High affinity of host human microRNAs to SARS-CoV-2 genome: An in silico analysis

Background: Coronavirus disease 2019 (COVID-19) caused by a novel betacoronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has attracted top health concerns worldwide within a few months after its appearance. Since viruses are highly dependent on the host small RNAs (microRNAs) for their replication and propagation, in this study, top miRNAs targeting SARS-CoV-2 genome and top miRNAs targeting differentially expressed genes (DEGs) in lungs of patients infected with SARS-CoV-2, were predicted. Methods: All human mature miRNA sequences were acquired from miRBase database. MiRanda tool was used to predict the potential human miRNA binding sites on the SARS-CoV-2 genome. EdgeR identified differentially expressed genes (DEGs) in response to SARS-CoV-2 infection from GEO147507 data. Gene Set Enrichment Analysis (GSEA) and DEGs annotation analysis were performed using ToppGene and Metascape tools. Results: 160 miRNAs with a perfect matching in the seed region were identified. Among them, there was 15 miRNAs with more than three binding sites and 12 miRNAs with a free energy binding of �29 kCal/Mol. MiR-29 family had the most binding sites (11 sites) on the SARS-CoV-2 genome. MiR-21 occupied four binding sites and was among the top miRNAs that targeted up-regulated DEGs. In addition to miR-21, miR-16, let-7b, let-7e, and miR-146a were the top miRNAs targeting DEGs. Conclusion: Collectively, more experimental studies especially miRNA-based studies are needed to explore detailed molecular mechanisms of SARS-CoV-2 infection. Moreover, the role of DEGs including STAT1, CCND1, CXCL-10, and MAPKAPK2 in SARS-CoV-2 should be investigated to identify the similarities and differences between SARS-CoV-2 and other respiratory viruses. © 202

Secondary toxic effect of graphene oxide and graphene quantum dots alters the expression of miR-21 and miR-29a in human cell lines

For in vitro studies, non-toxic doses of nanomaterials are routinely selected by quantification of live cells after exposing to different concentrations of nanoparticles but considering only morphological changes or viability of cells is not sufficient to conclude that these nanomaterials are non-cytotoxic. Here we investigated if secondary toxicity is active in the cells exposed to non-toxic doses of graphene oxide (GO) and graphene quantum dots (GQDs). Non-cytotoxic dose of 15 μg mL�1 of GO (100 nm) and GQDs (50 nm) was selected according to MTT and Hoechst 33342/PI double staining assays. In order to investigate the secondary toxicity, the expression of miR-21, miR-29a and three genes at both mRNA and protein level were evaluated in MCF-7, HUVEC, KMBC/71 cells 4 and 24 h post exposure. Mitochondrial membrane potential (MMP) was assessed by Rhodamine 123 staining. According to our results, there was no significant decrease in viability of cells after exposure to the non-cytotoxic dose of GO and GQDs, but we observed significant alterations in the expression level of miR-21, miR-29a, Bax, Bcl2 and PTEN genes after treatment in all three cells. In addition to molecular changes, we observed alteration in mitochondrial activity at cellular level. However, we also observed that GO influenced the basal level of genes and MMP more compare to GQDs. Considering that all these genes are involved in breast tumor development and metastasis, the observed changes in miRNA expression and protein synthesis may alter cell fate and susceptibility and cause deviation in the desired outcome of GO and GQDs application in medical research. © 2020 Elsevier Lt

Fabrication and biocompatibility assessment of polypyrrole/cobalt(II) metal-organic frameworks nanocomposites

Nowadays, metal-organic frameworks (MOFs) have emerged as promising tools for different biological applications and therefore, efforts are ongoing to develop more biocompatible MOFs-based nanocomposites. We aimed to fabricate some new conductive nanocomposites of polypyrrole and cobalt-MOF with different weight percentages (PPy/xCo-MOF) using the solution mixing method and characterize them through FT-IR (Fourier-transform infrared), PXRD (powder X-ray diffraction), SEM (scanning electron microscope), and TEM (transmission electron microscope) techniques. The biocompatibility of nanocomposites was assessed by haemolytic, cytotoxic, and quantitative reverse transcription PCR (qRT-PCR) assays. FT-IR and PXRD results revealed that nanocomposites consisted of pure MOFs and PPy. Moreover, SEM results indicated their spherical morphology along with an average diameter of 190 nm. (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed a concentration, and percentage-dependent cytotoxic effect of the nanocomposites on some cell lines including 3T3 fibroblasts, MCF-7, and J774.A1 macrophages. Haematological toxicity of PPy/xCo-MOF composites was less than 7 in most concentrations. Furthermore, PPy/xCo-MOF composites did not show any significant effect on the expression of cyclooxygenase�2(COX-2) and inducible nitric oxide synthase(iNOS) genes. In sum, regarding the haemolytic, proinflammatory, and cytotoxic tests, prepared nanocomposite demonstrated the reasonable in vitro biocompatibility which may be considered as a hopeful platform for further investigations including clinical applications. © T�BİTA

