Expression of Resistin, Chemerin, and Chemerin's Receptor in the Unstable Carotid Atherosclerotic Plaque.

Background and Purpose: Unstable carotid plaques are a common cause of ischemic strokes. Identifying markers that reflect/contribute to plaque instability has become a prominent focus in cardiovascular research. The adipokines, resistin and chemerin, and ChemR23 (chemerin receptor), may play a role in carotid atherosclerosis, making them potential candidates to assess plaque instability. However, the expression and interrelationship of resistin and chemerin (and ChemR23) protein and mRNA within the carotid atherosclerotic plaque remains elusive. Thus, we investigated herein, the association between plaque mRNA and protein expression of resistin and chemerin (and ChemR23) and carotid plaque instability in humans, and whether sex differences exist in the relationship between these adipokines and plaque instability. Methods: Human carotid plaques were processed for immunohistochemical/mRNA analysis of resistin, chemerin, and ChemR23. Plaque instability was assessed by gold-standard histological classifications. A semi-quantitative scoring system was used to determine the intensity of adipokine expression on macrophages/foam cells, as well as the percentage of inflammatory cells stained positive. Plaque adipokine protein expression was also digitally quantified and mRNA expression was assessed by qRT-PCR. Results: Resistin and chemerin mRNA expression was 80% and 32% lower, respectively, in unstable versus stable plaques (P<0.05), while no difference in ChemR23 mRNA expression was observed. In contrast, greater resistin staining intensity and percentage of cells stained positive were detected in unstable versus stable plaques (P<0.01). Similarly, chemerin and ChemR23 staining intensity and percentage of cells stained were positively associated with plaque instability (P<0.05). No strong sex-specific relationship was observed between adipokines and plaque instability. Conclusions: This study examined the relationship between resistin, chemerin, and ChemR23, and carotid plaque instability, with a specific analysis at the plaque level. We reported a positive association between plaque instability and protein levels of resistin, chemerin, and ChemR23 but a negative association with resistin and chemerin mRNA expression. This suggests these adipokines exert proinflammatory roles in the process of carotid atherosclerosis and may be regulated via a negative feedback regulatory mechanism.

Browning deficiency and low mobilization of fatty acids in gonadal white adipose tissue leads to decreased cold-tolerance of transglutaminase 2 knock-out mice.

During cold-exposure 'beige' adipocytes with increased mitochondrial content are activated in white adipose tissue (WAT). These cells, similarly to brown adipose tissue (BAT), dissipate stored chemical energy in the form of heat with the help of uncoupling protein 1 (UCP1). We investigated the effect of tissue transglutaminase (TG2) ablation on the function of ATs in mice. Although TG2+/+ and TG2-/- mice had the same amount of WAT and BAT, we found that TG2+/+ animals could tolerate acute cold exposure for 4h, whereas TG2-/- mice only for 3h. Both TG2-/- and TG2+/+ animals used up half of the triacylglycerol content of subcutaneous WAT (SCAT) after 3h treatment; however, TG2-/- mice still possessed markedly whiter and higher amount of gonadal WAT (GONAT) as reflected in the larger size of adipocytes and lower free fatty acid levels in serum. Furthermore, lower expression of 'beige' marker genes such as UCP1, TBX1 and TNFRFS9 was observed after cold exposure in GONAT of TG2-/- mice, paralleled with a lower level of UCP1 protein and a decreased mitochondrial content. The detected changes in gene expression of Resistin and Adiponectin did not provoke glucose intolerance in the investigated TG2-/- mice, and TG2 deletion did not influence adrenaline, noradrenaline, glucagon and insulin production. Our data suggest that TG2 has a tissue-specific role in GONAT function and browning, which becomes apparent under acute cold exposure.

Expression of resistin in the liver of patients with non-alcoholic fatty liver disease.

