scholarly journals Decompensation ofβ-Cells in Diabetes: When Pancreaticβ-Cells Are on ICE(R)

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Roberto Salvi ◽  
Amar Abderrahmani
Keyword(s):  
Adaptive Response ◽  
Cell Function ◽  
Oxidized Ldl ◽  
Cell Activity ◽  
Negative Regulation ◽  
Early Gene ◽  
Insulin Production ◽  
Inducible Camp Early Repressor ◽  
Chronic Hyperglycemia ◽  
Genes Expression

Insulin production and secretion are temporally regulated. Keeping insulin secretion at rest after a rise of glucose prevents exhaustion and ultimately failure ofβ-cells. Among the mechanisms that reduceβ-cell activity is the inducible cAMP early repressor (ICER). ICER is an immediate early gene, which is rapidly induced by the cyclic AMP (cAMP) signaling cascade. The seminal function of ICER is to negatively regulate the production and secretion of insulin by repressing the genes expression. This is part of adaptive response required for properβ-cells function in response to environmental factors. Inappropriate induction of ICER accounts for pancreaticβ-cells dysfunction and ultimately death elicited by chronic hyperglycemia, fatty acids, and oxidized LDL. This review underlines the importance of balancing the negative regulation achieved by ICER for preservingβ-cell function and survival in diabetes.

scholarly journals Multiple Roles for Cholinergic Signaling from the Perspective of Stem Cell Function

2021 ◽  
Vol 22 (2) ◽  
pp. 666
Author(s):  
Toshio Takahashi
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Function ◽  
Cell Activity ◽  
Embryonic Stem ◽  
Cholinergic Neurons ◽  
Cell Types ◽  
Proliferative Potential ◽  
True Nature ◽  
Cholinergic Signaling

Stem cells have extensive proliferative potential and the ability to differentiate into one or more mature cell types. The mechanisms by which stem cells accomplish self-renewal provide fundamental insight into the origin and design of multicellular organisms. These pathways allow the repair of damage and extend organismal life beyond that of component cells, and they probably preceded the evolution of complex metazoans. Understanding the true nature of stem cells can only come from discovering how they are regulated. The concept that stem cells are controlled by particular microenvironments, also known as niches, has been widely accepted. Technical advances now allow characterization of the zones that maintain and control stem cell activity in several organs, including the brain, skin, and gut. Cholinergic neurons release acetylcholine (ACh) that mediates chemical transmission via ACh receptors such as nicotinic and muscarinic receptors. Although the cholinergic system is composed of organized nerve cells, the system is also involved in mammalian non-neuronal cells, including stem cells, embryonic stem cells, epithelial cells, and endothelial cells. Thus, cholinergic signaling plays a pivotal role in controlling their behaviors. Studies regarding this signal are beginning to unify our understanding of stem cell regulation at the cellular and molecular levels, and they are expected to advance efforts to control stem cells therapeutically. The present article reviews recent findings about cholinergic signaling that is essential to control stem cell function in a cholinergic niche.

scholarly journals A biomimetic assay platform for the interrogation of antigen-dependent anti-tumor T-cell function

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jeremy To ◽  
Doug Quackenbush ◽  
Emily Rowell ◽  
Lilin Li ◽  
Connor Reed ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Function ◽  
Cell Activity ◽  
Cytotoxic T Cell ◽  
Dependent Manner ◽  
Cyclin Dependent Kinase ◽  
Histocompatibility Complex ◽  
T Cell Function ◽  
Cytolytic Granule ◽  
Screening Platform

AbstractOvercoming tumor-mediated immunosuppression and enhancing cytotoxic T-cell activity within the tumor microenvironment are two central goals of immuno-oncology (IO) drug discovery initiatives. However, exploratory assays involving immune components are often plagued by low-throughput and poor clinical relevance. Here we present an innovative ultra-high-content assay platform for interrogating T-cell-mediated killing of 3D multicellular tumor spheroids. Employing this assay platform in a chemical genomics screen of 1800 annotated compounds enabled identification of small molecule perturbagens capable of enhancing cytotoxic CD8+ T-cell activity in an antigen-dependent manner. Specifically, cyclin-dependent kinase (CDK) and bromodomain (BRD) protein inhibitors were shown to significantly augment anti-tumor T-cell function by increasing cytolytic granule and type II interferon secretion in T-cells in addition to upregulating major histocompatibility complex (MHC) expression and antigen presentation in tumor cells. The described biotechnology screening platform yields multi-parametric, clinically-relevant data and can be employed kinetically for the discovery of first-in-class IO therapeutic agents.

scholarly journals Nfatc1’s Role in Mammary Epithelial Morphogenesis and Basal Stem/progenitor Cell Self-renewal

