Abstract MP241: Roflumilast-mediated Phosphodiesterase 4d Inhibition Reverses Diabetes-associated Cardiac Dysfunction And Remodeling: Effects Beyond Glucose Lowering

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Rui Xu ◽  
Jing Fu ◽  
Qin Fu

Introduction: Patients with type 2 diabetes (T2DM) have a substantial risk of developing cardiovascular disease. Our recent studies reveal that hyperinsulinemia attenuates cardiac contractility by inducing expression of phosphodiesterase 4D (PDE4D) that increases cAMP degradation. Furthermore, there is growing evidence that PDE4 dysregulation is of pathophysiological importance in metabolic disorders. Hypothesis: We propose that inhibition of PDE4D might ameliorate diabetes-associated cardiac dysfunction, in addition to lowering glucose. Methods: Male C57BL/6J mice fed with high-fat diet (HFD) were treated with PDE4 inhibitor roflumilast (currently used to treat chronic obstructive pulmonary disease, COPD). Myocardial structure, contractile function and remodeling were evaluated. For mechanistic studies, specific silencing of cardiac PDE4D and overexpression of miR-1 were administrated in mice undergoing high-fat feeding. These studies were complemented by in vitro analysis in primary cultured rat cardiomyocytes and cardiac fibroblasts. Results: Mice on HFD developed greater body weight compared to normal chow diet-fed mice, manifesting hyperglycemia, hyperinsulinemia, cardiac contractile dysfunction and remodeling, and cardiac PDE4D5 upregulation by 24 weeks. The expression of PDE4D5 was also elevated in human hearts with diabetes. In comparison with vehicle-treated HFD controls, PDE4 inhibitor roflumilast (1mg/kg/day) can prevent and even reverse hyperglycemia and cardiac dysfunction, accompanied by the decrease of cardiac PDE4D expression. In addition, cardiac miR-1 level was reduced in HFD mice, which was restored by PDE4 inhibitor roflumilast treatment. Either cardiac specific PDE4D5 knockdown or miR-1 overexpression significantly reversed cardiac dysfunction in HFD-mice, despite persistence of hyperglycemia and glucose intolerance. Gain- and loss-of-function studies of PDE4D in cardiomyocytes implicated that suppression of PDE4D protected cardiac hypertrophy via SERCA2a-mediated miR-1 restoration. Moreover, inhibition of PDE4D prevented insulin-activated TGF-β1 signaling which promotes miR-1 reduction in cardiac fibroblasts and subsequent fibrosis. Conclusions: These studies elucidate a novel mechanism by which PDE4D contributes to HFD-induced heart failure through reducing miR-1 expression in both cardiomyocytes and cardiac fibroblasts and suggest a therapeutic potential of PDE4 inhibitor roflumilast in preventing or treating cardiac dysfunction associated with diabetes.

2018 ◽  
Author(s):  
Sophie Deckx ◽  
Daniel M. Johnson ◽  
Marieke Rienks ◽  
Paolo Carai ◽  
Elza van Deel ◽  
...  

Secreted protein acidic and rich in cysteine (SPARC) is a non-structural extracellular matrix protein that regulates interactions between the matrix and neighboring cells. In the cardiovascular system, it is expressed by cardiac fibroblasts, endothelial cells, and in lower levels by ventricular cardiomyocytes. SPARC expression levels are increased upon myocardial injury and also during hypertrophy and fibrosis. We have previously shown that SPARC improves cardiac function after myocardial infarction by regulating post-synthetic procollagen processing, however whether SPARC directly affects cardiomyocyte contraction is still unknown. In this study we demonstrate a novel inotropic function for extracellular SPARC in the healthy heart as well as in the diseased state after myocarditis-induced cardiac dysfunction. We demonstrate SPARC presence on the cardiomyocyte membrane where it is co-localized with the integrin-beta1 and the integrin-linked kinase. Moreover, extracellular SPARC directly improves cardiomyocyte cell shortening ex vivo and cardiac function in vivo, both in healthy myocardium and during coxsackie virus-induced cardiac dysfunction. In conclusion, we demonstrate a novel inotropic function for SPARC in the heart, with a potential therapeutic application when myocyte contractile function is diminished such as that caused by a myocarditis-related cardiac injury.


Author(s):  
Ian C Smith ◽  
Curtis Ostertag ◽  
Jennifer J O'Reilly ◽  
Jaqueline Lourdes Rios ◽  
Teja Klancic ◽  
...  

