The difference of the retinal structural and microvascular characteristics in patients with MOGAD-ON and AQP4-ON.

BACKGROUND: Antibodies against myelin-oligodendrocyte-glycoprotein (MOG-Abs) associated disease (MOGAD) has been recognized as a disease entity. Optic neuritis (ON) is the most common symptom in MOGAD. To demonstrate the differences in retinal microvascular characteristics between patients with MOGAD-ON and aquaporin-4 antibody (AQP4-Ab) positive ON. METHODS: In a prospective study, optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) were used to measure retinal and microvascular parameters. RESULTS: Twenty-six MOGAD-ON eyes, 40 AQP4-ON eyes, and 60 control eyes were included in the study. The thickness of RNFL and GCC in MOGAD-ON eyes was significantly lower than that of HC (p < 0.001, respectively), but comparable to AQP4-ON eyes. The vessel density in retina capillary plexus (RCP) was reduced significantly in MOGAD-ON than that in AQP4-ON (p < 0.05, respectively). The visual accuracy was positively correlated with vessel density of superficial RCP in MOG-ON (p = 0.001) and positively correlated with the thickness of the inner retina layer in AQP4-ON (p < 0.001). CONCLUSION: The retinal neuro-axonal damages between MOGAD-ON and AQP4-ON were comparable. Unlike AQP4-ON eyes, microvascular densities were significantly reduced in MOGAD-ON and were positively correlated with the deterioration of visual acuity in MOGAD-ON. TRIAL REGISTRATION: Clinical and Imaging Patterns of Neuroinflammation Diseases in China (CLUE, NCT: 04106830).

Blockade of SK4 channels suppresses atrial fibrillation by attenuating atrial fibrosis in canines with prolonged atrial pacing.

Background: We previously found that intermediate conductance Ca2+-activated K+ channel (SK4) might be an important target in atrial fibrillation (AF). Objective: To investigate the role of SK4 in AF maintenance. Methods: Twenty beagles were randomly assigned to the sham group (n=6), pacing group (n=7), and pacing+TRAM-34 group (n=7). Rapid atrial pacing continued for 7 days in the pacing and TRAM-34 groups. During the pacing, the TRAM-34 group received TRAM-34 intravenous injection (10 mg/Kg) 3 times per day. Atrial fibroblasts isolated from canines were treated with angiotensin II or adenovirus carrying the SK4 gene (Ad-SK4) to overexpress SK4 channels. Results: TRAM-34 treatment significantly suppressed the increased intra-atrial conducting time (CT) and AF duration in canines after rapid atrial pacing (P<0.05). Compared with the sham group, the expression of SK4 in atria was higher in the pacing group, which was associated with an increased number of myofibroblasts and levels of extracellular matrix in atrium (all P<0.05), and this effect was reversed by TRAM-34 treatment (all P<0.05). In atrial fibroblasts, the increased expression of SK4 induced by angiotensin II stimulation or Ad-SK4 transfection contributed to higher levels of P38, ERK1/2 and their downstream factors c-Jun and c-Fos, leading to the increased expression of α-SMA (all P<0.05), and all these increases were markedly reduced by TRAM-34 treatment. Conclusion: SK4 blockade suppressed AF by attenuating cardiac fibroblast activity and atrial fibrosis, which was realized through not only a decrease in fibrogenic factors but also inhibition of fibrotic signaling pathways.

Left Stellate Ganglion Ablation Inhibits Ventricular Arrhythmias through Macrophage Regulation in Canines with Acute Ischemic Stroke.