Adipokines are cytokines that presumably connect the pathologies of metabolic syndrome. One of the adipokines is resistin, the role of which in insulin resistance, obesity, and non-alcoholic fatty liver disease (NAFLD) needs to be determined. Liver biopsy specimens were obtained intraoperatively from 214 obese patients. Histological assessment was based on NAFLD activity score according to Kleiner. Statistical analysis involved semi-quantitive immunohistochemistry assessment of resistin staining and: NAFLD status in obese patients compared with a non-obese control group, selected clinical data (age, sex, body mass index - BMI), selected biochemical data, comorbidities (hypertension, type 2 diabetes mellitus, dyslipidaemia), and metformin treatment in patients with type 2 diabetes mellitus. Resistin expression was observed in the histiocytes of inflammatory infiltrate, Kupffer cells, and histiocytes surrounding the hepatocytes with steatosis. There was a positive correlation between the total expression of resistin and: (1) NAFLD advancement (NAFLD Activity Score- NAS), (2) AST, ALT, BMI, glucose, insulin, Homeostasis Model Assessment (HOMA), LDH, GGT, triglycerides (TG), and glycated haemoglobin (HbA1c). Resistin expression was more intense in patients with type 2 diabetes mellitus and dyslipidaemia and less intense in the control group. Resistin probably plays a role in the pathogenesis of hepatic insulin resistance and aggravates pathologic changes in the liver of patients with NAFLD.

Effects of 17ß-estradiol and progesterone on the production of adipokines in differentiating 3T3-L1 adipocytes: Role of Rho-kinase.

Effect of female sex hormones on the production/release of adipocyte-derived cytokines has been debatable. Furthermore, whether the cellular signaling triggered by these hormones involve Rho-kinase has not been investigated yet. Therefore, in this study, effects of 17ß-estradiol and progesterone as well as the Rho-kinase inhibitor, Y-27632 on the level of adipokines such as resistin, adiponectin, leptin, TNF-α and IL-6 were investigated in 3T3-L1-derived adipocytes. Differentiation was induced in the post-confluent preadipocytes by the standard differentiation medium (Dulbecco's modified Eagle's medium with 10% fetal bovine serum together with the mixture of isobutylmethylxanthine, dexamethasone and insulin) in the presence of 17ß-estradiol (10(-8)-10(-7)M), progesterone (10(-6)-10(-5)M), the Rho-kinase inhibitor, Y-27632 (10(-5)M) and their combination for 8days. Measurements of the adipokines were performed in the culturing medium by ELISA kits using specific monoclonal antibodies. 17ß-estradiol elevated resistin but decreased adiponectin and IL-6 levels; however, it did not alter the concentration of leptin and TNF-α. Y-27632 pretreatment inhibited the rise of resistin and the fall of adiponectin by 17ß-estradiol without any effects by its own. Progesterone did not change resistin, leptin and TNF-α level; however, it elevated adiponectin and decreased IL-6 production. Neither 17ß-estradiol nor Y-27632 was able to antagonize the increase of adiponectin and the reduction of IL-6 levels by progesterone. While Y-27632 alone lowered IL-6 level, it increased leptin and TNF-α concentration without altering resistin and adiponectin. In conclusion, 17ß-estradiol could modify adipokine production in 3T3-L1 adipocytes with the actions some of which involve Rho-kinase mediation.

Interleukin-17A Gene Expression in Morbidly Obese Women.

Data from recent studies conducted in rodent models and humans suggest that interleukin-17A (IL-17A) plays a role in the induction of inflammation in adipose tissue during obesity. The aim of this study was to assess the gene expression of IL-17A in adipose tissue of morbidly obese patients. We used RT-PCR to evaluate the expression of IL-17A and several adipo/cytokines in the visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) of 10 normal-weight control women (BMI < 25 kg/m2) and 30 morbidly obese women (MO, BMI > 40 kg/m2). We measured serum levels of IL-17A and adipo/cytokines in MO and normal weight women. IL-17A expression was significantly higher in VAT than in SAT in MO patients (p = 0.0127). It was very low in normal-weight controls in both VAT and SAT tissues. We found positive correlations between IL-17A and IL-6, lipocalin-2 and resistin in VAT of MO patients. The circulating level of IL-17A was higher in the normal-weight group than the MO patients (p = 0.032), and it was significantly related to adiponectin and TNFRII levels. In conclusion, IL-17A expression in VAT is increased in morbidly obese women, which suggests a link between obesity and innate immunity in low-grade chronic inflammation in morbidly obese women.

Elevated serum resistin in juvenile idiopathic arthritis: relation to categories and disease activity.

