Combination Of Rosiglitazone Research Articles

Vimentin protein is a factor for decreasing breast cancer cell proliferation co-culture with human bone marrow-derived mesenchymal stem cells pre-treated with thiazolidinedione solutions.

Our previous study investigated the levels of soluble growth factors in the conditioned media of bone marrow-derived mesenchymal stem cells (BMSCs) pre-treated with thiazolidinedione solutions. The present study aimed to investigate the complex intracellular proteins extracted from BMSCs pre-treated with pioglitazone and/or rosiglitazone using proteomics. The proliferative effect of the identified protein on MCF-7 cells that interacted non-adhesively with BMSCs pre-treated with pioglitazone and/or rosiglitazone was evaluated using cell culture inserts and conditioned media. The mRNA expression of proliferation and lipid accumulation markers was also evaluated in the interacted MCF-7 cells by reverse transcription-quantitative PCR. Finally, the correlation between the identified protein and fibroblast growth factor 4 (FGF-4) proteinin the conditioned media of the pre-treated BMSCs was evaluated by ELISA. The present study identified vimentin as the specific protein among the complex intracellular proteins that likely plays a role in MCF-7 cell proliferation when the breast cancer cells interacted non-adhesively with BMSCs pre-treated with a combination of pioglitazone and rosiglitazone. The inhibition of this protein promoted the proliferation of MCF-7 cells when the breast cancer cells interacted with pre-treated BMSCs. Gene expression analysis indicated that pre-treatment of BMSCs with a combination ofpioglitazone and rosiglitazone decreased the mRNA expression of Ki67 and proliferating cell nuclear antigen in MCF-7 cells. The pre-treatment did not induce mRNA expression of PPARγ, which is a sign of lipid accumulation. The level of vimentin protein was also associated with the FGF-4 protein expression level in the conditioned media of the pre-treated BMSCs. Bioinformatics analysis revealed that vimentin regulated the expression of FGF-4 through its interaction with SRY-box 2 and POU class 5 homeobox 1. The present study identified a novel intracellular protein that may represent the promising target in pre-treated BMSCs to decrease the proliferation of breast cancer MCF-7 cells for human health and wellness.

Intra-Amniotic Sildenafil and Rosiglitazone Late in Gestation Ameliorate the Pulmonary Hypertension Phenotype in Congenital Diaphragmatic Hernia

BackgroundPulmonary hypertension remains difficult to manage in congenital diaphragmatic hernia (CDH). Prenatal therapy may ameliorate postnatal pulmonary hypertension. We hypothesized that intra-amniotic (IA) injection of either sildenafil, a phosphodiesterase 5 inhibitor, or rosiglitazone, a PPAR-γ agonist, or both late in gestation would decrease the detrimental pulmonary vascular remodeling seen in CDH and improve peripheral pulmonary blood flow. MethodsPregnant rats were gavaged with nitrogen on embryonic day (E) 9.5 to induce fetal CDH. Sildenafil and/or rosiglitazone were administered to each fetus via an intra-amniotic injection after laparotomy on the pregnant dam at E19.5, and fetuses delivered at E21.5. Efficacy measures were gross necropsy, histology, peripheral blood flow assessment using intra-cardiac injection of a vascular tracer after delivery, and protein expression analysis. ResultsIntra-amniotic injections did not affect fetal survival, the incidence of CDH, or lung weight-to-body weight ratio in CDH fetuses. IA sildenafil injection decreased pulmonary vascular muscularization, and rosiglitazone produced an increase in peripheral pulmonary blood flow distribution. The combination of sildenafil and rosiglitazone decreased pulmonary artery smooth muscle cell proliferation. These intra-amniotic treatments did not show any negative effects in either CDH fetuses or control fetuses. ConclusionIA injection of sildenafil and rosiglitazone late in gestation ameliorates the pulmonary hypertensive phenotype of CDH and may have utility in clinical translation. Level of EvidenceNot applicable.

