Homing Of MSCs Research Articles

Bone marrow mesenchymal stromal cells support regeneration of intestinal damage in a colitis mouse model, independent of their CXCR4 expression.

Inflammatory bowel disease (IBD) is characterized by a chronically dysregulated immune response in the gastrointestinal tract. Bone marrow multipotent mesenchymal stromal cells have an important immunomodulatory function and support regeneration of inflamed tissue by secretion of soluble factors as well as through direct local differentiation. CXCR4 is the receptor for CXCL12 (SDF-1, stromal-derived factor-1) and has been shown to be the main chemokine receptor, required for homing of MSCs. Increased expression of CXCL12 by inflamed intestinal tissue causes constitutive inflammation by attracting lymphocytes but can also be used to direct MSCs to sites of injury/inflammation. Trypsin is typically used to dissociate MSCs into single-cell suspensions but has also been shown to digest surface CXCR4. Here, we assessed the regenerative effects of CXCR4high and CXCR4low MSCs in an immune-deficient mouse model of DSS-induced colitis. We found that transplantation of MSCs resulted in clinical improvement and histological recovery of intestinal epithelium. In contrary to our expectations, the levels of CXCR4 on transplanted MSCs did not affect their regenerative supporting potential, indicating that paracrine effects of MSCs may be largely responsible for their regenerative/protective effects.

Abstract 557: EGFR-targeted mesenchymal stem cells for enhanced tumor retention and inhibition

Abstract MSCs have been studied as gene therapy vehicles, and several preclinical and clinical studies support the use of genetically modified MSCs to deliver therapeutics to tumor tissues. We were one of the early groups to demonstrate that MSCs can be engineered to carry cytotoxic drugs by using nanoparticle-encapsulated form of the drug. However, tumor homing of MSCs is inefficient. We hypothesized that the targeting effectiveness of MSCs can be significantly improved by incorporating tumor-targeting ligands on the MSC surface that will allow for enhanced arrest and binding within the tumor tissue. In this study, we designed anti-EGFR Ab (cetuximab, Cmab) functionalized MSCs and studied the comparative therapeutic efficacy of paclitaxel-loaded, Cmab functionalized MSCs relative to that of paclitaxel-loaded, unfunctionalized MSCs. Cmab functionalized MSCs demonstrated improved binding to A549 adenocarcinoma cells. Mice bearing orthotopic A549 tumors were dosed i.v. with the various treatments. Similar to what we have shown previously, MSCs loaded with paclitaxel nanoparticles were effective in slowing tumor growth and improving the overall survival relative to that of other controls. However, the greatest inhibition of tumor growth was observed in mice that received anti-EGFR Ab functionalized, paclitaxel-loaded MSCs. Compared to a median survival of 21 days for saline and 27 days for paclitaxel-loaded MSC treated group and paclitaxel-loaded IgG functionalized MSCs, Cmab Ab functionalized, paclitaxel-loaded MSCs treated mice resulted in significantly improved median survival of 35 days (p<0.001). Biodistribution studies revealed a sixfold higher retention of functionalized MSCs when compared to unfunctionalized MSCs. These results demonstrate the potential for improved tumor targeting with EGFR-targeted MSCs. Citation Format: Susheelkumar Nethi, Shubhmita Bhatnagar, Xiaolei Li, Swayam Prabha. EGFR-targeted mesenchymal stem cells for enhanced tumor retention and inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 557.

Human integrin α10β1-selected mesenchymal stem cells home to cartilage defects in the rabbit knee and assume a chondrocyte-like phenotype

