Bone marrow-derived mononuclear cells ameliorate neurological function in chronic cerebral infarction model mice via improvement of cerebral blood flow.

BACKGROUND AIMS: Stroke is a frequently observed neurological disorder that might lead to permanent and severe disability. Recently, various regenerative therapies have been developed, some of which have already been applied clinically. However, their outcomes have not been fully satisfactory. In particular, the development of regenerative therapies for chronic ischemic stroke is greatly needed. Herein intracerebral administration of bone marrow-derived mononuclear cells (BM-MNCs) was assessed as a potential treatment for chronic ischemic stroke using a severe combined immunodeficiency mouse model characterized by minimal vascular variation unrelated to immunodeficiency. METHODS: A reproducible model of permanent middle cerebral artery occlusion was prepared, and intracerebral BM-MNC transplantation was performed 14 days after stroke induction in the infarcted brain. RESULTS: Sensorimotor behavioral function and cerebral blood flow were significantly improved upon treatment with BM-MNCs compared to control medium injection. The transplanted cells exhibited characteristics of the vascular endothelium and microglia/macrophages. Significant angiogenesis and suppression of astrogliosis and microgliosis were observed in the affected brain. Messenger RNA expression analysis showed significant increases in anti-inflammatory cytokines, A2 astrocyte/anti-inflammatory microglia markers and vascular endothelial markers such as vascular endothelial growth factor and significant decreases in pro-inflammatory cytokines and A1 astrocyte/pro-inflammatory microglia markers following BM-MNC transplantation. CONCLUSIONS: These results suggest that intracerebral administration of BM-MNCs should be considered an effective cell therapy for chronic stroke.

Bone Marrow-Derived Mononuclear Cells in the Treatment of Neurological Diseases: Knowns and Unknowns.

Bone marrow-derived mononuclear cells (BMMNCs) have been used for decades in preclinical and clinical studies to treat various neurological diseases. However, there is still a knowledge gap in the understanding of the underlying mechanisms of BMMNCs in the treatment of neurological diseases. In addition, prerequisite factors for the efficacy of BMMNC administration, such as the optimal route, dose, and number of administrations, remain unclear. In this review, we discuss known and unknown aspects of BMMNCs, including the cell harvesting, administration route and dose; mechanisms of action; and their applications in neurological diseases, including stroke, cerebral palsy, spinal cord injury, traumatic brain injury, amyotrophic lateral sclerosis, autism spectrum disorder, and epilepsy. Furthermore, recommendations on indications for BMMNC administration and the advantages and limitations of BMMNC applications for neurological diseases are discussed. BMMNCs in the treatment of neurological diseases. BMMNCs have been applied in several neurological diseases. Proposed mechanisms for the action of BMMNCs include homing, differentiation and paracrine effects (angiogenesis, neuroprotection, and anti-inflammation). Further studies should be performed to determine the optimal cell dose and administration route, the roles of BMMNC subtypes, and the indications for the use of BMMNCs in neurological conditions with and without genetic abnormalities.

A Multicenter Prospective Interventional Trial of Therapeutic Angiogenesis Using Bone Marrow-Derived Mononuclear Cell Implantation for Patients With Critical Limb-Threatening Ischemia Caused by Thromboangiitis Obliterans.

BACKGROUND: Thromboangiitis obliterans (TAO) can lead to the development of critical limb-threatening ischemia (CLTI). Despite conventional treatments, such as smoking cessation or revascularization, young patients (<50 years) still require limb amputation. Therapeutic angiogenesis using bone marrow-derived mononuclear cell (BM-MNC) implantation has been tested and shown to have reasonable efficacy in CLTI. In this multicenter prospective clinical trial, we evaluated the safety and efficacy of BM-MNC implantation in CLTI patients with TAO.Methods and Results: We enrolled 22 CLTI patients with skin perfusion pressure (SPP) <30 mmHg. The primary endpoint of this trial is the recovery of SPP in the treated limb after a 180-day follow-up period. Secondary endpoints include the pain scale score and transcutaneous oxygen pressure (TcPO2). One patient dropped out during follow-up, leaving 21 patients (mean age 48 years, 90.5% male, Fontaine Class IV) for analysis. BM-MNC implantation caused no serious adverse events and increased SPP by 1.5-fold compared with baseline. Surprisingly, this effect was sustained over the longer term at 180 days. Secondary endpoints also supported the efficacy of this novel therapy in relieving pain and increasing TcPO2. Major amputation-free and overall survival probabilities at 3 years among all enrolled patients were high (95.5% and 89.5%, respectively). CONCLUSIONS: BM-MNC implantation showed safety and significant efficacy in CLTI patients with TAO.

