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Background: Insulin resistance (IR) can increase atherosclerotic and cardiovascular risk by inducing endothelial dysfunction, decreasing nitric oxide (NO) production, and accelerating arterial inflammation. The aim is to determine the mechanism by which insulin action and NO production in endothelial cells can improve systemic bioenergetics and decrease atherosclerosis via differentiation of perivascular progenitor cells (PPCs) into brown adipocytes (BAT). Methods: Studies used various endothelial transgenic and deletion mutant ApoE −/− mice of insulin receptors, eNOS (endothelial NO synthase) and ETBR (endothelin receptor type B) receptors for assessments of atherosclerosis. Cells were isolated from perivascular fat and micro-vessels for studies on differentiation and signaling mechanisms in responses to NO, insulin, and lipokines from BAT. Results: Enhancing insulin’s actions on endothelial cells and NO production in ECIRS1 transgenic mice reduced body weight and increased systemic energy expenditure and BAT mass and activity by inducing differentiation of PPCs into beige/BAT even with high-fat diet. However, positive changes in bioenergetics, BAT differentiation from PPCs and weight loss were inhibited by N(gamma)-nitro-L-arginine methyl ester ( L -NAME), an inhibitor of eNOS, in ECIRS1 mice and eNOSKO mice. The mechanism mediating NO’s action on PPC differentiation into BAT was identified as the activation of solubilized guanylate cyclase/PKGIα (cGMP protein-dependent kinase Iα)/GSK3β (glycogen synthase kinase 3β) pathways. Plasma lipidomics from ECIRS1 mice with NO-induced increased BAT mass revealed elevated 12,13-diHOME production. Infusion of 12,13-diHOME improved endothelial dysfunction and decreased atherosclerosis, whereas its reduction had opposite effects in ApoE − /− mice. Conclusions: Activation of eNOS and endothelial cells by insulin enhanced the differentiation of PPC to BAT and its lipokines and improved systemic bioenergetics and atherosclerosis, suggesting that endothelial dysfunction is a major contributor of energy disequilibrium in obesity.

OBJECTIVE To correlate inflammatory cytokines and vascular endothelial growth factor (VEGF) in vitreous and plasma with vitreous retinol binding protein 3 (RBP3), diabetic retinopathy (DR) severity, and DR worsening in a population with type 1 and type 2 diabetes. RESEARCH DESIGN AND METHODS RBP3, VEGF, and inflammatory cytokines were measured in plasma and vitreous samples (n = 205) from subjects of the Joslin Medalist Study and Beetham Eye Institute. RESULTS Higher vitreous RBP3 concentrations were associated with less severe DR (P < 0.0001) and a reduced risk of developing proliferative DR (PDR) (P < 0.0001). Higher RBP3 correlated with increased photoreceptor segment thickness and lower vitreous interleukin-12 (IL-12), tumor necrosis factor-α (TNF-α), and TNF-β (P < 0.05). PDR was associated with lower vitreous interferon-γ and IL-10 and higher VEGF, IL-6, and IL-15 (P < 0.05), but was not associated with their plasma concentrations. CONCLUSIONS Higher vitreous RBP3 concentrations are associated with less severe DR and slower rates of progression to PDR, supporting its potential as a biomarker and therapeutic agent for preventing DR worsening, possibly by lowering retinal VEGF and inflammatory cytokines.

Insulin resistance and hyperglycemia are risk factors for periodontitis and poor wound healing in diabetes, which have been associated with selective loss of insulin- activation of the PI3K/Akt pathway in the gingiva. This study showed that insulin resistance in the mouse gingiva due to selective deletion of smooth muscle and fibroblast insulin receptor (SMIRKO mice) or systemic metabolic changes induced by high fat diet (HFD) in HFD-fed mice exacerbated periodontitis-induced alveolar bone loss, preceded by delayed neutrophil and monocyte recruitment and impaired bacterial clearance compared to their respective controls. The immunocytokines, CXCL1, CXCL2, MCP-1, TNFα, IL-1β and IL-17A exhibited delayed maximal expression in the gingiva of male SMIRKO and HFD-fed mice compared to controls. Targeted overexpression of CXCL1 in the gingiva by adenovirus normalized neutrophil and monocyte recruitment and prevented bone loss in both mouse models of insulin resistance. Mechanistically, insulin enhanced bacterial lipopolysaccharide-induced CXCL1 production in mouse and human gingival fibroblasts (GFs), via Akt pathway and NF-κB activation, which were reduced in GFs from SMIRKO and HFD-fed mice. These results provided the first report that insulin signaling can enhance endotoxin induced CXCL1 expression to modulate neutrophil recruitment, suggesting CXCL1 as a new therapeutic direction for periodontitis or wound healing in diabetes.

Background: An activated, proinflammatory endothelium is a key feature in the development of complications of obesity and type 2 diabetes and can be caused by insulin resistance in endothelial cells. Methods: We analyzed primary human endothelial cells by RNA sequencing to discover novel insulin-regulated genes and used endothelial cell culture and animal models to characterize signaling through CXCR4 (C-X-C motif chemokine receptor 4) in endothelial cells. Results: CXCR4 was one of the genes most potently regulated by insulin, and this was mediated by PI3K (phosphatidylinositol 3-kinase), likely through FoxO1, which bound to the CXCR4 promoter. CXCR4 mRNA in CD31+ cells was 77% higher in mice with diet-induced obesity compared with lean controls and 37% higher in db/db mice than db/+ controls, consistent with upregulation of CXCR4 in endothelial cell insulin resistance. SDF-1 (stromal cell–derived factor-1)—the ligand for CXCR4—increased leukocyte adhesion to cultured endothelial cells. This effect was lost after deletion of CXCR4 by gene editing while 80% of the increase was prevented by treatment of endothelial cells with insulin. In vivo microscopy of mesenteric venules showed an increase in leukocyte rolling after intravenous injection of SDF-1, but most of this response was prevented in transgenic mice with endothelial overexpression of IRS-1 (insulin receptor substrate-1). Conclusions: Endothelial cell insulin signaling limits leukocyte/endothelial cell interaction induced by SDF-1 through downregulation of CXCR4. Improving insulin signaling in endothelial cells or inhibiting endothelial CXCR4 may reduce immune cell recruitment to the vascular wall or tissue parenchyma in insulin resistance and thereby help prevent several vascular complications.

Diabetic nephropathy (DN) is the result of abnormal systemic and local changes in metabolism and hemodynamics. We have reported that many glycolytic enzymes, such as pyruvate kinase M2 (PKM2) , were elevated in the renal glomeruli of type 1 and type 2 diabetic patients who were protected from DN. TEPP46, a small-molecule which activates PKM2 by inducing oligomerization, reversed glomerular pathology in diabetic mice. Here, mice with PKM2-specific overexpression in podocytes (PPKM2Tg) were generated to uncover its renal protective function as potential therapeutic target, which prevented elevated albumin-creatinine ratio (ACR) , mesangial expansion, basement membrane thickness and podocyte foot process effacement after 7-months of STZ-induced diabetes. Further, diabetes-induced impairment of glycolytic rate and mitochondrial function were normalized in diabetic PPKM2Tg glomeruli, in concordance with elevated Ppargc1a and Vegf expressions. Restored VEGF expression improved glomerular maximal mitochondrial function in diabetic PPKM2Tg and WT mice. Elevated VEGF levels were observed in the glomeruli of DN-protected patients with chronic type 1 diabetes, and clinically correlated with estimated GFR, but not glycemic control. Mechanistically, the preservations of mitochondrial function and VEGF expression were dependent on tetrameric structure and enzymatic activities of PKM2 in podocyte. Thus, these findings show that PKM2 activation in the podocyte can regulate mitochondrial metabolism of the entire glomeruli and prevent mitochondrial dysfunction induced by chronic diabetes and even reverse metabolic memory. PKM2 structures and enzymatic activities are necessary to mediate glomerular metabolism against toxicity of hyperglycemia via paracrine factors such as VEGF. Thus, PKM2 activation in podocyte is a potential therapeutic target to protect against DN. Disclosure J.Fu: None. T.Shinjo: None. Q.Li: None. K.Park: None. M.Yu: None. H.Yokomizo: None. Q.Huang: None. I.Wu: None. G.L.King: Advisory Panel; Medtronic, Research Support; Janssen Pharmaceuticals, Inc.

