Apelin Levels Research Articles

Quercetin Attenuates Atherosclerosis via Modulating Apelin Signaling Pathway Based on Plasma Metabolomics.

To interpret the pharmacology of quercetin in treatment of atherosclerosis (AS). Fourteen apolipoprotein E-deficient (ApoE-/-) mice were divided into 2 groups by a random number table: an AS model (ApoE-/-) group and a quercetin treatment group (7 in each). Seven age-matched C57 mice were used as controls (n=7). Quercetin [20 mg/(kg·d)] was administered to the quercetin group intragastrically for 8 weeks for pharmacodynamic evaluation. Besides morphological observation, the distribution of CD11b, F4/80, sirtuin 1 (Sirt1) and P21 was assayed by immunohistochemistry and immunofluorescence to evaluate macrophage infiltration and tissue senescence. Ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MSC/MS) was performed to study the pharmacology of quercetin against AS. Then, simultaneous administration of an apelin receptor antagonist (ML221) with quercetin was conducted to verify the possible targets of quercetin. Key proteins in apelin signaling pathway, such as angiotensin domain type 1 receptor-associated proteins (APJ), AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), tissue plasminogen activator (TPA), uncoupling protein 1 (UCP1) and angiotensin II receptor 1 (AT1R), were assayed by Western blot. Quercetin administration decreased lipid deposition in arterial lumen and improved the morphology of ApoE-/- aortas in vivo. Quercetin decreased the densities of CD11b, F4/80 and P21 in the aorta and increased the level of serum apelin and the densities of APJ and Sirt1 in the aorta in ApoE-/- mice (all P<0.05). Plasma metabolite profiling identified 118 differential metabolites and showed that quercetin affected mainly glycerophospholipids and fatty acyls. Bioinformatics analysis suggested that the apelin signaling pathway was one of the main pathways. Quercetin treatment increased the protein expressions of APJ, AMPK, PGC-1α, TPA and UCP1, while decreased the AT1R level (all P<0.05). After the apelin pathway was blocked by ML221, the effect of quercetin was abated significantly, confirming that quercetin attenuated AS by modulating the apelin signaling pathway (all P<0.05). Quercetin alleviated AS lesions by up-regulation the apelin signaling pathway.

Expression of Apelin in Rotator Cuff Tears and Examination of Its Regulatory Mechanism: A Translational Study.

Inflammatory mediators play important roles in the pain associated with rotator cuff tears (RCTs), but their underlying mechanisms are unclear. Apelin, a neuropeptide, is upregulated under inflammatory conditions and possibly contributes to pain induced by rotator cuff tears. This translational study aimed to examine apelin expression and regulation by tumor necrosis factor alpha (TNF-α) in patients with RCT and in rat RCT models. Synovial tissues were harvested from the glenohumeral joints of the shoulders in 46 patients who underwent arthroscopic Bankart repair for recurrent shoulder dislocations (RSDs) or arthroscopic rotator cuff repair for RCTs. The harvested tissues were extracted and processed by reverse transcriptase-polymerase chain reaction (RT-PCR). Rats underwent sham or RCT surgery; the rotator cuff tissues were extracted 1, 7, 14, 28, and 56 days after surgery and analyzed for mRNA expression levels of the TNF-α and apelin using RT-PCR. The cultured rotator cuff cells (RCCs) were stimulated with TNF-α to examine their role in the regulation of apelin expression. Apelin expression was higher in the RCT group than in the RSD group and significantly correlated with pain intensity. In rats, the expression was also higher in RCT. Apelin expression significantly increased during the acute and chronic phases in rats. In cultured RCCs, apelin mRNA levels significantly increased after TNF-α stimulation. Apelin levels were regulated by TNF-α and were highly expressed in patients with RCT and rats in RCT models. Thus, apelin may be a new pain management target for RCTs.

