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Objective To investigate the role and regulatory mechanism of stress-inducing protein 1(SESN1)in liver gluconeogenesis of fasting mice.Methods RT-qPCR was used to detect mRNA expression of SESN1 in liver tissues of C57BL/6J mice and primary mouse hepatocytes treated with forskolin(Fsk)and dexamethasone(Dex).HepG2 cells were transfected with plasmids and the effects of SESN1 overexpression on mRNA expression of gluconeogenesis related genes PGC-1α,PEPCK and G6Pase was detected by RT-qPCR.The effect of SESN1 on the promoter activity of PGC-1α in HepG2 cells was studied using a dual luciferase reporter system.The effect of SESN1 on PGC-1α deacetylation was detected by overexpression of SESN1 and inhibition of SIRT1 expression.By knocking down SIRT1 expression,we detected whether it mediated the changes in mRNA levels of SESN1 in-duced gluconeogenesis related genes.Results The mRNA expression of SESN1 was significantly increased in liver tissues of starved C57BL/6J mice and in primary hepatocytes treated with Fsk and Dex(P<0.001).Over-expression of SESN1 in HepG2 cells promoted mRNA expression of PGC-1α,PEPCK and G6Pase(P<0.001)and promoter activity of PGC-1α(P<0.001).Over-expression of SESN1 decreased the acetylation level of PGC-1α in primary hepatocytes.Sirt family inhibitors NAM and shRNA adenovirus interfered with SIRT1 expression respective-ly,and antagonized the deacetylation effect of SESN1 on PGC-1α.The expression of PGC-1α,PEPCK and G6Pase induced by SIRT1 was also significantly impaired(P<0.000 1).Conclusions SESN1 regulates liver gluconeogene-sis in mice with a SIRT1-dependent mechanism.
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Sepsis is the organ dysfunction caused by infection.It is one of the most common critical diseases in clinic.Its morbidity and mortality are increasing year by year，which has seriously threatened human health.Innate immunity is the first line of defense against pathogens.Nature killer（NK）cells are important cells involved in the regulation of innate immunity in sepsis，and can play an important role on the progression of sepsis by secreting cytokines，inducing apoptosis and mediating cytotoxic effects.It has been found that the changes of NK cells in the early stage of sepsis are related to the prognosis of the disease.Therefore，further study on the role of NK cells in sepsis can provide a new idea for the clinical diagnosis and treatment of sepsis，and contribute to the early identification of sepsis and the improvement of prognosis.This review summarized the role and changes of NK cell in sepsis.
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ObjectiveTo observe the effect of the combination of total saponin of Astragali Radix-total alkaloids of Nelumbinis Folium on reversal cholesterol transport （RCT） in hyperlipidemia rats， and to discuss its mechanism. MethodSixty SD rats were randomly divided into control group， high-fat diet group， total saponin of Astragali Radix-total alkaloids of Nelumbinis Folium low （17 mg·kg-1+40 mg·kg-1）， middle （34 mg·kg-1+80 mg·kg-1）， high dose （68 mg·kg-1+160 mg·kg-1） groups and simvastatin （2.1 mg·kg-1） group， with 10 mice in each group. The Hyperlipidemia model was duplicated by feeding rats with a high-fat diet for 6 weeks. From the 3rd week， except for the control group and the high-fat diet group given distilled water， other groups were given corresponding drugs intragastric treatment for 4 weeks. The changes in blood lipid and liver function of rats were detected by an automatic biochemical analyzer. Hematoxylin-eosin （HE） and oil red O staining were used to observe the pathological morphological changes and steatosis of rat liver tissue. The contents of total cholesterol （TC） and total bile acid （TBA） in rat liver tissue and feces were determined by a semi-automatic biochemical analyzer. The mRNA and protein expression levels of peroxisome proliferators-activated receptors γ （PPARγ）， liver X receptors α （LXRα）， ATP-binding cassette transporter G1 （ABCG1） and cholesterol 7α-hydroxylase （CYP7A1） in rat liver tissue were detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot. ResultCompared with the control group， the contents or activities of TC， triglyceride （TG）， low-density lipoprotein cholesterol （LDL-C）， TBA， aspartate aminotransferase （AST）， alanine aminotransferase （ALT） in serum were significantly increased （P<0.01）， and the contents of high-density lipoprotein cholesterol （HDL-C） in the high-fat diet group were significantly decreased （P<0.01）. The hepatocyte was clearly swollen like ballooning degeneration， with a lot of fat vacuoles and red fat droplets. The contents of TC and TBA in liver tissue and feces were significantly increased （P<0.01）， and the mRNA and protein expression levels of PPARγ， LXRα， ABCG1， and CYP7A1 in liver tissue were significantly decreased （P<0.01）. Compared with the high-fat diet group， the contents or activities of TC， TG， LDL-C， TBA， AST， and ALT in the serum of rats in administered groups were significantly decreased （P<0.01）， while the content of HDL-C was significantly increased （P<0.01）. Hepatocyte swelling was significantly reduced， and the ballooning degeneration， fat vacuoles， and red lipid droplets in liver tissue were significantly decreased. The contents of TC and TBA in liver tissue were significantly decreased （P<0.05， P<0.01）， and the contents of TC and TBA in feces were significantly increased （P<0.05， P<0.01）. The mRNA and protein expression levels of PPARγ， LXRα， ABCG1， and CYP7A1 in liver tissue were significantly increased （P<0.05， P<0.01）. ConclusionTotal saponin of Astragali Radix-total alkaloids of Nelumbinis Folium has a positive effect on the prevention and treatment of hyperlipidemia rats， and its mechanism may be related to the activation of PPARγ/LXRα/ABCG1 signaling pathway and regulation of RCT.
