His-Purkinje conduction system pacing and atrioventricular node ablation in treatment of persistent atrial fibrillation refractory to multiple ablation procedures: A case report.

In patients with symptomatic atrial fibrillation refractory to optimal medical therapy, atrioventricular node ablation followed by permanent pacemaker implantation is an effective treatment option. A 66-year-old woman with symptomatic persistent atrial fibrillation refractory to multiple ablation procedures was referred to our institution. After optimal drug therapy, the patient still had obvious symptoms. Sequential His-Purkinje conduction system pacing and atrioventricular node ablation were performed. Left bundle branch pacing was used as a backup pacing method if thresholds of His bundle pacing were too high or loss of His bundle capture occurred in the follow-up. At the 6-month follow-up, the European Heart Rhythm Association classification for AF was improved, the score of the Atrial Fibrillation Effect on Quality of Life was enhanced, and the 6-Minute Walk Test was ameliorated. The present case was subjected to His-Purkinje conduction system pacing in combination with atrioventricular node ablation as treatment for a symptomatic persistent atrial fibrillation refractory to multiple ablation procedures, and this procedure alleviated symptoms and improved the quality of life in a short-term follow-up.

PPARG Silencing Improves Blood Pressure Control and Alleviates Renal Damage by Modulating RAS Circadian Rhythm in Hypertensive Rats.

OBJECTIVE: Peroxisome proliferator-activated receptor gamma (PPARG) polymorphisms are associated with hypertension, but the role of PPARG in hypertensive nephropathy is poorly understood. METHODS: Male Sprague-Dawley rats were applied to construct renovascular hypertension model by 2-kid-ney, 1-clip (2K1C) method. Tail vein bolus injection of adeno-associated virus (rAAV)-shPPARG was performed to knockout PPARG in 2K1C rats. The heart rate (HR), systolic pressure (SBP), diastolic pressure (DBP) and activity of rats were monitored after treatments. The role of PPARG in hypertension, renal damage, and circadian rhythm of renin-angiotensin system (RAS) was explored by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), western blot, Masson staining, hematoxylin eosin (HE) staining, Sirius red staining and enzyme-linked immunosorbent assay. RESULTS: PPARG was over-expressed in thoracic aortas of 2K1C rats. 2K1C treatment enhanced DBP and SBP in rats, which was reversed by PPARG silencing. PPARG silencing alleviated 2K1C-induced renal damage. 2K1C treatment reduced angiotensin II and increased angiotensin converting enzyme (ACE) and plasma renin activity (PRA) concentrations in rat plasma during the light period and decreased plasma PRA concentration during the dark period, which were all overturned by PPARG silencing. PPARG silencing effectively improved the RAS circadian rhythm in hypertension. CONCLUSION: PPARG silencing improved blood pressure control and alleviated renal damage by regulating RAS circadian rhythm in hypertensive rats.

Pentraxin 3 depletion (PTX3 KD) inhibited myocardial fibrosis in heart failure after myocardial infarction.

BACKGROUND: HF is a common complication of MI. The underlying mechanisms of myocardial fibrosis in HF after MI are incompletely defined. Here, this study aims to investigate the role of PTX3 KD in HF after MI. METHODS: Bioinformatics analysis based on GSE86569 dataset was performed to explore the potential role of PTX3 in HF. Male C57/BL6J mice were administered with lentiviral vector encoding PTX3 KD or empty vector, and then underwent either coronary ligation or sham surgery. Echocardiography, Masson staining, and immunofluorescence counterstaining were conducted to evaluate the cardiac function and fibrosis. Cardiac fibroblasts were isolated and transfected with lentiviral vector encoding PTX3 KD in vitro to verify the in vivo findings. RESULTS: Bioinformatics analysis based on GSE86569 revealed the aberrant expression of PTX3 in HF patients. Echocardiography showed that PTX3 KD reversed the HF-induced cardiac dysfunction with better cardiac function parameters. Masson staining demonstrated that the obvious infarct and high fibrosis ratio in HF mice were remarkably improved after PTX3 KD. Immunofluorescence staining indicated that the HF-induced increase expression of α-SMA was significantly suppressed by PTX3 KD. Additionally, both in vivo and in vitro results confirmed that PTX3 KD decreased the fibrosis-related up-regulation of collagen I, collagen III, and p-STAT3. However, the result was opposite after IL-6 treatment. CONCLUSIONS: PTX3 KD protects the cardiac function and counteracts the myocardial fibrosis by down-regulating IL-6/STAT3 pathway in HF.

