Effective protective mechanisms of HO-1 in diabetic complications: a narrative review.

Diabetes mellitus is a metabolic disorder with persistent hyperglycemia caused by a variety of underlying factors. Chronic hyperglycemia can lead to diverse serious consequences and diversified complications, which pose a serious threat to patients. Among the major complications are cardiovascular disease, kidney disease, diabetic foot ulcers, diabetic retinopathy, and neurological disorders. Heme oxygenase 1 (HO-1) is a protective enzyme with antioxidant, anti-inflammatory and anti-apoptotic effects, which has been intensively studied and plays an important role in diabetic complications. By inducing the expression and activity of HO-1, it can enhance the antioxidant, anti-inflammatory, and anti-apoptotic capacity of tissues, and thus reduce the degree of damage in diabetic complications. The present study aims to review the relationship between HO-1 and the pathogenesis of diabetes and its complications. HO-1 is involved in the regulation of macrophage polarization and promotes the M1 state (pro-inflammatory) towards to the M2 state (anti-inflammatory). Induction of HO-1 expression in dendritic cells inhibits them maturation and secretion of pro-inflammatory cytokines and promotes regulatory T cell (Treg cell) responses. The induction of HO-1 can reduce the production of reactive oxygen species, thereby reducing oxidative stress and inflammation. Besides, HO-1 also has an important effect in novel programmed cell death such as pyroptosis and ferroptosis, thereby playing a protective role against diabetes. In conclusion, HO-1 plays a significant role in the occurrence and development of diabetic complications and is closely associated with a variety of complications. HO-1 is anticipated to serve as a novel target for addressing diabetic complications, and it holds promise as a potential therapeutic agent for diabetes and its associated complications. We hope to provide inspiration and ideas for future studies in the mechanism and targets of HO-1 through this review.

The neuroprotective role of celastrol on hippocampus in diabetic rats by inflammation restraint, insulin signaling adjustment, Aß reduction and synaptic plasticity alternation.

Celastrol, the primary constituent of Tripterygium wilfordii, has demonstrated neuroprotective properties in rats with dementia by reducing inflammation. A high-fat diet and streptozotocin injection were utilized to establish a diabetic rat model, which was then employed to investigate the possible protective effect of celastrol against the development of diabetes-induced learning and memory deficits. Afterwards, the experimental animals received a dose of celastrol by gavage (4 mg/kg/d). An animal study showed that celastrol enhanced insulin sensitivity and glucose tolerance in diabetic rats. In the Morris water maze test, rats with diabetes performed poorly in terms of spatial learning and memory; treatment with celastrol improved these outcomes. Additionally, administration of celastrol downregulated the expression of inflammatory-related proteins (NF-κB, IKKα, TNF-α, IL-1ß, and IL-6) and greatly reduced the generation of Aß in the diabetic hippocampus tissue. Moreover, the insulin signaling pathway-related proteins PI3K, AKT, and GSK-3ß were significantly upregulated in diabetic rats after celastrol was administered. Also, celastrol prevented damage to the brain structures and increased the synthesis of synaptic proteins like PSD-95 and SYT1. In conclusion, celastrol exerts a neuroprotective effect by modulating the insulin signaling system and reducing inflammatory responses, which helps to ameliorate the cognitive impairment associated with diabetes.

Schisandrin A Attenuates Diabetic Nephropathy via EGFR/AKT/GSK3ß Signaling Pathway Based on Network Pharmacology and Experimental Validation.

Diabetic nephropathy (DN) is one of the common complications of diabetes and the main cause of end-stage renal disease (ESRD) in clinical practice. Schisandrin A (Sch A) has multiple pharmacological activities, including inhibiting fibrosis, reducing apoptosis and oxidative stress, and regulating immunity, but its pharmacological mechanism for the treatment of DN is still unclear. In vivo, streptozotocin (STZ) and a high-fat diet were used to induce type 2 diabetic rats, and Sch A was administered for 4 weeks. At the same time, protein-protein interaction (PPI) networks were established to analyze the overlapping genes of DN and Sch A. Subsequently, the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were performed to determine the hub pathway. In addition, molecular docking was used to preliminarily verify the affinity of hub proteins and Sch A. Further, H&E staining, Sirius red staining, immunohistochemistry, immunofluorescence, and western blot analysis were used to detect the location and expression of related proteins in DN. This study revealed the multi-target and multi-pathway characteristics of Sch A in the treatment of DN. First, Sch A could effectively improve glucose tolerance, reduce urine microprotein and urine creatinine levels, and alleviate renal pathological damage in DN rats. Second, EGFR was the hub gene screened in overlapping genes (43) of Sch A (100) and DN (2524). Finally, it was revealed that Sch A could inhibit the protein expression levels of EGFR and PTRF and reduced the expression of apoptosis-related proteins, and this effect was related to the modulation of the AKT/GSK-3ß signaling pathway. In summary, Sch A has a protective effect in DN rats, EGFR may be a potential therapeutic target, throughout modulating AKT/GSK-3ß pathway.

