Miocardio salvado en infarto agudo de miocardio con supradesnivel del ST post reperfusión: Análisis mediante resonancia magnética cardiaca

Objetivo: Cuantificar el miocardio salvado mediante resonancia magnética cardiaca, en miocardio irrigado por la arteria relacionada con el infarto en pacientes con IAM con SDST reperfundidos y no reperfundidos. Pacientes y Métodos: A 25 pacientes con un primer infarto de miocardio con elevación del ST (no reperfundidos, 10 pacientes; trombólisis, 10 pacientes; angioplastía Miocardio salvado post reperfusión en infarto agudo de miocardio -R. Díaz-Navarro et al primaria, 5 pacientes) se les realizó resonancia magnética cardíaca 3 a 6 días después de la coronariografía. Se cuantificó el miocardio salvado y el índice de miocardio salvado. Resultados: Los valores máximos de troponina fueron más bajos en los pacientes con angioplastía primaria que en los pacientes trombolizados y no reperfundidos (14,1 ng/mL versus 515,4 ng/mL y 123,1 ng/mL, respectivamente; p < 0,007) y el tamaño del infarto menor (14,1 gr versus 31,2 gr y 31,5 gr, respectivamente; p < 0,003). La masa de miocardio salvado y el índice de miocardio salvado fue mayor en los pacientes con angioplastía primaria que en los pacientes trombolizados y no reperfundidos (27,4 gr versus 4,7 gr y 2,1 gr, respectivamente; p < 0,003) y (65,2 % versus 14,9 % y 6,6 %, respectivamente; p < 0,0001). Conclusiones: Este estudio propone la necesidad de reevaluar la realización de angioplastía coronaria e implantación de stents, en pacientes con un primer IAM con SDST, trombolizados y no trombolizados, sin la realización de estudios de viabilidad previos. La resonancia magnética cardiaca permite cuantificar el miocardio salvado y podría ser considerada una aplicación clínica emergente, para la evaluación precoz de viabilidad miocárdica.

Objective: To quantify by cardiovascular magnetic resonance the salvaged myocardium in the myocardium supplied by the infarct-related artery in reperfused and non-reperfused patients with a first ST-segment elevation myocardial infarction (STEMI). Patients and Method: Twenty-five patients with a first STEMI (non-reperfused, ten patients; thrombolysis, ten patients; primary angioplasty, five patients) underwent cardiac magnetic resonance imaging 3 to 6 days after coronary angiography. Myocardial salvage and myocardial salvage index were quantified. Results: Peak troponin values were lower in patients with primary angioplasty than in thrombolysis and non-reperfused patients (14,1 ng/ mL versus 515,4 ng/mL and 123,1 ng/mL, respectively; p < 0,007) and smaller infarct size (14,1 g versus 31,2 g and 31,5 g, respectively; p < 0,003). Myocardial salvage mass and myocardial salvage index were higher in patients with primary angioplasty than in thrombolysis and non-reperfused patients (27,4 g versus 4,7 g and 2,1 g, respectively; p < 0,003) and (65,2% versus 14,9% and 6,6%, respectively; p < 0,0001). Conclusions: The results of this study indicate the need to reassess the performance of coronary angioplasty and stent implantation in patients with a first STEMI, thrombolysis, and non-thrombolysis without prior myocardial viability studies. Cardiac magnetic resonance allows the quantification of salvaged myocardium and could be considered an emerging clinical application for the early evaluation of myocardial viability.

Placenta-Derived Extracellular Vesicles From Preeclamptic Pregnancies Impair Vascular Endothelial Function via Lectin-Like Oxidized LDL Receptor-1.

