Marrow Mesenchymal Stem Cells Research Articles

Effect of book-shaped acellular tendon scaffold with bone marrow mesenchymal stem cells sheets on bone–tendon interface healing

BackgroundTissue engineering has exhibited great effect on treatment for bone-tendon interface (BTI) injury. The aim of this study was to evaluate the effect of a book-shaped acellular tendon scaffold (ATS) with bone marrow mesenchymal stem cells sheets (MSCS) for BTI injury repair.MethodsATS was designed based on the shape of “book”, decellularization effect was evaluated by Hematoxylin and eosin (H&E), 4′, 6-diamidino-2-phenylindole (DAPI) and scanning electron microscopy (SEM), then bone marrow mesenchymal stem cells (MSCs) were cultured on ATS to assess the differentiation inductivity of ATS. A rabbit right partial patellotomy model was established, and MSCS seeded on ATS were implanted into the lesion site. The patella-patellar tendon (PPT) at 2, 4, 8 or 16 weeks post-operation were obtained for histological, biomechanical and immunofluorescence analysis.ResultsH&E, DAPI and SEM results confirmed the efficiency of decellularization of ATS, and their in vitro tenogenic and chondrogenic ability were successfully identified. In vivo results showed increased macrophage polarization toward the M2 phenotype, IL-10 expression, regenerated bone and fibrocartilage at the patella-patellar tendon interface of animals received MSCS modified ATS implantation. In addition, the level of tensile strength was also the highest in MSCS modified ATS implantation group.ConclusionThis study suggests that ATS combined with MSCS performed therapeutic effects on promoting the regeneration of cartilage layer and enhancing the healing quality of patella-patellar tendon interface.The translational potential of this articleThis study showed the good biocompatibility of the ATS, as well as the great efficacy of ATS with MSCS on tendon to bone healing. The results meant that the novel book-shaped ATS with MSCS may have a great potential for clinical application.

Comparative efficacy of 20 graft-versus-host disease prophylaxis therapies for patients after hematopoietic stem-cell transplantation: A multiple-treatments network meta-analysis.

Graft-versus-host disease (GVHD) is a leading cause of death in patients after hematopoietic stem-cell transplantation (HSCT). Previous studies have shown different efficacy of GVHD prophylaxis therapies. We reviewed 46 randomized controlled trials (including 8050 participants) systematically from Jun 20, 2004 to Aug 20, 2019. These investigations compared the following drugs or their combination at therapeutic dose range for GVHD after HSCT. The main results were based on the proportion of patients who respond to these therapies. Cyclosporine + methotrexate + Anti-T cell globulin (ATG), tacrolimus + methotrexate + ATG, tacrolimus + bortezomib + sirolimus and cyclosporine + marrow mesenchymal stem cells (MMSCs) were significantly more efficacious than corticosteroids alone (OR: 12.15, 6.71, 6.25, 3.73). corticosteroids alone were less efficacious than all the other GVHD prophylaxis therapies tested. Cyclosporine + methotrexate + ATG may be the best choice when starting treatment for GVHD.

Parathyroid hormone ameliorates temporomandibular joint osteoarthritic-like changes related to age.

ObjectivesAgeing could be a contributing factor to the progression of temporomandibular joint osteoarthritis (TMJ OA), whereas its pathogenesis and potential therapeutic strategy have not been comprehensively investigated.Materials and methodsWe generated ageing mouse models (45‐week and 60‐week; 12‐week mice as control) and intermittently injected 45‐week mice with parathyroid hormone (PTH(1‐34)) or vehicle for 4 weeks. Cartilage and subchondral bone of TMJ were analysed by microCT, histological and immunostaining. Western blot, qRT‐PCR, ChIP, ELISA and immunohistochemical analysis were utilized to examination the mechanism of PTH(1‐34)’s function.ResultsWe showed apparent OA‐like phenotypes in ageing mice. PTH treatment could ameliorate the degenerative changes and improve bone microarchitecture in the subchondral bone by activating bone remodelling. Moreover, PTH inhibited phosphorylation level of Smad3, which can combine with p16ink4a gene promoter region, resulting in reduced senescent cells accumulation and increased cellular proliferation of marrow mesenchymal stem cells (MSCs). ELISA also showed relieved levels of specific senescent‐associated secretory phenotype (SASP) in ageing mice after PTH treatment.ConclusionsIn summary, PTH may reduce the accumulation of senescent cells in subchondral bone by inhibiting p16ink4a and improve bone marrow microenvironment to active bone remodelling process, indicating PTH administration could be a potential preventative and therapeutic treatment for age‐related TMJ OA.

