OBJECTIVE-Estradiol (E 2 ) is known to modulate insulin sensitivity and, consequently, glucose homeostasis. Resveratrol (RSV), an agonist of estrogen receptor (ER), has exerted antihyperglycemic effects in streptozotocin-induced type 1 diabetic rats in our previous study and was also shown to improve insulin resistance in other reports. However, it remains unknown whether activation of ER is involved in the metabolic effects of RSV via insulin-dependent and -independent mechanisms. RESEARCH DESIGN AND METHODS-MaleSprague-Dawley rats were given a high cholesterol-fructose (HCF) diet for 15 weeks and were treated with RSV for either 15 days or 15 weeks.RESULTS-Here, we show that RSV shifts the metabolic characteristics of rats on an HCF diet toward those of rats on a standard diet. RSV treatment increased insulin-stimulated wholebody glucose uptake and steady-state glucose uptake of soleus muscle and liver in HCF-fed rats as well as enhanced membrane trafficking activity of GLUT4 and increased phosphorylation of insulin receptor in insulin-resistant soleus muscles. Interestingly, the phosphorylated ER level in insulin-resistant soleus muscle was significantly elevated in rats with RSV treatment in both basal and euglycemic-hyperinsulinemic conditions. RSV exerted an insulin-like stimulatory effect on isolated soleus muscle, epididymal fat and hepatic tissue, and C2C12 myotubes. The RSV-stimulated glucose uptake in C2C12 myotubes was dependent on extracellular signal-related kinase/p38 (early phase, 1 h) and p38/phosphoinositide 3-kinase (late phase, 14 h) activation. Inhibition of ER abrogated RSV-induced glucose uptake in both early and late phases.CONCLUSIONS-Collectively, these results indicate that ER is a key regulator in RSV-stimulating insulin-dependent and -independent glucose uptake, which might account for the protective effects of RSV on diet-induced insulin resistance syndrome.

ABSTRACT:We examined the involvement of adipocyte cyclooxygenase-2 (COX-2) and prostaglandin E 2 (PGE 2 )-prostaglandin E receptor (EP)3-mediated signaling during hypertrophy and hypoxia in the development of obesityassociated adipose tissue (AT) inflammation and insulin resistance. The experiments were conducted with high-fat diet (HFD)-induced obese rats, db/db mice, human subjects, and 3T3-L1 and the human Simpson-Golabi-Behmel syndrome (SGBS) adipocytes; the groups were treated with selective inhibitors of COX-2 [celecoxib 30 mg/kg, half maximal inhibitory concentration (IC 50 ) 0.04 mM] and EP3 (L-798106 100 mg/kg, IC 50 0.5 mM) or a short interfering RNA. There were strong, positive correlations between adipocyte COX-2 and EP3 gene expressions and the AT TNF-a and monocyte chemotactic protein-1 contents and the homeostatic model assessment for insulin resistance in HFD-induced obese rats, as well as body mass index in human subjects. Treatment with COX-2 and EP3 inhibitors significantly reversed AT inflammatory gene and protein expressions (250%) and impaired glucose and insulin tolerance in db/db mice. COX-2 inhibition diminished the chemotaxis of adipocytes isolated from HFD rats to macrophages and T cells. Targeting inhibition of adipocyte COX-2 and EP3 during hypertrophy and hypoxia reversed the release of the augmented proinflammatory adipokines and the diminished adiponectin and also suppressed NFkB and hypoxia-inducible factor-1a transcription activation. These findings suggest that adipocyte COX-2 PGE 2 -EP3-mediated signaling is crucially involved in the development of obesity-associated AT inflammation and insulin resistance.-Chan, P.-C., Hsiao, F.-C., Chang, H.-M., Wabitsch, M., Hsieh, P. S. Importance of adipocyte cyclooxygenase-2 and prostaglandin E 2 -prostaglandin E receptor 3 signaling in the development of obesityinduced adipose tissue inflammation and insulin resistance. FASEB J. 30, 2282FASEB J. 30, -2297FASEB J. 30, (2016 Adipose tissue (AT) inflammation has been suggested to play a central role in the pathogenesis of many obesityassociated complications, including insulin resistance (1), type 2 diabetes (2, 3), atherosclerosis (2-4), and nonalcoholic fatty liver disease (1). However, the underlying mechanisms of this process remain elusive.Adipocytes in an obesity setting are characterized by hypertrophy and hypoxia, and they are important sources of inflammation (5-7). This inflammation is mediated by the production of a substantial number of cytokines and chemokines, including TNF-a (3, 5), IL-6 (8), monocyte chemotactic protein-1 (MCP-1) (9), and RANTES (10). These cytokines and chemokines are crucially involved in the initiation of the adipocyte-mediated inflammatory response in obese individuals. The capacity of the constitutive and regulated release of immune mediators from adipocytes demonstrates a causal link between the biology of adipocytes and immune cells, such as macrophages and T cells. Moreover, the synergistic effect of inflamed

