Cilostazol protects mice against myocardium ischemic/reperfusion injury by activating a PPARγ/JAK2/STAT3 pathway

Protective effect of cilostazol on vascular injury in rats with acute ischemic stroke complicated with chronic renal failure

Chronic renal failure (CRF) resulting in vascular calcification, which does damage to blood vessels and endothelium, is an independent risk factor for stroke. It has been reported that cilostazol has a protective effect on the focal cerebral ischemic infarct. However, its impact on vascular injury in CRF combined stroke and its molecular protection mechanism have not been investigated. In this study, we carried out the effect of cilostazol on CRF combined stroke rats, and the results confirmed that it improved the neurobehavior, renal function as well as pathologic changes in both the kidney and brain. In addition, the inflammation and oxidative stress factors in the kidney and brain were suppressed. Moreover, the rates of brain edema and infarction were decreased. The injured brain-blood barrier (BBB) was recovered with less Evans blue extravasation and more expressions of zonula occludens-1(ZO-1) and occludin. More cerebral blood flow (CBF) in the ipsilateral hemisphere and more expression of CD31 and vascular endothelial growth factor (VEGF) in brain and kidney were found in the cilostazol group. Furthermore, cell apoptosis and cell autophagy became less, on the contrary, proteins of vascular endothelial growth factor receptor 2 (VEGFR2) after the cilostazol treatment were increased. More importantly, this protective effect is related to the pathway of Janus Kinase (JAK)/signal transducer and activator of transcription 3 (STAT3), mammalian target of rapamycin (mTOR), and the hypoxia inducible factor-1α (HIF-1α). In conclusion, our results confirmed that cilostazol exerted a protective effect on the brain and kidney function, specifically in vascular injury, oxidative stress, cell apoptosis, cell autophagy, and inflammation response in CRF combined with stroke rats which were related to the upregulation of JAK/STAT3/mTOR signal pathway.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-023-00217-w.

Targeting the JAK2/STAT3 signaling pathway with natural plants and phytochemical ingredients: A novel therapeutic method for combatting cardiovascular diseases

The aim of this article is to introduce the roles and mechanisms of the JAK2/STAT3 pathway in various cardiovascular diseases, such as myocardial fibrosis, cardiac hypertrophy, atherosclerosis, myocardial infarction, and myocardial ischemiareperfusion. In addition, the effects of phytochemical ingredients and different natural plants, mainly traditional Chinese medicines, on the regulation of different cardiovascular diseases via the JAK2/STAT3 pathway are discussed. Surprisingly, the JAK2 pathway has dual roles in different cardiovascular diseases. Future research should focus on the dual regulatory effects of different phytochemical ingredients and natural plants on JAK2 to pave the way for their use in clinical trials.

The Role of Cilostazol, a Phosphodiesterase-3 Inhibitor, in the Development of Atherosclerosis and Vascular Biology: A Review with Meta-Analysis

Atherosclerotic cardiovascular disease (ASCVD) stands as the leading global cause of mortality. Addressing this vital and pervasive condition requires a multifaceted approach, in which antiplatelet intervention plays a pivotal role, together with antihypertensive, antidiabetic, and lipid-lowering therapies. Among the antiplatelet agents available currently, cilostazol, a phosphodiesterase-3 inhibitor, offers a spectrum of pharmacological effects. These encompass vasodilation, the impediment of platelet activation and aggregation, thrombosis inhibition, limb blood flow augmentation, lipid profile enhancement through triglyceride reduction and high-density lipoprotein cholesterol elevation, and the suppression of vascular smooth muscle cell proliferation. However, the role of cilostazol has not been clearly documented in many guidelines for ASCVD. We comprehensively reviewed the cardiovascular effects of cilostazol within randomized clinical trials that compared it to control or active agents and involved individuals with previous coronary artery disease or stroke, as well as those with no previous history of such conditions. Our approach demonstrated that the administration of cilostazol effectively reduced adverse cardiovascular events, although there was less evidence regarding its impact on myocardial infarction. Most studies have consistently reported its favorable effects in reducing intermittent claudication and enhancing ambulatory capacity in patients with peripheral arterial disease. Furthermore, cilostazol has shown promise in mitigating restenosis following coronary stent implantation in patients with acute coronary syndrome. While research from more diverse regions is still needed, our findings shed light on the broader implications of cilostazol in the context of atherosclerosis and vascular biology, particularly for individuals at high risk of ASCVD.

