Tovit Rosenzweig

Related to Testes-Specific, Vespid, and Pathogenesis Protein-1 (RTVP-1) Is Overexpressed in Gliomas and Regulates the Growth, Survival, and Invasion of Glioma Cells

In this study, we examined the expression and functions of related to testes-specific, vespid, and pathogenesis protein 1 (RTVP-1) in glioma cells. RTVP-1 was expressed in high levels in glioblastomas, whereas its expression in low-grade astrocytomas and normal brains was very low. Transfection of glioma cells with small interfering RNAs targeting RTVP-1 decreased cell proliferation in all the cell lines examined and induced cell apoptosis in some of them. Overexpression of RTVP-1 increased astrocyte and glioma cell proliferation and the anchorage-independent growth of the cells. In addition, overexpression of RTVP-1 rendered glioma cells more resistant to the apoptotic effect of tumor necrosis factor-related apoptosis-inducing ligand and serum deprivation. To delineate the molecular mechanisms involved in the survival effects of RTVP-1, we examined the expression and phosphorylation of various apoptosis-related proteins. We found that overexpression of RTVP-1 decreased the phosphorylation of c-Jun-NH2-kinase and increased the expression of Bcl2 and that the protective effect of RTVP-1 was partially mediated by Bcl2. Finally, we found that RTVP-1 regulated the invasion of glioma cells as was evident by their enhanced migration through Matrigel and by their increased invasion in a spheroid confrontation assay. The increased invasive potential of the RTVP-1 overexpressors was also shown by the increased activity of matrix metalloproteinase 2 in these cells. Our results suggest that the expression of RTVP-1 is correlated with the degree of malignancy of astrocytic tumors and that RTVP-1 is involved in the regulation of the growth, survival, and invasion of glioma cells. Collectively, these findings suggest that RTVP-1 is a potential therapeutic target in gliomas.

Sarcopoterium spinosum extract as an antidiabetic agent: In vitro and in vivo study

ETHNOPHARMACOLOGICAL RELEVANCE Sarcopoterium spinosum (L.) sp., a common plant in the Mediterranean region, is widely used as an antidiabetic drug by Bedouin healers. However, the antidiabetic properties of Sarcopoterium spinosum had not been fully validated using scientific tools. AIM OF THE STUDY To determine the effectiveness of Sarcopoterium spinosum extract as an antidiabetic agent in vitro and in vivo. MATERIALS AND METHODS RINm pancreatic beta-cells, L6 myotubes, 3T3-L1 adipocytes and AML-12 hepatocytes were treated with an aqueous Sarcopoterium spinosum extract (0.001-10mg/ml). The effect of the extract on specific physiological functions, including insulin secretion, pancreatic beta-cell viability, GSK3 beta phosphorylation, lipolysis and glucose uptake was measured. In vivo studies were performed using KK-A(y) mice, given the extract for several weeks. IPGTT was performed, and plasma insulin, FFA, food consumption and body weight were measured. In addition, diabetic KK-A(y) mice were given a single dose of the extract, and IPGTT was performed. RESULTS Sarcopoterium spinosum extract increased basal and glucose/forskolin-induced insulin secretion in RINm cells, and increased cell viability. The extract inhibited lipolysis in 3T3-L1 adipocytes, and induced glucose uptake in these cells as well as in AML-12 hepatocytes and L6 myotubes. GSK3 beta phosphorylation was also induced in L6 myotubes, suggesting increased glycogen synthesis. Sarcopoterium spinosum extract had a preventive effect on the progression of diabetes in KK-A(y) mice. Catechin and epicatechin were detected in Sarcopoterium spinosum extract using hyphenated LC-MS/MS. CONCLUSIONS Sarcopoterium spinosum extract has effects that mimic those of insulin and provide the basis for antidiabetic activity of the extract.

