Diabetic retinal disease (DRD) is characterised by progressive neurovascular unit (NVU) dysfunction, often occurring before visible microvascular damage. Our previous studies suggested that the accumulation of acrolein (ACR)-derived protein adducts on retinal Müller cells and neuronal proteins may contribute to NVU dysfunction in diabetes, although this has yet to be directly tested. In this study, we evaluated the effects of the novel ACR-scavenging drug 2-hydrazino-4,6-dimethylpyrimidine (2-HDP) on retinal NVU dysfunction in experimental diabetes and explored its potential for systemic delivery in humans. Sprague Dawley rats were divided into three groups: non-diabetic rats; streptozocin (STZ)-induced diabetic rats; and STZ-induced diabetic rats treated with 2-HDP in their drinking water throughout the duration of diabetes. Endpoint measures were taken at varying time points, ranging from 1 to 6 months post-diabetes induction. Retinal function and structure were evaluated using electroretinography (ERG) and spectral-domain optical coherence tomography (SD-OCT). Retinal vessel calibre, BP and vasopermeability (assessed by Evans Blue leakage) were also monitored. Immunohistochemistry was employed to assess retinal neurodegenerative and vasodegenerative changes, while cytokine arrays were used to investigate the effect of 2-HDP on diabetes-induced retinal inflammation. The accumulation of the ACR–protein adduct Nε-(3-formyl-3,4-dehydropiperidino)lysine (FDP-Lys) in human diabetic retinas was analysed. Computational chemistry simulations were performed to predict 2-HDP’s passive permeability properties and its potential for systemic delivery. 2-HDP treatment had no effect on blood glucose, body weight, water intake, HbA1c levels or BP in diabetic rats (p>0.05). However, it protected against retinal FDP-Lys accumulation (p<0.05) and neurophysiological dysfunction, preserving ERG waveforms at 3 and 6 months post-diabetes induction (p<0.05 to p<0.001 for scotopic for a-wave, b-wave and summed oscillatory potentials). SD-OCT imaging revealed that 2-HDP prevented retinal thinning at 3 months (p<0.01) and protected against synaptic dysfunction, as evidenced by preserved synaptophysin expression (p<0.01 and p<0.001 for inner and outer plexiform layers, respectively). It also prevented neurodegeneration by maintaining retinal ganglion cells, amacrine cells, bipolar cells, and photoreceptors (p<0.05 to p<0.01). In addition, 2-HDP prevented retinal arteriolar dilation (p<0.01), reduced microvascular permeability (p<0.05) and attenuated microvascular damage, as indicated by preserved pericyte numbers and reduced acellular capillary formation (p<0.05). Mechanistically, 2-HDP inhibited microglial activation (p<0.05), suppressed the upregulation of proinflammatory molecules associated with NVU dysfunction in the diabetic retina (p<0.05 to p<0.001) and preserved the expression of the Müller cell glutamate-handling proteins, glutamate aspartate transporter 1 and glutamine synthetase (p<0.05 to p<0.01). FDP-Lys accumulation was observed in post-mortem human retinas from individuals with type 2 diabetes (p<0.05), in a pattern that was similar to that in the rat model of diabetes. Molecular dynamics simulations showed that the neutral form of 2-HDP readily crosses cell membranes, with enhanced permeation in the presence of ACR, highlighting its potential for systemic delivery. 2-HDP protects against retinal NVU dysfunction in diabetic rats by reducing FDP-Lys accumulation, preserving neuroretinal function and preventing microvascular damage, independent of glycaemic control. These results, combined with evidence from human diabetic retinas and molecular dynamics simulations, support 2-HDP’s potential as a promising therapeutic agent for DRD, warranting further preclinical and clinical investigation.