Reversal of spatial memory impairment by phosphodiesterase 3 inhibitor cilostazol is associated with reduced neuroinflammation and increased cerebral glucose uptake in aged male mice

The nucleotide second messenger 3', 5'-cyclic adenosine monophosphate (cAMP) and 3', 5'-cyclic guanosine monophosphate (cGMP) mediate fundamental functions of the brain, including learning and memory. Phosphodiesterase 3 (PDE3) can hydrolyze both cAMP and cGMP and appears to be involved in the regulation of their contents in cells. We previously demonstrated that long-term administration of cilostazol, a PDE3 inhibitor, maintained good memory performance in aging mice. Here, we report on studies aimed at determining whether cilostazol also reverses already-impaired memory in aged male mice. One month of oral 1.5% cilostazol administration in 22-month-old mice reversed age-related declines in hippocampus-dependent memory tasks, including the object recognition and the Morris water maze. Furthermore, cilostazol reduced neuroinflammation, as evidenced by immunohistochemical staining, and increased glucose uptake in the brain, as evidence by positron emission tomography (PET) with 2-deoxy-2-[¹⁸F]fluoro-d-glucose ([¹⁸F]FDG). These results suggest that already-expressed memory impairment in aged male mice that depend on cyclic nucleotide signaling can be reversed by inhibition of PDE3. The reversal of age-related memory impairments may occur in the central nervous system, either through cilostazol-enhanced recall or strengthening of weak memories that otherwise may be resistant to recall.

Induction of JAK2/STAT3 pathway contributes to protective effects of different therapeutics against myocardial ischemia/reperfusion

Insufficiency in coronary blood supply results in myocardial ischemia and consequently, various clinical syndromes and irreversible injuries. Myocardial damage occurs as a result of two processes during acute myocardial infarction (MI): ischemia and subsequent reperfusion. According to the available evidence, oxidative stress, excessive inflammation reaction, reactive oxygen species (ROS) generation, and apoptosis are crucial players in the pathogenesis of myocardial ischemia/reperfusion (IR) injury. There is emerging evidence that Janus tyrosine kinase 2 (JAK2) signal transducer and activator of the transcription 3 (STAT3) pathway offers cardioprotection against myocardial IR injury. This article reviews therapeutics that exert cardioprotective effects against myocardial IR injury through induction of JAK2/STAT3 pathway.

Lycium barbarum polysaccharide protects rats and cardiomyocytes against ischemia/reperfusion injury via Nrf2 activation through autophagy inhibition

The irreversible loss of cardiomyocytes is mainly the result of ischemic/reperfusion (I/R) myocardial injury, leading to persistent heart dysfunction and heart failure. It has been reported that Lycium barbarum polysaccharide (LBP) has protective effects on cardiomyocytes, but the specific mechanism is still not completely understood. The present study examined the protective role of LBP in myocardial I/R injury. Rats were subjected to myocardial I/R injury and LBP treatment. Moreover, rat myocardial H9C2 cells exposed to hypoxia/reoxygenation (H/R) were used to simulate cardiac injury during myocardial I/R process and were exposed to LBP, rapamycin (an autophagy activator) or nuclear factor-erythroid factor 2-related factor 2 (Nrf2) transfection. Morphological examination, histopathological examination and echocardiography were used to determine the cardiac injury after I/R injury. Cell viability and apoptosis were determined via MTT and flow cytometry assays, respectively. The levels of lactate dehydrogenase (LDH), creatine kinase (CK), cardiac troponin T (cTnT), IL-1β, IL-6, TNF-α, malondialdehyde (MDA) and superoxidase dismutase (SOD) in rat serum, hearts and/or cells were assessed using ELISAs. The expression levels of Beclin 1, LC3II/LC3I, P62 and Nrf2 were analyzed via reverse transcription-quantitative PCR and western blotting. The results demonstrated that LBP improved heart function and repaired cardiomyocyte damage in I/R model rats, as well as reduced the production of cTnT, CK, LDH, IL-1β, IL-6 and TNF-α. The in vitro study results indicated that LBP increased cell viability, the apoptosis rate, and the levels of SOD and P62, as well as reduced the levels of LDH, CK, IL-1β, IL-6, TNF-α, MDA, Beclin 1 and LC3-II/LC3-I in H/R-injured H9C2 cells. Moreover, LBP promoted Nrf2 nuclear translocation, but decreased Nrf2 expression in the cytoplasm. Rapamycin exacerbated the aforementioned effects in H/R injured H9C2 cells, and partially reversed LBP-induced effects. Overexpressing Nrf2 counteracted I/R-induced effects and partially resisted rapamycin-induced effects. These findings demonstrated that LBP exhibited a cardiac protective effect on the ischemic myocardium of rats after reperfusion and attenuated myocardial I/R injury via autophagy inhibition-induced Nrf2 activation.

