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  1. Article ; Online: Physiology. Partitioning the circadian clock.

    Xi, Yannan / Chen, Danica

    Science (New York, N.Y.)

    2014  Volume 345, Issue 6201, Page(s) 1122–1123

    MeSH term(s) Animals ; Liver/metabolism ; Sirtuins/metabolism
    Chemical Substances Sirt6 protein, mouse (EC 2.4.2.31) ; Sirtuins (EC 3.5.1.-)
    Language English
    Publishing date 2014-09-04
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Comment
    ZDB-ID 128410-1
    ISSN 1095-9203 ; 0036-8075
    ISSN (online) 1095-9203
    ISSN 0036-8075
    DOI 10.1126/science.1259601
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Correction to: Pancreatic T cell protein-tyrosine phosphatase deficiency affects beta cell function in mice.

    Xi, Yannan / Liu, Siming / Bettaieb, Ahmed / Matsuo, Kosuke / Matsuo, Izumi / Hosein, Ellen / Chahed, Samah / Wiede, Florian / Zhang, Sheng / Zhang, Zhong-Yin / Kulkarni, Rohit N / Tiganis, Tony / Haj, Fawaz G

    Diabetologia

    2023  Volume 67, Issue 1, Page(s) 215

    Language English
    Publishing date 2023-10-20
    Publishing country Germany
    Document type Published Erratum
    ZDB-ID 1694-9
    ISSN 1432-0428 ; 0012-186X
    ISSN (online) 1432-0428
    ISSN 0012-186X
    DOI 10.1007/s00125-023-06023-1
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  3. Article: Partitioning the circadian clock

    Xi, Yannan / Chen, Danica

    Science. 2014 Sept. 5, v. 345, no. 6201

    2014  

    Abstract: Many physiological and behavioral events exhibit circadian rhythms, which are driven by internal circadian “clocks” that coordinate biological functions through the cyclic expression of at least 10 to 20% of the genes in any given tissue (1). The ... ...

    Abstract Many physiological and behavioral events exhibit circadian rhythms, which are driven by internal circadian “clocks” that coordinate biological functions through the cyclic expression of at least 10 to 20% of the genes in any given tissue (1). The robustness of circadian rhythms deteriorates with age, and circadian perturbation results in the development of disorders such as diabetes, obesity, and brain dysfunction. Central to the mammalian clock is the complex of transcriptional regulatory proteins CLOCK and BMAL1 (2). A recent study by Masri et al. (3) proposes that SIRT1 and SIRT6, two sirtuin family members with nicotinamide adenine dinucleotide (NAD +)-dependent deacetylase activity, regulate different facets of the CLOCK-BMAL1 network, and more surprisingly, control distinct classes of hepatic circadian genes. Partitioning circadian transcription by sirtuins suggests that in response to internal and external stimuli, circadian clocks selectively control sirtuin-dependent functions that are broadly associated with metabolism, stress resistance, inflammation, aging, and tissue regeneration, to provide organisms with plasticity to adapt to changing environments.
    Keywords NAD (coenzyme) ; brain ; circadian rhythm ; diabetes ; genes ; inflammation ; mammals ; metabolism ; obesity ; regulatory proteins ; stress tolerance ; tissue repair ; transcription (genetics)
    Language English
    Dates of publication 2014-0905
    Size p. 1122-1123.
    Publishing place American Association for the Advancement of Science
    Document type Article
    ZDB-ID 128410-1
    ISSN 1095-9203 ; 0036-8075
    ISSN (online) 1095-9203
    ISSN 0036-8075
    DOI 10.1126/science.1259601
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  4. Article ; Online: Small-molecule inhibition of glycogen synthase 1 for the treatment of Pompe disease and other glycogen storage disorders.