Effects of DPP4 Inhibitors as Neuroprotective Drug on Cognitive Impairment in Patients with Type 2 Diabetes Mellitus: A Meta-Analysis and Systematic Review.

Purpose: Type 2 diabetes mellitus is considered as one of the risk factors for cognitive impairment. DPP4 inhibitors are effective drugs for the treatment of type 2 diabetes mellitus. However, the relationship between DPP4 inhibitors and cognitive dysfunction remains unclear. Therefore, we used a meta-analysis to determine the association between DPP4 inhibitors and cognitive impairment in type 2 diabetes mellitus. Methods: We systematically searched PubMed, CNKI, and the Cochrane Library at the time of establishment, 2022, and then made inclusion criteria and screened strategies to identify studies with more precise correlations. Results: We included 10 studies with 5,583 participants. The data showed that DPP4 inhibitors significantly reduced the incidence rate of cognitive impairment in type 2 diabetes mellitus (SMD: 0.99; 95% CI [0.59, 1.38]). Furthermore, there was a linear correlation found between cognitive impairment in type 2 diabetes mellitus and fasting blood glucose, 2-hour postprandial blood glucose, and glycosylated hemoglobin. DPP4 inhibitors decreased fasting blood glucose (FPG) (SMD: 0.52; 95% CI [-0.68, -0.37]), blood glucose (2hPPG) at 2 hours after the meal (SMD: 0.82; 95% CI, [-1.2, -0.43]), and HbA1c (SMD: 0.34; 95% CI [-0.48, -0.21]). All data were statistically significant (P < 0.0001). Furthermore, we conducted subgroup analyses of the following measures at various treatment durations and ages: cognitive scores, fasting blood glucose, glycosylated hemoglobin, and two-hour postprandial blood glucose. Conclusion: DPP4 inhibitors significantly improved type 2 diabetic mellitus individuals' cognitive impairment and reduced fasting blood glucose, 2-hour postprandial blood glucose, and glycosylated hemoglobin. Subgroup analysis showed that people aged 60 to 70 years had better treatment effects at 0-180 days. This trial is registered with CRD42023399473.

Dapagliflozin improves diabetic cognitive impairment via indirectly modulating the mitochondria homeostasis of hippocampus in diabetic mice.

Cognitive impairment is increasingly recognized as an important comorbidity of diabetes progression; however, the underlying molecular mechanism is unclear. Dapagliflozin, an inhibitor of sodium-glucose co-transporter 2 (SGLT2), has shown promising effects against diabetes in rodent experiments and human clinical assays. This study aimed to determine the underlying mechanism and examine the effect of dapagliflozin on diabetic cognitive impairment. To create an in vivo model of diabetic cognitive impairment, streptozotocin (STZ)-induced diabetic mice were used. Dapagliflozin was administered to mice for 8 weeks. The context fear condition and Morris water maze test was used to evaluate mice's behavioral change. Western blotting was used to evaluate protein expression. Hematoxylin and eosin (HE) and Nissl staining were applied to monitor morphological and structural changes. Congo red staining was performed to identify the formation of senile plaques. Mitochondria morphology was examined using a transmission electron microscope, and blood flow in the mouse cerebral cortex was measured using a laser Doppler imaging assay. Comparison to the diabetes mellitus (DM) group, the dapagliflozin group had lower glucose levels. Behavioral studies have shown that dapagliflozin can restore memory deficits in diabetic mice. The murky cell membrane edges and Nissl bodies more difficult to identify in the DM group were revealed by HE and Nissl staining, which were both improved by dapagliflozin treatment. Dapagliflozin inhibited the progression of Aß generation and the reduced cerebral blood flow in the DM group was rescued. After dapagliflozin treatment, damaged mitochondria and lack of SGLT2 in the hippocampus and cortex of diabetic mice were repaired. Diabetes-induced cognitive dysfunction was attenuated by dapagliflozin and the effect was indirect rather than direct.

