Reconstruction of bone marrow microenvironment for expansion of hematopoietic stem cells by a histone deacetylase inhibitor

Ex vivo expansion of hematopoietic stem cells (HSCs) is an approach for overcoming cell insufficiency for umbilical cord blood transplantation. It was suggested that in common ex vivo cultures, the stemness specificity of HSCs is rapidly reducing due to DNA hypermethylation. Here, Nicotinamide (NAM), a DNA methyltransferase and histone deacetylase inhibitor, is used with a bioengineered Bone Marrow-like niche (BLN) for HSC ex vivo expansion. The CFSE cell proliferation assay was used for tracking HSCs division. qRT-PCR was conducted to assay the HOXB4 mRNA expression levels. The morphology of BLN-cultured cells was analyzed using scanning electron microscopy (SEM). NAM boosted the induction of HSC proliferation in the BLN group compared to the control group. In addition, the ability of HSCs to colonize was more significant in the BLN group than in the control group. Our data suggest that the presence of NAM in bioengineered niches promotes HSC proliferation. The presented approach showed that small molecules could be used in the clinical setting to overcome the limited number of CD34+ cells in cord blood units.

Gut microbiota intervention by pre and probiotics can induce regulatory T cells and reduce the risk of severe acute GVHD following allogeneic hematopoietic stem cell transplantation

BACKGROUND

Acute graft-versus-host disease (aGVHD) is one of the leading causes of limitation and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Numerous studies have shown that changes in the gut microbiome diversity increased post-transplant problems, including the occurrence of aGVHD. Probiotics and prebiotics can reconstitute the gut microbiota and thus increase bacterial metabolites such as short-chain fatty acids (SCFAs) that have immunomodulatory effects preventing aGVHD in recipients of allo-HSCTs.

METHODS/STUDY DESIGN

We conducted a pilot randomized clinical trial to investigate whether oral synbiotics are associated with the prevention or reduction in occurrence/severity and mitigate complications of aGVHD following allo-HSCT. A commercially available synbiotic mixture containing high levels of 7 safe bacterial strains plus fructo-oligosaccharides as a prebiotic was administered to allo-HSCT recipients. Out of 40 allo-HSCT patients, 20 received daily a synbiotic 21 days prior to transplantation (days -21 to day 0). In contrast, in the control group 20 recipients of allo-HSCT did not receive a symbiotic therapy.

RESULTS

Within first 100 days of observation, the incidence of severe (grade III/IV) aGVHD in the a synbiotic-therapy group was 0% (0 out of 20 patients), whereas it was 25% (5 out of 20 patients) in the control group (P = 0.047). The median percentage of CD4 + CD25 + Foxp3+ regulatory T cells (Tregs) among CD4+ lymphocytes on day 28 after HSCT in the synbiotic group was higher (2.54%) than in control group (1.73%; P = 0.01). There was no difference in Treg cells on day 7 after HSCT between two groups. However, the median percentage and the absolute count of Tregs in patients who experience aGVHD was significantly lower on days 7 and 28 after HSCT (both P < 0.05). The overall 12-month survival (OS) rate was higher (90%) in the symbiotic-treated patients than in the control group (75%), but the difference was not statistically significant (P = 0.234).

CONCLUSION

Our preliminary findings suggest that synbiotic intake before and during the conditioning regimen of allo-HSCT patients may lead to a reduction in the incidence and severity of aGVHD through the induction of CD4 + CD25 + Foxp3+ regulatory T cells, thus contributing to the improvement of transplant outcomes. Much larger studies are needed to confirm our observations.

The evaluation of reactive oxygen species generation and free mitochondrial DNA in platelet concentrates during 5 days of storage

Oxidative stress and mitochondrial damage are causes of platelet storage lesions (PSLs). Mitochondrial damage causes mitochondrial DNA (mtDNA) to be released into the extracellular space. MtDNA in platelet concentrates is considered damage-associated molecular patterns (DAMPs) and is one of the major causes of PSLs. The mechanism of mtDNA release in platelet concentrates has not been thoroughly investigated. This study aimed to determine the effect of reactive oxygen species (ROS) on mtDNA release in platelet concentrates during storage. Ten platelet concentrates from healthy donors were obtained in this investigation. Platelet concentrates were prepared by platelet-rich plasma (PRP) and stored at 22 ± 2 C° with gentle agitation. Platelet concentrates were subjected to flow cytometry and real-time PCR to evaluate total ROS and free mtDNA on days 0, 3, and 5 of platelet concentrate storage. Total ROS detected significantly increased from day 0 to day 5 of platelet concentrate storage (P = 0.0079). The mean of copy numbers of free mtDNA on day 0 increased from 3.43 × 106 ± 1.57 × 106 to 2.85 × 107 ± 1.51 × 107 (molecules/μl) on the fifth day of platelet concentrate storage, and it was statistically significant (P = 0.0039). In addition, LDH enzyme activity significantly increased during platelet concentrate storage (P < 0.0001). Also, releasing mtDNA in platelet concentrates was directly correlated with total ROS generation (P = 0.021, r = 0.61) and LDH activity (P = 0.04, r = 0.44). The evidence from this study confirmed the increasing level mtDNA copy numbers in platelet concentrates during storage, and the amount of free mtDNA is directly correlated with ROS generation and platelet lysis during 5 days of platelet concentrate storage. Finally, these changes may be related to DAMPs in the platelet concentrates.

