Stem cell investigation最新文献

Immune thrombocytopenic purpura (ITP) is an autoimmune state of decreased platelets caused by antibody or T-cell mediated destruction of platelets through the reticuloendothelial system and impairment of their production. Symptoms of ITP include bleeding usually from nose or gums, easy bruising, petechiae commonly of lower extremities, menorrhagia, hematuria, hematemesis, hematochezia and most dreadful, intra cranial hemorrhage. Molecular mimicry between viral antigens and host platelet antigens forming cross-reactive anti-platelet autoantibodies may lead to increased platelet clearance in ITP associated with viral infections. One of the many viruses associated with this is the Coronavirus disease 2019 (COVID-19). It has caused a devastating pandemic. It can activate innate and adaptive immune responses. It has numerous signs and symptoms including but not limited to dyspnea, fever, cough, fatigue, myalgias, loss of taste and smell. It leads to diseases such as pneumonia, acute respiratory distress syndrome, thrombosis and cardiomyopathy. Hematologic manifestations include thrombocytopenia and more commonly lymphopenia. Treatment includes steroids, immune globulin, romiplostim, eltrombopag, rituximab or splenectomy. Contact sports should be avoided due to risk of intra cranial bleeding with head impact. Nonsteroidal anti-inflammatory drugs (NSAIDs) and aspirin should be used with caution since they impair platelet function. We discuss a patient with COVID-19 who developed thrombocytopenia thought to be due to ITP. Not much is known about the association between the two. It is important to keep this differential in mind when taking care of patients with COVID-19 who develop thrombocytopenia.

The large economic burden on the global health care systems is due to the increasing number of symptomatic osteoarthritis (OA) knee patients whereby accounting for greater morbidity and impaired functional quality of life. The recent developments and impulses in molecular and regenerative medicine have paved the way for inducing the biological active cells such as stem cells, bioactive materials, and growth factors towards the healing and tissue regenerative process. Mesenchymal stem cells (MSCs) act as a minimally invasive procedure that bridges the gap between pharmacological treatment and surgical treatment for OA. MSCs are the ideal cell-based therapy for treating disorders under a minimally invasive environment in conjunction with cartilage regeneration. Due to the worldwide recognized animal model for such cell-based therapies, global researchers have started using the various sources of MSCs towards cartilage regeneration. However, there is a lacuna in literature on the comparative efficacy and safety of various sources of MSCs in OA of the knee. Hence, the identification of a potential source for therapeutic use in this clinical scenario remains unclear. In this article, we compared the therapeutic effects of various sources of MSCs in terms of efficacy, safety, differentiation potential, durability, accessibility, allogenic preparation and culture expandability to decide the optimal source of MSCs for OA knee.

Background: Burn injuries constitute a major health problem which cause more severe physiological stress than other traumas. Aloe vera has been used in traditional medicine for a long time for burn treatment. Mesenchymal stem cells (MSCs) have delivered new approaches to the management of deep burns. The present study assessed the effect of aloe vera versus MSCs on experimentally induced deep second-degree burn.

Methods: Sixty adult female albino rats randomized into 6 groups: group I served as negative control, group II received topical aloe vera only, group III were injected intradermally with MSCs, group IV subjected to burn injury, group V received topical aloe vera post burn and group VI were injected intradermally with MSCs post burn. Healing of burn injury was evaluated grossly. Skin specimens were obtained after 14 & 21-days post-burn induction and prepared for histological techniques (H&E and Masson's trichrome stain). Polymerase chain reaction (PCR) analysis of Sry gene for group VI was done.

Results: After 14 days, groups V&VI showed fully regenerated epidermis with a significant increase in the epidermal thickness and a significant decrease in the optical density of collagen fibers compared to control groups. After 21 days, group V showed less epidermal thickness compared to that of day 14 and nearly normal collagen fibers arrangement. However, group VI showed a significant increase in the epidermal thickness compared to groups V&I and an interwoven collagen fibers arrangement with a significant decrease in the optical density of collagen fibers in comparison to control groups. PCR results of the tested samples revealed that 100% of the recipient rats contain Sry positive gene.

Conclusions: Topical aloe vera promoted burn wound healing faster and better than intradermal injection of MSCs.

The linchpin for COVID-19 pathogenesis is the severe inflammatory process in the respiratory tract wherein the accumulation of excessive cytokines paves the way for a series of systemic hemodynamic alterations and mortality. The mortality rate is higher in individuals with co-morbidities and advancing age. The absence of a specific therapy is responsible for this uncontrolled spread and the significant mortality. This renders potential insight for considering biologics as a plausible option to repair and regenerate the affected lung tissue and pulverize the causative organism. The plausible role of megakaryocytes against invading microbes was not clearly understood. Platelet lysate is an acellular product consisting of regenerative molecules released from a cluster of platelets. It attenuates the changes caused by immune reactions in allogenic utility with the introduction of growth factors, cytokines, and proteins at supraphysiologic levels and thereby serves as a regenerative immunomodulatory agent to combat COVID-19. This platelet lysate can be used in nebulized form for such acute respiratory distress conditions in COVID-19 elderly patients. Platelet lysate may emerge as a pivotal player provided investigations pace up in this context. Here, we discuss how the platelet lysate can plausibly perquisite to relegate COVID-19. Undertaking prospective randomized controlled trials to prove its efficacy is the need of the hour in this pandemic scenario.