    Ullman, Julie C / Mellem, Kevin T / Xi, Yannan / Ramanan, Vyas / Merritt, Hanne / Choy, Rebeca / Gujral, Tarunmeet / Young, Lyndsay E A / Blake, Kerrigan / Tep, Samnang / Homburger, Julian R / O'Regan, Adam / Ganesh, Sandya / Wong, Perryn / Satterfield, Terrence F / Lin, Baiwei / Situ, Eva / Yu, Cecile / Espanol, Bryan /
    Sarwaikar, Richa / Fastman, Nathan / Tzitzilonis, Christos / Lee, Patrick / Reiton, Daniel / Morton, Vivian / Santiago, Pam / Won, Walter / Powers, Hannah / Cummings, Beryl B / Hoek, Maarten / Graham, Robert R / Chandriani, Sanjay J / Bainer, Russell / DePaoli-Roach, Anna A / Roach, Peter J / Hurley, Thomas D / Sun, Ramon C / Gentry, Matthew S / Sinz, Christopher / Dick, Ryan A / Noonberg, Sarah B / Beattie, David T / Morgans, David J / Green, Eric M

    Science translational medicine

    2024  Volume 16, Issue 730, Page(s) eadf1691

    Abstract: Glycogen synthase 1 (GYS1), the rate-limiting enzyme in muscle glycogen synthesis, plays a central role in energy homeostasis and has been proposed as a therapeutic target in multiple glycogen storage diseases. Despite decades of investigation, there are ...

    Abstract Glycogen synthase 1 (GYS1), the rate-limiting enzyme in muscle glycogen synthesis, plays a central role in energy homeostasis and has been proposed as a therapeutic target in multiple glycogen storage diseases. Despite decades of investigation, there are no known potent, selective small-molecule inhibitors of this enzyme. Here, we report the preclinical characterization of MZ-101, a small molecule that potently inhibits GYS1 in vitro and in vivo without inhibiting GYS2, a related isoform essential for synthesizing liver glycogen. Chronic treatment with MZ-101 depleted muscle glycogen and was well tolerated in mice. Pompe disease, a glycogen storage disease caused by mutations in acid α glucosidase (GAA), results in pathological accumulation of glycogen and consequent autophagolysosomal abnormalities, metabolic dysregulation, and muscle atrophy. Enzyme replacement therapy (ERT) with recombinant GAA is the only approved treatment for Pompe disease, but it requires frequent infusions, and efficacy is limited by suboptimal skeletal muscle distribution. In a mouse model of Pompe disease, chronic oral administration of MZ-101 alone reduced glycogen buildup in skeletal muscle with comparable efficacy to ERT. In addition, treatment with MZ-101 in combination with ERT had an additive effect and could normalize muscle glycogen concentrations. Biochemical, metabolomic, and transcriptomic analyses of muscle tissue demonstrated that lowering of glycogen concentrations with MZ-101, alone or in combination with ERT, corrected the cellular pathology in this mouse model. These data suggest that substrate reduction therapy with GYS1 inhibition may be a promising therapeutic approach for Pompe disease and other glycogen storage diseases.
    MeSH term(s) Mice ; Animals ; Glycogen Storage Disease Type II/drug therapy ; Glycogen Synthase/metabolism ; Glycogen Synthase/pharmacology ; Mice, Knockout ; Glycogen/metabolism ; Muscle, Skeletal/metabolism ; Enzyme Replacement Therapy/methods
    Chemical Substances Glycogen Synthase (EC 2.4.1.11) ; Glycogen (9005-79-2)
    Language English
    Publishing date 2024-01-17
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2518854-9
    ISSN 1946-6242 ; 1946-6234
    ISSN (online) 1946-6242
    ISSN 1946-6234
    DOI 10.1126/scitranslmed.adf1691
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Glucagon-receptor-antagonism-mediated β-cell regeneration as an effective anti-diabetic therapy.

    Xi, Yannan / Song, Benbo / Ngan, Iris / Solloway, Mark J / Humphrey, Mark / Wang, Yan / Mondal, Kalyani / Wu, Hao / Liu, Wenhui / Lindhout, Darrin A / Li, Diana / Matern, Hugo / Kekatpure, Avantika / Haldankar, Raj / Kaplan, Daniel D / Yang, Hong / Pedersen, Ophelia / Chen, Anna / Zhou, Mei /
    Winans, Bethany / Guo, Wei / Kutach, Alan / Fanget, Marie / Fox, Michael / Tang, Jie / Zha, Jiping / Younis, Husam / Shen, David / DePaoli, Alex / Tian, Hui / Liu, Zhonghao

    Cell reports

    2022  Volume 39, Issue 9, Page(s) 110872

    Abstract: Type 1 diabetes mellitus (T1D) is a chronic disease with potentially severe complications, and β-cell deficiency underlies this disease. Despite active research, no therapy to date has been able to induce β-cell regeneration in humans. Here, we discover ... ...

