Role of symmetry in 3,3-diphenyl-1,3-dihydroindol-2-one derivatives as inhibitors of translation initiation.

The ternary complex (eIF2·GTP·Met-tRNAiMet) and the eIF4F complex assembly are two major regulatory steps in the eukaryotic translation initiation. Inhibition of the ternary complex assembly is therefore a promising target for the development of novel anti-cancer therapeutics. Building on the finding that clotrimazole (CLT), a molecular probe that depletes intracellular Ca2+ stores and subsequently induce eIF2α phosphorylation, inhibit translation initiation, and reduce preferentially the expression of oncoproteins over "housekeeping" ones,1-3 we undertook structure activity relationship (SAR) studies that identified 3,3-diarylindoline-2-one #1181 as an interesting scaffold. Compound #1181 also induce phosphorylation of eIF2α thereby reducing the availability of the ternary complex, which leads to inhibition of translation initiation.4 Our subsequent efforts focused on understanding SAR iterative lead optimization to enhance potency and improve bioavailability. Herein, we report a complementing study focusing on heavily substituted symmetric and asymmetric 3,3-(o,m-disubstituted)diarylindoline-2-ones. These compounds were evaluated by the dual luciferase reporter ternary complex assay that recapitualates phosphorylation of eIF2α in a quantitative manner. We also evaluated all compounds by sulforhodamine B assay, which measures the overall effect of compounds on cell proliferations and/or viability.

A distinctive histidine residue is essential for in vivo glycation-inactivation of human CD59 transgenically expressed in mice erythrocytes: Implications for human diabetes complications.

Clinical and experimental evidences support a link between the complement system and the pathogenesis of diabetes complications. CD59, an extracellular cell membrane-anchored protein, inhibits formation of the membrane attack complex (MAC), the main effector of complement-mediated tissue damage. This complement regulatory activity of human CD59 (hCD59) is inhibited by hyperglycemia-induced ɛ-amino glycation of Lys41 . Biochemical and structural analyses of glycated proteins with known three-dimensional structure revealed that glycation of ɛ-amino lysyl residues occurs predominantly at "glycation motives" that include lysyl/lysyl pairs or proximity of a histidyl residue, in which the imidazolyl moiety is ≈ 5Å from the ɛ-amino group. hCD59 contains a distinctive Lys41 /His44 putative glycation motif within its active site. In a model of transgenic diabetic mice expressing in erythrocytes either the wild type or a H44Q mutant form of hCD59, we demonstrate in vivo that the His44 is required for Lys41 glycation and consequent functional inactivation of hCD59, as evidenced using a mouse erythrocytes hemolytic assay. Since (1) the His44 residue is not present in CD59 from other animal species and (2) humans are particularly prone to develop complications of diabetes, our results indicate that the Lys41 /His44 glycation motif in human CD59 may confer humans a higher risk of developing vascular disease in response to hyperglycemia.

Structure of the eukaryotic translation initiation factor eIF4E in complex with 4EGI-1 reveals an allosteric mechanism for dissociating eIF4G.

The interaction of the eukaryotic translation initiation factor eIF4E with the initiation factor eIF4G recruits the 40S ribosomal particle to the 5' end of mRNAs, facilitates scanning to the AUG start codon, and is crucial for eukaryotic translation of nearly all genes. Efficient recruitment of the 40S particle is particularly important for translation of mRNAs encoding oncoproteins and growth-promoting factors, which often harbor complex 5' UTRs and require efficient initiation. Thus, inhibiting the eIF4E/eIF4G interaction has emerged as a previously unpursued route for developing anticancer agents. Indeed, we discovered small-molecule inhibitors of this eIF4E/eIF4G interaction (4EGIs) that inhibit translation initiation both in vitro and in vivo and were used successfully in numerous cancer-biology and neurobiology studies. However, their detailed molecular mechanism of action has remained elusive. Here, we show that the eIF4E/eIF4G inhibitor 4EGI-1 acts allosterically by binding to a site on eIF4E distant from the eIF4G binding epitope. Data from NMR mapping and high-resolution crystal structures are congruent with this mechanism, where 4EGI-1 attaches to a hydrophobic pocket of eIF4E between ß-sheet2 (L60-T68) and α-helix1 (E69-N77), causing localized conformational changes mainly in the H78-L85 region. It acts by unfolding a short 310-helix (S82-L85) while extending α-helix1 by one turn (H78-S82). This unusual helix rearrangement has not been seen in any previous eIF4E structure and reveals elements of an allosteric inhibition mechanism leading to the dislocation of eIF4G from eIF4E.