AIMS: To investigate the potential mechanism of ventricular arrhythmias (VAs) after acute ischemic stroke and explore the effects of left stellate gangling (LSG) ablation on VAs induced by stroke in canines. Materials and Methods: Twenty canines were randomly divided into the sham-operated group (n=6), AS group (n=7) and SGA group (n=7). Cerebral ischemic model was established in the AS group and the SGA group by right acute middle cerebral artery occlusion (MCAO). LSG ablation was performed in the SGA group as soon as MCAO. After 3 days, atrial electrophysiology and neural activity were measured in vivo. The levels of norepinephrine (NE) in plasma and ventricle were detected by ELISA. The levels of monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-α (TNF-α) and NF-κB p65 in ventricle were detected by western blotting. The pro-inflammatory polarization of macrophages in ventricle was detected by immunofluorescence. Results: Higher ventricular tachycardia (VT) inducibility and lower ventricular fibrillation threshold (VFT) were observed in the AS group compared with those in the sham-operated group, associated with higher LSG activity and NE levels, increased number of M1 macrophages and secretion of inflammatory cytokines in ventricle (all P<0.001). Compared with the AS group, the SGA group had lower VT inducibility and higher VFT, combined with lower NE levels, and reduced number of M1 macrophages and secretion of inflammatory cytokines in ventricle (all P<0.001). Conclusion: LSG ablation could reduce VAs vulnerability after acute stroke by preventing the macrophages polarization and activation induced by sympathetic hyperactivity.

Efficacy and safety of apheresis therapy in AQP4 antibody-positive NMOSD attack: A propensity score-matched cohort study.

OBJECTIVE: Plasma exchange (PE) and immunoadsorption (IA) are recognized as effective ways to treat attacks in AQP4 antibody-positive NMOSD, but high-quality evidence was lacking. To evaluate the efficacy and safety of PE/IA plus intravenous methylprednisolone (IVMP) in NMOSD attacks using propensity scores to match IVMP as control. METHODS: Patients were from a prospective observational cohort study. Stratification and interval propensity score matching (PSM) were used to reduce selection bias by matching baseline characteristics (gender, age, time to IVMP, EDSS at attack) between PE/IA + IVMP and IVMP group (in a ratio of 1:2). The primary endpoint of efficacy was EDSS change at 6 months. Adverse events and changes in laboratory tests were recorded. RESULTS: Four hundred and eleven attacks of 336 patients were screened for PSM, and 90 attacks (30 PE/IA + IVMP and 60 IVMP) were included in the analysis. There were significant differences in EDSS [6.25 vs. 6.75; IQR (4.50-8.38 vs. 5.00-8.00), p = 0.671] and visual acuity [median logMAR = 0.35 vs. 1.00; IQR (0.30-0.84 vs. 0.95-1.96), p = 0.002] change between two groups at 6 months. PE/IA + IVMP treatment demonstrated predictive capacity for good recovery as indicated by an area under the curve (AUC) of 0.726. Fibrinogen reduction was found during PE/IA + IVMP treatment [n = 15 (50.00%)], but no severe adverse events led to apheresis treatment discontinuation. DISCUSSION: After PSM analysis, IVMP+PE/IA in acute attack of NMOSD achieved better and continuous improvement in neurological function within 6 months compared with IVMP alone. PE/IA treatment showed a good safety profile.

M2 macrophage­derived exosomes alleviate KCa3.1 channel expression in rapidly paced HL­1 myocytes via the NF­κB (p65)/STAT3 signaling pathway.

The present study was designed to explore the role of M2 macrophage­derived exosomes (M2­exos) on the KCa3.1 channel in a cellular atrial fibrillation (AF) model using rapidly paced HL­1 myocytes. M2 macrophages and M2­exos were isolated and identified. MicroRNA (miR)­146a­5p levels in M2 macrophages and M2­exos were quantified using reverse transcription­quantitative PCR (RT­qPCR). HL­1 myocytes were randomly divided into six groups: Control group, pacing group, pacing + coculture group (pacing HL­1 cells cocultured with M2­exos), pacing + mimic­miR­146a­5p group, pacing + NC­miR­146a­5p group and pacing + pyrrolidine dithiocarbamate (PDTC; a special blocker of the NF­κB signaling pathway) group. Transmission electron microscopy, nanoparticle tracking analysis, western blotting, RT­qPCR and immunohistochemistry were performed in the present study. A whole­cell clamp was also applied to record the current density of KCa3.1 and action potential duration (APD) in each group. The results revealed that miR­146a­5p was highly expressed in both M2 macrophages and M2­exos. Pacing HL­1 cells led to a shorter APD, an increased KCa3.1 current density and higher protein levels of KCa3.1, phosphorylated (p­)NF­κB p65, p­STAT3 and IL­1ß compared with the control group. M2­exos, miR­146a­5p­mimic and PDTC both reduced the protein expression of KCa3.1, p­NF­κB p65, p­STAT3 and IL­1ß and the current density of KCa3.1, resulting in a longer APD in the pacing HL­1 cells. In conclusion, M2­exos and their cargo, which comprised miR­146a­5p, decreased KCa3.1 expression and IL­1ß secretion in pacing HL­1 cells via the NF­κB/STAT3 signaling pathway, limiting the shorter APD caused by rapid pacing.

