ResearchPad - stem-cell-therapy https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Characterization of limbal explant sites: Optimization of stem cell outgrowth in <i>in vitro</i> culture]]> https://www.researchpad.co/article/elastic_article_14624 Simple limbal epithelial transplantation (SLET) and cultivated limbal epithelial transplantation (CLET) are proven techniques for treating limbal stem cell deficiency (LSCD). However, the precise regions that are most suitable for preparing explants for transplantation have not been identified conclusively. Accordingly, this in vitro study aimed at determining ideal sites to be selected for tissue harvest for limbal stem cell culture and transplantation. We evaluated cell outgrowth potential and the expression of stem cell markers in cultures from 48 limbal explants from five cadaveric donors. The limbal explants were generated from the three specific sites: Lcor (located innermost and adjacent to the cornea), Lm (middle limbus), and Lconj (located outermost adjacent to the conjunctiva). We found that explants from the Lconj and Lm sites exhibited higher growth potential than those from the Lcor site. Transcript encoding the stem cell marker and p63 isoform, ΔNp63, was detected in cells from Lm and Lconj explants; expression levels were slightly, though significantly (p-value < 0.05), higher in Lm than in Lconj, although expression of ΔNp63α protein was similar in cells from all explants. Differential expression of ATP-Binding Cassette Subfamily G Member 2 (ABCG2) did not reach statistical significance. Immunohistochemistry by indirect immunofluorescence analysis of limbus tissue revealed that the basal layer in explant tissue from Lconj and Lm contained markedly more stem cells than found in Lcor explant tissue; these findings correlate with a higher capacity for growth. Collectively, our findings suggest that explants from the Lconj and Lm sites should be selected for limbal cell expansion for both CLET and SLET procedures. These new insights may guide surgeons toward specific limbal sites that are most suitable for stem cell culture and transplantation and may ultimately improve treatment outcomes in the patients with LSCD.

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<![CDATA[Physical stimulation by REAC and BMP4/WNT-1 inhibitor synergistically enhance cardiogenic commitment in iPSCs]]> https://www.researchpad.co/article/5c5217b6d5eed0c48479441d

It is currently known that pluripotent stem cells can be committed in vitro to the cardiac lineage by the modulation of specific signaling pathways, but it is also well known that, despite the significant increase in cardiomyocyte yield provided by the currently available conditioned media, the resulting cardiogenic commitment remains a highly variable process. Previous studies provided evidence that radio electric fields asymmetrically conveyed through the Radio Electric Asymmetric Conveyer (REAC) technology are able to commit R1 embryonic stem cells and human adipose derived stem cells toward a cardiac phenotype. The present study aimed at investigating whether the effect of physical stimulation by REAC in combination with specific chemical inductors enhance the cardiogenic potential in human induced pluripotent stem cells (iPSCs). The appearance of a cardiac-like phenotype in iPSCs cultured in the presence of a cardiogenic medium, based upon BMP4 and a WNT-inhibitor, was consistently increased by REAC treatment used only during the early fate differentiation for the first 72 hours. REAC-exposed iPSCs exhibited an upregulation in the expression of specific cardiogenic transcripts and morphologically in the number of beating clusters, as compared to cells cultured in the cardiogenic medium alone. Our results indicate that physical modulation of cellular dynamics provided by the REAC offers an affordable strategy to mimic iPSC cardiac-like fates in the presence of a cardiogenic milieu.

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<![CDATA[A transient DMSO treatment increases the differentiation potential of human pluripotent stem cells through the Rb family]]> https://www.researchpad.co/article/5c1ab82ed5eed0c484027053

The propensity for differentiation varies substantially across human pluripotent stem cell (hPSC) lines, greatly restricting the use of hPSCs for cell replacement therapy or disease modeling. Here, we investigate the underlying mechanisms and demonstrate that activation of the retinoblastoma (Rb) pathway in a transient manner is important for differentiation. In prior work, we demonstrated that pre-treating hPSCs with dimethylsulfoxide (DMSO) before directed differentiation enhanced differentiation potential across all three germ layers. Here, we show that exposure to DMSO improves the efficiency of hPSC differentiation through Rb and by repressing downstream E2F-target genes. While transient inactivation of the Rb family members (including Rb, p107, and p130) suppresses DMSO’s capacity to enhance differentiation across all germ layers, transient expression of a constitutively active (non-phosphorylatable) form of Rb increases the differentiation efficiency similar to DMSO. Inhibition of downstream targets of Rb, such as E2F signaling, also promotes differentiation of hPSCs. More generally, we demonstrate that the duration of Rb activation plays an important role in regulating differentiation capacity.