ABSTRACT Aims/Hypothesis In diabetes haptoglobin (Hp) 2 vs Hp 1 allelic product is associated with cardiac and renal complications. Few studies report both Hp phenotype and Hp levels. In a Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) trial substudy we evaluated the Hp phenotype, Hp levels, and fenofibrate effects. Materials and Methods In 480 adults with type 2 diabetes (T2D) the Hp phenotype was assessed and the Hp level quantified (both using ELISAs assays) in plasma from baseline, after 6 weeks of fenofibrate, and (in n = 200) at 2 years post‐randomization to fenofibrate or placebo. Results The Hp phenotypes 1‐1, 2‐1, and 2‐2 frequencies were 15%, 49%, and 36%, respectively. Baseline Hp levels differed by phenotype (P < 0.0001) and decreased (median 21%) after 6 weeks fenofibrate in all phenotypes (adjusted mean (95% CI): −0.27 (−0.32, −0.23) mg/mL in Hp 1‐1, −0.29 (−0.31, −0.27) mg/mL in Hp 2‐1 and −0.05 (−0.07, −0.02) mg/mL in Hp 2‐2 (P = 0.005 and P = 0.055 vs Hp 1‐1 and Hp 2‐1, respectively)). At 2 years post‐randomization the Hp levels in the placebo group had returned to baseline, whilst the fenofibrate‐group levels remained similar to the 6 week levels. Conclusions In type 2 diabetes, Hp levels differ by Hp phenotype and are decreased by fenofibrate in all phenotypes, but the effect is diminished in Hp 2‐2.

Introduction & Objective: In South Carolina, risks of pregnancy associated with maternal diabetes are worsened by disparities. Expert team-based care that is equitable, feasible, meets real-life needs, and improves communication is essential. Objective: to improve pregnancy outcomes through a ‘Management of Maternal (MOMs) Diabetes Program’ implemented at three centers across SC, intended to provide a ‘one stop shop’ and utilize new technologies. Methods: We compared outcomes for 948 MOMs patients (13% Type 1, 31% Type 2, and 56% gestational diabetes A2: 2020-2023) with 680 ‘standard care’ comparator patients (‘COMP’, from chart abstractions, Medical University of South Carolina perinatal database: 2017-2019). Maternal age and ‘diabetes type’ distributions were similar between groups, but COMP had a higher proportion of Black patients (52.1% vs. 24.8%) and fewer categorized as Hispanic or ‘other’. Two Proportion Z-Tests (two-tailed) were used for statistical analyses, with/without adjustment for race. Results: Maternal and infant outcomes in MOMs vs. COMP are shown for all patients and for Black and White patients (Table 1). Conclusions: Despite COVID-19, the MOMs program reduced C-sections, pre-term birth and neonatal hypoglycemia, and improved APGAR scores. Emphasizing the challenge of racial disparities, benefits were greater for White than Black patients. Disclosure D. Fu: None. M.J. Leyva: None. M.M. Schellinger: None. B.A. Campbell: None. C.U. Cart: None. M. Finneran: None. J. Britt: None. U. Lilavivat: None. M.K. Smith: None. M.E. Manson: None. K.J. Hunt: None. T. Lyons: None. Funding BlueCross BlueShield of South Carolina Foundation (2020-09,2020-08); Duke Endowment (6877-SP)

Metabolic disorder significantly contributes to diabetic vascular complications, including diabetic retinopathy, the leading cause of blindness in the working-age population. However, the molecular mechanisms by which disturbed metabolic homeostasis causes vascular dysfunction in diabetic retinopathy remain unclear. O-GlcNAcylation modification acts as a nutrient sensor particularly sensitive to ambient glucose. Here, we observe pronounced O-GlcNAc elevation in retina endothelial cells of diabetic retinopathy patients and mouse models. Endothelial-specific depletion or pharmacological inhibition of O-GlcNAc transferase effectively mitigates vascular dysfunction. Mechanistically, we find that Yes-associated protein (YAP) and Transcriptional co-activator with PDZ-binding motif (TAZ), key effectors of the Hippo pathway, are O-GlcNAcylated in diabetic retinopathy. We identify threonine 383 as an O-GlcNAc site on YAP, which inhibits its phosphorylation at serine 397, leading to its stabilization and activation, thereby promoting vascular dysfunction by inducing a pro-angiogenic and glucose metabolic transcriptional program. This work emphasizes the critical role of the O-GlcNAc-Hippo axis in the pathogenesis of diabetic retinopathy and suggests its potential as a therapeutic target. Metabolic disorder significantly contributes to diabetic vascular complications, including diabetic retinopathy (DR). This study reveals that O-GlcNAcylation, a nutrient-sensitive protein modification, drives vascular dysfunction in DR by stabilizing Hippo signaling key components YAP/TAZ. Targeting O-GlcNAc-YAP/TAZ shows therapeutic potential for mitigating DR pathology.

