Marrow Mesenchymal Stem Cells Research Articles

MESENCHYMAL STEM CELLS SUPPRESS LEUKEMIA VIA MACROPHAGE-MEDIATED BONE MARROW NICHE RESTORATION

Bone marrow mesenchymal stem cells (MSC) play essential roles in supporting hematopoiesis, and dysfunctions of these cells are associated with leukemia. However, whether restoration of the impaired bone marrow (BM) microenvironment can inhibit leukemia remains unknown. Using an established model of mimicking chronic MPN/MDS diseases, we uncovered a deteriorating bone marrow microenvironment associated with the disease development. Intra-bone-marrow instead of systemic transfusion of healthy MSC restored the local bone marrow microenvironment, systemically improved thrombopoiesis and reduced tumor burden, and prolonged survivals in leukemia setting. Mechanistically, the transient donor MSC immediately reprogrammed the leukemia macrophages to fulfill tissue repairing function. Further, transfusion of in vitro MSC-reprogrammed macrophages largely recapitulated the microenvironment restoration and therapeutic effects of MSC. Our study reveals the pivotal role of resident macrophages for MSC-mediated microenvironment restoration and therapeutic effects in a chronic leukemia setting, which provides insights into translational application of MSC in MDS/MPN leukemia patients.

Stem cells and extracellular vesicles: biological regulators of physiology and disease.

Many different subpopulations of subcellular extracellular vesicles (EVs) have been described. EVs are released from all cell types and have been shown to regulate normal physiological homeostasis, as well as pathological states by influencing cell proliferation, differentiation, organ homing, injury and recovery, as well as disease progression. In this review, we focus on the bidirectional actions of vesicles from normal and diseased cells on normal or leukemic target cells; and on the leukemic microenvironment as a whole. EVs from human bone marrow mesenchymal stem cells (MSC) can have a healing effect, reversing the malignant phenotype in prostate and colorectal cancer, as well as mitigating radiation damage to marrow. The role of EVs in leukemia and their bimodal cross talk with the encompassing microenvironment remains to be fully characterized. This may provide insight for clinical advances via the application of EVs as potential therapy and the employment of statistical and machine learning models to capture the pleiotropic effects EVs endow to a dynamic microenvironment, possibly allowing for precise therapeutic intervention.

Enhanced osteogenesis of bone marrow stem cells cultured on hydroxyapatite/collagen I scaffold in the presence of low-frequency magnetic field.

As a non-invasive biophysical therapy, electromagnetic fields (EMF) have been widely used to promote the healing of fractures. In the present study, hydroxyapatite/collagen I (HAC) loaded with rabbit bone marrow mesenchymal stem cells (MSCs) were cultured in a dynamic perfusion bioreactor and exposed to EMF of 15 Hz/1mT. Osteogenic differentiation of the seeded cells was analyzed through the evaluation of ALP activity and osteogenesis-related genes expression in vitro. The in vivo osteogenesis efficacy of the cell laden HAC constructs treated with/without EMF was evaluated through a rabbit femur condyle defect model. The results showed that EMF of 15 Hz/1mT could enhance the osteogenic differentiation of the cells seeded on HAC scaffold. Furthermore, the in vivo experiments demonstrated that EMF exposure could promote bone regeneration within the defect and bone integration between the graft and host bone. Taking together, the MSCs seeded HAC scaffold combined with EMF exposure could be a promising approach for bone tissue engineering.