Ursolic acid and rosiglitazone combination prevent low-grade inflammation and hepatic insulin resistance by modulating cytokine expression in mice fed a high-fat diet

<p class="MsoNormal" style="text-align: justify;"><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; mso-ascii-theme-font: minor-bidi; mso-hansi-theme-font: minor-bidi; mso-bidi-theme-font: minor-bidi;">Background:</span></p> <p class="MsoNormal" style="text-align: justify;"><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; mso-ascii-theme-font: minor-bidi; mso-hansi-theme-font: minor-bidi; mso-bidi-theme-font: minor-bidi;">The objective of this research endeavor was to assess the effects of rosiglitazone (RSG) and ursolic acid (UA) on hepatic insulin signaling indicators and inflammatory marker concentrations in C57/BL/6J mice that were provided with a high-fat diet (HFD). </span></p> <p class="MsoNormal" style="text-align: justify;"><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; mso-ascii-theme-font: minor-bidi; mso-hansi-theme-font: minor-bidi; mso-bidi-font-family: PMingLiU;">Methods:</span></p> <p class="MsoNormal" style="text-align: justify;"><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; mso-ascii-theme-font: minor-bidi; mso-hansi-theme-font: minor-bidi; mso-bidi-theme-font: minor-bidi;">C57BL/6J mice were fed a HFD for 16 weeks and orally administered UA (5 mg/kg BW), RSG (4 mg/kg BW), and UA (5 mg/kg BW) + RSG (4 mg/kg BW) for the last 6 weeks. </span></p> <p class="MsoNormal" style="text-align: justify;"><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; mso-ascii-theme-font: minor-bidi; mso-hansi-theme-font: minor-bidi; mso-bidi-font-family: PMingLiU;">Results:</span></p> <p class="MsoNormal" style="text-align: justify;"><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; mso-ascii-theme-font: minor-bidi; mso-hansi-theme-font: minor-bidi; mso-bidi-theme-font: minor-bidi;">The HFD groups showed a significant increase in leptin, TNF-α, and IL-6, whereas adiponection level significantly decreased. The expression of insulin signaling markers in the liver also significantly increased in HFD mice. </span></p> <p class="MsoNormal" style="text-align: justify;"><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; mso-ascii-theme-font: minor-bidi; mso-hansi-theme-font: minor-bidi; mso-bidi-font-family: PMingLiU;">Conclusions:</span></p> <p><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; mso-ascii-theme-font: minor-bidi; mso-fareast-font-family: PMingLiU; mso-hansi-theme-font: minor-bidi; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: EN-US;">Combination treatment </span><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; mso-ascii-theme-font: minor-bidi; mso-fareast-font-family: PMingLiU; mso-hansi-theme-font: minor-bidi; mso-bidi-font-family: PMingLiU; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: EN-US;">improves</span><span style="font-size: 10.0pt; font-family: 'Arial',sans-serif; mso-ascii-theme-font: minor-bidi; mso-fareast-font-family: PMingLiU; mso-hansi-theme-font: minor-bidi; mso-bidi-theme-font: minor-bidi; mso-ansi-language: EN-US; mso-fareast-language: EN-US; mso-bidi-language: EN-US;"> above said parameters than individual parameters. These data suggest that combination treatment (UA with RSG) has potential benefits for the treatment of HFD-induced insulin resistance, and its effects may be associated with improvements in the inhibition of the expression of inflammatory markers in plasma and liver.</span></p>

A novel therapy for hepatic cholestasis treatment—the combination of rosiglitazone and fenofibrate

Hepatic cholestasis can develop into liver fibrosis and eventually liver failure. Currently, ursodeoxycholic acid (UDCA) or UDCA combined with fenofibrate is used for cholestasis treatment. Rosiglitazone inhibited α-naphthyl isothiocyanate (ANIT)-induced cholestasis in mice. In this study, we compared the effect of rosiglitazone, UDCA, fenofibrate, combined rosiglitazone and fenofibrate or UDCA and fenofibrate on ANIT-induced cholestasis. C57BL/6J mice were induced cholestasis by ANIT while treated with rosiglitazone, UDCA, fenofibrate, combination of rosiglitazone and fenofibrate, or combination of UDCA and fenofibrate. Liver and serum samples were collected to determine liver necrosis and serum biochemical parameters. Rosiglitazone alone or combined with fenofibrate demonstrated better effects than UDCA alone or UDCA combined with fenofibrate in reduction of cholestasis-induced serum biochemical parameters and liver necrosis. Surprisingly, UDCA combined with fenofibrate, but not rosiglitazone combined with fenofibrate, potently increased accumulation of free fatty acids (FFAs) in the liver. Mechanistically, the protection of combination of rosiglitazone and fenofibrate against cholestasis was attributed to activated adiponectin pathway to enhance FXR and mitochondrial functions and reduce apoptosis in the liver. The accumulation of FFAs in the liver by combination of UDCA and fenofibrate was caused by activation of fatty acid biosynthesis and uptake, and triglyceride hydrolysis. Taken together, our study not only demonstrates the adverse effect of combination therapy of UDCA and fenofibrate, but also suggests the combination of rosiglitazone and fenofibrate can be another option for cholestasis treatment.