Independent and reproducible hippocampal radiomics biomarkers for multisite multiple sclerosis and neuromyelitis optica spectrum disorders.

OBJECTIVE: To investigate the abnormal radiomics features of the hippocampus in patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) and to explore the clinical implications of these features. METHODS: 752 participants were recruited in this retrospective multicenter study (7 centers), which included 236 MS, 236 NMOSD, and 280 normal controls (NC). Radiomics features of each side of the hippocampus were extracted, including intensity, shape, texture, and wavelet features (N = 431). To identify the variations in these features, two-sample t-tests were performed between the NMOSD vs. NC, MS vs. NC, and NMOSD vs. MS groups at each site. The statistical results from each site were then integrated through meta-analysis. To investigate the clinical significance of the hippocampal radiomics features, we conducted further analysis to examine the correlations between these features and clinical measures such as Expanded Disability Status Scale (EDSS), Brief Visuospatial Memory Test (BVMT), California Verbal Learning Test (CVLT), and Paced Auditory Serial Addition Task (PASAT). RESULTS: Compared with NC, patients with MS exhibited significant differences in 78 radiomics features (P < 0.05/862), with the majority of these being texture features. Patients with NMOSD showed significant differences in 137 radiomics features (P < 0.05/862), most of which were intensity features. The difference between MS and NMOSD patients was observed in 47 radiomics features (P < 0.05/862), mainly texture features. In patients with MS and NMOSD, the most significant features related to the EDSS were intensity and textural features, and the most significant features related to the PASAT were intensity features. Meanwhile, both disease groups observed a weak correlation between radiomics data and BVMT. CONCLUSION: Variations in the microstructure of the hippocampus can be detected through radiomics, offering a new approach to investigating the abnormal pattern of the hippocampus in MS and NMOSD.

KCa3.1 Promotes Proinflammatory Exosome Secretion by Activating AKT/Rab27a in Atrial Myocytes during Rapid Pacing.

Purpose: The aim of this study was to investigate the role of the medium-conductance calcium-activated potassium channel (KCNN4, KCa3.1) in the secretion of proinflammatory exosomes by atrial myocytes. Methods: Eighteen beagles were randomly divided into the sham group (n = 6), pacing group (n = 6), and pacing+TRAM-34 group (n = 6). Electrophysiological data, such as the effective refractory period, atrial fibrillation (AF) induction, and AF duration, were collected by programmed stimulation. Atrial tissues were subjected to hematoxylin and eosin, Masson's trichrome, and immunofluorescence staining. The expression of KCa3.1 and Rab27a was assessed by immunohistochemistry and western blotting. The downstream signaling pathways involved in KCa3.1 were examined by rapid pacing or overexpressing KCNN4 in HL-1 cells. Results: Atrial rapid pacing significantly induced electrical remodeling, inflammation, fibrosis, and exosome secretion in the canine atrium, while TRAM-34 (KCa3.1 blocker) inhibited these changes. Compared with those in control HL-1 cells, the levels of exosome markers and inflammatory factors were increased in pacing HL-1 cells. Furthermore, the levels of CD68 and iNOS in macrophages incubated with exosomes derived from HL-1 cells were higher in the pacing-exo group than in the control group. More importantly, KCa3.1 regulated exosome secretion through the AKT/Rab27a signaling pathway. Similarly, inhibiting the downstream signaling pathway of KCa3.1 significantly inhibited exosome secretion. Conclusions: KCa3.1 promotes proinflammatory exosome secretion through the AKT/Rab27a signaling pathway. Inhibiting the KCa3.1/AKT/Rab27a signaling pathway reduces myocardial tissue structural remodeling in AF.

Immune remodeling and atrial fibrillation.

