BackgroundN6-methyladenosine (m6A) is an important epitranscriptomic mark with high abundance in the brain. Recently, it has been found to be involved in the regulation of memory formation and mammalian cortical neurogenesis. However, while it is now established that m6A methylation occurs in a spatially restricted manner, its functions in specific brain regions still await elucidation.ResultsWe identify widespread and dynamic RNA m6A methylation in the developing mouse cerebellum and further uncover distinct features of continuous and temporal-specific m6A methylation across the four postnatal developmental processes. Temporal-specific m6A peaks from P7 to P60 exhibit remarkable changes in their distribution patterns along the mRNA transcripts. We also show spatiotemporal-specific expression of m6A writers METTL3, METTL14, and WTAP and erasers ALKBH5 and FTO in the mouse cerebellum. Ectopic expression of METTL3 mediated by lentivirus infection leads to disorganized structure of both Purkinje and glial cells. In addition, under hypobaric hypoxia exposure, Alkbh5-deletion causes abnormal cell proliferation and differentiation in the cerebellum through disturbing the balance of RNA m6A methylation in different cell fate determination genes. Notably, nuclear export of the hypermethylated RNAs is enhanced in the cerebellum of Alkbh5-deficient mice exposed to hypobaric hypoxia.ConclusionsTogether, our findings provide strong evidence that RNA m6A methylation is controlled in a precise spatiotemporal manner and participates in the regulation of postnatal development of the mouse cerebellum.Electronic supplementary materialThe online version of this article (10.1186/s13059-018-1435-z) contains supplementary material, which is available to authorized users.

N6-methyladenosine (m6A) is the most abundant epitranscriptomic mark found on mRNA and has important roles in various physiological processes. Despite the relatively high m6A levels in the brain, its potential functions in the brain remain largely unexplored. We performed a transcriptome-wide methylation analysis using the mouse brain to depict its region-specific methylation profile. RNA methylation levels in mouse cerebellum are generally higher than those in the cerebral cortex. Heterogeneity of RNA methylation exists across different brain regions and different types of neural cells including the mRNAs to be methylated, their methylation levels and methylation site selection. Common and region-specific methylation have different preferences for methylation site selection and thereby different impacts on their biological functions. In addition, high methylation levels of fragile X mental retardation protein (FMRP) target mRNAs suggest that m6A methylation is likely to be used for selective recognition of target mRNAs by FMRP in the synapse. Overall, we provide a region-specific map of RNA m6A methylation and characterize the distinct features of specific and common methylation in mouse cerebellum and cerebral cortex. Our results imply that RNA m6A methylation is a newly identified element in the region-specific gene regulatory network in the mouse brain.

Endozoochorous dispersal of seeds by livestock has long attracted the attention of grassland scientists. However, little is known about seed dispersal after ingestion by Kazakh sheep on dry grasslands in the Tianshan Mountains. The objective of this experiment was to learn more about the recovery and germinability of seeds from 17 plant species after either actual or simulated ingestion (i.e. insertion through a rumen fistula) by Kazakh sheep. The passage time of seeds through the sheep gut ranged from 12 to 96 h. More than 80% of all recovered seeds were defecated 24-48 h after ingestion. The mean retention time of seeds in the gut ranged from 27.3 to 42.2 h. Seed recovery percentage ranged between 12.6 and 17.6% for leguminous species and between 0.8 and 3.2% for gramineous species. Seed recovery percentage was positively correlated with seed mass, but negatively correlated with seed shape. The germination percentages of the gramineous species were greater in the non-ingested treatment (66-98%) than in the simulated ingestion treatment (3-10%). In contrast, for leguminous species, seed germination percentages were greater in the simulated ingestion treatment (23-70%) than in the non-ingested one (5-12%). Seed germination percentage after simulated ingestion was positively correlated with seed mass, but negatively correlated with seed shape. In conclusion, leguminous seeds were more likely than gramineous ones to pass through the gut of Kazakh sheep and then germinate. Free-ranging Kazakh sheep can contribute to the spread of plant species, especially leguminous species, in the Tianshan Mountains.

Genes related to immune response, inflammatory response and homeostasis presumably have critical roles in RA pathogenesis. Sanguinarine and papaverine have a potential therapeutic effect against RA.

