The Effect of Exosomes Derived from Unrestricted Somatic Stem Cells on Murine Model of Sepsis.

Sepsis is a systemic infection mainly caused by bacterial infections. Despite all efforts and advances in the treatment of sepsis, it is still considered one of the leading causes of death in hospitalized patients. Today, we have to use novel therapies and one of the most important is cell-free therapy. Exosomes have been shown to contain the contents of their parent cells and that they do not generate an immune response between different individuals which makes them a good candidate for transplantation. Unrestricted somatic stem cells (USSC), also known as mesenchymal stem cell progenitors due to their high proliferative capacity and low immune response, may be a novel therapy for sepsis. In this study, the effect of USSC-derived exosomes on sepsis was investigated using a mouse model. USSCs were isolated from human cord blood and characterized by flow cytometry and multi-lineage differentiation. The exosomes were then harvested from USSCs and characterized by transmission electron microscopy, Western blotting, and dynamic light scattering. The harvested exosomes were injected into the mouse model of sepsis. Biochemical, histological, molecular, and survival studies were performed in different groups. Our observations showed that USSC-derived exosomes can reduce inflammation in septic mice. Histopathologic and biochemical findings in the sham group showed multiorgan involvement, but these changes disappeared after 7 days of exosome administration. Moreover, the expression of IRAK-1 and TRAF-6 (main adapter molecules in signaling pathways of inflammation) was decreased through negative regulation by miR-146a after 72 h of exosome administration. A 2-fold increase in the level of IL-10 and a 2-fold decrease in the levels of IL-6 and TNF-α was observed. In conclusion, we showed that direct injection of USSC-derived exosomes can be one of the important methods for the treatment of various aspects of sepsis due to their immunomodulatory properties.

High percentage of Cancer Stem cells in metastatic locations: Upregulation of cicBIRC6 in highly metastatic breast Cancer Subline.

BACKGROUND: Metastasis is a devastating complication of breast cancer. Cancer relapse and metastasis are associated with cancer stem cells. CicBIRC6 is a circular RNA that is proposed to be involved in the stemness of stem cells. In breast cancer, metastatic tumor cells have higher stem cell properties. In the present study, we evaluate the expression of cicBIRC6 in these cells. METHODS: After the development of a syngeneic animal model of TNBC, primary breast cancer cells named 4T1T were isolated from the tumor mass. Highly metastatic tumor cells named 4T1B and 4T1L were isolated and expanded from brain metastasis lesions and lungs of cancerous mice respectively. Sphere formation ability in metastatic and primary tumor cells was evaluated separately. The quantitative real-time polymerase chain reaction was performed to analyze the expression of cicBIRC6 in primary and metastatic tumor cells. RESULTS: Our data revealed that, sphere formation ability among metastatic tumor cells was significantly higher. Surprisingly expression of cicBIRC6 was significantly upregulated in these metastatic tumor cells. In comparison with 4T1T, cicBIRC6 was upregulated 5.7 and 3.5 times in 4T1B and 4T1L respectively. CONCLUSION: These findings provided important insights regarding the molecular properties of metastatic tumor cells and can be used for designing a targeted therapeutic strategy in combat with these cells.

Mir-122 upregulation and let-7f downregulation combination: The effects on hepatic differentiation of hiPSCs on the PCL-Gel-HA nanofibrous scaffold.

