scholarly journals Distinct alterations of gut morphology and microbiota characterize accelerated diabetes onset in nonobese diabetic mice

2019 ◽  
Vol 295 (4) ◽  
pp. 969-980 ◽  
Author(s):  
Marie-Christine Simon ◽  
Anna Lena Reinbeck ◽  
Corinna Wessel ◽  
Julia Heindirk ◽  
Tomas Jelenik ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Nod Mice ◽  
Short Chain Fatty Acids ◽  
Oxidative Capacity ◽  
Lifestyle Changes ◽  
Gut Morphology ◽  
Microbiome Composition ◽  
Nonobese Diabetic ◽  
Diabetes Development

The rising prevalence of type 1 diabetes (T1D) over the past decades has been linked to lifestyle changes, but the underlying mechanisms are largely unknown. Recent findings point to gut-associated mechanisms in the control of T1D pathogenesis. In nonobese diabetic (NOD) mice, a model of T1D, diabetes development accelerates after deletion of the Toll-like receptor 4 (TLR4). We hypothesized that altered intestinal functions contribute to metabolic alterations, which favor accelerated diabetes development in TLR4-deficient (TLR4−/−) NOD mice. In 70–90-day-old normoglycemic (prediabetic) female NOD TLR4+/+ and NOD TLR4−/− mice, gut morphology and microbiome composition were analyzed. Parameters of lipid metabolism, glucose homeostasis, and mitochondrial respiratory activity were measured in vivo and ex vivo. Compared with NOD TLR4+/+ mice, NOD TLR4−/− animals showed lower muscle mass of the small intestine, higher abundance of Bacteroidetes, and lower Firmicutes in the large intestine, along with lower levels of circulating short-chain fatty acids (SCFA). These changes are associated with higher body weight, hyperlipidemia, and severe insulin and glucose intolerance, all occurring before the onset of diabetes. These mice also exhibited insulin resistance–related abnormalities of energy metabolism, such as lower total respiratory exchange rates and higher hepatic oxidative capacity. Distinct alterations of gut morphology and microbiota composition associated with reduction of circulating SCFA may contribute to metabolic disorders promoting the progression of insulin-deficient diabetes/T1D development.

scholarly journals Phytochemical Compounds and Protection from Cardiovascular Diseases: A State of the Art

2015 ◽  
Vol 2015 ◽  
pp. 1-17 ◽  
Author(s):  
Beniamino Pagliaro ◽  
Caterina Santolamazza ◽  
Francesca Simonelli ◽  
Speranza Rubattu
Keyword(s):  
Cardiovascular Diseases ◽  
Dietary Habits ◽  
Ex Vivo ◽  
Lifestyle Changes ◽  
In Vivo Models ◽  
Beneficial Effects ◽  
Phytochemical Compounds ◽  
Cardioprotective Effects ◽  
Reference Tool

Cardiovascular diseases represent a worldwide relevant socioeconomical problem. Cardiovascular disease prevention relies also on lifestyle changes, including dietary habits. The cardioprotective effects of several foods and dietary supplements in both animal models and in humans have been explored. It was found that beneficial effects are mainly dependent on antioxidant and anti-inflammatory properties, also involving modulation of mitochondrial function. Resveratrol is one of the most studied phytochemical compounds and it is provided with several benefits in cardiovascular diseases as well as in other pathological conditions (such as cancer). Other relevant compounds areBrassica oleracea, curcumin, and berberine, and they all exert beneficial effects in several diseases. In the attempt to provide a comprehensive reference tool for both researchers and clinicians, we summarized in the present paper the existing literature on both preclinical and clinical cardioprotective effects of each mentioned phytochemical. We structured the discussion of each compound by analyzing, first, its cellular molecular targets of action, subsequently focusing on results from applications in both ex vivo and in vivo models, finally discussing the relevance of the compound in the context of human diseases.

scholarly journals Pancreatic Lymph Nodes Are Required for Priming of β Cell Reactive T Cells in NOD Mice

