Alterations of the m6A Methylation Induced by TGF-ß2 in ARPE-19 Cells.

BACKGROUND: N6-methyladenosine (m6A) participates in diverse physiological processes and contributes to many pathological conditions. Epithelial-mesenchymal transition (EMT) of retinal pigmental epithelial (RPE) cells plays an essential role in retinal-related diseases, and transforming growth factor ß2 (TGF-ß2) is known to induce EMT in vitro. However, the effect of TGF-ß2 on m6A methylation in RPE cells is not yet known. METHODS: RNA-seq and MeRIP-seq were performed to analyze changes at the mRNA and m6A levels after TGF-ß2 treatment of human ARPE-19 cells. mRNA levels and total m6A levels were subsequently validated. RESULTS: Sequencing revealed 929 differentially expressed genes and 7328 differentially methylated genes after TGF-ß2 treatment. Conjoint analysis identified 290 genes related to microtubule cytoskeleton, focal adhesion, ECM-receptor interaction, cell division, cell cycle, AGE-RAGE, PI3K-Akt and cGMP-PKG pathways. Further analysis revealed that 12 EMT-related genes were altered at the mRNA and m6A levels after TGF-ß2 treatment (CALD1, CDH2, FN1, MMP2, SPARC, KRT7, CLDN3, ELF3, FGF1, LOXL2, SHROOM3 and TGFBI). Moreover, the total m6A level was also reduced. CONCLUSIONS: This study revealed the transcriptional profiling of m6A modification induced by TGF-ß2 in RPE cells. Novel connections were discovered between m6A modification and TGF-ß2-induced EMT, suggesting that m6A may play crucial roles in the EMT process.

Potential Impact of N6-Methyladenosine RNA Methylation on Vision Function and the Pathological Processes of Ocular Diseases: New Discoveries and Future Perspectives.

N6-methyladenosine (m6A) methylation/modification plays a critical role in various biological processes through post-transcriptional ribonucleic acid (RNA) modification, which involves RNA processing, nuclear export, translation and decay. Functionally, m6A modification may be involved in ocular cell growth and differentiation, stem cell identity, development, haemostasis and innate versus adaptive immunity. Aberrations in m6A methylation may mediate numerous pathological conditions in the eye, including microorganism infection, inflammation, autoimmune disease, senescence, degeneration, epithelial-mesenchymal transition, fibrosis, angiogenesis, tumorigenesis and complex eye diseases. In this review, we have discussed the relevance of m6A modification to precision medicine, stem cell directional differentiation, biomarkers of eye diseases and m6A methylation activators and inhibitors. In addition, we summarised the challenges and future research directions in the field related to visual function and eye diseases.

Herpes B virus gD interaction with its human receptor--an in silico analysis approach.

BACKGROUND: The glycoprotein D (gD) is essential for Herpes B virus (BV) entry into mammalian cells. Nectin-1, an HSV-1 gD receptor, is found to be the receptor which mediated BV induced cell-cell fusion, while HVEM does not mediate fusion by BV glycoprotein. However, the specific sequence and structural requirements of the BV gD for the recognition of and binding to Nectin-1 are unknown. Moreover, the 3D structures of BV gD and the BV gD-receptor complex have not been determined. In this study, we propose a reliable model of the interaction of the BV gD with receptor using bioinformatics tools. RESULTS: The three-dimensional structures of two BV gD-receptor complexes were constructed using homology modelling and docking strategy. Based on the models of these complexes, the BV gD receptor interaction patterns were calculated. The results showed that the interface between the BV gD and nectin-1 molecule is not geometrically complementary. The computed molecular interactions indicated that two terminal extensions were the main region of BV gD that binds to nectin-1 and that hydrophobic contacts between the two molecules play key roles in their recognition and binding. The constructed BV gD-HVEM complex model showed that this complex had a lower shape complementarity value and a smaller interface area compared with the HSV-1 gD-HVEM complex, and the number of intermolecular interactions between BV gD-HVEM were fewer than that of HSV-1 gD-HVEM complex. These results could explain why HVEM does not function as a receptor for BV gD. CONCLUSION: In this study, we present structural model for the BV gD in a complex with its receptor. Some features predicted by this model can explain previously reported experimental data. This complex model may lead to a better understanding of the function of BV gD and its interaction with receptor and will improve our understanding of the activation of the BV fusion and entry process.

A novel, recovery, and reproducible minimally invasive cardiopulmonary bypass model with lung injury in rats.

