Large Number Of Mesenchymal Stem Cells Research Articles

Mesenchymal Stem Cell Implantation in Knee Osteoarthritis: Midterm Outcomes and Survival Analysis in 467 Patients.

Background:A cell-based tissue engineering approach that uses mesenchymal stem cells (MSCs) has addressed the issue of articular cartilage repair in knees with osteoarthritis (OA).Purpose:To evaluate the midterm outcomes, analyze the survival rates, and identify the factors affecting the survival rate of MSC implantation to treat knee OA.Study Design:Case series; Level of evidence, 4.Methods:We retrospectively evaluated 467 patients (483 knees) who underwent MSC implantation on a fibrin glue scaffold for knee OA with a minimum 5-year follow-up. Clinical outcomes were determined based on the International Knee Documentation Committee (IKDC) and Tegner activity scale results measured preoperatively and during follow-up. Standard radiographs were evaluated using Kellgren-Lawrence grading. Statistical analyses were performed to determine the survival rate and the effect of different factors on the clinical outcomes.Results:The mean IKDC scores (baseline, 39.2 ± 7.2; 1 year, 66.6 ± 9.6; 3 years, 67.2 ± 9.9; 5 years, 66.1 ± 9.7; 9 years, 62.8 ± 8.5) and Tegner scores (baseline, 2.3 ± 1.0; 1 year, 3.4 ± 0.9; 3 years, 3.5 ± 0.9; 5 years, 3.4 ± 0.9; 9 years, 3.2 ± 0.9) were significantly improved until 3 years postoperatively and gradually decreased from 3- to 9-year follow-up (P < .05 for all, except for Tegner score at 5 years vs 1 year [P = .237]). Gradual deterioration of radiological outcomes according to the Kellgren-Lawrence grade was found during follow-up. Survival rates based on either a decrease in IKDC or an advancement of radiographic OA with Kellgren-Lawrence scores were 99.8%, 94.5%, and 74.5% at 5, 7, and 9 years, respectively. Based on multivariate analyses, older age and the presence of bipolar kissing lesion were associated with significantly worse outcomes (P = .002 and .013, respectively), and a larger number of MSCs was associated with significantly better outcomes (P < .001) after MSC implantation.Conclusion:MSC implantation provided encouraging outcomes with acceptable duration of symptom relief at midterm follow-up in patients with early knee OA. Patient age, presence of bipolar kissing lesion, and number of MSCs were independent factors associated with failure of MSC implantation.

Mesenchymal stem cells promote chemoresistance by activating autophagy in intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a type of cancer that is difficult to cure; chemoresistance of cholangiocarcinoma cells affect the prognosis of patients who cannot be treated with surgery. The mechanism underlying this chemoresistance remains unknown. Mesenchymal stem cells (MSCs) are known to be important components of the tumor microenvironment. In the present study, a large number of MSCs were observed to infiltrate the tumor sites of ICC; thus, MSCs were isolated from ICC tumor tissues. It was revealed that herpesvirus entry mediator (HVEM) was overexpressed in ICC-MSCs. The present study then investigated the role of HVEM-overexpressing MSCs in the chemoresistance of cholangiocarcinoma cells. It was demonstrated that HVEM-overexpressing MSCs could support cell survival of chemotherapeutic cholangiocarcinoma cells and inhibited their apoptosis. Further investigations revealed that HVEM-overexpressing MSCs could secrete IL-6 and also activated AMPK/mTOR-dependent autophagy of cholangiocarcinoma cells. Thus, it was concluded that ICC-MSC-induced autophagy is the primary cause of chemoresistance in ICC.

Abstract 473: IL-7 Increases Fusion of Rat Bone Marrow Mesenchymal Stem Cells With Cardiomyocytes In Vitro and Improve Cardiac Function In Vivo