3-substituted indazoles as configurationally locked 4EGI-1 mimetics and inhibitors of the eIF4E/eIF4G interaction.

4EGI-1, the prototypic inhibitor of eIF4E/eIF4G interaction, was identified in a high-throughput screening of small-molecule libraries with the aid of a fluorescence polarization assay that measures inhibition of binding of an eIF4G-derived peptide to recombinant eIF4E. As such, the molecular probe 4EGI-1 has potential for the study of molecular mechanisms involved in human disorders characterized by loss of physiological restraints on translation initiation. A hit-to-lead optimization campaign was carried out to overcome the configurational instability in 4EGI-1, which stems from the E-to-Z isomerization of the hydrazone function. We identified compound 1 a, in which the labile hydrazone was incorporated into a rigid indazole scaffold, as a promising rigidified 4EGI-1 mimetic lead. In a structure-activity relationship study directed towards probing the structural latitude of this new chemotype as an inhibitor of eIF4E/eIF4G interaction and translation initiation we identified 1 d, an indazole-based 4EGI-1 mimetic, as a new and improved lead inhibitor of eIF4E/eIF4G interaction and a promising molecular probe candidate for elucidation of the role of cap-dependent translation initiation in a host of pathophysiological states.

Chemical genetics identify eIF2α kinase heme-regulated inhibitor as an anticancer target.

Translation initiation plays a critical role in cellular homeostasis, proliferation, differentiation and malignant transformation. Consistently, increasing the abundance of the eIF2-GTP-tRNA(i)(Met) translation initiation complex transforms normal cells and contributes to cancer initiation and the severity of some anemias. The chemical modifiers of the eIF2-GTP-tRNA(i)(Met) ternary complex are therefore invaluable tools for studying its role in the pathobiology of human disorders and for determining whether this complex can be pharmacologically targeted for therapeutic purposes. Using a cell-based assay, we identified N,N'-diarylureas as unique inhibitors of ternary complex accumulation. Direct functional-genetic and biochemical evidence demonstrated that the N,N'-diarylureas activate heme-regulated inhibitor kinase, thereby phosphorylating eIF2α and reducing the abundance of the ternary complex. Using tumor cell proliferation in vitro and tumor growth in vivo as paradigms, we demonstrate that N,N'-diarylureas are potent and specific tools for studying the role of eIF2-GTP-tRNA(i)(Met) ternary complex in the pathobiology of human disorders.

Cell surface complement regulators moderate experimental myasthenia gravis pathology.

INTRODUCTION: Intrinsic mouse complement regulators influence the severity of passively induced experimental acquired myasthenia gravis (EAMG). To assess the potential influence of CD59b in the absence of CD59a background, we used the mCD59ab(-/-) mouse model to re-evaluate mCD59 in protecting the neuromuscular junction (NMJ). METHODS: EAMG was induced with monoclonal antibody to the acetylcholine receptor (AChR) in Daf1(-/-) , CD59ab(-/-) , Daf1(-/-) CD59ab(-/-) , and wild-type C57Bl/6 mice. Animals were monitored throughout the experiment. Diaphragms were analyzed for NMJ injury. RESULTS: Daf1(-/-) CD59ab(-/-) mice required euthanasia 24 hours after disease induction because of severe weakness. Histological assessment demonstrated reduced AChR density, simplification of synaptic folds, and disrupted mitochondria. CD59ab-deficient mice demonstrated mild weakness and reduction in weight after 24 hours. In contrast, Daf1(-/-) had more severe weakness at 60 hours. The NMJ of EAMG-induced Daf1(-/-) and CD59ab(-/-) mice demonstrated similar AChR density. CONCLUSION: NMJs of CD59 and DAF mice are protected from complement-mediated injury of passive EAMG.