Effect of MicroRNA-126a-3p on Bone Marrow Mesenchymal Stem Cells Repairing Blood-brain Barrier and Nerve Injury after Intracerebral Hemorrhage

Objective: Intracerebral hemorrhage (ICH) is a disease that threatens human health due to its high morbidity and mortality. On behalf of finding the better methods in the treatment of ICH, researchers pay more attention to a new technology which is finding effective genes to modify stem cells. Methods: In this study, we isolated, cultured and identified bone marrow mesenchymal stem cells (MSCs) in vitro. Further, the MSCs (transfected with lentivirus expressing microRNA-126a-3p (miR-126)) were injected into the type Ⅶ collagenase-induced ICH rats to investigate the recovery effects of blood-brain barrier (BBB) and nerve damage in vivo. Results: The MSCs surface marker molecules (CD29: 98.5%; CD90: 96.5%) were highly expressed, and the blood cell surface molecule was negatively expressed (CD45: 2%). Meanwhile, it was verified that miR-126 facilitated the differentiation of MSCs into vascular endothelial cells, owing to the rise of markers (CD31 and VE-cadherin). The modified neurological severity score, modified limb placing test score, brain water content and evans blue content were reduced after transplanted miR-126-modified MSCs. It was found that miR-126 accelerated the differentiation of MSCs into vascular endothelial cells via immunohistochemical staining in vivo. HE staining indicated the area of edema was obviously decreased compared with that in ICH + vector-MSCs group. MiR-126-modified MSCs alleviated the cell apoptosis in brain tissues by TUNEL assay. In addition, the mRNA and protein expression of protease activated receptor-1 and matrix metalloproteinase-9 were diminished, whilst the expression of zonula occludens-1 (ZO-1) and claudin-5 were enhanced in ICH+miR-126-MSCs group. Immunofluorescence assay revealed that miR-126-modified MSCs decreased the disruption of tight junction (ZO-1 and claudin-5). Conclusions: All data illustrate that miR-126-modified MSCs repair BBB and nerve injury after ICH.

TNFα-Mediated Priming of Mesenchymal Stem Cells Enhances Their Neuroprotective Effect on Retinal Ganglion Cells.

PurposeTo determine whether priming of bone marrow mesenchymal stem cells (MSCs) by signals from injured retina, particularly tumor necrosis factor α (TNFα), increase their exosomes’ neuroprotective efficacy on retinal ganglion cells (RGCs).MethodsMSCs were primed with retinal cell culture conditioned medium, with or without the TNFα blocker etanercept or TNFα prior to isolation of exosomes. MSC conditioned medium or exosomes were added to rat retinal cultures or human stem cell–derived retinal ganglion cell (hRGC) cultures, and RGC neuroprotective effects were quantified. Luminex assays were used to compare primed versus unprimed exosomes.ResultsMSC conditioned medium and exosomes exerted a significant neuroprotective effect on injured rat and hRGC. This effect was significantly increased after MSCs were primed with retinal conditioned medium or TNFα. Blocking of TNFα signaling with etanercept prevented priming-induced RGC neuroprotective efficacy. Priming increased Pigment epithelium-derived factor (PEDF) and VEGF-AA exosomal abundance.ConclusionsMSC exosomes promote RGC survival not just in rodent retinal cultures but also with hRGC. Their efficacy can be further enhanced through TNFα priming with the mechanism of action potentially mediated, at least in part, through increased levels of PEDF and VEGF-AA.

