ABSTRACT
Objective To investigate the effect of parthenolide ( PTL) and PKC inhibitor on human gastrointestinal stromal tumor (GIST) cell proliferation and apoptosis and the mechanism involved .Methods Human GIST cell lines were cultured in vitro, and the cell proliferation rate of GIST , was determinate by MTT;flow cytometry was used to test the early apoptosis rate of GIST;Western blot assay was applied to detect the expression of endoplasmic reticulum stress-related proteins , GRP78 and GADD153.There were four groups: control group , PTL group, PKC inhibitor group , combine PTL and PKC inhibitor group .Results PTL and PKC inhibitor combination therapy for GIST was sig-nificantly more effective than a single-drug therapy (P<0.05);as for the early apoptosis rate , the combination ther-apy for GIST cells was significantly higher than that medication alone group (P<0.05).the expression of endoplas-mic reticulum stress-associated protein GRP 78 and GADD153 was obviously higher in PTL and PKC inhibitor combi-nation group than that in medication alone group (P<0.05).Conclusions PTL and PKC inhibitor combination therapy for GIST cells can induce apoptosis , which is possibly mediated via endoplasmic reticulum stress pathway .
ABSTRACT
Chondroitin sulfate proteoglycan (CSPG) inhibits neurite outgrowth of various neuronal cell types, and CSPG-associated inhibition of neurite outgrowth is mediated by the Rho/ROCK pathway. Mesenchymal stromal/stem cells (MSCs) have the potential to differentiate into neuron-like cells under specific conditions and have been shown to differentiate into neuron-like cells by co-treatment with the ROCK inhibitor Y27632 and the hypoxia condition mimicking agent CoCl2. In this study, we addressed the hypothesis that a ROCK inhibitor might be beneficial to regenerate neurons during stem cell therapy by preventing transplanted MSCs from inhibition by CSPG in damaged tissues. Indeed, dose-dependent inhibition by CSPG pretreatment was observed during morphological changes of Wharton's jelly-derived MSCs (WJ-MSCs) induced by Y27632 alone. The formation of neurite-like structures was significantly inhibited when WJ-MSCs were pre-treated with CSPG before induction under Y27632 plus CoCl2 conditions, and pretreatment with a protein kinase C inhibitor reversed such inhibition. However, CSPG treatment resulted in no significant inhibition of the WJ-MSC morphological changes into neuron-like cells after initiating induction by Y27632 plus CoCl2. No marked changes were detected in expression levels of neuronal markers induced by Y27632 plus CoCl2 upon CSPG treatment. CSPG also blocked the morphological changes of human bone marrow-derived MSCs into neuron-like cells under other neuronal induction condition without the ROCK inhibitor, and Y27632 pre-treatment blocked the inhibitory effect of CSPG. These results suggest that a ROCK inhibitor can be efficiently used in stem cell therapy for neuronal induction by avoiding hindrance from CSPG.
Subject(s)
Humans , Hypoxia , Chondroitin Sulfate Proteoglycans , Chondroitin Sulfates , Chondroitin , Neurites , Neurons , Protein Kinase C , Stem CellsABSTRACT
Objective To study the potential role of PKC inhibitor Rottlerin in the treatment of asthma. Methods Balb/c mice were sensitized and challenged with ovalbumin(OVA) protein to construct murine experimental model of asthma. Then the mice were treated by means of injection of Rottlerin or phosphate buffered saline (PBS) into the abdominal cavity. Changes of the total serum IgE, pulmonary eosinophils, cytokines and pulmonary inflammation were investigated. Results Injection of Rottlerin at the dose 0.3 mg/kg into the murine abdominal cavity could inhibit the infiltration of pulmonary eosinophils and pulmonary inflammation and significantly decrease the production of total serum IgE and Th 2 cytokines as well. Conclusion Rottlerin can inhibit murine experimental asthma.