LY294002 Enhances Inhibitory Effect of Gemcitabine on Proliferation of Human Pancreatic Carcinoma PANC-1 Cells

Phosphatidylinositide 3-kinase （PI3K）/protein kinase B （PKB, Akt） pathway plays a major role in proliferation and survival of many types of cells. The inhibitory effect of LY294002, widely ap- plied as an inhibitor of PI3K, in combination with gemcitabine on proliferation of PANC-1 ceils was investigated. The expression of PI3K, phosphorylated AM （p-Akt） and multidrng-resistance like protein （MRP） in normal pancreas tissues, chronic pancreatitis tissues and pancreatic carcinoma tissues was de- tected. The effects of LY294002 combined with gemcitabine on proliferation of PANC-1 cells and pro- tein levels of p-Akt and MRP were detected. The results showed that the positive expression rate of PI3K, p-Akt and MRP in pancreatic carcinoma tissues was significantly higher than that in normal pan- creas tissues and chronic pancreatitis tissues （P〈0.01 and P〈0.05 respectively）. LY294002 could effec- tively enhance the inhibitory effect of gemcitabine on proliferation of PANC-1 cells. Furthermore, Western blotting revealed that LY294002 combined with gemcitabine reduced the protein levels of p-Akt and MRP, which contributed to the inhibition of proliferation. It is concluded that LY294002 in combination with gemcitabine may represent an alternative therapy for pancreatic carcinoma.

Effect of moxibustion on mTOR-mediated autophagy in rotenone-induced Parkinson's disease model rats

Defects in autophagy-mediated clearance of α-synuclein may be one of the key factors leading to progressive loss of dopaminergic neurons in the substantia nigra. Moxibustion therapy for Parkinson’s disease has been shown to have a positive effect, but the underlying mechanism remains unknown. Based on this, we explored whether moxibustion could protect dopaminergic neurons by promoting autophagy mediated by mammalian target of rapamycin （mTOR）, with subsequent elimination of α-syn. A Parkinson’s disease model was induced in rats by subcutaneous injection of rotenone at the back of their necks, and they received moxibustion at Zusanli （ST36）, Guanyuan （CV4）and Fengfu （GV16）, for 10 minutes at every point, once per day, for 14 consecutive days. Model rats without any treatment were used as a sham control. Compared with the Parkinson’s disease group, the moxibustion group showed significantly greater tyrosine hydroxylase immunoreactivity and expression of light chain 3-II protein in the substantia nigra, and their behavioral score, α-synuclein immunoreactivity,the expression of phosphorylated mTOR and phosphorylated ribosomal protein S6 kinase （p-p70S6K） in the substantia nigra were significantly lower. These results suggest that moxibustion can promote the autophagic clearance of α-syn and improve behavioral performance in Parkinson’s disease model rats. The protective mechanism may be associated with suppression of the mTOR/p70S6K pathway.

Effects of Lactobacillus plantarum on gut barrier function in experimental obstructive jaundice

AIM:To investigate the mechanisms of Lactobacillus plantarum(L.plantarum)action on gut barrier in preoperative and postoperative experimental obstructive jaundice in rats.METHODS:Forty rats were randomly divided into groups of sham-operation,bile duct ligation(BDL),BDL +L.plantarum,BDL+internal biliary drainage(IBD),and BDL+IBD+L.plantarum.Ten days after L.plantarum administration,blood and ileal samples were collected from the rats for morphological examination,and intestinal barrier function,liver function,intestinal oxidative stress and protein kinase C(PKC)activity measurement.The distribution and expression of the PKC and tight junction(TJ)proteins,such as occludin,zonula occludens-1,claudin-1,claudin-4,junction adhesion molecule-A and F-actin,were examined by confocal laser scanning microscopy,immunohistochemistry,Western blotting,real-time fluorescent quantitative polymerase chain reaction assay.RESULTS:L.plantarum administration substantially restored gut barrier,decreased enterocyte apoptosis,improved intestinal oxidative stress,promoted the activity and expression of protein kinase(BDL vs BDL+L.plantarum,0.295±0.007 vs 0.349±0.003,P<0.05;BDL+IBD vs BDL+IBD+L.plantarum,0.407±0.046 vs 0.465±0.135,P<0.05),and particularly enhanced the expression and phosphorylation of TJ proteins in the experimental obstructive jaundice(BDL vs BDL+L.plantarum,0.266±0.118 vs 0.326±0.009,P<0.05).The protective effect of L.plantarum was more prominent after internal biliary drainage(BDL+IBD vs BDL +IBD+L.plantarum,0.415±0.105 vs 0.494±0.145,P<0.05).CONCLUSION:L.plantarum can decrease intestinal epithelial cell apoptosis,reduce oxidative stress,and prevent TJ disruption in biliary obstruction by activating the PKC pathway.

