lncR-GAS5 upregulates the splicing factor SRSF10 to impair endothelial autophagy, leading to atherogenesis / 医学前沿

Long noncoding RNAs (lncRNAs) play a critical role in the regulation of atherosclerosis. Here, we investigated the role of the lncRNA growth arrest-specific 5 (lncR-GAS5) in atherogenesis. We found that the enforced expression of lncR-GAS5 contributed to the development of atherosclerosis, which presented as increased plaque size and reduced collagen content. Moreover, impaired autophagy was observed, as shown by a decreased LC3II/LC3I protein ratio and an elevated P62 level in lncR-GAS5-overexpressing human aortic endothelial cells. By contrast, lncR-GAS5 knockdown promoted autophagy. Moreover, serine/arginine-rich splicing factor 10 (SRSF10) knockdown increased the LC3II/LC3I ratio and decreased the P62 level, thus enhancing the formation of autophagic vacuoles, autolysosomes, and autophagosomes. Mechanistically, lncR-GAS5 regulated the downstream splicing factor SRSF10 to impair autophagy in the endothelium, which was reversed by the knockdown of SRSF10. Further results revealed that overexpression of the lncR-GAS5-targeted gene miR-193-5p promoted autophagy and autophagic vacuole accumulation by repressing its direct target gene, SRSF10. Notably, miR-193-5p overexpression decreased plaque size and increased collagen content. Altogether, these findings demonstrate that lncR-GAS5 partially contributes to atherogenesis and plaque instability by impairing endothelial autophagy. In conclusion, lncR-GAS5 overexpression arrested endothelial autophagy through the miR-193-5p/SRSF10 signaling pathway. Thus, miR-193-5p/SRSF10 may serve as a novel treatment target for atherosclerosis.

Global endothelial function assessment using pulse wave analysis in hypercholesterolemia

To compare global endothelial function assessed by pulse wave analysis (PWA) using the ratio of endothelium dependent vasodilatation (EDV) to endothelium independent vasodilatation (EIV) in patients with hypercholesterolemia and controls. 92 subjects [46 hypercholesterolemics, 46 controls] were studied at standardized conditions. Baseline augmentation index (AIx) was assessed followed by the administration of 0.5 mg sublingual nitroglycerine, an endothelium independent vasodilator. AIx was assessed and the maximum change in AIx after nitroglycerine was recorded as EIV. After a washout period of 30 minutes, 400 µg of inhaled salbutamol, an endothelium dependent vasodilator was administered. AIx was assessed again and the maximum change in AIx after salbutamol was recorded as EDV. Global endothelial function was calculated as EDV:EIV ratio. EDV and EIV in patients with hypercholesterolemia compared to controls were 2.97 ± 3.95 and 6.65 ± 3.80 (p<0.001); and 13.41 ± 4.57 and 15.88 ± 4.78 (p=0.01) respectively. EDV:EIV ratio was significantly reduced in patients with hypercholesterolemia compared to controls; 0.21 ± 0.38 and 0.44 ± 0.24 (p<0.001) respectively. EDV:EIV ratio was significantly reduced in patients with hypercholesterolemia compared to controls. PWA is a potential clinical tool to assess global endothelial function in patients with hypercholesterole

Hepatocyte growth factor protects pulmonary endothelial barrier against oxidative stress and mitochondria-dependent apoptosis / 中华医学杂志(英文版)

BACKGROUND@#Pulmonary microvascular endothelial cells (PMVECs) were not complex, and the endothelial barrier was destroyed in the pathogenesis progress of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Previous studies have demonstrated that hepatocyte growth factor (HGF), which was secreted by bone marrow mesenchymal stem cells, could decrease endothelial apoptosis. We investigated whether mTOR/STAT3 signaling acted in HGF protective effects against oxidative stress and mitochondria-dependent apoptosis in lipopolysaccharide (LPS)-induced endothelial barrier dysfunction and ALI mice.@*METHODS@#In our current study, we introduced LPS-induced PMEVCs with HGF treatment. To investigate the effects of mammalian target of rapamycin (mTOR)/signal transducer and activator of transcription 3 (STAT3) pathway in endothelial oxidative stress and mitochondria-dependent apoptosis, mTOR inhibitor rapamycin and STAT3 inhibitor S3I-201 were, respectively, used to inhibit mTOR/STAT3 signaling. Moreover, lentivirus vector-mediated mTORC1 (Raptor) and mTORC2 (Rictor) gene knockdown modifications were introduced to evaluate mTORC1 and mTORC1 pathways. Calcium measurement, reactive oxygen species (ROS) production, mitochondrial membrane potential and protein, cell proliferation, apoptosis, and endothelial junction protein were detected to evaluate HGF effects. Moreover, we used the ALI mouse model to observe the mitochondria pathological changes with an electron microscope in vivo.@*RESULTS@#Our study demonstrated that HGF protected the endothelium via the suppression of ROS production and intracellular calcium uptake, which lead to increased mitochondrial membrane potential (JC-1 and mitochondria tracker green detection) and specific proteins (complex I), raised anti-apoptosis Messenger Ribonucleic Acid level (B-cell lymphoma 2 and Bcl-xL), and increased endothelial junction proteins (VE-cadherin and occludin). Reversely, mTOR inhibitor rapamycin and STAT3 inhibitor S3I-201 could raise oxidative stress and mitochondria-dependent apoptosis even with HGF treatment in LPS-induced endothelial cells. Similarly, mTORC1 as well as mTORC2 have the same protective effects in mitochondria damage and apoptosis. In in vivo experiments of ALI mouse, HGF also increased mitochondria structural integrity via the mTOR/STAT3 pathway.@*CONCLUSION@#In all, these reveal that mTOR/STAT3 signaling mediates the HGF suppression effects to oxidative level, mitochondria-dependent apoptosis, and endothelial junction protein in ARDS, contributing to the pulmonary endothelial survival and barrier integrity.