BACKGROUND: Preeclampsia is a complex syndrome that includes maternal vascular dysfunction. Syncytiotrophoblast-derived extracellular vesicles from preeclampsia placentas (preeclampsia-STBEVs) were shown to induce endothelial dysfunction, but an endothelial transmembrane mediator is still unexplored. The LOX-1 (lectin-like oxidized low-density lipoprotein receptor-1) is a transmembrane scavenger receptor that can cause endothelial dysfunction, and its expression is increased in the endothelium of preeclampsia women. In this study, we hypothesized that LOX-1 mediates the effects of preeclampsia-STBEVs on endothelial function. METHODS: Preeclampsia-STBEVs were collected by perfusion of placentas from women with preeclampsia and in vitro and ex vivo endothelial cell function were assessed. RESULTS: In human umbilical vein endothelial cells, inhibition of LOX-1 with LOX-1 blocking antibody (TS20) reduced the uptake of preeclampsia-STBEVs (61.3±8.8%). TS20 prevented the activation of ERK (extracellular signal-regulated kinase, a kinase downstream of LOX-1) and reduced the activation of NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells; 21.1±8.0%) and nitrative stress (23.2±10.3%) that was induced by preeclampsia-STBEVs. Vascular function was assessed by wire myography in isolated mesenteric arteries from pregnant rats that were incubated overnight with preeclampsia-STBEVs±TS20. TS20 prevented endothelium-dependent vasodilation impairment induced by preeclampsia-STBEVs. Nitric oxide contribution to the relaxation was reduced by preeclampsia-STBEVs, which was prevented by TS20. Superoxide dismutase or apocynin, an inhibitor of NOX (nicotinamide adenine dinucleotide phosphate oxidase), restored the impaired endothelium-dependent vasodilation in arteries exposed to preeclampsia-STBEVs. CONCLUSIONS: Taken together, our findings demonstrate that LOX-1 mediates the endothelial dysfunction induced by preeclampsia-STBEVs. Our study further expands on the mechanisms that may lead to adverse outcomes in preeclampsia and proposes LOX-1 as a potential target for future interventions.

Síndrome de Takotsubo: Actualización 2022

El síndrome de Takotsubo es una enfermedad cardíaca aguda que se presenta con un cuadro clínico similar al de un síndrome coronario agudo y se caracteriza por alteraciones segmentarias de la contracción ventricular transitorias, con un árbol coronario normal o con lesiones coronarias no significativas que las expliquen. Se observa, generalmente, en mujeres posmenopáusicas; el cual se desencadena principalmente por un estrés emocional o físico severo y su diagnóstico es un desafío clínico. Este artículo entrega una revisión de los factores desencadenantes y de riesgo y las principales hipótesis causales de esta enfermedad. Proporciona, además, una revisión actualizada de las pruebas diagnósticas que deben ser realizadas, el algoritmo para su diagnóstico, las complicaciones y el manejo terapéutico actual.

Takotsubo syndrome is an acute cardiomyopathy with a clinical presentation resembling an acute coronary syndrome. It is characterized by transient segmental ventricular dysfunction with a normal underlying coronary tree or coronary lesions that cannot explain the ventricular dysfunction. It is usually seen in postmenopausal women, triggered by severe emotional or physical stress, and is clinically challenging to diagnose. This article provides an exhaustive review of the risk factors, triggers, and main hypotheses to explain this disease. In addition, it provides an updated review of the diagnostic tests that must be performed, the diagnostic algorithms, their complications, and current therapeutic management.

A High Cholesterol Diet During Late Pregnancy Impairs Long-Term Maternal Vascular Function in Mice.

BACKGROUND: Gestational dyslipidemia is associated with pregnancy complications including preeclampsia. However, whether gestational dyslipidemia leads postpartum vascular dysfunction, which could increase the risk for cardiovascular complications later in life, is not known. Here, we aimed to determine whether a gestational dyslipidemia affects postpartum vascular health and induces early signs of atherosclerosis. METHODS: Pregnant C57BL/6 mice received a high cholesterol diet or control diet from gestational day 13.5 until term. After delivery, all mice received the control diet for ≈3 months postpartum (PP). Age-matched nulliparous females were on the same diets for equal periods. After 3 months, all mice were euthanized, serum was collected, and aortas were isolated to assess vascular function (wire myography) and markers of oxidative stress and early atherosclerosis. RESULTS: PP-high cholesterol diet females had increased circulating cholesterol levels compared with PP-control diet mice, without effect of the diet in nulliparous mice. Methacholine-induced vasodilation was impaired, and nitric oxide contribution reduced, by the high cholesterol diet in aortas of PP mice, but not in nulliparous mice. Exposure to oxidized low-density-protein cholesterol further impaired methylcholine-induced vasodilation in PP-high cholesterol diet aortas only. Compared with PP-control diet mice, aortic inducible nitric oxide synthase expression, reactive oxygen species and nitrotyrosine levels were increased in aortas from PP-high cholesterol diet mice. No differences in aortic lipid deposition and macrophage infiltration were found. CONCLUSIONS: Exposure to a high cholesterol diet in pregnancy impairs vascular function postpartum. Our results support the hypothesis that gestational dyslipidemia impacts maternal vascular function after pregnancy, which could potentially predispose these women to future cardiovascular complications.