Exploring the Effects of Human Bone Marrow-Derived Mononuclear Cells on Angiogenesis In Vitro.

Cell therapies involving the administration of bone marrow-derived mononuclear cells (BM-MNCs) for patients with chronic limb-threatening ischemia (CLTI) have shown promise; however, their overall effectiveness lacks evidence, and the exact mechanism of action remains unclear. In this study, we examined the angiogenic effects of well-controlled human bone marrow cell isolates on endothelial cells. The responses of endothelial cell proliferation, migration, tube formation, and aortic ring sprouting were analyzed in vitro, considering both the direct and paracrine effects of BM cell isolates. Furthermore, we conducted these investigations under both normoxic and hypoxic conditions to simulate the ischemic environment. Interestingly, no significant effect on the angiogenic response of human umbilical vein endothelial cells (HUVECs) following treatment with BM-MNCs was observed. This study fails to provide significant evidence for angiogenic effects from human bone marrow cell isolates on human endothelial cells. These in vitro experiments suggest that the potential benefits of BM-MNC therapy for CLTI patients may not involve endothelial cell angiogenesis.

SDF-1/CXCR4 signalling is involved in blood vessel growth and remodelling by intussusception.

The precise mechanisms of SDF-1 (CXCL12) in angiogenesis are not fully elucidated. Recently, we showed that Notch inhibition induces extensive intussusceptive angiogenesis by recruitment of mononuclear cells and it was associated with increased levels of SDF-1 and CXCR4. In the current study, we demonstrated SDF-1 expression in liver sinusoidal vessels of Notch1 knockout mice with regenerative hyperplasia by means of intussusception, but we did not detect any SDF-1 expression in wild-type mice with normal liver vessel structure. In addition, pharmacological inhibition of SDF-1/CXCR4 signalling by AMD3100 perturbs intussusceptive vascular growth and abolishes mononuclear cell recruitment in the chicken area vasculosa. In contrast, treatment with recombinant SDF-1 protein increased microvascular density by 34% through augmentation of pillar number compared to controls. The number of extravasating mononuclear cells was four times higher after SDF-1 application and two times less after blocking this pathway. Bone marrow-derived mononuclear cells (BMDC) were recruited to vessels in response to elevated expression of SDF-1 in endothelial cells. They participated in formation and stabilization of pillars. The current study is the first report to implicate SDF-1/CXCR4 signalling in intussusceptive angiogenesis and further highlights the stabilizing role of BMDC in the formation of pillars during vascular remodelling.

Long-Term Clinical Outcomes Survey of Bone Marrow-Derived Cell Therapy in Critical Limb Ischemia in Japan.

BACKGROUND: The Therapeutic Angiogenesis by Cell Transplantation (TACT) trial demonstrated the efficacy and safety of autologous bone marrow-derived mononuclear cells (BM-MNCs) in patients with critical limb ischemia (CLI). The present study aimed to assess the long-term clinical outcomes of therapeutic angiogenesis using autologous BM-MNC implantation under advanced medical treatment in Japan.Methods and Results:The study was retrospective, observational, and non-controlled. We assessed no-option CLI patients who had BM-MNC implantation performed in 10 institutes. Overall survival (OS), major amputation-free (MAF), and amputation-free survival (AFS) rates were primary endpoints of this study. The median follow-up duration was 31.7 months. The 10-year OS rate was 46.6% in patients with arteriosclerosis obliterans (ASO) (n=168), 90.5% in patients with thromboangiitis obliterans (TAO) (n=108), and 67.6% in patients with collagen disease-associated vasculitis (CDV) (n=69). The 10-year MAF rate was 70.1%, 87.9%, and 90.9%, respectively. The 10-year AFS rate was 37.8%, 80.9%, and 61.2%, respectively. Major adverse cardiovascular events occurred in 6.0% of patients with ASO, 1.9% of patients with TAO, and no patients with CDV. CONCLUSIONS: Therapeutic angiogenesis using autologous BM-MNC implantation may be feasible and safe in patients with no-option CLI, particularly those with CLI caused by TAO or CDV.