2002 ◽  
Vol 196 (3) ◽  
pp. 369-377 ◽  
Author(s):  
Marie-Claude Gagnerault ◽  
Jian Jian Luan ◽  
Chantal Lotton ◽  
Françoise Lepault
Keyword(s):  
T Cells ◽  
Lymph Nodes ◽  
Autoimmune Diabetes ◽  
Adult Life ◽  
Nod Mice ◽  
Autoreactive T Cells ◽  
Nonobese Diabetic ◽  
Autoreactive T Cell ◽  
Pancreatic Lymph Nodes ◽  
Diabetes Development

Nonobese diabetic (NOD) mice develop spontaneous autoimmune diabetes that results from the destruction of insulin secreting β cells by diabetogenic T cells. The time and location of the encounter of autoantigen(s) by naive autoreactive T cells in normal NOD mice are still elusive. To address these issues, we analyzed diabetes development in mice whose spleen or pancreatic lymph nodes (panLNs) had been removed. Excision of panLNs (panLNx) at 3 wk protected mice against insulin autoantibodies (IAAs), insulitis, and diabetes development almost completely, but had no effect when performed at 10 wk. The protection afforded by panLNx at weaning was not due to modifications of the immune system, the absence of autoreactive T cells, or the increase in the potency of regulatory T cells. That panLNs are dispensable during adult life was confirmed by the capacity of 10-wk-old panLNx irradiated recipients to develop diabetes upon transfer of diabetogenic T cells. In contrast, splenectomy had no effect at any age. Partial excision of mesenteric LN at 3 wk did not prevent accelerated diabetes by cyclophosphamide as panLNx did. Thus, in normal NOD mice, autoreactive T cell initial priming occurs in LNs draining the target organ of the disease from 3 wk of age.

scholarly journals PD-1 restraint of regulatory T cell suppressive activity is critical for immune tolerance

2020 ◽  
Vol 218 (1) ◽  
Author(s):  
Catherine L. Tan ◽  
Juhi R. Kuchroo ◽  
Peter T. Sage ◽  
Dan Liang ◽  
Loise M. Francisco ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Nod Mice ◽  
T Cell Tolerance ◽  
Cell Tolerance ◽  
Nonobese Diabetic ◽  
Suppressive Capacity ◽  
Significant Mechanism

Inhibitory signals through the PD-1 pathway regulate T cell activation, T cell tolerance, and T cell exhaustion. Studies of PD-1 function have focused primarily on effector T cells. Far less is known about PD-1 function in regulatory T (T reg) cells. To study the role of PD-1 in T reg cells, we generated mice that selectively lack PD-1 in T reg cells. PD-1–deficient T reg cells exhibit an activated phenotype and enhanced immunosuppressive function. The in vivo significance of the potent suppressive capacity of PD-1–deficient T reg cells is illustrated by ameliorated experimental autoimmune encephalomyelitis (EAE) and protection from diabetes in nonobese diabetic (NOD) mice lacking PD-1 selectively in T reg cells. We identified reduced signaling through the PI3K–AKT pathway as a mechanism underlying the enhanced suppressive capacity of PD-1–deficient T reg cells. Our findings demonstrate that cell-intrinsic PD-1 restraint of T reg cells is a significant mechanism by which PD-1 inhibitory signals regulate T cell tolerance and autoimmunity.

