Journal of Stem Cells最新文献

Background: The importance of solid organ transplants is increasing due to the increasing incidence of end-stage organ diseases. With the limitations facing the recruitment of the suitable grafts, ex vivo organ perfusion (EVOP) techniques have been developed to increase the graft acceptance rates and improve the clinical outcomes.

Methodology: The role of mesenchymal stem cells (MSCs) in this regard is not limited to the regenerative ability. MSCs have proved their ability to effectively modulate the immune response and inflammation. Accordingly, the idea of the combined ex vivo organ perfusion and MSCs transplant came to focus. This manuscript reviews some points that should be considered, while applying this technique.

Conclusion: The combined EVOP-MSCs is a therapeutic technique that should be soon applied in the practice of solid organ transplants. However, certain remarks should be considered on the pre-clinical levels before taking the studies further into the clinical levels. Although the present report will focus on the lung transplant, the ideas and the remarks are also to be considered for all other solid organ transplants, such as heart, liver and kidney.

The majority of populations of differentiated cells are subject to renewal. Progenitor cells (cells-predecessors) and differentiated cells, having started the differentiation pathway or having finished it, can divide a limited number of times and are not capable of ensuring tissue regeneration during the whole period of ontogenesis. Renewal of tissues over such a long period is impossible without the participation of a specialized system which is responsible for regeneration. The given system is represented by pluripotent stem cells. Pluripotent stem cells, which conduct regeneration of all body tissues during ontogeny, are formed during implementation of the development program of the fertilized ovum, along with the formation of tissues and organs of the new organism. Being a separate direction of differentiation of embryonic cells, pluripotent stem cells are not embryonic cells. The immune system takes part in the formation of tissue-specific receptors among pluripotent stem cells. The latter remain pluripotent until the formation of tissue-specific receptors in them, and become committed (tissue-specific stem cells) after the formation of such receptors. Committed stem cells (tissue-specific stem cells) that migrate through the extracellular matrix replenish the progenitor cells of all tissues. Mesenchymal stem cells are the precursors of fibroblasts, and they only create conditions in the extracellular matrix for the migration and differentiation of committed (tissue-specific) stem cells in the places of cell death.

Hair loss can have major psychological impact on affected population belonging to varied ethnic background. Hair is a mini organ in itself and serves many distinguishing functions ranging from maintaining body temperature to promoting social interactions. Major cause of hair loss is androgenic alopecia. Hair follicles possess receptor for androgen. However, DHT (Dihydrotestosterone) in excess results into shrinkage of hair follicle affecting hair growth adversely.

The present review is focused on etiology of hair loss, traditional treatment approach and their limitations with side effects with special emphasis on unique properties of stem cells, favourable growth factors secreted by stem cells and strategies to enhance favourable growth factor/cytokine production for hair loss therapeutics. We discussed in details the present available treatment options for hair loss like drugs (Finasteride and Minoxidil), follicular hair transplant, laser therapy and serum therapy. These treatment options have their own disadvantages and side effects with appropriate alerts from regulatory authorities. The side effects of these modalities cannot be ignored and demands alternate therapy approach with less or no side effects.

We feel that the stem cell therapy is advancing and is a promising modality in near future owing to its advantages and promising outcomes. This review article discusses possible stem cell therapy for hair regrowth and its advantages. We focused on use of conditioned media derived from stem cells instead of using stem cells directly for the therapy.

Introduction: Spinal cord injury is a traumatic neurological condition which makes the patient disable. Its management still remains challenging but advancements in the regenerative medicine have changed the approach of treating this serious debilitating condition of the central nervous system. Cell based therapies can restore function in spinal cord injury by replacing the lost neural tissue. These therapies also rejuvenate the existing intact neurons by facilitating remyelination and by repairing and reducing progressive tissue damage and scarring.

Methods: Autologous bone marrow stem cells were collected from the patients. 5 ml of the processed sample was injected back into the patients via lumbar puncture at L1/L2 level. The bone marrow harvesting and administration was repeated every 4 weeks 3 times (12 weeks).

Results: Significant improvements were noticed following the injections into the patients with the duration of injury less than 6 months. ASIA grade improvements were observed in 6 out of 10 patients. VTC and walking, at least with the support, was restored in eight patients. Bladder control and sexual functions improved in three and five patients respectively. Eight patients exhibited decreased spasticity.

Discussion: We believe that autologous bone marrow stem cells contributed towards the neuroplaticity and/or paracrine effect due to which we observed the considerable improvements in the conditions of the patients.

Conclusion: This preliminary proof of patient improvement reinforces the potential of autologous bone marrow stem cell treatment in the patients suffering from Spinal Cord Injury. Although the results are encouraging further studies are needed to substantiate the claims.

Background: Avascular Necrosis (AVN) of hip is a devastating condition seen in younger individuals. It is the ischemic death of the constituents of the bone cartilage of the hip. The femoral head (FH) is the most common site for AVN. It results from interruption of the normal blood flow to the FH that fits into the hip socket. Earlier studies using autologous bone marrow stem cell concentrate injections have shown encouraging results with average success rates. The current study was designed to improve significantly the cartilage regeneration and clinical outcome.

