After biosynthesis, bacterial lipopolysaccharides (LPS) are transiently anchored to the outer leaflet of the inner membrane (IM). The ATP-binding cassette (ABC) transporter LptBFG extracts LPS molecules from the IM and transports them to the outer membrane. Here we report the crystal structure of nucleotide-free LptBFG from Pseudomonas aeruginosa. The structure reveals that lipopolysaccharide transport proteins LptF and LptG each contain a transmembrane domain (TMD), a periplasmic β-jellyroll-like domain and a coupling helix that interacts with LptB on the cytoplasmic side. The LptF and LptG TMDs form a large outward-facing V-shaped cavity in the IM. Mutational analyses suggest that LPS may enter the central cavity laterally, via the interface of the TMD domains of LptF and LptG, and is expelled into the β-jellyroll-like domains upon ATP binding and hydrolysis by LptB. These studies suggest a mechanism for LPS extraction by LptBFG that is distinct from those of classical ABC transporters that transport substrates across the IM.
BackgroundReconstruction of the aortic major branches during thoracic endovascular aortic repair is complicated because of the complex anatomic configuration and variation of the aortic arch. In situ laser fenestration has shown great potential for the revascularization of aortic branches. This study aims to evaluate the feasibility, effectiveness, and safety of in situ laser fenestration on the three branches of the aortic arch during thoracic endovascular aortic repair.Methods and ResultsBefore clinical application, the polytetrafluoroethylene and Dacron grafts were fenestrated by an 810‐nm laser system ex vivo, which did not damage the bare metal portion of the endografts and created a clean fenestration while maintaining the integrity of the endografts. In vivo, 6 anesthetized female swine survived after this operation, including stent‐graft implantation in the aortic arches, laser fenestration, and conduit implantation through the innominate arteries and the left carotid arteries. Based on the animal experiments, in situ laser fenestration during thoracic endovascular aortic repair was successively performed on 24 patients (aged 33–86 years) with aortic artery diseases (dissection type A: n=4, type B: n=7, aneurysm: n=2, mural thrombus: n=7). Fenestration of 3 aortic branches was performed in 2 (8.3%) patients. Both the left carotid artery and the left subclavian artery were fenestrated in 6 (25%) patients. Only left subclavian artery fenestration surgery was done in 16 (66.7%) patients. Among these patients, 1 fenestration was abandoned secondary to an acute takeoff of the innominate artery in a type III aortic arch. The average operative time was 137±15 minutes. The technical success rate was 95.8% (n=23). No fenestration‐related complications or neurological morbidity occurred after this operation. During a mean postoperative 10‐month follow‐up (range: 2–17 months), 1 patient died of severe pneumonia, and all the left subclavian artery and carotid artery stents were patent with no fenestration‐related endoleaks upon computed tomography angiography images.ConclusionsIn situ laser fenestration is a feasible, effective, rapid, repeatable, and safe option for the reconstruction of aortic arch during thoracic endovascular aortic repair, which might be available to revascularize the 3 branches. However, follow‐up periods should be extended to evaluate the robustness of this technique.
Atherosclerosis is one of the most common type of cardiovascular disease and the prime cause of mortality in the aging population worldwide. However, the detail mechanisms and special biomarkers of atherosclerosis remain to be further investigated. Lately, long non-coding RNAs (lncRNAs) has attracted much more attention than other types of ncRNAs. In our work, we found and confirmed differently expressed lncRNAs and mRNAs in atherosclerosis by analyzing GSE28829. We performed the weighted gene co-expression network analysis (WGCNA) by analyzing GSE40231 to confirm highly correlated genes. Gene Ontology (GO) analysis were utilized to assess the potential functions of differential expressed lncRNAs in atherosclerosis. Co-expression networks were also constructed to confirm hub lncRNAs in atherosclerosis. A total of 5784 mRNAs and 654 lncRNAs were found to be dysregulated in the progression of atherosclerosis. A total of 15 lncRNA-mRNA co-expression modules were identified in this study based on WGCNA analysis. Moreover, a few lncRNAs, such as ZFAS1, LOC100506730, LOC100506691, DOCK9-AS2, RP11-6I2.3, LOC100130219, were confirmed as important lncRNAs in atherosclerosis. Taken together, bioinformatics analysis revealed these lncRNAs were involved in regulating the leukotriene biosynthetic process, gene expression, actin filament organization, t-circle formation, antigen processing, and presentation, interferon-gamma-mediated signaling pathway, and activation of GTPase activity. We believed that this study would provide potential novel therapeutic and prognostic targets for atherosclerosis.