MiR-124 Regulates the Inflammation and Apoptosis in Myocardial Infarction Rats by Targeting STAT3

This study aimed to discover the effect of miR-124/STAT3 axis on the inflammation and cell apoptosis in myocardial infarction (MI) rats. Sprague-Dawley (SD) male rats were selected for establishing MI models and divided into Sham, MI, MI + anti-miR-124 and MI + Ad-miR-124 groups. Cardiac function was detected via echocardiography. Hematoxylin & eosin (HE) and triphenyltetrazolium chloride (TTC) staining were used to observe the pathological changes and infarction area, while transferase (TdT)-mediated D-UTP-biotin nick end labeling (TUNEL) assay was to observe myocardial apoptosis. Enzyme-linked immunosorbent assay (ELISA) was used to determine the serum levels of inflammatory cytokines. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and western blotting were performed to determine the mRNA and protein levels, respectively. Dual luciferase reporter gene assay revealed that STAT3 was a target gene of miR-124. The expression levels of miR-124 were increased and the pSTAT3/STAT3 ratio was reduced in the MI rats. The rats in the MI group showed enhanced LVEDD and LVESD, reduced LVEF and LVFS, as well as larger myocardial infarction area compared with the Sham group, Besides, IL-1β, IL-6, TNF-α and MCP-1 levels were elevated and the expressions of Bax/Bcl-2 ratio and cleaved caspase-3 were downregulated in MI group. We further found that silencing miR-124 improved cardiac function, reduced infarction area and the levels of inflammatory cytokines, as well as prevented myocardial apoptosis in MI rats. Silencing miR-124 could inhibit the inflammation and apoptosis of myocardial cells, thereby relieving the MI injury via upregulation of STAT3.

PPARγ in Ischemia-Reperfusion Injury: Overview of the Biology and Therapy

Ischemia-reperfusion injury (IRI) is a complex pathophysiological process that is often characterized as a blood circulation disorder caused due to various factors (such as traumatic shock, surgery, organ transplantation, burn, and thrombus). Severe metabolic dysregulation and tissue structure destruction are observed upon restoration of blood flow to the ischemic tissue. Theoretically, IRI can occur in various tissues and organs, including the kidney, liver, myocardium, and brain, among others. The advances made in research regarding restoring tissue perfusion in ischemic areas have been inadequate with regard to decreasing the mortality and infarct size associated with IRI. Hence, the clinical treatment of patients with severe IRI remains a thorny issue. Peroxisome proliferator-activated receptor γ (PPARγ) is a member of a superfamily of nuclear transcription factors activated by agonists and is a promising therapeutic target for ameliorating IRI. Therefore, this review focuses on the role of PPARγ in IRI. The protective effects of PPARγ, such as attenuating oxidative stress, inhibiting inflammatory responses, and antagonizing apoptosis, are described, envisaging certain therapeutic perspectives.

Cilostazol: a Review of Basic Mechanisms and Clinical Uses

Primarily used in the treatment of intermittent claudication, cilostazol is a 2-oxyquinolone derivative that works through the inhibition of phosphodiesterase III and related increases in cyclic adenosine monophosphate (cAMP) levels. However, cilostazol has been implicated in a number of other basic pathways including the inhibition of adenosine reuptake, the inhibition of multidrug resistance protein 4, among others. It has been observed to exhibit antiplatelet, antiproliferative, vasodilatory, and ischemic-reperfusion protective properties. As such, cilostazol has been investigated for clinical use in a variety of settings including intermittent claudication, as an adjunctive for reduction of restenosis after coronary and peripheral endovascular interventions, and in the prevention of secondary stroke, although its widespread implementation for indications other than intermittent claudication has been limited by relatively modest effect sizes and lack of studies in western populations. In this review, we highlight the pleiotropic effects of cilostazol and the evidence for its clinical use.