Regenerative medicine is considered as an alternative approach to healthcare. Owing to their pluripotent abilities and their relative lack of ethical and legal issues, adult stem cells are considered as optimal candidates for use in the treatment of various diseases. Bone marrow-derived mesenchymal stem cells are among the most promising candidates for clinical applications as they have expressed a higher degree of plasticity in vitro. Many investigators have begun to examine how bone marrow stem cells might be used to rebuild damaged tissues. The systemic administration of cells for therapeutic applications requires efficient migration and homing of cells to the target site. Cell adhesion molecules and their ligands, chemokines, extracellular matrix components and specialized bone marrow niches all participate in the proper regulation of this process. MSCs suppress the pathophysiological process that is mediated by chronic inflammation and contributes to a modification of the microenvironment and tissue regeneration. Due to the intricacy of the mesenchymal stem cell, there is ever-increasing amount of data emerging about their migration and regenerative mechanisms. Many factors influence MSC mobilization and their homing to injured tissues. This review summarizes the current clinical and pre-clinical data available in literature regarding the use of MSC in tissue repair and their prospective therapeutic role in various diseases and the underlying repair mechanisms will be discussed.

Background: Mesenchymal stem cells (MSCs) with immunoregulatory properties affect immune systems. Many studies showed that antioxidants such as vitamin E (Vit E) and selenium (Se) could improve stem cells survival. This study aims to investigate the effects of MSC conditioned media (CM) treated with Vit E and Se on immune cells.

Methods: MSCs were isolated and cultured with Vit E and Se. Immature dendritic cells (DCs) and peripheral blood mononuclear cells (PBMCs) were cultured with MSC CM treated with Vit E and Se. The expression of HLA-DR, CD86, CD40, and CD83 on mature DC were evaluated. DC supernatant and PBMCs supernatant was collected for the study of TGF-β, IL-10, and IL-12. PBMCs evaluated for the expression of T-bet, GATA3, RORγt, and FOXP3.

Results: MSC CM increased CD40 on myeloid DC (mDC). CD40 has been decreased in DC treated with MSC (Vit E) and MSC (Se) CM. HLA-DR expression on DCs and IL-12 level were significantly reduced in MSC (Vit E) CM. IL-10 concentration increased in DCs treated with MSC (Vit E) and MSC (Se) CM. Treatment of PBMCs with MSC CM decreased IL-10 level, FOXP3, and RORγt expression. On the other hand, the MSC (Vit E) CM and MSC (Se) CM decreased the IL-10 level and increased IL-12, T-bet, and RORγt.

Conclusions: According to the results, the treatment of MSC with Vit E and Se enhanced the ability of MSCs to inhibit DCs and improved immunomodulatory effects. Concerning the effect of MSC on PBMC, it seems that it increased RORγt expression through monocytes.

Background: Cell therapies and chimerism-based strategies are currently the most successful approach for tolerance induction in transplantation. This study aimed to establish and characterize novel Donor Recipient Chimeric Ccell (DRCC) therapy of bone marrow (BM) origin presenting donor-recipient phenotype to support tolerance induction.

Methods: Ex vivo fusions of fully MHC-mismatched BM cells from ACI (RT1^a) and Lewis (RT1^l) rats were performed using polyethylene-glycol (PEG). The creation of rat DRCC was tested by flow cytometry (FC), confocal microscopy and PCR. FC characterized DRCC's phenotype (CD3, CD4, CD8, CD45, CD90, CD11b/c, CD45RA, OX-82, or CD4/CD25) and apoptosis, while mixed lymphocyte reaction assessed DRCC's immunogenicity and colony forming unit assay tested DRCC's differentiation and proliferation. DRCC's polyploidy was evaluated using Hoechst33342 staining and COMET assay tested genotoxicity of fusion procedure. ELISA analyzed the secretion of IL-2, IL-4, IL-10, TGFß1, IFNγ and TNFα by DRCC at day 1, 5 and 14 post-fusion. The DRCC's phenotype after long-term culturing was assessed by reverse-transcription PCR.

Results: The chimeric state of DRCC was confirmed. Fusion did not change the expression of hematopoietic markers compared to BM controls. Although an increased number of early and late apoptotic (Annexin V⁺/Sytox blue^- and Annexin V⁺/Sytox blue⁺, respectively) DRCC was detected at 24h post-fusion, the number significantly decreased at day 5 (38.4%±3.1% and 22.6%±2.5%, vs. 28.3%±2.5% and 13.9%±2.6%, respectively, P<0.05). DRCC presented decreased immunogenicity, increased expression of IL-10 and TGFβ1 and proliferative potential comparable to BM controls. The average percentage of tetraploid DRCC was 3.1%±0.2% compared to 0.96%±0.1% in BM controls. The lack of damage to the DRCC's DNA content supported the DRCC's safety. In culture, DRCC maintained proliferation for up to 28 days while preserving hematopoietic profile.