The recovery of mitochondrial quality control (MQC) may bring innovative solutions for neuroprotection, while imposing a significant challenge given the need of holistic approaches to restore mitochondrial dynamics (fusion/fission) and turnover (mitophagy and biogenesis). In diabetic retinopathy, this is compounded by our lack of understanding of human retinal neurodegeneration, but also how MQC processes interact during disease progression. Here, we show that mitochondria hyperfusion is characteristic of retinal neurodegeneration in human and murine diabetes, blunting the homeostatic turnover of mitochondria and causing metabolic and neuro-inflammatory stress. By mimicking this mitochondrial remodelling in vitro, we ascertain that N6-furfuryladenosine enhances mitochondrial turnover and bioenergetics by relaxing hyperfusion in a controlled fashion. Oral administration of N6-furfuryladenosine enhances mitochondrial turnover in the diabetic mouse retina (Ins2 Akita males), improving clinical correlates and conferring neuroprotection regardless of glycaemic status. Our findings provide translational insights for neuroprotection in the diabetic retina through the holistic recovery of MQC.

Low-dose aspirin (LDA) is efficacious in preventing preeclampsia, but its mechanism of action is unclear. Conflicting evidence suggests that it may inhibit placental trophoblast release of soluble fms-like tyrosine kinase-1 (sFlt1), a key mediator of preeclampsia. We examined whether, and at what concentrations, aspirin and its principal metabolite, salicylic acid, modulate sFlt1 release and/or expression in trophoblasts. Human trophoblast lines BeWo and HTR-8/SVneo were cultured; BeWo cells were also treated with 1% oxygen vs. normoxia to mimic hypoxia in preeclamptic placentas. Cells were treated with aspirin or salicylic acid vs. vehicle for 24 h at concentrations relevant to LDA and at higher concentrations. Protein concentrations (ELISA) and mRNA expression (RT-PCR) of sFlt1 were determined. Under normoxia, LDA-relevant concentrations of aspirin (10–50 µmol/L) or salicylic acid (20–100 µmol/L) had no significant effect on sFlt1 protein release or mRNA expression in BeWo cells. However, inhibition was observed at higher concentrations (1 mmol/L for aspirin and ≥200 μmol/L for salicylic acid). Hypoxia enhanced sFlt1 protein release and mRNA expression in BeWo cells, but these responses were not significantly affected by either aspirin or salicylic acid at LDA concentrations. Similarly, neither drug altered sFlt1 protein secretion or mRNA expression in normoxic HTR-8/SVneo cells at LDA concentrations. We suggest that direct modulation of trophoblast release or expression of sFlt1 is unlikely to be a mechanism underlying the clinical efficacy of LDA in preeclampsia.

