Comparison of polycytidylic acid-induced and dexamethasone-induced thymic atrophy and their thymic expression of RIG-Ⅰ like receptors signaling pathway / 中国免疫学杂志

Objective:To provide experimental evidences for choosing murine models in the pathogenesis research of thymic impairment induced by viral infection,we compared the impacts of polycytidylic acid(Poly(I:C)) and dexamethasone(DEX) on the thymic morphology and thymic output function,and explored the implication of RLR signaling pathway.Methods: 24 male C57BL/6 mice were randomly assigned into three groups and treated with Poly(I:C),DEX,or saline respectively.Thereafter,their thymic morphology,pathological changes,thymic index,and thymic pathology were examined.Their contents of T-cell receptor excision circles (TRECs) and proportions of the naive CD4+T cell in the peripheral blood were determined to evaluate their thymic output function.The expression levels of thymic RLR/MAVS/IFN-α/β signaling pathway and IL-1β were also measured.Results: Both Poly (I:C) and DEX treatment caused thymic atrophy in appearance and structural destruction under the microscope inspection,and DEX treatment did much more severe damage,especially to the thymic cortex.TRECs decreased significantly in both groups.The proportions of na?ve/memory CD4+T cell subsets remained stable,though total CD4+T cell decreased in DEX group,while the proportion of na?ve CD4+T cell in Poly (I:C) group increased significantly.The expression of RIG-Ⅰ,MDA5,LGP2,and IFN-α/β were up-regulated in DEX group, while it remained unchanged in Poly (I:C) group.Conclusion:Both Poly (I:C) and DEX induced thymic atrophy and the impaired thymic output function.Nevertheless,the expression of RLR-IFN signaling pathway up-regulated more significantly in DEX group instead of in Poly (I:C) group.These results implied the existence of different pathological manifestations and mechanisms underlying the impaired thymic function in different animal models,as well as impact on na?ve/memory CD4+T cell proportions.Our research provides references for choosing animal models in the basic research and drug development for viral infection induced thymic atrophy based on the RLR signaling pathway.

Effect of Chinese Herbal Extract HNA-1 on the Thymic Output Function in Simian Immunodeficiency Virus Chronically Infected Chinese Rhesus Macaques / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effect of Chinese herbal extract HuNan A-1 (HNA-1) on the thymic output function in Simian immunodeficiency virus (SIV) chronically infected rhesus macaques.</p><p><b>METHODS</b>Eight Chinese rhesus macaques had been infected by SIVmac239 for 16 to 21 months, and then they were randomly divided into the treatment group and the control group, 4 in each group. Monkeys in the treatment group were administered with HNA-1 by gastrogavage, once daily for 2 successive months, while those in the control group were administered with equal volume of normal saline by gastrogavage, once daily for 2 successive months. The general condition and body weight of monkeys were observed. Plasma viral loads were detected using real-time fluorescent quantitative PCR assay. CD4 percentages and counts, as well as naive CD subsets were detected using flow cytometry. T-cell receptor excision circles (TREC) were detected using real-time fluorescent quantitative PCR assay. The thymus tissue was pathologically observed using routine HE staining. The correlation between lesions of the thymus tissue, CD4 counts, naive CD counts, and TREC were analyzed.</p><p><b>RESULTS</b>There was no statistical difference in body weight, viral loads, absolute CD ratios between the two groups after treatment (P > 0.05). The altered TREC multiple showed an obvious decreasing tendency in the control group, while it showed an increasing tendency in the treatment group (P < 0.05). In both groups, destroyed structures of the thymus tissue could be seen, filled with pink unstructured material. Increased connective tissues, lowered connective cell density, and confused arrangement could also be seen in the two groups, with no obvious difference. TREC contents were positively correlated with naive CD4 counts after removing extremum (r = 0.926, P = 0.001). Naive CD4 counts were positively correlated with CD4 counts (r = 0.961, P = 0.005).</p><p><b>CONCLUSIONS</b>TREC content determination, as a marker of newly thymic emigrants, could be taken as a testing method for evaluating the thymic output function. Besides, HNA-1 treatment increased the thymic output significantly in SIV chronically infected monkeys. Correlation existed among TREC contents, naive CD4 counts, and pathologies of thymus tissues, especially in late infection stage.</p>