The Joslin Medalist Study identified Retinol-binding protein 3 (RBP3) as a potential protective factor against diabetic retinopathy (DR) in the vitreous and retina of individuals with type 1 diabetes for 50 years or longer. This study evaluated the association of aqueous RBP3 concentration to vitreous RBP3 concentrations and DR severity. We measured 131 aqueous samples from patients with type 1 and 2 diabetes undergoing cataract surgery at the Joslin Beetham Eye Institute (BEI) and postmortem samples of Medalists. Aqueous RBP3 concentrations in BEI and Medalists samples were similar for eyes with proliferative DR (PDR, P=0.11) and were well correlated between fellow eyes (r=0.65, P Disclosure T.Chokshi: None. J.Sun: Consultant; American Diabetes Association, American Medical Association, Research Support; Adaptive Sensory Technology, Boehringer Ingelheim International GmbH, Genentech, Inc., Jaeb Center for Health Research, Janssen Pharmaceuticals, Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk, Optovue, Incorporated, Physical Sciences, Inc, Roche Pharmaceuticals. G.L.King: Advisory Panel; Medtronic, Research Support; Janssen Pharmaceuticals, Inc. W.Fickweiler: None. M.G.Mitzner: None. I.Wu: None. T.Boumenna: None. D.B.Robinson: None. H.Park: None. K.Park: None. L.P.Aiello: Consultant; KalVista Pharmaceuticals, Inc., Novo Nordisk, Stock/Shareholder; KalVista Pharmaceuticals, Inc. Funding American Diabetes Association (7-21-PDF-022) ; National Eye Institute (R01EYE26080-01) , the National Institute of Diabetes and Digestive and Kidney Diseases and National Institutes of Health (DP3-DK-094333-01) ; JDRF (17-2013-310) ; the Dianne Nunnally Hoppes Fund; the Beatson Pledge Fund

Background: Anti-vascular endothelial growth factor (anti-VEGF) therapy has revolutionized the treatment of severe diabetic retinopathy (DR) , but significant subset of patients showed inadequate response to anti-VEGF. We have previously reported that retinol binding protein 3 (RBP3) prevented hyperglycemia induced retinal pathologies and progression to severe DR. Hypothesis: RBP3 and Anti-VEGF have differential protective profiles in preventing retinal dysfunctions induced by diabetes. Methods and Results: Recombinant human RBP3 (rhRBP3, 5ug/ml) and anti-VEGF (Avastin, 250mg/ml) inhibited VEGF-induced retinal vascular permeability (RVP) by 70% when intravitreal injections were given together in Lewis rats (P < 0.01) . After 2 months of diabetes induced by streptozotocin (STZ) , intravitreal injection of rhRBP3 and anti-VEGF for 3 days suppressed RVP by 64% and 53% (P < 0.01) in Lewis rats. This was accompanied by reductions of VEGF levels by both proteins. Electroretinogram (ERG) amplitudes of A wave, B wave, C wave were decreased in rats after 2 months of diabetes (P < 0.01) . rhRBP3 increased amplitudes of C wave (P < 0.01) , while anti-VEGF did not improve any waveforms. Furthermore, rhRBP3 decreased retinal mRNA expression of Cd11b and Tnfa (P =0.1) in diabetic rats. In cultured primary bovine Müller cells, rhRBP3 decreased mRNA expressions of Tnfa and Il-6 induced by high glucose (25mM) (P < 0.01) , whereas, anti-VEGF showed no effect. Metabolic function studies using Seahorse assays showed that isolated retina from intravitreal rhRBP3 treated rats exhibited reduced glycolysis rate in ECAR while anti-VEGF treatments had no effects. Conclusions: Both intravitreal anti-VEGF and RBP3 treatments normalized retinal vascular dysfunctions caused by diabetes. However, only RBP3 reversed abnormal neural-retinal dysfunctions and elevated inflammatory cytokines induced by hyperglycemia, possible by decreasing glucose uptake and glycolysis levels in retinal cells. Disclosure Q.Li: None. S.Onizuka: None. K.Park: None. H.Park: None. Q.Li: None. W.Fickweiler: None. J.Fu: None. I.Wu: None. G.L.King: Advisory Panel; Medtronic, Research Support; Janssen Pharmaceuticals, Inc.

Although inflammatory cytokines and vascular endothelial growth factor (VEGF) have been proposed to underlie the progression of diabetic retinopathy (DR) , there remains an important need to identify biomarkers for early stages of DR. Findings from the Joslin Medalist Study, composed of individuals who have had insulin-dependent diabetes for 50 years or longer, showed that Retinol Binding Protein 3 (RBP3) was significantly higher both in retina and vitreous samples with no to mild DR compared to those with proliferative DR (PDR) . In this study, we examined vitreous and plasma samples from 2people with type 1 and type 2 diabetes from the Joslin Beetham Eye Institute and Medalist Study to evaluate the relationship between vitreous RBP3, inflammatory cytokines, and DR severity and progression. PDR was associated with lower levels of IL- (P=0.007) , IFN-γ (P=0.001) , and higher levels of IL-15 (P=0.01) and IL-6 (P=0.02) in vitreous. Vitreous VEGF was positively associated with increasing DR severity in surgical samples (P Disclosure W.Fickweiler: None. J.D.Cavallerano: None. L.P.Aiello: Consultant; KalVista Pharmaceuticals, Inc., Novo Nordisk, Stock/Shareholder; KalVista Pharmaceuticals, Inc. J.Sun: Consultant; American Diabetes Association, American Medical Association, Research Support; Adaptive Sensory Technology, Boehringer Ingelheim International GmbH, Genentech, Inc., Jaeb Center for Health Research, Janssen Pharmaceuticals, Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk, Optovue, Incorporated, Physical Sciences, Inc, Roche Pharmaceuticals. G.L.King: Advisory Panel; Medtronic, Research Support; Janssen Pharmaceuticals, Inc. H.Park: None. K.Park: None. M.G.Mitzner: None. D.B.Robinson: None. T.Chokshi: None. T.Boumenna: None. J.Gauthier: None. I.Wu: None. Funding American Diabetes Association (7-21-PDF-022) ; National Eye Institute (R01EYE26080-01) , the National Institute of Diabetes and Digestive and Kidney Diseases and National Institutes of Health (DP3-DK-094333-01) ; JDRF (17-2013-310) ; the Dianne Nunnally Hoppes Fund; the Beatson Pledge Fund

This brief presents a readout IC with a 20 V high-voltage (HV) transmitter (Tx) and On-Chip Differentially Modulated Time-Interleaved Sensing Method (DM-TISM) in a BCD process for a mutual-capacitive Transparent Fingerprint Sensor (TFPS) in order to achieve high SNR, AC & DC offset reduction, high noise immunity, and compensate for the signal loss under thick cover glass. A proposed readout IC with on-chip DM-TISM is composed of 42 identical HV Tx channels, 32 identical Rx channels, and a diamond-patterned TFPS. The performance results including those for transient noise show that the DM-TISM achieves greater SNR than conventional TISM. The measured raw data show that the proposed readout IC achieves SNR of 32 dB with current consumption of 25 mA for the Tx and 13 mA for the Rx. It can be applied to any type of mobile device that needs fingerprint recognition. The ICs for the Tx and Rx are fabricated using 0.25- $\mu \text{m}$ BCD process and 0.18- $\mu \text{m}$ CMOS process with $1.6\,\,\mathrm {mm} \times 3.5$ mm and $2.5\,\,\mathrm {mm} \times 2.5$ mm areas, respectively.