BackgroundMesenchymal stem cells (MSCs) have shown promising results in stimulating cartilage repair and in the treatment of osteoarthritis (OA). However, the fate of the MSCs after intra-articular injection and their role in cartilage regeneration is not clear. To address these questions, this study investigated (1) homing of labeled human adipose tissue derived integrin α10β1-selected MSCs (integrin α10-MSCs) to a cartilage defect in a rabbit model and (2) the ability of the integrin α10-MSCs to differentiate to chondrocytes and to produce cartilage matrix molecules in vivo.DesignIntegrin α10-MSCs were labeled with superparamagnetic iron oxide nanoparticles (SPIONs) co-conjugated with Rhodamine B to allow visualization by both MRI and fluorescence microscopy. A cartilage defect was created in the articular cartilage of the intertrochlear groove of the femur of rabbits. Seven days post-surgery, labeled integrin α10-MSCs or vehicle were injected into the joint. Migration and distribution of the SPION-labeled integrin α10-MSCs was evaluated by high-field 9.4 T MRI up to 10 days after injection. Tissue sections from the repair tissue in the defects were examined by fluorescence microscopy.ResultsIn vitro characterization of the labeled integrin α10-MSCs demonstrated maintained viability, proliferation rate and trilineage differentiation capacity compared to unlabeled MSCs. In vivo MRI analysis detected the labeled integrin α10-MSCs in the cartilage defects at all time points from 12 h after injection until day 10 with a peak concentration between day 1 and 4 after injection. The labeled MSCs were also detected lining the synovial membrane at the early time points. Fluorescence analysis confirmed the presence of the labeled integrin α10-MSCs in all layers of the cartilage repair tissue and showed co-localization between the labeled cells and the specific cartilage molecules aggrecan and collagen type II indicating in vivo differentiation of the MSCs to chondrocyte-like cells. No adverse effects of the α10-MSC treatment were detected during the study period.ConclusionOur results demonstrated migration and homing of human integrin α10β1-selected MSCs to cartilage defects in the rabbit knee after intra-articular administration as well as chondrogenic differentiation of the MSCs in the regenerated cartilage tissue.

Combined Treatment of Levetiracetam and Mesenchymal Stem Cells Reverses the Biochemical Aberrations in the Acute Phase of Epilepsy Induced by Pilocarpine in Rats

In spite of the enormous evolution of the novel anti-seizure medications, about one-third of epilepsy patients stay resistant to the existing therapeutic drugs. Stem cells have provoked hopeful for treating diverse neurologic diseases comprises epilepsy. The rational of this investigation was to appraise the therapeutic intervention of a combination of levetiracetam (LEV) with rodent adipose-derived mesenchymal stem cells (ADMSCs) or rodent bone marrow-derived mesenchymal stem cells (BMMSCs) in counteracting pilocarpine-induced acute epilepsy in rats. In this research, the isolation and preparation of ADMSCs and BMMSCs from male albino rats were carried out. The identification of ADMSCs and BMMSCs was performed morphologically in the culture by using the inverted microscope and by the detection of the cell surface profile by using the flow cytometry technique. The induction of acute epilepsy was achieved by intraperitoneal injection of a single dose of pilocarpine (380 mg/kg b.wt). This study was conducted on fifty six adult male albino rats which were assigned into seven equal groups (8 rats/group); Group (1): Control, Group (2): Epileptic, Group (3): Epileptic + LEV (300 mg/kg b.wt daily for 12 weeks by gastric intubation with an oral gavage), Group (4): Epileptic + ADMSCs (single dose of ADMSCs; 3 × 106 cells/rat; intravenously), Group (5): Epileptic + BMMSCs (single dose of BMMSCs 3 × 106 cells/rat; intravenously), Group (6) : Epileptic + ADMSCs + LEV and Group (7) Epileptic + BMMSCs + LEV. After the end of the experimental period (12 weeks), all rats were tested by the mean electric shock (MES) test to prove the presence of strong seizures in the epileptic group and the modulation of these seizures after treatments. Then, the rats were decapitated and the whole brain of each rat was dissected into two halves, the first half was used for the quantitative determination of GABA, glutamate, dopamine, bFGF, BDNF, IL-6 and TNF-α, while the second half was fixed in formalin saline for histological investigation. The findings of the present work demonstrated that the morphological appearance of the isolated MSCs manifests spindle-shape. The flow cytometric analysis showed that the isolated MSCs are positive for CD90 and negative for CD14 and CD45. The homing of MSCs in the brain tissue of the treated rats was verified by their staining with the fluorescent dye. The recordings of the MES indicated the presence of strong seizures in the epileptic rats which were ameliorated after treatment with LEV, ADMSCs, BMMSCs. The level of brain GABA decreased significantly in the epileptic rats, whereas the level of brain glutamate, dopamine, bFGF, BDNF, IL-6 and TNF-α increased significantly; these alterations were improved after treatment with LEV or ADMSCs or BMMSCs. The histological examination of the brain tissue of the epileptic rats showed great histopathological alterations which were amended by the different treatment options. The combined treatment of either ADMSCs or BMMSCs with LEV displayed superior advantageous effect versus the single use of each type of cell in combating the acute phase of epilepsy. In conclusion, the outcomes of the present approach disclosed that the combined treatment of either ADMSCs or BMMSCs with the antiepileptic drug LEV has synergistic effect in alleviation of the behavioral and biochemical aberrations as well as brain histological deformation during the acute phase of epilepsy.