Could cilostazol be beneficial in COVID-19 treatment? Thinking about phosphodiesterase-3 as a therapeutic target

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19) that has emerged and rapidly spread across the world. The COVID-19 severity is associated to viral pneumonia with additional extrapulmonary complications. Hyperinflammation, dysfunctional immune response and hypercoagulability state are associated to poor prognosis. Therefore, the repositioning of multi-target drugs to control the hyperinflammation represents an important challenge for the scientific community. Cilostazol, a selective phosphodiesterase type-3 inhibitor (PDE-3), is an antiplatelet and vasodilator drug, that presents a range of pleiotropic effects, such as antiapoptotic, anti-inflammatory, antioxidant, and cardioprotective activities. Cilostazol also can inhibit the adenosine uptake, which enhances intracellular cAMP levels. In the lungs, elevated cAMP promotes anti-fibrotic, vasodilator, antiproliferative effects, as well as mitigating inflammatory events. Interestingly, a recent study evaluated antiplatelet FDA-approved drugs through molecular docking-based virtual screening on viral target proteins. This study revealed that cilostazol is a promising drug against COVID-19 by inhibiting both main protease (M^pro) and Spike glycoprotein, reinforcing its use as a promising therapeutic approach for COVID-19. Considering the complexity associated to COVID-19 pathophysiology and observing its main mechanisms, this article raises the hypothesis that cilostazol may act on important targets in development of the disease. This review highlights the importance of drug repurposing to address such an urgent clinical demand safely, effectively and at low cost, reinforcing the main pharmacological actions, to support the hypothesis that a multi-target drug such as cilostazol could play an important role in the treatment of COVID-19.

Cilostazol preconditioning alleviates cyclophosphamide-induced cardiotoxicity in male rats: Mechanistic insights into SIRT1 signaling pathway

AIMS

Cyclophosphamide (CYP) is a potent anticancer agent with well-known cardiotoxicity that limits its clinical applications. Cilostazol is a vosodilating drug, showing a cardioprotective effect in some cardiac disorders; however its effect in CYP-induced cardiotoxicity is still uncertain. We investigated the effect of cilostazol against CYP-induced cardiotoxicity and the contribution of SIRT1 signaling.

MATERIALS AND METHODS

7 week-old male Wistar albino rats were treated with cilostazol (30 mg/kg/day, orally) in the absence or presence of SIRT1 inhibitor, EX-527 (5 mg/kg/day, IP) for 10 days and injected with CYP (200 mg/kg, IP) on the 7th day of the study. Age-matched rats were used as control group. On the 11th day, hearts were harvested for biochemical, immunoblotting and histological analyses. Markers of cardiac injury were assessed in plasma samples.

KEY FINDINGS

CYP injection contributed to cardiac injury manifested as significant increases in plasma activities of heart enzymes and cardiac troponin I levels. Cilostazol attenuated cardiac injury and minimized the histological lesions in hearts of CYP-treated rats. Cilostazol induced 3 fold up-regulation of SIRT1 and promoted the antioxidant defense response through FoxO1-related mechanism in hearts of CYP-treated rats. Cilostazol suppressed the CYP-induced up-regulation of PARP1 and p53, and blocked the NF-kB p65-mediated inflammatory response in hearts of CYP-treated rats. All the beneficial effects of cilostazol were almost abolished by EX-527.

SIGNIFICANCE

These data provided insights into the mechanism underlying the cardioprotective effect of cilostazol in CYP-treated rats through upregulation of SIRT1 signaling, suggesting that cilostazol might be a candidate modality for CYP-induced cardiotoxicity.

Pre- and Post-Conditioning of the Heart: An Overview of Cardioprotective Signaling Pathways

Since the discovery of ischemic pre- and post-conditioning, more than 30 years ago, the knowledge about the mechanisms and signaling pathways involved in these processes has significantly increased. In clinical practice, on the other hand, such advancement has yet to be seen. This article provides an overview of ischemic pre-, post-, remote, and pharmacological conditioning related to the heart. In addition, we reviewed the cardioprotective signaling pathways and therapeutic agents involved in the above-mentioned processes, aiming to provide a comprehensive evaluation of the advancements in the field. The advancements made over the last decades cannot be ignored and with the exponential growth in techniques and applications. The future of pre- and post-conditioning is promising.

