mesenchymal stem cells

When Total Hip Arthroplasty (THA) is required in a patient with developmental dysplasia of the hip (DDH), bone deficiency in the acetabular roof often remains a problem. The iliac crest (IC) has long been the preferred source of autograft material, but graft harvest is associated with frequent complications and pain. Autologous bone graft can also be obtained from the femoral head (FH) for reconstruction of the acetabulum in hip arthroplasty. However, in certain challenging clinical scenarios, incorporation of the femoral head autograft appears less successful than the iliac crest autograft. The difference in potential for proliferation and osteoblastic differentiation between the two sites has still not been evaluated; therefore, it is not known how to compensate for this difference when it is present. We designed this study to evaluate the number of mesenchymal stem cells (MSCs) in both the iliac crest and femoral head of the same patient. We also determined the best operating room procedure for loading the femoral head with MSCs to achieve equivalent numbers of MSCs as in the IC. Twenty patients (8 men and 16 women) undergoing THA for DDH were enrolled in the study. The mean age was 55.5 years (range 41–65 years). Bone marrow aspirates were obtained from three depths within the femoral head and the aspirates were quantified relative to matched iliac crest aspirates that were obtained from the same patient at the same time. The cell count, progenitor cell concentration (cells/mL marrow), and progenitor cell prevalence (progenitor cells/million nucleated cells) were calculated. Aspirates of FH marrow demonstrated less concentrations of mononuclear cells compared with matched controls from the iliac crest. Progenitor cell concentrations were consistently lower in FH aspirates compared to matched controls from the iliac crest (p = 0.05). The concentration of osteogenic progenitor cells was, on average, 40% lower in the FH aspirates than in the paired iliac crest samples (p = 0.05). However, with bone marrow aspirated from the iliac crest, we were able to load the femoral head autograft with sufficient MSCs to obtain the same number as present in an iliac crest. With concentrated bone marrow from the IC, supercharging the femoral autograft with MSCs to numbers above that present in the IC was possible in the operating room, and the number of MSCs supercharged in the femoral head was predictable. Based on these findings we suggest that FH graft supercharged with BM-MSCs from the IC is comparable to IC graft for osseous graft supplementation especially in THA for patients with DDH.

Mesenchymal stem cells (MSCs) are multipotent adult stem cells that can self-renew and differentiate into a variety of cell types including chondrocytes, osteocytes and adipocytes. MSCs reside in bone marrow, adipose tissues, cord blood, peripheral blood, placenta, Wharton’s jelly, fetal liver and lung among others. MSCs represent one of the most promising stem cells for regenerative medicine due to their multipotency, immunoprivileged properties and easy expansion in vitro. So far, MSCs are already in various phases of clinical application [1-4].

Background: Mesenchymal stem cell (MSC) effects can shift immune responses toward anti-inflammatory and tolerogenic phenotypes, potentially helping patients with bronchiolitis obliterans syndrome (BOS). Methods: We evaluated the effect of infusing allogeneic MSC intravenously in 9 patients with moderate BOS refractory to standard therapy who were not candidates for retransplant, dividing them into 3 dosing groups: Group 1, 1×106 MSC/kg (n=3); Group 2, 2×106 MSC/kg (n=3); and Group 3, 4×106 MSC/kg (n=3). We recorded pulmonary function tests, laboratory variables, and serum biomarkers pre- and post-MSC infusion. Results: These patients had significant decline in forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) over 1 year pre-MSC infusion (mean ± SD) FVC, 3.11±0.98 L, and FEV1 1.99+0.64 L versus FVC 2.58±1.03 and FEV1 1.61±0.52 just before infusion (P<0.05); representing a mean loss of 530 mL in FVC and 374 mL in FEV1 over 12 months. One year post-MSC infusion, mean FVC and FEV1 increased to 2.66±1.01 L and 1.63±0.55 L, respectively (changes no longer significant compared to before MSC infusion). Patients in Group 1 showed elevation of tolerance-inducing T regulatory cells and increased levels of epidermal growth factor. Tolerance-inducing Th-2 cytokines increased in Groups 1 and 2. These changes were not significantly different in these small sub-groups. Conclusion: MSC infusion appears to slow down or reverse the progressive decline in lung function in some patients with moderate BOS, possibly by inducing anti-inflammatory effects and promoting cell proliferation and angiogenesis.

Mesenchymal stem cells (MSCs) conditioned medium (CM) has a promising prospect towards skin regeneration. Therefore, human dental pulp and adipose stem cells (DPSCs and ADSCs) were isolated, propagated and evaluated for their stemness and genetic stability over time in culture before making CM. We aimed to characterize the applicability of lyophilized ADSCs and DPSCs derived CM (AD-CM and DP-CM) at 5 mg, 10 mg and 20 mg for wound healing process. The ability of wound closure was assessed by direct human dermal fibroblast cell scratch assay, treated with variable concentrations of AD-CM and DP-CM in vitro. Additionally, we also assessed the expression of different cytokines and growth factors secreted from ADSCs and DPSCs in the CM relevant to the wound healing by cytokine array analysis. Our data demonstrates a significant effect of both the AD-CM and DP-CM in wound healing within 24 hrs compared to that in control.

