Atherosclerotic and Cardio-Metabolic Diseases::From Molecular Basis to Therapeutic Advances

Cardiovascular diseases (CVDs) still remain the major cause of death worldwide; however, CVD-related mortality has been reduced due to lifestyle modification interventions, as well as novel pharmacological therapies and advances in cardiovascular surgery [...

Orexin-A exerts equivocal role in atherosclerosis process depending on the duration of exposure : in vitro study

Orexin-A is a peptide hormone that plays a crucial role in feeding regulation and energy homeostasis. Diurnal intermittent fasting (DIF) has been found to increase orexin-A plasma levels during fasting hours, while Ramadan fasting which resembles DIF, has led to beneficial effects on endothelial function. Herein, we aimed to investigate the effects of orexin-A on the expression of molecules involved in the atherogenesis process: Monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9) and tissue inhibitor of metalloproteinase-1 and 2 (TIMP-1 and TIMP-2), in human aortic endothelial cells (HAECs). HAECs were incubated with orexin-A at concentrations of 40 ng/mL, 200 ng/mL and 400 ng/mL for 6, 12 and 24 h. The mRNA levels of MCP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 and orexin-1 receptor were measured by real-time qPCR. We also evaluated the MMP-2, p38, phospho-p38, NF-κΒ/p65 as well as TIMP-1 protein levels by Western blot and ELISA, respectively. MMP-2 activity was measured by gelatin zymography. Short-term 6-h incubation of HAECs with orexin-A at a high concentration (400 ng/mL) decreased MCP-1, MMP-2 expression, MMP-2/TIMP-1 ratio (p < 0.05), and MMP-2 activity, while incubation for 24 h increased MCP-1, MMP-2 expression (p < 0.05), MMP-2/TIMP-1 and MMP-2/TIMP-2 ratio (p < 0.01 and p < 0.05, respectively) as well as MMP-2 activity. The dual effects of orexin-A are mediated, at least in part, via regulation of p38 and NF-κΒ pathway. Orexin-A may have an equivocal role in atherosclerosis process with its effects depending on the duration of exposure

Lack of Association Between Estrogen Receptor-Alpha Single-Nucleotide Polymorphism (Codon 594 G-->A) and Postmenopausal Osteoporosis: A Pilot Study

Background: Recent studies have suggested that the estrogen receptor alpha (ERα) gene is implicated in reduced bone mineral density (BMD). Objective: In the present study, we investigated the relationship between genetic polymorphism in ΕRα 2014G--&gt;A (T594T) (codon 594 G--&gt;A) and osteoporosis in postmenopausal women. Methods: A total of 59 postmenopausal women were included in the study (21 normal, 24 osteoporotic, 14 osteopenic). The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used to identify the ΕRα 2014G-&gt;A polymorphism. Results: The three groups were found to be in genetic equilibrium. Also, there were no allele (p=0.578) and/or genotype frequencies (p=0.59) among the groups, i.e. the three groups could be treated as a genetically uniform population. As expected, normal women exhibited the highest BMD values (1.11 g/cm2) followed by the osteopenic (0.91 g/cm2) and the osteoporotic women (0.73 g/cm2). There was significant difference (p&lt;0.05) in age only between the osteoporotic group (mean age 48.7 years) and either the normal (mean age 46 years) or the osteopenic group (mean age 45 years). No allele and/or genotype effect on BMD or age was detected. Conclusion: Our results support the lack of association between ERα codon 594 and BMD in postmenopausal women, since we found no allele and/or genotype effect on BMD or age. Further studies in a larger sample of postmenopausal women are needed to confirm our results

Non-invasive Scores and Serum Biomarkers for Fatty Liver in the Era of Metabolic Dysfunction-associated Steatotic Liver Disease (MASLD):A Comprehensive Review From NAFLD to MAFLD and MASLD

Purpose of Review: The prevalence of non-alcoholic fatty liver disease (NAFLD) is rapidly increasing worldwide, making it the leading cause of liver related morbidity and mortality. Currently, liver biopsy is the gold standard for assessing individuals with steatohepatitis and fibrosis. However, its invasiveness, sampling variability, and impracticality for large-scale screening has driven the search for non-invasive methods for early diagnosis and staging. In this review, we comprehensively summarise the evidence on the diagnostic performance and limitations of existing non-invasive serum biomarkers and scores in the diagnosis and evaluation of steatosis, steatohepatitis, and fibrosis.Recent Findings: Several non-invasive serum biomarkers and scores have been developed over the last decade, although none has successfully been able to replace liver biopsy. The introduction of new NAFLD terminology, namely metabolic dysfunction-associated fatty liver disease (MAFLD) and more recently metabolic dysfunction-associated steatotic liver disease (MASLD), has initiated a debate on the interchangeability of these terminologies. Indeed, there is a need for more research on the variability of the performance of non-invasive serum biomarkers and scores across the diagnostic entities of NAFLD, MAFLD and MASLD.Summary: There remains a significant need for finding valid and reliable non-invasive methods for early diagnosis and assessment of steatohepatitis and fibrosis to facilitate prompt risk stratification and management to prevent disease progression and complications. Further exploration of the landscape of MASLD under the newly defined disease subtypes is warranted, with the need for more robust evidence to support the use of commonly used serum scores against the new MASLD criteria and validation of previously developed scores.</p