Hyperglycemia has been evaluated extensively as risk factors for cardiovascular disease (CVD) in people with type 1 diabetes (T1DM). However, the effects of the autoantibody on atherosclerosis and immunogenic trigger are not well understood in T1D. Using the generated several mice models of atherosclerosis including NOD, congenic ApoE-/-/NOD (NDM and no- autoimmune), ApoE-/-/NOD (autoimmunity with insulitis, NDM) and ApoE-/-/NOD autoimmune DM mice, we analyzed immune cells composition of aorta and have observed the increasing numbers of CD3+(CD3+/CD25-), Th1 and Th17 subset of T cells and B cells and decreased Treg (CD3+/CD25+/Foxp3+) in the ApoE-/-/NOD and ApoE-/-/NOD-DM mice vs. control. In addition, we postulate that the identification of specific autoantibody(s) which induce dysregulaton of T-cells, resulting in enhancing its infiltration and accumulation at the plaques could aid new immunotherapies for atherosclerosis. Here we performed autoantigen microarrays to profile and identify specific autoantibodies, enhancing the severe atherosclerosis in subgroups of Medalist patients with chronic duration of T1D due to autoimmunity with positive HLA DR3/4 risk alleles and autoantibodies and compared to the people with monogenic diabetes lacking HLA DR3/4 risk alleles for T1D and autoantibodies. Autoantigen microarrays from the plasma of T1D patients with positive DR3/4 risk and CVD identified 8 autoantibodies changed in the context of atherosclerosis, compared to the people with monogenic diabetes. To confirm the autoantibody profiling data from the patients, we analyzed the autoantibody profiles in the T1D mice models of atherosclerosis described above. Autoantigen microarrays analysis of the plasma of T1D patients and mice showed several common findings that reached significance anti-Nucleolin Ab, p=0.005. These findings indicate autoimmunity may contribute to the progression of atherosclerosis in T1D. Further studies are in progress to replicate these findings in other cohorts of T1D. Disclosure K. Park: None. Q. Li: None. H. Park: None. J. Fu: None. S. Kissler: None. E. Maddaloni: Research Support; Self; European Foundation for the Study of Diabetes, Speaker's Bureau; Self; Abbott, AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes, Merck KGaA. I. Wu: None. A. H. Lichtman: None. G. L. King: Consultant; Self; Agios, Inc., Medtronic, Other Relationship; Self; Janssen Pharmaceuticals, Inc. Funding DK036836, DK036836, EY026080

Risks of unstable arterial plaques are increased in diabetes or insulin resistance. We hypothesized that insulin resistance in VSMCs contributes to reduced plaque stability since we have reported that insulin receptors (IR) on VSMCs are potent regulators of its proliferation and apoptosis. Further, insulin induced Akt phosphorylation was decreased in the aorta of diabetic mice. Lipid deposition were increased in the aortas of ApoE-/- and VSMCs IR double knockout (SMIRKO/ApoE-/-) mice vs. control mice. Pathological analysis of the atherosclerotic plaques of SMIRKO/ApoE-/- mice demonstrated features of unstable plaques, including reduced VSMCs proliferation and reduced cap thickness and collagen, but increased VSMCs apoptosis and more macrophages and necrosis area. VSMCs from SMIRKO/ApoE-/- mice exhibited less insulin induced proliferation and more apoptosis which were not inhibited by insulin compared to VSMCs from ApoE-/- mice. Artery relaxation induced by sodium nitroprusside (SNP) (NO donor) was impaired in artery from SMIRKO/ApoE-/- mice vs. control mice. Insulin and SNP induced VASP phosphorylation, a downstream signaling protein of NO in VSMCs, were reduced in SMIRKO/ApoE-/- mice vs. control mice. Expressions of MMP2, THBS1, sFRP3, and COMP were increased in the aorta of SMIRKO/ApoE-/- mice vs. ApoE-/- mice, which were also observed in the aorta of diabetic mice fed with high fat diet or diabetes induced by STZ. Insulin induced Akt and Foxo1 phosphorylation were impaired in cultured VSMCs from SMIRKO/ApoE-/- mice vs. control mice. Overexpression of constitutively activated Akt increased VASP phosphorylation and downregulated THBS1 expression in cultured VSMCs, whereas overexpression of FoxO1 increased THBS1 expression. This is the first report that selective inhibition of IR activation of pAkt in VSMCs is partially causing the elevated risk of unstable atherosclerotic plaques found in insulin resistance or diabetes. Disclosure Q. Li: None. J. Fu: None. K. Park: None. I. Wu: None. G. L. King: Consultant; Self; Agios, Inc., Medtronic, Other Relationship; Self; Janssen Pharmaceuticals, Inc. Funding National Institutes of Health (R01DK053105)

Diabetic nephropathy (DN) is the result of abnormal systemic and local changes in metabolism and hemodynamics. We have reported that many glycolytic enzymes, such as pyruvate kinase M2 (PKM2), were elevated in the renal glomeruli of type 1 and type 2 diabetic patients who were protected from DN. TEPP46, a small-molecule which activates PKM2 by inducing oligomerization, reversed glomerular pathology in diabetic mice. After 7 months of STZ induced diabetes, mice with PKM2 specific overexpression in podocytes (PPKM2Tg) with podocin promoter, exhibited lower albumin-creatinine ratio (ACR), kidney-body weight ratio, mesangial expansion, basement membrane thickness and podocyte foot process effacement vs. WT diabetic littermates. PPKM2Tg mice exhibited lower expression of fibrotic (FN, TGFβ1 and Col4a) and oxidative stress (p47phox, NOX2 and NOX4) genes and improvement in endothelial function with increased eNOS and VEGF expressions in the glomeruli, compared to diabetic WT mice. Glycolytic and mitochondrial metabolisms as measured by oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) using Seahorse showed striking improvement of impaired mitochondrial maximal respiration capacity and glycolytic rate in isolated glomeruli of diabetic PPKM2Tg mice, in concordance with elevated expressions of mitochondrial related-genes, such as PGC1α. Knocking-down PKM by shRNA in podocyte cell line (pPKMKD) replicated metabolic findings induced by diabetes with dramatic decline of both OCR and glycolytic rate. Re-expressing human PKM1 or PKM2 in pPKMKD cell line reversed impaired mitochondrial function and glycolysis, which were not improved in pPKMKD cells re-expressing with enzymatically inactive human PKM2 gene. These results indicate that PKM2 and its enzymatical function are both necessary in podocytes to improve glomerular mitochondrial abnormalities and delay the progression of DN. Disclosure J. Fu: None. G. L. King: Consultant; Self; Agios, Inc., Medtronic, Other Relationship; Self; Janssen Pharmaceuticals, Inc. T. Shinjo: None. Q. Li: None. R. St-louis: None. K. Park: None. H. Yokomizo: None. M. Yu: None. H. Shah: None. I. Wu: None. Funding Iacocca Family Foundation

