Effects of irisin and exercise on adropin and betatrophin in a new metabolic syndrome model

Metabolic syndrome (MetS) is a prevalent public health problem. Uric acid (UA) is increased by MetS. We investigated whether administration of UA and 10% fructose (F) would accelerate MetS formation and we also determined the effects of irisin and exercise. We used seven groups of rats. Group 1 (control); group 2 (sham); group 3 (10% F); group 4 (1% UA); group 5 (2% UA); group 6 (10% F + 1% UA); and Group 7, (10% F + 2% UA). After induction of MetS (groups 3 -7), Group 3 was divided into three subgroups: 3A, no further treatment; 3B, irisin treatment; 3C, irisin treatment + exercise. Group 4, 1% UA, which was divided into three subgroups: 4A, no further treatment; 4B, irisin treatment; 4C, Irisin treatment + exercise. Group 5, 2% UA, which was divided into three subgroups: 5A, no further treatment; 5B, irisin treatment; 5C, irisin treatment + exercise. Group 6, 10% F + 1% UA, which was divided into three subgroups: 6A, no further treatment; 6B, irisin treatment; 6C, irisin treatment + exercise. Group 7, 10% F + 2% UA, which was divided into three subgroups: 7A, no further treatment; 7B, irisin treatment; 7C, irisin treatment + exercise., İrisin was administered 10 ng/kg irisin intraperitoneally on Monday, Wednesday, Friday, Sunday each week for 1 month. The exercise animals (in addition to irisin treatment) also were run on a treadmill for 45 min on Monday, Wednesday, Friday, Sunday each week for 1 month. The rats were sacrificed and samples of liver, heart, kidney, pancreas, skeletal muscles and blood were obtained. The amounts of adropin (ADR) and betatrophin in the tissue supernatant and blood were measured using an ELISA method. Immunohistochemistry was used to detect ADR and betatrophin expression in situ in tissue samples. The duration of these experiments varied from 3 and 10 weeks. The order of development of MetS was: group 7, 3 weeks; group 6, 4 weeks; group 5, 6 weeks; group 4, 7 weeks; group 3, 10 weeks. Kidney, liver, heart, pancreas and skeletal muscle tissues are sources of adropin and betatrophin. In these tissues and in the circulation, adropin was decreased significantly, while betatrophin was increased significantly due to MetS; irisin + exercise reversed this situation. We found that the best method for creating a MetS model was F + UA2 supplementation. Our method is rapid and simple. Irisin + exercise was best for preventing MetS.

Effects of an energy drink on myonectin in the liver, kidney and skeletal muscle of exercised rats

Myonectin is a hormone that is produced mainly by skeletal muscle. We investigated the effects of exercise and energy drink (ED) administration on myonectin expression in skeletal muscle, liver and kidney tissue in rats; myonectin is produced by all three tissues. We used 28 male albino rats in four groups: untreated control (C), exercise (E), energy drink (ED) and exercise + energy drink (E + ED). The E and E + ED groups were exercised using a treadmill for 4 weeks. We also administered 3.5 ml/kg/day ED during week 1, 7 ml/kg/day during week 2 and 10 ml/kg/day during weeks 3 and 4 in the E and E + ED groups. We used ELISA to measure the levels of myonectin in skeletal muscle, liver and kidney tissues. We used immunohistochemical staining to investigate the localization and intensity of myonectin in these tissues. The amount of myonectin in skeletal muscle tissue was increased significantly in all experimental groups compared to group C. The amount of myonectin in the ED group was significantly greater than group E. No significant difference was observed in liver tissue; however, the amount of myonectin in the liver of group C was the greatest among all groups. The amount of myonectin in kidney tissue exhibited no significant difference among groups. Consumption of ED during exercise increased the amount of myonectin in kidney and skeletal muscle tissues and decreased it in liver tissue. We suggest that consumption of ED might adapt metabolism to incresed exercise by controling synthesis of myonectin in liver, kidney and skeletal muscle.