A specific and sensitive assay for blood levels of glycated CD59: a novel biomarker for diabetes.

Increasing evidence links the complement system with complications of human diabetes. The complement regulatory protein CD59, an inhibitor of formation of membrane attack complex (MAC), is inhibited by hyperglycemia-induced glycation fostering increased deposition of MAC, a major effector of complement-mediated tissue damage. CD59, an ubiquitous GPI-anchored membrane protein, is shed from cell membranes by phospholipases generating a soluble form present in blood and urine. We established an enzyme-linked immunosorbent assay (ELISA) to measure serum/plasma glycated human CD59 (hCD59) (GCD59) and evaluated its potential as a diabetes biomarker. We used a synthetic peptide strategy to generate (a) a mouse monoclonal antibody to capture hCD59, (b) a rabbit monoclonal antibody to detect GCD59, and (c) a GCD59 surrogate for assay standardization. ELISA conditions were optimized for precision, reproducibility, and clinical sensitivity. The clinical utility of the assay was initially evaluated in 24 subjects with or without diabetes and further validated in a study that included 100 subjects with and 90 subjects without a diagnosis of diabetes. GCD59 (a) was significantly higher in individuals with than in individual without diabetes, (b) was independently associated with HbA1c, and (c) identified individuals with diabetes with high specificity and sensitivity. We report the development and standardization of a novel, sensitive, and specific ELISA for measuring GCD59 in blood. The assay distinguished individuals with diabetes from those without, and showed strong correlation between GCD59 and HbA1c. Because GCD59 likely contributes to the pathogenesis of diabetes complications, measurement of blood levels of GCD59 may be useful in the diagnosis and management of diabetes.

The ability of pGCD59 to predict adverse pregnancy outcomes: a prospective study of non-diabetic pregnant women in Ireland.

AIM: Even though most pregnancies are uneventful, occasionally complications do occur. Gestational diabetes is linked to an increased risk of adverse pregnancy outcomes. Early identification of women at risk of experiencing adverse outcomes, ideally through a single blood test, would facilitate early intervention. Plasma glycated CD59 (pGCD59) is an emerging biomarker which has shown promise in identifying hyperglycaemia during pregnancy and has been associated with the risk of delivering an LGA infant. The aim of this study was to explore the ability of the first- and second-trimester pGCD59 to predict adverse pregnancy outcomes. METHODS: This was a prospective study of 378 pregnant women. Samples for pGCD59 were taken at the first antenatal visit and at the time of the 2 h 75 g OGTT (24-28 weeks of gestation). Adjusted receiver operating characteristic curves were used to evaluate the ability of pGCD59 to predict maternal and neonatal outcomes. RESULTS: First-trimester pGCD59 levels were higher in women with gestational diabetes who delivered a macrosomic infant (4.2 ± 0.7 vs. 3.5 ± 1.0 SPU, p < 0.01) or an LGA infant (4.3 ± 0.3 vs. 3.6 ± 1.0 SPU, p = 0.01) compared to women with GDM that did not experience these outcomes. Second-trimester pGCD59 levels were higher in women that developed polyhydramnios (2.9 ± 0.4 vs. 2.5 ± 1.1 SPU, p = 0.03). First- and second-trimester pGCD59 predicted pregnancy-induced hypertension with good accuracy (AUC:0.85, 95%CI:0.78-0.91; AUC: 0.80, 95%CI: 0.73-0.88, respectively) and neonatal hypoglycaemia with fair to good accuracy (AUC:0.77, 95%CI: 0.54-0.99, AUC:0.81, 95%CI:0.62-0.99). CONCLUSIONS: This study has shown that pGCD59 has the potential to predict adverse pregnancy outcomes. Prospective studies with a larger number of cases are necessary to fully explore and validate the potential of this emerging biomarker in predicting adverse pregnancy outcomes.

