Use Of Rosiglitazone Research Articles

ROSIGLITAZONE, A REPURPOSED DRUG AS ANTICANCER AGENT: A REVIEW

Different medicinal products can be used to treat various disorders. Finding promising compounds for both established and new illnesses is the goal of drug development. Finding new therapeutic uses for already-approved, withdrawn-from-use, abandoned, and experimental medications is the process of "drug repurposing." Recently, the medication rosiglitazone (ROSI) was used as an anticancer agent. The status and its application as an anticancer agent are described in the current review. In this review, we outlined the function of ROSI as an anticancer agent and covered a variety of ROSI-related topics, including its molecular mechanism of action, anti-angiogenesis properties, function in oxidative stress and inflammation, function in apoptosis and cell cycle, function in cell migration and invasion, and the use of ROSI in combination therapy with other drug agents.

Rosiglitazone Does Not Show Major Hidden Cardiotoxicity in Models of Ischemia/Reperfusion but Abolishes Ischemic Preconditioning-Induced Antiarrhythmic Effects in Rats In Vivo.

Clinical observations are highly inconsistent with the use of the antidiabetic rosiglitazone regarding its associated increased risk of myocardial infarction. This may be due to its hidden cardiotoxic properties that have only become evident during post-marketing studies. Therefore, we aimed to investigate the hidden cardiotoxicity of rosiglitazone in ischemia/reperfusion (I/R) injury models. Rats were treated orally with either 0.8 mg/kg/day rosiglitazone or vehicle for 28 days and subjected to I/R with or without cardioprotective ischemic preconditioning (IPC). Rosiglitazone did not affect mortality, arrhythmia score, or infarct size during I/R. However, rosiglitazone abolished the antiarrhythmic effects of IPC. To investigate the direct effect of rosiglitazone on cardiomyocytes, we utilized adult rat cardiomyocytes (ARCMs), AC16, and differentiated AC16 (diffAC16) human cardiac cell lines. These were subjected to simulated I/R in the presence of rosiglitazone. Rosiglitazone improved cell survival of ARCMs at 0.3 μM. At 0.1 and 0.3 μM, rosiglitazone improved cell survival of AC16s but not that of diffAC16s. This is the first demonstration that chronic administration of rosiglitazone does not result in major hidden cardiotoxic effects in myocardial I/R injury models. However, the inhibition of the antiarrhythmic effects of IPC may have some clinical relevance that needs to be further explored.

Ceiling culture of human mature white adipocytes with a browning agent: A novel approach to induce transdifferentiation into beige adipocytes.

Excess and dysfunctional adipose tissue plays an important role in metabolic diseases, including obesity, atherosclerosis and type 2 diabetes mellitus. In mammals, adipose tissue is categorized into two types: white and brown. Adult brown tissue is mainly composed of beige adipocytes, which dispose of stored energy as heat and have become increasingly popular as a therapeutic target for obesity. However, there is still a paucity of cell models that allow transdifferentiation of mature white adipocytes into beige adipocytes, as seen in vivo. Here, we describe a novel, ceiling culture-based model of human mature white adipocytes, which transdifferentiate into beige adipocytes under the mechanical force and hypoxia of ceiling culture. We also show that the use of rosiglitazone and rapamycin can modulate transdifferentiation, up and down regulating expression of beige adipocyte-specific genes, respectively. Rosiglitazone additionally facilitated the upregulation of fatty acid lipolysis and oxidation genes. Finally, these beige adipocytes derived from dedifferentiated adipocytes exhibited a progenitor-specific phenotype, with higher expression of mature adipocyte-specific genes than adipocyte-derived stem cells. Overall, we report a novel approach to conveniently cultivate beige adipocytes from white adipocytes in vitro, suitable for mechanistic studies of adipose biology and development of cell and drug therapies in the future.

Impact of pharmacological interventions on biochemical hyperandrogenemia in women with polycystic ovary syndrome: a systematic review and meta-analysis of randomised controlled trials.