Trafficking and effect of released DNA on cGAS-STING signaling pathway and cardiovascular disease.

Evidence from clinical research and animal studies indicates that inflammation is an important factor in the occurrence and development of cardiovascular disease (CVD). Emerging evidence shows that nucleic acids serve as crucial pathogen-associated molecular patterns (PAMPs) or non-infectious damage-associated molecular patterns (DAMPs), are released and then recognized by pattern recognition receptors (PRRs), which activates immunological signaling pathways for host defense. Mechanistically, the released nucleic acids activate cyclic GMP-AMP synthase (cGAS) and its downstream receptor stimulator of interferon genes (STING) to promote type I interferons (IFNs) production, which play an important regulatory function during the initiation of an innate immune response to various diseases, including CVD. This pathway represents an essential defense regulatory mechanism in an organism's innate immune system. In this review, we outline the overall profile of cGAS-STING signaling, summarize the latest findings on nucleic acid release and trafficking, and discuss their potential role in CVD. This review also sheds light on potential directions for future investigations on CVD.

Schisandrin A Alleviates Spatial Learning and Memory Impairment in Diabetic Rats by Inhibiting Inflammatory Response and Through Modulation of the PI3K/AKT Pathway.

Clinical and epidemiological research shows that people with diabetes mellitus frequently experience diabetic cognitive impairment. Schisandrin A (SchA), one of the lignans found in the dried fruit of Schisandra chinensis, has a variety of pharmacological effects on immune system control, apoptosis suppression, anti-oxidation and anti-inflammation. The goal of the current investigation was to clarify the probable neuro-protective effects of SchA against streptozotocin-induced diabetes deficiencies of the spatial learning and memory in rats. The outcomes show that SchA therapy effectively improved impaired glucose tolerance, fasting blood glucose level and serum insulin level in diabetic rats. Additionally, in the Morris water maze test, diabetic rats showed deficits in spatial learning and memory that were ameliorated by SchA treatment. Moreover, giving diabetic rats SchA reduced damage to the hippocampus structure and increased the production of synaptic proteins. Further research revealed that SchA therapy reduced diabetic-induced hippocampus neuron damage and the generation of Aß, as demonstrated by the upregulated phosphorylation levels of insulin signaling pathway connected proteins and by the decreased expression levels of inflammatory-related factors. Collectively, these results suggested that SchA could improve diabetes-related impairments in spatial learning and memory, presumably by reducing inflammatory responses and regulating the insulin signaling system.

Trelagliptin relieved cognitive impairment of diabetes mellitus rats: Involvement of PI3K/Akt/GSK-3ß and inflammation pathway.

Cognitive impairment frequently coexists with diabetes. Trelagliptin is a once-weekly taking selective dipeptidyl peptidase-4 (DPP-4) inhibitor and a long-term effective hypoglycemic medicine; nonetheless, its effects for the treatment of diabetes-related cognitive impairment have only sometimes been explored. In this study, a DM model was built using streptozotocin (STZ) and a high-fat diet (HFD). The morris water maze test on DM rats revealed a considerably reduced capacity for spatial learning and memory, but trelagliptin was able to restore function. Trelagliptin could lower the mRNA expression of inflammatory factors such IL-1ß, TNF-α, and IL-6 in DM rats. It could also reduce the ratio of p-IKKα/IKKα, and the immunofluorescence result of NF-κB also demonstrated a drop. Trelagliptin partially restored dendritic spines and prevented the loss or shrinkage of neurons, respectively, according to the results of Nissl's staining and golgi staining. Furthermore, PI3K/Akt/GSK-3ß has been activated, and synaptic plasticity has been modified during this process. In conclusion, trelagliptin improved the cognitive lesion in DM rats by suppressing the activation of the inflammatory route and by activating the PI3K/Akt/GSK-3ß pathway at the same time, as well as interacting with the pathways that protect neurons, which still need further research.

