Project description:BackgroundMesenchymal stem cells (MSCs) are known to have different differentiation potential depending on the tissue of origin. Dedifferentiated fat cells (DFATs) are MSC-like multipotent cells that can be prepared from mature adipocytes by ceiling culture method. It is still unknown whether DFATs derived from adipocytes in different tissue showed different phenotype and functional properties. In the present study, we prepared bone marrow (BM)-derived DFATs (BM-DFATs), BM-MSCs, subcutaneous (SC) adipose tissue-derived DFATs (SC-DFATs), and adipose tissue-derived stem cells (ASCs) from donor-matched tissue samples. Then, we compared their phenotypes and multilineage differentiation potential in vitro. We also evaluated in vivo bone regeneration ability of these cells using a mouse femoral fracture model.MethodsBM-DFATs, SC-DFATs, BM-MSCs, and ASCs were prepared from tissue samples of knee osteoarthritis patients who received total knee arthroplasty. Cell surface antigens, gene expression profile, and in vitro differentiation capacity of these cells were determined. In vivo bone regenerative ability of these cells was evaluated by micro-computed tomography imaging at 28 days after local injection of the cells with peptide hydrogel (PHG) in the femoral fracture model in severe combined immunodeficiency mice.ResultsBM-DFATs were successfully generated at similar efficiency as SC-DFATs. Cell surface antigen and gene expression profiles of BM-DFATs were similar to those of BM-MSCs, whereas these profiles of SC-DFATs were similar to those of ASCs. In vitro differentiation analysis revealed that BM-DFATs and BM-MSCs had higher differentiation tendency toward osteoblasts and lower differentiation tendency toward adipocytes compared to SC-DFATs and ASCs. Transplantation of BM-DFATs and BM-MSCs with PHG enhanced bone mineral density at the injection sites compared to PHG alone in the mouse femoral fracture model.ConclusionsWe showed that phenotypic characteristics of BM-DFATs were similar to those of BM-MSCs. BM-DFATs exhibited higher osteogenic differentiation potential and bone regenerative ability compared to SC-DFATs and ASCs. These results suggest that BM-DFATs may be suitable sources of cell-based therapies for patients with nonunion bone fracture.
Project description:BACKGROUND:Regarding regenerative medicine for diabetes, accessible sources of Mesenchymal Stem Cells (MSCs) for induction of insular beta cell differentiation may be as important as mastering the differentiation process itself. METHODOLOGY/PRINCIPAL FINDINGS:In the present work, stem cells from pancreatic islets (human islet-mesenchymal stem cells, HI-MSCs) and from human bone marrow (bone marrow mesenchymal stem cells, BM-MSCs) were cultured in custom-made serum-free medium, using suitable conditions in order to induce differentiation into Islet-like Cells (ILCs). HI-MSCs and BM-MSCs were positive for the MSC markers CD105, CD73, CD90, CD29. Following this induction, HI-MSC and BM-MSC formed evident islet-like structures in the culture flasks. To investigate functional modifications after induction to ILCs, ultrastructural analysis and immunofluorescence were performed. PDX1 (pancreatic duodenal homeobox gene-1), insulin, C peptide and Glut-2 were detected in HI-ILCs whereas BM-ILCs only expressed Glut-2 and insulin. Insulin was also detected in the culture medium following glucose stimulation, confirming an initial differentiation that resulted in glucose-sensitive endocrine secretion. In order to identify proteins that were modified following differentiation from basal MSC (HI-MSCs and BM-MSCs) to their HI-ILCs and BM-ILCs counterparts, proteomic analysis was performed. Three new proteins (APOA1, ATL2 and SODM) were present in both ILC types, while other detected proteins were verified to be unique to the single individual differentiated cells lines. Hierarchical analysis underscored the limited similarities between HI-MSCs and BM-MSCs after induction of differentiation, and the persistence of relevant differences related to cells of different origin. CONCLUSIONS/SIGNIFICANCE:Proteomic analysis highlighted differences in the MSCs according to site of origin, reflecting spontaneous differentiation and commitment. A more detailed understanding of protein assets may provide insights required to master the differentiation process of HI-MSCs to functional beta cells based only upon culture conditioning. These findings may open new strategies for the clinical use of BM-MSCs in diabetes.