Polycystic ovary syndrome (PCOS) is a complex endocrine disease that affects women of reproductive age and is characterised by biochemical and clinical androgen excess. To evaluate the efficacy of pharmacological interventions used to decrease androgen hormones in women with PCOS. We searched PubMed, MEDLINE, Scopus, Embase, Cochrane library and the Web of Science from inception up to March 2021. Two reviewers selected eligible studies and extracted data, and the review is reported according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Of the 814 randomised clinical trials (RCTs) located in the search, 92 met the eligibility criteria. There were significant reductions in total testosterone level with metformin versus (vs) placebo (SMD:-0.33; 95% CI -0.49 to -0.17, p < 0.0001, moderate grade evidence) and dexamethasone vs placebo (MD:-0.86nmol/L; 95% CI -1.34 to -0.39, p = 0.0004, very low-grade evidence). Significant reductions in the free testosterone with sitagliptin vs placebo (SMD: -0.47; 95% CI -0.97 to 0.04, p = 0.07, very low-grade evidence), in dehydroepiandrosterone sulphate (DHEAS) with flutamide vs finasteride (MD: -0.37µg/dL; 95% CI -0.05 to -0.58, p = 0.02, very low-grade evidence), a significant reduction in androstenedione (A4) with rosiglitazone vs placebo (SMD: -1.67; 95% CI -2.27 to -1.06; 59 participants, p < 0.00001, very low-grade evidence), and a significant increase in sex hormone-binding globulin (SHBG) with oral contraceptive pill (OCP) (35µg Ethinyl Estradiol (EE)/2mg cyproterone acetate (CPA)) vs placebo (MD: 103.30nmol/L; 95% CI 55.54-151.05, p < 0.0001, very low-grade evidence) were observed. Metformin, OCP, dexamethasone, flutamide, and rosiglitazone use were associated with a significant reduction in biochemical hyperandrogenemia in women with PCOS, though their individual use may be limited due to their side effects. CRD42020178783.

Inhibition of Acyl-CoA Synthetase Long-Chain Family Member 4 Facilitates Neurological Recovery After Stroke by Regulation Ferroptosis

BackgroundIschemic stroke is the main cause of disability worldwide, leading to a serious socioeconomic burden. Ferroptosis is a non-apoptotic form of programmed cell death and is related to various diseases. Acyl-CoA synthetase long-chain family member 4 (ACSL4) is considered a target of ferroptosis, but its specific role in ischemic stroke remains unclear. In this study, we investigate whether the inhibition of ACSL4 promotes the recovery of neurological function in a way that prevents ferroptosis.MethodsA transient cerebral ischemia model was established for mice by middle cerebral artery occlusion (MCAO); glutathione peroxidase 4 (GPx4), ACSL4 and cyclooxygenase 2 (COX2) were detected by Western blot, and changes to mitochondria were observed by a transmission electron microscope. A kit was used to determine iron levels and lipid peroxide indicators, such as glutathione peroxidase (GPx), reduced glutathione (GSH), total glutathione/oxidized glutathione (GSH/GSSG), lipid peroxidation, reactive oxygen species, superoxide and malonaldehyde. Following MCAO, a ferroptosis inhibitor, liproxstatin-1, was administered intranasally immediately at a concentration of 10 mg/kg. Rosiglitazone was used to inhibit ACSL4 and was administered intravenously 1 h before MCAO at a concentration of 0.4 mg/kg. Brain injury was determined by neurological deficit scores, neuroscore (28-point), corner test and gait analyses, at 24 and 72 h after stroke. Brain infarct volume was determined by 2, 3, 5-Triphenyltetrazolium chloride (TTC) staining at 72 h after stroke.ResultsAfter MCAO, GPx4 protein expression decreased, ACSL4 and COX2 protein expression increased, GPx activity decreased and iron accumulation. Transmission electron microscopy confirmed that the outer mitochondrial membrane of neurons had ruptured and mitochondrial cristae had decreased or disappeared. Liproxstatin-1 could significantly attenuate the decrease of GPx4 and the increase of COX2 after MCAO, dramatically reducing iron accumulation and decreasing GPx activity, accompanied by a marked reduction in changes in lipid peroxidation indicators. The use of rosiglitazone to inhibit ACSL4 could significantly improve neurological function and reduce the brain infarct volume at 72 h after stroke. Importantly, inhibiting ACSL4 could significantly attenuate the decline of GPx4 after MCAO and markedly attenuate iron accumulation and a decrease in GPx activity. Additionally, changes in lipid peroxidation indicators were also significantly inhibited.ConclusionThis study indicates that inhibiting ACSL4 can promote the recovery of neurological function after stroke by suppression of ferroptosis.

