Manjula Nandakumar

Endothelial dysfunction has been reported in polyendocrine metabolic ovarian syndrome (PMOS) and is associated with obesity. We hypothesised that circulating biomarkers of endothelial dysfunction would not differ between non-obese women with PMOS and age- and BMI-matched controls in the absence of major between-group differences in insulin resistance (IR), systemic inflammation or vitamin D status. Plasma concentrations of 20 endothelial-associated proteins were measured using Slow Off-rate Modified Aptamer (SOMAscan) technology in 29 non-obese women with PMOS and 29 age- and BMI-matched controls. Women with PMOS had higher Ferriman–Gallwey scores, free androgen index (FAI) and anti-Müllerian hormone (AMH), whereas HOMA-IR, C-reactive protein (CRP), vitamin D metabolites and endothelial-associated biomarkers did not differ significantly between groups. Within the PMOS cohort, FAI was strongly positively associated with E-selectin (Pearson r = 0.718, p < 0.001, FDR-adjusted q = 0.027), and HOMA-IR was positively associated with ICAM-2 (r = 0.670, p = 0.001, q = 0.046). The FAI–E-selectin association remained robust in Spearman sensitivity analysis (ρ = 0.720, p < 0.001, q = 0.009), whereas the HOMA-IR–ICAM-2 association remained nominally significant (ρ = 0.579, p = 0.007) but not after FDR correction. A positive association between 24,25(OH)₂D₃ and tumour necrosis factor (TNF) was observed using Pearson correlation (r = 0.648, p = 0.002, q = 0.042), but was not retained after FDR correction in Spearman sensitivity analysis. Thus, non-obese women with PMOS did not demonstrate a generalised alteration in circulating endothelial biomarkers compared with matched controls. Hyperandrogenism, in particular, was robustly associated with endothelial activation, whereas associations with IR were less consistent and vitamin D metabolites showed no robust relationship with the endothelial biomarker profile. Collectively, the findings suggest that variation in endothelial activation in non-obese PMOS is more closely associated with metabolic dysfunction and androgen excess than with circulating vitamin D status, while the cross-sectional design precludes inference regarding causality.

Unexplained infertility (UI) accounts for an estimated 15–30% of infertility but its biological basis remains poorly defined. Plasma haemostatic abnormalities have been implicated in recurrent pregnancy loss; however, whether the circulating coagulation–fibrinolysis axis differs between women with UI and those with infertility attributable to other causes has not been characterised. The aim of this study was to compare 20 coagulation- and fibrinolysis-related proteins between women with UI and women with male-factor infertility (MFI) as control. In this exploratory case–control study, plasma from 11 women with UI and 14 women with MFI were analysed using SOMAscan proteomics. Group means were compared using Welch’s two-sample t-test, Cohen’s d with 95% confidence intervals, and a two-sided permutation test on the mean difference (20,000 random label permutations). False discovery rate (FDR) was used for multiple comparisons. Pairwise Pearson and Spearman correlations were performed. Three proteins differed between groups (p < 0.05), all lower in UI than in MFI: vitamin K-dependent protein S (Cohen’s d = −1.11, 95% CI −1.95 to −0.26; Welch p = 0.016; permutation p = 0.015), antithrombin-III (d = −1.00, 95% CI −1.84 to −0.16; p = 0.024; permutation p = 0.020) and α2-antiplasmin (d = −0.82, 95% CI −1.64 to 0.00; p = 0.051; permutation p = 0.054). No protein survived FDR correction. Within UI, the three proteins co-varied positively, with significant pairwise correlations between protein S and antithrombin-III (r = 0.67, p = 0.024) and between antithrombin-III and α2-antiplasmin (r = 0.71, p = 0.015). Within MFI, antithrombin-III and α2-antiplasmin remained tightly correlated (r = 0.70, p = 0.006) but protein S decoupled from both (r = 0.20 and 0.10, both non-significant). In this hypothesis-generating study, women with UI showed reduction in three plasma regulators of anticoagulant and antifibrinolytic capacity, protein S, antithrombin-III and α2-antiplasmin relative to women with MFI, raising the possibility that UI may be in part a subtle immunothrombotic/endothelial implantation disorder.