Atrial fibrillation (AF) is a highly prevalent arrhythmia that causes high morbidity and mortality. However, the underlying mechanism of AF has not been fully elucidated. Recent research has suggested that, during AF, the immune system changes considerably and interacts with the environment and cells involved in the initiation and maintenance of AF. This may provide a new direction for research and therapeutic strategies for AF. In this review, we elaborate the concept of immune remodeling based on available data in AF. Then, we highlight the complex relationships between immune remodeling and atrial electrical, structural and neural remodeling while also pointing out some research gaps in these field. Finally, we discuss several potential immunomodulatory treatments for AF. Although the heterogeneity of existing evidence makes it ambiguous to extrapolate immunomodulatory treatments for AF into the clinical practice, immune remodeling is still an evolving concept in AF pathophysiology and further studies within this field are likely to provide effective therapies for AF.

Median nerve stimulation elevates ventricular fibrillation threshold via the cholinergic anti-inflammatory pathway in myocardial infarction canine model.

Background: Median nerve stimulation (MNS) diminishes regional myocardial ischemia and ventricular arrhythmia; however, the underlying mechanism has not been elucidated. Methods: In this study, we randomly categorized 22 adult mongrel dogs into a control group, MNS group 1, and MNS group 2. After a 4-week experimental myocardial infarction (MI), ventricular electrophysiology was measured in the MNS group 1 before and after 30 min of MNS. The same measurements were performed in the MNS group 2 dogs via bilateral vagotomy. Venous blood and ventricular tissue were collected to detect molecular indicators related to inflammation and cholinergic pathways by enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), and Western blot (WB). Results: No significant changes were reported in the ventricular effective refractory period (ERP) in the MNS group 1 and MNS group 2 dogs before and after MNS. The ventricular fibrillation threshold (VFT) in the MNS group 1 was significantly higher than that in the MNS group 2 (20.3 ± 3.7 V vs. 8.7 ± 2.9 V, P < 0.01). The levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and nuclear transcription factor-κB (NF-κB) were lower (P < 0.01), whereas the levels of Ach were higher in the peri-infarct zone tissues in the MNS group 1 dogs than those in the MNS group 2 dogs (P < 0.01). Conclusion: This study demonstrated that MNS increases VFT in a canine model with MI. The effects of MNS on VFT are potentially associated with the cholinergic anti-inflammatory pathway.

Cardiac Fibroblasts Promote Ferroptosis in Atrial Fibrillation by Secreting Exo-miR-23a-3p Targeting SLC7A11.

The exact mechanism of atrial fibrillation (AF) has been not well elucidated. Ferroptosis is an iron-dependent cell death due to excessive accumulation of peroxidized polyunsaturated fatty acids. However, the molecular mechanism underlying AF and ferroptosis has never been reported. Here, we established the rapid pacing model in vivo and vitro to investigate the relationship between AF and ferroptosis. In canine model of rapid atrial pacing, the content of malondialdehyde and total ions in the atrial tissue of the Pacing group was significantly increased and the exosome inhibitor GW4869 reduced ferroptosis, fibrosis, and inflammation and improved histological and electrophysiological remodeling. In rapid pacing h9c2 cells, the expression of antioxidative stress genes associated with ferroptosis presented sequential changes and proteins involved in ferroptosis such as FTH1, SLC7A11, and GPX4 were gradually depleted. Furthermore, pacing cardiac fibroblast-derived exosomes (CF-exos) exacerbated ferroptosis in h9c2 cells and pretreated pacing-CF-exos with GW4869 alleviated injury to h9c2 cells. In mechanism, our results demonstrated that pacing-CF-exos highly expressed miR-23a-3p by informatics analysis and experimental verification. Inhibitor-miR-23a-3p protected h9c2 cells from ferroptosis accompanying with upregulation of SLC7A11. In addition, SLC7A11 was shown to be the target gene of miR-23a-3p. In conclusion, our results suggest that CF-exos-miR-23a-3p may promote ferroptosis. The development of AF in a persistent direction could be prevented by intervening with exosomal miRNAs to reduce oxidative stress injury and ferroptosis.

Clinical, imaging features and treatment response of idiopathic hypertrophic pachymeningitis.