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Background Arsenic exposure is a common and important environmental and occupational hazardous factor in China, and arsenic-induced insulin resistance (IR) has attracted widespread attention as a negative health outcome to the population. Objective To explore part of the mechanism of hepatic IR induced by arsenic exposure based on the peroxisome proliferators-activated receptors γ (PPARγ)/ glucose transporter 4 (GLUT4) pathway, and to investigate potential effects of Ginkgo biloba extract (GBE) on hepatic IR induced by arsenic exposure and associated mechanism of action. Methods The target of drug action was predicted by network pharmacology and verified by in vivo and in vitro experiments. In vivo experiments: 48 SPF C57BL/6J male mice were divided into 4 groups, including control group, 50 mg·L−1 NaAsO2 model group (NaAsO2), 50 mg·L−1 NaAsO2+10 mg·kg−1 GBE intervene group (NaAsO2+GBE), and 10 mg·kg−1 GBE group (GBE), 12 mice in each group. The animals were given free access to purified water containing 50 mg·L−1 NaAsO2, or given intraperitoneal injection of normal saline containing 10 mg·kg−1 GBE once per week. After 6 months of exposure, blood glucose detection, intraperitoneal glucose tolerance test (IPGTT), and insulin tolerance test (ITT) were performed. Serum and liver tissues were collected after the mice were neutralized, liver histopathological sections were obtained, serum insulin levels, liver tissue glycogen content, glucose content were detected by enzyme linked immunosorbent assay (ELISA), and the expression of PPARγ and GLUT4 proteins was detected by Western blot (WB). In vitro experiments: HepG2 cells were divided into 4 groups, including control group, 8 μmol·L−1 NaAsO2 group (NaAsO2), 8 μmol·L−1 NaAsO2 + 200 mg·L−1 GBE intervene group (NaAsO2+GBE), and 200 mg·L−1 GBE group (GBE). The levels of glycogen and glucose were detected by ELISA, and the expression of PPARγ and GLUT4 proteins was detected by WB. Results A strong binding effect between GBE and PPARγ was revealed by network pharmacology. In in vivo experiments, the NaAsO2 group exhibited an elevated blood glucose compared to the control group, and the NaAsO2+GBE group showed a decreased blood glucose compared to the NaAsO2 group (P<0.01). The histopathological sections indicated severe liver structural damage in the arsenic exposure groups (NaAsO2 group and NaAsO2+GBE group), with varying staining intensity, partial liver cell necrosis, and diffuse red blood cell appearance. Both results of in vitro and in vivo experiments showed a decrease in glycogen synthesis and glucose uptake in the NaAsO2 groups compared to the control groups, which was alleviated in the NaAsO2+GBE group (P<0.01). The results of WB revealed inhibited PPARγ expression and reduced GLUT4 levels on the cell membrane, and all these changes were alleviated in the NaAsO2+GBE group (P<0.01). Conclusion This study findings suggest that GBE antagonizes arsenic exposure-induced hepatic IR by regulating the PPARγ/GLUT4 pathway, indicating that GBE has a protective effect on arsenic exposure-induced hepatic IR, and PPARγ may be a potential therapeutic target for arsenic exposure-induced hepatic IR.
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Peroxisome proliferator-activated receptors (PPAR) are members of the nuclear estrogen receptor family, and they are involved in a variety of physiological and pathological processes in the human body and play important roles in cellular metabolism, inflammation, and cancer. At present, there are three known subtypes of PPAR, i.e., α, β/δ, and γ. Studies have shown that PPARs are highly expressed in the liver and are widely involved in various physiological and pathological activities such as liver energy metabolism, oxidative stress, and inflammation, and they are also closely associated with the progression of liver diseases. This article reviews the role of PPAR in common liver diseases such as viral hepatitis, metabolic associated fatty liver disease, cholestatic liver disease, liver fibrosis, and primary liver cancer, and the current status of their application in the treatment of liver diseases.
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Peroxisome proliferator-activated receptors (PPARs) are widely involved in lipid metabolism, glucose metabolism, cell growth and differentiation, and inflammation in the human body. PPARγ agonists can inhibit skin inflammatory response, protect epidermal barrier function, and repair skin injury. This review summarizes various roles of PPARγ in skin biology, and discusses its function in skin diseases, such as psoriasis and skin tumors.
