Myokine Irisin promotes osteogenesis by activating BMP/SMAD signaling via αV integrin and regulates bone mass in mice

Irisin is well-known to contribute to bone homeostasis due to its bidirectional regulation on osteogenesis and osteoclastogenesis. However, the mechanisms of irisin involved in mesenchymal stem/stromal cells (MSCs)-derived osteogenesis are still under investigated. Fibronectin type III domain-containing protein 5 (FNDC5) is the precursor protein of irisin, compare with wild type (WT) littermates, FNDC5^-/- mice lost bone mass significantly, collectively evidenced by the decrease of bone mineral density (BMD), impaired bone formation and reduced N-terminal propertied of type I procollagen (P1NP) in sera. Meanwhile, the bone resorbing of FNDC5^-/- mice has enhanced accompanied by increased tartrate phosphatase (TRAP) staining cells morphologically and cross-Linked C-telopeptide of type 1 collagen (CTX) level in sera. In vitro study showed that lack of irisin impeded the MSC-derived osteogenesis of FNDC5^-/- mice. The addition of irisin promote the osteogenesis of WT and irisin-deficient MSCs, by activating αV integrin-induced ERK/STAT pathway, subsequently enhancing bone morphogenetic protein 2 (BMP2) expression and BMP/SMAD signaling activation. Taken together, these findings further indicate that irisin regulates bone homeostasis. Moreover, irisin promotes MSC-derived osteogenesis by binding to αV integrin and activating BMP/SMAD signaling consequently. Thus, irisin may be a promising therapeutic target for osteoporosis and bone defects.     

Characteristics of nutrient intakes,basal physical fitness and serum markers in elderly women with osteopenia

Purpose

This study investigated the correlations among BMD, nutrient intake, basal physical fitness and serum markers in elderly women with osteopenia.

Methods

Bone Mineral Density (BMD) was measured in 54 elderly women (60–77yrs) by using dual energy X-ray absorptiometry (DEXA). The subjects were divided into an osteopenia group (OG; n = 29) and a normal group (NG; n = 25). A physical fitness test was conducted to determine muscle strength, muscle endurance, flexibility, agility, and balance. The dietary nutrient intake for one day was analyzed. The serum Ca, Pi and Mg concentration was also analyzed.

Results

There was significant correlation between All subject’s weight and their total-BMD as well as the T-score (p < .01). There was also significant correlation between the fat free mass and Total-BMD (p < .01). There was significant positive correlation between energy intake and dietary carbohydrate with Total-BMD and T-score in the OG (p < .05). The Serum Pi of the OG was significantly lower than that of the NG (p < .05), and there was significant correlation with the BMD in most regions as well as with the Total-BMD and T-score (p < .05, p < .01).

Conclusion

These results suggested that the fat free mass in elderly women plays an important role in maintaining their BMD and that sufficient caloric intake would be likely to improve BMD in elderly women with osteopenia. In addition, the results suggested the possibility of a decrease in bone mass by hypophosphatemia in elderly women.     

Circulating Irisin Concentrations Are Associated with a Favourable Lipid Profile in the General Population

Background/aimsIrisin is a myokine, which is mainly inversely associated with the risk for non-communicable diseases. Irisin improves cellular energy metabolism by uncoupling the mitochondrial respiratory chain resulting in increased energy expenditure using lipids. To date potential associations between irisin concentration and lipid profile are poorly understood. Therefore, this investigation aimed to evaluate potential associations between irisin and lipid levels in the general population.MethodsData of 430 men and 537 women from the population-based Study of Health in Pomerania (SHIP-TREND) with available irisin and lipid concentrations were used. Analyses of variance, linear and logistic regression models adjusted for age, HBA1c, waist circumference, physical activity, smoking, alcohol consumption, systolic blood pressure, ALAT were calculated.ResultsWe detected significantly inverse associations between irisin and circulating levels of total [beta coefficient 0.21 (standard error 0.08), p = 0.01], low-density cholesterol [-0.16 (0.07), p = 0.03] and triglycerides [-0.17 (0.08), p = 0.02] for men. Females without lipid lowering medication had an inverse association between irisin and total cholesterol [-0.12 (0.06), p = 0.05]. Further, male subjects with irisin concentrations in the third tertile had an increased odds for elevated low-density cholesterol [odds ratio 1.96 (95% confidence interval 1.07–3.48), p = 0.03) and triglyceride [1.95 (1.09–3.47), p = 0.02] levels, even after exclusion of subjects with lipid lowering medication. In addition, our data revealed an annual rhythm of serum irisin levels with peak levels arise in winter and summer months.ConclusionThis is the first investigation to report a significant association between circulating irisin and a favourable lipid profile in the general population. This may infer that higher irisin concentrations are associated with a reduced risk for non-communicable diseases.     

