LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 8 of total 8

Search options

  1. Article ; Online: Deoxycholic acid supplementation impairs glucose homeostasis in mice.

    Karolina E Zaborska / Seon A Lee / Darline Garribay / Eumee Cha / Bethany P Cummings

    PLoS ONE, Vol 13, Iss 7, p e

    2018  Volume 0200908

    Abstract: Bile acids are critical contributors to the regulation of whole body glucose homeostasis; however, the mechanisms remain incompletely defined. While the hydrophilic bile acid subtype, ursodeoxycholic acid, has been shown to attenuate hepatic endoplasmic ... ...

    Abstract Bile acids are critical contributors to the regulation of whole body glucose homeostasis; however, the mechanisms remain incompletely defined. While the hydrophilic bile acid subtype, ursodeoxycholic acid, has been shown to attenuate hepatic endoplasmic reticulum (ER) stress and thereby improve glucose regulation in mice, the effect of hydrophobic bile acid subtypes on ER stress and glucose regulation in vivo is unknown. Therefore, we investigated the effect of the hydrophobic bile acid subtype, deoxycholic acid (DCA), on ER stress and glucose regulation. Eight week old C57BL/6J mice were fed a high fat diet supplemented with or without DCA. Glucose regulation was assessed by oral glucose tolerance and insulin tolerance testing. In addition, circulating bile acid profile and hepatic insulin and ER stress signaling were measured. DCA supplementation did not alter body weight or food intake, but did impair glucose regulation. Consistent with the impairment in glucose regulation, DCA increased the hydrophobicity of the circulating bile acid profile, decreased hepatic insulin signaling and increased hepatic ER stress signaling. Together, these data suggest that dietary supplementation of DCA impairs whole body glucose regulation by disrupting hepatic ER homeostasis in mice.
    Keywords Medicine ; R ; Science ; Q
    Language English
    Publishing date 2018-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  2. Article ; Online: Synovial fluid lubricin increases in spontaneous canine cruciate ligament rupture

    Yuyan Wang / David W. Gludish / Kei Hayashi / Rory J. Todhunter / Ursula Krotscheck / Philippa J. Johnson / Bethany P. Cummings / Jin Su / Heidi L. Reesink

    Scientific Reports, Vol 10, Iss 1, Pp 1-

    2020  Volume 10

    Abstract: Abstract Lubricin is an important boundary lubricant and chondroprotective glycoprotein in synovial fluid. Both increased and decreased synovial fluid lubricin concentrations have been reported in experimental post-traumatic osteoarthritis (PTOA) animal ... ...

    Abstract Abstract Lubricin is an important boundary lubricant and chondroprotective glycoprotein in synovial fluid. Both increased and decreased synovial fluid lubricin concentrations have been reported in experimental post-traumatic osteoarthritis (PTOA) animal models and in naturally occurring joint injuries in humans and animals, with no consensus about how lubricin is altered in different species or injury types. Increased synovial fluid lubricin has been observed following intra-articular fracture in humans and horses and in human late-stage osteoarthritis; however, it is unknown how synovial lubricin is affected by knee-destabilizing injuries in large animals. Spontaneous rupture of cranial cruciate ligament (RCCL), the anterior cruciate ligament equivalent in quadrupeds, is a common injury in dogs often accompanied by OA. Here, clinical records, radiographs, and synovial fluid samples from 30 dogs that sustained RCCL and 9 clinically healthy dogs were analyzed. Synovial fluid lubricin concentrations were nearly 16-fold greater in RCCL joints as compared to control joints, while IL-2, IL-6, IL-8, and TNF-α concentrations did not differ between groups. Synovial fluid lubricin concentrations were correlated with the presence of radiographic OA and were elevated in three animals sustaining RCCL injury prior to the radiographic manifestation of OA, indicating that lubricin may be a potential biomarker for early joint injury.
    Keywords Medicine ; R ; Science ; Q
    Subject code 630
    Language English
    Publishing date 2020-10-01T00:00:00Z
    Publisher Nature Publishing Group
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  3. Article ; Online: GLP-1 receptor signaling increases PCSK1 and β cell features in human α cells

    Mridusmita Saikia / Marlena M. Holter / Leanne R. Donahue / Isaac S. Lee / Qiaonan C. Zheng / Journey L. Wise / Jenna E. Todero / Daryl J. Phuong / Darline Garibay / Reilly Coch / Kyle W. Sloop / Adolfo Garcia-Ocana / Charles G. Danko / Bethany P. Cummings

    JCI Insight, Vol 6, Iss

    2021  Volume 3

    Abstract: Glucagon-like peptide-1 (GLP-1) is an incretin hormone that potentiates glucose-stimulated insulin secretion. GLP-1 is classically produced by gut L cells; however, under certain circumstances α cells can express the prohormone convertase required for ... ...