Tirzepatide ameliorates spatial learning and memory impairment through modulation of aberrant insulin resistance and inflammation response in diabetic rats.

Background: One of the typical symptoms of diabetes mellitus patients was memory impairment, which was followed by gradual cognitive deterioration and for which there is no efficient treatment. The anti-diabetic incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were demonstrated to have highly neuroprotective benefits in animal models of AD. We wanted to find out how the GLP-1/GIP dual agonist tirzepatide affected diabetes's impairment of spatial learning memory. Methods: High fat diet and streptozotocin injection-induced diabetic rats were injected intraperitoneally with Tirzepatide (1.35 mg/kg) once a week. The protective effects were assessed using the Morris water maze test, immunofluorescence, and Western blot analysis. Golgi staining was adopted for quantified dendritic spines. Results: Tirzepatide significantly improved impaired glucose tolerance, fasting blood glucose level, and insulin level in diabetic rats. Then, tirzepatide dramatically alleviated spatial learning and memory impairment, inhibited Aß accumulation, prevented structural damage, boosted the synthesis of synaptic proteins and increased dendritic spines formation in diabetic hippocampus. Furthermore, some aberrant changes in signal molecules concerning inflammation signaling pathways were normalized after tirzepatide treatment in diabetic rats. Finally, PI3K/Akt/GSK3ß signaling pathway was restored by tirzepatide. Conclusion: Tirzepatide obviously exerts a protective effect against spatial learning and memory impairment, potentially through regulating abnormal insulin resistance and inflammatory responses.

Effects of miR-143 regulation on cardiomyocytes apoptosis in doxorubicin cardiotoxicity based on integrated bioinformatics analysis.

This study aimed to investigate the effect of miRNAs involving oxidative stress response in doxorubicin (DOX)-induced cardiotoxicity based on the data from Gene Expression Omnibus (GEO) database and experimental results via integrated bioinformatics analysis. MiRNA expression profiles of DOX-induced cardiotoxicity in rat myocardial tissues and adult rat cardiomyocytes (ARC) were extracted from GEO datasets (GSE36239). Differential expression miRNA (DEMs) were separately captured in rat myocardial tissues and in ARC, and intersected between rat myocardial tissues and ARC via Venny 2.1. Subsequently, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) analyzed 46 target genes of miR-143, one of 6 DEMs, and HIF-1 and PI3K-Akt signaling pathway were significantly enriched. Further experimental results showed DOX-induced oxidative stress downregulated the expression of miR-143, and then promoted target gene Bbc3 expression and H9c2 apoptosis, the intervention of phosphocreatine (PCr) or N-acetyl-L-cystine (NAC) alleviated oxidative stress, apoptosis and Bbc3 expression, upregulated miR-143 in DOX-induced cardiotoxicity in vivo and in vitro. Our findings elucidated the regulatory network between miR-143 and oxidative stress in DOX-induced cardiotoxicity, and might unveiled a potential biomarker and molecular mechanisms, which could be helpful to the diagnosis and treatment of DOX-induced cardiotoxicity.

Functions of actin-binding proteins in cilia structure remodeling and signaling.

Cilia are microtubule-based organelles found on the surfaces of many types of cells, including cardiac fibroblasts, vascular endothelial cells, human retinal pigmented epithelial-1 (RPE-1) cells, and alveolar epithelial cells. These organelles can be classified as immotile cilia, referred to as primary cilia in mammalian cells, and motile cilia. Primary cilia are cellular sensors that detect extracellular signals; this is a critical function associated with ciliopathies, which are characterized by the typical clinical features of developmental disorders. Cilia are extensively studied organelles of the microtubule cytoskeleton. However, the ciliary actin cytoskeleton has rarely been studied. Clear evidence has shown that highly regulated actin cytoskeleton dynamics contribute to normal ciliary function. Actin-binding proteins (ABPs) play vital roles in filamentous actin (F-actin) morphology. Here, we discuss recent progress in understanding the roles of ABPs in ciliary structural remodeling and further downstream ciliary signaling with a focus on the molecular mechanisms underlying actin cytoskeleton-related ciliopathies.

Associations between anthropometric indicators and refraction in school-age children during the post-COVID-19 era.

