Apelin serum level in Egyptian patients with chronic hepatitis C

Monocytes subsets altered distribution and dysregulated plasma hsa-miR-21-5p and hsa-miR-155-5p in HCV-linked liver cirrhosis progression to hepatocellular carcinoma

PURPOSE

The authors aim to investigate the altered monocytes subsets distribution in liver cirrhosis (LC) and subsequent hepatocellular carcinoma (HCC) in association with the expression level of plasma Homo sapiens (has)-miR-21-5p and hsa-miR-155-5p. A step toward non-protein coding (nc) RNA precision medicine based on the immune perturbation manifested as altered monocytes distribution, on top of LC and HCC.

METHODS

Seventy-nine patients diagnosed with chronic hepatitis C virus (CHCV) infection with LC were enrolled in the current study. Patients were sub-classified into LC group without HCC (n = 40), LC with HCC (n = 39), and 15 apparently healthy controls. Monocyte subsets frequencies were assessed by flow cytometry. Real-time quantitative PCR was used to measure plasma hsa-miR-21-5p and hsa-miR-155-5p expression.

RESULTS

Hsa-miR-21-5p correlated with intermediate monocytes (r = 0.30, p = 0.007), while hsa-miR-155-5p negatively correlated with non-classical monocytes (r = - 0.316, p = 0.005). ROC curve analysis revealed that combining intermediate monocytes frequency and hsa-miR-21 yielded sensitivity = 79.5%, specificity = 75%, and AUC = 0.84. In comparison, AFP yielded a lower sensitivity = 69% and 100% specificity with AUC = 0.85. Logistic regression analysis proved that up-regulation of intermediate monocytes frequency and hsa-miR-21-5p were independent risk factors for LC progression to HCC, after adjustment for co-founders.

CONCLUSION

Monocyte subsets differentiation in HCC was linked to hsa-miR-21-5p and hsa-miR-155-5p. Combined up-regulation of intermediate monocytes frequency and hsa-miR-21-5p expression could be considered a sensitive indicator of LC progression to HCC. Circulating intermediate monocytes and hsa-miR-21-5p were independent risk factors for HCC evolution, clinically and in silico proved.

Acute restraint stress induces cholecystokinin release via enteric apelin

Stress increases the apelin content in gut, while exogenous peripheral apelin has been shown to induce cholecystokinin (CCK) release. The present study was designed to elucidate (i) the effect of acute stress on enteric production of apelin and CCK, (ii) the role of APJ receptors in apelin-induced CCK release depending on the nutritional status. CCK levels were assayed in portal vein blood samples obtained from stressed (ARS) and non-stressed (NS) rats previously injected with APJ receptor antagonist F13A or vehicle. Duodenal expressions of apelin, CCK and APJ receptor were detected by immunohistochemistry. ARS increased the CCK release which was abolished by selective APJ receptor antagonist F13A. The stimulatory effect of ARS on CCK production was only observed in rats fed ad-libitum. Apelin and CCK expressions were upregulated by ARS. In addition to the duodenal I cells, APJ receptor was also detected in CCK-producing myenteric neurons. Enteric apelin appears to regulate the stress-induced changes in GI functions through CCK. Therefore, apelin/APJ receptor systems seem to be a therapeutic target for the treatment of stress-related gastrointestinal disorders.

Function and regulation of apelin/APJ system in digestive physiology and pathology

Apelin is an endogenous ligand of seven-transmembrane G-protein-coupled receptor APJ. Apelin and APJ are distributed in various tissues, including the heart, lung, liver, kidney, and gastrointestinal tract and even in tumor tissues. Studies show that apelin messenger RNA is widely expressed in gastrointestinal (GI) tissues, including stomach and small intestine, which is closely correlated with GI function. Thus, the apelin/APJ system may exert a broad range of activities in the digestive system. In this paper, we review the role of the apelin/APJ system in the digestive system in physiological conditions, such as gastric acid secretion, control of appetite and food intake, cell proliferation, cholecystokinin secretion and histamine release, gut-brain axis, GI motility, and others. In pathological conditions, the apelin/APJ system plays an important role in the healing process of stress gastric injury, the clinical features and prognosis of patients with gastric cancers, the reduction of inflammatory response to enteritis and pancreatitis, the mediation of liver fibrogenesis, the promotion of liver damage, the inhibition of liver regeneration, the contribution of splanchnic neovascularization in portal hypertension, the treatment of colon cancer, and GI oxidative damage. Overall, the apelin/APJ system plays diversified functions and regulatory roles in digestive physiology and pathology. Further exploration of the relationship between the apelin/APJ system and the digestive system will help to find new and effective drugs for treating and alleviating the pain of digestive diseases.