Bone Marrow Mesenchymal Stem Cell-Derived Exosomes Improve Osteoporosis by Inhibiting Osteoblasts Apoptosis

Osteoporosis (OP) is a metabolic bone disease which is characterized by loss of bone mineral content, decreased bone density, destruction of bone microstructure, and declined bone biomechanical evaluation index. In recent years, it was shown that bone marrow mesenchymal stem cells (MSCs) are involved in the form of exosomes, which has become a hot spot in the research of the pathogenesis of metabolic diseases. In this study, we intend to explore the effects of exosomes derived from MSCs on osteoblast apoptosis and OP. MSC-derived exosomes were obtained by ultracentrifugation and characterized by transmission electron microscopy (TEM). Exosomes were used to treat osteoblasts to observe cell apoptosis. The expression of apoptosis-related protein was detected by Western blot. Cell viability was examined by MTT assay. Cell apoptosis was assessed by TUNEL staining. TEM confirmed successfully extracted MSCs-derived exosomes. Exosomes intervention significantly reduced the expression of apoptosis-related pro-apoptotic proteins cytochrome c and caspase3, enhanced cell viability, and attenuated cell apoptosis in osteoblasts. MSCs-derived exosomes can inhibit osteoblasts apoptosis by suppressing apoptosis signaling pathways, thus improving osteoporosis, indicating that they might be used for the treatment of osteoporosis.

Para-nonylphenol Toxicity Induces Oxidative Stress and Arrests the Cell Cycle in Mesenchymal Stem Cells of Bone Marrow

Background: The mechanism of para-nonylphenol (PNP) reducing the proliferation and differentiation of bone marrow mesenchymal stem cells (MSCs) is not known. The present study was designed to investigate the mechanism. Methods: MSCs were extracted under sterile condition from Wistar rat and cultured in DMEM, containing 15 % FBS and penicillin/streptomycin until the 3rd passage, then cells were treated with 0, 0.5 and 2.5 µM of PNP for 5, 10, 15 and 20 days. We studied the viability, proliferation, cell cycle and morphology of the cells. In addition, the concentration of total protein, sodium, potassium and calcium and the activity of metabolic enzymes (ALT, AST and LDH) were determined. Also, induction of oxidative stress was estimated by determining the total antioxidant and MDA levels in addition to the activity of SOD and CAT. Results: The concentrations of PNP caused a significant increase in metabolic enzymes activity and reduced the total protein dose dependently from day 5 to day 20. But only the higher PNP concentration reduced the sodium level and increased the calcium concentration during the treatment period. In addition, we observed a significant decrease in the total antioxidant level and of SOD and CAT activities whereas a significant increase in MDA was seen. Also, PNP stopped the cell cycle at “S” and “G2/M” phases. Conclusion: Para-NP, used in many industries, was able to reduce the viability and proliferation of the MSCs via metabolic and electrolyte imbalance and by induction of oxidative stress and cell cycle disruption.

Ganoderma spore lipid protects mouse bone marrow mesenchymal stem cells and hematopoiesis from the cytotoxicity of the chemotherapeutic agent.

Cancer chemotherapeutic agents are frequently toxic to bone marrow and impair bone marrow functions. It is unclear whether ganoderma spore lipid (GSL) can protect bone marrow cells from the cytotoxicity of chemotherapy. To investigate the protective effects of GSL on bone marrow mesenchymal stem cells (MSCs) and hematopoiesis, we examined the effects of GSL on MSCs in vitro and hematopoiesis in vivo after treatment with the chemotherapeutic agent cyclophosphamide. MSCs and peripheral blood cells were isolated and counted from the bone marrow of normal mice were pre-treated with GSL before CTX treatment or co-treated with GSL and CTX, followed by examining the changes in phenotype, morphology, proliferation, apoptosis, and differentiation potentials. The results showed that GSL could reduce the CTX-induced changes in the phenotype of MSCs and maintain the elongated fibroblast-like morphology. MTT and annexin V/propidium iodide (PI) analyses found that GSL pre-treatment and co-treatment increased the proliferation and decreased the apoptosis in CTX-treated MSCs. Furthermore, GSL improved the osteogenic and adipogenic differentiation potentials of CTX-treated MSCs. In vivo, GSL treatment increased the number of peripheral blood cells including white blood cells (WBC) and platelets (PLT) in the CTX-treated mice and enhanced the in vitro formation of hematopoietic lineage colonies (erythrocyte colony forming unit, CFU-E; erythroid burst-forming units, BFU-E; and granulocyte macrophage colony-forming units, CFU-GM) from bone marrow cells in these mice. These findings suggest GSL could protect MSCs and hematopoiesis from the cytotoxicity of CTX and might become an effective adjuvant to attenuate side effects of chemotherapy during cancer treatment.