Platelet regulation of myeloid suppressor of cytokine signaling 3 accelerates atherosclerosis

Platelets are best known as mediators of hemostasis and thrombosis; however, their inflammatory effector properties are increasingly recognized. Atherosclerosis, a chronic vascular inflammatory disease, represents the interplay between lipid deposition in the artery wall and unresolved inflammation. Here, we reveal that platelets induce monocyte migration and recruitment into atherosclerotic plaques, resulting in plaque platelet-macrophage aggregates. In Ldlr ^-/- mice fed a Western diet, platelet depletion decreased plaque size and necrotic area and attenuated macrophage accumulation. Platelets drive atherogenesis by skewing plaque macrophages to an inflammatory phenotype, increasing myeloid suppressor of cytokine signaling 3 (SOCS3) expression and reducing the Socs1:Socs3 ratio. Platelet-induced Socs3 expression regulates plaque macrophage reprogramming by promoting inflammatory cytokine production (Il6, Il1b, and Tnfa) and impairing phagocytic capacity, dysfunctions that contribute to unresolved inflammation and sustained plaque growth. Translating our data to humans with cardiovascular disease, we found that women with, versus without, myocardial infarction have up-regulation of SOCS3, lower SOCS1:SOCS3, and increased monocyte-platelet aggregate. A second cohort of patients with lower extremity atherosclerosis demonstrated that SOCS3 and the SOCS1:SOCS3 ratio correlated with platelet activity and inflammation. Collectively, these data provide a causative link between platelet-mediated myeloid inflammation and dysfunction, SOCS3, and cardiovascular disease. Our findings define an atherogenic role of platelets and highlight how, in the absence of thrombosis, platelets contribute to inflammation.

Exogenous hydrogen sulfide protects against high glucose-induced apoptosis and oxidative stress by inhibiting the STAT3/HIF-1α pathway in H9c2 cardiomyocytes

Hydrogen sulfide (H2S), an endogenous gasotransmitter, possesses multiple physiological and pharmacological properties including anti-apoptotic, anti-oxidative stress and cardiac protective activities in diabetic cardiomyopathy. An increasing body of evidence has suggested that signal transducer and activator of transcription 3 (STAT3) has beneficial effects in the heart. However, the effect of diabetes on the phosphorylation or activation of cardiac STAT3 appears to be controversial. The present study was designed to investigate the precise function of the STAT3/hypoxia-inducible factor-1α (HIF-1α) signaling pathway in high glucose (HG)-induced H9c2 cardiomyocyte injury and the function of the STAT3/HIF-1α pathway in the cardioprotective action of H2S. The results revealed that GYY4137 pretreatment substantially ameliorated the HG-induced decrease in cell viability and the increase in lactate dehydrogenase (LDH) release in H9c2 cells. Additionally, HG treatment resulted in the upregulation of the phosphorylated (p)-STAT3/STAT3 ratio and HIF-1α protein expression in H9c2 cells, indicating that the activation of the STAT3/HIF-1α pathway was induced by HG. STAT3/HIF-1α pathway inhibition induced by transfection with STAT3 small interfering (si)-RNA attenuated the HG-induced downregulation of cell viability and the upregulation of LDH release. Furthermore, STAT3 siRNA transfection and GYY4137 pretreatment combined attenuated HG-induced apoptosis as illustrated by the decrease in the number of terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells, caspase-3 activity, apoptosis ratio and BCL2 associated X, apoptosis regulator/BCL2 apoptosis regulator ratio in H9c2 cells. In addition, STAT3 siRNA transfection and GYY4137 blocked HG-induced oxidative stress as evidenced by the decrease in reactive oxygen species generation, malondialdehyde content and NADPH oxidase 2 expression, and the increase in superoxide dismutase activity and glutathione level. Notably, GYY4137 pretreatment was revealed to reduce the p-STAT3/STAT3 ratio and HIF-1α protein expression, resulting in the inhibition of the STAT3/HIF-1α signaling pathway in HG-treated H9c2 cells. Altogether, the present results demonstrated that H2S mitigates HG-induced H9c2 cell damage, and reduces apoptosis and oxidative stress by suppressing the STAT3/HIF-1α signaling pathway.

