6 research outputs found
Synergetic Insulin Sensitizing Effect of Rimonabant and BGP-15 in Zucker-Obes Rats
Abdominal obesity is referred for as a common pathogenic root of
multiple risk factors, which include insulin resistance,
dyslipidemia, hypertension, and a pro-atherogenic and pro-
inflammatory state. Irrespective of its psychiatric side
effects, rimonabant through blocking cannabinoid-1 receptor
(CB1R) induces an increase in whole body insulin sensitivity.
The aim of this work was to study the effect of selected doses
of another insulin sensitizer compound BGP-15, and rimonabant on
insulin resistance in Zucker obese rats with a promise of
inducing insulin sensitization together at lower doses than
would have been expected by rimonabant alone. We found that BGP-
15 potentiates the insulin sensitizing effect of rimonabant. The
combination at doses, which do not induce insulin sensitization
by themselves, improved insulin signaling. Furthermore our
results suggest that capsaicin-induced signal may play a role in
insulin sensitizing effect of both molecules. Our data might
indicate that a lower dose of rimonabant in the treatment of
insulin resistance and type 2 diabetes is sufficient to
administer, thus a lower incidence of the unfavorable
psychiatric side effects of rimonabant are to be expected
Hsp90 chaperones PPARγ and regulates differentiation and survival of 3T3-L1 adipocytes
Adipose tissue dysregulation has a major role in various human diseases. The peroxisome proliferator-activated receptor-γ (PPARγ) is a key regulator of adipocyte differentiation and function, as well as a target of insulin-sensitizing drugs. The Hsp90 chaperone stabilizes a diverse set of signaling 'client' proteins, thereby regulates various biological processes. Here we report a novel role for Hsp90 in controlling PPARγ stability and cellular differentiation. Specifically, we show that the Hsp90 inhibitors geldanamycin and novobiocin efficiently impede the differentiation of murine 3T3-L1 preadipocytes. Geldanamycin at higher concentrations also inhibits the survival of both developing and mature adipocytes, respectively. Further, Hsp90 inhibition disrupts an Hsp90-PPARγ complex, leads to the destabilization and proteasomal degradation of PPARγ, and inhibits the expression of PPARγ target genes, identifying PPARγ as an Hsp90 client. A similar destabilization of PPARγ and a halt of adipogenesis also occur in response to protein denaturing stresses caused by a single transient heat-shock or proteasome inhibition. Recovery from stress restores PPARγ stability and adipocyte differentiation. Thus, our findings reveal Hsp90 as a critical stress-responsive regulator of adipocyte biology and offer a potential therapeutic target in obesity and the metabolic syndrome.Cell Death and Differentiation advance online publication, 4 October 2013; doi:10.1038/cdd.2013.129
Ustekinumab as induction and maintenance therapy for ulcerative colitis
BACKGROUND The efficacy of ustekinumab, an antagonist of the p40 subunit of interleukin-12 and interleukin-23, as induction and maintenance therapy in patients with ulcerative colitis is unknown. METHODS We evaluated ustekinumab as 8-week induction therapy and 44-week maintenance therapy in patients with moderate-to-severe ulcerative colitis. A total of 961 patients were randomly assigned to receive an intravenous induction dose of ustekinumab (either 130 mg [320 patients] or a weight-range\u2013based dose that approximated 6 mg per kilogram of body weight [322]) or placebo (319). Patients who had a response to induction therapy 8 weeks after administration of intravenous ustekinumab were randomly assigned again to receive subcutaneous maintenance injections of 90 mg of ustekinumab (either every 12 weeks [172 patients] or every 8 weeks [176]) or placebo (175). The primary end point in the induction trial (week 8) and the maintenance trial (week 44) was clinical remission (defined as a total score of 642 on the Mayo scale [range, 0 to 12, with higher scores indicating more severe disease] and no subscore >1 [range, 0 to 3] on any of the four Mayo scale components). RESULTS The percentage of patients who had clinical remission at week 8 among patients who received intravenous ustekinumab at a dose of 130 mg (15.6%) or 6 mg per kilogram (15.5%) was significantly higher than that among patients who received placebo (5.3%) (P<0.001 for both comparisons). Among patients who had a response to induction therapy with ustekinumab and underwent a second randomization, the percentage of patients who had clinical remission at week 44 was significantly higher among patients assigned to 90 mg of subcutaneous ustekinumab every 12 weeks (38.4%) or every 8 weeks (43.8%) than among those assigned to placebo (24.0%) (P=0.002 and P<0.001, respectively). The incidence of serious adverse events with ustekinumab was similar to that with placebo. Through 52 weeks of exposure, there were two deaths (one each from acute respiratory distress syndrome and hemorrhage from esophageal varices) and seven cases of cancer (one each of prostate, colon, renal papillary, and rectal cancer and three nonmelanoma skin cancers) among 825 patients who received ustekinumab and no deaths and one case of cancer (testicular cancer) among 319 patients who received placebo. CONCLUSIONS Ustekinumab was more effective than placebo for inducing and maintaining remission in patients with moderate-to-severe ulcerative colitis