scholarly journals Reprogramming of pancreatic exocrine cells towards a beta (β) cell character using Pdx1, Ngn3 and MafA

2012 ◽  
Vol 442 (3) ◽  
pp. 539-550 ◽  
Author(s):  
Ersin Akinci ◽  
Anannya Banga ◽  
Lucas V. Greder ◽  
James R. Dutton ◽  
Jonathan M. W. Slack
Keyword(s):  
Beta Cell ◽  
Cell Function ◽  
Cell Model ◽  
Severe Combined Immunodeficiency ◽  
Rapid Change ◽  
Cell Phenotype ◽  
Gene Promoters ◽  
Exocrine Cells ◽  
Pancreatic Exocrine

Pdx1 (pancreatic and duodenal homeobox 1), Ngn3 (neurogenin 3) and MafA (v-maf musculoaponeurotic fibrosarcoma oncogene family, protein A) have been reported to bring about the transdifferentiation of pancreatic exocrine cells to beta (β) cells in vivo. We have investigated the mechanism of this process using a standard in vitro model of pancreatic exocrine cells, the rat AR42j-B13 cell line. We constructed a new adenoviral vector encoding all three genes, called Ad-PNM (adenoviral Pdx1, Ngn3, MafA construct). When introduced into AR42j-B13 cells, Ad-PNM caused a rapid change to a flattened morphology and a cessation of cell division. The expression of exocrine markers is suppressed. Both insulin genes are up-regulated as well as a number of transcription factors normally characteristic of beta cells. At the chromatin level, histone tail modifications of the Pdx1, Ins1 (insulin 1) and Ins2 (insulin 2) gene promoters are shifted in a direction associated with gene activity, and the level of DNA CpG methylation is reduced at the Ins1 promoter. The transformed cells secrete insulin and are capable of relieving diabetes in streptozotocin-treated NOD-SCID (non-obese diabetic severe combined immunodeficiency) mice. However the transformation is not complete. The cells lack expression of several genes important for beta cell function and they do not show glucose-sensitive insulin secretion. We conclude that, for this exocrine cell model, although the transformation is dramatic, the reprogramming is not complete and lacks critical aspects of the beta cell phenotype.

scholarly journals Characterizing T Cells in SCID Patients Presenting with Reactive or Residual T Lymphocytes

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Atar Lev ◽  
Amos J. Simon ◽  
Luba Trakhtenbrot ◽  
Itamar Goldstein ◽  
Meital Nagar ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Cell Function ◽  
Severe Combined Immunodeficiency ◽  
Cell Activity ◽  
Mhc Ii ◽  
Cell Functions ◽  
Circulating T Cells

Introduction. Patients with severe combined immunodeficiency (SCID) may present with residual circulating T cells. While all cells are functionally deficient, resulting in high susceptibility to infections, only some of these cells are causing autoimmune symptoms.Methods. Here we compared T-cell functions including the number of circulating CD3+T cells,in vitroresponses to mitogens, T-cell receptor (TCR) repertoire, TCR excision circles (TREC) levels, and regulatory T cells (Tregs) enumeration in several immunodeficinecy subtypes, clinically presenting with nonreactive residual cells (MHC-II deficiency) or reactive cells. The latter includes patients with autoreactive clonal expanded T cell and patients with alloreactive transplacentally maternal T cells.Results. MHC-II deficient patients had slightly reduced T-cell function, normal TRECs, TCR repertoires, and normal Tregs enumeration. In contrast, patients with reactive T cells exhibited poor T-cell differentiation and activity. While the autoreactive cells displayed significantly reduced Tregs numbers, the alloreactive transplacentally acquired maternal lymphocytes had high functional Tregs.Conclusion. SCID patients presenting with circulating T cells show different patterns of T-cell activity and regulatory T cells enumeration that dictates the immunodeficient and autoimmune manifestations. We suggest that a high-tolerance capacity of the alloreactive transplacentally acquired maternal lymphocytes represents a toleration advantage, yet still associated with severe immunodeficiency.

scholarly journals Gene delivery to pancreatic exocrine cells in vivo and in vitro

