First trimester serum afamin concentrations are associated with the development of pre-eclampsia and gestational diabetes mellitus in pregnant women

First Trimester Placental Biomarkers for Pregnancy Outcomes

The placenta plays a key role in several adverse obstetrical outcomes, such as preeclampsia, intrauterine growth restriction and gestational diabetes mellitus. The early identification of at-risk pregnancies could significantly improve the management, therapy and prognosis of these pregnancies, especially if these at-risk pregnancies are identified in the first trimester. The aim of this review was to summarize the possible biomarkers that can be used to diagnose early placental dysfunction and, consequently, at-risk pregnancies. We divided the biomarkers into proteins and non-proteins. Among the protein biomarkers, some are already used in clinical practice, such as the sFLT1/PLGF ratio or PAPP-A; others are not yet validated, such as HTRA1, Gal-3 and CD93. In the literature, many studies analyzed the role of several protein biomarkers, but their results are contrasting. On the other hand, some non-protein biomarkers, such as miR-125b, miR-518b and miR-628-3p, seem to be linked to an increased risk of complicated pregnancy. Thus, a first trimester heterogeneous biomarkers panel containing protein and non-protein biomarkers may be more appropriate to identify and discriminate several complications that can affect pregnancies.

Circulating afamin positively correlated with the miR-122 expression and type 2 diabetes mellitus-related phenotype according to the duration of diabetes

Background

Afamin is a hepatokine that involves in glucose and lipids metabolism. miR-122 is mainly expressed in liver and involves in lipid and carbohydrate metabolism. This study aimed at investigating the circulating afamin, its correlation with type 2 diabetes mellitus (T2DM) and miR-122 gene expression in T2DM patients and healthy control subjects according to the duration of diabetes.

Methods

This case-control study included 220 participants, with 100 individuals serving as controls and 120 individuals diagnosed with type 2 diabetes mellitus (T2DM). The miR-122 gene expression was assessed using real-time PCR. The serum concentration of biochemical parameters such as glucose levels, lipid profile, and small-dense low-density lipoprotein (sdLDL) were measured using colorimetric kits. Circulating afamin and insulin levels were assayed using an ELISA kit. Glycated hemoglobin (HbA1c) was measured using capillary electrophoresis.

Results

Circulating afamin level was significantly higher in T2DM patients compared to the control group, (73.8 ± 10.8 vs. 65.9 ± 8.7, respectively; P < 0.001). Similarly, miR122 expression was significantly increased in T2DM patients compared to healthy control subjects (4.24 ± 2.01 vs. 1.00 ± 0.85, respectively; P < 0.001). Among patients diagnosed with T2DM, those with longstanding diabetes (>5 years) exhibited significantly higher levels of circulating afamin and miR-122 expression compared to individuals with a shorter duration of diabetes (≤5 years) (P < 0.05). Circulating afamin levels were significantly correlated with waist circumference, small-dense low-density lipoprotein (sdLDL), fasting blood sugar (FBS), insulin, resistance to insulin, and miR-122 expression, depending on the duration of the disease (P < 0.05). Furthermore, the performance of afamin as a diagnostic marker for T2DM was confirmed through receiver operating characteristic (ROC) analysis, yielding an area under the curve (AUC) of 0.7 (P < 0.001).

Conclusions

Circulating afamin involved in the T2DM-related complications and its concentration is positively correlated to the miR-122 expression, especially in patient with longstanding diabetes.

Comparison of Afamin Values in Umbilical Cord Blood After Delivery in Pregnancies With and Without Gestational Diabetes Mellitus

OBJECTIVE

Afamin is a protein that increases in gestational diabetes but its concentration in neonates hasn't been investigated. Our objective is to compare cord blood afamin levels in neonates born to mothers with and without diabetes, and to explore its relationship with maternal and neonatal variables.

METHODS

In this case control study, umbilical cord blood was collected for afamin measurement in pregestational/gestational diabetic pregnancies (n = 40) and healthy pregnancies (n = 45) after delivery. Correlation analysis was conducted to examine the relationship between afamin levels and maternal BMI, age, HbA1c, fasting and postprandial blood glucose, gestational age, birth weight.