Graft-Versus-Host-Disease of the Central Nervous System and Lung in a Patient With Acute Myeloid Leukemia After Allogeneic Hematopoietic Stem Cell Transplantation: A Case Report.

INTRODUCTION: The common etiology of central nervous system (CNS) complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT) includes CNS infection, metabolic abnormalities, drug toxicity, cerebrovascular events, Epstein-Barr virus-associated posttransplant lymphoproliferative diseases, and hematologic CNS relapse of leukemia. Although graft-versus-host disease (GVHD) is a major complication of allo-HSCT, its CNS involvement is exceedingly rare. CASE PRESENTATION: In this report, we describe a patient who exhibited acute myeloid leukemia with t(8;21) (q22;q22) and who suddenly lost visual acuity ~1 year after receipt of allo-HSCT. Given the observation of negative cerebrospinal fluid findings, cyclosporine-related encephalopathy, intracranial hemorrhage, CNS infection, leukemia recurrence, and tumors were excluded. He was diagnosed with both CNS and pulmonary GVHD. After steroid treatment, the lesions gradually reduced in images acquired via cranial and pulmonary computed tomography. CONCLUSIONS: CNS-GVHD is a rare, serious complication of allo-HSCT that is difficult to diagnose. Biopsy and autopsy may identify the CNS as the target of GVHD in some patients. Treatment is mainly based on the use of immunosuppressive drugs, including high doses of steroids. Early diagnosis and treatment can improve disease outcome.

Prevalence of modifiable risk factors and relation to stroke and death in patients with atrial fibrillation: A report from the China atrial fibrillation registry study.

BACKGROUND: Lifestyle and risk factor management may improve outcomes in patients with atrial fibrillation (AF). We aim to evaluate the prevalence of modifiable risk factors and how these factors impact clinical outcomes in patients with AF. METHODS AND RESULTS: Data on 17 898 AF cohort patients with AF enrolled between 2011 and 2016 was analyzed. A healthy lifestyle was defined as not smoking, not drinking, a healthy body mass index (BMI), untreated total cholesterol less than 200 mg/dL, untreated blood pressure (BP) less than 120/80 mm Hg, and untreated fasting plasma glucose (FPG) less than 100 mg/dL. The association between risk factors and risk of the composite endpoint of all-cause mortality and nonfatal ischemic stroke were assessed using Cox proportional hazards regression model. Only 4.0% of patients achieved a healthy lifestyle. In multivariate analysis, current smoking, a low BMI, not well-controlled FPG were independently and significantly associated with higher risk of all-cause mortality and nonfatal ischemic stroke, with corresponding hazard ratio (HR) estimates 1.22 (95% confidence interval [CI], 1.00-1.47), HR = 1.72 (95% CI, 1.34-2.20), and HR = 1.25 (95% CI, 1.06-1.46), respectively. High BP was also associated with higher risk with the outcomes (HR = 1.15, 95% CI, 1.00-1.34). Compared with patients with no risk factor, those who failed to maintained or achieved optimal risk factor control had a progressively higher risk of death and nonfatal ischemic stroke (HR for 1 risk factor = 1.44; 95% CI, 1.07-1.92; and more than 2 risk factors = 1.75; 95% CI, 0.99-3.09). CONCLUSIONS: Maintenance of well-controlled risk factors may substantially lower the risk of death and ischemic stroke in patients with AF.