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<![CDATA[A Newly Defined and Xeno-Free Culture Medium Supports Every-Other-Day Medium Replacement in the Generation and Long-Term Cultivation of Human Pluripotent Stem Cells]]> https://www.researchpad.co/article/5989da9bab0ee8fa60ba3bff

Human pluripotent stem cells (hPSCs) present an unprecedented opportunity to advance human health by offering an alternative and renewable cell resource for cellular therapeutics and regenerative medicine. The present demand for high quality hPSCs for use in both research and clinical studies underscores the need to develop technologies that will simplify the cultivation process and control variability. Here we describe the development of a robust, defined and xeno-free hPSC medium that supports reliable propagation of hPSCs and generation of human induced pluripotent stem cells (hiPSCs) from multiple somatic cell types; long-term serial subculturing of hPSCs with every-other-day (EOD) medium replacement; and banking fully characterized hPSCs. The hPSCs cultured in this medium for over 40 passages are genetically stable, retain high expression levels of the pluripotency markers TRA-1-60, TRA-1-81, Oct-3/4 and SSEA-4, and readily differentiate into ectoderm, mesoderm and endoderm. Importantly, the medium plays an integral role in establishing a cGMP-compliant process for the manufacturing of hiPSCs that can be used for generation of clinically relevant cell types for cell replacement therapy applications.

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<![CDATA[An Evaluation of the Stemness, Paracrine, and Tumorigenic Characteristics of Highly Expanded, Minimally Passaged Adipose-Derived Stem Cells]]> https://www.researchpad.co/article/5989da34ab0ee8fa60b85b60

The use of adipose-derived stem cells (ADSC) in regenerative medicine is rising due to their plasticity, capacity of differentiation and paracrine and trophic effects. Despite the large number of cells obtained from adipose tissue, it is usually not enough for therapeutic purposes for many diseases or cosmetic procedures. Thus, there is the need for culturing and expanding cells in-vitro for several weeks remain. Our aim is to investigate if long- term proliferation with minimal passaging will affect the stemness, paracrine secretions and carcinogenesis markers of ADSC. The immunophenotypic properties and aldehyde dehydrogenase (ALDH) activity of the initial stromal vascular fraction (SVF) and serially passaged ADSC were observed by flow cytometry. In parallel, the telomerase activity and the relative expression of oncogenes and tumor suppressor genes were assessed by q-PCR. We also assessed the cytokine secretion profile of passaged ADSC by an ELISA. The expanded ADSC retain their morphological and phenotypical characteristics. These cells maintained in culture for up to 12 weeks until P4, possessed stable telomerase and ALDH activity, without having a TP53 mutation. Furthermore, the relative expression levels of TP53, RB, and MDM2 were not affected while the relative expression of c-Myc decreased significantly. Finally, the levels of the secretions of PGE2, STC1, and TIMP2 were not affected but the levels of IL-6, VEGF, and TIMP 1 significantly decreased at P2. Our results suggest that the expansion of passaged ADSC does not affect the differentiation capacity of stem cells and does not confer a cancerous state or capacity in vitro to the cells.

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<![CDATA[A Novel In Vitro Method for Detecting Undifferentiated Human Pluripotent Stem Cells as Impurities in Cell Therapy Products Using a Highly Efficient Culture System]]> https://www.researchpad.co/article/5989db14ab0ee8fa60bccb62

