| 1. |
- Jonsson, Alexander, et al.
(författare)
-
Protein Kinase R Is Constitutively Expressed in the Human Pancreas
- 2019
-
Ingår i: Journal of Histochemistry & Cytochemistry. - : SAGE Publications. - 0022-1554 .- 1551-5044. ; 67:2, s. 99-105
-
Tidskriftsartikel (refereegranskat)abstract
- Viral infection of the insulin-producing cells in the pancreas has been proposed in the etiology of type 1 diabetes. Protein kinase R (PKR) is a cytoplasmic protein activated through phosphorylation in response to cellular stress and particularly viral infection. As PKR expression in pancreatic beta-cells has been interpreted as a viral footprint, this cross-sectional study aimed at characterizing the PKR expression in non-diabetic human pancreases. PKR expression was evaluated in pancreas tissue from 16 non-diabetic organ donors, using immunohistochemistry, qPCR, and western blot. Immunohistochemistry and western blot showed readily detectable PKR expression in the pancreatic parenchyma. The qPCR detected PKR mRNA in both endocrine and exocrine samples, with a slightly higher expression in the islets. In conclusion, PKR is constitutively expressed in both endocrine and exocrine parts of the pancreas and its expression should not be interpreted as a viral footprint in pancreatic beta cells.
|
|
| 2. |
- Lundberg, Marcus, et al.
(författare)
-
Insulitis in human diabetes : a histological evaluation of donor pancreases
- 2017
-
Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 60:2, s. 346-353
-
Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis According to the consensus criteria developed for type 1 diabetes, an individual can be diagnosed with insulitis when >= 15 CD45(+) cells are found within the parenchyma or in the islet-exocrine interface in >= 3 islets. The aim of this study was to determine the frequency of individuals with type 2 diabetes fulfilling these criteria with reference to non-diabetic and type 1 diabetic individuals. Methods Insulitis was determined by examining CD45(+) cells in the pancreases of 50, 13 and 44 organ donors with type 2 diabetes, type 1 diabetes and no diabetes, respectively. CD3(+) cells (T cells) infiltrating the islets were evaluated in insulitic donors. In insulitic donors with type 2 diabetes, the pancreases were characterised according to the presence of CD68 (macrophages), myeloperoxidase (MPO; neutrophils), CD3, CD20 (B cells) and HLA class I hyperstained islets. In all type 2 diabetic donors, potential correlations of insulitis with dynamic glucose-stimulated insulin secretion in vitro or age, BMI, HbA(1c) or autoantibody positivity were examined. Results Overall, 28% of the type 2 diabetic donors fulfilled the consensus criteria for insulitis developed for type 1 diabetes. Of the type 1 diabetic donors, 31% fulfilled the criteria. None of the non-diabetic donors met the criteria. Only type 1 diabetic donors had >= 15 CD3(+) cells in >= 3 islets. Type 2 diabetic donors with insulitis also had a substantial number of CD45(+) cells in the exocrine parenchyma. Macrophages constituted the largest fraction of CD45(+) cells, followed by neutrophils and T cells. Of type 2 diabetic pancreases with insulitis, 36% contained islets that hyperstained for HLA class I. Isolated islets from type 2 diabetic donors secreted less insulin than controls, although with preserved dynamics. Insulitis in the type 2 diabetic donors did not correlate with glucose-stimulated insulin secretion, the presence of autoantibodies, BMI or HbA(1c). Conclusions/interpretation The current definition of insulitis cannot be used to distinguish pancreases retrieved from individuals with type 1 diabetes from those with type 2 diabetes. On the basis of our findings, we propose a revised definition of insulitis, with a positive diagnosis when >= 15 CD3(+) cells, not CD45(+) cells, are found in >= 3 islets.
|
|
| 3. |
|
|
| 4. |
- Stenwall, Anton, et al.
(författare)
-
Characterization of host defense molecules in the human pancreas
- 2019
-
Ingår i: Islets. - : Informa UK Limited. - 1938-2014 .- 1938-2022. ; 11:4, s. 89-101
-
Tidskriftsartikel (refereegranskat)abstract
- The gut microbiota can play a role in pancreatitis and, likely, in the development of type 1 diabetes (T1D). Anti-microbial peptides and secretory proteins are important mediators of the innate immune response against bacteria but their expression in the human pancreas is not fully known. In this study, immunohistochemistry was used to analyze the expression of seven anti-microbial peptides (Defensin alpha 1, alpha 4, beta 1-4 and Cathelicidin) and two secretory proteins with known antimicrobial properties (REG3A and GP2) in pancreatic and duodenal biopsies from 10 non-diabetic organ donors and one organ donor that died at onset of T1D. Immunohistochemical data was compared with previously published whole-transcriptome data sets. Seven (Defensin alpha 1, beta 2, beta 3, alpha 4, GP2, Cathelicidin, and REG3A) host defense molecules showed positive staining patterns in most non-diabetic organ donors, whereas two (Defensin beta 1 and beta 4) were negative in all non-diabetic donors. Two molecules (Defensin alpha 1 and GP2) were restricted to the exocrine pancreas whereas two (Defensin beta 3, alpha 4) were only expressed in islet tissue. Cathelicidin, beta 2, and REG3A were expressed in both islets and exocrine tissue. The donor that died at onset of T1D had generally less positivity for the host defense molecules, but, notably, this pancreas was the only one where defensin beta 1 was found. Neither donor age, immune-cell infiltration, nor duodenal expression correlated to the pancreatic expression of host defense molecules. In conclusion, these findings could have important implications for the inflammatory processes in diabetes and pancreatitis as we find several host defense molecules expressed by the pancreatic tissue.
|
|
| 5. |
- Wiberg, Anna, et al.
(författare)
-
Characterization of human organ donors testing positive for type 1 diabetes-associated autoantibodies
- 2015
-
Ingår i: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 182:3, s. 278-288
-
Tidskriftsartikel (refereegranskat)abstract
- In this study we aim to describe the characteristics of non-diabetic organ donors with circulating diabetes-associated autoantibodies collected within the Nordic Network for Islet Transplantation. One thousand and thirty organ donors have been screened in Uppsala for antibodies against glutamic acid decarboxylase (GADA) and islet antigen-2 (IA-2A). The 32 non-diabetic donors that tested positive for GADA (33% of all non-diabetic donors) were studied in more detail, together with 32 matched controls. Mean age among the autoantibody-positive donors was 526 (range 21-74), family history of type 1 diabetes (T1D) was unknown, and no donor was genetically predisposed for T1D regarding the human leucocyte antigen (HLA) locus. Subjects were analysed for islet cell antibodies (ICA), insulin autoantibodies (IAA) and zinc transporter 8 antibodies (ZnT8A), and pancreas morphology and clinical data were examined. Eight non-diabetic donors tested positive for two antibodies and one donor tested positive for four antibodies. No insulitis or other signs of a diabetic process were found in any of the donors. While inflammatory cells were present in all donors, subjects with high GADA titres had significantly higher CD45 cell numbers in exocrine tissue than controls. The extent of fibrosis was more pronounced in autoantibody-positive donors, even in subjects with lower GADA titres. Notably, it is possible that events not related directly to T1D (e.g. subclinical pancreatitis) may induce autoantibodies in some cases.
|
|