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Objective:To analyze the clinical value of relative expression of peroxisome proliferators-activated receptors mRNA (PPAR mRNA) and protein in placental tissues of pregnant women with gestational diabetes mellitus (GDM) .Methods:52 pregnant women (the study group) with GDM who were admitted to our hospital from Jan. 2019 to Nov. 2020 and 50 normal pregnant women (the control group) who underwent physical examination and gave birth during the same period were selected. Serum samples were collected to detect the islet cell function. Placental tissue samples of the two groups of pregnant women were collected after delivery to measure the content of PPARγmRNA and protein in placental tissues and adipose tissues. The correlations between PPARγ in placental, adipose tissues of GDM pregnant women with islet cell function were analyzed.Results:The HOMA-IR level of the study group was higher than that of the control group [ (3.45±1.06) % vs (1.40±0.43) %], and the HOMA-β level [ (126.59±23.59) % vs (153.12±27.34) %] was lower than that of the control group ( P<0.05). The PPARγ mRNA [ (1.65±0.21) vs (0.93±0.16) ] and PPARγ protein content [ (1.89±0.51) vs (1.02±0.23) ] of placenta tissue in the study group were higher than those in the control group ( P<0.05), the PPARγmRNA [ (0.49±0.12) vs (1.15±0.26) ] and PPARγ protein content [ (0.43±0.11) % vs (0.96±0.22) %] in adipose tissue were lower than those of the control group ( P<0.05). Adipose tissue PPARγ mRNA and PPARγ protein were negatively correlated with HOMA-IR ( r=-0.45, -0.33), and positively correlated with HOMA-β ( r=0.47, 0.43) ( P<0.05) ; placental tissue PPARγ mRNA and PPARγ protein were positively correlated with HOMA-IR ( r=0.40, 0.37), and negatively correlated with HOMA-β ( r=-0.44, -0.35) ( P<0.05) . Conclusion:The levels of PPARγ mRNA and PPARγ protein are low expressed in adipose tissue of GDM patients, and highly expressed in placental tissues, and PPARγ expression is significantly correlated with HOMA-IR and HOMA-β, which can provide new clinical treatment for GDM Target and direction.
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Objective:To explore the role of SUMOylaiton of peroxisome proliferator-activated receptor γ (PPARγ) in diabetes mellitus prompted inflammation and atherosclerosis in vascular and endothelial cells.Methods:From September 2014 to January 2017, 32 Sprague-Dawley rats in 14 weeks-old were divided into sham operated group, artery injured without diabetes group, artery injured with diabetes group and ubiquitin-conjugating enzyme 9 (UBC9) transfection group (Group D) by random digits table method with 8 rats each. Model of type 1 diabetes mellitus (T1DM) and rat carotid artery balloon injury was made in the assigned group. One rat was excluded because of model failure in each group. Systolic and diastolic common carotid artery diameter and intimal thickness of injured and healthy common carotid artery were evaluated by vascular ultrasound, and the standardized common carotid artery diastolic diameter (sCADD) was calculated. Histological tests and immunohistochemical staining were performed to evaluate intimal hyperplasia, and the ratio of intimal area to media area was calculated when the media area was equal. Human umbilical vein endothelial cells (HUVEC) were cultured 24 h in high glucose medium with different duration and concentration, and the expression levels of interleukin (IL)-8 and IL-1β mRNA were determined by real time reverse transcription polymerase chain reaction (RT-PCR), the expression level of UBC9 was determined by Western blot method, SUMOylation assay kit was used to evaluate SUMOylation of PPARγ. HUVEC was cultured in vitro and PPAR was stimulated by high glucose at different concentrations and different times PPARγ SUMOylation level. UBC9 was overexpressed by lentivirus in vivo and in vitro, and the PPARγ SUMOylation level was detected.Results:The intimal thickness, intimal area and ratio of intimal area to media area 8 weeks after carotid artery injuring in sham operated group, artery injured without diabetes group and artery injured with diabetes group were increased respectively: (0.026 ± 0.018), (0.084 ± 0.007) and (0.264 ± 0.022) mm; (0.18 ± 0.09) × 10 6, (0.32 ± 0.06) × 10 6 and (1.64 ± 0.22)×10 6 μm 2; 0.345 ± 0.073, 0.570 ± 0.080 and 2.710 ± 0.220, the sCADD was decreased respectively: 0.903 ± 0.084, 0.800 ± 0.071 and 0.330 ± 0.036, and there were statistical differences ( F = 10.40, 9.40, 8.20 and 8.60; P<0.05). After HUVEC was cultured in high glucose for 24 h, the IL-8 mRNA at sugar concentrations of 10, 20 and 40 mmol/L was 1.00 ± 0.11, 3.57 ± 0.22 and 4.07 ± 0.40, the IL-1β mRNA was 1.00 ± 0.07, 3.32 ± 0.29 and 5.13 ± 0.19, and there were statistical differences ( F = 73.05 and 205.80, P<0.05). The level of PPARγ SUMOylation and UBC9 in artery injured with diabetes group were significantly lower than those in artery injured without diabetes group (0.46 ± 0.25 vs. 1.00 ± 0.21 and 0.45 ± 0.02 vs. 1.00 ± 0.07), and there were statistical differences ( P<0.05); there was no statistical difference in PPARγ between 2 groups (0.94 ± 0.07 vs. 1.00 ± 0.04, P>0.05). The UBC9 and PPARγ SUMOylation at