Saturation of cholesteryl esters produced by human meibomian gland epithelial cells after treatment with rosiglitazone

PurposeThe purpose of this study was to compare the cholesteryl ester (CE) profiles expressed from human meibomian gland epithelial cells (HMGECs) in response to rosiglitazone-induced differentiation to that of normal human meibum. MethodsHMGECs were cultured with rosiglitazone (vehicle control, 20 μM, or 50 μM) and fetal bovine serum (FBS, 2% or 10%) for 2 days or 5 days. Following culture, lipid extracts were processed and analyzed by ESI-MSMSALL in positive ion mode. CEs were identified using both LipidView 1.2 and PeakView 2.2 (SCIEX, Framingham, MA) and compared to literature reports of CEs in normal human meibum. ResultsThere were 34 CEs with carbon number ranging from 14 to 34 detected from HMGECs. Across all conditions, HMGECs provided a CE profile that was 14.0% saturated, 60.6% monounsaturated, and 25.4% polyunsaturated. Culturing with 50 μM rosiglitazone and 2% FBS for 2 days resulted in the greatest number of upregulated saturated and monounsaturated CEs and downregulated polyunsaturated CEs. Five CEs were identified as being the most responsive to 50 μM rosiglitazone: CE 24:1, CE 28:1, CE 26:1, CE 18:1, and CE 22:1. ConclusionAlthough differences in the CE profile exist between meibum and HMGECs, rosiglitazone promotes upregulation of highly expressed meibum-relevant CEs and shifts the saturation level toward a more meibum-like profile. The use of rosiglitazone as a differentiating agent is recommended in HMGEC research, and analysis by ESI-MSMSALL is encouraged to differentiate meibum-relevant CEs from other nonpolar distractors detected by vital stains.

Rosiglitazone ameliorates palmitic acid-induced endoplasmic reticulum stress and steroidogenic capacity in granulosa cells

Granulosa cells play essential roles in follicular development, oocyte maturation and sex hormone secretion. The exposure of granulosa cells to palmitic acid (PA), the main component of dietary saturated fat, inhibits cell viability. However, the mechanism underlying PA-induced cytotoxicity in granulosa cells has not been deeply investigated. Rosiglitazone (RSG) is a member of the thiazolidinedione family and is reported to protect cells from cytotoxicity and endoplasmic reticulum (ER) stress in other cell types, but whether RSG protects granulosa cells remain unknown. In this study, KGN cell line and primary granulosa cells were used as models of granulosa cells to explore the effects of PA and RSG and the underlying mechanisms. The results showed that PA inhibits cell viability and estradiol secretion through inducing ER stress and cAMP/PKA/CREB pathway. CCAAT/enhancer-binding protein homologous protein (CHOP), an ER stress marker, was demonstrated to participate in PA-induced cytotoxicity. RSG treatment rescued granulosa cells from PA-induced cell death and ER stress. Moreover, RSG was identified to ameliorate ER stress induced by tunicamycin in granulosa cells. In addition, RSG treatment rescued granulosa cells from PA-induced decrease of estrogen secretion by cAMP/PKA/CREB pathway. In conclusion, RSG can protect granulosa cells against PA-induced cytotoxicity by inhibiting ER stress, and can recover steroidogenic capacity, indicating a potential use of RSG in the treatment of granulosa cell dysfunction.

Hypothesis validation of rosiglitazone a potential inhibitor against glycogen synthase kinase-3β, for the management of multifaceted pathophysiology of the diabetic wound: An insilico study

Diabetic wound (DW) is a major complication of diabetes mellitus that often ends up with amputation of the concerned organ. The current therapies for DW include glucose regulation, wound debridement, pressure off-loading, surgeries, hyperbaric oxygen therapy, maggot therapy, and so on. However, the majority are not meeting all the prerequisites of DW because of extensive pathology and cost associated with the strategies. So, to overcome the problems related to the existing conventional therapies, we hypothesized to repurpose the current drugs, which can target a receptor having a considerable role in the progression of DW might be beneficial. One major challenge of DW is multifaceted pathophysiology includes prolonged inflammation, increased infections, decreased cell proliferation, and migration. Many shreds of evidence disclosed that inhibition of GSK-3β could result in reduced inflammation and infection, followed by increased cell proliferation and migration. Thus, we selected the GSK-3β receptor as a ubiquitous target for the treatment of multifactorial pathophysiology of DW. In the current hypothetical study, we investigated the use of rosiglitazone as a therapeutic modulator against the GSK-3β receptor. To validate our hypothesis, computational studies such as molecular docking and MMGBSA were performed. From the in silico methods, it is evident that rosiglitazone established a higher binding affinity against the selected receptor. Further, the Molecular Dynamic simulation study has revealed stable interaction of rosiglitazone against GSK-3β complex. Thus, rosiglitazone might be a drug of choice in the therapeutic management of DW.

