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Acupuncture has become an effective approach in clinic for treating obesity, but its mechanism has not been clarified yet. A large number of researches have been conducted on the obesity mechanism in the aspects of neurophysiological regulation, feeding center regulation and peripheral digestion and absorption regulation at home and abroad. But, regarding the main storage site of excess energy, i．e. the remodeling and functional regulation of white adipose tissue (WAT), is still a new field in research. In the paper, focusing on the new filed of weight loss, in view of the promotion of WAT browning through the re-gulation of UCP1 and PPARγ signal pathway with acupuncture, the potential peripheral mechanism of acupuncture was explored on weight loss.
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Objective To investigate the role of SIRT1/PGC-1α pathway in the auditory cortex aging of guinea pigs with age-related hearing loss and whether the electroacupuncture can delay aging process of the auditory cortex in the aged guinea pigs induced by D-galactose through the regulation of SIRT1/PGC-1α pathway.Methods Thirty 4-month-old guinea pigs were randomly divided into three groups including the control group (n=10),D-galactose group (model group,n =10),and D-galactose and electroacupuncture group (electroacupuncture group,n =10).The elderly group (n=10) was composed of 18-month-old guinea pigs.The guinea pigs in model group and electroacupuncture group had been subcutaneously injected with D-galactose(300 mg· kg-1· d-1)for 6 weeks.Moreover,the guinea pigs in electroacupuncture group electroacupunctured at Tinggong and Yifeng for 15 minutes half an hour later once a day.After 6 weeks,the ABR threshold of guinea pigs in each group was detected.The mRNA and protein expression of SIR1 and PG-C-1α in auditory cortex of guinea pigs were detected by real -time fluoreacence quantitative PCR and Western Blot.Results There was a significant increase in the ABR threshold of the model group and elderly group (P＜0.001,compared with the control group),decrease in the electroacupuncture group (P＜0.001,compared with the model group),and no significant difference between model group and elderly group(P＞0.05).There was significant decrease in the expression of SIRT1 and PGC-1α in the model groupand elderly group(P＜0.05,compared with the control group),and significant increase at mRNA and protein levels in the electroacupuncture group (P＜0.05,compared with the model group).Conclusion SIRT1/PG-C-1α pathway may play a role in aging process of the auditory cortex in the aged guinea pigs induced by D-galactose,and electroacupuncture at Tinggong and Yifeng may increase the antioxidant capacity of auditory cortex by activating SIRT1/PGC 1α in guinea pigs with age-related hearing loss,thus delaying the aging process of auditory cortex.
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Aim To explore the mechanism of the protective effect of curcumin on advanced glycation end products (AGEs)-induced chondrocyte apoptosis and mitochondrial dysfunction whether by elevating peroxisome proliferators-activated receptor-γ (PPARγ) or not.Methods The ratio of apoptotic cells was assayed by TUNEL;the mitochondrial membrane potential(△Ψm) was evaluated by Rhodamine-123 fluorescence.The ATP content was assayed by related kits.The activity of caspase-3 was detected by spectrophotometry.The expression of cytochrome C,Bax,and Bcl-2 was detected by Western blot.The PPARγ expression was determined by Western blot and real-time PCR;in addition,its activity was assayed by DNA-binding method.Results AGEs could induce chondrocyte apoptosis and up-regulate the levels of cytochrome C and caspase-3.Simultaneously,AGEs decreased the levels of △ Ψm and ATP production.Mitochondrial permeability conversion pore inhibitor cyclosporine A could significantly protect the cells from apoptosis.In addition,both PPARγ specific agonist pioglitazone and curcumin significantly inhibited AGEs-induced chondrocytes apoptosis and mitochondrial dysfunction.However,pretreatment with PPARγ specific inhibitor GW9662 (10 μ mol · L-1) could significantly antagonize the protective effect of curcumin on mitochondrial damage induced by AGEs.Curcumin could also significantly increase PPARγtranscriptional activity induced by AGEs,together with a significant induction of PPARγprotein and mRNA expression.Conclusion Curcumin could effectively protect AGEs-induced chondrocyte mitochondrial dysfunction by upregulating PPARγ,thus protecting chondrocytes from apoptosis.