Natural killer cells represent the first line of defense against infections and tumors and can be derived from various sources including: bone marrow, peripheral blood, specific types of human stem cells, and certain cell lines. The functions of natural killer cells are influenced by: several cytokines, activating and inhibitory receptors, as well as other immune cells such as dendritic cells and mesenchymal stem cells. Natural killer cells are attractive candidates for adoptive cellular therapy in patients with hematologic malignancies and solid tumors in addition to recipients of various forms of hematopoietic stem cell transplantation as they enhance antitumor effects without causing graft versus host disease. Several clinical trials have shown safety and efficacy of natural killer cell products obtained from autologous as well as allogeneic sources and used in conjunction with cytotoxic chemotherapy, monoclonal antibodies and novel agents. The following review, which includes extensive literature review on several aspects of natural killer cells, will give particular attention to: the rising role of natural killer cell therapies in patients with malignant hematological disorders, solid tumors and in recipients of stem cell therapies; preparation and manufacture of natural killer cell products; challenges facing the utilization of this form of cellular therapy including evolution of resistance; and maneuvers that can be employed to enhance the efficacy of natural killer cell therapies as well as suggested solutions to resolve the remaining challenges.

Infectious diseases are a leading cause of death worldwide [1,2]. The Mid-20th century witnessed most of the antimicrobial discoveries but recently there is dramatic shortage of new classes of antimicrobial agents due to failure to build a sustainable antimicrobial discovery platform [1-4]. For example, antibiotics comprise ˂ 1.5% of the compounds under investigation at the major pharmaceutical and biotechnology companies [1,5]. 

Varicella zoster virus behaves differently from other herpes viruses as it differs from them in many aspects. Recently, there has been growing evidence on the beneficial effects of the virus in immune compromised hosts and these effects are translated into prolongation of survival. The reported beneficial effects of the virus include: (1) stimulation of bone marrow activity in patients with hematologic malignancies and bone marrow failure syndromes, (2) antitumor effects in various hematologic malignancies and solid tumors, and (3) association with graft versus host disease which has anticancer effects. Additionally, there are several reports on the safety of the live-attenuated even in severely immune suppressed individuals and on the emerging role of the virus in cancer immunotherapy. In this review, the following aspects of the virus will be thoroughly discussed: (1) new data on the genetic background, pathogenesis, vaccination, and new therapeutic modalities; (2) bone marrow microenvironment and hematopoiesis; (3) cells involved in the pathogenesis of the virus such as: mesenchymal stem cells, dendritic cells, natural killer cells, T-cells and mononuclear cells; (4) cellular proteins such as open reading frames, glycoproteins, promyelocytic leukemia protein, chaperons, and SUMOs; (5) extracellular vesicles, exosomes, and micro-RNAs; and (6) signaling pathways, cytokines, and interferons.

There is evidence that complement components induce cell migration in mesenchymal stem cells and regulate cytokine production in osteoblastic cells thus playing a regulatory role in normal bone formation. The aim of the present study was to investigate the involvement of complement system in the differentiation of bone marrow cells in complement-depleted model of rheumatoid arthritis (RA). Arthritis was induced by intraarticular injection of zymosan in cobra venom factor (CVF)-treated mice depleted of functional complement. The expression of different markers by bone marrow [1], on fibroblasts (CD29), mesenchymal cells (CD105), dendritic cells (CD14, CD86), osteoclasts (CD265), cells expressing Dectin1 (CD369) and megakaryocytes (CD62P) was determined by flowcytometry. The lack of functional complement activity at the point of arthritis initiation (day 3) lead to an increase of fibroblast and megakaryocyte populations, to a decrease of mature and dectin1 positive populations, while the number of mesenchymal cells was not changed, all compared to arthritic mice. Immunohistochemical staining showed that low complement activity diminished arthritis-induced generation of megakaryocytes and platelets in BM. Chronic inflammation during erosive conditions such as rheumatoid arthritis, leads to dysregulated differentiation and prolifеration of bone cells, inflammation of synovial membrane and bone marrow, and degradation of cartilage and bone. Present results point that the lack of functional complement changed the ratio between different cell populations that can be used for determining the development and stage of rheumatoid arthritis and can help finding of new therapeutic approaches.

Infantile cystinosis is a lysosomal storage disease leading to end stage kidney disease at early ages. There is no effective treatment and patients require long term dialysis or kidney transplant for survival. We present our experience on three affected children who received HLA matched allogeneic stem cell transplant. The protocol used was novel and designed to promote engraftment. The primary endpoint was safety for treatment related mortality or morbidity; All three children survived without serious adverse effects during extended follow up for over 4 years. Although we could not prove engraftment, all three children met secondary end point of sustained target functions over a 6 month follow-up. Further studies are warranted to further evaluate safety and efficacy of MSC treatment for infantile cystinosis.

