Abdi, M. | bioRxiv Science

bioRxiv2023

Longitudinal Survey of Astrovirus infection in different bat species in Zimbabwe: Evidence of high genetic Astrovirus diversity

Astroviruses (AstVs) have been discovered in over 80 animal species including diverse bat species and avian species. A study on Astrovirus circulation and diversity in different insectivorous and frugivorous chiropteran species roosting in trees, caves and building basements was carried out at 11 different sites across Zimbabwe. Pooled and individual faecal sampling methods were used for this study, with collection dates ranging from June 2016 to July 2021. In two sites, Magweto and Chirundu, sampling was carried out at monthly intervals from August 2020 to July 2021. Astroviruses and bat mitochondrial genes were amplified using pan-AstVs and CytB /12S RNA PCR systems respectively. Phylogenetic analysis of the RdRp Astrovirus sequences revealed a high genetic diversity of astroviruses. All the bat astroviruses tested in this study clustered with the Mamastrovirus genus. Two distinct groups of amplified sequences were identified. One group was comprised of sequences isolated from Hipposideros, Rhinolophus and Eidolon helvum spp. clustered with Human Astrovirus strains: HuAstV types1-6, HuAstV-MLB1-3 and HuAstV-VA-1. The second group comprising the majority of the sequences clustered with different strains of Bat AstVs. Results from the longitudinal study at Magweto and Chirundu showed an overall AstV prevalence of 13.7% and 10.4% respectively. Peaks of AstV infection at Chirundu coincided with the period when juveniles are 4-6 months old. By combining data from our previous work on Coronaviruses, we also anaylzed co-infection of bats with Coronaviruses and Astroviruses at Magweto and Chirundu sites for which the prevalence of co-infection was 2.6% and 3.5% respectively.

molecular biology↗

bioRxiv2018

miR-216b-5p is Down-Regulated in Human Breast Cancer and Inhibits Proliferation and Progression by Targeting HDAC8 Oncogene

BackgroundPrevious studies showed the role of histone deacetylases (HDACs) on the progression of some malignancies. Recently, there is more attention to therapeutic applications of epigenetic factors such as microRNAs (miRs). To the best of our knowledge, there are no other results regarding the contribution of miR-216b-5p and its potential target, HDAC8, in progression of cancer.\n\nAimIn the present study, we investigated the role of miR-216b-5p on HDAC8 and there following impacts on breast cancer (BC) progression.\n\nMethodsHuman BC specimens and noncancerous tissues were acquired from Iran Tumor Bank (I.T.B). The MDA-MB-231, MCF-7 and MCF-10A BC cell lines were also prepared. The tissue and cell line expression levels of miR-216b-5p and HDAC8 were determined by quantitative real-time PCR (qPCR). Protein levels of HDAC8 were also measured by Western blotting assay. The cell cycle, cell proliferation and colony formation assay were determined and the role of HDAC8 was investigated using a knockout vector. Targeting the 3' untranslated region (3'UTR) of HDAC8 by miR-216b-5p were confirmed using a luciferase reporter assay.\n\nResultsOur results show the significant decline in miR-216b-5p and highly increase in HDAC8 levels in human breast cancer tissues and cell lines. Overexpression of miR-216b-5p in BC cell lines inhibited cellular proliferation and progression and inhibition of miR-216b-5p reverse these effects. We also confirmed that HDAC8 is directly down-regulated by miR-216b-5p. Knockout of HDAC8 had also the effects as miR-216b-5p overexpression. Furthermore, we found that lower levels of miR-216b-5p are negatively correlated with lymph node metastasis and advanced tumor size.\n\nConclusionTaken together, our data shown that targeted overexpression of miR-216b-5p can suppress the growth of BC cells down-regulation of HDAC8. Therefore, inhibition of HDAC8 by miR-216b-5p will be helpful developing newer therapies for the effective treatment of BC.

cancer biology↗