Elevated circulating miR-494 in plasma of children with enterovirus 71 induced hand, foot, and mouth disease and its potential diagnostic value.

Hand, foot, and mouth disease (HFMD) is a common pediatric disease, whose outcome depends of the enterovirus genotype infecting the patient. The present study is focused on the potential diagnostic value and the role of circulating microRNA-494 (miR-494) in enterovirus 71-induced more severe form of HFMD. We included 102 children with enterovirus 71 (EV71)-induced HFMD, 42 coxsackievirus A16 (CA16)-induced HFMD and 102 healthy controls. The plasma and serum samples were collected. The expression level of circulating miR-494 was determined by RT-PCR method. Moreover, ROC curve has been drawn to evaluate the sensitivity and specificity of circulating miR-494 for the diagnosis of EV71-induced HFMD. Furthermore, the correlation between the circulating miR-494 and the levels of interleukin 6 (IL-6), interleukin 4 (IL-4) and interferon γ (IFN-γ) in the serum of patients were analyzed. Circulating miR-494 was significantly increased in plasma of children with EV71-induced HFMD compared with the healthy children or CA16-induced HFMD, and level of miR-494 in the EV71 severe group was significantly higher than the EV71 mild group. Moreover, results of ROC analysis suggested that miR-494 is a sensitive biomarker to distinguish EV71 patients from healthy controls and CA16 patients. Furthermore, IL-6 and IFN-γ were elevated in serum of patients with EV71-induced HFMD and the level of circulating miR-494 in patients with EV71-induced HFMD was positively correlated with the serum levels of both IL-6 and IFN-γ, respectively. Circulating miR-494 was abnormally up-regulated in plasma of the children with EV71-induced HFMD, and miR-494 may serve as potential biomarker for the diagnosis and treatment of the disease. Keywords: miR-494; HFMD; biomarker; enterovirus 71; inflammation.

MicroRNA 34b inhibits cell proliferation in pediatric acute myeloid leukemia via regulating LDHA.

OBJECTIVE: To elucidate the regulatory effect of microRNA-34b on the occurrence of pediatric acute myeloid leukemia and the underlying mechanism. PATIENTS AND METHODS: The expression of microRNA-34b in the bone marrow of 72 children with newly diagnosed acute myeloid leukemia (AML) was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between microRNA-34b expression and pathological characteristics was analyzed. Kaplan-Meier curve was introduced for evaluating the prognostic value of microRNA-34b in pediatric AML. The regulatory effects of microRNA-34b on proliferation, cell cycle, and apoptosis of leukemia cells were accessed by cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. Bioinformatics prediction and dual-luciferase reporter gene assay were conducted to evaluate the binding between microRNA-34b and lactate dehydrogenase A (LDHA). LDHA expression after overexpression of microRNA-34b was determined by qRT-PCR and Western blot. Rescue experiments were conducted to verify whether microRNA-34b could regulate proliferative and apoptotic behaviors of leukemia cells by suppressing LDHA expression. RESULTS: MicroRNA-34b was markedly downregulated in AML children. Low expression of microRNA-34b was correlated to FAB typing, cytogenetic abnormality, and day 7 response to the treatment of pediatric AML. By collecting the follow-up data, it was found that low expression of microRNA-34b was correlated to the poor prognosis of AML. Overexpression of microRNA-34b inhibited proliferative ability and cell cycle progression, but accelerated apoptosis of AML cells. Dual-luciferase reporter gene assay verified that microRNA-34b could bind to LDHA, thereafter inhibiting LDHA expression. Overexpression of LDHA reversed the regulatory effects of microRNA-34b on proliferation, cell cycle, and apoptosis of AML cells. CONCLUSIONS: We found that microRNA-34b is lowly expressed in pediatric AML patients, and low expression of microRNA-34b may serve as an indicator of malignant progression and poor prognosis of pediatric AML. MicroRNA-34b may affect the proliferation and apoptosis of leukemia cells by regulating the expression of LDHA.

Islet autoantibodies are associated with HLA-DQ genotypes in Han Chinese patients with type 1 diabetes and their relatives.

The objective of this study was to explore the relationship between islet autoantibodies of glutamic acid decarboxylase (GADA), islet antigen-2A (IA-2A), insulin autoantibody (IAA), and human leukocyte antigen (HLA)-DQ genotypes in type 1 diabetes (T1D) patients and their first-degree relatives (FDRs). Cross-sectional and case-control study. Four hundred and ninety-five T1D patients, 419 FDRs, and 376 control subjects in Han Chinese populations were recruited and tested for GADA and IA-2A, while 71 cases, all FDRs and 300 controls were tested for IAA. The 338 T1D patients (including 187 antibody-positive and 151 antibody-negative patients), 173 FDRs and 278 controls were genotyped for HLA-DQ with polymerase chain reaction sequencing-based method. Compared with the control, the frequency of DQA1*03-DQB1*0303, DQA1*05-DQB1*0201, and DQA1*03-DQB1*0401 haplotypes was higher (P < 0.05-0.01) but DQA1*0102-DQB1*0602 haplotype was lower (P < 0.01) in T1D patients. DQA1*03 allele was less in the FDRs than in their probands (P < 0.05). GADA was more prevalent in T1D patients carrying DQA1*05-DQB1*0201 or DQA1*03-DQB1*0401 haplotype (55.8% vs 41.0%, 65.5% vs 40.3%, P < 0.05-0.01), whereas IA-2A presented more in the patients carrying DQA1*03-DQB1*0303 haplotype (27.0% vs 7.9%, P < 0.05-0.01), both GADA and IA-2A showed frequently in the patients with DQA1*03-DQB1*0303/DQA1*05-DQB1*0201 haplotypes (34.5% vs 9.7%, P < 0.01). GADA positivity was lower in the patients with DQA1*0102-DQB1*0602 haplotype (16.7% vs 45.9%, P < 0.05). The frequency of IAA was not different between patients with and without susceptible DQ haplotypes (P > 0.05). GADA, IA-2A or IAA presented frequently in FDRs with DQA1*03-DQB1*0303 haplotype. The findings in the study indicate that some of specific HLA-DQA1/-DQB1 genotypes and haplotypes not only confer susceptibility to T1D but also are associated with the presence of the islet autoantibodies in the Han Chinese population.