Detection of Microvesicle miRNA Expression in ALL Subtypes and Analysis of Their Functional Roles

Microvesicles （MVs） are the heterogeneous mixtures of vesicles. MVs released by leukemia cells constitute an important part of the leukemia microenvironment. MVs might act as important reser- voirs of microRNAs （miRNAs）. It is worth evaluating whether MVs possess some unique miRNA con- tents that are valuable in understanding the pathogenesis. In this study, we investigated the miRNA ex- pression patterns of Nalm-6-derived MVs, Jurkat-derived MVs and normal cell-derived MVs using miRNA microarrays. The potential target genes regulated by differentially expressed miRNAs were also predicted and analyzed. Results demonstrated that 182 miRNAs and 166 miRNAs were differentially expressed in Nalm-6-MVs and Jurkat-MVs, respectively. Many oncogenes, tumor suppressors and sig- nal pathway genes were targeted by these aberrantly expressed miRNAs, which might contribute to the development of B-ALL or T-ALL. Our findings expanded the potential diagnostic markers of ALL and provided useful information for ALL pathogenesis.

MicroRNAs: a novel promising therapeutic target for cerebral ischemia/reperfusion injury?

To determine the molecular mechanism of cerebral ischemia/reperfusion injury, we examined the micro RNA（mi RNA） expression profile in rat cortex after focal cerebral ischemia/reperfusion injury using mi RNA microarrays and bioinformatic tools to systematically analyze Gene Ontology（GO） function classifications, as well as the signaling pathways of genes targeted by these differentially expressed mi RNAs. Our results show significantly changed mi RNA expression profiles in the reperfusion period after focal cerebral ischemia, with a total of 15 mi RNAs up-regulated and 44 mi RNAs down-regulated. Target genes of these differentially expressed mi RNAs were mainly involved in metabolic and cellular processes, which were identified as hub nodes of a mi RNA-GO-network. The most correlated pathways included D-glutamine and D-glutamate metabolism, the renin-angiotensin system, peroxisomes, the PPAR signaling pathway, SNARE interactions in vesicular transport, and the calcium signaling pathway. Our study suggests that mi RNAs play an important role in the pathological process of cerebral ischemia/reperfusion injury. Understanding mi RNA expression and function may shed light on the molecular mechanism of cerebral ischemia/reperfusion injury.

Herb-partitioned moxibustion regulated the miRNA expression profile in the thyroid tissues of rats with experimental autoimmune thyroiditis

OBJECTIVE:To observe the effect of herb-partitioned moxibustion(HPM)on the miRNA expression profile of thyroid tissue in experimental autoimmune thyroiditis(EAT)rats.METHODS:Rats were randomly divided into normal control(NC)group,EAT model(EAT)group,HPM group and western medicine(Med)group.EAT model rats were prepared by a combined immunization with complete and incomplete Freund’s adjuvant emulsified with porcine thyroglobulin and iodine.Rats in the HPM group were treated with HPM,while rats in the Med group were treated with levothyrocine(1μg/2 m L)by gavage.HE staining was used to observe the pathological morphological changes of thyroid tissue,ELISAs was uaed to detect the serum concentrations of TGAb,TPOAb,FT3,FT4,TSH.We then performed high-throughput mi RNA sequencing to analyse the mi RNA expression profiles in the thyroid tissues,followed by a bioinformatics analysis.RT-q PCR was used to verify the identified differentially expressed mi RNAs.RESULTS:HPM improved the thyroid tissue morphology and reduced serum TPOAb,TGAb,TSH concentration in EAT rats(P<0.05),but with no obvious effect on FT3 and FT4 concentration.While the TSH,FT3 and FT4 concentration was significantly changed in the Med group(P<0.01 or P<0.05)compared with that of EAT group.Sequencing results showed that a total of 17 mi RNAs were upregulated,and 4 were downregulated in the EAT rats,in which the expression levels of mi R-346 and mi R-331-5 p were reversed by HPM.The target genes of the mi RNAs that regulated by HPM wereassociated with a variety of immune factors and immune signals.RT-q PCR verification showed that the expression of mi RNA-346 and mi RNA-331-5 p was consistent with the sequencing results.CONCLUSIONS:HPM could regulate the the expression of mi RNA-346 and mi RNA-331-5 p,then act on their target genes to immune and inflammation-related pathways,which may be one of the mechanisms of HPM on EAT rats.