Conclusions: This study confirmed feasibility of DRCC creation via ex vivo PEG mediated fusion. The created DRCC revealed pro-tolerogenic properties indicating potential immunomodulatory effect of DRCC therapy when applied in vivo to support tolerance induction in solid organ and vascularized composite allograft transplantation.

The recent advances in translational and nanomedicine have paved the way for developing the targeted drug delivery system at a greater pace among global researchers. On par with these technologies, exosomes act as a potential portal for cell-free drug delivery systems as these are bestowed with the native characteristics of the parent cell of origin. Exosomes, called extracellular vesicles (EcVs), are present in almost all cells, tissues, and body fluids. They help in intercellular signaling and maintains tissue homeostasis in the disease pathobiology. Researchers have characterized 9,769 proteins, 2,838 miRNAs, 3,408 mRNAs, and 1,116 lipids being present in exosomal cargo. The separation of exosomes from cells, tissues, and body fluids follow different patterned kinetics. Exosomes interact with the recipient cells through their surface receptor molecules and ligands and internalize within recipient cells through micropinocytosis and phagocytosis. Advancing technologies in regenerative medicine have facilitated the researchers to isolate exosomes from mesenchymal stem cells (MSCs) as these cells are blessed with supreme regenerative potentiality in targeting a disease. Exosomal cargo is a key player in establishing the diagnosis and executing therapeutic role whilst regulating a disease process. Various in vitro studies have exhibited the safety, efficacy, and therapeutic potentiality of exosomes in various cancers, neurodegenerative, cardiovascular, and orthopedic diseases. This article throws light on the composition, therapeutic role, and regulatory potentials of exosomes with the widening of the horizon in the field of regenerative medicine.

Background: Cytopenia is the primary phenomenon in myelodysplastic syndrome (MDS) amidst hypercellular bone marrow. The soluble CD40 ligand (sCD40L) is considered as a cytokine that can trigger synthesis of tumor necrosis factor α (TNFα) that promotes apoptosis. The objective of this study is to prove that recombinant human sCD40L (rh-sCD40L) exposure on bone marrow mononuclear cells (BMMC) MDS increases TNFα expression at mRNA level and at protein level.

Methods: BMMC from MDS patients whom diagnosed and classified using the WHO 2008 criteria, were exposed to rh-sCD40L and antiCD40L. The expressions of TNFα mRNAs were quantified by qRT-PCR, level of TNFα were measured using the ELISA method.

Results: Exposure of rh-sCD40L significantly increased the expression of TNFα mRNA. The similar exposure also significantly increased the level of TNFα compared to controls. TNFα mRNA expression on BMMC in MDS samples exposed to rh-sCD40L is 3.32 times compared to TNFα mRNA expression without exposure. level of TNFα in supernatant media exposed to rh-sCD40L in MDS samples was higher than that of control samples which were 44.44 and 4.85 pg/mL, P=0.018.

Conclusions: The sCD40L plays a role in increasing the synthesis of TNFα in mRNA level and protein level in BMMC MDS.

Mesenchymal stem cells (MSCs) have gained wide therapeutic acceptance in regenerative medicine due to their potential in repair process in restoring the damaged tissues and controlling inflammation. In the present study, we report for the first time the beneficial effects of combining placental-derived MSCs (hPMSCs) with stigmasterol-a plant-derived sterol to accelerate cartilage repair and regeneration in a monosodium-iodoacetate (MIA) induced osteoarthritis (OA) rat model. Control animals (Group I) received no treatment. Experimental animals (Group II) received a single intra-articular injection of MIA (2 mg) in the right knee joints. The Group II animals developed OA-like lesions within a week of MIA injection. They were subdivided further as: (II-A): OA, (II-B): OA+hPMSCs (2×10⁶ cells, single-dose/intra-articular injection), (II-C): OA+stigmasterol (20 µg/mL, single-dose/intra-articular injection) and (II-D): OA+hPMSCs+stigmasterol. The animals were monitored for four more weeks after which they were sacrificed, the right limbs dissected out and assessed for cartilage repair and regeneration using micro-computed tomography (micro-CT) and histology. Results showed that the combined administration of hPMSCs with stigmasterol (II-D) was the most effective in correcting the OA lesions, with concomitant repair and regeneration. However, hPMSCs (II-B) or stigmasterol (II-C) per se treated groups showed only marginal beneficial effects and were not significant. Thus the present study provides valuable insights in situ using a combination of hPMSCs and stigmasterol towards cartilage repair and regeneration. We advocate the participation of populating cells or residual chondrocytes in addition to its anti-inflammatory functions.