Resveratrol; a Double-Edged Sword Antioxidant Agent for Preserving Platelet Cell Functions During Storage; Molecular Insights

Background

In the current study we have aimed to find the effects of Resveratrol treatment on platelet concentrates (PCs) at the dose dependent manner. We have also attempted to find the molecular mechanism of the effects.

Methods

The PCs, have received from Iranian blood transfusion organization (IBTO). Totally 10 PCs were studied. The PCs divided into 4 groups including untreated (control) and treated by different dose of Resveratrol; 10, 30 and 50 µM. Platelet aggregation and total reactive oxygen species (ROS) levels were evaluated at day 3 of PCs storage. In silico analysis was carried out to find out the potential involved mechanisms.

Results

The aggregation against collagen has fallen dramatically in all studied groups but at the same time, aggregation was significantly higher in the control versus treated groups (p<0.05). The inhibitory effect was dose dependent. The aggregation against Ristocetin did not significantly affect by Resveratrol treatment. The mean of total ROS significantly increased in all studied groups except those PCs treated with 10 µM of Resveratrol (P=0.9). The ROS level significantly increased with increasing Resveratrol concentration even more than control group (slope=11.6, P=0.0034). Resveratrol could potently interact with more than 15 different genes which, 10 of them enrolled in cellular regulation of the oxidative stress.

Conclusions

Our findings indicated that the Resveratrol affect the platelet aggregation at the dose dependent manner. Moreover, we have also found that the Resveratrol play as double-edged sword in the controlling oxidative state of the cells. Therefore, Using the optimal dose of Resveratrol is the great of importance.

L-carnitine modulates free mitochondrial DNA DAMPs and platelet storage lesions during storage of platelet concentrates

Platelet storage lesions may occur in Platelet concentrates (PCs) storage time, reducing PCs' quality. Mitochondrial damage causes mitochondrial DNA (mtDNA) to be released into the extracellular space. In this study, we evaluated the effect of L-carnitine (LC) as an antioxidant on free mtDNA DAMPs release in PCs during storage. Ten PCs prepared by the PRP method were studied. The copy numbers of free mtDNA, total reactive oxygen species (ROS), lactate dehydrogenase (LDH) enzyme activity, pH, and platelet counts were measured on days 0, 3, 5, and 7 of PCs storage in LC-treated and untreated platelets. LDH activity was significantly lower than the control group during 7 days of PCs storage (p = 0.041). Also, ROS production decreased in LC-treated PCs compared to the control group during storage (p = 0.026), and the difference mean of ROS between the two groups was significant on day 3, 5, and 7 (P_day3 = 0.02, P_day5 = 0.0001, P_day7 = 0.031). Moreover, LC decreased the copy numbers of free mtDNA during 7 days of storage (p = 0.021), and the difference mean of the copy numbers of free mtDNA in LC-treated PCs compared to the control group was significant on day 5 and 7 (P_day5 = 0.041، P_day7 = 0.022). It seems that LC can maintain the metabolism and antioxidant capacity of PCs and thus can reduce mitochondrial damage and mtDNA release; consequently, it can decrease DAMPs in PCs. Therefore, it may be possible to use this substance as a platelet additive solution in the future.

In-line Leukoreduction Filters; a New Source of Microparticle for Human and Animal Study

INTRODUCTION

The isolation of microparticles (MPs) from leukoreduction filters (LRFs) during cell extraction process introduced LRFs as a precious source of MPs for animal and human study.

METHOD

LRFs were collected from Tehran Blood Transfusion Center. The back-flushing method was used for leukocyte extraction from the LRFs. MPs were isolated through double-step centrifugation. Dynamic light scattering (DLS), electron microscopy (EM), and flow cytometry were performed for the evaluation of MPs size, morphology, and structural properties respectively. Statistical analyses were carried out to evaluation of differences between test and control groups. a p-value less than 0.05 indicates significant differences.

RESULT

DLS analysis showed that the average MP size in the test and control groups was 654.83 nm and 233.68 nm respectively. SEM images showed the spherical, oval, cell fragment, and micro-aggregate particles and TEM images demonstrated the mitochondrial-like body in the MPs. Flow cytometry studies also showed a significant increase in the percent of CD41, and CD14, and a significant decrease in the percent of CD235a in the test group compared to control (P value=0.029, P value=0.035, P value= 0.001 respectively). Moreover, the percentage of CD34 MPs indicated a borderline difference between the two groups (P value= 0.075). Finally count of MPs in the test and control groups was 1202095.34 and 280948.64, respectively and the difference was significant (P value=0.008).

CONCLUSION

It is concluded that LRFs are a potential source of the large volume of various cell MPs with different phenotypical and structural properties for animal and human phase studies. Moreover, the investigation of LRFs as a source of different types of exosomes can shed new light on extracellular vesicle studies.