Different Effects of Thiazolidinediones on Cardiovascular Events among Type 2 Diabetic Patients Implanted with Bare Metal Stents: A Nationwide Study

Background: This study aimed to evaluate the effect of thiazolidinediones (TZDs) on re-hospitalization rates for revascularization after bare-metal stent (BMS) implantation. Methods: Data from the National Health Insurance Research Database (NHIRD), a government-operated, population-based database, were analyzed from March, 2000 to December, 2006. Type 2 diabetes subjects treated with BMS implantations who used TZDs (either rosiglitazone or pioglitazone) were compared with subjects not on TZDs (non-TZD group) to evaluate the risk of readmission for coronary revascularization. Endpoints were acute coronary syndrome (ACS) and readmission for revascularization (percutaneous coronary intervention or coronary artery bypass graft surgery) after 3, 6, and 12 months. Results: In total, 6911 type 2 diabetes patients were hospitalized for BMS implantation (average follow-up, 294.4 ± 108.9 days). Rosiglitazone treatment in patients who received BMSs was associated with a higher risk of re-hospitalization for revascularization at 6 and 12 months (hazard ratio (HR) = 1.33; 95% CI: 1.08-1.64 and HR = 1.20 95% CI: 1.01-1.43). However, there were no significant differences between the pioglitazone and non-TZD groups. Conclusion: The use of rosiglitazone in type 2 diabetes patients after BMS implantation may increase the risk of re-hospitalization for revascularization. Our study suggests that rosiglitazone should be used cautiously in diabetes patients with BMS implantation.

Annals for Educators - 4 February 2020.

Annals for Educators - 4 February 2020.

Anti-Diabetic Countermeasures Against Tobacco Smoke-Dependent Cerebrovascular Toxicity: Use and Effect of Rosiglitazone.

Tobacco smoking (TS) is one of the most addictive habit sand a main public health hazards, impacting the vascular endothelium through oxidative stress (OS) stimuli, exposure to nicotine, and smoking-induced inflammation in a dose-dependent manner. Increasing evidence also suggested that TS increases glucose intolerance and the risk factor of developing type-2 diabetes mellitus (2DM), which, along with TS, is connected to blood–brain barrier (BBB) injuries, and heightens the risk of cerebrovascular disorders. Although the exact mechanism of rosiglitazone (RSG) is unknown, our previous in vitro work showed how RSG, an oral anti-diabetic drug belonging to the family of thiazolidinedione class, can protect BBB integrity through enhancement of nuclear factor erythroid 2-related factor (Nrf2) activity. Herein, we have validated the protective role of rosiglitazone against TS-induced BBB impairment in vivo. Our results revealed that RSG as a peroxisome proliferator-activated receptor gamma (PPARγ), activates counteractive mechanisms primarily associated with the upregulation of Nrf2 and PPARγ pathways which reduce TS-dependent toxicity at the cerebrovascular level. In line with these findings, our results show that RSG reduces inflammation and protects BBB integrity. In conclusion, RSG offers a novel and promising therapeutic application to reduce TS-induced cerebrovascular dysfunction through activation of the PPARγ-dependent and/or PPARγ-independent Nrf2 pathway.

Detecting Secular Trends in Clinical Treatment through Temporal Analysis.

Medical treatments change over time for multiple reasons, including introduction of new treatments, availability of new scientific evidence, change in institutional guidelines, and market efforts by pharmaceutical and medical device companies. Monitoring and analyzing these secular trends will also inform the evaluation of evidence based practice as well as outcome research. Using a large national clinical dataset from the United States Veterans Health Administration (VHA), we measured the change in prevalence of all diseases, medications, and procedures by year from 2001 to 2014. To assess statistical significance, we used ageneralized linear model. Among the large number of changes that were observed, multiple significant changes were related to diabetes mellitus type II (DM2). Prevalence of DM2 in the VHA increased after 2001 but plateaued by 2008; blood sugar testing by glycosylated hemoglobin increased consistently while glucose testing decreased; and the trend of insulin and metformin use was consistent with the trend in DM2 prevalence, while glyburide and rosiglitazone use dropped sharply.