[Saved myocardium in acute ST-segment elevation myocardial infarction post-reperfusion: Analysis by cardiac magnetic resonance]. / Miocardio salvado en infarto agudo de miocardio con supradesnivel del ST post reperfusión: Análisis mediante resonancia magnética cardiaca.

OBJECTIVE: To quantify by cardiovascular magnetic resonance the salvaged myocardium in the myocardium supplied by the infarct-related artery in reperfused and non-reperfused patients with a first ST-segment elevation myocardial infarction (STEMI). PATIENTS AND METHOD: Twenty-five patients with a first STEMI (non-reperfused, ten patients; thrombolysis, ten patients; primary angioplasty, five patients) underwent cardiac magnetic resonance imaging 3 to 6 days after coronary angiography. Myocardial salvage and myocardial salvage index were quantified. RESULTS: Peak troponin values were lower in patients with primary angioplasty than in thrombolysis and non-reperfused patients (14,1 ng/ mL versus 515,4 ng/mL and 123,1 ng/mL, respectively; p < 0,007) and smaller infarct size (14,1 g versus 31,2 g and 31,5 g, respectively; p < 0,003). Myocardial salvage mass and myocardial salvage index were higher in patients with primary angioplasty than in thrombolysis and non-reperfused patients (27,4 g versus 4,7 g and 2,1 g, respectively; p < 0,003) and (65,2% versus 14,9% and 6,6%, respectively; p < 0,0001). CONCLUSIONS: The results of this study indicate the need to reassess the performance of coronary angioplasty and stent implantation in patients with a first STEMI, thrombolysis, and non-thrombolysis without prior myocardial viability studies. Cardiac magnetic resonance allows the quantification of salvaged myocardium and could be considered an emerging clinical application for the early evaluation of myocardial viability.

[Takotsubo Syndrome: 2022 Update]. / Síndrome de Takotsubo: Actualización 2022.

Takotsubo syndrome is an acute cardiomyopathy with a clinical presentation resembling an acute coronary syndrome. It is characterized by transient segmental ventricular dysfunction with a normal underlying coronary tree or coronary lesions that cannot explain the ventricular dysfunction. It is usually seen in postmenopausal women, triggered by severe emotional or physical stress, and is clinically challenging to diagnose. This article provides an exhaustive review of the risk factors, triggers, and main hypotheses to explain this disease. In addition, it provides an updated review of the diagnostic tests that must be performed, the diagnostic algorithms, their complications, and current therapeutic management.

Placenta-derived extracellular vesicles from preeclamptic and healthy pregnancies impair ex vivo vascular endothelial function.

Preeclampsia (PE) is a pregnancy syndrome characterized by new-onset hypertension and end-organ dysfunction. The pathophysiology of PE remains undetermined, but it is thought that maternal vascular dysfunction plays a central role, potentially due, in part, to the release of syncytiotrophoblast-derived extracellular vesicles (STBEVs) into the maternal circulation by a dysfunctional placenta. STBEVs from normal pregnancies (NP) impair vascular function, but the effect of PE STBEVs (known to differ in composition with elevated circulating levels) on vascular function are not known. We hypothesized that PE STBEVs have more detrimental effects on vascular function compared with NP STBEVs. STBEVs were collected by perfusion of placentas from women with NP or PE. Mesenteric arteries from pregnant rats were incubated overnight with NP or PE STBEVs, and vascular function was assessed by wire myography. NP and PE STBEVs impaired endothelial function, partially by reducing nitric oxide (NO) bioavailability. Incubation of human umbilical vein endothelial cells with NP and PE STBEVs increased nuclear factor κ-light-chain-enhancer of activated B cell (NF-κB) activation, reactive oxygen species, nitrotyrosine levels, and reduced NO levels. However, PE STBEVs increased NF-κB activation and nitrotyrosine levels to a lesser extent than NP STBEVs. Taken together, no greater impact of PE STBEVs compared with NP STBEVs on endothelial function was found. However, the impaired vascular function by PE STBEVs and increased levels of STBEVs in PE suggest PE STBEVs may contribute to maternal vascular dysfunction in PE. Our study further expands on the potential mechanisms that lead to adverse outcomes in PE and provides potential targets for future interventions.

