Injection Of Mesenchymal Stromal Cells Research Articles

Pulsed focused ultrasound pretreatment improves mesenchymal stromal cell efficacy in preventing and rescuing established acute kidney injury in mice.

Animal studies have shown that mesenchymal stromal cell (MSC) infusions improve acute kidney injury (AKI) outcomes when administered early after ischemic/reperfusion injury or within 24 hours after cisplatin administration. These findings have spurred several human clinical trials to prevent AKI. However, no specific therapy effectively treats clinically obvious AKI or rescues renal function once advanced injury is established. We investigated if noninvasive image-guided pulsed focused ultrasound (pFUS) could alter the kidney microenvironment to enhance homing of subsequently infused MSC. To examine the efficacy of pFUS-enhanced cell homing in disease, we targeted pFUS to kidneys to enhance MSC homing after cisplatin-induced AKI. We found that pFUS enhanced MSC homing at 1 day post-cisplatin, prior to renal functional deficits, and that enhanced homing improved outcomes of renal function, tubular cell death, and regeneration at 5 days post-cisplatin compared to MSC alone. We then investigated whether pFUS+MSC therapy could rescue established AKI. MSC alone at 3 days post-cisplatin, after renal functional deficits were obvious, significantly improved 7-day survival of animals. Survival was further improved by pFUS and MSC. pFUS prior to MSC injections increased IL-10 production by MSC that homed to kidneys and generated an anti-inflammatory immune cell profile in treated kidneys. This study shows pFUS is a neoadjuvant approach to improve MSC homing to diseased organs. pFUS with MSC better prevents AKI than MSC alone and allows rescue therapy in established AKI, which currently has no meaningful therapeutic options.

Photoluminescent Mesoporous Silicon Nanoparticles with siCCR2 Improve the Effects of Mesenchymal Stromal Cell Transplantation after Acute Myocardial Infarction

Background: Despite the benefits of mesenchymal stromal cell (MSC) transplantation in cardiac tissue, detailed in vivo observations have shown that MSCs only survive for a brief period after transplantation due to harsh microenvironmental conditions, including ischemia, inflammation and anoikis, in the infarcted myocardium. Thus, new strategies are needed to enhance MSC survival and inhibit cardiac remodeling. Studies have now demonstrated that chemokine [C-C motif] ligand 2 (CCL2) and its cognate receptor C-C chemokine receptor 2 (CCR2) promote excessive Ly6Chigh inflammatory monocyte infiltration at the infarct in response to ischemic myocardial injury. Therefore, decreasing the activities of these monocytes immediately after acute myocardial infarction (AMI) could be beneficial for AMI patients. Objectives: This study tested the hypothesis that therapeutic siRNA-loaded photoluminescent mesoporous silicon nanoparticles (PMSNs) targeting CCR2 expression in Ly6Chigh inflammatory monocytes decrease the accumulation of these cells in the infarct, improve the efficacy of MSC transplantation and attenuate myocardial remodeling.Methods: PMSNs carrying therapeutic siCCR2 were first synthesized without the inclusion of fluorescent materials or dyes. After AMI BALB/c mice were established, 105 5-ethynyl-2'- deoxyuridine (EdU)-labeled MSCs suspended in 100 µl of phosphate buffered saline (PBS) were injected into the border zone of the infarct of each mouse. PMSNs-siCCR2 (25 µg/g) were also intravenously injected via the tail vein immediately following AMI induction. Control mice were injected with an equal amount of PMSNs without siCCR2. PMSNs-siCCR2 were examined in vivo using near-infrared imaging technology. The therapeutic effects of PMSNs-siCCR2 for MSC transplantation were determined at the mRNA, protein and functional levels.Results: PMSNs-siCCR2 circulated freely in vivo and were cleared in a relatively short period of time (t½=37 min) with no evidence of toxicity. The therapeutic PMSNs-siCCR2 showed higher levels of cellular accumulation in Ly6Chigh monocytes in the spleen and more efficient degradation of CCR2 compared with the control (8.04%±2.17% vs. 20.02%±4.55%, p<0.001). Subsequently, the PMSNs-siCCR2 decreased the accumulation of CD11b-positive monocytes at the infarct (49.3%±17.34% vs. 61.32%±22.43%, p<0.001) on day 1. Increased survival of transplanted MSCs (13±3/mm2 vs. 4±1/mm2, p<0.001) and significantly decreased TdT-mediated dUTP nick end labeling (TUNEL)+ cardiac myocytes (17.44%±6.26% vs. 39.49%±13.28%, p<0.001) were then identified in the infarct zone three days after AMI induction in the PMSNs-siCCR2 group. Three weeks after MSC injection, significant increases were observed in the vascular density (235.5±39.6/mm2 vs. 147.4±20.3/mm2, p<0.001) and the cardiac myosin-positive area (21.7%±8.4% vs. 13.2%±4.4%, p<0.001) of the infarct border zone. In addition, significant amelioration of left ventricular (LV) remodeling (thickness of the LV posterior walls) (0.84±0.11 mm vs. 0.61±0.08 mm, p<0.001) was also observed at the same time compared with the control group.Conclusions: PMSNs-siCCR2-mediated CCR2 gene silencing in Ly6Chigh monocytes improved the effectiveness of MSC transplantation and selectively ameliorated myocardial remodeling after AMI. These results suggest that PMSNs-siCCR2 could potentially be used to develop an anti-inflammatory therapy for post-AMI MSC transplantation.