Type 1 diabetes mellitus is caused by T-cell-mediated autoimmune destruction of pancreatic β-cells. Systemic administration of mesenchymal stem cells (MSCs) brings about their incorporation into a variety of tissues with immunosuppressive effects, resulting in regeneration of pancreatic islets. We previously showed that human MSCs isolated from Wharton's jelly (WJ-MSCs) represent a potential cell source to treat diabetes. However, the underlying mechanisms are unclear. The purpose of this study was to discern whether undifferentiated WJ-MSCs can differentiate into pancreatic insulin-producing cells (IPCs) and modify immunological responses in nonobese diabetic (NOD) mice. Undifferentiated WJ-MSCs underwent lentiviral transduction to express green fluorescent protein (GFP) and then were injected into the retro-orbital venous sinus of NOD mice. Seven days after transplantation, fluorescent islet-like cell clusters in the pancreas were apparent. WJ-MSC-GFP-treated NOD mice had significantly lower blood glucose and higher survival rates than saline-treated mice. Systemic and local levels of autoaggressive T-cells, including T helper 1 cells and IL-17-producing T-cells, were reduced, and regulatory T-cell levels were increased. Furthermore, anti-inflammatory cytokine levels were increased, and dendritic cells were decreased. At 23 days, higher human C-peptide and serum insulin levels and improved glucose tolerance were found. Additionally, WJ-MSCs-GFP differentiated into IPCs as shown by colocalization of human C-peptide and GFP in the pancreas. Significantly more intact islets and less severe insulitis were observed. In conclusion, undifferentiated WJ-MSCs can differentiate into IPCs in vivo with immunomodulatory effects and repair the destroyed islets in NOD mice.

Background/Aims: Hyperlipidemia induces dysfunction in the smooth muscle cells (SMCs) of the blood vessels, and the vascular remodeling that ensues is a key proatherogenic factor contributing to cardiovascular events. Chemokines and chemokine receptors play crucial roles in vascular remodeling. Here, we examined whether the hyperlipidemia-derived chemokine CCL5 and its receptor CCR5 influence vascular SMC proliferation, phenotypic switching, and explored the underlying mechanisms. Methods: Thoracoabdominal aorta were isolated from wild-type, CCL5 and CCR5 double-knockout mice (CCL5^–/–CCR5^–/–) fed a high-fat diet (HFD) for 12 weeks. Expression of the contractile, synthetic, and proliferation markers were assayed using immunohistochemical and western blotting. The effects of CCL5 and palmitic acid on cultured SMC proliferation and phenotypic modulation were evaluated using flow cytometry, bromodeoxyuridine (BrdU), and western blotting. Results: Wild-type mice fed an HFD showed markedly increased total cholesterol, triglyceride, and CCL5 serum levels, as well as significantly increased CCL5 and CCR5 expression in the thoracoabdominal aorta vs. normal-diet-fed controls. HFD-fed CCL5^-/-CCR5^-/- mice showed significantly decreased expression of the synthetic phenotype marker osteopontin and the proliferation marker proliferating cell nuclear antigen, and increased expression of the contractile phenotype marker smooth muscle α-actin in the thoracoabdominal aorta vs. wild-type HFD-fed mice. Human aorta-derived SMCs stimulated with palmitic acid showed significantly increased expression of CCL5, CCR5, and synthetic phenotype markers, as well as increased proliferation. CCL5-treated SMCs showed increased cell cycle regulatory protein expression, paralleling increased synthetic and decreased contractile phenotype marker expression. Inhibition of CCR5 activity by the specific antagonist maraviroc or its expression using small interfering RNA significantly inhibited human aortic SMC proliferation and synthetic phenotype formation. Therefore, CCL5 induces SMC proliferation and phenotypic switching from a contractile to synthetic phenotype via CCR5. CCL5-mediated SMC stimulation activated ERK1/2, Akt/p70S6K, p38 MAPK, and NF-κB signaling. NF-κB inhibition significantly reduced CCR5 expression along with CCR5-induced SMC proliferation and synthetic phenotype formation. Conclusions: Hyperlipidemia-induced CCL5/CCR5 axis activation serves as a pivotal mediator of vascular remodeling, indicating that CCL5 and CCR5 are key chemokine-related factors in atherogenesis. SMC proliferation and synthetic phenotype transformation attenuation by CCR5 pharmacological inhibition may offer a new approach to treatment or prevention of atherosclerotic diseases associated with hyperlipidemia.

Circulating Gas6 levels are strongly associated with adiposity, inflammation, and insulin resistance status among overweight and obese adolescents. The potential role of the Gas6/TAM system in the initiation of childhood obesity and obesity-associated complications deserves further attention.

Regulated upon activation, normal T cell expressed, and secreted (RANTES), also known as chemokine ligand 5 (CCL5), has been reported to facilitate macrophage migration, which plays a crucial role in tissue inflammation. The aim of this study is to investigate the characteristics and underlying mechanism of RANTES on macrophage chemotaxis under physiological and pathological conditions. The study was conducted on macrophage RAW264.7 cell and bone marrow-derived macrophages (BMDM) isolated from CCL receptor 5 (CCR5) knockout mice. The macrophage migration and glucose uptake was assessed in time and dose dependent manners. Moreover, reverse transcription-polymerase chain reaction (RT-PCR) and western blot analysis were used to characterize mRNA and protein level related to the underlying mechanism. The present result showed that the maraviroc, a selective CCR5 inhibitor, dose-dependently suppressed RANTESinduced rapid increases in glucose uptake and cell migration in RAW264.7 cells. Similar effects were observed in the BMDM isolated from CCR5 knockout mice compared with wild type control. RANTES treatment promptly enhanced membrane glucose transporter 1 (GLUT1) expression, glucose uptake as well as phosphorylation of AKT on Thr308, Ser473 within min and has prolonged effect on phosphorylation of AMP-activated protein kinase (AMPK) on Thr172, which were abrogated by maraviroc, CCR5 siRNA or phospholipase C (PLC) inhibitor in RAW264.7 cells. Inhibition of PI3K and AMPK by LY294002 and Compound C significantly suppress RANTESstimulated macrophage glucose uptake and migration, respectively. RANTES has biphasic effect on activating PLC signaling including prompt action on PI3K/AKT phosphorylation and prolong action on AMPK phosphorylation via CCR5 which leads to increased GLUT1-mediated glucose uptake and macrophage migration under physiopathological states.

Although islet transplantation holds promise for the treatment of diabetes, the scarcity of donor tissue remains a major drawback. The aim of this study is to generate insulinproducing cells from adult human pancreatic cells isolated from surgically resected pancreatic tissue. To isolate pancreatic endocrine precursor cells from 57 surgically resected pancreases, the cells were cultured and propagated in conditioned medium after which they were differentiated in Matrigel. The resultant cells were characterized using morphology, immunofluorescent studies, expression of differentiated pancreatic islet-specific genes using quantitative reverse transcription-PCR, and glucose-induced insulin secretion through analysis of C-peptide secretion. The relationships between propagation of insulin-producing cells and clinical variables of the donor were also analyzed. Finally, insulin-producing cell function was examined in streptozotocin-induced diabetic rats. Pancreatic endocrine precursor cells were successfully cultured; insulin-producing cells cultured from soft pancreas parenchyma had a significantly higher success rate. Morphological examination revealed islet-like cluster formation upon transfer to Matrigel. The presence of the neural stem cell marker nestin, duct cell marker cytokeratin 19, and endocrine cell markers C-peptide and pancreatic and duodenal homeobox 1, was also observed. In addition, glucose-stimulated C-peptide release was significantly increased in the insulinproducing cells. Furthermore, in diabetic rats, transplantation of insulin-producing cells reduced hyperglycemia. Isolated pancreatic endocrine precursor cells from surgically resected pancreatic tissue differentiated into insulin-producing cells and showed characteristics of functional endocrine cells. Thus, surgically resected pancreatic tissue may represent an alternative source of functional insulin-producing cells.

Food restriction and weight loss are known to prevent obesity-related heart diseases. This study investigates whether food restriction elicits anti-apoptotic and pro-survival effects on high-fat diet-induced obese hearts. Histopathological analysis, TUNEL assay, and Western blotting were performed on the excised hearts from three groups of Sprague-Dawley rats which were fed with regular chow diet (CON, 13.5 % fat), a high-fat ad libitum diet (HFa, 45 % fat), or a high-fat food-restricted diet (HFr, 45 % fat, maintaining the same weight as CON) for 12 weeks. Body weight, blood pressure, heart weight, triglycerides, insulin, HOMA, interstitial spaces, cardiac fibrosis, and cardiac TUNEL-positive apoptotic cells were increased in HFa relative to CON, whereas these parameters were decreased in HFr relative to HFa. The protein levels of cardiac Fas ligand, Fas receptors, Fas-associated death domain (FADD), activated caspase-8, and activated caspase-3 (Fas receptor-dependent apoptotic pathways), as well as t-Bid/Bid, Bax/Bcl-2, Bad/p-Bad, Cytochrome c, activated caspase-9, and activated caspase-3 (mitochondria-dependent apoptotic pathways) in HFr were lower than those in HFa. Moreover, the Bcl-xL and IGF-1-related components of IGF-1, p-PI3 K/PI3 K, p-Akt/Akt in HFr were higher than those in HFa. Our findings suggest that a restricted high-fat diet for maintaining weight control could diminish cardiac Fas receptor-dependent and mitochondria-dependent apoptotic pathways as well as might enhance IGF-1-related pro-survival pathways. In sum, food restriction for maintaining normal weight could elicit anti-apoptotic and pro-survival effects on high-fat diet-induced obese hearts.