Heart diseases are one of the main causes of morbidity and mortality all over the world particularly in the developing countries. Cardiac endogenous repair mechanisms have limited potential to regenerate myocardium following myocardial infarction. Mesenchymal stem cells (MSCs) hold significant promise as potential therapeutic candidates following cardiac tissue damage. Engrafted stem cells consistently experience programmed cell death and a large number of MSCs die in the ischemic area of the heart after transplantation. To ensure the survival of engrafted stem cells, it is beneficial to precondition these stem cells prior to their transplantation into the injured heart. In this study, we used interleukin-7 (IL-7), a hematopoietic growth factor having significant role in the cell survival, to transfect MSCs and observed its effect on cell-cell fusion in vitro and cardiac function in vivo . Cell fusion analyzed by co-culturing IL-7 transfected MSCs with neonatal rat cardiomyocytes (CMs) showed significantly (p&lt;0.01) higher number of fused cells as compared to that in case of normal MSCs. Transplantation of IL-7 transfected MSCs into the rat model of myocardial infarction showed improvement in the cardiac function by significantly increasing the ejection fraction (EF) and fractional shortening (FS) (p&lt;0.01), and significantly decreasing the diastolic and systolic left ventricular internal diameters (LVIDd and LVIDs) (p&lt;0.001) and end systolic and diastolic volumes (ESV and EDV) (p&lt;0.01 and p&lt;0.001 respectively) as assessed by echocardiography after 4 weeks. IL-7 is able to enhance the fusogenic properties of MSCs and improve cardiac function. This Improvement in cardiac function may be attributed to the supportive action of IL-7 on cell proliferation and cell survival contributing to the regeneration of damaged myocardium.

Enhanced Cell Growth of Adipocyte-Derived Mesenchymal Stem Cells Using Chemically-Defined Serum-Free Media.

The multipotency and anti-inflammatory effects of mesenchymal stem cells (MSCs) make them attractive for cell therapy in regenerative medicine. A large number of MSCs is required for efficient therapy owing to the low homing efficiency of MSCs to target sites. Furthermore, owing to limitations in obtaining sufficient amounts of MSCs, in vitro expansion of MSCs that preserves their differentiation and proliferative potential is essential. The animal factor included in culture media also limits clinical application. In this study, adipose-derived MSCs showed a significantly higher proliferation rate in STK2, a chemically-defined medium, than in DMEM/FBS. The expression of MSC surface markers was increased in the culture using STK2 compared to that using DMEM/FBS. Tri-lineage differentiation analyses showed that MSCs cultured in STK2 were superior to those cultured in DMEM/FBS. In addition, MSCs cultured in STK2 showed a reduced senescence rate, small and homogenous cell size, and were more genetically stable compared to those cultured in DMEM/FBS. Furthermore, secretome analysis showed that the expression of factors related to proliferation/migration, anti-inflammation, and differentiation were increased in STK2 culture medium compared to DMEM/FBS. Taken together, these results suggest that culture using STK2 medium offers many advantages through which it is possible to obtain safer, superior, and larger numbers of MSCs.

Preparation of spider silk protein bilayer small-diameter vascular scaffold and its biocompatibility and mechanism research

In this study, recombinant spider silk protein (pNSR16) was blended with polycaprolactone (PCL), gelatin (Gt), and chitosan (CS) to prepare (pNSR16/PCL/CS)/(pNSR16/PCL/Gt) bilayer small-diameter vascular scaffold through electrospinning in order to imitate multilayer structure of natural vessel. The surface morphology and properties were characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, water contact angle, and mechanical tensile testing. The blood compatibility of scaffold was evaluated by recalcification coagulation time. Mesenchymal stem cells (MSC) were separated from SD rat bone marrow, and MTT assay was used to evaluate cell growth. Cell compatibility and interaction mechanism between bilayered vascular scaffold and MSC were studied. Subcutaneous implantation was performed to evaluate in vivo inflammatory reaction and degradation behavior. The preliminary results indicated that the scaffold fibers were relatively uniform, and hydrophilic performance and blood compatibility were good. The values of the tensile strength and elongation at break of vascular scaffold were 39 ± 2 MPa and 118 ± 4%, respectively. MSC morphology was uniform and spindle, whose steady growth period was reached on the fifth day. MSC adhered well and proliferated vigorously on vascular scaffold surface. A large number of MSC could migrate into (pNSR16/PCL/CS)/(pNSR16/PCL/Gt) scaffold interior. pNSR16 and Notch receptor had interaction function at protein level. The preparation of (pNSR16/PCL/CS)/(pNSR16/PCL/Gt) laid foundation for the construction of tissue engineering vessel.

Yield optimisation and molecular characterisation of uncultured CD271+ mesenchymal stem cells in the reamer irrigator aspirator waste bag

