Lactate and succinate were produced by Corynebacterium acetoacidophilum from glucose under oxygen deprivation conditions. To construct knockout mutant, lactate dehydrogenase gene (ldh) of C. acetoacidophilum was deleted by double-crossover chromosome replacement with sacB gene. Comparing with the wild strain ATCC13870, ldhA-deficent mutant produced no lactate with glucose consumption rate decreased by 29.3%, while succinate and acetate concentrations were increased by 45.6% and 182%, respectively. Moreover, the NADH/NAD+ rate was less than 1 (about 0.7), and the activities of phosphoenolpyruvate carboxylase and acetate kinase of the ldhA-deficent mutant were enhanced by 84% and 12 times, respectively. Our studies show that succinicate and acetate production pathways are strengthened by blocking lactate synthesis. It also suggests that improving NADH supply and eliminating acetate generation are alternative strategies to get high succinate-producer.
Corynebacterium glutamicum ; genetics ; metabolism ; Glucose ; Industrial Microbiology ; L-Lactate Dehydrogenase ; genetics ; metabolism ; Lactic Acid ; metabolism ; Oxygen ; metabolism ; Phosphoenolpyruvate Carboxylase ; Succinic Acid ; metabolism

Objective To investigate the role of autophagy in podocyte damage,and the intracellular mechanism of autophagy activation through passive Heymann nephritis (PHN) animal model.Methods Male Sprague-Dawley rats (n=40) were studied on day 0,2,4,7,and 21 after induction of PHN by injection of anti-Fx1A.Podocyte morphology and autophagosomes were observed by transmission electron microscopy.Podocyte numerical density was estimated by Weibel-Gomez =method.Cell apoptosis was detected by TUNEL assay and caspase-3 immunohistochemical staining.Expressions of autophagy markers and endoplasmic reticulum stress (ERS)-associated proteins were analyzed by Western blotting.Results (1) In PHN rats,immunohistochemical staining showed that C5b-9 deposited along glomerular basement membrane on day 4 to day 21.Small subepithelial electron -dense deposits and a part of foot process fusion were detected in the glomerulus of PHN rats on day 4 by transmission electron microscope,and podocyte damage was aggravated on day 21.Furthermore,compared with control,the urinary protein levels of PHN rats began to increase on day 3,and reached the top on day 21 [(50.6±6.0) mg/24 h].(2) The number of podocytes significantly decreased in PHN rats compared with control group on day 21(P ＜ 0.05).(3) In PHN rats,apoptotic podocytes were found by caspase-3 immunohistochemical staining and TUNEL assay on day 21.(4) The expression of autophagy marker LC3 Ⅱ was markedly increased on day 7 and 21,but down-regulated on day 21 compared with day 7.Moreover,accumulated autophagosomes in podocytes were detected on day 7 and 21 by transmission electron microscope.(5) The level of GRP78 was significantly increased on day 2 and 7 but reduced to baseline on day 21.At the same time,the downstream pathways (ATF6α,p-PERK and p-JNK) of unfolded protein response were also up-regulated in the early process of PHN and down-regulated later.Conclusions Autophagy is an important way to protect against immunemediated podocyte injury in membranous nephropathy.Autophagy activation is mainly related to endoplasmic reticulum stress induced by complement attack.This provides an important basis for a thorough understanding of the role of autophagy in the process of podocyte damage and the pathogenesis of membranous nephropathy.

AIM: To determine the effect of rapamycin on the progression of passive Heymann nephritis (PHN), and whether autophagy is involved in this process .METHODS:Male Sprague-Dawley rats (n=24) were ran-domly divided into 3 groups:control group , PHN group and rapamycin treatment group .The rat PHN model was induced by injection of anti-Fx1A serum through penile vein , and all rats were sacrificed on day 21.Automatic biochemical analyzer was used to detect 24 h urine protein , blood urea nitrogen and serum creatinine .Renal damage was observed through per-iodic acid-silver methenamine staining .The number of podocyte was estimated by Weibel-Gomez method .The glomerular deposition of C5b-9, the expression of caspase-3 and expression of autophagy marker LC 3 in glomeruli were examined by immunofluorescence staining , immunohistochemical staining and Western blotting , respectively.RESULTS: Rapamycin significantly reduced proteinuria in the PHN rats (P<0.05), while the renal functions in 3 groups were normal, without significant difference .Although rapamycin limited weight gain in the rats , the health of the rats during drug treatment was not affected .Rapamycin retarded glomerular basement membrane thickening in the PHN rats .Rapamycin significantly re-duced the podocyte deletion by preventing podocyte apoptosis .Rapamycin enhanced the level of autophagy of glomerular in-herent cells .CONCLUSION:In the disease process of PHN , appropriate strength of autophagy plays a protective role . Rapamycin appropriately enhances autophagy and prevents podocyte apoptosis , thus reducing nephropathy and proteinuria . This may be one of the important mechanisms of rapamycin to slow down the progress of PHN .