Epigenetic derepression converts PPAR\u03b3 into a druggable target in triple-negative and endocrine-resistant breast cancers

Clinical trials repurposing peroxisome proliferator-activated receptor-gamma (PPARγ) agonists as anticancer agents have exhibited lackluster efficacy across a variety of tumor types. Here, we report that increased PPARG expression is associated with a better prognosis but is anticorrelated with histone deacetylase (HDAC) 1 and 2 expressions. We show that HDAC overexpression blunts anti-proliferative and anti-angiogenic responses to PPARγ agonists via transcriptional and post-translational mechanisms, however, these can be neutralized with clinically approved and experimental HDAC inhibitors. Supporting this notion, concomitant treatment with HDAC inhibitors was required to license the tumor-suppressive effects of PPARγ agonists in triple-negative and endocrine-refractory breast cancer cells, and combination therapy also restrained angiogenesis in a tube formation assay. This combination was also synergistic in estrogen receptor-alpha (ERα)–positive cells because HDAC blockade abrogated ERα interference with PPARγ-regulated transcription. Following a pharmacokinetics optimization study, the combination of rosiglitazone and a potent pan-HDAC inhibitor, LBH589, stalled disease progression in a mouse model of triple-negative breast cancer greater than either of the monotherapies, while exhibiting a favorable safety profile. Our findings account for historical observations of de-novo resistance to PPARγ agonist monotherapy and propound a therapeutically cogent intervention against two aggressive breast cancer subtypes.

Obestatin and Rosiglitazone Differentially Modulate Lipid Metabolism Through Peroxisome Proliferator-activated Receptor-γ (PPARγ) in Pre-adipose and Mature 3T3-L1 Cells.

Obestatin is a 23-residue peptide, obtained after posttranslational modification of preproghrelin. It has been shown, in Swiss albino mice, to upregulate glycerolipid metabolism and PPARγ signaling. It was opined that the by-products of increased glycerolipid metabolism triggered PPARγ signaling. It was hypothesized that obestatin upon co-administration with a full agonist of PPARγ should reveal the comparative significance or possible synergy in PPARγ signaling. We postulated they would act synergistically by obestatin increasing PPARγ expression and rosiglitazone enhancing PPARγ activity. We evaluated the combination in DIO-C57BL/6 mice and observed that obestatin completely reversed the increase in subcutaneous fat brought about by rosiglitazone. To understand their role at the adipocyte level, 3T3-L1 cells were treated with a combination of obestatin and rosiglitazone during (1) initiation of differentiation and (2) after 14 days from initiation of differentiation when the adipocytes were mature. Interestingly, their influence was mainly adipogenic and showed double lipid accumulation when estimated 14 days after initiation of differentiation. There was an upregulation of Pparγ by fourfold, Hsl by eightfold, Glut4 by fourfold, Leptin by 2.7-fold, Atgl by sixfold, Fasn by sixfold, and Fabp4 by sevenfold at the mRNA level, whereas in mature adipocytes there was a significant decrease in fat accumulation by 20%. There was downregulation of Pparγ, Hsl, Lpl, and Fasn by 0.5-fold at the mRNA level. These results show that the combined influence of obestatin and rosiglitazone is significant and the outcome is dependent on the metabolic stage of the adipocyte.

PNPLA3 I148M Up-Regulates Hedgehog and Yap Signaling in Human Hepatic Stellate Cells.

Liver fibrosis represents the wound healing response to sustained hepatic injury with activation of hepatic stellate cells (HSCs). The I148M variant of the PNPLA3 gene represents a risk factor for development of severe liver fibrosis. Activated HSCs carrying the I148M variant display exacerbated pro-inflammatory and pro-fibrogenic features. We aimed to examine whether the I148M variant may impair Hedgehog and Yap signaling, as key pathways implicated in the control of energy expenditure and maintenance of myofibroblastic traits. First, we show that TGF-β rapidly up-regulated the PNPLA3 transcript and protein and Yap/Hedgehog target gene expression. In addition, HSCs overexpressing PNPLA3 I148M boosted anaerobic glycolysis, as supported by higher lactate release and decreased phosphorylation of the energy sensor AMPK. These cells displayed higher Yap and Hedgehog signaling, due to accumulation of total Yap protein, Yap promoter activity and increased downstream targets expression, compared to WT cells. HSCs exposed to TGF-β and leptin rapidly increased total Yap, together with a reduction in its inhibited form, phosphorylated Yap. In line, Yap-specific inhibitor Verteporfin strongly abolished Yap-mediated genes expression, at baseline as well as after TGF-β and leptin treatments in HSCs with I148M PNPLA3. Finally, Yap transcriptional activity was strongly reduced by a combination of Verteporfin and Rosiglitazone, a PPARγ synthetic agonist. In conclusion, HSCs carrying the PNPLA3 variant show activated Yap/Hedgehog pathways, resulting in altered anaerobic glycolysis and enhanced synthesis of Hedgehog markers and sustained Yap signaling. TGF-β and leptin exacerbate Yap/Hedgehog-related fibrogenic genes expression, while Yap inhibitors and PPARγ agonists abrogate these effects in PNPLA3 I148M carrying HSCs.