sugar concentrations of 0, 10, 20 and 40 mmol/L were decreased respectively (0.99 ± 0.05, 0.80 ± 0.06 and 0.62 ± 0.05; 1.00 ± 0.05, 0.57 ± 0.13 and 0.55 ± 0.08), and there were statistical differences ( F = 21.02 and 14.31, P<0.05); there was no statistical difference in PPARγ (1.00 ± 0.03, 0.90 ± 0.04 and 0.91 ± 0.05; F = 3.11, P>0.05). In HUVEC cultured in high glucose medium (20 mmol/L) for 6, 12, 24 and 48 h, the UBC9 and PPARγ SUMOylation were downregulated progressively (1.00 ± 0.09, 0.75 ± 0.05, 0.70 ± 0.08, 0.38 ± 0.04 and 0.35 ± 0.03; 1.00 ± 0.03, 0.86 ± 0.01, 0.59 ± 0.01, 0.51 ± 0.11 and 0.35 ± 0.08), and there were statistical differences ( F = 36.06 and 33.13, P<0.05); but there was no statistical difference in PPARγ (1.00 ± 0.03, 1.14 ± 0.02, 1.18 ± 0.17, 0.98 ± 0.01 and 1.04 ± 0.05; F = 1.90, P>0.05). After overexpression of UBC9 in rats with diabetes, histological analysis showed that UBC9 in artery injured without diabetes group, artery injured with diabetes group and UBC9 transfection group was 1.53 ± 0.18, 1.00 ± 0.22 and 3.62 ± 0.35, there was statistical difference ( F = 5.64, P<0.05). Ultrasonic test results show that in artery injured without diabetes group, artery injured with diabetes group and UBC9 transfection group intimal thickness was increased respectively: (0.077 ± 0.015), (0.216 ± 0.007) and (0.125 ± 0.014) mm, and there was statistical difference ( F = 27.18, P<0.05). Histological analysis showed that intimal area in artery injured without diabetes group, artery injured with diabetes group and UBC9 transfection group was (0.335 ± 0.066) ×10 6, (1.053 ± 0.103) ×10 6 and (0.544 ± 0.040) ×10 6 μm 2, the ratio of intimal area to media area was 0.63 ± 0.063, 2.03 ± 0.052 and 0.93 ± 0.100, there were statistical differences ( F = 13.58 and 53.96, P<0.05). Conclusions:Diabetes mellitus could inhibit the PPARγ SUMOylaiton and prompt inflammation and atherosclerosis in vascular and endothelial cells. Upregulation of PPARγ SUMOylaiton though UBC9 overexpressioncould play a protecting role in diabetes mellitus prompted atherosclerosis.
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Nonalcoholic fatty liver disease (NAFLD) is the manifestation of metabolic syndrome in the liver and is closely associated with glucose and lipid metabolism disorders, and they interact as both cause and effect of each other, with insulin resistance as the common pathogenesis. About three quarters of patients with obesity and type 2 diabetes mellitus have NAFLD, and current guidelines recommend reducing metabolic risk factors and treating metabolic syndrome as the primary treatment goals for patients with NAFLD. Although there are no approved drugs for the treatment of NASH at present, the hypoglycemic drugs on the market can bring varying degrees of benefits to NAFLD patients while lowering blood glucose. This article reviews the prospects of three types of hypoglycemic drugs on the market (thiazolidinediones, GLP-1 receptor agonists, and SGLT-2 inhibitors) in the treatment of NAFLD.
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This study investigated the effects of ginkgolide B on the long-chain fatty acid metabolism-related enzyme protein peroxisome proliferators-activated receptors α (PPARα), long-chain specific acyl-CoA dehydrogenase (LCAD), carnitine palmitoyl transterase-1 (CPT-1), and acyl coenzyme A oxidase 1 (ACOX1) expression in the liver of rats with non-alcoholic fatty liver disease (NAFLD). All the animal welfare and experimental procedures are in accordance with the regulations of the Animal Ethics Committee of Yunnan University of Traditional Chinese Medicine. After successfully building the rat model of non-alcoholic abnormal liver disease, the rats were divided into the model group, the simvastatin group, and the low-dose, middle-dose, and high-dose groups of ginkgolide B according to random number method, and were given corresponding drug treatment 4 weeks. We detected liver pathological indicators and determined blood lipids, transaminase and anti-oxidation indexes. Western blot and RT-PCR assays were used to detect the protein and mRNA levels of PPARα, LCAD, CPT-1, and ACOX1 in livers. The results showed that: ① the liver histopathology showed that the liver slices of the model group had obvious structural disorder, the nucleus was squeezed, and there were obvious fat vacuoles. The treatment groups improved significantly compared with the model group; ② compared with the normal group, the liver function and blood lipid indexes of the model group increased significantly, while the anti-oxidation indexes decreased significantly. Compared with the model group, each treatment groups were significantly improved; ③ compared with the normal group, the protein and mRNA expression levels of PPARα, ACOX1, CPT-1, and LCAD in the model group were significantly reduced, compared with the model group, those indexes in the treatment groups were significantly up-regulated. This study found that ginkgolide B could regulate the expression of long-chain fatty acid metabolism-related proteins PPARα, ACOX1, CPT-1, and LCAD, meanwhile improve the body's antioxidant capacity, thereby reduce blood lipids, further improve liver function and protect the liver.