The potential effect of leukocyte filtration methods on erythrocyte-derived microvesicles: One step forward

By harmonizing the pre-preparation conditions and also removing some donors’ variations, the current study took one step forward to investigate whether different leukocyte filtration sets influence the quality of RBCs throughout the storage time. Twelve whole blood units were collected, and each unit was split into three equal parts. Thirty-six divided bags were filtered using three different leukocyte-filtration sets including Red Cell and Whole Blood Filters (12 units per filter). The prepared RBCs were refrigerated for up to 42 days and assessed for microvesicle count and size, clotting- and prothrombin time, hemolysis index, and biochemical parameters. A significant increment in erythrocytes microvesicle count (EMVs/μL) was observed during the time in the three filtration sets. The number of EMVs in WBF-RBCs was higher (~1.6 fold) than in F-RCF on day 42 (p=0.035). Interestingly the median fluorescence intensity of EMVs decreased during the storage. The size of MVs rose during the time without any significant differences among the filters. Coagulation time decreased in RBCs over the storage, with no significant differences among the filters. Hemolysis index and lactate concentration increased while glucose level decreased significantly throughout the time. The changes in WBF-RBCs were more drastic rather than RCF-RBCs. The only significant difference in the count of EMVs was between WBF and F-RCF components on day 42. Though the changes in WBF products were more drastic, all the values fell within the standard limits. Accordingly, all three filtration sets can be considered.

Tumor Microenvironment Changing through Application of MicroRNA-34a Related Mesenchymal Stem Cells Conditioned Medium: Modulation of Breast Cancer Cells toward Non-aggressive Behavior

Conditioned medium (CM) derived from mesenchymal stem cells (MSCs) contains bioactive molecules including microRNAs (miRs) that could be a potential tool for controlling cancer cells' behavior. Due to the properties of CM, this study assesses the effects of miR-34a related MSC-CM on tumor behavior through the evaluation of migration, invasion, apoptosis, and PDL1 expression in breast cancer cell lines. The miR-34a overexpression vector or scramble control was produced using lentiviral vectors, DNA cloning, and the transfection of the HEK-293T cell line. It was then transduced into human adipose-derived mesenchymal stem cells (hAD-MSCs). MSC-CMs were collected and added onto MDA-MB-231 cell lines. The functional evaluations were performed by transwell, wound healing, and Annexin V/PI methods on the treated MDA-MB-231 cell lines. The PDL1 expression was also assessed by Real-time PCR and western blot. The findings of this study showed that ectopic miR‑34a expression was significantly upregulated in manipulated hASC with miR-34a (p<0.0001). Treatment of MDA-MB-231 cell line with miR-34a-hAD-MSC-CM, scramble-hAD-MSC-CM, or hAD-MSC-CM displayed not only a reduction in the number of migrated or invaded cells (p=0.01) but also an increase in the apoptotic cells in the test group (p=0.02) when compared to the control groups. It also showed down-regulation in the gene (p=0.05) and protein expression levels of PDL1 in the test group. The results of the present study showed that simultaneous application of miR-34a and MSC-CM can be considered as a new method for changing the cancerous microenvironment; and therefore, as a potential strategy in breast cancer therapy.

Iron depletion with deferoxamine protects bone marrow-derived mesenchymal stem cells against oxidative stress-induced apoptosis

Bone marrow mesenchymal stem cells (BM-MSCs) are multipotent cells with self-renewal properties, making them an ideal candidate for regenerative medicine. Recently, numerous studies show that about more than 99% of transplanted cells are destroyed because of the stressful microenvironment. Meanwhile, in the target organs, iron overload can produce oxidative stress introducing it as the most important stress factor. The present study was aimed at increasing BM-MSCs' viability against oxidative stress microenvironment using iron depletion by deferoxamine (DFO). Mesenchymal stem cells are isolated and characterized from rat bone marrow. Then, the sensitivity of BM-MSCs against H2O2-induced oxidative stress was evaluated through half of the inhibitory concentration (IC50) estimation by using MTT assay. The maximum non-inhibitory concentration of DFO on BM-MSCs was determined. The next step was the comparison between DFO pre-treated BM-MSCs and untreated cells against H2O2-induced apoptosis. BM-MSCs were identified with morphologic and flow cytometry analysis. IC50 of H2O2 was determined as 0.55 mM at 4 h. Also, the maximum non-inhibitory concentration of DFO was ascertained as 5 μM at 48 h. Our results demonstrated that pretreatment with DFO significantly potentiates BM-MSCs against H2O2-induced oxidative stress which was confirmed by MTT assay, AO/EB double staining, DAPI staining, and activated caspase 3 quantification as well as western blot test. Expression of cleaved caspase 3 and pAKT/AKT ratio obviously demonstrated DFO can resist the cells against cytotoxicity. These findings may help to develop better stem cell culture medium for MSC-based cell therapy. Moreover, regulation of cell stress can be used in practical subjects.

Peripheral blood CD163(+) monocytes and soluble CD163 in dry and neovascular age-related macular degeneration

Macrophages are the main infiltrating immune cells in choroidal neovascularization (CNV), a hallmark of the human wet, or neovascular age-related macular degeneration (AMD). Due to their plasticity and ability to adapt to the local microenvironment in a tissue-dependent manner, macrophages display polar functional phenotypes characterized by their cell surface markers and their cytokine profiles. We found accumulation of hemoglobin-scavenging cluster of differentiation 163 (CD163)(+) macrophages in laser-induced CNV lesions and higher expression of CD163(+) monocytes in the peripheral blood on day 7 post injury in mice. In comparison, CD80(+) macrophages did not differ with laser-injury in young or aged mice and did not significantly change in the peripheral blood of CNV mice. We examined the percentages of CD163(+), CD206(+), and CD80(+) monocytes in the peripheral blood of patients with wet AMD, patients with dry AMD, and in age-matched individuals without AMD as controls. Percentages of peripheral blood CD163(+) monocytes in both dry AMD (P < .001) and wet AMD (P < .05) were higher than in age-matched non-AMD controls, while there was no difference between the groups in the percentages of peripheral CD206(+) and CD80(+) monocytes. Further, serum level of soluble CD163 (sCD163) was elevated only in patients with wet AMD (P < .05). An examination of 40 cytokine levels across the study groups revealed that anti-VEGF treated patients with wet AMD, who showed no exudative signs on the day of blood drawing had a cytokine profile that was similar to that of non-AMD individuals. These results indicate that CD163 could be further evaluated for its potential as a useful marker of disease activity in patients with neovascular AMD. Future studies will address the origin and potential mechanistic role of CD163(+) macrophages in wet AMD pathologies of angiogenesis and leakage of blood components.