The critical roles of platelet activation and reduced NO bioavailability in fatal pulmonary arterial hypertension in a murine hemolysis model.

Pulmonary arterial hypertension (PAH) is suspected to be a strong mortality determinant of hemolytic disorders. However, direct contribution of acute intravascular hemolysis to fatal PAH has not been investigated. The roles of nitric oxide (NO) insufficiency and platelet activation in hemolysis-associated fatal PAH have been suspected but not been experimentally studied. We recently generated a unique intravascular hemolysis mouse model in which the membrane toxin, intermedilysin (ILY), exclusively lyses the erythrocytes of transgenically expressing human CD59 mice (ThCD59(RBC)), thereby inducing ILY-dose-dependent massive hemolysis. Using this murine hemolysis model, we found that the acute increase in pulmonary arterial pressure leading to right ventricle failure caused sudden death. Reduced NO bioavailability and massive platelet activation/aggregation leading to the formation of massive thrombosis specifically in the pulmonary microvasculature played the critical roles in pathogenesis of acute hemolysis-associated fatal PAH. Therapeutic interventions enhancing NO bioactivity or inhibiting platelet activation prevented sudden death or prolonged survival time via the suppression of the acute increase in pulmonary arterial pressure and improvement of right ventricle function. These findings further highlight the importance of the inhibition of platelet activation and the enhancement of NO bioavailability for the treatment and prevention of hemolysis-associated (fatal) PAH.

In vitro inhibition of translation initiation by N,N'-diarylureas--potential anti-cancer agents.

Symmetrical N,N'-diarylureas: 1,3-bis(3,4-dichlorophenyl)-, 1,3-bis[4-chloro-3-(trifluoromethyl)phenyl]- and 1,3-bis[3,5-bis(trifluoromethyl)phenyl]urea, were identified as potent activators of the eIF2α kinase heme regulated inhibitor. They reduce the abundance of the eIF2·GTP·tRNA(i)(Met) ternary complex and inhibit cancer cell proliferation. An optimization process was undertaken to improve their solubility while preserving their biological activity. Non-symmetrical hybrid ureas were generated by combining one of the hydrophobic phenyl moieties present in the symmetrical ureas with the polar 3-hydroxy-tolyl moiety. O-alkylation of the later added potentially solubilizing charge bearing groups. The new non-symmetrical N,N'-diarylureas were characterized by ternary complex reporter gene and cell proliferation assays, demonstrating good bioactivities. A representative sample of these compounds potently induced phosphorylation of eIF2α and expression of CHOP at the protein and mRNA levels. These inhibitors of translation initiation may become leads for the development of potent, non-toxic, and target specific anti-cancer agents.

A high-affinity inhibitor of human CD59 enhances complement-mediated virolysis of HIV-1: implications for treatment of HIV-1/AIDS.

Many pathogenic enveloped viruses, including HIV-1, escape complement-mediated virolysis by incorporating host cell regulators of complement activation into their own viral envelope. The presence of complement regulators including CD59 on the external surface of the viral envelope confers resistance to complement-mediated virolysis, which may explain why human pathogenic viruses such as HIV-1 are not neutralized by complement in human fluids, even in the presence of high Ab titers against the viral surface proteins. In this study, we report the development of a recombinant form of the fourth domain of the bacterial toxin intermedilysin (the recombinant domain 4 of intermedilysin [rILYd4]), a 114 aa protein that inhibits human CD59 function with high affinity and specificity. In the presence of rILYd4, HIV-1 virions derived from either cell lines or peripheral blood mononuclear cells of HIV-1-infected patients became highly sensitive to complement-mediated lysis activated by either anti-HIV-1 gp120 Abs or by viral infection-induced Abs present in the plasma of HIV-1-infected individuals. We also demonstrated that rILYd4 together with serum or plasma from HIV-1-infected patients as a source of anti-HIV-1 Abs and complement did not mediate complement-mediated lysis of either erythrocytes or peripheral blood mononuclear cells. These results indicate that rILYd4 may represent a novel therapeutic agent against HIV-1/AIDS.

