scholarly journals Obesity-Induced Methylation of Osteopontin Contributes to Adipogenic Differentiation of Adipose-Derived Mesenchymal Stem Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Min Tang ◽  
Rui Chen ◽  
Hao Wang ◽  
Guowei Sun ◽  
Fan Yin ◽  
...  

Obesity is a major risk factor for many chronic diseases, including diabetes, fatty livers, and cancer. Expansion of the adipose mass has been shown to be related to adipogenic differentiation of adipose-derived mesenchymal stem cells (ASCs). However, the underlying mechanism of this effect has yet to be elucidated. We found that osteopontin (OPN) is downregulated in ASCs and adipose tissues of obese mice and overweight human beings because of methylation on its promoter, indicating that OPN may affect the development of obesity. Silencing of OPN in wild-type ASCs promotes adipogenic differentiation, while reexpression of OPN reduced adipogenic differentiation in OPN−/− ASCs. The role of extracellular OPN in ASC differentiation was further demonstrated by supplementation and neutralization of OPN. Additionally, OPN suppresses adipogenic differentiation in ASCs through the C/EBP pathways. Consistent with these in vitro results, by intravenous injection of OPN-expressing adenovirus to the mice, we found OPN can delay the development of obesity and improve insulin sensitivity. Therefore, our study demonstrates an important role of OPN in regulating the development of obesity, indicating OPN might be a novel target to attenuate obesity and its complications.

2016 ◽  
Vol 96 (3) ◽  
pp. 347-354 ◽  
Author(s):  
X.W. Dou ◽  
W. Park ◽  
S. Lee ◽  
Q.Z. Zhang ◽  
L.R. Carrasco ◽  
...  

Mandibular torus (MT) is a common intraoral osseous outgrowth located on the lingual surface of the mandible. Histologic features include hyperplastic bone consisting of mature cortical and trabecular bone. Some theories on the etiology of MT have been postulated, such as genetic factors, masticatory hyperfunction, trauma, and continued growth, but the underlying mechanism remains largely unknown. In this study, we investigated the potential role of mesenchymal stem cells (MSCs) derived from human MT in the pathogenesis of bone outgrowth. We demonstrated that MT harbored a distinct subpopulation of MSCs, with enhanced osteogenic and decreased adipogenic differentiation capacities, as compared with their counterparts from normal jaw bone. The increased osteogenic differentiation of mandibular torus MSCs was associated with the suppression of Notch3 signaling and its downstream target genes, Jag1 and Hey1, and a reciprocal increase in the transcriptional activation of ATF4 and NFATc1 genes. Targeted knockdown of Notch3 expression by transient siRNA transfection promoted the expression of osteogenic transcription factors in normal jaw bone MSCs. Our data suggest that the loss of Notch3 signaling may contribute partly to bone outgrowth in MT, as mediated by enhanced MSC-driven osteogenic differentiation in the jaw bone.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8970 ◽  
Author(s):  
Yu Xia ◽  
Xiao-Tao He ◽  
Xin-Yue Xu ◽  
Bei-Min Tian ◽  
Ying An ◽  
...  

Background Different phenotypes of macrophages (M0, M1 and M2 Mφs) have been demonstrated to play distinct roles in regulating mesenchymal stem cells in various in vitro and in vivo systems. Our previous study also found that cell-conditioned medium (CM) derived from M1 Mφs supported the proliferation and adipogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs), whereas CM derived from either M0 or M2 Mφs showed an enhanced effect on cell osteogenic differentiation. However, the underlying mechanism remains incompletely elucidated. Exosomes, as key components of Mφ-derived CM, have received increasing attention. Therefore, it is possible that exosomes may modulate the effect of Mφ-derived CM on the property of BMMSCs. This hypothesis was tested in the present study. Methods In this study, RAW264.7 cells were induced toward M1 or M2 polarization with different cytokines, and exosomes were isolated from the unpolarized (M0) and polarized (M1 and M2) Mφs. Mouse BMMSCs were then cultured with normal complete medium or inductive medium supplemented with M0-Exos, M1-Exos or M2-Exos. Finally, the proliferation ability and the osteogenic, adipogenic and chondrogenic differentiation capacity of the BMMSCs were measured and analyzed. Results We found that only the medium containing M1-Exos, rather than M0-Exos or M2-Exos, supported cell proliferation and osteogenic and adipogenic differentiation. This was inconsistent with CM-based incubation. In addition, all three types of exosomes had a suppressive effect on chondrogenic differentiation. Conclusion Although our data demonstrated that exosomes and CM derived from the same phenotype of Mφs didn’t exert exactly the same cellular influences on the cocultured stem cells, it still confirmed the hypothesis that exosomes are key regulators during the modulation effect of Mφ-derived CM on BMMSC property.


