Age- and sex-dependent alteration of functions and epigenetic modifications of vessel and endothelium related biomarkers

Hydrogen sulfide ameliorates endothelial dysfunction in aging arteries by regulating ferroptosis

Aging causes vascular endothelial dysfunction. We aimed to investigate the causes of vascular endothelial dysfunction during aging using plasma and renal arteries from patients who underwent nephrectomy and animal models. The results showed that the endogenous H2S-producing enzyme cystathione-γ-lyase (CSE) protein expression was downregulated in renal artery tissue, plasma H2S levels were reduced. Moreover, elevated lipid peroxidation and iron accumulation levels led to ferroptosis and endothelial diastolic function in the renal arteries was impaired in the elderly group. H2S enhanced the endogenous CSE expression in the elderly group, promoted endogenous H2S production, decreased lipid peroxide expression, and inhibited ferroptosis, which in turn improved vascular endothelial function in the elderly group. In animal models, we also observed the same results. In addition, we applied NaHS, Ferrostatin-1 (ferroptosis inhibitor) and erastin (ferroptosis inducer) to incubate renal arteries of SD rats. The results showed that NaHS enhanced ferroptosis related proteins expression, inhibited ferroptosis and improved vascular endothelial function. We demonstrated that endothelial dysfunction associated with aging is closely related to reduced endogenous H2S levels and ferroptosis in vascular endothelial cells. Notably, H2S reduced lipid peroxidation levels in vascular endothelial cells, inhibited ferroptosis in vascular endothelial cells, and improved endothelial dysfunction.

Physiological roles of hydrogen sulfide in mammalian cells, tissues and organs

H2S belongs to the class of molecules known as gasotransmitters, which also includes nitric oxide (NO) and carbon monoxide (CO). Three enzymes are recognized as endogenous sources of H2S in various cells and tissues: cystathionine g-lyase (CSE), cystathionine β-synthase (CBS) and 3-mercaptopyruvate sulfurtransferase (3-MST). The current article reviews the regulation of these enzymes as well as the pathways of their enzymatic and non-enzymatic degradation and elimination. The multiple interactions of H2S with other labile endogenous molecules (e.g. NO) and reactive oxygen species are also outlined. The various biological targets and signaling pathways are discussed, with special reference to H2S and oxidative posttranscriptional modification of proteins, the effect of H2S on channels and intracellular second messenger pathways, the regulation of gene transcription and translation and the regulation of cellular bioenergetics and metabolism. The pharmacological and molecular tools currently available to study H2S physiology are also reviewed, including their utility and limitations. In subsequent sections, the role of H2S in the regulation of various physiological and cellular functions is reviewed. The physiological role of H2S in various cell types and organ systems are overviewed. Finally, the role of H2S in the regulation of various organ functions is discussed as well as the characteristic bell-shaped biphasic effects of H2S. In addition, key pathophysiological aspects, debated areas, and future research and translational areas are identified A wide array of significant roles of H2S in the physiological regulation of all organ functions emerges from this review.

Influence of sex and age on inferior vena cava diameter and implications for the implantation of vena cava filters

Abstract Background Measuring the venous diameter and choosing a compatible vena cava filter are essential to reduce the risk of complications resulting from implantation of these devices. However, there is little information on how the diameter of the inferior vena cava varies with sex and age. Objectives To determine the influence of patients’ gender and age on their inferior vena cava diameter and the suitability of the different models of available filters. Methods Retrospective analytical study based on computed tomography images. The diameter of the inferior vena cava was measured at 3 points: above the confluence of the common iliac veins, below the renal veins, and midway between these two points (cranial point, caudal point, and midpoint) using Arya® and Carestream PACS® software. The results were classified by sex and age groups. Results CT scans of 417 patients were analyzed: 245 women and 172 men. The diameters at the midpoint and caudal point were, respectively, 19.1 mm and 20.6 mm in women from 81 to 92 years old and were statistically smaller (p< 0.05) when compared to women aged 19 to 40 years (midpoint: 22.7 mm; caudal point: 23 mm). Similar results were seen in men. Venous diameters at the cranial and caudal points in patients aged from 51 to 70 years were statistically larger in men (cranial point: 24.4 mm; caudal point:22.3 mm) than in women (cranial point: 22.6 mm; caudal point:20.8 mm) (p< 0.05). Conclusions A smaller diameter was found for the inferior vena cava in older patients of both sexes and the rate of diameter change was similar among men and women.

Influência do sexo e da idade sobre o diâmetro da cava inferior e implicações para o implante de filtros de veia cava