Project description:The regenerative potential of the heart is insufficient to fully restore functioning myocardium after injury, motivating the quest for a cell-based replacement strategy. Bone marrow-derived mesenchymal stem cells (MSCs) have the capacity for cardiac repair that appears to exceed their capacity for differentiation into cardiac myocytes.Here, we test the hypothesis that bone marrow derived MSCs stimulate the proliferation and differentiation of endogenous cardiac stem cells (CSCs) as part of their regenerative repertoire.Female Yorkshire pigs (n=31) underwent experimental myocardial infarction (MI), and 3 days later, received transendocardial injections of allogeneic male bone marrow-derived MSCs, MSC concentrated conditioned medium (CCM), or placebo (Plasmalyte). A no-injection control group was also studied. MSCs engrafted and differentiated into cardiomyocytes and vascular structures. In addition, endogenous c-kit(+) CSCs increased 20-fold in MSC-treated animals versus controls (P<0.001), there was a 6-fold increase in GATA-4(+) CSCs in MSC versus control (P<0.001), and mitotic myocytes increased 4-fold (P=0.005). Porcine endomyocardial biopsies were harvested and plated as organotypic cultures in the presence or absence of MSC feeder layers. In vitro, MSCs stimulated c-kit(+) CSCs proliferation into enriched populations of adult cardioblasts that expressed Nkx2-5 and troponin I.MSCs stimulate host CSCs, a new mechanism of action underlying successful cell-based therapeutics.
Project description:Neuron-glial antigen 2 (NG2, gene name: Cspg4) has been characterized as an important factor in many diseases. However, the pathophysiological relevance of NG2 in liver disease specifically regarding bone marrow mesenchymal stem cell (BMSC) differentiation to myofibroblast (MF) and the molecular details remain unknown. Human liver tissues were obtained from patients with different chronic liver diseases, and mouse liver injury models were induced by feeding a methionine-choline-deficient and high-fat diet, carbon tetrachloride administration, or bile duct ligation operation. NG2 expression was increased in human and mouse fibrotic liver and positively correlated with MF markers α-smooth muscle actin (αSMA) and other fibrotic markers in the liver. There was a co-localization between NG2 and αSMA, NG2 and EGFP (BMSC-derived MF) in the fibrotic liver determined by immunofluorescence analysis. In vitro, TGFβ1-treated BMSC showed a progressive increase in NG2 levels, which were mainly expressed on the membrane surface. Interestingly, there was a translocation of NG2 from the cell membrane into cytoplasm after the transfection of Cspg4 siRNA in TGFβ1-treated BMSC. siRNA-mediated inhibition of Cspg4 abrogated the TGFβ1-induced BMSC differentiation to MF. Importantly, inhibition of NG2 in vivo significantly attenuated the extent of liver fibrosis in methionine-choline-deficient and high fat (MCDHF) mice, as demonstrated by the decreased mRNA expression of fibrotic parameters, collagen deposition, serum transaminase levels, liver steatosis and inflammation after the administration of Cspg4 siRNA in MCDHF mice. We identify the positive regulation of NG2 in BMSC differentiation to MF during liver fibrosis, which may provide a promising target for the treatment of liver disease.
Project description:Health is dependent on the homeostasis of both inner and external microenvironments. The microbiota as the external microenvironment plays a critical role in regulation of several organ systems in mammals. However, it is unclear whether the microbiota regulates homeostasis of the skeletal system and bone marrow mesenchymal stem cells (BMMSCs). Here, using a well-established germ-free (GF) mouse model, we show that the microbiota significantly alters the stemness of BMMSCs in comparison to specific-pathogen-free (SPF)-derived BMMSCs. Colonization of GF mice with SPF microbiota (conventionalized (ConvD)) normalizes the proliferation and differentiation abilities of BMMSCs. On the other hand, normal microbiota is required to maintain immunomodulatory properties of BMMSCs through induction of activated T-cell apoptosis and cytokine secretion. GF-derived BMMSCs lose the capacity to ameliorate disease phenotypes in dextran sulfate sodium-induced experimental colitis mice. Mechanistically, single-cell RNA-sequencing analysis shows that ConvD BMMSCs have a similar gene expression pattern to SPF-derived BMMSCs, which have a distinct gene distribution from GF-derived BMMSCs.