Methods: Total of 48 patients underwent autologous bone marrow stem cell and activated platelet-rich plasma derived growth factor concentrate (PRP-GFC) therapy for early and advanced stages AVN of femoral head in a single multi-specialty center. The total treatment was divided into three phases. In the phase I, all the clinical diagnostic measurements such as magnetic resonance imaging (MRI), computed tomography (CT) etc. with respect to the AVN patients and bone marrow aspiration from posterior iliac spine from the patients were carried out. In the phase II, isolation of stem cells and preparation from the patients were performed. Subsequently, in phase III, the stem cells and PRP- GFCs were transplanted in the enrolled patients.

Results: Ninety three percent of the enrolled AVN patients showed marked enhancement in the hip bone joint space (more than 3mm) after combined stem cells and PRP-GFC treatment as evidenced by comparison of the pre- and post-treatment MRI data thus indicative of regeneration of cartilage. The treated patients showed significant improvement in their motor function, cartilage regrowth (3 to 10mm), and high satisfaction in the two-year follow-up.

Conclusion: Combination of stem cell and PRP-GFC therapy has shown promising cartilage regeneration in 45 out of 48 patients of AVN. This study clearly demonstrates the safety and efficacy of this treatment. Larger numbers of patients need to be evaluated to better understand the efficacy of the combined stem cell and PRP-GFC therapy on AVN patients.

Introduction: Once people reach 40 years of age, they have a decrease in their pool of pluripotent stem cells, and an increased risk for development of oncological diseases.

Materials and methods: The first part of the study was conducted in 11 patients aging 54 to 76 years old with cancer of the kidney, bladder, or prostate in stages III-IV of the disease. The second part of the study was conducted in four patients aged 60-82 years old, who were given from 4 to 7 transfusions of mononuclear fraction of peripheral blood from young donors 19-23 years old, with the same sex and blood types as the recipients, in order to restore cell regeneration.

Results: In the first part of the study, 1 month after chemotherapy or targeted therapy, all 11 cancer patients had leukopenia accompanied by an increase in the contents of FGFb in the blood by 1.74 times on average. Four of these patients had an increase in the level of human VEGF-A of 1.25 times on average, while three patients had an increase in the level of human EGF of 1.13 times on average. In the second part of the study, 3-6 months after the completion of a cycle of 4-7 blood transfusions of mononuclear fraction of periphery blood, four patients had an in increase in the contents of hematopoietic progenitor cells CD34+ of periphery blood by 3.25 times on average, to the level normal in young people, while the level of FGFb decreased by 1.78 times on average. Among two patients, the level of human VEGF-A decreased by 1.48 times on average, while for three patients the level of human EGF decreased by 4.12 times on average. In the buccal epithelium, all four patients had a decrease in the expression of p53 by 6.02 times on average, while three of them had a decrease in the expression of Bcl-2 by 60.0 times on average.

Conclusion: Violation of tissue renewal is a major cause of carcinogenesis in people older than 40 years old. Excessive stimulation of mitotic activity among people over 40 can be reduced to normal levels by restoring the pool of pluripotent stem cells through transfusion of mononuclear fraction of peripheral blood from young donors 18-23 years old with the same blood groups and sex as the recipient (RF patent number 2350340).

Objective: Cervical cancer is a challenging pathologic entity because of its lack of response to conventional chemotherapy. Imiquimod is a synthetic analogue which seems to activate skin immune cells, acting as a Toll-like receptor 7 agonist. Previous studies in the field of cervical cancer have showed that its application may play a significant role in the treatment of cervical HPV infection with or without cervical intraepithelial neoplasia (CIN). In the present study we investigate the therapeutic potential of imiquimod in a cervical carcinoma cell line and evaluate whether the expression of HLA-G and OCT-4 is altered during this treatment.

Methods: HeLa cells were cultured in Dulbecco's modified Eagle medium and treated with 200 μl of imiquimod diluted solution (50 μg/ml). Cultured cells were allocated in four groups 1) control, 2) DMSO only, 3) DMSO and imiquimod for 48 hours, 4) DMSO and imiquimod for 72 hours.

Results: In the imiquimod treated cell lines we observed a significant reduction of viable cells at 48 and 72 hours (p = .001). The relative expression analysis of OCT-4 and HLA-G genes at 48 and 72 hours did not reveal significant differences after imiquimod treatment.

Conclusion: Imiquimod effectively reduces the percentage of viable HeLa cells and should be further evaluated in future clinical trials. This effect takes place as of 48 hours after its initial application and seems to persist at least until 72 hours. HLA-G and OCT-4 expression is not affected by this type of treatment.

