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  • Human Mesenchymal Stem Cells Retain Multilineage Differentiation Capacity Including Neural Marker Expression after Extended In Vitro Expansion. 26356539

    The suitability of human mesenchymal stem cells (hMSCs) in regenerative medicine relies on retention of their proliferative expansion potential in conjunction with the ability to differentiate toward multiple lineages. Successful utilisation of these cells in clinical applications linked to tissue regeneration requires consideration of biomarker expression, time in culture and donor age, as well as their ability to differentiate towards mesenchymal (bone, cartilage, fat) or non-mesenchymal (e.g., neural) lineages. To identify potential therapeutic suitability we examined hMSCs after extended expansion including morphological changes, potency (stemness) and multilineage potential. Commercially available hMSC populations were expanded in vitro for greater than 20 passages, equating to greater than 60 days and greater than 50 population doublings. Distinct growth phases (A-C) were observed during serial passaging and cells were characterised for stemness and lineage markers at representative stages (Phase A: P+5, approximately 13 days in culture; Phase B: P+7, approximately 20 days in culture; and Phase C: P+13, approximately 43 days in culture). Cell surface markers, stem cell markers and lineage-specific markers were characterised by FACS, ICC and Q-PCR revealing MSCs maintained their multilineage potential, including neural lineages throughout expansion. Co-expression of multiple lineage markers along with continued CD45 expression in MSCs did not affect completion of osteogenic and adipogenic specification or the formation of neurospheres. Improved standardised isolation and characterisation of MSCs may facilitate the identification of biomarkers to improve therapeutic efficacy to ensure increased reproducibility and routine production of MSCs for therapeutic applications including neural repair.
    Tipo de documento:
    Referencia
    Referencia del producto:
    AB5603
    Nombre del producto:
    Anti-Sox2 Antibody

  • Human mesenchymal stem cells inhibit metastasis of a hepatocellular carcinoma model using the MHCC97-H cell line. 20942864

    The effects of mesenchymal stem cells (MSC) on the growth and metastasis of human malignancies including hepatocellular carcinoma (HCC) are controversial, and the underlying mechanisms are not yet understood. The aim of this study was to explore the role of MSC in the progression of HCC. We investigated the effect of MSC on in vitro proliferation and invasion and in vivo tumor growth and pulmonary metastasis of MHCC97-H HCC cells with a high metastatic potential. The mRNA and protein levels of transforming growth factor-beta 1 (TGF?1) and MMP, and their association with the effects of MSC on HCC cells were also evaluated. Co-culture of MHCC97-H cells with MSC conditioned medium significantly enhanced in vitro proliferation but inhibited invasiveness. Following MSC treatment of a nude mouse model bearing human HCC, the MSC were predominantly located in the HCC tissues. Compared with controls, MSC-treated mice exhibited significantly larger tumors (3080.51 ± 1234.78 mm(3) vs 2223.75 ± 1000.60 mm(3), P = 0.045), but decreased cellular numbers of lung metastases (49.75 ± 18.86 vs 227.22 ± 74.67, P = 0.046). Expression of TGF?1 and MMP-2 was significantly downregulated in the MSC-treated HCC cells. TGF? siRNA concurrently downregulated expression of TGF? and MMP-2 in HCC cells and blocked the MSC-induced proliferation and invasiveness of MHCC97-H cells. The MSC enhanced tumor growth but significantly inhibited the invasiveness and metastasis of HCC, possibly through downregulation of TGF?1. These findings suggest that MSC could be useful in controlling metastatic recurrence of HCC.
    Tipo de documento:
    Referencia
    Referencia del producto:
    AP189P
    Nombre del producto:
    Donkey Anti-Rat IgG Antibody, HRP conjugate, Species Adsorbed

  • The angiogenic factor angiopoietin-1 is a proneurogenic peptide on subventricular zone stem/progenitor cells. 20357108