    Abstract Type 1 diabetes mellitus (T1D) is a chronic disease with potentially severe complications, and β-cell deficiency underlies this disease. Despite active research, no therapy to date has been able to induce β-cell regeneration in humans. Here, we discover the β-cell regenerative effects of glucagon receptor antibody (anti-GcgR). Treatment with anti-GcgR in mouse models of β-cell deficiency leads to reversal of hyperglycemia, increase in plasma insulin levels, and restoration of β-cell mass. We demonstrate that both β-cell proliferation and α- to β-cell transdifferentiation contribute to anti-GcgR-induced β-cell regeneration. Interestingly, anti-GcgR-induced α-cell hyperplasia can be uncoupled from β-cell regeneration after antibody clearance from the body. Importantly, we are able to show that anti-GcgR-induced β-cell regeneration is also observed in non-human primates. Furthermore, anti-GcgR and anti-CD3 combination therapy reverses diabetes and increases β-cell mass in a mouse model of autoimmune diabetes.
    MeSH term(s) Animals ; Diabetes Mellitus, Type 1 ; Disease Models, Animal ; Glucagon ; Glucagon-Secreting Cells ; Hyperglycemia/drug therapy ; Insulin-Secreting Cells ; Mice ; Receptors, Glucagon
    Chemical Substances Receptors, Glucagon ; Glucagon (9007-92-5)
    Language English
    Publishing date 2022-06-01
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2649101-1
    ISSN 2211-1247 ; 2211-1247
    ISSN (online) 2211-1247
    ISSN 2211-1247
    DOI 10.1016/j.celrep.2022.110872
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Stem cell aging. A mitochondrial UPR-mediated metabolic checkpoint regulates hematopoietic stem cell aging.

    Mohrin, Mary / Shin, Jiyung / Liu, Yufei / Brown, Katharine / Luo, Hanzhi / Xi, Yannan / Haynes, Cole M / Chen, Danica

    Science (New York, N.Y.)

    2015  Volume 347, Issue 6228, Page(s) 1374–1377

    Abstract: Deterioration of adult stem cells accounts for much of aging-associated compromised tissue maintenance. How stem cells maintain metabolic homeostasis remains elusive. Here, we identified a regulatory branch of the mitochondrial unfolded protein response ( ...

    Abstract Deterioration of adult stem cells accounts for much of aging-associated compromised tissue maintenance. How stem cells maintain metabolic homeostasis remains elusive. Here, we identified a regulatory branch of the mitochondrial unfolded protein response (UPR(mt)), which is mediated by the interplay of SIRT7 and NRF1 and is coupled to cellular energy metabolism and proliferation. SIRT7 inactivation caused reduced quiescence, increased mitochondrial protein folding stress (PFS(mt)), and compromised regenerative capacity of hematopoietic stem cells (HSCs). SIRT7 expression was reduced in aged HSCs, and SIRT7 up-regulation improved the regenerative capacity of aged HSCs. These findings define the deregulation of a UPR(mt)-mediated metabolic checkpoint as a reversible contributing factor for HSC aging.
    MeSH term(s) Animals ; Cell Cycle Checkpoints ; Cellular Senescence ; Energy Metabolism ; HEK293 Cells ; Hematopoietic Stem Cells/metabolism ; Hematopoietic Stem Cells/physiology ; Humans ; Mice ; Mice, Mutant Strains ; Mitochondria/metabolism ; Mitochondrial Proteins/genetics ; Mitochondrial Proteins/metabolism ; Nuclear Respiratory Factor 1/metabolism ; Protein Biosynthesis ; Sirtuins/genetics ; Sirtuins/metabolism ; Unfolded Protein Response
    Chemical Substances Mitochondrial Proteins ; NRF1 protein, human ; Nuclear Respiratory Factor 1 ; SIRT7 protein, human ; Sirtuins (EC 3.5.1.-)
    Language English
    Publishing date 2015-03-20
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 128410-1
    ISSN 1095-9203 ; 0036-8075
    ISSN (online) 1095-9203
    ISSN 0036-8075
    DOI 10.1126/science.aaa2361
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Disruption of protein-tyrosine phosphatase 1B expression in the pancreas affects β-cell function.