Effect of Artemisia decoction on liver function and pERK/eIF2a signaling pathway in rats with alcoholic liver fibrosis

Objective: To investigate the effects of Artemisia decoction on liver function and phosphorylation of extracellular regulated protein kinase/eukaryotic translation initiation factor 2α (pERK/eIF2a) signaling pathway in rats with alcoholic liver fibrosis. Methods: A total of 40 healthy Sprague-Dole (SD) rats were randomly divided into 4 groups: the normal group, the sham operation group, the model group and the Artemisia decoction group, with 10 rats in each group. Alcoholic liver fibrosis model was established by "alcohol-corn oil-pyrazole" combined with a 12-week high-fat diet. After successful modeling, the normal group was not treated, and the sham operation group was given saline. The model group and the Artemisia decoction group were given the same amount of wormwood soup at the same time. The serum hydroxyproline (HYP), hyaluronidase (HA), laminin (LN), type IV collagen (CIV), type III procollagen (PIIINP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltranspeptidase (γ-TG), total bile acid (TBA), total bilirubin (TB), albumin (ALB), total cholesterol (CHOL), triglyceride (TG), glutathione (GSH), superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured after 12 weeks of continuous treatment. The degree of liver fibrosis was observed by hematoxylin-eosin staining (HE). The expression of pERK/eIF2a signaling pathway in liver tissue was detected by enzyme-linked immunosorbent assay (ELISA). Results: Compared with the normal group, the levels of serum HYP, HA, LN, CIV, PIIINP, AST, ALT, γ-GT, ALP, TBL and TB in the sham operation group were not significantly changed (P>0.05), while these indexes in the model group were significantly elevated (P<0.01). After treatment with Artemisia decoction, the levels of serum HYP, HA, LN, CIV, PIIINP, AST, ALT, γ-GT, ALP, TBL and TB were significantly lower than those in the model group (P<0.01). The serum albumin, lipid metabolism and oxidative damage indicators showed that there was no significant change in serum ALB, CHOL, TG, GSH, SOD and MDA levels in the sham operation group compared with the normal group (P>0.01). The levels of GSH and SOD in the model group were significantly decreased (P<0.01), and the levels of CHOL, TG and MDA in the model group were significantly increased (P<0.01). Compared with the model group, the serum ALB, GSH and SOD levels were significantly increased (P<0.01), and CHOL, TG and MDA levels were significantly decreased after giving intervention with Artemisia decoction (P<0.01). The results of HE staining showed that compared with the control group, the morphology of the liver sections of the sham operation group was normal, while the liver sections of the model group showed obvious vacuolization changes. The liver sections of the rats treated with Artemisia decoction were significantly improved. The results of ELISA showed that there was no significant change in the levels of pERK and eIF2a in the liver tissue of the sham operation group compared with the normal group (P>0.05). The levels of pERK and eIF2a in the liver tissue of the model group were significantly increased (P<0.01). After treatment with Artemisia decoction, the levels of pERK and eIF2a in rat liver tissues were significantly lower than those in the model group (P<0.01). Conclusion: Artemisia decoction can effectively block the degree of liver fibrosis in rats with alcoholic liver fibrosis, reduce liver fibrosis index and improve hepatobiliary function. This effect may be related to inhibition of the pERK/eIF2a signaling pathway.

Protective Effects of Sapindus Saponins in Spontaneously Hypertensive Rats

Objectives： To investigate the protective effects of Sapindus saponins in spontaneously hypertensive rats, and the possible cellular and molecular mechanisms. Methods： Thirty-two 16-week-old spontaneously hypertensive rats were randomly divided into four groups （8 in each group）： model group （placebo）, positive control group （27 mg/kg of Captopril Tablets）, Sapindus saponins groups （27 mg/kg and 108 mg/kg, respectively）. Another 8 healthy Wistar-Kyoto strain （WKY） rats were used as the normal group. The animals were treated for 8 weeks. Blood pressure of rats was determined by non-invasive blood pressure meter （BP-6）. Furthermore, the contents of angiotensin Ⅱ （Ang Ⅱ） in plasma and myocardial tissue were determined by enzyme-linked immunosorbent assay （ELISA）, the gene expression of receptor angiotensin type 1 （AT1R） in aorta was determined by quantitative real- time polymerase chain reaction （qRT-PCR）. The protein expression of transforming growth factor- β1 （TGF- 1β1） and AT1R in heart was determined by immunohistochemical staining. The protein expression of p-phosphorylation of p38 mitogen-activated protein kinase （p-p38MAPK） was determined by Western blotting. The contents of interleukin （IL）-1, IL-6 and tumor necrosis factor （TNF） in serum were determined by radioimmunoassay. And the histopathological and morphological changes of aorta and heart tissue samples were assessed semi-quantitatively by hematoxylin-eosin （HE） or Masson staining. Results： Thirty minutes after single or continuous treatment, systolic blood pressure （SBP） was reduced significantly in Sapindus saponins groups. And the contents of Ang 11, IL-1, IL-6 and TNF-α in serum, the expression of AT1R mRNA, p-p38MAPK and TGF- β1 were significantly suppressed dose-dependently （P〈0.05 or 1=〈0.01）. With the Sapindus saponins treatment, compared with those of the model group, the cardiac and aortic pathological changes were ameliorated significantly. Conclusions： Our findings suggest that Sapindus saponins might have protective effects in spontaneously hypertensive rats, the cellular and molecular mechanisms of which might be relevant to the regulation of inflammatory responses mediated by p-p38MAPK signal pathway based on activated Ang Ⅱ and AT1R.