Molecular phenotyping of the surfaceome of migratory chondroprogenitors and mesenchymal stem cells using biotinylation, glycocapture and quantitative LC-MS/MS proteomic analysis

The complement of cell surface proteins, collectively referred to as the surfaceome, is a useful indicator of normal differentiation processes, and the development of pathologies such as osteoarthritis (OA). We employed biochemical and proteomic tools to explore the surfaceome and to define biomarkers in chondrogenic progenitor cells (CPC) derived from human OA knee articular cartilage. These cells have great therapeutic potential, but their unexplored biology limits their clinical application. We performed biotinylation combined with glycocapture and high throughput shotgun proteomics to define the surface proteome of human bone marrow mesenchymal stem cells (MSCs) and human CPCs. We prepared cell surface protein-enriched fractions from MSCs and CPCs, and then a proteomic approach was used to compare and evaluate protein changes between undifferentiated MSCs and CPCs. 1256 proteins were identified in the study, of which 791 (63%) were plasma membrane, cell surface or extracellular matrix proteins. Proteins constituting the surfaceome were annotated and categorized. Our results provide, for the first time, a repository of quantitative proteomic data on the surfaceome of two closely related cell types relevant to cartilage biology and OA. These results may provide novel insights into the transformation of the surfaceome during chondrogenic differentiation and phenotypic changes during OA development.

Bmi1 Overexpression in Mesenchymal Stem Cells Exerts Antiaging and Antiosteoporosis Effects by Inactivating p16/p19 Signaling and Inhibiting Oxidative Stress

We previously demonstrated that Bmi1 deficiency leads to osteoporosis phenotype by inhibiting the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (MSCs), but it is unclear whether overexpression of Bmi1 in MSCs stimulates skeletal development and rescues Bmi1 deficiency‐induced osteoporosis. To answer this question, we constructed transgenic mice (Bmi1Tg) that overexpressed Bmi1 driven by the Prx1 gene and analyzed their skeletal phenotype differences with that of wild‐type littermates. We then hybridized Bmi1Tg to Bmi1−/− mice to generate Bmi1−/− mice overexpressing Bmi1 in MSCs and compared their skeletal phenotypes with those of Bmi1−/− and wild‐type mice using imaging, histopathological, immunohistochemical, histomorphometric, cellular, and molecular methods. Bmi1Tg mice exhibited enhanced bone growth and osteoblast formation, including the augmentation of bone size, cortical and trabecular volume, number of osteoblasts, alkaline phosphatase (ALP)‐positive and type I collagen‐positive areas, number of total colony forming unit fibroblasts (CFU‐f) and ALP+ CFU‐f, and osteogenic gene expression levels. Consistently, MSC overexpressing Bmi1 in the Bmi1−/− background not only largely reversed Bmi1 systemic deficiency‐induced skeletal growth retardation and osteoporosis, but also partially reversed Bmi1 deficiency‐induced systemic growth retardation and premature aging. To further explore the mechanism of action of MSCs overexpressing Bmi1 in antiosteoporosis and antiaging, we examined changes in oxidative stress and expression levels of p16 and p19. Our results showed that overexpression of Bmi1 in MSCs inhibited oxidative stress and downregulated p16 and p19. Taken together, the results of this study indicate that overexpression of Bmi1 in MSCs exerts antiaging and antiosteoporosis effects by inactivating p16/p19 signaling and inhibiting oxidative stress. stem cells 2019;37:1200–1211