    Liu, Siming / Xi, Yannan / Bettaieb, Ahmed / Matsuo, Kosuke / Matsuo, Izumi / Kulkarni, Rohit N / Haj, Fawaz G

    Endocrinology

    2014  Volume 155, Issue 9, Page(s) 3329–3338

    Abstract: Protein-tyrosine phosphatase 1B (PTP1B) is a physiological regulator of glucose homeostasis and energy balance. However, the role of PTP1B in pancreatic endocrine function remains largely unknown. To investigate the metabolic role of pancreatic PTP1B, we ...

    Abstract Protein-tyrosine phosphatase 1B (PTP1B) is a physiological regulator of glucose homeostasis and energy balance. However, the role of PTP1B in pancreatic endocrine function remains largely unknown. To investigate the metabolic role of pancreatic PTP1B, we generated mice with pancreas PTP1B deletion (panc-PTP1B KO). Mice were fed regular chow or a high-fat diet, and metabolic parameters, insulin secretion and glucose tolerance were determined. On regular chow, panc-PTP1B KO and control mice exhibited comparable glucose tolerance whereas aged panc-PTP1B KO exhibited mild glucose intolerance. Furthermore, high-fat feeding promoted earlier impairment of glucose tolerance and attenuated glucose-stimulated insulin secretion in panc-PTP1B KO mice. The secretory defect in glucose-stimulated insulin secretion was recapitulated in primary islets ex vivo, suggesting that the effects were likely cell-autonomous. At the molecular level, PTP1B deficiency in vivo enhanced basal and glucose-stimulated tyrosyl phosphorylation of EphA5 in islets. Consistently, PTP1B overexpression in the glucose-responsive MIN6 β-cell line attenuated EphA5 tyrosyl phosphorylation, and substrate trapping identified EphA5 as a PTP1B substrate. In summary, these studies identify a novel role for PTP1B in pancreatic endocrine function.
    MeSH term(s) Animals ; Female ; Gene Knockout Techniques ; Glucose/metabolism ; Glucose Intolerance ; Insulin/metabolism ; Insulin-Secreting Cells/enzymology ; Insulin-Secreting Cells/metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Pancrelipase/genetics ; Pancrelipase/metabolism ; Protein Tyrosine Phosphatase, Non-Receptor Type 1/genetics ; Protein Tyrosine Phosphatase, Non-Receptor Type 1/metabolism
    Chemical Substances Insulin ; Pancrelipase (53608-75-6) ; Protein Tyrosine Phosphatase, Non-Receptor Type 1 (EC 3.1.3.48) ; Glucose (IY9XDZ35W2)
    Language English
    Publishing date 2014-06-23
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 427856-2
    ISSN 1945-7170 ; 0013-7227
    ISSN (online) 1945-7170
    ISSN 0013-7227
    DOI 10.1210/en.2013-2004
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Pancreatic T cell protein-tyrosine phosphatase deficiency ameliorates cerulein-induced acute pancreatitis.

    Bettaieb, Ahmed / Xi, Yannan / Hosein, Ellen / Coggins, Nicole / Bachaalany, Santana / Wiede, Florian / Perez, Salvador / Griffey, Stephen M / Sastre, Juan / Tiganis, Tony / Haj, Fawaz G

    Cell communication and signaling : CCS

    2014  Volume 12, Page(s) 13

    Abstract: Background: Acute pancreatitis (AP) is a common clinical problem whose incidence has been progressively increasing in recent years. Onset of the disease is trigged by intra-acinar cell activation of digestive enzyme zymogens that induce autodigestion, ... ...