Review: Apelin in disease

Apelin, a regulatory peptide, is a ligand of the APJ receptor that belongs to the G protein-coupled receptor family. Apelin and APJ are widely distributed in the body and play potential physiological roles in the cytoprotection of many internal organs. This review article summarizes information about the roles of the apelin/APJ system in neurological, metabolic, hypertension, respiratory, gastrointestinal, hepatic, kidney and cancerous diseases. It is suggested that apelin positively affects the treatment of non-cancerous diseases and may be considered as a therapeutic drug in many illnesses. However, in cancers, apelin appears as a tumour growth stimulator, and its suggested role is as a marker in the diagnosis of tumour cancers in tissues. In summary, apelin has certain therapeutic abilities and can be useful in the treatment of, e.g., insulin resistance, hypertension, etc., but it also can sometimes serve as a negative factor.

Apelin/APJ system: A key therapeutic target for liver disease

Apelin, a new bioactive peptide, was identified as an endogenous ligand for APJ (Angiotensin II receptor-like 1). Apelin and its receptor have an abundant distribution in central nervous system and peripheral tissues, including liver. Apelin/APJ has diverse physiological and pathological effects, including regulation of cardiovascular function, angiogenesis, fluid homeostasis and so on. Apelin/APJ system may act as a novel potential therapeutic target for liver disease. In this article, we review the role of apelin/APJ system in liver fibrosis, hepatitis, hepatic cirrhosis, liver injury and metabolic liver disease.

Peripheral apelin-13 administration inhibits gastrointestinal motor functions in rats: The role of cholecystokinin through CCK1 receptor-mediated pathway

Apelin is the endogenous ligand of the G protein-coupled receptor APJ. The APJ receptor is widely expressed in gastrointestinal (GI) tissues including stomach and small intestine. Apelin administration was shown to induce the release of cholecystokinin (CCK) which is a well-known alimentary hormone with its inhibitory actions on GI motor functions through CCK₁ receptors on vagal afferent fibers. We investigated whether; (i) peripherally injected apelin-13 alters GI motor functions, (ii) apelin-induced changes are mediated by APJ receptor or CCK₁ receptor and (iii) vagal afferents are involved in inhibitory effects of apelin. Solid gastric emptying (GE) and colon transit (CT) were measured, whereas duodenal phase III-like contractions were recorded in rats administered with apelin-13 (300μg/kg, ip). CCK₁ receptor antagonist lorglumide (10mg/kg, ip) or APJ receptor antagonist F13A (300μg/kg, ip) was administered 30min prior to the apelin-13 injections. Vagal afferent denervation was achieved by systemic administration of vanilloid receptor agonist capsaicin (125mg/kg, sc). Apelin-13 administration significantly (p<0.01) increased the CCK level in portal venous plasma samples. Compared with vehicle-treated rats, apelin-13 significantly delayed both GE (p<0.001) and CT (p<0.01). Pretreatment of lorglumide or F13A completely abolished the apelin-13-induced inhibitory effects on GE and CT, moreover, apelin-13 was found ineffective in rats underwent afferent denervation. F13A administration alone significantly accelerated the basal CT. Apelin-13 noticeably disturbed the duodenal fasting motor pattern by impairing phase III-like contractions while increasing the amplitudes of phase II contractions which were prevented by pretreatment of lorglumide and capsaicin. Compared with vehicle-treated rats, lorglumide and capsaicin significantly (p<0.05) reduced the apelin-13-induced increases in phase II motility index. Peripherally administered apelin-13 inhibits GI motor functions through CCK-dependent pathway which appears to be mediated by CCK₁ receptors on vagal afferents. Peripheral apelin might contribute to the motility changes occurred in postprandial period.