Innovative applications of cell therapy products (CTPs) derived from human pluripotent stem cells (hPSCs) in regenerative medicine are currently being developed. The presence of residual undifferentiated hPSCs in CTPs is a quality concern associated with tumorigencity. However, no simple in vitro method for direct detection of undifferentiated hPSCs that contaminate CTPs has been developed. Here, we show a novel approach for direct and sensitive detection of a trace amount of undifferentiated human induced pluripotent stem cells (hiPSCs) using a highly efficient amplification method in combination with laminin-521 and Essential 8 medium. Essential 8 medium better facilitated the growth of hiPSCs dissociated into single cells on laminin-521 than in mTeSR1 medium. hiPSCs cultured on laminin-521 in Essential 8 medium were maintained in an undifferentiated state and they maintained the ability to differentiate into various cell types. Essential 8 medium allowed robust hiPSC proliferation plated on laminin-521 at low cell density, whereas mTeSR1 did not enhance the cell growth. The highly efficient culture system using laminin-521 and Essential 8 medium detected hiPSCs spiked into primary human mesenchymal stem cells (hMSCs) or human neurons at the ratio of 0.001%–0.01% as formed colonies. Moreover, this assay method was demonstrated to detect residual undifferentiated hiPSCs in cell preparations during the process of hMSC differentiation from hiPSCs. These results indicate that our highly efficient amplification system using a combination of laminin-521 and Essential 8 medium is able to detect a trace amount of undifferentiated hPSCs contained as impurities in CTPs and would contribute to quality assessment of hPSC-derived CTPs during the manufacturing process.

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<![CDATA[PIM1-minicircle as a therapeutic treatment for myocardial infarction]]> https://www.researchpad.co/article/5989db50ab0ee8fa60bdc014

PIM1, a pro-survival gene encoding a serine/ threonine kinase, influences cell proliferation and survival. Modification of cardiac progenitor cells (CPCs) or cardiomyocytes with PIM1 using a lentivirus-based delivery method showed long-term improved cardiac function after myocardial infarction (MI). However, lentivirus based delivery methods have stringent FDA regulation with respect to clinical trials. To provide an alternative and low risk PIM1 delivery method, this study examined the use of a non-viral modified plasmid-minicircle (MC) as a vehicle to deliver PIM1 into mouse CPCs (mCPCs) in vitro and the myocardium in vivo. MC containing a turbo gfp reporter gene (gfp-MC) was used as a transfection and injection control. PIM1 was subcloned into gfp-MC (PIM1-MC) and then transfected into mCPCs at an efficiency of 29.4±3.7%. PIM1-MC engineered mCPCs (PIM1-mCPCs) exhibit significantly (P<0.05) better survival rate under oxidative treatment. PIM1-mCPCs also exhibit 1.9±0.1 and 2.2±0.2 fold higher cell proliferation at 3 and 5 days post plating, respectively, as compared to gfp-MC transfected mCPCs control. PIM1-MC was injected directly into ten-week old adult FVB female mice hearts in the border zone immediately after MI. Delivery of PIM1 into myocardium was confirmed by GFP+ cardiomyocytes. Mice with PIM1-MC injection showed increased protection compared to gfp-MC injection groups measured by ejection fraction at 3 and 7 days post injury (P = 0.0379 and P = 0.0262 by t-test, respectively). Success of PIM1 delivery and integration into mCPCs in vitro and cardiomyocytes in vivo by MC highlights the possibility of a non-cell based therapeutic approach for treatment of ischemic heart disease and MI.

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<![CDATA[Clinical Efficacy of Stem Cell Therapy for Diabetes Mellitus: A Meta-Analysis]]> https://www.researchpad.co/article/5989d9d3ab0ee8fa60b650d3

Background

Stem cell therapy is a promising therapeutic modality for advanced diabetes mellitus (DM). This study presents a meta-analysis of relevant clinical trials to determine the efficacy of stem cell therapy in DM. We aim to critically evaluate and synthesize clinical evidence on the safety and efficiency of different types of stem cell therapy for both T1DM and T2DM.

Methods and Findings

We pooled participant-level data from twenty-two eligible clinical trials that satisfied our inclusion criteria, with a total of 524 patients. There were significant differences in the outcome based on the type and source of the infused cells. Out of all T1DM patients who received CD34+ hematopoietic stem cell (HSC) infusion, 58.9% became insulin independent for a mean period of 16 months, whereas the results were uniformly negative in patients who received umbilical cord blood (UCB). Infusion of umbilical cord mesenchymal stem cells (UC-MSCs) provided significantly beneficial outcome in T1DM, when compared to bone-marrow mesenchymal stem cells (BM-MSCs) (P<0.0001 and P = 0.1557). Administration of stem cell therapy early after DM diagnosis was more effective than intervention at later stages (relative risk = 2.0, P = 0.0008). Adverse effects were observed in only 21.72% of both T1DM and T2DM stem cell recipients with no reported mortality. Out of all poor responders, 79.5% were diagnosed with diabetic ketoacidosis.