    Abstract Background: Acute pancreatitis (AP) is a common clinical problem whose incidence has been progressively increasing in recent years. Onset of the disease is trigged by intra-acinar cell activation of digestive enzyme zymogens that induce autodigestion, release of pro-inflammatory cytokines and acinar cell injury. T-cell protein tyrosine phosphatase (TCPTP) is implicated in inflammatory signaling but its significance in AP remains unclear.
    Results: In this study we assessed the role of pancreatic TCPTP in cerulein-induced AP. TCPTP expression was increased at the protein and messenger RNA levels in the early phase of AP in mice and rats. To directly determine whether TCPTP may have a causal role in AP we generated mice with pancreatic TCPTP deletion (panc-TCPTP KO) by crossing TCPTP floxed mice with Pdx1-Cre transgenic mice. Amylase and lipase levels were lower in cerulein-treated panc-TCPTP KO mice compared with controls. In addition, pancreatic mRNA and serum concentrations of the inflammatory cytokines TNFα and IL-6 were lower in panc-TCPTP KO mice. At the molecular level, panc-TCPTP KO mice exhibited enhanced cerulein-induced STAT3 Tyr705 phosphorylation accompanied by a decreased cerulein-induced NF-κB inflammatory response, and decreased ER stress and cell death.
    Conclusion: These findings revealed a novel role for pancreatic TCPTP in the progression of cerulein-induced AP.
    MeSH term(s) Amylases/blood ; Animals ; Ceruletide/toxicity ; Interleukin-6/blood ; Lipase/blood ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; NF-kappa B/metabolism ; Pancreatitis, Acute Necrotizing/chemically induced ; Pancreatitis, Acute Necrotizing/metabolism ; Phosphorylation ; Protein Tyrosine Phosphatase, Non-Receptor Type 2/deficiency ; Protein Tyrosine Phosphatase, Non-Receptor Type 2/genetics ; Protein Tyrosine Phosphatase, Non-Receptor Type 2/metabolism ; RNA, Messenger/genetics ; RNA, Messenger/metabolism ; Rats ; Rats, Wistar ; STAT3 Transcription Factor/metabolism ; Tumor Necrosis Factor-alpha/blood
    Chemical Substances Interleukin-6 ; NF-kappa B ; RNA, Messenger ; STAT3 Transcription Factor ; Tumor Necrosis Factor-alpha ; Ceruletide (888Y08971B) ; Lipase (EC 3.1.1.3) ; Protein Tyrosine Phosphatase, Non-Receptor Type 2 (EC 3.1.3.48) ; Amylases (EC 3.2.1.-)
    Language English
    Publishing date 2014-03-10
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ISSN 1478-811X
    ISSN (online) 1478-811X
    DOI 10.1186/1478-811X-12-13
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  9. Article ; Online: Pancreatic T cell protein-tyrosine phosphatase deficiency affects beta cell function in mice.

    Xi, Yannan / Liu, Siming / Bettaieb, Ahmed / Matsuo, Kosuke / Matsuo, Izumi / Hosein, Ellen / Chahed, Samah / Wiede, Florian / Zhang, Sheng / Zhang, Zhong-Yin / Kulkarni, Rohit N / Tiganis, Tony / Haj, Fawaz G

    Diabetologia

    2014  Volume 58, Issue 1, Page(s) 122–131

    Abstract: Aims/hypothesis: T cell protein tyrosine phosphatase (TCPTP, encoded by PTPN2) regulates cytokine-induced pancreatic beta cell apoptosis and may contribute to the pathogenesis of type 1 diabetes. However, the role of TCPTP in pancreatic endocrine ... ...

    Abstract Aims/hypothesis: T cell protein tyrosine phosphatase (TCPTP, encoded by PTPN2) regulates cytokine-induced pancreatic beta cell apoptosis and may contribute to the pathogenesis of type 1 diabetes. However, the role of TCPTP in pancreatic endocrine function and insulin secretion remains largely unknown.
    Methods: To investigate the endocrine role of pancreatic TCPTP we generated mice with pancreas Ptpn2/TCPTP deletion (panc-TCPTP KO).
    Results: When fed regular chow, panc-TCPTP KO and control mice exhibited comparable glucose tolerance. However, when challenged with prolonged high fat feeding panc-TCPTP KO mice exhibited impaired glucose tolerance and attenuated glucose-stimulated insulin secretion (GSIS). The defect in GSIS was recapitulated in primary islets ex vivo and after TCPTP pharmacological inhibition or lentiviral-mediated TCPTP knockdown in the glucose-responsive MIN6 beta cells, consistent with this being cell autonomous. Reconstitution of TCPTP in knockdown cells reversed the defect in GSIS demonstrating that the defect was a direct consequence of TCPTP deficiency. The reduced insulin secretion in TCPTP knockdown MIN6 beta cells was associated with decreased insulin content and glucose sensing. Furthermore, TCPTP deficiency led to enhanced tyrosyl phosphorylation of signal transducer and activator of transcription 1 and 3 (STAT 1/3), and substrate trapping studies in MIN6 beta cells identified STAT 1/3 as TCPTP substrates. STAT3 pharmacological inhibition and small interfering RNA-mediated STAT3 knockdown in TCPTP deficient cells restored GSIS to control levels, indicating that the effects of TCPTP deficiency were mediated, at least in part, through enhanced STAT3 phosphorylation and signalling.
    Conclusions/interpretation: These studies identify a novel role for TCPTP in insulin secretion and uncover STAT3 as a physiologically relevant target for TCPTP in the endocrine pancreas.
    MeSH term(s) Animals ; Cells, Cultured ; Diet, High-Fat ; Female ; Glucose/metabolism ; Glucose/pharmacology ; Glucose Intolerance/genetics ; Glucose Intolerance/metabolism ; Insulin/metabolism ; Insulin Secretion ; Insulin-Secreting Cells/metabolism ; Insulin-Secreting Cells/physiology ; Male ; Mice ; Mice, Knockout ; Pancreas/metabolism ; Protein Tyrosine Phosphatase, Non-Receptor Type 2/genetics ; Protein Tyrosine Phosphatase, Non-Receptor Type 2/metabolism ; STAT3 Transcription Factor/metabolism
    Chemical Substances Insulin ; STAT3 Transcription Factor ; Stat3 protein, mouse ; Protein Tyrosine Phosphatase, Non-Receptor Type 2 (EC 3.1.3.48) ; Glucose (IY9XDZ35W2)
    Language English
    Publishing date 2014-10-23
    Publishing country Germany
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't
    ZDB-ID 1694-9
    ISSN 1432-0428 ; 0012-186X
    ISSN (online) 1432-0428
    ISSN 0012-186X
    DOI 10.1007/s00125-014-3413-7
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  10. Article: Soluble epoxide hydrolase deficiency alters pancreatic islet size and improves glucose homeostasis in a model of insulin resistance