Assessment of Serum Apelin Levels and Its Relation to Insulin Resistance in Acne Vulgaris Patients

Abstract Introduction Apelin is one of the adipokines. Acne vulgaris is a very common dermatological disease with a multifactorial background and hyperinsulinemia and insulin resistance are considered to play a pivotal role in its development and severity. Aim To evaluate serum apelin levels in acne vulgaris patients and to reveal the possible relation between its serum levels and the insulin resistance state in acne vulgaris patients. Material and methods Thirty-two acne vulgaris patients and thirty-two healthy controls were enrolled into the study. The blood levels of apelin, insulin and glucose were measured in patients and controls. Homeostasis model assessment index (HOMA-IR) was calculated to evaluate the insulin resistance state. Results Acne vulgaris patients experienced significant higher levels of fasting insulin, serum apelin, and HOMA-IR compared to controls. Conclusions These results suggest that serum apelin and insulin resistance may have a role in the pathogenesis of acne.

Effect of Apelin on Hepatic Dysfunction in a Rat Model of Heart Failure

Background Severe heart failure can be accompanied with liver dysfunction. The role of apelin in liver disease is still a matter of debate. The aim of this study is to examine the effect of apelin on liver dysfunction in heart failure rat model and the underlying mechanisms of this effect. Materials and Methods 39 female Wistar rats were divided into three groups 13 each; control (Intraperitoneal saline for 2 weeks, daily), Isoprenaline (ISO) (Intraperitoneal saline for 2 weeks, ISO in the last 2 days (100 mg/kg, subcutaneous) and Apelin group (apelin, 15 µg/kg/day Intraperitoneal for 2 weeks and ISO in the last 2 days). Body weights, heart and liver weights, ECG record, isolated heart study and histopathological examination for both heart and liver were carried out. Serum cardiac troponin T (cTnT), liver enzymes (alanine transaminase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH) and apelin and liver APJ receptors, malondialdehyde (MDA), reactive oxygen species (ROS) and cytochrome C were measured. Results Apelin decreased heart weights, shortened QRS complex as well as observed and corrected Q-T intervals, increased R voltage, peak developed tension, peak developed tension per left ventricular weights and mean coronary flow rate compared to ISO treated rats. It decreased serum levels of cTnT, ALT, AST&amp; LDH and improved serum apelin level. Also, it enhanced the hepatic expression of APJ receptor and decreased MDA &amp; ROS and cytochrome C in liver tissue. Conclusion Apelin had a protective role against hepatic dysfunction that accompanied heart failure through its antioxidant and anti-apoptotic effects.

Can Dietary n-3 Polyunsaturated Fatty Acids Affect Apelin and Resolvin in Testis and Sperm of Male Rabbits?

Apelin and other novel adipokines have been associated with normal and pathological reproductive conditions in humans and animals. In this paper, we used a rabbit model to investigate if apelin and resolvin (RvD1) in testis and sperm are associated with the oxidative status of semen and serum testosterone of rabbits fed different diets enriched with flaxseed (alpha-linolenic acid, ALA) or with fish oil (eicosapentaenoic acid, EPA, docosapentaenoic acid, DPAn-3, and docosahexaenoic acid, DHA). Apelin and RvD1 were detected by ELISA and apelin and the apelin receptor by immunofluorescence. Increased levels of apelin in testes from both enriched diets were shown, particularly in the interstitial tissue of the FLAX group. The FLAX diet enhanced serum testosterone, and both enriched diets showed higher levels of malondialdehyde and RvD1 in the testis. In ejaculated sperm, apelin and its receptor were localized in the entire tail of the control and both treated groups. The ryanodine receptor was investigated in rabbit testis; the fluorescent signal was increased in mature elongated spermatids of the FLAX group. In conclusion, this data seems to indicate that FLAX increases the amount of apelin in testis, suggesting an involvement of this adipokine in male reproduction and probably a role in the resolution of the inflammatory status.

Study of Serum Apelin and Insulin Resistance in Type 2 Diabetes Mellitus Patients With or Without Obesity.