Purpose: To explore the associations between anthropometric indicators and refraction in school-aged children in the post-COVID-19 era. Methods: Data were collected from 25,644 children aged 7 to 12 years in 48 elementary schools in Tianjin. The comprehensive examination included height, weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), refraction, and calculation of BMI, with a follow-up visit after 6 months. Myopia was defined as spherical equivalent refraction (SER) ≤-0.50 diopter (D). Bivariate correlation coefficients and multiple linear regression models were used to explore the cross-sectional and longitudinal associations between anthropometric indicators (height, weight, BMI, SBP, and DBP) and refraction. Results: The mean changes in height, weight, BMI, SBP, DBP, and SER of the participants were 4.03 ± 2.18 cm, 3.10 ± 2.39 kg, 0.45 ± 1.16 kg/m2, 2.26 ± 14.74 mmHg, 2.18 ± 11.79 mmHg and -0.17 ± 0.51 D, respectively. Overall, height, weight, BMI, SBP, and DBP were all correlated with SER (r = -0.324, r = -0.234, r = -0.121, r = -0.112, r = -0.066, both p < 0.001), and changes in height and weight were correlated with changes in SER (r = -0.034, -0.031, both p < 0.001). Furthermore, multiple linear regression analysis revealed that the association of BMI, SBP, and DBP with SER was significant in myopic children but not in non-myopic children. The association between changes in weight and changes in SER was only present in non-myopic children but not in myopic children. Conclusion: Height and weight were negatively correlated with SER in both cross-sectional analysis and longitudinal changes, indicating that children's height, weight and growth rate may be used as a reference indicator for myopia risk prediction and myopia progression monitoring.

Meta-analysis of randomized clinical trials comparing PCSK9 monoclonal antibody versus ezetimibe/placebo in patients at high cardiovascular risk.

BACKGROUND AND AIMS: Proprotein convertase subtilisin/kexin type 9 monoclonal antibodies (PCSK9 mAbs) reduce circulating low-density lipoprotein cholesterol (LDL-C) by controlling the expression of LDL-receptor on the surface of hepatocytes. This meta-analysis aimed at evaluating the efficacy of PCSK9 mAbs on clinical and lipid-lowering outcomes. METHODS: PubMed, Embase, and ClinicalTrials.gov were searched from inception until November 2020 for randomized controlled trials (RCTs) that compared PCSK9 mAbs with ezetimibe or placebo in patients at high cardiovascular risk. RESULTS: Twenty eight RCTs with a total of 89,115 participants were included. Compared with placebo, PCSK9 mAbs significantly reduced the risk of major adverse cardiac events (MACEs) (RR 0.83, 95% CI 0.79 to 0.88, p < 0.00001). However, no difference was observed in occurring MACEs between PCSK9 mAbs and ezetimibe (RR 0.70, 95% CI 0.40 to 1.20, p = 0.20). Secondary analyses show that PCSK9 mAbs were not superior to ezetimibe in preventing stroke (RR 0.38, 95% CI 0.09 to 1.69, p = 0.20), myocardial infarction (RR 0.95, 95% CI 0.47 to 1.90, p = 0.88), and cardiovascular death (RR 0.44, 95% CI 0.14 to 1.43, p = 0.17). Compared with placebo, PCSK9 mAbs significantly reduced the incidence of stroke (RR 0.75, 95% CI 0.66 to 0.86, p < 0.0001) and myocardial infarction (RR 0.81, 95% CI 0.76 to 0.87, p < 0.00001), but not the risk of cardiovascular death (RR 0.96, 95% CI 0.86 to 1.07, p = 0.45). As for lipid-lowering efficacy, PCSK9 mAbs markedly reduced percent change of LDL-C from baseline to week 12 and 24 compared to ezetimibe or placebo. CONCLUSIONS: In patients at high cardiovascular risk, PCSK9 mAbs could effectively reduce MACEs, stroke, and myocardial infarction compared with placebo. However, PCSK9 mAbs were not superior to ezetimibe in preventing adverse cardiovascular events in our study; RCTs with long-term follow-up and cardiovascular events as the research endpoint are still needed.

Chloroplast genome structure and phylogenetic position of Lophatherum gracile.