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Traumatic brain injury (TBI) triggers the activation of the endogenous coagulation mechanism, and a large amount of thrombin is released to curb uncontrollable bleeding through thrombin receptors, also known as protease-activated receptors (PARs). However, thrombin is one of the most critical factors in secondary brain injury. Thus, the PARs may be effective targets against hemorrhagic brain injury. Since the PAR1 antagonist has an increased bleeding risk in clinical practice, PAR4 blockade has been suggested as a more promising treatment. Here, we explored the expression pattern of PAR4 in the brain of mice after TBI, and explored the effect and possible mechanism of BMS-986120 (BMS), a novel selective and reversible PAR4 antagonist on secondary brain injury. Treatment with BMS protected against TBI in mice. mRNA-seq analysis, Western blot, and qRT-PCR verification in vitro showed that BMS significantly inhibited thrombin-induced inflammation in astrocytes, and suggested that the Tab2/ERK/NF-κB signaling pathway plays a key role in this process. Our findings provide reliable evidence that blocking PAR4 is a safe and effective intervention for TBI, and suggest that BMS has a potential clinical application in the management of TBI.
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Objective:To evaluate the role of peroxidase proliferator-activated receptor γ (PPARγ)/nuclear factor kappa B (NF-κB) signaling pathway in sodium butyrate-induced reduction of intestinal ischemia-reperfusion (I/R) injury in mice.Methods:Thirty-two SPF-grade healthy adult male C57BL/6J mice, aged 7-9 weeks, weighing 20-25 g, were divided into 4 groups ( n=8 each) using a random number table method: sham operation group (Sham group), intestinal I/R group (IIR group), sodium butyrate group (NaB group) and PPARγ inhibitor GW9662 group (GW9662 group). The model of intestinal I/R was established by occlusion of superior mesenteric artery for 45 min followed by 2-h reperfusion in anesthetized animals.GW9662 2 mg/kg was intraperitoneally injected at 1 h before ischemia in GW9662 group, and sodium butyrate 500 mg/kg was intraperitoneally injected at 30 min before ischemia in NaB and GW9662 groups.Blood samples were obtained via cardiac puncture at 2 h of reperfusion, and the animals were then sacrificed.The intestinal tissues were removed for determination of diamine oxidase (DAO), tumor necrosis factorα (TNF-α) and interleukins 6 (IL-6) concentrations in serum (by enzyme-linked immunosorbent assay) and the expression of PPAR and NF-κB p65 (by Western blot). The damage to intestinal mucous membrane was assessed and scored according to Chiu. Results:Compared with group Sham, the Chiu′s score was significantly increased, levels of DAO, TNF-α and IL-6 in serum and intestinal tissues were increased, expression of PPARγ was down-regulated, and expression of NF-κB p65 was up-regulated in group IIR ( P<0.05). Compared with group IIR, the Chiu′s score, levels of DAO, TNF-α and IL-6 in serum and intestinal tissues were decreased, and expression of PPARγ was up-regulated in group NaB, and expression of NF-κB p65 was up-regulated in NaB and GW9662 groups ( P<0.05). Compared with group NaB, the Chiu′s score, levels of DAO, TNF-α and IL-6 in serum and intestinal tissues were increased, and expression of PPARγ was down-regulated, and expression of NF-κB p65 was up-regulated in group GW9662 ( P<0.05). Conclusion:The mechanism by which sodium butyrate reduces intestinal I/R injury may be related to activating PPARγ/NF-κB signaling pathway and inhibiting inflammatory responses in mice.