Project description:It remains elusive as to what bone marrow (BM) cell types infiltrate into injured and/or diseased tissues and subsequently differentiate to assume the phenotype of residential cells, for example, neurons, cardiac myocytes, keratocytes, etc., to repair damaged tissue. Here, we examined the possibility of whether BM cell invasion via circulation into uninjured and injured corneas could assume a keratocyte phenotype, using chimeric mice generated by transplantation of enhanced green fluorescent protein (EGFP)(+) BM cells into keratocan null (Kera(-/-)) and lumican null (Lum(-/-)) mice. EGFP(+) BM cells assumed dendritic cell morphology, but failed to synthesize corneal-specific keratan sulfate proteoglycans, that is KS-lumican and KS-keratocan. In contrast, some EGFP(+) BM cells introduced by intrastromal transplantation assumed keratocyte phenotypes. Furthermore, BM cells were isolated from Kera-Cre/ZEG mice, a double transgenic mouse line in which cells expressing keratocan become EGFP(+) due to the synthesis of Cre driven by keratocan promoter. Three days after corneal and conjunctival transplantations of such BM cells into Kera(-/-) mice, green keratocan positive cells were found in the cornea, but not in conjunctiva. It is worthy to note that transplanted BM cells were rejected in 4 weeks. MSC isolated from BM were used to examine if BM mesenchymal stem cells (BM-MSC) could assume keratocyte phenotype. When BM-MSC were intrastromal-transplanted into Kera(-/-) mice, they survived in the cornea without any immune and inflammatory responses and expressed keratocan in Kera(-/-) mice. These observations suggest that corneal intrastromal transplantation of BM-MSC may be an effective treatment regimen for corneal diseases involving dysfunction of keratocytes.
Project description:Background. The interests in mesenchymal stem cells (MSCs) and their application in cell therapy have resulted in a better understanding of the basic biology of these cells. Recently hypoxia has been indicated as crucial for complete chondrogenesis. We aimed at analyzing bone marrow MSCs (BM-MSCs) differentiation capacity under normoxic and severe hypoxic culture conditions. Methods. MSCs were characterized by flow cytometry and differentiated towards adipocytes, osteoblasts, and chondrocytes under normoxic or severe hypoxic conditions. The differentiations were confirmed comparing each treated point with a control point made of cells grown in DMEM and fetal bovine serum (FBS). Results. BM-MSCs from the donors displayed only few phenotypical differences in surface antigens expressions. Analyzing marker genes expression levels of the treated cells compared to their control point for each lineage showed a good differentiation in normoxic conditions and the absence of this differentiation capacity in severe hypoxic cultures. Conclusions. In our experimental conditions, severe hypoxia affects the in vitro differentiation potential of BM-MSCs. Adipogenic, osteogenic, and chondrogenic differentiations are absent in severe hypoxic conditions. Our work underlines that severe hypoxia slows cell differentiation by means of molecular mechanisms since a decrease in the expression of adipocyte-, osteoblast-, and chondrocyte-specific genes was observed.