Association Between Glycemic Control and Risk of Fracture in Diabetic Patients: A Nested Case-Control Study.

Diabetes mellitus (DM) has been associated with an increased risk of fractures. However, the effect of glycemic control on the risk of fracture is not well understood. To evaluate the association between glycemic control and the risk of low-trauma fractures in patients with type 1 DM (T1DM) and type 2 DM (T2DM). Nested case-control analysis. UK-based Clinical Practice Research Datalink. The study population was patients whose T1DM or T2DM had been newly diagnosed between 1995 and 2015. The cases were patients with a low-trauma fracture after DM onset. We matched four controls to each case by age, sex, general practice, fracture date, and DM type and duration. Conditional logistic regression analyses were performed, adjusted for covariates, including body mass index, smoking, DM complications and medications. The study population included 3329 patients with T1DM and 44,275 patients with T2DM. The median duration between DM onset and fracture date was 4.5 years for both T1DM and T2DM. The risk of fracture was increased in the patients with T1DM with a mean hemoglobin A1c >8.0% (adjusted OR, 1.39; 95% CI, 1.06 to 1.83) compared with those patients with T1DM and a mean hemoglobin A1c ≤7.0%. No such effect was found in the patients with T2DM. Independently of glycemic control, the risk of fracture was elevated in patients with T2DM and the current use of rosiglitazone and pioglitazone. The effect of glycemic control on the risk of low-trauma fracture differs between patients with T1DM and T2DM. Poor glycemic control increased the risk of fractures in patients with T1DM but not in those with T2DM.

Concomitant use of rapamycin and rosiglitazone delays the progression of polycystic kidney disease in Han:SPRD rats: a study of the mechanism of action.

Attributing to their antiproliferative effect, both rapamycin and peroxisome proliferator-activated receptor-γ (PPARγ) can halt the progression of autosomal dominant polycystic kidney disease (ADPKD). Whether combined use could enhance this effect is unknown. The present study used rapamycin and the PPARγ agonist rosiglitazone concomitantly to observe their combined effects on the proliferation of ADPKD cyst-lining epithelial cells and the progression of ADPKD in Han:SPRD rats. Concomitant use of the two drugs inhibited the proliferation of WT9-12 cells significantly through a superimposition effect. Rosiglitazone inhibited the phosphorylation of mammalian target of rapamycin p70S6K. Concomitant use of rosiglitazone and rapamycin further downregulated the p-p70S6K level. Rosiglitazone also inhibited the phosphorylation of Akt and antagonized the activation of Akt induced by rapamycin. Concomitant use of rosiglitazone and rapamycin significantly retarded the deterioration of renal function, decreased cyst cell proliferation and interstitial fibrosis in Han:SPRD rats. Rapamycin significantly increased cholesterol levels in the blood, whereas rosiglitazone mitigated rapamycin-induced hyperlipidemia. These results indicate that the effects of concomitant use of rosiglitazone and rapamycin in inhibiting the proliferation of WT9-12 cells and delaying the progression of ADPKD in Han:SPRD rats are stronger than those of either drug alone. The present study may provide a new strategy for the long-term treatment of ADPKD.

Pioglitazone and risk of bladder cancer in type 2 diabetes mellitus patients: A systematic literature review and meta-analysis of observational studies using real-world data

ObjectivesPatients with type 2 diabetes mellitus (T2DM) have a higher incidence of bladder cancer (BC); however, the evidence underlining the association between pioglitazone use and BC risk remains inconclusive. We conducted a systematic review and meta-analysis of observational studies to investigate the effect of pioglitazone on risk of BC in T2DM patients. MethodsWe searched all publications regarding risk of BC with pioglitazone use through PubMed, Web of Science and Cochrane library databases from inception to March, 2017. Pooled hazard ratio (HR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method. ResultsTotal 15 observational (9 cohort and 6 case-control) studies were meta-analyzed. The pooled results showed a significant association between risk of BC and pioglitazone use (HR 1.20, 95%CI 1.09–1.31; P<0.0001; I2=4%). In subgroup analysis, cumulative dose of pioglitazone (− and >mg) showed a significant association with risk of BC (HR 1.27; 95%CI 1.05–1.54; P=0.01; I2=0% and HR 1.68, 95%CI 1.36–2.08; P<0 I2=0% respectively). In addition, a significant association was seen with risk of BC and pioglitazone treatment duration (12–24 months and >24 months) (HR 1.43; 95%CI 1.19–1.71; P=0.0001; I2=0% and HR 1.58; 95%CI 1.27–1.97; P<0.0001; I2=29% respectively). Meta-analysis of pioglitazone vs. rosiglitazone use, showed a significant association (HR 1.34; 95%CI 1.05–1.71; P=0.02; I2=0%) with BC risk and pioglitazone use. ConclusionPioglitazone use is associated with risk of BC in T2DM patients. Risk of bladder cancer appears to be associated with higher dose and longer duration of pioglitazone use.