Cilostazol Promotes Angiogenesis and Increases Cell Proliferation After Myocardial Ischemia-Reperfusion Injury Through a cAMP-Dependent Mechanism

PURPOSE

Previous study indicated the protective role of cilostazol in ischemia-reperfusion (I/R) injury. Here, we aimed to explore the function of cilostazol in myocardial I/R injury and the underlying mechanism.

METHODS

The myocardial I/R injury rat model was constructed, and the expression levels of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor receptor b (PDGF-B) and the number of new blood vessels were measured by qRT-PCR and immunohistochemistry. VSMC and HUVEC cells were treated with hypoxia to induce in vivo I/R injury model. The protein expression of AKT, endothelial nitric oxide synthase (eNOS) and apoptosis-related protein levels were detected by western blotting. Besides, the positive staining rate and cell viability were tested by 5-bromo-2-deoxyuridine (Brdu)/4',6-diamidino-2-phenylindole (DAPI) or DAPI/TdT-mediated dUTP Nick-End Labeling (TUNEL) staining and MTT assay.

RESULTS

Cilostazol promoted angiogenesis by increasing the number of new blood vessels and up-regulating the expression of VEGF, HGF, bFGF and PDGF-B in myocardial I/R-injury rat model. The in vitro experiments showed that cilostazol increased the level of eNOS and AKT, and also enhanced cell proliferation in hypoxia-treated VSMC and HUVEC cells. Furthermore, after 8-Br-cAMP treatment, VEGF, HGF, bFGF, PDGF-B, p-AKT and p-eNOS expression were up-regulated, while cleaved-caspase 3 and cleaved-PARP expression were down-regulated. In addition, the effects of cilostazol on cell viability and apoptosis were aggravated by 8-Br-cAMP and attenuated after KT-5720 treatment.

CONCLUSION

Cilostazol could promote angiogenesis, increase cell viability and inhibit cell apoptosis, consequently protecting myocardial tissues against I/R-injury through activating cAMP.

Dexmedetomidine protects H9c2 cardiomyocytes against oxygen-glucose deprivation/reoxygenation-induced intracellular calcium overload and apoptosis through regulating FKBP12.6/RyR2 signaling

Purpose

Intracellular calcium ([Ca²⁺]i) overload is a major cause of cell injury during myocardial ischemia/reperfusion (I/R). Dexmedetomidine (DEX) has been shown to exert anti-inflammatory and organ protective effects. This study aimed to investigate whether pretreatment with DEX could protect H9c2 cardiomyocytes against oxygen-glucose deprivation/reoxygenation (OGD/R) injury through regulating the Ca²⁺ signaling.

Methods

H9c2 cardiomyocytes were subjected to OGD for 12 h, followed by 3 h of reoxygenation. DEX was administered 1 h prior to OGD/R. Cell viability, lactate dehydrogenase (LDH) release, level of [Ca²⁺]i, cell apoptosis, and the expression of 12.6-kd FK506-binding protein/ryanodine receptor 2 (FKBP12.6/RyR2) and caspase-3 were assessed.

Results

Cells exposed to OGD/R had decreased cell viability, increased LDH release, elevated [Ca²⁺]i level and apoptosis rate, down-regulated expression of FKBP12.6, and up-regulated expression of phosphorylated-Ser2814-RyR2 and cleaved caspase-3. Pretreatment with DEX significantly blocked the above-mentioned changes, alleviating the OGD/R-induced injury in H9c2 cells. Moreover, knockdown of FKBP12.6 by small interfering RNA abolished the protective effects of DEX.

Conclusion

This study indicates that DEX pretreatment protects the cardiomyocytes against OGD/R-induced injury by inhibiting [Ca²⁺]i overload and cell apoptosis via regulating the FKBP12.6/RyR2 signaling. DEX may be used for preventing cardiac I/R injury in the clinical settings.

The Adipokine Metrnl Ameliorates Chronic Colitis in Il-10-/- Mice by Attenuating Mesenteric Adipose Tissue Lesions During Spontaneous Colitis

BACKGROUND

Crosstalk between mesenteric adipose tissue [MAT] and the intestines affects the progression of Crohn's disease [CD]. The adipokine metrnl regulates adipocyte function and has anti-inflammatory activity. We aimed to explore metrnl expression in CD MAT, investigate the influence of metrnl on the experimental colitis disease course and determine the mechanism underlying this effect.