2021 ◽  
Author(s):  
Melissa McNeil ◽  
Yingying Han ◽  
Peng Sun ◽  
Kazuhide Watanabe ◽  
Jun Jiang ◽  
...  
Keyword(s):  
Stem Cell ◽  
Mammary Gland ◽  
Progenitor Cell ◽  
Cell Function ◽  
Cell Activity ◽  
Basal Layer ◽  
Mammary Epithelial ◽  
Epithelial Morphogenesis ◽  
Small Subset ◽  
Self Renewal

AbstractMammary gland is an outstanding system to study the regulatory mechanisms governing adult epithelial stem cell activity. Stem cells in the basal layer of the mammary gland fuel the morphogenesis and regeneration of a complex epithelial network during development and upon transplantation. The self-renewal of basal stem/progenitor cells is subjected to regulation by both cell-intrinsic and extrinsic mechanisms. Nfatc1 is a transcription factor that regulates breast tumorigenesis and metastasis, but its role in mammary epithelial development and stem cell function has not been investigated. Here we show that Nfatc1 is expressed in a small subset of mammary basal epithelial cells and its epithelial-specific deletion results in mild defects in side branching and basal-luminal cell balance. Moreover, Nfatc1-deficient basal cells exhibit reduced colony forming ability in vitro and somewhat compromised regenerative potential upon transplantation. Thus, our study provides evidence for a detectable yet non-essential role of Nfatc1 in mammary epithelial morphogenesis and basal stem/progenitor cell self-renewal.

Cell function in the bovine mammary gland: a preliminary study on interdependence of healthy and infected udder quarters

2007 ◽  
Vol 74 (2) ◽  
pp. 174-179 ◽  
Author(s):  
Roswitha Merle ◽  
Anke Schröder ◽  
Jörn Hamann
Keyword(s):  
Cell Count ◽  
Cell Function ◽  
Cell Activity ◽  
Polymorphonuclear Leucocytes ◽  
Differential Cell Count ◽  
Immune Reactions ◽  
Cell Counts ◽  
Differential Cell ◽  
Group A ◽  
Group B

Udder defence mechanisms are not completely explained by current mastitis research. The anatomical construction of the udder implies that infection of one udder quarter does not influence the immune status of neighbouring quarters. To test this hypothesis, we compared the immune reactions of individual udder quarters in response to microbial attacks. In the course of immune reactions, polymorphonuclear leucocytes (PMN) release oxygen radicals, which can be determined by chemiluminescence (CL). Milk from 140 udder quarters of 36 cows was analysed for somatic cell count (SCC), differential cell count, viability and CL activity. Quarters with an SCC <100000 cells/ml and free of pathogens were defined as uninfected, all other quarters were categorized as infected. Three groups of cows were classified cytologically: group A (healthy, 11 animals, SCC limit <100000 cells/ml); group B (moderate mastitis, 8 cows, SCC [ges ]100000 and <400000 cells/ml in at least one quarter); and group C (severe mastitis, 17 cows, SCC [ges ]400000 cells/ml in at least one quarter). Infected and uninfected quarters in groups B and C were analysed separately. Viability of PMN leucocytes was significantly (P=0·0012) lower in group A (72·6%) than in healthy quarters of group C (84·0%). Lowering the SCC limit of healthy quarters to <50000 cells/ml (group A: all quarters within the udder) revealed striking differences between samples of groups B and C: in addition to varying differential cell counts and viabilities, CL activity of group B<50 (2929 CL units/million PMN) was markedly lower than that of the other groups (5616 in group A<50 and 6445 CL units/million PMN in group C<50). These results allow the conclusion that the infection of one udder quarter influences the cell activity of neighbouring quarters. When the SCC threshold for healthy quarters was reduced to 50000 cells/ml, greater differences in cell activities were detected between healthy udders and healthy quarters of infected udders.

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 A longitudinal immunologic evaluation of hemophiliac patients

Blood ◽  
1985 ◽  
Vol 66 (4) ◽  
pp. 993-998 ◽  
Author(s):  
RD deShazo ◽  
CB Daul ◽  
WA Andes ◽  
BE Bozelka
Keyword(s):  
Mononuclear Cell ◽  
Cell Function ◽  
Killer Cell ◽  
Cell Activity ◽  
Suppressor Cell ◽  
Cell Mediated Immunity ◽  
Biologic Response ◽  
Life Threatening ◽  
Generalized Lymphadenopathy ◽  
One Year