Rosiglitazone ameliorates senescence and promotes apoptosis in ovarian cancer induced by olaparib.

Senescence mechanisms are vital to resistance to long-term olaparib maintenance treatment. Recently, peroxisome proliferator-activated receptor-γ agonists (e.g., rosiglitazone) have been reported to ameliorate the senescence-like phenotype by modulating inflammatory mediator production. This study examined synergistic effects on the anti-tumor activity of rosiglitazone combined with olaparib in ovarian cancer treatment. A2780 and SKOV3 mouse subcutaneous xenograft models were established for observing anti-tumor effects in living organisms and were randomly split into combination (both olaparib and rosiglitazone), rosiglitazone (10mg/kg), olaparib (10mg/kg), control (solvent) groups that received treatment once every 2 or 3days (n = 6 per group). Cell counting kit-8 (CCK-8) assays were used to test the influences of rosiglitazone and olaparib on cell proliferation. PI and Annexin-V-FITC staining was used with flow cytometry to assess the cell cycle distribution and cell apoptosis. Senescence-associated β-galactosidase (SA-β-Gal) staining was used to observe cellular senescence. We performed quantitative real-time polymerase chain reaction assays to study the senescence-related secretory phenotype (SASP). Olaparib and rosiglitazone were observed to synergistically retard subcutaneous ovarian cancer growth in vivo, and synergistically suppress ovarian cancer cell proliferation in vitro. Compared with olaparib alone, the percentage of positive cells expressed SA-β-gal and SASP were significantly decreased in the treatment of combination of olaparib and rosiglitazone. Furthermore, olaparib plus rosiglitazone increased the percentage of apoptosis in ovarian cancer cell compared with olaparib alone. In A2780 cells, it showed lower expression of P53, phospho-p53 (Ser15), P21, and P18 protein in combination treatment compared with olaparib alone. While, in SKOV3 cells, it showed lower expression of phosphor-retinoblastoma protein (Rb) (Ser807/811), and higher expression of cyclin D1, P21, and P16 protein in combination treatment compared with olaparib alone. Rosiglitazone combined with olaparib can help manage ovarian cancer by ameliorating olaparib-induced senescence and improving anti-tumor effects.

Co-administration of conjugated linoleic acid and rosiglitazone increases atherogenic co-efficient and alters isoprenaline-induced vasodilatation in rats fed high fat diet.

The cis(c)-9, trans(t)-11 (c9,t11) and t10,c12 isomers of conjugated linoleic acid (CLA) have been reported as agonists of peroxisome proliferator-activated receptor (PPAR) and beneficial in lipidemia and glycemia. However, it is unclear whether CLA isomers enhance or antagonize effects of conventional drugs targeting PPAR. Male Sprague-Dawley rats were fed high fat diet (HFD) for 8 weeks and treated without or with CLA, rosiglitazone or both for 4 weeks. Oral glucose tolerance and surrogate markers of insulin resistance were not significantly different for all treatments compared to untreated normal diet (ND) or HFD group, except lipoprotein levels. The combination of CLA and rosiglitazone had suppressed levels of low and high density lipoproteins (46 % and 25 %, respectively), compared to HFD-alone. Conversely, the atherogenic co-efficient of the animals received HFD or HFD+rosiglitazone+CLA was 2-folds higher than ND, HFD+rosiglitazone or HFD+CLA. Isolated aortic rings from the combined CLA and rosiglitazone treated animals were less sensitive to isoprenaline-induced relaxation among endothelium-denuded aortas with a decreased efficacy and potency (R(max)=53+/-4.7 %; pEC50=6+/-0.2) compared to endothelium-intact aortas (R(max)=100+/-9.9 %; pEC50=7+/-0.2). Our findings illustrate that the combination of CLA and rosiglitazone precede the atherogenic state with impaired endothelium-independent vasodilatation before the onset of HFD-induced insulin resistance.