The Diagnostic Accuracy of Second Trimester Plasma Glycated CD59 (pGCD59) to Identify Women with Gestational Diabetes Mellitus Based on the 75 g OGTT Using the WHO Criteria: A Prospective Study of Non-Diabetic Pregnant Women in Ireland.

The aim of this study was to evaluate the ability of second trimester plasma glycated CD59 (pGCD59), a novel biomarker, to predict the results of the 2 h 75 g oral glucose tolerance test at 24−28 weeks of gestation, employing the 2013 World Health Organisation criteria. This was a prospective study of 378 pregnant women. The ability of pGCD59 to predict gestational diabetes (GDM) was assessed using adjusted ROC curves for maternal age, BMI, maternal ethnicity, parity, previous GDM, and family history of diabetes. The pGCD59 levels were significantly higher in women with GDM compared to women with normal glucose tolerance (p = 0.003). The pGCD59 generated an adjusted AUC for identifying GDM cases of 0.65 (95%CI: 0.58−0.71, p < 0.001). The pGCD59 predicted GDM status diagnosed by a fasting glucose value of 5.1 mmol/L with an adjusted AUC of 0.74 (95%CI: 0.65−0.81, p < 0.001). Analysis of BMI subgroups determined that pGCD59 generated the highest AUC in the 35 kg/m2 ≤ BMI < 40 kg/m2 (AUC: 0.84 95%CI: 0.69−0.98) and BMI ≥ 40 kg/m2 (AUC: 0.96 95%CI: 0.86−0.99) categories. This study found that second trimester pGCD59 is a fair predictor of GDM status diagnosed by elevated fasting glucose independent of BMI and an excellent predictor of GDM in subjects with a very high BMI.

The Role of Early Pregnancy Maternal pGCD59 Levels in Predicting Neonatal Hypoglycemia-Subanalysis of the DALI Study.

CONTEXT: Neonatal hypoglycaemia (NH) is the most common metabolic problem in infants born of mothers with gestational diabetes. Plasma glycated CD59 (pGCD59) is an emerging biomarker that has shown potential in identifying women at risk of developing gestational diabetes. The aim of this study was to assess the association between early maternal levels of pGCD59 and NH. OBJECTIVE: The aim of this study was to assess the association between early pregnancy maternal levels of plasma glycated CD59 (pGCD59) and neonatal hypoglycemia (NH). METHODS: This is an observational study of pregnant women with a prepregnancy body mass index (BMI) greater than or equal to 29 screened for eligibility to participate in the Vitamin D and Lifestyle Intervention for Gestational Diabetes (DALI) trial. This analysis included 399 pregnancies. Levels of pGCD59 were measured in fasting maternal samples taken at the time of a 75-g, 2-hour oral glucose tolerance test performed in early pregnancy (< 20 weeks). NH, the study outcome, was defined as a heel-prick capillary glucose level of less than 2.6 mmol/L within 48 hours of delivery. RESULTS: We identified 30 infants with NH. Maternal levels of pGCD59 in early pregnancy were positively associated with the prevalence of NH (one-way analysis of variance, P < .001). The odds of NH were higher in infants from mothers in tertile 3 of pGCD59 levels compared to those from mothers in tertile 1 (odds ratio [OR]: 2.41; 95% CI, 1.03-5.63). However, this was attenuated when adjusted for maternal BMI (OR: 2.28; 95% CI, 0.96-5.43). The cross-validated area under the curve (AUC) was 0.64 (95% CI, 0.54-0.74), and adjusted for maternal BMI, age, and ethnicity, the AUC was 0.70 (95% CI, 0.56-0.78). CONCLUSION: Although pGCD59 levels in early pregnancy in women with BMI greater than or equal to 29 are associated with NH, our results indicate that this biomarker by itself is only a fair predictor of NH.

