Knockdown of has_circ_0010452 Promotes Proliferation and Osteogenic Differentiation via Up-Regulating miR-543 in Human Bone Marrow Mesenchymal Stem Cells

Objective: The aim of this study was to explore the role of has_circ_0010452 in the progression of osteoporosis (OP) targeting miR-543, as well as their functions in regulating proliferation and osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs). Methods: The expression levels of circ_0010452 and miR-543 in hBMSCs at different time points of osteogenic differentiation were determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). After transfection of circ_0010452 siRNA or miR-543 inhibitor in hBMSCs, the relative expression levels of osteogenic marker proteins, including oat spelt xylan (OSX), osteocalcin (OCN) and collagen I (Col-1), were determined by western blot. Cell proliferation of hBMSCs was valued by Cell Counting Kit 8 (CCK-8) assay. Dual-Luciferase reporter gene assay was performed to verify the relationship between circ_0010452 and miR-543. Subsequently, the regulatory effects of circ_0010452 and miR-543 on osteogenic differentiation and the capability of mineralization were evaluated by alkaline phosphatase (ALP) determination and alizarin red staining, respectively. Results: The expression of circ_0010452 decreased gradually and miR-543 increased in hBMSCs with the prolongation of osteogenic differentiation. circ_0010452 could bind to miR-543, which was negatively regulated by miR-543 in hBMSCs. Moreover, knockdown of circ_0010452 inhibited proliferation and osteogenic differentiation by upregulating miR-543, as well as upregulating expressions of OSX, OCN and Col-1. Furthermore, knockdown of circ_0010452 markedly promoted the capability of mineralization of hBMSCs, which was further reversed by transfection of miR-543 inhibitor. The knockdown of miR-543 partially reversed the inhibitory effect of circ_0010452 on the osteogenesis of hBMSCs. Conclusions: Silence of circ_0010452 promotes the development of OP via binding to miR-543 regulating proliferation and osteogenic differentiation of hBMSCs, thus promoting the progression of osteoporosis.

Icariin Promotes In Vitro Cardiomyocyte Proliferation and Differentiation in Human Bone Marrow-Derived Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are the excellent candidates in myocardial regeneration given their easy accessibility, low immunogenicity and high potential for cardiomyocyte differentiation. This work focused on investigating the role of icariin, a main active component of the Traditional Chinese herb epimedium, in human bone marrow-derived MSCs (BMSCs) proliferation and differentiation into cardiomyocytes In Vitro. Human BMSCs were cultivated In Vitro, and MTT assay was conducted to measure their proliferation. On this basis, we selected the optimal icariin dose for promoting the proliferation to induce cardiomyocyte differentiation of MSCs, which were pretreated with or without 5-azacytidine (5-Aza). Cardiac-specific cardiac troponin I (cTnI) and connexin 43 (Cx43)-positive cells were detected by immunofluorescent staining. The differentiation ratio of MSCs was examined by flow cytometry. This study measured early cardiac transcription factors (TFs) Nkx2.5 and GATA4 levels through RT-PCR and Western blotting (WB). As a result, icariin increased MSC proliferation dependent on its dose, and the optimal dose was determined to be 80 μg/l. Furthermore, MSCs showed minimal cardiomyogenic differentiation when induced by icariin alone as confirmed by the expression of cardiac-related markers. Moreover, a synergic interaction was observed when icariin and 5-Aza cooperated to induce cardiomyocyte differentiation of MSCs. In conclusion, Icariin stimulates proliferation and facilitates cardiomyocyte differentiation of MSCs In Vitro and may be potentially used as a new method for enhancing the MSCs efficacy in cardiovascular disease.