Mesenchymal stem cell-derived exosomes ameliorate cardiomyocyte apoptosis in hypoxic conditions through microRNA144 by targeting the PTEN/AKT pathway

BackgroundA growing body of evidence suggests that stem cell-derived exosomal microRNAs (miRNAs) could be a promising cardioprotective therapy in the context of hypoxic conditions. The present study aims to explore how miRNA-144 (miR-144), a miRNA contained in bone marrow mesenchymal stem cell (MSC)-derived exosomes, exerts a cardioprotective effect on cardiomyocyte apoptosis in the context of hypoxic conditions and identify the underlying mechanisms.MethodsMSCs were cultured using the whole bone marrow adherent method. MSC-derived exosomes were isolated using the total exosome isolation reagent and confirmed by nanoparticle trafficking analysis as well as western blotting using TSG101 and CD63 as markers. The hypoxic growth conditions for the H9C2 cells were established using the AnaeroPack method. Treatment conditions tested included H9C2 cells pre-incubated with exosomes, transfected with miR-144 mimics or inhibitor, or treated with the PTEN inhibitor SF1670, all under hypoxic growth conditions. Cell apoptosis was determined by flow cytometry using 7-ADD and Annexin V together. The expression levels of the miRNAs were detected by real-time PCR, and the expression levels of AKT/p-AKT, Bcl-2, caspase-3, HIF-1α, PTEN, and Rac-1 were measured by both real-time PCR and western blotting.ResultsExosomes were readily internalized by H9C2 cells after co-incubation for 12 h. Exosome-mediated protection of H9C2 cells from apoptosis was accompanied by increasing levels of p-AKT. MiR-144 was found to be highly enriched in MSC-derived exosomes. Transfection of cells with a miR-144 inhibitor weakened exosome-mediated protection from apoptosis. Furthermore, treatment of cells grown in hypoxic conditions with miR-144 mimics resulted in decreased PTEN expression, increased p-AKT expression, and prevented H9C2 cell apoptosis, whereas treatment with a miR-144 inhibitor resulted in increased PTEN expression, decreased p-AKT expression, and enhanced H9C2 cell apoptosis in hypoxic conditions. We also validated that PTEN was a target of miR-144 by using luciferase reporter assay. Additionally, cells treated with SF1670, a PTEN-specific inhibitor, resulted in increased p-AKT expression and decreased H9C2 cell apoptosis.ConclusionsThese findings demonstrate that MSC-derived exosomes inhibit cell apoptotic injury in hypoxic conditions by delivering miR-144 to cells, where it targets the PTEN/AKT pathway. MSC-derived exosomes could be a promising therapeutic vehicle to facilitate delivery of miRNA therapies to ameliorate ischemic conditions.

High oxygen preservation hydrogels to augment cell survival under hypoxic condition

Cell therapy is a promising approach for ischemic tissue regeneration. However, high death rate of delivered cells under low oxygen condition, and poor cell retention in tissues largely limit the therapeutic efficacy. Using cell carriers with high oxygen preservation has potential to improve cell survival. To increase cell retention, cell carriers that can quickly solidify at 37 °C so as to efficiently immobilize the carriers and cells in the tissues are necessary. Yet there lacks cell carriers with these combined properties. In this work, we have developed a family of high oxygen preservation and fast gelation hydrogels based on N-isopropylacrylamide (NIPAAm) copolymers. The hydrogels were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization of NIPAAm, acrylate-oligolactide (AOLA), 2-hydroxyethyl methacrylate (HEMA), and methacrylate-poly(ethylene glycol)-perfluorooctane (MAPEGPFC). The hydrogel solutions exhibited sol-gel temperatures around room temperature and were flowable and injectable at 4°C. They can quickly solidify (≤6 s) at 37°C to form flexible gels. These hydrogels lost 9.4~29.4% of their mass after incubation in Dulbecco's Phosphate-Buffered Saline (DPBS) for 4 weeks. The hydrogels exhibited a greater oxygen partial pressure than DPBS after being transferred from a 21% O2 condition to a 1% O2 condition. When bone marrow mesenchymal stem cells (MSCs) were encapsulated in the hydrogels and cultured under 1% O2, the cells survived and proliferated during the 14-day culture period. In contrast, the cells experienced extensive death in the control hydrogel that had low oxygen preservation capability. The hydrogels possessed excellent biocompatibility. The final degradation products did not provoke cell death even when the concentration was as high as 15 mg/ml, and the hydrogel implantation did not induce substantial inflammation. These hydrogels are promising as cell carriers for cell transplantation into ischemic tissues. Statement of SignificanceStem cell therapy for ischemic tissues experiences low therapeutic efficacy largely due to poor cell survival under low oxygen condition. Using cell carriers with high oxygen preservation capability has potential to improve cell survival. In this work, we have developed a family of hydrogels with this property. These hydrogels promoted the encapsulated stem cell survival and growth under low oxygen condition.