Anti-osteoporotic treatments in the era of non-alcoholic fatty liver disease: friend or foe

Over the last years non-alcoholic fatty liver disease (NAFLD) has grown into the most common chronic liver disease globally, affecting 17-38% of the general population and 50-75% of patients with obesity and/or type 2 diabetes mellitus (T2DM). NAFLD encompasses a spectrum of chronic liver diseases, ranging from simple steatosis (non-alcoholic fatty liver, NAFL) and non-alcoholic steatohepatitis (NASH; or metabolic dysfunction-associated steatohepatitis, MASH) to fibrosis and cirrhosis with liver failure or/and hepatocellular carcinoma. Due to its increasing prevalence and associated morbidity and mortality, the disease-related and broader socioeconomic burden of NAFLD is substantial. Of note, currently there is no globally approved pharmacotherapy for NAFLD. Similar to NAFLD, osteoporosis constitutes also a silent disease, until an osteoporotic fracture occurs, which poses a markedly significant disease and socioeconomic burden. Increasing emerging data have recently highlighted links between NAFLD and osteoporosis, linking the pathogenesis of NAFLD with the process of bone remodeling. However, clinical studies are still limited demonstrating this associative relationship, while more evidence is needed towards discovering potential causative links. Since these two chronic diseases frequently co-exist, there are data suggesting that anti-osteoporosis treatments may affect NAFLD progression by impacting on its pathogenetic mechanisms. In the present review, we present on overview of the current understanding of the liver-bone cross talk and summarize the experimental and clinical evidence correlating NAFLD and osteoporosis, focusing on the possible effects of anti-osteoporotic drugs on NAFLD

Fatty Acids Derived from Royal Jelly Are Modulators of Estrogen Receptor Functions

Royal jelly (RJ) excreted by honeybees and used as a nutritional and medicinal agent has estrogen-like effects, yet the compounds mediating these effects remain unidentified. The possible effects of three RJ fatty acids (FAs) (10-hydroxy-2-decenoic-10H2DA, 3,10-dihydroxydecanoic-3,10DDA, sebacic acid-SA) on estrogen signaling was investigated in various cellular systems. In MCF-7 cells, FAs, in absence of estradiol (E2), modulated the estrogen receptor (ER) recruitment to the pS2 promoter and pS2 mRNA levels via only ERβ but not ERα, while in presence of E2 FAs modulated both ERβ and ERα. Moreover, in presence of FAs, the E2-induced recruitment of the EAB1 co-activator peptide to ERα is masked and the E2-induced estrogen response element (ERE)-mediated transactivation is inhibited. In HeLa cells, in absence of E2, FAs inhibited the ERE-mediated transactivation by ERβ but not ERα, while in presence of E2, FAs inhibited ERE-activity by both ERβ and ERα. Molecular modeling revealed favorable binding of FAs to ERα at the co-activator-binding site, while binding assays showed that FAs did not bind to the ligand-binding pocket of ERα or ERβ. In KS483 osteoblasts, FAs, like E2, induced mineralization via an ER-dependent way. Our data propose a possible molecular mechanism for the estrogenic activities of RJ's components which, although structurally entirely different from E2, mediate estrogen signaling, at least in part, by modulating the recruitment of ERα, ERβ and co-activators to target genes

Estrogen Receptor Subtypes Elicit a Distinct Gene Expression Profile of Endothelial-Derived Factors Implicated in Atherosclerotic Plaque Vulnerability