Cell therapy and tissue engineering as promising candidates for the liver transplantation dilemma are of special interest. Induced pluripotent stem cells (iPSCs) are one of the best sources in this field, but their differentiation methods to hepatocytes have remained challenging. We transduced human iPSCs (hiPSCs) with miR-122 and off-let-7f (hiPSCsmiR-122 + off-let-7f ) to evaluate how they can differentiate hiPSCs to hepatocyte-like cells (HLCs) without any extrinsic growth factor. Additionally, we studied the effect of Poly ɛ-caprolactone-gelatin-hyaluronic acid (PCL-Gel-HA) nanofibrous scaffold as an extracellular matrix (ECM) simulator on differentiation improvement. Definitive endoderm markers (FOXA2 and SOX17), as well as hepatic markers (AFP, Albumin, CK18, HNF4α) expression, were significantly higher in hiPSCsmiR-122 + off-let-7f derived HLCs (hiPSCs-HLCs) compared to the control group (miR-scramble transduced hiPSCs: hiPSCsscramble ). hiPSCs-HLCs indicated hepatocyte morphological characteristics and positive immunostaining for AFP, Albumin and HNF4α. Albumin and urea secretion were significantly higher in hiPSCs-HLCs than hiPSCsscramble . Comparing these markers in the PCL-Gel-HA group with the tissue culture plate (TCP) group revealed that PCL-Gel-HA could improve differentiation towards HLCs significantly. Regarding our results, these microRNAs can be used to differentiate hiPSCs to the functional hepatocytes for disease modelling, drug screening and cell-based therapy in future studies.

Thrombosis in COVID-19 infection: Role of platelet activation-mediated immunity.

BACKGROUND: Thrombosis plays an important role in the Coronavrus Disease 2019 (COVID-19) infection-related complications such as acute respiratory distress syndrome and myocardial infarction. Multiple factors such as oxygen demand injuries, endothelial cells injury related to infection, and plaque formation. MAIN BODY: Platelets obtained from the patients may have severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA, showing that the increased activation potential recommends platelet can be hyper-activated in severely ill SARS-CoV-2 cases. Platelets contain multiple receptors that interact with specific ligands. Pathogen's receptors such as Toll-like receptors (TLRs), NOD-like receptor, C-type lectin receptor family, glycoprotein (GP) such as GPαIIbß3 and GPIbα which allow pathogens to interact with platelets. Platelet TLRs and NOD2 are involved in platelet activation and thrombosis. Accordingly, TLRs are critical receptors that could recognize various endogenous damage-associated molecular patterns and exogenous pathogen-associated molecular patterns (PAMPs). TLRs are considered as important components in the activation of innate immunity response against pathogenic and non-pathogenic components like damaged tissues. TLRs-1,-2,-4,-6,-7 expression on or within platelets has been reported previously. Various PAMPs were indicated to be capable of binding to platelet-TLRs and inducing both the activation and promotion of downstream proinflammatory signaling cascade. CONCLUSION: It is possible that the increased TLRs expression and TLR-mediated platelets activation during COVID-19 may enhance vascular and coronary thrombosis. It may be hypothesized using TLRs antagonist and monoclonal antibody against P-selectin, as the marker of leukocyte recruitment and platelet activation, besides viral therapy provide therapeutic advances in fighting against the thrombosis related complications in COVID-19.

Generation of an in vitro model of ß-thalassemia using the CRISPR/Cas9 genome editing system.

ß-Thalassemia is a common monogenic disease characterized by defective ß-globin chains synthesis. In vitro ß-thalassemia-related research on increasing ß-like globin genes or identification of factors reducing the severity of the disease, has been performed on mouse erythroleukaemia or K562 cell lines. The aim of this study was the production of an in vitro model of ß-thalassemia using the highly efficient CRISPR-Cas9 system. Embryonic stem (ES) cells were nucleofected with guide RNA (gRNA)-Cas9 expression vectors. Molecular testing was done on extracted DNA to assess Hbb-b1 mutation. Analysis of transcription factors and hemoglobin genes were evaluated using quantitative reverse transcription-polymerase chain reaction following erythroid differentiation of ES cells. Sequencing data confirmed Hbb-b1 knockout alleles. Significant expression of erythroid transcription factors was observed in wild-type, Hbb-b1+/- and Hbb-b1-/- groups (P < .001). Compared with the wild-type group, the absolute number of Hbb-b1 mRNA in Hbb-b1+/- group significantly decreased from 6.44 × 106 to 3.23 × 106 copy number (P < .01), whereas in Hbb-b1-/- group had zero expression. The CRISPR/Cas9-mediated Hbb-b1 knockout in ES cells provides accessibility to an in vitro thalassemia model following erythroid differentiation. Considering the need for in vitro and mouse models to investigate the molecular basis of ß-thalassemia which also enables testing of therapeutic approaches, this method can be utilized to produce a mouse model of ß-thalassemia intermedia (Hbbth1/th1).

miR-30a regulates γ-globin expression in erythoid precursors of intermedia thalassemia through targeting BCL11A.