Association between cytokines and two circulating micro-RNAs and development of premature ventricular contractions-induced cardiomyopathy

Objective(s):

Recent progress in understanding the pathogenesis of premature ventricular contraction (PVC)-induced cardiomyopathy (PIC) has suggested a key role for inflammation. The aim of this study was to evaluate the expression of messenger RNAs (mRNAs) and the protein production of interleukin-6 (IL-6), IL-10, tumor necrosis factor alpha (TNF-α) and interferon-γ (IFN-γ) and two circulating micro-RNAs related to inflammation and cardiovascular disease; miR-155 and miR-146.

Materials and Methods:

The study population was comprised 25 patients with PIC and 25 patients with normal left ventricular ejection fraction despite frequent PVCs. TNF-α, IL-6, IL10, and IFN-γ levels were evaluated in peripheral blood mononuclear cells (PBMCs) by flow cytometry and their mRNAs were assessed by real time PCR. We analyzed circulating levels of these cytokines by enzyme linked immunosorbent assay (ELISA). Two circulating micro-RNAs, miR-155 and miR-146a, were also investigated.

Results:

The flow cytometry findings showed that the median fluorescence intensity (MFI) of antibodies reacted with the IL-6 and TNF-α were higher in PIC group than the control group (P-value<0.001). In ELISA, the levels of IL-6 (P-value<0.001) and TNF-α (P-value <0.001) and in RT-PCR the relative expression levels of IL-6 (P-value<0.001) and TNF-α (P-value<0.001) were significantly higher in the PIC group. The relative expression levels of miR-155 and miR-146a were not significantly different between 2 groups (P-value>0.05).

Conclusion:

In our patients with PIC, there was an elevation in the expression levels of IL-6 and TNF-α in PBMCs. This finding may provide further insights into the inflammatory pathways involved in PIC.

Effects of Quercetin Supplementation on Hematological Parameters in Non-Alcoholic Fatty Liver Disease: a Randomized, Double-Blind, Placebo-Controlled Pilot Study

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease which has become a public health concern. Since oxidative stress plays a crucial role in the pathogenesis of NAFLD, subsequent hematological disorders are expected. Therefore, antioxidant compounds such as quercetin could ameliorate the related side-effect of oxidative stress. The aim of the current study was to assess the effect of quercetin on hematological parameters in NAFLD patients. A randomized, double-blind, placebo-controlled trial was conducted as a pilot study. In this study 90 patients with NAFLD were supplemented with either a quercetin or a placebo capsule twice daily (500 mg) for 12 weeks. Blood sample was obtained for laboratory parameters at baseline and the end of week 12. End of trial values for red blood cell (RBC; p = 0.002), mean corpuscular hemoglobin concentration (p = 0.029), and mean platelet volume (p = 0.017), significantly increased and the levels of mean corpuscular volume (MCV; p = 0.023), RBC distribution width-coefficient of variation (p = 0.005), platelet distribution width (p = 0.015), and ferritin (p = 0.002) significantly decreased compared to the baseline in group receiving quercetin. Between group analysis revealed that RBC significantly increased (p = 0.025) but, mean corpuscular volume (p = 0.004), mean corpuscular hemoglobin (MCH; p = 0.002), and ferritin (p = 0.013) significantly decreased compared to placebo group. In this work quercetin showed significant effect on RBC, ferritin, MCV, and MCH in intervention group.

Bone marrow microenvironment: The guardian of leukemia stem cells

Bone marrow microenvironment (BMM) is the main sanctuary of leukemic stem cells (LSCs) and protects these cells against conventional therapies. However, it may open up an opportunity to target LSCs by breaking the close connection between LSCs and the BMM. The elimination of LSCs is of high importance, since they follow cancer stem cell theory as a part of this population. Based on cancer stem cell theory, a cell with stem cell-like features stands at the apex of the hierarchy and produces a heterogeneous population and governs the disease. Secretion of cytokines, chemokines, and extracellular vesicles, whether through autocrine or paracrine mechanisms by activation of downstream signaling pathways in LSCs, favors their persistence and makes the BMM less hospitable for normal stem cells. While all details about the interactions of the BMM and LSCs remain to be elucidated, some clinical trials have been designed to limit these reciprocal interactions to cure leukemia more effectively. In this review, we focus on chronic myeloid leukemia and acute myeloid leukemia LSCs and their milieu in the bone marrow, how to segregate them from the normal compartment, and finally the possible ways to eliminate these cells.

