scholarly journals Making Insulin and Staying Out of Autoimmune Trouble: The Beta-Cell Conundrum

2021 ◽  
Vol 12 ◽  
Author(s):  
Alexia Carré ◽  
Roberto Mallone
Keyword(s):  
Beta Cell ◽  
Beta Cells ◽  
Mhc Class I ◽  
Antigen Processing ◽  
Cell Function ◽  
Immune Cell ◽  
Current Knowledge ◽  
Cell Types ◽  
Class I ◽  
Cellular Models

Autoimmune type 1 diabetes (T1D) results from the intricate crosstalk of various immune cell types. CD8+ T cells dominate the pro-inflammatory milieu of islet infiltration (insulitis), and are considered as key effectors of beta-cell destruction, through the recognition of MHC Class I-peptide complexes. The pathways generating MHC Class I-restricted antigens in beta cells are poorly documented. Given their specialized insulin secretory function, the associated granule processing and degradation pathways, basal endoplasmic reticulum stress and susceptibility to additional stressors, alternative antigen processing and presentation (APP) pathways are likely to play a significant role in the generation of the beta-cell immunopeptidome. As direct evidence is missing, we here intersect the specificities of beta-cell function and the literature about APP in other cellular models to generate some hypotheses on APPs relevant to beta cells. We further elaborate on the potential role of these pathways in T1D pathogenesis, based on the current knowledge of antigens presented by beta cells. A better understanding of these pathways may pinpoint novel mechanisms amenable to therapeutic targeting to modulate the immunogenicity of beta cells.

scholarly journals Neonatal Fc receptor (FcRn) – not only transporter of maternal IgG

2018 ◽  
Vol 72 ◽  
pp. 701-727
Author(s):  
Joanna E. Mikulska
Keyword(s):  
Mhc Class I ◽  
Current Knowledge ◽  
Cell Types ◽  
Fc Receptor ◽  
Class I ◽  
Neonatal Fc Receptor ◽  
The Status ◽  
And Function ◽  
Different Cell Types ◽  
Maternal Igg

The neonatal Fc receptor, (FcRn) is a transmembrane, heterodimeric glycoprotein with a structure similar to MHC class I molecules. In contrast to MHC class I antigens, FcRn does not bind to peptides (antigens) but interacts with the Fc fragment of IgG and albumin. The FcRn-IgG interaction as well as the FcRn-albumin interaction occur at acidic pH (optimally at pH 5.0-6.5) but not in physiological environment. These two ligands bind to distinct binding sites on the receptor molecule and by different mechanisms. Now, it is known that the expression of FcRn is not restricted to sites involved in the transport of maternal IgG, and this receptor is not responsible only for transfer the passive immunity from mother to the offspring. But FcRn has a much broader range of expression and function, throughout life and in many different cell types and tissues of humans and animals. This review summarizes the status of our knowledge on the expression, interaction with ligands and functions of the neonatal Fc receptor. This article shows also the possibilities of utilizing a current knowledge on FcRn for therapeutic purposes.

scholarly journals Alpha cell regulation of beta cell function

Diabetologia ◽  
2020 ◽  
Vol 63 (10) ◽  
pp. 2064-2075
Author(s):  
Tilo Moede ◽  
Ingo B. Leibiger ◽  
Per-Olof Berggren
Keyword(s):  
Blood Glucose ◽  
Beta Cell ◽  
Beta Cells ◽  
Endocrine Cell ◽  
Beta Cell Function ◽  
Cell Function ◽  
Cell Types ◽  
Alpha Cell ◽  
Alpha Cells