BACKGROUND:Preeclampsia is prevalent in women with diabetes, but the mechanism is unclear. We previously found that oxidized, glycated lipoproteins robustly upregulated soluble fms-like tyrosine kinase-1 (sFlt1), a key mediator of preeclampsia. Here, we determined the role of protein kinase C (PKC) and its subtypes in sFlt1 regulation in placental trophoblasts, and whether this mechanism might mediate the effect of modified lipoproteins. METHODS:Cultured human HTR8/SVneo and BeWo trophoblasts were treated with the PKC activator phorbol-12-myristate-13-acetate (PMA) for 24h, ± PKC inhibitors GF109203X (general), Ro31-8220 (PKCα-selective), LY333531 (PKCβ-selective) and rottlerin (PKCδ-selective). The effect of 'heavily oxidized, glycated' low-density lipoproteins (HOG-LDL) vs. native LDL (N-LDL), ± high glucose (30 mM), was evaluated in HTR8/SVneo cells. sFlt1 secretion (ELISA), mRNA expression (RT-qPCR), and cellular PKC activity were measured. RESULTS:PMA stimulated robust sFlt1 release and mRNA expression in both cell lines; these effects were inhibited by GF109203X, Ro31-8220 and LY333531 in a concentration-dependent manner. Rottlerin inhibited sFlt1 in BeWo, but modestly enhanced it in HTR8/SVneo cells. HOG-LDL enhanced PKC activity vs. N-LDL in HTR8/SVneo cells. Also, HOG-LDL, but not high glucose, significantly increased sFlt1 secretion and mRNA expression; this response was inhibited by GF109203X, Ro31-8220 and LY333531 at concentrations comparable to those that blocked PMA induction of sFlt1. CONCLUSION:Modified lipoproteins upregulate sFlt1 in trophoblasts via a PKC-mediated mechanism, involving at least α and β isoforms. The data suggest potential therapeutic targets to reduce the risk of preeclampsia in women with diabetes.

Background: Management of Maternal Diabetes (MOMs) program provides comprehensive, single-site team care for pregnant patients who are for medically-complex. Objective: To determine whether MOMs improves glycemic control through specialized care and patient engagement in diabetes self-management (DSMES). Methods: General linear models compared longitudinal A1c and time in range (TIR) to pre-enrollment baseline values for patients delivering June 2020 through March 2023. Surveys were conducted on patient satisfaction, diabetes self-management. Results: Among 482 patients, 26% were Black, 30% Hispanic, 39% White, 5% Other. For preferred language, 27% cited Spanish. Insurance included 54% Medicaid and 31% Uninsured with Medicaid only for delivery. At baseline, 44% were obese and 28% morbidly obese. Diabetes type comprised 9% Type 1, 35% Type 2, 45% Gestational-A2, 10% Other. Type 1 patients had A1c decrease (p < 0.01) across all trimesters. Type 2 patients had A1c decrease (p < 0.01) in the 2nd and 3rd trimester. Patients using CGMs increased (p = 0.01) TIR from 64% to 77% to 81% across trimesters. Patient surveys showed 93% were very satisfied/satisfied with the availability of multiple providers and services at a single visit; 91% strongly agreed/agreed that MOMs helped them develop healthier lifestyles. Conclusion: MOMs improved glycemic control and demonstrated a high degree of patient engagement. Disclosure M.M. Schellinger: None. J. Britt: None. D.N. Pasko: None. S. Keiser: None. S.L. Weber: None. H. White: None. J. Odom: None. M.D. Stancil: None. P.L. Schult: None. K. Hunt: None. C.J. Fiocchi: None. K. Fincher: None. C.U. Cart: None. A. Kelly: None. D. Londono: None. L. Perez-Cano: None. D. Fu: None. M.J. Leyva: None. T. Lyons: None. Funding BlueCross BlueShield of South Carolina Foundation, Diabetes Free SC (2020-09)

