Dabigatran is an orally active direct thrombin inhibitor, initially approved by FDA for the prophylaxis of stroke and systemic embolism in the setting of non-valvular atrial fibrillation (NVAF). Major bleeding is its most common adverse event which is of great concern. However, other types of adverse events such as esophagitis, esophageal ulcer, exanthem and pustular eruptions were reported increasingly in recent years. We present a case of immune hemolytic anemia (IHA) due to dabigatran use in a 72-year-old male with NVAF. This new and rare reported type of adverse event associated with dabigatran suggests that dabigatran may be a new cause of drug-induced immune hemolytic anemia (DIIHI).

Papillary thyroid cancer (PTC) accounts for 80% of all thyroid cancers and seriously impacts the quality of people's lives. Long noncoding RNAs (lncRNAs) play an important role in PTC. In previous studies, thousands of lncRNAs were screened to study their potential relationships with PTC. The aim of this study was to investigate the effect of RPL34-AS1 in PTC and to explore its potential mechanisms. Bioinformatic analyses were performed to characterize the possible function and biological features of RPL34-AS1. Apoptosis, proliferation, and invasion were detected to assess the effect of RPL34-AS1. Cell proliferation was measured using a Cell Counting Kit-8 assay. Western blot analysis was used to assess the apoptosis proteins Bax and Bcl-2. Cell invasion was measured using a Transwell assay. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis was performed to examine RPL34-AS1, miR-3663-3P, and RGS4 expression. Dual-luciferase assay was performed to assess the binding of miR-3663-3P by RPL34-AS1. RIP experiment was used to verify the combination between miR-3663-3p and RGS4. We found that overexpression of RPL34-AS1 could inhibit proliferation and invasion while promoting apoptosis in PTC cell lines. Moreover, RPL34-AS1 could also competitively bind miR-3663-3p and exert its function by regulating the miR-3663-3p/RGS4 in PTC cell lines. We found a previously uncharacterized lncRNA, RPL34-AS1, and studied its function and mechanism in PTC. Our research will provide new insights into PTC and new clues for its clinical treatment.

Background: Glioma is a highly malignant brain tumor with limited therapeutic options. We reported previously that the DNA and protein of human herpesvirus 6 (HHV-6) could be detected in glioma tumor tissues. However, the effects of HHV-6 U94, which is abundantly expressed during the virus' latency period, on glioma progression remain unknown. In the present study, we aimed to determine on the roles of HHV-6 U94 in glioma progression.Methods: The ectopic expression of U94 in glioma U87 cells was achieved using lentivirus infection. The effects of HHV-6 U94 on cell proliferation, migration, and invasion were examined using cell counting kit-8 (CCK-8), colony formation, wound healing, Transwell migration, and invasion assays. The gene expression profiles of U94-expressing U87 cells were analyzed using microarray analysis and confirmed by quantitative RT-PCR and western blotting analysis. The effects of HHV-6 U94 on glioma tumor growth were evaluated using a xenograft nude mouse model.Results: We found that ectopic expression of U94 in glioma U87 cells dramatically inhibited colony formation and cell proliferation in vitro, and suppressed xenograft tumorigenesis in glioma-bearing nude mice. In addition, overexpression of U94 suppressed the migration and invasion of glioma U87 cells. Furthermore, enhanced expression of U94 in glioma cells downregulated ras-related protein rap-1A (RAP1A), solute carrier family 7 member 11 (SLC7A11), forkhead box P1 (FOXP1), and transcription factor 4 (TCF4) expression by inhibiting Akt kinase (AKT/glycogen synthase kinase 3 beta (GSK3β) signaling, which proteins are associated with the malignant phenotypes of glioma cells.Conclusions: Taken together, these data indicated that HHV-6 U94 could suppress tumor cell proliferation and invasion by inhibiting AKT/GSK3β signaling in glioma.

Co-infection with HIV-1 and Kaposi's sarcoma-associated herpesvirus (KSHV) is the cause of aggressive AIDS-related Kaposi's sarcoma (AIDS-KS) characterized by abnormal angiogenesis. The impact of HIV-1 and KSHV interaction on the pathogenesis and extensive angiogenesis of AIDS-KS remains unclear. Here, we explored the synergistic effect of HIV-1 Tat and KSHV oncogene Orf-K1 on angiogenesis. Our results showed that soluble Tat or ectopic expression of Tat enhanced K1-induced cell proliferation, microtubule formation and angiogenesis in chorioallantoic membrane and nude mice models. Mechanistic studies revealed that Tat promoted K1-induced angiogenesis by enhancing NF-κB signaling. Mechanistically, we showed that Tat synergized with K1 to induce the expression of miR-891a-5p, which directly targeted IκBα 3′ untranslated region, leading to NF-κB activation. Consequently, inhibition of miR-891a-5p increased IκBα level, prevented nuclear translocation of NF-κB p65 and ultimately suppressed the synergistic effect of Tat- and K1-induced angiogenesis. Our results illustrate that, by targeting IκBα to activate the NF-κB pathway, miR-891a-5p mediates Tat and K1 synergistic induction of angiogenesis. Therefore, the miR-891a-5p/NF-κB pathway is important in the pathogenesis of AIDS-KS, which could be an attractive therapeutic target for AIDS-KS.

