Assessment of safety and tolerability of remogliflozin etabonate (GSK189075) when administered with total daily dose of 2000 mg of metformin.

BACKGROUND: Patients with type 2 diabetes mellitus (T2DM) are characterized by an elevated glycemic index and are at a higher risk for complications such as cardiovascular disease, nephropathy, retinopathy and peripheral neuropathy. Normalization of glycemic index can be achieved by dosing combinations of metformin with other anti-diabetic drugs. The present study (Clintrials number NCT00519480) was conducted to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of remogliflozinetabonate, an SGLT2 inhibitor, withdoses (500 mg and 750 mg BID) greater than the commercial dose (100 mg BID)in combination with metformin with minimum daily dose of 2000 mg given in two divided doses. METHODS: This was a randomized, double-blinded, repeat dose study in 50 subjects with T2DM. The study was conducted in three phases; run-in, randomization, and treatment. All subjects were on a stable metformin dosing regimen. Cohort 1 subjects were randomly allocated to receive either remogliflozin etabonate 500 mg BID or placebo BID (2:1) in addition to metformin. Cohort 2 subjects were administered with either remogliflozin etabonate 750 mg BID or placebo BID (2:1) in addition to metformin for 13 days. All the subjects were assessed for safety (adverse events, lactic acid levels, vital signs, electrocardiogram [ECG]), pharmacokinetic evaluation, and pharmacodynamics (Oral Glucose Tolerance Testing) parameters. RESULTS: Co-administration of remogliflozin etabonate and metformin was well tolerated in all subjects during the observation period. There were no severe or serious adverse events (SAEs) and no increase in lactic acid concentration was reported during the study. The statistical results showed that concomitant administration of remogliflozin etabonate, either 500 mg or 750 mg BID, with metformin had no effect on the pharmacokinetics of metformin. The accumulation ratios, Day 13 vs. Day 1, for AUC values of remogliflozin etabonate and its metabolites were all very close to 1, indicating no accumulation in plasma concentrations of remogliflozin etabonate and its metabolites. Mean glucose values from baseline and glucose and insulin values following oral glucose tolerance test (OGTT) were decreased in all treatment groups. CONCLUSION: Co-administration of doses of remogliflozin etabonate (500 mg BID or 750 mg BID) greater than the commercial dose (100 mg BID) with metformin (2000 mg BID) was shown to be safe and effective during the observation period. TRIAL REGISTRATION: ClinicalTrials.gov , NCT00519480 . Registered:22 August 2007.

Remogliflozin Etabonate Improves Fatty Liver Disease in Diet-Induced Obese Male Mice.

BACKGROUND: Nonalcoholic fatty liver disease and nonalcoholic steatohepatitis (NASH) are serious conditions and are being diagnosed at an increased rate. The etiology of these hepatic disorders is not clear but involves insulin resistance and oxidative stress. Remogliflozin etabonate (Remo) is an inhibitor of the sodium glucose-dependent renal transporter 2 (SGLT2), and improves insulin sensitivity in type 2 diabetics. In the current study, we examined the effects of Remo in a diet-induced obese mouse model of NAFLD. METHODS: After 11-weeks on High-Fat-Diet 32 (HFD32), C57BL/6J mice were obese and displayed characteristics consistent with NAFLD. Cohorts of obese animals were continued on HFD32 for an additional 4-week treatment period with or without Remo. RESULTS: Treatment with Remo for 4 weeks markedly lowered both plasma alanine aminotransferase (76%) and aspartate aminotransferase (48%), and reduced both liver weight and hepatic triglyceride content by 42% and 40%, respectively. Remo also reduced hepatic mRNA content for tumor necrosis factor (TNF)-α (69%), and monocyte chemoattractant protein (MCP)-1 (69%). The diet-induced increase in thiobarbituric acid-reactive substances, a marker of oxidative stress, was reduced following treatment with Remo, as measured in both liver homogenates (22%) and serum (37%). Finally, the oxygen radical absorbance capacity (ORAC) in three different SGLT2 inhibitors was determined: remogliflozin, canagliflozin and dapagliflozin. Only remogliflozin had any significant ORAC activity. CONCLUSIONS: Remo significantly improved markers associated with NAFLD in this animal model, and may be an effective compound for the treatment of NASH and NAFLD due to its insulin-sensitizing and antioxidant properties.

Obesity Contributes to Ovarian Cancer Metastatic Success through Increased Lipogenesis, Enhanced Vascularity, and Decreased Infiltration of M1 Macrophages.