The Therapeutic Efficacy of Adipose Tissue-Derived Mesenchymal Stem Cell Conditioned Medium on Experimental Colitis Was Improved by the Serum From Colitis Rats.

Adipose derived mesenchymal stem cells (AD-MSCs) have shown therapeutic potential in treatments of inflammatory bowel disease (IBD). Due to the harsh host environment and poor survival of the cells, controversy concerning the homing, proliferation and differentiation of MSCs in lesion tissue still remains. It has been reported that conditioned media from MSCs could improve the colitis, whereas the therapeutic efficiency could be significantly elevated by the stimulation of pro-cytokines. In this study, we pre-treated the adipose derived MSCs with the serum from colitis rats and then the activated conditioned media (CM-AcMSC) were collected. To compare the therapeutic effects of CM-MSC and CM-AcMSC on IBD, we constructed dextran sodium sulphate (DSS)-induced colitis rat models. The colitis was induced in rats by administrating 5% DSS in drinking water for 10 days, and the disease symptoms were recorded daily. The colon histopathological changes were observed by different staining methods (H&E and PAS). The expression levels of MUC2 and tight junctions (TJs) were determined by RT-qPCR. The levels of inflammatory cytokines were analyzed by ELISA and western blot analysis. Our findings suggested that CM-AcMSC was more effective in ameliorating the clinical features and histological damage scores. Treatment with CM-AcMSC significantly increased the expression of MUC2 and TJs and suppressed the production of pro-inflammatory cytokines in colonic tissues of colitis rats. The inhibitory effects of CM-AcMSC on inflammatory responses of colitis rats were mediated by NF-κB signaling pathway. These results suggested that pre-activation of MSCs with serum from colitis rats could promote the production of paracrine factors and improve the therapeutic effects of conditioned medium on colitis rats.

Enhanced anti-inflammatory effects of mesenchymal stromal cells mediated by the transient ectopic expression of CXCR4 and IL10

BackgroundMesenchymal stromal cells (MSCs) constitute one of the cell types most frequently used in cell therapy. Although several studies have shown the efficacy of these cells to modulate inflammation in different animal models, the results obtained in human clinical trials have been more modest. Here, we aimed at improving the therapeutic properties of MSCs by inducing a transient expression of two molecules that could enhance two different properties of these cells. With the purpose of improving MSC migration towards inflamed sites, we induced a transient expression of the C-X-C chemokine receptor type 4 (CXCR4). Additionally, to augment the anti-inflammatory properties of MSCs, a transient expression of the anti-inflammatory cytokine, interleukin 10 (IL10), was also induced.MethodsHuman adipose tissue-derived MSCs were transfected with messenger RNAs carrying the codon-optimized versions of CXCR4 and/or IL10. mRNA-transfected MSCs were then studied, first to evaluate whether the characteristic phenotype of MSCs was modified. Additionally, in vitro and also in vivo studies in an LPS-induced inflamed pad model were conducted to evaluate the impact associated to the transient expression of CXCR4 and/or IL10 in MSCs.ResultsTransfection of MSCs with CXCR4 and/or IL10 mRNAs induced a transient expression of these molecules without modifying the characteristic phenotype of MSCs. In vitro studies then revealed that the ectopic expression of CXCR4 significantly enhanced the migration of MSCs towards SDF-1, while an increased immunosuppression was associated with the ectopic expression of IL10. Finally, in vivo experiments showed that the co-expression of CXCR4 and IL10 increased the homing of MSCs into inflamed pads and induced an enhanced anti-inflammatory effect, compared to wild-type MSCs.ConclusionsOur results demonstrate that the transient co-expression of CXCR4 and IL10 enhances the therapeutic potential of MSCs in a local inflammation mouse model, suggesting that these mRNA-modified cells may constitute a new step in the development of more efficient cell therapies for the treatment of inflammatory diseases.