Effect of stromal cell-derived factor 1α/cysteine X cysteine receptor 4 signaling pathway on axial stress stimulation promoting bone regeneration

To observe the change of stromal cell-derived factor 1α/cysteine X cysteine receptor 4 (SDF-1α/CXCR4) signaling pathway during the process of axial stress stimulation promoting bone regeneration, and to further explore its mechanism. A total of 72 male New Zealand white rabbits were selected to prepare the single cortical bone defect in diameter of 8 mm at the proximal end of the right tibia that repaired with deproteinized cancellous bone. All models were randomly divided into 3 groups ( n=24). Group A was treated with intraperitoneally injection of PBS; Group B was treated with stress stimulation and intraperitoneally injection of PBS; Group C was treated with stress stimulation and intraperitoneally injection of AMD3100 solution. The X-ray films were taken and Lane-Sandhu scores of bone healing were scored at 2, 4, 8, and 12 weeks after operation, while specimens were harvested for HE staining, immunohistochemical staining of vascular endothelial growth factor (VEGF) and CXCR4, and Western blot (SDF-1α and CXCR4). The bone healing area was scanned by Micro-CT at 12 weeks after operation, and the volume and density of new bone were calculated. X-ray film showed that the Lane-Sandhu scores of bone healing in group B were significantly higher than those in groups A and C at 4, 8, and 12 weeks after operation ( P<0.05). Micro-CT scan showed that the bone defect was repaired in group B and the pulp cavity was re-passed at 12 weeks after operation. The volume and density of new bone were higher in group B than in groups A and C ( P<0.05). HE staining showed that the new bone growth in bone defect area and the degradation of scaffolds were faster in group B than in groups A and C after 4 weeks. The immunohistochemical staining showed that the expressions of VEGF and CXCR4 in 3 groups reached the peak at 4 weeks, and group B was higher than groups A and C ( P<0.05). Western blot analysis showed that the expressions of SDF-1α and CXCR4 in group B were significantly higher than those in groups A and C at 4 and 8 weeks after operation ( P<0.05). Axial stress stimulation can promote the expression of SDF-1α in bone defect tissue, activate and regulate the CXCR4 signal collected by marrow mesenchymal stem cells, and accelerate bone regeneration in bone defect area.

Substance P improves MSC-mediated RPE regeneration by modulating PDGF-BB

Stem cells have regenerative potentials that can be used for the treatment of critical and incurable diseases. Age-related macular degeneration (ARMD) and diabetic retinopathy are one of the most severe retinal disorders, which are mostly attributed to impairment of retinal pigmented epithelium (RPE). Thus, restoration of RPE is the main therapeutic approach to prevent the development of ocular diseases, such as ARMD. In this study, we have investigated the role of substance P (SP) on bone marrow mesenchymal stem cell (MSC)-mediated RPE regeneration in vitro. The MSCs were primed with SP followed by the addition of conditioned medium (MSCSP−CM) to RPE. The effects of MSCSP−CM on RPE activity was evaluated by assessing viability, proliferation rate, and migration of RPE. Ex vivo long-term culture led to altered cellular characteristics of MSCs by weakening cell viability, cytokine secretion, and differentiation potential. The conditioned medium of early passage MSC (E-MSCCM) enhanced the RPE viability and migration, whereas the late passage MSC (L-MSCCM) hardly influenced the RPE activity. SP priming, however, facilitated the inductive effects of MSC, and SP effect was more distinct in the late passage than in the early passage. Moreover, it was revealed that SP could exert its effects by modulating PDGF-BB secretion in the MSCs.Taken together, these results suggested that SP could restore the therapeutic effects of MSCs on retinal diseases by elevating their proliferative and paracrine activities through PDGF-PDGFR signaling in ex vivo culture.

Effect of Photobiomodulation Therapy on the Increase of Viability and Proliferation of Human Mesenchymal Stem Cells.