Patients with ß-thalassemia suffer from a lack or absence of the beta-globin chain of normal hemoglobin (Hb). Therefore, an increase in fetal Hb (HbF) levels could improve the clinical status of these patients. Downregulation of BCL11A, a key regulatory transcription factor, could ameliorate the clinical status of thalassemic patients by increasing HbF levels. miR-30a expression and its relationship with the BCL11A gene in erythroid precursors was explored in patients with ß-thalassemia. The relevance of miR-30a to clinical parameters was also investigated. We evaluated the expressions of miR-30a, BCL11A, and γ-globin genes by quantitative real-time PCR (qRT-PCR) on isolated erythroid precursors from peripheral blood samples of ß-thalassemia intermedia (TI) patients and in bone marrow samples from healthy individuals as controls. The correlation between miR-30a expression and clinical indices that included HbF levels, ferritin, and the frequency of blood transfusions were assessed. We observed increased expression of miR-30a in conjunction with decreased BCL11A expression and elevated γ-globin and HbF levels. Patients with elevated miR-30a expression had a higher percentage of HbF and a lower level of ferritin. In addition, we observed that overexpression of miR-30a in erythroid precursor cells led to reduced BCL11A expression and was associated with elevated γ-globin expression. Our findings showed the importance of miR-30a in BCL11A and HbF regulation, and in the clinical status of patients with ß-thalassemia.

Upregulation of Pro-inflammatory Cytokine Genes by Parvovirus B19 in Human Bone Marrow Mesenchymal Stem Cells.

Chronic inflammation plays a prominent role in cancer initiation and development. On the other hand, the Inflammation can be established by a number of factors such as viral infections. Parvovirus B19 (B19V) is a pathogen with widespread infection, which infects bone marrow erythroid progenitor cells. It has been shown that B19V can also enter human bone marrow mesenchymal stem cells (BM-MSCs). In this study, we hypothesized that BM-MSCs as the main cellular component of bone marrow niche may be induced to secret pro-inflammatory cytokines after B19V infection. BM-MSCs were cultured up to passage 3. The cells were then subjected to nucleofection to transfer a plasmid containing B19V genome. After 36 h, total RNA was extracted and the expression levels of IL-1ß, IL-6, TNF-α and NF-κB genes were examined using qRT-PCR. Data analysis showed the significant increase in expression levels of all studied genes in the B19V-transfected cells (P < 0.05). Although further researches are required, our findings for the first time suggest the importance of B19V infection to establish an inflammatory microenvironment in the bone marrow and its involvement in inflammation-related diseases. Finally, based on our results, molecular assay to diagnose B19V infection of BM-MSCs prior to stem cell therapy is strongly recommended.

Human unrestricted somatic stem cells ameliorate sepsis-related acute lung injury in mice.

BACKGROUND AIMS: Sepsis and related disorders, especially acute lung injury (ALI), are the most challenging life-threatening diseases in the hospital intensive care unit. Complex pathophysiology, unbalanced immune condition, and high rate of mortality complicate the treatment of sepsis. Recently, cell therapy has been introduced as a promising option to recover the sepsis symptoms. The aim of this study was to investigate the therapeutic potential of human unrestricted somatic stem cells (USSCs) isolated from human umbilical cord blood in the mouse model of ALI. USSCs significantly enhanced the survival rate of mice suffering from ALI and suppressed concentrations of proinflammatory mediators TNF-α, and interleukin (IL)-6, and the level of anti-inflammatory cytokine IL-10. ALI mice injected by USSCs showed notable reduction in lung and liver injury, pulmonary edema, and hepatic enzymes, compared with the control group. These results determined the in vivo immunomodulatory effect of USSCs for recovery of immune balance and reduction of tissue injury in the mouse model of ALI. Therefore, USSCs can be a suitable therapeutic approach to manage sepsis disease through the anti-inflammatory potential.