BACKGROUND: Juvenile Idiopathic Arthritis (JIA) is one of the more common chronic diseases of childhood that often persists into adulthood and can result in significant long-term morbidity, including physical disability. The aim of the present study was to assess the serum level of resistin in JIA patients and compare its levels according to the categories, clinical manifestations and disease activity. METHODS: Sixty-eight JIA patients and 33 age and sex matched control children were included in the present study. All patients included in this study were subjected to full history taking, clinical examination. Juvenile arthritis disease activity score in 27 joints (JADAS-27) was calculated and Childhood Health Assessment Questionnaire (CHAQ) was used to measure the functional status. Serum resistin levels were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The mean serum resistin was significantly higher in the JIA patients (4.01 ± 2.46 ng/ml) compared to the control (2.08 ± 1.23 ng/ml) (p<0.001) especially those with systemic-onset. Its level was significantly higher in those receiving steroids and those with a positive antinuclear antibody. Resistin significantly correlated with the JADAS27 (r 0.26, p 0.035) and CHAQ (r 0.4, p 0.001). The JIA patients were 50 females and 18 males; however, the level of resistin was insignificantly different according to the gender although there was a tendency to be higher in females. CONCLUSION: Our results reinforce the proposition of an important role for resistin in JIA and may be considered an interesting biomarker for disease activity especially those with systemic onset.

Resistin expression correlates with steatohepatitis in morbidly obese patients.

BACKGROUND: Morbidly obese patients are at risk for nonalcoholic steatohepatitis (NASH) even in the absence of risk factors for liver disease. Unfortunately, NASH is usually not clinically evident, and a definitive, noninvasive test for NASH does not exist. Resistin, a cytokine originating from adipose tissue, is involved in insulin resistance and also initiates proinflammatory signaling from hepatic stellate cells. This study explores the relationship between resistin expression and liver pathology in bariatric surgery patients. METHODS: Blood samples from 30 patients undergoing bariatric surgery were collected. Total RNA was extracted and cDNA was synthesized. Quantitative RT-PCR was used to quantify relative gene expression using 18s rRNA gene as an internal control. Wedge liver biopsies from these patients were sectioned and stained. Based on a previously published scoring method, biopsies were assigned an overall NASH severity score and subscores for steatosis, inflammation, and fibrosis. Results were analyzed by using Student's t test. RESULTS: Resistin mRNA levels ranged from 0.5 to 9.7. A group of five patients with very high resistin expression (>4) was identified. These patients had a significantly higher average NASH score compared with the rest of the group (7.9 vs. 4.48, p = 0.019). Steatosis and inflammation scores were significantly higher in the high-resistin group (p < 0.05 for both comparisons). There also was a trend toward higher fibrosis score in this group, which approached statistical significance (p = 0.051). CONCLUSIONS: In morbidly obese patients, high resistin expression in serum is associated with hepatic steatosis, inflammation, and fibrosis. The development of elevated resistin expression may represent a link between obesity and the onset of steatohepatitis.

Resistin expression in breast cancer tissue as a marker of prognosis and hormone therapy stratification.

OBJECTIVE: Adipocytokines are adipocyte-derived hormones and well documented to be involved in carcinogenesis. The expression of resistin, a newly discovered adipocytokine, in breast cancer tissues was determined and correlated with patient clinicopathological variables. METHODS: Resistin expression in breast cancer tissues and the normal adjacent breast tissues was analyzed by immunohistochemistry and was correlated with clinicopathological variables as well as recurrence rates by the chi-square test. The prognostic value of resistin for disease-free and overall survival was determined by Kaplan-Meier estimates, and the significance of differences between curves was evaluated by the log-rank test. RESULTS: High resistin expression was predominantly observed in breast cancer tissues but not the adjacent normal breast tissues. High resistin expression in breast cancer tissues was correlated significantly with tumor stage, tumor size, lymph node metastasis and estrogen receptor status. Hormone therapy, but not radiotherapy or chemotherapy, decreased the recurrence rate in patients with high resistin expression. While high resistin expression was associated with poor disease-free and overall survival, Cox regression analysis also revealed that resistin was an independent predictor of disease-free and overall survival. CONCLUSIONS: High resistin expression in breast cancer tissue is associated with a more malignant clinicopathological status as well as poor patient survival. Resistin may therefore hold promise as an independent prognosis predictor for breast cancer, as a marker for hormone therapy stratification and as a potential therapeutic target.

Association of the resistin gene promoter region polymorphism with Kawasaki disease in Chinese children.

