1.Prevalence of severe fever with thrombocytopenia syndrome virus in ticks and molecular phylogenetic study of viruses in an epidemic area of Suizhou, Hubei Province
DAI Ying ; LIU Cong ; ZHUANG Hang ; YUE Miaomiao ; ZHANG Yating ; HU Bing
China Tropical Medicine 2024;24(4):426-
Abstract: Objective To study severe fever with thrombocytopenia syndrome virus (SFTSV) in tick samples from different species and genera in Suizhou City, Hubei Province, China, and to explore the phylogenetic relationship between ticks and patients sources of viruses at the molecular evolutionary level. Methods In 2016 and 2017, over a continuous two-year period, 1 158 ticks were collected from Suizhou, Hubei, and their species and genera were identified. Meanwhile, 86 serum samples were collected to detect SFTSV RNA by real-time quantitative reverse transcription-PCR. All viral RNA-positive supernatants of tick homogenates were inoculated into Vero cells for viral isolation, and full genome sequencing of isolated strains was conducted. Phylogenetic tree research on SFTSV strains from ticks and cases was performed using the bootstrapped maximum-likelihood (1 000 iterations) method with Molecular Evolutionary Genetics Analysis (MEGA) software, ver. 11.0 to provide confidence estimates. Results Haemaphysalis longicornis, Ixodes sinensis, and Rhipicephalus microplus were the dominant species (95.34%) in Suizhou City, Hubei Province, China. Tick samples were pooled according to their species and developmental stage, yielding 832 pools, of which 4 were positive for SFTSV by qRT-PCR. The overall minimum infection rate (MIR) in the region was 0.35%. One SFTSV strain named HB 2016-P35, was successfully isolated from Haemaphysalis longicornis and demonstrated high homology to 16 previously reported patient-derived viruses in Hubei Province, especially to the human strain HB 2017-49 from the same region, with a genome similarity of 99.9%. In addition, the molecular phylogenetic analysis revealed five distinct SFTSV genotypes in Hubei, covering almost all currently known SFTSV genotypes. Conclusions Some areas of Suizhou City, Hubei Province, demonstrate a relatively low level of SFTSV carrying and transmission by ticks. The new SFTSV strain isolated from ticks exhibits similar genotype characteristics and high sequence homology with viruses carried by cases in surrounding cases. The study suggests that tick-to-human transmission is most likely the pathway for human infection with SFTSV, highlighting the need for continual and long-term monitoring of tick carriage of SFTSV in endemic areas.
2.Effect of miR-30a-5p on the proliferation, apoptosis, invasion and migration of SMCC-7721 human hepatocellular carcinoma cells.
Hang DAI ; Bing KANG ; Deyu ZUO ; Guoqing ZUO
Chinese Journal of Hepatology 2014;22(12):915-920
OBJECTIVETo explore the effect of microRNA-30a-5p (miRNA-30a-5p) on the biological behavior of human hepatoma cells.
METHODSThe liver cancer cell line SMCC-7721 cells and the normal liver cell line L02 cells (control) were transiently transfected with miRNA-30a-5p mimics and an miRNA-30a-5p inhibitor by Lipofectamine 2000 (Life Technologies). miR-30a-5p mRNA expression was detected by quantitative real-time (q)PCR. Cell proliferation was evaluated using the Cell Counting Kit-8 (CCK-8) assay and apoptosis was assessed by flow cytometry.Invasion and migration were measured by transwell chamber assays. The SMCC-7721 cells was injected subcutaneously into nude mice to establish a tumor animal model.
RESULTSThe SMCC-7721 cells transfected with miRNA-30a-5p mimics showed significantly higher miRNA-30a-5p mRNA expression than the non-transfected SMCC-7721 cells and the transfected control L02 cells (P<0.01). The miRNA-30a-5p mRNA expression was significantly lower in the SMCC-7721 cells transfected with the miRNA-30a-5p inhibitor than the non-transfected SMCC-7721 cells the control L02 cells (P<0.01). The overexpression of miRNA-30a-5p inhibited the viability, colony formation rate, and invasion and migration abilities, as shown in the cells transfected with the miRNA-30a-5p mimics (P<0.05); in addition, the miRNA-30a-5p promoted proliferation of cells (P<0.05), as shown by more S phase cells detected by flow cytometry. SMCC-7122 cells transfected with miRNA-30a-5p mimics produced tumors with significantly higher average weight than tumors produced by SMCC-7122 cells that were untransfected or transfected with empty vector (both P<0.01).