A Novel Humanized Bone Marrow Niche Xenotransplantation Model Allows Superior Engraftment of Human Normal and Malignant Hematopoietic Cells and Reveals Myelofibrosis-Initiating Cells in the HSC Compartment

Xenotransplantation into immunocompromised mice is a powerful tool for studying human normal and malignant hematopoiesis. However, xenotransplant models do not necessarily recapitulate human physiology since environmental factors provided by bone marrow (BM) niche cells may differ between mice and humans. Although existing mouse models allow for propagation of hematopoietic stem and progenitor cells (HSPCs) and aggressive acute leukemias, engraftment of more committed normal progenitor cells and many other hematopoietic malignancies is still lacking. Here, we report the development of a novel mouse model bearing a subcutaneously accessible human bone ossicle formed by in situ differentiation of BM-derived mesenchymal stromal cells (MSCs). These human ossicles contain a functional humanized BM niche that facilitates robust engraftment of normal human HSPC and exhibits superior engraftment and expansion of primary AML. Interestingly, this model allows robust engraftment of PML-RARA positive APL and JAK2 V617F+ PMF, both of which fail to engraft in conventional xenotransplantation models.Subcutaneous injection of human BM-derived MSCs resulted in the formation of human ossicles through endochondral ossification resulting in a bone marrow cavity harboring normal mouse hematopoietic elements. After conditioning irradiation, direct intraossicle injection of cord blood CD34+ HSPC (n=5) resulted in robust multi-lineage human engraftment including B cells, T cells, NK cells, mature neutrophils, eosinophils, monocytes, as well as red blood cell precursors and platelets, as assessed by flow cytometric analysis of aspirates taken directly from the ossicles. The self-renewal potential of engrafted HSPCs was demonstrated by re-establishing multi-lineage hematopoiesis in secondary recipients. Unlike conventional NSG mice, this xenograft model allowed engraftment of phenotypically defined L-MPP (n=7) and GMP (n=7). Engraftment analysis 2 weeks post transplantation showed human engraftment with a majority of CD33+ myeloid cells (LMPP: 77.3±14.4%; GMP: 97.3±1.8%) and intermediate (LMPP: 20.8±14.4%) to low (GMP: 1.8±1.8%) numbers of B lymphoid cells.In the investigation of AML, direct intraossicle transplantation of blasts (n=5) resulted in faster (as early as 6 weeks) and significantly higher leukemic engraftment in humanized niches compared to mouse BM. Furthermore, engraftment was also significantly higher in humanized niches after intravenous transplantation and demonstrated a paratrabecular engraftment pattern, suggesting preferential homing and expansion of AML cells in a human BM microenvironment. Limiting dilution analysis revealed a 10-250 fold higher leukemia-initiating cell frequency using direct intraossicle transplantation compared to intrafemoral injection into mouse BM. Intraossicle transplantation also allowed for engraftment and propagation of PML-RARA-positive APL blasts (n=3) resulting in almost 100% leukemic chimerism and granulocytic sarcoma formation 10-15 weeks post-transplantation. Finally, transplantation of PMF patient-derived CD34+ cells (n=5) into the humanized niche led to robust engraftment with up to 50% human chimerism, and further subpopulation studies demonstrated that PMF-engraftment was exclusively initiated from the HSC (CD34+/CD38-/CD90+) population. Engrafted cells showed marked myeloid skewing with JAK2 V617F-positive cells, and detection of only minimal JAK2 wild type lymphoid cells.In summary, we report the development of a novel xenotransplantation model using human bone ossicles formed by in situ differentiation of BM-derived MSCs that substantially improves the engraftment of normal and malignant hematopoietic populations, leading to the formal demonstration that PMF-initiating cells reside in the immunophenotypic HSC compartment. DisclosuresNo relevant conflicts of interest to declare.