Crohn's disease is a chronic syndrome of the gastrointestinal tract that produces idiopathic inflammation. Approximately half of the patients develop abscesses and/or fistulas throughout their history that are located, mainly, in the perianal region. Current treatments are based on individualized plans that generally use combined pharmacology for symptomatic relief based on glucocorticoids, immunosuppressants or immunomodulators, antibiotics, anti-inflammatories, probiotics, and antibodies, or surgical therapies such as intestinal resections or ostomizations (colostomy and ileostomy) that tend to cause notable side effects in a considerable percentage of patients and a significant decrease in their quality of life.Perianal fistulas consist of abnormal tracts, inflammatory tunnels, or chronic tracts of granular tissue that connect two surfaces lined with epithelium, have an external hole in the skin that borders the anus, and an internal hole located inside it around the anal canal, rectus and sphincters. Treatment is a complex process that requires a multidisciplinary approach and the combination of several treatments. In the short term, the goal is to drain abscesses, reduce inflammatory and infectious processes, guard the fistulous tract with seton or lax lines, facilitate patency, and hinder new formations. In the long term, a total cure and the avoidance of complications that require surgery or the creation of intestinal stomas are pursued.For this reason, new effective remedies with fewer adverse effects continue to be investigated, one of the most promising being the use of mesenchymal stem cells for the regeneration and cure of perianal fistulas and the remission of symptoms. The present bibliographic review delves into this new therapy and analyzes the current state of the situation regarding its efficacy and safety.

Graft Versus Host Disease (GVHD) is a major limitation to the success of allogeneic Hematopoietic Stem Cell Transplantation (HSCT) as Steroid-Refractory (SR) acute GVHD carries poor prognosis due to the absence of an efficacious second-line therapy. Mesenchymal Stem Cells (MSCs) which have immunosuppressive, immunomodulatory, and regenerative properties may become a highly effective therapeutic modality for SR-GVHD in the near future. MSCs have already been approved to treat childhood SR-GVHD in Japan, and they have been conditionally licensed in New Zealand and Canada. It is expected that MSCs will be approved for the treatment of SR-GVHD in adults in Europe, North America, and other parts of the world within a few years. Utilization of the recently introduced techniques including the use of MSC products such as exosomes and Extracellular Vesicles (ECVs) instead of the parent MSCs, robotic manufacturing technology, and genetic engineering of MSCs will ultimately overcome the remaining obstacles facing the widespread utilization of MSCs and their products as therapeutics not only in HSCT but also in other medical fields. The aim of this review is to provide an update on the remarkable progress achieved in the use of MSCs and their products in the field of HSCT.

Mesenchymal Stem Cells (MSCs) have antimicrobial, anti-inflammatory, immunomodulatory, and regenerative potentials. Additionally, utilization of MSCs in the clinical arena has been shown to be safe and well tolerated. Hence, this form of cellular therapy has gained particular attention in the treatment of several infectious disorders and their complications. MSCs have been successfully used in the treatment of the following infections and their complications: bacterial infections including complicated sepsis; viral infections including Human Immunodeficiency Virus (HIV), hepatitis B and C viruses, and Coronavirus disease (COVID-19) complicated by acute respiratory distress syndrome; parasitic infections including schistosomiasis, malaria, and Chagas disease; and mycobacterial infections including tuberculosis. The use of MSCs derived from certain sources and Extracellular Vesicles (ECVs) derived from MSCs has improved their efficacy and reduced their side effects. However, the clinical application of MSCs in the treatment of several infectious diseases still faces real challenges that need to be resolved. The current status of MSCs and the controversies related to their utilization in various infections will be thoroughly discussed in this review. 

Mesenchymal stem cells are heterogenous adult multipotent stromal cells that can be isolated from various sources including bone marrow, peripheral blood, umbilical cord blood, dental pulp, and adipose tissue. They have certain regenerative, anti-inflammatory, immunomodulatory, immunosuppressive, antimicrobial, and other properties that enable them to have several therapeutic and clinical applications including treatment of various autoimmune disorders; role in hematopoietic stem cell transplantation and regenerative medicine; treatment of skin, pulmonary and cardiovascular disorders; treatment of neurological and eye diseases; as well as treatment of various infections and their complications. Different factors including donor age, biological source, route of administration, and signaling pathways have an impact on the functions and consequently the clinical applications of mesenchymal stromal cells. The products of mesenchymal stem cells such as extracellular vesicles and exosomes reproduce the biological effects and most of the therapeutic actions of the parent stem cells. Genetic engineering and the use of specific mesenchymal stromal cell products have improved their clinical efficacy and decreased their adverse effects. However, despite the recent progress in the use of mesenchymal stem cells, the clinical application of these cells in the treatment of several diseases still faces real challenges that need to be resolved. The current status of mesenchymal stem cells and the controversies related to their clinical utilization in various disease conditions will be thoroughly discussed in this review.

Mesenchymal Stromal/Stem Cells (MSCs); which can be isolated from Bone Marrow (BM) in addition to several tissues and body fluids; have the following characteristic features: self-renewal, differentiation into various cell types, plastic adherence, and specific surface markers on flow cytometry [1-3].