TBX18 transcription factor overexpression in human-induced pluripotent stem cells increases their differentiation into pacemaker-like cells.

BACKGROUND: The discovery of gene- and cell-based strategies has opened a new area to investigate novel approaches for the treatment of many conditions caused by cardiac cell failure. The TBX18 (T-box 18) transcription factor is considered as a prominent factor in the sinoatrial node (SAN) formation during the embryonic development. In this in vitro study, the effect of TBX18 gene expression on human-induced pluripotent-stem-cell-derived cardiomyocytes (hiPS-CMs) to induce pacemaker-like cells was examined. METHODS: The human-dermal-fibroblast-derived iPSCs were transfected using chemical, physical, and Lentiviral methods of TBX18 gene delivery during differentiation into cardiomyocytes (CMs). After the differentiation process through small-molecule-based temporal modulation of the Wnt signaling pathway, the hiPSC-CMs were analyzed using the real-time polymerase chain reaction, immunocytochemistry, immunofluorescence, whole-cell patch-clamp recording, and western blotting to investigate the accuracy of differentiation and identify the effect exerted by TBX18. RESULTS: The hiPS-CMs showed spontaneous beating and expressed specific markers of cardiac cells. The lentiviral-mediated TBX18 delivery was the most efficient method for transfection. The results showed the increment in Connexin 43 expression among untransfected hiPS-CMs, whereas this protein was significantly downregulated followed by TBX18 overexpression. TBX18-hiPSCMs were detected with pacemaker cell features. CONCLUSIONS: It was demonstrated that the TBX18 gene is able to conduct hiPSCs to differentiate into pacemaker-like cells. The TBX18 gene delivery seems to have the potential for the development of biological pacemakers; however, more investigations are still needed to assess its usefulness to fix arrhythmic conditions with SAN failure basis.

Comparison of cord blood CD34 + stem cell expansion in coculture with mesenchymal stem cells overexpressing SDF-1 and soluble /membrane isoforms of SCF.

AIM: Umbilical cord blood hematopoietic stem cells (UCB HSCs) have been considered for the treatment of hematological malignancies due to their noninvasive collection, greater capacity of expansion, and remarkable tolerance for HLA mismatch in transplantation. On the other hand, the most considerable limitation of these cells is their inadequate amount of CD34 + HSCs which leads to delayed engraftment. The aim of this study was the expansion of CD34 + HSCs by coculturing with mesenchymal stem cells (MSCs) overexpressing stromal cell-derived factor-1, soluble and membrane isoforms of stem cell factor (sSCF/mSCF). Keeping structure and function of overexpressed cytokines by MSCs was expected which could beneficially affect the CD34 + HSC expansion. METHODS: MSCs and CD34 + HSCs were isolated from UCB mononuclear cells. UCB MSCs were nucleofected with one or more of sSCF, mSCF, and SDF-1 expression vectors. Isolated CD34 + HSCs were then cocultured with nucleofected MSCs in 10 groups in culture medium containing TPO and Flt3L with or without SCF (3F or 2F groups). Then the CD34 + HSCs numeration, clonogenic capacity, and transcriptional levels of well-known HSCs regulatory and stemness genes (CXCR4, HOXB4, BMI1, and SALL4) were assessed following coculture with modified MSCs. RESULTS: CD34 + HSCs which expanded on MSCs overexpressing mSCF/sSCF/SDF-1 in the 3F group showed the most significant increase in the expansion (4.73 ± 0.26 fold), clonogenic capacity (5.3 ± 0.25 fold) and also transcriptional levels of CXCR4, HOXB4, and BMI1 (3.49 ± 0.13, 9.49 ± 0.78, and 11.6 ± 0.9 fold), respectively ( P < 0.05). CONCLUSION: Overexpression of SCF and SDF-1 by UCB MSCs in coculture system has efficient effect on UCB HSCs expansion. Furthermore nucleofected MSC overexpressing either sSCF/mSCF or mSCF/ sSCF /SDF-1 could substitute the rhu SCF in HSC expansion culture medium.

