Current Medicinal Chemistry - Volume 25, Issue 13, 2018

Pigment epithelium-derived factor (PEDF) is a glycoprotein that belongs to the superfamily of serine protease inhibitors, serpins. It was first identified as a neuronal differentiating factor secreted by human retinal pigment epithelial cells, and then found to be the most potent inhibitor of pathological angiogenesis in mammalian eyes. Recently, PEDF has been shown not only to suppress oxidative stress and inflammatory reactions in vascular wall cells, T cells and macrophages, and adipocytes, but also to exert antithrombotic and anti-fibrotic properties, thereby protecting against the development and progression of various cardiometabolic diseases and related complications. Furthermore, accumulating evidence has suggested that circulating PEDF levels may be a biomarker of severity and prognosis of these devastating disorders. Number of subjects with visceral obesity and insulin resistance is increasing, and the metabolic syndrome and its related complications, such as diabetes, nonalcoholic fatty liver disease/non-alcoholic steatohepatits, and atherosclerotic cardiovascular disease are a growing health challenge. Therefore, in this study, we review the pathophysiological role of PEDF in obesity and metabolic disorders, cardiovascular disease, diabetic eye and kidney complications, liver diseases, and reproductive system disorders, and discuss the potential clinical utility of modulating the expression and actions of PEDF for preventing these cardiometabolic disorders. We also refer to the clinical value of PEDF as a biomarker in cardiometabolic complications.

Background: Obese insulin-resistance is one of the most important risk factor for cardiovascular diseases including ischemic heart disease (IHD). Growing evidences suggest that the susceptibility to myocardial ischemia-reperfusion (I/R) injury is increased in an obese insulin-resistance condition. Based on the currently available evidence from human and animal studies, this review mainly focuses on the influence of obese insulinresistance on the outcome of the I/R insult to the heart. Moreover, we have discussed whether improving insulin sensitivity by pharmacological interventions could ameliorate reperfusion induced myocardial injury. Methods: The electronic database Pubmed was used as the source of selected peerreviewed research articles published in English. Both pre-clinical studies and clinical trials were obtained using obesity, insulin resistance, ischemia-reperfusion injury and myocardial infarction as keywords. Results: Twenty-seven pre-clinical studies were obtained using obesity, insulin resistance, and cardiac ischemia-reperfusion injury as keywords, and five clinical trials were obtained using obesity, insulin resistance, and myocardial infarction as keywords. The underlying mechanisms responsible for the exacerbation of I/R injury in obese insulinresistance were the main subject of our review. Conclusion: The findings of this review suggest that the susceptibility to I/R injury is increased in an obese insulin-resistance condition. However, the underlying mechanisms responsible for the exacerbation of I/R injury in obese insulin-resistance have not been fully elucidated, but increased basal oxidative stress, the impairment of anti-oxidant capacities, insulin signaling and pro-survival signaling and increased inflammation, likely play an important role.

Background: Diabetic Cardiomyopathy (DC) has been defined as a distinct entity characterized by the presence of diastolic or systolic cardiac dysfunction in a diabetic patient in the absence of other causes for Cardiomyopathy, such as coronary artery disease (CAD), hypertension (HTN), or valvular heart disease. Diabetes affects every organ in the body and cardiovascular disease accounts for two-thirds of the mortality in the diabetic population. Diabetes-related heart disease occurs in the form of coronary artery disease (CAD), cardiac autonomic neuropathy or DC. The prevalence of cardiac failure is high in the diabetic population and DC is a common, but underestimated cause of heart failure in diabetes. The strong association between diabetes and heart failure has fueled intense human and animal research aimed at identifying the mechanisms underlying diabetic myocardial disease. Despite significant progress made, the precise pathogenesis of diabetic Cardiomyopathy is yet to be clearly defined. Hyperglycemia, dyslipidemia and inflammation are thought to play key roles in the generation of reactive oxygen or nitrogen species which are in turn involved. Methods: We have reviewed the up-to-date scientific literature addressing these issues. Results: The myocardial interstitium undergoes alterations resulting in abnormal contractile function noted in DC. In the early stages of the disease, diastolic dysfunction is the only abnormality, but systolic dysfunction supervenes in the later stages with impaired left ventricular ejection fraction. Transmitral Doppler echocardiography is usually used to assess diastolic dysfunction, but tissue Doppler Imaging and Cardiac Magnetic Resonance Imaging are being increasingly used for early detection of DC. Diabetic patients with microvascular complications show the strongest association between diabetes and Cardiomyopathy, an association that parallels the duration and severity of hyperglycemia. Conclusion: The management of DC involves improvement in lifestyle, control of glucose and lipid abnormalities, together with treatment of hypertension and CAD, if present.