Pluripotency and immunomodulatory signatures of canine induced pluripotent stem cell-derived mesenchymal stromal cells are similar to harvested mesenchymal stromal cells

With a view towards harnessing the therapeutic potential of canine mesenchymal stromal cells (cMSCs) as modulators of inflammation and the immune response, and to avoid the issues of the variable quality and quantity of harvested cMSCs, we examined the immunomodulatory properties of cMSCs derived from canine induced pluripotent stem cells (ciMSCs), and compared them to cMSCs harvested from adipose tissue (cAT-MSC) and bone marrow (cBM-MSC). A combination of deep sequencing and quantitative RT-PCR of the ciMSC transcriptome confirmed that ciMSCs express more genes in common with cBM-MSCs and cAT-MSCs than with the ciPSCs from which they were derived. Both ciMSCs and harvested cMSCs express a range of pluripotency factors in common with the ciPSCs including NANOG, POU5F1 (OCT-4), SOX-2, KLF-4, LIN-28A, MYC, LIF, LIFR, and TERT. However, ESRRB and PRDM-14, both factors associated with naïve, rather than primed, pluripotency were expressed only in the ciPSCs. CXCR-4, which is essential for the homing of MSCs to sites of inflammation, is also detectable in ciMSCs, cAT- and cBM-MSCs, but not ciPSCs. ciMSCs constitutively express the immunomodulatory factors iNOS, GAL-9, TGF-β1, PTGER-2α and VEGF, and the pro-inflammatory mediators COX-2, IL-1β and IL-8. When stimulated with the canine pro-inflammatory cytokines tumor necrosis factor-α (cTNF-α), interferon-γ (cIFN-γ), or a combination of both, ciMSCs upregulated their expression of IDO, iNOS, GAL-9, HGF, TGF-β1, PTGER-2α, VEGF, COX-2, IL-1β and IL-8. When co-cultured with mitogen-stimulated lymphocytes, ciMSCs downregulated their expression of iNOS, HGF, TGF-β1 and PTGER-2α, while increasing their expression of COX-2, IDO and IL-1β. Taken together, these findings suggest that ciMSCs possess similar immunomodulatory capabilities as harvested cMSCs and support further investigation into their potential use for the management of canine immune-mediated and inflammatory disorders.

Ultrasound augmenting injectable chemotaxis hydrogel for articular cartilage repair in osteoarthritis

The increasing incidence of osteoarthritis (OA) seriously affects life quality, posing a huge socioeconomic burden. Tissue engineering technology has become a hot topic in articular cartilage repair as one of the key treatment methods to alleviate OA. Hydrogel, one of the most commonly used scaffold materials, can provide a good extracellular matrix microenvironment for seed cells such as bone marrow mesenchymal stem cells (BMSCs), which can promote cartilage regeneration. However, the low homing rate of stem cells severely limits their role in promoting articular cartilage regeneration. Stromal cell-derived factor-1α (SDF-1α) plays a crucial role in the activation, mobilization, homing, and migration of MSCs. Herein, a novel injectable chemotaxis hydrogel, composed of chitosan-based injectable hydrogel and embedding SDF-1α-loaded nanodroplets (PFP@NDs-PEG-SDF-1α) was designed and fabricated. The ultrasound was then used to augment the injectable chemotaxis hydrogel and promote the homing migration of BMSCs for OA cartilage repair. The effect of ultrasound augmenting injectable PFP@NDs-PEG-SDF-1α/hydrogel on the migration of BMSCs was verified in vitro and in vivo, which remarkably promotes stem cell homing and the repair of cartilage in the OA model. Therefore, the treatment strategy of ultrasound augmenting injectable chemotaxis hydrogel has a bright potential for OA articular cartilage repair.

Genetic Engineering Of Mesenchymal Stem Cells To Improve Therapeutic Effects

Based on the therapeutic potential of MSCs, including homing to damaged sites, trans-differentiation, secretion of trophic factors, and immunomodulation, approximately 1,100 clinical studies have been registered in the ClinicalTrials.Gov, and several drugs using MSCs have been approved worldwide. However, despite their therapeutic potential, MSCs have not yet shown sufficient therapeutic effects in humans. Therefore, in order to increase the therapeutic potential of MSCs, methods such as MSC priming, genetic modification, Three-Dimensional (3-D) culture, and MSC-derived exosomes are being studied intensively. Among them, genetic modification increases the expression of therapeutic genes, leading to increased homing of MSCs to the damaged sites, increased engraftment rates, and increased survival durations of transplanted MSCs.

The Effect of Intra-articular versus Intravenous Injection of Mesenchymal Stem Cells on Experimentally-Induced Knee Joint Osteoarthritis.