Correlation Between Bone Markers and Bone Mineral Density in Postmenopausal Women with Osteoporosis

ObjectiveTo study the relationship between bone markers and bone mineral density (BMD) in an effort to identify their utility in postmenopausal women with osteoporosis.MethodsEighty-two consecutive postmenopausal women with untreated osteoporosis were included in the study. Forearm, spinal, and femoral BMD by dual-energy x-ray absorptiometry and markers of bone formation (serum osteocalcin and bone-specific alkaline phosphatase) and bone resorption (urinary free deoxypyridinoline) were measured in all patients. Patients with low serum vitamin D levels, secondary osteoporosis, or clinically significant systemic disease were excluded from the study. The patients were classified on the basis of BMD of the lumbar spine into the following 3 groups: mild (n = 23) (T score -2.5 through -3), moderate (n = 42) (T score -3.1 through -4), or severe (n = 17) (T score ≤-4.1) osteoporosis. One-way analysis of variance and Pearson correlation were used for statistical analysis, with a P value < .05 being considered significant.ResultsSerum osteocalcin was significantly different among the 3 study groups (4.1 ± 2.7, 4.5 ± 3.1, and 6.7 ± 5.6 ng/mL, respectively; P = .0349) and had a significant negative correlation with BMD (r² = -0.0779; P = .0168). Other bone markers such as bone-specific alkaline phosphatase and urinary free deoxypyridinoline did not correlate with the underlying BMD.ConclusionIn our study, osteocalcin was significantly correlated with BMD in postmenopausal women with osteoporosis. Other bone markers did not correlate with BMD. Further large-scale population data and analyses are needed to confirm these findings. (Endocr Pract. 2008;14:1102-1107)     

Relationship between Irisin Concentration and Serum Cytokines in Mother and Newborn

IntroductionIrisin is considered to be a myokine and adipokine that may also participate in reproductive functions, as it increases significantly throughout pregnancy. However, the regulation of circulating irisin and its relationship with other cytokines has not been assessed thus far in pregnant women and their offspring.ObjectiveThe aim of this study was to evaluate differences in irisin and cytokine concentrations between women at the end of pregnancy and their offspring, as well as the relationship between maternal and newborn irisin and maternal and newborn biomarkers.MethodsTwenty-eight mother/newborn pairs were included in this study. The following biomarkers were evaluated in maternal venous and arterial umbilical cord blood samples: irisin, 27 cytokine panel, total antioxidant capacity (TAC), total plasma protein, and free fatty acid concentration.ResultsThe newborns had significantly lower irisin concentrations compared to their mothers (p = 0.03), but this difference was present only in babies born from mothers without labor prior to cesarean section delivery (p = 0.01). No significant differences in maternal and newborn irisin concentrations were found between diabetic and non-diabetic mothers or between overweight/obese and normal weight mothers. A significant positive correlation was found between TAC level and irisin concentration in newborns. Maternal and newborn interleukin (IL)-1β, IL-1RA, IL-5, IL-7, and interferon gamma-induced protein (IP)-10 levels were significantly positively correlated with irisin concentrations in both study groups. In addition, maternal IL1β, IL-5, IL-7, and IP-10 levels positively predicted maternal irisin concentrations. Furthermore, arterial cord blood TAC and IL-1β and IL1-RA levels positively predicted newborn irisin concentrations. Multiple regression analyses showed that maternal IL-13 negatively predicted offspring irisin levels (p = 0.03) and that maternal IL-1β positively predicted newborn irisin concentrations (p = 0.046).ConclusionNo evidence was found that serum irisin concentrations in mothers at pregnancy termination or those of their newborns correlated with maternal body mass index, the presence of diabetes mellitus, or free fatty acid levels. However, the results of this study indicated that cytokines might predict irisin concentration in mothers and their offspring, although interactions between irisin levels during pregnancy and the newborn have not yet been fully elucidated.     