Intra-articular administration of xenogeneic neonatal Mesenchymal Stromal Cells early after meniscal injury down-regulates metalloproteinase gene expression in synovium and prevents cartilage degradation in a rabbit model of osteoarthritis

The anti-inflammatory and anti-catabolic effects of neonatal Mesenchymal Stromal Cell (MSC) were investigated in a xenogeneic model of mild osteoarthritis (OA). The paracrine properties of MSC on synoviocytes were further investigated invitro. OA was induced by medial meniscal release (MMR) in 30 rabbit knees. A single early (day 3) or delayed (day 15) intra-articular (IA) injection of MSC isolated from equine Umbilical Cord Wharton's jelly (UC-MSC) was performed. Rabbits were euthanized on days 15 or 56. OA grading was performed and gene expression of inflammatory cytokines and metalloproteinases was measured in synovial tissue. Paracrine effects of UC-MSC were investigated using UC-conditioned vs control medium on rabbit primary synoviocytes stimulated with interleukin 1 beta invitro. No adverse local or systemic responses were observed clinically after xenogeneic UC-MSC injection. At study end point, cartilage fibrillation was lower in early treatment than in delayed treatment group. Cellular infiltrate was observed in the synovium of both UC-MSC groups. OA synovium exhibited a reduced expression of metalloproteinases-1, -3, -13 in the early cell-treated group at d56. Invitro, UC-conditioned medium exerted anti-inflammatory and anti-catabolic effects on synoviocytes exposed to pro-inflammatory stimulus. Early IA injection of equine UC-MSC was effective in preventing OA signs in rabbit knees following MMR. UC-MSC target the synovium and modulate the gene expression pattern of synoviocytes to promote an anti-catabolic environment. This confirms the synovium is a major target and mediator of MSC therapy, modulating the expression of matrix-degrading enzymes.

Effect of bone marrow–derived mesenchymal stromal cells on hepatoma

Background aimsThe aim of the study was to evaluate the effect of mesenchymal stromal cells (MSCs) on tumor cell growth in vitro and in vivo and to elucidate the apoptotic and anti-proliferative mechanisms of MSCs on a hepatocellular carcinoma (HCC) murine model. MethodsThe growth-inhibitory effect of MSCs on the Hepa 1–6 cell line was tested by means of methyl thiazolyl diphenyl-tetrazolium assay. Eighty female mice were randomized into four groups: group 1 consisted of 20 mice that received MSCs only by intrahepatic injection; group 2 consisted of 20 HCC mice induced by inoculation of Hepa 1–6 cells into livers without MSC treatment; group 3 consisted of 20 mice that received MSCs after induction of liver cancer; group 4 consisted of 20 mice that received MSCs after induction of liver cancer on top of induced biliary cirrhosis. ResultsMSCs exhibited a growth-inhibitory effect on Hepa 1–6 murine cell line in vitro. Concerning in vivo study, decreases of serum alanine transaminase, aspartate transaminase and albumin levels after MSC transplantation in groups 2 and 3 were found. Gene expression of α-fetoprotein was significantly downregulated after MSC injection in the HCC groups. We found that gene expression of caspase 3, P21 and P53 was significantly upregulated, whereas gene expression of Bcl-2 and survivin was downregulated in the HCC groups after MSC injection. Liver specimens of the HCC groups confirmed the presence of dysplasia. The histopathological picture was improved after administration of MSCs to groups 2 and 3. ConclusionsMSCs upregulated genes that help apoptosis and downregulated genes that reduce apoptosis. Therefore, MSCs could inhibit cell division of HCC and potentiate their death.

Mesenchymal Stromal Cell Dependent Regression of Pulmonary Metastasis from Ewing's.