Background:Osteoarthritis (OA) is a chronic degenerative debilitating disease, primarily affects joints, particularly weight-bearing areas. The surface layer of the articular cartilage breaks down and wears away leading to rubbing of bones, pain, swelling, and joint stiffness.Aim and Objectives:This study investigates the possible therapeutic effects of intra-articular versus intravenous injection of umbilical cord blood mesenchymal stem cells (UCB-MSCs) against mono-iodoacetate-induced OA of the knee joints in male albino rats, using histological and immunohistochemical techniques.Materials and Methods:Thirty male adult albino rats were randomized into five groups as follows: Group (I) and (II): Served as control. Group (III): Osteoarthritic group. Group IV: Osteoarthritic and intraarticularly-injected MSCs. Group V: Osteoarthritic and intravenously-injected MSCs. Animals were sacrificed 1 month after stem cell injection, the right knee was prepared for histological techniques (Hematoxylin and Eosin and Toluidine blue stains) and immunohistochemical technique (Bax stain). Prussian blue stain was used to assess homing of MSCs in Groups IV and V.Results:Knee joint surface was irregular, fissured, and fragmented in Group III. In Groups IV and V, affected area was filled with newly formed tissue. Toluidine blue showed a decrease in matrix staining in Group III compared to both control and MSCs-treated groups. Chondrocytes in Group III showed strong Bax immunoreactivity and this reaction decreased in Group IV and V; however, Group V immunoreactivity was more than Group IV. Prussian blue stain showed labeled UCB-MSCs in many chondrocytes in Group IV and few chondrocytes in Group V.Conclusion:Intraarticularly-injected UCB-MSCs showed better healing of knee OA than intravenously-injected UCB-MSCs.

Modelling of the SDF-1/CXCR4 regulated in vivo homing of therapeutic mesenchymal stem/stromal cells in mice.

BackgroundMesenchymal stem/stromal cells (MSCs) are a promising tool for cell-based therapies in the treatment of tissue injury. The stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) axis plays a significant role in directing MSC homing to sites of injury. However in vivo MSC distribution following intravenous transplantation remains poorly understood, potentially hampering the precise prediction and evaluation of therapeutic efficacy.MethodsA murine model of partial ischemia/reperfusion (I/R) is used to induce liver injury, increase the hepatic levels of SDF-1, and study in vivo MSC distribution. Hypoxia-preconditioning increases the expression of CXCR4 in human bone marrow-derived MSCs. Quantitative assays for human DNA using droplet digital PCR (ddPCR) allow us to examine the in vivo kinetics of intravenously infused human MSCs in mouse blood and liver. A mathematical model-based system is developed to characterize in vivo homing of human MSCs in mouse models with SDF-1 levels in liver and CXCR4 expression on the transfused MSCs. The model is calibrated to experimental data to provide novel estimates of relevant parameter values.ResultsImages of immunohistochemistry for SDF-1 in the mouse liver with I/R injury show a significantly higher SDF-1 level in the I/R injured liver than that in the control. Correspondingly, the ddPCR results illustrate a higher MSC concentration in the I/R injured liver than the normal liver. CXCR4 is overexpressed in hypoxia-preconditioned MSCs. An increased number of hypoxia-preconditioned MSCs in the I/R injured liver is observed from the ddPCR results. The model simulations align with the experimental data of control and hypoxia-preconditioned human MSC distribution in normal and injured mouse livers, and accurately predict the experimental outcomes with different MSC doses.DiscussionThe modelling results suggest that SDF-1 in organs is an effective in vivo attractant for MSCs through the SDF-1/CXCR4 axis and reveal the significance of the SDF-1/CXCR4 chemotaxis on in vivo homing of MSCs. This in vivo modelling approach allows qualitative characterization and prediction of the MSC homing to normal and injured organs on the basis of clinically accessible variables, such as the MSC dose and SDF-1 concentration in blood. This model could also be adapted to abnormal conditions and/or other types of circulating cells to predict in vivo homing patterns.

Bone marrow mesenchymal stem cells and condition media diminish inflammatory adhesion molecules of pulmonary endothelial cells in an ovalbumin-induced asthmatic rat model