Association between circulating irisin levels and epicardial fat in patients with treatment-naïve overt hyperthyroidism

Abstract

Background: Hyperthyroidism is associated with increased metabolic activity and thermogenesis. Irisin is a key molecule in thermogenesis and energy expenditure via adipose tissue browning. Epicardial fat was previously defined as brown-like fat. Thus, here we aimed to evaluate the association between serum irisin level and epicardial fat thickness (EFT) in patients with hyperthyroidism.

Methods: A total of 25 hyperthyroid patients and 24 age-, sex- and BMI-matched healthy controls were enrolled. Serum irisin levels, thyroid hormone levels, and body compositions were compared. EFT was measured via transthoracic echocardiography.

Results: Serum irisin level and EFT were significantly higher in the hyperthyroid group (p?<?0.001 and p?=?0.001, respectively). The distributions of fat-free mass, muscle mass and fat mass were similar between the study groups. Serum irisin level was negatively correlated with TSH (p?<?0.001) and positively correlated with fT3 (p?<?0.001), fT4 (p?<?0.001) and TSH receptor antibody (p?=?0.002) levels and EFT (p?=?0.001). In multivariate linear regression analysis, TSH (β?=??0.475, p?<?0.001) and EFT (β?=?0.290, p?=?0.023) levels were significantly associated with serum irisin levels.

Conclusions: An increased serum irisin level associated with EFT might contribute to metabolic derangement in hyperthyroidism. Further studies are needed to elucidate whether irisin levels and EFT are affected by hyperthyroidism or vice versa.     

Irisin and Carcinoembryonic Antigen (CEA) as Potential Diagnostic Biomarkers in Gastric and Colorectal Cancers

Background:Carcinoembryonic antigen (CEA) is a common gastrointestinal tumor biomarker. Irisin is adipo-myokines that has been suggested to have a potential role in cancer development. However, limited studies test irisin as biomarker in gastric and colorectal cancers. Therefore, this study aims to investigate whether CEA and irisin could be a potential diagnostic biomarker in gastric and colorectal cancer.Methods:A case-control study consists of 90 subjects, 21 gastric cancer patients, 49 colorectal cancer patients and 20 control. Serum CEA was detected by fluorescence immunoassay (FIA) kit. Serum irisin was determined by enzyme-linked immunosorbent assay (ELISA) kit.Results:Serum CEA increases significantly and serum irisin decreases significantly in gastric and colorectal cancer patients. According to Receiver Operating Characteristic (ROC) curve analysis, in gastric cancer, the area under curve of CEA is 1.00 (95% CI, 1.000-1.000, p< 0.0001). The diagnostic cut-off of CEA is< 3.08 ng/ml with %100 sensitivity and 100% specificity. The area under curve of irisin is 0.94 (95% CI, 0.8177-1.000, p< 0.0001). The cut-off of irisin is> 30.2 ng/ml with %90 sensitivity and 100%, specificity. In colorectal cancer, the area under curve of CEA is 0.99 (95% CI, 0.9866-1.000, p< 0.0001) and the diagnostic value< 2.6 ng/ml with %98 sensitivity and %100 specificity. The area under curve of irisin is 0.96 (95% CI, 0.9155-1.000, p< 0.0001). The diagnostic cut-off of irisin is> 41.9 ng/ml with 88.1sensitivity and 90.5 specificity.Conclusion:CEA and irisin could be powerful potential diagnostic biomarkers which would be use for early detection of gastric and colorectal cancers.Key Words: Biomarker, Carcinoembryonic antigen (CEA), Colorectal cancer, Gastric cancer, Irisin     

Bone Mineral Density,Bone Turnover Markers and Fractures in Patients with Systemic Sclerosis: A Case Control Study

Objective

The aim of our study was to elucidate the pathophysiology of systemic sclerosis-related osteoporosis and the prevalence of vertebral fragility fracture in postmenopausal women with systemic sclerosis (SSc).