BACKGROUND: Idiopathic hypertrophic pachymeningitis (IHP) is a rare inflammatory disease that causes focal or diffuse thickening of the dura mater. However, longitudinal follow up studies are still lacking for these patients. OBJECTIVE: To investigate the clinical characteristics, neuroimaging findings, treatment response and outcome of IHP. METHOD: A retrospective case series of 30 patients admitted Beijing Tiantan Hospital were screened via Hospital Information System from January 1st, 2011, to January 31st, 2021. All patients' clinical symptoms, imaging, and treatment response were collected via a standardized form. We compared the effects of high-dose and low-dose corticosteroids on headache, impaired vision, and MRI remission during acute onset. The effects of different immunosuppressants on preventing relapses were also compared. RESULTS: Headache (93.3%) and multiple cranial neuropathy (66.7%) were the most common symptoms of IHP. Cerebral spinal fluid test showed that protein levels were elevated in 17 (56.7%) patients, and white blood cells were increased in seven patients. MRI demonstrated that diffuse (60%) and focal (40%) enhancement occurred in the dura mater, especially in the tentorium cerebellum (80%). High-dose and low-dose corticosteroids reduced headache and dural enhancement during the acute phase. The high dose corticosteroid significantly relieved the headache than the low dose group (p = 0.041). Patients treated with mycophenolate mofetil and cyclophosphamide might achieve longer remission (months, p = 0.428). CONCLUSION: Headache and multiple cranial neuropathy are the most common clinical manifestations of IHP. In this study, almost all patients had a good initial response to corticosteroid therapy during the acute phase. Mycophenolate mofetil and cyclosporine may be effective for preventing relapses.

Blocking Intermediate-Conductance Calcium-Activated Potassium Channels in the Macrophages Around Ganglionated Plexi Suppresses Atrial Fibrillation Vulnerability in Canines With Rapid Atrial Pacing.

Previous studies have indicated that ganglionated plexi (GP) function influences atrial fibrillation (AF) vulnerability, and intermediate-conductance calcium-activated potassium channels (SK4) have a close relationship with cardiomyocyte automaticity and the induction of AF. However, the effects of the SK4 inhibitor on GP function and AF vulnerability are unknown. Eighteen beagles were randomly divided into a control group (n = 6), rapid atrial pacing (RAP) group (n = 6), and triarylmethane-34 (TRAM-34, an SK4 inhibitor) group (n = 6). TRAM-34 (0.3 ml, 15 mmol/L) and saline were locally injected into GPs in the TRAM-34 group dogs and dogs from the other groups, respectively. After that, dogs in the RAP and TRAM-34 groups were subjected to RAP, and the neural activity of anterior right GP (ARGP) and atrial electrophysiology were measured. The levels of inflammatory cytokines and function of macrophages in the ARGP were measured in the three groups. At 10 min after TRAM-34 injection, ARGP activity and atrial electrophysiology did not significantly change. The atrial pacing shortened effective refractory period (ERP) values at all sites and increased the AF vulnerability and ARGP neural activity, while TRAM-34 reversed these changes. The levels of CD68 + cells, induced nitric oxide synthase (iNOS), interleukin (IL)-1ß, IL-6, and tumor necrosis factor (TNF)-α in the ARGP tissues were higher in the RAP group and TRAM-34 group than they were in the control group. Furthermore, the levels of the CD68 + cells, iNOS, and inflammatory cytokines in the ARGP tissues were higher in the pacing group than those in the TRAM-34 group. Based on these results, administration of TRAM-34 into the atrial GP can suppress GP activity and AF vulnerability during atrial pacing. The effects of TRAM-34 might be related to macrophage polarization and the inflammatory response of GP.

Dapagliflozin Protects Methamphetamine-Induced Cardiomyopathy by Alleviating Mitochondrial Damage and Reducing Cardiac Function Decline in a Mouse Model.