RESULTS

The diabetic group had a higher median afamin level (p < 0.001). Afamin concentrations did not differ significantly between diabetic subgroups. The concentration of afamin in cord blood was independent of maternal BMI, age, HbA1c, blood glucose, gestational age, birth weight.

CONCLUSION

The concentration of afamin in cord blood of diabetic pregnancies is significantly higher, irrespective of other clinical factors.

Early Pregnancy Markers in the Serum of Ewes Identified via Proteomic and Metabolomic Analyses

The diagnosis of ewes' pregnancy status at an early stage is an efficient way to enhance the reproductive output of sheep and allow producers to optimize production and management. The techniques of proteomics and metabolomics have been widely used to detect regulatory factors in various physiological processes of animals. The aim of this study is to explore the differential metabolites and proteins in the serum of pregnant and non-pregnant ewes by proteomics and metabolomics. The serum of ewes at 21, 28 and 33 days after artificial insemination (AI) were collected. The pregnancy stratus of the ewes was finally determined through ultrasound examination and then the ewes were grouped as Pregnant (n = 21) or N on-pregnant (n = 9). First, the serum samples from pregnant or non-pregnant ewes at 21 days after AI were selected for metabolomic analysis. It was found that the level of nine metabolites were upregulated and 20 metabolites were downregulated in the pregnant animals (p < 0.05). None of these differential metabolomes are suitable as markers of pregnancy due to their small foldchange. Next, the proteomes of serum from pregnant or non-pregnant ewes were evaluated. At 21 days after AI, the presence of 321 proteins were detected, and we found that the level of three proteins were upregulated and 11 proteins were downregulated in the serum of pregnant ewes (p < 0.05). The levels of serum amyloid A (SAA), afamin (AFM), serpin family A member 6 (SERPINA6) and immunoglobulin-like domain-containing protein between pregnant and non-pregnant ewes at 21-, 28- and 33-days post-AI were also analyzed via enzyme-linked immunosorbent assay (ELISA). The levels of SAA and AFM were significantly higher in pregnant ewes than in non-pregnant ewes, and could be used as markers for early pregnancy detection. Overall, our results show that SAA and AFM are potential biomarkers to determine the early pregnancy status of ewes.

Serum afamin levels in predicting gestational diabetes mellitus and preeclampsia: A systematic review and meta-analysis

OBJECTIVES

The association between biomarkers and the risk of gestational diabetes mellitus (GDM) or preeclampsia (PE) has been extensively studied. However, there is still a lack of convenient, specific, and sensitive indicators for early identification of GMD and PE. Therefore, we conducted a meta-analysis of published articles to investigate the value of afamin circulating levels in the early diagnosis of GDM and PE.

METHODS

We searched the PubMed, Embase, Cochrane Library, and Web of Science databases for English studies published before November 16, 2022, that examined the association between afamin and GDM or PE. In addition, we searched Clinicaltrials.gov for the relevant completed and ongoing clinical trials. Pooled standard mean differences (SMDs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs) were used to compare the levels of afamin in different groups.

RESULTS

Eleven studies were included in our analysis (N = 3047 participants: 1195 GDM, 1407 non-GDM, 195 PE, and 250 non-PE). Subgroup analysis based on different blood collection periods found that the plasma afamin levels in pregnant women with GDM in the first trimester were significantly higher than those in healthy pregnant women (SMD = 0.481, 95% CI: 0.280-0.682), but the analysis showed the opposite results in the second and late stages (SMD = 0.292, 95% CI: -0.092-0.676). The plasma afamin levels of pregnant women with PE in the first trimester (SMD = 0.808, 95% CI: 0.558-1.059) and second/third trimesters (SMD = 0.904, 95% CI: 0.570-1.239) were significantly higher than those in healthy pregnant women.