OBJECTIVES: The -420 C > G polymorphism located in the resistin gene (RETN) promoter has recently been suggested to play a potential role in proinflammatory conditions and cardiovascular disease. This study investigated the association of the RETN promoter polymorphism with Kawasaki disease (KD) and its clinical parameters in Chinese children. METHODS: We compared patients with complete KD to incomplete KD children. Genotyping of the RETN promoter polymorphism was performed using MassARRAY system, and serum resistin levels were estimated using the sandwich enzyme immunoassay method. RESULTS: There was no significant difference in RETN (-420 C > G) genotypes between KD and control groups. However, the frequency of the G allele was higher in iKD patients than in cKD children due to a significantly increased frequency of the GG genotypes. Serum levels of resistin were significantly higher in KD patients than in controls regardless of the presence of coronary artery lesions (CALs). CONCLUSION: The present findings suggest that while resistin may play a role in the pathogenesis of KD, there is no apparent association between CAL and the RETN (-420 C > G) gene polymorphism in KD children. However, the diagnosis of iKD is challenging but can be supported by the presence of the G allele and the GG genotypes.

Resistin, but not adiponectin and leptin, is associated with the risk of ischemic stroke among postmenopausal women: results from the Women's Health Initiative.

BACKGROUND AND PURPOSE: Adipose tissue is considered an endocrine organ that secretes adipokines, which possibly mediate the effects of obesity on the risk of cardiovascular disease. However, there are yet limited prospective data on the association between circulating adipokine levels and the risk of ischemic stroke. We aimed to examine the associations of 3 adipokines (adiponectin, leptin, and resistin) with the risk of ischemic stroke. METHODS: We conducted a prospective nested case-control study (972 stroke cases and 972 matched control subjects) within the Women's Health Initiative Observational Study cohort. The control subjects were matched to cases on age, race/ethnicity, date of study enrollment, and follow-up time. RESULTS: Adipokine levels were associated with established stroke risk factors such as obesity and systolic blood pressure. Adjusted for body mass index, the ORs for incident ischemic stroke comparing the highest (Quartile 4) with the lowest quartile (Quartile 1) were 0.81 (95% CI, 0.61 to 1.08; P trend=0.068) for adiponectin, 1.15 (95% CI, 0.83 to 1.59; P trend=0.523) for leptin, and 1.57 (95% CI, 1.18 to 2.08; P trend=0.002) for resistin. The association for resistin remained significant even after accounting for established stroke risk factors (OR, 1.39; 95% CI, 1.01 to 1.90; P trend=0.036). Further adjustment for markers for inflammation, angiogenesis, and endothelial function also did not affect our results. CONCLUSIONS: Circulating levels of resistin, but not those of adiponectin or leptin, are associated with an increased risk of incident ischemic stroke in postmenopausal women, independent of obesity and other cardiovascular disease risk factors.

Role of nitric oxide (NO) metabolism and inflammatory mediators in childhood obesity.

OBJECTIVE AND DESIGN: The role of NO and adipocytokines in childhood obesity was studied, supposing that obesity provokes inflammation. Children were admitted to the pediatric clinic for a regular check up because of obesity. SUBJECTS: Obese (n = 79) and healthy (n = 12) children were selected and divided into subgroups according to their age, gender, glucose tolerance and nitric oxide synthase (NOS II) positivity. METHODS: Urine and blood nitrite plus nitrate, the expression of NOS II in white blood cells, serum adipocytokines and clinical characteristics were analyzed in each group. Significance was tested by unpaired two-tailed t test and by ANOVA. RESULTS: NOS II was only detected in the white blood cells of a subgroup (17/79) of obese children. Serum leptin and resistin concentrations were significantly higher, adiponectin was lower compared to healthy children. Significant correlations were observed between serum adiponectin and resistin levels (reciprocal, R (2) = 0.4), and between body mass index and serum leptin levels. CONCLUSIONS: NOS II expression in white blood cells was observed in a minority of patients. Low-grade inflammation in obese children was suggested by the increased resistin levels, particularly in NOS II-positive patients. Correlation between different adipocytokines was restricted for a few subgroups.

Caffeic acid phenethyl ester suppresses the production of adipocytokines, leptin, tumor necrosis factor -alpha and resistin, during differentiation to adipocytes in 3T3-L1 cells.