Type 2 diabetes mellitus (T2DM) is a chronic disorder characterized by persistent hyperglycemia. Chronic hyperglycemia in diabetes mellitus can cause microvascular and macrovascular complications. Obesity is a major risk factor contributing to disease progression and complications of T2DM. Apelin is an adipokine having a compensatory role in reducing insulin resistance (IR)in morbidly obese individuals. This study was undertaken to find a correlation between Apelin, IR, and obesity. This case-control study included 180 participants, cases (n=90) having T2DM, and healthy controls (n=90). Further, the case and control groups were divided into group I (non-obese) and group II (obese) according to their body mass index (BMI) as per the Asia Pacific classification of BMI. Following obtainingconsent, anthropometrical measurements and blood parameters likeserum total lipid profile, fasting and postprandial glucose level, Apelin, and insulin were done,and results were analyzed statistically usingStatistical Package for the Social Sciences (SPSS) version 21(IBM Corp., Armonk, NY). A significantly higher Apelin level was observed in diabetes patients with obesity (265.16±11.0 pg/mL) as compared to non-obese (206.44±83.0 pg/mL). A positive correlation between serum Apelin levels and BMI was found (r=0.367, p=0.003). Homeostasis Model Assessment of IR (HOMA-IR) is increased in obese patients in comparison to the control group. A significant positive correlation between BMI and HOMA-IR (r=0.429, p=0.001) and Apelin and IR (r=0.742, p=0.000) was found in this study. On the basis of the finding of this study, we may conclude that Apelin has a role in improving insulin sensitivity in T2DM. Larger and multicentric studies are further required to discover the therapeutic role of Apelin in T2DM.

Supplementation with spinach-derived thylakoid augments the benefits of high intensity training on adipokines, insulin resistance and lipid profiles in males with obesity.

This study investigated the effects of 12 weeks of high-intensity functional training (HIFT) combined with spinach-derived thylakoid supplementation on some selected Adipokines and insulin resistance in males with obesity. Sixty-eight participants (mean age: 27.6 ± 8.4 yrs.; mean height: 168.4 ± 2.6cm; mean weight: 95.7 ± 3.8kg, mean BMI: 32.6 ± 2.6 kg/m2) were randomly divided into four groups of 17 per group: Control group (CG), Supplement group (SG), Training group (TG), and Training + supplement group (TSG). Following baseline measurements, the two training groups (TG and TSG) started the 12 weeks of exercise training program (3 sessions per week). A total of 36 sessions lasting up to 60min were included in the HIFT program using the CrossFit program. The eligible participants received 5 g/day of thylakoid-rich spinach extract or matching placebo as 5 g/day of raw corn starch (one sachet, 30min before lunch) for 12 weeks. Baseline assessments were obtained 48 hours before the start of the training protocols and 48 hours after the last training session in all groups. There were significant interactions (p<0.001 for all) between exercise and time for adiponectin (ES:0.48), leptin (ES:0.46), resistin (ES:0.3), omentin (ES:0.65), vaspin (ES:0.46), visfatin (ES:0.62), apelin (ES:0.42), RBP4 (ES:0.63), chemrin (0.36) and semaphorin3c (ES: 0.5). Plasma levels of semaphorin3c were significantly correlated (p<0.05) with body weight (r= 0.57), BMI (r= 0.43), FFM (r= -0.612), FAT (r= 0.768), VO2peak (r=-0.53), insulin (r= 0.756), glucose (r= 0.623), and HOMA-IR (r= 0.727). There were also significant group differences in insulin (ES: 0.77), glucose (ES: 0.21), and HOM-IR (ES: 0.44) (p<0.05). Our findings indicate that 12 weeks of HIFT supplemented with spinach-derived thylakoid reduced levels of leptin, resistin, vaspin, visfatin, apelin, RBP4, chemrin, semaphorin3c and insulin resistance while increasing adiponectin and omentin levels in men with obesity.

A cross-sectional study of the association between circulating sex hormone-binding globulin levels and selected adipokines in women with polycystic ovary syndrome.