CONCLUSION

The plasma afamin levels in pregnant women with GDM in the first trimester were significantly higher than those in healthy pregnant women, but the analysis showed the opposite results in the second and third trimesters. The plasma afamin levels in pregnant women with PE in the first, second, and third trimesters were significantly higher than those in healthy pregnant women. Additional large-scale prospective studies are desired to verify these findings, and it is recommended that afamin should be included as a routine diagnostic test for women with GDM and PE.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=339171, identifier CRD42022339171.

Evaluation of first- and third-trimester afamin levels in preeclampsia

OBJECTIVE

The aim of this study was to investigate serum afamin levels in the first and third trimesters in preeclampsia.

METHODS

Serum samples from 118 patients in the first and third trimesters were analyzed. Serum samples were collected from pregnant women who had enrolled in the first trimester. Blood was then collected from pregnant women who had developed preeclampsia and from healthy controls in the third trimester. The collected blood samples were resolved for analysis, and serum afamin concentrations were measured in the first and third trimesters. Preeclampsia and healthy controls were compared.

RESULTS

There was no significant difference between the control and preeclampsia groups in terms of age, body mass index, and smoking. Afamin levels in the first and third trimesters were higher in the preeclampsia group than in the control group (p<0.05). In the subgroup analysis of the preeclampsia group, afamin levels were higher in the early-onset preeclampsia group than in the late-onset preeclampsia group in the first and third trimesters (p<0.05). In the receiver operating characteristic analysis afamin levels were 96.23 ng/mL in the first trimester and 123.57 ng/mL in the third trimester as cut-off values for preeclampsia.

CONCLUSION

Serum afamin levels are useful for predicting preeclampsia in the first trimester in pregnant women and can be used in clinical practice as a supportive biomarker for the diagnosis of preeclampsia in the third trimester. Meta-analyzes are needed to investigate the effect of afamin levels in the prediction and diagnosis of preeclampsia and to determine the cut-off value.

Clinical Significance of Neuregulin 4, Afamin, and SERPINB1 in Gestational Diabetes Mellitus and Their Relationship with Insulin Resistance

Objective

This study aims to explore the serum levels of neuregulin 4 (NRG4), afamin (AFM), and serpin family B member 1 (SERPINB1) in gestational diabetes mellitus (GDM) patients and their relationship with insulin resistance.

Method

Serum levels of AFM, SERPINB1, and NRG4 were measured in GDM (n = 58), and non-GDM women (n = 60) using enzyme-linked immunosorbent assay (ELISA) kits. Besides, the serum insulin and glucose levels were also measured followed by calculating the homeostatic model assessment of insulin resistance (HOMA-IR). The correlation was performed using the Pearson analysis.

Results

The increased serum levels of AFM and SERPINB1 were revealed in GDM patients as compared with non-GDM women, accompanied by the lower NRG4 serum level. ROCs for AFM concentrations showed an AUC of 0.629 (95% CI: 0.527∼0.731), 0.832 (95% CI: 0.754∼0.909) for the SERPINB1 serum level, and 0.626 (95% CI: 0.524∼0.728) for the NRG4 serum level. The threshold was 108.05 mg/L, 8.75 ng/mL, and 96.25 ng/mL of AFM, SERPINB1, and NRG4. Moreover, the combined ROC of AFM, SERPINB1, and NRG4 serum levels showed higher sensitivity (72.41%) and specificity (85.00%) for the diagnosis of GDM (AUC = 0.839; 95% CI: 0.764∼0.913). In GDM patients, the Pearson analysis revealed a significant correlation between AFM and SERPINB1 (r = 0.776), AFM and NRG4 (r = -0.799), as well as SERPINB1 and NRG4 (r = -0.783). Moreover, AFM and SERPINB1 serum concentrations in GDM patients were positively related to insulin levels, fasting glucose levels, and HOMA-IR values. However, the SERPINB1 serum level was negatively correlated with serum insulin and glucose levels and HOMA-IR.

Conclusion

Abnormal serum levels of NRG4, AFM, and SERPINB1, as highly sensitive diagnostic tools, are closely related to insulin resistance in GDM patients.

