A Mouse Model for Infection with Enterovirus A71 in Small Extracellular Vesicles.

Enterovirus A71 (EV-A71) is the major pathogen of hand, foot, and mouth disease (HFMD); in some severe cases, it could develop into central nervous system (CNS) disease such as aseptic meningitis, encephalitis, and neurogenic pulmonary edema in children under 5 years. The EV-A71 pathogenesis which is involved with the CNS is unclear due to the lack of a simple and reliable mouse model thus far. Most clinical EV-A71 isolates could not effectively infect the neonatal mouse, which used to be an EV-A71 infection model. The small extracellular vesicles (sEVs) released from clinical EV-A71 isolate-infected cells were infectious in cell lines and could cause a high viral replication in mice. Neonatal ICR mice were injected intraperitoneally with these infectious sEVs and showed more weight loss and higher mortality than those mice injected with the clinical EV-A71 isolate. By using these sEVs, we provided a simple and effective method by which we can generate a stable and valuable animal model for the studies of EV-A71 pathogenesis and therapy.IMPORTANCE EV-A71 was supposed to infect the CNS through the neural pathway and the circulation of the blood in previous studies. Reverse axon transport had been confirmed as an important pathway for EV-A71 to infect the CNS; however, it is still unknown how EV-A71 infects the CNS through the circulation of the blood. Combined with the infectivity of sEVs secreted from EV-A71-infected cells and the characteristic that sEVs could cross the blood-brain barrier, we considered that sEVs may play a vital role in EV-A71 pathogenesis of the CNS.

Exosomes cloak the virion to transmit Enterovirus 71 non-lytically.

Enterovirus 71 (EV71) is a non-enveloped virus and it can be released from host cells through a traditional cytolytic manner. Now, we showed EV71 could be spread non-lytically between cells during early viral infection. In order to explain this phenomenon, we separated supernatant fluids of rhabdomyosarcoma (RD) cells cultures infected with EV71 by isopycnic gradient centrifugation. Two populations of virus particles were morphology indistinguishable by transmission electron microscope (TEM). It showed that some EV71 particles were wrapped inside extracellular vesicles which were verified to be exosomes by immunoassay and morphologic analysis. In addition, exosomes containing viral RNA were shed in plasma of EV71-infected encephalitis in children. Our findings indicate that the "non-enveloped" EV71 virions could be wrapped within exosomes which promote their spread in the absence of cell lysis.Abbreviation: EV71: enterovirus 71; EXO: exosome; RD: rhabdomyosarcoma; TEM: transmission electron microscope; HFMD: hand, foot, and mouth disease; HIV: immunodeficiency virus; HCV: hepatitis C virus; HTLV: Human T-cell lymphotropic virus; HAV: hepatitis A virus; MOI: multiplicity of infection; EVs: extracellular vesicles; VP1: viral capsid protein 1; NTA: nanoparticle tracking analysis; CNS: central nervous system.

Exosomal MicroRNA-155 Inhibits Enterovirus A71 Infection by Targeting PICALM.

Enterovirus A71 (EV-A71) causes hand, foot, and mouth disease (HFMD) that is associated with neurological complications. Researchers have shown that exosomes containing host cellular microRNA (miRNA) can modulate the recipient's cellular response during viral infection. However, it is unclear how exosomal miRNAs regulate this response during EV-A71 infection. In this study, we used an exosomal miRNA chip to show that microRNA-155 (miR-155) was markedly enriched in exosomes after EV-A71 infection. Moreover, exosomal miR-155 efficaciously inhibited EV-A71 infection by targeting phosphatidylinositol clathrin assembly protein (PICALM) in recipient cells. Importantly, we confirmed that exosomal miR-155 reduced EV-A71 infection severity in vivo. Additionally, miR-155 levels in throat swabs from EV-A71-infected patients were higher than in those from healthy individuals. Collectively, our findings provide evidence that exosomal miR-155 plays a role in host-pathogen interactions by mediating EV-A71 infection via the repression of PICALM; these results provide insights into the regulatory mechanisms of viral infection.

Metformin Attenuates Neurological Deficit after Intracerebral Hemorrhage by Inhibiting Apoptosis, Oxidative Stress and Neuroinflammation in Rats.

Intracerebral hemorrhage (ICH) can lead to brain damage and even death, and there is lack of effective therapeutic methods for treating ICH. Although recent studies have focused on the administration of metformin in treating stroke, there is no literature to support whether it can be used to treat ICH. Therefore, the aim of this study was to evaluate the possible effects of metformin on ICH and the underlying mechanisms of those effects. An ICH model was established in adult male Sprague-Dawley rats. Rats were randomly divided into three groups: sham group, ICH group, and ICH+metformin group. The neurobehavioral deficit scoring method was used to examine neurological function in rats. The levels of lipid peroxidation antioxidant enzyme and 8-iso-PGF2α were detected to evaluate oxidative stress. Survival of striatal neurons was examined by TUNEL staining, immunohistochemistry and HE staining. The levels of p-JNK, p-c-Jun and cleaved caspase-3 in the striatum were measured by western blotting. The results demonstrated that metformin protected rats from neurological deficits induced by ICH. Moreover, metformin reduced oxidative stress and preserved the survival of striatal neurons under ICH conditions. Furthermore, metformin downregulated the levels of apoptotic factors (p-JNK3, p-c-Jun and cleaved caspase-3) as well as pro-inflammatory cytokines (IL-1ß, IL-4 and IL-6 and TNF-α). Collectively, we speculate that metformin may be a potential clinical treatment for ICH patients.