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To investigate the effects of Gegen Qinlian decoction(GQD) in improving adipocytic insulin resistance(IR) and explore its related molecular mechanism. Diabetic rats models were induced by high glucose and high-fat diet with a small dose of streptozotocin, and after GQD treatment for 3 months, blood biochemical indexes such as fasting blood-glucose(FBG), insulin, glycosylated serum protein(GSP) and HOMA-IRI were detected and assessed. After the total RNA was extracted from the adipose tissue of diabetic SD rats, PPARγ, ADPN, GLUT4, GLUT2, ACACA and ACACB mRNA expression levels were separately detected by qPCR. Then, stable IR-3T3-L1 adipocyte model was built with 1 μmol•L⁻¹ dexamethasone. After the cell viability was detected by CCK-8 assay, 5%, 10% and 15% GQD-containing serum(GQD-CS) were respectively used to treat IR-3T-L1 adipocytes for 24 h. The contents of glucose, nonesterified fatty acid(NEFA) and adiponectin in cell culture supernatants were separately detected whereas the intracellular triglyceride(TG) contents of IR-3T3-L1 adipocytes were also measured. The ADPN, PPARγ and GLUT4 mRNA and protein expression levels were respectively detected by qPCR and Western blot in IR-3T3-L1 adipocytes. Results showed that GQD significantly decreased fasting blood glucose, insulin and GSP(P<0.01), and down-regulated HOMA-IRI(P<0.05) after the high-fat diet/streptozotocin-induced diabetic SD rats were treated for three months, with a good hypoglycemic effect. Moreover, PPARγ, ADPN, GLUT4, GLUT2, ACACA and ACACB mRNA expression levels were significantly elevated in the adipose tissue of GQD-treated diabetic SD rats. The 5%, 10% and 15% GQD-CS significantly increased glucose consumption of IR-3T3-L1 adipocytes at 24 h treatment(P<0.01), significantly decreased the intracellular TG content (P<0.01), and down-regulated NEFA to a certain extent but not significantly. Moreover, GQD-CS significantly up-regulated GLUT4 and ADPN expression. The results indicated that GQD could activate PPARγ to ameliorate adipocytic insulin resistance in the diabetic SD rats and IR-3T3-L1 adipocytes.
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Objective To investigate whether the inhibition of caveolin-1 (Cav-1) phosphorylation will regulate effectively nuclear factor-erythroid 2-related factor (Nrf2) signal pathway and downstream effector molecules and protest against ventilation induced lung injury (VILI) in an animal model in vivo. Methods Ninety male Sprague-Dawley (SD) rats were randomly divided into nine groups (each n = 10): sham group in which rats did not receive ventilation but received tracheotomy; lung protective ventilation (PV) for 1 hour or 2 hours group; mechanical ventilation (MV) at high volume tidal (VT, 40 mL/kg) for 1 hour or 2 hours group; protein tyrosine kinase inhibitor PP2 or rosiglitazone (Rsg) pretreatment + high VT ventilation for 1 hour or 2 hours groups. The two pretreatment groups were given intraperitoneal injection PP2 15 mg/kg or intragastric administration of Rsg 5 mg/kg 1 hour before ventilation respectively. The rats were sacrificed after model reproduction, and bronchoalveolar lavage fluid (BALF) was collected. Pulmonary vascular permeability was measured by Evans blue (EB). The levels of tumor necrosis factor-α (TNF-α), activator protein-1 (AP-1), nuclear factor-κB (NF-κB), and interleukin-8 (IL-8) in BALF were determined by enzyme linked immunosorbent assay (ELISA). Then the lung tissues were collected, the lung wet/dry ratio (W/D) was calculated, the changes in pathology was observed with light microscope, and myeloperoxidase (MPO) activity was determined by colorimetric analysis. Nrf2 mRNA was determined by reverse transcription-polymerase chain reaction (RT-PCR). The expressions of Cav-1 tyrosine residues 14 phosphorylation (pCav-1-Y14), Cav-1, peroxisome proliferators-activated receptor γ (PPARγ) and claudin-5 as well as Nrf2 in cytoplasm and nucleus were determined by Western Blot. The positive expressions of PPARγ and claudin-5 in lung tissues were assayed with immunohistochemistry staining. Results There