Delayed Engraftment of Nonobese Diabetic/Severe Combined Immunodeficient Mice Transplanted With Ex Vivo–Expanded Human CD34+ Cord Blood Cells

Blood ◽  
1999 ◽  
Vol 93 (3) ◽  
pp. 1097-1105 ◽  
Author(s):  
G. Güenechea ◽  
J.C. Segovia ◽  
B. Albella ◽  
M. Lamana ◽  
M. Ramı́rez ◽  
...  
Keyword(s):  
Cord Blood ◽  
Ex Vivo ◽  
Ex Vivo Expansion ◽  
Hematopoietic Progenitors ◽  
Short Term ◽  
Immunodeficient Mice ◽  
Nonobese Diabetic ◽  
Cd34 Cells

Abstract The ex vivo expansion of hematopoietic progenitors is a promising approach for accelerating the engraftment of recipients, particularly when cord blood (CB) is used as a source of hematopoietic graft. With the aim of defining the in vivo repopulating properties of ex vivo–expanded CB cells, purified CD34+ cells were subjected to ex vivo expansion, and equivalent proportions of fresh and ex vivo–expanded samples were transplanted into irradiated nonobese diabetic (NOD)/severe combined immunodeficient (SCID) mice. At periodic intervals after transplantation, femoral bone marrow (BM) samples were obtained from NOD/SCID recipients and the kinetics of engraftment evaluated individually. The transplantation of fresh CD34+ cells generated a dose-dependent engraftment of recipients, which was evident in all of the posttransplantation times analyzed (15 to 120 days). When compared with fresh CB, samples stimulated for 6 days with interleukin-3 (IL-3)/IL-6/stem cell factor (SCF) contained increased numbers of hematopoietic progenitors (20-fold increase in colony-forming unit granulocyte-macrophage [CFU-GM]). However, a significant impairment in the short-term repopulation of recipients was associated with the transplantation of the ex vivo–expanded versus the fresh CB cells (CD45+repopulation in NOD/SCIDs BM: 3.7% ± 1.2% v 26.2% ± 5.9%, respectively, at 20 days posttransplantation; P < .005). An impaired short-term engraftment was also observed in mice transplanted with CB cells incubated with IL-11/SCF/FLT-3 ligand (3.5% ± 1.7% of CD45+ cells in femoral BM at 20 days posttransplantation). In contrast to these data, a similar repopulation with the fresh and the ex vivo–expanded cells was observed at later stages posttransplantation. At 120 days, the repopulation of CD45+ and CD45+/CD34+ cells in the femoral BM of recipients ranged between 67.2% to 81.1% and 8.6% to 12.6%, respectively, and no significant differences of engraftment between recipients transplanted with fresh and the ex vivo–expanded samples were found. The analysis of the engrafted CD45+ cells showed that both the fresh and the in vitro–incubated samples were capable of lymphomyeloid reconstitution. Our results suggest that although the ex vivo expansion of CB cells preserves the long-term repopulating ability of the sample, an unexpected delay of engraftment is associated with the transplantation of these manipulated cells.

scholarly journals Interleukin 4 reverses T cell proliferative unresponsiveness and prevents the onset of diabetes in nonobese diabetic mice.

1993 ◽  
Vol 178 (1) ◽  
pp. 87-99 ◽  
Author(s):  
M J Rapoport ◽  
A Jaramillo ◽  
D Zipris ◽  
A H Lazarus ◽  
D V Serreze ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nod Mice ◽  
Interleukin 4 ◽  
Con A ◽  
Diabetes Onset ◽  
Nonobese Diabetic ◽  
Alpha Beta

