High glucose down-regulates the expression of miR-26b in H9C2 cardiomyocytes / 医学研究生学报

Objective　Diabetic cardiomyopathy (DCM) is one of the complications of diabetes, which is closely related to the change of miRNA. In this study, we observed the characteristic expression of miR-26b in the tissues of the C57BL/6J mouse and in the heart, adipose tissue and liver of the ob/ob mouse, and investigated the effect of high glucose (Glu) on the expression of miR-26b in H9C2 cardiomyocytes.　Methods　Using RT-PCR, we measured the levels of miR-26b in the heart, adipose tissue, liver and other tissues of C57BL/6J and ob/ob mice. H9C2 cardiomyocytes were treated with Glu at 5.5, 15, 25 and 35 mmol/L for 0, 24, 48, 72, 96 and 120 hours, followed by detection of the proliferation of cardiomyocytes by CCK-8 and determination of thelevels miR-26b.　Results　The expression of miR-26b was the highest in the heart of the C57BL/6J mice, significantly higher than in the cardiac and white adipose tissues of the ob/ob mice (P < 0.05). The proliferation of cardiomyocytes was markedly increased in the 15, 25 and 35 mmol/L Glu groups at 24, 48, 72, 96 and 120 hours as compared with that in the 5.5 mmol/L Glu group (P < 0.05), higher in the 25 than in the 15 mmol/L Glu group at 24 hours (0.74±0.02 vs 0.72±0.01, P<0.05), but lower in the 35 than in the 15 mmol/L Glu group at 48 hours (0.92±0.01 vs 0.94±0.01, P<0.05), in the 25 and 35 mmol/L Glu groups at 96 hours (P < 0.05), in the 35 mmol/L Glu group at 120 hours (1.12±0.02 vs 1.19±0.05, P<0.05), in the 35 than in the 25 mmol/L Glu group at 24 and 48 hours (P<0.05). The expression of miR-26b in the H9C2 cardiomyocytes was significantly down-regulated in the 25 and 35 mmol/L Glu groups in comparison with that in the 5.5 mmol/L Glu group (P<0.05), remarkably lower in the 25 mmol/L Glu group at 96 and 120 hours than at 0 hour (P<0.05).　Conclusion　High glucose can down-regulate the expression of miR-26b in H9C2 cardiomyocytes, which suggests that miR-26b may participate in the pathogenesis of DCM.

TFPR1 acts as a novel adjuvant by activating dendritic cells and promoting its matu-ration / 军事医学

Objective To study the role of dendritic cells in the function of a recombinant protein TFPR 1 as an adjuvant .Methods Bone marrow cells were collected from four-to five-week-old male BALB/c mice under aseptic conditions, and cultured with complete RPMI 1640 containing rmGM-CSF and rmIL-4 for six days.TFPR1 was added on day 6, and cells were incubated for another 24 hours.LPS was used as positive control , while PBS as negative .The morphology of dendritic cells was observed under an optical microscope and laser confocal microscope , cell surface makers (CD40,CD80,CD86 and MHCⅡ)were detected with flow cytometry, and the cytokines in the supernatant were detected with ELISA.Results Compared with negative control ,dendritic cells incubated with TFPR1 for 24 hours were significantly different in morphology as was observed by optical and laser confocal microscopes , but were similar to positive control .Most of the dendritic cells treated with TFPR 1 showed less adherence and became round , whose podosomes became shorter , and even disappeared .Actin distribution changed from two poles of the cell to the membrane .CD40,CD80, CD86 and MHCⅡon the cell surface were up-regulated on stimulation by TFPR1,as was detected by FACS.These results showed that TFPR1 was capable of promoting dendritic cell maturation .ELISA showed dendritic cells treated with TFPR 1 secreted high levels of cytokines(IL-6, IL-8 and TNF-α).Conclusion TFPR1 is capable of promoting dendritic cell maturation , and activating cells to produce cytokines , indicating that dendritic cells can play an important role in the function of TFPR 1 as a novel ad-juvant .