Resumo Contexto A aferição do diâmetro venoso e a escolha de um filtro de veia cava compatível são fundamentais para diminuir o risco de complicações decorrentes do implante desses dispositivos. Entretanto, são escassas as informações sobre como o diâmetro da cava inferior varia de acordo com o sexo e a idade. Objetivos Determinar a influência do sexo e da idade dos pacientes sobre o diâmetro da cava inferior e a adequação dos diferentes modelos de filtro disponíveis. Métodos Estudo analítico retrospectivo, realizado a partir de imagens de tomografia computadorizada. O diâmetro no segmento infrarrenal da veia cava inferior foi aferido em três pontos (cranial, médio e caudal). Os resultados foram classificados de acordo com o sexo e as faixas etárias. Resultados Foram analisadas tomografias de 417 pacientes: 245 mulheres e 172 homens. Os diâmetros nos pontos médio e caudal foram, respectivamente, 19,1 mm e 20,6 mm em mulheres de 81 a 92 anos, sendo estatisticamente menores (p < 0,05) quando comparados aos de mulheres com idade entre 19 e 40 anos (diâmetro no ponto médio: 22,7 mm; diâmetro no ponto caudal: 23 mm). Resultados semelhantes foram observados em homens. Os diâmetros venosos nos pontos cranial e caudal foram estatisticamente maiores em homens (ponto cranial: 24,4 mm; ponto caudal: 22,3 mm) do que em mulheres (ponto cranial: 22,6 mm; ponto caudal: 20,8 mm) em pacientes com idade entre 51 e 70 anos (p < 0,05). Conclusões O diâmetro da veia cava inferior foi menor em pacientes com idade mais avançada em ambos os sexos, e a taxa de variação do diâmetro foi semelhante entre homens e mulheres.

Enhanced dimethylarginine degradation improves coronary flow reserve and exercise tolerance in Duchenne muscular dystrophy carrier mice

Duchenne muscular dystrophy (DMD) is an X-linked disease caused by null mutations in dystrophin and characterized by muscle degeneration. Cardiomyopathy is common and often prevalent at similar frequency in female DMD carriers irrespective of whether they manifest skeletal muscle disease. Impaired muscle nitric oxide (NO) production in DMD disrupts muscle blood flow regulation and exaggerates postexercise fatigue. We show that circulating levels of endogenous methylated arginines including asymmetric dimethylarginine (ADMA), which act as NO synthase inhibitors, are elevated by acute necrotic muscle damage and in chronically necrotic dystrophin-deficient mice. We therefore hypothesized that excessive ADMA impairs muscle NO production and diminishes exercise tolerance in DMD. We used transgenic expression of dimethylarginine dimethylaminohydrolase 1 (DDAH), which degrades methylated arginines, to investigate their contribution to exercise-induced fatigue in DMD. Although infusion of exogenous ADMA was sufficient to impair exercise performance in wild-type mice, transgenic DDAH expression did not rescue exercise-induced fatigue in dystrophin-deficient male mdx mice. Surprisingly, DDAH transgene expression did attenuate exercise-induced fatigue in dystrophin-heterozygous female mdx carrier mice. Improved exercise tolerance was associated with reduced heart weight and improved cardiac β-adrenergic responsiveness in DDAH-transgenic mdx carriers. We conclude that DDAH overexpression increases exercise tolerance in female DMD carriers, possibly by limiting cardiac pathology and preserving the heart's responses to changes in physiological demand. Methylated arginine metabolism may be a new target to improve exercise tolerance and cardiac function in DMD carriers or act as an adjuvant to promote NO signaling alongside therapies that partially restore dystrophin expression in patients with DMD.NEW & NOTEWORTHY Duchenne muscular dystrophy (DMD) carriers are at risk for cardiomyopathy. The nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) is released from damaged muscle in DMD and impairs exercise performance. Transgenic expression of dimethylarginine dimethylaminohydrolase to degrade ADMA prevents cardiac hypertrophy, improves cardiac function, and improves exercise tolerance in DMD carrier mice. These findings highlight the relevance of ADMA to muscular dystrophy and have important implications for therapies targeting nitric oxide in patients with DMD and DMD carriers.

Sexo e idade e sua influência sobre a anatomia da aorta abdominal e seus ramos

Resumo Contexto Não se sabe ao certo como a idade e o sexo do paciente influenciam na anatomia da aorta abdominal e de seus ramos. Objetivos Determinar os padrões anatômicos (diâmetro e angulações) mais frequentes da aorta abdominal e de seus ramos e a influência do sexo e da idade dos pacientes sobre esses padrões. Métodos Foram avaliadas tomografias computadorizadas de abdome com contraste endovenoso de 157 pacientes. Foram aferidos calibre e angulação de artérias abdominais em indivíduos de ambos os sexos, agrupados em cinco faixas etárias: 20 a 30 anos, 31 a 40 anos, 41 a 50 anos, 51 a 60 anos e 61 a 70 anos. Foram analisadas 18 variáveis: seis ângulos de emergências arteriais, nove diâmetros arteriais, taxas de dilatação, sexo e faixa etária. Para a obtenção das medidas, utilizou-se o programa de computador RadiAnt 4.2.1 DICOM viewer (Medixant, Poznan, Polônia). Resultados Entre as 157 tomografias, 69 eram de homens e 88, de mulheres. Apresentaram diferença estatística (p < 0,05): ângulo de origem e diâmetro da artéria mesentérica superior; ângulo e diâmetro das artérias renais; diâmetro das artérias ilíacas comuns; diâmetro e taxa de dilatação em diversos segmentos da aorta, exceto na porção proximal ao tronco celíaco. Conclusões Os diâmetros da aorta (em diversos segmentos) e de seus ramos (exceto da artéria renal esquerda) aumentam progressivamente com o passar da idade em ambos os sexos e são maiores e possuem taxa de dilatação mais elevada em homens do que em mulheres da mesma faixa etária. Entre os sexos, o ângulo de emergência da artéria mesentérica superior foi maior em homens, exceto entre 20 e 30 anos; o ângulo de origem da artéria renal esquerda foi maior em mulheres entre 51 e 60 anos.