Retinol Binding Protein 3 (RBP3), a retinol transport protein secreted mainly by photoreceptors, may inhibit progression of diabetic retinopathy (DR) by decreasing glucose uptake and inflammation in the retina. In people with type 1 diabetes with duration of ≥50yrs (Joslin Medalist Study), >40% of Medalists exhibited no to mild non-proliferative diabetic retinopathy (NPDR) and increased expression of RBP3 compared to those with severe DR. We examined 213 vitreous samples from a larger population of Medalists and patients with type 1 and type 2 diabetes with shorter diabetes duration (mean±SD 26.5±12.7 years) from the Joslin Beetham Eye Institute to determine whether vitreous RBP3 levels are correlated with DR severity and progression in a broad population with diabetes. RBP3 was increased in vitreous from people with no diabetes compared to subjects with type 1 and type 2 diabetes (p Disclosure W. Fickweiler: None. G. L. King: Consultant; Self; Agios, Inc., Medtronic, Other Relationship; Self; Janssen Pharmaceuticals, Inc. H. Park: None. K. Park: None. T. Boumenna: None. J. Gauthier: None. I. Wu: None. J. D. Cavallerano: None. L. P. Aiello: Consultant; Self; KalVista Pharmaceuticals, Novo Nordisk, Regeneron Pharmaceuticals Inc., Stock/Shareholder; Self; KalVista Pharmaceuticals. J. Sun: Other Relationship; Self; Novo Nordisk, Roche Pharma, Research Support; Self; Adaptive Sensory Technology, Boehringer Ingelheim Pharmaceuticals, Inc., KalVista Pharmaceuticals, Optovue, Roche Pharma. Funding National Eye Institute (R01EY026080-01); National Institute of Diabetes and Digestive and Kidney Diseases (DP3DK094333-01); JDRF (17-2013-310); Beatson Foundation; Dianne Nunnally Hoppes Fund

OBJECTIVE Elevated glycolytic enzymes in renal glomeruli correlated with preservation of renal function in the Medalist Study, individuals with ≥50 years of type 1 diabetes. Specifically, pyruvate kinase M2 (PKM2) activation protected insulin-deficient diabetic mice from hyperglycemia-induced glomerular pathology. This study aims to extend these findings in a separate cohort of individuals with type 1 and type 2 diabetes and discover new circulatory biomarkers for renal protection through proteomics and metabolomics of Medalists’ plasma. We hypothesize that increased glycolytic flux and improved mitochondrial biogenesis will halt the progression of diabetic nephropathy. RESEARCH DESIGN AND METHODS Immunoblots analyzed selected glycolytic and mitochondrial enzymes in postmortem glomeruli of non-Medalists with type 1 diabetes (n = 15), type 2 diabetes (n = 19), and no diabetes (n = 5). Plasma proteomic (SOMAscan) (n = 180) and metabolomic screens (n = 214) of Medalists with and without stage 3b chronic kidney disease (CKD) were conducted and significant markers validated by ELISA. RESULTS Glycolytic (PKM1, PKM2, and ENO1) and mitochondrial (MTCO2) enzymes were significantly elevated in glomeruli of CKD− versus CKD+ individuals with type 2 diabetes. Medalists’ plasma PKM2 correlated with estimated glomerular filtration rate (r2 = 0.077; P = 0.0002). Several glucose and mitochondrial enzymes in circulation were upregulated with corresponding downregulation of toxic metabolites in CKD-protected Medalists. Amyloid precursor protein was also significantly upregulated, tumor necrosis factor receptors downregulated, and both confirmed by ELISA. CONCLUSIONS Elevation of enzymes involved in the metabolism of intracellular free glucose and its metabolites in renal glomeruli is connected to preserving kidney function in both type 1 and type 2 diabetes. The renal profile of elevated glycolytic enzymes and reduced toxic glucose metabolites is reflected in the circulation, supporting their use as biomarkers for endogenous renal protective factors in people with diabetes.

Background Insulin has been demonstrated to exert direct and indirect effects on vascular tissues. Its actions in vascular cells are mediated by two major pathways: the insulin receptor substrate 1/2-phosphoinositide-3 kinase/Akt (IRS1/2/PI3K/Akt) pathway and the Src/mitogen-activated protein kinase (MAPK) pathway, both of which contribute to the expression and distribution of metabolites, hormones, and cytokines. Scope of review In this review, we summarize the current understanding of insulin's physiological and pathophysiological actions and associated signaling pathways in vascular cells, mainly in endothelial cells (EC) and vascular smooth muscle cells (VSMC), and how these processes lead to selective insulin resistance. We also describe insulin's potential new signaling and biological effects derived from animal studies and cultured capillary and arterial EC, VSMC, and pericytes. We will not provide a detailed discussion of insulin's effects on the myocardium, insulin's structure, or its signaling pathways' various steps, since other articles in this issue discuss these areas in depth. Major conclusions Insulin mediates many important functions on vascular cells via its receptors and signaling cascades. Its direct actions on EC and VSMC are important for transporting and communicating nutrients, cytokines, hormones, and other signaling molecules. These vascular actions are also important for regulating systemic fuel metabolism and energetics. Inhibiting or enhancing these pathways leads to selective insulin resistance, exacerbating the development of endothelial dysfunction, atherosclerosis, restenosis, poor wound healing, and even myocardial dysfunction. Targeted therapies to improve selective insulin resistance in EC and VSMC are thus needed to specifically mitigate these pathological processes., Highlights • Insulin's actions in vascular cells have a significant influence on systemic metabolism. • Insulin exerts its vascular effects through its receptors and signaling cascades. • Inhibition or enhancement of different insulin signaling leads to selective insulin resistance. • Loss of insulin's actions causes endothelial dysfunction and vascular complications in diabetes.

A growing body of evidence suggests a potential link between bone metabolism and cardiovascular disease. Aim of this study was to investigate the relationship between levels of circulating bone turnover biomarkers and advanced atherosclerosis. Klotho (KL), sclerostin (SOST), osteopontin (OPN) and osteoprotegerin (OPG) were measured in patients undergoing elective coronary angiography and carotid Doppler ultrasound. The primary outcome was the difference in bone biomarkers levels between participants with and without advanced atherosclerosis, defined as the presence of a critical coronary (≥70%) and/or carotid (≥50%) stenosis. A total of 80 subjects (32.5% females) with a mean age of 68 ± 10 years were included. Advanced atherosclerosis was detected in 55 (68.8%) patients. Subjects with advanced atherosclerosis showed higher serum levels of OPG (p = 0.0015) and SOST (p = 0.017) and similar levels of KL (p = 0.62) and OPN (p = 0.06) compared to patients without. After adjustment for age and sex, only elevated levels of OPG remained significantly associated with advanced atherosclerosis (p = 0.011). Higher serum levels of OPG are independently associated with advanced atherosclerosis confirming a common bond between bone metabolism and vascular disease. Further investigations on the role of selected bone biomarkers in the pathogenesis of cardiovascular disease are needed.

A chromosome 1q25 variant (rs10911021) has been associated with coronary heart disease (CHD) in type 2 diabetes (T2D). In human umbilical vein endothelial cells (HUVECs), the risk allele ‘C’ is associated with lower expression of the adjacent gene GLUL encoding glutamine synthase, converting glutamic acid to glutamine. To further investigate the mechanisms through which this locus affects CHD risk, we measured 35 intracellular metabolites involved in glutamic acid metabolism and g-glutamyl cycle in 62 HUVEC strains carrying different rs10911021 genotypes. Eight metabolites were positively associated with the risk allele (17%-58% increase/allele copy, p=0.046-0.002), including five g-glutamyl amino acids, b-citryl-glutamate, N-acetyl-aspartyl-glutamate, and ophthalmate - a marker of g-glutamyl cycle malfunction. Consistent with these findings, the risk allele was also associated with decreased glutathione/glutamate ratio (-9%, p=0.012), decreased S-lactoylglutathione (-41%, p=0.019), and reduced detoxification of the atherogenic compound methylglyoxal (+54%, p=0.008). GLUL down-regulation by shRNA caused a 40% increase in methylglyoxal level, which was completely prevented by glutamine supplementation. In summary, we have identified intracellular metabolic traits associated with the 1q25 risk allele in HUVECs, including impairments of the g-glutamyl cycle and methylglyoxal detoxification. Glutamine supplementation abolishes the latter abnormality, suggesting that such treatment may prevent CHD in 1q25 risk allele carriers.