Functional biological pacemaker generation by T-Box18 protein expression via stem cell and viral delivery approaches in a murine model of complete heart block.

Despite recent advances in the treatment of cardiac arrhythmia, the available options are still limited and associated with some complications. Induction of biological pacemakers via Tbx18 gene insertion in the heart tissue has been suggested as a promising therapeutic strategy for cardiac arrhythmia. Following a previous in vitro study reporting the production of Tbx18-expressing human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs), we aimed to investigate the efficacy of these engineered cells to generate pacemaker rhythms in a murine model of complete heart block. We also attempted to generate a functional pacemaker by Tbx18 overexpression in native cardiac cells of rat heart. The hiPSC-derived pacemaker cells were produced by lentiviral delivery of Tbx18 gene to stem cells during a small molecule-based differentiation process. In the present study, 16 male albino Wistar rats were randomly assigned to Tbx18-lentivirus (n = 4) and Tbx18-pacemaker cells (n = 4) administered via injection into the left ventricular anterolateral wall. The control rats received GFP-lentiviruses (n = 4) and GFP-pacemaker cells (n = 4). Fourteen days after the injection, the rats were sacrificed and analyzed by electrocardiography (ECG) recording using a Langendorff-perfused heart model following complete heart block induced by hypokalemia and crashing. Immunofluorescence staining was used to investigate the expression of Tbx18, HCN4 and connexin 43 (Cx43) proteins in Tbx18-delivered cells of heart tissues. The heart rate was significantly reduced after complete heart block in all of the experimental rats (P < 0.05). Heart beating in the Tbx18-transduced hearts was slower compared with rats receiving Tbx18-pacemaker cells (P = 0.04). The duration of ventricular fibrillation (VF) was higher in the lentiviral Tbx18 group compared with the GFP-injected controls (P = 0.02) and the Tbx18-pacemaker cell group (P = 0.02). The ECG recording data showed spontaneous pacemaker rhythms in both intervention groups with signal propagation in Tbx18-transduced ventricles. Immunostaining results confirmed the overexpression of HCN4 and downregulation of Cx43 as a result of the expression of the Tbx18 gene and spontaneously contracting myocyte formation. We confirmed the formation of a functional pacemaker after introduction of Tbx18 via cell and gene therapy strategies. Although the pacemaker activity was better in gene-received hearts since there were longer VF duration and signal propagation from the injection site, more data should be gathered from the long-term activity of such pacemakers in different hosts.

Introduction of hsa-miR-103a and hsa-miR-1827 and hsa-miR-137 as new regulators of Wnt signaling pathway and their relation to colorectal carcinoma.

Wnt signaling is hyper-activated in most of human cancers including colorectal carcinoma (CRC). Therefore, the introduction of new regulators for Wnt pathway possesses promising diagnostic and therapeutic applications in cancer medicine. Bioinformatics analysis introduced hsa-miR-103a, hsa-miR-1827, and hsa-miR-137 as potential regulators of Wnt signaling pathway. Here, we intended to examine the effect of these human miRNAs on Wnt signaling pathway components, on the cell cycle progression in CRC originated cell lines and their expression in CRC tissues. RT-qPCR results indicated upregulation of hsa-miR-103a, hsa-miR-1827, and downregulation of hsa-miR-137 in CRC tissues. Overexpression of hsa-miR-103a and hsa-miR-1827 in SW480 cells resulted in elevated Wnt activity, detected by both Top/Flash assay and RT-qPCR analysis. Inhibition of Wnt signaling by using PNU-74654 or IWP-2 small molecules suggested that these miRNAs exerts their effect at the ß-catenin degradation complex level. Then, RT-qPCR, dual luciferase assay, and western blotting analysis indicated that APC and APC2 transcripts were targeted by hsa-miR-103a, hsa-miR-1827 while, Wnt3a and ß-catenin genes were upregulated. However, hsa-miR-137 downregulated Wnt3a and ß-catenin genes. Further, hsa-miR-103a and hsa-miR-1827 overexpression resulted in cell cycle progression and reduced apoptotic rate in SW480 cells, unlike hsa-miR-137 overexpression which resulted in cell cycle suppression, detected by flowcytometry and Anexin analysis. Overall, our data introduced hsa-miR-103a, hsa-miR-1827 as onco-miRNAs and hsa-miR-137 as tumor suppressor which exert their effect through regulation of Wnt signaling pathway in CRC and introduced them as potential target for therapy.