Abstract The islet of Langerhans is a complex endocrine micro-organ consisting of a multitude of endocrine and non-endocrine cell types. The two most abundant and prominent endocrine cell types, the beta and the alpha cells, are essential for the maintenance of blood glucose homeostasis. While the beta cell produces insulin, the only blood glucose-lowering hormone of the body, the alpha cell releases glucagon, which elevates blood glucose. Under physiological conditions, these two cell types affect each other in a paracrine manner. While the release products of the beta cell inhibit alpha cell function, the alpha cell releases factors that are stimulatory for beta cell function and increase glucose-stimulated insulin secretion. The aim of this review is to provide a comprehensive overview of recent research into the regulation of beta cell function by alpha cells, focusing on the effect of alpha cell-secreted factors, such as glucagon and acetylcholine. The consequences of differences in islet architecture between species on the interplay between alpha and beta cells is also discussed. Finally, we give a perspective on the possibility of using an in vivo imaging approach to study the interactions between human alpha and beta cells under in vivo conditions.

scholarly journals Aging of human endocrine pancreatic cell types is heterogeneous and sex-specific

2019 ◽  
Author(s):  
Rafael Arrojo e Drigo ◽  
Galina Erikson ◽  
Swati Tyagi ◽  
Juliana Capitanio ◽  
James Lyon ◽  
...  
Keyword(s):  
Beta Cell ◽  
Beta Cells ◽  
Endocrine Pancreas ◽  
Cell Function ◽  
Meta Analysis ◽  
Cell Types ◽  
Pancreatic Cell ◽  
Transcriptional Signature ◽  
Human Lifespan ◽  
Functional Analyses

SummaryThe human endocrine pancreas must regulate glucose homeostasis throughout the human lifespan, which is generally decades. We performed meta-analysis of single-cell, RNA-sequencing datasets derived from 36 individuals, as well as functional analyses, to characterize age-associated changes to the major endocrine pancreatic cell types. Increasing age was associated with shifts in pancreatic alpha and beta cell identity and loss of nuclear integrity in non-diabetic humans. In non-diabetic individuals ≥ 50 years old, 80% of their beta cells exhibited a transcriptional signature similar to cells from type-2 diabetic (T2D) donors. Surprisingly, ∼5% of beta cells from T2D donors retained a youthful, N.D. transcriptional profile. Furthermore, beta cell function was reduced by 50% during aging in men but not women, which may explain sex-associated differences in diabetes etiology. These analyses reveal that aging of the human endocrine pancreas is sex- and cell-type specific.

scholarly journals Butyrate and Class I Histone Deacetylase Inhibitors Promote Differentiation of Neonatal Porcine Islet Cells into Beta Cells

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3249
Author(s):  
Yichen Zhang ◽  
Yutian Lei ◽  
Mohsen Honarpisheh ◽  
Elisabeth Kemter ◽  
Eckhard Wolf ◽  
...  
Keyword(s):  
Beta Cell ◽  
Histone Deacetylase ◽  
Beta Cells ◽  
Histone Deacetylase Inhibitors ◽  
Cell Function ◽  
Islet Cells ◽  
Class I ◽  
Specific Class ◽  
Porcine Islet ◽  
Promising Source

Neonatal porcine islets-like clusters (NPICCs) are a promising source for cell therapy of type 1 diabetes. Freshly isolated NPICCs are composed of progenitor cells and endocrine cells, which undergo a maturation process lasting several weeks until the normal beta cell function has developed. Here, we investigated the effects of short-chain fatty acids on the maturation of islet cells isolated from two to three day-old piglets. NPICCs were cultivated with acetate, butyrate and propionate (0–2000 µM) for one to eight days. Incubation with butyrate resulted in a significant upregulation of insulin gene expression and an increased beta cell number, whereas acetate or propionate had only marginal effects. Treatment with specific inhibitors of G-protein-coupled receptor GPR41 (β-hydroxybutyrate) and/or GPR43 (GPLG0974) did not abolish butyrate induced insulin expression. However, incubation of NPICCs with class I histone deacetylase inhibitors (HDACi) mocetinostat and MS275, but not selective class II HDACi (TMP269, MC1568) mimicked the butyrate effect on beta cell differentiation. Our study revealed that butyrate treatment has the capacity to increase the number of beta cells, which may be predominantly mediated through its HDAC inhibitory activity. Butyrate and specific class I HDAC inhibitors may represent beneficial supplements to promote differentiation of neonatal porcine islet cells towards beta cells for cell replacement therapies.