Metabolic alteration that a stem cell undergoes during proliferation and quiescence are decisive. These cells survive in extreme hypoxic environment that prevails in bone marrow. The present study is aimed to understand this nature in hematopoietic stem cells. These stem cells were mobilized from bone marrow into peripheral blood by giving G-CSF at a concentration of 5 μg/Kg/d and the cells were isolated by apheresis technique. The morphological analysis of these cells using Giemsa stain and SEM showed presence of only single type of cells with conspicuous nuclei, the hematopoietic nature was assessed by the presence of CD34, a glycoprotein using anti-CD34 monoclonal antibodies. The ICC results revealed presence of CD34 marker further; pure population of CD34+ stem cells was described by FACS. These cells were cultured separately in DMEM having 5.5mM, 11.1mM and 25mM glucose respectively. In these cells GK, PK and L-LDH enzyme activities were estimated which showed increased activities at 5.5mM glucose concentration and further elevation of glucose concentration the activities were fallen considerably. Similarly, qPCR analysis of HIF1α and GAPDH genes showed very high expression of HIF1α at 5.5mM glucose concentration which reduced with increased glucose concentration. While GAPDH gene expression enhanced on elevation of glucose concentration. Thus, these results indicate high HIF1α expression in low glucose condition with improved anaerobic glycolysis seems to be one of the key factors in maintaining the quiescent state of CD34+ stem cells.

Background: The retinal pigment epithelium (RPE), an important tissue monolayer of retina, sustains visual function and retinal homeostasis. In disease conditions such as Retinitis Pigmentosa (RP) and Age related Macular degeneration (AMD), the integrity and functional capacity of RPE monolayer is compromised. Human embryonic stem cells derived RPE (hESC-RPE) is ideal for cell based therapy because of their ability to morphologically and functionally mimic native fetal and adult RPE. However protocols for optimum culture of hESC-RPE are not well established.

Aim: To describe a simplified protocol for differentiating human embryonic stem cells (hESC) into retinal pigment epithelial cells.

Methods: hESC (WA09-DL-11) cell lines were grown with standard stem cell culture protocol. After cell colonies were established, basic fibroblast growth factor (bFGF) was deprived (day 0). hESC colonies expressing pigmentation were characterized for expression of RPE65 and Zonular occludens--1 (ZO-1) with immunocytochemistry on days 0, 36, 42, 56 and 70 and western blot analysis on days 0, 40, 48, 53 and 63. In addition, morphological assessment was conducted on transformed cells longitudinally.

Results: Pigmented cells were noted 36 days after deprivation of bFGF from growth media. Immunofluorescence demonstrated progressive up regulation of RPE specific proteins (ZO-1 & RPE 65). Immunofluorescence of ZO-1 (in pixels) was (3.08 ± 0.31) on day 42, (5.33 ± 0.89, p = 0.0001) on day 56 and (4.87 ± 0.57, p = 0.0011) on day 70. Similarly expression of RPE 65 was (2.44 ± 0.31) on day 42, which continued to increase (4.23 ± 0.60, p = 0.0011) on day 56 and (5.59 ± 0.36, p < 0.0001) on day 70. Protein expression patterns using western blot confirmed the trends seen in immunofluorescence. Western blot analysis of ZO-1 expression (in optical density unit) was 272.57 ± 31.75 on day 40, 4212.20 ± 911.31 (p = 0.0004) on day 48, 5182.43 ± 1230.38 (p = 0.030) on day 53 and 5848.76 ± 241.04 (p < 0.0001) on day 63. Protein expression of RPE 65 was 1607.64 ± 247.76 on day 40, 2448.07 ± 152.66 on day 48 and (2341.15 ± 52.84) on day 63. hESC-RPE cells displayed a series of specific morphological changes (cytoplasmic, nuclear pigmentary and cell shape) over the course of time frame. By day 70, cells with hexagonal pattern, dark dense nucleus and uniform cytoplasm were noted in densely pigmented RPE colonies.

Conclusion: bFGF deprivation leads to successful differentiation of hESC into RPE cells. Longitudinal transformative changes were confirmed with measurement of ZO-1 and RPE 65, specific markers of RPE.

Quantitative real-time PCR can detect variations in gene expression. The identification of the stable reference genes (RGs) is necessary to evaluate the expression of specific genes of interest under various conditions in many cell types, including human adipose-derived stromal cells (hASCs). In this study, we used the algorithms BestKeeper, NormFinder, geNorm, and RefFinder to investigate the stability of 15 potential RGs (B2M, eEF1A1, GAPDH, H2AFZ, HMBS, HPRT1, PGK1, PPIA, RPL5, SDHA, TBP, TKT, TRFC, TUBB, and UBC) in hASCs during control, adipo-, chondro-, and osteogenic differentiation for 28 days. RPL5, GAPDH, H2AFZ, and HPRT1 were the most stable RGs, while B2M and UBC were the least stable RGs for the majority of group analyses (tri-lineage differentiation and control analyzed combined or individually; each lineage combined with the control). These RGs were used to normalize adipo- (FABP4, LPL, and PPARG), chondro- (COMP and SOX9), and osteogenic gene expression markers (BMP4, COL1A1, and RUNX2). Each marker showed a similar expression when normalized by H2AFZ, HPRT1, or RPL5, confirming that these RGs exhibit stable expression. However, GAPDH, B2M, and UBC exhibited high standard deviation (SD), down-regulated and/or up-regulated differentiation gene expression markers when compared with stable RGs, demonstrating that these RGs are unstable.