Diabetes mellitus encompasses a heterogeneous group of metabolic disorders defined by abnormalities in insulin secretion, function, or both. Exogenous insulin therapy has long been the principal treatment strategy for patients with type 1 diabetes and for those in advanced stages of type 2 diabetes. Stem cell therapy has gained significant attention in recent years as a potential curative approach for several life-threatening disorders. In this review, we focus on the use of induced pluripotent stem cells as an alternative source for beta-cell generation, offering a solution to organ scarcity and providing a sustainable supply of insulin-producing cells. We further evaluate current developments in encapsulation technologies and transplantation sites, while noting that the issue of immune-mediated graft rejection continues to be widely debated. The aim of this review is to outline encapsulation techniques and transplantation approaches explored in animal models, and to discuss the risks and challenges anticipated in human clinical trials.

Diabetes mellitus, both type 1 (T1D) and type 2 (T2D), has become the epidemic of the century and a major public health concern given its rising prevalence and the increasing adoption of a sedentary lifestyle globally. This multifaceted disease is characterized by impaired pancreatic beta cell function and insulin resistance (IR) in peripheral organs, namely the liver, skeletal muscle, and adipose tissue. Additional insulin target tissues, including cardiomyocytes and neuronal cells, are also affected. The advent of stem cell research has opened new avenues for tackling this disease, particularly through the regeneration of insulin target cells and the establishment of disease models for further investigation. Human-induced pluripotent stem cells (iPSCs) have emerged as a valuable resource for generating specialized cell types, such as hepatocytes, myocytes, adipocytes, cardiomyocytes, and neuronal cells, with diverse applications ranging from drug screening to disease modeling and, importantly, treating IR in T2D. This review aims to elucidate the significant applications of iPSC-derived insulin target cells in studying the pathogenesis of insulin resistance and T2D. Furthermore, recent differentiation strategies, protocols, signaling pathways, growth factors, and advancements in this field of therapeutic research for each specific iPSC-derived cell type are discussed.

Previous research has linked both endothelial protein changes and vitamin D with infertility. This study was undertaken to investigate the association of proteins associated with endothelial function and vitamin D status in the luteal phase at day 21 in a group of non-obese women prior to in vitro fertilization (IVF) with either unexplained infertility (UI) or male factor infertility (MFI). Twenty-five non-obese Caucasian women from a UK academic center with MFI (n = 14) and UI (n = 11) were recruited. Blood was withdrawn at day 21 of the menstrual cycle at the time of mock embryo transfer. Vitamin D parameters were measured by tandem mass spectroscopy. Off-rate Modified Aptamer (SOMA)-scan plasma protein measurement was undertaken for 20 protein markers of endothelial dysfunction. Baseline demographics did not differ between groups and parameters of response following IVF did not differ. Vitamins D₂ and D₃, and 1,25 Vitamin D₃ did not differ between groups. In UI, markers of endothelial activation/dysfunction were investigated; vascular cell adhesion molecule 1 (VCAM-1) decreased and this is associated with endothelial stress; vascular endothelial growth factor (VEGF) decreased and this may suggest impaired endometrial angiogenesis; while intercellular adhesion molecule 1 (ICAM-3) increased (p < 0.05) and is associated with increased immunological activity. A marker of vascular integrity, angiopoietin-1, increased while soluble angiopoietin-1 receptor (sTie-2) decreased (p < 0.05), suggesting increased vascular development. Endothelial markers of inflammation, coagulation, and endothelial progenitor cells were unchanged. Vitamin D and its metabolites show no relationship to UI, but endothelial activation/dysfunction and vascular integrity changes in VCAM-1, VEGF, sICAM-3, angiopoietin-1, and sTie-2 may contribute to UI, though the mechanisms through which they work require further evaluation; however, these protein changes have been associated with endometriosis, raising the suggestion that subclinical/undiagnosed endometriosis may have contributed to UI in these subjects.