Astrocytes are proving to be critical for the development of cognitive functions. In addition, astrocytic activation contributes to cognitive impairment induced by chronic cerebral hypoperfusion. Minocycline has been shown to exhibit long-term neuroprotective effects in vascular cognitive impairment rat models through the inhibition of astrogliosis, and has demonstrated potential for the prevention and treatment of postoperative cognitive decline in elderly patients. This study aimed to examine the effect of minocycline on hippocampal astrocytes and long-term postoperative cognitive dysfunction in aged mice. Mice were intraperitoneally injected with 45 mg/kg minocycline once a day for 30 days after 70% hepatectomy. Hippocampus-dependent spatial memory ability was evaluated using the Morris water maze test. The expression levels of hippocampal glial fibrillary acidic protein (GFAP) and ionized calcium-binding adaptor molecule-1 were evaluated by western blotting, and the hippocampal mRNA relative expression levels of tumor necrosis factor-α, interleukin-1β, and interleukin-6 were tested using real-time PCR. The Morris water maze test showed that escape latency and swim distance were significantly prolonged by the surgery, but the extent of impairment was mitigated by minocycline treatment. Hippocampal GFAP levels and mRNA levels of tumor necrosis factor-α, interleukin-1β, and interleukin-6 showed corresponding changes that were consistent with the variations in spatial memory. Minocycline was able to alleviate hepatectomy-related long-term spatial memory impairment in aged mice, and was associated with reduced levels of hippocampal GFAP and proinflammatory cytokines resulting from astrocytic activation.

In this study, we demonstrate that infection of HSB-2 cells with human herpesvirus 6 (HHV-6) resulted in the accumulation of infected cells in the G2/M phase of the cell cycle. Analysis of various cell-cycle-regulatory proteins indicated that the levels of cyclins A2, B1, and E1 were increased in HHV-6-infected cells, but there was no difference in cyclin D1 levels between mock-infected and HHV-6-infected cells. Our data also showed that inducing G2/M phase arrest in cells infected by HHV-6 provided favorable conditions for viral replication.

Kaposi's sarcoma (KS) is an AIDS-defining cancer with aberrant neovascularization caused by KS-associated herpesvirus (KSHV). Although the interaction between HIV-1 and KSHV plays a pivotal role in promoting the aggressive manifestations of KS, the pathogenesis underlying AIDS-KS remains largely unknown. Here we examined HIV-1 Nef protein promotion of KSHV oncoprotein K1-induced angiogenesis. We showed that both internalized and ectopic expression of Nef in endothelial cells synergized with K1 to facilitate vascular tube formation and cell proliferation, and enhance angiogenesis in a chicken CAM model. In vivo experiments further indicated that Nef accelerated K1-induced angiogenesis and tumorigenesis in athymic nu/nu mice. Mechanistic studies revealed that Nef and K1 synergistically activated PI3K/AKT/mTOR signaling by downregulating PTEN. Furthermore, Nef and K1 induced cellular miR-718, which inhibited PTEN expression by directly targeting a seed sequence in the 3′ UTR of its mRNA. Inhibition of miR-718 expression increased PTEN synthesis and suppressed the synergistic effect of Nef- and K1-induced angiogenesis and tumorigenesis. These results indicate that, by targeting PTEN, miR-718 mediates Nef- and K1-induced angiogenesis via activation of AKT/mTOR signaling. Our results demonstrate an essential role of miR-718/AKT/mTOR axis in AIDS-KS and thus may represent an attractive therapeutic target.