The Joslin Medalist Study, which characterizes people with type 1 diabetes duration of 50 years or more, reported that the levels of Retinol Binding Protein 3 (RBP3) are increased in the retina and vitreous of Medalists who are protected from the development of severe diabetic retinopathy (DR). This protective capacity of RBP3 is potentially mediated by its ability to delay the uptake of glucose into the cells of the retinal vasculature and neural retina in hyperglycemia. This study correlated the relationship between DR severity and neural retinal layer thickness with vitreous and serum RBP3 levels in a broad population of people with diabetes. Optical coherence tomography (OCT) was performed to obtain neural retinal layer thicknesses and structure. Specific ELISA assays were developed to measure vitreous and serum RBP3 concentrations in individuals with type 1 and type 2 diabetes recruited from the Joslin Beetham Eye Institute, Medalist Study, and the FinnDiane study. Vitreous RBP3 concentration was associated with DR severity (p Disclosure W. Fickweiler: None. K. Park: None. E. Wolfson: None. H. Park: None. H. Yokomizo: None. I. Wu: None. D. Gordin: Consultant; Self; GE Healthcare. Speaker’s Bureau; Self; AstraZeneca, Fresenius Medical Care, Novo Nordisk A/S. Other Relationship; Self; CVRx, Sanofi-Aventis. V. Harjutsalo: None. P. Groop: Advisory Panel; Self; Boehringer Ingelheim International GmbH, Sanofi, Sanofi. Speaker’s Bureau; Self; Astellas Pharma Inc., AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Medscape, Merck Sharp & Dohme Corp., Mundipharma International. L.P. Aiello: Advisory Panel; Self; Novo Nordisk Inc. Consultant; Self; KalVista Pharmaceuticals, Inc., Novo Nordisk Inc. Stock/Shareholder; Self; KalVista Pharmaceuticals, Inc. Other Relationship; Self; Optos. J. Sun: Research Support; Self; Adaptive Sensory Technology, Boehringer Ingelheim Pharmaceuticals, Inc., KalVista Pharmaceuticals, Inc., Novo Nordisk Inc., Optovue, Inc., Roche Pharma. Other Relationship; Self; Merck Foundation, Novartis Pharmaceuticals Corporation, Novo Nordisk Inc., Roche Pharma. G.L. King: Research Support; Self; Janssen Pharmaceuticals, Inc. Funding National Eye Institute (R01EY026080-01); National Institute of Diabetes and Digestive and Kidney Diseases (DP3DK094333-01); JDRF (17-2013-310); Thomas J. Beatson, Jr. Foundation; Dianne Nunnally Hoppes Scholarship Fund

Vascular smooth muscle cells (VSMCs) play an important role in the development of the stability of atherosclerotic plaque. We reported that knockout of insulin receptor (IR), but not IGF1 receptor, in VSMCs reduced intimal hyperplasia of femoral artery after wire injury. To investigate the role of IR in VSMCs on atherosclerotic plaque, ApoE and smooth muscle cells IR double knockout (SMIRKO/ApoE-/-) mice were generated. Extent of lipid deposition and atherosclerosis were increased in the aorta of SMIRKO/ApoE-/- mice compared to control mice (p Disclosure Q. Li: None. J. Fu: None. K. Park: None. Y. Zaitsu: Employee; Self; Sunstar Group. R. St-Louis: None. C. Rask-Madsen: None. G.L. King: Research Support; Self; Janssen Pharmaceuticals, Inc. Funding National Institutes of Health (R01DK053105)

Clinical studies have suggested that loss of insulin’s action and excessive IGF-1 levels in the glomeruli elevate the risk for diabetic kidney disease (DKD). To define the potential pathogenic role of IGF-1 and insulin signaling in DKD, we generated mice with selective loss of insulin receptor (IR) or IGF-1 receptor (IGF-1R) in the mesangial cells (MCs) by cross breeding IRflox/flox mice with Sm22α-Cre mice (SMIRKO) or IGF-1Rflox/flox mice with Myh11-Cre mice (SMIGF1RKO), and examined urinary albumin excretion (ACR) and mesangial expansion with 6 month duration of streptozotocin (STZ)-induced diabetes. IGF-1 levels were significantly increased by 1.5 fold in the renal cortex, but not in the plasma of all three types of diabetic mice. Diabetes induced elevation of ACR (2.0 fold), glomerular size and mesangial expansion (2.1 fold), in parallel with increased glomerular expressions of fibrosis-related (Tgfβ1, fibronectin and Col3a) and matrix (Has2) genes by 2-3 fold, significantly, in Wt and SMIRKO mice, but were prevented in diabetic SMIGF1RKO mice. In cultured MCs, IGF-1, at physiological levels, and insulin, only at supra-physiological levels, induced the expressions of Has2 (3.8 fold) and Tgfβ1 (1.7 fold). Deletion of IGF-1R, but not IR, in MCs inhibited both IGF-1 and insulin-induced expressions of Has2. Inhibitor of MAP kinase pathway, but not inhibitor of PI3 kinase reduced insulin or IGF-1-induced expressions of Has2 in MCs. IGF-1-induced phosphorylations of IGF-1R (39 fold), Akt (34 fold) and Erk/MAPK (8 fold) were significantly inhibited in both IR or IGF-1R-deleted MCs. Insulin-induced phosphorylations of IR-β (11 fold) and Akt (27 fold) were also decreased in IR-deleted MCs, but surprisingly increased in IGF-1R-deleted MCs. Thus, MAPK activation by elevated glomerular IGF-1 levels via IGF-1R, but not IR, on MCs, may contribute to the pathogenesis of DKD through induction of Has2 and fibrotic genes. Disclosure A. Ishikado: Employee; Self; Sunstar Group. Employee; Spouse/Partner; Sunstar Group. T. Shinjo: None. H. Yokomizo: None. Y. Maeda: None. K. Park: None. W. Qi: None. R. St-Louis: None. Q. Li: None. G.L. King: Research Support; Self; Janssen Pharmaceuticals, Inc.

Increased white rice (WR) with parallel decreased brown rice (BR) consumption has been associated with increased prevalence of type 2 diabetes (T2DM). To test whether WR and BR have differential effects on energy and glucose metabolism, C57BL/6 mice were fed 6 different diets: control diet (CD, 10% Fat), high-fat diet (HFD, 46% Fat) with either no rice, WR or BR. BR and, surprisingly, WR activated PGC1α and UCP-1 expressions in brown adipose tissue (BAT) and increased energy expenditure as measured by oxygen consumption, CO2 release and heat production, resulting in reduced body weight (36%, 23%) and improvements of glucose tolerance and insulin sensitivity while on HFD after 18 weeks. To investigate the underlying mechanism, gut microbial analysis was performed. Gut microbiota composition showed clear differences between HFD vs. CD or vs. the addition of BR or WR. Ratio of Firmicutes to Bacteroidetes was 3.7-fold increased in HFD vs.CD, but decreased by the WR (46%) or BR (59%). Increased alpha diversity was observed by WR and BR on HFD. Heat map binary showed that several genera are different in HFD+BR vs. HFD or HFD+WR vs. HFD. Analysis of family abundance revealed that Lachnospiraceae, Ruminococcaceae and Streptococcaceae are 2.5, 1.2 and 2.6-fold increased in HFD, which were reduced by WR or BR. Analysis of genus abundance showed that Lactococcus, Dorea, Peptococcus, Clostridium XIVb, Johnsonella, Anaerovorax are 2.6, 3.7, 2.9, 2.7, 4.7 and 1.7-fold respectively, increased in HFD, which were reduced by WR or BR on HFD. In addition, mice on BR+HFD showed greater reductions than mice on WR+HFD in family and genus levels. Our results demonstrated that supplementation with BR or WR, to a lesser degree, changed HFD-induced gut microbial composition at family and genus levels, in parallel with improved systemic energy and glucose metabolism via activation of BAT and increased energy expenditure, resulting in reduced body weight and improved insulin sensitivity. Disclosure H. Yokomizo: None. A. Ishikado: Employee; Self; Sunstar Group. Employee; Spouse/Partner; Sunstar Group. T. Shinjo: None. K. Park: None. Y. Maeda: None. Q. Li: None. I. Wu: None. M. Matsumoto: Employee; Self; Sunstar Group. S. Devkota: None. A. Kostic: None. G.L. King: Research Support; Self; Janssen Pharmaceuticals, Inc.