Dense carbon-nanotube coating scaffolds stimulate osteogenic differentiation of mesenchymal stem cells.

Carbon nanotubes (CNTs) have desirable mechanical properties for use as biomaterials in orthopedic and dental area such as bone- and tooth- substitutes. Here, we demonstrate that a glass surface densely coated with single-walled carbon nanotubes (SWNTs) stimulate the osteogenic differentiation of rat bone marrow mesenchymal stem cells (MSCs). MSCs incubated on SWNT- and multi-walled carbon nanotube (MWNT)-coated glass showed high activities of alkaline phosphatase that are markers for early stage osteogenic differentiation. Expression of Bmp2, Runx2, and Alpl of MSCs showed high level in the early stage for MSC incubation on SWNT- and MWNT-coated surfaces, but only the cells on the SWNT-coated glass showed high expression levels of Bglap (Osteocalcin). The cells on the SWNT-coated glass also contained the most calcium, and their calcium deposits had long needle-shaped crystals. SWNT coating at high density could be part of a new scaffold for bone regeneration.

Construction of calcitonin gene-related peptide-modified mesenchymal stem cells and analysis of their effects on the migration and proliferation of vascular smooth muscle cells.

Lentiviral expression vectors for calcitonin gene-related peptide (CGRP) were used to transfect rat bone marrow mesenchymal stem cells (MSCs). After assessing the biological characteristics of proliferation and aging in MSCs transfected with CGRP, we observed the effects of the CGRP-modified rat MSCs on the migration and proliferation of rat vascular smooth muscle cells (VSMCs) in vitro. Rat MSCs were isolated, cultured in vitro, and identified by flow cytometry. A CGRP recombinant lentivirus was transfected into MSCs. The transfection efficiency was determined by fluorescence microscopy and flow cytometry, and CGRP in MSCs was detected by real-time quantitative PCR, ELISA, and immunofluorescence. The proliferation and senescence of CGRP-modified MSCs were evaluated by MTT assay and beta-galactosidase staining. VSMCs were isolated, cultured in vitro, and identified by immunofluorescence. CGRP-modified MSCs and VSMCs were cocultured in a Transwell system. The proliferation and migration of VSMCs were evaluated by scratch testing and the MTT method. Rat bone marrow MSCs showed a spindle-shaped morphology, adherent growth in vitro, positive CD29 and CD90 expression, and negative CD45 expression. CGRP was stably expressed in MSCs after 48h of recombinant lentivirus transfection. CGRP mRNA and protein secretion in CGRP recombinant lentivirus-transfected MSCs were higher than that in control MSCs. Immunofluorescence showed that CGRP protein could be expressed in CGRP-modified MSCs. The proliferation ability and senescence rates did not differ between lentivirus-transfected MSCs and untransfected MSCs. Rat VSMCs expressed α-SMA protein and exhibited a spindle-shaped morphology and adherent growth in vitro. In Transwell coculture experiments, scratch testing of VSMCs showed that CGRP-modified MSCs could reduce VSMC proliferation and migration. The CGRP gene can be stably expressed in MSCs after CGRP recombinant lentivirus transfection. CGRP recombinant lentivirus transfection has little effect on the proliferation or senescence of MSCs, and CGRP-modified MSCs can inhibit the proliferation and migration of VSMCs. These results lay a foundation for research on the use of CGRP gene-engineered MSCs in restenosis therapy.