Complement regulator CD59 protects against angiotensin II-induced abdominal aortic aneurysms in mice.

BACKGROUND: Complement system, an innate immunity, has been well documented to play a critical role in many inflammatory diseases. However, the role of complement in the pathogenesis of abdominal aortic aneurysm, which is considered an immune and inflammatory disease, remains obscure. METHODS AND RESULTS: Here, we evaluated the pathogenic roles of complement membrane attack complex and CD59, a key regulator that inhibits the membrane attack complex, in the development of abdominal aortic aneurysm. We demonstrated that in the angiotensin II-induced abdominal aortic aneurysm model, deficiency of the membrane attack complex regulator CD59 in ApoE-null mice (mCd59ab(-/-)/ApoE(-/-)) accelerated the disease development, whereas transgenic overexpression of human CD59 (hCD59(ICAM-2+/-)/ApoE(-/-)) in this model attenuated the progression of abdominal aortic aneurysm. The severity of aneurysm among these 3 groups positively correlates with C9 deposition, and/or the activities of MMP2 and MMP9, and/or the levels of phosphorylated c-Jun, c-Fos, IKK-alpha/beta, and p65. Furthermore, we demonstrated that the membrane attack complex directly induced gene expression of matrix metalloproteinase-2 and -9 in vitro, which required activation of the activator protein-1 and nuclear factor-kappaB signaling pathways. CONCLUSIONS: Together, these results defined the protective role of CD59 and shed light on the important pathogenic role of the membrane attack complex in abdominal aortic aneurysm.

Complement regulator CD59 protects against atherosclerosis by restricting the formation of complement membrane attack complex.

Complement is a central effector system within the immune system and is implicated in a range of inflammatory disorders. CD59 is a key regulator of complement membrane attack complex (MAC) assembly. The atherogenic role of terminal complement has long been suspected but is still unclear. Here, we demonstrate that among mice deficient in apolipoprotein (Apo)E, the additional loss of murine CD59 (mCd59ab(-/-)/ApoE(-/-)) accelerated advanced atherosclerosis featuring occlusive coronary atherosclerosis, vulnerable plaque, and premature death and that these effect could be attenuated by overexpression of human CD59 in the endothelium. Complement inhibition using a neutralizing anti-mouse C5 antibody attenuated atherosclerosis in mCd59ab(-/-)/ApoE(-/-) mice. Furthermore, MAC mediated endothelial damage and promoted foam cell formation. These combined results highlight the atherogenic role of MAC and the atheroprotective role of CD59 and suggest that inhibition of MAC formation may provide a therapeutic approach for the treatment of atherosclerosis.

Plasma glycated CD59 predicts postpartum glucose intolerance after gestational diabetes.

AIM: To assess whether in women with gestational diabetes mellitus (GDM), postpartum plasma glycated CD59 (pGCD59) levels predict conversion to glucose intolerance diagnosed with an oral glucose tolerance test (OGTT). METHODS: Blood levels of pGCD59 were measured in a case-control study of 105 women with GDM who underwent a 75 g OGTT 3 months postpartum. The 35 postpartum glucose intolerant cases were individually matched for age, BMI, ethnic origin, and parity with 70 women with GDM but normal postpartum OGTT (controls). The GDM cohort (105) was also matched with 105 normal glucose tolerant women during pregnancy. pGCD59 was measured by ELISA in standard peptide units (SPU). RESULTS: Mean pGCD59 postpartum was significantly higher in cases than in controls (1.5 ± 0.6 SPU vs 1.0 ± 0.6 SPU, P < 0.001). The area under the receiving operating characteristic curve (AUC) in cases vs controls was 0.72 (95% CI: 0.62-0.83) for postpartum pGCD59 and 0.50 (95% CI: 0.36-0.61) for postpartum HbA1c. A 0.5-unit increase in postpartum pGCD59 was associated with an odds ratio (OR) of 3.3 (95% CI: 1.82-6.16, P < 0.001) for glucose intolerance postpartum. A pGCD59 cut-off postpartum of 0.9 SPU had a sensitivity of 85.7% (95% CI: 69.7-95.2%), specificity of 47.8% (95% CI: 35.6-60.2%), positive predictive value of 45.4% (95% CI: 33.1-58.2%), and negative predictive value of 86.8% (95% CI: 71.9-95.6%). pGCD59 in pregnancy was a poor predictor for glucose intolerance postpartum (AUC of 0.61 (95% CI: 0.50-0.72)). CONCLUSION: pGCD59 might identify women at low risk for glucose intolerance postpartum and could help to avoid an OGTT.