ObjectivesAlthough excitements related to stem cell therapeutic outcomes have been highlighted enormously in asthma, the vast majority of works were conducted by researchers in animal models. Elucidating the mechanisms underlying the therapeutic effects of MSCs in asthmatic rats will provide a rational basis for assuring maximal safety of future clinical application of stem cells. In the current study, we sought to investigate the possible paracrine mechanism by which direct injection of MSCs and/or CM attenuate efficiently Th2-mediated inflammation in asthmatic lung tissues with the focus on ICAM-1 and VCAM-1 expression. MethodsMale rats were divided into four experimental groups (n = 6); healthy rats received PBS intratracheally (group C), sensitized rats received PBS intratracheally (group S), sensitized rats received CM intratracheally (group S + CM), and sensitized rats received PBS intratracheally containing 2 × 106 rBMMSCs (group S + MSCs). Two weeks post-transplantation, the expression of interleukin (IL)-5, -12 and INF-γ, ICAM-1 and VCAM-1 were assessed along with pathological injuries and the homing of MSCs into the lung tissues. ResultsOur results showed CM, and notably rBMMSCs, returned the expression of IL-5, IL-12, INF-γ, ICAM-1, and VCAM-1 (p < 0.001 to p < 0.05) to the normal levels. Based on data, pathological injuries in pulmonary specimens of asthmatic rats were significantly attenuated (p < 0.001 to p < 0.05). Moreover, rBMMSCs had potential to successfully home to an asthmatic niche in cell-administrated rats. ConclusionsOur data noted the potency of CM and especially MSCs in ameliorating pathological changes via intra-tracheal route presumably by targeting ICAM-1 and VCAM-1 in lung tissues in rat asthma model.

Resveratrol pretreatment enhanced homing of SDF-1α-preconditioned bone marrow-derived mesenchymal stem cells in a rat model of liver cirrhosis.

Stromal cell-derived factor-1α (SDF-1α) has been known to implicate in homing of MSCs, and resveratrol has been reported to have a positive influence on SDF-1 level in the site of injury. In this study, a combined strategy was applied to evaluate bone marrow-derived MSCs (BMSCs) homing to the rat model of liver cirrhosis induced by common bile duct ligation (CBDL): (1) pretreatment delivery of resveratrol into the cirrhotic liver, and (2) transplantation of ex vivo BMSC preconditioning with SDF-1α. BMSCs were preconditioned with 10 ng/µL SDF-1α for 1 h and then labeled with the CM-Dil. Cirrhosis was induced by CBDL. Animals received intraperitoneal injection of resveratrol for 7 days, started on day 28 of CBDL post-operative. On day 36 post-operative, 1 × 106 of SDF-1α-preconditioned BMSCs was injected via caudal vein. Animals were sacrificed at 72 h post-cell transplantation. Immunofluorescence and flow cytometry assessments showed that the BMSC+SDF+RV group had an increased rate of homing into the liver, but it had a decreased rate of homing into the lung and spleen, as compared with the other groups (P < 0.05). The BMSC+SDF+RV group showed high protein expression of SIRT1, but low protein expression of p53 in the liver (P < 0.05 vs other groups). CXCR4 and matrix metalloproteinase (MMP)-9 highly expressed in SDF-1α-preconditioned BMSCs in vitro, and that AKTs and CXCL12 expressed in injured liver undergoing resveratrol injection. Our findings suggest that reseveratrol pretreatment prior to SDF-1α preconditioning could be a promising strategy for designing cell-based therapies for liver cirrhosis.

Chemokine Receptors Expression in MSCs: Comparative Analysis in Different Sources and Passages.

MSC-based therapy is providing a cure for degenerative diseases with unmet medical need and usually iliac crest bone marrow (ICBM) are being applied in clinics. Alternative sources, including adipose tissue and reamer/irrigator/aspirator hold great potential for isolating MCSs. Here, we compared original MSCs features of adipose tissue (Ad-MSCs) and bone marrow of long-bone (RIA-MSCs) or iliac crest, and the expression of chemokine receptors (including CXCR4, CX3CR1, CXCR6, CXCR2, CCR1 and CCR7) in these three sources, which are important in the context of homing. We further investigated the role of SDF-1/CXCR4 axis as a key player in motility of different population of MSCs using Transwell migration assay.All cells exhibited typical MSCs characteristics. However, different MSCs sources expressed different levels of chemokine receptors. Generally, the expression of these chemokine receptors was decreased with increasing passage (P) number from 2 to 3. Interestingly, it was observed that the CXCR4 expression and migration capacity in Ad-MSCs is significantly higher than ICBM and RIA-MSCs in P2. Although our data showed that CXCR4 had highest expression in P2 Ad-MSCs, but it dramatically declined following sub-culturing in the P3. Hence, to improve homing of MSCs by means of chemokine/their receptors axis, the source of isolation and passage number should be considered for clinical applications.

G-CSF Administration after the Intraosseous Infusion of Hypertonic Hydroxyethyl Starches Accelerating Wound Healing Combined with Hemorrhagic Shock.

