1.Improvement of the Optimum Temperature of Penicillium expansum Lipase by Site-directed Mutagenesis
Guo-Ren CHEN ; Lin LIN ;
Microbiology 1992;0(01):-
In order to improve the optimum temperature of lipases, The Penicillum expansum lipase (PEL) gene was mutated by site-directed mutagenesis using overlap extension PCR technique. The recombinant plasmid pPIC3.5K-lip-E83V containing matant gene was expressed in Pichia pastoris GS115. The comparison experiments of the mutant PEL-E83V-GS with the wild-type PEL-GS showed that: the optimum temperature of the mutant (45℃) was higher by 5℃ than that of the wild type. The thermostability of the mutant was similar to the wild type. The enzymatic activity of the mutant was 188 U/mL at 37 ℃, which was 80% that of the wild type at the same conditions. The hydrophobic interaction may be enhanced in the surface region by the hydrophilic amino acid, Glu substituted with the hydrophobic amino acid, Val, and be responsible for the improvement of optimum temperature.
2.Pathology of lipid storage myopathy presenting as polymyositis
Lin CHEN ; Yupu GUO ; Haitao REN
Chinese Journal of Neurology 2001;0(02):-
Objective Some cases of lipid storage myopathy (LSM) are similar to the polymyositis(PM) in clinic.To study the muscle pathology is helpful as to making clear the diagnosis and elucidating the mechanism of the LSM. Methods 14 cases of LSM with high level of CK in serum were analyzed clinically and compared with their muscle morphological and histochemical changes.Results Muscle weakness and fatigue were the main complaints of these patients.Most of them had acute or sub acute onset,some of them had relapse courses.All of the muscle specimens showed typical accumulation of lipid in muscle fibers.Necrotic fibers were found in 9 cases,3 of them showed changes with the courses. Conclusion Muscle biopsies and histochemical studies are necessary to differentiate LMS with PM.The fiber necrosis and CK leakage in LSM may be caused by changes of the inter circumstance and the membrane disturbance of cells.
3.The clinical and muscular pathological study of dermatomyositis with perifascicular atrophy changes
Zhi LIU ; Lin CHEN ; Yupu GUO ; Haitao REN ; Yanhuan ZHAO
Chinese Journal of Internal Medicine 2012;51(9):698-701
ObjectiveTo investigate the clinical and pathological characteristics of dermatomyositis with muscular perifascicular atrophy (PFA).MethodsA series of 104 consecutive patients clinically and pathologically diagnosed as dermatomyositis by muscle biopsy in our laboratory from December,2003 to August,2011,were enrolled in this study. Muscle biopsy of all the enrolled patients had shown PFA of muscle fibers.ResultsAmong the 104 patients,34 were males and 70 were females with a mean age of 45 years old.Among them,8 cases had normal electromyogram;42 had normal serum creatine kinase level;11 were diagnosed as carcinoma;75 were found to be combined with interstitial lung disease (ILD).Based on morphologic changes of muscle biopsy,they were divided into pure PFA group with 54 cases and PFA plus focal damage group with 50 cases.Compared with the pure PFA group,there was prominent mononuclear cell infiltration into perimysial intermediate sized vessels and membrane attack complement (MAC) deposition in the intramuscular capillaries in the PFA plus group.Skin biopsy had been taken in 12 cases together with muscle biopsy and had shown the border effectof both PFA and interface dermatitis in muscle and skin.ConclusionsOur study suggests that chronic immune vascular damage and insufficiency in dermatomyositis may cause ischemia and focal myofiber damage in watershed regions. The incidence of ILD in our dermatomyositis patients with PFA is high.
5.Advances in cardiovascular effects of tanshinone II(A).
Fen-yan CHEN ; Ren GUO ; Bi-kui ZHANG
China Journal of Chinese Materia Medica 2015;40(9):1649-1653
Cardiovascular diseases, like coronary heart disease and myocardial infarction, are the most common cause of death worldwide. Chinese medicines have demonstrated rich cardioprotective activities for clinical applications. Salvia miltiorrhiza, a very important component of traditional Chinese medicine, can promote blood circulation and relieve blood stasis. Salvia miltiorrhiza is widely used in treatment of cardiovascular and cerebrovascular disease such as coronary heart disease and cerebral infarction ( CI). Tanshinone II(A), the major lipophilic components extracted from the root of S. miltiorrhiza, possesses anti-atherosclerosis, anti-cardiac hypertrophy, anti-oxidant, anti-arrhythmia and so on. This paper discusses current research status of tanshinone II(A) in cardioprotective effects.