Betatrophin, elabela, asprosin, glucagon and subfatin peptides in breast tissue, blood and milk in gestational diabetes

We investigated the presence of asprosin (ASP), betatrophin, elabela (ELA), glucagon and subfatin (SUB) in the milk of mothers with gestational diabetes mellitus (GDM) and compared their levels with blood levels. We also investigated whether these peptides are synthesized by the breast. We investigated 12 volunteer mothers with GDM and 14 pregnant non-GDM control mothers. The peptides were measured using ELISA and their tissue localization was determined using immunohistochemistry. Breast milk contains ASP, betatrophin, ELA, glucagon and SUB. The amount of the peptides ranged from highest to the lowest in colostrum, transitional milk and mature milk. The amount of peptides in the milk was greater than for blood. The peptides, except for ELA, were increased in milk and blood by GDM. Betatrophin and ELA are synthesized in the connective tissue of the breast. ASP, glucagon and SUB are synthesized in the alveolar tissue of the breast. These peptides in breast milk may contribute to the development of the gastrointestinal tract of newborns and infants.

Vitamin D supplementation alleviates diabetic complications by increasing the amount of irisin in testicular tissues and blood of rats with experimental diabetes

OBJECTIVE

Diabetes is an important endocrinological disease that has an increasing incidence in the world and affects all biological tissues including testicles. Therefore, this study aimed to reveal the histological and biochemical effects of vitamin D on irisin, apoptosis, total antioxidant status (TAS), and total oxidant status (TOS) in testicular tissues of rats with experimental diabetes.

MATERIALS AND METHODS

41 male Wistar rats, 8-10 weeks old, weighing between 200-220 g, were included in the study as the following groups: control group (n=7; no treatment), sham group [only sodium citrate buffer (SCB)] [n=7; single dose 0.1 Molar (M) SCB given intraperitoneally (i.p)], vitamin D group (n=7; 50 IU/day given orally), diabetes group [n=10; single dose 50 mg/kg Streptozotocin (STZ) dissolved in 0.1 M SCB and given i.p (tail vein blood glucose level above 250 mg/dl after 72 hours)] and diabetes+vitamin D group [n=10, single dose 50 mg/kg STZ, dissolved in 0.1 M SCB and given i.p (tail vein blood glucose level above 250 mg/dl after 72 hours) and when diabetes occurs, oral vitamin D administration of 50 IU/day)]. At the end of the 8 weeks experiment, blood was drawn from the tail vein of all rats, they were sacrificed and testicular tissues were taken. While the amount of irisin in the blood and testicular tissue supernatants was analyzed with the Enzyme-Linked Immunosorbent Assay (ELISA) method, TAS and TOS measurements were analyzed with the REL method, testicular tissues were analyzed histopathologically, immunohistochemically, and with the TUNEL method.

RESULTS

When the diabetes group was compared with the control and sham groups, it was reported that the amounts of blood and tissue supernatant irisin and TAS significantly decreased and the TOS was significantly increased; a statistically significant increase in irisin and TAS of blood and tissue supernatants and a significant decrease in TOS were detected when diabetes+vitamin D and diabetes groups were compared among themselves. Similar results were obtained in the immunohistochemical studies. Tissue expressions of irisin decreased in the diabetes group compared to the control and sham groups, while the application of vitamin D increased the tissue expressions of irisin. Additionally, when the numbers of apoptotic cells were compared, it was reported that apoptotic cells in the diabetes group increased significantly compared to the control and sham groups, and vitamin D administration significantly decreased the number of apoptotic cells.

CONCLUSIONS

Taken together, vitamin D administration to diabetic rats decreased the number of apoptotic cells and increased the amount of irisin. Vitamin D had an effective role in maintaining the physiological integrity of rat testicular tissues, so vitamin D may be a potent agent to be used in the treatment of diabetes in the future.

Molecular communication between Apelin-13, Apelin-36, Elabela, and nitric oxide in gestational diabetes mellitus

OBJECTIVE

Gestational diabetes mellitus (GDM) is a type of diabetes that affects from 3.8% to 6.9% of pregnancies worldwide, causing significant mortality and unfavorable obstetric outcomes, such as delivery trauma and macrosomia risk. The fundamental processes of this metabolic disorder that first appeared during pregnancy are still unknown. Tissue hormones, particularly adipokines, have aided in understanding the pathophysiology of numerous disorders in recent years. This study aims to determine if Apelin-13 (APLN-13), Apelin-36 (APLN-36), Elabela (ELA), and nitric oxide (NO) molecules have all a part in the pathophysiology of GDM.

