1
|
Abstract
Rat models of human type 1 diabetes have been shown to be of great importance for the elucidation of the mechanisms underlying the development of autoimmune diabetes. The three major well-established spontaneous rat models are the BioBreeding (BB) diabetes-prone rat, the Komeda diabetes-prone (KDP) rat, and the IDDM (LEW.1AR1-iddm) rat. Their distinctive features are described with special reference to their pathology, immunology, and genetics and compared with the situation in patients with type 1 diabetes mellitus. For all three established rat models, a distinctive genetic mutation has been identified that is responsible for the manifestation of the diabetic syndrome in these rat strains.
Collapse
Affiliation(s)
- Sigurd Lenzen
- Institute of Experimental Diabetes Research, Hannover Medical School, Hannover, Germany. .,Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
| | - Tanja Arndt
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Matthias Elsner
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Dirk Wedekind
- Institute for Laboratory Animal Science, Hannover Medical School, Hannover, Germany
| | - Anne Jörns
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| |
Collapse
|
2
|
Koffert JP, Mikkola K, Virtanen KA, Andersson AMD, Faxius L, Hällsten K, Heglind M, Guiducci L, Pham T, Silvola JMU, Virta J, Eriksson O, Kauhanen SP, Saraste A, Enerbäck S, Iozzo P, Parkkola R, Gomez MF, Nuutila P. Metformin treatment significantly enhances intestinal glucose uptake in patients with type 2 diabetes: Results from a randomized clinical trial. Diabetes Res Clin Pract 2017; 131:208-216. [PMID: 28778047 DOI: 10.1016/j.diabres.2017.07.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 06/13/2017] [Accepted: 07/07/2017] [Indexed: 12/26/2022]
Abstract
AIMS Metformin therapy is associated with diffuse intestinal 18F-fluoro-deoxyglucose (FDG) accumulation in clinical diagnostics using routine FDG-PET imaging. We aimed to study whether metformin induced glucose uptake in intestine is associated with the improved glycaemic control in patients with type 2 diabetes. Therefore, we compared the effects of metformin and rosiglitazone on intestinal glucose metabolism in patients with type 2 diabetes in a randomized placebo controlled clinical trial, and further, to understand the underlying mechanism, evaluated the effect of metformin in rats. METHODS Forty-one patients with newly diagnosed type 2 diabetes were randomized to metformin (1g, b.i.d), rosiglitazone (4mg, b.i.d), or placebo in a 26-week double-blind trial. Tissue specific intestinal glucose uptake was measured before and after the treatment period using FDG-PET during euglycemic hyperinsulinemia. In addition, rats were treated with metformin or vehicle for 12weeks, and intestinal FDG uptake was measured in vivo and with autoradiography. RESULTS Glucose uptake increased 2-fold in the small intestine and 3-fold in the colon for the metformin group and associated with improved glycemic control. Rosiglitazone increased only slightly intestinal glucose uptake. In rodents, metformin treatment enhanced intestinal FDG retention (P=0.002), which was localized in the mucosal enterocytes of the small intestine. CONCLUSIONS Metformin treatment significantly enhances intestinal glucose uptake from the circulation of patients with type 2 diabetes. This intestine-specific effect is associated with improved glycemic control and localized to mucosal layer. These human findings demonstrate directs effect of metformin on intestinal metabolism and elucidate the actions of metformin. Clinical trial number NCT02526615.
Collapse
Affiliation(s)
- Jukka P Koffert
- Turku PET Centre, University of Turku, Turku, Finland; Department of Gastroenterology, Turunmaa Hospital, Southwest Finland Hospital District, Turku, Finland
| | - Kirsi Mikkola
- Turku PET Centre, University of Turku, Turku, Finland
| | | | | | - Linda Faxius
- Department of Clinical Sciences in Malmö, Lund University Diabetes Centre, Sweden
| | | | - Mikael Heglind
- Department of Clinical and Medical Genetics, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE 40530 Gothenburg, Sweden
| | - Letizia Guiducci
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Tam Pham
- Turku PET Centre, University of Turku, Turku, Finland
| | | | - Jenni Virta
- Turku PET Centre, University of Turku, Turku, Finland
| | - Olof Eriksson
- Turku PET Centre, University of Turku, Turku, Finland; Department of Biosciences, Åbo Akademi University, Turku, Finland; Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Saila P Kauhanen
- Turku PET Centre, University of Turku, Turku, Finland; Division of Digestive Surgery and Urology, Turku University Hospital, Turku, Finland
| | - Antti Saraste
- Turku PET Centre, University of Turku, Turku, Finland; Heart Center, Turku University Hospital, Turku, Finland
| | - Sven Enerbäck
- Department of Clinical and Medical Genetics, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE 40530 Gothenburg, Sweden
| | - Patricia Iozzo
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Riitta Parkkola
- Department of Radiology, Turku University, Finland; Department of Radiology, Turku University Hospital, Finland
| | - Maria F Gomez
- Department of Clinical Sciences in Malmö, Lund University Diabetes Centre, Sweden
| | - Pirjo Nuutila
- Turku PET Centre, University of Turku, Turku, Finland; Department of Endocrinology, Turku University Hospital, Turku, Finland.