We have investigated how low intensity laser irradiation emitted by a multiwave-locked system (MLS M1) affects the viability and proliferation of human bone marrow mesenchymal stem cells (MSCs) depending on the parameters of the irradiation. Cells isolated surgically from the femoral bone during surgery were identified by flow cytometry and cell differentiation assays. For irradiation, two wavelengths (808 and 905 nm) with the following parameters were used: power density 195, 230, and 318 mW/cm 2 , doses of energy 3, 10, and 20 J (energy density 0.93-6.27 J/cm 2 ), and in continuous (CW) or pulsed emission (PE) (frequencies 1,000 and 2,000 Hz). There were statistically significant increases of cell viability and proliferation after irradiation at 3 J (CW; 1,000 Hz), 10 J (1,000 Hz), and 20 J (2,000 Hz). Irradiation with the MLS M1 system can be used in vitro to modulate MSCs in preparation for therapeutic applications. This will assist in designing further studies to optimize the radiation parameters and elucidate the molecular mechanisms of action of the radiation. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Teriparatide Promotes Bone Marrow Mesenchymal Stem Cell Proliferation and Differentiation by Down-Regulating miR-339 to Target DLX5

Osteoporosis (OP) is a metabolic bone disease which is characterized as loss of bone mineral content, decreased bone density, bone microstructural destruction, and reduced bone biomechanical evaluation index. Proliferation and differentiation of bone marrow mesenchymal stem cells (MSCs) is important for the treatment of OP. It is proposed that down-regulation of miR-339 can target DLX to promote the proliferation and differentiation of MSCs. However, whether teriparatide promotes osteogenic differentiation through this pathway remains unclear. MSCs were isolated from 4–6 week-old Wister rats. The effect of teriparatide on cell proliferation was evaluated by tetrazolium salt colorimetric method (MTT) and BrdU staining. Cell differentiation was measured by alkaline phosphatase staining. miR-339 expression was detected by real-time quantitative PCR (qRT-PCR). DLX5 expression was detected by Western-blot. It was found that teriparatide can promote the proliferation and differentiation of MSCs. MiR-339 level was significantly decreased and DLX5 expression was significantly upregulated after teriparatide treatment. After knocking down miR-339, teriparatide-induced upregulation of DLX5 by was attenuated. Teriparatide promotes the proliferation and differentiation of MSCs by down-regulating miR-339 to improve osteoporosis. It provides theoretical and experimental basis for the treatment of osteoporosis by teriparatide.

PS1490 BERBERINE MAY CORRECT GUT MICROBIOTA‐INDUCED CORTICOSTEROID RESISTANCE AND MESENCHYMAL STEM CELL DYSFUNCTION IN IMMUNE THROMBOCYTOPENIA BY REGULATING GUT MICROBIOTA STRUCTURE