Clear cell renal cell carcinoma (ccRCC) has been associated with one of the highest mortality rates among all cancers. Fatty acid binding proteins (FABPs) are 14-15 kDa proteins that are highly abundant in the cytosol of most tissues. FABP5, a member of the FABP family, has been observed to promote tumor cell growth in numerous cancer types. In order to investigate the function of FABP5 in ccRCC cells in the present study, RNA sequencing data from The Cancer Genome Atlas were analyzed to determine the expression levels of FABP5 in ccRCC patient samples. Survival and Cox regression analyses were performed to measure the association between FABP5 expression and clinicopathological features of patients with ccRCC. Subsequent in vitro experiments downregulated or overexpressed FABP5 in Caki-1 and 786O ccRCC cells using lentiviral vectors to evaluate cell proliferation ability, and a xenograft transplantation model was established to examine the effect of FABP5 on tumorigenesis in vivo. The results demonstrated that FABP5 expression was significantly upregulated in samples from patients with ccRCC when compared with normal tissue samples. High FABP5 expression was also significantly correlated with tumor and metastasis classifications and predicted poor survival in patients with ccRCC. In ccRCC cells, silencing of FABP5 significantly inhibited cell proliferation, while overexpression of FABP5 promoted cell proliferation when compared to the respective controls. In addition, treatment with the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/AKT inhibitor, LY294002, attenuated the pro-proliferative effects of exogenous FABP5 expression in Caki-1 and 786O cells. This indicated that the PI3K/AKT signaling pathway may be partially involved in the FABP5-mediated increase in ccRCC cell proliferation. Furthermore, FABP5 was observed to regulate tumor growth in nude mice in vivo. In conclusion, the results of the present study suggest that FABP5 may exert a pro-proliferative role in ccRCC and may be associated with malignant progression and tumorigenesis.

Background: Circular RNAs (circRNAs), a novel class of endogenous noncoding RNAs, are involved in a variety of diseases, including several types of cancers. We hypothesized that circRNAs are involved in the tumorigenesis and development of clear cell renal cell carcinoma (ccRCC). Methods : To verify our hypothesis, we explored the circRNA expression profiles in 4 pairs of ccRCC tissues and their adjacent non-carcinoma tissues via microarray analysis. Selected circRNAs were further validated by qPCR. Moreover, hsa_circ_0005875 was selected for further study and the potential clinical values of hsa_circ_0005875 were investigated in 60 pairs of ccRCC tissues and adjacent normal controls. In addition, the role of hsa_circ_0005875 in ccRCC progression were performed using colony formation assay, Transwell assay and Martrigel-Transwell assay respectively. Finally, interactions between the circRNAs and miRNAs were predicted using Arraystar's miRNA target prediction software. Luciferase reporter assays were performed to evaluate the interaction between hsa_circ_0005875 and hsa_miR-145-5p. Results: The microarray data showed 1988 circRNAs were significantly dysregulated circRNAs, including 1033 upregulated and 955 downregulated ones in the ccRCC tissues. Hsa_circ_0005875 was confirmed to be significantly upregulated in the ccRCC tumor tissues and renal carcinoma cells. Further analysis revealed that hsa_circ_0005875 expression was associated with tumor size, pathological TNM stage, histological differentiation, and lymphatic metastasis. Functional experiments demonstrated that overexpression of hsa_circ_0005875 increased proliferation, migration and invasion abilities. Moreover, bioinformatics analysis and luciferase reporter assays suggest that hsa_circ_0005875 may serve as a ceRNA (competing endogenous RNA) of miR-145-5p to relieve the repressive effect of miR-145-5p on target ZEB2. Conclusions: These data indicate that hsa_circ_0005875 might play a role in promoting tumor growth and metastasis and be a potential biomarker of ccRCC.

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BackgroundOsteosarcoma is the most common malignancy of bone. Intratumoral hypoxia occurs in many solid tumors, where it is associated with the development of aggressive phenotype. ANRIL has been shown to be a long noncoding RNA that facilitates the progression of a number of malignancies. Yet, few studies have explored the expression pattern of ANRIL in osteosarcoma and the effect of hypoxia on ANRIL.MethodsWe evaluated the expression levels of ANRIL in osteosarcoma tissues, adjacent normal tissues and cells with quantitative real-time polymerase chain reaction. Multiple approaches including luciferase reporter assay with nucleotide substitutions, chromatin immunoprecipitation assay and electrophoretic mobility shift assay were used to confirm the direct binding of HIF-1α to the ANRIL promoter region. SiRNA-based knockdown and other molecular biology techniques were employed to measure the effect of HIF-1α on the expression of ANRIL.ResultsWe found that the expression of ANRIL was upregulated in 15 pairs of osteosarcoma compared with adjacent normal tissues. We found that hypoxia is sufficient to upregulate ANRIL expression in osteosarcoma cells (MNNG and U2OS). HIF-1α directly binds to the putative hypoxia response element in the upstream region of ANRIL. What’s more, siRNA and small molecular inhibitors-mediated HIF-1α suppression attenuated ANRIL upregulation under hypoxic conditions. Upon hypoxia, ANRIL promoted cancer cell invasion and suppressed cell apoptosis.ConclusionTaken together, these data suggest that HIF-1α may contribute to the upregulation of ANRIL in osteosarcoma under hypoxic conditions. ANRIL is involved in hypoxia-induced aggressive phenotype in osteosarcoma.