Control Adipose-derived Stem Cells Research Articles

Interleukin 4 improved adipose-derived stem cells engraftment via interacting with fibro/adipogenic progenitors in dystrophic mice

Adipose-derived stem cells (ADSC) therapy shows promise as an effective treatment for dystrophinopathy. Fibro-/adipogenic progenitors (FAPs) play an essential role in the myogenesis of muscle satellite cells and contribute to muscle fibrosis and adipocyte infiltration. The interleukin 4 (IL-4) pathway acts as a switch that regulates the functions of FAPs. The interaction between FAPs and engrafted cells remains unclear. In this study, we used a co-culture system to investigate possible crosstalk between the FAPs of dystrophic mice and ADSC overexpressing IL4 (IL4-ADSC) and control ADSC. Systemic transplantation of IL4-ADSC and control ADSC in dystrophic mice was conducted for 16 weeks, after which motor function and molecular improvements were evaluated. Overexpression of IL4 in ADSC significantly promoted myogenesis in vitro, increasing the expression of Pax7, Myogenin, and MyHC. Co-culture indicated that although myoblasts derived from control ADSC promoted adipogenic and fibrogenic differentiation of FAPs, FAPs did not significantly affect myogenesis of ADSC-derived myoblasts. However, overexpression of IL4 in ADSC inhibited their myotube-dependent promotion of FAPs differentiation on the one hand and promoted FAPs to enhance myogenesis on the other. Dystrophic mice administered with IL4-ADSC-derived myoblasts displayed significantly better motor ability, more engrafted cells showing dystrophin expression, and less muscle fibrosis, intramuscular adipocytes, and macrophage infiltration than mice administered control-ADSC-derived myoblasts. In conclusion, IL4 activation enhanced the therapeutic potential of ADSC transplantation in dystrophic mice, possibly by improving the myogenesis of IL4-ADSC and altering the crosstalk between engrafted stem cells and resident FAPs.

Overexpression of integrin β2 improves migration and engraftment of adipose-derived stem cells and augments angiogenesis in myocardial infarction.

BackgroundAdipose-derived stem cells (ASCs) hold a great promise for myocardial infarction, but therapeutic efficacy appears to be limited by their poor survival and engraftment. Integrins are transmembrane proteins known to regulate the biological behaviors of stem cells. Integrin β2 (ITGB2) specifically binds to intercellular cell adhesion molecule-1 (ICAM-1), which is upregulated in infarcted myocardium. ASCs typically express an insufficient amount of ITGB2, and this may limit their homing and engraftment abilities.MethodsASCs were lentivirally transduced to overexpress ITGB2. ITGB2 messenger RNA (mRNA) and protein expression were examined by quantitative polymerase chain reaction (PCR) and western blot. Cell viability, proliferation, and migration were assessed in vitro. Adipogenic and osteogenic differentiation were induced, and the mRNA expressions of specific differentiation markers were quantified by PCR. ICAM-1 expression in the infarcted myocardium was quantified at 3 and 7 days after myocardial infarction. ITGB2-transfected ASCs (ITGB2-ASCs), control ASCs (CTRL-ASCs), and phosphate-buffered saline (PBS) were intramyocardially injected into the peri-infarct region at 3 days after coronary ligation. Four weeks after transplantation, myocardial blood perfusion was measured by 13N·NH3·H2O2 positron emission tomography (PET)/computed tomography (CT). Explanted hearts were then processed for the measurement of capillary density, the quantification of survived green fluorescent protein (GFP+) ASCs, and the identification of ASCs coexpressing angiogenic growth factors.ResultsICAM-1 expression peaked at 3 days after myocardial infarction and remained elevated over the remote normal myocardium at 7 days after myocardial infarction. ITGB2-ASCs displayed a significant increase in cell viability, proliferation rate, and migration index when compared with CTRL-ASCs. Adipogenic and osteogenic differentiation were more enhanced in ITGB2-ASCs than in CTRL-ASCs. Four weeks after transplantation, surviving GFP+ ASCs were significantly increased, ASCs expressing angiogenic growth factors were more pronounced, capillary density was substantially enlarged, and myocardial blood perfusion was markedly improved in the hearts that received ITGB2-ASCs implantation when compared to those that underwent CTRL-ASC treatment.ConclusionsITGB2 overexpression of ASCs enhanced cell viability, proliferation, and migration and induced differentiation in vitro. ITGB2 overexpression significantly improved the survival and engraftment of ASCs into infarcted myocardium via ITGB2/ICAM-1 interaction, augmented angiogenesis, and ultimately improved blood perfusion in infarcted myocardium.