Synergy Between Peroxisome Proliferator-Activated Receptor γ Agonist and Radiation Therapy in Cancer

Approximately 60% of newly diagnosed cancer patients receive radiotherapy to accomplish neoadjuvant, definitive, adjuvant or palliative purpose as required. However, radiotherapy may trigger host-mediated proangiogenic and proinflammatory effects that lead to tumor recurrence. Angiogenesis and inflammation are crucial processes, through which tumor microenvironment (TME) influences tumor growth, invasiveness and metastasis. Peroxisome proliferator-activated receptor γ (PPARγ) agonist rosiglitazone has anti-inflammatory, antiangiogenic and antineoplastic activities from preclinical data. We hypothesize that rosiglitazone and radiation therapy synergistically amplify the antitumor effect, which is based on the evidence that rosiglitazone remodels tumor vasculature and limits tumor-associated macrophages (TAMs) infiltration. The aim of this study is to evaluate the synergistic effect of PPARγ agonist rosiglitazone combined with radiation therapy. Each female Balb/c mouse was inoculated with 5X105 murine colon carcinoma cell line CT26 or breast cancer 4T1. When tumor size approximately reached 250-300 mm3, 12Gy in a fraction as hypofractionated irradiation therapy (HFRT) or 12Gy in 4 daily fractions of 3Gy as conventional fractionated irradiation therapy (CFRT) was delivered to the tumor, meanwhile administration of 100mg/kg rosiglitazone was started daily for 2 weeks. Tumors were harvested according to the schedule. Flow cytometry, ELISA, immunofluorescence, western blot, and so forth were performed to test the synergistic mechanisms. We presented that rosiglitazone has antiangiogenic effect by inhibiting VEGF-VEGFR2 signaling pathways. Immunofluorescence work identified that rosiglitazone can remodel tumor vasculature contributing to decrease of microvessel density, promotion of pericyte coverage, reduction of TAMs infiltration, and even further accompanied improvement of intratumoral hypoxia and vessel perfusion compared with the control (P<0.05). 4T1 or CT26 tumor-bearing mice treated with rosiglitazone in combination with HFRT or CFRT showed a significant reduction in lesion size and lung metastases compared with the control (P<0.001), rosiglitazone(P<0.001) or radiotherapy group (P<0.05). Analysis of ELISA, immunofluorescence and flow cytometry showed that tumor-derived chemokine CCL2 in reaction to HFRT facilitates the recruitment of migrating CD11b+ myeloid monocytes and TAMs into irradiated sites that initiates vasculogenesis and allows tumor recurrence after HFRT. We found that rosiglitazone decreased CCL2 and suppressed CD11b+ myeloid monocytes and TAMs infiltrations after HFRT, which delayed tumor recurrence. Rosiglitazone may elicit normalization of tumor vasculature and limit TAMs infiltration, and thereby delay tumor progression with a fresh perspective. Rosiglitazone, as an adjuvant therapy to HFRT, inhibits CCL2 mediating tumor recurrence.

Inhaled combination of sildenafil and rosiglitazone improves pulmonary hemodynamics, cardiac function, and arterial remodeling.

Currently, dual- or triple-drug combinations comprising different vasodilators are the mainstay for the treatment of pulmonary arterial hypertension (PAH). However, the patient outcome continues to be disappointing because the existing combination therapy cannot restrain progression of the disease. Previously, we have shown that when given as a monotherapy, long-acting inhaled formulations of sildenafil (a phosphodiesterase-5 inhibitor) and rosiglitazone (a peroxisome proliferator receptor-γ agonist) ameliorate PAH in rats. Thus, with a goal to develop a new combination therapy, we prepared and characterized poly(lactic-co-glycolic acid) (PLGA)-based long-acting inhalable particles of sildenafil and rosiglitazone. We then assessed the efficacy of the combinations of sildenafil and rosiglitazone, given in plain forms or as PLGA particles, in reducing mean pulmonary arterial pressure (mPAP) and improving pulmonary arterial remodeling and right ventricular hypertrophy (RVH) in Sugen 5416 plus hypoxia-induced PAH rats. After intratracheal administration of the formulations, we catheterized the rats and measured mPAP, cardiac output, total pulmonary resistance, and RVH. We also conducted morphometric studies using lung tissue samples and assessed the degree of muscularization, the arterial medial wall thickening, and the extent of collagen deposition. Compared with the plain drugs, given via the pulmonary or oral route as a single or dual combination, PLGA particles of the drugs, although given at a longer dosing interval compared with the plain drugs, caused more pronounced reduction in mPAP without affecting mean systemic pressure, improved cardiac function, slowed down right heart remodeling, and reduced arterial muscularization. Overall, PLGA particles of sildenafil and rosiglitazone, given as an inhaled combination, could be a viable alternative to currently available vasodilator-based combination therapy for PAH.