Bone reconstruction requires the use of autografts from patients' iliac crest (IC); for large-volume defects bone void fillers and autologous mesenchymal stem cells (MSCs) are often added. The Reamer/Irrigator/Aspirator (RIA) device provides the means of harvesting large amounts of autograft and additionally yields a waste bag containing MSCs, which is currently discarded. The aim of this study was to enumerate and characterise native MSCs from RIA waste bag and compare them to 'gold-standard' donor-matched MSCs from IC bone marrow (BM). IC-BM from age matched trauma patients was used as control. In RIA waste bags the median MSC yield established using a colony-forming fibroblast assay was 314333 (range 5 x 104-1.4 x 106), equivalent to approximately one litre of IC-BM aspirate. CD271+ cells were present at high levels in RIA waste bags, had MSC surface phenotype (CD90+CD73+CD105+CD34>sup>-CD61-CD19-CD31-CD33-) and expressed genes associated with multipotentiality, osteogenesis, adipogenesis and angiogenic support. RIA- CD271+ MSCs were transcriptionally similar to donor-matched IC-CD271+ MSCs (76 % transcripts); with the majority of bone-related and Wnt pathway molecules being expressed at comparable levels. Lower-level expression of MCAM/CD146 and 5/13 hypoxia-related molecules was found in RIA-CD271+ MSCs, potentially reflecting their native residence in a more hypoxic environment of the endosteum and bone cortex. These data suggest that long bones contain very large numbers of MSCs, transcriptionally-similar to IC-BM MSCs; they can be procured by reaming using the RIA device and used, following concentration, as autologous and potentially allogeneic bone repair therapy.

Mesenchymal stem cell therapy in HIV-infected HAART-treated nonimmune responders restores immune competence

Mesenchymal stem cell therapy in HIV-infected HAART-treated nonimmune responders restores immune competence

Manufacturing and banking of mesenchymal stem cells

Introduction: Mesenchymal stem cells (MSC) and MSC-like cells hold great promise and offer many advantages for developing effective cellular therapeutics. Current trends indicate that the clinical application of MSC will continue to increase markedly. For clinical applications, large numbers of MSC are usually required, ideally in an off-the-shelf format, thus requiring extensive MSC expansion ex vivo and subsequent cryopreservation and banking.Areas covered: To exploit the full potential of MSC for cell-based therapies requires overcoming significant cell-manufacturing, banking and regulatory challenges. The current review will focus on the identification of optimal cell source for MSC, the techniques for production scale-up, cryopreservation and banking and the regulatory challenges involved.Expert opinion: There has been considerable success manufacturing and cryopreserving MSC at laboratory scale. Surprisingly little attention, however, has been given to translate these technologies to an industrial scale. The development of cost-effective advanced technologies for producing and cryopreserving commercial-scale MSC is important for successful clinical cell therapy.

The use of the reamer-irrigator-aspirator to harvest mesenchymal stem cells

The scarcity of mesenchymal stem cells (MSCs) in iliac crest bone marrow aspirate (ICBMA), and the expense and time in culturing cells, has led to the search for alternative harvest sites. The reamer-irrigation-aspirator (RIA) provides continuous irrigation and suction during reaming of long bones. The aspirated contents pass via a filter, trapping bony fragments, before moving into a 'waste' bag from which MSCs have been previously isolated. We examined the liquid and solid phases, performed a novel digestion of the solid phase, and made a comparative assessment in terms of number, phenotype and differentiation capacity with matched ICBMA. The solid fraction from the filtrate was digested for 60 minutes at 37° C with collagenase. Enumeration was performed via the colony-forming unit fibroblast (CFU-F) assay. Passage (P2) cells were differentiated towards osteogenic, adipogenic and chondrogenic lineages, and their phenotypes assessed using flow cytometry (CD33, CD34, CD45, CD73, CD90, and CD105). MSCs from the RIA phases were able to differentiate at least as well as those from ICBMA, and all fractions had phenotypes consistent with other established sources. The median number of colonies for the three groups was: ICBMA = 8.5 (2 to 86), RIA-liquid = 19.5 (4 to 90), RIA-solid = 109 (67 to 200) per 200 μl. The mean total yield of cells for the three groups was: ICBMA = 920 (0 to 4275), RIA-liquid = 114,983 (16,500 to 477,750), RIA-solid = 12,785 (7210 to 28 475). The RIA filtrate contains large numbers of MSCs that could potentially be extracted without enzymatic digestion and used for bone repair without prior cell expansion.