Abstract Over an average span of one year, we performed a prospective clinical and immunologic evaluation of 30 patients with hemophilia. No patient developed life-threatening opportunistic infection or malignancy; however, the immunologic abnormalities and lymphadenopathy initially present in nine patients (lymphadenopathy group) persisted. In addition, five patients, representing 24% of the initial group without lymphadenopathy, developed generalized lymphadenopathy (converter group). One episode of idiopathic thrombocytopenia (ITP) and one episode of staphylococcal sepsis occurred in this “converter” group; one episode of ITP also occurred in the lymphadenopathy group. Sixteen patients remained asymptomatic. At the time of the follow-up evaluation, those differences in mononuclear cell (MNC) percentages and numbers noted initially among the three hemophiliac groups were no longer present. Natural killer cell function alone or in the presence of biologic response modifiers was not different among hemophiliac and control groups. Before developing lymphadenopathy, the converter group of patients had significantly better lymphocyte mitogenic function than did the other two groups of patients with hemophilia. However, lymphocyte mitogenic responses of all groups of patients with hemophilia significantly deteriorated over the course of the study. The abnormal mitogenic responses noted in these patients was explained in part by higher levels of spontaneous suppressor cell activity in mononuclear cell preparations from patients with hemophilia. We conclude that long-term immunologic studies of this patient population requires both quantitative and qualitative evaluations. Our data show that patients with hemophilia have progressive dysfunction of cell- mediated immunity.

scholarly journals Ataxin-1 regulates B cell function and the severity of autoimmune experimental encephalomyelitis

2020 ◽  
Vol 117 (38) ◽  
pp. 23742-23750 ◽  
Author(s):  
Alessandro Didonna ◽  
Ester Canto Puig ◽  
Qin Ma ◽  
Atsuko Matsunaga ◽  
Brenda Ho ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Function ◽  
Cell Activity ◽  
Cell Polarization ◽  
Spinocerebellar Ataxia Type ◽  
Loss Of Function ◽  
Th1 Cell ◽  
Aberrant Expression

Ataxin-1 (ATXN1) is a ubiquitous polyglutamine protein expressed primarily in the nucleus where it binds chromatin and functions as a transcriptional repressor. Mutant forms of ataxin-1 containing expanded glutamine stretches cause the movement disorder spinocerebellar ataxia type 1 (SCA1) through a toxic gain-of-function mechanism in the cerebellum. Conversely, ATXN1 loss-of-function is implicated in cancer development and Alzheimer’s disease (AD) pathogenesis.ATXN1was recently nominated as a susceptibility locus for multiple sclerosis (MS). Here, we show thatAtxn1-null mice develop a more severe experimental autoimmune encephalomyelitis (EAE) course compared to wildtype mice. The aggravated phenotype is mediated by increased T helper type 1 (Th1) cell polarization, which in turn results from the dysregulation of B cell activity. Ataxin-1 ablation in B cells leads to aberrant expression of key costimulatory molecules involved in proinflammatory T cell differentiation, including cluster of differentiation (CD)44 and CD80. In addition, comprehensive phosphoflow cytometry and transcriptional profiling link the exaggerated proliferation of ataxin-1 deficient B cells to the activation of extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription (STAT) pathways. Lastly, selective deletion of the physiological binding partner capicua (CIC) demonstrates the importance of ATXN1 native interactions for correct B cell functioning. Altogether, we report a immunomodulatory role for ataxin-1 and provide a functional description of theATXN1locus genetic association with MS risk.

The Old and the New in the Treatment of Type 2 Diabetes: Focus on the Combination Therapy with Dipeptidyl Peptidase-4 Inhibitors and Metformin

2010 ◽  
Vol 2 ◽  
pp. CMT.S3420 ◽  
Author(s):  
Giovanni Anfossi ◽  
Isabella Russo ◽  
Katia Bonomo ◽  
Mariella Trovati
Keyword(s):  
Type 2 Diabetes ◽  
Cell Function ◽  
Microvascular Complications ◽  
Chronic Complications ◽  
Dipeptidyl Peptidase 4 ◽  
Chronic Hyperglycemia ◽  
Oral Agents ◽  
Dipeptidyl Peptidase 4 Inhibitors

Type 2 diabetes mellitus (T2DM) is a complex multifactorial disease which affects the length and quality of life by severe chronic complications. Chronic hyperglycemia, which is the main alteration in T2DM, is strictly related to microvascular complications (such as retinopathy and nephropathy) and neuropathy, whereas large vessel atherosclerosis is also dependent on lipid and hemostasis abnormalities, arterial hypertension and other known cardiovascular risk factors. An early intervention to control hyperglycemia and to prevent deterioration of β-cell function is considered mandatory in patients with T2DM to minimize the risk of chronic complications. Recently, the availability of new pharmacological agents with different targets, including the activation of the incretin system has allowed the proposal of more effective strategies for early treatment of metabolic alterations in patients with T2DM. This commentary will focus on the role of new oral agents influencing the incretin system and the putative advantages of their co-administration with metformin, an old, effective anti-hyperglycemic agent also able to exert beneficial actions on arterial vessels, reducing the risk of macrovascular-related events. The vasoprotective role of metformin is largely independent of its hypoglycemic action, and has been ascribed to pleiotropic effects.

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