Methodology

Fifty-four postmenopausal women with scleroderma and 54 postmenopausal controls matched for age, BMI, and smoking habits were studied. BMD was measured by dual energy-x-ray absorptiometry at spine and femur, and by ultrasonography at calcaneus The markers of bone turnover included serum osteocalcin and urinary deoxypyridinoline. All subjects had a spine X-ray to ascertain the presence of vertebral fractures.

Results

bone mineral density at lumbar spine (BMD 0.78±0.08 vs 0.88±0.07; p<0,001), femoral neck (BMD: 0.56±0.04 vs 0.72±0.07; p<0,001) and total femur (BMD: 0.57±0.04 vs 0.71±0.06; p<0,001) and ultrasound parameter at calcaneus (SI: 80.10±5.10 vs 94.80±6.10 p<0,001) were significantly lower in scleroderma compared with controls; bone turnover markers and parathyroid hormone level were significantly higher in scleroderma compared with controls, while serum of 25(OH)D3 was significantly lower. In scleroderma group the serum levels of 25(OH)D3 significantly correlated with PTH levels, BMD, stiffness index and bone turnover markers. One or more moderate or severe vertebral fractures were found in 13 patients with scleroderma, wherease in control group only one patient had a mild vertebral fracture.

Conclusion

Our data shows, for the first time, that vertebral fractures are frequent in subjects with scleroderma, and suggest that lower levels of 25(OH)D3 may play a role in the risk of osteoporosis and vertebral fractures.     

Low selenium levels are associated with decreased bone mineral densities

PurposeOsteoporosis has a high worldwide prevalence and detrimental consequences (e.g., increased fracture risk). The amount of bone mineral in bone tissue (i.e., bone mineral density [BMD]) is most widely used indicator of osteoporosis in clinical medicine. Selenium is an essential micronutrient for animals and humans. It is a cofactor for antioxidant enzyme reduction (e.g., glutathione peroxidase). It also enhances immune surveillance and modulates cell proliferation. Study findings on the associations between BMD and selenium levels are inadequate and contradictory. The purpose of this study was to examine the associations between hair selenium levels and lumbar spine and femur BMD values.MethodsUsing a cross-sectional study design, we assessed the associations between hair selenium levels and BMD values in 1,167 Korean adults who underwent a health check-up. Each subject was assigned to one of two groups based on BMD (normal group [T-score ≥ -1.0] or low BMD group [T-score < -1.0]). The associations between hair selenium levels and the risk for low BMD were estimated using multivariate logistic regression models.ResultsStudy participants with lower hair selenium levels were older and had higher phosphorous, alkaline phosphatase, and osteocalcin levels. They also had lower BMDs, corrected serum calcium levels, uric acid levels, and creatinine clearance. Participants with low BMDs had significantly lower hair selenium levels (P < 0.001). After adjusting for osteoporosis-related risk factors, the risk of a low BMD was significantly greater for the lower hair selenium quartile groups (P = 0.045).ConclusionIn conclusion, this study found that lower hair selenium levels were associated with low BMD values, independent of the other osteoporosis risk factors examined. Further prospective studies are warranted to determine the role of selenium in the development of osteoporosis.     

Aged-Related Changes in Body Composition and Association between Body Composition with Bone Mass Density by Body Mass Index in Chinese Han Men over 50-year-old

Objectives

Aging, body composition, and body mass index (BMI) are important factors in bone mineral density (BMD). Although several studies have investigated the various parameters and factors that differentially influence BMD, the results have been inconsistent. Thus, the primary goal of the present study was to further characterize the relationships of aging, body composition parameters, and BMI with BMD in Chinese Han males older than 50 years.