We previously reported that caffeic acid phenethyl ester (CAPE) suppresses 3T3-L1 differentiation to adipocytes through the inhibition of peroxisome proliferator-activated receptor (PPAR) gamma, CCAAT/enhancer-binding protein (C/EBP) alpha, fatty acid synthase (Fas) and adipocytes-specific fatty acid binding protein 2 (aP2) expressions (Juman et al., Biol. Pharm. Bull., 33, 1484-1488 (2010)). In the present study, we confirmed that CAPE had inhibitory effects on increased glycerol-3-phosphate dehydrogenase (GPDH) activity and an increased insulin receptor substrate 1 (IRS-1). Our data show that treatment with 50 µM CAPE significantly reduced the levels of leptin (p<0.05), resistin (p<0.05) and tumor necrosis factor (TNF)-alpha (p<0.05) which are known to aid adipocytokines production in adipocytes. In 3T3-L1 cells, treatment of CAPE decreased the triglyceride deposition similar to resveratrol, which is known to have an inhibitory effect on 3T3-L1 differentiation to adipocytes. In conclusion, we found that CAPE suppresses the production and secretion of adipocytokines from mature adipocytes in 3T3-L1 cells.

Enamel matrix derivative stimulates expression and secretion of resistin in mesenchymal cells.

In this study we wanted to identify the effect of enamel matrix derivative (EMD) on adipocytokines, so-called adipokines. Primary human cells of mesenchymal origin (osteoblasts, periodontal ligament cells, mesenchymal stem cells, and pulp cells) and hematopoietic origin (monocytes) were incubated with EMD. The levels of adipokines in cell culture medium were quantified using the Lincoplex human adipocyte panel (Luminex) and by real-time PCR of mRNA isolated from cell lysates. Rats were injected with 2 mg of EMD or saline intramuscularly every third day for 14 d. Blood samples were taken before and after injections, and the level of resistin in rat plasma was measured by ELISA. We found a dramatic increase in the secretion of resistin from mesenchymal stem cells, and verified this result in all the cells of mesenchymal origin tested. However, we observed no significant changes in the amount of resistin secreted from monocytes exposed to EMD compared with the control. Injections of EMD significantly enhanced the circulating levels of resistin in rats, and EMD also significantly enhanced the activity of the resistin promoter in transfected mesenchymal stem cells, indicating a direct effect on resistin expression. Our results indicate that resistin may play a role in mediating the biological effect of EMD in mesenchymal tissues.

High Expression of Both Resistin and Fascin-1 Predicts a Poor Prognosis in Patients with Colorectal Cancer.

Emerging evidence indicates that resistin and fascin-1 may possess a causal role in the development of several types of cancers. However, the clinical significance of resistin expression in colorectal cancer (CRC) tissues is unclear, and there are no reports of any correlation between resistin and fascin-1. Our analyses explored the expression of resistin in CRC tissue and analyzed the clinical and prognostic significance of the observed positive correlation between resistin and fascin-1. The rate of strongly positive resistin expression (27.5%) was significantly higher in CRC tissues than in normal colorectal tissues (5.2%). Strongly positive resistin expression is related to multiple poor prognostic factors in CRC, including depth of tumor invasion, lymph node metastasis, and tumor stage. In this study, survival was worse in CRC patients with high levels of both resistin and fascin-1 expression than in those with high levels of only one protein or normal levels of both proteins. We suggest that a combined high level of resistin and fascin-1 expression correlates reliably with survival in CRC, so it may serve as a potential therapeutic target.

Homocysteine promotes vascular smooth muscle cell migration by induction of the adipokine resistin.