    Luria, Ayala / Bettaieb, Ahmed / Xi, Yannan / Shieh, Guang-Jong / Liu, Hsin-Chen / Inoue, Hiromi / Tsai, Hsing-Ju / Imig, John D / Haj, Fawaz G / Hammock, Bruce D

    Proceedings of the National Academy of Sciences of the United States of America. 2011 May 31, v. 108, no. 22

    2011  

    Abstract: Visceral obesity has been defined as an important element of the metabolic syndrome and contributes to the development of insulin resistance and cardiovascular disease. Increasing endogenous levels of epoxyeicosatrienoic acids (EETs) are known for their ... ...

    Abstract Visceral obesity has been defined as an important element of the metabolic syndrome and contributes to the development of insulin resistance and cardiovascular disease. Increasing endogenous levels of epoxyeicosatrienoic acids (EETs) are known for their analgesic, antihypertensive, and antiinflammatory effects. The availability of EETs is limited primarily by the soluble epoxide hydrolase (sEH, EPHX2), which metabolizes EETs to their less active diols. In this study, we tested the hypothesis that EETs are involved in glucose regulation and in retarding the development of insulin resistance. To address the role of EETs in regulating glucose homeostasis and insulin signaling, we used mice with targeted gene deletion of sEH (Ephx2-null mice) and a subsequent study with a selective sEH inhibitor. When wild-type mice are fed a high fat diet, insulin resistance develops. However, knockout or inhibition of sEH activity resulted in a significant decrease in plasma glucose. These findings are characterized by enhancement of tyrosyl phosphorylation of the insulin receptor, insulin receptor substrate 1, and their downstream cascade. In addition, pancreatic islets were larger when sEH was disrupted. This effect was associated with an increase in vasculature. These observations were supported by pharmacological inhibition of sEH. These data suggest that an increase in EETs due to sEH-gene knockout leads to an increase in the size of islets and improved insulin signaling and sensitivity.
    Keywords acids ; analgesics ; anti-inflammatory activity ; blood glucose ; cardiovascular diseases ; epoxide hydrolase ; gene deletion ; glucose ; glycols ; high fat diet ; homeostasis ; insulin ; insulin receptors ; insulin resistance ; islets of Langerhans ; metabolic syndrome ; mice ; models ; obesity ; phosphorylation ; signal transducing adaptor proteins
    Language English
    Dates of publication 2011-0531
    Size p. 9038-9043.
    Publishing place National Academy of Sciences
    Document type Article
    ZDB-ID 209104-5
    ISSN 1091-6490 ; 0027-8424
    ISSN (online) 1091-6490
    ISSN 0027-8424
    DOI 10.1073/pnas.1103482108
    Database NAL-Catalogue (AGRICOLA)

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