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Bragazzi Cunha J, Leix K, Sherman EJ, Mirabelli C, Frum T, Zhang CJ, Kennedy AA, Lauring AS, Tai AW, Sexton JZ, Spence JR, Wobus CE, Emmer BT. Type I interferon signaling induces a delayed antiproliferative response in respiratory epithelial cells during SARS-CoV-2 infection. J Virol 2023; 97:e0127623. [PMID: 37975674 PMCID: PMC10734423 DOI: 10.1128/jvi.01276-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/22/2023] [Indexed: 11/19/2023] Open
Abstract
ABSTRACT Disease progression during SARS-CoV-2 infection is tightly linked to the fate of lung epithelial cells, with severe cases of COVID-19 characterized by direct injury of the alveolar epithelium and an impairment in its regeneration from progenitor cells. The molecular pathways that govern respiratory epithelial cell death and proliferation during SARS-CoV-2 infection, however, remain unclear. We now report a high-throughput CRISPR screen for host genetic modifiers of the survival and proliferation of SARS-CoV-2-infected Calu-3 respiratory epithelial cells. The top four genes identified in our screen encode components of the same type I interferon (IFN-I) signaling complex—IFNAR1, IFNAR2, JAK1, and TYK2. The fifth gene, ACE2, was an expected control encoding the SARS-CoV-2 viral receptor. Surprisingly, despite the antiviral properties of IFN-I signaling, its disruption in our screen was associated with an increase in Calu-3 cell fitness. We validated this effect and found that IFN-I signaling did not sensitize SARS-CoV-2-infected cultures to cell death but rather inhibited the proliferation of surviving cells after the early peak of viral replication and cytopathic effect. We also found that IFN-I signaling alone, in the absence of viral infection, was sufficient to induce this delayed antiproliferative response in both Calu-3 cells and iPSC-derived type 2 alveolar epithelial cells. Together, these findings highlight a cell autonomous antiproliferative response by respiratory epithelial cells to persistent IFN-I signaling during SARS-CoV-2 infection. This response may contribute to the deficient alveolar regeneration that has been associated with COVID-19 lung injury and represents a promising area for host-targeted therapeutic development.
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Affiliation(s)
- Juliana Bragazzi Cunha
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Kyle Leix
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Emily J. Sherman
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Carmen Mirabelli
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Tristan Frum
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Charles J. Zhang
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan, USA
| | - Andrew A. Kennedy
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Adam S. Lauring
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Andrew W. Tai
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- VA Ann Arbor Healthcare System, Ann Arbor, Michigan, USA
| | - Jonathan Z. Sexton
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan, USA
| | - Jason R. Spence
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, USA
- Department of Biomedical Engineering, University of Michigan College of Engineering, Ann Arbor, Michigan, USA
| | - Christiane E. Wobus
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Brian T. Emmer
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
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Arble DM, Hutch CR, Hafner H, Stelmak D, Leix K, Sorrell J, Pressler JW, Gregg B, Sandoval DA. The role of preproglucagon peptides in regulating β-cell morphology and responses to streptozotocin-induced diabetes. Am J Physiol Endocrinol Metab 2023; 324:E217-E225. [PMID: 36652401 PMCID: PMC9970646 DOI: 10.1152/ajpendo.00152.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 11/29/2022] [Accepted: 01/09/2023] [Indexed: 01/19/2023]
Abstract
Insulin secretion from β-cells is tightly regulated by local signaling from preproglucagon (Gcg) products from neighboring α-cells. Physiological paracrine signaling within the microenvironment of the β-cell is altered after metabolic stress, such as high-fat diet or the β-cell toxin, streptozotocin (STZ). Here, we examined the role and source of Gcg peptides in β-cell function and in response to STZ-induced hyperglycemia. We used whole body Gcg null (GcgNull) mice and mice with Gcg expression either specifically within the pancreas (GcgΔPanc) or the intestine (GcgΔIntest). With lower doses of STZ exposure, insulin levels were greater and glucose levels were lower in GcgNull mice compared with wild-type mice. When Gcg was functional only in the intestine, plasma glucagon-like peptide-1 (GLP-1) levels were fully restored but these mice did not have any additional protection from STZ-induced diabetes. Pancreatic Gcg reactivation normalized the hyperglycemic response to STZ. In animals not treated with STZ, GcgNull mice had increased pancreas mass via both α- and β-cell hyperplasia and reactivation of Gcg in the intestine normalized β- but not α-cell mass, whereas pancreatic reactivation normalized both β- and α-cell mass. GcgNull and GcgΔIntest mice maintained higher β-cell mass after treatment with STZ compared with control and GcgΔPanc mice. Although in vivo insulin response to glucose was normal, global lack of Gcg impaired glucose-stimulated insulin secretion in isolated islets. Congenital replacement of Gcg either in the pancreas or intestine normalized glucose-stimulated insulin secretion. Interestingly, mice that had intestinal Gcg reactivated in adulthood had impaired insulin response to KCl. We surmise that the expansion of β-cell mass in the GcgNull mice compensated for decreased individual β-cell insulin secretion, which is sufficient to normalize glucose under physiological conditions and conferred some protection after STZ-induced diabetes.NEW & NOTEWORTHY We examined the role of Gcg on β-cell function under normal and high glucose conditions. GcgNull mice had decreased glucose-stimulated insulin secretion, increased β-cell mass, and partial protection against STZ-induced hyperglycemia. Expression of Gcg within the pancreas normalized these endpoints. Intestinal expression of Gcg only normalized β-cell mass and glucose-stimulated insulin secretion. Increased β-cell mass in GcgNull mice likely compensated for decreased insulin secretion normalizing physiological glucose levels and conferring some protection after STZ-induced diabetes.