In the presence of established atherosclerosis, estrogens are potentially harmful. MMP-2 and MMP-9, their inhibitors (TIMP-2 and TIMP-1), RANK, RANKL, OPG, MCP-1, lysyl oxidase (LOX), PDGF-β, and ADAMTS-4 play critical roles in plaque instability/rupture. We aimed to investigate (i) the effect of estradiol on the expression of the abovementioned molecules in endothelial cells, (ii) which type(s) of estrogen receptors mediate these effects, and (iii) the role of p21 in the estrogen-mediated regulation of the aforementioned factors. Human aortic endothelial cells (HAECs) were cultured with estradiol in the presence or absence of TNF-α. The expression of the aforementioned molecules was assessed by qRT-PCR and ELISA. Zymography was also performed. The experiments were repeated in either ERα- or ERβ-transfected HAECs and after silencing p21. HAECs expressed only the GPR-30 estrogen receptor. Estradiol, at low concentrations, decreased MMP-2 activity by 15-fold, increased LOX expression by 2-fold via GPR-30, and reduced MCP-1 expression by 3.5-fold via ERβ. The overexpression of ERα increased MCP-1 mRNA expression by 2.5-fold. In a low-grade inflammation state, lower concentrations of estradiol induced the mRNA expression of MCP-1 (3.4-fold) and MMP-9 (7.5-fold) and increased the activity of MMP-2 (1.7-fold) via GPR-30. Moreover, p21 silencing resulted in equivocal effects on the expression of the abovementioned molecules. Estradiol induced different effects regarding atherogenic plaque instability through different ERs. The balance of the expression of the various ER subtypes may play an important role in the paradoxical characterization of estrogens as both beneficial and harmful

SGLT-2 Inhibitors in NAFLD: Expanding Their Role beyond Diabetes and Cardioprotection?

Non-alcoholic fatty liver disease (NAFLD) is an ‘umbrella’ term, comprising a spectrum ranging from benign, liver steatosis to non-alcoholic steatohepatitis, liver fibrosis and eventually cirrhosis and hepatocellular carcinoma. NAFLD has evolved as a major health problem in recent years. Discovering ways to prevent or delay the progression of NAFLD has become a global focus. Lifestyle modifications remain the cornerstone of NAFLD treatment, even though various pharmaceutical interventions are currently under clinical trial. Among them, sodium-glucose co-transporter type-2 inhibitors (SGLT-2i) are emerging as promising agents. Processes regulated by SGLT-2i, such as endoplasmic reticulum (ER) and oxidative stress, low-grade inflammation, autophagy and apoptosis are all implicated in NAFLD pathogenesis. In this review, we summarize the current understanding of the NAFLD pathophysiology, and specifically focus on the potential impact of SGLT-2i in NAFLD development and progression, providing current evidence from in vitro, animal and human studies. Given this evidence, further mechanistic studies would advance our understanding of the exact mechanisms underlying the pathogenesis of NAFLD and the potential beneficial actions of SGLT-2i in the context of NAFLD treatment

Endothelial cell dysfunction and nonalcoholic fatty liver disease (NAFLD) : a concise review

Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases worldwide. It is strongly associated with obesity, type 2 diabetes (T2DM), and other metabolic syndrome features. Reflecting the underlying pathogenesis and the cardiometabolic disorders associated with NAFLD, the term metabolic (dysfunction)-associated fatty liver disease (MAFLD) has recently been proposed. Indeed, over the past few years, growing evidence supports a strong correlation between NAFLD and increased cardiovascular disease (CVD) risk, independent of the presence of diabetes, hypertension, and obesity. This implies that NAFLD may also be directly involved in the pathogenesis of CVD. Notably, liver sinusoidal endothelial cell (LSEC) dysfunction appears to be implicated in the progression of NAFLD via numerous mechanisms, including the regulation of the inflammatory process, hepatic stellate activation, augmented vascular resistance, and the distortion of microcirculation, resulting in the progression of NAFLD. Vice versa, the liver secretes inflammatory molecules that are considered pro-atherogenic and may contribute to vascular endothelial dysfunction, resulting in atherosclerosis and CVD. In this review, we provide current evidence supporting the role of endothelial cell dysfunction in the pathogenesis of NAFLD and NAFLD-associated atherosclerosis. Endothelial cells could thus represent a “golden target” for the development of new treatment strategies for NAFLD and its comorbid CVD

Genetic and Diet-Induced Animal Models for Non-Alcoholic Fatty Liver Disease (NAFLD) Research

A rapidly increasing incidence of non-alcoholic fatty liver disease (NAFLD) is noted worldwide due to the adoption of western-type lifestyles and eating habits. This makes the understanding of the molecular mechanisms that drive the pathogenesis of this chronic disease and the development of newly approved treatments of utmost necessity. Animal models are indispensable tools for achieving these ends. Although the ideal mouse model for human NAFLD does not exist yet, several models have arisen with the combination of dietary interventions, genetic manipulations and/or administration of chemical substances. Herein, we present the most common mouse models used in the research of NAFLD, either for the whole disease spectrum or for a particular disease stage (e.g., non-alcoholic steatohepatitis). We also discuss the advantages and disadvantages of each model, along with the challenges facing the researchers who aim to develop and use animal models for translational research in NAFLD. Based on these characteristics and the specific study aims/needs, researchers should select the most appropriate model with caution when translating results from animal to human