Matrix metalloproteinases (MMPs) are M2 macrophage markers that are modulated by inflammation. A disintegrin and metalloproteinases (ADAMS) and those with thrombospondin motifs (ADAMTS) regulate the shedding of membrane-bound proteins, growth factors, cytokines, ligands, and receptors; MMPs, ADAMS, and ADAMTS may be regulated by tissue inhibitors of metalloproteinases (TIMPs). This study aimed to determine whether these interacting proteins were dysregulated in PCOS. A Somascan proteomic analysis of 12 MMPs, three of their inhibitors (TIMP-1, 2, 3), two ADAMS (9, 12), five ADAMTS (1, 4, 5, 13, 15), insulin-like growth factor binding protein-1 (IGFBP-1), and insulin-like growth factor-1 (IGF-1) was undertaken in a well-validated PCOS database of 143 women with PCOS and 97 controls. Women with PCOS had significantly higher levels of MMP-9 and lower levels of MMP-2, MMP-14, TIMP-2, IGFBP-1, and IGF-1 compared to the controls (p < 0.0001, p < 0.005, p < 0.04, p < 0.05, p < 0.0001, and p < 0.0001, respectively). No differences were observed for any other MMPs. The ADAMS or ADAMTS levels did not differ between groups. Body mass index (BMI) was correlated with MMP-9 (p < 0.01), MMP-1 (p < 0.05), MMP-2 (p < 0.05), MMP-10 (p < 0.005), MMP-12 (p < 0.005), ADAM-9 (p < 0.05), and IGFBP-1 (p < 0.0001), but only MMP-9 still differed after accounting for BMI. MMP-9/TIMP-1, MMP-9/TIMP-2, and MMP-9/TIMP-3 ratios were higher in the PCOS group (p < 0.01), whilst MMP-17/TIMP-1 and MMP-17/TIMP-2 were lower (p = 0.01). MMP-2/TIMP ratios showed no difference between groups. TIMP-2 was positively correlated with CRP (p < 0.01). MMP changes in PCOS are largely driven by BMI, though increased MMP-9 is BMI-independent, suggesting that any deleterious effects of MMP-9 would be potentially exacerbated by a concomitantly increased BMI. The significant increases in the MMP-9/TIMP ratios suggests MMP-9 overactivity in PCOS.

Objective: Polycystic ovary syndrome (PCOS) is a prevalent metabolic disorder with an increased risk for cardiovascular disease (CVD) that is enhanced by obesity. This study sought to determine whether a panel of cardiovascular risk proteins (CVRPs) would be dysregulated in overweight/obese PCOS patients, highlighting potential biomarkers for CVD in PCOS. Methods: In this exploratory cross-sectional study, plasma levels of 54 CVRPs were analyzed in women with PCOS (n = 147) and controls (n = 97). CVRPs were measured using the SOMAscan proteomic platform (version 3.1), with significant proteins identified through linear models, regression analysis, and receiver operating characteristic (ROC) analysis. Analysis on BMI-matched subsets of the cohort were undertaken. Functional enrichment and protein–protein interaction analyses elucidated the pathways involved. Results: Eleven CVRPs were dysregulated in PCOS (whole set, without matching for body mass index (BMI) or insulin resistance (IR)): leptin, Interleukin-1 receptor antagonist protein (IL-1Ra), polymeric immunoglobulin receptor (PIGR), interleukin-18 receptor (IL-18Ra), C-C motif chemokine 3 (MIP-1a), and angiopoietin-1 (ANGPT1) were upregulated whilst advanced glycosylation end product-specific receptor, soluble (sRAGE), bone morphogenetic protein 6 (BMP6); growth/differentiation factor 2 (GDF2), superoxide dismutase [Mn] mitochondrial (MnSOD), and SLAM family member 5 (SLAF5) were downregulated versus the controls. In BMI-matched (overweight/obese, BMI ≥ 26 kg/m²) subset analysis, six CVRPs were common to the whole set: ANGPT1 and IL-1Ra were upregulated; and sRAGE, BMP6, GDF2, and Mn-SOD were downregulated. In addition, lymphotactin (XCL1) was upregulated and placenta growth factor (PIGF), alpha-L-iduronidase (IDUA), angiopoietin-1 receptor, and soluble (sTie-2) and macrophage metalloelastase (MMP12) were downregulated. A subset analysis of BMI-matched plus insulin resistance (IR)-matched women revealed only upregulation of tissue factor (TF) and renin in PCOS, potentially serving as biomarkers for cardiovascular risk in overweight/obese women with PCOS. Conclusions: A combination of upregulated obesity-related CVRPs (ANGPT1/IL/1Ra/XCL1) and downregulated cardioprotective proteins (sRAGE/BMP6/Mn-SOD/GDF2) in overweight/obese PCOS women may contribute to the increased risk for CVD. TF and renin upregulation observed in the BMI- and IR-matched limited sample PCOS subgroup indicates their potential risk of CVD.