Obesity is a worldwide health concern associated with impaired physical function. It is not clear if contractile protein dysfunction contributes to the impairment of muscle function observed with obesity. The purpose of this study was to examine if diet-induced obesity affects contractile function of chemically permeabilized vastus intermedius fibres of male Sprague Dawley rats expressing fast myosin heavy chain (MHC) IIa or slow MHC I. Rats consumed either a high-fat, high-sucrose (HFHS) diet or a standard (CHOW) diet beginning as either weanlings (7-week duration: WEAN7 cohort, or 14-week duration: WEAN14 cohort) or young adults (12-week duration: ADULT12 cohort, 24-week duration: ADULT24 cohort). HFHS-fed rats had higher (P<0.05) whole-body adiposity (derived from dual-energy X-ray absorptiometry) than CHOW-fed rats in all cohorts. Relative to CHOW diet groups, the HFHS diet was associated with impaired force production in a) MHC I fibres in the ADULT24 cohort, and b) MHC IIa fibres in the ADULT12 and ADULT24 cohorts combined. However, the HFHS diet did not significantly affect the Ca2+-sensitivity of force production, unloaded shortening velocity, or ratio of active force to active stiffness in any cohort. We conclude that diet-induced obesity can impair force output of permeabilized muscle fibres of adult rats. Novelty Bullets: • We assessed contractile function of permeabilized skeletal muscle fibres in a rat model of diet-induced obesity. • The high-fat, high-sucrose diet was associated with impaired force output of fibres expressing MHC I or MHC IIa in some cohorts of rats. • Other measures of contractile function were not significantly affected by diet.


PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255976
Author(s):  
Sanzio Dimai ◽  
Lukas Semmler ◽  
Ashok Prabhu ◽  
Harald Stachelscheid ◽  
Judith Huettemeister ◽  
...  

Background Cardiac injury associated with cytokine release frequently occurs in SARS-CoV-2 mediated coronavirus disease (COVID19) and mortality is particularly high in these patients. The mechanistic role of the COVID19 associated cytokine-storm for the concomitant cardiac dysfunction and associated arrhythmias is unclear. Moreover, the role of anti-inflammatory therapy to mitigate cardiac dysfunction remains elusive. Aims and methods We investigated the effects of COVID19-associated inflammatory response on cardiac cellular function as well as its cardiac arrhythmogenic potential in rat and induced pluripotent stem cell derived cardiomyocytes (iPS-CM). In addition, we evaluated the therapeutic potential of the IL-1β antagonist Canakinumab using state of the art in-vitro confocal and ratiometric high-throughput microscopy. Results Isolated rat ventricular cardiomyocytes were exposed to control or COVID19 serum from intensive care unit (ICU) patients with severe ARDS and impaired cardiac function (LVEF 41±5%; 1/3 of patients on veno-venous extracorporeal membrane oxygenation; CK 154±43 U/l). Rat cardiomyocytes showed an early increase of myofilament sensitivity, a decrease of Ca2+ transient amplitudes and altered baseline [Ca2+] upon exposure to patient serum. In addition, we used iPS-CM to explore the long-term effect of patient serum on cardiac electrical and mechanical function. In iPS-CM, spontaneous Ca2+ release events were more likely to occur upon incubation with COVID19 serum and nuclear as well as cytosolic Ca2+ release were altered. Co-incubation with Canakinumab had no effect on pro-arrhythmogenic Ca2+ release or Ca2+ signaling during excitation-contraction coupling, nor significantly influenced cellular automaticity. Conclusion Serum derived from COVID19 patients exerts acute cardio-depressant and chronic pro-arrhythmogenic effects in rat and iPS-derived cardiomyocytes. Canakinumab had no beneficial effect on cellular Ca2+ signaling during excitation-contraction coupling. The presented method utilizing iPS-CM and in-vitro Ca2+ imaging might serve as a novel tool for precision medicine. It allows to investigate cytokine related cardiac dysfunction and pharmacological approaches useful therein.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Yang K Xiang

Accumulating evidence suggests that hyperinsulinemia contributes to heart dysfunction. Here we show that insulin signaling is responsible for high fat diet (HFD) feeding-induced expression of phosphodiesterase 4D (PDE4D) in the myocardium of mice. The increased expression of PDE4D, in concert with reduced phosphorylation of phospholamban (PLB), promotes systolic and diastolic heart dysfunction. We revealed that insulin-mediated induction of PDE4D was dependent on β2AR-mediaed β-arrestin2-ERK pathway, which is transactivated in a GRK2-dependent fashion. Deletion of β2AR gene significantly attenuated insulin-induced phosphorylation of extracellular signal-regulated kinase (ERK) and Akt, as well as the upregulation of PDE4D expression, which prevented the heart dysfunction. β-arrestin2 KO mice did not display increased PDE4D expression and did not develop systolic or diastolic dysfunction following HFD. In brief, these data indicate that chronic hyperinsulinimia leads to heart dysfunction by increasing PDE4D expression via β2AR-GRK2-β-arrestin2 -ERK pathway, which suggests that β2AR signaling could be an attractive therapeutic target for preserving or improving cardiac function in subjects with insulin resistance.