Gestational Diabetes Mellitus in Europe: A Systematic Review and Meta-Analysis of Prevalence Studies

Background

Gestational Diabetes Mellitus (GDM) is defined as the type of hyperglycemia diagnosed for the first-time during pregnancy, presenting with intermediate glucose levels between normal levels for pregnancy and glucose levels diagnostic of diabetes in the non-pregnant state. We aimed to systematically review and meta-analyze studies of prevalence of GDM in European countries at regional and sub-regional levels, according to age, trimester, body weight, and GDM diagnostic criteria.

Methods

Systematic search was conducted in five databases to retrieve studies from 2014 to 2019 reporting the prevalence of GDM in Europe. Two authors have independently screened titles and abstracts and full text according to eligibility using Covidence software. A random-effects model was used to quantify weighted GDM prevalence estimates. The National Heart, Lung, and Blood Institute criteria was used to assess the risk of bias.

Results

From the searched databases, 133 research reports were deemed eligible and included in the meta-analysis. The research reports yielded 254 GDM-prevalence studies that tested 15,572,847 pregnant women between 2014 and 2019. The 133 research reports were from 24 countries in Northern Europe (44.4%), Southern Europe (27.1%), Western Europe (24.1%), and Eastern Europe (4.5%). The overall weighted GDM prevalence in the 24 European countries was estimated at 10.9% (95% CI: 10.0-11.8, I2 : 100%). The weighted GDM prevalence was highest in the Eastern Europe (31.5%, 95% CI: 19.8-44.6, I2 : 98.9%), followed by in Southern Europe (12.3%, 95% CI: 10.9-13.9, I2 : 99.6%), Western Europe (10.7%, 95% CI: 9.5-12.0, I2 : 99.9%), and Northern Europe (8.9%, 95% CI: 7.9-10.0, I2 : 100). GDM prevalence was 2.14-fold increased in pregnant women with maternal age ≥30 years (versus 15-29 years old), 1.47-fold if the diagnosis was made in the third trimester (versus second trimester), and 6.79- fold in obese and 2.29-fold in overweight women (versus normal weight).

Conclusions

In Europe, GDM is significant in pregnant women, around 11%, with the highest prevalence in pregnant women of Eastern European countries (31.5%). Findings have implications to guide vigilant public health awareness campaigns about the risk factors associated with developing GDM.

Systematic Review Registration

PROSPERO [https://www.crd.york.ac.uk/PROSPERO/], identifier CRD42020161857.

Protein biomarkers in serum as a conservation tool to assess reproduction: a case study on brown bears (Ursus arctos)

Monitoring the reproductive characteristics of a species can complement existing conservation strategies by understanding the mechanisms underlying demography. However, methodology to determine important aspects of female reproductive biology is often absent in monitoring programs for large mammals. Protein biomarkers may be a useful tool to detect physiological changes that are indicative of reproductive state. This study aimed to identify protein biomarkers of reproductive status in serum collected from free-ranging female brown bears (Ursus arctos) in Alberta, Canada, from 2001 to 2018. We hypothesized that the expression of proteins related to reproduction in addition to energetics and stress can be used to answer specific management-focused questions: (i) identify when a female is pregnant, (ii) detect if a female is lactating, (iii) determine age of sexual maturity (i.e. primiparity) and (iv) assess female fertility (i.e. reproduction rate). Furthermore, we investigated if silver spoon effects (favourable early life conditions provide fitness benefits through adulthood) could be determined using protein expression. A target panel of 19 proteins with established relationships to physiological function was measured by peptide-based analysis using liquid chromatography and multiple reaction monitoring mass spectrometry and their differential expression was evaluated using a Wilcoxon signed-rank test. We found biomarkers of pregnancy (apolipoprotein B-100 and afamin), lactation (apolipoprotein B-100 and alpha-2-macroglobulin) and sexual maturity (corticosteroid-binding globulin), but there were no statistically significant relationships with protein expression and fertility. The expression of proteins related to reproduction (afamin) and energetics (vitamin-D binding protein) was associated with the nutritional quality of the individual's present habitat rather than their early life habitat. This study highlights potential biomarkers of reproductive status and provides additional methods for monitoring physiological function in wildlife to inform conservation.