METHODS

Metrnl expression in MAT specimens obtained from patients with and without CD was tested by immunohistochemistry. Male Il-10-/- mice with spontaneous enteritis were divided into positive control and metrnl-treated [Metrnl-Fc, 10 mg/kg/d, intraperitoneally, 8 weeks] groups. Age-matched male wild-type [WT] mice were used as negative controls. The effects of metrnl on enteritis and mesenteric lesions and the potential controlling mechanisms were evaluated.

RESULTS

Metrnl expression was higher in human CD MAT than in control MAT. Systemic delivery of metrnl significantly ameliorated chronic colitis in Il-10-/- mice, as demonstrated by decreases in the disease activity index, inflammatory score and proinflammatory mediators. The protective effects of metrnl on MAT included reduced mesenteric hypertrophy, increased adipocyte size, improved adipocyte intrinsic function and ameliorated inflammation. Metrnl treatment activated STAT5/PPAR-γ signaling and promoted adipocyte differentiation in the MAT.

CONCLUSIONS

Metrnl expression was increased in the MAT of CD patients. Metrnl administration attenuated mesenteric lesions by promoting adipocyte function and differentiation partly through STAT5/PPAR-γ signaling pathway activation, thereby ameliorating CD-like colitis in mice.

YB1 protects cardiac myocytes against H2O2‑induced injury via suppression of PIAS3 mRNA and phosphorylation of STAT3

Oxidative stress serves important roles in cardiac injury during the process of ischemia/reperfusion (I/R). Y-box protein 1 (YB1), a member of the highly conserved Y-box protein family, is closely associated with inflammation and stress responses by regulating gene transcription, RNA splicing and mRNA translation. However, the roles of YB1 in oxidative stress-induced myocardial-I/R (M-I/R) injury are unknown. The aim of the present study was to examine the effects of YB1 on H₂O₂-induced cardiomyocyte injury and its underlying mechanism. The results demonstrated that YB1 expression was upregulated during H₂O₂-induced myocardial injury. YB1 knockdown through transfection of small interfering RNA significantly aggravated cardiac cell apoptosis. Furthermore, YB1 knockdown significantly reversed the H₂O₂-mediated increase in phosphorylated signal transducer and activator of transcription (STAT)3, but did not affect the phosphorylation of P38, extracellular signal-regulated kinases 1/2, c-Jun N-terminal kinases, P65, Janus kinase 1 and 2 or STAT1. Moreover, protein co-immunoprecipitation and RNA-binding protein immunoprecipitation assays revealed that YB1 interacted with protein inhibitor of activated STAT 3 (PIAS3) mRNA but not its translated protein. YB1 overexpression may have promoted PIAS3 mRNA decay, decreasing PIAS3 protein levels, and therefore increased the levels of phosphorylated STAT3. Finally, YB1 knockdown, mediated by a lentivirus carrying YB1 targeted short hairpin RNA, significantly decreased left ventricle percentage fractional shortening and ejection fraction values, while increasing the infarct sizes in a rat model of M-I/R injury. These results demonstrated for the first time (to the best of our knowledge) that YB1 may protect cardiac myocytes against H₂O₂ or M-I/R-induced injury by binding to PIAS3 mRNA and resulting in the phosphorylation of STAT3.

Risk of Heart Failure Hospitalization Associated With Cilostazol in Diabetes: A Nationwide Case-Crossover Study

Background and Objective: It has been suggested to avoid cilostazol, the first-line therapy for peripheral arterial disease, in patients with congestive heart failure (HF). The objective of this study was to evaluate the risk of hospitalization for heart failure (HHF) associated with cilostazol use in the patients of diabetes mellitus. Methods: This case-crossover study retrieved records on diabetic patients > 20 years of age who were hospitalized for heart failure during the period of 2009-2011 from the Taiwan National Health Insurance Database. The "current" period was defined as 1-30 days prior to HHF whereas the 91-120 days prior to HHF served as the "reference" period. The exposure status just preceding the event is compared with exposure of the same person in one or more referent remote to the event. Adjusted odds ratios (OR) were used to estimate time-varying discordant exposure by the ratio of the number exposed to cilostazol only during the case period to the number exposed to cilostazol only during the control period. Results: A total of 47,506 diabetic patients were included in the analysis (average age: 72.7 ± 12.4, percentage of males: 48%). A total of 399 patients (0.84%) received cilostazol only in the current period, and 252 (0.53%) received cilostazol only in the reference period. After adjustment for other medications, a significant association was found between cilostazol and HHF (OR: 1.35, 95% CI: 1.14-1.59). After further adjustment for time-varying co-morbidities the ORs remained essentially the same. Sensitivity analyses using different definitions of control period (ranging from 31-60, 61-90, to 121-150 days before index date) yielded adjusted ORs of 1.43 (95% CI: 1.14-1.79), 1.31 (95% CI: 1.09-1.57) and 1.23 (95% CI: 1.06-1.44), respectively suggesting the robustness of our study findings. Conclusion: Use of cilostazol may be positively related to the risk of HHF. Further studies are warranted to explore the underlying mechanisms and to confirm the association.