Advanced Maternal Age Impairs Uterine Artery Adaptations to Pregnancy in Rats.

Advanced maternal age (≥35 years) is associated with pregnancy complications. Aging impairs vascular reactivity and increases vascular stiffness. We hypothesized that uterine artery adaptations to pregnancy are impaired with advanced age. Uterine arteries of nonpregnant and pregnant (gestational day 20) young (4 months) and aged (9 months; ~35 years in humans) Sprague-Dawley rats were isolated. Functional (myogenic tone, n = 6−10/group) and mechanical (circumferential stress-strain, n = 10−24/group) properties were assessed using pressure myography and further assessment of elastin and collagen (histology, n = 4−6/group), and matrix metalloproteinase-2 (MMP-2, zymography, n = 6/group). Aged dams had worse pregnancy outcomes, including smaller litters and fetal weights (both p < 0.0001). Only in arteries of pregnant young dams did higher pressures (>100 mmHg) cause forced vasodilation. Across the whole pressure range (4−160 mmHg), myogenic behavior was enhanced in aged vs. young pregnant dams (p = 0.0010). Circumferential stress and strain increased with pregnancy in young and aged dams (p < 0.0001), but strain remained lower in aged vs. young dams (p < 0.05). Arteries from young nonpregnant rats had greater collagen:elastin ratios than the other groups (p < 0.05). In aged rats only, pregnancy increased MMP-2 active capacity. Altered functional and structural vascular adaptations to pregnancy may impair fetal growth and development with advanced maternal age.

Características clínicas de pacientes en edad pediátrica con infección por SARS-CoV-2. Cienfuegos, 2020-2021

RESUMEN Fundamento: el aumento significativo en las cifras de pacientes con COVID-19 en Cuba y la creciente tasa de incidencia en la edad pediátrica representan un problema de salud emergente. Objetivo describir las características clínicas y epidemiológicas de los niños confirmados con COVID-19 en Cienfuegos, durante el primer año de pandemia. Métodos estudio observacional, descriptivo, transversal, ambispectivo. El universo de estudio fue de 104 pacientes en edad pediátrica diagnosticados con la enfermedad. El horizonte temporal fue desde marzo 2020 hasta marzo 2021. Se analizaron las variables: edad, sexo, procedencia, antecedentes patológicos personales, sintomatología inicial, estado nutricional, fuente de infección, resultados de laboratorio, persistencia de PCR-RT positivo, manifestaciones clínicas asociadas al tratamiento y evolución. Se confeccionó historia clínica individual durante la hospitalización. Resultados: la edad más representada fue la adolescencia, discreto predominio del sexo masculino. Más del 50 % de los casos estaban asintomáticos. Los síntomas iniciales más frecuentes fueron la fiebre y la secreción nasal. El 94 % de los confirmados fueron autóctonos. Los exámenes complementarios mostraron alteraciones enzimáticas asociadas a la infección viral. El 100 % de los niños tuvo una evolución favorable. Conclusiones: la COVID-19 continúa como problema de salud a nivel mundial. Los niños constituyen un grupo vulnerable que necesita seguimiento continuado. Los signos y síntomas pueden ser similares a otras infecciones respiratorias virales, lo que requiere mantener un alto índice de sospecha de COVID-19 en niños.