Metabolism Regulates Cellular Functions of Bone Marrow-Derived Cells used for Cardiac Therapy.

Administration of bone marrow-derived mononuclear cells (BMC) may increase cardiac function after myocardial ischemia. However, the functional capacity of BMC derived from chronic heart failure (CHF) patients is significantly impaired. As modulation of the energy metabolism allows cells to match the divergent demands of the environment, we examined the regulation of energy metabolism in BMC from patients and healthy controls (HC). The glycolytic capacity of CHF-derived BMC is reduced compared to HC, whereas BMC of metabolically activated bone marrow after acute myocardial infarction reveal increased metabolism. The correlation of metabolic pathways with the functional activity of cells indicates an influence of metabolism on cell function. Reducing glycolysis without profoundly affecting ATP-production reversibly reduces invasion as well as colony forming capacity and abolishes proliferation of CD34(+) CD38(-) lin(-) hematopoietic stem and progenitor cells (HSPC). Ex vivo inhibition of glycolysis further reduced the pro-angiogenic activity of transplanted cells in a hind limb ischemia model in vivo. In contrast, inhibition of respiration, without affecting total ATP production, leads to a compensatory increase in glycolytic capacity correlating with increased colony forming capacity. Isolated CD34(+) , CXCR4(+) , and CD14(+) cells showed higher glycolytic activity compared to their negative counterparts. Metabolic activity was profoundly modulated by the composition of media used to store or culture BMC. This study provides first evidence that metabolic alterations influence the functional activity of human HSPC and BMC independent of ATP production. Changing the balance between respiration and glycolysis might be useful to improve patient-derived cells for clinical cardiac cell therapy. Stem Cells 2016;34:2236-2248.

Clinical outcome of autologous mononuclear cells transplantation for spinal cord injury: a systematic review and meta-analysis.

BACKGROUND: Cell-based therapies can be used to treat neurological diseases and spinal cord injuries. The aim of this study was to assess the clinical outcome of bone marrow derived mononuclear cells (BM-MNCs) transplantation in patients with spinal cord injuries. METHODS: Following a systematic review to detect clinical intervention studies, a meta-analysis was done for pooling data to estimate the outcome of BM-MNCs transplantation. The percentage of the patients with improved ASIA scale from one grade to a higher grade was defined as the main outcome. By considering the study design and outcome measurement, two reviewers independently extracted the data. RESULTS: Eight relevant primary studies were found; seven qualified studies, with a combined total of 328 patients were assessed by meta-analysis, including 314 ASIA-A, 13 ASIA-B, 94 cervical, 227 thoracic and 60 acute injuries. The percentage of the patients' improvement was tested by meta-analysis through random and fixed models. The overall percentage of all patients' improved ASIA scale after a one- year follow-up (95% CIs) was 43 (0.27-0.59). CONCLUSION: Data from published trials revealed that encouraging results were achieved by autologous BMMNCs for the treatment of spinal cord injury. However, the number of clinical trials included in the systematic review was too limited to reach a definite conclusion. More qualified clinical trials with standardized methods are needed to truly justify the outcome of this therapeutic modality in SCI patients.

The Use of 99mTc-Labeled Stem Cells for Evaluation of Chronic Kidney Disease.

The labeling of stem cells with radionuclides allows in vivo monitoring of cell migration and homing. Here, we describe the labeling of mononuclear stem cells with 99mTc and show their biodistribution in preclinical models and patients with chronic kidney disease.

Transplantation of autologous bone marrow-derived mononuclear cells into cerebrospinal fluid in a canine model of spinal cord injury.