Maintenance of redox state and pancreatic beta‐cell function: Role of leptin and adiponectin

Whereas oxidative stress is linked to cellular damage, reactive oxygen species (ROS) are also believed to be involved in the propagation of signaling pathways. Studies on the role of ROS in pancreatic beta‐cell physiology, in contrast to pathophysiology, have not yet been reported. In this study we investigate the importance of maintaining cellular redox state on pancreatic beta‐cell function and viability, and the effects of leptin and adiponectin on this balance. Experiments were conducted on RINm and MIN6 pancreatic beta‐cells. Leptin (1–100 ng/ml) and adiponectin (1–100 nM) increased ROS accumulation, as was determined by DCFDA fluorescence. Using specific inhibitors, we found that the increase in ROS levels was mediated by NADPH oxidase (Nox), but not by AMP kinase (AMPK) or phosphatidyl inositol 3 kinase (PI3K). Leptin and adiponectin increased beta‐cell number as detected by the XTT method, but did not affect apoptosis, indicating that the increased cell number results from increased proliferation. The adipokines‐induced increase in viability is ROS dependent as this effect was abolished by N‐acetyl‐L‐cysteine (NAC) or PEG‐catalase. In addition, insulin secretion was found to be regulated by alterations in redox state, but not by adipokines. Finally, the effects of the various treatments on activity and mRNA expression of several antioxidant enzymes were determined. Both leptin and adiponectin reduced mRNA levels of superoxide dismutase (SOD)1. Adiponectin also decreased SOD activity and increased catalase and glutathione peroxidase (GPx) activities in the presence of H2O2. The results of this study show that leptin and adiponectin, by inducing a physiological increase in ROS levels, may be positive regulators of beta‐cell mass. J. Cell. Biochem. 113: 1966–1976, 2012.

Autocrine/Paracrine Function of Globular Adiponectin: Inhibition of Lipid Metabolism and Inflammatory Response in 3T3-L1 Adipocytes

Adiponectin is an adipose‐derived hormone, with beneficial effects on insulin sensitivity and inflammation. The aim of this study was to clarify the autocrine/paracrine effects of globular adiponectin (gAd) administrated during differentiation on the function of the mature adipocytes. Experiments were performed on 3T3‐L1 preadipocytes treated with gAd (10 nM), starting at an early stage of differentiation. gAd treatment during differentiation was without effect on mRNA expression of adiponectin and AdipoR2, but increased AdipoR1 expression. PPARgamma, perillipin and FABP4 mRNA expressions were lower in gAd‐treated adipocytes, accompanied by a reduction in lipid accumulation. While mRNA expression of HSL was not affected by gAd compared to untreated adipocytes, both ATGL and FAS were reduced, indicating that gAd regulates both lipolysis and lipogenesis. PPARα, ACOX2 and UCPs mRNA expressions were not affected by gAd, indicating that the reduction in lipid content is not attributed to an increase in fatty‐acid oxidation. In accord with the lower PPARγ expression, there was reduced Glut4 mRNA expression; however, insulin‐induced PKB phosphorylation was enhanced by gAd, and glucose uptake was not altered. To investigate the effect of gAd on LPS‐induced inflammatory response, cells were treated with gAd either during differentiation or 24 h before induction of inflammation in differentiated adipocytes. LPS‐induced inflammatory response, as indicated by increase in IL6 and MCP‐1 mRNA expression. gAd given through differentiation was much more effective in abrogating LPS‐dependent cytokines production than gAd given to the mature adipocyte. In conclusion, elevated gAd at differentiation of 3T3‐L1 cells leads to reduced lipid content, reduced lipid metabolism and high resistance to inflammation. J. Cell. Biochem. 116: 754–766, 2015.

C-reactive protein velocity to distinguish febrile bacterial infections from non-bacterial febrile illnesses in the emergency department