Patient-Reported Treatment Satisfaction with Dabigatran versus Warfarin in Patients with Non-Valvular Atrial Fibrillation in China.

BACKGROUND: Anti-coagulant therapy satisfaction for patients with atrial fibrillation is a critical issue, which impacts on their treatment adherence and clinical outcomes. The disadvantages of long-term warfarin treatment are well-described, and novel oral anti-coagulants have become an alternative option. MATERIALS AND METHODS: We compared patient-reported treatment satisfaction with dabigatran versus warfarin in non-valvular atrial fibrillation (NVAF) patients in China. Treatment satisfaction was assessed using the Anti-Clot Treatment Scale (ACTS) questionnaire, which included a 12-item ACTS Burdens scale and a 3-item ACTS Benefits scale. RESULTS: Among 834 patients, 246 patients (29.5%) were taking dabigatran and the others were on warfarin. Propensity score matching was employed to identify 182 patient pairs with balanced baseline characteristics. The global ACTS Burdens score and the global ACTS Benefits score were comparable between the dabigatran and warfarin groups (44.86 ± 3.95 vs. 44.28 ± 3.51, p = 0.423; 11.49 ± 2.92 vs. 11.42 ± 3.03, p = 0.194, respectively). The monthly cost of dabigatran was significantly higher compared with that of warfarin due to a lack of insurance coverage (USD 176.78 ± 9.15 vs. USD 2.49 ± 0.76, p = 0.000). The discontinuation rate of dabigatran was significantly higher than warfarin at the 6-month follow-up (33.5% vs. 19.2%, p = 0.003). Adjusted logistic regression showed that dabigatran was associated with a significant greater odds of non-persistence (odds ratio: 2.13, 95% confidence interval: 1.27-3.59, p = 0.004). CONCLUSION: Dabigatran therapy in patients with NVAF in China associated with no improvement in satisfaction and a higher discontinuation rate compared with warfarin therapy largely due to increased economic burden.

Effects of Dual-Dose Clopidogrel, Clopidogrel Combined with Tongxinluo Capsule, and Ticagrelor on Patients with Coronary Heart Disease and CYP2C19*2 Gene Mutation After Percutaneous Coronary Interventions (PCI).

BACKGROUND In recent years, genetic factors have attracted research interest as important predisposing factors for cardiovascular susceptibility. This study aimed to investigate the influences of dual-dose clopidogrel, clopidogrel combined with tongxinluo, and ticagrelor on the platelet activity and MACE events of patients with CYP2C19*2 gene function deficiency and poor clopidogrel response after PCI. MATERIAL AND METHODS We selected 458 patients with coronary heart disease undergoing PCI, and the genotype of CYP2C19*2 was detected by TaqMan real-time PCR. We finally enrolled 212 patients and divided them into 4 groups: a standard anti-platelet group of 46 patients, a clopidogrel double-dose group of 50 cases, a clopidogrel combined with tongxinluo group of 59 cases, and a ticagrelor group of 57. The platelet inhibition rate was detected by TEG. We analyzed and compared differences in platelet activity and the occurrence of MACE events in these 4 groups at different follow-up times. RESULTS The results showed that inhibition of platelet aggregation was better in the double-dose clopidogrel group, the clopidogrel combined with tongxinluo group, and the ticagrelor group than in the regular-dose clopidogrel group, and ticagrelor was the best. We also found that the total incidence of MACE was much lower in the double-dose clopidogrel group, the clopidogrel combined with tongxinluo group, and the ticagrelor group, while the incidence of hemorrhage in the ticagrelor group was higher. CONCLUSIONS Adjusting the dose or combining with other drugs improves the efficacy of anti-platelet therapy and reduces the incidence of ischemic events after PCI.

Expression of miRNA-26a in platelets is associated with clopidogrel resistance following coronary stenting.