2020 ◽  
Author(s):  
Yadong Luo ◽  
Huan Ji ◽  
Yan Cao ◽  
Xu Ding ◽  
Meng Li ◽  
...  

Abstract Background: Our study was designed to investigate the role of miR-26b-5p on TCF-4, affecting the adipogenic differentiation of human adipose-derived mesenchymal stem cells (hADMSCs). METHODS: The adipogenic differentiation of hADMSCs was induced by adipogenic medium for 6 days (d). Bioinformatic and dual-luciferase analyses were used to confirm the relationship between TCF-4 and miR-26b-5p. Immunofluorescence was used to detect the effect of miR-26b-5p on TCF-4 and β-catenin in hADMSCs transfected with miR-26b-5p mimic and inhibitor. Mimic, inhibitor, and small interfering RNA (siRNA) transfected in hADMSCs to against LEF1 and β-catenin. Quantitative real-time PCR and western blotting were used to examine the adipogenic markers and Wnt/β-catenin pathway at the mRNA and protein levels, respectively. Immunofluorescence was performed to locate β-catenin. RESULTS: hADMSCs could differentiate toward adipocytes by the adipogenic medium. The results of bioinformatic and dual-luciferase analyses show that TCF-4 is a potential target of miR-26b-5p. The immunofluorescence intensity of TCF4 and β-catenin were inhibited by miR-26b-5p in hADMSCs. Overexpression of miR-26b-5p promotes the adipogenic differentiation of hADMSCs. Overexpression of TCF-4 and β-catenin inhibits the adipogenic differentiation of hADMSCs. The adipogenic differentiation of hADMSCs that promoted by knocking down TCF4 could be weakened by low-expression of miR-26b-5p. The stimulative effect of β-catenin low-expression in adipogenic differentiation was inhibited by miR-26b-5p inhibitor. Conclusions: miR-26b-5p is a negative regulator to inhibit TCF-4 directly, and then inactivated Wnt/β-catenin pathway, which promotes the adipogenic differentiation of hADMSCs in vitro.


Author(s):  
Bruna O. S. Câmara ◽  
Bruno M. Bertassoli ◽  
Natália M. Ocarino ◽  
Rogéria Serakides

The use of stem cells in cell therapies has shown promising results in the treatment of several diseases, including diabetes mellitus, in both humans and animals. Mesenchymal stem cells (MSCs) can be isolated from various locations, including bone marrow, adipose tissues, synovia, muscles, dental pulp, umbilical cords, and the placenta. In vitro, by manipulating the composition of the culture medium or transfection, MSCs can differentiate into several cell lineages, including insulin-producing cells (IPCs). Unlike osteogenic, chondrogenic, and adipogenic differentiation, for which the culture medium and time are similar between studies, studies involving the induction of MSC differentiation in IPCs differ greatly. This divergence is usually evident in relation to the differentiation technique used, the composition of the culture medium, the cultivation time, which can vary from a few hours to several months, and the number of steps to complete differentiation. However, although there is no “gold standard” differentiation medium composition, most prominent studies mention the use of nicotinamide, exedin-4, ß-mercaptoethanol, fibroblast growth factor b (FGFb), and glucose in the culture medium to promote the differentiation of MSCs into IPCs. Therefore, the purpose of this review is to investigate the stages of MSC differentiation into IPCs both in vivo and in vitro, as well as address differentiation techniques and molecular actions and mechanisms by which some substances, such as nicotinamide, exedin-4, ßmercaptoethanol, FGFb, and glucose, participate in the differentiation process.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Hyun Sook Hong ◽  
Suna Kim ◽  
Youngsook Son