Changes in the proportion of pro-inflammatory and anti-inflammatory adipokines may reflect the accumulation of lipids in the liver and the development of insulin resistance. Both liver steatosis and insulin resistance result in decreased sex hormone-binding globulin (SHBG) synthesis. This study aimed to analyze associations between circulating SHBG and adipokines levels in women with polycystic ovary syndrome (PCOS). A cross-sectional cohort study involved 87 women with phenotype A of PCOS (39 normal weight and 48 obese). Body mass, height, and waist circumference were measured, and BMI was calculated. In addition, body composition was assessed using the bioimpedance method. Serum SHBG levels and plasma apelin-36 and apelin-12, adiponectin, leptin, omentin-1, and RBP-4 were determined by using the ELISA method. The participants were divided into subgroups with SHBG concentrations above and below this lower limit [N = 35 (40.2%) and N = 52 (59.8%), respectively]. The median adiponectin, apelin-12, and apelin-36 levels were significantly lower, and leptin levels were significantly higher in the subgroup with low SHBG levels than that in the subgroup above the lower limit of the reference range, while there were no differences in median omentin-1 and RBP-4 between the study subgroups. There were positive correlations between SHBG and omentin-1, adiponectin, apelin-36, and apelin-12 levels, as well as negative correlation with leptin levels. However, after adjustment by BMI, waist circumference, and body fat percentage, only the association between SHBG and omentin-1 remained significant. Our results show associations between circulating SHBG and adipokine levels in women with PCOS and support the role of hormonal dysfunction of the adipose tissue in the pathogenesis of PCOS.

An evaluation of both serum Klotho/FGF-23 and apelin-13 for detection of diabetic nephropathy.

The aim of our study is to evaluate whether serum Klotho/FGF-23 and apelin-13 can be used as new biomarkers for detection of development of nephropathy. In this cross-sectional study, 88 type 2 diabetes mellitus (T2DM) patients and 38 healthy controls were included. The mean duration of T2DM was 11.4 ± 9.7years. T2DM individuals were categorized into two groups as group 1 with e-GFR < 60mL/min/1.73 m2 and group 2 with e-GFR > 60mL/min/1.73 m2. They were also divided into two groups according to their 24h urine albumin levels, classifying them as follows: normoalbuminuria if less than 30mg/day and albuminuria if more than 30mg/day. Mean serum Klotho levels in the T2DM group were observed to be significantly higher than in the control group. Serum apelin-13 levels were observed to be significantly lower in the T2DM group compared to the control group (p < 0.001). In the diabetic group, apelin-13 levels were positively correlated with age, waist circumference, and albuminuria while they were negatively correlated with e-GFR. Apelin-13 levels were seen to be significantly higher in group 1 (p < 0.001). Apelin-13 levels were found to be significantly higher in individuals with diabetic nephropathy than in those without diabetic nephropathy. In the diabetic group, a significant relationship was detected between apelin-13 levels and albumin excretion. Based on these findings, we consider that serum Klotho and apelin-13 levels may have a protective effect on diabetic nephropathy and can additionally be used as a biomarker to predict diabetic nephropathy.

The cardioprotective effects of secoisolariciresinol diglucoside (flaxseed lignan) against cafeteria diet-induced cardiac fibrosis and vascular injury in rats: an insight into apelin/AMPK/FOXO3a signaling pathways.

Introduction: Fast food is a major risk factor for atherosclerosis, a leading cause of morbidity and mortality in the Western world. Apelin, the endogenous adipokine, can protect against cardiovascular disease via activating its receptor, APJ. Concurrently, secoisolariciresinol diglucoside (SDG), a flaxseed lignan extract (FLE), showed a therapeutic impact on atherosclerosis. The current study aimed to examine the effect of SDG on cafeteria diet (CAFD)-induced vascular injury and cardiac fibrosis via tracking the involvement of the apelin/APJ pathway. Methods: Thirty male rats were allocated into control, FLE-, CAFD-, CAFD/FLE-, and CAFD/FLE/F13A-treated rats, where F13A is an APJ blocker. All treatments lasted for 12weeks. Results and discussion: The CAFD-induced cardiovascular injury was evidenced by histological distortions, dyslipidemia, elevated atherogenic indices, cardiac troponin I, collagen percentage, glycogen content, and apoptotic markers. CAFD increased both the gene and protein expression levels of cardiac APJ, apelin, and FOXO3a, in addition to increasing endothelin-1, VCAM1, and plasminogen activator inhibitor-1 serum levels and upregulating cardiac MMP-9 gene expression. Moreover, CAFD reduced serum paraoxonase 1 and nitric oxide levels, cardiac AMPK, and nuclear Nrf2 expression. FLE attenuated CAFD-induced cardiovascular injury. Such effect was reduced in rats receiving the APJ blocker, implicating the involvement of apelin/APJ in FLE protective mechanisms. Conclusion: FLE supplementation abrogated CAFD-induced cardiac injury and endothelial dysfunction in an apelin/APJ-dependent manner.