Methods

The present study was a retrospective analysis of the body composition, BMI, and BMD of 358 Chinese male outpatients between 50 and 89 years of age that were recruited from our hospital between 2009 and 2011. Qualified subjects were stratified according to age and BMI as follows: 50–59 (n = 35), 60–69 (n = 123), 70–79 (n = 93), and 80–89 (n = 107) years of age and low weight (BMI: < 20 kg/m²; n = 21), medium weight (20 ≤ BMI < 24 kg/m²; n = 118), overweight (24 ≤ BMI < 28 kg/m²; n = 178), and obese (BMI ≥ 28 kg/m²; n = 41). Dual-energy X-ray absorptiometry (DEXA) was used to assess bone mineral content (BMC), lean mass (LM), fat mass (FM), fat-free mass (FFM), lumbar spine (L1-L4) BMD, femoral neck BMD, and total hip BMD. Additionally, the FM index (FMI; FM/height²), LM index (LMI; LM/height²), FFM index (FFMI; [BMC+LM]/height²), percentage of BMC (%BMC; BMC/[BMC+FM+LM] × 100%), percentage of FM (%FM; FM/[BMC+FM+LM] × 100%), and percentage of LM (%LM; LM/(BMC+FM+LM) × 100%) were calculated. Osteopenia or osteoporosis was identified using the criteria and T-score of the World Health Organization.

Results

Although there were no significant differences in BMI among the age groups, there was a significant decline in height and weight according to age (p < 0.0001 and p = 0.0002, respectively). The LMI and FFMI also declined with age (both p < 0.0001) whereas the FMI exhibited a significant increase that peaked in the 80-89-years group (p = 0.0145). Although the absolute values of BMC and LM declined with age (p = 0.0031 and p < 0.0001, respectively), there was no significant difference in FM. In terms of body composition, there were no significant differences in %BMC but there was an increase in %FM (p < 0.0001) and a decrease in %LM (p < 0.0001) with age. The femoral neck and total hip BMD significantly declined with age (p < 0.0001 and p = 0.0027, respectively) but there were no differences in L1-L4. BMD increased at all sites (all p < 0.01) as BMI increased but there were declines in the detection rates of osteoporosis and osteopenia (both p < 0.001). A logistic regression revealed that when the medium weight group was given a BMI value of 1, a decline in BMI was an independent risk factor of osteoporosis or osteopenia, while an increase in BMI was a protective factor for BMD. At the same time, BMD in L1-L4 exhibited a significant positive association with FMI (p = 0.0003) and the femoral neck and total hip BMDs had significant positive associations with FFMI and LMI, respectively (both p < 0.0001).

Conclusions

These data indicate that LMI and FFMI exhibited significant negative associations with aging in Chinese Han males older than 50 years, whereas FMI had a positive association. BMD in the femoral neck and total hip declined with age but an increased BMI was protective for BMD. LMI and FFMI were protective for BMD in the femoral neck and total hip.     

Intrauterine growth restriction affects bone mineral density of the mandible and the condyle in growing rats

Objectives:To investigate in growing rats the effect of intrauterine growth restriction (IUGR) on the bone mineral density of the mandible and tibia, as well as the quality of the mandibular and condylar bone.Methods:Twelve male rats were born IUGR by mothers sustaining 50% food restriction during pregnancy. Twelve control male rats were born by mothers fed ad libitum. Dual-energy X-ray absorptiometry (DEXA) of the tibia, proximal tibial metaphysis and the mandible, biochemical markers, histology and histomorphometrical analysis on the mandibular and subchondral bone of the condyle were performed.Results:IUGR significantly affected bone mineral density (BMD) of both tibial and mandibular bones. IUGR rats had significantly lower osteocalcin values (p=0.021) and phosphorus (p=0.028), but not 25-OH vitamin D (p=0.352). Bone area percentage in the mandible was significantly lower (51.21±5.54) in IUGR compared to controls (66.00±15.49), and for subchondral bone of the condyle for IUGR (47.01±6.82) compared to controls (68.27±13.37). IUGR had a significant reduction in the fibrous layer, but not the proliferating layer, with the hypertrophic layer significantly increased.Conclusion:Maternal restricted nutrition during gestation can affect BMD of the mandible and the tibia of the offspring animals.     