Disfunción endotelial. Mecanismos e implicancias en Covid-19 / Endothelial dysfunction. Mechanisms and implications on Covid-19

Endothelium is the inner layer of vessels that separates circulating blood from the rest of the body tissues. Since its discovery, it has been involved in various functions, both systemic and organ specific. Currently, endothelial damage and failure in its functions is considered a key element in pathophysiology of various clinical scenarios, among which we may find COVID-19.Hence, it has been a target in development of strategies that seek to maintain, enhance or repair its function. The purpose of the following review is to describe what an endothelial function is about, its relation with current medical practice, and its implications in the SARS- CoV-2 pandemic. (AU)

Early growth response protein 1 acts as an activator of SOX18 promoter

Sex-determining region Y box 18 (Sox18/SOX18) gene is an important regulator of vascular development playing a role in endothelial cell specification or differentiation, angiogenesis and atherogenesis. The aim of this study was to perform comprehensive functional characterization of the human SOX18 promoter, including determination of transcription start point (tsp) and identification of control elements involved in the regulation of SOX18 gene expression, with an emphasis on angiogenesis-related transcription factors. Analyses were performed in HeLa cells, representing a tumor cell line, and in EA.hy926 cells used as an endothelial model system. We have determined unique tsp of SOX18 gene, located 172 nucleotides upstream from ATG codon. Further, we have shown that SOX18 promoter region, -726 to -89 bp relative to tsp, contains positive cis-regulatory element(s) that stimulates SOX18 promoter activity, while region -89 to + 166 represents the minimal promoter. Within this region we have recognized the presence of essential element(s), positioned from -89 to +29, which harbors cluster of three putative early growth response 1 (EGR1) binding sites. By in vitro binding assays and functional analyses we have shown that these three putative binding sites are functionally relevant and sufficient for EGR1-induced SOX18 transcription. Mutations of these binding sites significantly impaired activity of the SOX18 promoter, particularly in EA.hy926 cells, indicating the importance of these regulatory elements for SOX18 promoter activity in endothelial setting. By data presented in this study, we have established SOX18 as a novel target gene regulated by EGR1 transcription factor, thus providing the first functional link between two transcription factors previously shown to be involved in the control of angiogenesis.

A Case of Hypertrophic Osteoarthropathy Associated with Epithelioid Hemangioendothelioma

Epithelioid hemangioendothelioma is a rare vascular tumor, which occurs in the lung, liver, bone, and soft tissue. Hypertrophic osteoarthropathy is a syndrome characterized by subperiosteal new bone formation, joint effusion and clubbing, and may be associated with cyanotic heart disease, chronic pulmonary disease, liver disease, and other miscellaneous diseases. The activation of endothelium and platelets has been suggested to be involved in the development of hypertrophic osteoarthropathy. We report a rare case of hypertrophic osteoarthropathy, which developed in association with hepatic epithelioid hemangioendothelioma with pulmonary metastasis. We also discuss the role of vascular endothelial growth factor in its pathogenesis.

The TGF beta receptor endoglin in systemic sclerosis.