2021 ◽  
Vol 12 ◽  
Author(s):  
Wan Xu ◽  
Jingjing Zhang ◽  
Jing Xiao

Obesity and related disorders have increasingly become global health problems over the years. In recent years, obesity has been recognized as the most important risk factor for a variety of diseases including cardiovascular diseases, type 2 diabetes, steatohepatitis, and cancer. The medical anti-obesity treatment is to intervene in the metabolic process of adipocytes by suppressing adipogenesis and promoting lipolysis. The Phosphodiesterase-4 (PDE4) pathway is involved in fat mass control and metabolic regulation. The present study aimed to investigate the effects of Roflumilast, a selective PDE4 inhibitor, on the differentiation of 3T3-L1 cells and the high fat diet-induced obesity in mice. We showed that treatment with Roflumilast inhibited lipid accumulation and triglycerides storage in mature 3T3-L1 cells, suggesting that Roflumilast suppressed adipogenesis. Mechanistically, we found that Roflumilast decreased the differentiation-induced expression of the adipogenesis genes including SREBP1C, FABP4, and Glut4, as well as their regulators including PPAR-γ and C/EBPα. Moreover, we proved that the effect of Roflumilast was dependent on the activation of the metabolic regulator AMPKα. The treatment with Roflumilast remarkably decreased the animals’ body weight, visceral adipose tissue weight, and adipocyte size in high fat diet-induced obese mice. In conclusion, our study revealed that Roflumilast suppressed adipogenesis and promoted lipolysis in cell culture and mice models via AMPK-mediated inhibition of PPAR-γ and C/EBPα. These findings imply roflumilast could have therapeutic potential in obesity-related diseases.


2019 ◽  
Vol 72 (8) ◽  
pp. 1491-1493
Author(s):  
Viktor P. Boriak ◽  
Svitlana V. Shut’ ◽  
Tetiana A. Trybrat ◽  
Olena V. Filatova

Introduction: In recent years, COPD is observed as not an isolated, but an associated pathology, in particular, concurrent with metabolic syndrome. The aim of the research is to identify the differences in changes of the rheopulmonography parameters (RPG) depending on the presence of hypertrophy or atrophy of the right ventricular myocardium in patients with COPD concurrent with metabolic syndrome.. Materials and methods: We studied changes in rheopulmonography (RPG) in 145 patients with chronic obstructive pulmonary disease (COPD) concurrent with metabolic syndrome. Results: We detected precapillary hypertension of the pulmonary circulation in patients with right ventricular myocardial hypertrophy: anacrotism serration; flattened peak of the systolic wave; decreased Vcp; high placement of incisura; horizontal course of catacrotism; decreased amplitude of the systolic wave (in this case, due to a greater increase in the resistance of the blood flow in the pulmonary vessels than the decreased impact volume of the right ventricle); prolonged Q-a (in this group of patients, it depends more on hypertension of the pulmonary circulation than on the reduction of contractile function of the myocardium). In atrophy of the right ventricular myocardium, the following changes in the RPG were revealed: decreased systolic wave at its dramatic rise; prolonged Q-a (in this case, due to the weakened heart contraction); Vmax reduction (it reflects the reduction of myocardial contractility); in hypertrophy of the myocardium, Vcp., unlike RPG, does not decrease, which is explained by the decrease in the pressure of the pulmonary circulation. Conclusions: We believe that these changes in RPG allow differentiating hypertrophy and right ventricular myocardial atrophy along with established diagnostic criteria, and can be used as markers for the diagnosis and treatment of COPD concurrent with metabolic syndrome.


2021 ◽  
pp. 153537022110060
Author(s):  
Yue Chen ◽  
Jie Ding ◽  
Yufei Zhao ◽  
Shenghong Ju ◽  
Hui Mao ◽  
...  