The anticancer effects of pharmacological inhibition of autophagy in acute erythroid leukemia cells.

Although recent studies have reported different aspects of autophagy, from pro-survival to pro-death roles of this process in malignant cells, the underlying mechanisms by which autophagy inhibitors contribute toward the induction of programmed cell death in cancerous cells are still unclear. In the present study, we have attempted to explore some of the molecular features of pharmacological inhibition of autophagy in TF-1 cells (an acute erythroid leukemia model). Our findings indicated that ara-C induces autophagy (with alteration of LC3B, p62, and Beclin-1) in the cells; however, targeting autophagy by 3-methyladenine and chloroquine significantly increased caspase-dependent apoptosis and the sub-G1 compartment in ara-C-treated cells. Moreover, cell cycle analysis showed that 3-MA, as an early-stage autophagy inhibitor, could elevate the cell population in the G0/G1 cell cycle phase, which was associated with upregulation of p21 and p27 expressions. Interestingly, autophagy inhibition was also accompanied by downregulation of c-Myc gene and protein expression levels and upregulated levels of Bax and Bak gene expressions. In addition, following inhibition of autophagy, the levels of tumor-suppressive miRNA (i.e. miR-204) increased, whereas the values of oncogenic miRNAs (including miR-21, miR-221, miR-30a, and miR-17) decreased. Overall, our experiments indicate that autophagy inhibitors (especially chloroquine) seem to be promising agents for combination therapy in acute erythroid leukemia.

Down-regulation of the non-coding RNA H19 and its derived miR-675 is concomitant with up-regulation of insulin-like growth factor receptor type 1 during neural-like differentiation of human bone marrow mesenchymal stem cells.

The differentiation of human bone marrow mesenchymal stem cells (BMSCs) into specific lineages offers new opportunities to use the therapeutic efficiency of these pluripotent cells in regenerative medicine. Multiple lines of evidence have revealed that non-coding RNAs play major roles in the differentiation of BMSCs into neural cells. Here, we applied a cocktail of neural inducing factors (NIFs) to differentiate BMSCs into neural-like cells. Our data demonstrated that during neurogenic induction, BMSCs obtained a neuron-like morphology. Also, the results of gene expression analysis by qRT-PCR showed progressively increasing expression levels of neuron-specific enolase (NSE) as well as microtubule-associated protein 2 (MAP-2) and immunocytochemical staining detected the expression of these neuron-specific markers along differentiated BMSC bodies and cytoplasmic processes, confirming the differentiation of BMSCs into neuronal lineages. We also compared differences in the expression levels of the long non-coding RNA (lncRNA) H19 and H19-derived miR-675 between undifferentiated and neurally differentiated BMSCs and found that during neural differentiation down-regulation of the lncRNA H19/miR-675 axis is concomitant with up-regulation of insulin-like growth factor type-1 (IGF-1R), a well-established target of miR-675 involved in neurogenesis. The findings of the current study provide support for the hypothesis that miR-675 may confer functionality to H19, suggesting a key role for this miRNA in the neural differentiation of BSMCs. However, further investigation is required to gain deeper insights into the biological roles of this miRNA in the complex process of neurogenesis.

Tissue-Specific Down-Regulation of the Long Non-Coding RNAs PCAT18 and LINC01133 in Gastric Cancer Development.