The Role of Afamin and Other Trace Elements in the Prediction of GDM: a Tertiary Center Experience

The objective of this study was to evaluate the utility of first trimester maternal serum afamin levels together with vitamin E and various elements (zinc, copper, selenium, and magnesium) for the prediction of gestational diabetes mellitus (GDM). All pregnant women between 11th and 14th weeks of gestation admitted for combined test were asked to participate in the study. A total of 797 women gave permission to participate in the study between January and September 2019. Serum was obtained by centrifugation and samples were frozen and kept at - 80 °C. For final analysis, forty-three GDM patients and forty-four healthy controls were selected. Levels of afamin, vitamin E, zinc, copper, selenium, and magnesium were compared between groups. The mean levels of afamin were found to be higher in women with GDM without statistical significance (63.69 ± 82.33 vs 44.25 ± 32.25 mg/L, p = 0.149). Vitamin E levels were found to be higher in women with GDM compared to controls without any statistical significance (5.04 ± 5.33 vs 4.47 ± 3.83 μg/mL, p = 0.568). While first trimester copper concentrations were higher among diabetic women (187.26 ± 34.78 vs 175.17 ± 30.40 μg/L, p = 0.088), this was not statistically significant. The other element levels (zinc, selenium, and magnesium) were found to be similar between the two groups (p = 0.624, p = 0.088, p = 0.254, p = 0.872, respectively). The results of our study demonstrated that mean levels of afamin, vitamin E, and copper were higher in women with GDM compared to controls. Additionally, first trimester maternal zinc, selenium, and magnesium levels were similar between diabetic and healthy pregnant women. However, more studies are needed to clarify the relationship between blood trace concentrations and GDM.

Hepatokine levels during the first or early second trimester of pregnancy and the subsequent risk of gestational diabetes mellitus: a systematic review and meta-analysis

PURPOSE

The relationship between hepatokine levels during the first or early second trimester of pregnancy and the subsequent risk of gestational diabetes mellitus (GDM) have been studied extensively. However, conclusions remain debateable whether hepatokines are potential markers of GDM. We conducted a meta-analysis of published articles to understand the association between circulating levels of selected hepatokines (including FGF21, fetuin-A, afamin, adropin, ficolin-3, selenoprotein P, ANGPTL4 and AGF) and the risk of GDM.

MATERIALS AND METHODS

We searched the PubMed, Embase, Cochrane Library and Web of Science databases for studies published before January 2021 that examined the association between hepatokines and GDM (Prospero Registration# CRD42020191408). The quality was assessed by the Newcastle-Ottawa Scale (NOS). Pooled standard mean differences (SMDs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs) were used to compare the levels of hepatokines in different groups using fixed effects or random effects models. Meta-regression analysis and publication bias were conducted in accordance with standard methods. The trim-fill adjustment method was used to further assess the possible effect of publication bias. Sensitivity analysis was performed by omitting each study one at a time.

RESULTS

The meta-analysis included 31 observational studies relating hepatokine levels to GDM in 4729 participants (1908 GDM, 2821 non-GDM). Serum FGF21 levels in patients with GDM were higher than those in healthy pregnant women during the second trimester and after delivery (SMD 0.89, [95% CI] 0.01-1.78 for the second trimester; SMD 1.42, [95% CI] 0.86-1.98 for after delivery). The serum levels of afamin in patients with GDM were significantly higher than those in healthy pregnant women during the first trimester and before pregnancy (SMD 0.51, [95% CI] 0.15-0.86 for first trimester; SMD 0.97, [95% CI] 0.45-1.50 for before pregnancy). Serum adropin levels in patients with GDM were higher than those in healthy pregnant women during the first and third trimesters of pregnancy (SMD 4.26, [95% CI] 3.30-5.23 for the first trimester; SMD 4.02, [95% CI] 3.09-4.94 for the third trimester). The serum levels of ficolin-3 in GDM patients were higher than those in healthy pregnant women during the second and third trimesters of pregnancy (WMD 1.43, [95% CI] 0.91-1.96 for the second trimester; SMD 1.28, [95% CI] 0.72-1.84 for the third trimester). The serum AGF level of patients with GDM was higher than that of healthy pregnant women in the control group in the third trimester (WMD 61 [95% CI] 37.04-81.96). The serum levels of selenoprotein P in patients with GDM were higher than those in healthy pregnant women in the control group during the first trimester (WMD 7.09 [95% CI] 4.6-9.57).