Serum levels of irisin in gestational diabetes mellitus during pregnancy and after delivery

ObjectiveIrisin has recently been introduced as a novel an exercise-inducible myokine which improves glucose metabolism in mice. However, regulation of circulating irisin in gestational diabetes mellitus (GDM) and in the peripartal period has not been assessed so far.MethodsCirculating irisin was quantified in 74 GDM patients and in 74 healthy, pregnant, gestational age-matched controls. In a subset of these patients (44 GDM, 41 controls), postpartum follow-up data were also available. In a second study population of 40 healthy women with singleton pregnancies undergoing elective Cesarean section, irisin was assessed in maternal serum before and within 24 h after delivery, as well as in umbilical cord blood and in placental tissue.ResultsIn the first study population, median [interquartile range] irisin levels were significantly higher in GDM patients as compared to controls after delivery (previous GDM: 446.3 [146.9] μg/l; controls: 378.0 [111.4] μg/l) but not during pregnancy (GDM: 482.1 [132.1] μg/l; controls: 466.6 [178.0] μg/l). Interestingly, fasting insulin (FI) was independently and positively associated with serum irisin in multivariate analysis during pregnancy. In agreement with these findings, relative changes (ratio) of FI independently and positively predicted relative changes of irisin (ratio) in the second study population.ConclusionsThe myokine irisin is independently associated with FI in pregnancy. The physiological significance of these findings needs to be assessed in future experiments.     

血清胰岛素样生长因子结合蛋白3、血清N端骨钙素、25羟基维生素D在骨质疏松检测价值分析

摘要 目的：研究骨质疏松患者行血清胰岛素样生长因子结合蛋白3（IGFBP-3）、血清N端骨钙素（N-MID）、25羟基维生素D[25(OH)D]、骨密度（BMD）检测的效果。方法：数据取自本院2021年4月-2022年5月收治的80例骨质疏松患者,均行IGFBP-3、N-MID及25（OH）D检测,分析检测结果。结果：实验组患者的IGFBP-3、25(OH)D及N-MID、BMD水平均低于参照组患者相应指标水平（P<0.05）;实验组患者IGFBP-3、25(OH)D及N-MID、BMD变化水平相互为正相关关系（P<0.05）;采用多元回归分析显示影响BMD的主要因素中,IGFBP-3、25(OH)D、N-MID均为骨质疏松保护因素。结论：骨质疏松患者行IGFBP-3、25(OH)D及N-MID检测可切实观察病情、为疾病治疗提供参考数据,利于改善预后、效果显著。     

绝经后骨质疏松症患者血清LECT2水平的临床意义及其预测价值分析

摘要 目的：探讨绝经后骨质疏松症患者血清白细胞衍生趋化因子2（LECT2）水平的临床意义及其预测价值。方法：选择2020年1月～2022年1月湖南师范大学第一附属医院收治的绝经后骨质疏松症患者125例作为研究组,另选取同期体检的绝经后健康女性志愿者120例作为对照组。比较两组血清LECT2水平,并分析血清LECT2水平与腰椎和股骨颈骨密度（BMD）及骨代谢相关指标的相关性;应用受试者工作特征（ROC）曲线分析血清LECT2对绝经后骨质疏松症患者的预测价值。结果：研究组血清LECT2、骨钙素（OC）、I型原胶原N端前肽（PINP）、 I型胶原交联C末端肽（S-CTX）显著高于对照组,腰椎和股骨颈BMD显著低于对照组（P<0.05）。Pearson相关分析显示,绝经后骨质疏松症患者血清LECT2水平与OC、PINP、S-CTX水平呈正相关（P<0.05）,与腰椎和股骨颈BMD呈负相关（P<0.05）。ROC曲线分析显示,血清LECT2、OC、PINP、S-CTX联合检验对绝经后骨质疏松症患者的预测价值的曲线下面积（AUC）为0.856,大于各单一指标预测。结论：绝经后骨质疏松症女性血清LECT2水平升高,其水平与骨代谢指标OC、PINP、S-CTX水平呈正相关,与腰椎BMD和股骨颈BMD呈负相关,血清LECT2联合OC、PINP、S-CTX对绝经后骨质疏松症患者的预测价值较高。     

The role of different exercises in irisin,heat shock protein 70 and some biochemical parameters