Effects of resveratrol on aging of mesenchymal stem cells and its mechanism

To investigate the effects of resveratrol (Res) on aging of marrow mesenchymal stem cells (MSCs), and to explore its mechanism. MSCs were isolated from young SD rats and cultured in vitro. The optimal D-gal concentration for induction of MSCs senescence was determined. Then MSCs were randomly divided into four groups, namely the control group, 10μmol/L, 50μmol/L and 100μmol/L Res groups. After the cells were treated with different concentration of Res for 48 h, the senescence-associated changes were examined with senescence-associated-β-galactosidase (SA-β-gal) staining; the expression of p53, p16 and γ-H2AX was evaluated by Western blot. The total active oxygen species (ROS) level was determined by flow cytometry with DCFH-DA staining. In order to assess the effect of Res on the mitochondrial function, MitoSox Red staining was used to detect mitochondrial ROS levels in each group, mitochondrial membrane potential was detected by JC-1 assay, mPTP method was used to detect mitochondrial membrane channel opening level, and Western blot was used to detect the expression level of cytoplasmic cytochrome C (Cyt-C). D-gal 10 and 50 g/L significantly increased the number of SA-β-gal positive cells and the level of mitochondrial ROS (all P<0.01). Therefore, 10 g/L D-gal was used to induce the senescence of MSCs in subsequent experiment. Compared with the control group, the number of SA-β-gal positive cells in Res groups significantly decreased (all P<0.01), the expression of p53, p16 and γ-H2AX decreased, and the total and mitochondrial ROS level also decreased (all P<0.01). Moreover, mitochondrial membrane potential, open level of mitochondrial membrane channels and the levels of cytoplasm Cyt-C in the Res treatment groups decreased compared with the control group (P<0.05 or P<0.01). Resveratrol can protect the mitochondrial function of MSCs, and effectively delay the MSC senescence.

Bone marrow mesenchymal stem cells encapsulated thermal-responsive hydrogel network bridges combined photo-plasmonic nanoparticulate system for the treatment of urinary bladder dysfunction after spinal cord injury

Spinal cord injury (SCI) is a distressing injury and an irretrievable dramatic event that can debilitate victims for lifespan. Recovery and treatment of SCI is critical challenges for medicine, to overcome the hurdles stem cells and hydrogel scaffolds implantation is a boon for SCI recovery. In this regard, we reported the synthesis of Gold nanoparticles (Au NPs) loaded Agarose/Poly (N-isopropylacrylamide) (PNIPAM) as promising materials for SCI treatment. Herein, Au NPs was synthesized by well-established citrate reduction method and the prepared materials were characterised by UV–visible spectroscopy (UV–vis), Transmission electron microscopy (TEM), Fourier- transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), and EDAX analysis. The microscopic images showed an elliptical or ovoid porous structure nature of hydrogel, and successful and homogenous loading of photo plasmonic nanoparticles into the hydrogel structure. The in vitro cell viability and inflammation analyses data exhibited that prepared hydrogels have no toxic to the cells and displayed high anti-regenerative ability with bone marrow Mesenchymal stem cells (MSCs) and macrophages cells. The in vivo analysis study demonstrated that the treated materials with encapsulated MSCs have greater nerve tissue regeneration efficacy which was confirmed by the results of BBB scores. The hind limb locomotion of treated model animals was totally vanished after post-operational surgery. It's established that implanted nano-hydrogel materials combined with MSCs have quicker recovery of motor function after post-operative surgery, when compared to the other implanted animal groups.

Exosome-Derived miR21/SMAD7 Derived from Donor Osteoporosis Mesenchymal Stem Cells Inhibits Osteogenic Differentiation of Reconstituted Hosts

Exogenous bone marrow mesenchymal stem cells (MSCs) can regulate osteogenic differentiation. MicroRNA-21 has been shown to target SMAD7. This study explored the mechanism by which miR-21/SMAD7 inhibits osteogenic differentiation from exosomes secreted by osteoporosis patients-derived MSCs. Exosomes were obtained from MSCs and miR-21 expression was detected. Normal MSCs were treated with exosomes secreted by MSCs from different sources for osteogenic differentiation followed by detection of ALP, Bglap and Runx2 level and ALP activity. Normal MSCs were divided into three groups, which were treated with exosomes from normal adult MSCs, osteoporosis patients-derived MSCs and osteoporosis patients-derived MSCs + SMAD7 overexpression followed by analysis of the mRNA expression of ALP, Bglap and Runx2 by qRT-PCR and ALP activity. miR-21 expression in exosomes from osteoporosis patients-derived MSCs was significantly higher than that from normal adults MSCs. After treatment with exosomes from osteoporosis patients-derived MSCs, Runx2 expression and ALP activity was significantly decreased. SMAD7 expression in osteoporosis patients was significantly lower than that in normal adults. The expression of ALP, Bglap and Runx2 is significantly decreased after overexpression of SMAD7. SMAD7 is a target gene of miR-21 and plays a role in inhibiting osteogenic differentiation induced by exosomes from osteoporosis-derived MSCs.

Mesenchymal Stem Cell-Platelet Aggregates Increased in the Peripheral Blood of Patients with Acute Myocardial Infarction and Might Depend on the Stromal Cell-Derived Factor 1/CXCR4 Axis.