LncRNA-AK137033 inhibits the osteogenic potential of adipose-derived stem cells in diabetic osteoporosis by regulating Wnt signaling pathway via DNA methylation.

ObjectivesBone tissue engineering based on adipose‐derived stem cells (ASCs) is expected to become a new treatment for diabetic osteoporosis (DOP) patients with bone defects. However, compared with control ASCs (CON‐ASCs), osteogenic potential of DOP‐ASCs is decreased, which increased the difficulty of bone reconstruction in DOP patients. Moreover, the cause of the poor osteogenesis of ASCs in a hyperglycemic microenvironment has not been elucidated. Therefore, this study explored the molecular mechanism of the decline in the osteogenic potential of DOP‐ASCs from the perspective of epigenetics to provide a possible therapeutic target for bone repair in DOP patients with bone defects.Materials and methodsAn animal model of DOP was established in mice. CON‐ASCs and DOP‐ASCs were isolated from CON and DOP mice, respectively. AK137033 small interfering RNA (SiRNA) and an AK137033 overexpression plasmid were used to regulate the expression of AK137033 in CON‐ASCs and DOP‐ASCs in vitro. Lentiviruses that carried shRNA‐AK137033 or AK137033 cDNA were used to knockdown or overexpress AK137033, respectively, in CON‐ASCs and DOP‐ASCs in vivo. Hematoxylin and eosin (H&E), Masson's, alizarin red, and alkaline phosphatase (ALP) staining, micro‐computed tomography (Micro‐CT), flow cytometry, qPCR, western blotting, immunofluorescence, and bisulfite‐specific PCR (BSP) were used to analyze the functional changes of ASCs.ResultsThe DOP mouse model was established successfully. Compared with CON‐ASCs, AK137033 expression, the DNA methylation level of the sFrp2 promoter region, Wnt signaling pathway markers, and the osteogenic differentiation potential were decreased in DOP‐ASCs. In vitro experiments showed that AK137033 silencing inhibited the Wnt signaling pathway and osteogenic ability of CON‐ASCs by reducing the DNA methylation level in the sFrp2 promoter region. Additionally, overexpression of AK137033 in DOP‐ASCs rescued these changes caused by DOP. Moreover, the same results were obtained in vivo.ConclusionsLncRNA‐AK137033 inhibits the osteogenic potential of DOP‐ASCs by regulating the Wnt signaling pathway via modulating the DNA methylation level in the sFrp2 promoter region. This study provides an important reference to find new targets for the treatment of bone defects in DOP patients.

JKAMP inhibits the osteogenic capacity of adipose-derived stem cells in diabetic osteoporosis by modulating the Wnt signaling pathway through intragenic DNA methylation