BackgroundThe aim of the study was to determine the effects of different and regularly applied exercise programs on irisin, heat shock protein 70 and some biochemical parameters.Methods120 male university students participated in the study. Participants were divided into 4 equal groups as control (C), resistance exercise group (RE), high intensity interval (HIIT) and aerobic exercise group (AE). While the control group did not perform any exercise, the pre-determined exercise programs were applied to the other groups for 8 weeks and 3 days in a week. Blood samples were taken from all participants before and after the exercise program. Cholesterol, High-density Lipoprotein (HDL) and Low-density Lipoprotein (LDL) cholesterol, triglyceride (TG), Creatine kinase (CK), Lactate dehydrogenase (LDH), Irisin and Heat shock protein 70 (HSP70) levels were analyzed in blood samples.ResultsIt is determined that there are significant differences in pre-posttest values of the AE group''s LDH, cholesterol, HDL-cholesterol, TG and HSP 70 levels, HIIT group''s CK, LDH, Cholesterol, HDL-cholesterol, TG, Irisin and HSP70 levels and RE group''s CK, LDH, Cholesterol, LDL-cholesterol, TG and Irisin levels (p<0.05).ConclusionsIt can be said that exercise can provide improvements in lipid profile, changes in HSP70 levels may vary depending on muscle damage, the increase of irisin due to exercise.     

Cardiac,skeletal muscle and serum irisin responses to with or without water exercise in young and old male rats: Cardiac muscle produces more irisin than skeletal muscle

Irisin converts white adipose tissue (WAT) into brown adipose tissue (BAT), as regulated by energy expenditure. The relationship between irisin concentrations after exercise in rats compared humans after exercise remains controversial. We therefore: (1) measured irisin expression in cardiac and skeletal muscle, liver, kidney, peripheral nerve sheath and skin tissues, as also serum irisin level in 10 week-old rats without exercise, and (2) measured tissue supernatant irisin levels in cardiac and skeletal muscle, and in response to exercise in young and old rats to establishing which tissues produced most irisin. Young (12 months) and old rats (24 months) with or without 10 min exercise (water floating) and healthy 10 week-old Sprague-Dawley rats without exercise were used. Irisin was absent from sections of skeletal muscle of unexercised rats, the only part being stained being the perimysium. In contrast, cardiac muscle tissue, peripheral myelin sheath, liver, kidneys, and skin dermis and hypodermis were strongly immunoreactivity. No irisin was seen in skeletal muscle of unexercised young and old rats, but a slight amount was detected after exercise. Strong immunoreactivity occurred in cardiac muscle of young and old rats with or without exercise, notably in pericardial connective tissue. Serum irisin increased after exercise, being higher in younger than older rats. Irisin in tissue supernatants (cardiac and skeletal muscle) was high with or without exercise. High supernatant irisin could come from connective tissues around skeletal muscle, especially nerve sheaths located within it. Skeletal muscle is probably not a main irisin source.     

Association of Serum Irisin with Metabolic Syndrome in Obese Chinese Adults

Irisin, a recently identified novel myokine, drives brown-fat-like conversion of white adipose tissues and has been proposed to mediate beneficial effects of exercise on metabolism. Circulating irisin was significantly reduced in type 2 diabetes patients; however, no evidence is available about its association with metabolic syndrome (MetS) and effects of adiposity and muscle mass on circulating irisin have been controversial. Cross-sectional data on socio-demographic, lifestyle, clinical characteristics and serum irisin were collected for 1,115 community-living Chinese adults with central obesity. Associations of serum irisin with MetS (central obesity plus any two of the following four factors (raised blood pressure (BP), raised fasting plasma glucose (FPG), raised triglyceride (TG), and reduced HDL cholesterol) and each component of MetS were analyzed using multivariable logistic regression. Among the 1,115 obese Chinese adults with a mean age of 53.2(±7.2) years, serum irisin levels (log-transformed) were significantly reduced in subjects with MetS and raised FPG than their control groups (p = 0.034 and 0.041, respectively). After adjustment for potential confounders, serum irisin was significantly associated with reduced risks of MetS and raised FPG, with odds ratios (ORs) (95% CI) per standard deviation of log-transformed irisin of 0.796 (0.505–0.959, p = 0.027) and 0.873 (0.764–0.998, p = 0.046), respectively. Associations of irisin with raised BP, raised TG and reduced HDL were not statistically significant ((ORs) (95% CI): 0.733(0.454–1.182, p = 0.202), 0.954(0.838–1.086, p = 0.478) and 1.130(0.980–1.302, p = 0.092), respectively). Stepwise multivariable linear regression analysis showed that fasting insulin, HbA1c and albumin/globulin ratio were negatively associated with serum irisin level with statistical significance (all p-values <0.05) and waist circumference was negatively associated with serum risin with marginally statistical significance (p = 0.055). These results imply that irisin may play an important role in insulin resistance and MetS and should be confirmed in future prospective studies.     