Bone marrow stem cells, especially, endothelial precursor cells (EPC), mesenchymal stem cells (MSC) or hematopoietic stem cell (HSC) are expected as reparative cells for the repair of a variety of tissue damages such as stroke and myocardial infarction, even though their role in the repair is not demonstrated. This report was investigated to find a role of Substance-p (SP) as a reparative agent in the tissue repair requiring EPC and MSC. In order to examine EPC (EPC SP ) and MSC (MSC SP ) mobilized by SP, we injected SP intravenously for consecutive 2 days and saline was injected as a vehicle. At 3 post injection, peripheral blood (PB) was collected.To get mesenchymal stem cells or endothelial progenitor cells, MNCs were incubated in MSCGM or EGM-2 respectively for 10 days. Functional characteristics of the EPC SP were proven by the capacity to form endothelial tubule network in the matrigel in vitro and in the matrigel plug assay in vivo. In contrast, MSC SP did not form a tube-like structure but formed a pellet-structure on matrigel. However, when both cells were premixed before the matrigel assay, much longer and branched tubular network was formed, in which a-SMA expressing MSC SP were decorating outside of the endothelial tube, especially enriched at the bifurcating point. MSC SP may contribute and reinforce elaborate vascular network formation in vivo by working as pericyte-like cells. Thus, the EPC SP and MSC SP were labeled with PKH green and PKH red respectively and their tubular network was examined. Well organized tubular network was formed, which was covered by PKH green labeled cells and was decorated in a punctate pattern by PKH red labeled cells. In order to investigate the role of EPC SP and MSC SP specifically in vivo, rabbit EPC SP and MSC SP were transplanted to full thickness skin wound. The vessel of EPC SP -transplanted groups was UEA-lectin+, which was not covered with a-SMA+ pericytes but EPC SP + MSC SP -transplanted groups showed, in part, a-SMA+ pericyte-encircled UEA-lectin+ vessels. This proved the specific role of MSC SP as pericytes. From these data, we have postulated that the collaboration of MSC and EPC is essential for normal vessel structure and furthermore, accelerated wound healing as ischemia diseases, which can be stimulated through by SP injection.


2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Doaa Aboalola ◽  
Victor K. M. Han

As mesenchymal stem cells (MSCs) are being investigated for regenerative therapies to be used in the clinic, delineating the roles of the IGF system in MSC growth and differentiation, in vitro, is vital in developing these cellular therapies to treat degenerative diseases. Muscle differentiation is a multistep process, starting with commitment to the muscle lineage and ending with the formation of multinucleated fibers. Insulin-like growth factor binding protein-6 (IGFBP-6), relative to other IGFBPs, has high affinity for IGF-2. However, the role of IGFBP-6 in muscle development has not been clearly defined. Our previous studies showed that in vitro extracellular IGFBP-6 increased myogenesis in early stages and could enhance the muscle differentiation process in the absence of IGF-2. In this study, we identified the signal transduction mechanisms of IGFBP-6 on muscle differentiation by placental mesenchymal stem cells (PMSCs). We showed that muscle differentiation required activation of both AKT and MAPK pathways. Interestingly, we demonstrated that IGFBP-6 could compensate for IGF-2 loss and help enhance the muscle differentiation process by triggering predominantly the MAPK pathway independent of activating either IGF-1R or the insulin receptor (IR). These findings indicate the complex interactions between IGFBP-6 and IGFs in PMSC differentiation into the skeletal muscle and that the IGF signaling axis, specifically involving IGFBP-6, is important in muscle differentiation. Moreover, although the major role of IGFBP-6 is IGF-2 inhibition, it is not necessarily the case that IGFBP-6 is the main modulator of IGF-2.


PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e32481 ◽  
Author(s):  
Elisa Monaco ◽  
Massimo Bionaz ◽  
Sandra Rodriguez-Zas ◽  
Walter L. Hurley ◽  
Matthew B. Wheeler

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