Mitochondrial abnormalities induced by diabetes have been postulated to cause several complications including nephropathy. Elevated expressions of enzymes for glycolysis and mitochondrial functions in the glomeruli have been associated with protection against the development of diabetic nephropathy of chronic duration. Activation of a glycolytic enzyme, pyruvate kinase M2 (PKM2), by a small molecule selective activator (TEPP-46) or its targeted overexpression to the podocytes in mice reversed glomerular mitochondrial dysfunction and pathology in insulin deficient diabetic mice. However, the effects of PKM2 activation to stop glomerular dysfunction and pathology have not been studied in animal models of type 2 diabetes (T2D). Thus, we studied the effect of activating glycolysis and mitochondrial metabolism with PKM2 activator, TEPP-46, in db/db mice (with obesity and hyperglycemia) and BLKS mice on regular diet (RD) or high fat diet (HFD). HFD feeding induced obesity in BLKS but did not cause changes in glomerular PKM activities or functions as measured by urinary albumin to creatinine ratio (ACR). Oral feeding with TEPP-46 did not affect body weight (BW), glucose tolerance, lipids, ACR, glomerular pathology in BLKS mice on RD or HFD. In contrast, db/db mice on RD had elevated BW and hyperglycemia that were significantly increased by HFD, which also induced loss of glomerular PKM2 protein expression and activities, elevations of gene expression for fibrosis (fibronectin, TGF-b), mesangial expansion and ACR after 3 months. Intervention with oral TEPP-46 treatment for 3 months, but not 1 month, after 3 months of diabetes and HFD, (total of 6 months of diabetes), improved significantly both glomerular PK activities and ACR, without lowering hyperglycemia and hyperlipidemia of the db/db mice. These findings support the idea that systemic activation of PKM2 can improve renal functions in both T1D and T2D. Disclosure R. St-Louis: None. J. Fu: None. K. Park: None. T. Shinjo: None. J. Ludeke: None. H. Yokomizo: None. Q. Li: None. E. Wolfson: None. G.L. King: Research Support; Self; Janssen Pharmaceuticals, Inc.

Diabetic nephropathy (DN) is the result of systemic and local changes in metabolism and hemodynamics. We have found that the elevation of glycolytic enzymes, such as pyruvate kinase M2 (PKM2) in the renal glomeruli is correlated with preservation of renal function in human type 1 and type 2 diabetes. A small-molecule PKM2 activator, TEPP46, prevented or reversed glomerular pathology in diabetic mice of chronic duration. Mice with PKM2 overexpression specifically in podocytes (PPKM2Tg) were generated, which after 7 months of diabetes induced by streptozotocin, exhibited significantly lower albumin-creatinine ratio (ACR), kidney weight-body weight ratio, and glomeruli pathology such as reduced glomeruli size, mesangial expansion, and basement membrane thickness compared to diabetic WT mice. Furthermore, the glomeruli of diabetic PPKM2Tg mice exhibited lower expressions of fibrotic (FN, TGFβ1 and Col4a) and oxidative stress (p47phox, NOX2 and NOX4) genes compared to WT diabetic mice. Interestingly, the decreased expression of endothelial-trophic genes and mitochondrial-related genes were improved in the whole glomeruli of diabetic PPKM2Tg mice. Oxygen consumption rate (OCR) of glomeruli as measured by Seahorse showed significant improvement in diabetic PPKM2Tg mice versus WT mice (p < 0.05). In vitro studies showed that the activation of PKM2 in mouse podocyte cell line by TEPP-46 decreased high glucose-induced ROS production, improved mitochondrial membrane potential (MMP) by increased the level of mitochondrial OCR and enhanced glycolytic rate. Furthermore, PKM-knockdown stable podocyte cell line, mimicking diabetic conditions, showed dramatical decline of OCR and glycolytic rate. These results showed that PKM2 specific overexpression in podocytes can significantly reduce diabetes-induced mitochondrial abnormalities and oxidative stress in the whole glomeruli, and delay the progression of diabetic nephropathy. Disclosure J. Fu: None. T. Shinjo: None. R. St-Louis: None. Q. Li: None. K. Park: None. H. Yokomizo: None. Y. Zaitsu: Employee; Self; Sunstar Group. M. Yu: None. I. Wu: None. H. Shah: None. G.L. King: Research Support; Self; Janssen Pharmaceuticals, Inc.

Hyperglycemia, hyperlipidemia and hypertension have been evaluated extensively as risk factors for cardiovascular disease (CVD) in people with type 1 diabetes (T1DM). However, the impact of autoimmunity in T1DM on CVD has not been determined. We have generated several mice models of atherosclerosis including ApoE-/-/NOD, ApoE-/-/NOD (congenic non diabetes and non-autoimmune), ApoE-/-/NOD (autoimmunity with insulitis, nondiabetes) and ApoE-/-/NOD autoimmune diabetic mice. All groups of mice have high plasma lipids but only ApoE-/-/NOD diabetic mice had hyperglycemia. However, ApoE-/-/NOD (insulitis and nondiabetes) and ApoE-/-/NOD (insulitis and diabetes) had high titers of autoantibodies to IA2 compared to control CongApoE-/-/NOD mice or nondiabetic ApoE-/-/NOD mice (P Disclosure K. Park: None. Q. Li: None. H. Park: None. R. St-Louis: None. J. Fu: None. C. Rask-Madsen: None. E. Maddaloni: Consultant; Self; Merck KGaA. Speaker’s Bureau; Self; Abbott, AstraZeneca, Pikdare. H. Yokomizo: None. S. Kissler: None. A.H. Lichtman: None. G.L. King: Research Support; Self; Janssen Pharmaceuticals, Inc. Funding National Institutes of Health (R01DK053105); Thomas J. Beatson, Jr. Foundation

Novel markers of vascular disease in diabetes could help identify new disease pathways and enhance risk stratification. Osteoprotegerin (OPG) and osteopontin (OPN) are key molecules involved in bone and vascular calcification processes, both compromised in diabetes. To evaluate whether OPG and/or OPN are associated with diabetic vascular complications, we measured their serum concentrations in 995 type 2 diabetes subjects enrolled in the Sapienza University Mortality and Morbidity Event Rate (SUMMER) Study. Any association with history of cardiovascular disease (CVD), diabetic retinopathy (DR) and reduced eGFR were examined with ANOVA, correcting for age, gender, HbA1c and lipid profile. Among the population, 15.7% had CVD, 18.4% had DR, 12.0% had an eGFR between 45-59 ml/min/1.73m2 and 7.5% had an eGFR Disclosure E. Maddaloni: Consultant; Self; Merck KGaA. Speaker’s Bureau; Self; Abbott, AstraZeneca, Pikdare. K. Park: None. M. Di Guida: None. L. Coraggio: None. C. Luordi: None. L. D’Onofrio: None. M.G. Baroni: None. M.G. Cavallo: None. P. D’Angelo: None. S. De Cosmo: None. F. Leonetti: None. S. Morano: None. L. Morviducci: None. P. Pozzilli: Advisory Panel; Self; Abbott, AstraZeneca, Eli Lilly and Company. Research Support; Self; Medtronic, Sanofi. S. Prudente: None. G. Pugliese: Advisory Panel; Self; Novo Nordisk A/S. Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Merck Sharp & Dohme Corp., Mundipharma International, Sanofi-Aventis, Sigma-tau, Takeda Pharmaceutical Company Limited. Other Relationship; Self; Laboratori Guidotti. V. Trischitta: None. R.R. Holman: Advisory Panel; Self; Merck Sharp & Dohme Corp., Novartis AG, Novo Nordisk A/S. Research Support; Self; AstraZeneca, Bayer AG, Merck Sharp & Dohme Corp. G.L. King: Research Support; Self; Janssen Pharmaceuticals, Inc. R. Buzzetti: Advisory Panel; Self; Sanofi. Speaker’s Bureau; Self; AstraZeneca, Lilly Diabetes, Merck Sharp & Dohme Corp. Funding European Foundation for the Study of Diabetes; AstraZeneca (MS 2017_2); Società Italiana di Diabetologia