Bone marrow mesenchymal stem cells (MSCs) are a rare subset of nonhematopoietic progenitor cells and are appealing biomaterial for multiple tissue damage repairs. Transplantation of MSCs is proved to improve heart function after myocardial ischemia. However, the limitations of MSC injection approaches are equally obvious. As a multiple-function cell, platelets (PLTs) are also known playing important roles in cardiac recovery after myocardial infarction. In this study, we analyzed circulating MSC-PLT aggregate numbers in acute myocardial infarction (AMI) patients by flow cytometry. We found more MSC-PLT aggregates in patients with AMI than in healthy controls, and the patients with higher MSC-PLT aggregates had better prognosis. When stromal cell-derived factor 1 (SDF-1) binds to its receptor CXC chemokine receptor 4 (CXCR4), they play an important role in MSC migration and engraftment. We explored SDF-1 and CXCR4 expression on PLT surface by flow cytometry and found relative mean fluorescence intensity of PLT CXCR4 and the number of MSC-PLT aggregates showed a significant correlation. Meanwhile, in vitro experiments demonstrated that SDF-1/CXCR4 was crucial in MSC-PLT aggregate formation, which might suggest a novel mechanism that SDF-1/CXCR4 is involved in MSCs homing and myocardial repair after AMI. There may be another strategy to encourage myocardial repair in AMI patients by increasing the expression of SDF-1 on MSCs and promoting the formation of MSC-PLT aggregates.

Immobilization of BMP-2-derived peptides on 3D-printed porous scaffolds for enhanced osteogenesis

Three-dimensional (3D) printing technologies open up new perspectives for customizing the external shape and internal architecture of bone scaffolds. In this study, an oligopeptide (SSVPT, Ser-Ser-Val-Pro-Thr) derived from bone morphogenetic protein 2 was conjugated with a dopamine coating on a 3D-printed poly(lactic acid) (PLA) scaffold to enhance osteogenesis. Cell experiments in vitro showed that the scaffold was highly osteoconductive to the adhesion and proliferation of rat marrow mesenchymal stem cells (MSCs). In addition, RT-PCR analysis showed that the scaffold was able to promote the expression of osteogenesis-related genes, such as alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2), osteocalcin (OCN) and osteopontin (OPN). Images of the micro-CT 3D reconstruction from the rat cranial bone defect model showed that bone regeneration patterns occurred from one side edge towards the center of the area implanted with the prepared biomimetic peptide hydrogels, demonstrating significantly accelerated bone regeneration. This work will provide a basis to explore the application potential of bioactive scaffolds further.

Bone Marrow Mesenchymal Stem Cells Decrease the Expression of RANKL in Collagen-Induced Arthritis Rats via Reducing the Levels of IL-22.

Objective To investigate the transplantation effect of bone marrow mesenchymal stem cells (MSCs) on the expression of interlukin-22 (IL-22) and RANKL in collagen-induced arthritis (CIA) rats. Methods 32 CIA models were established. 16 CIA rats were transplanted with MSCs, and others were used as nontreatment CIA controls. The concentrations of IL-22 and RANKL in serum were detected by ELISA and those in synovial tissue of rats' joints by immunohistochemical staining. In addition, the expression of RANKL mRNA was measured by RT-PCR in the fibroblast-like synoviocytes (FLSs), cultured with IL-22 in vitro, which were delivered from the joints of CIA rats treated with or without MSCs. Results The transplantation of MSCs into CIA rats relieved the destruction of joints, measured by AI score, X-ray, and histopathology. MSCs also reduced the expression of IL-22 and RANKL in serum by ELISA (P < 0.001) and similarly in FLSs by immunohistochemical staining. In vitro, IL-22 induced significantly the expression of RANKL mRNA in cultured FLSs in a dose-dependent manner, whereas this induction was significantly reduced in FLSs derived from CIA rats transplanted with MSCs (normal controls: F = 79.33, P < 0.001; CIA controls: F = 712.72, P < 0.001; and CIA-MSC rats: F = 139.04, P < 0.001). Conclusion Our results suggest that the transplantation of MSCs can reduce the expression of RANKL in vivo by downregulating the levels of IL-22, thereby ameliorating the degree of RA bone destruction. This study provides a theoretical basis for a potential therapy of RA with MSCs, and IL-22 and RANKL may become two new targets to treat RA.