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Affiliation(s)
- Deanna M Arble
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States
| | - Chelsea R Hutch
- Department of Surgery, University of Michigan, Ann Arbor, Michigan, United States
| | - Hannah Hafner
- Department of Pediatrics, Division of Diabetes, Endocrinology and Metabolism, University of Michigan Medicine, Ann Arbor, Michigan, United States
| | - Daria Stelmak
- Department of Surgery, University of Michigan, Ann Arbor, Michigan, United States
| | - Kyle Leix
- Department of Surgery, University of Michigan, Ann Arbor, Michigan, United States
| | - Joyce Sorrell
- Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, United States
| | - Joshua W Pressler
- Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, United States
| | - Brigid Gregg
- Department of Pediatrics, Division of Diabetes, Endocrinology and Metabolism, University of Michigan Medicine, Ann Arbor, Michigan, United States
| | - Darleen A Sandoval
- Department of Pediatrics, Section of Nutrition and Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
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Cunha JB, Leix K, Sherman EJ, Mirabelli C, Kennedy AA, Lauring AS, Tai AW, Wobus CE, Emmer BT. Type I interferon signaling induces a delayed antiproliferative response in Calu-3 cells during SARS-CoV-2 infection. bioRxiv 2023:2023.02.28.530557. [PMID: 36909579 PMCID: PMC10002732 DOI: 10.1101/2023.02.28.530557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Disease progression during SARS-CoV-2 infection is tightly linked to the fate of lung epithelial cells, with severe cases of COVID-19 characterized by direct injury of the alveolar epithelium and an impairment in its regeneration from progenitor cells. The molecular pathways that govern respiratory epithelial cell death and proliferation during SARS-CoV-2 infection, however, remain poorly understood. We now report a high-throughput CRISPR screen for host genetic modifiers of the survival and proliferation of SARS-CoV-2-infected Calu-3 respiratory epithelial cells. The top 4 genes identified in our screen encode components of the same type I interferon signaling complex - IFNAR1, IFNAR2, JAK1, and TYK2. The 5th gene, ACE2, was an expected control encoding the SARS-CoV-2 viral receptor. Surprisingly, despite the antiviral properties of IFN-I signaling, its disruption in our screen was associated with an increase in Calu-3 cell fitness. We validated this effect and found that IFN-I signaling did not sensitize SARS-CoV-2-infected cultures to cell death but rather inhibited the proliferation of surviving cells after the early peak of viral replication and cytopathic effect. We also found that IFN-I signaling alone, in the absence of viral infection, was sufficient to induce this delayed antiproliferative response. Together, these findings highlight a cell autonomous antiproliferative response by respiratory epithelial cells to persistent IFN-I signaling during SARS-CoV-2 infection. This response may contribute to the deficient alveolar regeneration that has been associated with COVID-19 lung injury and represents a promising area for host-targeted therapeutic development.