Beginning at the time of insulitis (7 wk of age), CD4+ and CD8+ mature thymocytes from nonobese diabetic (NOD) mice exhibit a proliferative unresponsiveness in vitro after T cell receptor (TCR) crosslinking. This unresponsiveness does not result from either insulitis or thymic involution and is long lasting, i.e., persists until diabetes onset (24 wk of age). We previously proposed that it represents a form of thymic T cell anergy that predisposes to diabetes onset. This hypothesis was tested in the present study by further investigating the mechanism responsible for NOD thymic T cell proliferative unresponsiveness and determining whether reversal of this unresponsiveness protects NOD mice from diabetes. Interleukin 4 (IL-4) secretion by thymocytes from > 7-wk-old NOD mice was virtually undetectable after treatment with either anti-TCR alpha/beta, anti-CD3, or Concanavalin A (Con A) compared with those by thymocytes from age- and sex-matched control BALB/c mice stimulated under identical conditions. NOD thymocytes stimulated by anti-TCR alpha/beta or anti-CD3 secreted less IL-2 than did similarly activated BALB/c thymocytes. However, since equivalent levels of IL-3 were secreted by Con A-activated NOD and BALB/c thymocytes, the unresponsiveness of NOD thymic T cells does not appear to be dependent on reduced IL-2 secretion. The surface density and dissociation constant of the high affinity IL-2 receptor of Con A-activated thymocytes from both strains are also similar. The patterns of unresponsiveness and lymphokine secretion seen in anti-TCR/CD3-activated NOD thymic T cells were also observed in activated NOD peripheral spleen T cells. Exogenous recombinant (r)IL-2 only partially reverses NOD thymocyte proliferative unresponsiveness to anti-CD3, and this is mediated by the inability of IL-2 to stimulate a complete IL-4 secretion response. In contrast, exogenous IL-4 reverses the unresponsiveness of both NOD thymic and peripheral T cells completely, and this is associated with the complete restoration of an IL-2 secretion response. Furthermore, the in vivo administration of rIL-4 to prediabetic NOD mice protects them from diabetes. Thus, the ability of rIL-4 to reverse completely the NOD thymic and peripheral T cell proliferative defect in vitro and protect against diabetes in vivo provides further support for a causal relationship between this T cell proliferative unresponsiveness and susceptibility to diabetes in NOD mice.

scholarly journals Systemic Delivery of TNF-Related Apoptosis-Inducing Ligand (TRAIL) Elevates Levels of Tissue Inhibitor of Metalloproteinase-1 (TIMP-1) and Prevents Type 1 Diabetes in Nonobese Diabetic Mice

Endocrinology ◽  
2010 ◽  
Vol 151 (12) ◽  
pp. 5638-5646 ◽  
Author(s):  
Soojeong Kang ◽  
Eun-Jin Park ◽  
Yeonsoo Joe ◽  
Eunhui Seo ◽  
Mi-Kyoung Park ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Blood Glucose ◽  
Gelatin Zymography ◽  
Nod Mice ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Tissue Inhibitor ◽  
Nonobese Diabetic ◽  
Induced Apoptosis

Recent studies have demonstrated that TNF-related apoptosis-inducing ligand (TRAIL) is a modulator of the immune response. The relation between TRAIL and type 1 diabetes (T1D) as an autoimmune inflammatory disease in vivo is relatively unknown. To explore the potential role of TRAIL in the development of T1D, we examined its in vivo effects in nonobese diabetic (NOD) mice. NOD mice at 7 wk of age were iv injected with an adenovirus carrying either human TRAIL (Ad.hTRAIL) or β-galactosidase genes. Blood glucose was monitored weekly, and the expression of hTRAIL was evaluated in plasma and liver of mice. To investigate whether hTRAIL elicits its effect through the induction of tissue inhibitor of metalloproteinase-1 (TIMP-1), we examined the concentration of plasma TIMP-1 by ELISA and the inhibition of matrix metalloproteinase (MMP) by gelatin zymography. Here, we show that Ad.hTRAIL-transduced mice had significantly reduced blood glucose levels and markedly increased production of TIMP-1 compared with control β-galactosidase animals. Pancreatic tissue isolated from Ad.hTRAIL-treated NOD mice showed reduced MMP activities associated with significantly improved insulitis. In addition, TIMP-1 in vitro suppressed cytokine-induced apoptosis in insulin-producing INS-1 cells. These results indicate that T1D can be prevented by TRAIL overexpression through enhancement of TIMP-1 function. Elevated TIMP-1 production inhibits the activity of MMPs, which may contribute to suppress the transmigration of diabetogenic T cells into the pancreatic islets and protects pancreatic β-cells from cytokine-induced apoptosis. Therefore, TRAIL and TIMP-1 induction may be potential targets to prevent development of T1D.