Immunostaining characteristics of irisin in benign and malignant renal cancers

ABSTRACT

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.     

Effect of cervus and cucumis polypeptide combined with zoledronic acid on bone metabolic biochemical markers in glucocorticoids – Induced osteoporosis patients

ObjectiveTo investigate the effect of cervus and cucumis polypeptide combined with zoledronic acid on bone metabolic biochemical markers in glucocorticoids - induced osteoporosis patients.MethodsA total of 100 patients with glucocorticoids - induced osteoporosis admitted to our hospital from January 2015 to June 2017 were enrolled in this study. Patients were divided into observation group and control group by random number table method, 50 cases in each group. Patients in the observation group were treated with deer melon polypeptide in combination with zoledronic acid, and patients in the control group were treated with zoledronic acid alone. The patients in both groups were treated for 2 months. The changes of bone mineral density (BMD) and biochemical markers of bone metabolism in lumbar vertebrae L1-4, left femoral neck and large trochanter were analyzed before and after treatment.ResultsThe pre- BMD at lumbar spine L_1-4, left femoral neck and great trochanter had no statistic difference (P > 0.05), the BMD at each sites improved after treatment, and the difference were statistical before and after treatment (P < 0.05). BMD at above sites of two groups after treatment had statistical difference (P < 0.05), and the BMD at lumbar spine L_1-4, left femoral neck and great trochanter in the observation group was higher than that of the control group. There were no significant differences in PTH, 25-(OH)D3, TRACP, β-CTX and BGP levels between the two groups before treatment (P > 0.05). The levels of 25-(OH)D3, TRACP, β-CTX and BGP in the two groups were significantly improved after treatment (P < 0.05), and the levels of PTH, TRACP and β-CTX in the observation group were significantly lower than those in the control group. The levels of 25-(OH) D3 and BGP were significantly higher than those of the control group (P < 0.05).ConclusionThe cervus and cucumis polypeptide combined with zoledronic acid can improve the BMD at lumbar spine L_1-4, left femoral neck and great trochanter, and ameliorate the bone metabolic biochemical markers for patients with glucocorticoids - induced osteoporosis.     

Irisin regulates thermogenesis and lipolysis in 3T3-L1 adipocytes

BackgroundAdipose tissue plays a pivotal role in the development and progression of the metabolic syndrome which along with its complications is an epidemic of the 21st century. Irisin is an adipo-myokine secreted mainly by skeletal muscle and targeting, among others, adipose tissue. In brown adipose tissue it upregulates uncoupling protein-1 (UCP1) which is responsible for mitochondrial non-shivering thermogenesis.MethodsHere we analyzed the effects of irisin on the metabolic activity of 3T3-L1 derived adipocytes through a mitochondrial flux assay. We also assessed the effects of irisin on the intracellular signaling through Western Blot. Finally, the gene expression of ucp1 and lipolytic genes was examined through RT-qPCR.ResultsIrisin affects mitochondrial respiration and lipolysis in a time-dependent manner through the regulation of PI3K-AKT pathway. Irisin also induces the expression of UCP1 and the regulation of NF-κB, and CREB and ERK pathways.ConclusionOur data supports the role of irisin in the induction of non-shivering thermogenesis, the regulation of energy expenditure and lipolysis in adipocytes.General significanceIrisin may be an attractive therapeutic target in the treatment of obesity and related metabolic disorders.