Conformation changes of albumin and lysozyme on electrospun TiO2 nanofibers and its effects on MSC behaviors

Protein adsorption plays a key role in bone repair and regeneration by affecting cell behavior. In this study, TiO2 nanofibers (TiO2 NFs) with different structures, including anatase TiO2 nanofibers (A-NFs), anatase TiO2 nanofibers with beads (B-NFs), anatase-rutile TiO2 nanofibers (AR-NFs) and rutile TiO2 nanofibers (R-NFs), were prepared by electrospinning method. Bovine serum albumin (BSA) and lysozyme (LYZ) were used to explore the adsorption behaviors of TiO2 NFs and then the effects of materials with protein on bone marrow mesenchymal stem cells (MSCs) were studied. Pure titanium metal (PT) was used as control. The results displayed that the adsorption amounts of BSA on samples were B-NFs > AR-NFs > A-NFs ≈ R-NFs > PT, and that for LYZ were B-NFs > AR-NFs > R-NFs > A-NFs > PT. The conformation of proteins changed remarkably when they were adsorbed on meterials. Soaking the TiO2 NFs with and without protein into SBF revealed that the BSA and LYZ on B-NFs, A-NFs and AR-NFs could accelerate the HA deposition on its surface, but it had no promoting effect on HA deposition on B-NFs. MTT and PCR tests showed that the BSA and LYZ adsorbed on materials could promote the proliferation and osteogenic differentiation of MSCs to different degrees due to their different adsorption amount and conformation changes on different TiO2 NFs. The current work demonstrated that the surface properties and crystal structure of TiO2 NFs could influence the adsorption behavior and conformational change of BSA and LYZ, and then further regulate MSCs biological behavior.

Combinatorial treatment of acute myocardial infarction using stem cells and their derived exosomes resulted in improved heart performance

BackgroundBone marrow mesenchymal stem cells (MSCs) are among the most common cell types to be used and studied for cardiac regeneration. Low survival rate and difficult retention of delivered MSCs in infarcted heart remain as major challenges in the field. Co-delivery of stem cell-derived exosomes (Exo) is expected to improve the recruitment and survival of transplanted MSCs.MethodsExo was isolated from MSCs and delivered to an acute myocardial infarction (AMI) rat heart through intramyocardial injection with or without intravenous infusion of atrovastatin-pretreated MSCs on day 1, day 3, or day 7 after infarction. Echocardiography was performed to evaluate cardiac function. Histological analysis and ELISA test were performed to assess angiogenesis, SDF-1, and inflammatory factor expression in the infarct border zone. The anti-apoptosis effect of Exo on MSCs was evaluated using flow cytometry and Hoechst 33342 staining assay.ResultsWe found that intramyocardial delivery of Exo followed by MSC transplantation (in brief, Exo+MSC treatment) into MI hearts further improved cardiac function, reduced infarct size, and increased neovascularization when compared to controls treated with Exo or MSCs alone. Of note, comparing the three co-transplanting groups, intramyocardially injecting Exo 30 min after AMI combined with MSCs transplantation at day 3 after AMI achieved the highest improvement in heart function. The observed enhanced heart function is likely due to an improved microenvironment via Exo injection, which is exemplified as reduced inflammatory responses and better MSC recruitment and retention. Furthermore, we demonstrated that pre-transplantation injection of Exo enhanced survival of MSCs and reduced their apoptosis both in vitro and in vivo.ConclusionsCombinatorial delivery of exosomes and stem cells in a sequential manner effectively reduces scar size and restores heart function after AMI. This approach may represent as an alternative promising strategy for stem cell-based heart repair and therapy.