Impact of clinical evidence communications and drug regulation changes concerning rosiglitazone on prescribing patterns of antidiabetic therapies.

Cardiovascular safety alerts about rosiglitazone resulted in regulatory actions in several countries in 2010, but the Food and Drug Administration eliminated access restrictions in 2013, reflecting new evidence concerning the drug safety. We investigated the effects of safety signals and regulation shifts concerning rosiglitazone on prescribing of antidiabetic drugs (ADs). Patient data were extracted from the Korean health insurance claims database for 2007 to 2015. Linear regression and interrupted time series analyses were performed to examine drug utilization trends and the impact of 5 milestone events regarding rosiglitazone safety on AD utilization. A steady growth was observed in the AD consumption, with metformin preserving its dominant market share throughout the period. Pioglitazone use has increased since 2008 in response to safety issues surrounding rosiglitazone. A significant decline in rosiglitazone use was observed after Nissen's meta-analysis and safety warnings (2007) and after restriction/suspension of access to rosiglitazone (2010), associated with a drop in prevalence by 29.5%/year and 99.5%/year, respectively. The most common AD newly started among users who discontinued rosiglitazone in 2010 was pioglitazone, followed by dipeptidyl peptidase-4 (DPP-4) inhibitors. Our concomitancy analysis showed that DPP-4 inhibitors have overtaken sulfonylureas since 2014 as the most common add-on to metformin. The most frequently added AD in diabetes patients who had switched off rosiglitazone in 2010 was pioglitazone, followed by DPP-4 inhibitors. Despite new evidence from a long-term clinical trial and the Food and Drug Administration's subsequent decision to eliminate access restrictions on rosiglitazone in 2013, domestic regulations were left intact; hence, its use remained negligible in Korea.

Thiazolidinedione use and atrial fibrillation in diabetic patients: a meta-analysis

BackgroundAccumulating evidence suggests that thiazolidinediones (TZDs) may exert protective effects in atrial fibrillation (AF). The present meta-analysis investigated the association between TZD use and the incidence of AF in diabetic patients.MethodsElectronic databases were searched until December 2016. Of the 346 initially identified records, 3 randomized clinical trials (RCTs) and 4 observational studies with 130,854 diabetic patients were included in the final analysis.ResultsPooled analysis of the included studies demonstrated that patients treated with TZDs had approximately 30% lower risk of developing AF compared to controls [odds ratio (OR): 0.73, 95% confidence interval (CI): 0.62 to 0.87, p = 0.0003]. This association was consistently observed for both new onset AF (OR =0.77, p = 0.002) and recurrent AF (OR =0.41, p = 0.002), pioglitazone use (OR =0.56, p = 0.04) but not rosiglitazone use (OR =0.78, p = 0.12). The association between TZD use and AF incidence was not significant in the pooled analysis of three RCTs (OR =0.77, 95% CI = 0.53–1.12, p = 0.17), but was significantly in the pooled analysis of the four observational studies (OR =0.71, p = 0.0003).ConclusionsThis meta-analysis suggests that TZDs may confer protection against AF in the setting of diabetes mellitus (DM). This class of drugs can be used as upstream therapy for DM patients to prevent the development of AF. Further large-scale RCTs are needed to determine whether TZDs use could prevent AF in the setting of DM.

Perspectives on Some Controversies in Cardiovascular Disease Risk Assessment in the Pharmaceutical Development of Glucose-Lowering Medications.