Synergy between peroxisome proliferator-activated receptor γ agonist and radiotherapy in cancer.

Angiogenesis and inflammation are crucial processes through which the tumor microenvironment (TME) influences tumor progression. In this study, we showed that peroxisome proliferator‐activated receptor γ (PPARγ) is not only expressed in CT26 and 4T1 tumor cell lines but also in cells of TME, including endothelial cells and tumor‐associated macrophages (TAM). In addition, we showed that rosiglitazone may induce tumor vessel normalization and reduce TAM infiltration. Additionally, 4T1 and CT26 tumor‐bearing mice treated with rosiglitazone in combination with radiotherapy showed a significant reduction in lesion size and lung metastasis. We reported that a single dose of 12 Gy irradiation strongly inhibits local tumor angiogenesis. Secretion of C‐C motif chemokine ligand 2 (CCL2) in response to local irradiation facilitates the recruitment of migrating CD11b+ myeloid monocytes and TAM to irradiated sites that initiate vasculogenesis and enable tumor recurrence after radiotherapy. We found that rosiglitazone partially decreases CCL2 secretion by tumor cells and reduces the infiltration of CD11b+ myeloid monocytes and TAM to irradiated tumors, thereby delaying tumor regrowth after radiotherapy. Therefore, combination of the PPARγ agonist rosiglitazone with radiotherapy enhances the effectiveness of radiotherapy to improve local tumor control, decrease distant metastasis risks and delay tumor recurrence.

Enhanced Tumor Inhibitory Effects by Combining Metformin with Rosiglitazone in Glioblastoma Cells

Metformin, as a diabetic drug, has been studied extensively in various types of cancer including glioblastoma (GBM) in cell cultures and animal models. However, clinical applications of the medication are limited due to the much higher than physiological concentrations required for in vitro experiments. We hypothesize that combining metformin with rosiglitazone in GBM could enhance tumor inhibitory effects of metformin alone, thus improving radiation therapy (RT) outcome. The hypothesis is based on the fact that both drugs work on PI3K/PTEN/Akt/mTORC pathway thus synergistic effects could be induced when combined. GBM cell lines from both human and mice with genotypes harboring different combinations of p53 and PTEN mutations were used. Two primary murine cell lines, MGPP3 (PDGF overexpression, p53-/- and PTEN-/- double knockout), and PPC2 (PDGF overexpression, p53-/- PTEN+/+) were generated and maintained in vitro. Intracranial injection of these cells led to formation of GBM-like tumors with 100% efficiency. Human U87MG cells (p53 +/+, PTEN mutant/mutant) were also used. In vitro cell proliferation assays was ascertained using the MTT assay. Metformin and rosiglitazone were added to the culture media at various concentrations alone or in combinations two hours before radiation. The treated cells were cultured for additional 72 hours before MTT assays were performed. MGPP3 cells were much more sensitive to metformin treatment alone (TD50 being 3 mM, 8 mM, and 25 mM for MGPP3, PPC2 and U87MG, respectively) while rosiglizatone alone showed significant tumor inhibitory effects at physiological concentrations of above 10 μM in MGPP3 and PPC2 cell lines but less effectively in U87MG. Although short term culture (3 days) of the cells with both drugs did not reveal significant synergistic effects without or without RT, longer culturing time (10 days after 4 Gy of RT) showed much improved durable inhibitory effects even by adding 1 μM Rosiglitazone to various concentrations of metformin of as low as 1 mM concentration in these cell lines. Combined drug treatment is most likely preventing rebound phosphorylation of AKT at S473 after prolonged drug treatment alone. Significantly reduced c-Myc expression at protein level is also seen with combined therapy than using either drug alone. We have demonstrated enhanced growth inhibitory effects of metformin and rosiglitazone in combination on GBM cells with variable genotypes when compared with each drug used alone, particularly in prolonged culturing time in vitro after RT. The enhanced effect might be through c-Myc inhibition. These preliminary results prompt future clinical investigations of combining treatment with metformin and rosiglitazone with both drugs shown to have capabilities to pass blood-brain barrier, in patients.

Beneficial effects of rosiglitazone and losartan combination in diabetic rats.