Objective. To evaluate the therapeutic effects of G-CSF administration after intraosseous (IO) resuscitation in hemorrhagic shock (HS) combined with cutaneous injury rats. Methods. The rats were randomly divided into four groups: (1) HS with resuscitation (blank), (2) HS with resuscitation + G-CSF (G-CSF, 200 μg/kg body weight, subcutaneous injection), (3) HS with resuscitation + normal saline solution injection (normal saline), and (4) HS + G-CSF injection without resuscitation (Unres/G-CSF). To estimate the treatment effects, the vital signs of alteration were first evaluated, and then wound closure rates and homing of MSCs and EPCs to the wound skins and vasculogenesis were measured. Besides, inflammation and vasculogenesis related mRNA expressions were also examined. Results. IO infusion hypertonic hydroxyethyl starch (HHES) exhibited beneficial volume expansion roles and G-CSF administration accelerated wound healing 3 days ahead of other groups under hemorrhagic shock. Circulating and the homing of MSCs and EPCs at wound skins were significantly elevated at 6 h after G-CSF treatment. Inflammation was declined since 3 d while angiogenesis was more obvious in G-CSF treated group on day 9. Conclusions. These results suggested that the synergistical application of HHES and G-CSF has life-saving effects and is beneficial for improving wound healing in HS combined with cutaneous injury rats.

Interferon Gamma–treated Dental Pulp Stem Cells Promote Human Mesenchymal Stem Cell Migration In Vitro

IntroductionChronic inflammation disrupts dental pulp regeneration by disintegrating the recruitment process of progenitors for repair. Bone marrow–derived mesenchymal stem cells (BM-MSCs) share the common features with dental pulp stem cells (DPSCs). The aim of the study was to investigate the migration of BM-MSCs toward DPSCs in response to inflammatory chemoattractants. Additionally, our studies also delineated the signaling mechanisms from BM-MSCs in mediating the proliferation and differentiation of DPSCs in vitro. MethodsHuman DPSCs and BM-MSCs between passages 2 and 4 were used and were grown in odontogenic differentiation medium. Mineralization was determined by alizarin red staining analysis. Migration was assessed using crystal violet staining in cells grown in Boyden chamber Transwell inserts (Corning Inc Foundation, Tewksbury, MA). The mineralization potential of DPSCs was evaluated using alkaline phosphatase activity assay. Real-time polymerase chain reaction analysis was performed to assess the gene expression profile of chemokine (C-X-C motif) ligand (Cxcl) 3, 5, 6, 10, 11, 12, 14, and 16; stromal cell-derived factor (SDF) α; vascular endothelial growth factor; and fibroblast growth factor. ResultsInterferon gamma (FN-γ) treatment significantly abrogated the differentiation potential of DPSCs as shown by using alizarin red and alkaline phosphatase activity analysis. An increase in the migration of BM-MSCs was documented when cocultured with IFN-γ–treated DPSCs. RNA expression studies showed an increase in the levels of Cxcl6 and Cxcl12 in BM-MSCs when cocultured with IFN-γ–treated DPSCs. Additionally, an up-regulation of proangiogenic factors vascular endothelial growth factor and fibroblast growth factor were observed in DPSCs exposed to IFN-γ. ConclusionsOur findings indicate that inflamed IFN-γ–treated DPSCs release factors (presumably Cxcl6 and 12) that contribute to the homing of MSCs. This model might provide a potential research tool for studying MSC-DPSC cross talk and for future studies involving the recruitment and sustainability of progenitor stem cells sustaining the inflammatory cascade to treat pulp inflammation.

Multipotent Mesenchymal Stromal Cells: Possible Culprits in Solid Tumors?

The clinical use of bone marrow derived multipotent mesenchymal stromal cells (BM-MSCs) in different settings ranging from tissue engineering to immunotherapies has prompted investigations on the properties of these cells in a variety of other tissues. Particularly the role of MSCs in solid tumors has been the subject of many experimental approaches. While a clear phenotypical distinction of tumor associated fibroblasts (TAFs) and MSCs within the tumor microenvironment is still missing, the homing of bone marrow MSCs in tumor sites has been extensively studied. Both, tumor-promoting and tumor-inhibiting effects of BM-MSCs have been described in this context. This ambiguity requires a reappraisal of the different studies and experimental methods employed. Here, we review the current literature on tumor-promoting and tumor-inhibiting effects of BM-MSCs with a particular emphasis on their interplay with components of the immune system and also highlight a potential role of MSCs as cell of origin for certain mesenchymal tumors.

Mesenchymal Stem Cells Pretreated with HGF and FGF4 Can Reduce Liver Fibrosis in Mice.