Background: Glomerular capillaries are lined with highly specialized fenestrated endothelium which are primarily responsible to regulate high flux filtration of fluid and small solutes. During filtration, plasma passes through the fenestrated endothelium and basement membrane before it reaches the slit diaphragm, a specialized type of intercellular junction that connects neighbouring podocytes. Methods: A PubMed search was done for recent articles on components of the glomerular filtration barrier such as glomerular endothelial cells, podocytes and glomerular basement membrane, and the effect of diabetes on these structures. Results and Conclusion: Generally, the onset of kidney dysfunction in many diabetic patients is characterized by albuminuria/proteinuria, a pathophysiological event triggered by several factors including; (i) endothelial activation and shading of glycocalyx, (ii) loss of endothelial cell function, (ii) re-uptake of albumin by podocyte through a scavenger receptors and (iv) rearrangement of podocyte cytoskeleton. Howeover, as podocyte effacement does not always lead to proteinuria, the dynamic interplay between all constituents of the glomerular filtration barrier including podocytes, endothelial cells and the basement membrane may be fundamental for the effective filtration in healthy individuals. Thus, a putative cross-talk amongst podocytes, endothelial cells and the basement membrane in the homeostasis of glomerular function is envisaged. Although, the exact nature of this cross-talk remains to be clearly elucidated, it is possible that the interaction between: (i) glomerular endothelial cells and podocytes, (ii) glomerular endothelial cells and glomerular basement membrane, (iii) podocytes and glomerular basement membrane, and (iv) the simultaneous interaction amongst the three components collectively underpin effective filtration in healthy individuals. A comprehensive understanding of these different interactions still remains elusive. The elucidation of these multifaceted interactions will set the stage for greater understanding of the pathophysiology of kidney dysfunction.

Background: Fabry disease is an X-linked lysosomal storage disorder caused by deficient activity of α -galactosidase A which leads to progressive intracellular accumulation of globotriaosylceramide in tissues and organs including heart, kidney, vascular endothelium, the nervous system, the eyes and the skin. Cardiac involvement is common, leads to fatal complications and is mainly responsible for reduced life expectancy in Fabry disease. The exact staging of disease progression and timely initiation of treatment is essential in Fabry disease. Therefore, it is essential to use the possibilities of specific biomarkers for early detection of organ involvement or early diagnosis. Methods: By the use of Pubmed all relevant papers for biomarkers in Fabry disease were screened. The quality of retrieved papers was appraised using standard tools. Finally, 70 peer reviewed paper were included. Results: In the past biomarkers for Fabry disease biomarkers did not have clinical relevance. Nowadays, a lot of research is focusing on identification of new biomarkers and their clinical relevance. Only two biomarkers reached clinical applicability. Lyso-GB3 for identification of atypical FD variants and hsTNT for identification of cardiac involvement, which should indicate further diagnostics. Treatment response to ERT can be monitored by lyso-GB3 but data for long-time outcome are missing. A lot of GB3-related analogs are identified in urine and plasma, some of which might play an important role for managing Fabry disease in future. Conclusion: In conclusion, we suggest to measure lyso-GB3 and hsTNT at least once a year. The routine measurement of these two biomarkers will help now for the staging of every individual patient and in addition, will help for a better general understanding of Fabry disease.

Statin intolerance is usually defined as the inability of a patient to tolerate statintreatment due to muscle-related complaints. While randomised trials show that these complaints occure with similar frequency in patients receiving placebo, namely in up to ~5% of the subjects, and data from registries as well as clinical experience indicate a much higher frequency of up to ~30%. The lack of standard definition or of a diagnostic marker of statin intolerance confounds the problem. The diagnosis remains subjective based on the symptoms the patient reports. Therefore, a large number of patients who need a statin are not receiving it, or receiving only very-low and/or intermittent doses unable to achieve a robust decrease in low-density lipoprotein cholesterol (LDL-C), leaving patients at high or very high risk for cardiovascular events requiring an alternative form of lipid-lowering therapy. Until recently, the only available alternatives were niacin, ezetimibe, bile-acid sequestrants and fibrates that decrease LDL-C concentrations by up to 15-20%. Recently the fully human monoclonal antibodies against proprotein convertase subtilisin/kexin 9 (PCSK9), alirocumab (Praluent®) and evolocumab (Repatha®), which have been shown to decrease LDL-C by up to 70% have been approved in Europe for use in patients with primary hypercholesterolemia not at LDL-C target while on maximally tolerated lipid-lowering therapy and specifically for patients with statin intolerance and in the USA for patients with atherosclerotic cardiovascular disease or familial hypercholesterolemia requiring additional LDL-C lowering. Ongoing large clinical trials with cardiovascular endpoints will provide a definitive answer for the role of anti-PCSK9 antibodies in clinical practice.