Combination therapy with cilostazol and pravastatin improves antiatherogenic effects in low-density lipoprotein receptor knockout mice

AIMS

Despite the therapeutic efficacy of statins and antiplatelet agents for atherosclerosis, monotherapy with each drug alone is often insufficient to achieve the patient's therapeutic goals. We previously showed that combined statin/antiplatelet agent/anti-tumor necrosis factor (TNF) agent therapy (pravastatin/sarpogrelate/etanercept) reduces atherosclerotic lesions by inhibiting TNF, an atherogenic cytokine that contributes to the progression of arteriosclerosis. In addition, our previous study showed that combined treatment with pravastatin and cilostazol is effective for reducing TNF-driven inflammation through anti-TNF activity. Therefore, in the present study, we evaluated the additive effects of combined pravastatin and cilostazol therapy on atherosclerotic progression using low-density lipoprotein receptor (LDLR) knockout (KO) mice.

METHODS

Ten-week-old LDLR KO mice were fed a high-fat, high-cholesterol diet and orally administered pravastatin and cilostazol alone or in combination. Body weight, plasma lipid levels, and the levels of intracellular adhesion molecules and inflammatory cytokines were analyzed. In addition, aortas and aortic roots were stained with Oil Red O, and atherosclerotic plaques were quantified.

RESULTS

The atherosclerotic plaques in the combined pravastatin and cilostazol treatment groups were significantly reduced compared to those in each drug monotherapy group. The combination therapy group also showed the downregulation of ICAM-1, MOMA-2, TNF, interleukin (IL)-6, triglyceride, total cholesterol, and low-density lipoprotein levels and the upregulation of high-density lipoprotein levels compared to those of the pravastatin- or cilostazol-treated groups.

CONCLUSIONS

Our results suggest that combination therapy with pravastatin and cilostazol exerts beneficial effects by decreasing atherosclerotic lesion progression and improving the pro-inflammatory state in the vascular endothelium. These effects are mediated by the reduction in adhesion molecule expression, immune cell infiltration, and cytokine levels and the antiatherosclerotic modulation of serum cholesterol levels. Therefore, we conclude that combined treatment with pravastatin and cilostazol may be a more effective antiatherosclerotic strategy than treatment with either agent alone.

Eriodictyol Attenuates Myocardial Ischemia-Reperfusion Injury through the Activation of JAK2

Myocardial ischemia-reperfusion (I/R) injury remains the leading risk factor of disability and mortality worldwide. In this study, the myocardial protective effect of eriodictyol (EDT) and the underlying mechanism in an ex vivo model of global myocardial I/R was investigated. After treatment with different concentrations of EDT, the decreased hemodynamic parameters induced by myocardial I/R injury were significantly attenuated by EDT. The elevated levels of IL-6, CRP, IL-8, and TNF-α were effectively reduced by EDT treatment. EDT also remarkably suppressed the levels of Bax and cleaved Caspase-3, and up-regulated the level of Bcl-2 in cardiac tissues from EDT-treated groups. Further studies showed that EDT could increase the levels of p-JAK2 and p-STAT3 in cardiac tissues. Meanwhile, treatment of AG490, a specific inhibitor of JAK2, abolished the protective effect of EDT on hemodynamic parameters, myocardial inflammation and myocardial cell apoptosis induced by I/R injury. These results demonstrated that EDT could protect against myocardial I/R injury through the activation of JAK2, providing a potential treatment with EDT during myocardial I/R injury.