scholarly journals Prevention of type 1 diabetes in mice by tolerogenic vaccination with a strong agonist insulin mimetope

2011 ◽  
Vol 208 (7) ◽  
pp. 1501-1510 ◽  
Author(s):  
Carolin Daniel ◽  
Benno Weigmann ◽  
Roderick Bronson ◽  
Harald von Boehmer
Keyword(s):  
T Cells ◽  
Type 1 Diabetes ◽  
Nod Mice ◽  
Nonobese Diabetic ◽  
Cell Clones ◽  
Autoimmune Attack ◽  
Agonistic Activity ◽  
Novel Strategy

Type 1 diabetes (T1D) results from the destruction of insulin-secreting pancreatic β cells by autoreactive T cells. Insulin is an essential target of the autoimmune attack. Insulin epitopes recognized by diabetogenic T cell clones bind poorly to the class II I-Ag7 molecules of nonobese diabetic (NOD) mice, which results in weak agonistic activity of the peptide MHC complex. Here, we describe a strongly agonistic insulin mimetope that effectively converts naive T cells into Foxp3+ regulatory T cells in vivo, thereby completely preventing T1D in NOD mice. In contrast, natural insulin epitopes are ineffective. Subimmunogenic vaccination with strongly agonistic insulin mimetopes might represent a novel strategy to prevent T1D in humans at risk for the disease.

scholarly journals Carbohydrate maldigestion induces necrotizing enterocolitis in preterm pigs

2009 ◽  
Vol 297 (6) ◽  
pp. G1115-G1125 ◽  
Author(s):  
Thomas Thymann ◽  
Hanne K. Møller ◽  
Barbara Stoll ◽  
Ann Cathrine F. Støy ◽  
Randal K. Buddington ◽  
...  
Keyword(s):  
Enteral Nutrition ◽  
Necrotizing Enterocolitis ◽  
Ex Vivo ◽  
Gastrointestinal Disorder ◽  
Short Chain Fatty Acids ◽  
Hydrolytic Activity ◽  
Bacterial Composition ◽  
Principal Source ◽  
Total Enteral Nutrition

Necrotizing enterocolitis (NEC) remains the most severe gastrointestinal disorder in preterm infants. It is associated with the initiation of enteral nutrition and may be related to immature carbohydrate digestive capacity. We tested the hypothesis that a formula containing maltodextrin vs. a formula containing lactose as the principal source of carbohydrate would predispose preterm pigs to a higher NEC incidence. Cesarean-derived preterm pigs were given total parenteral nutrition for 48 h followed by total enteral nutrition with a lactose-based ( n = 11) or maltodextrin-based ( n = 11) formula for 36 h. A higher incidence (91% vs. 27%) and severity (score of 3.3 vs. 1.8) of NEC were observed in the maltodextrin than in the lactose group. This higher incidence of NEC in the maltodextrin group was associated with significantly lower activities of lactase, maltase, and aminopeptidase; reduced villus height; transiently reduced in vivo aldohexose uptake; and reduced ex vivo aldohexose uptake capacity in the middle region of the small intestine. Bacterial diversity was low for both diets, but alterations in bacterial composition and luminal concentrations of short-chain fatty acids were observed in the maltodextrin group. In a second study, we quantified net portal absorption of aldohexoses (glucose and galactose) during acute jejunal infusion of a maltodextrin- or a lactose-based formula ( n = 8) into preterm pigs. We found lower net portal aldohexose absorption (4% vs. 42%) and greater intestinal recovery of undigested carbohydrate (68% vs. 27%) in pigs acutely perfused with the maltodextrin-based formula than those perfused with the lactose-based formula. The higher digestibility of the lactose than the maltodextrin in the formulas can be attributed to a 5- to 20-fold higher hydrolytic activity of tissue-specific lactase than maltases. We conclude that carbohydrate maldigestion is sufficient to increase the incidence and severity of NEC in preterm pigs.

scholarly journals Seaweed Components as Potential Modulators of the Gut Microbiota