ABSTRACT Background: the significant increase in the numbers of COVID-19 patients in Cuba and the increasing incidence rate in the pediatric age represent an emerging health problem. Objective: to describe the clinical and epidemiological characteristics of children confirmed with COVID-19 in Cienfuegos, during the first year of the pandemic. Methods: observational, descriptive, cross-sectional, ambispective study. The study universe consisted of 104 pediatric patients diagnosed with the disease. The time horizon was from March 2020 to March 2021. The analyzed variables were: age, sex, origin, personal pathological history, initial symptoms, nutritional status, source of infection, laboratory results, persistence of positive RT-PCR, associated clinical manifestations to treatment and evolution. An individual medical history was taken during hospitalization. Results: the most frequent age was adolescence, discrete male predominance. More than 50% of the cases were asymptomatic. The most frequent initial symptoms were fever and runny nose. The 94% of those confirmed were autochthonous. The complementary tests showed enzymatic alterations associated with the viral infection. The 100% of the children had a favorable evolution. Conclusions: COVID-19 continues as a health problem worldwide. Children are a vulnerable group that needs continuous monitoring. The signs and symptoms can be similar to other viral respiratory infections, which require maintaining a high index of suspicion for COVID-19 in children.

Increased oxidative stress and endothelial activation in umbilical veins from pregnancies diagnosed with preeclampsia.

Vascular dysfunction is a hallmark of cardiovascular disease (CVD). Offspring from preeclamptic pregnancies are at risk of CVD later in life. Whether fetal vasculature from preeclamptic pregnancies displays signs of vascular dysfunction (i.e., oxidative/nitrosative stress, endothelial activation) associated with increased expression of lectin-like oxidized LDL receptor-1 (LOX-1) and angiotensin-II type-1 receptor (AT1) is unknown. We demonstrated increased superoxide, nitrotyrosine and ICAM-1 levels in umbilical vein tissues of preeclamptic vs. normal pregnancies; without changes in LOX-1 and AT1 levels. Our findings suggest that the fetal vasculature may be impacted in preeclampsia, which could contribute to an increased risk of offspring CVD.

High-cholesterol diet during pregnancy induces maternal vascular dysfunction in mice: potential role for oxidized LDL-induced LOX-1 and AT1 receptor activation.

The lectin-like oxidized low-density-lipoprotein (oxLDL) receptor-1 (LOX-1) has been shown to induce angiotensin II (AngII) type 1 receptor (AT1) activation, contributing to vascular dysfunction. Preeclampsia is a pregnancy complication characterized by vascular dysfunction and increased LOX-1 and AT1 activation; however, whether LOX-1 and AT1 activity contributes to vascular dysfunction in preeclampsia is unknown. We hypothesized that increased oxLDL levels during pregnancy lead to LOX-1 activation and subsequent AT1 activation, resulting in vascular dysfunction. Pregnant wild-type (WT) and transgenic LOX-1 overexpressing (LOX-1tg) mice were fed a control diet (CD) or high-cholesterol diet (HCD, to impair vascular function) between gestational day (GD) 13.5-GD18.5. On GD18.5, AngII-induced vasoconstriction and methylcholine (MCh)-induced endothelium-dependent vasodilation responses were assessed in aortas and uterine arteries. HCD decreased fetal weight and increased circulating oxLDL/cholesterol levels in WT, but not in LOX-1tg mice. HCD did not alter AngII responsiveness or AT1 expression in both vascular beds; however, AngII responsiveness and AT1 expression were lower in aortas from LOX-1tg compared with WT mice. In aortas from WT-CD mice, acute oxLDL exposure induced AT1-mediated vasoconstriction via LOX-1. HCD impaired endothelium-dependent vasodilation and increased superoxide levels in WT aortas, but not uterine arteries. Moreover, in WT-CD mice oxLDL decreased MCh sensitivity in both vascular beds, partially via LOX-1. In summary, HCD impaired pregnancy outcomes and vascular function, and oxLDL-induced LOX-1 activation may contribute to vascular dysfunction via AT1. Our study suggests that LOX-1 could be a potential target to prevent adverse outcomes associated with vascular dysfunction in preeclampsia.

Exosomes derived from monocytes and from endothelial cells mediate monocyte and endothelial cell activation under high d-glucose conditions.