2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Isabelle Houbracken ◽  
Luc Baeyens ◽  
Philippe Ravassard ◽  
Harry Heimberg ◽  
Luc Bouwens
Keyword(s):  
Gene Delivery ◽  
Exocrine Cells ◽  
Pancreatic Exocrine

scholarly journals PBF, a proto-oncogene in esophageal carcinoma

Open Medicine ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 748-756
Author(s):  
Shi-hai Lian ◽  
Jun-ding Song ◽  
Yi Huang
Keyword(s):  
Cell Cycle ◽  
Esophageal Carcinoma ◽  
Cell Function ◽  
Function Analysis ◽  
Cell Phenotype ◽  
Down Regulation ◽  
Apoptosis Pathway ◽  
Related Cell ◽  
Rnai Technology

AbstractEmerging evidence shows that the pituitary tumour-transforming gene (PTTG)-binding factor (PBF) functions as a proto-oncogene in some tumors. However, the precise functions of PBF in tumorigenesis and its action mechanisms remain largely unknown. Here for the first time we demonstrated that PBF was associated with a tumor-related cell phenotype in esophageal carcinoma (ESCA) and identified the involved signaling pathways. PBF was up-regulated in ESCA tissues (Data from GEPIA) and cells. Then we down-regulated PBF in ESCA cell lines, Eca-109 and TE-1, by using RNAi technology. Cell function analysis suggested that down-regulation of PBF could inhibit tumor-related cell phenotypes, including proliferation, motility, apoptosis and cell cycle, in Eca-109 and TE-1 cells. Mechanism investigation suggested that apoptosis induced by PBF knockdown may be mediated by the activation of the mitochondrial apoptosis pathway and cell cycle arrest. AKT/mTOR and Wnt3a/β-catenin, key pathways in regulating tumor proliferation and metastasis, were found to be inactivated by the down-regulation of PBF in ESCA cells. In conclusion, our study demonstrates that PBF functions as a proto-oncogene in ESCA in vitro, which may be mediated through AKT/mTOR and Wnt3a/β-catenin pathways.

scholarly journals Primary CLL Xenograft: A Model System to Study the Role of T-Cells in CLL Biology and Therapeutic Response

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3284-3284
Author(s):  
Ceri E Oldreive ◽  
Anna Skowronska ◽  
Angelo Agathanggelou ◽  
Helen M Parry ◽  
Sergey Krysov ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Function ◽  
Conflicts Of Interest ◽  
Xenograft Model ◽  
Cell Number ◽  
Biological Properties ◽  
T Cell Subsets ◽  
Cell Phenotype

Abstract The interaction between chronic lymphocytic leukaemia (CLL) cells and T-cells is an important aspect of CLL biology. CLL cells require T-cell support for their proliferation and in addition induce proliferation of regulatory and cytotoxic (CD8+) T-cells. T-cell number and repertoire are both markedly affected by CLL therapy and there is considerable interest in how current treatments modulate the interaction between T-cells and the tumour clone. In this study we investigated whether this relationship was maintained in a xenotransplantation model. CLL engraftment in NOG mice was facilitated by humanisation of the murine microenvironment by allogeneic CD34+ umbilical cord cells or CD14+ monocytes. Accelerated engraftment of both CLL and T-cell compartments was observed in xenografts derived from patients with progressive CLL, suggesting that the biological properties of both subsets are maintained in the murine model. Furthermore, the distribution of helper (CD4+), cytotoxic (CD8+) and regulatory (CD4+CD25+FoxP3+) T-cells was maintained within the xenografts, including retention of the CD4:CD8 ratio. Interestingly, the anergic PD-1+CD160+CD244+TIM3+ T-cell phenotype reported in CLL patients was also evident in T-cells expanded in xenograft models. Consistent with an anergic T-cell phenotype, T-cells from CLL xenografts lacked anti-tumour activity in vitro. Importantly, such anergic cells were observed when T-cells were reconstituted from allogeneic cord blood cells as well as autologous cells, suggesting that CLL cells have the ability to shape T-cell populations of different origin in diverse microenvironments. Finally, to investigate the interaction between specific T-cell subsets and engrafted CLL cells, CD4+, CD8+, and CD25+ T-cells were depleted prior to generation of xenografts. CD8+ T-cell depletion significantly prolonged CLL engraftment (p≤0.01) whereas neither depletion of CD4+ nor CD25+cells had a significant impact. In summary, our results demonstrate that the relationship between CLL tumour cells and reactive T-cells is accurately maintained in a murine xenograft model. Such models will be of great value for investigation of aspects of T-cell function in CLL biology. Disclosures No relevant conflicts of interest to declare.