Emerging Protein Biomarkers for the Diagnosis or Prediction of Gestational Diabetes-A Scoping Review.

Introduction: Gestational diabetes (GDM), defined as hyperglycemia with onset or initial recognition during pregnancy, has a rising prevalence paralleling the rise in type 2 diabetes (T2DM) and obesity. GDM is associated with short-term and long-term consequences for both mother and child. Therefore, it is crucial we efficiently identify all cases and initiate early treatment, reducing fetal exposure to hyperglycemia and reducing GDM-related adverse pregnancy outcomes. For this reason, GDM screening is recommended as part of routine pregnancy care. The current screening method, the oral glucose tolerance test (OGTT), is a lengthy, cumbersome and inconvenient test with poor reproducibility. Newer biomarkers that do not necessitate a fasting sample are needed for the prompt diagnosis of GDM. The aim of this scoping review is to highlight and describe emerging protein biomarkers that fulfill these requirements for the diagnosis of GDM. Materials and Methods: This scoping review was conducted according to preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines for scoping reviews using Cochrane Central Register of Controlled Trials (CENTRAL), the Cumulative Index to Nursing & Allied Health Literature (CINAHL), PubMed, Embase and Web of Science with a double screening and extraction process. The search included all articles published in the literature to July 2020. Results: Of the 3519 original database citations identified, 385 were eligible for full-text review. Of these, 332 (86.2%) were included in the scoping review providing a total of 589 biomarkers studied in relation to GDM diagnosis. Given the high number of biomarkers identified, three post hoc criteria were introduced to reduce the items set for discussion: we chose only protein biomarkers with at least five citations in the articles identified by our search and published in the years 2017-2020. When applied, these criteria identified a total of 15 biomarkers, which went forward for review and discussion. Conclusions: This review details protein biomarkers that have been studied to find a suitable test for GDM diagnosis with the potential to replace the OGTT used in current GDM screening protocols. Ongoing research efforts will continue to identify more accurate and practical biomarkers to take GDM screening and diagnosis into the 21st century.

Novel Biochemical Markers of Glycemia to Predict Pregnancy Outcomes in Women With Type 1 Diabetes.