It is known that Cardiovascular (CV) disease is the leading cause of morbidity and mortality in individuals with type 2 diabetes. Over the last years, one of the most discussed topics is the CV safety of anti-diabetic medications. Regarding CV safety of older antidiabetic agents the data are less clear and conclusions about their CV safety are mostly based on randomized controlled trials designed to assess their glucose lowering efficacy. In this review, we summarize the current knowledge about the CV safety of older and newer antidiabetic medications. According to the published literature metformin is the first line agent for the treatment of type 2 diabetes and seems to have cardio-protective effects. The choice of the second line agent when metformin monotherapy fails to achieve HbA1c targets is less clear. In the light of the findings of the EMPA-REG OUTCOME trial and the recently published LEADER and SUSTAIN 6 trials, empagliflozin, liraglutide and semaglutide seem reasonable options as second line agents for patients with CV disease. Sulfonylureas on the other hand, with the exception of gliclazide, should be avoided in those patients, although CV safety trials are still lacking. In individuals without CV disease any of the other classes of anti-diabetic medication can be selected on a patient-centered approach. Saxagliptin, alogliptin, sitagliptin and lixisenatide have been evaluated in CV safety trials and have neutral effects on CV outcomes, while pioglitazone may have some CV benefits. Saxagliptin and alogliptin, however, should be avoided in patients with heart failure, while pioglitazone is contraindicated in this population.

Elevated triglyceride levels (higher than ~1000 mg/dL) are associated with an increased risk for pancreatitis. Apolipoprotein-CIII (apoC-III) plays a key role in the metabolism of triglycerides and triglyceride-rich lipoproteins. Loss of function mutations in the gene encoding apoC-III (APOC3) is associated with low triglyceride levels and a decreased risk for cardiovascular disease (CVD) while overexpression of APOC3 is associated with hypertriglyceridemia. Although many drugs such as fibrates, statins and omega-3 fatty acids modestly decrease triglyceride levels (and apoC-III concentrations), there are many patients who still have severe hypertriglyceridemia and are at increased risk for pancreatitis and potentially for CVD. The antisense oligonucleotide (ASO) against APOC3 mRNA volanesorsen (previously called ISIS 304801, ISIS-ApoCIIIRx and IONIS-ApoCIIIRx) robustly decreases both, apoC-III production and triglyceride concentrations and is being currently evaluated in phase 3 trials. In this narrative review, we present the currently available clinical evidence on the efficacy and safety of volanesorsen for the treatment of hypertriglyceridemia.

Background: The aim of this review is to summarize the effects of various naturally occurring polyphenols in the management of metabolic dysfunctions. This cluster of metabolic abnormalities comprises insulin resistance, increased levels of free fatty acids, hypercholesterolemia, obesity, hyperglycemia and hypertension, diabetes mellitus (DM) type 1 (T1DM) and type 2 (T2DM) along with DM-induced complications. Most of them are included in the well-known metabolic syndrome (MS). These metabolic dysfunctions in turn are tightly associated to a high risk of development of cardiovascular diseases. Although molecular mechanisms underlying the onset of metabolic dysfunctions and related complications are not yet clear, it is widely recognized that they are associated to oxidative stress and chronic low-grade of inflammatory levels. Methods: We undertook a structured search of bibliographic references through the use of SciFinder. The database was provided by a division of ACS (American Chemical Society) and guarantees access to the world's most extensive and authoritative source of references. The search was performed using “heme oxygenase-1” as research topic and a subsequent refinement was done by using inclusion/exclusion criteria. The quality of retrieved papers was evaluated on the basis of standard tools. Results: From a careful review of the selected literature, of interest, the use of natural antioxidant polyphenols seems to be the ideal pharmacological treatment since they are endowed with strong antioxidant and anti-inflammatory properties. In particular, some polyphenols such as curcumin, quercetin, genistein, and caffeic acid phenethyl ester are able to potently activate nuclear factor erythroid 2-related factor 2 (Nrf2) and related downstream expression of enzymes such as heme oxygenase-1 (HO-1). Indeed, an overexpression of HO-1 has been demonstrated to play a beneficial role in metabolic diseases. Conclusion: The following review is intended to stimulate interest in the role of natural occurring HO-1 inducers in metabolic dysfunction, focusing on the clinical potential of HO-1 activity to restore the balance between pro-oxidant and anti-oxidants systems.