Long noncoding RNA PVT1: potential oncogene in the development of acute lymphoblastic leukemia

Emerging evidence shows that long noncoding RNAs (lncRNAs) participate in various cellular processes, and that plasmacytoma variant translocation 1 (PVT1), a newly described oncogene that interacts with various molecules such as p15, p16, NOP2, and c-Myc, is a major contributing factor in tumor development. However, the role of this oncogene remains unknown in the pathogenesis of acute lymphoblastic leukemia (ALL), the most prevalent form of childhood leukemia. In this study, we first measure the expression level of PVT1 in a Jurkat cell line, then small interfering (siRNA) PVT1 is applied to demonstrate the impact of PVT1 knockdown in apoptosis, proliferation, the cell cycle, and its downstream targets. Our findings show that lncRNA was significantly higher in the ALL cell line than normal lymphocytes and that PVT1 knock-down increased the rate of apoptosis, caused G0/G1 arrest in the cell cycle, reduced the proliferation rate, and, above all, reduced the stability of c-Myc protein. All findings were confirmed at the molecular level. Our results may indicate the role of PVT1 knock-down in the suppression of ALL development and might provide an option for targeted therapy for leukemic conditions.

Long non-coding RNA PVT1 as a novel candidate for targeted therapy in hematologic malignancies

Cancerous cells show resistance to various forms of therapy, so applying up to the minute targeted therapy is crucial. For this purpose, long non-coding RNA PVT1 as shown by recent studies is an important oncogene that interacts with vital cellular signaling pathways and different proteins such as c-Myc, NOP2 and LATS2. Due to the enormous role of long non-coding RNAs in development of leukemias, we aimed to show the role of PVT1 knock-down on fate of different hematologic cell lines. owing to this matter, various experiments such as Real-time PCR, cell cycle analysis and apoptosis assay were performed. Meanwhile, proliferation rate by CFSE, protein expression of c-Myc and hTERT by western blot and flow cytometry analysis were investigated. Our results demonstrated that PVT1 knock-down results in c-Myc degradation, proliferation down-regulation, induction of apoptosis and G0/G1 arrest. Simultaneously, for the first time, we posited the relation between this oncogene with hTERT that reduced after PVT1 knock-down. Considering these results, long non-coding RNA PVT1 may be a potential option for targeted therapy in hematologic malignancies.

MicroRNA Microarray Profiling during Megakaryocyte Differentiation of Cord Blood CD133+ Hematopoietic Stem Cells

Objective

In order to clarify the role of microRNAs (miRNA) in megakaryocyte differentiation, we ran a microRNA microarray experiment to measure the expression level of 961 human miRNA in megakaryocytes differentiated from human umbilical cord blood CD133+ cells.

Materials and Methods

In this experimental study, human CD133+ hematopoietic stem cells were collected from three human umbilical cord blood (UCB) samples, and then differentiated to the megakaryocytic lineage and characterized by flow cytometry, CFU-assay and ploidy analysis. Subsequently, microarray analysis was undertaken followed by quantitative polymerase chain reaction (qPCR) to validate differentially expressed miRNA identified in the microarray analysis.

Results

A total of 10 and 14 miRNAs were upregulated (e.g. miR-1246 and miR-148-a) and down-regulated (e.g. miR- 551b and miR-10a) respectively during megakaryocyte differentiation, all of which were confirmed by qPCR. Analysis of targets of these miRNA showed that the majority of targets are transcription factors involved in megakaryopoiesis.

Conclusion

We conclude that miRNA play an important role in megakaryocyte differentiation and may be used as targets to change the rate of differentiation and further our understanding of the biology of megakaryocyte commitment.

Comparison of human umbilical cord blood processing with or without hydroxyethyl starch

BACKGROUND

Umbilical cord blood (UCB) processing with hydroxyethyl starch (HES) is the most common protocol in the cord blood banks. The quality of UCB volume reduction was guaranteed by minimum manipulation of cord blood samples in the closed system. This study aimed to analyze and compare cell recovery and viability of UCB processed using the Sepax automated system in the presence and absence of HES.

STUDY DESIGN AND METHODS

Thirty UCB bags with a total nucleated cell (TNC) count of more than 2.5 × 109 were divided in two bags with equal volume. HES solution was added to one bag and another was intact. Both bags were processed with the Sepax. To determine cell recovery, viability, and potential of colony-forming cells (CFCs), preprocessing, postprocessing, and thawing samples were analyzed.

RESULTS

The mean TNC recovery after processing and after thaw was significantly better with the HES method (p < 0.01 for the postprocessing step and p < 0.05 for the postthaw step). There were no significant differences to mononucleated cells (MNCs) and CD34+ cell recovery between the two methods after processing and after thaw. TNC and MNC viability was significantly higher without HES after processing and after thaw (p < 0.01). The results of the CFC assay were similar for both methods after processing and after thaw.

CONCLUSION

These results showed that processing of UCB using the Sepax system with the without-HES protocol due to the lower manipulation of samples could be used as an eligible protocol to reduce the volume of UCB.

