MicroRNA-15a-5p plays a role in osteogenic MC3T3-E1 cells differentiation by targeting PDCD4 (programmed cell death 4) via Wnt/β-catenin dependent signaling pathway

Osteoporosis is defined as a bone condition characterized by bone mass reduction, bone micro-architectural and quality deterioration, leading to compromised strength and increased chances of fracture. Evidence have shown an essential role of microRNAs (miRNAs) in various osteogenic differentiation processes. However, the function of miR-15a-5p in the differentiation of osteogenic cells and possible mechanisms remains unclear. The present study explored the expression of miR-15a-5p in human osteoporosis specimens and during the osteogenic differentiation of MC3T3-E1 cells. Functions of miR-15a-5p were determined using miR-15a-5p mimics and inhibitors. Luciferase assay was used to verify the binding of miR-15a-5p and PDCD4 3ʹUTR. Alizarin Red Staining (ARS) and Alkaline phosphatase (ALP) activity were used to determine the miR-15a-5p role in osteogenic differentiation. Finally, Wnt pathway inhibitor was used to determine the miR-15a-5p/PDCD4/Wnt signaling pathway in regulating osteogenic differentiation. We found miR-15a-5p expression was increased in human osteoporosis specimens and during differentiation of MC3T3-E1 cells. PDCD4 was also identified as a target of miR-15a-5p and was found to be involved in osteogenic differentiation. Further, miR-15a-5p mimics attenuated the effects of PDCD4 overexpression. Finally, use of XAV939 (Wnt pathway inhibitor) downregulated osteogenic differentiation in miR-15a5p/PDCD4/Wnt-dependent signaling pathway. In conclusion, miR-15a-5p induced differentiation of osteoblasts and mineralization by modulating osteoblast differentiation factors, mainly OSX, ALP, OCN, and RUNX2, by inhibiting PDCD4 and Wnt signaling pathways. This study provides a modality for the future use of miR-15a-5p in the treatment and prevention of osteoporosis.

Transcriptome analysis of the immune response of silkworm at the early stage of Bombyx mori bidensovirus infection

Bombyx mori bidensovirus (BmBDV) infects silkworm midgut and causes chronic flacherie disease; however, the interaction between BmBDV and silkworm is unclear. Twenty-four hours after BmBDV infection, the midgut was extracted for RNA-seq to analyze the factors associated with BmBDV-invasion and the early antiviral immune response in silkworms. The total reads from each sample were more than 16100000 and the number of expressed genes exceeded 8200. There were 334 upregulated and 272 downregulated differentially expressed genes (DEGs). Gene ontology analysis of DEGs showed that structural constituents of cuticle, antioxidant, and immune system processes were upregulated. Further analysis revealed BmBDV-mediated induction of BmorCPR23 and BmorCPR44, suggesting possible involvement in viral invasion. Antioxidant genes that protect host cells from virus-induced oxidative stress, were significantly upregulated after BmBDV infection. Several genes related to peroxisomes, apoptosis, and autophagy-which may be involved in antiviral immunity-were induced by BmBDV. These results provide insights into the mechanism of BmBDV infection and host defense.

The Molecular Evolution and Functional Divergence of Lamprey Programmed Cell Death Genes

The programmed cell death (PDCD) family plays a significant role in the regulation of cell survival and apoptotic cell death. However, the evolution, distribution and role of the PDCD family in lampreys have not been revealed. Thus, we identified the PDCD gene family in the lamprey genome and classified the genes into five subfamilies based on orthologs of the genes, conserved synteny, functional domains, phylogenetic tree, and conserved motifs. The distribution of the lamprey PDCD family and the immune response of the PDCD family in lampreys stimulated by different pathogens were also demonstrated. In addition, we investigated the molecular function of lamprey PDCD2, PDCD5, and PDCD10. Our studies showed that the recombinant lamprey PDCD5 protein and transfection of the L-PDCD5 gene induced cell apoptosis, upregulated the expression of the associated X protein (BAX) and TP53 and downregulated the expression of B cell lymphoma 2 (BCL-2) independent of Caspase 3. In contrast, lamprey PDCD10 suppressed apoptosis in response to cis-diaminedichloro-platinum (II) stimuli. Our phylogenetic and functional data not only provide a better understanding of the evolution of lamprey PDCD genes but also reveal the conservation of PDCD genes in apoptosis. Overall, our results provide a novel perspective on lamprey immune regulation mediated by the PDCD family.

RNA sequencing uncovers the key long non-coding RNAs and potential molecular mechanism contributing to XAV939-mediated inhibition of non-small cell lung cancer

The present study aimed to reveal the key long non-coding RNAs (lncRNAs) and the potential molecular mechanisms of XAV939 treatment in non-small cell lung cancer (NSCLC). The NSCLC cell line, NCI-H1299, was cultured with 10 µM XAV939 for 12 h, and NCI-H1299 cells without XAV939 treatment were used as controls. Following RNA isolation from the two groups, RNA-sequencing was performed to detect transcript expression levels, and differentially-expressed lncRNAs (DE-lncRNAs) and DE-genes (DEGs) were identified between groups and analyzed for their functions and associated pathways. The potential associations between proteins encoded by DEGs were revealed via a protein-protein interaction (PPI) network. Subsequently, the microRNA (miRNA/miR)-mRNA, lncRNA-miRNA and lncRNA-mRNA interactions were explored, followed by competing endogenous RNA (ceRNA) network construction. A total of 396 DEGs and 224 DE-lncRNAs were identified between the XAV939 and control groups. These lncRNAs were mainly enriched in pathways such as ‘ferroptosis’ [DEG, solute carrier family 7 member 11 (SLC7A11)]. The PPI network consisted of 97 nodes and 112 interactions. Furthermore, a total of 10 noteworthy lncRNAs were revealed in the DE-lncRNA-DEG interaction. Finally, the lncRNA-miRNA-mRNA regulatory association, including MIR503 host gene (MIR503HG)-miR1273c-SRY-box 4 (SOX4), was explored in the current ceRNA network. The downregulation of lncRNA MIR503HG induced by XAV939 may serve an important role in NSCLC suppression via sponging miR-1273c and regulating SOX4 expression. Furthermore, the downregulation of SLC7A11 induced by XAV939 may also inhibit the development of NSCLC via the ferroptosis pathway.