Diabetes with vascular complication needs strict interventions to retard possible serious complications. This research estimated the possible interaction of rosiglitazone (RGN) with losartan (Los) in diabetic rats. Male Sprague-Dawley rats were randomly divided into nondiabetic rats, diabetic rats, and diabetic rats that received RGN, Los, or a combination of RGN and Los. Measurement of serum glucose, vascular adhesion molecule-1, interleukin-6, tumor necrosis factor-α, aortic lipid peroxide (malondialdehyde), glutathione, superoxide dismutase, and total nitrate/nitrite levels was done. Also, the effects of RGN on the relaxation created by acetylcholine and sodium nitroprusside, contraction of isolated aortic rings provoked by phenylephrine and angiotensin II were determined. Results revealed that RGN or Los had a vasodilating effect to variable degrees indicated by enhanced effects on both acetylcholine-induced relaxation and the antagonistic effect on angiotensin II and phenylephrine-stimulated contraction of diabetic aortas with significant amelioration in serum glucose, vascular adhesion molecule-1, interleukin-6, and tumor necrosis factor-α levels and aortic oxidant/antioxidant balance. Treatment of diabetic rats with a combination of RGN and Los produced a more pronounced effect on the measured parameters compared to the diabetic, RGN-, and Los-treated groups. These findings point out the beneficial effects of RGN and Los combination in diabetic rats.

Is insulin the preferred treatment for HbA1c &gt;9%?

Is insulin the preferred treatment for <scp>HbA1c</scp> &gt;9%?

An Additive Effect of Promoting Thermogenic Gene Expression in Mice Adipose-Derived Stromal Vascular Cells by Combination of Rosiglitazone and CL316,243.

It is well-documented that CL316,243 (a β3 agonist) or rosiglitazone (a PPARγ agonist) can induce white adipocyte populations to brown-like adipocytes, thus increasing energy consumption and combating obesity. However, whether there is a combined effect remains unknown. In the present study, stromal vascular cells of inguinal white adipose tissue (iWAT-SVCs for short) from mice were cultured and induced into browning by CL316,243, rosiglitazone, or both. Results showed that a combination of CL316,243 and rosiglitazone significantly upregulated the expression of the core thermogenic gene Ucp1 as well as genes related with mitochondrial function (Cidea, Cox5b, Cox7a1, Cox8b, and Cycs), compared with the treatment of CL316,243 or rosiglitazone alone. Moreover, co-treatment with rosiglitazone could reverse the downregulation of Adiponectin resulting from CL316,243 stimuli alone. Taken together, a combination of rosiglitazone and CL316,243 can produce an additive effect of promoting thermogenic gene expression and an improvement of insulin sensitivity in mouse iWAT-SVCs.

Rosiglitazone , Metformin or both for Treatment of Polycystic Ovary Syndrome

This study was designed to show the advantages of using the combination of metformin and rosiglitazone over using each drug alone in treatment of women with polycystic ovary syndrome (PCOS).Forty four women with PCOS were classified into 3 groups , group 1 received rosiglitazone (4mg/day) for 3 months , group ΙΙ received metformin ( 1500 mg/day)for three months and groupΙΙΙ received the combination ( rosiglitazone 4mg/day + metformin 1500 mg/day) for the same period of treatment . The blood samples were drawn before treatment and after 3 months of treatment . The fasting serum glucose , insulin , progesterone , testosterone , leutinizing hormone were measured before and after treatment. The reduction of serum insulin , glucose ,homostasis model assessment of insuline resistance ( HOMA-IR) , LH and testosterone levels were greater in the group received the combination of rosiglitazone with metformin than that those taken each one alone. Testosterone levels decreased significantly (P&lt;0.05) from baseline level 1±0.04ng/ml to 0.073±0.32ng/ml after treatment with combination.The rate of ovulation is 29.4%,36.4% , 62.5% in rosiglitazone , metformin and combination of both, respectively.The combination of rosiglitazone with metformin has more beneficial effect on ovulation rate. &#x0D; Key words: polycystic ovary syndrome, rosiglitazone, metformin, ovulation rate .

All-trans retinoic acid shifts rosiglitazone-induced adipogenic differentiation to osteogenic differentiation in mouse embryonic fibroblasts.