Intravenous Administration of Granulocyte-Colony Stimulating Factor for Stem Cells Mobilization and Third Degree Burn Wound Healing in Rats

Introduction: Burns are one the most common skin damages which require medical intervention to be fully-recovered. In this light, tissue engineering field presents a vide verity of strategies including both scaffold-based and cell-based approaches to recover the damaged site. Materials and Methods: In this study, the effects of granulocyte-colony stimulating factor (G-CSF) administration on mobilization of the bone marrow mesenchymal stem cells (MSCs) into defect area and treatment of the skin burn wound was examined in vivo. The G-CSF was injected intravenously into rats subjected to third degree burn wound. At days 3, 5, 7, 15 and 30 post-injections, the defect site was removed and investigated by H&E and Malory’s trichrome staining. The number of MSCs in blood samples was also determined by flow cytometry assay. Results: According to the results, intravenously administration of G-CSF significantly increased collagenesis and number of fibroblast cells infiltrated into the burned site, while decreased the severity of acute inflammatory response and amount of inflammatory cells comparing to control. The number of MSCs in bloodstream, representing the rate of MSCs migration, showed a 4-fold increase in the experimental group compared to control. Conclusions: The current study suggests the potential of intravenously administration of G-CSF as an effective strategy for treatment of severe burn injuries.

Paper-based 3D culture device integrated with electrochemical sensor for the on-line cell viability evaluation of amyloid-beta peptide induced damage in PC12 cells

In this communication, a paper-based 3D cell culture device integrated with electrochemical biosensor was applied to on-line monitoring of dopamine release from PC12 cell damage models induced by amyloid-beta peptide (Aβ25-35) and cell intervene models protected by curcumin (Cur) and marrow mesenchymal stem cells (MSC) supernatant. The adhesion and proliferation of PC12 cells cultured on the paper scaffold was characterized by scanning electron microscopy and laser scanning confocal microscopy, which verify unique biocompatibility and 3D microarchitecture similar to human body microenvironment of paper substrate, so an artificial model simulating 3D microenvironment in vivo was constructed easily. The PC12 cells in paper-based devices consisted of four groups containing control group, Aβ25-35 group, Aβ25-35+Cur group and Aβ25-35+MSC supernatant group. Under optimal conditions, this proposed device displayed a wide linear range from 0.05 to 1 μmol/L with a detection limit of 0.009 μmol/L (S/N = 3) and exhibited high sensitivity, good selectivity and excellent reproducibility. Furtherly, electrochemcial analysis and MTT assay gave a clue that the cell viability of Aβ25-35+MSCs supernatant group was higher than that of Aβ25-35+Cur group. Therefore, the detachable paper-based 3D device paves the way to a direct detection of exocytosis DA from neuron cells for on-line cell viability evaluation of neurodegenerative disease cell damage models.

Abstract 139: Systemic Analysis and Discovery of Embryonic Stem Cell-derived Exosomal Long Non-coding RNAs as Potential Therapeutic Modulators of Myocardial Repair

Cardiovascular disease is the leading cause of death in the U.S. Exogenous stem cell therapy has emerged as a novel therapeutic approach and various stem cell types, including embryonic stem cells (ESCs), bone marrow stem cells and mesenchymal stem cells, have been studied for cardiac regenerative cell therapy. Even though there was great enthusiasm with promising initial results in pre-clinical disease models, stem cell-based therapy demonstrated modest benefits in clinical trials. Emerging evidence suggests that stem cells can secrete a large number of soluble factors to evoke a resident cell response for tissue regeneration. In this perspective, stem cells-derived exosome therapy has been recently put forward as an alternative cell-free modality for cardiac repair after myocardial infarction (MI). Our previous study indicated that ESC-derived exosomes (ESC-exo) promote endogenous cardiac repair and enhanced cardiac function following MI. However, the mechanisms underlying ESC-exo mediated cardiac repair and regeneration still need to be fully elucidated. RNA-sequencing data on ESC-exo revealed that non-coding RNAs, including long non-coding RNAs (lncRNA), are selectively sorted into exosomes and highly enriched compared to control fibroblasts. Unlike exosomal miRNA, exosomal lncRNAs have not been well-studied in the context of tissue repair. To investigate the reparative role of lncRNA in protecting against MI, we first systemically analyzed and discovered ESC-derived exosomal lncRNAs in silico. We analyzed novel lncRNAs from ESC- and MEF-exo based on differential expression by microarray analysis, lncRNA classification, human homology and non-coding potential prediction. For lncRNAs enriched in the ESC-exo population, we selected 2 potential lncRNAs of interest for further study: Gm4890 and XLOC 01990, which are confirmed for expression by qRT-PCR results. Gm4890 and XLOC are mainly located in nucleus rather than cytoplasm implicating their function on transcriptional regulation. Ongoing studies are evaluating the functional roles for these ESC-exo enriched lncRNAs.