This study aimed to track and evaluate the effect of low-dose irisin on the browning of white adipose tissue (WAT) in mice using magnetic resonance imaging (MRI) noninvasively in vivo. Mature white adipocytes extracted from mice were cultured, induced and characterized before being treated by irisin. The volume and fat fraction of WAT were quantified using MRI in normal chow diet and high fat mice after injection of irisin. The browning of cultured white adipocytes and WAT in mice were validated by immunohistochemistry and western blotting for uncoupling protein 1 (UCP1) and deiodinase type II (DIO2). The serum indexes were examined with high fat diet after irisin intervention. UCP1 and DIO2 in adipocytes showed increases responding to the irisin treatment. The size of white adipocytes in mice receiving irisin intervention was reduced. MRI measured volumes and fat fraction of WAT were significantly lower after Irisin treatment. Blood glucose and cholesterol levels were reduced in high fat diet mice after irisin treatment. Irisin intervention exerted browning of WAT, resulting reduction of volume and fat fraction of WAT as measured by MRI. Furthermore, it improved the condition of mice with diet-induced obesity and related metabolic disorders.


Author(s):  
P. Comeglio ◽  
E. Sarchielli ◽  
S. Filippi ◽  
I. Cellai ◽  
G. Guarnieri ◽  
...  

Abstract Purpose Low free testosterone (T) level in men is independently associated with presence and severity of Non-Alcoholic Steatohepatitis (NASH). The histological and molecular effects of oral testosterone prodrug LPCN 1144 treatment on hepatic fibrosis and NASH features are unknown. A metabolic syndrome-induced NASH model in rabbits consuming high fat diet (HFD) has been previously used to assess treatment effects of injectable T on hepatic fibrosis and NASH features. Here we present results on LPCN 1144 in this HFD-induced, NASH preclinical model. Methods Male rabbits were randomly assigned to five groups: regular diet (RD), HFD, HFD + 1144 vehicle (HFD + Veh), HFD + 1144 (1144), and HFD + 1144 + α-tocopherol (1144 + ALPHA). Rabbits were sacrificed after 12 weeks for liver histological, biochemical and genetic analyses. Histological scores were obtained through Giemsa (inflammation), Masson’s trichrome (steatosis and ballooning), and Picrosirius Red (fibrosis) staining. Results Compared to RD, HFD and HFD + Veh significantly worsened NASH features and hepatic fibrosis. Considering HFD and HFD + Veh arms, histological and biomarker features were not significantly different. Both 1144 and 1144 + ALPHA arms improved mean histological scores of NASH as compared to HFD arm. Importantly, percentage of fibrosis was improved in both 1144 (p < 0.05) and 1144 + ALPHA (p = 0.05) treatment arms vs. HFD. Both treatment arms also reduced HFD-induced inflammation and fibrosis mRNA markers. Furthermore, 1144 treatments significantly improved HFD-induced metabolic dysfunctions. Conclusions Histological and biomarker analyses demonstrate that LPCN 1144 improved HFD-induced hepatic fibrosis and NASH biochemical, biomolecular and histochemical features. These preclinical findings support a therapeutic potential of LPCN 1144 in the treatment of NASH and of hepatic fibrosis.


2021 ◽  
Vol 22 (10) ◽  
pp. 5390
Author(s):  
Qianhui Zeng ◽  
Nannan Wang ◽  
Yaru Zhang ◽  
Yuxuan Yang ◽  
Shuangshuang Li ◽  
...  

Obesity-induced adipose tissue dysfunction and disorders of glycolipid metabolism have become a worldwide research priority. Zfp217 plays a crucial role in adipogenesis of 3T3-L1 preadipocytes, but about its functions in animal models are not yet clear. To explore the role of Zfp217 in high-fat diet (HFD)-induced obese mice, global Zfp217 heterozygous knockout (Zfp217+/−) mice were constructed. Zfp217+/− mice and Zfp217+/+ mice fed a normal chow diet (NC) did not differ significantly in weight gain, percent body fat mass, glucose tolerance, or insulin sensitivity. When challenged with HFD, Zfp217+/− mice had less weight gain than Zfp217+/+ mice. Histological observations revealed that Zfp217+/− mice fed a high-fat diet had much smaller white adipocytes in inguinal white adipose tissue (iWAT). Zfp217+/− mice had improved metabolic profiles, including improved glucose tolerance, enhanced insulin sensitivity, and increased energy expenditure compared to the Zfp217+/+ mice under HFD. We found that adipogenesis-related genes were increased and metabolic thermogenesis-related genes were decreased in the iWAT of HFD-fed Zfp217+/+ mice compared to Zfp217+/− mice. In addition, adipogenesis was markedly reduced in mouse embryonic fibroblasts (MEFs) from Zfp217-deleted mice. Together, these data indicate that Zfp217 is a regulator of energy metabolism and it is likely to provide novel insight into treatment for obesity.


Sign in / Sign up

Export Citation Format

Share Document