Introduction: Spinal cord injury (SCI) is associated with severe dysfunction of nervous tissue, and repair via the transplantation of bone marrow-derived mononuclear cells (BM-MNCs) into cerebrospinal fluid yields promising results. It is essential to understand the underlying mechanisms; therefore, this study aimed to evaluate the regenerative potential of autologous BM-MNC transplantation in a canine model of acute SCI. Methods: Six dogs were included in this study, and SCI was induced using an epidural balloon catheter between L2 and L3, particularly in the area of the anterior longitudinal ligament. BM-MNC transplantation was performed, and T2-weighted magnetic resonance imaging (MRI) was conducted at specific time points (i.e., immediately after inducing SCI and at 1, 2, and 4 weeks after inducing SCI); moreover, the expression of growth-associated protein 43 (GAP-43) was evaluated. Results: MRI revealed that the signal intensity reduced over time in both BM-MNC-treated and control groups. However, the BM-MNC-treated group exhibited a significantly faster reduction than the control group during the early stages of SCI induction (BM-MNC-treated group: 4.82 ± 0.135 cm [day 0], 1.71 ± 0.134 cm [1 week], 1.37 ± 0.036 cm [2 weeks], 1.21 cm [4 weeks]; control group: 4.96 ± 0.211 cm [day 0], 2.49 ± 0.570 cm [1 week], 1.56 ± 0.045 cm [2 weeks], 1.32 cm [4 weeks]). During the early stages of treatment, GAP-43 was significantly expressed at the proximal end of the injured spinal cord in the BM-MSC-treated group, whereas it was scarcely expressed in the control group. Conclusions: In SCI, transplanted BM-MNCs can activate the expression of GAP-43, which is involved in axonal elongation (an important process in spinal cord regeneration). Thus, cell therapy with BM-MNCs can provide favorable outcomes in terms of better regenerative capabilities compared with other therapies.

Current advances in the translation of vascular tissue engineering to the treatment of pediatric congenital heart disease.

Tissue-engineered vascular grafts (TEVGs) hold great promise for the improvement of outcomes in pediatric patients with congenital cardiac anomalies. Currently used synthetic grafts have several limitations, including thrombogenicity, increased risk of infection, and lack of growth potential. The first pilot clinical trial of TEVGs demonstrated the feasibility of this new technology and revealed an excellent safety profile. However, long-term follow-up from this trial revealed the primary graft-related complication to be stenosis, affecting 16 percent of grafts within 7 years post-implantation. In order to determine the mechanism behind TEVG stenosis and ultimately to create improved second generation TEVGs, our group has returned to the bench to study vascular neotissue formation in a variety of large and small animal models. The purpose of this report is to review the recent advances in the understanding of neotissue formation and vascular tissue engineering.

Size matters: Effect of granule size of the bone graft substitute (Herafill®) on bone healing using Masquelet's induced membrane in a critical size defect model in the rat's femur.

The Masquelet technique for the treatment of large bone defects is a two-stage procedure based on an induced membrane. The size of a scaffold is reported to be a critical factor for bone healing response. We therefore aimed to investigate the influence of the granule size of a bone graft substitute on bone marrow derived mononuclear cells (BMC) supported bone healing in combination with the induced membrane. We compared three different sizes of Herafill® granules (Heraeus Medical GmbH, Wehrheim) with or without BMC in vivo in a rat femoral critical size defect. A 10 mm defect was made in 126 rats and a membrane induced by a PMMA-spacer. After 3 weeks, the spacer was taken out and membrane filled with different granule sizes. After 8 weeks femurs were taken for radiological, biomechanical, histological, and immunohistochemical analysis. Further, whole blood of the rat was incubated with granules and expression of 29 peptide mediators was assessed. Smallest granules showed significantly improved bone healing compared to larger granules, which however did not lead to an increased biomechanical stability in the defect zone. Small granules lead to an increased accumulation of macrophages in situ which could be assigned to the inflammatory subtype M1 by majority. Increased release of chemotactic respectively proangiogenic active factors in vitro compared to syngenic bone and beta-TCP was observed. Granule size of the bone graft substitute Herafill® has significant impact on bone healing of a critical size defect in combination with Masquelet's technique in terms of bone formation and inflammatory potential.

Therapeutic Angiogenesis Using Bone Marrow-Derived Mononuclear Cell Implantation for Patients With Critical Limb-Threatening Ischemia Caused by Thromboangiitis Obliterans　- Study Protocol for a Multicenter Prospective Interventional Trial.

