Effects of GW501516 on the injury of pulmonary artery endothelial cells induced by hypoxia and its mechanism / 中国药房

OBJECTIVE To investigate the effects of the peroxisome proliferator-activated receptors δ （PPARδ） agonist GW501516 on the injury of pulmonary artery endothelial cells （PAECs） induced by hypoxia and its mechanism. METHODS The cytotoxic effects of GW501516 were observed by detecting the relative survival rate of PAECs； the protein expression of PPARδ was determined by Western blot assay. The cellular model of PAECs injury was established under hypoxic conditions； using antioxidant N-acetylcysteine （NAC） as positive control， the effects of GW501516 on cell injury and reactive oxygen species （ROS） production were investigated by detecting cell apoptotic rate， cell viability， lactate dehydrogenase （LDH） activity and ROS levels. Using nuclear factor erythroid 2-related factor 2（Nrf2） activator dimethyl fumarate （DMF） as positive control， PAECs were incubated with GW501516 and/or Nrf2 inhibitor ML385 under hypoxic conditions； the mechanism of GW501516 on PAECs injury induced by hypoxia was investigated by detecting cell injury （cell apoptosis， cell viability， LDH activity）， the levels of superoxide dismutase （SOD）， glutathione peroxidase （GPx）， catalase （CAT）， malondialdehyde （MDA） and ROS， the expressions of Nrf2， heme oxygenase-1 （HO-1） and cleaved-caspase-3 （C-caspase-3） protein. RESULTS The results demonstrated that hypoxia inhibited the protein expression of PPARδ （P＜0.05）， while GW501516 promoted the protein expression of PPARδ in hypoxia- exposed PAECs without obvious cytotoxic effects. GW501516 inhibited the apoptosis of PAECs， improved cell viability， and reduced LDH activity and ROS levels. GW501516 could up-regulate the protein expression of HO-1 in PAECs and the levels of SOD， GPx and CAT， while down-regulated the levels of MDA and ROS by activating the Nrf2 pathway （P＜0.05）； but Nrf2 inhibitor ML385 could reverse the above effects of GW501516 （P＜0.05）. GW501516 exerted similar effects to Nrf2 activator DMF in down-regulating the expression of C-caspase-3 and inhibiting the injury of PAECs under conditions of hypoxia （P＜0.05）. Moreover， Nrf2 inhibitor ML385 reversed the 163.com inhibition effects of GW501516 on PAECs injury （P＜0.05）. CONCLUSIONS GW501516 can relieve the hypoxia-induced injury of PAECs via the inhibition of oxidative stress， the mechanism of which may be associated with activating Nrf2.

The Peroxisome Proliferator-Activated Receptor delta Agonist, GW501516, Inhibits Angiogenesis through Dephosphorylation of Endothelial Nitric Oxide Synthase

OBJECTIVE: Peroxisome proliferator-activated receptor delta (PPAR-delta) is an ubiquitously expressed nuclear receptor that has been implicated in adipose tissue formation, brain development, and atherosclerosis. Despite mouse studies demonstrating that PPAR-delta activation has favorable anti-atherogenic properties by improving systemic lipid profiles, the relationship between PPAR-delta agonist and angiogenesis is unknown. We hypothesized that PPAR-delta ligands modulate the angiogenesis. METHODS: To test this hypothesis we treated primary cultures of bovine aortic endothelial cells with PPAR-delta specific ligand, GW501516 (50-800 nM) for 6 h. RESULTS: GW501516 dose-dependently decreased nitric oxide production without alteration in endothelial nitric oxide synthase (eNOS) expression. Analysis with phospho-specific antibodies against eNOS demonstrated that GW501516 significantly decreased the phosphorylation of eNOS at Serine1179 (eNOS-Ser1179). Concurrently, GW501516 also decreased the Akt phosphorylation. GW501516 did not affect endothelial cell proliferation or induce apoptosis. However, GW501516 inhibited endothelial cell migration, and tube formation in a high nanomolar concentration. The inhibition of endothelial cell tube formation by GW501516 was prevented by addition of the nitric oxide donor, DETA NONOate (5 microM). GW501516 was also found to inhibit angiogenesis in vivo in the chicken chorioallantoic membrane assay. CONCLUSION: These results provide that high nanomolar range of GW501516 inhibits angiogenesis by a mechanism involving dephosphorylation of eNOS-Ser1179.

Peroxisome proliferator activated receptor β agonist, GW501516,ameliorates insulin resistance in glucose intolerant mouse model / 中国药理学与毒理学杂志

AIM The effects of GW501516, a peroxisome proliferator-activated receptor β (PPARβ) agonist, in long term diet induced obesity (DIO, high fat and maltose diet for 4 months) mice were evaluated, and the efficacy of GW501516 against insulin resistance and the involved mechanism was investigated. METHODSMice were divided into 3 groups: normal control, DIO model and DIO model+GW501516. GW501516 (10 mg·kg-1·d-1) was administered by ig once a day for 14 d. During the treatment, body weight and food intake were monitored every other day. The oral glucose tolerance test, and the serum biochemical parameters including the serum triglyceride, total cholesterol and high density lipoprotein cholesterol (HDL-C) levels were measured according to the specifications. To confirm the GW501516-mediated PPARβ activation, the mRNA levels of downstream genes related to glucose, lipid metabolism and energy expenditure was measured. RESULTS GW501516 treatment effectively improved the glucose intolerance, increased the area under the glucose curves[DIO model, (32.4±4.6) mmol·h·L-1 compared with DIO model+GW501516, (23.4±2.5) mmol·h·L-1, n=7-8, P<0.05], normalized the fasted blood glucose, and increased serum HDL-C level, besides, histological analysis revealed the decreased hepatic lipid accumulation and hypertrophy of hepatocyte in DIO mice. Moreover, RT-PCR results indicated that carnitine palmitoyltransferase 1b, uncoupling protein 2, uncoupling protein 3 and glucose transport protein 4 were all upregulated. CONCLUSIONGW501516 significantly ameliorates glucose intolerance, decreases fasted blood glucose and hepatic steatosis, which might be related to ① the enhancement of fatty acid oxidation and energy uncoupling in muscle, and ②the improvement of insulin-stimulated glucose transportation in skeletal muscle in the long term DIO mice.