Diabetes mellitus type 2 (DMT2) is characterized by hyperglycemia and associated with low grade inflammation affecting both endothelial cells and monocytes. Exosomes are nanovesicles, allow communication between endothelial cells and monocytes and have been associated with diabetic complications. In this study we evaluated whether high glucose can activate monocytes and endothelial cells and whether exosomes play a role in this activation. Moreover, we studied whether endothelial cells and monocytes communicate with each other via exosomes under high and basal glncubation. In the first experiment, monomac 6 cells (MM6) were exposed to high glucose (HG; 25 mmol/L) or to exosomes from MM6 exposed to HG (exoMM6-HG) or basal glucose (5.5 mmol/L) (exoMM6-BG). In the second experiment, MM6 were exposed to exosomes from human umbilical vein endothelial cells (HUVECs) and HUVECs to exosomes from MM6. In the third experiment, MM6 and HUVECs were exposed to a mixture of exosomes from MM6 and HUVECs (exoMix). Cell activation was evaluated by measuring the protein surface expression of intracellular adhesion molecule-1 (ICAM-1) by flow cytometry. HG increased ICAM-1 expression in MM6 and monocytic exosomes from HG or BG shown similar effect in HG and BG MM6 cells. Exosomes from HUVECs increased ICAM-1 expression in MM6 cells, incubated under HG or BG, while also exosomes from MM6 increased ICAM-1 expression in HUVECs incubated under HG or BG. The combination of exosomes from both cell types (exoMixHG or exoMixBG) also increased ICAM-1 expression in both type cells in most conditions. However, the exoMixBG reversed the effect of HG in both MM6 and HUVECs. Our results show that HG activated monocytes and endothelial cells and that exosomes play a role in this HG-induced cell ICAM-1 expression. We hypothesize that during DMT2, exosomes may act as a communication mechanism between monocytes and endothelial cells, inducing and maintaining activating of both cell types in the presence of high glucose.

Impaired signalling pathways mediated by extracellular vesicles in diabesity.

Diabesity, obesity, and type 2 diabetes mellitus (T2DM) are the most prevalent diseases nowadays and associate with high risk of cardiovascular complications. The impaired signalling pathways associated with the metabolism of D-glucose, lipids, and insulin have been studied for many years aiming to understand the cellular mechanisms of these diseases. Extracellular vesicles (EVs), including exosomes and microvesicles, carry different microRNAs or proteins as cargoes, acting as a mechanism of cell-to-cell communication to modulate different cell functions altering the metabolic regulatory pathways. Several studies have shown an altered number or cargo of EVs in metabolic diseases, including T2DM and obesity, suggesting that these vesicles may play an important role in the regulation of metabolic signalling pathways in diabesity. In this review, we described some of the current studies involving EVs and hypothesize about the role of these structures in the impaired metabolism in T2DM, obesity, and diabesity.

Extracellular Vesicles and Insulin Resistance: A Potential Interaction in Vascular Dysfunction.

Insulin resistance plays a key role in cardiovascular complications associated with diabetes mellitus and hypertensive disorders. In states of insulin resistance several circulating factors may contribute to a defective insulin sensitivity in different tissues, including the vasculature. One of these factors influencing the vascular insulin resistance are the extracellular vesicles. The extracellular vesicles include exosomes, microvesicles, and apoptotic bodies which are released to the circulation by different vascular cells. Since the cargo of extracellular vesicles seems to be altered in metabolic complications associated with insulin resistance, these vesicles may be candidates contributing to vascular insulin resistance. Despite the studies linking insulin resistance signalling pathways with the vascular effect of extracellular vesicles, the involvement of these structures in vascular insulin resistance is a phenomenon that remains unclear.

Fetoplacental endothelial exosomes modulate high d-glucose-induced endothelial dysfunction.