Background:Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by abnormal immune response. Though many therapies have been used, corticosteroid‐resistance remains to be a challenge clinically. Extensive research shows that environmental factors affect the disease profile, such as Helicobacter pylori being proven to be associated with thrombocytopenia. Though evidence that the gut microbiota contributes to the development of auto‐immune disorders is accumulating, there is no information available on relationship between gut microbiome and ITP. Berberine(BBR), a traditional compound isolated from a Chinese herb, has been widely used as a nonprescription drug to treat diarrhea. Recently, BBR has been reported to modulate microbiota structure, which contributes to improving metabolic disorders. Here, we hypothesized that BBR might regulate gut microbiota thus enhancing bone marrow mesenchymal stem cell (MSC) function to treat ITP.Aims:To investigate the relationship between gut microbiota and ITP, and determine the mechanism of corticosteroid resistance induced by gut microbiota, as well as the effect of BBR on treating ITP.Methods:We performed deep shotgun sequencing on 151 fecal samples from 99 ITP patients and 52 healthy controls to characterize the gut microbiota and gene function of ITP. To better determine the relationship between gut microbiota and impaired MSCs function, we detected serum lipopolysaccharide (LPS) of ITP patients and healthy controls, and assessed MSCs function with and without LPS stimulation in vitro. Certainly, a pilot cohort study was performed to assess the efficacy of BBR in corticosteroid‐resistant ITP patients. To better characterize the role of gut microbiota in the development of ITP and its underling mechanism, as well as the effect of BBR, we performed colonization of mice with specific bacterium and established active ITP murine model.Results:We constructed a gene catalogue containing 3,548,820 non‐redundant genes totally and identified significant gut microbiota dysbiosis in ITP patients. The abundance of Flarobacterium succinicans (F. succinicans) was markedly increased in ITP especially in corticosteroid‐resistant ITP patients. Gene function annotation indicated that LPS biosynthesis was down‐regulated remarkably in corticosteroid‐resistant ITP patients. ELISA detection indicated that serum LPS was significantly lower in corticosteroid‐resistant ITP patients, which was consistent with the result of gene function annotation. LPS stimulation could restore the function of MSCs from corticosteroid‐resistant ITP patients in vitro. Colonization of F. succinicans altered gut microbiota structure and serum LPS level, impaired MSCs function and the response to corticosteroid therapy in active ITP model. Improving MSCs function induced by F. succinicans colonization by ARTA could enhance the response to corticosteroid therapy. Moreover, BBR treatment could modulate gut microbiota dysbiosis, thus reversing the effect of F. succinicans colonization, and eventually enhancing the response to corticosteroid therapy in ITP model. Pilot study validated the effect of BBR in corticosteroid‐resistant ITP patients.Summary/Conclusion:Our findings demonstrated that gut microbiome altered in ITP and might contribute to the development of corticosteroid‐resistance. Impaired MSC function induced by microbiota might mediated corticosteroid resistance in ITP. BBR might correct corticosteroid‐resistance by modulating gut microbiota structure, thus being a novel potential second‐line candidate to treat ITP.

Bone marrow mononuclear cells versus mesenchymal stem cells from adipose tissue on bone healing in an Old World primate: can this be extrapolated to humans?

ABSTRACT In veterinary medicine, the cell therapy is still unexplored and there are many unanswered questions that researchers tend to extrapolate to humans in an attempt to treat certain injuries. Investigating this subject in nonhuman primates turns out to be an unparalleled opportunity to better understand the dynamics of stem cells against some diseases. Thus, we aimed to compare the efficiency of bone marrow mononuclear cells (BMMCs) and mesenchymal stem cells (MSCs) from adipose tissue of Chlorocebus aethiops in induced bone injury. Ten animals were used, male adults subjected, to bone injury the iliac crests. The MSCs were isolated by and cultured. In an autologous manner, the BMMCs were infused in the right iliac crest, and MSCs from adipose tissue in the left iliac crest. After 4.8 months, the right iliac crests fully reconstructed, while left iliac crest continued to have obvious bone defects for up to 5.8 months after cell infusion. The best option for treatment of injuries with bone tissue loss in old world primates is to use autologous MSCs from adipose tissue, suggesting we can extrapolate the results to humans, since there is phylogenetic proximity between species.

Electrospun PLGA/PCL/OCP nanofiber membranes promote osteogenic differentiation of mesenchymal stem cells (MSCs).