Aims:We aimed to determine whether plasma advanced glycation end products or oxidation products (AGE/oxidation-P) predict altered renal function and/or preeclampsia (PE) in pregnant women with type 1 diabetes.Methods:Prospectively, using a nested case-control design, we studied 47 pregnant women with type 1 diabetes, of whom 23 developed PE and 24 did not. Nineteen nondiabetic, normotensive pregnant women provided reference values. In plasma obtained at ~12, 22, and 32 weeks' gestation (visits 1, 2, and 3; V1-V3), we measured five AGE products (carboxymethyllysine (CML), carboxyethyl-lysine (CEL), methylglyoxal-hydroimidazolone (MGH1), 3-deoxyglucosone hydroimidazolone (3DGH), and glyoxal-hydroimidazolone (GH1)) and four oxidation products (methionine sulfoxide (MetSO), 2-aminoadipic acid (2-AAA), 3-nitrotyrosine (3NT), and dityrosine (DT)), by liquid chromatography/mass spectroscopy. Clinical outcomes were "estimated glomerular filtration rate" (eGFR) at each visit and onset of PE.Results:In diabetic women, associations between AGE/oxidation-P and eGFR were found only in those who developed PE. In this group, CEL, MGH1, and GH1 at V2 and CML, CEL, MGH1, and GH1 at V3 were inversely associated with contemporaneous eGFR, while CEL, MGH1, 3DGH, and GH1 at V2 were inversely associated with eGFR at V3 (all p < 0.05). There were no associations of plasma AGE or oxidation-P with pregnancy-related development of proteinuria or PE.Conclusions:Inverse associations of second and early third trimester plasma AGE with eGFR among type 1 diabetic women who developed PE suggest that these patients constitute a subset susceptible to AGE-mediated injury and thus to cardiorenal complications later in life. However, AGE/oxidation-P did not predict PE in type 1 diabetic women.

Diabetic retinopathy (DR) is generally viewed as a consequence of hyperglycemia, but to a large extent, it may be driven by effects of plasma lipoproteins.

The perinatal period is a time of substantial bone mass accrual with many factors affecting long-term bone mineralization. Currently it is unclear what effect maternal gestational/type 2 diabetes has on infant bone mass accrual. This is a prospective study of offspring of Native American and Hispanic mothers with normoglycemia (n = 94) and gestational diabetes or type 2 diabetes (n = 64). Infant anthropometrics were measured at birth, 1, and 6 months of age. Cord blood leptin, high-molecular weight adiponectin (HMWA), pigment epithelium-derived factor (PEDF), vascular epithelium growth factor (VEGF), endoglin, and C-peptide were measured by ELISA. Infants had bone mineral density measurement at 1 month or/and 6 months of age using dual-energy x-ray absorptiometry scan. Mothers with diabetes were older (31 ± 6 years vs 25 ± 4 years) and had higher pre-pregnancy BMI (32.6 ± 5.8 vs 27.2 ± 6.4 kg/m2) than control mothers. Mean HbA1C of mothers with diabetes was 5.9 ± 1.0% compared to 5.1 ± 0.3% in controls early in pregnancy. Infants born to mothers with diabetes (DM-O) were born at a slightly lower gestational age compared to infants born to control mothers (Con-O). There was no difference in total body less head bone mineral content (BMC) or bone mineral density (BMD) between DM-O and Con-O. For both groups together, bone area, BMD, and BMC tracked over the first 6 months of life (r: 0.56, 0.38, and 0.48, respectively). Percent fat was strongly and positively correlated with BMC at 1 month of age (r = 0.44; p < 0.001) and BMC at both 1 and 6 months of age correlated strongly with birth weight. There were no associations between infant bone mass and cord blood leptin, PEDF, or VEGF, while C-peptide had a significant correlation with BMC at 1 and 6 months only in DM-O (p = 0.01 and 0.03, respectively). Infants born to mothers with well-controlled gestational/type 2 diabetes have normal bone mass accrual. Bone mineral content during this time is highly correlated with indices of infant growth and the association of bone mineral indices with percent body fat suggests that bone-fat crosstalk is operative early in life.