Conclusions

Stem cell transplantation can represent a safe and effective treatment for selected patients with DM. In this cohort of trials, the best therapeutic outcome was achieved with CD34+ HSC therapy for T1DM, while the poorest outcome was observed with HUCB for T1DM. Diabetic ketoacidosis impedes therapeutic efficacy.

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<![CDATA[Therapeutic Benefits of Induced Pluripotent Stem Cells in Monocrotaline-Induced Pulmonary Arterial Hypertension]]> https://www.researchpad.co/article/5989dab0ab0ee8fa60bab40f

Pulmonary arterial hypertension (PAH) is characterized by progressive increases in vascular resistance and the remodeling of pulmonary arteries. The accumulation of inflammatory cells in the lung and elevated levels of inflammatory cytokines in the bloodstream suggest that inflammation may play a role in PAH. In this study, the benefits of induced pluripotent stem cells (iPSCs) and iPSC-conditioned medium (iPSC CM) were explored in monocrotaline (MCT)-induced PAH rats. We demonstrated that both iPSCs and iPSC CM significantly reduced the right ventricular systolic pressure and ameliorated the hypertrophy of the right ventricle in MCT-induced PAH rats in models of both disease prevention and disease reversal. In the prevention of MCT-induced PAH, iPSC-based therapy led to the decreased accumulation of inflammatory cells and down-regulated the expression of the IL-1β, IL-6, IL-12α, IL-12β, IL-23 and IFNγ genes in lung specimens, which implied that iPSC-based therapy may be involved in the regulation of inflammation. NF-κB signaling is essential to the inflammatory cascade, which is activated via the phosphorylation of the NF-κB molecule. Using the chemical inhibitor specifically blocked the phosphorylation of NF-κB, and in vitro assays of cultured human M1 macrophages implied that the anti-inflammation effect of iPSC-based therapy may contribute to the disturbance of NF-κB activation. Here, we showed that iPSC-based therapy could restore the hemodynamic function of right ventricle with benefits for preventing the ongoing inflammation in the lungs of MCT-induced PAH rats by regulating NF-κB phosphorylation.

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<![CDATA[Hematopoietic Stem Cells in Neonates: Any Differences between Very Preterm and Term Neonates?]]> https://www.researchpad.co/article/5989da1aab0ee8fa60b7ca20

Background

In the last decades, human full-term cord blood was extensively investigated as a potential source of hematopoietic stem and progenitor cells (HSPCs). Despite the growing interest of regenerative therapies in preterm neonates, only little is known about the biological function of HSPCs from early preterm neonates under different perinatal conditions. Therefore, we investigated the concentration, the clonogenic capacity and the influence of obstetric/perinatal complications and maternal history on HSPC subsets in preterm and term cord blood.

Methods

CD34+ HSPC subsets in UCB of 30 preterm and 30 term infants were evaluated by flow cytometry. Clonogenic assays suitable for detection of the proliferative potential of HSPCs were conducted. Furthermore, we analyzed the clonogenic potential of isolated HSPCs according to the stem cell marker CD133 and aldehyde dehydrogenase (ALDH) activity.

Results

Preterm cord blood contained a significantly higher concentration of circulating CD34+ HSPCs, especially primitive progenitors, than term cord blood. The clonogenic capacity of HSPCs was enhanced in preterm cord blood. Using univariate analysis, the number and clonogenic potential of circulating UCB HSPCs was influenced by gestational age, birth weight and maternal age. Multivariate analysis showed that main factors that significantly influenced the HSPC count were maternal age, gestational age and white blood cell count. Further, only gestational age significantly influenced the clonogenic potential of UCB HSPCs. Finally, isolated CD34+/CD133+, CD34+/CD133– and ALDHhigh HSPC obtained from preterm cord blood showed a significantly higher clonogenic potential compared to term cord blood.

Conclusion

We demonstrate that preterm cord blood exhibits a higher HSPC concentration and increased clonogenic capacity compared to term neonates. These data may imply an emerging use of HSPCs in autologous stem cell therapy in preterm neonates.