The Role of the Apelin/APJ System in the Regulation of Liver Disease

Apelin is an endogenous peptide that is a ligand for the APJ receptor (angiotensin II receptor like-1, AT-1). The apelin/APJ system is distributed in diverse periphery organ tissues. It has been shown that the apelin/APJ system plays various roles in physiology and pathophysiology of many organs. It regulates cardiovascular development or cardiac disease, glycometabolism and fat metabolism as well as metabolic disease. The apelin/APJ system participates in various cell activities such as proliferation, migration, apoptosis or inflammation. However, apelin/APJ function in the liver is still under investigation. In the liver, the apelin-APJ system could play an inhibitory role in liver regeneration and promote Fas-induced apoptosis. It may participate in the formation of hepatic fibrosis or cirrhosis, and even cancer. In this review, we summarize the role of the apelin/APJ system in liver disease.

Characterization of the apelin -1860T>C polymorphism in Turkish coronary artery disease patients and healthy individuals

To evaluate the association between the apelin -1860T>C polymorphism and plasma apelin levels in Turkish patients with coronary artery disease (CAD). A total of 276 individuals were enrolled in the present study, including 158 patients with CAD and 118 individuals without CAD as controls. The presence of the apelin -1860T>C gene polymorphism and plasma apelin levels were determined using polymerase chain reaction/restriction fragment length polymorphism and enzyme-linked immunosorbent assay, respectively. Significance was set at p≤0.05 for all statistical analyses. The genotype and allele frequencies of interested genes were significantly different between groups (χ(2)=10.2; df=2; p=0.006 and χ(2)=13.4; df=1; p=0.000, respectively). Frequency of CC genotype and the C allele of -1860T>C site was significantly higher in CAD patients compared to healthy controls. We found that individuals with the TC and CC genotypes were associated with an increased risk of CAD when compared with the TT genotype in CAD patients, and the adjusted ORs (95% CI) were 6.50 (1.27-33.0) and 6.39 (1.77-23.0), respectively. Plasma apelin levels were significantly lower in CAD patients compared to control group. Apelin level of CAD patient group having CC genotype of -1860T>C site was significantly lower compared to those having TT genotypes, but it was not statistically significant (p > 0.05). The homozygous CC genotype of apelin gene is associated with high risk of CAD. Apelin gene polymorphism -1860T>C is a significant predictor of predisposition to CAD in in Turkish population.

Genotype screening of APLN rs3115757 variant in Egyptian women population reveals an association with obesity and insulin resistance

AIMS

Apelin is one of adipokines that plays a pivotal role in energy metabolism, insulin sensitivity and vascular integrity. A definite genetic variant of apelin gene (APLN), rs3115757, was recently introduced to potentially influence apelin expression in adipocytes. The aim of our study was to explore the sights of a potential association of this functional variant with obesity traits, insulin resistance indices as well as type 2 diabetes mellitus (T2DM) prevalence.

METHODS

Genotype screening for rs3115757 variant in 151 Egyptian female samples was conducted. Fasting levels of serum insulin and lipid profile, in addition to plasma glucose were measured. Cochran-Armitage trend test was used to decide the risk allele and evaluate the association between the candidate variant and obesity using a case-control design.

RESULTS

The homozygous G risk allele carriers showed higher values of body mass index (BMI) and waist circumference (P=0.001,0.02, respectively) as compared to CC or CG genotypes. As for GG genotype carriers, the risk of developing morbid obesity in lean subjects, (BMI<25), is twelve times the risk in subjects carrying other genotypes (OR=12.09, 95% CI: 1.4, 104.8, P=0.024). On the other hand, GG carriers are shown to be more resistant to insulin. Significantly after correction for BMI and age effects, GG genotype carriers showed 14% and 41% increment in insulin level and resistance (OR=1.14, 95% CI: 1.06, 1.23, P=0.001), (OR=1.42, 95% CI: 1.19, 1.70, P<0.001), respectively.

CONCLUSION

These results suggest a prospective role mediated by this variant in mounting obesity disorders and as significant as insulin resistance complications.

Emerging role of adipokine apelin in hepatic remodelling and initiation of carcinogensis in chronic hepatitis C patients

BACKGROUND

Although accumulating data has implicated a role for the Apelinergic system in cirrhosis, the role of Apelin during different stages of fibrogenesis has not been clarified, whereas no studies have been conducted on its expression in human hepatocellular carcinoma (HCC). This study aimed to elucidate its role in hepatic remodelling and carcinogenesis.

METHODS

Immunolocalization of Apelin was compared during different stages of HCV-induced liver disease (n=123).