Project description:Human stromal (mesenchymal) stem cells (hMSCs) are multipotent stem cells with ability to differentiate into mesoderm-type cells e.g. osteoblasts and adipocytes and thus they are being introduced into clinical trials for tissue regeneration. Traditionally, hMSCs have been isolated from bone marrow, but the number of cells obtained is limited. Here, we compared the MSC-like cell populations, obtained from alternative sources for MSC: adipose tissue and skin, with the standard phenotype of human bone marrow MSC (BM-MSCs). MSC from human adipose tissue (human adipose stromal cells (hATSCs)) and human skin (human adult skin stromal cells, (hASSCs) and human new-born skin stromal cells (hNSSCs)) grew readily in culture and the growth rate was highest in hNSSCs and lowest in hATSCs. Compared with phenotype of hBM-MSC, all cell populations were CD34(-), CD45(-), CD14(-), CD31(-), HLA-DR(-), CD13(+), CD29(+), CD44(+), CD73(+), CD90(+),and CD105(+). When exposed to in vitro differentiation, hATSCs, hASSCs and hNSSCs exhibited quantitative differences in their ability to differentiate into adipocytes and to osteoblastic cells. Using a microarray-based approach we have unveiled a common MSC molecular signature composed of 33 CD markers including known MSC markers and several novel markers e.g. CD165, CD276, and CD82. However, significant differences in the molecular phenotype between these different stromal cell populations were observed suggesting ontological and functional differences. In conclusion, MSC populations obtained from different tissues exhibit significant differences in their proliferation, differentiation and molecular phenotype, which should be taken into consideration when planning their use in clinical protocols.
Project description:Bone marrow-derived mesenchymal stem cells (BMSCs) exhibit multi-lineage differentiation potential and robust proliferative capacity. The late stage of differentiation signifies the functional maturation and characterization of specific cell lineages, which is crucial for studying lineage-specific differentiation mechanisms. However, the molecular processes governing late-stage BMSC differentiation remain poorly understood. This study aimed to elucidate the key biological processes involved in late-stage BMSC differentiation. Publicly available transcriptomic data from human BMSCs were analyzed after approximately 14 days of osteogenic, adipogenic, and chondrogenic differentiation. Thirty-one differentially expressed genes (DEGs) associated with differentiation were identified. Pathway enrichment analysis indicated that the DEGs were involved in extracellular matrix (ECM)-receptor interactions, focal adhesion, and glycolipid biosynthesis, a ganglion series process. Subsequently, the target genes were validated using publicly available single-cell RNA-seq data from mouse BMSCs. Lamc1 exhibited predominant distribution in adipocytes and osteoblasts, primarily during the G2/M phase. Tln2 and Hexb were expressed in chondroblasts, osteoblasts, and adipocytes, while St3gal5 was abundantly distributed in stem cells. Cell communication analysis identified two receptors that interact with LAMCI. q-PCR results confirmed the upregulation of Lamc1, Tln2, Hexb, and St3gal5 during osteogenic differentiation and their downregulation during adipogenic differentiation. Knockdown of Lamc1 inhibited adipogenic and osteogenic differentiation. In conclusion, this study identified four genes, Lamc1, Tln2, Hexb, and St3gal5, that may play important roles in the late-stage differentiation of BMSCs. It elucidated their interactions and the pathways they influence, providing a foundation for further research on BMSC differentiation.
Project description:The effect and related mechanisms of miR-127-5p on the cartilage differentiation of rat bone marrow mesenchymal stem cells (BMSCs) was investigated. Rat BMSCs were generated and transfected with miR-127-5p, RT-PCR and Safranin O staining were used to detect the effect of miR-127-5p on the cartilage differentiation of rat BMSCs. Western blot analysis was used to detect the related mechanisms of miR-127-5p on the cartilage differentiation of rat BMSCs. Genes related to cartilage differentiation such as Sox9, collagen II and aggrecan were significantly increased in the group which were transfected with miR-127-5p, while collagen X, which was related to cartilage hypertrophy, was decreased in the miR-127-5p transfected group. Safranin O staining revealed that the expression of chondroitin sulfate was significantly increased in the group of miR-127-5p, than the miRNA control group. Western blot analysis showed that miR-127-5p transfection promoted the expression of Sox9, while decreased the expression of Runx2 of rat BMSCs. In conclusion, via increasing the expression of Sox9 and decreasing the expression of Runx2, miR-127-5p could promote cartilage differentiation and decrease cartilage hypertrophy of rat BMSCs.