Study on the differences of two mouse models of hepatitis B virus infection by transduction with rAAV8-1. 3HBV / 病毒学报

We recently developed a mouse model of hepatitis B virus (HBV) chronic infection by intravenous (i.v.) injection with rAAV8-1. 3HBV to C57BL/6 mice. To define the responses of different mouse strains after injection with rAAV8-1. 3HBV, we intravenously injected rAAV8-1. 3HBV at doses of 4 x10(9) (Viral genome,vg), 4 x 10(10) vg and 4 x 10(11) vg to C57BL/6 and BALB/c mice,respectively, and determined the levels of serum HBV antigen and antibody by ELISA,serum viral DNA by real-time PCR,and HBcAg expression in liver by immunohistochemical staining. For C57BL/6 mouse strain with injection of rAAV8-1. 3HBV at three doses, 100% of the mice carried HBV for more than 8 months. The levels of serum HBsAg and HBeAg, serum viral DNA and HBcAg-positive hepatocytes increased in a rAAV8-1. 3HBV dose-dependent manner. For C57BL/6 mice injected with rAAV8-1. 3HBV at the dose of 4 x 10(11) vg,over 40% of hepatocytes expressed HBcAg and serum viral DNA reached over 10(5) IU/mL. No HBV antibody was detected in sera of C57BL/6 mice. For BALB/c mice with injection of rAAV8-1. 3HBV at three doses, serum HBeAg, serum viral DNA and HBcAg-positive hepatocytes persisted for more than 8 months, but serum HBsAg declined remarkably at 2 weeks after injection. The levels of serum HBeAg and HBcAg-positive hepatocytes in BALB/c mice increased in a rAAV8-1. 3HBV dose-dependent manner. Injection with rAAV8-1. 3HBV at the dose of 4 x 10(11) vg resulted in over 50% of BALB/c mice hepatocytes expressing HBcAg. Serum anti-HBsAg were detected in BALB/c mice with rAAV8-1. 3HBV injection at the dose of 4 x10 (10) vg. In conclusion, both C57BL/6 and BALB/c strains can be developed to chronic HBV infection mouse models by i. v. injection with rAAV8-1. 3HBV at doses of 4 x10(9) - 4 x 10(11) vg and the levels of HBV replication increase in a rAAV8-1. 3HBV dose-dependent manner. In contrast to C57BL/6 strain, the BALB/c mice carry out humoral immunity to HBsAg, but fail to mediate HBV clearance.

Immunosuppressant dexamethasone can significantly extend the expression of hepatitis B virus antigens in the HBV mouse model by hydrodynamic transfection method / 病毒学报

To develop a HBV infection mouse model by hydrodynamic-based transfection and further to optimize the method of development of HBV infection mouse model. We first developed a construct which contained inverted terminal repeat elements (ITR) of adeno-associated virus (AAV) and 1. 3 copies of HBV genome (ayw subtype). The pAAV-HBV1. 3 DNA was then injected hydrodynamically into the tail veins of C57BL/6 mice in 5 seconds. The virus load in serum and liver was assayed by ELISA and Real-time PCR. The expression of virus antigen and the pathologic changes of liver were analyzed by HE and immunohistochemical staining. Meanwhile, to develop HBV transfected immunosuppressied mouse, mice were injected intraperitoneally triple with 0.2 ml dexamethason (50 mg/kg) every two days before HBV transfection. The levels of HBsAg and HBeAg were assayed by ELISA. Our data showed: (1) HBsAg and HBeAg were positive (100%) in serum and liver of experimental normal mouse at day 10 after HBV transfection, and became negative at day 30 and day 60. Meanwhile the viral load in serum and liver in experimental group was significantly higher than that in control group at day 10, 30 and 60 after HBV transfection (P < 0.01, P < 0.05, respectively). (2) HBsAg and HBeAg in serum in immunosuppressed mouse model were positive until 60 days. In conclusion, a HBV infection mouse model was developed successfully by hydrodynamic-based transfection. By suppressing the immune status of mice injected with dexamethasone, the expression of HBV antigens was extended longer than that in normal adult mice. These models pave a way for HBV research and evaluation of HBV vaccine and drug development.

Construction of HCV-producing cell model based on self-cleaving ribozyme / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To construct a stable HCV-producing cell model for anti-HCV drug research.</p><p><b>METHODS</b>The HCV-ribozyme recombinant plasmid pJFH1-Rbz was constructed to generate the exact 5' and 3' ends of HCV genomic RNA by placing two self-cleaving ribozymes at both ends of the HCV JFH-1 cDNA. The plasmid was then transfected into HepG2 cells and the resultant clones were screened with G418. Subsequently, immunofluorescence and Western blot were performed to detect the expression of HCV core protein, HCV RNA level was quantitated by TaqMan real-time PCR method and HCV particles was detected by electron microscopy.</p><p><b>RESULTS</b>HCV core protein was detected in the screened cell clone, and the level of HCV RNA was up to 1000,0000 copies/ml in the culture medium. Electron microscopy showed the viral particles in the culture suspension were approximately 55 nm in diameter. IFN-treating experiment demonstrated that the HCV RNA level decreased with the increasing concentration of IFN alpha.</p><p><b>CONCLUSION</b>We constructed a stable HCV-producing cell model which can be used for anti-HCV drug research.</p>