RESULTS

Apelin level in hepatic stellate cells (HSC), portal fibroblast and endothelial cells was significantly elevated in F3 stage .In cirrhosis, the expression was markedly striking and extended as linear staining in the cirrhotic septa and proliferated capillaries. In liver cirrhosis with high grade dysplastic nodule (HGDN) group and liver cirrhosis with HCC group, Apelin was constantly expressed in the hepatocytes with the exemption of non-parenchymatous cells. Apelin gradually increased in HGDN, HCC grade-I and HCC grade II (P<0.0001). In contrast, Apelin gradually decreased in the cirrhosis adjacent to HGDN, HCC grade-I and HCC grade II (P<0.0001). The gradual incline in Apelin expression in dysplastic and malignant cells was paralleled by a decline in their adjacent cirrhotic liver (P=0.013).

CONCLUSION

In HCV chronic hepatitis, Apelin seems to manipulate the differentiation of HSC ending in hepatic remodelling. The uptake of Apelin from the stromal components by the epithelial cells may initiate the transformation of adjacent epithelial cells and supports the evolution and progression of dysplastic nodules and hepatocellular carcinoma. These findings could have both prognostic and therapeutic applications.

The relationship between apelin and cardiac parameters in patients on peritoneal dialysis: is there a new cardiac marker?

Background

Many markers have been proposed for CVD risk assessment in dialysis population. Apelin is a peptide that has roles in cardiovascular functions and volume regulation namely vasodilation, decreased blood pressure (BP), positive inotropic effect and inhibition of antidiuretic hormone release. The aim of this study was to examine relationship of apelin levels with echocardiographic findings and laboratory parameters related with cardiovascular function and bone mineral metabolism among peritoneal dialysis (PD) patients.

Methods

This is a cross-sectional study in which chronic PD patients aged between 18 and 80 without active cardiac, infectious or malignant diseases and hypervolemia have been included. Apelin-36 levels and echocardiographic findings were recorded as well as clinical and laboratory data.

Results

Of the 53 patients, the mean age and female/male ratio was 52.8 ± 15.3 years and 30/23, respectively. Mean apelin level was 1.45 ± 0.37 ng/ml. Gender, drugs (renin-angiotensin-aldosteron inhibitors, statins), presence of left ventricular hypertrophy, diabetes mellitus, hypertension, hyperlipidemia and significant residual renal function did not affect apelin-36 levels. Apelin-36 was correlated negatively with age and left atrium diameter; and positively with diastolic BP, ejection fraction (EF), total cholesterol, LDL-cholesterol, HDL-cholesterol, parathyroid hormone and alkaline phosphatase (ALP) levels. Diastolic BP, LDL-cholesterol, ALP and EF were found to be the independent determinants of apelin-36 levels with linear regression analysis.

Conclusions

Apelinergic system has important roles in volume regulation, cardiovascular functions, lipid metabolism and bone mineral disorders in PD patients. Prospective studies with large population are required.

The serine protease granzyme B as an inflammatory marker, in relation to the insulin receptor cleavage in human obesity and type 2 diabetes mellitus

Chronic inflammation and insulin resistance form hallmarks of type 2 diabetes mellitus (T2DM). An increased circulating level of the serine protease granzyme B (GzmB) is observed during prolonged inflammation and is implicated in the pathogenesis of several chronic inflammatory diseases. Moreover, insulin receptor cleavage by unknown proteases, yielding elevated levels of insulin receptor α-subunit (IRα), was observed in T2DM and was proposed as a new mechanism of insulin resistance. Therefore, a possible association between GzmB and IRα is suggested. Accordingly, this study was set to explore whether GzmB and IRα levels are altered in T2DM patients with the impact of obesity. Furthermore, we aimed to identify if GzmB contributes towards inflammation and insulin resistance through its suggested extracellular activities. All subjects were assessed for anthropometric and metabolic parameters related to obesity and T2DM. In addition, fasting plasma insulin, GzmB, interleukin-1β (IL-1β), and IRα levels were estimated by enzyme linked immunosorbent assay. Levels of GzmB and IRα were found to be significantly elevated in T2DM patients compared to nondiabetic subjects. In addition, GzmB levels were positively correlated with measures of obesity and insulin resistance, IL-1β, IRα, and other metabolic parameters. While multiple linear regression analysis revealed that both T2DM and central obesity were predicting factors for GzmB, our findings reveal a possible role of GzmB in T2DM.