[Application of esmolol in severe hand, foot, and mouth disease].

OBJECTIVE: To study the clinical effect and mechanism of action of esmolol in the treatment of severe hand, foot, and mouth disease (HFMD). METHODS: A prospective randomized controlled trial was performed. A total of 102 children with severe HFMD were enrolled in the study and were randomly divided into conventional treatment and esmolol treatment groups (n=51 each). The children in the conventional treatment group were given conventional treatment according to the guidelines for the diagnosis and treatment of HFMD. Those in the esmolol treatment group were given esmolol in addition to the conventional treatment. The heart rate (HR), systolic blood pressure (SBP), and respiratory rate (RR) were continuously monitored for all children. Blood samples were collected from all children before treatment and 1, 3, and 5 days after treatment to measure the levels of norepinephrine (NE), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and nuclear factor-kappa B (NF-κB) p65 in mononuclear cells. Serum levels of myocardial enzymes and N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured before treatment and after 5 days of treatment. RESULTS: There were no significant differences in HR, SBP, RR, NE, TNF-α, IL-6, NF-κB p65, serum myocardial enzymes, and NT-proBNP before treatment between the conventional treatment and esmolol treatment groups. Both groups had significant reductions in these parameters at each time point (P<0.05). Compared with the conventional treatment group, the esmolol treatment group had significant improvements in the above parameters after 1 and 3 days of treatment (P<0.05). After 5 days of treatment, the esmolol treatment group had significant improvements in serum levels of myocardial enzymes and NT-proBNP compared with the conventional treatment group (P<0.05). CONCLUSIONS: Early application of esmolol can effectively stabilize the vital signs of the children with severe HFMD. Its mechanism of action may be related to reducing serum catecholamine concentration, alleviating myocardial damage, improving cardiac function, and reducing inflammatory response.

[Expression of vasoactive intestinal peptide in peripheral blood of children with hand, foot and mouth disease].

OBJECTIVE: To investigate the expression of vasoactive intestinal peptide (VIP) in peripheral blood of children with hand, foot and mouth disease and its significance. METHODS: According to the condition of the disease, 86 children with hand, foot and mouth disease were classified into phase 1 group (19 children) and phase 2 group (67 children). ELISA was used to measure the concentrations of plasma VIP, interferon-γ (IFN-γ), and interleukin-4 (IL-4) in peripheral blood. Flow cytometry was used to measure CD3+, CD4+, and CD8+ T lymphocyte subsets. RT-PCR was used for qualitative detection of enterovirus 71 (EV71) RNA in stool. RESULTS: Compared with the phase 1 group, the phase 2 group had a significantly higher positive rate of EV71-RNA (P<0.05) and significantly higher serum levels of IgG, IgA, IgM, and C3 (P<0.05). The phase 2 group had significantly lower proportions of peripheral CD3+, CD4+, and CD8+ T lymphocyte subsets than the phase 1 group (P<0.05), as well as significantly lower proportion of peripheral B cells and CD4+/CD8+ ratio than the phase 1 group (P<0.05). The phase 2 group also had a significantly lower concentration of VIP in peripheral blood than the phase 1 group (P<0.05). In the 86 children with hand, foot and mouth disease, the concentration of VIP in peripheral blood was positively correlated with the proportion of CD4+ T lymphocyte subset and CD4+/CD8+ ratio (r=0.533 and 0.532 respectively; P<0.05). CONCLUSIONS: VIP may be an important marker of the severity of hand, foot and mouth disease.

Clinical significance of lymphocyte subset changes in hemophagocytic lymphohistiocytosis of children.

In order to examine the role of peripheral blood lymphocyte subsets on the diagnosis, treatment and prognosis of hemophagocytic lymphohistiocytosis (HLH), 30 affected children during the acute period of the disease and 30 healthy children within the same age range were selected to test their peripheral blood lymphocyte subsets using flow cytometry and compare these subsets. At the same time, the peripheral blood lymphocyte subsets of 20 children with complete remission from HLH were compared to those of 10 cases who succumbed to the disease. The proportion of CD3+ and CD8+ T cells were increased in children during the acute period. Additionally, the proportion of CD4+ T and CD3-CDl6+CD56+ natural killer (NK) cells and the ratio of CD4+/CD8+ cells were decreased in the same group of children, with the differences being statistical significance (P<0.05). The proportion of CD19+ B cells showed no differences in the affected and healthy groups. HLH children during the remission period had a higher proportion of CD3+ and CD8+ T cells than that in the control group, but the ratio of CD4+ T and CD4+/CD8+ were lower than that in the control group, with the differences being statistically significant (P<0.05). The proportion of CD19+ B cells and CD3-CD16+CD56+ NK cells revealed no significant difference between the two groups. In addition, regarding the proportion of CD3+, CD4+, CD8+ T, CD19+ B cells, CD3-CDl6+CD56+ NK cells and the ratio of CD4+/CD8+, and there were no significant differences. The results showed that HLH modifies the peripheral blood lymphocyte subsets and causes cellular immunity disorders. Thus, monitoring these dynamic changes can be useful in the diagnosis of HLH and evaluate the response to therapy.

