proliferation And Apoptosis ◽  
Underlying Mechanisms ◽  
Competitive Endogenous Rna

AbstractAn increasing number of studies have shown that long noncoding RNAs (lncRNAs) play important roles in diverse cellular processes, including proliferation, apoptosis, migration, invasion, chromatin remodeling, metabolism and immune escape. Clinically, the expression of MIR22HG is increased in many human tumors (colorectal cancer, gastric cancer, hepatocellular carcinoma, lung cancer, and thyroid carcinoma), while in others (esophageal adenocarcinoma and glioblastoma), it is significantly decreased. Moreover, MIR22HG has been reported to function as a competitive endogenous RNA (ceRNA), be involved in signaling pathways, interact with proteins and interplay with miRNAs as a host gene to participate in tumorigenesis and tumor progression. In this review, we describe the biological functions of MIR22HG, reveal its underlying mechanisms for cancer regulation, and highlight the potential role of MIR22HG as a novel cancer prognostic biomarker and therapeutic target that can increase the efficacy of immunotherapy and targeted therapy for cancer treatment.

scholarly journals Computational Approaches to Understanding the Role of Fibroblast-Myocyte Interactions in Cardiac Arrhythmogenesis

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Tashalee R. Brown ◽  
Trine Krogh-Madsen ◽  
David J. Christini
Keyword(s):  
Gap Junctions ◽  
Potential Role ◽  
Cardiac Tissue ◽  
Cardiac Fibroblasts ◽  
Cardiac Arrhythmogenesis ◽  
Voltage Dependent ◽  
Underlying Mechanisms ◽  
Slow Propagation

The adult heart is composed of a dense network of cardiomyocytes surrounded by nonmyocytes, the most abundant of which are cardiac fibroblasts. Several cardiac diseases, such as myocardial infarction or dilated cardiomyopathy, are associated with an increased density of fibroblasts, that is, fibrosis. Fibroblasts play a significant role in the development of electrical and mechanical dysfunction of the heart; however the underlying mechanisms are only partially understood. One widely studied mechanism suggests that fibroblasts produce excess extracellular matrix, resulting in collagenous septa. These collagenous septa slow propagation, cause zig-zag conduction paths, and decouple cardiomyocytes resulting in a substrate for arrhythmia. Another emerging mechanism suggests that fibroblasts promote arrhythmogenesis through direct electrical interactions with cardiomyocytes via gap junctions. Due to the challenges of investigating fibroblast-myocyte coupling in native cardiac tissue, computational modeling andin vitroexperiments have facilitated the investigation into the mechanisms underlying fibroblast-mediated changes in cardiomyocyte action potential morphology, conduction velocity, spontaneous excitability, and vulnerability to reentry. In this paper, we summarize the major findings of the existing computational studies investigating the implications of fibroblast-myocyte interactions in the normal and diseased heart. We then present investigations from our group into the potential role of voltage-dependent gap junctions in fibroblast-myocyte interactions.

scholarly journals Kidney osteoclast factors and matrix metalloproteinase expression in a mice model of diet-induced obesity and diabetes

2019 ◽  
Author(s):  
Francine dos Santos-Macedo ◽  
Bianca Martins-Gregorio ◽  
Elan Cardozo Paes-de-Almeida ◽  
Leonardo de Souza Mendonça ◽  
Rebeca de Souza Azevedo ◽  
...  
Keyword(s):  
Inflammatory Cell ◽  
Renal Tissue ◽  
Inflammatory Cell Infiltrate ◽  
Mice Model ◽  
Diet Induced Obesity ◽  
Obesity And Diabetes ◽  
Underlying Mechanisms ◽  
Mononuclear Inflammatory Cell ◽  
High Sucrose

ABSTRACTThe role of RANKL/RANK/OPG system on bone remodeling is well known, and there is evidence that it is also important to cardiovascular and kidney pathology, although the underlying mechanisms are not elucidated so far. Thus, we investigated in a mice model of diet-induced obesity and diabetes if renal histopathological changes are associated with the expression of RANKL/RANK/OPG system and matrix metalloproteinases (MMPs). Three months old C57BL/6 mice were fed with control (AIN93M) or high-fat high sucrose (HFHS) diets for 21 weeks (CEUA/UFF #647/15). The HFHS group showed weight gain (+35%, P=0.0001), increased epididymal, inguinal and retroperitoneal fat pad weight (+121 %, P = 0.0006; +287 %, P = 0.0007 and; +286 %, P < 0.0001, respectively), and hyperglycemia (+43%, P=0.02). The kidney of some HFHS fed mice displayed mononuclear inflammatory cell infiltrate (40%), perivascular fibrosis (20%), and focal tubule mineralization (20%). Glomeruli hypertrophy was not detected. Unexpectedly, OPG, RANK, MMP-2 and MMP-9 expression was not altered in HFHS groups (Western blot analysis). In conclusion, the expression of RANKL/RANK/OPG system proteins and MMPs was not influenced by diet-induced obesity and diabetes in the kidney of male C57BL/6 mice, although some adverse histopathological remodeling is noticed in the renal tissue.

Interleukin-17A in Alzheimer’s disease: recent advances and controversies

2021 ◽  
Vol 19 ◽  
Author(s):  
Xin-Zhu Yan ◽  
Laijun Lai ◽  
Qiang Ao ◽  
Xiao-hong Tian ◽  
Yan-hui Zhang
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
Potential Role ◽  
Global Burden ◽  
Future Studies ◽  
The Past ◽  
Interleukin 17A ◽  
Underlying Mechanisms

: Alzheimer’s disease (AD) is a progressive neurodegenerative disease which mainly affects older adults. Although the global burden of AD is increasing year by year, the causes of AD remain largely unknown. Numerous basic and clinical studies have shown that interleukin-17A (IL-17A) may play a significant role in the pathogenesis of AD. A comprehensive assessment ofthe role of IL-17A in AD would benefit the diagnosis, understanding of etiology and treatment. However, over the past decade controversies remain regarding the expression level and role of IL-17A in AD. We have incorporated newly published researches and point out that IL-17A expression levels may vary along with the development of AD, exercising different roles at different stages of AD, although much more work remains to be done to support the potential role of IL-17A in AD-related pathology.Here, it is our intention to review the underlying mechanisms of IL-17A in AD and address the current controversies, in an effort to clarify the results of existing research and suggest future studies.

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