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Objective:To investigate the effect and mechanism of ginsenoside Rg1（G-Rg1）in ameliorating lipid uptake and oxidation in HepG2 cells induced by free fatty acids (FFA). Method:HepG2 cells were divided into normal group, model group，low-dose ginsenoside Rg1 group (25 μmol·L-1) and high-dose G-Rg1 group (50 μmol·L-1). HepG2 cells were treated with 1 mmol·L-1 free fatty acid for 24 h to construct the NAFLD cell model, and then treated with 25，50 μmol·L-1 G-Rg1 for 24 h. The effect of G-Rg1 on HepG2 cell activity was determined by cell counting kit-8（CCK-8） assay. The level of triglyceride (TG) was detected by micro method. The accumulation of lipid droplets was observed by oil red O staining. Quantitative real-time fluorescence polymerase chain reaction (Real-time PCR) and Western blot were used to detect the alterations of key genes and proteins relating to lipid uptake and metabolism. Result:Compared with the normal group, the intracellular TG level and the absorbance of the oil red O staining in the model group were significantly increased (P<0.01). Compared with the model group, G-Rg1 reduced TG and lipid deposition were significantly reduced (P<0.01).Results of Real-time PCR and Western blot showed that compared with normal group, model group peroxisome proliferators-activated receptors gamma（PPARγ），fatty acid binding protein 1（FABP1），fatty acid transport protein 2/5（FATP2/5）and fatty acid translocase（CD36）expressions increased（P<0.05），whereas peroxisome proliferators-activated receptors α（PPARα），carnitine palmitoyltransferase 1（CPT1）and peroxisomal acyl-coenzyme A oxidase 1（ACOX1）expressions decreased（P<0.05）. Compared with the model group, the expressions of PPARγ, FABP1, FATP2, FATP5 and CD36 in the G-Rg1 group were decreased (P<0.05，P<0.01), while the expressions of PPARα, CPT1 and ACOX1 were increased (P<0.05，P<0.01). Conclusion:G-Rg1 can ameliorate lipid deposition in NAFLD cell model by reducing lipid uptake and increasing lipid oxidation.
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@#[Abstract] Objective: To investigate the mechanisms of carnitine palmitoyltransferase 1c (CPT1c) expression to affect the proliferation and apoptosis of human thyroid papillary cancer B-CPAP cells through the AMP-dependent/activated protein kinase (AMPK) pathway in the low glucose and hypoxic conditions. Methods: Firstly,humanthyroidpapillarycarcinomaB-CPAP cells were cultured under normal condition or low glucose and hypoxic condition respectively, followed with the treatment of AMPK inhibitor compound C. Western blotting was used to detect the expressions of AMPK, p-AMPK, peroxisome proliferator-activated receptor α (PPARα) and CPT1c; the proliferation and apoptosis were detected by CCK-8 and Flow cytometry, respectively. Then PPARα-siRNA was synthesized and transfected into B-CPAP cells to knock down PPARα, and then the cells were cultured under normal or low glucose and hypoxic condition respectively.Above indicators were also detected to verify the regulation of PPARα on CPT1c. Finally, the human luciferase reporter plasmid containing CPT1c gene promoter was constructed, and the effect of PPARα on the activity of CPT1c promoter luciferase activity was observed by immunofluorescence. Results: The expressions ofAMPK, p-AMPK, PPARα and CPT1c were significantly increased in B-CPAP cells under low glucose and hypoxia condition (P<0.05 or P<0.01), while cell proliferation and apoptosis rate did not change significantly (P>0.05). After the treatment of AMPK inhibitor compound C, the expressions of p-AMPK, PPARα and CPT1c in low glucose and hypoxia group were significantly decreased (P<0.05 or P<0.01), the inhibitory rate on cell proliferation and apoptosis rate were significantly increased (P<0.05). However, the change range was smaller than that in the normal culture + compound C group (P<0.05).After PPARα knockdown, the expressions ofAMPK, p-AMPK, PPARα and CPT1c in cancer cells cultured under normal conditions were significantly decreased (P<0.05 or P<0.01), and the inhibitory rate on cell proliferation and apoptosis rate were significantly increased (P<0.05). While under low glucose and hypoxia condition, the expression of CPT1c in cells after transfection was significantly decreased (P<0.05), and the inhibition rate on cell proliferation and the apoptosis rate were significantly increased (P<0.05); However, the change range was still lower than that of normal condition group after transfection (P<0.05).After PPARα overexpression, the ratio of fluorescence in the empty vector group was not significantly different from that of the blank group (P>0.05), and the ratio of fluorescence was significantly increased in PPARα over-expression group (P<0.05). Conclusions: AMPK can increase the expression of PPARα to promote the expression of CPT1c in thyroid cancer B-CPAP cells under low glucose and hypoxia conditions, thereby inhibiting cell apoptosis and maintaining cell proliferation ability.