Metabolic switching and cell wall remodelling of Mycobacterium tuberculosis during bone tuberculosis

Bone tuberculosis is widely characterized by irreversible bone destruction caused by Mycobacterium tuberculosis . Mycobacterium has the ability to adapt to various environmental stresses by altering its transcriptome in order to establish infection in the host. Thus, it is of critical importance to understand the transcriptional profile of M. tuberculosis during infection in the bone environment compared to axenic cultures of exponentially growing M.tb. In the current study, we characterized the in vivo transcriptome of M. tuberculosis within abscesses or necrotic specimens obtained from patients with bone TB using whole genome microarrays in order to gain insight into the M. tuberculosis adaptive response within this host microenvironment. A total of 914 mycobacterial genes were found to be significantly over-expressed and 1688 were repressed (fold change>2; p-value ≤ 0.05) in human bone TB specimens. Overall, the mycobacteria displayed a hypometabolic state with significant (p ≤ 0.05) downregulation of major pathways involved in translational machinery, cellular and protein metabolism and response to hypoxia. However, significant enrichment (p ≤ 0.05) of amino-sugar metabolic processes, membrane glycolipid biosynthesis, amino acid biosynthesis (serine, glycine, arginine and cysteine) and accumulation of mycolyl-arabinogalactan-peptidoglycan complex suggests possible mycobacterial survival strategies within the bone lesions by strengthening its cell wall and cellular integrity. Data were also screened for M.tb virulence proteins using Virulent-Pred and VICM-Pred tools, which revealed five genes (Rv1046c, Rv1230c, DppD, PE_PGRS26 and PE_PGRS43) with a possible role in the pathogenesis of bone TB. Next, an osteoblast cell line model for bone TB was developed allowing for significant intracellular multiplication of M.tb. Interestingly, three virulence genes (Rv1046c, DppD and PE_PGRS26) identified from human bone TB microarray data were also found to be overexpressed by intracellular M. tuberculosis in osteoblast cell lines. Overall, these data demonstrate that M. tuberculosis alters its transcriptome as an adaptive strategy to survive in the host and establish infection in bone. Additionally, the in vitro osteoblast model we describe may facilitate our understanding of the pathogenesis of bone TB.

Dracunculin Inhibits Adipogenesis in Human Bone Marrow-Derived Mesenchymal Stromal Cells by Activating AMPK and Wnt/β-Catenin Signaling

Increased bone marrow adiposity is widely observed in patients with obesity and osteoporosis and reported to have deleterious effects on bone formation. Dracunculin (DCC) is a coumarin isolated from Artemisia spp. but, until now, has not been studied for its bioactive potential except antitrypanosomal activity. In this context, current study has reported the anti-adipogenic effect of DCC in human bone marrow-derived mesenchymal stromal cells (hBM-MSCs). DCC dose-dependently inhibited the lipid accumulation and expression of adipogenic transcription factors peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα) in hBM-MSCs induced to undergo adipogenesis. To elucidate its action mechanism, the effect of DCC on Wnt/β-catenin and AMPK pathways was examined. Results showed that DCC treatment activated Wnt/β-catenin signaling pathway via AMPK evidenced by increased levels of AMPK phosphorylation and Wnt10b expression after DCC treatment. In addition, DCC treated adipo-induced hBM-MSCs exhibited significantly increased nuclear levels of β-catenin compared with diminished nuclear PPARγ levels. In conclusion, DCC was shown to be able to hinder adipogenesis by activating the β-catenin via AMPK, providing potential utilization of DCC as a nutraceutical against bone marrow adiposity.

Stable Isotope and Radiocarbon Analysis for Diet, Climate and Mobility Reconstruction in Agras (Early Iron Age) and Edessa (Roman Age), Northern Greece

In this article we present an isotopic analysis of human bone collagen (δ13Ccol, and δ15Ncol) and bone apatite (δ13C) for diet reconstruction, as well as δ18Oap of human bone apatite for climate reconstruction, using samples from Northern Greece. Radiocarbon dating analysis was conducted on three of the Agras samples and the results (from 1000 to 800 BC) correspond to the Early Iron Age. Isotopic values for δ13Ccol range from −20.5‰ to −16‰ and for δ15Ncol from 6‰ to 11.1‰—a strong indication of a C3-based diet, with contributions by C4 and freshwater fish elements. The results were compared to the ones from Roman Edessa, and Alexandreia (a contemporary city near Edessa), as well as to other Early Iron sites in Greece and wider Europe. In general, the results from Agras are in good agreement with the results from Northern Greece, with the exception of the Makriyalos site, and are quite close to those of Croatia’s and Hungary’s sites. Additionally, from the δ18Oap results we calculated the oxygen isotopic composition of consumed water for Agras (from −9.6‰ to −10.9‰) and for Roman Edessa (from −9.6‰ to −11.2‰) for the palaeoclimate and palaeomobility reconstruction.