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<![CDATA[Hepatocyte Growth Factor Modification Enhances the Anti-Arrhythmic Properties of Human Bone Marrow-Derived Mesenchymal Stem Cells]]> https://www.researchpad.co/article/5989da35ab0ee8fa60b861f6

Background/Aims

Chronic myocardial infarction (MI) results in the formation of arrhythmogenic substrates, causing lethal ventricular arrhythmia (VA). We aimed to determine whether mesenchymal stem cells (MSCs) carrying a hepatocyte growth factor (HGF) gene modification (HGF-MSCs) decrease the levels of arrhythmogenic substrates and reduce the susceptibility to developing VA compared with unmodified MSCs and PBS in a swine infarction model.

Methods

The left descending anterior artery was balloon-occluded to establish an MI model. Four weeks later, the randomly grouped pigs were administered MSCs, PBS or HGF-MSCs via thoracotomy. After an additional four weeks, dynamic electrocardiography was performed to assess heart rate variability, and programmed electrical stimulation was conducted to evaluate the risk for VA. Then, the pigs were euthanized for morphometric, immunofluorescence and western blot analyses. Results: The HGF-MSC group displayed the highest vessel density and Cx43 expression levels, and the lowest levels of apoptosis, and tyrosine hydroxylase (TH) and growth associated protein 43 (GAP43) expression. Moreover, the HGF-MSC group exhibited a decrease in the number of sympathetic nerve fibers, substantial decreases in the low frequency and the low-/high- frequency ratio and increases in the root mean square of successive differences (rMSSD) and the percentage of successive normal sinus R-R intervals longer than 50 ms (pNN50), compared with the other two groups. Finally, the HGF-MSC group displayed the lowest susceptibility to developing VA.

Conclusion

HGF-MSCs displayed potent antiarrhythmic effects, reducing the risk for VA.

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<![CDATA[Targeting chronic cardiac remodeling with cardiac progenitor cells in a murine model of ischemia/reperfusion injury]]> https://www.researchpad.co/article/5989db50ab0ee8fa60bdbf4a

Background

Translational failure for cardiovascular disease is a substantial problem involving both high research costs and an ongoing lack of novel treatment modalities. Despite the progress already made, cell therapy for chronic heart failure in the clinical setting is still hampered by poor translation. We used a murine model of chronic ischemia/reperfusion injury to examine the effect of minimally invasive application of cardiac progenitor cells (CPC) in cardiac remodeling and to improve clinical translation.

Methods

28 days after the induction of I/R injury, mice were randomized to receive either CPC (0.5 million) or vehicle by echo-guided intra-myocardial injection. To determine retention, CPC were localized in vivo by bioluminescence imaging (BLI) two days after injection. Cardiac function was assessed by 3D echocardiography and speckle tracking analysis to quantify left ventricular geometry and regional myocardial deformation.

Results

BLI demonstrated successful injection of CPC (18/23), which were mainly located along the needle track in the anterior/septal wall. Although CPC treatment did not result in overall restoration of cardiac function, a relative preservation of the left ventricular end-diastolic volume was observed at 4 weeks follow-up compared to vehicle control (+5.3 ± 2.1 μl vs. +10.8 ± 1.5 μl). This difference was reflected in an increased strain rate (+16%) in CPC treated mice.

Conclusions

CPC transplantation can be adequately studied in chronic cardiac remodeling using this study set-up and by that provide a translatable murine model facilitating advances in research for new therapeutic approaches to ultimately improve therapy for chronic heart failure.

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<![CDATA[Intrapericardial Delivery of Cardiosphere-Derived Cells: An Immunological Study in a Clinically Relevant Large Animal Model]]> https://www.researchpad.co/article/5989d9e0ab0ee8fa60b696c7

Introduction

The intrapericardial delivery has been defined as an efficient method for pharmacological agent delivery. Here we hypothesize that intrapericardial administration of cardiosphere-derived cells (CDCs) may have an immunomodulatory effect providing an optimal microenvironment for promoting cardiac repair. To our knowledge, this is the first report studying the effects of CDCs for myocardial repair using the intrapericardial delivery route.

Material and Methods

CDCs lines were isolated, expanded and characterized by flow cytometry and PCR. Their differentiation ability was determined using specific culture media and differential staining. 300,000 CDCs/kg were injected into the pericardial space of a swine myocardial infarcted model. Magnetic resonance imaging, biochemical analysis of pericardial fluid and plasma, cytokine measurements and flow cytometry analysis were performed.