Adipose‐derived stem cell (ADSC)‐based therapy is promising for critical limb ischemia (CLI) treatment, especially in patients with diabetes. However, the therapeutic effects of diabetic ADSCs (D‐ADSCs) are impaired by the diabetes, possibly through intracellular reactive oxygen species (ROS) accumulation. The objective of the present study was to detect whether overexpression of methylglyoxal‐metabolizing enzyme glyoxalase‐1 (GLO1), which reduces ROS in D‐ADSCs, can restore their proangiogenic function in a streptozotocin‐induced diabetic mice model of CLI. GLO1 overexpression in D‐ADSCs (G‐D‐ADSCs) was achieved using the lentivirus method. G‐D‐ADSCs showed a significant decrease in intracellular ROS accumulation, increase in cell viability, and resistance to apoptosis under high‐glucose conditions compared with D‐ADSCs. G‐D‐ADSCs also performed better in terms of migration, differentiation, and proangiogenic capacity than D‐ADSCs in a high‐glucose environment. Notably, these properties were restored to the same level as that of nondiabetic ADSCs under high‐glucose conditions. G‐D‐ADSC transplantation induced improved reperfusion and an increased limb salvage rate compared D‐ADSCs in a diabetic mice model of CLI. Histological analysis revealed higher microvessel densities and more G‐D‐ADSC‐incorporated microvessels in the G‐D‐ADSC group than in the D‐ADSC group, which was comparable to the nondiabetic ADSC group. Higher expression of vascular endothelial growth factor A and stromal cell‐derived factor‐1α and lower expression of hypoxia‐induced factor‐1α were also detected in the ischemic muscles from the G‐D‐ADSC group than that of the D‐ADSC group. The results of the present study have demonstrated that protection from ROS accumulation by GLO1 overexpression is effective in reversing the impaired biological function of D‐ADSCs in promoting neovascularization of diabetic CLI mice model and warrants the future clinical application of D‐ADSC‐based therapy in diabetic patients. Stem Cells Translational Medicine 2017;6:261–271
Baicalin is a bioactive ingredient from the herb and has possessed various pharmacological actions. The present study was performed to evaluate the cardioprotective potential of baicalin against myocardial infarction and explore the potential mechanism. Baicalin was intraperitoneally injected into the rats by the doses of 50, 100 and 200 mg/kg, respectively, once a day for 7 d and, 30 min after the last administration, the left coronary artery was ligated. Infarct size was measured to analyze the myocardial damage. Myocardial specific enzymes, including creatine kinase (CK), the MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH) and cardiac troponin T (cTnT) were determined with the colorimetric method. Evidence for myocardial apoptosis was detected by caspase-3 activity measurement and Western blot analysis. We also examined the protein levels of three major subgroups of mitogen-activated protein kinases (MAPKs), namely, extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 by immuoblotting. Our results indicated that baicalin significantly reduced the infarct size and myocardial enzymes (CK, CK-MB, LDH and cTnT). Administration of baicalin also suppressed the activity and protein expression of caspase-3. Moreover, the protein level of phosphorylated ERK (p-ERK) was found to be evidently augmented while the phosphorylated JNK (p-JNK) and phosphorylated p38 (p-p38) were strikingly diminished in infarcted rats with baicalin treatment. These findings suggest that the baicalin's cardioprotection associates with mediation of MAPK cascades in acute myocardial infarction of rats.
Ongoing efforts to remove pathological inflammatory stimuli are crucial for the protection of endothelial cells in diabetes. Nerve injury-induced protein 1 (Ninj1) is an adhesion molecule that not only contributes to inflammation but also regulates the apoptosis of endothelial cells. In the present study, Ninj1 was found highly expressed in endothelial cells in Type 2 diabetic mice and increased in high-glucose (HG) cultured HUVECs. Furthermore, we found that Ninj1 levels are up-regulated in endothelial cells in clinical specimens of diabetic patients when compared with nondiabetic tissues, indicating a biological correlation between Ninj1 and endothelial pathophysiology in diabetic condition. Functional blocking of Ninj1 promoted endothelial tube formation and eNOS phosphorylation in the HG condition. Additionally, blocking Ninj1 inhibited the activation of caspase-3 and increased the Bcl-2/Bax ratio, thus inhibiting HUVECs apoptosis induced by HG. HG-induced ROS overproduction, p38 MAPK and NF-κB activation, and the overexpression of, and genes were ameliorated after Ninj1 was blocked. Using the signaling pathway inhibitor LY294002, we found that Bcl-2 expression and eNOS phosphorylation after Ninj1 blockade were regulated via PI3K/Akt signaling pathway. The endothelial contents, α-SMAPECAM-1 vascular numbers, and blood perfusion in the hindlimb were markedly up-regulated after Ninj1 was blocked. According to our findings, functional blocking of Ninj1 shows protective effects on diabetic endothelial cells both and Thus, we consider Ninj1 to be a potential therapeutic target for preventing endothelial dysfunction in diabetes mellitus.
Treatment of congenital EVMs with endovenous laser ablation under US guidance achieved palliation in most symptomatic patients; it was safe, with minimal morbidity during short-term follow-up.
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