A chromosome 1q25 variant (rs10911021) has been associated with coronary heart disease (CHD) in type 2 diabetes. In human umbilical vein endothelial cells (HUVECs), the risk allele “C” is associated with lower expression of the adjacent gene GLUL encoding glutamine synthase, converting glutamic acid to glutamine. To further investigate the mechanisms through which this locus affects CHD risk, we measured 35 intracellular metabolites involved in glutamic acid metabolism and the γ-glutamyl cycle in 62 HUVEC strains carrying different rs10911021 genotypes. Eight metabolites were positively associated with the risk allele (17–58% increase/allele copy, P = 0.046–0.002), including five γ-glutamyl amino acids, β-citryl-glutamate, N-acetyl-aspartyl-glutamate, and ophthalmate—a marker of γ-glutamyl cycle malfunction. Consistent with these findings, the risk allele was also associated with decreased glutathione-to-glutamate ratio (−9%, P = 0.012), decreased S-lactoylglutathione (−41%, P = 0.019), and reduced detoxification of the atherogenic compound methylglyoxal (+54%, P = 0.008). GLUL downregulation by shRNA caused a 40% increase in the methylglyoxal level, which was completely prevented by glutamine supplementation. In summary, we have identified intracellular metabolic traits associated with the 1q25 risk allele in HUVECs, including impairments of the γ-glutamyl cycle and methylglyoxal detoxification. Glutamine supplementation abolishes the latter abnormality, suggesting that such treatment may prevent CHD in 1q25 risk allele carriers.

Pigment epithelium-derived factor (PEDF) expression is down- regulated in the kidneys of diabetic rats and delivery of PEDF suppressed renal fibrotic factors in these animals. PEDF has multiple functions including anti-angiogenic, anti-inflammatory and anti-fibrotic activities. Since the mechanism underlying its anti-fibrotic effect remains unclear, we studied this in several murine models of renal disease. Renal PEDF levels were significantly reduced in genetic models of type 1 and type 2 diabetes (Akita and db/db, respectively), negatively correlating with Wnt signaling activity in the kidneys. In unilateral ureteral obstruction, an acute renal injury model, there were significant decreases of renal PEDF levels. The kidneys of PEDF knock-out mice with ureteral obstruction displayed exacerbated expression of fibrotic and inflammatory factors, oxidative stress, tubulointerstitial fibrosis and tubule epithelial cell apoptosis, compared to the kidneys of wild-type mice with obstruction. PEDF knock-out enhanced Wnt signaling activation induced by obstruction, while PEDF inhibited the Wnt pathway-mediated fibrosis in primary renal proximal tubule epithelial cells. Additionally, oxidative stress was aggravated in renal proximal tubule epithelial cells isolated from knock-out mice, and suppressed by PEDF treatment of renal proximal tubule epithelial cells. PEDF also reduced oxidation-induced apoptosis in renal proximal tubule epithelial cells. Thus, the renoprotective effects of PEDF are mediated, at least partially, by inhibition of the Wnt pathway. Hence, restoration of renal PEDF levels may have therapeutic potential for renal fibrosis.

Insulin and IGF-1 actions in vascular smooth muscle cells (VSMC) are associated with accelerated arterial intima hyperplasia and restenosis after angioplasty, especially in diabetes. To distinguish their relative roles, we delete insulin receptor (SMIRKO) or IGF-1 receptor (SMIGF1RKO) in VSMC and in mice. Here we report that intima hyperplasia is attenuated in SMIRKO mice, but not in SMIGF1RKO mice. In VSMC, deleting IGF1R increases homodimers of IR, enhances insulin binding, stimulates p-Akt and proliferation, but deleting IR decreases responses to insulin and IGF-1. Studies using chimeras of IR(extracellular domain)/IGF1R(intracellular-domain) or IGF1R(extracellular domain)/IR(intracellular-domain) demonstrate homodimer IRα enhances insulin binding and signaling which is inhibited by IGF1Rα. RNA-seq identifies hyaluronan synthase2 as a target of homo-IR, with its expression increases by IR activation in SMIGF1RKO mice and decreases in SMIRKO mice. Enhanced intima hyperplasia in diabetes is mainly due to insulin signaling via homo-IR, associated with increased Has2 expression., Both insulin and IGF-1 signaling have been implicated in arterial intimal hyperplasia. Here the authors dissect the relative contributions of insulin and IGF-1 receptors, showing that homodimers of insulin receptors, but not IGF-1 receptor, induce proliferation of vascular smooth muscle cells.

The Joslin Medalist Study characterized people affected with type 1 diabetes for 50 years or longer. More than 35% of these individuals exhibit no to mild diabetic retinopathy (DR), independent of glycemic control, suggesting the presence of endogenous protective factors against DR in a subpopulation of patients. Proteomic analysis of retina and vitreous identified retinol binding protein 3 (RBP3), a retinol transport protein secreted mainly by the photoreceptors, as elevated in Medalist patients protected from advanced DR. Mass spectrometry and protein expression analysis identified an inverse association between vitreous RBP3 concentration and DR severity. Intravitreal injection and photoreceptor-specific overexpression of RBP3 in rodents inhibited the detrimental effects of vascular endothelial growth factor (VEGF). Mechanistically, our results showed that recombinant RBP3 exerted the therapeutic effects by binding and inhibiting VEGF receptor tyrosine phosphorylation. In addition, by binding to glucose transporter 1 (GLUT1) and decreasing glucose uptake, RBP3 blocked the detrimental effects of hyperglycemia in inducing inflammatory cytokines in retinal endothelial and Müller cells. Elevated expression of photoreceptor-secreted RBP3 may have a role in protection against the progression of DR due to hyperglycemia by inhibiting glucose uptake via GLUT1 and decreasing the expression of inflammatory cytokines and VEGF.

A major cause of poor wound healing and periodontitis in diabetes is defective immune response to infections. Insulin signaling via the PI3K/Akt pathway is selectively inhibited in the gingival and wound fibroblasts of diabetic rodents and patients. To determine how loss of insulin actions in gingival fibroblasts can affect periodontitis development, myofibroblast insulin receptors (IR) were deleted by crossbreeding IRβ-flox/flox mice with SM22-Cre C57BL/6 (SMIRKO) mice, which were fed with regular diet (RD), while wild type (WT) littermates were fed with high-fat diet (HFD) for 10 weeks. To induce periodontitis, 7-0 silk ligatures were tied around maxillary molars for 4, 7 or 14 days. When mice were sacrificed to assess alveolar bone loss, immune cell populations and inflammatory cytokine expression in the gingiva was assessed. Gingival IRβ expression in SMIRKO and HFD-fed mice was decreased by 70% and 50%, respectively, with comparable reductions in insulin-induced (100nM) phosphorylation of Akt (pAkt). Ligature-induced alveolar bone loss in SMIRKO and HFD-fed mice was greater by 70% and 40%, respectively, as compared to RD-fed WT mice. Post-ligature time course analysis showed that while neutrophil recruitment was delayed significantly, macrophages and lymphocyte numbers were elevated in both SMIRKO and HFD-fed mice. Similarly, neutrophil-recruiting factors CXCL1 and 2 expression were decreased in the gingiva, whereas TNFα and IL-1β expression were elevated. Gingival myofibroblasts from SMIRKO and HFD-fed mice showed dramatic reductions of IRβ expression and insulin-induced pAkt with parallel lowering of E.coli LPS-induced CXCL1 expression via downregulation of TLR2, compared to RD-fed mice. These data provided the first evidence that insulin action is critical for neutrophil recruitment during infection by enabling CXCL1 expression in gingival myofibroblasts, which is inhibited in diabetes. Disclosure T. Shinjo: None. Q. Li: None. A. Ishikado: Employee; Self; SunStar Inc. Employee; Spouse/Partner; SunStar Inc. K. Park: None. R. St-Louis: None. H. Yokomizo: None. J. Fu: None. M. Yu: None. H. Wang: None. H. Hasturk: None. T.E. Van Dyke: None. G.L. King: Research Support; Self; Sanofi. Funding Sunstar Foundation; Iacocca Family Foundation