were no obvious pathological changes in the lung tissue in sham group and PV groups, and there were no significant differences in all the parameters between the two groups either. However, the injury in lung tissue was severe in the high VT groups in which W/D ratio, EB contents, MPO activity, and TNF-α, AP-1, IL-8, NF-κB levels in BALF as well as the protein expressions of Cav-1 and pCav-1-Y14 were significantly higher than those of sham group and PV groups, and the protein expressions of PPARγ and claudin-5 were significant lower than those of sham group and PV groups with a dose-dependent manner; but Nrf2 expressions in cytoplasm and nucleus did not show a statistical increase. After pretreatment of PP2 or Rsg, W/D ratio, MPO activity, EB contents, TNF-α, AP-1, IL-8, and NF-κB in BALF were significantly decreased as compared with those of high VT group, and RT-PCR showed significant up-regulation of Nrf2 mRNA in lung tissues too. Moreover, there was a statistically significant increase in expressed Nrf2 proteins in nucleus in PP2 or Rsg groups as compared with those of high VT groups [Nrf2 in nucleus (gray value): 0.61±0.06, 0.56±0.06 vs. 0.31±0.02 at 1 hour, 0.38±0.06, 0.43±0.07 vs. 0.22±0.03 at 2 hours; all P < 0.05], but no significant difference was found in the expression of Nrf2 protein in the cytoplasm among all groups. The protein expressions of pCav-1-Y14 in PP2 pretreatment groups were significantly lower than those of high VT groups (gray value: 0.89±0.04 vs. 1.48±0.02 at 1 hour, 0.86±0.02 vs. 1.31±0.01 at 2 hours; both P < 0.05); but expressed PPARγ proteins and expressed claudin-5 proteins in PP2 or Rsg pretreatment groups were significantly higher than those of high VT groups [PPARγ (gray value): 0.34±0.07, 0.42±0.13 vs. 0.17±0.07 at 1 hour, 0.38±0.09, 0.33±0.07 vs. 0.16±0.03 at 2 hours; claudin-5 (gray value): 0.33±0.05, 0.38±0.07 vs. 0.14±0.03 at 1 hour; 0.30±0.06, 0.31±0.04 vs. 0.17±0.04 at 2 hours; all P < 0.05]. Conclusions The inhibition of Cav-1-Y14 phosphorylation can increase the expression of Nrf2 in the nucleus, then result in an increase in the protein expressions of PPARγ and claudin-5 of its effector molecules. This effect can reduce the inflammation and capillary permeability of lung tissue in the model of VILI.
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AIM: To investigate the effect of rosiglitazone , a peroxisome proliferators-activated receptor γ(PPARγ) agonist, on the expression of PPARγ, the activation of NF-κB and intestine injury in the rats undergoing ortho-topic autologous liver transplantation ( OALT ) .METHODS: Sprague-Dawley male rats were randomly divided into 4 groups:control group, sham group, OALT group and rosiglitazone (0.3 mg/kg, iv) pretreatment (ROS+OALT) group. The OALT model was established , and the intestinal tissues were collected 8 h after the liver reperfusion .The intestinal tis-sue sections were stained to visualize the damage .The expression of PPARγand NF-κB in the tissues, the concentrations of diamine oxidase (DAO) and fatty acid-binding protein 2 (FABP2) in the serum and the concentration of TNF-αand IL-6 in the tissues were measured .RESULTS:Compared with sham group , the intestinal mucosa of the rats showed obvious pathological injury after liver reperfusion in OALT group and ROS group , the Chiu’s scores of intestinal mucosa was signifi-cantly higher , and the serum concentrations of DAO and FABP 2 increased ( P<0.05 ) .After rosiglitazone pretreatment , the injury of intestinal mucosa of the rats was alleviated , the Chiu’s scores was lower and the serum concentrations of DAO and FABP2 decreased (P<0.05), the PPARγexpression was obviously up-regulated in the intestinal tissues, the nuclear translocation of NF-κB was reduced and the concentrations of IL-6 and TNF-αwere decreased .CONCLUSION: During perioperative period of OALT in rats , the inflammatory responses are obvious .Furthermore, obvious intestinal injury oc-curs .PPARγagonist rosiglitazone obviously up-regulates PPARγexpression and inhibits the inflammation in the intestines , thus protecting against intestinal injury in rats undergoing OALT .