#3642 SERUM APELIN AND RENAL PROGNOSIS IN PATIENTS WITH NON-DIALYSIS DEPENDENT CHRONIC KIDNEY DISEASE

Abstract Background and Aims The apelin/APJ system is a novel pleiotropic system with an essential role in renal and cardiovascular physiology and disease. A role for the apelin/APJ system in diverse pathological states, including disorders of sodium and water balance, hypertension, heart failure, pre-eclampsia, acute kidney injury, sepsis and diabetic nephropathy, has recently been reported. Especially, the impact of apelin/APJ system on cardiovascular system has been attracting attention, but scarce data is available in chronic kidney disease (CKD). Method We measured serum apelin-36 by ELISA in 411 outpatients with non-dialysis dependent (NDD) CKD and analyzed factors associated with serum apelin. Furthermore, we examined the association of serum apelin with renal outcome (renal replacement therapy, RRT) using multivariate Cox proportional hazards model. Results Median age and eGFR were 71 years and 21.7 ml/min/1.73 m2, respectively and the prevalence of male gender and diabetes was 26.8% and 50.8%, respectively. Median serum apelin was 0.81pg/ml. There was no significant difference in serum apelin level between male and female patients, or those with and without diabetes. Moreover, serum apelin level had no significant association with age and eGFR; however, there was a significant relationship between serum apelin and brain natriutetic peptide. During the follow-up period of 38 months, 126 patients started RRT. eGFR and age were associated with the time to RRT induction. Serum apelin was not associated with renal outcome (HR, 1.05; 95%CI, 0.64-1.71; P,0.86); however, this association was interacted by diabetes and gender (P for interaction, 0.073 and 0.070, respectively). Conclusion Serum apelin could be a predictive marker of renal prognosis in male and non-diabetic CKD patients.

IMPROVEMENT OF PREDICTIVE UTILITY OF NATRIURETIC PEPTIDE FOR HEART FAILURE WITH PRESERVED EJECTION FRACTION WITH APELIN IN TYPE 2 DIABETES MELLITUS PATIENTS

Objective: Apelin plays a pivotal role in adverse cardiac remodeling and the occurrence of heart failure (HF) with reduced ejection fraction in type 2 diabetes mellitus (T2DM). The purpose of the study was to investigate whether serum levels of apelin predict HF with preserved ejection fraction (HFpEF) in patients with T2DM Design and method: The study was retrospectively involved 76 T2DM individuals aged from 41 to 65 years (48 patients with overt HFpEF and 28 non-HFpEF patients). Healthy control group was consisted of 25 individuals matched with age and sex. Serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), apelin, and high sensitive C-reactive protein (hs-CRP) were determined by ELISA Results: Serum levels of apelin and NT-proBNP were significantly increased in patients with HFpEF (7.74 ng/mL, 95% CI = 6.31-8.25 ng/mL and 954.8 pmol/mL, 95% CI = 476.2-1764.3 pmol/mL, respectively) when compared with non-HFpEF diabetics (2.26 ng/mL; 95% CI = 1.70-2.90 ng/mL; and 113.5 pmol/mL, 95% CI = 75.4-144.9 pmol/mL, respectively) and healthy volunteers (1.52 ng/mL 95% CI = 1.12-2.13 ng/mL and 67.8 pmol/mL, 95% CI = 49.1-87.4 pmol/mL; respectively). Apelin levels correlated positively with body mass index (r = 0.32, P = 0.001), serum uric acid (r = 0.30, P = 0.016), HDL cholesterol (r = 0.28, P = 0.001), hs-CRP (r = 0.26, P = 0.001) and were negatively associated with ejection fraction (r = 0.34, P = 0.002), and age (r = -0.30, P = 0.001). The ROC curve showed that the best fitted cut-off point for the apelin to NT-proBNP ratio was 0.82 units (area under curve = 0.76; sensitivity = 69.5%, and specificity 94.2%, P = 0.001). In multivariate logistic regression analysis the apelin to NT-proBNP ratio &lt; 0.82 × 10-2 units independently predicted (odds ratio = 1.44; 95% confidence interval: 1.18 – 2.77; P = 0.001) HFpEF in T2DM patients. Conclusions: Apelin to NT-proBNP ratio &lt; 0.82 × 10-2 was independent predictor for HFpEF in T2DM patients