BACKGROUND: Cardiopulmonary bypass (CPB) has been shown to be associated with a systemic inflammatory response leading to postoperative organ dysfunction. Elucidating the underlying mechanisms and developing protective strategies for the pathophysiological consequences of CPB have been hampered due to the absence of a satisfactory recovery animal model. The purpose of this study was to establish a good rat model of CPB to study the pathophysiology of potential complications. METHODS: Twenty adult male Sprague-Dawley rats weighing 450-560 g were randomly divided into a CPB group (n = 10) and a control group (n = 10). All rats were anaesthetized and mechanically ventilated. The carotid artery and jugular vein were cannulated. The blood was drained from the right atrium via the right jugular and transferred by a miniaturized roller pump to a hollow fiber oxygenator and back to the rat via the left carotid artery. Priming consisted of 8 ml of homologous blood and 8 ml of colloid. The surface of the hollow fiber oxygenator was 0.075 m(2). CPB was conducted for 60 minutes at a flow rate of 100-120 ml× kg(-1)×min(-1) in the CPB group. Oxygen flow/perfusion flow was 0.8 to 1.0, and the mean arterial pressure remained 60-80 mmHg. Blood gas analysis, hemodynamic investigations, and lung histology were subsequently examined. RESULTS: All CPB rats recovered from the operative process without incident. Normal cardiac function after successful weaning was confirmed by electrocardiography and blood pressure measurements. Mean arterial pressure remained stable. The results of blood gas analysis at different times were within the normal range. Levels of IL-1ß and TNF-α were higher in the lung tissue in the CPB group (P < 0.005). Histological examination revealed marked increases in interstitial congestion, edema, and inflammation in the CPB group. CONCLUSION: This novel, recovery, and reproducible minimally invasive CPB model may open the field for various studies on the pathophysiological process of CPB and systemic ischemia-reperfusion injury in vivo.

Effect of partial liquid ventilation on lung function in oleic acid-induced lung injury model of piglets.

BACKGROUND: Pediatric patients are susceptible to lung injury that does not respond to traditional therapies. Partial liquid ventilation (PLV) has been developed as an alternative ventilatory strategy for treating severe lung injury. The aim of this study is to investigate the effect of PLV on lung function in immature piglets. METHODS: Acute lung injury was induced in 12 Chinese immature piglets by oleic acid (OA). The animals were randomly assigned to two groups (n = 6 each group): (1) conventional mechanical ventilation (MV) group and (2) PLV with FC-77 (10 ml/kg) group. Mean arterial blood pressure (MAP), mean pulmonary arterial pressure (MPAP), central venous pressure (CVP), left atrial pressure (LAP), systemic vascular resistance (SVR), pulmonary vascular resistance (PVR), cardiac output (CO), mean pressure of airway (Paw), dynamic lung compliance (Cydn), and arterial blood gases were measured during the observation period. RESULTS: No piglet died in either group with severe lung injury. After four hours of ventilation, pH in the MV group gradually decreased to lower than 7.20, while in the PLV group, pH also gradually decreased but remained higher than 7.20 (P < 0.05). Partial pressure of oxygen in artery (PaO2) decreased in both groups, but with a significant difference between the PLV group and MV group (P < 0.05). Partial pressure of carbon dioxide in artery (PaCO2) increased in both groups, but with a significant difference between the PLV group and MV group (P < 0.05). Paw increased in both groups, but was not significantly different (P > 0.05). Cydn decreased in both groups, but without a significant difference (P > 0.05). At four hours, heart rate (HR) and MAP in both groups decreased. MPAP in both groups increased, and there was a significant difference between the two groups (P < 0.05). CVP was stable in both groups. At four hours, PVR and LAP were increased in both groups. CO was decreased in both groups (P < 0.05). SVR was stable during the observation time. CONCLUSION: PLV did not improve outcome in changes of lung function.

Off-pump coronary artery bypass grafting using a bilateral internal mammary artery Y graft.

OBJECTIVE: To evaluate the outcome of off-pump coronary artery bypass grafting (OPCABG) using a bilateral internal mammary artery (BIMA) Y configuration graft to achieve total arterial myocardial revascularization. METHODS: From October 2002 to December 2008, 208 patients (196 males and 12 females) underwent OPCABG using a BIMA Y configuration graft. The average age of the patients was 56.5 ± 11.3 years, with an age range of 33-78 years. A total of 167 (80.2%) cases had triple-vessel disease. Left main stem disease was found in 33 (15.9%) cases, and double-vessel disease was found in 8 (3.9%) cases. The semi-skeletonization technique was used to harvest the two internal mammary arteries (IMAs), and then the free right internal mammary artery was connected end-to-side to the left internal mammary artery (LIMA) in situ to complete the Y configuration graft. Off-pump and sequential anastomosis methods were used to perform coronary artery bypass surgery in all patients. Graft patency was assessed intra-operatively with the HT311 transit time flowmeter. RESULTS: A total of 728 distal anastomoses were performed in 208 patients, with the average being 3.5 ± 1.3 per person. No one died or experienced recurrent angina within 30 days after the operation. CONCLUSIONS: OPCABG using the BIMA Y graft was safe and effective to achieve total arterial revascularization. This method avoids surgical operation on the ascending aorta and other incisions.