IntroductionC-reactive protein (CRP) is a real-time and low-cost biomarker to distinguish febrile bacterial infections from non-bacterial febrile illnesses. We hypothesised that measuring the velocity of the biomarker instead of its absolute serum concentration could enhance its ability to differentiate between these two conditions.MethodsWe prospectively recruited adult patients (age ≥ 18 years) who presented to the emergency department with fever. We recorded their data regarding the onset of fever and accompanying symptoms. CRP measurements were obtained upon admission. CRP velocity (CRPv) was defined as the ratio between CRP on admission and the number of hours since the onset of fever. Patients were diagnosed by clinical symptoms, blood cultures and imaging studies, and the diagnoses were confirmed by an infectious disease specialist. The efficacy of CRPv as a diagnostic marker was evaluated by using receiver operator curves (ROC). Excluded were patients who did not know the time fever started with certainty, patients with malignancy, patients with HIV infection and patients who had been using antibiotics upon presentation.ResultsOf 178 eligible patients, 108 (60.7%) had febrile bacterial infections (mean CRP: 63.77 mg/L, mean CRPv: 3.61 mg/L/hour) and 70 (39.3%) had non-bacterial febrile illnesses (mean CRP: 23.2 mg/L, mean CRPv: 0.41 mg/L/hour). The area under the curve for CRP and CRPv were 0.783 (95% confidence interval (CI) = 0.717 to 0.850) and 0.871 (95% CI = 0.817 to 0.924), respectively. In a 122-patient subgroup with a CRP level of less than 100 mg/L, the area under the curve increased from 0.689 (95% CI = 0.0595 to 0.782) to 0.842 (95% CI = 0.77 to 0.914) by using the CRPv measurements.ConclusionsCRPv improved differentiation between febrile bacterial infections and non-bacterial febrile illnesses compared with CRP alone, and could identify individuals who need prompt therapeutic intervention.

Anti-diabetic activity of Chiliadenus iphionoides.

ETHNOPHARMACOLOGICAL RELEVANCE Chiliadenus iphionoides (Boiss. & Blanche) Brullo (Asteraceae), a small aromatic shrub found throughout Israel, is used traditionally in the treatment of diabetes mellitus. In this study, Chiliadenus iphionoides anti-diabetic activity was characterized using cellular and animal models. MATERIALS AND METHODS Pancreatic β cells, adipocytes, and skeletal myotubes were treated with an ethanolic extract of Chiliadenus iphionoides to study the extracts effects on insulin secretion and glucose uptake. The sand rat (Psammomys obesus) was used to study Chiliadenus iphionoides acute and long term effects in vivo. An oral starch tolerance test was performed as well as a 30 day feeding study. RESULTS Chiliadenus iphionoides extract increased insulin secretion in β cells as well as glucose uptake in adipocytes and skeletal myotubes. The extract also displayed hypoglycemic activity in the diabetic sand rat. CONCLUSIONS Chiliadenus iphionoides exhibits considerable anti-diabetic activity, although the mechanism of action remains to be determined.

The effect of two iso-caloric meals containing equal amounts of fats with a different fat composition on the inflammatory and metabolic markers in apparently healthy volunteers.

BackgroundLittle is known about the time-course of the postprandial appearance of macronutrient-induced inflammatory response. Our aim was to investigate the postprandial inflammatory and metabolic response following high fat, high caloric popular meals in apparently healthy participants.MethodsFifty four apparently healthy normal weight volunteers (BMI of 25.9±0.9) were given two iso-caloric meals with similar amounts but different composition of fats: a meal high in monounsaturated fats (MUFA), and a meal high in saturated fat (SFA). Three main effects and the interactions between them were analyzed: the time (before and 2 and 4 hours following the meals), the meal (MUFA or SFA) and the gender.ResultsThe effect of time from the meal on hs-CRP level was highly significant (p=0.004). The highest responses were observed 2 hours after the meal (p=0.002). A statistically significant interaction was found between the time and the meal (p≤0.0001), which reflects the higher increase in hs-CRP values 2 hours after the SFA meal, with no effect by the MUFA meal. The white blood cell counts were affected significantly by the time (p≤0.0001) however, other inflammatory markers (fibrinogen, IL-6, TNFα, ICAM and VICAM) were not. All the metabolic markers (insulin, glucose, HOMA-R, QUICKI and triglycerides) were affected by the time (p≤0.0001), with no interactions observed.ConclusionsMetabolic and modest inflammatory changes occur within a few hours after the ingestion of a high SFA meal in apparently healthy adults.