Introduction: Ewing’s sarcoma (ES) is the second most common bone tumor in children. Survival has not improved over the last decade and once pulmonary metastatic disease is present, survival is dismal. Mesenchymal stromal cell (MSC) therapy has shown potential benefit for Kaposi’s sarcoma; however, the role of progenitor cell therapies for cancer remains controversial. MSC treatment of ES or pulmonary metastatic disease has not been demonstrated. We have developed an orthotopic xenograft model of ES in which animals develop spontaneous pulmonary metastases. Within this model, we demonstrate the use of MSCs to target ES lung metastasis.Materials and Methods: Human ES cells were transfected with luciferase and injected into the rib of nude mice. Development of pulmonary metastases was confirmed by imaging. After flow cytometry based characterization, MSCs were injected into the tail vein of nude mice with established local ES tumor or pulmonary metastasis. Mice were treated with intravenous MSCs weekly followed by bioluminescent imaging.Results: The intravenous injection of MSCs in an ES model decreases the volume of pulmonary metastatic lesions; however, no effect on primary chest wall tumor size is observed. Thus verifying the MSC preferential homing to the lung. MSCs are found to “home to” the pulmonary parenchyma and remain engrafted up to 5 days after delivery.Discussion: MSC treatment of ES slows growth of pulmonary metastasis. MSCs have more affinity for pulmonary metastasis and can effect a greater decrease in tumor growth in the lungs compared to the primary tumor site.

Injection of mesenchymal stromal cells into a mechanically stimulated in vitro model of cardiac fibrosis has paracrine effects on resident fibroblasts

Background aimsMyocardial infarction results in the formation of scar tissue populated by myofibroblasts, a phenotype characterized by increased contractility and matrix deposition. Mesenchymal stromal cells (MSC) delivered to the myocardium can attenuate scar growth and restore cardiac function, though the mechanism is unclear. MethodsThis study describes a simple yet robust three-dimensional (3D) in vitro co-culture model to examine the paracrine effects of implanted MSC on resident myofibroblasts in a controlled biochemical and mechanical environment. The fibrosis model consisted of fibroblasts embedded in a 3D collagen gel cultured under defined oxygen tensions and exposed to either cyclic strain or interstitial fluid flow. MSC were injected into this model, and the effect on fibroblast phenotype was evaluated 48 h after cell injection. ResultsAnalysis of gene and protein expression of the fibroblasts indicated that injection of MSC attenuated the myofibroblast transition in response to reduced oxygen and mechanical stress. Assessment of vascular endothelial growth factor and insulin-like growth factor-1 levels demonstrated that their release by fibroblasts was markedly upregulated in hypoxic conditions but attenuated by strain or fluid flow. In fibroblast-MSC co-cultures, vascular endothelial growth factor levels were increased by hypoxia but not affected by mechanical stimuli, whereas insulin-like growth factor-1 levels were generally low and not affected by experimental conditions. ConclusionsThis study demonstrates how a 3D in vitro model of the cardiac scar can be used to examine paracrine effects of MSC on the phenotype of resident fibroblasts and therefore illuminates the role of injected progenitor cells on the progression of cardiac fibrosis.

Mesenchymal stromal cell injection protects against oxidative stress in Escherichia coli–induced acute lung injury in mice

Background aimsStem cells may be a promising therapy for acute respiratory distress syndrome. Recent in vivo and in vitro studies suggested that the mesenchymal stromal cells (MSCs) have anti-oxidative stress properties. We hypothesized that intravenous injection of bone marrow–derived mesenchymal stem cells (MSCs) could attenuate Escherichia coli–induced acute lung injury (ALI) in mice by controlling the oxidative stress status. MethodsEighty mice were randomly divided into four groups: group 1 (control group) received 25 μL of saline as a vehicle; group 2 contained E coli–induced ALI mice; group 3 included mice that received MSCs before induction of ALI; group 4 included mice that received MSCs after induction of ALI. Lung samples were isolated and assayed for oxidative stress variables and histopathologic analysis. Total anti-oxidant capacity was measured in broncho-alveolar lavage. ResultsPre- and post-injury MSC injection increased survival, reduced pulmonary edema and attenuated lung injuries in ALI mice. Histologically, MSCs exhibited a considerable degree of preservation of the pulmonary alveolar architecture. An increase of anti-oxidant enzyme activities and a decrease of myeloperoxidase activity and malondialdehyde levels in the MSC recipient groups versus the ALI group were found. Furthermore, the total anti-oxidant capacity and reduced glutathione levels were significantly increased in MSCs recipient groups versus the ALI group. Weak +ve inducible nitric oxide synthase immuno-expression in groups that received MSCs was detected. Pre-injury MSC injection showed better effects than did post-injury MSC injection. ConclusionsSystemic bone marrow–derived MSC injection was effective in modulating the oxidative stress status in E coli–induced acute lung injury in mice.