MicroRNA-21 and microRNA-29a modulate the expression of collagen in dermal fibroblasts of patients with systemic sclerosis

MicroRNAs (miRNAs) are well-known candidates for modulating the dysregulated signaling pathways during fibrosis. In this study, we investigated the expression pattern of 16 miRNAs, which have previously been confirmed or predicted to target genes involved in extracellular matrix (ECM) homeostasis. Primary culture of dermal fibroblasts was obtained from skin biopsies of diffused cutaneous SSc (dcSSc) patients and healthy controls. Expression of let-7a, miR-1, miR-15a, miR-17, miR-19a, miR-20a, miR-21, miR-27b, miR-26a, miR-29a, miR-29b, miR29c, miR-141, miR-125a-5p, miR-193a-3p, and miR-200a were quantified by Real-time PCR. Functional analysis of microRNAs was performed using synthetic oligonucleotides. To further confirm the pro- or anti-fibrotic effects of miRNAs, normal fibroblasts were treated with 10 ng/mL of transforming growth factor (TGF)-β to generate an in vitro model of dermal fibrosis. miR-21 and miR-29a were upregulated and downregulated, respectively, in both dcSSc and TGF-β-treated fibroblasts. We observed that restoration of miR-29a expression or blockade of miR-21 function negatively affected collagen production. COL1A1 expression in SSc fibroblasts is more sensitive to changes of miR-29a and miR-21 expression in compare to normal fibroblasts. miR-29a alone was effective to decrease TGF-β-induced collagen production in dermal fibroblasts. miR-21 and TGF-β had synergistic effects on induction of collagen production. However, neither miR-21 nor miR-29a affected alpha smooth muscle actin (α-SMA) expression in the presence or absence of TGF-β in dermal fibroblasts. miR-21 and miR-29a as pro- and anti-fibrotic miRNAs modulate collagen production in an opposing manner. Focusing on miR-21 and miR-29s as therapeutic targets would be effective in patients with SSc or other fibrotic diseases which show aberrant expression of collagen expression

Curcumin loaded on graphene nanosheets induced cell death in mammospheres from MCF-7 and primary breast tumor cells

Elimination of tumor cells is still a therapeutic challenge for breast cancer (BC) in men and women. Mammospheres serve as valuable in vitro tools for evaluating tumor behavior and sensitivity to anticancer treatments. Graphene nanosheets with unique physicochemical properties have been considered as potential biomedical approaches for drug delivery, bioimaging, and therapy. Graphene oxide (GO) and graphene quantum dots (GQDs) are suitable nanocarriers for hydrophobic and low bioaccessible anti-tumor materials like curcumin. Despite extensive studies on the potential application of graphene nanosheets in medicine, our knowledge of how different cells function and respond to these nanoparticles remains limited. Here, we evaluated cell death in mammospheres from MCF-7 and primary tumor cells in response to curcumin loaded on graphene nanosheets. Mammospheres were exposed to graphene oxide-curcumin (GO-Cur) and graphene quantum dots-curcumin (GQDs-Cur), and the incidence of cell death was evaluated by Hoechst 33342/propidium iodide double staining and flow cytometry. Besides, the expression of miR-21, miR-29a, Bax, and Bcl-2 genes were assessed using RT-qPCR. We observed, GO, and GQDs had no cytotoxic effect on Kerman male breast cancer/71 (KMBC/71) and MCF-7 tumor cells, while curcumin induced death in more than 50 of tumor cells. GO-Cur and GQDs-Cur synergistically enhanced anti-tumor activity of curcumin. Moreover, GQDs-Cur induced cell death in almost all cells of KMBC/71 mammospheres (99; p < 0.0001). In contrast, GO-Cur induced cell death in only 21 of MCF-7 mammosphere cells (p < 0.0001). Also, the expression pattern of miR-21, miR-29a, and Bax/Bcl-2 ratio in KMBC/71 and MCF-7 mammospheres was different in response to GO-Cur and GQDs-Cur. Although KMBC/71 and MCF-7 tumor cells had similar clinical features and displayed similar responses to curcumin, more investigations are needed to clarify the detailed molecular mechanisms underlying observed differences in response to GO-Cur and GQDs-Cur. © 2021 IOP Publishing Ltd