INTRODUCTION: Gestational diabetes mellitus (GDM) is associated with fetoplacental endothelial dysfunction, which may be induced by hyperglycemia. We hypothesized that endothelial exosomes, which are extracellular nanovesicles affecting endothelial function, play a role in the high glucose (HG)-induced endothelial dysfunction. METHODS: Exosomes were isolated from HUVECs incubated with basal glucose (5.5 mmol/L; HUVEC- BG; exo-BG) and from HUVECs incubated with HG for 24 h (25 mmol/L; HUVEC-HG; exo-HG) in exosome-free medium. Exosomes were isolated and characterized by ultracentrifugation, sucrose gradient, electron microscopy, nanotracking analysis and Western blotting. HUVEC-BG and HUVEC-HG were exposed to exo-BG and exo-HG in two different concentrations: 5 µg and 1 µg exosome protein/mL. The exosomal effect on endothelial cell function was determined by wound healing assay, expression of endothelial nitric oxide synthase (eNOS), human cationic amino acid transporter type 1 (hCAT-1), vascular endothelial growth factor (VEGF) and intracellular adhesion molecule type 1 (ICAM-1) by Western blotting, qPCR or flow cytometry. RESULTS: HG increased the exosomal release from HUVECs, endothelial wound healing and expression of phosphorylated (P∼Ser1177)-eNOS, hCAT-1, VEGF and ICAM-1. Exo-HG also increased endothelial cell wound healing, P∼Ser1177-eNOS, hCAT-1 and ICAM-1 expression in HUVEC-BG. Exo-BG reverted the effect of HG on endothelial cell wound healing and hCAT-1 mRNA expression to normal values. DISCUSSION: Our results show that HG may induce endothelial dysfunction in HUVECs and that exosomes from HUVEC-HG mimicked some of the effects of HG. This study contributes to the unraveling of the mechanism by which hyperglycemia affects the fetoplacental vasculature in GDM.

Human umbilical vein endothelium-derived exosomes play a role in foetoplacental endothelial dysfunction in gestational diabetes mellitus.

Gestational diabetes mellitus (GDM) characterizes by foetoplacental endothelial dysfunction. Human umbilical vein endothelial cells (HUVECs) from women with GDM show increased L-arginine transport via the human cationic amino acid transporter 1 (hCAT-1). Moreover, expression of endothelial nitric oxide synthase (eNOS) and nitric oxide synthesis are increased. Exosomes are increased in maternal plasma from GDM. We evaluated the role of foetoplacental endothelial exosomes on endothelial dysfunction in GDM. Exosomes were isolated from HUVECs from normal (ExN) and GDM (ExGDM) pregnancies. HUVECs were exposed (8h) to ExN or ExGDM and used for wound recovery assay (up to 8h), L-arginine transport, hCAT-1 and eNOS expression and activity, reactive oxygen species (ROS) generation, and 44 and 42kDa mitogen activated protein kinases (p44/42mapk) and protein kinase B/Akt (Akt) activation. Wound recovery was slower in GDM compared with normal pregnancies and was recovered by ExN. However, ExGDM delayed wound recovery in cells from normal pregnancies. GDM-increased L-arginine transport, hCAT-1 and eNOS expression and activity, and p44/42mapk activation were blocked by ExN, but ExGDM increased these parameters and ROS generation, and reduced eNOS phosphorylation at threonine495 in cells from normal pregnancies. Inhibition of p44/42mapk, but not Akt reversed GDM-increased L-arginine uptake. In conclusion foetoplacental endothelial-released exosomes play a role in the maintenance of a GDM phenotype in HUVECs. It is suggested that ExN and ExGDM cargo are different with differential effects in cells from normal or GDM pregnancies. This phenomenon could contribute to the understanding of mechanisms behind foetoplacental endothelial dysfunction in GDM pregnancies.

Is there a role for exosomes in foetoplacental endothelial dysfunction in gestational diabetes mellitus?

Gestational diabetes mellitus (GDM) is a disease of pregnancy associated with endothelial dysfunction in the foetoplacental vasculature. Foetoplacental endothelial dysfunction is characterized by changes in the l-arginine-adenosine signalling pathway and inflammation. The mechanisms involved in these alterations are suggested to be hyperglycaemia, hyperinsulinemia, and oxidative stress. These conditions increase the release of exosomes, nanovesicles that are generated from diverse cell types, including endothelial cells. Since exosomes can modulate vascular function, they may play an important role in foetoplacental endothelial dysfunction seen in GDM pregnancies. In this review, we summarized current knowledge on the potential role of exosomes in foetoplacental endothelial dysfunction seen in this disease of pregnancy.

Akt/mTOR Role in Human Foetoplacental Vascular Insulin Resistance in Diseases of Pregnancy.