Rosiglitazone (RSG) is a potent drug used in the treatment of insulin resistance; however, it is associated with marked skeletal toxicity. RSG-induced osteoporosis may contribute to the promotion of adipogenic differentiation at the expense of osteogenic differentiation in bone marrow stromal cells. The aim of this study was to investigate whether RSG-induced bone toxicity can be reversed by combined treatment with all-trans retinoic acid (ATRA). We examined different osteogenic markers in mouse embryonic fibroblasts (MEFs) following treatment with RSG, ATRA, or RSG and ATRA in combination. We examined the effects of RSG and/or ATRA on ectopic bone formation, and dissected the possible molecular mechanisms underlying this process. We found that ATRA or RSG both induced alkaline phosphatase (ALP) activity in the MEFs, and that the ATRA-induced ALP activity was enhanced by RSG and vice versa. However, only the combination of RSG and ATRA increased the expression of osteopontin and osteocalcin, promoted matrix mineralization, and induced ectopic ossification in MEFs. Mechanistically, we found that the osteogenic differentiation induced by the combination of RSG and ATRA may be mediated partly by suppressing RSG-induced adipogenic differentiation and activating bone morphogenetic protein (BMP)/Smad signaling. On the whole, our findings demonstrate that RSG in combination with ATRA promotes the commitment of MEFs to the osteoblast lineage. Thus, the combination of these two agents may prove to be a promising and novel therapeutic regimen for insulin resistance without skeletal toxicity. It may also be a better strategy with which to prevent RSG-induced osteoporosis.

A highly sensitive LC–MS/MS method for concurrent determination of sildenafil and rosiglitazone in rat plasma

Patients with pulmonary arterial hypertension (PAH) are currently treated with more than one drug. Sildenafil, a phosphodiesterase type 5 (PDE-5) inhibitor, and rosiglitazone, a peroxisome proliferator-activated receptor γ (PPAR-γ) activator, is one of those combinations that could be used in PAH. To monitor the pharmacokinetics of sildenafil in the presence of rosiglitazone, we have developed and validated a sensitive, specific and rapid liquid chromatography-tandem mass spectrometric (LC–MS/MS) method. We have used this validated method to study the pharmacokinetics of sildenafil and rosiglitazone after intravenous administration of sildenafil alone or a combination of sildenafil plus rosiglitazone to adult male Sprague-Dawley rats. Sildenafil and rosiglitazone were extracted from plasma by protein precipitation with methanol. With an octadeuterated sildenafil as the internal standard, the drugs were separated via gradient elution using a C18 column and formic acid in methanol or in water as the mobile phase with a flow rate of 0.25mL/min. Both sildenafil and rosiglitazone samples in rat plasma produced linear response, when the concentration ranged between 5 and 1000ng/mL (r2>0.99). The pharmacokinetics study suggests that intravenous co-administration rosiglitazone plus sildenafil increases the plasma concentration of sildenafil and extends the drug’s elimination half-life.

Rosiglitazone and Metformin in patients with type-2 Diabetes Mellitus who are inadequately controlled on Metformin alone

Type 2 Diabetes Mellitus is almost reaching epidemic levels. With tight hyperglycemic control the risk reduction is 24% for any diabetes related end-point and 32% for death related to diabetes, against only 0.9% decrease in HbAlc level. Complementary mode of actions of Rosiglitazone and Metformin can be used to maximize the therapeutic effect and to decrease the side effects. We evaluated the efficacy, safety and tolerability of the combination of Rosiglitazone and Metformin on change in HbAlc levels from baseline over a period 24 weeks in patients with type 2 diabetes mellitus. Twenty eight type 2 diabetes mellitus patients were recruited randomly presenting to West Medical Ward, Mayo hospital Lahore, through OPD, Diabetic Clinic and Emergency, who were on Metformin alone and were poorly controlled from September 2003 to July 2004. They were given Rosiglitazone 4 mg/day or 8 mg/day with metformin for a period of 24 weeks. Only 2 patients were dropped and 26 patients completed the study (46% were males and 54% were females), and none of patient was dropped due to adverse effects. Their fasting blood sugar measured at baseline and at 4, 8, 16 and 24 week. HbAlc was measured at start and at 24 weeks. The fasting blood glucose responders were 84.6%, with mean fall of 46 mg/dl. HbAlc responders were 73% patients. Average weight gain was 1.125 kg over 24 weeks. Out of 26 patients, 89% showed a mild decrease in hemoglobin concentration but none reaching anemic levels. Only 10% patients had a rise in liver enzymes, which was less than 2 times the normal. Addition of rosiglitazone, in patients with type 2 diabetes mellitus, who are inadequately controlled on metformin alone, resulted in better glycemic control but a large scale study is required and other combinations with Rosiglitazone like sulphonylurea and insulin should be compared.