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Aim of Study: This study is to investigate the effects of a novel peroxisome proliferator-activated receptor (PPAR) α/γ dual agonist TZD18 on cell growth, apoptosis, caspase activity, mitochondrial membrane potential, cytochrome c release, and apoptotic-related protein expression in MKN-45 cells. Materials and Methods: 3-(4, 5-dimethylthiazolyl)-2,5-diphenyltetrazolium bromide assay against various human cancer cell lines was performed to investigate the whether TZD18 could in reduce the proliferation rates of cancer cells. The percentages of apoptotic cells and mitochondrial membrane potential level were determined by flow cytometry. The subcellular localization of cytochrome c was examined by immunofluorescence microscopy. Western blotting assay was performed to reveal the expression of apoptosis-related proteins. Results: The results showed that the administration of TZD18 could inhibit the growth of MKN-45 cells in a dose- and time-dependent manner. In addition, the apoptotic ratio increased sharply along with a significant increase of caspase activities, mitochondrial membrane potential, and cytochrome c release following TZD18 exposure. The expression of Bax and p27kip1 increased significantly, whereas the expression level of Bcl-2 protein was downregulated. Conclusion: These results indicated that the administration of PPAR α/γ agonist TZD18 may inhibit cell growth by inducing the apoptotic process in MKN-45 cells
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Objective: To study the effect of Buyang Huanwu Tang on myocardial energy metabolism in rats with diastolic heart failure (DHF) based on adenosine monophosphate (AMP)-activated protein kinase (AMPK)/peroxisome proliferators-activated receptors α (PPARα) signaling pathway,and investigate its mechanism of action.Method: The 48 SD rats were randomly divided into sham operation group and model group.DHF rat model was established by abdominal aorta constriction method.The successfully modeled rats were randomly divided into model group,Buyang Huanwu Tang group (12.72 g·kg-1·d-1),metoprolol tartrate group (0.004 5 g·kg-1·d-1),with corresponding drugs in each group by intragastric administration.The sham operation group and model group were given with equal amount of deionized water,once a day.After 8 weeks of continuous drug intervention,the contents of adenosine monophosphate (AMP),adenosine diphosphate (ADP) and adenosine triphophate (ATP) in peripheral blood of rats were determined by enzyme linked immunosorbent assay (ELISA).The changes of myocardial mitochondrial ultrastructure were detected by electron microscope.The protein expression levels of AMPK,PPARα and peroxisome proliferator-activated receptor-γ coactivator-1α(PGC-1α) in rat myocardium were detected by Western blot.Result: As compared with sham operation group,the contents of AMP and ADP in model group were increased significantly,and ATP content was decreased significantly (PPPPα and PGC-1α protein in the model group were decreased significantly (Pα and PGC-1α protein in Buyang Huanwu Tang group and metoprolol tartrate group were increased significantly (PConclusion: Buyang Huanwu Tang may improve the energy metabolism of the failed heart and delay the progression of heart failure by improving the structure and function of mitochondria,activating AMPK and up-regulating the expression of AMPK/PPARα signaling pathway.
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Objective@#To explore the regulatory mechanism of E2F1 transcription factor on M2 macrophages in full-thickness skin defect wounds of mice.@*Methods@#E2F1 gene knockout heterozygotes C57BL/6 mice and wild-type C57BL/6 mice were introduced and self-reproduced. Two weeks after birth, E2F1 gene knockout homozygotes mice and wild-type mice were identified by polymerase chain reaction (PCR). Twelve identified 6-8 weeks old male E2F1 gene knockout homozygotes C57BL/6 mice and wild-type C57BL/6 mice were selected respectively according to the random number table and set as E2F1 gene knockout group and wild-type group. A full-thickness skin defect wound was made on the back of each mouse. On post injury day (PID) 2 and 7, 6 mice in each group were selected according to the random number table and sacrificed, and the wound tissue was excised. The expression of CD68 and CD206 double positive M2 macrophages was observed by immunofluorescence method, and the percentage of CD206 positive cells was calculated. The protein expression of CD206 was detected by Western blotting. The mRNA expression of arginase 1 was detected by real-time fluorescent quantitative reverse transcription PCR (RT-PCR). Wound tissue specimens of the two groups on PID 7 were obtained, and the protein and mRNA expressions of peroxisome proliferator-activated receptor gamma (PPAR-γ) were detected by Western blotting and real-time fluorescent quantitative RT-PCR respectively. The above-mentioned experiments were repeated four times. Three specimens of wound tissue of mice in wild-type group on PID 7 were obtained to detect the relationship between E2F1 and PPAR-γ by co-immunoprecipitation and Western blotting, and this experiment was repeated two times. Data were processed with unpaired t test.@*Results@#The size of PCR products of E2F1 gene knockout homozygotes C57BL/6 mice and wild-type C57BL/6 mice were 227 and 172 bp respectively, which were the same as those of the designed DNA fragments. On PID 2 and 7, the number of CD68 and CD206 double positive M2 macrophages in the wound tissue of mice in E2F1 gene knockout group was more than that of wild-type group, and the percentages of CD206 positive cells in the wound tissue of mice in E2F1 gene knockout group were (0.234±0.032)% and (0.584±0.023)% respectively, which were significantly higher than (0.129±0.017)% and (0.282±0.071)% of wild-type group (t=3.29, 3.54, P<0.05). On PID 2 and 7, the protein expression of CD206 in the wound tissue of mice in E2F1 gene knockout group were 1.00±0.23 and 1.63±0.26 respectively, which were significantly higher than 0.43±0.06 and 0.97±0.08 of wild-type group (t=2.41, 2.45, P<0.05). On PID 2 and 7, the mRNA expressions of arginase 1 in the wound tissue of mice in E2F1 gene knockout group were 0.482±0.105 and 0.195±0.031 respectively, which were significantly higher than 0.163±0.026 and 0.108±0.017 of wild-type group (t=3.04, 2.86, P<0.05). On PID 7, the protein and mRNA expressions of PPAR-γ in the wound tissue of mice in E2F1 gene knockout group were 0.61±0.12 and 0.51±0.13 respectively, which were significantly higher than 0.20±0.04 and 0.20±0.04 of wild-type group (t=3.36, 2.86, P<0.05). On PID 7, detection of the wound tissue of mice in wild-type group showed that PPAR-γ had unidirectional effect on E2F1.@*Conclusions@#E2F1 transcription factor affects the polarization of M2 macrophages by inhibiting the expression of PPAR-γ, thereby inhibiting the healing process of full-thickness skin defect wounds in mice.