Serum Apelin Level in Type 2 Diabetic Mellitus Patients and Its Association With Metabolic Syndrome Components

Serum Apelin Level in Type 2 Diabetic Mellitus Patients and Its Association With Metabolic Syndrome Components

Apelin and Visfatin Expression in Placental Tissue in Women With Preeclampsia and Overweight/Obesity.

Preeclampsia (PE) is a multifunctional and multisystem disorder. Several factors favor the development of PE, including obesity. Cytokines are also expressed in the placenta, predisposing to local alterations that favor the development of distinct pathological processes, including PE. This study aimed to evaluate the apelin and visfatin mRNA expression in the placental tissue of women with preeclampsia and overweight/obesity and correlates with maternal and fetal variables. A cross-sectional analytical study was performed with 60 pregnant women and their newborns. Clinical, anthropometric, and laboratory variables were collected. Placental tissue samples were obtained, and the apelin and visfatin mRNA expression levels were assessed by qRT-PCR. The main findings evidenced lower levels of apelin expression in overweight/obese women, accompanied by a negative correlation with BMI and pre-pregnancy weight; a higher expression of apelin was also observed in women with late PE and no personal history of PE. For visfatin levels, higher expression levels were observed in women with late PE and term delivery. Furthermore, a positive correlation was observed between visfatin levels and fetal anthropometric parameters, such as weight, length, and head circumference. Apelin levels were less expressed in overweight/obese women. Apelin and visfatin levels were correlated/associated with maternal-fetal variables.

Plasma visfatin and apelin levels in adolescents with polycystic ovary syndrome

Background Polycystic ovary syndrome (PCOS) is a common endocrine disorder that usually begins during adolescence. Patients may have severe metabolic disorders. Objective To investigate the levels of visfatin and apelin in adolescent girls with PCOS and to explore the importance of visfatin and apelin in glucose and lipid metabolism. Methods A total of 88 girls (aged 12–20 years) were prospectively and consecutively recruited during two years for the PCOS group (n = 44) and the control group (n = 44). Serum visfatin, apelin and other metabolic parameters were measured. Receiver operator characteristics (ROC) curve analysis was performed to reveal the diagnostic potential. Results Visfatin, apelin and indicators of glucose and lipid-metabolism were not different for PCOS patients compared to control. However, insulin resistance (IR) in the PCOS-group was more frequent (p < 0.05). Visfatin in non-IR patients was higher than in IR-patients in the PCOS-group (p < 0.05). However, there was no difference in apelin levels between IR and non-IR patients in the PCOS-group (p > 0.05). ROC-curve analyses demonstrated that the optimal value of visfatin for predicting IR in PCOS-patients was 7.14 ng/mL, with 78.1% sensitivity and 68.7% specificity. In the PCOS-group, visfatin was positively correlated with high density lipoprotein cholesterol (HDL-C), and negatively correlated with HOMA-IR, apolipoprotein B (Apo-B), cholesterol (CHO), low density lipoprotein cholesterol (LDL-C) and CHO/HDL-C ratio (p < 0.05). Apelin had no correlation with all indices (p > 0.05). Conclusions Higher visfatin levels may prevent IR in adolescent PCOS patients, showing a positive predictive value for IR and also reflecting a beneficial effect on lipids. It is a possible protective factor at certain stages of metabolic syndrome.