Evaluating the anti-diabetic effects of Sarcopoterium spinosum extracts in vitro

Natural medicine has traditionally used medicinal plants to treat diabetes. However, the efficacy of most of these folk medicine plants has rarely been tested and validated using scientific methods. Sarcopoterium spinosum, an abundant plant in Israel, was suggested to have a beneficial effect on diabetes symptoms. In this study we determined the antidiabetic effect of an S. spinosum extract in vitro. Results: Treatment of L6 myotubes with an S. spinosum extract induced GSK3β phosphorylation, suggesting that the extract increases glycogen synthesis. In pancreatic β-cells, the S. spinosum extract increased basal insulin secretion, but reduced glucose/forskolin-induced insulin secretion. The extract also inhibited isoproterenol-induced lipolysis in 3T3-L1 adipocytes, as determined by measuring the free fatty acids in the supernatant. Conclusion: The study shows that S. spinosum extract affects insulin secretion in pancreatic β-cells, and has insulin-like effects on metabolic pathways in classic insulin-respo...

Prolonged insulin treatment sensitizes apoptosis pathways in pancreatic β cells.

Insulin resistance results from impaired insulin signaling in target tissues that leads to increased levels of insulin required to control plasma glucose levels. The cycle of hyperglycemia and hyperinsulinemia eventually leads to pancreatic cell deterioration and death by a mechanism that is yet unclear. Insulin induces ROS formation in several cell types. Furthermore, death of pancreatic cells induced by oxidative stress could be potentiated by insulin. Here, we investigated the mechanism underlying this phenomenon. Experiments were done on pancreatic cell lines (Min-6, RINm, INS-1), isolated mouse and human islets, and on cell lines derived from nonpancreatic sources. Insulin (100nM) for 24h selectively increased the production of ROS in pancreatic cells and isolated pancreatic islets, but only slightly affected the expression of antioxidant enzymes. This was accompanied by a time- and dose-dependent decrease in cellular reducing power of pancreatic cells induced by insulin and altered expression of several ER stress response elements including a significant increase in Trb3 and a slight increase in iNos The effect on iNos did not increase NO levels. Insulin also potentiated the decrease in cellular reducing power induced by H2O2 but not cytokines. Insulin decreased the expression of MCL-1, an antiapoptotic protein of the BCL family, and induced a modest yet significant increase in caspase 3/7 activity. In accord with these findings, inhibition of caspase activity eliminated the ability of insulin to increase cell death. We conclude that prolonged elevated levels of insulin may prime apoptosis and cell death-inducing mechanisms as a result of oxidative stress in pancreatic cells.

Insulin-sensitizing and insulin-mimetic activities of Sarcopoterium spinosum extract.

ETHNOPHARMACOLOGICAL RELEVANCE Sarcopoterium spinosum is an abundant plant in Israel, used by Bedouin medicinal practitioners for the treatment of diabetes. In our previous study we validated the anti-diabetic activity of Sarcopoterium spinosum. The aim of this study was to further clarify its mechanism of action. MATERIALS AND METHODS In-vivo studies were performed on KK-a/y mice given the extract for 6 weeks. Insulin tolerance test was performed, and relative pancreatic islets area was measured. Mechanisms of action were investigated in L6 myotubes using protein array, Western blot analysis and confocal microscopy. Glucose uptake assays were performed in 3T3-L1 adipocytes. RESULTS Sarcopoterium spinosum extract reduced fasting blood glucose and improved insulin sensitivity in treated mice. Hypertrophic islets were detected in diabetic, but not in Sarcopoterium spinosum-treated mice. Sarcopoterium spinosum phosphorylated PTEN on ser380 and thr382/383, which are known inhibitory sites. PKB was not phosphorylated by Sarcopoterium spinosum, however, translocation of PKB from cytoplasm to the membrane and nucleus was detected. Target proteins of PKB were regulated by Sarcopoterium spinosum; GSK3β was phosphorylated and cytosolic localization of FoxO was increased. Glucose uptake was increased in a PI3K and AMPK-independent mechanism. CONCLUSIONS We suggest that Sarcopoterium spinosum inhibited PTEN and activated PKB by a mechanism which is independent of ser473 and thr308 phosphorylation. Other post translation modifications might be involved and should be analyzed further in order to understand this unique PKB activation. Identifying the active molecules in the extract, may lead to the development of new agents for the treatment of insulin resistance.