Epithelial ovarian cancer (EOC) is the leading cause of death from gynecologic malignancy, with high mortality attributable to widespread intraperitoneal metastases. Recent meta-analyses report an association between obesity, ovarian cancer incidence, and ovarian cancer survival, but the effect of obesity on metastasis has not been evaluated. The objective of this study was to use an integrative approach combining in vitro, ex vivo, and in vivo studies to test the hypothesis that obesity contributes to ovarian cancer metastatic success. Initial in vitro studies using three-dimensional mesomimetic cultures showed enhanced cell-cell adhesion to the lipid-loaded mesothelium. Furthermore, in an ex vivo colonization assay, ovarian cancer cells exhibited increased adhesion to mesothelial explants excised from mice modeling diet-induced obesity (DIO), in which they were fed a "Western" diet. Examination of mesothelial ultrastructure revealed a substantial increase in the density of microvilli in DIO mice. Moreover, enhanced intraperitoneal tumor burden was observed in overweight or obese animals in three distinct in vivo models. Further histologic analyses suggested that alterations in lipid regulatory factors, enhanced vascularity, and decreased M1/M2 macrophage ratios may account for the enhanced tumorigenicity. Together, these findings show that obesity potently affects ovarian cancer metastatic success, which likely contributes to the negative correlation between obesity and ovarian cancer survival.

Pharmacokinetics and Pharmacodynamics of the SGLT2 Inhibitor Remogliflozin Etabonate in Subjects with Mild and Moderate Renal Impairment.

Remogliflozin etabonate (RE), the prodrug of remogliflozin, is an inhibitor of the sodium glucose-dependent renal transporter 2 (SGLT2), enabling urinary glucose excretion to reduce hyperglycemia for the treatment of type 2 diabetes. Renal function declines more rapidly in patients with type 2 diabetes, making it difficult or unsafe to continue on some antidiabetic therapeutics. In an initial effort to understand the potential utility of RE in patients with renal impairment, the pharmacodynamics and pharmacokinetics of RE were evaluated in a single oral dose (250 mg) in patients with renal impairment as compared with control subjects. As shown by pharmacodynamic measurements of urinary glucose excretion, there was no clinically significant reduction in the ability of remogliflozin to inhibit SGLT2. In addition, there were no significant changes in area under the curve (from 0 to infinity) or half-life of remogliflozin, suggesting renal impairment does not alter the pharmacokinetics of remogliflozin. In contrast to other SGLT2 inhibitors which accumulate in patients with renal impairment, adjustment of the dosage of RE in subjects with mild or moderate renal impairment is not indicated based on the observations in this study.

Metabolomic signatures in lipid-loaded HepaRGs reveal pathways involved in steatotic progression.

OBJECTIVES: A spectrum of disorders including simple steatosis, nonalcoholic steatohepatitis, fibrosis, and cirrhosis is described by nonalcoholic fatty liver disease (NAFLD). With the increased prevalence of obesity, and consequently NAFLD, there is a need for novel therapeutics in this area. To facilitate this effort, a cellular model of hepatic steatosis was developed using HepaRG cells and the resulting biochemical alterations were determined. DESIGN AND METHODS: Using global metabolomic profiling, by means of a novel metabolite extraction procedure, the metabolic profiles in response to the saturated fatty acid palmitate, and a mixture of saturated and unsaturated fatty acids, palmitate and oleate (1:2) were examined. RESULTS: We observed elevated levels of the branched chain amino acids, tricarboxylic acid cycle intermediates, sphingosine and acylcarnitines, and reduced levels of carnitine in the steatotic HepaRG model with both palmitate and palmitate:oleate treatments. In addition, elevated levels of diacylglycerols and monoacylglycerols as well as altered bile acid metabolism were selectively displayed by palmitate-induced steatotic cells. CONCLUSIONS: Biochemical changes in pathways important in the transition to hepatic steatosis including insulin resistance, altered mitochondrial metabolism, and oxidative stress are revealed by this global metabolomic approach. Moreover, the utility of this in vitro model for investigating the mechanisms of steatotic progression, insulin resistance, and lipotoxicity in NAFLD was demonstrated.

Isolation and characterization of human adipose-derived stem cells for use in tissue engineering.

Human adipose-derived adult stem cells (ASCs) represent a unique population of multipotent stem cells. Their utility in a variety of tissue engineering applications, and as a model system for the study of molecular mechanisms of differentiation, is well established. In addition, their relative abundance, ease of isolation from human subcutaneous lipoaspirates, and functional stability make them an excellent physiologically relevant platform. Here, we describe detailed procedures for handling and purification of ASCs from lipoaspirate, as well as their expansion, cryopreservation, quality control, and functional assays.

