The Arabian camel is the largest known mammal that can survive in severe hot climatic conditions. We provide the molecular explanation for the thermotolerance of camel granulosa somatic cells after exposure to 45 °C for 2 (acute heat shock) or 20 h (chronic heat shock). The common features of the cellular responses to acute heat stress were the increase of heat shock proteins and DNA repair enzymes expression. Actin polymerization and Rho signaling were critically activated as a cellular defense against heat shock. Cells exposed to chronic heat shock showed altered cell architecture with a decrease in total detected proteins, metabolic enzymes, and cytoskeletal protein expression. Treatment with transforming growth factor beta (TGFβ) pathway inhibitor SB-431542 suppressed the morphological alterations of cells exposed to chronic heat shock. Moreover, during the recovery stage at 38 °C for 24 h, proteomic changes were partially restored with an exponential increase in HSP70 expression, and the cells restored their normal cellular morphology on the 9th day of recovery. Full proteomics data are available via ProteomeXchange with identifier PXD012159. The strategies of cellular defense and tolerance to both thermal conditions reflect the flexible adaptability of camel somatic cells to conserve life under extremely hot conditions.
Molecular profiling of colorectal cancer (CRC) based on global gene expression has revealed multiple dysregulated signalling pathways associated with drug resistance and poor prognosis. However, the role of BMP2 signaling in CRC is not fully characterised. Bioinformatics data analysis were conducted on the GSE21510 dataset. Leniviral technology was utilized to stably express BMP2 in the HCT116 CRC model. Gene expression profiling was conducted using Agilent microarray platform while data normalization and bioinformatics were conducted using GeneSpring software. Changes in gene expression were assessed using qRT-PCR. AlamarBlue assay was used to assess cell viability in vitro. In vivo experiments were conducted using SCID mice. Our data revealed frequent downregulation of BMP2 in primary CRC tissues. Additionally, interrogation of publically available gene expression datasets revealed significant downregulation of BMP2 in metastatic recurrent compared to non-metastatic cancer (p = 0.02). Global gene expression analysis in CRC cells over-expressing BMP2 revealed multiple dysregulated pathways mostly affecting cell cycle and DNA damage response. Concordantly, lentiviral-mediated re-expression of BMP2 inhibited HCT116 CRC growth, sphere formation, clonogenic potential, cell migration, and sensitized CRC cells to 5-fluorouracil (5-FU) in vitro. Additionally, BMP2 inhibited CRC tumor formation in SCID mice. Our data revealed an inhibitory role for BMP2 in CRC, suggesting that restoration of BMP2 expression could be a potential therapeutic strategy for CRC.
This study assessed the dose-dependent effect on the cytotoxicity of BioRoot RCS (BR) and Endosequence BC (BC) sealers in human bone marrow mesenchymal stem cells (hMSCs) compared to those of the AH Plus sealer. Cells were exposed to different dilutions of extracts from freshly prepared sealers (1:2, 1:8, 1:32). Unexposed cells acted as the negative control. Cytotoxicity was evaluated by an alamar blue assay. Cell morphology was analyzed by using scanning electron microscopy after exposure to the different sealers’ extracts. Statistical analysis was performed using a one-way analysis of variance and the Bonferroni post hoc test (p < 0.05). The cytotoxicities of BC and BR were less than that of AH Plus. In the presence of 1:2 BR, the cell proliferation was significantly lower than the control. At 1:8 and 1:32 concentrations, both the tricalcium silicate sealers led to similar cellular proliferation. Cells in BC and BR sealers’ extracts spread better than those in AH Plus extract.
Understanding the regulatory networks underlying lineage differentiation and fate determination of human bone marrow stromal cells (hBMSC) is a prerequisite for their therapeutic use. The goal of the current study was to unravel the novel role of the low-density lipoprotein receptor-related protein 3 (LRP3) in regulating the osteogenic and adipogenic differentiation of immortalized hBMSCs. Gene expression profiling revealed significantly higher LRP3 levels in the highly osteogenic hBMSC clone imCL1 than in the less osteogenic clone imCL2, as well as a significant upregulation of LRP3 during the osteogenic induction of the imCL1 clone. Data from functional and gene expression assays demonstrated the role of LRP3 as a molecular switch promoting hBMSC lineage differentiation into osteoblasts and inhibiting differentiation into adipocytes. Interestingly, microRNA (miRNA) expression profiling identified miR-4739 as the most under-represented miRNA (-36.11 fold) in imCL1 compared to imCL2. The TargetScan prediction algorithm, combined with functional and biochemical assays, identified LRP3 mRNA as a novel target of miR-4739, with a single potential binding site for miR-4739 located in the LRP3 3' UTR. Regulation of LRP3 expression by miR-4739 was subsequently confirmed by qRT-PCR, western blotting, and luciferase assays. Over-expression of miR-4739 mimicked the effects of LRP3 knockdown on promoting adipogenic and suppressing osteogenic differentiation of hBMSCs. Hence, we report for the first time a novel biological role for the LRP3/hsa-miR-4739 axis in balancing osteogenic and adipocytic differentiation of hBMSCs. Our data support the potential utilization of miRNA-based therapies in regenerative medicine.
Small-molecule-inhibitor-based bone differentiation has been recently exploited as a novel approach to regulating osteogenesis-related signaling pathways. In this study, we identified 1-Azakenpaullone, a highly selective inhibitor of glycogen synthase kinase-3β (GSK-3β), as a powerful inducer of osteoblastic differentiation and mineralization of human mesenchymal stem cells (MSCs). GSK-3β is a serine-threonine protein kinase that plays a major role in different disease development. GSK-3β is a key regulator of Runx2 activity in osteoblastic formation. We evaluated alkaline phosphatase activity and staining assays to assess osteoblast differentiation and Alizarin Red staining to assess the mineralization of cultured human MSCs. Gene expression profiling was assessed using an Agilent microarray platform, and bioinformatics were performed using Ingenuity Pathway Analysis software. Human MSCs treated with 1-Azakenpaullone showed higher ALP activity, increased in vitro mineralized matrix formation, and the upregulation of osteoblast-specific marker gene expression. Global gene expression profiling of 1-Azakenpaullone-treated human MSCs identified 1750 upregulated and 2171 downregulated mRNA transcripts compared to control cells. It also suggested possible changes in various signaling pathways, including Wnt, TGFβ, and Hedgehog. Further bioinformatics analysis employing Ingenuity Pathway Analysis recognized significant enrichment in the 1-Azakenpaullone-treated cells of genetic networks involved in CAMP, PI3K (Complex), P38 MAPK, and HIF1A signaling and functional categories associated with connective tissue development. Our results suggest that 1-Azakenpaullone significantly induced the osteoblastic differentiation and mineralization of human MSCs mediated by the activation of Wnt signaling and the nuclear accumulation of β-catenin, leading to the upregulation of Runx2, a key transcription factor that ultimately promotes the expression of osteoblast-specific genes. Thus, 1-Azakenpaullone could be used as an osteo-promotor factor in bone tissue engineering.