目的:构建含人类疱疹病毒6A亚型DR7基因的慢病毒,研究DR7基因表达对神经胶质瘤细胞U87增殖、迁移、侵袭能力的影响。方法:PCR扩增DR7基因,克隆至慢病毒载体pLenti6.3-MCS-IRES2-EGFP,构建pLenti6.3-DR7-IRES2-EGFP重组慢病毒载体,经293T细胞包装重组病毒转染至神经胶质瘤细胞U87,经blasticidin筛选建立稳定表达株,通过细胞增殖实验、细胞周期实验、细胞划痕及Transwell实验研究稳定表达DR7基因对U87细胞的增殖、迁移及侵袭能力的影响。结果:成功构建了pLenti6.3-DR7-6×His-IRES2-EGFP慢病毒表达载体,筛选了稳定表达DR7基因的U87-DR7-EGFP细胞株,CCK-8细胞增殖实验显示,稳定表达DR7基因的U87-DR7-EGFP细胞与阴性对照细胞U87-NC-EGFP、U87细胞相比,细胞增殖活性明显增高,差异具有统计学意义（P＜0.001）。细胞周期检测发现U87-DR7-EGFP细胞S、G2/M期细胞所占比例多于U87-NC-EGFP、U87细胞:S期的比例分别为（34.73±1.12）%、（24.89±0.93）%、（25.39±0.96）%,差异具有统计学意义（P＜0.001）;G2/M期分别为（17.35±1.61）%、（11.36±1.50）%、（13.17±1.95）%,差异具有统计学意义（P＜0.05）。细胞划痕实验表明,U87-DR7-EGFP细胞愈合能力明显强于U87-NC-EGFP、U87细胞,划痕6 h愈合率分别为:（33.55±2.83）%、（23.50±3.18）%、（22.03±1.47）%,差异具有统计学意义（P＜0.01）;划痕12 h愈合率分别为（70.50±5.39）%、（53.60±4.67）%、（55.09±2.83）%,差异具有统计学意义（P＜0.001）。Transwell实验表明,U87-DR7-EGFP细胞的穿膜数量明显多于U87-NC-EGFP、U87细胞,分别为:（543.00±22.94）、（387.00±15.63）、（412.00±20.30）个,差异具有统计学意义（P＜0.001）。结论:人类疱疹病毒6A亚型DR7基因表达能在体外促进人神经胶质瘤细胞U87增殖、迁移及侵袭,提示其在神经胶质瘤的发生和发展中可能起一定作用。

ABSTRACT Human herpesvirus 6 (HHV-6) is an important immunosuppressive and immunomodulatory virus. The mechanisms by which HHV-6 establishes latency and immunosuppression in its host are not well understood. Here we characterized HHV-6-specific T cells in peripheral blood mononuclear cells (PBMCs) from HHV-6-infected donors. Our results showed that HHV-6 infection could induce both CD4+ and CD8+ HHV-6-specific regulatory T (Treg) cells. These HHV-6-specific Treg cells had potent suppressive activity and expressed high levels of Treg-associated molecules CD25, FoxP3, and GITR. Both CD4+ and CD8+ Treg cells secreted gamma interferon (IFN-γ) and interleukin-10 (IL-10) but little or no IL-2, IL-4, or transforming growth factor β (TGF-β). Furthermore, HHV-6-specifc Treg cells not only could suppress naive and HHV-6-specific CD4+ effector T cell immune responses but also could impair dendritic cell (DC) maturation and functions. In addition, the suppressive effects mediated by HHV-6-specific Treg cells were mainly through a cell-to-cell contact-dependent mechanism but not through the identified cytokines. These results suggest that HHV-6 may utilize the induction of Treg cells as a strategy to escape antivirus immune responses and maintain the latency and immunosuppression in infected hosts.

Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) is etiologically associated with KS, the most common AIDS-related malignancy. KS is characterized by vast angiogenesis and hyperproliferative spindle cells. We have previously reported that HIV-1 Tat can trigger KSHV reactivation and accelerate Kaposin A-induced tumorigenesis. Here, we explored Tat promotion of KSHV vIL-6-induced angiogenesis and tumorigenesis. Tat promotes vIL-6-induced cell proliferation, cellular transformation, vascular tube formation and VEGF production in culture. Tat enhances vIL-6-induced angiogenesis and tumorigenesis of fibroblasts and human endothelial cells in a chicken chorioallantoic membrane (CAM) model. In an allograft model, Tat promotes vIL-6-induced tumorigenesis and expression of CD31, CD34, SMA, VEGF, b-FGF, and cyclin D1. Mechanistic studies indicated Tat activates PI3K and AKT, and inactivates PTEN and GSK-3β in vIL-6 expressing cells. LY294002, a specific inhibitor of PI3K, effectively impaired Tat's promotion of vIL-6-induced tumorigenesis. Together, these results provide the first evidence that Tat might contribute to KS pathogenesis by synergizing with vIL-6, and identify PI3K/AKT pathway as a potential therapeutic target in AIDS-related KS patients.