High-content screening of human primary muscle satellite cells for new therapies for muscular atrophy/dystrophy.

Myoblast proliferation and differentiation are essential for normal skeletal muscle growth and repair. Muscle recovery is dependent on the quiescent population of muscle stem cells - satellite cells. During muscle injury, satellite cells become mitotically active and begin the repair process by fusing with each other and/or with myofibers. Aging, prolonged inactivity, obesity, cachexia and other muscle wasting diseases are associated with a decreased number of quiescent and proliferating satellite cells, which impedes the repair process. A high-content/high-throughput platform was developed and utilized for robust phenotypic evaluation of human primary satellite cells in vitro for the discovery of chemical probes that may improve muscle recovery. A 1600 compound pilot screen was developed using two highly annotated small molecule libraries. This screen yielded 15 dose responsive compounds that increased proliferation rate in satellite cells derived from a single obese human donor. Two of these compounds remained dose responsive when counter-screened in 3-donor obese superlot. The Alk-5 inhibitor LY364947, was used as a positive control for assessing satellite cell proliferation/delayed differentiation. A multivariate approach was utilized for exploratory data analysis to discover proliferation vs. differentiation-dependent changes in cellular phenotype. Initial screening efforts successfully identified a number of phenotypic outcomes that are associated with desired effect of stimulation of proliferation and delayed differentiation.

Cytokine profile of human adipose-derived stem cells: expression of angiogenic, hematopoietic, and pro-inflammatory factors.

Adipose tissue serves as a source of adipokines and cytokines with both local and systemic actions in health and disease. In this study, we examine the hypothesis that multipotent human adipose-derived stem cells (ASCs), capable of differentiating along the adipocyte, chondrocyte, and osteoblast pathways, contribute to adipose tissue-derived cytokine secretion. Following exposure to basic fibroblast growth factor (bFGF) or epidermal growth factor (EGF), the ASCs significantly increase their secretion of hepatocyte growth factor (HGF), a cytokine implicated in hematopoiesis, vasculogenesis, and mammary epithelial duct formation. Ascorbic acid synergizes with these inductive factors, further increasing HGF levels. Following exposure to lipopolysaccharide, ASCs increase their secretion of both hematopoietic (granulocyte/monocyte, granulocyte, and macrophage colony stimulating factors, interleukin 7) and proinflammatory (interleukins 6, 8, and 11, tumor necrosis factor alpha) cytokines based on ELISA and RT-PCR. In co-cultures established with umbilical cord blood-derived CD34(+) cells, the ASCs support long-term hematopoiesis in vitro. Furthermore, in short-term 12-day co-cultures, the ASC maintain and expand the numbers of both myeloid and lymphoid progenitors. These observations are consistent with the functionality of the secreted cytokines and confirm recent reports by other laboratories concerning the hematopoietic supportive capability of ASCs. We conclude that the ASCs display cytokine secretory properties similar to those reported for bone marrow-derived mesenchymal stem cells (MSCs).

Melanin-concentrating hormone activates signaling pathways in 3T3-L1 adipocytes.

Energy homeostasis is regulated by peripheral signals, such as leptin, and by several orexigenic and anorectic neuropeptides. Recently, we reported that the orexigenic neuropeptide melanin-concentrating hormone (MCH) stimulates leptin production by rat adipocytes and that the MCH receptor (MCH-R1) is present on these cells. Here, we show that MCH-R1 is present on murine 3T3-L1 adipocytes. Treatment of 3T3-L1 adipocytes with 1 micromolar MCH for up to 2 h acutely downregulated MCH-R1, indicating a mechanism of ligand-induced receptor downregulation. Potential signaling pathways mediating MCH-R1 action in adipocytes were investigated. Treatment of 3T3-L1 adipocytes with 1 micromolar MCH rapidly induced a threefold and a fivefold increase in p44/42 MAPK and pp70 S6 kinase activities, respectively. In addition, 3T3-L1 adipocytes transiently transfected with a murine leptin-luciferase promoter construct showed a fourfold and a sixfold increase in leptin promoter-reporter gene expression at 1 h and 4 h, respectively, in response to MCH. Activity decreased to basal levels at 8 h. Furthermore, MCH-stimulated leptin promoter-driven luciferase activity was diminished in the presence of the MAP/ERK kinase inhibitor PD-98059 and in the presence of rapamycin, an inhibitor of pp70 S6 kinase activation. These results provide further evidence for a functional MCH signaling pathway in adipocytes.