PATIENTS AND METHODS

The study included 30 pregnant control women and 30 pregnant women who had been diagnosed with GDM in the second trimester and whose body mass index and age were compatible with each other. Blood samples were collected from 60 participants during the second trimester (30 control pregnant women and 30 GDM pregnant women) and postpartum (17 controls vs. 14 GDM). In these blood samples, the amounts of APLN-13, APLN-36, ELA, and NO were studied using the ELISA method. In addition, the participants' glucose, lipid profiles, and other parameters were obtained from the hospital record files. At postpartum, 29 pregnant women (13 control and 16 pregnant women with GDM) dropped out of the study without explanation.

RESULTS

In the second trimester and postpartum plasma of mothers with GDM, APLN-13, APLN-36, NO, and ELA molecules were found to be significantly higher (< 0.05), compared to those of the control mothers, while APLN-13, APLN-36, NO values were significantly lower (0.05). While APLN-13, APLN-36, NO amounts in mothers with GDM were positively correlated with glucose amounts, they were negatively correlated with ELA amounts. Similarly, the triglyceride amounts in mothers with GDM were positively correlated with APLN-13, APLN-36 and NO, while they were negatively correlated with the ELA amounts. Due to gestational diabetes, APLN-13, APLN-36, NO, glucose, and triglyceride increased, and ELA decreased.

CONCLUSIONS

It is predicted that the glucose increase in GDM is because Apelins reduce glucose transport to erythrocytes by inhibiting the sodium-dependent glucose transporter (SGLT) and that the increase in triglyceride and NO may be associated with high glucose levels in GDM. As a result, we believe that the above-mentioned chemicals may cause GDM Pathology by triggering one another.

Basal blood concentrations of some orexigenic and anorexigenic hormones in obese and nonobese individuals according to blood groups

OBJECTIVE

Obesity is a serious public health problem associated with excessive food intake. Regulation of food intake in highly organized organisms is under the control of a large number of orexigenic and anorexigenic molecules. Therefore, the main purpose of this study has been to determine the relationship between obesity and some of the circulating orexigenic and anorexigenic peptides that have a role in appetite control and to determine whether the concentrations of these molecules differ according to blood groups.

PATIENTS AND METHODS

The study included 400 individuals of whom 100 were obese women, 100 obese men, 100 healthy men and 100 healthy women. Obese women and men were divided into 4 groups, according to their blood groups. In the control group, healthy women and healthy men were similarly divided into 4 blood groups. Each blood group within the groups, therefore, had 25 participants.

RESULTS

When leptin, nesfatin-1, obestatin and neuropeptide-Y, ghrelin and galanin levels of the control group and obese participants were compared, regardless of blood groups, leptin, nesfatin-1, obestatin and neuropeptide-Y were significantly higher, whereas only the ghrelin levels were significantly lower in obese patients. When the amounts of these hormones were measured according to gender, the situation was similar. When leptin, nesfatin-1, obestatin and neuropeptide-Y values of the control and obese participants' blood groups were compared with each other; these hormones were high in all blood groups; however, leptin levels in A blood group, nesfatin-1 levels in AB and O blood group, obestatin levels in AB blood group, neuropeptide-Y levels in A, B, AB blood groups were significantly higher. When the ghrelin levels of the blood groups in the control group and obese participants were compared, it was only significantly lower in the AB blood group. The ghrelin levels in the other blood groups of the obese individuals were again low, but not significantly so. When the distribution of hormones according to gender was evaluated, a situation parallel to the above results was recorded.

CONCLUSIONS

Leptin, nesfatin-1, obestatin and neuropeptide-Y and galanin levels of obese individuals were significantly higher than the control values, whereas the ghrelin values were significantly lower regardless of blood groups. Also, these hormones in blood partly varied with ABO blood groups. These different concentrations of hormones in ABO blood groups might be related with stimulation or suppression of appetite in human. However, further studies in other ethnic groups are needed to confirm these results.