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Affiliation(s)
| | - Kyle Leix
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI
| | - Emily J. Sherman
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI
| | - Carmen Mirabelli
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor MI
| | - Andrew A. Kennedy
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI
| | - Adam S. Lauring
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor MI
| | - Andrew W. Tai
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor MI
- VA Ann Arbor Healthcare System, Ann Arbor MI
| | - Christiane E. Wobus
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor MI
| | - Brian T. Emmer
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor MI
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Li S, Leix K, Guo C, Chen J. ID:16277 Closed-Loop Intestinal Electrical Stimulation Ameliorates Hyperglycemia by Enhancing Incretin Hormones in Type 2 Diabetic Rats. Neuromodulation 2022. [DOI: 10.1016/j.neurom.2022.02.086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Sherman EJ, Mirabelli C, Tang VT, Khan TG, Leix K, Kennedy AA, Graham SE, Willer CJ, Tai AW, Sexton JZ, Wobus CE, Emmer BT. Identification of cell type specific ACE2 modifiers by CRISPR screening. PLoS Pathog 2022; 18:e1010377. [PMID: 35231079 PMCID: PMC8929698 DOI: 10.1371/journal.ppat.1010377] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 03/17/2022] [Accepted: 02/15/2022] [Indexed: 12/26/2022] Open
Abstract
SARS-CoV-2 infection is initiated by binding of the viral spike protein to its receptor, ACE2, on the surface of host cells. ACE2 expression is heterogeneous both in vivo and in immortalized cell lines, but the molecular pathways that govern ACE2 expression remain unclear. We now report high-throughput CRISPR screens for functional modifiers of ACE2 surface abundance. In liver-derived HuH7 cells, we identified 35 genes whose disruption was associated with a change in the surface abundance of ACE2. Enriched among these ACE2 regulators were established transcription factors, epigenetic regulators, and functional networks. We further characterized individual HuH7 cell lines with disruption of SMAD4, EP300, PIAS1, or BAMBI and found these genes to regulate ACE2 at the mRNA level and to influence cellular susceptibility to SARS-CoV-2 infection. Orthogonal screening of lung-derived Calu-3 cells revealed a distinct set of ACE2 modifiers comprised of ACE2, KDM6A, MOGS, GPAA1, and UGP2. Collectively, our findings clarify the host factors involved in SARS-CoV-2 entry, highlight the cell type specificity of ACE2 regulatory networks, and suggest potential targets for therapeutic development. The amount of ACE2 on the surface of human cells is an important determinant of SARS-CoV-2 infection, but the molecular pathways that regulate ACE2 remain poorly understood. Identification of these pathways may clarify host factors involved in COVID-19 outcomes and offer targets for therapeutic development. ACE2-targeted therapies may furthermore be less susceptible than viral spike-targeted therapies to evasion by SARS-CoV-2 variants. To systematically identify regulators of human ACE2, we therefore performed high-throughput CRISPR screening for modifiers of ACE2 surface abundance in HuH7 liver-derived and Calu-3 lung-derived cell lines. Unexpectedly, aside from ACE2 itself, we identified distinct sets of ACE2 modifiers in either cell line. For a subset of ACE2 regulators, we validated their functional effect on ACE2, confirmed their relevance to SARS-CoV-2 infection, and clarified their level of regulation. Our findings demonstrate the important influence of cell type on investigations of SARS-CoV-2 infection and nominate candidate pathways for ACE2-targeted therapeutic development.
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Affiliation(s)
- Emily J. Sherman
- Department of Internal Medicine, Division of Hospital Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Carmen Mirabelli
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Vi T. Tang
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, United States of America
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Taslima G. Khan
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, United States of America
- Chemical Biology Program, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Kyle Leix
- Department of Internal Medicine, Division of Hospital Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Andrew A. Kennedy
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sarah E. Graham
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Cristen J. Willer
- Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Andrew W. Tai
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Michigan, Ann Arbor, Michigan, United States of America
- VA Ann Arbor Healthcare System, Ann Arbor, Michigan, United States of America
| | - Jonathan Z. Sexton
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Christiane E. Wobus
- Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Brian T. Emmer
- Department of Internal Medicine, Division of Hospital Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
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Hutch CR, Stelmak D, Kanke M, Koch-Laskowski K, Cummings B, Griffin C, Leix K, Sethupathy P, Singer K, Sandoval DA. Diet-dependent sex differences in the response to vertical sleeve gastrectomy. Am J Physiol Endocrinol Metab 2021; 321:E11-E23. [PMID: 33998293 PMCID: PMC8321822 DOI: 10.1152/ajpendo.00060.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 12/14/2022]
Abstract
Nearly 80% of patients that receive bariatric surgery are women, yet mechanistic preclinical studies have focused on males. The goal of this study was to determine the metabolic impact of diet- and surgery-induced weight loss in males, females, and ovariectomized females. All mice were fed a 60% high-fat diet (HFD) before undergoing either vertical sleeve gastrectomy (VSG) or sham surgery. Mice either remained on an HFD or were switched to a standard chow diet postsurgically. When maintained on an HFD, males and females decreased fat mass and improved oral glucose tolerance after VSG. After dietary intervention, additional adiposity was lost in both surgical groups. Ovariectomized females showed a blunted decrease in fat mass on an HFD, but lost significant adiposity after dietary intervention. Energy expenditure was impacted by dietary and not surgical intervention across all groups. Males decreased hepatic triglyceride levels after VSG, which was further decreased after dietary intervention. Intact and ovariectomized females had a blunted decrease in hepatic triglycerides after VSG, but a significant decrease after dietary intervention. The more pronounced effect of VSG on hepatic lipids in males is strongly associated with changes in hepatic expression of genes and microRNAs previously linked to hepatic lipid regulation and systemic energy homeostasis. These data highlight the importance of postsurgical diet on metabolic outcomes across sexes. Furthermore, these data suggest the impact of VSG on hepatic triglycerides is diet-dependent in females and support the hypothesis that males and females achieve similar metabolic outcome, at least within the liver, via distinct mechanisms.NEW & NOTEWORTHY These data highlight the interaction of postsurgical diet after bariatric surgery on metabolic outcomes across sexes. These data suggest the impact of VSG on hepatic triglycerides is diet-dependent in females and support the hypothesis that males and females achieve similar metabolic outcome, at least within the liver, via distinct mechanisms.