The Joslin 50-Year Medalist Study discovered that elevated photoreceptor-secreted Retinol Binding Protein 3 (RBP3) in the retina and vitreous of individuals with extreme duration of type 1 diabetes is associated with long-term protection from advanced diabetic retinopathy (DR), independent of glycemic control. This represents the first neuroretinal protein identified with potential protective activity against the toxic effects of hyperglycemia on the retinal vasculature, a major cause of DR onset and worsening. We extended these findings by correlating vitreous and serum RBP3 concentrations and examining associated clinical characteristics. We developed a novel RBP3 ELISA assay with high sensitivity (0.1-1 nM), specificity (no detection of immunoglobulin G, albumin, or RBP4), and intra-and inter-assay correlations (p Disclosure W. Fickweiler: None. H. Yokomizo: None. K. Park: None. S.M. Paniagua: None. I. Wu: None. D.M. Pober: None. V. Bahnam: None. A. Clermont: Consultant; Self; KalVista Pharmaceuticals, Inc. L.P. Aiello: Advisory Panel; Self; Novo Nordisk A/S. Consultant; Self; Decision Resources Group, KalVista Pharmaceuticals, Inc., Mingsight, Retinal Solutions. Stock/Shareholder; Self; KalVista Pharmaceuticals, Inc. Other Relationship; Self; Optos. J.K. Sun: Research Support; Self; Adaptive Sensory Technology, Boston Micromachines Corporation, Genentech, Inc., KalVista Pharmaceuticals, Inc., Optovue, Incorporated. Other Relationship; Self; Genentech, Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk Inc. G.L. King: Research Support; Self; Sanofi. Funding National Eye Institute (R01EY026080-01); National Institute of Diabetes and Digestive and Kidney Diseases (DP3DK094333-01); JDRF (17-2013-310); Thomas J. Beatson, Jr. Foundation Inc.; Dianne Nunnally Hoppes Scholarship Fund

A variant on chromosome 1q25 (rs10911021) has been previously associated with coronary artery disease (CAD) in individuals with T2D. In human umbilical vein endothelial cells (HUVECs), the 1q25 risk allele (‘C’) was found to be associated with decreased expression of the adjacent gene GLUL encoding the enzyme glutamine synthase converting glutamate to glutamine. To further investigate the mechanisms through which the 1q25 locus modulates CAD risk in T2D, we performed a global metabolomics study (LC-MS, Metabolon) in 62 HUVECs (TT=11, CT=21, CC=30). Among 597 metabolites detected in HUVEC lysates, 23 attained p In summary, we have identified several metabolic pathways potentially mediating the 1q25 locus effect on CAD risk in T2D. These include impairment of the γ-glutamyl cycle, possibly increasing susceptibility to oxidative stress, and downregulation of PUFA derivatives and sphingomyelins. Further studies of these pathways may lead to the identification of novel therapeutic targets to reduce CAD risk in T2D. Disclosure C. Pipino: None. H. Shah: None. K. Park: None. S. Monti: None. C. Mendonca: None. G.L. King: Research Support; Self; Sanofi. A. Pandolfi: None. A. Doria: Research Support; Self; Sanofi-Aventis. Funding Sanofi-Aventis

The Joslin Medalist study reported that after having type 1 diabetes (T1D) for > 50 years, over 35% of Medalists exhibit no to mild diabetic retinopathy (DR) independent of glycemic control, suggesting presence of endogenous protective factors against DR. Proteomic analysis of Medalist retina and vitreous found that Retinol Binding Protein 3 (RBP3), secreted by photoreceptors, is elevated in individuals protected from DR. This finding was confirmed by RBP3 ELISA of replicate vitreous samples from Medalists and other T1D and T2D individuals. In contrast, vitreous VEGF concentrations increased with DR severity. Thus, elevated ratios of intravitreous RBP3/VEGF correlated with lack of progression to advanced DR. Intervention and prevention studies overexpressing RBP3 in retina/photoreceptors of nondiabetic and diabetic animals inhibited VEGF actions and normalized diabetes-induced retinal capillary permeability, neuro-retinal dysfunctions, expressions of VEGF and IL-6, and formation of acellular capillaries. Mechanistically, physiological levels of recombinant RBP3 (10-100nM), but not RBP4 or FGF, inhibited the increased in VEGFR2 tyrosine phosphorylation, hyperglycemia-induced expression of pro-inflammatory cytokines (VEGF and IL-6), and migration of retinal endothelial cells and Müller cells. RBP3, but not RBP4, physically bound to VEGFR2 in cross linkage studies. At physiological levels, RBP3 significantly inhibited glucose uptake into retinal endothelial and Müller cells, and subsequently decreased expression of VEGF and IL-6. These results suggest novel actions for RBP3 to slow glucose uptake in retinal cells and inhibit VEGF actions, thereby preventing, delaying and even arresting diabetes-induced neuro- and vascular retinal dysfunction, inflammatory abnormalities and DR pathologies. These findings strongly support therapeutic potential of RBP3 in DR. Disclosure H. Yokomizo: None. K. Park: None. A. Clermont: Consultant; Self; KalVista Pharmaceuticals, Inc. Y. Maeda: Research Support; Self; Abbott, Arkray, Inc. Speaker's Bureau; Self; Abbott, Arkray, Inc., Astellas Pharma Inc., AstraZeneca, Daiichi Sankyo Company, Limited, Eli Lilly and Company, Kissei Pharmaceutical Co., Ltd., Kyowa Hakko Kirin Co., Ltd., Mitsubishi Tanabe Pharma Corporation, Novartis Pharmaceuticals Corporation, Novo Nordisk Inc., Sanofi, Sumitomo Dainippon Pharma Co., Ltd., Taisho Toyama Pharmaceutical Co., Ltd., Terumo Medical Corporation. W. Fickweiler: None. A. Ishikado: Employee; Self; SunStar Inc. Employee; Spouse/Partner; SunStar Inc. Q. Li: None. C. Wang: None. D.M. Pober: None. I. Wu: None. H.A. Keenan: Employee; Self; Sanofi Genzyme. L.P. Aiello: Advisory Panel; Self; Novo Nordisk A/S. Consultant; Self; Decision Resources Group, KalVista Pharmaceuticals, Inc., Mingsight, Retinal Solutions. Stock/Shareholder; Self; KalVista Pharmaceuticals, Inc. Other Relationship; Self; Optos. J.K. Sun: Research Support; Self; Adaptive Sensory Technology, Boston Micromachines Corporation, Genentech, Inc., KalVista Pharmaceuticals, Inc., Optovue, Incorporated. Other Relationship; Self; Genentech, Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk Inc. G.L. King: Research Support; Self; Sanofi. Funding National Eye Institute; National Institute of Diabetes and Digestive and Kidney Diseases; JDRF; Thomas J. Beatson, Jr. Foundation Inc.; Dianne Nunnally Hoppes Scholarship Fund