BackgroundDiabetic osteoporosis (DOP) is a systemic metabolic bone disease caused by diabetes mellitus (DM). Adipose-derived stem cells (ASCs) play an important role in bone regeneration. Our previous study confirmed that ASCs from DOP mice (DOP-ASCs) have a lower osteogenesis potential compared with control ASCs (CON-ASCs). However, the cause of this poor osteogenesis has not been elucidated. Therefore, this study investigated the underlying mechanism of the decline in the osteogenic potential of DOP-ASCs from the perspective of epigenetics and explored methods to enhance their osteogenic capacity.MethodsThe expression level of JNK1-associated membrane protein (JKAMP) and degree of DNA methylation in CON-ASCs and DOP-ASCs were measured by mRNA expression profiling and MeDIP sequencing, respectively. JKAMP small interfering RNA (siRNA) and a Jkamp overexpression plasmid were used to assess the role of JKAMP in osteogenic differentiation of CON-ASCs and DOP-ASCs. Immunofluorescence, qPCR, and western blotting were used to measure changes in expression of Wnt signaling pathway-related genes and osteogenesis-related molecules after osteogenesis induction. Alizarin red and ALP staining was used to confirm the osteogenic potential of stem cells. Bisulfite-specific PCR (BSP) was used to detect JKAMP methylation degree.ResultsExpression of JKAMP and osteogenesis-related molecules (RUNX2 and OPN) in DOP-ASCs was decreased significantly in comparison with CON-ASCs. JKAMP silencing inhibited the Wnt signaling pathway and reduced the osteogenic ability of CON-ASCs. Overexpression of JKAMP in DOP-ASCs rescued the impaired osteogenic capacity caused by DOP. Moreover, JKAMP in DOP-ASCs contained intragenic DNA hypermethylated regions related to the downregulation of JKAMP expression.ConclusionsIntragenic DNA methylation inhibits the osteogenic ability of DOP-ASCs by suppressing expression of JKAMP and the Wnt signaling pathway. This study shows an epigenetic explanation for the reduced osteogenic ability of DOP-ASCs and provides a potential therapeutic target to prevent and treat osteoporosis.

CCR2 improves homing and engraftment of adipose-derived stem cells in dystrophic mice

BackgroundDystrophinopathy, a common neuromuscular disorder caused by the absence of dystrophin, currently lacks effective treatments. Systemic transplantation of adipose-derived stem cells (ADSCs) is a promising treatment approach, but its low efficacy remains a challenge. Chemokine system-mediated stem cell homing plays a critical role in systemic transplantation. Here, we investigated whether overexpression of a specific chemokine receptor could improve muscle homing and therapeutic effects of ADSC systemic transplantation in dystrophic mice.MethodsWe analysed multiple microarray datasets from the Gene Expression Omnibus to identify a candidate chemokine receptor and then evaluated the protein expression of target ligands in different tissues and organs of dystrophic mice. The candidate chemokine receptor was overexpressed using the lentiviral system in mouse ADSCs, which were used for systemic transplantation into the dystrophic mice, followed by evaluation of motor function, stem cell muscle homing, dystrophin expression, and muscle pathology.ResultsChemokine-profile analysis identified C–C chemokine receptor (CCR)2 as the potential target for improving ADSC homing. We found that the levels of its ligands C–C chemokine ligand (CCL)2 and CCL7 were higher in muscles than in other tissues and organs of dystrophic mice. Additionally, CCR2 overexpression improved ADSC migration ability and maintained their multilineage-differentiation potentials. Compared with control ADSCs, transplantation of those overexpressing CCR2 displayed better muscle homing and further improved motor function, dystrophin expression, and muscle pathology in dystrophic mice.ConclusionsThese results demonstrated that CCR2 improved ADSC muscle homing and therapeutic effects following systemic transplantation in dystrophic mice.

MicroRNA-150 Modulates Adipogenic Differentiation of Adipose-Derived Stem Cells by Targeting Notch3.