Effects of iloprost and sildenafil treatment on elabela, apelin-13, nitric oxide, and total antioxidant and total oxidant status in experimental enzyme-positive acute coronary syndrome in rats

Despite significant advances in medicine, mortality due to cardiovascular disease is not yet preventable. We investigated the amounts of elabela (ELA) and apelin, synthesized by cardiomyocytes, and changes of these compounds in cardiac tissue and circulation after administration of iloprost (ILO) and sildenafil (SIL) in rats with induced myocardial ischemia (MI). We also investigated a connection with circulating troponin-I, creatine kinase (CK), creatine kinase-myocardial band (CK-MB) and nitric oxide (NO), and total anti-oxidant (TAS)/total oxidant status (TOS). We established eight study groups of five rats each. Group 1, sham, was given only physiologic serum; group 2, ILO; group 3, SIL; group 4, ILO + SIL; group 5, MI; group 6, MI + ILO; group 7, MI + SIL; group 8, MI + ILO + SIL. Troponin-I, CK, CK-MB and TAS-TOS were investigated using an autoanalyzer. NO, ELA and apelin were analyzed by ELISA. Tissue apelin and ELA expressions and localizations were determined by immunohistochemistry. The MI group compared to the control (sham) group showed that ELA, apelin, troponin-I, CK, CK-MB, NO and TOS levels were elevated significantly. Concentrations of these factors increased in MI, but decreased after ILO and SIL administration. The largest decrease of TOS was identified in the ILO + SIL group. ELA and apelin may be novel indicators of MI and administration of ILO and SIL, individually or together, may be useful for treating MI.

Immunostaining characteristics of irisin in benign and malignant renal cancers

We investigated the expression of irisin in renal cancers using immunocytochemistry. Irisin has been reported to exhibit anticancer properties. The study groups consisted of 22 cases each of control renal tissue, oncocytoma, chromophobe renal cell carcinoma (RCC), clear cell RCC (Fuhrman nuclear grades 1, 2, 3 and 4) and papillary RCC. We evaluated 10 slides for each of 176 cases. Slides were immunostained for irisin and histoscores were calculated for the prevalence and strength of immunostaining. Fuhrman nuclear grade 1, 2, 3 clear cell RCC and papillary RCC exhibited no irisin immunoreactivity. Irisin immunoreactivity was observed in some Fuhrman nuclear grade 4 RCCs. We found a significant decrease in irisin staining in chromophobe RCC compared to the control. Immunoreactivity in the oncocytoma tissue was comparable to the control group. Irisin immunoreactivity in chromophobe RCC decreased and no immunoreactivity was observed in Fuhrman nuclear grade 1, 2, 3 clear cell RCC and papillary RCC. Immunistochemical screening of irisin in renal oncocytomas and renal cancers may be useful for differential diagnosis.

Irisin: a potentially candidate marker for myocardial infarction

Myocardial infarction (MI) causes energy depletion through imbalance between coronary blood supply and myocardial demand. Irisin produced by the heart reduces ATP production by increasing heat generation. Energy depletion affects irisin concentration in circulation and cardiac tissues, suggesting an association with MI. We examined: (1) irisin expression immunohistochemically in rat heart, skeletal muscle, kidney and liver in isoproterenol (ISO)-induced MI, and (2) serum irisin concentration by ELISA. Rats were randomly allocated into 6 groups (n=6), (i) control, (ii) ISO (1h), (iii) ISO (2h), (iv) ISO (4h), (v) ISO (6h), and (vi) ISO (24h), 200mg ISO in each case. Rats were decapitated and the blood and tissues collected for irisin analysis. Blood was centrifuged at 1792 g for 5 min. Tissues were washed with saline and fixed in 10% formalin for histology. Serum irisin levels gradually decreased from 1h to 24h in MI rats compared with controls, the minimum being at 2h, increasing again after 6h. Cardiac muscle cells, glomerular, peritubular renal cortical interstitial cells, hepatocytes and liver sinusoidal cells and perimysium, endomysium and nucleoi of skeletal muscle were irisin positive, but its synthesis decreased 1-4h after MI. At all time-points, irisin increased near myocardial connective tissue, with production in skeletal muscle, liver and kidney recovering after 6h, although slower than controls. Unique insight into the pathogenesis of MI is shown, and the gradually decrease of serum irisin might be a diagnostic marker for MI.