Kidney failure and associated uraemia have implications for the cardiovascular system, brain, and blood–brain barrier (BBB). We aim to examine BBB disruption, by assessing brain-derived neurotropic factor (BDNF), neuron-specific enolase (NSE) levels, and gut-blood barrier (GBB) disruption by trimethylamine N-oxide (TMAO), in chronic kidney disease (CKD) patients. Additionally, endothelial tight-junction protein expressions and modulation via TMAO were assessed. Serum from chronic kidney disease (CKD) female and male haemodialysis (HD) patients, and controls, were used to measure BDNF and NSE by enzyme-linked immunosorbent assays, and TMAO by mass spectrometry. Immunofluorescent staining of subcutaneous fat biopsies from kidney transplant recipients, and controls, were used to measure microvascular expression of tight-junction proteins (claudin-5, occludin, JAM-1), and control microvasculature for TMAO effects. HD patients versus controls, had significantly lower and higher serum levels of BDNF and NSE, respectively. In CKD biopsies versus controls, reduced expression of claudin-5, occludin, and JAM-1 were observed. Incubation with TMAO significantly decreased expression of all tight-junction proteins in the microvasculature. Uraemia affects BBB and GBB resulting in altered levels of circulating NSE, BDNF and TMAO, respectively, and it also reduces expression of tight-junction proteins that confer BBB maintenance. TMAO serves as a potential candidate to alter BBB integrity in CKD.

The pathophysiology of vascular disease is linked to accelerated biological aging and a combination of genetic, lifestyle, biological, and environmental risk factors. Within the scenario of uncontrolled artery wall aging processes, CKD (chronic kidney disease) stands out as a valid model for detailed structural, functional, and molecular studies of this process. The cardiorenal syndrome relates to the detrimental bidirectional interplay between the kidney and the cardiovascular system. In addition to established risk factors, this group of patients is subjected to a plethora of other emerging vascular risk factors, such as inflammation, oxidative stress, mitochondrial dysfunction, vitamin K deficiency, cellular senescence, somatic mutations, epigenetic modifications, and increased apoptosis. A better understanding of the molecular mechanisms through which the uremic milieu triggers and maintains early vascular aging processes, has provided important new clues on inflammatory pathways and emerging risk factors alike, and to the altered behavior of cells in the arterial wall. Advances in the understanding of the biology of uremic early vascular aging opens avenues to novel pharmacological and nutritional therapeutic interventions. Such strategies hold promise to improve future prevention and treatment of early vascular aging not only in CKD but also in the elderly general population.

Introduction: Previous evidence examining the association between socioeconomic status and pregnancy complications are conflicted and often limited to using area‐based measures of socioeconomic status. In this study, we aimed to examine the association between individual‐level socioeconomic factors and a wide range of adverse pregnancy and neonatal outcomes using data from the IMPROvED birth cohort conducted in Sweden, the Netherlands and Republic of Ireland.Material and methods: The study cohort consisted of women who participated in the IMPROvED birth cohort between 2013 and 2017. Data on socioeconomic factors were self‐reported and obtained at 15 weeks' gestation, and included level of education, employment status, relationship status, and income. Data on pregnancy and neonatal outcomes included gestational hypertension, pre‐eclampsia, gestational diabetes mellitus, emergency cesarean section, preterm birth, post term delivery, small for gestational age and Apgar score at 1 min. These data were obtained within 72 h following delivery and confirmed using medical records. Multivariable logistic regression examined the association between each socioeconomic variable and each outcome separately adjusting for maternal age, maternal body mass index, maternal smoking, maternal alcohol consumption and cohort center. We also examined the effect of exposure to any ≥2 risk factors compared to none.Results: A total of 2879 participants were included. Adjusted results suggested that those with less than third level of education had an increased odds of gestational hypertension (OR: 1.74, 95% CI: 1.23–2.46), while those on a middle level of income had a reduced odds of emergency cesarean section (OR: 0.59, 95% CI: 0.42–0.84). No significant associations were observed between socioeconomic variables and neonatal outcomes. Exposure to any ≥2 socioeconomic risk factors was associated with an increased risk of preterm birth (OR: 1.75, 95% CI: 1.06–2.89).Conclusions: We did not find strong evidence of associations between individual‐level socioeconomic factors and pregnancy and neonatal outcomes in high‐income settings overall, with only few significant associations observed among pregnancy outcomes.

