ABSTRACT
OBJECTIVE@#To Investigate the effects of lithocholic acid (LCA) on the balance between osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs).@*METHODS@#Twelve 10-week-old SPF C57BL/6J female mice were randomly divided into an experimental group (undergoing bilateral ovariectomy) and a control group (only removing the same volume of adipose tissue around the ovaries), with 6 mice in each group. The body mass was measured every week after operation. After 4 weeks post-surgery, the weight of mouse uterus was measured, femur specimens of the mice were taken for micro-CT scanning and three-dimensional reconstruction to analyze changes in bone mass. Tibia specimens were taken for HE staining to calculate the number and area of bone marrow adipocytes in the marrow cavity area. ELISA was used to detect the expression of bone turnover markers in the serum. Liver samples were subjected to real-time fluorescence quantitative PCR (RT-qPCR) to detect the expression of key genes related to bile acid metabolism, including cyp7a1, cyp7b1, cyp8b1, and cyp27a1. BMSCs were isolated by centrifugation from 2 C57BL/6J female mice (10-week-old). The third-generation cells were exposed to 0, 1, 10, and 100 μmol/L LCA, following which cell viability was evaluated using the cell counting kit 8 assay. Subsequently, alkaline phosphatase (ALP) staining and oil red O staining were conducted after 7 days of osteogenic and adipogenic induction. RT-qPCR was employed to analyze the expressions of osteogenic-related genes, namely ALP, Runt-related transcription factor 2 (Runx2), and osteocalcin (OCN), as well as adipogenic-related genes including Adiponectin (Adipoq), fatty acid binding protein 4 (FABP4), and peroxisome proliferator-activated receptor γ (PPARγ).@*RESULTS@#Compared with the control group, the body mass of the mice in the experimental group increased, the uterus atrophied, the bone mass decreased, the bone marrow fat expanded, and the bone metabolism showed a high bone turnover state. RT-qPCR showed that the expressions of cyp7a1, cyp8b1, and cyp27a1, which were related to the key enzymes of bile acid metabolism in the liver, decreased significantly ( P<0.05), while the expression of cyp7b1 had no significant difference ( P>0.05). Intervention with LCA at concentrations of 1, 10, and 100 μmol/L did not demonstrate any apparent toxic effects on BMSCs. Furthermore, LCA inhibited the expressions of osteogenic-related genes (ALP, Runx2, and OCN) in a dose-dependent manner, resulting in a reduction in ALP staining positive area. Concurrently, LCA promoted the expressions of adipogenic-related genes (Adipoq, FABP4, and PPARγ), and an increase in oil red O staining positive area.@*CONCLUSION@#After menopause, the metabolism of bile acids is altered, and secondary bile acid LCA interferes with the balance of osteogenic and adipogenic differentiation of BMSCs, thereby affecting bone remodelling.
Subject(s)
Female , Mice , Animals , Core Binding Factor Alpha 1 Subunit/pharmacology , PPAR gamma/metabolism , Steroid 12-alpha-Hydroxylase/metabolism , Mice, Inbred C57BL , Cell Differentiation , Osteogenesis , Mesenchymal Stem Cells , Bile Acids and Salts/pharmacology , Bone Marrow Cells , Cells, Cultured , Azo CompoundsABSTRACT
Androgen plays vital roles not only in reproductive function, but also in maintaining bone growth and in ensuring bone integrity. Traditionally, bone is nothing but a hormone-regulated organ. However, recent studies have shown that bone can also act as an endocrine organ to regulate the function of testis. In this review, we introduce the function of testis in bone metabolism, the role of bone on the regulation of testis, as well as explore related clinical significance.