    In the adult mammalian brain, the subventricular zone (SVZ) hosts stem cells constantly generating new neurons. Angiopoietin-1 (Ang-1) is an endothelial growth factor with a critical role in division, survival, and adhesion of endothelial cells via Tie-2 receptor activity. Expression of Tie-2 in nonendothelial cells, especially neurons and stem cells, suggests that Ang-1 may be involved in neurogenesis. In the present work, we investigated the putative role of Ang-1 on SVZ neurogenesis. Immature cells from SVZ-derived neurospheres express Ang-1 and Tie-2 mRNA, suggesting a role for the Ang-1/Tie-2 system in the neurogenic niche. Moreover, we also found that Tie-2 protein expression is retained on differentiation in neurons and glial cells. Ang-1 triggered proliferation via activation of the ERK1/2 (extracellular signal-regulated kinase 1/2) mitogen-activated protein kinase (MAPK) kinase pathway but did not induce cell death. Accordingly, coincubation with an anti-Tie-2 neutralizing antibody prevented the pro-proliferative effect of Ang-1. Furthermore, Ang-1 increased the number of NeuN (neuronal nuclear protein)-positive neurons in cultures treated for 7 d, as well as the number of functional neurons, as assessed by monitoring [Ca(2+)](i) rises after application of specific stimuli for neurons and immature cells. The proneurogenic effect of Ang-1 is mediated by Tie-2 activation and subsequent mTOR (mammalian target of rapamycin kinase) mobilization. In agreement, neuronal differentiation significantly decreased after exposure to an anti-Tie-2 neutralizing antibody and to rapamycin. Moreover, Ang-1 elicited the activation of the SAPK (stress-activated protein kinase)/JNK (c-Jun N-terminal kinase) MAPK, involved in axonogenesis. Our work shows a proneurogenic effect of Ang-1, highlighting the relevance of blood vessel/stem cell cross talk in health and disease.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo

  • One year survival and significant reversal of motor deficits in parkinsonian rats transplanted with hESC derived dopaminergic neurons. 18565328

    We report the generation of functional dopaminergic neurons from human embryonic stem cells (hESCs) using a growth factor mediated multistep EB protocol and its therapeutic effects in vivo. Embryoid bodies (EBs) were cultured in insulin-transferrin-selenium fibronectin (ITSFn) media for the selection of neural precursor cells (NPC). The selected cells on exposure to N2 media supplemented with EGF, bFGF initially aggregated to generate spontaneous free floating neurospheres and on exposure to signaling molecules Shh and FGF-8 differentiated into dopaminergic neurons (40% TH+ cells/total neurons). The differentiated NPC expressed dopaminergic specific markers both at cellular and molecular levels. They secreted detectable levels of dopamine into the culture supernatant. The most unique feature of our protocol is the generation of free floating neurospheres which can be expanded for a longer period without losing their capability to differentiate into DA neurons. Further, transplantation of NPCs into the substantia nigra of 6-OHDA lesioned rat model of Parkinson's disease elicited significant reversal of lesion induced motor deficits which was sustained upto the end of 1 year long study period. Immunohistochemical studies of the grafted area one year post transplantation revealed that transplanted hESC derived neural precursor cells survived, integrated in vivo and differentiated into dopaminergic neurons without teratoma formation. In summary, our results encourage the potential use of hESC derived dopaminergic neurons for future clinical application in Parkinson's disease.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MAB5262
    Nombre del producto:
    Anti-Neurofilament 200 kDa Antibody, clone RT97

  • Immunophenotype of human adipose-derived cells: temporal changes in stromal-associated and stem cell-associated markers. 16322640