Mimicking the Acute Myeloid Leukemia Niche for Molecular Study and Drug Screening

Bone marrow niche is a major contributing factor in leukemia development and drug resistance in acute myeloid leukemia (AML) patients. Although mimicking leukemic bone marrow niche relies on two-dimensional (2D) culture conditions, it cannot recapitulate complex bone marrow structure that causes introduction of different three-dimensional (3D) scaffolds. Simultaneously, microfluidic platform by perfusing medium culture mimic interstitial fluid flow, along with 3D scaffold would help for mimicking bone marrow microenvironment. In this study TF-1 cells were cocultured with bone marrow mesenchymal stem cells (BM-MSCs) in 2D and 3D microfluidic devices. Phenotype maintenance during cell culture and proliferation rate was assayed and confirmed by cell cycle analysis. Morphology of cells in 2D and 3D culture conditions was demonstrated by scanning electron microscopy. After these experiments, drug screening was performed by applying azacitidine and cytarabine and cytotoxicity assay and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) for B cell lymphoma 2 (BCL2) were done to compare drug resistance in 2D and 3D culture conditions. Our result shows leukemic cells in 3D microfluidic device retaining their phenotype and proliferation rate was significantly higher in 3D culture condition in comparison to 2D culture condition (p < 0.05), which was confirmed by cell cycle analysis. Cytotoxicity assay also illustrated drug resistance in 3D culture condition and qRT-PCR demonstrated higher BCL2 expression in 3D microfluidic device in contrast to 2D microfluidic device (p < 0.05). On balance, mimicking bone marrow niche would help the target therapy and specify the role of niche in development of leukemia in AML patients.

Molecular and Cellular Interactions of Allogenic and Autologus Mesenchymal Stem Cells with Innate and Acquired Immunity and Their Role in Regenerative Medicine

Mesenchymal stem cells (MSCs), as major stem cells for cell therapy, have been studied from different aspects in preclinical and clinical settings for more than a decade. These cells modulate the immune system (humoral and cellular immune responses) in vitro by producing soluble factors (anti-inflammatory molecules) and/or making cell-cell contacts. Hence, they could be used in regenerative medicine, tissue engineering and immune therapy. MSCs-based therapy have been recently used for treatment of cancer regarding the migratory potential of these cells towards tumor cells which makes them considerable candidates, also for cell therapy in both allogeneic and autologous settings. So, this review attempts to focus on the factors secreted by MSCs such as cytokines, their functional role in mounting and controlling immune responses mediated by different immune cell subpopulations and their significance in regenerative medicine in clinical trials. Although, further studies remain to be done to increase our knowledge of regulating development mechanisms, homeostasis and tissue repair in order to provide new tools to implement the efficacy of cell therapy trials. Although MSCs have been proved safe and effective for cell therapy, there are still challenges to overcome before widely applying MSCs in clinic.

Platelet Transfusion Outcome and Flow Cytometric Monocyte Phagocytic Assay (FMPA)

BACKGROUND

This study was designed to evaluate platelet transfusion outcome via flow cytometric monocyte phagocytic assay (FMPA).  

METHODS

Fifteen patients with a history of multiple platelet transfusions and fifteen controls were enrolled in this study. CMFDA-labeled platelets were incubated with patients' sera and were finally incubated with monocytes in a tube and analyzed by flow cytometry. Monocytes that phagocytosed platelets were detected as a CMFDA-positive platelet population via monocyte gate. The FMPA results were compared with CCI results for the patients.

RESULTS

The FMPA result correlated with 1-hour (r = -0.885, P = 0.001) and 24-hour (r = -0.884, P = 0.001) CCI. There is a significant difference in means of FMPA results between the patients with immune platelet refractoriness (68.46 ± 10.4%), non-refractory group (37.73 ± 15.21%) and the control group (18.27 ± 2.86%). 

CONCLUSION

Our data showed that FMPA has good results in evaluation of platelet transfusion outcome and may be useful as an indicator of platelet transfusion response.

The Effect of Mir-451 Upregulation on Erythroid Lineage Differentiation of Murine Embryonic Stem Cells

OBJECTIVE

MicroRNAs (miRNAs) are small endogenous non-coding regulatory RNAs that control mRNAs post-transcriptionally. Several mouse stem cells miRNAs are cloned differentially regulated in different hematopoietic lineages, suggesting their possible role in hematopoietic lineage differentiation. Recent studies have shown that specific miRNAs such as Mir-451 have key roles in erythropoiesis.

MATERIALS AND METHODS

In this experimental study, murine embryonic stem cells (mESCs) were infected with lentiviruses containing pCDH-Mir-451. Erythroid differentiation was assessed based on the expression level of transcriptional factors (Gata-1, Klf-1, Epor) and hemoglobin chains (α, β, γ , ε and ζ) genes using quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and presence of erythroid surface antigens (TER-119 and CD235a) using flow cytometery. Colony-forming unit (CFU) assay was also on days 14thand 21thafter transduction.

RESULTS

Mature Mir-451 expression level increased by 3.434-fold relative to the untreated mESCs on day 4 after transduction (P<0.001). Mir-451 up-regulation correlated with the induction of transcriptional factor (Gata-1, Klf-1, Epor) and hemoglobin chain (α, β, γ, ε and ζ) genes in mESCs (P<0.001) and also showed a strong correlation with presence of CD235a and Ter- 119 markers in these cells (13.084and 13.327-fold increse, respectively) (P<0.05). Moreover, mESCs treated with pCDH-Mir-451 showed a significant raise in CFU-erythroid (CFU-E) colonies (5.2-fold) compared with untreated control group (P<0.05).

CONCLUSION

Our results showed that Mir-451 up-regulation strongly induces erythroid differentiation and maturation of mESCs. Overexpression of Mir-451 may have the potential to produce artificial red blood cells (RBCs) without the presence of any stimulatory cytokines.