| |
Collapse
|
3
|
Mendu SK, Akesson L, Jin Z, Edlund A, Cilio C, Lernmark A, Birnir B. Increased GABA(A) channel subunits expression in CD8(+) but not in CD4(+) T cells in BB rats developing diabetes compared to their congenic littermates. Mol Immunol 2010; 48:399-407. [PMID: 21112637 DOI: 10.1016/j.molimm.2010.08.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/04/2010] [Accepted: 08/09/2010] [Indexed: 11/30/2022]
Abstract
GABA (γ-aminobutyric acid), the main inhibitory neurotransmitter in the central nervous system is also present in the pancreatic islet β cells where it may function as a paracrine molecule and perhaps as an immunomodulator of lymphocytes infiltrating the pancreatic islet. We examined CD4(+) and CD8(+) T cells from diabetes prone (DR(lyp/lyp)) or resistant (DR(+/+)) congenic biobreeding (BB) rats for expression of GABA(A) channels. Our results show that BB rat CD4(+) and CD8(+) T cells express α1, α2, α3, α4, α6, β3, γ1, δ, ρ1 and ρ2 GABA(A) channel subunits. In CD8(+) T cells from DR(lyp/lyp) animals the subunits were significantly upregulated relative to expression levels in the CD8(+) T cells from DR(+/+) rats as well as from CD4(+) T cells from both DR(lyp/lyp) and DR(+/+) rats. Functional channels were formed in the T cells and physiological concentrations of GABA (100 nM) decreased T cell proliferation. Our results are consistent with the hypothesis that GABA in the islets of Langerhans may diminish inflammation by inhibition of activated T lymphocytes.
Collapse
|
4
|
Fuller JM, Bogdani M, Tupling TD, Jensen RA, Pefley R, Manavi S, Cort L, Blankenhorn EP, Mordes JP, Lernmark A, Kwitek AE. Genetic dissection reveals diabetes loci proximal to the gimap5 lymphopenia gene. Physiol Genomics 2009; 38:89-97. [PMID: 19351909 DOI: 10.1152/physiolgenomics.00015.2009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Congenic DRF.(f/f) rats are protected from type 1 diabetes (T1D) by 34 Mb of F344 DNA introgressed proximal to the gimap5 lymphopenia gene. To dissect the genetic factor(s) that confer protection from T1D in the DRF.(f/f) rat line, DRF.(f/f) rats were crossed to inbred BBDR or DR.(lyp/lyp) rats to generate congenic sublines that were genotyped and monitored for T1D, and positional candidate genes were sequenced. All (100%) DR.(lyp/lyp) rats developed T1D by 83 days of age. Reduction of the DRF.(f/f) F344 DNA fragment by 26 Mb (42.52-68.51 Mb) retained complete T1D protection. Further dissection revealed that a 2 Mb interval of F344 DNA (67.41-70.17 Mb) (region 1) resulted in 47% protection and significantly delayed onset (P < 0.001 compared with DR.(lyp/lyp)). Retaining <1 Mb of F344 DNA at the distal end (76.49-76.83 Mb) (region 2) resulted in 28% protection and also delayed onset (P < 0.001 compared with DR.(lyp/lyp)). Comparative analysis of diabetes frequency in the DRF.(f/f) congenic sublines further refined the RNO4 region 1 interval to approximately 670 kb and region 2 to the 340 kb proximal to gimap5. All congenic DRF.(f/f) sublines were prone to low-grade pancreatic mononuclear cell infiltration around ducts and vessels, but <20% of islets in nondiabetic rats showed islet infiltration. Coding sequence analysis revealed TCR Vbeta 8E, 12, and 13 as candidate genes in region 1 and znf467 and atp6v0e2 as candidate genes in region 2. Our results show that spontaneous T1D is controlled by at least two genetic loci 7 Mb apart on rat chromosome 4.