    Abstract Glucagon-like peptide-1 (GLP-1) is an incretin hormone that potentiates glucose-stimulated insulin secretion. GLP-1 is classically produced by gut L cells; however, under certain circumstances α cells can express the prohormone convertase required for proglucagon processing to GLP-1, prohormone convertase 1/3 (PC1/3), and can produce GLP-1. However, the mechanisms through which this occurs are poorly defined. Understanding the mechanisms by which α cell PC1/3 expression can be activated may reveal new targets for diabetes treatment. Here, we demonstrate that the GLP-1 receptor (GLP-1R) agonist, liraglutide, increased α cell GLP-1 expression in a β cell GLP-1R–dependent manner. We demonstrate that this effect of liraglutide was translationally relevant in human islets through application of a new scRNA-seq technology, DART-Seq. We found that the effect of liraglutide to increase α cell PC1/3 mRNA expression occurred in a subcluster of α cells and was associated with increased expression of other β cell–like genes, which we confirmed by IHC. Finally, we found that the effect of liraglutide to increase bihormonal insulin+ glucagon+ cells was mediated by the β cell GLP-1R in mice. Together, our data validate a high-sensitivity method for scRNA-seq in human islets and identify a potentially novel GLP-1–mediated pathway regulating human α cell function.
    Keywords Endocrinology ; Metabolism ; Medicine ; R
    Subject code 571
    Language English
    Publishing date 2021-02-01T00:00:00Z
    Publisher American Society for Clinical investigation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  4. Article: Increasing body condition score is positively associated interleukin-6 and monocyte chemoattractant protein-1 in Labrador retrievers

    Frank, Lauren / Bethany P. Cummings / Corri B. Levine / Joseph J. Wakshlag / Sabine Mann

    Veterinary immunology and immunopathology. 2015 Oct. 15, v. 167, no. 3-4

    2015  

    Abstract: The accumulation of excess body fat is a growing problem in dogs as well as people. Contrary to prior understanding of adipose tissue, fat is now considered to be an active endocrine organ that promotes a chronic low-grade inflammatory state often ... ...

    Abstract The accumulation of excess body fat is a growing problem in dogs as well as people. Contrary to prior understanding of adipose tissue, fat is now considered to be an active endocrine organ that promotes a chronic low-grade inflammatory state often characterized by an increase in pro-inflammatory cytokines and chemokines. These have been implicated in several obesity-related disorders such as insulin resistance, cardiovascular disease, and neoplasia. The purpose of this study was to characterize fasting plasma cytokine concentrations in ninety-two healthy client-owned Labrador retriever dogs of various ages and body condition scores. The dogs were grouped according to body condition score (BCS) into three categories, lean, overweight and obese. The following cytokines and chemokines were evaluated; tumor necrosis factor-alpha, interleukin-2, interleukin-6, interleukin-8, and monocyte chemotactic protein-1 (TNF-α, IL-2, IL-6, IL-8, MCP-1). Our results indicated that fasting plasma IL-6 and MCP-1 concentrations are associated with increasing BCS. This data suggest that certain markers of inflammation increase with increasing body condition score, and that dogs, similar to humans, may be fostering a chronic inflammatory state due to obesity.
    Keywords body condition ; cardiovascular diseases ; chemokine CCL2 ; dogs ; fasting ; fat body ; humans ; inflammation ; insulin resistance ; interleukin-2 ; interleukin-6 ; interleukin-8 ; Labrador Retriever ; neoplasms ; obesity ; people ; tumor necrosis factor-alpha
    Language English
    Dates of publication 2015-1015
    Size p. 104-109.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 754160-0
    ISSN 1873-2534 ; 0165-2427
    ISSN (online) 1873-2534
    ISSN 0165-2427
    DOI 10.1016/j.vetimm.2015.07.010
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  5. Article ; Online: β Cell GLP-1R Signaling Alters α Cell Proglucagon Processing after Vertical Sleeve Gastrectomy in Mice

    Darline Garibay / Jon Lou / Seon A. Lee / Karolina E. Zaborska / Margot H. Weissman / Erica Sloma / Leanne Donahue / Andrew D. Miller / Andrew C. White / M. Dodson Michael / Kyle W. Sloop / Bethany P. Cummings

    Cell Reports, Vol 23, Iss 4, Pp 967-

    2018  Volume 973

    Abstract: Summary: Bariatric surgery, such as vertical sleeve gastrectomy (VSG), causes high rates of type 2 diabetes remission and remarkable increases in postprandial glucagon-like peptide-1 (GLP-1) secretion. GLP-1 plays a critical role in islet function by ... ...