CONCLUSIONS

Measurement of circulating hepatokines in the first or second trimester of pregnancy may improve the identification of women at risk of developing GDM later. Prospective evaluation of the combination of hepatokines and maternal characteristics for early identification of those who do and do not require OGTT is warranted. Additional well-designed prospective studies with longitudinal assessment of hepatokines during pregnancy are needed to understand the trajectories and dynamic associations of hepatokines with GDM risk.

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.

Serum Afamin a Novel Marker of Increased Hepatic Lipid Content

AIM

Afamin is a liver-produced glycoprotein, a potential early marker of metabolic syndrome. Here we investigated regulation of afamin in a course of the metabolic disease development and in response to 3-month exercise intervention.

METHODS

We measured whole-body insulin sensitivity (euglycemic hyperinsulinemic clamp), glucose tolerance, abdominal adiposity, hepatic lipid content (magnetic resonance imaging/spectroscopy), habitual physical activity (accelerometers) and serum afamin (enzyme-linked immunosorbent assay) in 71 middle-aged men with obesity, prediabetes and newly diagnosed type 2 diabetes. Effects of 3-month exercise were investigated in 22 overweight-to-obese middle-aged individuals (16M/6F).

RESULTS

Prediabetes and type 2 diabetes, but not obesity, were associated with increased serum afamin (p<0.001). Afamin correlated positively with hepatic lipids, fatty liver index and liver damage markers; with parameters of adiposity (waist circumference, %body fat, adipocyte diameter) and insulin resistance (fasting insulin, C-peptide, HOMA-IR; p<0.001 all). Moreover, afamin negatively correlated with whole-body insulin sensitivity (M-value/Insulin, p<0.001). Hepatic lipids and fasting insulinemia were the most important predictors of serum afamin, explaining >63% of its variability. Exercise-related changes in afamin were paralleled by reciprocal changes in insulinemia, insulin resistance and visceral adiposity. No significant change in hepatic lipid content was observed.

CONCLUSIONS

Subjects with prediabetes and type 2 diabetes had the highest serum afamin levels. Afamin was more tightly related to hepatic lipid accumulation, liver damage and insulin resistance than to obesity.

Is afamin a potential early biomarker for subsequent development of preeclampsia? A nested case-control study

OBJECTIVE

The objective of this study is to determine if the second-trimester serum afamin is a reasonable predictor of preeclampsia (PE).

METHODS

In this nested case-control study, all pregnant women were screened by second-trimester screening test between 15 and 20 weeks of gestation and serum samples were collected and stored at -80 °C for biochemical analysis. All available stored samples from pregnant women who subsequently developed PE were thawed and the concentrations of afamin in the serum were measured. Control cases, chosen randomly from the same cohort whose blood was collected and stored in the same period as with the study group, who did not develop PE. Afamin levels were expressed ng/mL. Logistic regression was used to calculate adjusted odds ratio (aORs) for the prediction of PE.

RESULTS

A total of 39 women with PE and 46 controls were studied. Afamin levels were found to be significantly higher during the second trimester in women who developed PE compared to the control group. Afamin, at a cut-off level of 96.2 ng/mL, the aORs for PE was 28.6 (95% CI: 7.458-110.193). After adjustment for BMI, age, smoking, the aORs for PE was 65.6 (95% CI: 11.6-371.4; p = .001).