Background: Methamphetamine (METH)-induced cardiovascular toxicity has been attributed to its destructive effect on mitochondrial function at least to some extent. Previous studies highlighted the benefits of dapagliflozin (DAPA) on the cardiovascular system, but the response of METH-induced cardiomyopathy to DAPA is never addressed before. The present study aimed to investigate the potential ability of DAPA in preventing METH-induced cardiomyopathy. Materials and Methods: C57BL/6 mice were randomly divided into control group (n = 24), METH group (n = 24), and METH + DAPA group (n = 24). The METH-induced cardiomyopathy group received intraperitoneal METH injections at gradually increasing doses thrice weekly for 14 weeks. Mice in the METH + DAPA group were simultaneously treated with DAPA 1 mg/kg/day by intragastric administration. Echocardiography was performed to assess cardiac function. Reactive oxygen species (ROS), JC-1, and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays were performed to evaluate oxidative stress, mitochondrial damage, and apoptosis, respectively. Mitochondrial and apoptosis-related protein expression was measured by western blotting. Results: Mice exposed to METH exhibited reduced cardiac function (left ventricular ejection fraction [LVEF]: 56.51 ± 6.49 vs. 73.62 ± 1.42, p < 0.01), fibrotic remodeling, and mitochondrial dysfunction, leading to apoptosis (apoptotic cells%: 7.4 ± 1.3 vs. 1.3 ± 0.5, p < 0.01). DAPA significantly reduced mitochondrial dynamics and function, ROS, apoptosis (apoptotic cells%: 2.4 ± 0.8 vs. 7.4 ± 1.3, p < 0.01), cardiac function decline (LVEF: 70.99 ± 4.936 vs. 56.51 ± 6.49, p < 0.01), and fibrotic remodeling. These results indicated that DAPA could be considered as an effective therapeutic agent in the protection against METH-associated cardiomyopathy. Conclusion: DAPA protects against METH-induced cardiomyopathy in mice by decreasing mitochondrial damage and apoptosis.

Structural and Functional Alterations in Visual Pathway After Optic Neuritis in MOG Antibody Disease: A Comparative Study With AQP4 Seropositive NMOSD.

Background: Optic neuritis (ON) is an important clinical manifestation of neuromyelitis optic spectrum disease (NMOSD). Myelin oligodendrocyte glycoprotein (MOG) antibody-related and aquaporin 4 (AQP4) antibody-related ON show different disease patterns. The aim of this study was to explore the differences in structure and function of the visual pathway in patients with ON associated with MOG and AQP4 antibodies. Methods: In this prospective study, we recruited 52 subjects at Beijing Tiantan Hospital, including 11 with MOG Ig+ ON (MOG-ON), 13 with AQP4 Ig+ ON (AQP4-ON), and 28 healthy controls (HCs). Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) of optic radiation (OR), primary visual cortex volume (V1), brain volume, and visual acuity (VA) were compared among groups. A multiple linear regression was used to explore associations between VA and predicted factors. In addition, we used optical coherence tomography (OCT) to examine thickness of the peripapillary retinal nerve fiber layer (pRNFL) and retinal ganglion cell complex (GCC) in a separate cohort consisting of 15 patients with ON (8 MOG-ON and 7 AQP4-ON) and 28 HCs. Results: Diffusion tensor imaging showed that the FA of OR was lower than controls in patients with AQP4-ON (p = 0.001) but not those with MOG-ON (p = 0.329) and was significantly different between the latter two groups (p = 0.005), while V1 was similar in patients with MOG-ON and AQP4-ON (p = 0.122), but was lower than controls in AQP4-ON (p = 0.002) but not those with MOG-ON (p = 0.210). The VA outcomes were better in MOG-ON than AQP4-ON, and linear regression analysis revealed that VA in MOG-ON and AQP4-ON was both predicted by the FA of OR (standard ß = -0.467 and -0.521, p = 0.036 and 0.034). Both patients of MOG-ON and AQP4-ON showed neuroaxonal damage in the form of pRNFL and GCC thinning but showed no statistically significant difference (p = 0.556, 0.817). Conclusion: The structural integrity of OR in patients with MOG-ON, which is different from the imaging manifestations of AQP4-ON, may be a reason for the better visual outcomes of patients with MOG-ON.

Inhibition of KCa3.1 Channels Suppresses Atrial Fibrillation via the Attenuation of Macrophage Pro-inflammatory Polarization in a Canine Model With Prolonged Rapid Atrial Pacing.