Adipokines may represent a mechanism linking insulin resistance to cardiovascular disease. We showed previously that homocysteine (Hcy), an independent risk factor for cardiovascular disease, can induce the expression and secretion of resistin, a novel adipokine, in vivo and in vitro. Since vascular smooth muscle cell (VSMC) migration is a key event in vascular disease, we hypothesized that adipocyte-derived resistin is involved in Hcy-induced VSMC migration. To confirm our hypothesis, Sprague-Dawley rat aortic SMCs were cocultured with Hcy-stimulated primary rat epididymal adipocytes or treated directly with increasing concentrations of resistin for up to 24 h. Migration of VSMCs was investigated. Cytoskeletal structure and cytoskeleton-related proteins were also detected. The results showed that Hcy (300-500 microM) increased migration significantly in VSMCs cocultured with adipocytes but not in VSMC cultured alone. Resistin alone also significantly increased VSMC migration in a time- and concentration-dependent manner. Resistin small interfering RNA (siRNA) significantly attenuated VSMC migration in the coculture system, which indicated that adipocyte-derived resistin mediates Hcy-induced VSMC migration. On cell spreading assay, resistin induced the formation of focal adhesions near the plasma membrane, which suggests cytoskeletal rearrangement via an alpha(5)beta(1)-integrin-focal adhesion kinase/paxillin-Ras-related C3 botulinum toxin substrate 1 (Rac1) pathway. Our data demonstrate that Hcy promotes VSMC migration through a paracrine or endocrine effect of adipocyte-derived resistin, which provides further evidence of the adipose-vascular interaction in metabolic disorders. The migratory action exerted by resistin on VSMCs may account in part for the increased incidence of restenosis in diabetic patients.

Different modulation by dietary restriction of adipokine expression in white adipose tissue sites in the rat.

BACKGROUND: White adipose tissue (WAT) is a disperse organ acting as energy storage depot and endocrine/paracrine controlling factor in the management of energy availability and inflammation. WAT sites response under energy-related stress is not uniform. In the present study we have analyzed how different WAT sites respond to limited food restriction as a way to better understand the role of WAT in the pathogenesis of the metabolic syndrome. METHODS: Overweight male rats had their food intake reduced a 40% compared with free-feeding controls. On day ten, the rats were killed; circulating glucose, insulin, leptin, adiponectin, triacylglycerols and other parameters were measured. The main WAT sites were dissected: mesenteric, retroperitoneal, epididymal and subcutaneous inguinal, which were weighed and frozen. Later all subcutaneous WAT was also dissected and weighed. Samples were used for DNA (cellularity) analysis and mRNA extraction and semiquantitarive RT-PCR analysis of specific cytokine gene expressions. RESULTS: There was a good correlation between serum leptin and cumulative WAT leptin gene mRNA, but not for adiponectin. Food restriction reduced WAT size, but not its DNA content (except for epididymal WAT). Most cytokines were correlated to WAT site weight, but not to DNA. There was WAT site specialization in the differential expression (and probably secretion) of adipokines: subcutaneous WAT showed the highest concentration for leptin, CD68 and MCP-1, mesenteric WAT for TNFalpha (and both tissues for the interleukins 1beta and 6); resistin was highly expressed in subcutaneous and retroperitoneal WAT. CONCLUSION: Food restriction induced different patterns for mesenteric and the other WAT sites, which may be directly related to both the response to intestine-derived energy availability, and an inflammatory-related response. However, retroperitoneal WAT, and to a lower extent, subcutaneous and epididymal, reacted decreasing the expression of inflammatory markers and the signaling of decreased energy availability in their stores. The varying cytokine expression patterns highlight the fact that WAT sites show different inflammatory and signaling responses to energy availability; they are too much different to simply extend to the whole-body WAT the findings of one or even a couple of sites.

Expression of Three Adipokines (Adiponectin, Leptin and Resistin) in Normal Canine Skin: a Pilot Study.

Adipokines are biologically active cytokines that are mainly produced in adipose tissue. There is evidence, in man and mice, that some adipokines may be secreted in other tissues including the vascular endothelium, epithelia and sebaceous glands. Moreover, modified serum levels of adipokines have been detected in people with acne vulgaris or psoriasis; it is suspected that adipokines could contribute to local and systemic inflammatory conditions. We aimed to evaluate the expression of three adipokines (i.e. leptin, adiponectin and resistin) in normal canine skin. Formalin-fixed, paraffin wax-embedded punch biopsy samples were obtained from the sparsely-haired skin of the caudal ventral abdomen of a single clinically healthy dog with no history of skin disease. Immunohistochemistry was applied, using rabbit polyclonal primary antibodies specific for leptin, adiponectin and resistin. Adipokines were not expressed in normal canine dermis or hypodermis. In contrast, they were detected in the keratinocytes of all epidermal layers and hair follicle segments, sebocytes, apocrine gland cells and in the vascular endothelium. This is the first report on the expression of adipokines in normal canine skin, a first step in studying their role in the skin physiology and inflammatory skin diseases of dogs.

Morus alba L. Diminishes visceral adiposity, insulin resistance, behavioral alterations via regulation of gene expression of leptin, resistin and adiponectin in rats fed a high-cholesterol diet.