Objective: To study the relationship between human herpesvirus(HHV)-6 infection and glioma.Methods:HHV-6,human cytomegalovirus(HCMV) and HHV-7 DNA in glioma samples(n = 40) and control samples(n = 13) were detected by nested PCR.The expression of HHV-6,HCMV and HHV-7 was detected by immunohistochemistry(IHC).Results:HHV-6 DNA was positive in 17/40(42.5%) of glioma samples and 1/13(7.7%) of normal brain samples(P = 0.020),while the positive rates of HCMV and HHV-7 DNA were 20.0% and 5.0% in glioma,respectively.HCMV and HHV-7 DNA hadn't been found in normal brain samples(P = 0.087 and 0.566 respectively).HHV-6 late antigen p41 was expressed in 11/40(27.5%) of tumors and 0 of the controls(P = 0.030),while HHV-6 early antigen gp116/64/54 was expressed in 13/40(32.5%) of tumors and 0 of the controls(P = 0.014).HCMV pp65 antigen was expressed in 5/40(12.5%) of glioma samples and 0/13 of the normal brain controls(P = 0.229).HHV-7 pp85 antigen hadn't been found in tumors and normal brain samples.Conclusion:Based on the results of nested PCR and immunohistochemistry,significant difference of HHV-6 infection between glioma and normal brain tissue was confirmed.HHV-6 infection may play a role on the pathagenesis and progression of glioma.

The etiology of glioma remains unclear so far. Human herpesvirus 6 (HHV-6) might be associated with glioma, but there is no direct evidence to support this. High percentages of HHV-6 DNA and protein were detected in tissue from gliomas, compared with normal brain tissue. In addition, a strain of HHV-6A was isolated from the fluid specimens from glioma cysts. High levels of interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor α, and transforming growth factor β (TGF-β) were detected in the cyst fluid specimens from HHV-6-positive patients with glioma. Furthermore, HHV-6A infection promoted IL-6, IL-8, and TGF-β production in astrocyte cultures. Our studies strongly suggest the involvement of HHV-6 infection in the pathogenesis of glioma.

Enterovirus 71(EV71) causes recurring outbreaks of hand, foot and mouth disease and encephalitis leading to complications or death in young children. More effective antiviral drugs are needed to prevent or reduce EV71-related disease and complications. However, there are no standard models currently in use to evaluate activity against EV71 infection both in vitro and in vivo. In this study, the activity of ribavirin and pleconaril against EV71 infection was evaluated in two models. An in vitro EV71 infection model was developed in RD cells, and an in vivo EV71 infection model was applied. Ribavirin and pleconaril effectively increased the viability of infected cells. Pleconaril reduced the morbidity and mortality of one-day-old infected mice, but ribavirin did not protect the infected mice. In all, the results demonstrated that infected cells and infected mice can be used to evaluate antiviral activity of ribavirin and pleconaril against EV71 infection in vitro and in vivo.

Human herpesvirus 6 (HHV‐6) is a beta‐herpesvirus capable of infecting cells from different origin. In this study, infection with HHV‐6A of human embryonic fibroblasts (HEFs) was performed. Infected cells showed obvious cytopathic effects (CPE). PCR and immunohistochemical tests also confirmed that HEFs are susceptible to HHV‐6A infection. The biological effects of HHV‐6A infection on HEFs were studied. Infected cells showed decreased proliferation as measured by [ 3 H] thymidine incorporation and cell counting. Further analysis demonstrated that infection with HHV‐6A leads to cell cycle arrest at G2/M phase and increasing cell death. This is the first demonstration that infection of HEFs with HHV‐6A causes profound alterations of cell properties. J. Med. Virol. 84:657–663, 2012. © 2011 Wiley Periodicals, Inc.

Human herpesvirus-6 (HHV-6) is an important immunosuppressive and immunomodulatory virus that primarily infects immune cells (mainly CD4(+) T cells) and strongly suppresses the proliferation of infected cells. Toll-like receptors are pattern-recognition receptors essential for the development of an appropriate innate immune defense against infection. To understand the role of CD4(+) T cells in the innate response to HHV-6 infection and the involvement of TLRs, we used an in vitro infection model and observed that the infection of CD4(+) T cells resulted in the activation of JNK/SAPK via up-regulation of toll-like receptor 9 (TLR9). Associated with JNK activation, annexin V-PI staining indicated that HHV-6A was a strong inducer of apoptosis. Apoptotic response associated cytokines, IL-6 and TNF-α also induced by HHV-6A infection.