Background: Patients with thromboangiitis obliterans (TAO) can develop critical limb-threatening ischemia (CLTI) and require limb amputation. Smoking cessation and exercise therapy are recommended as standard treatments, and revascularization by bypass surgery or endovascular therapy (EVT) is required for patients with CLTI. However, there are many cases in which revascularization is difficult because of vascular characteristics, and the patency rate after revascularization remains unsatisfactory. Therapeutic angiogenesis using bone marrow-derived mononuclear cell (BM-MNC) implantation is used clinically, with many trials demonstrating long-term efficacy and safety of the technique in patients with CLTI, especially that caused by TAO. To expand the use of BM-MNCs implantation in clinical practice, further evidence is required in patients with CLTI caused by TAO. Methods and Results: This trial is a multicenter, prospective, non-randomized interventional trial of an Advanced Medicine B treatment approach. We aim to enroll 25 patients aged 20-80 years with Fontaine classification Stage III or IV, who will undergo BM-MNC implantation. The primary endpoint is the improvement in skin perfusion pressure of the target limb 180 days after BM-MNC implantation, whereas secondary endpoints are improvements in rest pain or ulcer size. We will also investigate rates of major or minor amputation, survival, and adverse events during follow-up. Conclusions: BM-MNC implantation is expected to be an efficacious and feasible treatment for patients with CLTI caused by TAO.

Intrathecal transplantation of autologous bone marrow mononuclear cells in patients with sub-acute and chronic spinal cord injury: An open-label study.

OBJECTIVE: The objective of the study was to analyze the effect of intrathecal transplantation of autologous bone marrow-derived mononuclear cells (BMMNCs) in functional recovery of spinal cord injury (SCI) patients along with neurorehabilitation and to evaluate various factors influencing the outcome of cellular therapy. METHODS: We conducted an open-label study including 180 sub-acute and chronic SCI patients. All patients received intrathecal autologous BMMNCs along with neurorehabilitation. 80-100 mL of bone marrow was aspirated and BMMNCs were obtained using density gradient separation. An average of 1.06 × 108 cells with 97% viability was administered through lumbar puncture immediately. After transplantation, all patients underwent neurorehabilitation. Patients were followed up after an average of 9 ± 7 months. They were assessed for functional symptomatic changes and the outcome measures used were functional independence measure (FIM) and walking index for SCI (WISCI). RESULTS: Patients showed symptomatic improvement in sitting/standing balance, bed mobility, trunk stability, upper limb function, mobility, sensation, bowel/bladder functions, and activities of daily living with no serious adverse events. Scores on FIM and WISCI showed statistically significant improvement. On subgroup analysis, it was found that early intervention and more than one dose of BMMNCs demonstrate a better functional outcome. Younger patients demonstrated better improvements in functional independence. Both cervical and dorsolumbar levels of injury show significant improvements in motor and sensory deficits. CONCLUSIONS: Autologous BMMNC transplantation with neurorehabilitation is safe, effective, enhances functional recovery, and improves the quality of life of SCI patients in sub-acute and chronic stage.

Establishment of optimal exercise therapy using near-infrared spectroscopy monitoring of tissue muscle oxygenation after therapeutic angiogenesis for patients with critical limb ischemia: A multicenter, randomized, controlled trial.

Critical limb ischemia (CLI) is a potentially life-threatening condition that involves severely reduced blood flow to the peripheral arteries due to arteriosclerosis obliterans (ASO) of the limbs or a similar condition. CLI patients must undergo revascularization to avoid amputation of the lower limbs and improve their survival prognosis. However, the outcomes of conventional surgical revascularization or endovascular therapy are inadequate; therefore, establishing further effective treatment methods is an urgent task. We perform therapeutic angiogenesis using autologous bone marrow-derived mononuclear cells in clinical practice and demonstrated its safety and efficacy for CLI patients for whom conventional treatments failed or are not indicated. Exercise therapies must be devised for CLI patients who have undergone therapeutic angiogenesis to save their limbs and improve survival. Because evidence regarding the efficacy and safety of exercise therapy for CLI patients is lacking, we plan to perform a prospective trial of the efficacy and safety of optimal exercise therapy following therapeutic angiogenesis for CLI patients.The trial will enroll 30 patients between 20 and 79 years with Rutherford category 4 or 5 CLI caused by ASO who will undergo therapeutic angiogenesis. Participants will be randomly allocated to receive either optimal exercise therapy or fixed exercise therapy. Those receiving optimal exercise therapy will undergo tissue muscle oxygen saturation monitoring using near-infrared spectroscopy while performing exercises and will be prescribed optimal exercise therapy. The optimal amount of exercise will be determined on day 8, 31, 61, 91 and 181 after therapeutic angiogenesis. ETHICS AND DISSEMINATION: This protocol was approved by the Institutional Review Boards of Kyoto Prefectural University of Medicine. In accordance with the Helsinki Declaration, written informed consent has been obtained from all participants prior to enrollment. The results of this trial will be disseminated by publication in a peer-reviewed journal. TRIAL REGISTRATION: This trial is registered at http://www.umin.ac.jp/ctr/index.htm (identifier: UMIN000035288).