Ethanolic extract of leaves of Morus alba L. (M. alba), known as white mulberry, was orally administered (100 mg/kg b.wt) for 8 weeks to female Wistar rats that were fed a high-cholesterol diet (HCD), to investigate the potential of M. alba leaves in attenuation of obesity, dyslipidemia, insulin resistance, and deficits in mood, cognitive as well as motor activity that are linked to the adipokines secretions of visceral adipose tissue. Results showed that M. alba diminished body weight gain, hypercholesterolemia, hypertriglyceridemia, atherogenic (AI) & coronary artery indices (CRI), and ameliorated glucose level and insulin resistance index in rats on HCD, compared with untreated HCD rats. Moreover, M. alba administration significantly decreased serum leptin and resistin contents as well as their mRNA expression in visceral adipose tissue, but significantly increased serum adiponectin level, and its mRNA expression in visceral adipose tissue in rats fed on HCD, compared to those in untreated HCD group. Regarding behavioral alterations, M. alba attenuated motor deficit, declined memory, depression and anxiety-like behavior, as well in rats on HCD, compared to that noticed in untreated HCD rats. The current data showed that serum leptin and resistin showed a positive correlation with and body weight gain, triglycerides (TG), AI as well as CRI, but showed a negative correlation with exploration, declined memory, depression- and anxiety-like behavior. Conversely, serum adiponectin showed a negative correlation with and body weight gain, TG, AI as well as CRI, but showed a positive correlation with locomotor activity, exploration, declined memory, and depression- and anxiety-like behavior. In conclusion, M. alba leaves supplementation could attenuate adiposity, insulin resistance behavioral deficits via down-regulation of regulation of gene expression of leptin, resistin, but up-regulation of adiponectin gene expression in the visceral adipose tissue of rats fed a high-cholesterol diet.

Role of resistin in cardiac contractility and hypertrophy.

Cardiovascular sequelae including diabetic cardiomyopathy constitute the major cause of death in diabetic patients. Although several factors may contribute to the development of this cardiomyopathy, the underlying molecular/cellular mechanisms leading to cardiac dysfunction are still partially understood. Recently, a novel paradigm for the role of the adipocytokine resistin in diabetes has emerged. Resistin has been proposed to be a link between obesity, insulin resistance and diabetes. Using microarray analysis, we have recently found that cardiomyocytes isolated from type 2 diabetic hearts express high levels of resistin. However, the function of resistin with respect to cardiac function is unknown. In this study we show that resistin is not only expressed in the heart, but also promotes cardiac hypertrophy. Adenovirus-mediated overexpression of resistin in cultured neonatal rat ventricular myocytes (NRVM) significantly increased sarcomere organization and cell size, increased protein synthesis and increased the expression of atrial natriuretic factor and beta-myosin heavy chain. Overexpression of resistin in NRVM was also associated with activation of the mitogen-activated protein (MAP) kinases, ERK1/2 and p38, as well as increased Ser-636 phosphorylation of insulin receptor substrate-1 (IRS-1), indicating that IRS-1/MAPK pathway may be involved in the observed hypertrophic response. Overexpression of resistin in adult cultured cardiomyocytes significantly altered myocyte mechanics by depressing cell contractility as well as contraction and relaxation velocities. Intracellular Ca(2+) measurements showed slower Ca(2+) transients decay in resistin-transduced myocytes compared to controls, suggesting impaired cytoplasmic Ca(2+) clearing or alterations in myofilament activation. We conclude that resistin overexpression alters cardiac contractility, confers to primary cardiomyocytes all the features of the hypertrophic phenotype and promotes cardiac hypertrophy possibly via the IRS-1/MAPK pathway.

Reproductive endocrinology and clinical aspects of obesity in women.

Obesity is a growing worldwide problem and is associated with a wide range of adverse effects on the female reproductive system. The endocrinological changes in obesity that may cause these adverse effects are complex and include changes in circulating adipokines and sex steroids as well as insulin resistance. Considerable evidence suggests an adverse effect of obesity on the risk of miscarriage and other maternal and fetal complications. Obese patients are also more prone to infertility. The most important single method to improve reproductive performance in obese women is weight loss that can be achieved with lifestyle changes and diet. Antiobesity drugs may also be used and, in severe cases, bariatric surgery.