Effects of DKK-3, a Wnt signaling inhibitor, on dendritic cell phenotype and T cell polarization

Wnt signaling plays crucial roles in regulation of a wide range of processes in different cell types including immune cells and, in particular, dendritic cells and T cells. Growing indications point out that Wnt pathway components modulate the both innate and adaptive immune responses through regulating DC functions. We investigated the effects of recombinant DKK-3 protein on the phenotype and biological functions of bone marrow-derived DCs (BM-DCs) as well as T cell polarization. The phenotype and the cytokine production of BM-derived DCs in the presence DKK-3 were analyzed using flow cytometry and ELISA, respectively. Also, capability of DCs to activate T cells was evaluated by CFSE-labeled splenocytes. Regulatory T cell induction, T cell polarization, and cytokine secretion were assessed by flow cytometry and ELISA in splenocytes cultured in the presence of DKK-3. Our results showed that the expression of CD86 and CD40 increased in the DKK-3-treated DC, while the expression of PDL-1 and PDL-2 diminished. Furthermore, the presence of DKK-3 decreased IL-10 and IL-4 production and increased IFN-gamma production by treated DCs.DKK-3. Moreover, DKK-3 shifted naive CD4 T cells towards TH1 cells through up-regulation of T-bet and down-regulation of GATA-3. Our results, therefore, suggest that DKK-3 protein has the ability to promote the generation of Th1-immunostimulatory DCs from its precursors.

Expression of CXCR4 in cord blood-derived CD133+ cells treated with platelet micro-particles

Platelet micro-particles (MPs) contain CXCR4 markers and are able to transfer them into hematopoietic stem cells. Therefore, effect of platelet MPs (PMPs) on the expression levels of CXCR4 and CD34 markers in these cells was examined. Isolated CD 133+ cells cultivated for 5 d in the stem span medium and PMPs. Fold increase of CD34+ cells in the presence of 5 and 10 g/ml of PMPs was increased significantly. CXCR4+ cell percent in the presence of 10 g/ml PMPs compared with control cells (63.8 ± 6.4) was increased (P < 0.05). PMPs were no affect on clonogenicity of hematopoietic progenitor cells.

BACKGROUND

Cord blood CD133+ cells are able to maintain long-term hematopoiesis and to differentiate to hematopoietic lineages. CXCR4 over expression is involved in homing and successful transplantation of hematopoietic stem cells (HSCs) in the bone marrow. PMPs contain CXCR4 markers and are able to transfer them into hematopoietic stem cells. Therefore, considering the importance of CD133+ cells as primitive HSCs, the effect of PMPs on the expression levels of CXCR4 and CD34 markers in these cells was examined.

MATERIALS AND METHODS

Cord blood CD133+ cells were isolated by MACS. Isolated cells were divided into three groups: (i) control cells, (ii) cells treated with 5 μg/ml PMPs, (iii) cells treated with 10 μg/ml PMPs. Cells were cultivated for 5 d in the stem span medium. Expression of CD 133, CD34, and CXCR4 surface marker was analyzed by flow cytometry. Total cell numbers were counted by hemocytometer and clonogenicity were measured by colony assay.

RESULTS

PMPs were no effect on CD133+ cells proliferation, but fold increase of CD34+ cells in the presence of 5 and 10 g/ml of PMPs was increased significantly. CXCR4+ cell percent in the presence of 10 g/ml PMPs compared with control cells (63.8 ± 6.4) was increased (P < 0.05). PMPs were no affect on clonogenicity of hematopoietic progenitor cells.

CONCLUSIONS

Exposure of CD133+ cells isolated from cord blood to PMPs with 10 μg/ml concentration increased the expression of CXCR4 surface marker significantly.

The Important Role of FLT3-L in Ex Vivo Expansion of Hematopoietic Stem Cells following Co-Culture with Mesenchymal Stem Cells

Objective

Hematopoietic stem cells (HSCs) transplantation using umbilical cord blood (UCB) has improved during the last decade. Because of cell limitations, several studies focused on the ex vivo expansion of HSCs. Numerous investigations were performed to introduce the best cytokine cocktails for HSC expansion The majority used the Fms-related tyrosine kinase 3 ligand (FLT3-L) as a critical component. According to FLT3-L biology, in this study we have investigated the hypothesis that FLT3-L only effectively induces HSCs expansion in the presence of a mesenchymal stem cell (MSC) feeder.

Materials and Methods

In this experimental study, HSCs and MSCs were isolated from UCB and placenta, respectively. HSCs were cultured in different culture conditions in the presence and absence of MSC feeder and cytokines. After ten days of culture, total nucleated cell count (TNC), cluster of differentiation 34+(CD34⁺) cell count, colony forming unit assay (CFU), long-term culture initiating cell (LTC-IC), homeobox protein B4 (HoxB4) mRNA and surface CD49d expression were evaluated. The fold increase for some culture conditions was compared by the t test.

Results

HSCs expanded in the presence of cytokines and MSCs feeder. The rate of expansion in the co-culture condition was two-fold more than culture with cytokines (P<0.05). FLT3-L could expand HSCs in the co-culture condition at a level of 20-fold equal to the presence of stem cell factor (SCF), thrombopoietin (TPO) and FLT3-L without feeder cells. The number of extracted colonies from LTC-IC and CD49d expression compared with a cytokine cocktail condition meaningfully increased (P<0.05).