The present study aimed to evaluate the association between platelet microRNA (miRNA)-26a expression and clopidogrel resistance in patients who underwent coronary stenting. Between September 2013 and August 2014, 43 patients with coronary heart disease underwent percutaneous coronary intervention at Heibei General Hospital (Shijiazhuang, China). In the same period, 20 healthy volunteers without any history of cardiovascular disease were enrolled in the present study as the control group. Flow cytometry was used to measure the phosphorylation levels of vasodilator-stimulated phosphoprotein (VASP), and to calculate the platelet reactivity index (PRI). Low response to clopidogrel was defined as PRI ≥50% on day 7 following clopidogrel administration. Western blotting was used to measure protein expression of VASP and reverse transcription-quantitative polymerase chain reaction analysis was performed to determine the expression levels of mRNA and miRNAs. Bioinformatics tools were employed to predict that miR-26a, miR-199 and miR-23a may target VASP mRNA. The results of the present study demonstrated that the activity of platelets in patients with low or high clopidogrel response was increased, as compared with healthy subjects. No differences in platelet VASP protein expression levels were detected between patients with high clopidogrel response and healthy subjects; whereas VASP protein expression was elevated in patients with low clopidogrel response. Furthermore VASP gene transcription was maintained at low levels in healthy subjects and patients with high clopidogrel response, whereas patients with low clopidogrel response exhibited increased VASP mRNA expression levels. Platelet expression of miRNA-26a, but not miRNA-199 or miRNA-23a, was associated with high platelet reactivity. Serum miRNA-26a, miRNA-199 and miRNA-23a were not demonstrated to be involved in clopidogrel resistance. Therefore, the present study demonstrated that platelet miRNA-26a has an important role in clopidogrel resistance. Combined miRNA and VASP PRI tests may aid the early diagnosis and prediction of clopidogrel resistance.

Role of the Cytosolic Loop C2 and the C Terminus of YidC in Ribosome Binding and Insertion Activity.

Members of the YidC/Oxa1/Alb3 protein family mediate membrane protein insertion, and this process is initiated by the assembly of YidC·ribosome nascent chain complexes at the inner leaflet of the lipid bilayer. The positively charged C terminus of Escherichia coli YidC plays a significant role in ribosome binding but is not the sole determinant because deletion does not completely abrogate ribosome binding. The positively charged cytosolic loops C1 and C2 of YidC may provide additional docking sites. We performed systematic sequential deletions within these cytosolic domains and studied their effect on the YidC insertase activity and interaction with translation-stalled (programmed) ribosome. Deletions within loop C1 strongly affected the activity of YidC in vivo but did not influence ribosome binding or substrate insertion, whereas loop C2 appeared to be involved in ribosome binding. Combining the latter deletion with the removal of the C terminus of YidC abolished YidC-mediated insertion. We propose that these two regions play an crucial role in the formation and stabilization of an active YidC·ribosome nascent chain complex, allowing for co-translational membrane insertion, whereas loop C1 may be involved in the downstream chaperone activity of YidC or in other protein-protein interactions.

Defining the region of Bacillus subtilis SpoIIIJ that is essential for its sporulation-specific function.

Proteins of the YidC/OxaI/Alb3 family play a crucial role in the insertion, folding, and/or assembly of membrane proteins in prokaryotes and eukaryotes. Bacillus subtilis has two YidC-like proteins, denoted SpoIIIJ and YqjG. SpoIIIJ and YqjG are largely exchangeable in function, but SpoIIIJ has a unique role in sporulation, while YqjG stimulates competence development. To obtain more insight into the regions important for the sporulation specificity of SpoIIIJ, a series of SpoIIIJ/YqjG chimeras was constructed. These chimeras were tested for functionality during vegetative growth and for their ability to complement the sporulation defect of a spoIIIJ deletion strain. The data suggest an important role for the domain comprising transmembrane segment 2 (TMS2) and its flanking loops in sporulation specificity, with lesser contributions to specificity by TMS1 and TMS3.