CONCLUSION

High levels of afamin in the early weeks of gestation in patients going on to develop PE later may be promising as a potential marker to predict PE in the first and second trimesters.

Controlled dehydration, structural flexibility and gadolinium MRI contrast compound binding in the human plasma glycoprotein afamin

Afamin, which is a human blood plasma glycoprotein, a putative multifunctional transporter of hydrophobic molecules and a marker for metabolic syndrome, poses multiple challenges for crystallographic structure determination, both practically and in analysis of the models. Several hundred crystals were analysed, and an unusual variability in cell volume and difficulty in solving the structure despite an ∼34% sequence identity with nonglycosylated human serum albumin indicated that the molecule exhibits variable and context-sensitive packing, despite the simplified glycosylation in insect cell-expressed recombinant afamin. Controlled dehydration of the crystals was able to stabilize the orthorhombic crystal form, reducing the number of molecules in the asymmetric unit from the monoclinic form and changing the conformational state of the protein. An iterative strategy using fully automatic experiments available on MASSIF-1 was used to quickly determine the optimal protocol to achieve the phase transition, which should be readily applicable to many types of sample. The study also highlights the drawback of using a single crystallographic structure model for computational modelling purposes given that the conformational state of the binding sites and the electron density in the binding site, which is likely to result from PEGs, greatly varies between models. This also holds for the analysis of nonspecific low-affinity ligands, where often a variety of fragments with similar uncertainty can be modelled, inviting interpretative bias. As a promiscuous transporter, afamin also seems to bind gadoteridol, a magnetic resonance imaging contrast compound, in at least two sites. One pair of gadoteridol molecules is located near the human albumin Sudlow site, and a second gadoteridol molecule is located at an intermolecular site in proximity to domain IA. The data from the co-crystals support modern metrics of data quality in the context of the information that can be gleaned from data sets that would be abandoned on classical measures.

Omics-based biomarkers in the diagnosis of diabetes

Diabetes mellitus (DM) is a group of metabolic diseases related to the dysfunction of insulin, causing hyperglycaemia and life-threatening complications. Current early screening and diagnostic tests for DM are based on changes in glucose levels and autoantibody detection. This review evaluates recent studies on biomarker candidates in diagnosing type 1, type 2 and gestational DM based on omics classification, whilst highlighting the relationship of these biomarkers with the development of diabetes, diagnostic accuracy, challenges and future prospects. In addition, it also focuses on possible non-invasive biomarker candidates besides common blood biomarkers.

Down-regulated long non-coding RNA PVT1 contributes to gestational diabetes mellitus and preeclampsia via regulation of human trophoblast cells

OBJECTIVE

We aimed to explore the expression level and biological function of lncRNA PVT1 in human trophoblast cells.

METHODS

The expression levels of PVT1 in cancer cell lines, HTR8/SVneo cell, HUVEC cell, the maternal placenta of GDM patients, PE patients and normal pregnancy were detected by qRT-PCR. The cell culture, cell transfection, CCK-8 assay, flow cytometry, wound scratch assay and transwell were carried out to determine the effects of silencing and overexpression of PVT1 on the HTR8/SVneo trophoblast cell line. Nuclear and chromatin RNA fraction assay, RNA-sequencing, western blot and qRT-PCR were conducted to preliminarily explore possible mechanisms.

RESULTS

The relative PVT1 expression level in HTR-8/Svneo cells was higher compared to other cancer cells and HUVEC, and was lower in the GDM and PE placentas than in the normal placentas. The results showed that PVT1 knockdown notably inhibited the proliferation, migration and invasiveness abilities of trophoblast cells, and significantly promoted the apoptosis. Furthermore, overexpression of PVT1 showed the opposite results. We identified 105 differentially expressed genes after PVT1 knockdown, 23 were up-regulated and 82 were down-regulated. GO enrichment analysis and pathway enrichment analysis showed that the DEGs were closely related to the functional changes of trophoblast cells. Because of the enrichment of 7 DEGs and less Q value, PI3K/AKT pathway was prominent and attracted our attention. More importantly, we confirmed that knockdown of PVT1 obviously decreased AKT phosphorylation and decreased the expression of DEGs (GDPD3, ITGAV and ITGB8) while overexpression of PVT1 promoted the AKT phosphorylation and increased the expression of DEGs (GDPD3, ITGAV and ITGB8). PVT1 was primarily distributed in the nuclear compartment and also distributed in the cytoplasmic of HTR-8/Svneo cells.