Adipose Tissue-Derived Mesenchymal Stem Cells Facilitate Hematopoiesis in Vitro and in Vivo: Advantages Over Bone Marrow-Derived Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) have emerged as a new therapeutic modality for reconstituting the hematopoietic microenvironment by improving engraftment in stem cell transplantation. However, the availability of conventional bone marrow (BM)-derived MSCs (BMSCs) is limited. Recent studies showed that a large number of MSCs can be easily isolated from fat tissue (adipose tissue-derived MSCs [ADSCs]). In this study, we extensively evaluated the hematopoiesis-supporting properties of ADSCs, which are largely unknown. In vitro coculture and progenitor assays showed that ADSCs generated significantly more granulocytes and progenitor cells from human hematopoietic stem cells (HSCs) than BMSCs. We found that ADSCs express the chemokine CXCL12, a critical regulator of hematopoiesis, at levels that are three fold higher than those with BMSCs. The addition of a CXCL12 receptor antagonist resulted in a lower yield of granulocytes from ADSC layers, whereas the addition of recombinant CXCL12 to BMSC cocultures promoted the growth of granulocytes. In vivo cell homing assays showed that ADSCs facilitated the homing of mouse HSCs to the BM better than BMSCs. ADSCs injected into the BM cavity of fatally irradiated mice reconstituted hematopoiesis more promptly than BMSCs and subsequently rescued mice that had received a low number of HSCs. Secondary transplantation experiments showed that ADSCs exerted favorable effects on long-term HSCs. These results suggest that ADSCs can be a promising therapeutic alternative to BMSCs.

HUCB-MSCs transplants promote neurological functional recovery after traumatic brain injury

Objective To locally inject human umbilical cord blood (HUCB) mesenchymal stem cells (MSCs) to rat traumatic brain injury (TBI) model to investigate expression of neural markers and neurological functional improvement. Methods HUCB-MSCs were labeled by bis-benzimide for over 24 hours and stereotactically transplanted into the brain of the rats. All rats were divided into four groups, ie, sham injury group, TBI group, control (TBI + PBS) group and treatment (TBI + MSCs) group, Im-munohistochemical methods and immanofluorescence staining were used to observe the survival, migration and differentiation of the transplanted cells. The neurological functional improvement was evaluated by u-sing the neurological severity score (NSS). Results There existed a large number of MSCs survived in local region of the brain that received transplants, when some MSCs differentiated into neurons or astro-cytes and expressed the neurocyte markers including NSE and GFAP around the grafted site. Treatment group had significantly improved scores compared with sham injury group, TBI group and control group. Conclusions HUCB-MSCs transplantation can potentially improve neurological functional after TBI and may be a good alternative to bone marrow cells for stem cell transplantation or cell therapy. Key words: Brain injuries; Umbilical cord blood; Mesenchymal stem cells; Transplanta-tion

Conversion of red bone marrow into yellow – Cause and mechanisms

Marrow cavities in all the bones of newborn mammals contain active hematopoietic tissue, known as red bone marrow. From the early postnatal period onwards, the hematopoietic tissue, mainly in the bones of the extremities, is gradually replaced by non-hematopoietic mesenchymal cells that accumulate lipid drops, known as yellow or fatty bone marrow. For its maintenance, hematopoietic tissue depends on the support of special mesenchymal cells in the bone marrow cavity, known as hematopoietic microenvironment. Both bone-forming cells and hematopoietic microenvironment cells have common progenitors - mesenchymal stem cells (MSCs). We hypothesize that: (1) Hematopoietic microenvironment cells advance along a three stage differentiation/maturation pathway. In the first stage, they support hematopoiesis and contain no fat. In the second stage, cells accumulate fat and no longer support steady state hematopoiesis; however, under conditions of increased hematopoietic requirement, they lose fat and regain their ability to support hematopoiesis. In the last stage, hematopoietic microenvironment cells retain the appearance of yellow bone marrow and do not support hematopoiesis regardless of the state of hematopoietic requirement.(2) Since MSCs are bound to endosteal and trabecular surfaces, in tubular bones their number is relatively small, compared to cancellous bones that have much larger areas of internal bone surface. MSCs are exposed to proliferative and differentiative pressures, leading to gradual reduction of their number. Consequently, the MSC population in tubular bones becomes exhausted rather early, and the post-maturation compartment of mesenchymal cells finally consists of unipotential bone precursors maintaining bone tissue and hematopoietic microenvironment advancing towards the last (fatty) stage of differentiation. In contrast, in cancellous bones the relatively large number of MSCs does not suffer exhaustion and continues to provide newly differentiated hematopoietic microenvironment, thus maintaining red bone marrow throughout the organism's life.(3) Osteogenic and hematopoietic microenvironment differentiation pathways compete with each other for their common precursor. During the organism's growth period osteogenic stimuli prevail, while in the post-maturation period, MSC differentiation into hematopoietic microenvironment increases at the expense of differentiation into bone. This results in the reduction of bone volume and expansion of marrow cavities in hematopoietically active cancellous bones, but not in tubular bones already depleted of MSCs and not participating in hematopoiesis. Experimental and clinical data supporting these hypotheses are discussed.