Human immunodeficiency virus type 1 (HIV-1) infection significantly increases the risk and development of Kaposi's sarcoma (KS) in individuals infected with KS-associated herpesvirus (KSHV). Previously, we reported that HIV-1 Tat protein induced KSHV replication by modulating the Janus kinase/signal transducers and activators of transcription signaling pathway. Here, we further investigated the possible signaling pathways involved in HIV-1-induced reactivation of KSHV. We showed that HIV-1 infection of primary effusion lymphoma cell lines triggered the reactivation of KSHV, as demonstrated by the expression of KSHV replication and transcription activator, the early viral lytic protein vIL-6 and ORF59 and the production of progeny virions. By utilizing microarray gene expression analyses, transfecting a series of dominant negative mutants, and adding pharmacologic inhibitors, we identified a group of diverse cellular signaling proteins and found that HIV-1 infection of BCBL-1 cells activated phosphatidylinositol 3-kinase/AKT (also called protein kinase B, PKB) pathway and inactivated phosphatase and tensin homolog deleted on chromosome ten and glycogen synthase kinase-3β, which partially modulated HIV-1-induced KSHV reactivation. Furthermore, activation of Ras/c-Raf/MAPK/ERK kinase1/2 pathway contributed to HIV-1-induced KSHV replication. Finally, we discovered that HIV-1 infection activated nuclear factor κB signaling, which exhibits an inhibitory effect on KSHV reactivation in BCBL-1 cells. Collectively, our data demonstrated that HIV-1 infection stimulated these cell signaling pathways that, in turn, contributed to KSHV reactivation, which may be of therapeutic value in acquired immunodeficiency syndrome-related KS patients.

Objective:To study neural cell tropism of human herpesvirus 6A(HHV-6A) and its effect on neural cell cycle.Methods:The cell morphology was assessed by a light microscope.The fragment of HHV-6A U22 gene was amplified by PCR and relative amount of HHV-6A U22 gene was analyzed using quantitative real-time PCR.Expression of HHV-6A gB was examined by immunocytochemical and Western blot analysis.Cell proliferation was measured by MTT assay.Cell cycle analysis was evaluated by the propidium iodide assay.Results:On the fifth day after being infected by HHV-6A,U373 cells had no obvious change,but SK-N-SH and SHG44 cells showed cytopathic effect.HHV-6A U22 gene was detected in all three infected cell lines and its relative amounts kept reducing all the time.HHV-6A gB was positive in the three infected cell lines,furthermore,the expression levels in U373 and SHG44 were more than those in SK-N-SH.HHV-6A stimulated the proliferations of U373 and SHG44 cells,however,inhibited the proliferation of SK-N-SH cells significantly.Compared with uninfected cells,percentages of U373 and SGH44 cells were decreased in phase G1 but increased in phase S and G2 after cells were infected by HHV-6A,as to SK-N-SH,the percentages were increased in phase G1 but decreased in S and G2 phases.Conclusion:All three neural cell lines can sustain replication of HHV-6A,and moreover,HHV-6A can boost astrocyte proliferation and inhibit neuronal cell proliferation.

Human herpesvirus 6 (HHV-6) is an important immunosuppressive and immunomodulatory virus that primarily infects immune cells and strongly suppresses the proliferation of infected cells. However, the mechanisms responsible for the regulation and suppression mediated by HHV-6 are still unknown. In this study, we examined the ability of HHV-6A to manipulate cell cycle progression in infected cells and explored the potential molecular mechanisms. We demonstrated that infection with HHV-6A imposed a growth-inhibitory effect on HSB-2 cells by inducing cell cycle arrest at the G(2)/M phase. We then showed that the activity of the Cdc2-cyclin B1 complex was significantly decreased in HHV-6A-infected HSB-2 cells. Furthermore, we found that inactivation of Cdc2-cyclin B1 in HHV-6A-infected cells occurred through the inhibitory Tyr15 phosphorylation resulting from elevated Wee1 expression and inactivated Cdc25C. The reduction of Cdc2-cyclin B1 activity in HHV-6-infected cells was also partly due to the increased expression of the cell cycle-regulatory molecule p21 in a p53-dependent manner. In addition, HHV-6A infection activated the DNA damage checkpoint kinases Chk2 and Chk1. Our data suggest that HHV-6A infection induces G(2)/M arrest in infected T cells via various molecular regulatory mechanisms. These results further demonstrate the potential mechanisms involved in immune suppression and modulation mediated by HHV-6 infection, and they provide new insights relevant to the development of novel vaccines and immunotherapeutic approaches.