    Adipose tissue represents an abundant and accessible source of multipotent adult stem cells and is used by many investigators for tissue engineering applications; however, not all laboratories use cells at equivalent stages of isolation and passage. We have compared the immunophenotype of freshly isolated human adipose tissue-derived stromal vascular fraction (SVF) cells relative to serial-passaged adipose-derived stem cells (ASCs). The initial SVF cells contained colony-forming unit fibroblasts at a frequency of 1:32. Colony-forming unit adipocytes and osteoblasts were present in the SVF cells at comparable frequencies (1:28 and 1:16, respectively). The immunophenotype of the adipose-derived cells based on flow cytometry changed progressively with adherence and passage. Stromal cell-associated markers (CD13, CD29, CD44, CD63, CD73, CD90, CD166) were initially low on SVF cells and increased significantly with successive passages. The stem cell-associated marker CD34 was at peak levels in the SVF cells and/or early-passage ASCs and remained present, although at reduced levels, throughout the culture period. Aldehyde dehydrogenase and the multidrug-resistance transport protein (ABCG2), both of which have been used to identify and characterize hematopoietic stem cells, are expressed by SVF cells and ASCs at detectable levels. Endothelial cell-associated markers (CD31, CD144 or VE-cadherin, vascular endothelial growth factor receptor 2, von Willebrand factor) were expressed on SVF cells and did not change significantly with serial passage. Thus, the adherence to plastic and subsequent expansion of human adipose-derived cells in fetal bovine serum-supplemented medium selects for a relatively homogeneous cell population, enriching for cells expressing a stromal immunophenotype, compared with the heterogeneity of the crude SVF.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MAB4155F

  • LKB1 controls the pluripotent state of human embryonic stem cells. 22384927

    Human embryonic stem cells maintained on human amniotic epithelial cells (hESCs(hAEC)) are better preserved in an undifferentiated state and express pluripotency genes Oct4, Nanog, and Sox2 at higher levels compared with growth on mitotically inactivated mouse embryonic fibroblasts (hESCs(MEF)). Here we report that this correlates with the absence of the tumor suppressor and metabolic balancer gene, LKB1 expression in hESCs(hAEC). RNA interference knockdown of LKB1 in hESCs(MEF) resulted in upregulation of pluripotency marker genes of Oct4 and Nanog, while downregulation of differentiation markers (Runx1, AFP, GATA, Brachyury, Sox17 and Nestin). As in somatic cells, LKB1 controls p21/WAF1 expression by promoter binding in hESCs(MEF). Our results suggested that the absence of LKB1-mediated signaling is an important determinant of feeder cell-mediated support of hESC renewal.
    Tipo de documento:
    Referencia
    Referencia del producto:
    12-370
    Nombre del producto:
    Normal Rabbit IgG

  • Alpha2beta1 integrin regulates lineage commitment in multipotent human colorectal cancer cells. 18664572

    The human colorectal epithelium is maintained by multipotent stem cells that give rise to absorptive, mucous, and endocrine lineages. Recent evidence suggests that human colorectal cancers are likewise maintained by a minority population of so-called cancer stem cells. We have previously established a human colorectal cancer cell line with multipotent characteristics (HRA-19) and developed a serum-free medium that induces endocrine, mucous and absorptive lineage commitment by HRA-19 cells in vitro. In this study, we investigate the role of the beta1 integrin family of cell surface extracellular matrix receptors in multilineage differentiation by these multipotent human colorectal cancer cells. We show that endocrine and mucous lineage commitment is blocked in the presence of function-blocking antibodies to beta1 integrin. Function-blocking antibodies to alpha2 integrin also blocked both HRA-19 endocrine lineage commitment and enterocytic differentiation by Caco-2 human colon cancer cells; both effects being abrogated by the MEK inhibitor, PD98059, suggesting a role for ERK signaling in alpha2-mediated regulation of colorectal cancer cell differentiation. To further explore the role of alpha2 integrin in multilineage differentiation, we established multipotent cells expressing high levels of wild-type alpha2 integrin or a non-signaling chimeric alpha2 integrin. Overexpression of wild-type alpha2 integrin in HRA-19 cells significantly enhanced endocrine and mucous lineage commitment, while cells expressing the non-signaling chimeric alpha2 integrin had negligible ability for either endocrine or mucous lineage commitment. This study indicates that the collagen receptor alpha2beta1 integrin is a regulator of cell fate in human multipotent colorectal cancer cells.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo

  • CtBP-interacting BTB zinc finger protein (CIBZ) promotes proliferation and G1/S transition in embryonic stem cells via Nanog. 22315219