Stem cells have opened a new avenue to treat liver fibrosis. We investigated in vitro and in vivo the effect of cytokine (HGF and FGF4) pretreated MSCs in reduction of CCl4 liver injury. Mouse MSCs were pretreated with cytokines to improve their ability to reduce CCl4 injury. In vitro we gave CCl4 injury to mouse hepatocytes and cocultured it with untreated and cytokines pretreated MSCs. For in vivo study we labeled MSCs with PKH-26 and transplanted them into CCl4 injured mice by direct injection into liver. In vitro data showed that cytokines pretreated MSCs significantly reduce LDH level and apoptotic markers in CCl4 injured hepatocytes cocultured model. Furthermore the cytokines pretreated MSCs also improved cell viability and enhanced hepatic and antiapoptotic markers in injured hepatocytes cocultured model as compared to untreated MSCs. In vivo data in cytokines pretreated group demonstrated greater homing of MSCs in liver, restored glycogen storage, and significant reduction in collagen, alkaline phosphatase, and bilirubin levels. TUNEL assay and real time PCR also supported our hypothesis. Therefore, cytokines pretreated MSCs were shown to have a better therapeutic potential on reduction of liver injury. These results demonstrated the potential utility of this novel idea of cytokines pretreated MSCs for the treatment of liver fibrosis.

Effect of 17β-estradiol on mediators involved in mesenchymal stromal cell trafficking in cell therapy of diabetes

Background aimsMesenchymal stromal cells (MSCs) have shown great promise for cell therapy of a wide range of diseases such as diabetes. However, insufficient viability of transplanted cells reaching to damaged tissues has limited their potential therapeutic effects. Expression of estrogen receptors on stem cells may suggest a role for 17β-estradiol (E2) in regulating some functions in these cells. There is evidence that E2 enhances homing of stem cells. Induction of hypoxia-inducible factor-1α (HIF-1α) by E2 and the profound effect of HIF-1α on migration of cells have previously been demonstrated. We investigated the effect of E2 on major mediators involved in trafficking and subsequent homing of MSCs both in vitro and in vivo in diabetic rats. MethodsE2 has been selected to improve the poor migration capacity of MSCs toward sites of injury. MSCs were incubated with different concentrations of E2 for varying periods of time to investigate whether estradiol treatment could be effective to enhance the efficiency of MSC transplantation. ResultsE2 significantly enhanced the viability of the cells that were blocked by ICI 182,780 (estrogen receptor antagonist). E2 also increased HIF-1α, CXC chemokine receptor 4 and C-C chemokine receptor 2 protein and messenger RNA levels measured by Western blot and reverse transcription–polymerase chain reaction. The enzymatic activity of matrix metalloproteinase 2 and metalloproteinase 9 was elevated in E2-treated cells through the use of gelatin zymography. Finally, the improved migration capacity of E2-treated MSCs was evaluated with the use of a Boyden chamber and in vivo migration assays. ConclusionsOur data support that conditioning of MSCs with E2 promotes migration of cells in cultured MSCs in vitro and in a diabetic rat model in vivo through regulation of major mediators of cell trafficking.

Effect of Snake Venom Disintegrin like domain on the Homing of Mesenchymal Stem Cells

Mesenchymal stem cells have many advantages as grafts for cell transplantation. The homing of MSCs after systemic infusion is still poorly understood. This report explored the effect of the combination of BM-MSCs with Disintegrin like fraction obtained from Cerastes cerastes crude venom on the fibrotic liver of CCl 4 treated mice. It was observed that Disintegrin like fraction could increase homing of BM-MSCs labeled with the PKH26 into the liver tissue of CCl 4 treated mice. A significant decrease in AST and ALT serum levels after administration of Disintegrin like fraction and/or BM-MSCs in CCl 4 treated mice were detected. VEGF was expressed in mice injected with CCl 4 alone, followed by Disintegrin like fraction or both Disintegrin like fraction and BM-MSCs. β- catenin was expressed in mice injected with CCl 4 alone, followed by BM-MSCs or both BM-MSCs and Disintegrin like fraction. Caspase-3 gene was expressed in CCl 4 treated mice injected with BM-MSCs or both BM-MSCs and Disintegrin like fraction. TNF-α and HO-1 were expressed in all groups. Administration of Disintegrin like fraction and / or BM-MSCs improved the histo-pathological picture and showed signs of regeneration in CCl 4 induced liver fibrosis. In conclusion, Disintegrin like fraction could increase homing of BM-MSCs into the liver tissue of CCl 4 treated mice. Further studies need to be done to explore the mechanism of homing caused by Disintegrin.