Comparative microRNA profiling reveals microRNAs involved in rice resistant response to bacterial blight

Bacterial blight(BB), which is caused by Xanthomonas oryzae pv. oryzae(Xoo), is one of the most destructive bacterial diseases of rice(Oryza sativa L.). During plant defense responses, micro RNAs(mi RNAs) play important roles in regulating disease resistance. However, the functions of mi RNAs in the interaction between rice and Xoo remain relatively uncharacterized. In this study, we compared the mi RNA profiles of the BB resistant rice introgression line F329 and its susceptible recurrent parent Huang-Hua-Zhan(HHZ) at multiple time points after inoculation with Xoo. A total of 538 known and 312 novel mi RNAs were identified, among which only 17 and 26 were responsive to Xoo infection in F329 and HHZ, respectively. Compared with the expression levels in HHZ, 37 up-regulated and 53 down-regulated mi RNAs were detected in F329. The predicted target genes for the mi RNAs differentially expressed between F329 and HHZ were revealed to be associated with flavonoid synthesis, the reactive oxygen species regulatory pathway, plant hormone signal transduction, defense responses, and growth and development.Additionally, the patterns of interactions between osa-mi R390-3 p, novel_mi R_104, novel_mi R_238,osa-mi R166 k-5 p, osa-mi R529 b, and osa-mi R167 h-3 p and their target genes were further validated by quantitative real-time PCR. Furthermore, we overexpressed osa-mi R167 h-3 p in transgenic plants and proved that this mi RNA positively regulates the resistance of rice to BB. These results provide novel information regarding the mi RNA-based molecular mechanisms underlying the disease resistance of rice. The data presented herein may be useful for engineering rice BB resistance via mi RNAs.

Micro RNA profiles and potential regulatory pattern during the early stage of spermatogenesis in mice

Spermatogenesis is a complicated and poorly understood process that relies on the precise regulation of the self-renewal and differentiation of spermatogonia. In many organisms, micro RNAs(mi RNAs) are involved in multiple developmental processes as critical regulators of transcriptional and post-transcriptional gene silencing. This study investigated the expression pattern of mi RNAs in type B spermatogonia cells(BSc) and primary spermatocytes(PSc) of mice, using a high-throughput small RNA sequencing system. The results revealed that the expression levels of Let-7 family mi RNAs were remarkably high in both cell types. Furthermore, the expression levels of mi R-21, mi R-140-3p, mi R-103, mi R-30 a, mi R-101 b and mi R-99 b were decreased during the transformation from BSc to PSc. These mi RNAs target vital genes that participate in apoptosis, cell proliferation and differentiation, junction assembly and cell cycle regulation. These results highlight the indispensable role of mi RNAs in spermatogenesis.

Characterization of miRNomes in Acute and Chronic Myeloid Leukemia Cell Lines

Myeloid leukemias are highly diverse diseases and have been shown to be associated with microRNA（miRNA） expression aberrations. The present study involved an in-depth miRNome analysis of two human acute myeloid leukemia（AML） cell lines, HL-60 and THP-1, and one human chronic myeloid leukemia（CML） cell line, K562, via massively parallel signature sequencing. mRNA expression profiles of these cell lines that were established previously in our lab facilitated an integrative analysis of miRNA and mRNA expression patterns. miRNA expression profiling followed by differential expression analysis and target prediction suggested numerous miRNA signatures in AML and CML cell lines. Some miRNAs may act as either tumor suppressors or oncomiRs in AML and CML by targeting key genes in AML and CML pathways. Expression patterns of cell type-specific miRNAs could partially reflect the characteristics of K562, HL-60 and THP-1 cell lines, such as actin filament-based processes, responsiveness to stimulus and phagocytic activity. miRNAs may also regulate myeloid differentiation, since they usually suppress differentiation regulators. Our study provides a resource to further investigate the employment of miRNAs in human leukemia subtyping, leukemogenesis and myeloid development. In addition, the distinctive miRNA signatures may be potential candidates for the clinical diagnosis, prognosis and treatment of myeloid leukemias.