Aims: To investigate the role of KCa3. 1 inhibition in macrophage pro-inflammatory polarization and vulnerability to atrial fibrillation (AF) in a canine model with prolonged rapid atrial pacing. Materials and Methods: Twenty beagle dogs (weighing 8-10 kg) were randomly assigned to a sham group (n = 6), pacing group (n = 7) and pacing+TRAM-34 group (n = 7). An experimental model of AF was established by rapid pacing. TRAM-34 was administered to the Pacing+TRAM-34 group by slow intravenous injection (10 mg/kg), 3 times each day. After 7 days of pacing, the electrophysiology was measured in vivo. The levels of interleukin-1ß (IL-1ß), monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), CD68, c-Fos, p38, and NF-κB p65 in both atriums were measured by Western blotting, and the levels of inducible nitric oxide synthase (iNOS) and arginase1 (Arg-1) were measured by real-time PCR. Macrophage and KCa3.1 in macrophage in the atrium were quantized following double labeled immunofluorescent. Results: Greater inducibility of AF, an extended duration of AF and lower atrial effective refractory period (AERP) were observed in the pacing group compared with those in the sham group. Both CD68-labeled macrophage and the expression of KCa3.1 in macrophage were elevated in the pacing group and inhibited by TRAM-34, led to higher iNOS expression, lower Arg-1 expression, elevated levels of IL-1ß, MCP-1, and TNF-α in the atria, which could be reversed by TRAM-34 treatment (all P < 0.01). KCa3.1 channels were possibly activated via the p38/AP-1/NF-κB signaling pathway. Conclusions: Inhibition of KCa3.1 suppresses vulnerability to AF by attenuating macrophage pro-inflammatory polarization and inflammatory cytokine secretion in a canine model with prolonged rapid atrial pacing.

Blockade of Exosome Release Suppresses Atrial Fibrillation by Alleviating Atrial Fibrosis in Canines With Prolonged Atrial Pacing.

Background: Clinical studies have shown that exosomes are associated with atrial fibrillation (AF). However, the roles and underlying mechanisms remain unclear. Hence, this study aimed to investigate the function of exosomes in AF development. Methods: Twenty beagles were randomly divided into the sham group (n = 6), the pacing group (n = 7), and the pacing + GW4869 group (n = 7). The pacing and GW4869 groups underwent rapid atrial pacing (450 beats/min) for 7 days. The GW4869 group received intravenous GW4869 injection (an inhibitor of exosome biogenesis/release, 0.3 mg/kg, once a day) during pacing. Electrophysiological measurements, transmission electron microscopy, nanoparticle tracking analysis, western blotting, RT-PCR, Masson's staining, and immunohistochemistry were performed in this study. Results: Rapid atrial pacing increased the release of plasma and atrial exosomes. GW4869 treatment markedly suppressed AF inducibility and reduced the release of exosomes. After 7 days of pacing, the expression of transforming growth factor-ß1 (TGF-ß1), collagen I/III, and matrix metalloproteinases was enhanced in the atrium, and the levels of microRNA-21-5p (miR-21-5p) were upregulated in both plasma exosomes and the atrium, while the tissue inhibitor of metalloproteinase 3 (TIMP3), a target of miR-21-5p, showed a lower expression in the atrium. The administration of GW4869 abolished these effects. Conclusions: The blockade of exosome release with GW4869 suppressed AF by alleviating atrial fibrosis in a canine model, which was probably related to profibrotic miR-21-5p enriched in exosomes and its downstream TIMP3/TGF-ß1 pathway.

Effects of Different Selenium Sources on Laying Performance, Egg Selenium Concentration, and Antioxidant Capacity in Laying Hens.