In type 2 diabetes, hyperuricemia is associated with cardiovascular disease (CVD) and the metabolic syndrome (MetS), but associations in type 1 diabetes (T1D) have not been well-defined. This study examined the relationships between serum urate (SU) concentrations, clinical and biochemical factors, and subsequent cardiovascular events in a well-characterized cohort of adults with T1D. In 973 participants with T1D in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study (DCCT/EDIC), associations were defined between SU, measured once in blood collected 1997–2000, and (a) concurrent MetS and (b) incident ‘any CVD’ and major adverse cardiovascular events (MACE) through 2013. SU was higher in men than women [mean (SD): 4.47 (0.99) vs. 3.39 (0.97) mg/dl, respectively, p < 0.0001], and was associated with MetS features in both (men: p = 0.0016; women: p < 0.0001). During follow-up, 110 participants (11%) experienced “any CVD”, and 53 (5%) a MACE. Analyzed by quartiles, SU was not associated with subsequent CVD or MACE. In women, SU as a continuous variable was associated with MACE (unadjusted HR: 1.52; 95% CI 1.07–2.16; p = 0.0211) even after adjustment for age and HbA1c (HR: 1.47; 95% CI 1.01–2.14; p = 0.0467). Predominantly normal range serum urate concentrations in T1D were higher in men than women and were associated with features of the MetS. In some analyses of women only, SU was associated with subsequent MACE. Routine measurement of SU to assess cardiovascular risk in T1D is not merited. Trial registration clinicaltrials.gov NCT00360815 and NCT00360893.

Introduction Pre-eclampsia (PE) is increased ~4-fold by maternal diabetes. Elevated plasma antiangiogenic factors, soluble fms-like tyrosine kinase (sFLT-1) and soluble endoglin (sENG), precede PE onset. We investigated whether diabetes-related stresses, modified lipoproteins and elevated glucose enhance trophoblast sFLT-1 and sENG release and/or alter placental barrier function and whether oxidized low-density lipoprotein (Ox-LDL) is in placental tissue. Research design and methods HTR8/SVneo cells were exposed to ‘heavily-oxidized, glycated’ LDL (HOG-LDL) versus native LDL (N-LDL) (10–200 mg protein/L) for 24 hours ±pretreatment with glucose (30 mmol/L, 72 hours). Concentrations of sFLT-1 and sENG in supernatants (by ELISA) and expressions of sFLT-1-I13 and sFLT-1-E15A isoforms, endoglin (ENG) and matrix metalloproteinase-14 (MMP-14; by RT-PCR) were quantified. For barrier studies, JAR cells were cultured in Transwell plates (12–14 days), then exposed to LDL. Transepithelial electrical resistance (TEER) was measured after 6, 12 and 24 hours. In placental sections from women with and without type 1 diabetes, immunostaining of apolipoprotein B100 (ApoB, a marker of LDL), Ox-LDL and lipoxidation product 4-hydroxynonenal was performed. Results HOG-LDL (50 mg/L) increased sFLT-1 (2.7-fold, p<0.01) and sENG (6.4-fold, p<0.001) in supernatants versus N-LDL. HOG-LDL increased expression of sFLT-1-I13 (twofold, p<0.05), sFLT-1-E15A (1.9-fold, p<0.05), ENG (1.6-fold, p<0.01) and MMP-14 (1.8-fold, p<0.05) versus N-LDL. High glucose did not by itself alter sFLT-1 or sENG concentrations, but potentiated effects of HOG-LDL on sFLT-1 by 1.5-fold (p<0.05) and on sENG by 1.8-fold (p<0.01). HOG-LDL (200 mg/L) induced trophoblast barrier impairment, decreasing TEER at 6 hours (p<0.01), 12 hours (p<0.01) and 24 hours (p<0.05) versus N-LDL. Immunostaining of term placental samples from women both with and without diabetes revealed presence of intravillous modified lipoproteins. Conclusion These findings may explain, in part, the high risk for PE in women with diabetes. The trophoblast culture model has potential for evaluating novel therapies targeting barrier dysfunction.