AIM:In podocytes , autophagy occurs at a high basal level and dysregulated autophagy is associa -ted with a variety of podocytopathies .This paper is to investigate the role of autophagy in sublytic C 5b-9-induced podocyte injury.METHODS: Sublytic complement C5b-9 stimulation was used as an in vitro model.Autophagosomes were con-firmed using monodansylcadaverine (MDC) staining.Immunoblotting was used to measure the change of autophagy-related markers.Cellular morphological changes were observed by Wright-Giemsa staining.Immunofluorescence staining and con-focal microscopy were used to detect the expression and distribution of nephrin .The cell viability was assessed by methylth-iazol tetrazolium (MTT) assay.The cell apoptosis was assessed by Annexin V-fluorescein isothiocyanate/PI staining.RE-SULTS:For ensuring sublytic complement injury , the maximal amounts of anti-podocyte antiserum and 160 ×-diluted nor-mal human serum were used without inducing cell lysis (defined as >5%LDH release).Sublytic C5b-9 promoted autoph-agy of podocytes in vitro.The proautophagic effect of sublytic C 5b-9 manifested in the form of accumulated MDC-labeled vesicles and enhanced the expression of LC 3-Ⅱ.Autophagy inhibitor 3-methyladenosine (3-MA) promoted sublytic C5b-9-induced podocyte morphological abnormalities .Compared with the sublytic C5b-9-injured podocytes, 3-MA exposure further decreased the expression of nephrin .3-MA enhanced sublytic C5b-9-induced podocyte apoptosis .CONCLUSION: Sub-lytic C5b-9 attack induces autophagy , which may play a protective role against complement-mediated podocyte injury .

OBJECTIVE To study the effect of K252a on the chemotactic growth of Schwann Cell to salivary adenoid cystic carcinoma cell in vitro co-culture METHODS Co-culture of sciatic nerve blocked by K252a with salivary adenoid cystic carcinoma cell was regarded as experimental group. Co-culture of sciatic nerve with salivary adenoid cystic carcinoma cell was chosen as control group RESULTS In contrast to control group , the promotion growth and chemotactic growth of Schwann cell was blocked by K252a (P

OBJECTIVE: To synthesize the derivatives of 8-amino benzofuran[3, 2-d] pyrimidine and study their anticancer activiies. METHODS: The target compounds were synthesized through a series of reactions, and their anticancer activities in vitro were evaluated against COLO205, MCF-7 and K562 cell lines by MTT as assay. RESULTS: Nine title compounds were synthesized and confirmed by EI-MS, 1H-NMR and 13C-NMR. Compounds 2, 3d and 5c had good inhibition effect against COLO205, MCF-7 and K562 cells. The inhibition rates of compound 5c against COLO205, MCF-7 and K562 cells were 99.58%, 78.75% and 98.68% respectively at 10-4 mol · L-1. CONCLUSION: The anticancer activity of benzofuran[3, 2-d] pyrimidine derivatives is worthy of further study.

Objective To determine the effect of rapamycin on sublytic C5b-9-induced podocyte adhesion damage,and whether autophagy is involved in this progression.Methods Sublytic complement C5b-9 stimulation was used in vitro.Autophagosomes were viewed using electron microscopy.Western blotting was used to measure the change of autophagy-related markers.Attachment assay was used to assess the adhesion of podocyte.Confocal microscopy was used to explore the expression patterns of cytoskeletal protein F-actin.Flow cytometry was used to measure the level of adhesion-associated protein integrin α3.Results (1) For ensuring sublytic complement injury,the maximal amounts of anti-podocyte antiserum and 160×-diluted normal human serum were used without inducing cell lysis (defined as ＞ 5％ LDH release).(2) Sublytic C5b-9 promoted autophagy in podocyte in vitro.The proautophagic effect of sublytic C5b-9 manifested in the form of accumulated autophagosomes and enhanced expression of LC3-lⅡ.(3) Inhibition of autophagy by 3-methyadenine enhanced the effect of sublytic C5b-9-induced podocyte injury,including serious cytoskeleton damage and markedly reduced adhesion of podocyte.(4) Rapamycin treatment significantly improved the above lesions.(5) Rapamycin enhanced autophagy induced by sublytic C5b-9 in podocyte.Conclusions In summary,rapamycin can improve sublytic CSb-9-induced podocyte adhesion damage by appropriate autophagy activation.These findings provide important information for the development of appropriate protocols for the application of mTOR (mammalian target of rapamycin) inhibitors in podocytopathy.