Vitamin D supplementation induces CatG-mediated CD4+ T cell inactivation and restores pancreatic beta-cell function in mice with type 1 diabetes

2021 ◽  
Author(s):  
Xiaoyang Lai ◽  
Xuyang Liu ◽  
Xia Cai ◽  
Fang Zou
Keyword(s):  
Vitamin D ◽  
Type 1 Diabetes ◽  
Beta Cell ◽  
Cell Function ◽  
Pancreatic Beta Cell ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Β Cell Function

Type 1 diabetes (T1D) is a chronic autoimmune disease accompanied by the immune-mediated destruction of pancreatic β-cells. In this study, we aimed to explore the regulatory effects of Vitamin D (VD) supplementation on pancreatic β-cell function by altering the expression of bioinformatically identified cathepsin G (CatG) in T1D model mice. A T1D mouse model was established in non-obese diabetic (NOD) mice, and their islets were isolated and purified. Pancreatic mononuclear cells (MNCs) were collected, from which CD4+ T cells were isolated. The levels of interleukin (IL)-2, IL-10, tumor necrosis factor-α (TNF-α) and interferon-gamma (IFN-γ) in the supernatant of mouse pancreatic tissue homogenate were assessed using ELISA. Immunohistochemistry and TUNEL staining were conducted to evaluate the effects of VD supplementation on pancreatic tissues of T1D mice. The pancreatic beta-cell line MIN6 was used for in vitro substantiation of findings in vivo. VD supplementation reduced glucose levels and improved glucose tolerance in T1D mice. Further, VD supplementation improved pancreatic β-cell function and suppressed immunological and inflammatory reactions in the T1D mice. We documented overexpression of CatG in diabetes tissue samples, and then showed that VD supplementation normalized the islet immune microenvironment through down-regulating CatG expression in T1D mice. Experiments in vitro subsequently demonstrated that VD supplementation impeded CD4+ T activation by down-regulating CatG expression, and thereby enhanced pancreatic β-cell function. Results of the present study elucidated that VD supplementation can down-regulate the expression of CatG and inhibit CD4+ T cell activation, thereby improving β-cell function in T1D.

Free radicals and redox signalling in T-cells during chronic inflammation and ageing

2011 ◽  
Vol 39 (5) ◽  
pp. 1273-1278 ◽  
Author(s):  
Helen R. Griffiths ◽  
Christopher R. Dunston ◽  
Stuart J. Bennett ◽  
Melissa M. Grant ◽  
Darren C. Phillips ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Chronic Inflammation ◽  
Cell Function ◽  
Cell Phenotype ◽  
Cell Functions ◽  
Cytoplasmic Proteins ◽  
Local Cell ◽  
Species Production

During chronic inflammation and ageing, the increase in oxidative stress in both intracellular and extracellular compartments is likely to influence local cell functions. Redox changes alter the T-cell proteome in a quantitative and qualitative manner, and post-translational modifications to surface and cytoplasmic proteins by increased reactive species can influence T-cell function. Previously, we have shown that RA (rheumatoid arthritis) T-cells exhibit reduced ROS (reactive oxygen species) production in response to extracellular stimulation compared with age-matched controls, and basal ROS levels [measured as DCF (2′,7′-dichlorofluorescein) fluorescence] are lower in RA T-cells. In contrast, exposing T-cells in vitro to different extracellular redox environments modulates intracellular signalling and enhances cytokine secretion. Together, these data suggest that a complex relationship exists between intra- and extra-cellular redox compartments which contribute to the T-cell phenotype.

scholarly journals In vitro generation of insulin-secreting cells from human pancreatic exocrine cells

2011 ◽  
Vol 2 (4) ◽  
pp. 271-275 ◽  
Author(s):  
Kohtaro Minami ◽  
Ryuichiro Doi ◽  
Yoshiya Kawaguchi ◽  
Daiki Nukaya ◽  
Yoshiaki Hagiwara ◽  
...  
Keyword(s):  
Exocrine Cells ◽  
Insulin Secreting Cells ◽  
Pancreatic Exocrine
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