Peroxisome proliferator-activated receptor ␥ (PPAR␥) is a nuclear receptor that plays a pivotal role in obesity and diabetes. PPAR␥ has two isoforms, PPAR␥1 and PPAR␥2. We investigated the functional differences between PPAR␥1 and PPAR␥2 by selectively disrupting PPAR␥2 in mice. In contrast to the embryonic lethality of PPAR␥-deficient mice, PPAR␥2 ؊/؊ mice survived. Although normal development was identified in other tissues we examined, PPAR␥2 ؊/؊ mice exhibited an overall reduction in white adipose tissue, less lipid accumulation, and decreased expression of adipogenic genes in adipose tissue. In addition, insulin sensitivity was impaired in male PPAR␥2 ؊/؊ mice, with dramatically decreased expression of insulin receptor substrate 1 and glucose transporter 4 in the skeletal muscle, but thiazolidinediones were able to normalize this insulin resistance. Consistent with in vivo data, PPAR␥2 ؊/؊ mouse embryonic fibroblasts showed a dramatically reduced capacity for adipogenesis in vitro compared with wildtype mouse embryonic fibroblasts. Taken together, our data demonstrate that PPAR␥2 deficiency impairs the development of adipose tissue and insulin sensitivity. PPAR␥2 ؊/؊ mice may provide a tool to study the role of PPAR␥2 in obesity and diabetes.adipogenesis ͉ obesity ͉ diabetes

The cerebellum has critical roles in motor and sensory learning and motor coordination. Many cerebellumrelated disorders indicate cell therapy as a possible treatment of neural loss. Here we show that application of inductive signals involved in early patterning of the cerebellar region followed by application of different factors directs human embryonic stem cell differentiation into cerebellar-like cells such as granule neurons, Purkinje cells, interneuron, and glial cells. Neurons derived using our protocol showed a T-shaped polarity phenotype and express similar markers to the developed human cerebellum. Electrophysiological measurements confirmed functional electrical properties compatible with these cells. In vivo implantation of differentiated human embryonic stem cells transfected with MATH1-GFP construct into neonatal mice resulted in cell migration across the molecular and the Purkinje cell layers and settlement in the internal molecular layers. Our findings demonstrate that the universal mechanisms involved in the development of cerebellum can be efficiently recapitulated in vitro, which enables the design of new strategies for cell replacement therapy, to study early human development and pathogenesis of neurodegenerative diseases.

Cancer stem cells (CSCs), or tumor initiating cells, are a subpopulation of cancer cells with self-renewal and differentiation properties. However, there has been no direct observation of the properties of gastric CSCs in vitro. Here we describe a vincristine (VCR)-preconditioning approach to obtain cancer stem-like cells (CSLCs) from the gastric cancer cell line SGC7901. The CSLCs displayed mesenchymal characteristics, including the up-regulated mesenchymal markers Snail, Twist, and vimentin, and the down-regulated epithelial marker E-cadherin. Using a Matrigel-based differentiation assay, CSLCs formed 2D tube-like and 3D complex lumen-like structures, which resembled differentiated gastric crypts. The characteristic of cellular differentiation was also found by transmission electron microscopy and up-regulation of gastrointestinal genes CDX2 and SOX2. We further showed that CSLCs could self-renew through significant asymmetric division compared with parent cells by tracing PKH-26, BrdU, and EDU label-retaining cells. In addition, these CSLCs also increased expression of CD44, CD90, and CXCR4 at the mRNA level, which was identified as novel targets. Furthermore, drug sensitivity assays and xenograft experiments demonstrated that the cells developed multi-drug resistance (MDR) and significant tumorigenicity in vivo. In summary, gastric CSCs were identified from VCR-preconditioned SGC7901 cell line, characterized by high tumorigenicity and the capacity for self-renewal and differentiation.

BackgroundIn developed countries, prostate cancer (PCa) is a frequently diagnosed cancer with the second highest fatality rate. Circular RNAs (circRNAs) are a class of endogenous non-coding RNAs (ncRNAs) stably expressed in cells and involved in a series of carcinomas. However, few research studies have reported on the role of circRNAs in PCa.Material/MethodsWe used qRT-PCR to detect the expression of circMYLK (circRNA ID: hsa_circ_0141940) and miR-29a in PCa tissues and cell lines. MTT, colony formation, and TUNEL assays were performed to analysis the cell viability of PCa cells. Transwell and wound scratch assays were performed to investigate the cell invasion and migration of PCa cells.ResultsIn the present study, we confirmed that circMYLK expression level was significantly higher in PCa samples and PCa cells than in normal tissues and normal prostatic cells. The upregulated circRNA-MYLK promoted PCa cells proliferation, invasion, and migration; however, si-circRNA-MYLK significantly accelerated the PCa cell apoptosis. We also observed that the aforementioned function of circRNA-MYLK on PCa cells was affected through targeting miR-29a.ConclusionsWe confirmed circRNA-MYLK was an oncogene in PCa and revealed a novel mechanism underlying circRNA-MYLK in PC progression.

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Doxorubicin- (DOX-) induced cardiotoxicity is associated with oxidative stress and cardiomyocyte apoptosis. The adaptor protein p66Shc regulates the cellular redox status and determines cell susceptibility to apoptosis. This study is aimed at investigating the involvement of sirtuin 1- (SIRT1-) mediated p66Shc inhibition in DOX-induced redox signalling and exploring the possible protective mechanisms of berberine (Ber) against DOX-triggered cardiac injury in rats and a cultured H9c2 cell line. Our results showed that the Ber pretreatment markedly increased CAT, SOD, and GSH-PX activities, decreased the levels of MDA, and improved the electrocardiogram and histopathological changes in the myocardium in DOX-treated rats (in vivo). Furthermore, Ber significantly ameliorated the DOX-induced oxidative insult and mitochondrial damage by adjusting the levels of intracellular ROS, ΔΨm, and [Ca2+]m in H9c2 cells (in vitro). Importantly, the Ber pretreatment increased SIRT1 expression following DOX exposure but downregulated p66Shc. Consistent with the results demonstrating the SIRT1-mediated inhibition of p66Shc expression, the Ber pretreatment inhibited DOX-triggered cardiomyocyte apoptosis and mitochondrial dysfunction. After exposing H9c2 cells to DOX, the increased SIRT1 expression induced by Ber was abrogated by a SIRT1-specific inhibitor (EX527) or the use of siRNA against SIRT1. Accordingly, SIRT1 inhibition significantly abrogated the suppression of p66Shc expression and protection of Ber against DOX-induced oxidative stress and apoptosis. These results suggest that Ber protects the heart from DOX injury through SIRT1-mediated p66Shc suppression, offering a novel mechanism responsible for the protection of Ber against DOX-induced cardiomyopathy.

Doxorubicin (DOX), a potent broad‑spectrum chemotherapeutic agent used for the treatment of several types of cancer, is largely limited due to its serious side effects on non‑target organs. Thus, the present study aimed to investigate whether berberine (Ber), an isoquinoline alkaloid, could reduce DOX‑induced acute hepatorenal toxicity in rats. Fifty rats were randomly divided into five groups: i) Control group, ii) DOX group, iii) DOX+Ber (5 mg kg) group; iv) DOX+Ber (10 mg kg), and v) DOX+Ber (20 mg kg) group. In the tests, body weight, organ index, general condition and mortality were observed. In addition, the serum levels of alanine transaminase (ALT), aspartate aminotransferase (AST), total cholesterol (TCHO) and blood urea nitrogen (BUN) were determined to evaluate hepatorenal function. Hepatorenal toxicity was further assessed using hematoxylin and eosin stained sections. Furthermore, the levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and malondialdehyde (MDA) in rat serum or tissue homogenate were also assessed to determine the mechanisms of action. Results suggested that pretreatment with Ber ameliorated the DOX‑induced liver and kidney injury by lowering the serum ALT, AST, TCHO and BUN levels, and the damage observed histologically, such as hemorrhage and focal necrosis of liver and kidney tissues induced by DOX were also attenuated by Ber. Furthermore, Ber also exerted certain antioxidative properties through reversing the changes in the levels of MDA, SOD, GSH and MDA induced by DOX. These findings indicate that Ber has protective effects against DOX‑induced acute hepatorenal toxicity in rats. Combination of Ber with DOX is a novel strategy that has the potential for protecting against DOX‑induced hepatorenal toxicity in clinical practice.

Aim: To investigate the protection and the anti-oxidative mechanism afforded by chronic intermittent hypobaric hypoxia (CIHH) against ischemia/reperfusion (I/R) injury in guinea pig hearts. Methods: Adult male guinea pigs were exposed to CIHH by mimicking a 5000 m high altitude (p B =404 mmHg, p O2 =84 mmHg) in a hypobaric chamber for 6 h/day for 28 days. Langendorff-perfused isolated guinea pig hearts were used to measure variables of left ventricular function during baseline perfusion, ischemia and the reperfusion period. The activity and protein expression of antioxidant enzymes in the left myocardium were evaluated using biochemical methods and Western blotting, respectively. Intracellular reactive oxygen species (ROS) were assessed using ROS-sensitive fluorescence. Results: After 30 min of global no-flow ischemia followed by 60 min of reperfusion, myocardial function had better recovery rates in CIHH guinea pig hearts than in control hearts. The activity and protein expression of superoxide dismutase (SOD) and catalase (CAT) were significantly increased in the myocardium of CIHH guinea pigs. Pretreatment of control hearts with an antioxidant mixture containing SOD and CAT exerted cardioprotective effects similar to CIHH. The irreversible CAT inhibitor aminotriazole (ATZ) abolished the cardioprotection of CIHH. Cardiac contractile dysfunction and oxidative stress induced by exogenous hydrogen peroxide (H 2 O 2 ) were attenuated by CIHH and CAT. Conclusions: These data suggest that CIHH protects the heart against I/R injury through upregulation of antioxidant enzymes in guinea pig.