The effects of a functionally-graded scaffold and bone marrow-derived mononuclear cells on steroid-induced femoral head osteonecrosis.

Osteonecrosis of the femoral head (ONFH) is a debilitating disease that may progress to femoral head collapse and subsequently, degenerative arthritis. Although injection of bone marrow-derived mononuclear cells (BMMCs) is often performed with core decompression (CD) in the early stage of ONFH, these treatments are not always effective in prevention of disease progression and femoral head collapse. We previously described a novel 3D printed, customized functionally-graded scaffold (FGS) that improved bone growth in the femoral head after CD in a normal healthy rabbit, by providing structural and mechanical guidance. The present study demonstrates similar results of the FGS in a rabbit steroid-induced osteonecrosis model. Furthermore, the injection of BMMCs into the CD decreased the osteonecrotic area in the femoral head. Thus, the combination of FGS and BMMC provides a new therapy modality that may improve the outcome of CD for early stage of ONFH by providing both enhanced biological and biomechanical cues to promote bone regeneration in the osteonecrotic area.

Bone Marrow-Derived Mononuclear Cell Therapy in Papain-Induced Experimental Pulmonary Emphysema.

Murine papain-induced emphysema is a model that reproduces many of the features found in patients. Bone marrow-derived mononuclear cells (BMMC) have already been used to repair the alveolar epithelium in respiratory diseases, but not in the papain model. Thus, we hypothesized that BMMC could prevent the pathophysiological processes in papain-induced experimental emphysema. Female BALB/c mice received intratracheal instillation of 50 µL of saline (S groups) or papain (P groups, 10 IU/50 µl of saline) on days 1 and 7 of the experimental protocol. On the 14th day, 2 × 106 BMMC of male BALB/c mice (SC21 and PC21) or saline (SS21 and PS21) were injected by the jugular vein. Analyses were done on days 14 (S14 and P14) and 21 (SS21, PS21, SC21, and PC21) of the protocol. qPCR evaluated the presence of the Y chromosome in the lungs of BMMC recipient animals. Functional residual capacity (FRC), alveolar diameter, cellularity, elastic fiber content, concentrations of TNF-α, IL-1ß, IL-6, MIP-2, KC, IFN-γ, apoptosis, mRNA expression of the dual oxidase (DUOX1 and DUOX2), production of H2O2 and DUOX activity were evaluated in lung tissue. We did not detect the Y chromosome in recipients' lungs. FRC, alveolar diameter, polymorphonuclear cells (PMN) and levels of KC, MIP-2, and IFN-γ increased in P14 and PS21 groups; the changes in the latter were reverted by BMMC. TNF-α, IL-1ß e IL-6 were similar in all groups. The amount of elastic fibers was smaller in P14 and PS21 than in other groups, and BMMC did not increase it in PC21 mice. PS21 animals showed increased DUOX activity and mRNA expression for DUOX1 and 2. Cell therapy reverted the activity of DUOX and mRNA expression of DUOX1. BMMC reduced mRNA expression of DUOX2. Apoptosis index was elevated in PS21 mice, which was reduced by cell therapy in PC21. Static compliance, viscoelastic component of elastance and pressure to overcome viscoelasticity were increased in P14 and PS21 groups. These changes and the high resistive pressure found on day 21 were reverted by BMMC. In conclusion, BMMC showed potent anti-inflammatory, antiapoptotic, antioxidant, and restorative roles in papain-triggered pulmonary emphysema.

Cathelicidin Related Antimicrobial Peptide (CRAMP) Enhances Bone Marrow Cell Retention and Attenuates Cardiac Dysfunction in a Mouse Model of Myocardial Infarction.