Nanofibers as niche-biomimetic scaffolds hold promise in guided bone regeneration (GBR). Here we fabricated poly (lactic-co-glycolic acid) (PLGA)/poly(caprolactone) (PCL)-doped octacalcium phosphate (OCP) nanofiber membranes via electrospinning and investigated the osteogenic behavior of marrow mesenchymal stem cells (MSCs) on the membranes. By adjusting different ratio of OCP to PLGA/PCL, three hybrid stents including PLGA/PCL, PLGA/PCL/2 wt%OCP, PLGA/PCL/4wt%OCP were successfully prepared. The PLGA/PCL/OCP membranes showed a decrease in fiber diameter compared with PLGA/PCL, leading to enhanced mechanical strength. In-vitro studies showed that PLGA/PCL/OCP membranes better supported cell adhesion, spreading and proliferation than PLGA/PCL. The incorporation of OCP via electrospinning also endowed the membranes with osteoinductive capacity, as evidenced by activation of ALP activity, increased gene expression of bone specific markers (such as Runx2, ALP, Col 1a1, OPN, OCN, BMP2), and mineral nodules formation compared to PLGA/PCL. Comparatively, PLGA/PCL/4wt%OCP showed better mechanical and biological performance than PLGA/PCL/2 wt%OCP, demonstrating the role of OCP in nanofiber membranes. Thus, the electrospun PLGA/PCL/OCP nanofiber membranes can be potentially developed as a promising hybrid stent for GBR.

Preparation, Characterization and In Vitro Biological Evaluation of a Novel Pearl Powder/Poly-Amino Acid Composite as a Potential Substitute for Bone Repair and Reconstruction.

Many studies about fabricating organic-inorganic composite materials have been carried out in order to mimic the natural structure of bone. Pearl, which has a special block-and-mortar hierarchical structure, is a superior bone repair material with high osteogenic activity, but it shows few applications in the clinical bone repair and reconstruction because of its brittle and uneasily shaped properties. In this work, pearl powder (P)/poly (amino acid) (PAA) composites were successfully prepared by a method of in situ melting polycondensation to combine the high osteogenic activity of the pearl and the pliability of the PAA. The mechanical properties, in vitro bioactivity and biocompatibility as well as osteogenic activity of the composites were investigated. The results showed that P/PAA composites have both good mechanical properties and bioactivity. The compressive strength, bending strength and tensile strength of the composites reached a maximum of 161 MPa, 50 MPa and 42 MPa, respectively; in addition, apatite particles successfully deposited on the composites surface after immersion in simulated body fluid (SBF) for 7 days indicated that P/PAA composites showed an enhanced mineralization capacity and bioactivity due to incorporation of pearl powder and PAA. The cell culture results revealed that higher cell proliferation and better adhesion morphology of mouse bone marrow mesenchymal stem cells (MSCs) appeared on the composite surface. Moreover, cells growing on the surface of the composites exhibited higher alkaline phosphatase (ALP) activity, more calcium nodule-formation, and higher expression levels of osteogenic differentiation-related genes (COL 1, RunX2, OCN, and OPN) than cells grown on PAA surface. The P/PAA composites exhibited both superior mechanical properties to the pearl powder, higher bioactivity and osteogenic capability compared with those of PAA.

In Vitro Grown Micro-Tissues for Cardiac Cell Replacement Therapy in Vivo.

Different approaches have been considered to improve heart reconstructive medicine and direct delivery of pluripotent stem cell-derived cardiomyocytes (PSC-CMs) appears to be highly promising in this context. However, low cell persistence post-transplantation remains a bottleneck hindering the approach. Here, we present a novel strategy to overcome the low engraftment of PSC-CMs during the early post-transplantation phase into the myocardium of both healthy and cryoinjured syngeneic mice. Adult murine bone marrow mesenchymal stem cells (MSCs) and PSC-CMs were co-cultured on thermo-responsive polymers and later detached through temperature reduction, resulting in the protease-free generation of cell clusters (micro-tissues) composed of both cells types. Micro-tissues were transplanted into healthy and cryo-injured murine hearts. Short term cell retention was quantified by real-time-PCR. Longitudinal cell tracking was performed by bioluminescence imaging for four weeks. Transplanted cells were further detected by immunofluorescence staining of tissue sections. We demonstrated that in vitro grown micro-tissues consisting of PSC-CMs and MSCs can increase cardiomyocyte retention by >10fold one day post-transplantation, but could not fully rescue a further cell loss between day 1 and day 2. Neutrophil infiltration into the transplanted area was detected in healthy hearts and could be attributed to the cellular implantation rather than tissue damage exerted by the transplantation cannula. Injected PSC-CMs were tracked and successfully detected for up to four weeks by bioluminescence imaging. This approach demonstrated that in vitro grown micro-tissues might contribute to the development of cardiac cell replacement therapies.

