ABSTRACT
OBJECTIVE: To investigate the role and mechanism of the endoplasmic reticulum stress(ERS) pathway of apoptosis mediated by inositol-requiring enzyme-1(IRE1) in the intervention of silicosis fibrosis in rats using polyguanylic acid(PolyG).METHODS: The specific pathogen free adult male SD rats were randomly divided into control group(24rats),silicosis model group(24 rats),PolyG intervention group(16 rats) and PolyG treatment group(16 rats).The silicosis fibrosis rat model was constructed using the single inhalable intratracheal instillation method.The rats in the control group were injected with 1 mL of 0.9% sodium chloride solution.The other 3 groups were given 1 mL of silica suspension at 50.0 g/L mass concentration.The rats in PolyG intervention group on the day of model construction and rats in PolyG treatment group on the 28 th day after model construction were all given PolyG with 2.5 mg/kg body weight by one time tail vein intravenous injection.Eight rats in the PolyG intervention group and PolyG treatment group were sacrificed respectively on day 28 and day 56 after injection.The pathological changes of lung tissue in each group were observed.The expression of glucose regulated protein-78(GRP78),IRE1,CCAAT/enhancer-binding protein homologous protein(CHOP),Casepase-3,Casepase-12,type Ⅰ collagen and type Ⅲ collagen in lung tissue was detected by the Western blot.RESULTS: The histopathology examination results showed that the structure of lung tissue in control group was normal.The alveolar structure of the lung tissue of the silicosis model group was severe,and the fibrous nodules and a large amount of collagen deposition appeared.The silicosis nodules and collagen deposition in PolyG intervention group and PolyG treatment group were less than those in silicosis model group.The expression of GRP78,IRE1,CHOP,Casepase-3,Casepase-12,type Ⅰ collagen and type Ⅲ collagen in silicosis model group was higher than that of control group(P <0.05).The expression of the above 7 proteins in the PolyG intervention group and PolyG treatment group was lower than that of silicosis model group(P<0.05),higher than that of control group(P<0.05),except IRE1 and CHOP in PolyG intervention group.On day 56 after model construction,the expression of GRP78,IRE1,Casepase-3,Casepase-12,typeⅠ collagen and type Ⅲ collagen in PolyG intervention group were lower than that of PolyG treatment group(P<0.05).CONCLUSION: The unfolded protein response of ERS mediated by IRE1 may participate in the process of PolyG the intervention on silicosis fibrosis in rats.PolyG can effectively prevent and treat silicosis fibrosis.Prophylactic administration is recommended.
ABSTRACT
Objective: To investigate the effects and mechanism of Zhenzhu Mingmu Eye Drops (ZMED) on human corneal epithelial cells (HCEC) injury model induced by high permeability. Methods: The dye eyes disease model was established using 110 mmol/L NaCl to stimulate HCEC, and different concentration of ZMED was given to the treatment group. MTT assay and lactate dehydrogenase (LDH) leakage were used to evaluate the protection effects of ZMED on HCEC. The effects of ZMED on apoptosis of HCEC were analyzed by flow cytometry. AO/EB double staining and Hoechst 33258 analysis were used as sensitive assays for apoptosis. Moreover, HCEC treated with ZMED were subjected to Western blotting for protein levels of Caspase-9, Caspase-3 and PARP. Results: ZMED significantly increased cell viability of HCEC and decreased the LDH release in a dose-dependent manner. ZMED dramatically decreased the apoptosis rate. Furthermore, ZMED down-regulated the levels of cleaved Caspase-9, cleaved Caspase-3 and cleaved PARP. Conclusion: ZMED could protect HCEC against hypermeability, which may be related to the inhibition of Caspase-9/Casepase-3 signaling pathways.
ABSTRACT
[Objective] To study effects of the velvet antler polypeptides on spinal nerve cell apoptosis induced by ?-amyloid peptide. [Method]Spinal nerve cells were performed serial subcultivation,and entered into experiment during the exponential phase of growth.The viability of spinal nervecells 24h after induction by ?-amyloid peptide with different concentrations were detected by MTT assay,percentages of the cell apoptosis and expression of casepase-3 were detected after induction by 25?mol/L ?-amyloid peptide.[Result]It was revealed that 24 h after treatment with ?-amyloid peptide of different concentrations,the viability of spinal nerve cells was significantly decreased in a dose-dependent manner(P