    Abstract Summary: Bariatric surgery, such as vertical sleeve gastrectomy (VSG), causes high rates of type 2 diabetes remission and remarkable increases in postprandial glucagon-like peptide-1 (GLP-1) secretion. GLP-1 plays a critical role in islet function by potentiating glucose-stimulated insulin secretion; however, the mechanisms remain incompletely defined. Therefore, we applied a murine VSG model to an inducible β cell-specific GLP-1 receptor (GLP-1R) knockout mouse model to investigate the role of the β cell GLP-1R in islet function. Our data show that loss of β cell GLP-1R signaling decreases α cell GLP-1 expression after VSG. Furthermore, we find a β cell GLP-1R-dependent increase in α cell expression of the prohormone convertase required for the production of GLP-1 after VSG. Together, the findings herein reveal two concepts. First, our data support a paracrine role for α cell-derived GLP-1 in the metabolic benefits observed after VSG. Second, we have identified a role for the β cell GLP-1R as a regulator of α cell proglucagon processing. : The mechanisms by which GLP-1 enhances insulin secretion remain incompletely defined. Garibay et al. show that β cell GLP-1R signaling regulates α cell PC1/3 expression and GLP-1 production, pointing to an intra-islet paracrine positive feedback loop by which GLP-1-potentiated insulin secretion is amplified. Keywords: GLP-1, prohormone convertase 1/3, vertical sleeve gastrectomy, β cell
    Keywords Biology (General) ; QH301-705.5
    Subject code 571
    Language English
    Publishing date 2018-04-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  6. Article ; Online: Iron deficiency linked to altered bile acid metabolism promotes Helicobacter pylori–induced inflammation–driven gastric carcinogenesis

    Jennifer M. Noto / M. Blanca Piazuelo / Shailja C. Shah / Judith Romero-Gallo / Jessica L. Hart / Chao Di / James D. Carmichael / Alberto G. Delgado / Alese E. Halvorson / Robert A. Greevy / Lydia E. Wroblewski / Ayushi Sharma / Annabelle B. Newton / Margaret M. Allaman / Keith T. Wilson / M. Kay Washington / M. Wade Calcutt / Kevin L. Schey / Bethany P. Cummings /
    Charles R. Flynn / Joseph P. Zackular / Richard M. Peek Jr.

    The Journal of Clinical Investigation, Vol 132, Iss

    2022  Volume 10

    Abstract: Gastric carcinogenesis is mediated by complex interactions among Helicobacter pylori, host, and environmental factors. Here, we demonstrate that H. pylori augmented gastric injury in INS-GAS mice under iron-deficient conditions. Mechanistically, these ... ...

    Abstract Gastric carcinogenesis is mediated by complex interactions among Helicobacter pylori, host, and environmental factors. Here, we demonstrate that H. pylori augmented gastric injury in INS-GAS mice under iron-deficient conditions. Mechanistically, these phenotypes were not driven by alterations in the gastric microbiota; however, discovery-based and targeted metabolomics revealed that bile acids were significantly altered in H. pylori–infected mice with iron deficiency, with significant upregulation of deoxycholic acid (DCA), a carcinogenic bile acid. The severity of gastric injury was further augmented when H. pylori–infected mice were treated with DCA, and, in vitro, DCA increased translocation of the H. pylori oncoprotein CagA into host cells. Conversely, bile acid sequestration attenuated H. pylori–induced injury under conditions of iron deficiency. To translate these findings to human populations, we evaluated the association between bile acid sequestrant use and gastric cancer risk in a large human cohort. Among 416,885 individuals, a significant dose-dependent reduction in risk was associated with cumulative bile acid sequestrant use. Further, expression of the bile acid receptor transmembrane G protein–coupled bile acid receptor 5 (TGR5) paralleled the severity of carcinogenic lesions in humans. These data demonstrate that increased H. pylori–induced injury within the context of iron deficiency is tightly linked to altered bile acid metabolism, which may promote gastric carcinogenesis.
    Keywords Gastroenterology ; Infectious disease ; Medicine ; R
    Language English
    Publishing date 2022-05-01T00:00:00Z
    Publisher American Society for Clinical Investigation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  7. Article ; Online: Vertical sleeve gastrectomy reduces blood pressure and hypothalamic endoplasmic reticulum stress in mice

    Anne K. McGavigan / Zachariah M. Henseler / Darline Garibay / Scott D. Butler / Sisitha Jayasinghe / Ruth E. Ley / Robin L. Davisson / Bethany P. Cummings

    Disease Models & Mechanisms, Vol 10, Iss 3, Pp 235-

    2017  Volume 243

    Abstract: Bariatric surgery, such as vertical sleeve gastrectomy (VSG), causes remarkable improvements in cardiometabolic health, including hypertension remission. However, the mechanisms responsible remain undefined and poorly studied. Therefore, we developed and ...