Gastric cancer (GC) is the fifth most common cancer and the third most frequent cause of cancer deaths worldwide. The high death rate associated with GC, and lack of appropriate biomarkers for diagnosis, prognosis, and treatment emphasize the need for identification of novel molecules. Given the emerging roles for long non-coding RNAs (lncRNAs) in cancer development, we studied novel lncRNA candidates involved in gastric carcinogenesis. LncRNA candidate discovery was performed using analyses of available datasets and literature. Validation was done using an internal sample set of GC/normal tissues, and external independent datasets. Network analysis and functional annotation of co-expressed protein coding genes were performed using the weighted gene correlation network analysis (WGCNA) and ingenuity pathway analysis. Two novel lncRNAs, PCAT18 and LINC01133, associated with GC development were identified by analysis of the discovery Gene Expression Omnibus (GEO) datasets. The down-regulation of these genes in GC tissues was successfully validated internally and externally. The results showed a tissue-specific down-regulation of PCAT18 and LINC01133 in gastrointestinal tissues. WGCNA and ingenuity pathway analyses revealed that the genes co-expressed with the two lncRNAs were mostly involved in metabolic pathways and networks of gastrointestinal disease and function. Our findings of a tissue-specific down-regulation of PCAT18 and LINC01133 in gastric and other gastrointestinal cancers imply that these lncRNAs may have a tumor suppressive function in the development of these tumor entities. The two lncRNA biomarkers may contribute to a better understanding of the complex mechanisms of gastric carcinogenesis.

Erythropoietin induces production of hepatocyte growth factor from bone marrow mesenchymal stem cells in vitro.

BACKGROUND: Hepatocyte Growth Factor (HGF) plays a pivotal role in hematopoiesis, motility, growth and mobilization of hematopoietic stem/progenitor cells (HSPCs). HGF mainly is produced by bone marrow mesenchymal stem cells (BM-MSCs). MSCs express erythropoietin (EPO) receptor. In this study, we aimed to assess the effect of EPO on HGF secretion in BM-MSCs. METHODS: The BM-MSCs treated with EPO (4 IU/ml) for 6, 24 and 48 h. HGF gene expression and protein level were assessed using quantitative real time PCR (qRT-PCR) and Enzyme-linked immunosorbant Assay. In order to show the effect of secreted HGF on migration of HSPCs, hematopoietic stem cells (HSCs) were isolated from cord blood and evaluated using transwell migration assay. RESULTS: We observed a significant increase in level of HGF in cell supernatant after 48 h compared to control group (P < 0.05). Also, qRT-PCR results demonstrated a significant elevation in HGF expression level after 24 and 48 h treatment with EPO compared to control group (P < 0.05). Finally, migration assay results showed a significant increase in migration of HSCs in treated group after 48 h. CONCLUSION: Our data indicated that EPO may play an important role in stem cell mobilization through up regulating HGF in MSCs and inducing migration of HSCs.

Electrical stimulation of somatic human stem cells mediated by composite containing conductive nanofibers for ligament regeneration.

One of the advances in the field of biomedical nanotechnology, is conductive nanofiber fabrication and the discovery of its applications. Biocompatible flexible nanofibers that have a good biocompatibility, mechanical properties and morphology. Poly (3, 4-ethylene dioxythiophene) (PEDOT) is a conductive polymer that has recently been used in medical applications. In this study, the electrospinning technique and vapor phase polymerization combination method with freeze drying was used to produce Silk fibroin/PEDOT/Chitosan nanocomposite scaffold. The aim of our study was to develop a ligament construct of PEDOT/Silk bilayer nanofibrous scaffold, to mimic the aligned collagen fiber bundles and Chitosan sponge coating was done on these fibrous scaffolds, to mimic the glycosaminoglycans of ECM sheath. The developed constructs were characterized. The unrestricted somatic human stem cells (USSC), were cultured on the scaffold. Then, the effect of applying DC electric pulses to cells cultured on polymer was assessed. Cellular function was actively exhibited in scaffold with electrical induction, as evident by the high expression of collagen I, collagen III, decorin, biglycan and aggrecan genes. Novel scaffold plus electrical stimulation shows facilitating cell seeding and promoting cell proliferation, differentiation. This composites can be used in this new field for stem cells differentiation to target tissues.