Marine Drugs ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 358
Author(s):  
Emer Shannon ◽  
Michael Conlon ◽  
Maria Hayes
Keyword(s):  
Gut Microbiota ◽  
Large Scale ◽  
Current Knowledge ◽  
Ex Vivo ◽  
Short Chain Fatty Acids ◽  
In Vivo Studies ◽  
Therapeutic Effects ◽  
Oral Bioaccessibility

Macroalgae, or seaweeds, are a rich source of components which may exert beneficial effects on the mammalian gut microbiota through the enhancement of bacterial diversity and abundance. An imbalance of gut bacteria has been linked to the development of disorders such as inflammatory bowel disease, immunodeficiency, hypertension, type-2-diabetes, obesity, and cancer. This review outlines current knowledge from in vitro and in vivo studies concerning the potential therapeutic application of seaweed-derived polysaccharides, polyphenols and peptides to modulate the gut microbiota through diet. Polysaccharides such as fucoidan, laminarin, alginate, ulvan and porphyran are unique to seaweeds. Several studies have shown their potential to act as prebiotics and to positively modulate the gut microbiota. Prebiotics enhance bacterial populations and often their production of short chain fatty acids, which are the energy source for gastrointestinal epithelial cells, provide protection against pathogens, influence immunomodulation, and induce apoptosis of colon cancer cells. The oral bioaccessibility and bioavailability of seaweed components is also discussed, including the advantages and limitations of static and dynamic in vitro gastrointestinal models versus ex vivo and in vivo methods. Seaweed bioactives show potential for use in prevention and, in some instances, treatment of human disease. However, it is also necessary to confirm these potential, therapeutic effects in large-scale clinical trials. Where possible, we have cited information concerning these trials.

Consumption of indigestible saccharides and administration of Bifidobacterium pseudolongum reduce mucosal serotonin in murine colonic mucosa

2021 ◽  
pp. 1-30
Author(s):  
Misa Tatsuoka ◽  
Yosuke Osaki ◽  
Fumina Ohsaka ◽  
Takeshi Tsuruta ◽  
Yoshihiro Kadota ◽  
...  
Keyword(s):  
Colonic Mucosa ◽  
Ex Vivo ◽  
Short Chain Fatty Acids ◽  
Monoamine Oxidase A ◽  
Intragastric Administration ◽  
Mrna Levels ◽  
Cell Numbers ◽  
Ec Cells

Abstract Short-chain fatty acids (SCFAs) increase serotonin (5-hydroxytryptamine, 5-HT) synthesis and content in the colon in vitro and ex vivo, but little is known in vivo. We tested whether dietary indigestible saccharides, utilized as a substrate to produce SCFAs by gut microbiota, would increase colonic 5-HT content in mice. Male C57BL/6J mice were fed a purified diet and water supplemented with 4% (w/v) 1-kestose (KES) for 2 weeks. Colonic 5-HT content and enterochromaffin (EC) cell numbers were lower in mice supplemented with KES than those without supplementation, while monoamine oxidase A activity and mRNA levels of Tph1, Chga, Slc6a4 and Maoa genes in the colonic mucosa, serum 5-HT concentration and total 5-HT content in the colonic contents did not differ between groups. Cecal acetate concentration and Bifidobacterium pseudolongum population were higher in KES-supplemented mice. Similar trends were observed in mice supplemented with other indigestible saccharides, i.e., fructooligosaccharides, inulin and raffinose. Intragastric administration of live B. pseudolongum (108 colony-forming units/day) for 2 weeks reduced colonic 5-HT content and EC cell numbers. These results suggest that changes in synthesis, reuptake, catabolism and overflow of 5-HT in the colonic mucosa are not involved in the reduction of colonic 5-HT content by dietary indigestible saccharides in mice. We propose that gut microbes including B. pseudolongum could contribute to the reduction of 5-HT content in the colonic mucosa via diminishing EC cells.

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