BACKGROUND:Gestational diabetes mellitus (GDM) is a growing public health concern and maternal obesity and poor dietary intakes could be implicated. Dietary polyphenols and fiber mitigate the risk of diabetes and its complications, but little is known about their efficacy in preventing GDM. OBJECTIVES:We examined the effects of whole blueberry and soluble fiber supplementation on primary outcomes of cardiometabolic profiles in women at high risk of developing GDM. METHODS:Women (n = 34; mean ± SD age: 27 ± 5 y; BMI: 35.5 ± 4.0 kg/m2; previous history of GDM ∼56%; Hispanic ∼79%) were recruited in early pregnancy (<20 weeks of gestation) and randomly assigned to 1 of the following 2 groups for 18 wk: intervention (280 g whole blueberries and 12 g soluble fiber per day) and standard prenatal care (control). Both groups received nutrition education and maintained 24-h food recalls throughout the study. Data on anthropometrics, blood pressure, and blood samples for biochemical analyses were collected at baseline (<20 weeks), midpoint (24-28 weeks), and end (32-36 weeks) of gestation. Diagnosis of GDM was based on a 2-step glucose challenge test (GCT). Data were analyzed using a mixed-model ANOVA. RESULTS:Maternal weight gain was significantly lower in the dietary intervention than in the control group at the end of the trial (mean ± SD: 6.8 ± 3.2 kg compared with 12.0 ± 4.1 kg, P = 0.001). C-reactive protein was also lower in the intervention than in the control group (baseline: 6.1 ± 4.0 compared with 6.8 ± 7.2 mg/L; midpoint: 6.1 ± 3.7 compared with 7.5 ± 7.3 mg/L; end: 5.5 ± 2.2 compared with 9.5 ± 6.6 mg/L, respectively, P = 0.002). Blood glucose based on GCT was lower in the intervention than in the control (100 ± 33 mg/dL compared with 131 ± 40 mg/dL, P < 0.05). Conventional lipids (total, LDL, and HDL cholesterol and triglycerides) did not differ between groups over time. No differences were noted in infant birth weight. CONCLUSIONS:Whole blueberry and soluble fiber supplementation may prevent excess gestational weight gain and improve glycemic control and inflammation in women with obesity.This trial was registered at clinicaltrials.gov as NCT03467503.

Endothelial injury and hypertension are principal features of preeclampsia (PE), suggesting that plasma endothelial glycocalyx fragments are potential biomarkers. We aimed to: 1) compare the newer 'selective reduced uterine perfusion pressure' (sRUPP) model and the traditional RUPP model in their ability to simulate PE; and 2) determine whether plasma hyaluronic acid (HA), a major endothelial glycocalyx component, differs in the two models as compared to sham rats. Thirty-two timed-pregnant Sprague-Dawley rats underwent sham surgery (n=9), sRUPP procedure (n=10), or RUPP procedure (n=13) on gestational day 14. On day 18, each rat underwent carotid artery cannulation, and conscious mean arterial pressure (MAP; PowerLab, ADInstruments, CO) was measured on day 19, followed by plasma and tissue collection. Pup survival rate was calculated based on the number of pups on day 19 vs. day 14. Plasma HA on day 19 was quantified by Quantikine ELISA (R&D Systems, MN). Statistical significance was determined by one-way ANOVA or Kruskal-Wallis test, with post-hoc analyses as appropriate. Both the sRUPP and RUPP rats had significant yet comparable pup resorption (p<0.001) and blunted maternal weight gain (p<0.001) vs. sham rats, suggesting underlying placental ischemia. The RUPP rats showed significantly higher MAP than sham rats (p<0.01); this increase was approximately twice as large as that of the sRUPP rats. There was a trend towards increased plasma HA concentration in the RUPP animals, though it did not differ significantly across all three groups. Our preliminary data suggest that the rat RUPP model is superior to the sRUPP model in modeling blood pressure changes of PE; the latter may represent a milder disease phenotype. Plasma HA may not be a reliable marker in either model. Given the current evidence for endothelial glycocalyx damage occurring in human PE, future studies will investigate the role of other endothelial glycocalyx markers.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Purpose: Anesthesia is necessary to conduct rodent electroretinograms (ERGs). We evaluated utility of the alpha 2-agonist medetomidine versus xylazine for ERG studies in nondiabetic and diabetic rats. Pentobarbital was included as a comparator.Methods: Male Sprague-Dawley rats, with and without streptozotocin (STZ)-induced diabetes, were anesthetized with medetomidine (1 mg/kg), xylazine (10 mg/kg) (both with ketamine 75 mg/kg), or pentobarbital (70 mg/kg). The depth of anesthesia was assessed, and if adequate, scotopic ERGs were recorded. Blood glucose was monitored.Results: In nondiabetic rats, all three agents induced satisfactory anesthesia, but with differing durations: medetomidine > pentobarbital > xylazine. ERG responses were similar under medetomidine and xylazine, but relatively reduced under pentobarbital. Both alpha 2-agonists (but not pentobarbital) elicited marked hyperglycemia (peak values 316.1 & PLUSMN; 42.6 and 300.3 & PLUSMN; 29.5 mg/dL, respectively), persisting for 12 h. In diabetic rats, elevated blood glucose concentrations were not affected by any of the agents, but the depth of anesthesia under medetomidine and xylazine was inadequate for ERG recording.Conclusions: In nondiabetic rats, medetomidine and xylazine elicited comparable effects on ERGs that differ from pentobarbital, but both perturbed glucose metabolism, potentially confounding experimental outcomes. In STZ-diabetic rats, neither alpha 2-agent provided adequate anesthesia, while pentobarbital did so. Problems with alpha 2-anesthetic agents, including medetomidine, must be recognized to ensure meaningful interpretation of experimental results.