Optimization of the therapeutic efficacy of human umbilical cord blood–mesenchymal stromal cells in an NSG mouse xenograft model of graft-versus-host disease

Background aimsAlthough in vitro studies have demonstrated the immunosuppressive capacity of mesenchymal stromal cells (MSCs), most in vivo studies on graft-versus-host disease (GVHD) have focused on prevention, and the therapeutic effect of MSCs is controversial. Moreover, optimal time intervals for infusing MSCs have not been established. MethodsWe attempted to evaluate whether human umbilical cord blood–MSCs (hUCB-MSCs) could either prevent or treat GVHD in an NSG mouse xenograft model by injection of MSCs before or after in vivo clearance. Mice were infused with either a single dose or multiple doses of 5 × 105 hUCB-MSCs (3- or 7-day intervals) before or after GVHD onset. ResultsBefore onset, hUCB-MSCs significantly improved the survival rate only when repeatedly injected at 3-day intervals. In contrast, single or repeated injections after GVHD onset significantly increased the survival rate and effectively attenuated tissue damage and inflammation. Furthermore, the levels of prostaglandin E2 and transforming growth factor-β1 increased significantly, whereas the level of interferon-γ decreased significantly in all MSC treatment groups. ConclusionsThese data establish the optimal time intervals for preventing GVHD and show that hUCB-MSCs effectively attenuated symptoms and improved survival rate when administered after the onset of GVDH.

Treatment of Graft versus Host Disease with Mesenchymal Stromal Cells: A Phase I Study on 40 Adult and Pediatric Patients

This phase I multicenter study was aimed at assessing the feasibility and safety of intravenous administration of third party bone marrow–derived mesenchymal stromal cells (MSC) expanded in platelet lysate in 40 patients (15 children and 25 adults), experiencing steroid-resistant grade II to IV graft-versus-host disease (GVHD). Patients received a median of 3 MSC infusions after having failed conventional immunosuppressive therapy. A median cell dose of 1.5 × 106/kg per infusion was administered. No acute toxicity was reported. Overall, 86 adverse events and serious adverse events were reported in the study, most of which (72.1%) were of infectious nature. Overall response rate, measured at 28 days after the last MSC injection, was 67.5%, with 27.5% complete response. The latter was significantly more frequent in patients exhibiting grade II GVHD as compared with higher grades (61.5% versus 11.1%, P = .002) and was borderline significant in children as compared with adults (46.7 versus 16.0%, P = .065). Overall survival at 1 and 2 years from the first MSC administration was 50.0% and 38.6%, with a median survival time of 1.1 years. In conclusion, MSC can be safely administered on top of conventional immunosuppression for steroid resistant GVHD treatment. Eudract Number 2008-007869-23, NCT01764100.

Intravenous and Intratracheal Mesenchymal Stromal Cell Injection in a Mouse Model of Pulmonary Emphysema

The aim of this study was to characterize the evolution of lung function and -structure in elastase-induced emphysema in adult mice and the effect of mesenchymal stromal cell (MSC) administration on these parameters. Adult mice were treated with intratracheal (4.8 units/100 g bodyweight) elastase to induce emphysema. MSCs were administered intratracheally or intravenously, before or after elastase injection. Lung function measurements, histological and morphometric analysis of lung tissue were performed at 3 weeks, 5 and 10 months after elastase and at 19, 20 and 21 days following MSC administration. Elastase-treated mice showed increased dynamic compliance and total lung capacity, and reduced tissue-specific elastance and forced expiratory flows at 3 weeks after elastase, which persisted during 10 months follow-up. Histology showed heterogeneous alveolar destruction which also persisted during long-term follow-up. Jugular vein injection of MSCs before elastase inhibited deterioration of lung function but had no effects on histology. Intratracheal MSC treatment did not modify lung function or histology. In conclusion, elastase-treated mice displayed persistent characteristics of pulmonary emphysema. Jugular vein injection of MSCs prior to elastase reduced deterioration of lung function. Intratracheal MSC treatment had no effect on lung function or histology.