    Mouse embryonic stem cells (ESCs) require transcriptional regulation to ensure rapid proliferation that allows for self-renewal. However, the molecular mechanism by which transcriptional factors regulate this rapid proliferation remains largely unknown. Here we present data showing that CIBZ, a BTB domain zinc finger transcriptional factor, is a key transcriptional regulator for regulation of ESC proliferation. Here we show that deletion or siRNA knockdown of CIBZ inhibits ESC proliferation. Cell cycle analysis shows that loss of CIBZ delays the progression of ESCs through the G1 to S phase transition. Conversely, constitutive ectopic expression of exogenous CIBZ in ESCs promotes proliferation and accelerates G1/S transition. These findings suggest that regulation of the G1/S transition explains, in part, CIBZ-associated ESC proliferation. Our data suggest that CIBZ acts through the post-transcriptionally regulates the expression of Nanog, a positive regulator of ESC proliferation and G1/S transition, but does not affect Oct3/4 and Sox2 protein expression. Notably, constitutive overexpression of Nanog partially rescued the proliferation defect caused by CIBZ knockdown, indicating the role of CIBZ in ESC proliferation and G1/S transition at least in part depends on the Nanog protein level.
    Tipo de documento:
    Referencia
    Referencia del producto:
    AB5731
    Nombre del producto:
    Anti-Nanog Antibody, NT

  • Transgene-free disease-specific induced pluripotent stem cells from patients with type 1 and type 2 diabetes. 23197849

    The induced pluripotent stem cell (iPSC) technology enables derivation of patient-specific pluripotent stem cells from adult somatic cells without using an embryonic cell source. Redifferentiation of iPSCs from diabetic patients into pancreatic islets will allow patient-specific disease modeling and autologous cell replacement therapy for failing islets. To date, diabetes-specific iPSCs have been generated from patients with type 1 diabetes using integrating retroviral vectors. However, vector integration into the host genome could compromise the biosafety and differentiation propensities of derived iPSCs. Although various integration-free reprogramming systems have been described, their utility to reprogram somatic cells from patients remains largely undetermined. Here, we used nonintegrating Sendai viral vectors to reprogram cells from patients with type 1 and type 2 diabetes (T2D). Sendai vector infection led to reproducible generation of genomic modification-free iPSCs (SV-iPSCs) from patients with diabetes, including an 85-year-old individual with T2D. SV-iPSCs lost the Sendai viral genome and antigens within 8-12 passages while maintaining pluripotency. Genome-wide transcriptome analysis of SV-iPSCs revealed induction of endogenous pluripotency genes and downregulation of genes involved in the oxidative stress response and the INK4/ARF pathways, including p16(INK4a), p15(INK4b), and p21(CIP1). SV-iPSCs and iPSCs made with integrating lentiviral vectors demonstrated remarkable similarities in global gene expression profiles. Thus, the Sendai vector system facilitates reliable reprogramming of patient cells into transgene-free iPSCs, providing a pluripotent platform for personalized diagnostic and therapeutic approaches for diabetes and diabetes-associated complications.
    Tipo de documento:
    Referencia
    Referencia del producto:
    07-633
    Nombre del producto:
    Anti-HNF3β/FOXA2 Antibody

  • Exclusive multipotency and preferential asymmetric divisions in post-embryonic neural stem cells of the fish retina. 25142461

    The potency of post-embryonic stem cells can only be addressed in the living organism, by labeling single cells after embryonic development and following their descendants. Recently, transplantation experiments involving permanently labeled cells revealed multipotent neural stem cells (NSCs) of embryonic origin in the medaka retina. To analyze whether NSC potency is affected by developmental progression, as reported for the mammalian brain, we developed an inducible toolkit for clonal labeling and non-invasive fate tracking. We used this toolkit to address post-embryonic stem cells in different tissues and to functionally differentiate transient progenitor cells from permanent, bona fide stem cells in the retina. Using temporally controlled clonal induction, we showed that post-embryonic retinal NSCs are exclusively multipotent and give rise to the complete spectrum of cell types in the neural retina. Intriguingly, and in contrast to any other vertebrate stem cell system described so far, long-term analysis of clones indicates a preferential mode of asymmetric cell division. Moreover, following the behavior of clones before and after external stimuli, such as injuries, shows that NSCs in the retina maintained the preference for asymmetric cell division during regenerative responses. We present a comprehensive analysis of individual post-embryonic NSCs in their physiological environment and establish the teleost retina as an ideal model for studying adult stem cell biology at single cell resolution.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo