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Background Medications targeting the glucagon-like peptide-1 (GLP-1) pathway are an important therapeutic class currently used for the treatment of Type 2 diabetes (T2D). However, there is not enough known about which subgroups of patients would receive the most benefit from these medications. Objective The goal of this study was to develop a predictive model for patient responsiveness to medications, here collectively called GLP-1 M, that include GLP-1 receptor agonists and dipeptidyl peptidase-4 (DPP4) inhibitors (that normally degrade endogenously-produced GLP-1). Such a model could guide clinicians to consider certain patient characteristics when prescribing second line medications for T2D. Methods We analyzed de-identified electronic health records of 7856 subjects with T2D treated with GLP-1 M drugs at Vanderbilt University Medical Center from 2003–2019. Using common clinical features (including commonly ordered lab tests, demographic information, other T2D medications, and diabetes-associated complications), we compared four different models: logistic regression, LightGBM, artificial neural network (ANN), and support vector classifier (SVC). Results Our analysis revealed that the traditional logistic regression model outperforms the other machine learning models, with an area under the Receiver Operating Characteristic curve (auROC) of 0.77.Our model showed that higher pre-treatment HbA1C is a dominant feature for predicting better response to GLP-1 M, while features such as use of thiazolidinediones or sulfonylureas is correlated with poorer response to GLP-1 M, as assessed by lowering of hemoglobin A1C (HbA1C), a standard marker of glycated hemoglobin used for assessing glycemic control in individuals with diabetes. Among female subjects under 40 taking GLP-1 M, the simultaneous use of non-steroidal anti-inflammatory drugs (NSAIDs) was associated with a greater reduction in HbA1C (0.82 ± 1.72% vs 0.28 ± 1.70%, p  = 0.008). Conclusion These findings indicate a thorough analysis of real-world electronic health records could reveal new information to improve treatment decisions for the treatment of T2D. The predictive model developed in this study highlights the importance of considering individual patient characteristics and medication interactions when prescribing GLP-1 M drugs.

Tamoxifen (Tm)-inducible Cre recombinases are widely used to perform gene inactivation and lineage tracing studies in mice. Although the efficiency of inducible Cre-loxP recombination can be easily evaluated with reporter strains, the precise length of time that Tm induces nuclear translocation of CreER(Tm) and subsequent recombination of a target allele is not well defined, and difficult to assess. To better understand the timeline of Tm activity in vivo, we developed a bioassay in which pancreatic islets with a Tm-inducible reporter (from Pdx1(PB)-CreER(Tm);R26R(lacZ) mice) were transplanted beneath the renal capsule of adult mice previously treated with three doses of 1 mg Tm, 8 mg Tm, or corn oil vehicle. Surprisingly, recombination in islet grafts, as assessed by expression of the β-galactosidase (β-gal) reporter, was observed days or weeks after Tm treatment, in a dose-dependent manner. Substantial recombination occurred in islet grafts long after administration of 3×8 mg Tm: in grafts transplanted 48 hours after the last Tm injection, 77.9±0.4% of β-cells were β-gal+; in β-cells placed after 1 week, 46.2±5.0% were β-gal+; after 2 weeks, 26.3±7.0% were β-gal+; and after 4 weeks, 1.9±0.9% were β-gal+. Islet grafts from mice given 3×1 mg Tm showed lower, but notable, recombination 48 hours (4.9±1.7%) and 1 week (4.5±1.9%) after Tm administration. These results show that Tm doses commonly used to induce Cre-loxP recombination may continue to label significant numbers of cells for weeks after Tm treatment, possibly confounding the interpretation of time-sensitive studies using Tm-dependent models. Therefore, investigators developing experimental approaches using Tm-inducible systems should consider both maximal recombination efficiency and the length of time that Tm-induced Cre-loxP recombination occurs.

The cellular mechanisms underlying a greater risk of cardiometabolic disease in adult offspring exposed to maternal obesity are not known. Our prior work found reduced skeletal muscle mitochondrial metabolism and insulin sensitivity in offspring exposed to maternal (m) Western-style diet (WD), even when weaned onto a control diet (CD) in Japanese macaques. Here, we performed multiple comparisons of differentially expressed (DE) genes in skeletal muscle from lean juvenile offspring to test hypotheses specific to (1) the lasting effects of maternal diet composition and/or maternal adiposity on gene expression and (2) the transcriptional response to a chronic postweaning (pw)WD with and without prior exposure to mWD. Overall, we identified maternal (m)WD, and not maternal adiposity, as a principal driver of DE in offspring muscle even years after exposure with few differences observed in patterns of DE between offspring of lean vs. obese mWD dams. Transcriptional response to the pwWD was robust in mCD offspring but blunted by mWD, particularly in males, suggesting a potential priming of gene expression. KEGG enrichment analysis and assessment of top DE genes identified changes in key pathways associated with dysregulated metabolism and RNA processing. We conclude that mWD has a significant and lasting impact on offspring gene expression which likely contributes to observed skeletal muscle insulin resistance and metabolic dysregulation in these offspring.

Arachidonic acid (AA) is a polyunsaturated 20-carbon fatty acid present in phospholipids in the plasma membrane. The three primary pathways by which AA is metabolized are mediated by cyclooxygenase (COX) enzymes, lipoxygenase (LOX) enzymes, and cytochrome P450 (CYP) enzymes. These three pathways produce eicosanoids, lipid signaling molecules that play roles in biological processes such as inflammation, pain, and immune function. Eicosanoids have been demonstrated to play a role in inflammatory, renal, and cardiovascular diseases as well type 1 and type 2 diabetes. Alterations in AA release or AA concentrations have been shown to affect insulin secretion from the pancreatic beta cell, leading to interest in the role of AA and its metabolites in the regulation of beta-cell function and maintenance of beta-cell mass. In this review, we discuss the metabolism of AA by COX, LOX, and CYP, the roles of these enzymes and their metabolites in beta-cell mass and function, and the possibility of targeting these pathways as novel therapies for treating diabetes.

Gestational Diabetes Mellitus Resulting From Impaired β-Cell Compensation in the Absence of FoxM1, a Novel Downstream Effector of Placental Lactogen Hongjie Zhang 1 , Jia Zhang 2 , Christine F. Pope 1 , Laura A. Crawford 3 , Rupangi C. Vasavada 4 , Shubhada M. Jagasia 1 and Maureen Gannon 1 , 2 , 3 1 Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee; 2 Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee; 3 Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee; 4 Department of Medicine, Division of Endocrinology, The University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania. Corresponding author: Maureen Gannon, maureen.gannon{at}vanderbilt.edu . H.Z. and J.Z. contributed equally to this work. Abstract OBJECTIVE The objectives of the study were to determine whether the cell cycle transcription factor, FoxM1, is required for glucose homeostasis and β-cell mass expansion in maternal islets during pregnancy and whether FoxM1 is essential for placental lactogen (PL)-induced β-cell proliferation. RESEARCH DESIGN AND METHODS β-Cell mass, β-cell proliferation, and glucose homeostasis were assessed in virgin, pregnant, and postpartum mice with a pancreas-wide Foxm1 deletion (FoxM1 Δpanc ). Wild-type islets were cultured with or without PL and examined for Foxm1 induction. Transgenic mice overexpressing PL in β-cells were bred with FoxM1 Δpanc mice, and β-cell proliferation was examined. RESULTS Foxm1 was upregulated in maternal islets during pregnancy. In contrast to controls, β-cell proliferation did not increase in pregnant FoxM1 Δpanc females. Mutant islets showed increased Menin and nuclear p27. FoxM1 Δpanc females developed gestational diabetes mellitus as pregnancy progressed. After parturition, euglycemia was restored in FoxM1 Δpanc females, but islet size was significantly reduced. Strikingly, β-cell mass was normal in postpartum FoxM1 Δpanc pancreata due to a combination of increased β-cell size and islet neogenesis. Evidence for neogenesis included increased number of endocrine clusters, increased proportion of smaller islets, and increased neurogenin 3 or insulin expression in cells adjacent to ducts. PL induced Foxm1 expression in cultured islets, and FoxM1 was essential for PL-mediated increases in β-cell proliferation in vivo. CONCLUSIONS FoxM1 is essential for β-cell compensation during pregnancy. In the absence of increased β-cell proliferation, neogenesis is induced in postpartum FoxM1 Δpanc pancreata. Our results suggest that FoxM1 functions downstream of PL to mediate its effects on β-cell proliferation. Footnotes The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Received January 9, 2009. Accepted September 23, 2009. © 2010 American Diabetes Association

Growth hormone (GH) not only supports hepatic metabolism but also protects against hepatocyte cell death. Hnf6 (or Oc1) belonging to the Onecut family of hepatocyte transcription factors known to regulate differentiated hepatic function, is a GH-responsive gene. We evaluate if GH mediates Hnf6 activity to attenuate hepatic apoptotic injury. We used an animal model of hepatic apoptosis by bile duct ligation (BDL) with Hnf6 -/- (KO) mice in which hepatic Hnf6 was conditionally inactivated. GH was administered to adult wild type WT and KO mice for the 7 days of BDL to enhance Hnf6 expression. In vitro, primary hepatocytes derived from KO and WT liver were treated with LPS and hepatocyte apoptosis was assessed with and without GH treatment. In WT mice, GH treatment enhanced Hnf6 expression during BDL, inhibited Caspase -3, -8 and -9 responses and diminished hepatic apoptotic and fibrotic injury. GH-mediated upregulation of Hnf6 expression and parallel suppression of apoptosis and fibrosis in WT BDL liver were abrogated in KO mice. LPS activated apoptosis and suppressed Hnf6 expression in primary hepatocytes. GH/LPS co-treatment enhanced Hnf6 expression with corresponding attenuation of apoptosis in WT-derived hepatocytes, but not in KO hepatocytes. ChiP-on-ChiP and electromobility shift assays of KO and WT liver nuclear extracts identified Ciap1 (or Birc2) as an Hnf6-bound target gene. Ciap1 expression patterns closely follow Hnf6 expression in the liver and in hepatocytes. GH broad protective actions on hepatocytes during liver injury are effected through Hnf6, with Hnf6 transcriptional activation of Ciap1 as an underlying molecular mediator.

β-Cell Proliferation, but Not Neogenesis, Following 60% Partial Pancreatectomy Is Impaired in the Absence of FoxM1 Amanda Ackermann Misfeldt 1 2 , Robert H. Costa 3 and Maureen Gannon 1 2 4 5 1 Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee 2 Program in Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee 3 Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, Illinois 4 Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee 5 Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee Corresponding author: Maureen Gannon, maureen.gannon{at}vanderbilt.edu Abstract OBJECTIVE— This study was designed to determine whether the transcription factor FoxM1 was required for regeneration of β-cell mass via proliferation and/or neogenesis in the adult after 60% partial pancreatectomy (PPx). RESEARCH DESIGN AND METHODS— Adult mice with a pancreas-wide deletion of Foxm1 ( Foxm1 flox/flox ; Pdx1-Cre [FoxM1 Δpanc ]) and their control littermates ( Foxm1 flox/flox ) were subjected to PPx or a sham operation, after which islet expression of Foxm1 and several target genes, β-cell mass, proliferation, β-cell size, islet size, islet density, and neurogenin-3 expression were analyzed. RESULTS— In control mice, PPx stimulated β-cell proliferation and neogenesis and upregulated Foxm1 and several of its known targets ( Plk1 , Cenp-a , Birc5/Survivin , and Ccnb1 ) in islets. Within 1 week post-PPx, control mice underwent significant regeneration of β-cell mass, and average islet size within the regenerating lobe was similar to that after a sham operation. However, FoxM1 Δpanc mice exhibited specific impairments in β-cell mass regeneration and islet growth after PPx, with reduced proliferation of α- and β-cells but no impairments in acinar or ductal cell proliferation. Interestingly, FoxM1 was not required for proliferation of β-cells within small endocrine cell clusters located in the regenerating portion of the pancreas but was specifically required for proliferation of β-cells within larger islets. Additionally, FoxM1 was not required for β-cell neogenesis following PPx. CONCLUSIONS— Our results indicate that FoxM1 is partially required for increased β-cell proliferation, but not β-cell neogenesis, stimulated by PPx. Furthermore, FoxM1 seems to be dispensable for proliferation of β-cells following neogenesis but is required for proliferation of preexisting β-cells. Footnotes Published ahead of print at http://diabetes.diabetesjournals.org on 26 August 2008. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. See http://creativecommons.org/licenses/by-nc-nd/3.0/ for details. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Accepted August 15, 2008. Received July 1, 2008. DIABETES

Pancreas development begins with the formation of buds at specific sites in the embryonic foregut endoderm. We used recombination-based lineage tracing in vivo to show that Ptf1a (also known as PTF1-p48 ) is expressed at these early stages in the progenitors of pancreatic ducts, exocrine and endocrine cells, rather than being an exocrine-specific gene as previously described. Moreover, inactivation of Ptf1a switches the character of pancreatic progenitors such that their progeny proliferate in and adopt the normal fates of duodenal epithelium, including its stem-cell compartment. Consistent with the proposal that Ptf1a supports the specification of precursors of all three pancreatic cell types, transgene-based expression of Pdx1 , a gene essential to pancreas formation, from Ptf1a cis -regulatory sequences restores pancreas tissue to Pdx1 -null mice that otherwise lack mature exocrine and endocrine cells because of an early arrest in organogenesis. These experiments provide evidence that Ptf1a expression is specifically connected to the acquisition of pancreatic fate by undifferentiated foregut endoderm.

The prevalence of maternal obesity is increasing in the United States. Offspring born to women with obesity or poor glycemic control have greater odds of becoming obese and developing metabolic disease later in life. Our group has utilized a macaque model to study the metabolic effects of consumption of a calorically-dense, Western-style diet (WSD; 36.3% fat) during pregnancy. Here, our objective was to characterize the effects of WSD and obesity, alone and together, on maternal glucose tolerance and insulin levels in dams during each pregnancy. Recognizing the collinearity of maternal measures, we adjusted for confounding factors including maternal age and parity. Based on intravenous glucose tolerance tests, dams consuming a WSD showed lower glucose area under the curve during first study pregnancies despite increased body fat percentage and increased insulin area under the curve. However, with (1) prolonged WSD feeding, (2) multiple diet switches, and/or (3) increasing age and parity, WSD was associated with increasingly higher insulin levels during glucose tolerance testing, indicative of insulin resistance. Our results suggest that prolonged or recurrent calorically-dense WSD and/or increased parity, rather than obesity per se, drive excess insulin resistance and metabolic dysfunction. These observations in a highly relevant species are likely of clinical and public health importance given the comparative ease of maternal dietary modifications relative to the low likelihood of successfully reversing obesity in the course of any given pregnancy.

Pancreatic Islet Production of Vascular Endothelial Growth Factor-A Is Essential for Islet Vascularization, Revascularization, and Function Marcela Brissova 1 , Alena Shostak 1 , Masakazu Shiota 2 , Peter O. Wiebe 2 , Greg Poffenberger 1 , Jeannelle Kantz 2 , Zhongyi Chen 1 , Chad Carr 1 , W. Gray Jerome 3 4 , Jin Chen 4 5 , H. Scott Baldwin 6 , Wendell Nicholson 1 , David M. Bader 7 , Thomas Jetton 8 , Maureen Gannon 1 2 and Alvin C. Powers 1 2 9 1 Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 2 Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee 3 Department of Pathology, Vanderbilt University Medical Center, Nashville, Tennessee 4 Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, Tennessee 5 Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, Tennessee 6 Division of Pediatric Cardiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 7 Stahlman Laboratory, Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 8 Division of Endocrinology and Metabolism, Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont 9 Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee Address correspondence and reprint requests to Alvin C. Powers, Division of Diabetes, Endocrinology, and Metabolism, 715 PRB, Vanderbilt University, Nashville, TN 37232. E-mail: al.powers{at}vanderbilt.edu Abstract To investigate molecular mechanisms controlling islet vascularization and revascularization after transplantation, we examined pancreatic expression of three families of angiogenic factors and their receptors in differentiating endocrine cells and adult islets. Using intravital lectin labeling, we demonstrated that development of islet microvasculature and establishment of islet blood flow occur concomitantly with islet morphogenesis. Our genetic data indicate that vascular endothelial growth factor (VEGF)-A is a major regulator of islet vascularization and revascularization of transplanted islets. In spite of normal pancreatic insulin content and β-cell mass, mice with β-cell–reduced VEGF-A expression had impaired glucose-stimulated insulin secretion. By vascular or diffusion delivery of β-cell secretagogues to islets, we showed that reduced insulin output is not a result of β-cell dysfunction but rather caused by vascular alterations in islets. Taken together, our data indicate that the microvasculature plays an integral role in islet function. Factors modulating VEGF-A expression may influence islet vascularity and, consequently, the amount of insulin delivered into the systemic circulation. Ang, angiopoietin VEGF, vascular endothelial growth factor Footnotes Additional information for this article can be found in an online appendix at http://diabetes.diabetesjournals.org . The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Accepted July 19, 2006. Received May 18, 2006. DIABETES