MicroRNAs (miRNAs) influence stem cell functions, including mobilization, proliferation, and differentiation. miR-150 is abundantly expressed in monocytes. Knockdown of miR-150 promotes bone marrow stem cell migration. The role of miR-150 in adipose-derived stem cells (ADSCs) is unclear. In this study, the effects of miR-150 on adipogenic differentiation and proliferation of ADSCs were investigated. ADSCs were isolated from the inguinal adipose tissue of wild-type (WT) and miR-150 knockout (KO) mice and were induced for adipogenic differentiation. The miR-150 level was detected by real-time PCR. ADSCs were transfected by miR-150 or small-interfering RNA (siRNA) of Notch3. MTT assay and colony formation assay were performed in miR-150 knockdown and control ADSCs. Real-time PCR showed that miR-150 was expressed in ADSCs. miR-150 knockdown significantly decreased the capacity of adipogenic differentiation of ADSCs, as compared with their counterparts from WT mice. It is intriguing that the overexpression of miR-150 significantly increased C/EBPα and PPAR-γ expression and lipid formation in ADSCs with adipogenic induction. Overexpression of miR-150 significantly decreased Notch3 expression in ADSCs compared with the control groups. Furthermore, Notch3 inhibition promoted the adipogenic differentiation in ADSCs. miR-150 also suppressed proliferation potential and the expression of Nanog in ADSCs. In summary, this study demonstrates, for the first time, that miR-150 promotes adipogenic differentiation and inhibits proliferation of ADSCs. miR-150 regulates adipogenic differentiation of ADSCs, likely mediated by the downregulation of Notch3.

Exendin-4 pretreated adipose derived stem cells are resistant to oxidative stress and improve cardiac performance via enhanced adhesion in the infarcted heart.

Reactive oxygen species (ROS), which were largely generated after myocardial ischemia, severely impaired the adhesion and survival of transplanted stem cells. In this study, we aimed to determine whether Exendin-4 pretreatment could improve the adhesion and therapeutic efficacy of transplanted adipose derived stem cells (ADSCs) in ischemic myocardium. In vitro, H2O2 was used to provide ROS environments, in which ADSCs pretreated with Exendin-4 were incubated. ADSCs without pretreatment were used as control. Then, cell adhesion and viability were analyzed with time. Compared with control ADSCs, Exendin-4 treatment significantly increased the adhesion of ADSCs in ROS environment, while reduced intracellular ROS and cell injury as determined by dihydroethidium (DHE) staining live/Dead staining, lactate dehydrogenase-release assay and MTT assay. Western Blotting demonstrated that ROS significantly decreased the expression of adhesion-related integrins and integrin-related focal adhesion proteins, which were significantly reversed by Exendin-4 pretreatment and followed by decreases in caspase-3, indicating that Exendin-4 may facilitate cell survival through enhanced adhesion. In vivo, myocardial infarction (MI) was induced by the left anterior descending artery ligation in SD rats. Autologous ADSCs with or without Exendin-4 pretreatment were injected into the border area of infarcted hearts, respectively. Multi-techniques were used to assess the beneficial effects after transplantation. Longitudinal bioluminescence imaging and histological staining revealed that Exendin-4 pretreatment enhanced the survival and differentiation of engrafted ADSCs in ischemic myocardium, accompanied with significant benefits in cardiac function, matrix remodeling, and angiogenesis compared with non-pretreated ADSCs 4 weeks post-transplantation. In conclusion, transplantation of Exendin-4 pretreated ADSCs significantly improved cardiac performance and can be an innovative approach in the clinical perspective.

DNA Methylation Plasticity of Human Adipose-Derived Stem Cells in Lineage Commitment

Adult stem cells have an enormous potential for clinical use in regenerative medicine that avoids many of the drawbacks characteristic of embryonic stem cells and induced pluripotent stem cells. In this context, easily obtainable human adipose-derived stem cells offer an interesting option for future strategies in regenerative medicine. However, little is known about their repertoire of differentiation capacities, how closely they resemble the target primary tissues, and the potential safety issues associated with their use. DNA methylation is one of the most widely recognized epigenetic factors involved in cellular identity, prompting us to consider how the analyses of 27,578 CpG sites in the genome of these cells under different conditions reflect their different natural history. We show that human adipose-derived stem cells generate myogenic and osteogenic lineages that share much of the DNA methylation landscape characteristic of primary myocytes and osteocytes. Most important, adult stem cells and in vitro-generated myocytes and osteocytes display a significantly different DNA methylome from that observed in transformed cells from these tissue types, such as rhabdomyosarcoma and osteosarcoma. These results suggest that the plasticity of the DNA methylation patterns plays an important role in lineage commitment of adult stem cells and that it could be used for clinical purposes as a biomarker of efficient and safely differentiated cells.