Protective Role of Short-term Aerobic Exercise Against Zinc Oxide Nanoparticles-Induced Cardiac Oxidative Stress Via Possible Changes of Apelin, Angiotensin II/Angiotensin II Type I Signalling Pathway.

This study examined the protective role of short-term aerobic exercise on ZnO NPs-induced cardiac oxidative stress and possible changes of apelin, angiotensin II (AngII) and angiotensin II type I receptor (AT1R) signalling pathway. Thirty-five male Wistar rats were randomized into five groups of seven rats, including control, saline, ZnO NPs, exercise and exercise + ZnO NPs groups. The animal in ZnO NPs and exercise + ZnO NPs groups received 1mg/kg of ZnO NPs. Rats underwent the treadmill exercise program. Treatments lasted four weeks, 5 days/week. After 4weeks of treatment, superoxide dismutase (SOD) activity, malondialdehyde (MDA), apelin, Ang II and AT1R concentration were measured in heart tissue.Cardiac MDA, Ang II and AT1R levels significantly increased while SOD activity and apelin levels significantly decreased following ZnO NPs administration. The aerobic exercise induced a significant increase in the SOD activity and apelin levels and a significant decrease in the enhanced MDA, Ang II and AT1R levels in the heart of ZnO NPs-exposed rats. These results suggest that the exercise-induced attenuation of the Ang II-AT1R signalling pathway is mediated by reduced lipid peroxidation, augmented antioxidant defence and enhanced apelin synthesis that may be a protective mechanism to prevent and/or treatment ZnO NPs-induced cardiac oxidative stress.

Apelin as a Potential Regulator of Peak Athletic Performance

Apelin, as a cardiokine/myokine, is emerging as an important regulator of cardiac and skeletal muscle homeostasis. Loss of apelin signaling results in premature cardiac aging and sarcopenia. However, the contribution of apelin to peak athletic performance remains largely elusive. In this paper, we assessed the impact of maximal cardiorespiratory exercise testing on the plasma apelin levels of 58 male professional soccer players. Circulating apelin-13 and apelin-36, on average, increased transiently after a single bout of treadmill exercise; however, apelin responses (Δapelin = peak - baseline values) showed a striking interindividual variability. Baseline apelin-13 levels were inversely correlated with those of Δapelin-13 and Δapelin-36. Δapelin-13 showed a positive correlation with the maximal metabolic equivalent, relative maximal O2 consumption, and peak circulatory power, whereas such an association in the case of Δapelin-36 could not be detected. In conclusion, we observed a pronounced individual-to-individual variation in exercise-induced changes in the plasma levels of apelin-13 and apelin-36. Since changes in plasma apelin-13 levels correlated with the indicators of physical performance, whole-body oxygen consumption and pumping capability of the heart, apelin, as a novel exerkine, may be a determinant of peak athletic performance.

Effects of Danshensu Sodium Combined with Tongxinluo on Cardiac Function and Calcium Channels in a Rat Model of Heart Failure

The study aimed to investigate the protective effects of Danshensu sodium and Tongxinluo on cardiac function, apelin-13, and L-type calcium channel in a rat model of heart failure. Thirty-two rats were divided into three groups: Danshensu Sodium, Tongxinluo, and Experimental (combination of Danshensu Sodium and Tongxinluo). Twenty-four rat models of heart failure were treated with Danshensu Sodium, Tongxinluo, or Danshensu Sodium+Tongxinluo. Cardiac function, apelin-13, and L-type calcium channel expression were compared among the four groups. The injury and repair of myocardial tissue were observed by HE staining, and the fibrosis of myocardial tissues was observed by Masson staining. The results showed that the combination of Danshensu sodium and Tongxinluo significantly improved cardiac function, decreased apelin-13 levels, decreased L-type calcium channel current density, and increased Cav1.2 protein expression compared to the Danshensu Sodium group and Tongxinluo group. Histological observations showed that the morphology and structure of cardiomyocytes were better, and the fibrosis of myocardium was lower in the experimental group compared to the other two groups. In conclusion, Danshensu sodium and Tongxinluo combined effectively improved cardiac function and had a positive effect on the expression of apelin-13 and L-type calcium channel in rats with heart failure.