Substance P improves MSC-mediated RPE regeneration by modulating PDGF-BB

Background & Aim Stem cells have regenerative potentials that can be used for the treatment of critical and incurable diseases. Age-related macular degeneration (ARMD) and diabetic retinopathy are one of the most severe retinal disorders, which are mostly attributed to impairment of retinal pigmented epithelium (RPE). Thus, restoration of RPE is the main therapeutic approach to prevent the development of ocular diseases, such as ARMD. Methods, Results & Conclusion In this study, we have investigated the role of substance P (SP) on bone marrow mesenchymal stem cell (MSC)-mediated RPE regeneration in vitro. The MSCs were primed with SP followed by the addition of conditioned medium (MSCSP-CM) to RPE. The effects of MSCSP-CM on RPE activity was evaluated by assessing viability, proliferation rate, and migration of RPE. Ex vivo long-term culture led to altered cellular characteristics of MSCs by weakening cell viability, cytokine secretion, and differentiation potential. The conditioned medium of early passage MSC (E-MSCCM) enhanced the RPE viability and migration, whereas the late passage MSC (L-MSCCM) hardly influenced the RPE activity. SP priming, however, facilitated the inductive effects of MSC, and SP effect was more distinct in the late passage than in the early passage. Moreover, it was revealed that SP could exert its effects by modulating PDGF-BB secretion in the MSCs. Taken together, these results suggested that SP could restore the therapeutic effects of MSCs on retinal diseases by elevating their proliferative and paracrine activities through PDGF-PDGFR signaling in ex vivo culture.

Long noncoding RNA UCA1 promotes chondrogenic differentiation of human bone marrow mesenchymal stem cells via miRNA-145-5p/SMAD5 and miRNA-124-3p/SMAD4 axis

Long noncoding RNA (lncRNAs) UCA1 has been known to be critical for the chondrogenic differentiation of marrow mesenchymal stem cells (MSCs). In this study, we explore the effects and mechanisms of UCA1 on the promotion of chondrogenesis of MSCs. During the processes of chondrogenic differentiation of MSCs, UCA1, miRNA-145-5p or miRNA-124-3p was overexpressed into MSCs. UCA1 substantially improved chondrogenesis of MSCs. Furthermore, UCA1 obviously down-regulated the expression of miRNA-145-5p and miRNA-124-3p, which attenuated the chondrogenic differentiation of MSCs. In addition, UCA1 significantly stimulated TGF-β pathway member SMAD5 and SMAD4, which is targeted by miRNA-145-5p and miRNA-124-3p. Collectively, these outcomes suggest that UCA1 enhances chondrogenic differentiation of MSCs via the miRNA-145-5p/SMAD5 and miRNA-124-3p/SMAD4 axis.

Mechanism and Treatment Related to Oxidative Stress in Neonatal Hypoxic-Ischemic Encephalopathy.

Hypoxic ischemic encephalopathy (HIE) is a type of neonatal brain injury, which occurs due to lack of supply and oxygen deprivation to the brain. It is associated with a high morbidity and mortality rate. There are several therapeutic strategies that can be used to improve outcomes in patients with HIE. These include cell therapies such as marrow mesenchymal stem cells (MSCs) and umbilical cord blood stem cells (UCBCs), which are being incorporated into the new protocols for the prevention of ischemic brain damage. The focus of this review is to discuss the mechanism of oxidative stress in HIE and summarize the current available treatments for HIE. We hope that a better understanding of the relationship between oxidative stress and HIE will provide new insights on the potential therapy of this devastating condition.