PReS-FINAL-2107: In vitro investigation into mesenchymal stromal cells as a potential therapeutic in juvenile arthritis

Mesenchymal stromal cells (MSC) are multipotent cells with an immune suppressive capacity. In the last decade the therapeutic application of these cells has been tested in inflammatory diseases like graft versus host disease and rheumatoid arthritis. Injection of MSC can be a potential therapy for juvenile idiopathic arthritis patients refractory to conventional therapies.

Mesenchymal Stromal Cells Enhance G-CSF-Induced Mobilization Of Hematopoietic Stem- and Progenitor Cells

Hematopoietic stem- and progenitor cell (HSPC) mobilization is a property of most hematopoietic growth factors, such as Granulocyte Colony Stimulating Factor (G-CSF). Not all donors mobilize equally well and therefore the number of HSPC that are obtained following mobilization may be limited. Mesenchymal stromal cells (MSC) have the capacity to differentiate into cells of the mesodermal lineage and have immunomodulatory properties in vivo and in vitro. Here, we have investigated the effect of MSC co-administration on G-CSF-induced HSPC mobilization.MSC were obtained from bone marrow cells (bone marrow-derived) or bone fragments (bone-derived) and were expanded in alpha-MEM containing 10% fetal calf serum until sufficient cell numbers were obtained. Bone marrow or bone-derived MSC were administered intravenously for three days at a dose of 200 x103 cells per day to male C57BL/6 recipients that were simultaneously mobilized with G-CSF (10 μg per day intraperitoneally for 3 days) or PBS as a control. Co-injection of G-CSF and MSC lead to a 2-fold increase in HSPC mobilization compared to G-CSF alone (8,563 ± 3,309 vs. 4,268 ± 1,314 CFU-C per ml peripheral blood respectively; n=13, p<0.01). Administration of MSC alone did not induce HSPC mobilization (273 ± 229 CFU-C/ml blood; n=13). Furthermore, co-injection of splenocytes and G-CSF did not enhance HSPC mobilization, showing that the administration of exogeneous cells as such is not sufficient for enhancement of HSPC mobilization.It has been reported that G-CSF-induced HSPC mobilization is associated with a decrease in the number of osteal macrophages, B lymphocytes and erythroid progenitors. Administration of MSC alone induced a significant decrease in the frequency of osteal macrophages (7.9 ± 1.2 vs 6.2 ± 1.4% bone marrow cells for PBS vs. MSC respectively; n=8, p<0.05), but did not affect osteoblast numbers. Furthermore, the frequency of B lymphocytes was significantly decreased following MSC administration (29.9 ± 4.0 vs. 16.5 ± 4.9% bone marrow cells for PBS vs. MSC respectively; n=13, p<0.0001). No differences were observed in erythroid numbers following MSC administration.To investigate the mechanisms underlying these observations, the migratory capacity of luciferase transduced MSC was studied through bioluminescence imaging. Following intravenous injection, MSC were detected in the lungs, but not in other organs. In addition, no difference in MSC migration was observed between G-CSF and PBS treated mice. Moreover, intraperitoneal administration of G-CSF and MSC resulted in increased HSPC mobilization compared to G-CSF alone (10,178 ±3,039 vs. 5,158 ± 2,436 CFU-C per ml peripheral blood; n=5-12). Together, these data point to an endocrine effect of MSC on G-CSF-induced HSPC mobilization. No differences in IL-6, CXCL-12 or M-CSF levels in bone marrow extracellular fluid were observed.In conclusion, G-CSF-induced HSPC mobilization is enhanced by injection of MSC. We hypothesize that the MSC-induced partial depletion of B lymphocytes and osteal macrophages in the bone marrow are crucial factors involved in the enhancement of G-CSF-induced HSPC mobilization.▪ Disclosures:No relevant conflicts of interest to declare.

Isogeneic MSC application in a rat model of acute renal allograft rejection modulates immune response but does not prolong allograft survival

Application of mesenchymal stromal cells (MSCs) has been proposed for solid organ transplantation based on their potent immuno-modulatory effects in vitro and in vivo. We investigated the potential of MSCs to improve acceptance of kidney transplants in an MHC-incompatible rat model including isogeneic kidney transplantation (RTx) as control. MSCs were administered i.v. or i.a. at time of transplantation. No immunosuppression was applied. Renal function was monitored by serum-creatinine, histopathology, immunochemistry for graft infiltrating cells and expressions of inflammatory genes. We demonstrated the short-term beneficial effects of MSC injection. In the long term, however, MSC-related life-threatening/shortening events (thrombotic microangiopathy, infarctions, infections) were evident despite decreased T- and B-cell infiltration, lower interstitial inflammation and downregulated inflammatory genes particularly after i.a. MSC injection. We conclude that i.a. MSC administration provides efficient immunomodulation after allogeneic RTx, although timing and co-treatment strategies need further fine-tuning to develop the full potential of powerful cell therapy in solid organ transplantation.