Immunohistochemical, flow cytometric and ELISA studies were performed to examine the expression of endoglin (CD105, a TGF beta receptor) on dermal endothelial cells, peripheral blood monocytes and free and bound serum levels in patients with systemic sclerosis as compared with appropriate controls. Endoglin was found to be significantly upregulated on dermal blood vessels in patients with scleroderma (and in patients with inflammatory skin disorders) as compared to healthy skin (p < 0.05). In contrast, there was no significant difference in endoglin expression on circulating blood monocytes between scleroderma patients and patients with a rheumatic disoder or healthy control subjects; however, endoglin expression was upregulated on monocytes in inflammatory joint fluid from patients with rheumatoid arthritis. Endoglin expression on monocytes was also influenced by isolation techniques and during whole blood culture. No differences were found in circulating free or bound endoglin levels between scleroderma patients and healthy controls. In conclusion, endoglin expression on dermal endothelial cells was significantly enhanced in scleroderma but levels on circulating monocytes and in the serum were within normal limits. The functional significance of this upregulation is uncertain but may reflect endothelial activation in scleroderma.

Drug uptake from the airways and lungs.

This paper reviews the mechanisms and physiological processes that act when drugs or chemicals are administered into the lower airways and lungs. Administration is usually by aerosol. Agents can be given, for example, either to treat pulmonary diseases such as asthma, or the test for airways' responsiveness or other functions, or as a means of access of a drug to the systemic circulation. The first barrier to absorption is the airway surface liquid, including mucus. The thickness of this layer will determine the concentration of the drug in solution, and therefore its rate of entry into the tissue. The agent must then penetrate the airway epithelium, the strongest barrier for hydrophilic agents. Agents must then diffuse through the epithelial basement membrane and the interstitium. Finally, the agent may be taken up into the mucosal vasculature, and changes in blood flow will influence its uptake and distribution. If the drug is to reach a target organ, such as airway smooth muscle or glands, these barriers have first to be traversed.

Role of endothelium in angiotensin II formation by the rat aorta and mesenteric arterial bed

We investigated the angiotensin II (Ang II)-generating system by analyzing the vasoconstrictor effect of Ang II, angiotensin I (Ang I), and tetradecapeptide (TDP) renin substrate in the abscence and presence of inhibitors of the renin-angiotensin system in isolated rat aortic rings and mesenteric arterial beds with and without functional endothelium. Ang II, Ang I, and TDP elicited a dose-dependent vasoconstrictor effect in both vascular preparations that was completely blocked by the Ang II receptor antagonist saralasin (50 nM). The angiotensin converting enzyme (ACE) inhibitor captopril (36 muM) completely inhibited the vasoconstrictor effect elicited by Ang I and TDP in aortic rings without affecting that of Ang II. In contrast, captopril (36 muM) significantly reduced (80-90 percent) the response to bolus injection of Ang I, without affecting those to Ang II and TDP in mesenteric arteries. Mechanical removal of the endothelium greatly potentiated (70-95 percent) the vasoconstrictor response to Ang II, Ang I, and TDP in aortic rings while these responses were unaffected by the removal of the endothelium of mesenteric arteries with sodium deoxycholate infusion. In addition, endothelium disruption did not change the pattern of response elicited by these peptides in the presence of captopril. These findings indicate that the endothelium may not be essential for Ang II formation in rat mesenteric arteries and aorta, but it may modulate the response to Ang II. Although Ang II formation from Ang I is essentially dependent on ACE in both vessels, our results suggest the existence of an alternative pathway in the mesenteric arterial bed that may play an important role in Ang II generation from TDP in resistence but not in large vessels during ACE inhibition.

Rol del endotelio en el efecto vasodilatador de la acetilcolina cuando el vaso aislado se somete a la acción contráctil de norepinefrina o de potasio / Role of endothelium in the vasodilator effect of the acetylcholine when the vaso isolated with endothelium contratedeith no repinephrine of potassium chloride

La acetilcolina depende de la conservación del endotelio vascular, para producir su efecto vasodilatador que es ocasionado por la liberación de un factor relajador derivado del endotelio y que corresponde al óxido nítrico. Se estudiaron las acciones de la acetilcolina, en manguitos aislados de aorta de rata con endotelio, contraídos por norepinefrina o cloruro de potasio. Se ensayaron dosis únicas de norepinefrina, 10-6 M y también dosis crecientes y acumulativas desde 10-8 hasta 10-4 antes y después de la incubación con acetilcolina. Además, se sometió la preparación con endotelio a los efectos de una solución despolarizante de potasio y luego se le agregó acetilcolina 10-3. También se observaron los efectos de la acetilcolina añadida previamente a la solución despolarizante. A modo de control, en otra serie experimental, se utilizó solución Krebs-Henseleir. La acetilcolina adicionada previamente a la solución de potasio antagoniza la contracción producida por esta solución despolarizante. En cambio, cuando la preparación es contraída previamente con dicha solución la acetilcolina no produce vasodilatación. La incubación en acetilcolina disminuye la acción contráctil de dosis creciente y acumulativas de norepinefrina, probablemente por liberación de factor de relajación derivado del endotelio