Results

Our results showed that, phenotype and differentiation behavior of porcine CDCs were equivalent to previously described CDCs. Moreover, the intrapericardial administration of CDCs fulfilled the safety aspects as non-adverse effects were reported. Finally, the phenotypes of resident lymphocytes and TH1 cytokines in the pericardial fluid were significantly altered after CDCs administration.

Conclusions

The pericardial fluid could be considered as a safe and optimal vehicle for CDCs administration. The observed changes in the studied immunological parameters could exert a modulation in the inflammatory environment of infarcted hearts, indirectly benefiting the endogenous cardiac repair.

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<![CDATA[Real-World Use of 3rd Line Therapy for Multiple Myeloma in Austria: An Austrian Myeloma Registry (AMR) Analysis of the Therapeutic Landscape and Clinical Outcomes prior to the Use of Next Generation Myeloma Therapeutics]]> https://www.researchpad.co/article/5989da46ab0ee8fa60b8bc52

Objective

Clinical trials demonstrate improving survival in patients with multiple myeloma (MM) after treatment. However, it is unclear whether increased survival translates to a similar benefit in a real world setting.

Methods

We analyzed the overall survival of 347 multiple myeloma patients in Austria by means of a national registry (AMR), focused on results from 3rd and later lines of therapy. This benchmark was chosen to define a baseline prior to the broad application of upcoming 2nd generation drugs (carfilzomib, pomalidomide).

Results

Projected 10 years survival for patients with MM in Austria is estimated to be 56% in patients diagnosed in between the years 2011–2014, 21% in patients with a diagnosis made between 2000–2005, and 39% in those with a diagnosis made between 2006–2010). For the same intervals a significant increase in the use of both bortezomib, lenalidomide and thalidomide—so called IMiDs (from 2005 onwards) and their simultaneous use in combination therapies (from 2010 onwards) could be shown. The use of autologous transplantation (ASCT) remained more or less constant at ~ 35% of patients in the 1st line setting over the whole period, comparing well to international practice patterns, while the use of 2nd line ASCT increased from 5.5% to 18.7% of patients. Patients in 3rd or later line treatment (n = 105), showed that even in relapsed and refractory disease median survival was 27 months with a considerable proportion of long-term survivors (~20%).

Conclusion & Perspective

With the expected emergence of additional active anti-myeloma compounds, we aim to assess survival in patients with relapsed and refractory MM.

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<![CDATA[Differential Expression of Stem Cell Markers in Ocular Surface Squamous Neoplasia]]> https://www.researchpad.co/article/5989da1cab0ee8fa60b7d33e

Ocular Surface Squamous Neoplasm (OSSN) is the neoplasia arising from the conjunctiva, cornea and limbus. OSSN ranges from mild, moderate, severe dysplasia, carcinoma in situ (CIS) to squamous cell carcinoma (SCC). Recent findings on cancer stem cells theory indicate that population of stem-like cell as in neoplasia determines its heterogeneity and complexity leading to varying tumor development of metastatic behavior and recurrence. Cancer stem cell markers are not much explored in the cases of OSSN. In the present study, we aim to evaluate the expression of stem cells using stem cell markers mainly p63, ABCG2, c-KIT (CD117) and CD44 in OSSN tissue, which could have prognostic significance. The present study tries for the first time to explore expression of these stem markers in the cases of OSSN. These cases are subdivided into two groups. One group comprises of carcinoma in situ (n = 6) and the second group comprises of invasive carcinoma (n = 6). The mean age at presentation was 52 years; with 53 years for CIS group and 52 years for SCC group. From each group section from the paraffin block were taken for the IHC staining of p63, c-Kit, ABCG2 and CD44. Our experiments show high expression of P63 and CD44 in the cases of CIN and SCC. Both CIS and SCC displayed positive staining with p63, with more than 80% cells staining positive. However minimal expression of c-kit in both CIN and SCC. But surprisingly we got high expression of ABCG2 in cases of carcinoma in situ as compared to that of invasive squamous cell carcinoma. More than 50% of cells showed CD44 positivity in both CIS and SCC groups. Our results show for the first time that these four stem cells especially the limbal epithelium stem cells play a vital role in the genesis of OSSN but we need to explore more cases before establishing its clinical and biological significance.