Lophatherum gracile is distributed in south China, Japan and South Asia, and it is wild in the valley, stream, woodland, forest edge and gully edge. In this study, the complete chloroplast genome sequence of Lophatherum gracile was successfully obtained using Illumina sequencing. The full length of the chloroplast genome length was 137,749 bp with a typical quadripartite structure: one large single copy (LSC) region (80,610 bp), one small single copy (SSC) region (12,429 bp), and a pair of inverted repeats (IRs) (22,355 bp each). The GC content of this genome was 38.64%. The whole genome contained 130 genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis indicated that Lophatherum gracile was closely related to Cenchrus americanus and Cenchrus longispinus.

Compound Fu brick tea modifies the intestinal microbiome composition in high-fat diet-induced obesity mice.

Compound Fu Brick Tea (CFBT), which is from Duyun city in China, is a traditional Chinese dark tea, Fu Brick Tea, mixed with six herbal medicine. It is consumed by local people for reducing weight, but the mechanism is not clear. The disorder of intestinal microbiome caused by long-term high-fat diet (HFD) is one of the inducements of obesity and related metabolic syndrome. In this study, mice were fed with HFD to establish a high-fat model. Fifty mice were randomly divided into six groups: normal control (CK), HFD model control (NK), positive control with medicine (YK), CFBT groups with low, middle, and high dose (FL, FM, FH). The V3-V4 DNA region of fecal microbiome from mouse intestine was sequenced. The results showed that the diversity of intestinal microflora was highest in CK and lowest in NK. Compared with CK, the dominant bacterium Firmicutes was increased and Bacteroidetes decreased at phylum level in NK. Compared with NK, the abundance of microbiome in CFBT groups was significantly higher and the composition was changed: Muribaculaceae, Bacteroidaceae, and Prevotellaceae increased and Lachnospiraceae decreased in CFBT groups at family level, while at the genus level, Bacteroides increased and Lactobacillus decreased. These results conclude that CFBT can increase the abundance of intestinal microbiome in mice, promote the growth of beneficial bacteria and reduce the number of pathogenic bacteria, and restore the imbalance of intestinal microbiome caused by poor diet.

Systematic Review and Meta-analysis Appraising Efficacy and Safety of Vernakalant for Cardioversion of Recent-Onset Atrial Fibrillation.

Vernakalant is a novel, relatively atrial-selective antiarrhythmic agent. Despite its good efficacy profile and rapid onset of action, there was still controversial evidence regarding vernakalant-related adverse events. We searched PubMed and Embase for studies that compared intravenous vernakalant with placebo or antiarrhythmic agents in patients with recent-onset atrial fibrillation (AF) lasting no more than 7 days. Efficacy and safety outcomes were the treatment-induced cardioversion rate within 90 minutes and adverse events after first exposure to study drug respectively. Nine randomized controlled trials enrolling 1296 patients were analyzed. Quantitative synthesis showed that vernakalant was superior to placebo for cardioversion of recent-onset AF within 90 minutes [49.7% vs. 6.2%, risk ratio (RR) 8.13, 95% confidence interval (CI) 5.35-12.36, P < 0.00001], and it did not achieve statistical significance in cardioversion when vernakalant was compared with ibutilide (62.4% vs. 47.3%, RR 1.32, 95% CI 1.00-1.73, P = 0.05). As for safety assessment, no significant differences were found in occurring serious adverse events (9.9% vs. 10.4%, RR 0.91, 95% CI 0.67-1.25, P = 0.57) and hypotension (5.3% vs. 3.3%, RR 1.53, 95% CI 0.86-2.73, P = 0.15) between vernakalant and comparator (either placebo, ibutilide, or amiodarone). There were trends that patients receiving vernakalant experienced more drug discontinuation (2.5% vs. 1.0%, RR 2.21, 95% CI 0.96-5.11, P = 0.06) and less any ventricular tachycardia (6.1% vs. 8.1%, RR 0.70, 95% CI 0.49-1.00, P = 0.05) than those receiving comparator, but the differences were not statistically significant. Furthermore, vernakalant was associated with a higher risk of bradycardia in comparison with comparator (6.3% vs. 1.1%, RR 4.04, 95% CI 1.67-9.75, P = 0.002). Vernakalant is effective in converting recent-onset AF to sinus rhythm rapidly, while significantly more bradycardia events are related to vernakalant in our meta-analysis.