Conclusion

FLT3-L co-culture with MSCs can induce high yield expansion of HSCs and be a substitute for the universal cocktail of SCF, TPO and FLT3-L in feeder-free culture.

The relationship between HLA-G and viral loads in non-responder HCV-infected patients after combined therapy with IFN-α2α and ribavirin

Hepatitis C disease is a virus mediated infection causing major health problem worldwide. Conversions of immune surveillance play an important role in response to virus clearance. Immune modulating molecules such as HLA-G and IL-10 that convert immune response toward Th2 may play a role to inhibit response from combined therapy with IFN-α2α and ribavirin. The objective of this study was to investigate the expression of HLA-G and IL-10 in responder and non-responder HCV positive patients. In this study, characteristics of the virus and 48 responder and non-responder patients in response to the combined therapy with IFN-α2α and ribavirin were analyzed. The expression levels of HLA-G and IL-10 were conducted using real-time PCR. Also, soluble HLA-G in both groups of patients and healthy individuals were determined by enzyme-linked immunosorbent assay. According to the obtained data, HCV 1a was the predominant genotype in responder and non-responder patients. Expression levels of HLA-G and IL-10 in non-responder group was significantly more than responder and control groups (P<0.001). Additionally, expression levels of HLA-G and IL-10 were remarkably higher compared to healthy individuals at the beginning of treatment. Soluble HLA-G in non-responder patients was noticeably increased in comparison to responder patients after treatment (P<0.05). These findings suggest that elevation of HLA-G and IL-10 in HCV infected patients may play an important role in response to combined therapy with IFN-α2α and ribavirin.

Cord blood banking activity in Iran National Cord Blood Bank: a two years experience

Today umbilical cord blood (UCB) has known as a commonly used source of hematopoietic stem cells for allogeneic transplantation and many cord blood banks have been established around the world for collection and cryopreservation of cord blood units. Herein, we describe our experience at Iran National Cord Blood Bank (INCBB) during 2 years of activity. From November 2010 to 2012, UCBs were collected from 5 hospitals in Tehran. All the collection, processing, testing, cryopreservation and storage procedures were done according to standard operation procedures. Total nucleated cells (TNC) count, viability test, CD34+ cell count, colony forming unit (CFU) assay, screening tests and HLA typing were done on all banked units. Within 3770 collected units, only 32.9% fulfilled banking criteria. The mean volume of units was 105.2 ml and after volume reduction the mean of TNC, viability, CD34+ cells and CFUs was 10.76×10(8), 95.2%, 2.99×10(6) and 7.1×10(5), respectively. One unit was transplanted at Dec 2012 to a 5-year old patient with five of six HLA compatibilities. In our country banking of UCB is new and high rate of hematopoietic stem cell transplants needs expanding CB banks capacity to find more matching units, optimization of methods and sharing experiences to improve biological characterization of units.

The High Yield Expansion and Megakaryocytic Differentiation of Human Umbilical Cord Blood CD133(+) Cells

OBJECTIVE

Despite of many benefits, umbilical cord blood (UCB) hematopoietic stem cell (HSC) transplantation is associated with low number of stem cells and slow engraftment; in particular of platelets. So, expanded HSCs and co-transfusion of megakaryocyte (MK) progenitor cells can shorten this period. In this study, we evaluated the cytokine conditions for maximum expansion and MK differentiation of CD133(+) HSCs.

MATERIALS AND METHODS

In this experimental study, The CD133(+) cells were separated from three cord blood samples by magnetic activated cell sorting (MACS) method, expanded in different cytokine combinations for a week and differentiated in thrombopoietin (TPO) for the second week. Differentiation was followed by the flow cytometry detection of CD41 and CD61 surface markers. Colony forming unit (CFU) assay and DNA analysis were done for colonogenic capacity and ploidy assay.

RESULTS

CD133(+) cells showed maximum expansion in the stem span medium with stem cell factor (SCF) + FMS-like tyrosine kinase 3-ligand (Flt3-L) + TPO but the maximum differentiation was seen when CD133(+) cells were expanded in stem span medium with SCF + Interleukin 3 (IL-3) + TPO for the first and in TPO for the second week. Colony Forming Unit-MK (CFU-MK) was formed in three sizes of colonies in the mega-cult medium. In the DNA analysis; 25.2 ± 6.7% of the cells had more than 2n DNA mass.

CONCLUSION

Distinct differences in the MK progenitor cell count were observed when the cells were cultured in stem span medium with TPO, SCF, IL-3 and then the TPO in the second week. Such strategy could be applied for optimization of CD133(+) cells expansion followed by MK differentiation.

Isolation of stem cells from adult rat kidneys

The kidney has an inherent ability for recovery and regeneration following acute damage. However, there has been much contention as to the source of regenerating renal cells. The aim of this study was to isolate and characterize these cells. Normal rat kidneys were minced and cells were isolated with collagenase I and were cultured in an expansion medium. Adherent cells were isolated and expanded for more than 120 days in vitro. These cells had the potential of trans-lineage differentiation into neural cells, adipocytes and osteocytes. These cells also expressed Nucleostemin, Cyclin D1, Notch1 and Survivin which are commonly expressed in stem cells. The results of the current work show that the adult kidney contains a population of multipotent stem cells.