Insulin resistance is characteristic of pregnancies where the mother shows metabolic alterations, such as preeclampsia (PE) and gestational diabetes mellitus (GDM), or abnormal maternal conditions such as pregestational maternal obesity (PGMO). Insulin signalling includes activation of insulin receptor substrates 1 and 2 (IRS1/2) as well as Src homology 2 domain-containing transforming protein 1, leading to activation of 44 and 42 kDa mitogen-activated protein kinases and protein kinase B/Akt (Akt) signalling cascades in the human foetoplacental vasculature. PE, GDM, and PGMO are abnormal conditions coursing with reduced insulin signalling, but the possibility of the involvement of similar cell signalling mechanisms is not addressed. This review aimed to determine whether reduced insulin signalling in PE, GDM, and PGMO shares a common mechanism in the human foetoplacental vasculature. Insulin resistance in these pathological conditions results from reduced Akt activation mainly due to inhibition of IRS1/2, likely due to the increased activity of the mammalian target of rapamycin (mTOR) resulting from lower activity of adenosine monophosphate kinase. Thus, a defective signalling via Akt/mTOR in response to insulin is a central and common mechanism of insulin resistance in these diseases of pregnancy. In this review, we summarise the cell signalling mechanisms behind the insulin resistance state in PE, GDM, and PGMO focused in the Akt/mTOR signalling pathway in the human foetoplacental endothelium.

Insulin/adenosine axis linked signalling.

Regulation of blood flow depends on systemic and local release of vasoactive molecules such as insulin and adenosine. These molecules cause vasodilation by activation of plasma membrane receptors at the vascular endothelium. Adenosine activates at least four subtypes of adenosine receptors (A1AR, A2AAR, A2BAR, A3AR), of which A2AAR and A2BAR activation leads to increased cAMP level, generation of nitric oxide, and relaxation of the underlying smooth muscle cell layer. Vasodilation caused by adenosine also depends on plasma membrane hyperpolarization due to either activation of intermediate-conductance Ca2+-activated K+ channels in vascular smooth muscle or activation of ATP-activated K+ channels in the endothelium. Adenosine also causes vasoconstriction via a mechanism involving A1AR activation resulting in lower cAMP level and increased thromboxane release. Insulin has also a dual effect causing NO-dependent vasodilation, but also sympathetic activity- and increased endothelin 1 release-dependent vasoconstriction. Interestingly, insulin effects require or are increased by activation or inactivation of adenosine receptors. This is phenomenon described for d-glucose and l-arginine transport where A2AAR and A2BAR play a major role. Other studies show that A1AR activation could reduce insulin release from pancreatic ß-cells. Whether adenosine modulation of insulin biological effect is a phenomenon that depends on co-localization of adenosine receptors and insulin receptors, and adenosine plasma membrane transporters is something still unclear. This review summarizes findings addressing potential involvement of adenosine receptors to modulate insulin effect via insulin receptors with emphasis in the human vasculature.

Intracellular and extracellular pH dynamics in the human placenta from diabetes mellitus.

The placenta is a vital organ whose function in diseases of pregnancy is altered, resulting in an abnormal supply of nutrients to the foetus. The lack of placental vasculature homeostasis regulation causes endothelial dysfunction and altered vascular reactivity. The proper distribution of acid- (protons (H(+))) and base-equivalents through the placenta is essential to achieve physiological homeostasis. Several membrane transport mechanisms that control H(+) distribution between the extracellular and intracellular spaces are expressed in the human placenta vascular endothelium and syncytiotrophoblast, including sodium (Na(+))/H(+) exchangers (NHEs). One member of the NHEs family is NHE isoform 1 (NHE1), whose activity results in an alkaline intracellular pH (high intracellular pH (pHi)) and an acidic extracellular pH (pHo). Increased NHE1 expression, maximal transport activity, and turnover are reported in human syncytiotrophoblasts and lymphocytes from patients with diabetes mellitus type I (DMT1), and a positive correlation between NHEs activity and plasma factors, such as that between thrombin and platelet factor 3, has been reported in diabetes mellitus type II (DMT2). However, gestational diabetes mellitus (GDM) could result in a higher sensitivity of the human placenta to acidic pHo. We summarized the findings on pHi and pHo modulation in the human placenta with an emphasis on pregnancies in which the mother diagnosed with diabetes mellitus. A potential role of NHEs, particularly NHE1, is proposed regarding placental dysfunction in DMT1, DMT2, and GDM.