Expression and purification of TAT-HBX-EGFP fusion protein and its transmembrane distribution in mouse / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To highly express TAT-HBX-EGFP fusion protein and study its distribution in mouse liver.</p><p><b>METHODS</b>TAT-HBX-EGFP recombinant vector was constructed and fusion protein was induced by IPTG and expression in BL21; fusion protein was purified by Ni-NTA argarose, then injected into the peritoneal cavity of the mice. Distribution of fusion protein was observed by immunofluorescence.</p><p><b>RESULTS</b>TAT-HBX-EGFP was highly expression in E. coli; HBX could be induced into mouse liver by TAT.</p><p><b>CONCLUSION</b>HBX protein could be induced into mouse liver by TAT induced peptide.</p>

Expression of K18, Ser-33 and Ser-52 phosphorylated K18 in HBV infected human liver disease and its significance / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the expression of K18, Ser-33 and Ser-52 phosphorylated K18 in HBV infected human liver disease and its significance.</p><p><b>METHODS</b>The expression and localization of K18 and Ser-33, Ser-52 phosphorylated K18 in healthy liver tissue, in liver tissues of patients with post-HBV infection cirrhosis and severe chronic hepatitis were detected by histochemistry.</p><p><b>RESULTS</b>K18, Ser-33 and Ser-52 phosphorylated K18 were expressed in normal liver cells, in liver tissues of cirrhosis patients and severe chronic hepatitis cases. The expression of K18 in the liver cells from the 3 different sources had no significant difference in levels. Ser-33 and Ser-52 phosphorylated K18 were expressed in normal liver cells, in liver tissues of cirrhosis patients chronicity HBV hepatitis and severe chronic hepatitis cases. Ser-33 and Ser-52 located around cytoplasmic membrane, diffused into cytoplasm and expressed at a higher levels in cirrhosis and severe chronic hepatitis.</p><p><b>CONCLUSION</b>The expression levels of Ser-33 and Ser-52 phosphorylated K18 increased along with the progression of HBV infected human liver disease. The phosphorylation of K18 could be a marker of progression of HBV infected human liver disease.</p>

Molecular cloning and expression of the severe acute respiratory syndrome-associated coronavirus nucleocapsid protein and its clinical application / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To clone and express nucleocapsid (N) protein of the severe acute respiratory syndrome (SARS)-associated coronavirus, and to evaluate its antigenicity and application value in the development of serological diagnostic test for SARS.</p><p><b>METHODS</b>SARS-associated coronavirus N protein gene was amplified from its genomic RNA by reverse transcript nested polymerase chain reaction (RT-nested-PCR) and cloned into pBAD/Thio-TOPO prokaryotic expression vector. The recombinant N fusion protein was expressed and purified, and its antigenicity and specificity was analyzed by Western Blot, to establish the recombinant N protein-based ELISA for detection of IgG antibodies to SARS-associated coronavirus, and SARS-associated coronavirus lysates-based ELISA was compared parallelly.</p><p><b>RESULTS</b>The recombinant expression vector produced high level of the N fusion protein after induction, and that protein was purified successfully by affinity chromatography and displayed higher antigenicity and specificity as compared with whole virus lysates.</p><p><b>CONCLUSION</b>The recombinant SARS-associated coronavirus N protein possessed better antigenicity and specificity and could be employed to establish a new, sensitive, and specific ELISA for SARS diagnosis.</p>

A clinicopathological study on 3 cases of severe acute respiratory syndrome / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the pathological characteristics of severe acute respiratory syndrome (SARS) and its relationship to clinical manifestation.</p><p><b>METHODS</b>Tissue specimens from 3 autopsy cases of diagnosed SARS were studied under microscopy and the clinical data were reviewed.</p><p><b>RESULTS</b>The typical pathological changes of lungs were diffuse hemorrhage on surface. A mixture features of serous, fibrinous and hemorrhagic inflammation were seen in most pulmonary alveoli with engorgement of capillary and there were microthrombosis in some capillary. Pulmonary alveoli became thick with interstitial mononuclear inflammatory infiltration, diffused alveoli damage, desquamation of pneumocytes and hyaline-membrane formation. Fibrinoid materials and erythrocytes could be found in alveolar spaces. There were thrombo-embolisms in some bronchial artery. Meanwhile, haemorrhagic necrosis was showed in lymph nodes and spleen with attenuation of lymphocytes. Other atypical pathological changes, such as hydropic degeneration, fatty degeneration, interstitial cell proliferation and some lesions observed in liver, heart, kidney, pancreas may have existed before the hospitalization.</p><p><b>CONCLUSION</b>Severe damages of pulmonary and immunological system damage are responsible for clinical features of SARS and may lead to death of patients.</p>