Supplementation of selenium (Se) is a common practice in the poultry industry via sodium selenite (SS) and selenium yeast (SY), while the effects of nano-selenium (NS) on laying hens are poorly known. This study aimed to compare the effects of NS, SS, and SY on productivity; selenium (Se) deposition in eggs; and antioxidant capacity in laying hens. A total of 288 30-week-old Brown Hy-line laying hens were randomly assigned into four dietary treatments, which included corn-soybean meal basal diet (Con) without Se sources and basal diets supplemented with 0.3 mg Se/kg as SS, SY, or NS, respectively. The results exhibited that Se-supplemented treatments achieved greater egg production, egg weight, and daily egg mass, also better feed conversion ratio than Con group (p < 0.05). Se supplementation significant increased egg Se concentration and decreased the egg Se deposition efficiency (p < 0.05), while SY or NS supplementation had higher Se deposition efficiency than SS group at 35 days (p < 0.05). Moreover, serum glutathione peroxidase (GSH-Px) activity increased in SS or NS group compared to Con group (p < 0.05). The glutathione peroxidase 4 (GPX-4) mRNA levels in liver were significantly higher (p < 0.05) in SS or SY group than in NS group, and mRNA levels of the methionine (Met) metabolism gene glycine N-methyltranserfase (GNMT) were markedly upregulated (p < 0.05) in SY group compared to SS or NS group. Taken together, the results revealed Se from SY is deposited into eggs more efficiently than Se from NS or SS, probably via enhancing the route of Met metabolism. Meanwhile, it might be concluded that SS or SY supplementation directly regulated GSH-Px activity via enhancing GPx4 level, whereas NS via GPx1, thus affecting body oxidation and development.

CSF-S100B Is a Potential Candidate Biomarker for Neuromyelitis Optica Spectrum Disorders.

Astrocytic impairment is a pathologic feature of neuromyelitis optica spectrum disorder (NMOSD). S100B and glial fibrillary acidic protein (GFAP) are the two most commonly used astrocytic markers. The aim of this study was to evaluate whether CSF-S100B could serve as a marker of NMOSD. We enrolled 49 NMOSD patients [25 aquaporin-4 antibody (AQP4-Ab)-positive, 8 myelin-oligodendrocyte glycoprotein antibody (MOG-Ab)-positive, and 16 seronegative patients], 12 multiple sclerosis (MS) patients, and 15 other noninflammatory neurological diseases (OND) patients. The CSF levels of S100B and GFAP were measured by ELISA. Both CSF-S100B and GFAP levels significantly discriminated NMOSD from MS [area under curve (AUC) = 0.839 and 0.850, respectively] and OND (AUC = 0.839 and 0.850, respectively). The CSF-S100B levels differentiated AQP4-Ab-positive NMOSD from MOG-Ab-positive NMOSD with higher accuracy than the CSF-GFAP levels (AUC=0.865 and 0.772, respectively). The CSF-S100B levels also significantly discriminated MOG-Ab-positive patients from seronegative patients (AUC = 0.848). Both CSF-S100B and GFAP levels were correlated with the Expanded Disability Status Scale (EDSS) during remission. Only the CSF-S100B levels were correlated with the CSF WBC count and the EDSS during attack. The levels of CSF-S100B seemed to have a longer lasting time than the levels of CSF-GFAP, which may benefit patients who present late. As a result, CSF-S100B might be a potential candidate biomarker for NMOSD in discriminating, evaluating severity, and predicting disability.

Effects of dietary supplementation with tribasic zinc sulfate or zinc sulfate on growth performance, zinc content and expression of zinc transporters in young pigs.

An experiment was conducted to compare the effects of zinc sulfate (ZS) and tribasic zinc sulfate (TBZ) as sources of supplemental zinc on growth performance, serum zinc (Zn) content and messenger RNA (mRNA) expression of Zn transporters (ZnT1/ZnT2/ZnT5/ZIP4/DMT1) of young growing pigs. A total of 96 Duroc × Landrace × Yorkshire pigs were randomly allotted to two treatments and were fed a basal diet supplemented with 100 mg/kg Zn from either ZS or TBZ for 28 days. Feed : gain ratio in pigs fed TBZ were lower (P < 0.05) than pigs fed ZS, and average daily weight gain tended to increase (0.05 ≤ P ≤ 0.10) in pigs fed TBZ. Compared with pigs fed ZS, pigs fed TBZ had a higher CuZn-superoxide dismutase and Zn content in serum (P < 0.05) while they had a lower Zn content in feces (P < 0.05). In addition, ZIP4 mRNA expression of zinc transporter in either duodenum or jejunum of pigs fed TBZ were higher (P < 0.05) than pigs fed ZS. These results indicate that TBZ is more effective in serum Zn accumulation and intestinal Zn absorption, and might be a potential substitute for ZS in young growing pigs.