Vitamin D is proposed to have a protective effect against cardiovascular disease, though the mechanism is unclear. Vitamin D deficiency is common in polycystic ovary syndrome (PCOS), where it is strongly related to obesity, insulin resistance (IR) and risk of cardiovascular disease. To determine if the inherent pathophysiology of PCOS or vitamin D levels are linked to dysregulation of cardiovascular risk proteins (CVRPs), a study in non-obese women with PCOS and without IR was undertaken. Our hypothesis was that the levels of vitamin D₃ and its active metabolite would be associated with CVRPs comparably in women with and without PCOS. In women with PCOS (n = 29) and controls (n = 29), 54 CVRPs were determined by Slow Off-rate Modified Aptamer (SOMA)-scan plasma protein measurement and correlated to 25-hydroxyvitamin D₃ (25(OH)D₃) and the active 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) measured by gold standard isotope-dilution liquid chromatography tandem mass spectrometry. Women with PCOS had comparable IR and systemic inflammation (normal C-reactive protein) to control women, though had higher free androgen index and anti-Mullerian hormone levels. 25(OH)D₃ and 1,25(OH)₂D₃ levels did not differ between groups. Nine CVRPs were higher in PCOS (p < 0.05) (Galectin-9, Brother of CDO, C-motif chemokine 3, Interleukin-18 receptor-1, Thrombopoietin, Interleukin-1 receptor antagonist protein, Programmed cell death 1 ligand-2, Low-affinity immunoglobulin gamma Fc-region receptor II-b and human growth hormone), whilst 45 CVRPs did not differ. 25(OH)D₃ correlated with five CVRPs in PCOS and one in controls (p < 0.05). Despite the women with PCOS not exhibiting overt systemic inflammation, 9 of 54 CVRPs were elevated, all relating to inflammation, and 5 of these correlated with 25(OH)D_3, suggesting an ongoing underlying inflammatory process in PCOS even in the absence of obesity/IR.

Introduction: Hypoglycemia has been associated with cardiovascular events, and glucose variability has been suggested to be associated with increased cardiovascular risk. Therefore, in this study, we examined the effect on proteomic cardiovascular risk protein markers of (i) mild iatrogenic hypoglycemia and (ii) severe iatrogenic hypoglycemia followed by rebound hyperglycemia. Methods: Two iatrogenic hypoglycemia studies were compared; firstly, mild hypoglycemia in 18 subjects (10 type 2 diabetes (T2D), 8 controls; blood glucose to 2.8 mmoL/L (50 mg/dL) for 1 h), and secondly, severe hypoglycemia in 46 subjects (23 T2D, 23 controls; blood glucose to p < 0.01) and Dickkopf-1 (DKK1) (p < 0.01), but no changes were seen with mild hypoglycemia. In both the mild and severe hypoglycemia studies, at the point of hypoglycemia, T2D subjects showed suppression of Brother of CDO (BOC) (p < 0.01). At 1 h post-hypoglycemia, the changes in ANGPT1, DKK1, and BOC had resolved, with no additional protein biomarker changes despite rebound hyperglycemia from 1.8 ± 0.1 to 12.2 ± 2.0 mmol/L. Conclusions: Proteomic biomarkers of cardiovascular disease showed changes at hypoglycemia that resolved within 1 h following the hypoglycemic event and with no changes following hyperglycemia rebound, suggesting that any cardiovascular risk increase is due to the hypoglycemia and not due to glucose fluctuation per se.