Possible involvement of miRNAs in tropism of Parvovirus B19.

Human Parvovirus B19 (PVB19) is one of the most important pathogens that targets erythroid lineage. Many factors were mentioned for restriction to erythroid progenitor cells (EPCs). Previous studies showed that in non-permissive cells VP1 and VP2 (structural proteins) mRNAs were detected but could not translate to proteins. A bioinformatics study showed that this inhibition might be due to specific microRNAs (miRNAs) present in non-permissive cells but not in permissive EPCs. To confirm the hypothesis, we evaluated the effect of miRNAs on VP expression. CD34(+) HSCs were separated from cord blood. Then, CD34(+) cells were treated with differentiation medium to obtain CD36(+) EPCs. To evaluate the effect of miRNAs on VP expression in MCF7 and HEK-293 cell lines (non-permissive cells) and CD36(+) EPCs, dual luciferase assay was performed in presence of shRNAs against Dicer and Drosha to disrupt miRNA biogenesis. QRT-PCR was performed to check down-regulation of Dicer and Drosha after transfection. All measurements were done in triplicate. Data means were compared using one-way ANOVAs. MicroRNA prediction was done by the online microRNA prediction tools. No significant difference was shown in luciferase activity of CD36(+) EPCs after co-transfection with shRNAs, while it was significant in non-permissive cells. Our study revealed that miRNAs may be involved in inhibition of VP expression in non-permissive cells, although further studies are required to demonstrate which miRNAs exactly are involved in regulation of PVB19 replication.

The role of catecholamines in mesenchymal stem cell fate.

Mesenchymal stem cells (MSCs) are multipotent stem cells found in many adult tissues, especially bone marrow (BM) and are capable of differentiation into various lineage cells such as osteoblasts, adipocytes, chondrocytes and myocytes. Moreover, MSCs can be mobilized from connective tissue into circulation and from there to damaged sites to contribute to regeneration processes. MSCs commitment and differentiation are controlled by complex activities involving signal transduction through cytokines and catecholamines. There has been an increasing interest in recent years in the neural system, functioning in the support of stem cells like MSCs. Recent efforts have indicated that the catecholamine released from neural and not neural cells could be affected characteristics of MSCs. However, there have not been review studies of most aspects involved in catecholamines-mediated functions of MSCs. Thus, in this review paper, we will try to describe the current state of catecholamines in MSCs destination and discuss strategies being used for catecholamines for migration of these cells to damaged tissues. Then, the role of the nervous system in the induction of osteogenesis, adipogenesis, chondrogenesis and myogenesis from MSCs is discussed. Recent progress in studies of signaling transduction of catecholamines in determination of the final fate of MSCs is highlighted. Hence, the knowledge of interaction between MSCs with the neural system could be applied towards the development of new diagnostic and treatment alternatives for human diseases.

Effects of Tumor Microenvironment on the Primo Vascular Pattern in the Mouse Model of Metastatic Breast Cancer.

Background: : Tumor survival, promotion, and metastatic functions are regulated by the tumor microenvironment (TME). The primo vascular system (PVS), the third circulatory system in animals, is currently thought to be a highly effective pathway for the spread of cancer cells. Objectives: : In the present study, we intend to determine the TME effects on the PVS pattern in breast cancer for the first time. Methods: : Heterotopic and orthotopic metastatic triple-negative breast cancer (TNBC) mice models were created. After 35 days, the skin was retracted, and a 2 cm skin incision was made up and down from the surface of the tumor tissue. In preparation for PVS staining, the dyes (trypan blue and alamarBlue) were injected throughout the tumor tissues. Under a stereomicroscope, PVS in heterotopic and orthotopic tumors was seen. Results: : According to our data, there are no appreciable variations in PVS patterns and density between heterotopic and orthotopic animal models. Furthermore, alamarBlue is a good option for tumor PVS staining, as demonstrated by our research. Conclusion: : For the first time, our data gave significant new information about the PVS in TNBC. Creating new anti-cancer treatments may be made possible by a better understanding of the biological characteristics of the TME and PVS.