Microfluidic-Based Holonomic Constraints of siRNA in the Kernel of Lipid/Polymer Hybrid Nanoassemblies for Improving Stable and Safe In Vivo Delivery.

A safe and efficient delivery system is critical for clinical application of siRNA. However, the conventional electrostatic interaction-based siRNA nanoplexes with bulk mixing preparation were always unsatisfactory for its stability and safety. In this study, the new core-shell lipid/PCL-PEI/siRNA nanoparticles (LPS NPs) endowing holonomic constraint of siRNA in the inner core were prepared by microfluidic technology. On the microfluidic chip, siRNAs were completely compressed into the inner hydrophilic core of reverse PCL-PEI micelles at a low N/P ratio of 5, followed by coating a neutral lipid membrane to form core-shell nanoparticles, which had a uniform size (120.2 ± 1.4 nm) and a negative charge (-8.8 ± 1.6 mV). Compared to bulk mixing-based LMS NPs, the lower usage of cationic PCL-PEI materials and stronger protection of siRNA in serum were found in the microfluidic-based LPS NPs. Furthermore, it was demonstrated that the LPS NPs exhibited significant downregulation of EGFR mRNA and protein expression level both in vitro and in vivo, and showed significant inhibition of tumor growth following systemic administration along with no obvious systemic toxicity. These findings demonstrated that the microfluidic-based lipid/polymer hybrid nanoassemblies would offer a promising siRNA delivery system for clinical application.

Author Correction: Solution structure of extracellular loop of human ß4 subunit of BK channel and its biological implication on ChTX sensitivity.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Rectification ratio based determination of disulfide bonds of ß2 extracellular loop of BK channel.

Large-conductance Ca2+-activated K+ (BK) channels are composed of a pore-forming α and a variable number of auxiliary ß subunits and play important roles in regulating excitability, action potential waveforms and firing patterns, particularly in neurons and endocrine and cardiovascular cells. The ß2 subunits increase the diversity of gating and pharmacological properties. Its extracellular loop contains eight cysteine residues, which can pair to form a high-order structure, underlying the stability of the extracellular loop of ß2 subunits and the functional effects on BK channels. However, how these cysteines form disulfide bonds still remains unclear. To address this, based on the fact that the rectification and association of BK α to ß2 subunits are highly sensitive to disruption of the disulfide bonds in the extracellular loop of ß2, we developed a rectification ratio based assay by combining the site-directed mutagenesis, electrophysiology and enzymatic cleavage. Three disulfide bonds: C1(C84)-C5(C113), C3(C101)-C7(C148) and C6(C142)-C8C(174) are successfully deduced in ß2 subunit in complex with a BK α subunit, which are helpful to predict structural model of ß2 subunits through computational simulation and to understand the interface between the extracellular domain of the ß subunits and the pore-forming α subunit.

Solution structure of extracellular loop of human ß4 subunit of BK channel and its biological implication on ChTX sensitivity.

Large-conductance Ca2+- and voltage-dependent K+ (BK) channels display diverse biological functions while their pore-forming α subunit is coded by a single Slo1 gene. The variety of BK channels is correlated with the effects of BKα coexpression with auxiliary ß (ß1-ß4) subunits, as well as newly defined γ subunits. Charybdotoxin (ChTX) blocks BK channel through physically occluding the K+-conduction pore. Human brain enriched ß4 subunit (hß4) alters the conductance-voltage curve, slows activation and deactivation time courses of BK channels. Its extracellular loop (hß4-loop) specifically impedes ChTX to bind BK channel pore. However, the structure of ß4 subunit's extracellular loop and the molecular mechanism for gating kinetics, toxin sensitivity of BK channels regulated by ß4 are still unclear. To address them, here, we first identified four disulfide bonds in hß4-loop by mass spectroscopy and NMR techniques. Then we determined its three-dimensional solution structure, performed NMR titration and electrophysiological analysis, and found that residue Asn123 of ß4 subunit regulated the gating and pharmacological characteristics of BK channel. Finally, by constructing structure models of BKα/ß4 and thermodynamic double-mutant cycle analysis, we proposed that BKα subunit might interact with ß4 subunit through the conserved residue Glu264(BKα) coupling with residue Asn123(ß4).