BACKGROUND: Acute myocardial infarction (MI) and the ensuing ischemic heart disease are approaching epidemic state. Unfortunately, no definitive therapies are available and human regenerative therapies have conflicting results. Limited stem cell retention following intracoronary administration has reduced the clinical efficacy of this novel therapy. Cathelicidin related antimicrobial peptides (CRAMPs) enhance chemotactic responsiveness of BMSPCs to low SDF-1 gradients, suggesting a potential role in BMSPCs engraftment. Here, we assessed the therapeutic efficacy of CRAMPs in the context of BMSPCs recruitment and retention via intracardiac delivery of CRAMP-treated BMSPCs or CRAMP-releasing hydrogels (HG) post-AMI. METHODS: For cell transplantation experiments, mice were randomized into 3 groups: MI followed by injection of PBS, BMMNCs alone, and BMMNCs pre-incubated with CRAMP. During the in vivo HG studies, BM GFP chimera mice were randomized into 4 groups: MI followed by injection of HG alone, HG + SDF-1, HG + CRAMP, HG + SDF-1 + CRAMP. Changes in cardiac function at 5 weeks after MI were assessed using echocardiography. Angiogenesis was assessed using isolectin staining for capillary density. RESULTS: Mice treated with BMMNCs pre-incubated with CRAMP had smaller scars, enhanced cardiac recovery and less adverse remodeling. Histologically, this group had higher capillary density. Similarly, sustained CRAMP release from hydrogels enhanced the therapeutic effect of SDF-1, leading to enhanced functional recovery, smaller scar size and higher capillary density. CONCLUSION: Cathelicidins enhance BMMNC retention and recruitment after intramyocardial administration post-AMI resulting in improvements in heart physiology and recovery. Therapies employing these strategies may represent an attractive method for improving outcomes of regenerative therapies in human studies.

Tissue engineered vascular grafts for pediatric cardiac surgery.

New technologies and science have contributed to improved surgical outcomes in patients with congenital cardiovascular diseases. However, current materials display shortcomings, such as risk of infection and lack of growth capacity when applied to the pediatric patient population. Tissue engineering has the potential to address these limitations as the ideal tissue engineered vascular graft (TEVG) would be durable, biocompatible, nonthrombogenic, and ultimately remodel into native tissue. The traditional TEVG paradigm consists of a scaffold, cell source, and the integration of the scaffold and cells via seeding. The subsequent remodeling process is driven by cellular adhesion and proliferation, as well as, biochemical and mechanical signaling. Clinical trials have displayed encouraging results, but graft stenosis is observed as a frequent complication. Recent investigations have suggested that a host's immune response plays a vital role in neotissue formation. Current and future studies will focus on modulating host immunity as a means of reducing the incidence of stenosis.

Autologous bone marrow-derived mononuclear cells transplantation in type 2 diabetes mellitus: effect on ß-cell function and insulin sensitivity.

BACKGROUND: Insulin resistance and insulin deficiency are the cardinal defects in the pathogenesis of type 2 diabetes mellitus (T2DM). Despite the plethora of anti-diabetic medications, drugs specifically targeting the ß-cells are still desired. Stem cell therapy has emerged as a novel therapeutics strategy to target ß-cells; however, their mechanism of action has not been well defined. This study aims to examine the efficacy and safety of autologous bone marrow-derived mononuclear cells (ABM-MNCs) transplantation in T2DM, and explores the mechanistic insights into stem cells action through metabolic studies. METHODS: Seven T2DM patients with the duration of disease ≥5 years, receiving triple oral anti-diabetic drugs along with insulin (≥0.4 IU per kg per day) and HbA1c ≤ 7.5% (≤58.0 mmol/mol) were enrolled for ABM-MNCs administration through a targeted approach. The primary end-point was a reduction in insulin requirement by ≥50% from baseline, while maintaining HbA1c < 7.0% (<53.0 mmol/mol) with improvement in insulin secretion, and/or insulin sensitivity after ABM-MNCs transplantation. RESULTS: Six out of 7 (90%) patients achieved the primary end-point. At 6 months, there was a significant reduction in insulin requirement by 51% as compared to baseline (p < 0.003). This was accompanied by a significant increase in the 2nd phase C-peptide response during hyperglycemic clamp (p = 0.018), whereas there were no significant alterations in insulin sensitivity and glucose disposal rate during hyperinsulinemic-euglycemic clamp relative to the baseline. Other measures of ß-cell indices like HOMA-ß, and stimulated C-peptide response to glucagon and mixed meal tolerance test were non-contributory. CONCLUSION: ABM-MNCs transplantation results in significant reduction in insulin doses and improvement in C-peptide response in patients with T2DM. Metabolic studies may be more useful than conventional indices to predict ß-cell function in patients with advanced duration of T2DM. Trial registration-Clinicaltrials.gov NCT01759823.