Collapse
Affiliation(s)
- J M Fuller
- Department of Clinical Sciences, Lund University, Clinical Research Center, Malmö, Sweden.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Akesson L, Hawkins T, Jensen R, Fuller JM, Breslow NE, Lernmark A. Decreased core temperature and increased beta(3)-adrenergic sensitivity in diabetes-prone BB rats. Diabetes Technol Ther 2007; 9:354-62. [PMID: 17705691 DOI: 10.1089/dia.2006.0036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Diabetes-prone (DP) congenic DR.lyp/lyp BioBreeding (BB) rats all develop Type 1 diabetes between 50 and 81 days of age, while DR.lyp/+ or DR.+/+ BB rats are diabetes resistant (DR). The DP rats display reduced weight gain prior to developing hyperglycemia, implying that metabolic events may precede diabetes onset. We tested the hypothesis that temperature measurements could serve as a physiological marker for the impending onset of hyperglycemia. METHODS Prior to the onset of hyperglycemia, brain, lower back, and intrascapular brown adipose tissue temperatures were analyzed by thermal signature analysis, which measures infrared emission from tissues. A thermocoupled rectal probe measured core temperature. In addition we performed a beta(3)-adrenergic receptor challenge test with the beta(3)-adrenergic receptor agonist BRL37344. RESULTS DP rats displayed lower core temperature than DR rats prior to the onset of hyperglycemia. No temperature difference was detected in brain, lower back, or intrascapular brown adipose tissue between DP and DR rats. The beta(3)-adrenergic challenge showed that the rate of temperature increase after administration of BRL37344 was significantly higher (0.005 +/- 0.002 degrees C/min) in DP than in DR rats (P = 0.044). CONCLUSIONS These studies reveal that the prediabetic DP rats fail to maintain core temperature and that they display increased sensitivity to heat production induced by a beta(3)-adrenergic receptor agonist. These studies suggest that body temperature as a measure of metabolic dysregulation is altered in the prediabetic DP rat prior to the onset of hyperglycemia.
Collapse
Affiliation(s)
- Lina Akesson
- Diabetes and Celiac Disease Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | | | | | | | | | | |
Collapse
|
6
|
Nitta T, Takahama Y. The lymphocyte guard-IANs: regulation of lymphocyte survival by IAN/GIMAP family proteins. Trends Immunol 2006; 28:58-65. [PMID: 17196432 DOI: 10.1016/j.it.2006.12.002] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 11/13/2006] [Accepted: 12/12/2006] [Indexed: 01/10/2023]
Abstract
The life-or-death decision of immune cells makes an essential contribution to immune-system development and the regulation of immune responses. A new family of cell-survival regulators expressed in lymphocytes, termed immune-associated nucleotide-binding proteins (IANs) [also known as GTPase of immunity-associated proteins (GIMAPs)], has been described. The IAN/GIMAP family consists of GTP-binding proteins that share a unique primary structure and whose expression is finely regulated by T-cell receptor signals. Recent studies have shown that IAN/GIMAP family proteins crucially regulate the survival of T cells during development, selection and homeostasis, and are possibly linked to the onset of T-lymphopenia, leukemia and autoimmunity. IAN/GIMAP family proteins might also take part in mitochondrial regulation of lymphocyte apoptosis by interacting with Bcl-2 family proteins.
Collapse
Affiliation(s)
- Takeshi Nitta
- Division of Experimental Immunology, Institute for Genome Research, University of Tokushima, 3-18-15 Kuramoto, Tokushima 770-8503, Japan
| | | |
Collapse
|
7
|
Fuller JM, Kwitek AE, Hawkins TJ, Moralejo DH, Lu W, Tupling TD, Macmurray AJ, Borchardt G, Hasinoff M, Lernmark A. Introgression of F344 rat genomic DNA on BB rat chromosome 4 generates diabetes-resistant lymphopenic BB rats. Diabetes 2006; 55:3351-7. [PMID: 17130479 DOI: 10.2337/db06-0715] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Failure to express the Gimap5 protein is associated with lymphopenia (lyp) and linked to spontaneous diabetes in the diabetes-prone BioBreeding (BBDP) rat. Gimap5 is a member of seven related genes located within 150 Kb on rat chromosome 4. Congenic DR.(lyp/lyp) rats, where BBDP lyp was introgressed onto the diabetes-resistant BBDR background (BBDR.BBDP.(lyp/lyp)), all develop diabetes between 46 and 81 days of age (mean +/- SE, 61 +/- 1), whereas DR.(lyp/+) and DR.(+/+) rats are nonlymphopenic and diabetes resistant. In an intercross between F1(BBDP x F344) rats, we identified a rat with a recombination event on chromosome 4, allowing us to fix 33 Mb of F344 between D4Rat253 and D4Rhw6 in the congenic DR.lyp rat line. Gimap1 and Gimap5 were the only members of the Gimap family remaining homozygous for the BBDP allele. Offspring homozygous for the F344 allele (f/f) between D4Rat253 and D4Rhw6 were lymphopenic (85 of 85, 100%) but did not develop diabetes (0 of 85). During rescue of the recombination, 102 of 163 (63%) rats heterozygous (b/f) for the recombination developed diabetes between 52 and 222 days of age (88 +/- 3). Our data demonstrate that introgression of a 33-Mb region of the F344 genome, proximal to the mutated Gimap5 gene, renders the rat diabetes resistant despite being lymphopenic. Spontaneous diabetes in the BB rat may therefore be controlled, in part, by a diabetogenic factor(s), perhaps unrelated to the Gimap5 mutation on rat chromosome 4.
Collapse
Affiliation(s)
- Jessica M Fuller
- University of Washington, Department of Medicine, 1959 NE Pacific St., Box 357710, Seattle, WA 98195, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|