MHC Class I Antigen Processing Pathways

1997 ◽  
Vol 54 (2) ◽  
pp. 91-103 ◽  
Author(s):  
Antonella Maffei ◽  
Kyriakos Papadopoulos ◽  
Paul E Harris
Keyword(s):  
Mhc Class I ◽  
Antigen Processing ◽  
Class I ◽  
Processing Pathways ◽  
Mhc Class I Antigen

scholarly journals Effects of Extra Virgin Olive Oil Polyphenols on Beta-Cell Function and Survival

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 286
Author(s):  
Nicola Marrano ◽  
Rosaria Spagnuolo ◽  
Giuseppina Biondi ◽  
Angelo Cignarelli ◽  
Sebastio Perrini ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Beta Cell ◽  
Olive Oil ◽  
Beta Cells ◽  
Intracellular Signaling ◽  
Beta Cell Function ◽  
Cell Function ◽  
Virgin Olive Oil ◽  
Extra Virgin Olive Oil ◽  
Insulin Biosynthesis

Extra virgin olive oil (EVOO) is a major component of the Mediterranean diet and is appreciated worldwide because of its nutritional benefits in metabolic diseases, including type 2 diabetes (T2D). EVOO contains significant amounts of secondary metabolites, such as phenolic compounds (PCs), that may positively influence the metabolic status. In this study, we investigated for the first time the effects of several PCs on beta-cell function and survival. To this aim, INS-1E cells were exposed to 10 μM of the main EVOO PCs for up to 24 h. Under these conditions, survival, insulin biosynthesis, glucose-stimulated insulin secretion (GSIS), and intracellular signaling activation (protein kinase B (AKT) and cAMP response element-binding protein (CREB)) were evaluated. Hydroxytyrosol, tyrosol, and apigenin augmented beta-cell proliferation and insulin biosynthesis, and apigenin and luteolin enhanced the GSIS. Conversely, vanillic acid and vanillin were pro-apoptotic for beta-cells, even if they increased the GSIS. In addition, oleuropein, p-coumaric, ferulic and sinapic acids significantly worsened the GSIS. Finally, a mixture of hydroxytyrosol, tyrosol, and apigenin promoted the GSIS in human pancreatic islets. Apigenin was the most effective compound and was also able to activate beneficial intracellular signaling. In conclusion, this study shows that hydroxytyrosol, tyrosol, and apigenin foster beta-cells’ health, suggesting that EVOO or supplements enriched with these compounds may improve insulin secretion and promote glycemic control in T2D patients.

II. One size fits all: nonclassical MHC molecules fulfill multiple roles in epithelial cell function

1998 ◽  
Vol 274 (2) ◽  
pp. G227-G231 ◽  
Author(s):  
Richard S. Blumberg
Keyword(s):  
Epithelial Cell ◽  
Mhc Class I ◽  
Cell Biology ◽  
Cell Function ◽  
Surface Glycoprotein ◽  
Class I ◽  
Human Major Histocompatibility Complex ◽  
Cell Surface Glycoprotein ◽  
Mhc Molecules ◽  
Nonclassical Mhc

The human major histocompatibility complex (MHC) on chromosome 6 encodes three classical class I genes: human leukocyte antigen-A (HLA-A), HLA-B, and HLA-C. These polymorphic genes encode a 43- to 45-kDa cell surface glycoprotein that, in association with the 12-kDa β2-microglobulin molecule, functions in the presentation of nine amino acid peptides to the T cell receptor of CD8-bearing T lymphocytes and killer inhibitory receptors on natural killer cells. In addition to these ubiquitously expressed polymorphic proteins, the human genome also encodes a number of nonclassical MHC class I-like, or class Ib, genes that in general encode nonpolymorphic molecules involved in a variety of specific immunologic functions. Many of these genes, including CD1, the neonatal Fc receptor for immunoglobulin G, HLA-G, the MHC class I chain-related gene A, and Hfe, are prominently displayed on epithelial cells, suggesting an important role in epithelial cell biology.

Sign in / Sign up

Export Citation Format

Share Document