    Abstract Bariatric surgery, such as vertical sleeve gastrectomy (VSG), causes remarkable improvements in cardiometabolic health, including hypertension remission. However, the mechanisms responsible remain undefined and poorly studied. Therefore, we developed and validated the first murine model of VSG that recapitulates the blood pressure-lowering effect of VSG using gold-standard radiotelemetry technology. We used this model to investigate several potential mechanisms, including body mass, brain endoplasmic reticulum (ER) stress signaling and brain inflammatory signaling, which are all critical contributors to the pathogenesis of obesity-associated hypertension. Mice fed on a high-fat diet underwent sham or VSG surgery and radiotelemeter implantation. Sham mice were fed ad libitum or were food restricted to match their body mass to VSG-operated mice to determine the role of body mass in the ability of VSG to lower blood pressure. Blood pressure was then measured in freely moving unstressed mice by radiotelemetry. VSG decreased energy intake, body mass and fat mass. Mean arterial blood pressure (MAP) was reduced in VSG-operated mice compared with both sham-operated groups. VSG-induced reductions in MAP were accompanied by a body mass-independent decrease in hypothalamic ER stress, hypothalamic inflammation and sympathetic nervous system tone. Assessment of gut microbial populations revealed VSG-induced increases in the relative abundance of Gammaproteobacteria and Enterococcus, and decreases in Adlercreutzia. These results suggest that VSG reduces blood pressure, but this is only partly due to the reduction in body weight. VSG-induced reductions in blood pressure may be driven by a decrease in hypothalamic ER stress and inflammatory signaling, and shifts in gut microbial populations.
    Keywords Vertical sleeve gastrectomy ; Hypertension ; ER stress ; Mouse model ; Medicine ; R ; Pathology ; RB1-214
    Subject code 630
    Language English
    Publishing date 2017-03-01T00:00:00Z
    Publisher The Company of Biologists
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  8. Article ; Online: Bile-acid-mediated decrease in endoplasmic reticulum stress

    Bethany P. Cummings / Ahmed Bettaieb / James L. Graham / Jaehyoung Kim / Fangrui Ma / Noreene Shibata / Kimber L. Stanhope / Cecilia Giulivi / Frederik Hansen / Jacob Jelsing / Niels Vrang / Mark Kowala / Michael L. Chouinard / Fawaz G. Haj / Peter J. Havel

    Disease Models & Mechanisms, Vol 6, Iss 2, Pp 443-

    a potential contributor to the metabolic benefits of ileal interposition surgery in UCD-T2DM rats

    2013  Volume 456

    Abstract: SUMMARY Post-operative increases in circulating bile acids have been suggested to contribute to the metabolic benefits of bariatric surgery; however, their mechanistic contributions remain undefined. We have previously reported that ileal interposition ( ... ...

    Abstract SUMMARY Post-operative increases in circulating bile acids have been suggested to contribute to the metabolic benefits of bariatric surgery; however, their mechanistic contributions remain undefined. We have previously reported that ileal interposition (IT) surgery delays the onset of type 2 diabetes in UCD-T2DM rats and increases circulating bile acids, independently of effects on energy intake or body weight. Therefore, we investigated potential mechanisms by which post-operative increases in circulating bile acids improve glucose homeostasis after IT surgery. IT, sham or no surgery was performed on 2-month-old weight-matched male UCD-T2DM rats. Animals underwent an oral fat tolerance test (OFTT) and serial oral glucose tolerance tests (OGTT). Tissues were collected at 1.5 and 4.5 months after surgery. Cell culture models were used to investigate interactions between bile acids and ER stress. IT-operated animals exhibited marked improvements in glucose and lipid metabolism, with concurrent increases in postprandial glucagon-like peptide-1 (GLP-1) secretion during the OFTT and OGTTs, independently of food intake and body weight. Measurement of circulating bile acid profiles revealed increases in circulating total bile acids in IT-operated animals, with a preferential increase in circulating cholic acid concentrations. Gut microbial populations were assessed as potential contributors to the increases in circulating bile acid concentrations, which revealed proportional increases in Gammaproteobacteria in IT-operated animals. Furthermore, IT surgery decreased all three sub-arms of ER stress signaling in liver, adipose and pancreas tissues. Amelioration of ER stress coincided with improved insulin signaling and preservation of β-cell mass in IT-operated animals. Incubation of hepatocyte, adipocyte and β-cell lines with cholic acid decreased ER stress. These results suggest that postoperative increases in circulating cholic acid concentration contribute to improvements in glucose homeostasis after IT surgery by ameliorating ER stress.
    Keywords Medicine ; R ; Pathology ; RB1-214
    Language English
    Publishing date 2013-03-01T00:00:00Z
    Publisher The Company of Biologists
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

To top