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Recently,more and more researches focus on the relationship between bone marrow fat and osteoporosis.From a pathological point of view, osteoporosis is traditionally regarded as the dysfunction of osteoblastic bone formation and osteoclastic bone resorption.Actually, bone marrow adipose tissue that constitutes a large proportion of bone marrow cells is indispensable for the balance of bone metabolism.Bone marrow fat, which is abundant in yellow bone marrow, increases gradually with aging.Bone marrow adipocytes and osteoblasts differentiate from a common progenitor, bone marrow mesenchymal stem cells(BMSCs).It is generally acknowledged that they are reciprocal repellent in the process of BMSC differentiation.Exploring the association between bone marrow adipocytes and osteoporosis is critical for better understanding its role in the pathogenesis and the future treatment of osteoporosis.In this review, we summary the recent progress in the association between bone marrow adipocytes and osteoporosis.
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<p><b>OBJECTIVE</b>To construct a retroviral vector carrying human vascular endothelial growth factor (hVEGF (121)) cDNA for evaluation of the possibility of VEGF gene therapy in ischemic bone disease.</p><p><b>METHODS</b>hVEGF(121) cDNA was obtained from the plasmid pCDI/VEGF(121) and cloned into retroviral plasmid pLXSN. Recombinant plasmid was transferred to the retro virus packaging cell, PT-67, by lipofectamine mediated gene transfer. Mouse bone marrow stromal cells (MSCs) were transfected by the retrovirus. The integration of the hVEGF(121) cDNA into MSC genomic DNA and expression of the VEGF gene was detected. Proliferation assays of human umbilical vein endothelial cells (HUVECs) by VEGF(121) in culture medium were performed.</p><p><b>RESULTS</b>Recombinant pLXSN/VEGF(121) was correctly constructed and confirmed by restriction endonuclease analysis and DNA sequencing analysis. hVEGF(121) gene was integrated into MSC genomic DNA after transfection, and the VEGF(121) protein was expressed. Proliferation assays showed VEGF(121) in culture medium was a biologically active protein and had a mitogenic effect on HUVEC.</p><p><b>CONCLUSIONS</b>Recombinant retroviral vector carrying hVEGF(121) cDNA was successfully constructed. VEGF (121) protein expressed by MSCs had mitogenic effect biologically. This provides a further foundation for VEGF gene therapy for bone ischemic disease and bone tissue engineering.</p>
Subject(s)
Animals , Humans , Mice , Bone Marrow Cells , Metabolism , Cell Division , DNA, Complementary , Genetics , Endothelial Growth Factors , Genetics , Endothelium, Vascular , Cell Biology , Genetic Therapy , Lymphokines , Genetics , Plasmids , Retroviridae , Genetics , Stromal Cells , Metabolism , Transgenes , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factors , Virus AssemblyABSTRACT
<p><b>OBJECTIVE</b>To construct the adenoviral vector bringing hVEGF(121) cDNA for evaluation of the possibility of VEGF gene therapy in ischemic bone disease.</p><p><b>METHODS</b>Human vascular endothelial growth factor (hVEGF(121)) cDNA obtained from the plasmid pCDI/VEGF(121) was cloned into plasmid pshuttle and further cloned to Adeno-X Viral DNA. The recombinant adenoviral plasmid was identified and then transferred to the adenoviral packaging cell HEK293 by lipofectamine mediated gene transfer method to pack the virus. After titilating the virus, the mouse bone marrow stromal cells (MSC) were transfected by the adenovirus and the expression of VEGF gene was detected.</p><p><b>RESULTS</b>The recombinant Adeno-VEGF(121) was correctly constructed and confirmed by restriction endonuclease analysis and DNA sequencing analysis. After MSCs were tranfected by the virus, RT-PCR showed that hVEGF(121) mRNA was transcripted from the hVEGF(121) gene. Western blot and immune histochemistry showed VEGF(121) protein was expressed in transgene MSCs.</p><p><b>CONCLUSION</b>The recombinant adenoviral vector bringing hVEGF(121) cDNA was successfully constructed and the transgene MSC expressed hVEGF gene in vitro, it provided the further foundation of VEGF gene therapy for bone ischemic diseases.</p>