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Affiliation(s)
- Chelsea R Hutch
- Department of Surgery, University of Michigan Medical School, Ann Arbor, Michigan
| | - Daria Stelmak
- Department of Surgery, University of Michigan Medical School, Ann Arbor, Michigan
| | - Matt Kanke
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Kieran Koch-Laskowski
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Bethany Cummings
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Cameron Griffin
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan
| | - Kyle Leix
- Department of Surgery, University of Michigan Medical School, Ann Arbor, Michigan
| | - Praveen Sethupathy
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Kanakadurga Singer
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan
| | - Darleen A Sandoval
- Department of Pediatrics, Section of Nutrition and Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado
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Hutch CR, Roelofs K, Haller A, Sorrell J, Leix K, D'Alessio DD, Augustin R, Seeley RJ, Klein T, Sandoval DA. The role of GIP and pancreatic GLP-1 in the glucoregulatory effect of DPP-4 inhibition in mice. Diabetologia 2019; 62:1928-1937. [PMID: 31414143 PMCID: PMC6732043 DOI: 10.1007/s00125-019-4963-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/11/2019] [Indexed: 11/26/2022]
Abstract
AIMS/HYPOTHESIS Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are two peptides that function to promote insulin secretion. Dipeptidyl peptidase-4 (DPP-4) inhibitors increase the bioavailability of both GLP-1 and GIP but the dogma continues to be that it is the increase in GLP-1 that contributes to the improved glucose homeostasis. We have previously demonstrated that pancreatic rather than intestinal GLP-1 is necessary for improvements in glucose homeostasis in mice. Therefore, we hypothesise that a combination of pancreatic GLP-1 and GIP is necessary for the full effect of DPP-4 inhibitors on glucose homeostasis. METHODS We have genetically engineered mouse lines in which the preproglucagon gene (Gcg) is absent in the entire body (GcgRAΔNull) or is expressed exclusively in the intestine (GcgRAΔVilCre) or pancreas and duodenum (GcgRAΔPDX1Cre). These mice were used to examine oral glucose tolerance and GLP-1 and GIP responses to a DPP-4 inhibitor alone, or in combination with incretin receptor antagonists. RESULTS Administration of the DPP-4 inhibitor, linagliptin, improved glucose tolerance in GcgRAΔNull mice and control littermates and in GcgRAΔVilCre and GcgRAΔPDX1Cre mice. The potent GLP-1 receptor antagonist, exendin-[9-39] (Ex9), blunted improvements in glucose tolerance in linagliptin-treated control mice and in GcgRAΔPDX1Cre mice. Ex9 had no effect on glucose tolerance in linagliptin-treated GcgRAΔNull or in GcgRAΔVilCre mice. In addition to GLP-1, linagliptin also increased postprandial plasma levels of GIP to a similar degree in all genotypes. When linagliptin was co-administered with a GIP-antagonising antibody, the impact of linagliptin was partially blunted in wild-type mice and was fully blocked in GcgRAΔNull mice. CONCLUSIONS/INTERPRETATION Taken together, these data suggest that increases in pancreatic GLP-1 and GIP are necessary for the full effect of DPP-4 inhibitors on glucose tolerance.
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Affiliation(s)
- Chelsea R Hutch
- Department of Surgery, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
| | - Karen Roelofs
- Department of Surgery, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
| | - April Haller
- Department of Internal Medicine-Endocrinology, Diabetes, and Metabolism, University of Cincinnati, Cincinnati, OH, USA
| | - Joyce Sorrell
- Department of Internal Medicine-Endocrinology, Diabetes, and Metabolism, University of Cincinnati, Cincinnati, OH, USA
| | - Kyle Leix
- Department of Surgery, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
| | - David D D'Alessio
- Division of Endocrinology, Metabolism, and Nutrition, Duke University Medical Center, Durham, NC, USA
| | - Robert Augustin
- Cardiometabolic Diseases Research (Biberach), Boehringer Ingelheim, Ingelheim am Rhein, Germany
| | - Randy J Seeley
- Department of Surgery, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
| | - Thomas Klein
- Cardiometabolic Diseases Research (Biberach), Boehringer Ingelheim, Ingelheim am Rhein, Germany
| | - Darleen A Sandoval
- Department of Surgery, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA.
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