OBJECTIVE: The optimal method of monitoring glycemia in pregnant women with type 1 diabetes remains controversial. This study aimed to assess the predictive performance of HbA1c, continuous glucose monitoring (CGM) metrics, and alternative biochemical markers of glycemia to predict obstetric and neonatal outcomes. RESEARCH DESIGN AND METHODS: One hundred fifty-seven women from the Continuous Glucose Monitoring in Women With Type 1 Diabetes in Pregnancy Trial (CONCEPTT) were included in this prespecified secondary analysis. HbA1c, CGM data, and alternative biochemical markers (glycated CD59, 1,5-anhydroglucitol, fructosamine, glycated albumin) were compared at ∼12, 24, and 34 weeks' gestation using logistic regression and receiver operating characteristic (ROC) curves to predict pregnancy complications (preeclampsia, preterm delivery, large for gestational age, neonatal hypoglycemia, admission to neonatal intensive care unit). RESULTS: HbA1c, CGM metrics, and alternative laboratory markers were all significantly associated with obstetric and neonatal outcomes at 24 weeks' gestation. More outcomes were associated with CGM metrics during the first trimester and with laboratory markers (area under the ROC curve generally <0.7) during the third trimester. Time in range (TIR) (63-140 mg/dL [3.5-7.8 mmol/L]) and time above range (TAR) (>140 mg/dL [>7.8 mmol/L]) were the most consistently predictive CGM metrics. HbA1c was also a consistent predictor of suboptimal pregnancy outcomes. Some alternative laboratory markers showed promise, but overall, they had lower predictive ability than HbA1c. CONCLUSIONS: HbA1c is still an important biomarker for obstetric and neonatal outcomes in type 1 diabetes pregnancy. Alternative biochemical markers of glycemia and other CGM metrics did not substantially increase the prediction of pregnancy outcomes compared with widely available HbA1c and increasingly available CGM metrics (TIR and TAR).

Plasma Glycated CD59 Predicts Early Gestational Diabetes and Large for Gestational Age Newborns.

CONTEXT: Gestational diabetes mellitus (GDM) diagnosed in early pregnancy is a health care challenge because it increases the risk of adverse outcomes. Plasma-glycated CD59 (pGCD59) is an emerging biomarker for diabetes and GDM. The aim of this study was to assess the performance of pGCD59 as a biomarker of early GDM and its association with delivering a large for gestational age (LGA) infant. OBJECTIVES: To assess the performance of pGCD59 to identify women with GDM in early pregnancy (GDM < 20) and assess the association of pGCD59 with LGA and potentially others adverse neonatal outcomes linked to GDM. METHODS: Blood levels of pGCD59 were measured in samples from 693 obese women (body mass index > 29) undergoing a 75-g, 2-hour oral glucose tolerance test (OGTT) at <20 weeks' gestation in the Vitamin D and Lifestyle Intervention study: the main analyses included 486 subjects who had normal glucose tolerance throughout the pregnancy, 207 who met criteria for GDM at <20 weeks, and 77 diagnosed with GDM at pregnancy weeks 24 through 28. Reference tests were 75-g, 2-hour OGTT adjudicated based on International Association of Diabetes and Pregnancy Study Group criteria. The index test was a pGCD59 ELISA. RESULTS: Mean pGCD59 levels were significantly higher (P < 0.001) in women with GDM < 20 (3.9 ±â€…1.1 standard peptide units [SPU]) than in those without (2.7 ±â€…0.7 SPU). pGCD59 accurately identified GDM in early pregnancy with an area under the curve receiver operating characteristic curves of 0.86 (95% confidence interval [CI], 0.83-0.90). One-unit increase in maternal pGCD59 level was associated with 36% increased odds of delivering an LGA infant (odds ratio for LGA vs non-LGA infant: 1.4; 95% CI, 1.1-1.8; P = 0.016). CONCLUSION: Our results indicate that pGCD59 is a simple and accurate biomarker for detection of GDM in early pregnancy and risk assessment of LGA.

Generation and phenotyping of mCd59a and mCd59b double-knockout mice.

CD59 is a membrane protein inhibitor of the membrane attack complex (MAC) of complement. Humans express only one, whereas mice express two CD59 genes. We previously reported the targeted deletion of the mCd59b gene in which absence of mCd59b together with an unintended down regulation of mCd59a caused hemolytic anemia with spontaneous platelet activation. To confirm the complement role in the hemolytic anemia caused by abrogation of mCd59 function, we have developed a mCd59a and mCd59b double knock out mice and analyzed its phenotype in complement sufficient and deficient (C3(-/-)). We report here that total abrogation of mCd59 function in mCd59ab(-/-) mice results in complement-mediated hemolytic anemia that is rescued by the deficiency of C3 in compound mCd59ab(-/-)/C3(-/-) mice.