Background: Sex differences are underappreciated in the current understanding of cardiovascular disease (CVD) in association with chronic kidney disease (CKD). A hallmark of CKD is vascular aging that is characterised, amongst others, by; systemic inflammation, microbiota disbalance, oxidative stress, and vascular calcification—features linked to atherosclerosis/arteriosclerosis development. Thus, it is the necessary to introduce novel biomarkers related to athero-/arteriosclerotic damage for better assessment of vascular ageing in patients CKD. However, little is known about the relationship between uraemia and novel CVD biomarkers, such as growth differentiation factor-15 (GDF-15), cartilage glycoprotein-39 (YKL-40) and matrix metalloproteinase-9 (MMP-9). Therefore, we hypothesise that there are sex-specific relationships between GDF-15, YKL-40, MMP-9 levels in end-stage kidney disease (ESKD) patients in relation to gut microbiota, vascular calcification, inflammation, comorbidities, and all-cause mortality. Methods: ESKD patients, males (n = 151) and females (n = 79), not receiving renal replacement therapy were selected from two ongoing prospective ESKD cohorts. GDF-15, YKL-40 and MMP9 were analysed using enzyme-linked immunosorbent assay kits. Biomarker levels were analysed in the context of gut microbiota-derived trimethylamine N-oxide (TMAO), vascular calcification, inflammatory response, oxidative stress, comorbidities, and all-cause mortality. Results: Increased GDF-15 correlated with higher TMAO in females only, and with higher coronary artery calcification and IL-6. In females, diabetes was associated with elevated GDF-15 and MMP-9, whilst males with diabetes only had elevated GDF-15. No associations were found between biomarkers and CVD comorbidity. Deceased males and females had higher GDF-15 concentrations (p = 0.01 and p < 0.001, respectively), meanwhile only YKL-40 was increased in deceased males (p = 0.02). Conclusions: In conclusion, in males GDF-15 and YKL-40 were related to vascular calcification, inflammation, and oxidative stress, whilst in females GDF-15 was related to TMAO. Increased levels of YKL-40 and GDF-15 in males, and only GDF-15 in females, were associated with all-cause mortality. Our findings suggest that sex-specific associations of novel CVD biomarkers have a potential to affect development of cardiovascular complications in patients with ESKD.

Chronic kidney disease (CKD) is a strong risk factor for cardiovascular mortality and morbidity. We hypothesized that a senescent phenotype instigated by uremic toxins could account for early vascular aging (EVA) and vascular dysfunctions of microvasculature in end stage kidney disease (ESKD) patients which ultimately lead to increased cardiovascular complication. To test this hypothesis, we utilized both in vivo, and ex vivo approaches to study endothelial and smooth muscle function and structure, and characterized markers related to EVA in 82 ESKD patients (eGFR <15 ml/min) and 70 non-CKD controls. In vivo measurement revealed no major difference in endothelial function between ESKD and control group, aside from higher stiffness detected in the microcirculation of ESKD participants. In contrast, ex vivo measurements revealed a notable change in the contribution of endothelium-derived factors and increased stiffness in ESKD patients vs. controls. In support, we demonstrated that ex vivo exposure of arteries to uremic toxins such as Trimethylamine N-oxide, Phenylacetylglutamine, or extracellular vesicles from CKD patients impaired endothelial function via diminishing the contribution of endothelium-derived relaxing factors such as nitric oxide and endothelium derived hyperpolarizing factor. Uremic arteries displayed elevated expression of senescence markers (p21CIP1, p16INK4a, and SA-β-gal), calcification marker (RUNX2), and reduced expression of Ki67, sirtuin1, Nrf2, and MHY11 markers, indicating the accumulation of senescent cells and EVA phenotype. Correspondingly, treating uremic vessel rings ex vivo with senolytic agents (Dasatinib + Quercetin) effectively reduced the senescence-associated secretory phenotype and changed the origin of extracellular vesicles. Notably, sex differences exist for certain abnormalities suggesting the importance of biological sex in the pathogenesis of vascular complications. In conclusion, the uremic microvasculature is characterized by a "senescence signature", which may contribute to EVA and cardiovascular complications in ESKD patients and could be alleviated by treatment with senolytic agents.

Kidney transplantation (KT) may improve the neurological status of chronic kidney disease (CKD) patients, reflected by the altered levels of circulating BBB-specific biomarkers. This study compares the levels of neuron specific enolase (NSE), brain-derived neurotrophic factor (BDNF), neurofilament light chain (NfL), and circulating plasma extracellular vesicles (EVs) in kidney-failure patients before KT and at a two-year follow up. Using ELISA, NSE, BDNF, and NfL levels were measured in the plasma of 74 living-donor KT patients. Plasma EVs were isolated with ultracentrifugation, and characterized for concentration/size and surface protein expression using flow cytometry from a subset of 25 patients. Lower NSE levels, and higher BDNF and NfL were observed at the two-year follow-up compared to the baseline (p < 0.05). Male patients had significantly higher BDNF levels compared to those of females. BBB biomarkers correlated with the baseline lipid profile and with glucose, vitamin D, and inflammation markers after KT. BBB surrogate marker changes in the microcirculation of early vascular aging phenotype patients with calcification and/or fibrosis were observed only in NSE and BDNF. CD31+ microparticles from endothelial cells expressing inflammatory markers such as CD40 and integrins were significantly reduced after KT. KT may, thus, improve the neurological status of CKD patients, as reflected by changes in BBB-specific biomarkers.