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<![CDATA[Corneal stromal stem cells reduce corneal scarring by mediating neutrophil infiltration after wounding]]> https://www.researchpad.co/article/5989db50ab0ee8fa60bdbd97

Corneal scarring limits vision for millions of individuals worldwide. Corneal transplantation (keratoplasty) is the standard of care for corneal opacity; however, it bears the risk of graft rejection and infection and is not universally available. Stem cell therapy holds promise as an alternative to keratoplasty. Stem cells from human corneal stroma (CSSC) induce regeneration of transparent corneal tissue in a mouse wound-healing model. In this study we investigated the mechanism by which CSSC prevent deposition of fibrotic tissue. Infiltration by CD11b+/Ly6G+ neutrophils and myeloperoxidase expression were increased in corneas 24 hr after corneal wounding but were reduced in CSSC-treated wounds. Secretion of TSG-6, a protein known to regulate neutrophil migration, was up-regulated in CSSC in response to TNFα and as CSSC differentiate to keratocytes. In vivo, wounded mouse corneas treated with CSSC contained human TSG-6. Inhibition of neutrophil infiltration into cornea by CSSC was reversed when TSG-6 expression was knocked down using siRNA. Silencing of TSG-6 expression in CSSC reduced their ability to block scarring and the expression of mRNA for fibrosis-associated proteins collagen III, tenascin C, and smooth muscle actin in wounded corneas. Neutropenic mice exhibited a significant reduction in corneal scarring and fibrotic mRNA expression 2 weeks after wounding. These results support the conclusion that neutrophil infiltration is an essential event in the fibrotic response to corneal damage and that prevention of scarring by CSSC is mediated by secretion of TSG-6 by these cells.

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<![CDATA[Human Umbilical Cord Mesenchymal Stem Cells and Derived Hepatocyte-Like Cells Exhibit Similar Therapeutic Effects on an Acute Liver Failure Mouse Model]]> https://www.researchpad.co/article/5989da1eab0ee8fa60b7e00e

Mesenchymal stem cells (MSCs) have exhibited therapeutic effects in multiple animal models so that are promising liver substitute for transplantation treatment of end-stage liver diseases. However, it has been shown that over-manipulation of these cells increased their tumorigenic potential, and that reducing the in vitro culture time could minimize the risk. In this study, we used a D-galactosamine plus lipopolysaccharide (Gal/LPS)-induced acute liver failure mouse model, which caused death of about 50% of the mice with necrosis of more than 50% hepatocytes, to compare the therapeutic effects of human umbilical cord MSCs (hUCMSCs) before and after induction of differentiation into hepatocyte (i-Heps). Induction of hUCMSCs to become i-Heps was achieved by treatment of the cells with a group of growth factors within 4 weeks. The resulted i-Heps exhibited a panel of human hepatocyte biomarkers including cytokeratin (hCK-18), α-fetoprotein (hAFP), albumin (hALB), and hepatocyte-specific functions glycogen storage and urea metabolism. We demonstrated that transplantation of both cell types through tail vein injection rescued almost all of the Gal/LPS-intoxicated mice. Although both cell types exhibited similar ability in homing at the mouse livers, the populations of the hUCMSCs-derived cells, as judged by expressing hAFP, hCK-18 and human hepatocyte growth factor (hHGF), were small. These observations let us to conclude that the hUCMSCs was as effective as the i-Heps in treatment of the mouse acute liver failure, and that the therapeutic effects of hUCMSCs were mediated largely via stimulation of host hepatocyte regeneration, and that delivery of the cells through intravenous injection was effective.

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<![CDATA[Effect of Melatonin in Epithelial Mesenchymal Transition Markers and Invasive Properties of Breast Cancer Stem Cells of Canine and Human Cell Lines]]> https://www.researchpad.co/article/5989db11ab0ee8fa60bcc4a6