CONCLUSIONS

This study provided the evidence that PVT1 played a vital role in trophoblast cells, and it is important for maintaining the normal physiological function of trophoblast cells. The PVT1 expression was lower in the GDM and PE placentas than the normal placentas, which might disrupt the function of trophoblast cells through PI3K/AKT pathway.

First-trimester proteomic profiling identifies novel predictors of gestational diabetes mellitus

Background

Gestational diabetes mellitus (GDM) is a common pregnancy complication associated with adverse outcomes including preeclampsia, caesarean section, macrosomia, neonatal morbidity and future development of type 2 diabetes in both mother and child. Current selective screening strategies rely on clinical risk factors such as age, family history of diabetes, macrosomia or GDM in a previous pregnancy, and they possess a relatively low specificity. Here we hypothesize that novel first trimester protein predictors of GDM can contribute to the current selective screening strategies for early and accurate prediction of GDM, thus allowing for timely interventions.

Methods

A proteomics discovery approach was applied to first trimester sera from obese (BMI ≥27 kg/m²) women (n = 60) in a nested case-control study design, utilizing tandem mass tag labelling and tandem mass spectrometry. A subset of the identified protein markers was further validated in a second set of serum samples (n = 210) and evaluated for their contribution as predictors of GDM in relation to the maternal risk factors, by use of logistic regression and receiver operating characteristic analysis.

Results

Serum proteomic profiling identified 25 proteins with significantly different levels between cases and controls. Three proteins; afamin, serum amyloid P-component and vitronectin could be further confirmed as predictors of GDM in a validation set. Vitronectin was shown to contribute significantly to the predictive power of the maternal risk factors, indicating it as a novel independent predictor of GDM.

Conclusions

Current selective screening strategies can potentially be improved by addition of protein predictors.

Afamin: an early predictor of preeclampsia

Purpose

Oxidative stress is involved in the pathogenesis of hypertensive disorders such as preeclampsia (PE) and associated with the human vitamin E-binding protein afamin. The aim of this study was, therefore, to analyse afamin in the first trimester of patients developing PE later in pregnancy and in control subjects without pregnancy complications.

Methods

In this retrospective study, 137 serum samples from the first trimester of pregnancy were analysed in a case–control study design. 39 patients developed PE (10 patients with early-onset and 29 patients with late onset disease) and 98 women had an uncomplicated pregnancy. Mann–Whitney U test, t test, logistic regression and ROC analyses were performed for statistical evaluation.

Results

Pregnant women developing PE presented with higher afamin concentrations in the first trimester [median 101.81 mg/L; interquartile range (IQR) 88.94–113.26] compared to subjects with uncomplicated pregnancy (median 86.40; IQR 75.26–96.92; p < 0.001). After adjusting for confounders, the odds ratio per afamin standard deviation was 1.60 (95% CI: 1.04–2.58; p = 0.04). An afamin threshold concentration of 87.8 mg/L exhibited the best sensitivity (79.5%) and specificity (57.1%) in predicting PE. Subgroup analysis of early- and late-onset disease resulted in substantially higher afamin concentrations in women with developing late-onset PE compared to controls (p < 0.001) with an odds ratio per afamin standard deviation of 1.62 (95% CI: 0.98–2.70; p = 0.06).

Conclusions

Serum afamin concentrations are elevated in the first trimester among patients developing PE compared to controls. Substantial differences were observed mainly among patients with late-onset PE.