Intramyocardial injection of mesenchymal stromal cells in patients with severe stable coronary artery disease and refractory angina - final 3 year follow-up

Purpose: Regenerative stem cell therapy is an emerging treatment modality for patients with coronary artery disease (CAD). The study assessed long-term safety and efficacy of percutaneous intramyocardial injection of autologous bone-marrow derived mesenchymal stromal cells (MSC) in patients with severe stable CAD and refractory angina. Methods: Thirty-one patients with severe stable CAD and refractory angina were included. Patients had reversible myocardial ischemia and no further revascularization options. Autologous bone-marrow MSCs were isolated, culture expanded and stimulated with vascular endothelial growth-factor to facilitate endothelial differentiation. MSCs were injected into an ischemic, viable region of the myocardium using a electromechanical guided percutaneous catheter system. Patients were followed for 3 years. Results: We found significant and sustained clinical improvements in exercise time from 6:23±1:43 to 7:00±2:12 minutes (p = 0.0016), angina class (CCS) from 3.0±0.3 to 0.9±1.0 (p < 0.0001)), weekly number of angina attacks from 13.8±13.7 to 4.3±7.3 (p < 0.0001) and weekly uses of nitro-glycerine from 10.7±10.0 to 4.5±6.8 (p = 0.0017). In the Seattle Angina Questionnaire there were significant improvements in physical limitation score, angina stability score, angina frequency score and quality of life score (all p < 0.0001). When comparing all hospital admissions from 3 years before treatment and 3 years after treatment, we observed highly reduced admission rates for stable angina (p < 0.0001), revascularization (p = 0.003) and overall cardiovascular disease (p < 0.0001). No early or late side-effects of the treatment were observed. Conclusions: The final 3-year follow-up data after percutaneous intramyocardial injection of autologous MSCs, in patients with severe CAD and refractory angina, demonstrated sustained and significantly positive clinical effects, reduced hospital admissions for cardiovascular disease and excellent safety. The results indicate that the treatment does not only improve clinical symptoms but also slows down disease progression.

New insights for pelvic radiation disease treatment: Multipotent stromal cell is a promise mainstay treatment for the restoration of abdominopelvic severe chronic damages induced by radiotherapy

Radiotherapy may induce irreversible damage on healthy tissues surrounding the tumor. It has been reported that the majority of patients receiving pelvic radiation therapy show early or late tissue reactions of graded severity as radiotherapy affects not only the targeted tumor cells but also the surrounding healthy tissues. The late adverse effects of pelvic radiotherapy concern 5% to 10% of them, which could be life threatening. However, a clear medical consensus concerning the clinical management of such healthy tissue sequelae does not exist. Although no pharmacologic interventions have yet been proven to efficiently mitigate radiotherapy severe side effects, few preclinical researches show the potential of combined and sequential pharmacological treatments to prevent the onset of tissue damage. Our group has demonstrated in preclinical animal models that systemic mesenchymal stromal cell (MSC) injection is a promising approach for the medical management of gastrointestinal disorder after irradiation. We have shown that MSCs migrate to damaged tissues and restore gut functions after irradiation. We carefully studied side effects of stem cell injection for further application in patients. We have shown that clinical status of four patients suffering from severe pelvic side effects resulting from an over-dosage was improved following MSC injection in a compationnal situation.

Rationale and design of the first randomized, double-blind, placebo-controlled trial of intramyocardial injection of autologous bone-marrow derived Mesenchymal Stromal Cells in chronic ischemic Heart Failure (MSC-HF Trial)