Objective To study MRI findings of pancreatic ducts of piglets with chronic pancreatitis (CP) induced by pancreatic duct ligation and analyze the relationship between pancreatic duct changes in piglets with CP and the pathological severity of CP. Methods Thirty healthy piglets were included in this study. Five piglets were randomly selected as normal control group, and the remaining 25 piglets were served as the experimental group. The duct ligation operations were performed on experimental group. After 2 to 18 weeks, pancreas and pancreatic ducts were observed on MRI. Then the pancreas was removed and graded into three types by histopathology. The relationship between the diameter of pancreatic duct or the pancreatic branch displaying rate and the severity of CP was analyzed by Spearman correlation coefficient. Results CP was found in 21 piglets( 84. 0% ) in the experimental group including mild ( n = 7 ), moderate ( n = 8 ) and severe( n = 6) pancreatitis. Pancreatic ducts were shown in mild CP and the edge of pancreatic ducts was irregular in three cases. The dilated RPD, LPD and MPD constituted the "person" form in moderate and severe CP. The diameter of pancreatic ducts was(0. 9 ±0. 3)mm, (2. 9 ± 1.4)mm and (4. 8 ± 1.2)mm in mild, moderate, and severe CP respectively. The expansion extent of pancreatic ducts was correlated with the severity of CP of piglets (r = 0. 837, P ＜ 0. 05). The pancreatic branch displaying rate increased with the increase of the severity of CP ( r = 0. 990, P ＜ 0. 05 ); the displaying rate was 0/7 for mild, 3/8 for moderate, and 5/6 for severe CP. Conclusions The dilated pancreatic ducts with "person" form in piglets with obstructive CP created by pancreatic duct ligation. The pancreatic duct changes on MRI reflect the severity of CP of piglets.

OBJECTIVETo construct and express the recombinant human adiponectin (gAd) global domain.

METHODSgAd complementary DNA (cDNA) was obtained from human fat tissue by RT-PCR. The PCR product was cloned into the vector pMD18-T and the prokaryotic expression vector pET32a(+). The recombinant vector was identified by digestion with double restriction endonucleases SalI and EcoRI, PCR and sequence analysis. The recombinant plasmid containing gAd gene was transformed into E. coli BL21 (DE3), and the expression of the fusion protein His-gAd was induced by IPTG.

RESULTSThe gAd cDNA of 412 bp was obtained from the total RNA of the fat tissue and verified by sequence analysis.

CONCLUSIONThe recombinant plasmid could stably express the 34-kD fusion protein His-gAd in the engineered bacteria in the form of inclusion bodies.

Adiponectin ; biosynthesis ; genetics ; Adult ; Cloning, Molecular ; DNA, Complementary ; genetics ; Escherichia coli ; genetics ; Female ; Genetic Vectors ; genetics ; Humans ; Prokaryotic Cells ; cytology ; metabolism ; Recombinant Proteins ; biosynthesis

Objective:This study aimed to explore the effect of Yes-associated protein (YAP) on the growth of the human glioma cell line LN229. Methods:YAPsiRNA was transfected into LN229 cells to knock down the YAP expression. The downregulation of the YAP expression was identified through Western Blot analysis. Colorimetric assay using methyl-thiazolyl-tetrazolium was applied to evaluate cell proliferation ability. Cell invasive activity was examined using Transwell assay. Flow cytometry and AnnexinV were used to detect cell cycle and apoptosis, respectively. The relevant molecules regulating proliferation, invasion, cell cycle progression, and apoptosis were examined through Western Blot analysis. Results:The YAP expression was downregulated after YAPsiRNA was trans-fected into LN229 glioma cells. Reduced YAP expression could arrest the cell cycle at G0/G1 phase, inhibit cell proliferation and inva-sion, and promote apoptosis. The expression of the proliferating cell nuclear antigen (Ki-67), matrix metallopeptidase-9 (MMP-9), cy-clin D1, and Bcl-2 were downregulated. Conclusion:The downregulation of YAP in LN229 cells suppresses cell proliferation and inva-sion, as well as promotes cell apoptosis. This study provides a novel evidence for further study on Hippo-YAP signal pathway in molec-ular pathology of glioma.