Regulation of naotai recipe on the expression of HIF-lα/VEGF signaling pathway in cerebral ischemia/reperfusion rats / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the therapeutic angiogenesis effect of naotai recipe (NR) on local ischemia/reperfusion (I/R) injury of rats by observing signaling pathway of hypoxia-inducible factor-lα (HIF-1α) and vascular endothelial growth factor (VEGF).</p><p><b>METHODS</b>Totally 120 Sprague-Dawley (SD) rats were randomly divided into 4 groups, namely, the normal control group (n =12), the sham-operation group (n =12), the I/R model group (n =48), and the NR group (n =48). Cerebral I/R injury models were established using thread suture method. Rats in the I/R model group and the NR group were sub-divided into 4 sub-groups according to the 1st, 3rd, 5th, and 7th I/R day (n =12). The phenomenon of neovasculization was observed by immunofluorescence staining. The protein and mRNA expression levels of HIF-la, VEGF-A, and VEGFR II receptor were detected by RT-PCR.</p><p><b>RESULTS</b>There were a large amount of labels for neovasculization in the ischemic area of the NR group. Double-immunofluorescence labeling [vWF (red) and BrdU (green)] was observed in the NR group. Compared with the model group, the HIF-1α protein expression was obviously enhanced on the 1 st day of I/R (P <0.01), and the VEGF protein expression started to enhance on the 3rd day in the NR group (P <0.01). The VEGFR protein expression level was the highest in the NR group on the 5th day of I/R (P <0.01). The protein expression of VEGF and HIF-1α started to decrease on the 7th day of I/R.</p><p><b>CONCLUSION</b>NR could strengthen angiogenesis after I/R by elevating the expression of HIF-lα and activating HIF-lα/VEGF signaling pathway.</p>

Effects of 5-Aza-2-deoxycytidine on DNA methylation of anti-oncogenes in non-small cell lung cancer cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To observe the expression of SFRP1 gene methylation in non-small cell lung cancer (NSCLC), and study the effect of 5-Aza-2-deoxycytidine (5-Aza-CdR) on DNA methylation and expression of SFRP1, p16 and MGMT genes in the human lung cancer cell line SPC-A-1 cells.</p><p><b>METHODS</b>SP immunohistochemistry and methylation-specific PCR were used to detect the SFRP1 methylation in 60 NSCLC cases, and 21 cases of benign lung diseases were used as control group. SPC-A-1 cells were cultured and treated with 5-Aza-CdR. The promoter methylation status of SFRP1, p16 and MGMT genes were detected by methylation-specific polymerase (MSP) chain reaction, and mRNAs were detected by real-time PCR.</p><p><b>RESULTS</b>The positive rate of SFRP1 gene methylation in NSCLC was significantly higher than that in normal lung tissue (58.3% vs. 14.3%; χ(2) = 12.118, P = 0.001). SFRP1 gene methylation was closely correlated with lymph node metastasis and degree of differentiation in NSCLC (P < 0.05). SFRP1 protein expression was correlated with clinical stage, degree of differentiation and lymph node metastasis in NSCLC (P < 0.05). The positive expression of SFRP1 protein in 30 cases of NSCLC tissue containing SFRP1 gene methylation was significantly higher than that in non-methylated NSCLC (68.6% vs. 24.0%; χ(2) = 9.613, P = 0.002). SFRP1 gene methylation was closely correlated with SFRP1 gene protein expression in NSCLC (P < 0.05). Negative expression of SFRP1 protein was correlated with the differentiation, clinical stage, and lymph node metastasis in NSCLC (all P < 0.05). Without 5-Aza-CdR treatment, the expressions of methylation of SFRP1, p16 and MGMT genes and their mRNA were low. After 5-Aza-CdR treatment at different concentrations, their expressions were significantly elevated (all P < 0.05).</p><p><b>CONCLUSIONS</b>SFRP1 gene methylation is closely associated with carcinogenesis and development of NSCLC. 5-Aza-CdR may reverse the methylation of SFRP1, p16 and MGMT genes, and facilitate the re-expression of the anti-oncogenes.</p>

Genetic characterization of two Seoul virus strains isolated from patients and rats in Hebei province / 中华流行病学杂志

Objective Complete S and M segments of two Seoul virus (SEOV) strains were obtained to determine their genetic types and characteristics. Methods The complete S and M segments from the isolate Li and lung tissue (sample LF18) were amplified by RT-PCR. Genetic analyses were performed by using DNAStar and PHYLIP program package. Results Their sequences consisted of 1772 nucleotides, and had an open reading frame (ORF, 43 to 1332 nt)encoding a nucleoprotein of 429 amino acids for both two strains. The complete M segment sequences consisted of 3653 nucleotides and had an ORF encoding a GnGc precursor of 1133 amino acids. The GnGc precursor of the two strains had 62 cysteine and 6 N-glycosylation sites. Both two strains shared a high degree of homology with other known SEOV strains including strains L99, Gou3, and vaccine strain Z37, with 87.6% to 99.2% and 83.6% to 97.3% nucleotide identities, respectively. On the S-and M- trees, the two strains LF18 and Li were grouped into the third cluster of SEOV. Conclusion Both LF18 and Li strains belonged to SEOV and shared the congruent genetic characteristics with the vaccine strains Z37. Thus, the bivalent vaccine including the strain Z37 could effectively prevent HFRS which was caused by SEOV in Hebei province.