Stem cell therapy is an emerging treatment modality in cardiovascular disease. The best cell type and delivery method in different cardiovascular diseases remain to be determined. The MSC-HF trial is a phase 2, single-center, double-blind, randomized, placebo-controlled trial of intramyocardial delivery of autologous bone-marrow derived mesenchymal stromal cells (MSCs) in patients with chronic ischemic heart failure. A total of 60 patients will be randomized in a 2:1 pattern to receive intramyocardial injections of either MSCs or placebo. Patients will be followed up for 12 months. Bone marrow will be obtained by aspiration from the iliac crest. Mesenchymal stromal cells will be isolated, and culture will be expanded for 6 to 8 weeks. A total of 12 to 15 MSC or placebo injections will be placed in an ischemic viable region of the myocardium using the electromechanical NOGA-XP system (Biologics Delivery Systems Group, Johnson & Johnson, Irwindale, CA). The primary endpoint is change in left ventricle end-systolic volume, measured by magnetic resonance imaging (MRI) or computed tomography (CT) at 6-month follow-up. Secondary endpoints are left ventricle ejection fraction, ventricular volumes, wall thickness, and systolic wall thickening measured by MRI or CT in addition to measurement of myocardial scar tissue by MRI. Other secondary endpoints are safety of treatment, clinical symptoms and functional capacity, weekly angina attacks, use of short-term nitroglycerine, and quality of life. A randomized, double-blind, placebo-controlled, clinical trial of intramyocardial delivery of MSCs in patients with ischemic heart failure has been set up to confirm the positive findings in open-labeled clinical trials.

Human mesenchymal stromal cells improve scar thickness without enhancing cardiac function in a chronic ischaemic heart failure model

Few data address the role of human mesenchymal stromal cells (MSCs) in the management of chronic ischaemic heart failure. We assessed their effect in immune-deficient animals. MSCs were cultured from bone marrow of human volunteers. Non-obese diabetes severe combined immunodeficiency (NOD/SCID) gamma null mice were randomly assigned to intramyocardial injection of human MSCs or phosphate-buffered saline 4 weeks after induction of acute myocardial infarction (MI). Echocardiography was performed 4 weeks after MI and 1 and 4 weeks after injection. Donor cell chimerism was assessed by DNA for human Alu sequences 2 and 4 weeks after injection. Histological assessment and quantification of neovascularization were determined 4 weeks after treatment. Donor MSCs at frequencies of 0.006 and 0.001% were present 2 and 4 weeks after cell injection, respectively. The infarcted ventricular wall was significantly thicker in the cohort receiving MSCs compared with control mice. There was no difference in fractional shortening, left ventricular dimensions or scar area between the groups. Small vessel density was also similar between the groups. Human MSCs increased the thickness of the infarcted ventricular wall without improving cardiac function in this chronic ischaemic heart failure model. Further studies are required to assess the benefit of MSCs in this setting.

Can multiple intramuscular injections of mesenchymal stromal cells overcome insulin resistance offering an alternative mode of cell therapy for type 2 diabetes?

Insulin resistance is a hallmark of type 2 diabetes (T2D). The mechanisms underpinning β-cell mass expansion and their functionality in insulin-resistant states still remain elusive. It has recently been shown that insulin resistance in skeletal muscles leads to production of myokines that impact negatively on β-cell function. We hypothesize that multiple intramuscular injections (IM) of mesenchymal stromal cells (MSCs) at different sites would aid in countering the insulin resistance in T2D. These IM injections are expected to have dual effects in overcoming muscle insulin resistance. It is likely to modulate the micro environmental niche of insulin-insensitive myocytes under the influence of paracrine secretions from MSCs, in turn changing the myokine secretion pattern to positively regulate β-cell function. Further, it may stimulate the satellite cell population to generate new myocytes, which would be insulin-sensitive. If our hypothesis proves to be right, it might offer a user-friendly approach to control T2D.

Therapeutic Efficacy of Cord Blood-Derived Mesenchymal Stromal Cells for the Prevention of Acute Graft-Versus-Host Disease in a Xenogenic Mouse Model

Human mesenchymal stromal cells (MSCs) have been successfully utilized for the treatment of refractory graft-versus-host disease (GvHD). Despite the large number of in vitro and in vivo models developed for clarifying their immunomodulatory properties, the mechanism of action of MSCs remains elusive and their efficacy controversial. Here, we tested the ability of cord blood-derived MSCs to alleviate the symptoms of GvHD induced by the injection of human peripheral blood mononuclear cells into NOD/SCID/γc(-) mice. In this in vivo xeno-GvHD model, we demonstrate that a single MSC injection is able to inhibit GvHD in terms of clinical signs and related mortality. We also show that in this model MSCs act by both immunomodulating T-cells and fostering recovery after irradiation. The translational impact of these findings could provide a reliable preclinical model for studying the efficacy, dosage, and time of administration of human MSCs for the prevention of acute GvHD.