Cancer stem cells (CSCs) have been associated with metastasis and therapeutic resistance and can be generated via epithelial mesenchymal transition (EMT). Some studies suggest that the hormone melatonin acts in CSCs and may participate in the inhibition of the EMT. The objectives of this study were to evaluate the formation of mammospheres from the canine and human breast cancer cell lines, CMT-U229 and MCF-7, and the effects of melatonin treatment on the modulation of stem cell and EMT molecular markers: OCT4, E-cadherin, N-cadherin and vimentin, as well as on cell viability and invasiveness of the cells from mammospheres. The CMT-U229 and MCF-7 cell lines were subjected to three-dimensional culture in special medium for stem cells. The phenotype of mammospheres was first evaluated by flow cytometry (CD44+/CD24low/- marking). Cell viability was measured by MTT colorimetric assay and the expression of the proteins OCT4, E-cadherin, N-cadherin and vimentin was evaluated by immunofluorescence and quantified by optical densitometry. The analysis of cell migration and invasion was performed in Boyden Chamber. Flow cytometry proved the stem cell phenotype with CD44+/CD24low/- positive marking for both cell lines. Cell viability of CMT-U229 and MCF-7 cells was reduced after treatment with 1mM melatonin for 24 h (P<0.05). Immunofluorescence staining showed increased E-cadherin expression (P<0.05) and decreased expression of OCT4, N-cadherin and vimentin (P<0.05) in both cell lines after treatment with 1 mM melatonin for 24 hours. Moreover, treatment with melatonin was able to reduce cell migration and invasion in both cell lines when compared to control group (P<0.05). Our results demonstrate that melatonin shows an inhibitory role in the viability and invasiveness of breast cancer mammospheres as well as in modulating the expression of proteins related to EMT in breast CSCs, suggesting its potential anti-metastatic role in canine and human breast cancer cell lines.

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<![CDATA[Neurogenic Effects of Cell-Free Extracts of Adipose Stem Cells]]> https://www.researchpad.co/article/5989da28ab0ee8fa60b8171a

Stem-cell-based therapies are regarded as promising treatments for neurological disorders, and adipose-derived stem cells (ASCs) are a feasible source of clinical application of stem cell. Recent studies have shown that stem cells have a therapeutic potential for use in the treatment of various illnesses through paracrine action. To examine the effects of cell components of ASCs on neural stem cells (NSCs), we treated cell-free extracts of ASCs (CFE-ASCs) containing various components with brain-derived NSCs. To elucidate the effects of CFE-ASCs in NSC proliferation, we treated mouse subventricular zone-derived cultured NSCs with various doses of CFE-ASCs. As a result, CFE-ASCs were found to induce the proliferation of NSCs under conditions of growth factor deprivation in a dose-dependent manner (p<0.01). CFE-ASCs increase the expression of neuron and astrocyte differentiation markers including Tuj-1 (p<0.05) and glial fibrillary acidic protein (p<0.01) without altering the cell’s fate in differentiating NSCs. In addition, treatment with CFE-ASCs induces an increase in neurite numbers (p<0.01) and lengths of NSCs (p<0.05). Furthermore, CFE-ASCs rescue the hydrogen peroxide-induced reduction of NSCs’ viability (p<0.05) and neurite branching (p<0.01). Findings from our study indicate that CFE-ASCs support the survival, proliferation and differentiation of NSCs accompanied with neurite outgrowth, suggesting that CFE-ASCs can modulate neurogenesis in the central nervous system.

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<![CDATA[Notch ligands regulate the muscle stem-like state ex vivo but are not sufficient for retaining regenerative capacity]]> https://www.researchpad.co/article/5989db5aab0ee8fa60bdf796

Myogenic stem cells are a promising avenue for the treatment of muscular disorders. Freshly isolated muscle stem cells have a remarkable engraftment ability in vivo, but their cell number is limited. Current conventional culture conditions do not allow muscle stem cells to expand in vitro with their bona fide engraftment efficiency, requiring the improvement of culture procedures for achieving successful cell-therapy for muscle disorders. Here we expanded mouse muscle stem cells and human myoblasts with Notch ligands, DLL1, DLL4, and JAG1 to activate Notch signaling in vitro and to investigate whether these cells could retain their engraftment efficiency. Notch signaling promotes the expansion of Pax7+MyoD- mouse muscle stem-like cells and inhibits differentiation even after passage in vitro. Treatment with Notch ligands induced the Notch target genes and generated PAX7+MYOD- stem-like cells from human myoblasts previously cultured on conventional culture plates. However, cells treated with Notch ligands exhibit a stem cell-like state in culture, yet their regenerative ability was less than that of freshly isolated cells in vivo and was comparable to that of the control. These unexpected findings suggest that artificial maintenance of Notch signaling alone is insufficient for improving regenerative capacity of mouse and human donor-muscle cells and suggest that combinatorial events are critical to achieve muscle stem cell and myoblast engraftment potential.

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