Ratios of CD64 expressed on neutrophils, monocytes, and lymphocytes may be a novel method for diagnosis of neonatal sepsis.

INTRODUCTION: Neutrophil CD64 expression has been demonstrated as an improved diagnostic marker of infection and sepsis. The purpose of this study was to develop a new method to evaluate neutrophil CD64 expression for diagnosis of neonatal sepsis. METHODOLOGY: Eighty neonates with neonatal sepsis (21 culture positive, 59 negative) were enrolled in this prospective study along with 19 neonates with no symptoms or signs of infection as controls. Expressions of CD64 on monocytes, lymphocytes, and neutrophils were evaluated with flow cytometry (FCM). Ratios were calculated with these levels of CD64 expression. Blood culture and other laboratory exams were done at the same time for the diagnosis of neonatal sepsis. Results were compared between the neonatal sepsis and control groups. RESULTS: CD64 ratios showed significant difference between the groups (p < 0.01). Receiver operating curve (ROC) analysis showed that the CD64 ratios possessed high sensitivity (90%) and specificity (89.5%) in neonatal sepsis identification. CONCLUSIONS: The novel CD64 evaluation method, CD64 ratio, can be used as a supplementary method for diagnosis of neonatal sepsis.

Methionine synthase reductase A66G polymorphism and leukemia risk: evidence from published studies.

Methionine synthase reductase (MTRR) is required for the reductive methylation of cobalamin, which is the functional cofactorial form of methionine synthase (MS) in the remethylation of homocysteine to methionine. The MTRR A66G (rs1801394) polymorphism is found to be associated with decreased enzyme affinity for MTR, the gene that encodes MS, and has been widely investigated for cancer risk, including leukemia. However, the conclusions of epidemiological studies have always been contradictory. To further clarify the association of MTRR A66G polymorphism with the risk of leukemia, this meta-analysis was performed for 2913 cases and 4764 controls. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Pooled ORs were determined for the co-dominant model (GG vs. AA, AG vs. AA), dominant model (GG + AG vs. AA) and recessive model (GG vs. AA+ AG), respectively. No significant associations were found for all comparisons in the overall pooled analysis. However, the results of stratified analyses revealed that MTRR A66G GG genotype was associated with decreased leukemia risk in the Caucasian population, in children and for acute lymphoblastic leukemia (ALL). In contrast, increased risk was observed in the Asian population and for acute myeloid leukemia (AML). This meta-analysis suggests that MTRR A66G GG is associated with decreased risk of leukemia in a Caucasian population and in children, especially for ALL.

Differential effects of paraoxonase 1 (PON1) polymorphisms on cancer risk: evidence from 25 published studies.

Paraoxonase is an HDL-associated enzyme that plays a preventive role against oxidative stress, which is thought to contribute to cancer development. PON1 activity varies widely among individuals, which is in part related to two common nonsynonymous polymorphisms in the PON1 gene (Q192R and L55M). The polymorphisms in PON1 have been implicated in cancer risk. However, results from the studies to date have been conflicting. To clarify the association, a meta-analysis was performed for 7,073 cases and 9,520 controls from 25 published case-control studies. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. Significant associations between PON1-L55M but not Q192R polymorphism and total cancer were observed from all the comparisons. In stratified analyses, PON1-55M allele was a risk factor for breast cancer. Similarly, increased risk was observed for prostate cancer (OR = 1.18, 95% CI: 1.01-1.36, P (heterogeneity) = 0.260) and Caucasian population (OR = 1.18, 95% CI: 1.02-1.38, P (heterogeneity) = 0.1) of the LM genotype, compared with the LL genotype. For PON1-Q192R polymorphism, PON1-192R allele was a decreased risk factor for cancer in the Asian group (RR vs QQ: OR = 0.61, 95% CI: 0.38-0.98, P (heterogeneity) = 0.268; QR vs QQ: OR = 0.71, 95% CI: 0.52-0.96, P (heterogeneity) = 0.130; RR + QR vs QQ: OR = 0.71, 95% CI: 0.53-0.95, P (heterogeneity) = 0.135). Although some modest bias could not be eliminated, this meta-analysis suggests that the PON1-55M allele is a risk factor for the development of cancer, in particular for breast cancer. Future studies with larger sample sizes are warranted to further evaluate these associations.