A strategy of gene overexpression based on tandem repetitive promoters in Escherichia coli.

BACKGROUND: For metabolic engineering, many rate-limiting steps may exist in the pathways of accumulating the target metabolites. Increasing copy number of the desired genes in these pathways is a general method to solve the problem, for example, the employment of the multi-copy plasmid-based expression system. However, this method may bring genetic instability, structural instability and metabolic burden to the host, while integrating of the desired gene into the chromosome may cause inadequate transcription or expression. In this study, we developed a strategy for obtaining gene overexpression by engineering promoter clusters consisted of multiple core-tac-promoters (MCPtacs) in tandem. RESULTS: Through a uniquely designed in vitro assembling process, a series of promoter clusters were constructed. The transcription strength of these promoter clusters showed a stepwise enhancement with the increase of tandem repeats number until it reached the critical value of five. Application of the MCPtacs promoter clusters in polyhydroxybutyrate (PHB) production proved that it was efficient. Integration of the phaCAB genes with the 5CPtacs promoter cluster resulted in an engineered E.coli that can accumulate 23.7% PHB of the cell dry weight in batch cultivation. CONCLUSIONS: The transcription strength of the MCPtacs promoter cluster can be greatly improved by increasing the tandem repeats number of the core-tac-promoter. By integrating the desired gene together with the MCPtacs promoter cluster into the chromosome of E. coli, we can achieve high and stale overexpression with only a small size. This strategy has an application potential in many fields and can be extended to other bacteria.

Expression of active recombinant human tissue-type plasminogen activator by using in vivo polyhydroxybutyrate granule display.

Recombinant human tissue plasminogen activator (rPA) is a truncated version of tissue plasminogen activator (tPA), which contains nine disulfide bonds and is prone to forming inactive inclusion bodies when expressed in bacteria. To obtain functional rPA expression, we displayed the rPA on the surface of polyhydroxybutyrate (PHB) granules using phasin as the affinity tag. rPA was fused to the N terminus of the phasin protein with a thrombin cleavage site as the linker. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot analysis showed that rPA fusion was successfully displayed on the surface of PHB granules. An activity assay indicated that the rPA fusion is active. The in vivo surface display strategy for functional rPA expression in Escherichia coli is distinct for its efficient folding and easier purification and may be expanded to the expression of other eukaryotic proteins with complex conformation.

Engineering Escherichia coli for an efficient aerobic fermentation platform.

Acetate, as a major by-product, was excreted by Escherichia coli when aerobic fermentation runs at high growth rates. In order to reduce the acetate secretion during the fermentation fundamentally, a list of genes related to acetate accumulation in E. coli was selected and knocked out. Physiological characterization of each mutant demonstrated that the growth and metabolites accumulation properties of these mutations exhibited significant change upon pathway engineering. The final engineered E. coli QZ1110 with ptsG, poxB, pta and iclR gene mutations was confirmed to accumulate 270% more biomass with 90% less acetate secretion than that of wild type E. coli in LB medium supplied with 1% glucose. Polyhydroxybutyrate biosynthesis experiment showed that the acetate reduction of the engineered strain in minimal medium also reduced 90% while the PHB accumulation increased almost 100% compare to wild type E. coli.

[Construction of engineered Escherichia coli for aerobic succinate production].

Based on carbon metabolic pathway analysis of Escherichia coli MG1655, an aerobic succinate fermentation platform was constructed by knocking out five genes (ptsG, poxB, pta, iclR and sdhA), which was named E. coli QZ1111. Flask cultivation results showed that E. coli QZ1111 could accumulate succinate with a concentration of 26.4 g/L under aerobic conditions. The byproduct acetate was only 2.3 g/L. The production ratio of succinate and acetate reached 11.5:1.