Animals
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Cardiovascular Diseases
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drug therapy
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genetics
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metabolism
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physiopathology
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Coronary Vessels
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drug effects
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physiopathology
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Diterpenes, Abietane
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therapeutic use
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Humans
6.Protective effects and mechanisms of breviscapine on endothelial cells
Jianping CHEN ; Xinsheng REN ; Zhonghua SUN ; Zaiyu GUO
Journal of China Pharmaceutical University 2015;(5):610-616
This study was to investigate the protective effects and mechanisms of breviscapine on endothelial cells.ox-LDL was used to induce oxidative damage on human umbilical vein endothelial cells(HUVEC)for 20 h with or without 4 h pretreatment of various concentrations of breviscapine(10;20;40 μmol/L);then observe the protective effect and mechanism of breviscapine on endothelial cells insulted by ox-LDL.MTT method was used to detect cell viability;flow cytometry was used to detect cell apoptosis and reactive oxygen species;and Western blot and RT-PCR was used to detect cell signaling pathways.The results showed that breviscapine recovered HUVEC cell viability in a dose-dependent manner which inhibited by ox-LDL;and it also protected cell from apoptosis induced by ox-LDL.To explore the mechanisms of breviscapine;reactive oxygen species (ROS)was determined after pretreatment of various concentrations of breviscapine or different durations(2;4;6 h)of brevis-capine.Results showed that breviscapine decreased ROS production in a dose-and time-dependent manner.Fur-thermore;cell signaling pathway analysis showed that breviscapine increased the expression of BCL-2;decreased the expression of BAX and the release of Cytochrome C and cleavage of caspase-3.Breviscapine decreased Keap1 and activated the nuclear import of Nrf2;and subsequently increased the mRNA and protein expression of down-stream antioxidant enzyme as NAD(P)H:quinone oxidoreductase 1(NQO1)and glutathione transferase-S-Mu 1(GSTM1);and increasing the activity of NQO1.Besides;breviscapine decreased IKK and IKB;and inhibited nuclear translocation of NF-κB;while increasing the expression of eNOS.This study demonstrated that breviscap-ine has a protective role on ox-LDL-induced endothelial cell injury;which may be related to its antioxidant effects and inhibition of NF-κB activation.
7.Correlation between myocardial injury induced by acute carbon monoxide poisoning and NT proBNP.
Xiu-ling TAN ; Xu-gong REN ; Yu-guo CHEN
Chinese Journal of Industrial Hygiene and Occupational Diseases 2010;28(6):454-455
Adult
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Aged
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Carbon Monoxide Poisoning
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blood
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pathology
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Creatine Kinase
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blood
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Female
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Humans
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Male
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Middle Aged
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Myocardium
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pathology
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Natriuretic Peptide, Brain
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blood
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Peptide Fragments
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blood
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Troponin I
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blood
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Young Adult
8.Clinical analysis of 55 cases of primary esophageal small cell carcinoma
Silin CHEN ; Cuihua GUO ; Xi FU ; Dacheng REN ; Yukun YONG
Cancer Research and Clinic 2012;24(10):682-684
Objective To analyze the clinical characteristics,treatment and prognosis of primary esophageal small cell carcinoma (PESC).Methods Fifty-five patients with PESC were analyzed retrospectively.The survival rate was calculated by the Kaplan-Meier method and the Log-rank test using SPSS 17.0 software.Results The median survival time of 55 patients was 12 months.The 6,12,24.36months survival rates of these patients were 87.3 % (48/55),50.9 % (32/55),12.7 % (7/55),7.3 % (4/55),respectively.In multivariate analysis,stage and type of treatment were shown to be independent predictive.Conclusion PESC is a malignant tumor with early metastasis and poor prognosis.Combined therapy may improve the survival time of PESC patients.
9.Involvement of MMP-2 in adriamycin resistance dependent on ERK1/2 signal pathway in human osteosarcoma MG-63 cells.
Ye, REN ; Fengjing, GUO ; Anmin, CHEN ; Rui, DENG ; Jiang, WANG
Journal of Huazhong University of Science and Technology (Medical Sciences) 2012;32(1):82-6
Matrix metalloproteinase-2 (MMP-2) level and the ERK1/2 signal pathway are dependent factors for the growth and metastasis of cancer. However, the impact of MMP-2 in combination with ERK1/2 in tumor patients with drug resistance is unknown. To determine the relationship between MMP-2 and the ERK1/2 signal pathway, we established an adriamycin (ADM)-induced MG-63 (ADM-MG-63) cell line. With the increase of the ERK1/2 pathway blocker PD98059, we detected the expression levels of MMP-2 and p-ERK1/2 by Western blot in ADM-MG-63 cells. In ADM-MG-63 cells transfected with MMP-2-siRNA, the expression of ERK1/2 was detected for understanding the function of the ERK1/2 signal pathway. Three siRNAs for MMP-2 (MMP-2-siRNA) were designed, and the optimal one was selected and tested at different time points of 24, 48 and 72 h. Under an ADM-induced condition, ADM-MG-63 cells were finally stable living in the medium of ADM (200 ng/mL). PD98059 could effectively suppress the expression levels of p-ERK1/2 and MMP-2. When the MMP-2 was silenced by using MMP-2-siRNA, the expression of p-ERK1/2 was enhanced. It is concluded that MMP-2 may be involved in ADM resistance dependent on ERK1/2 signal pathway, suggesting interference in ERK1/2 may be a new method of targeted therapy for tumor resistance.
10.Evaluation of lipid accumulation in muscle fibers in inflammatory myopathies
Lin CHEN ; Yupu GUO ; Haitao REN ; Yanhuan ZHAO
Chinese Journal of Neurology 2000;0(04):-
Objective To study the frequency and correlate factors of lipid accumulation in muscle fibers in inflammatory myopathies Methods Muscle biopsy specimens were routinely processed for histopathological and histochemical studies Excepting inflammatory changes, lipid droplets were observed by ORO staining According to the amount of lipid droplets in the muscle fibers, these cases were separated into two groups, and then the differences in muscle power, serum CK level, morphologic changes of muscle, courses and corticosteroids administration between two groups were compared Results 37 7% specimens showed lipid accumulation in muscle fibers distinctly As compare with the lipid normal group, in the lipid increasing group, the generalized muscle fiber degenerating were more common and muscle weakness were more prominent Although more patients have long term therapy with steroid in lipid increasing group, there were no significant differences between these two groups Conclusions Lipid accumulation in muscle fibers was present in some patients with inflammatory myopathies Increasing of lipid droplets might result from the muscle fiber degenerating and might turn to impair the muscle function reversely