The U.S. Food and Drug Administration (FDA) issued guidance on requirements to assess cardiovascular disease (CVD) risk with drugs being developed for approval for clinical use. The guidance was triggered by a meta-analysis published by Nissen and Wolski that suggested an increased risk for myocardial infarction with the use of rosiglitazone. This article discusses controversies around CVD trials in diabetes beginning with the University Group Diabetes Program. This is followed by a brief description of the FDA guidance for evaluating CVD risk with glucose-lowering medications. Limitations of meta-analyses of data from phase 2 and 3 (phase 2/3) trials to inform CVD risk are highlighted. These include the differences between patient characteristics in phase 2/3 trials and those in cardiovascular outcome trials (CVOTs) and the relatively short exposure time in phase 2/3 trials. The differences may partly explain the observed disparity between phase 2/3 meta-analyses and the results of completed CVOTs. Approaches to understanding CVD risk with a new medication should get to the answer about risk as efficiently as possible to minimize any potential harm to patients. In that context, we discuss options for clinical trial design and an alternative approach for statistical analyses.

Sirtuin1 promotes osteogenic differentiation through downregulation of peroxisome proliferator-activated receptor γ in MC3T3-E1 cells

Osteoporosis is a skeletal disorder characterized by bone loss, resulting in architectural deterioration of the skeleton, decreased bone strength and an increased risk of fragility fractures. Strengthening osteogenesis is an effective way to relieve osteoporosis. Sirtuin1 (Sirt1) is a nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase, which is reported to be involved in improving osteogenesis. Sirt1 targets peroxisome proliferator-activated receptor γ (PPARγ) in the regulation of adipose tissues; however, the molecular mechanism of Sirt1 in osteogenic differentiation is still unknown. PPARγ tends to induce more adipogenic differentiation rather than osteogenic differentiation. Hence, we hypothesized that Sirt1 facilitates osteogenic differentiation through downregulation of PPARγ signaling. Mouse pre-osteoblastic MC3T3-E1 cells were cultured under osteogenic medium. Sirt1 was overexpressed through plasmid transfection. The results showed that high expression of Sirt1 was associated with increased osteogenic differentiation, as indicated by quantitative PCR and Western blot analysis of osteogenic markers, and Von Kossa staining. Sirt1 overexpression also directly and negatively regulated the expression of PPARγ and its downstream molecules. Use of the PPARγ agonist Rosiglitazone, reversed the effects of Sirt1 on osteogenic differentiation. Using constructed luciferase plasmids, we demonstrated a role of Sirt1 in inhibiting PPARγ–induced activity and expression of adipocyte–specific genes, including acetyl-coenzyme A carboxylase (Acc) and fatty acid binding protein 4 (Fabp4). The interaction between Sirt1 and PPARγ was further confirmed using co-immunoprecipitation analysis. Together, these results reveal a novel mechanism for Sirt1 in osteogenic differentiation through downregulation of PPARγ activity. These findings suggest that the Sirt1–PPARγ pathway may represent a potential target for enhancement of osteogenesis and treatment of osteoporosis.

Dual Outcomes of Rosiglitazone Treatment on Fatty Liver.

In previous studies, it has been reported that rosiglitazone has opposing effects on nonalcoholic fatty liver disease. The purpose of the current study is to test the hypothesis that such opposing effects are related to different levels of peroxisome proliferator-activated receptor gamma (PPAR-γ) in the liver. Using a gene transfer approach and mice fed a high-fat diet (HFD) as an animal model, we demonstrate that mice with low levels of PPAR-γ expression in the liver are resistant to HFD-induced development of fatty liver when treated with rosiglitazone. Conversely, rosiglitazone treatment actually exacerbates liver steatosis in obese mice that have a higher level of PPAR-γ. Mechanistic studies show that an elevated hepatic PPAR-γ level is associated with an increased expression of genes responsible for lipid metabolism in the liver, particularly Cd36, Fabp4, and Mgat1. The concurrent transfer of these three genes into the mouse liver fully recapitulates the phenotypic change induced by the overexpression of PPAR-γ. These results provide evidence in support of the importance of PPAR-γ in the liver when rosiglitazone is considered for the treatment of fatty liver disease. Clinically, our results suggest the necessity of verifying PPAR-γ levels in the liver when rosiglitazone is considered as a treatment option, and indicate that the direct use of rosiglitazone for treatment of nonalcoholic fatty liver may not be desirable when the patient's PPAR-γ level in the liver is significantly elevated.