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OBJECTIVE To invest igate the therapeutic effect and mechanism of PPAR gamma agonist on allergic rhinitis(AR) in mice. METHODS AR murine model was established by OVA sensitization and challenge. The behavior observation was used to understand the improvement effect of PIO on AR symptoms. The morphological characteristics of nasal tissues were observed by HE staining. The total RNA was extracted to investigate the level of mRNA expression of Foxp3, T-bet and GATA-3. The changes of CD4+Foxp3+T cells in spleen of mice were analyzed by flow cytometry. RESULTS BALB/c mice received OVA sensitization followed by OVA intranasal challenge, the frequencies of sneezing and nose-scratching increased signif icantly in AR group compared with control group. The frequencies decreased significantly in PIO group, compared with AR group. The continuity of nasal mucosa ciliated columnar epithelium in AR group was destroyed and appeared to be repaired in PIO group. Inflammatory cells infiltration was also markedly decreased by PIO treatment. PIO significantly increased the expression of Foxp3 mRNA(P ＜0.001) compared with AR and control group. There was no significant difference in T-bet between PIO group and AR group, but the expression of GATA-3 mRA in PIO group was significantly lower than AR group. The proportion of CD4+Foxp3+T cells in AR group (4.43％±0.25％) decreased compared with control group (5.19％±0.39％) (P ＜0.001). PIO treatment induced production of Tregs (6.35％±0.37％) compaered with control group(P ＜0.001). CONCLUSION PPAR-gamma agonist can effectively alleviate allergic symptoms of mice and regulate the balance of Th1/Th2. The role of PPAR gamma agonist in the treatment of AR may be the amplification of Tregs by promoting Foxp3 expression.
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Peroxisome proliferator activated receptors (PPARs) are ligand activated nuclear transcription factors and one of the members of the non steroidal nuclear receptor superfamily.It can be divided into PPAR alpha,PPAR beta / delta and PPAR gamma three subtypes according to the different of its structure and function.Previous studies showed that PPARs participated in biochemical reactions and the regulation of other important biological activities such as lipogenesis,glucose metabolism,inflammation,insulin sensitivity and so on.Recent researches showed that PPARs also had effect of anti-fibrosis,protecting ischemia-reperfusion injury and inhibiting the growth and differentiation of tumor cells.This article reviewed the recent research progress of PPARs in these liver diseases.
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Objective To investigate the role of peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1α) in high-fat diet-induced insulin resistance (IR) and mitochondrial degeneration in skeletal muscle.Methods Wistar rats were randomly divided into a normal chow (NC)group (n =10) and a high-fat diet(HFD)group (n =10).After eight weeks,fasting plasma glucose(FBG) levels,fasting insulin(FINS) levels and glucose infusion rates (GIR) in each group were measured (n=3).Samples of rat skeletal muscle were harvested.L6 myoblasts were divided into a control group,a PA group (cells were cultured in palmitic acid),a pcDNA3 group (cells were transfected by the plasmid pcDNA3)and a pcDNA3-PGC1α group (cells were transfected by the PGC1α-overexpressiorn plasmid).Expression levels of PGC1α,nuclear respiratory factor 1 (NRF1),uncoupling protein 3 (UCP3),and cytochrome C oxidase 1 (COX1) in skeletal muscle and L6 myoblasts were measured by real-time PCR and Western blotting.Results Levels of FBG and insulin were higher and those of GIR were lower in the HFD group than in the NC group,(6.0±0.7)mmol/L vs.(5.0±0.4)mmol/L、(23.3±3.0)mU/L vs.(12.9±1.8)mU/L、(14.2±1.8)％ vs.(22.6±2.4)％ (t =-3.578,-6.679,6.265,respectively,P ＜ 0.05).Expression levels of PGC1α,NRF1,UCP3,and COX1 were down in skeletal muscle in the HFD group compared with those in the NC group(P ＜0.05).In L6 myoblasts cultured with palmitic acid,the expression of PGC1 α,NRF1,UCP3,and COX1 were down compared with their expression in the NC group (P ＜ 0.05).However,the altered expression of PGC1α,NRF1,UCP3,and COX1 was reversed by transfecting with PGC1α-overexpression plasmids (F =30.079,96.883,226.772,respectively,P ＜ 0.001).Conclusions High-fat diets can lead to insulin resistance and decreased expression of mitochondrial energy metabolism-related genes,which can be reversed by PGC1α.The decreased expression of PGC1α may mediate the high-fat diet-induced mitochondrial dysfunction and IR.