Is There a Correlation between Apelin and Insulin Concentrations in Early Second Trimester Amniotic Fluid with Fetal Growth Disorders?

Fetal growth disturbances place fetuses at increased risk for perinatal morbidity and mortality. As yet, little is known about the basic pathogenetic mechanisms underlying deranged fetal growth. Apelin is an adipokine with several biological activities. Over the past decade, it has been investigated for its possible role in fetal growth restriction. Most studies have examined apelin concentrations in maternal serum and amniotic fluid in the third trimester or during neonatal life. In this study, apelin concentrations were examined for the first time in early second-trimester fetuses. Another major regulator of tissue growth and metabolism is insulin. This was a prospective observational cohort study. We measured apelin and insulin concentrations in the amniotic fluid of 80 pregnant women who underwent amniocentesis in the early second trimester. Amniotic fluid samples were stored in appropriate conditions until delivery. The study groups were then defined, i.e., gestations with different fetal growth patterns (SGA, AGA, and LGA). Measurements were made using ELISA kits. Apelin and insulin levels were measured in all 80 samples. The analysis revealed statistically significant differences in apelin concentrations among groups (p = 0.007). Apelin concentrations in large for gestational age (LGA) fetuses were significantly lower compared to those in AGA and SGA fetuses. Insulin concentrations did not differ significantly among groups. A clear trend towards decreasing apelin concentrations as birthweight progressively increased was identified. Amniotic fluid apelin concentrations in the early second trimester may be useful as a predictive factor for determining the risk of a fetus being born LGA. Future studies are expected/needed to corroborate the present findings and should ideally focus on the potential interplay of apelin with other known intrauterine metabolic factors.

Evaluating Salivary Apelin Level among Chronic Periodontitis Patients, with and without Type 2 Diabetes Mellitus utilizing Enzyme‑Linked Immunosorbent Assay: A Comparative Study

Background: Periodontitis is a chronic inflammatory disorder mainly due to a decrease in the immune system caused by periodontal pathogens. The relationship of apelin among chronic generalized periodontitis (CGP) and type 2 diabetes mellitus (T2DM) has been reported. This study intends to assess the level of apelin in saliva from patients of healthy individuals, individuals with CGP, and CGP + T2DM, and evaluate the role of apelin adipokine in inflammation and insulin resistance. New treatment modalities can be invented using apelin in host modulation therapies. Methods: The study comprised 300 patients that were enrolled according to their clinical findings and were divided into three groups chronic periodontitis (n=100), chronic periodontitis with T2DM (n=100), and healthy controls (n=100). Probing pocket depth (PPD), clinical attachment level (CAL), and salivary Apelin (AP) were obtained. With the help of the enzyme-linked immunosorbent assay (ELISA) kit, the salivary apelin level was measured. A statistical software package was used for the surveying of collected data. Results: Group three[CGP+DM] shows the highest salivary apelin level compared to CGP patients without DM. It was 15.43±2.05ng/dl in CGP and 24.08 ± 3.60ng/dl in CGP with DM. All three groups found a statistically significant difference in mean Apelin Level, PPD, and CAL. Conclusion: This study indicated a possible role of adipokines in inflammation and glucose level regulation in patients with T2DM and CGP. In the coming era, apelin levels in saliva can be used for screening objectives in large populations to assure the risk of destructive periodontal disease. Bangladesh Journal of Medical Science Vol. 22 No. 02 April’23 Page : 305-315