We have previously reported that inhibition of the Janus kinase 1 (JAK1) signaling ameliorates IL-17A-mediated blood-retinal barrier (BRB) dysfunction. Higher levels of IL-17A have been observed in the blood and intraocular fluids in patients with diabetic retinopathy (DR), in particular those with diabetic macular oedema. This study aimed to understand whether JAK1 inhibition could prevent BRB dysfunction in db/db mice, a model of type 2 diabetes (T2D). An in vitro study showed that high glucose treatment disrupted the junctional distribution of claudin-5 in bEnd3 cells and ZO-1 in ARPE19 cells and that tofacitinib citrate treatment prevented high glucose-mediated tight junction disruption. Albumin leakage, accompanied by increased levels of the phosphorylated form of JAK1 (pJAK1), was observed in three-month-old db/db mice. Treatment of two-and-a-half-month-old db/db mice with tofacitinib citrate for two weeks significantly reduced retinal albumin leakage and reduced pJAK1 expression. pJAK1 expression was also detected in human DR retina. Our results suggest that JAK1 inhibition can ameliorate BRB dysfunction in T2D, and JAK1 inhibitors such as tofacitinib citrate may be re-purposed for the management of diabetic macular oedema.

The risk for preeclampsia (PE) is enhanced ~4-fold by the presence of maternal type 1 diabetes (T1DM). Vitamin D is essential for healthy pregnancy. We assessed the total, bioavailable, and free concentrations of plasma 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)2D), and vitamin D binding protein (VDBP) at ~12, ~22, and ~32 weeks' gestation ("Visits" (V) 1, 2, and 3, respectively) in 23 T1DM women who developed PE, 24 who remained normotensive, and 19 non-diabetic, normotensive women (reference controls). 25(OH)D deficiency was more frequent in diabetic than non-diabetic women (69% vs. 22%, p < 0.05), but no measure of 25(OH)D predicted PE. By contrast, higher 1,25(OH)2D concentrations at V2 (total, bioavailable, and free: p < 0.01) and V3 (bioavailable: p < 0.05; free: p < 0.01), lower concentrations of VDBP at V3 (p < 0.05), and elevated ratios of 1,25(OH)2D/VDBP (V2, V3: p < 0.01) and 1,25(OH)2D/25(OH)D (V3, p < 0.05) were all associated with PE, and significance persisted in multivariate analyses. In summary, in women with T1DM, concentrations of 1,25(OH)2D were higher, and VDBP lower, in the second and third trimesters in women who later developed PE than in those who did not. 1,25(OH)2D may serve as a new marker for PE risk and could be implicated in pathogenesis.