CONCLUSIONOverexpression ofmiR-30a-5p had an inhibitory effect on cell proliferation, induced apoptosis, increased the number of cells in S phase, and markedly inhibited invasion and migration of SMCC-7721 HCC cells in vitro and in vivo.
Animals ; Apoptosis ; Carcinoma, Hepatocellular ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Humans ; Liver Neoplasms ; Mice ; Mice, Nude ; MicroRNAs ; Neoplasm Invasiveness ; Transfection
3.Quantitative analysis on the conditions adequate for the existence of the second gas effect
Han-Bing LIANG ; Dong-Hua SHAO ; Li-Hua HANG ; Ti-Jun DAI
The Chinese Journal of Clinical Pharmacology 2014;(9):813-815
Objective To make a quantitative analysis on the existence of the second gas effect.Methods Under the guidance of the macro-scopic theories in thermodynamics and quantitative analysis in mathematics, the second gas effect was discussed at three aspects: the conditions for the existence of the second gas effect , those for the non-existence of the second gas effect and those for the existence of the re-verse second gas effect.Results When the uptake rate of the second gas was equal to the average uptake rate of other gas mixtures , the second gas effect did not exist .When the former was less than the latter , the second gas effect existed .When the former was greater than the latter , the reverse second gas effect existed.Conclusion The existence of the second gas effect is not absolute but conditional.The key factor is the relative size of the uptake rate of the second gas and the average uptake rate of other gas mixtures in alveolar.
4.Intermedin in Paraventricular Nucleus Attenuates Sympathoexcitation and Decreases TLR4-Mediated Sympathetic Activation via Adrenomedullin Receptors in Rats with Obesity-Related Hypertension.
Jing SUN ; Xing-Sheng REN ; Ying KANG ; Hang-Bing DAI ; Lei DING ; Ning TONG ; Guo-Qing ZHU ; Ye-Bo ZHOU
Neuroscience Bulletin 2019;35(1):34-46
Intermedin/adrenomedullin-2 (IMD/AM2), a member of the calcitonin gene-related peptide/AM family, plays an important role in protecting the cardiovascular system. However, its role in the enhanced sympathoexcitation in obesity-related hypertension is unknown. In this study, we investigated the effects of IMD in the paraventricular nucleus (PVN) of the hypothalamus on sympathetic nerve activity (SNA), and lipopolysaccharide (LPS)-induced sympathetic activation in obesity-related hypertensive (OH) rats induced by a high-fat diet for 12 weeks. Acute experiments were performed under anesthesia. The dynamic alterations of sympathetic outflow were evaluated as changes in renal SNA and mean arterial pressure (MAP) in response to specific drugs. Male rats were fed a control diet (12% kcal as fat) or a high-fat diet (42% kcal as fat) for 12 weeks to induce OH. The results showed that IMD protein in the PVN was downregulated, but Toll-like receptor 4 (TLR4) and plasma norepinephrine (NE, indicating sympathetic hyperactivity) levels, and systolic blood pressure were increased in OH rats. LPS (0.5 µg/50 nL)-induced enhancement of renal SNA and MAP was greater in OH rats than in obese or control rats. Bilateral PVN microinjection of IMD (50 pmol) caused greater decreases in renal SNA and MAP in OH rats than in control rats, and inhibited LPS-induced sympathetic activation, and these were effectively prevented in OH rats by pretreatment with the AM receptor antagonist AM22-52. The mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) inhibitor U0126 in the PVN partially reversed the LPS-induced enhancement of SNA. However, IMD in the PVN decreased the LPS-induced ERK activation, which was also effectively prevented by AM22-52. Chronic IMD administration resulted in significant reductions in the plasma NE level and blood pressure in OH rats. Moreover, IMD lowered the TLR4 protein expression and ERK activation in the PVN, and decreased the LPS-induced sympathetic overactivity. These results indicate that IMD in the PVN attenuates SNA and hypertension, and decreases the ERK activation implicated in the LPS-induced enhancement of SNA in OH rats, and this is mediated by AM receptors.
Adrenomedullin
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metabolism
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Animals
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Blood Pressure
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drug effects
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physiology
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Hypertension
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etiology
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Lipopolysaccharides
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pharmacology
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Male
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Neuropeptides
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metabolism
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Obesity
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complications
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Rats, Sprague-Dawley
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Receptors, Adrenomedullin
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drug effects
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metabolism
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Sympathetic Nervous System
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drug effects
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metabolism
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Toll-Like Receptor 4
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metabolism