Circular RNA circRNF169 functions as a miR-30c-5p sponge to promote cellular senescence.

Circular RNAs (circRNAs), characterized as single-stranded closed circular RNA molecules, have been established to exert pivotal functions in various biological or pathological processes. Nonetheless, the effects and underlying mechanisms concerning circRNAs on the aging and aging-related diseases remain elusive. We herein compared the expression patterns of circRNAs in young and senescent mouse embryonic fibroblasts (MEFs), and uncovered that circRNF169 was dramatically up-regulated in senescent MEFs compared with that in young MEFs. Therefore, we further digged into the role and potential mechanisms of circRNF169 in the senescence of MEFs. The results of senescence-associate-ß-galactosidase staining and BrdU incorporation assay showed that silencing of circRNF169 significantly delayed MEFs senescence and promoted cell proliferation, while ectopic expression of circRNF169 exhibited the opposite effects. Moreover, the dual-luciferase reporter assay confirmed that circRNF169 acted as an endogenous miR-30c-5p sponge, which accelerated cellular senescence by sequestering and inhibiting miR-30c-5p activity. Taken together, our results suggested that circRNF169 exerted a crucial role in cellular senescence through sponging miR-30c-5p and represented a promising target for aging intervention.

The incidence and location of epicardial connections in the era of contact force guided ablation for pulmonary vein isolation.

BACKGROUND: The effects of epicardial connections (ECs) involving pulmonary veins (PVs) in atrial fibrillation (AF) ablation have been revealed recently. However, no systematic approaches to identify and ablate the ECs were established. METHODS: Patients with AF undergoing radiofrequency (RF) catheter ablation were retrospectively analyzed. ECs were identified when (1) PV isolation (PVI) cannot be achieved after first-pass isolation; (2) PVI was still absent although the conduction gap was detected and ablated; (3) the earliest activation area (EAA) was revealed located within the PV antrum distant from the initial ablation line using high-density mapping (HDM) technique; (4) focal ablation at the EAA was effective to achieve PVI. Relevant pacing maneuvers were performed to elucidate ECs' bidirectional conduction. RESULTS: Overall, 36 ECs were identified and ablated in 35/597 (5.86%) patients. Among the 35 patients with ECs, at least one PV insertion of ECs was located at the carina region. The most common pattern was a single breakthrough in 31 (88.6%) patients, followed by multiple breakthroughs in 3 and wide breakthroughs in 1. The median distance from EAA to the initial ablation line was 10.0 mm. The average number of RF energy delivery was 1.75 ± 1.00, and single RF delivery was adequate in 16/36 (44.4%) patients. Continuous potentials were present at the EAA in 9/34 (26.5%) patients. CONCLUSION: ECs were confirmed and ablated successfully in 5.86% (35/597) AF patients using HDM. PV insertions of ECs were mainly located at the carina region. Continuous potentials might assist in the prediction of ECs.

Association between cardiac autonomic function and physical activity in patients at high risk of sudden cardiac death: a cohort study.

BACKGROUND: High levels of physical activity (PA) and heart rate variability (HRV) are associated with cardiovascular benefits in patients with cardiovascular diseases. HRV, representing cardiac autonomic function, is positively associated with PA. However, the impacts of PA and cardiac autonomic function on cardiovascular outcomes were not analysed in the same study population. This lack of evidence supported our hypothesis that PA might contribute to cardiovascular benefits via enhanced cardiac autonomic function. METHODS: Patients with implantable cardioverter defibrillator (ICD) or cardiac resynchronisation therapy defibrillator (CRT-D) implantation were included from the SUMMIT registry. HRV and PA values were assessed during the first 30-60 days post device implantation using a continuous home monitoring system. Causal mediation analysis was conducted to explore the possible mediation function of HRV in the association of PA with long-term cardiac death and all-cause mortality in patients at a high risk of sudden cardiac death. RESULTS: Over a mean follow-up period of 47.7 months, 63 cardiac deaths (18.9%) and 85 all-cause death events (25.5%) were observed among 342 patients with ICD/CRT-D implantation. A positive linear association between HRV and PA was demonstrated and the ß value of HRV was 0.842 (95% confidence interval [CI]: 0.261-1.425, P = 0.005) in the multiple linear regression analysis. Multivariable Cox proportional hazards analysis revealed that high levels of PA (≥11.0%) and HRV (≥75.9 ms) were independent protective factors against cardiac death (PA: hazard ratio [HR] = 0.273; 95% CI, 0.142-0.526, P < 0.001; HRV: HR = 0.224; 95% CI, 0.103-0.489, P < 0.001) and all-cause mortality (PA: HR = 0.299; 95% CI, 0.177-0.505, P < 0.001; HRV: HR = 0.394; 95% CI, 0.231-0.674, P = 0.001). Causal mediation analysis demonstrated partial mediation effects of PA that were mediated through HRV on cardiac death (mediation proportion = 12.9, 95%CI: 2.2-32.0%, P = 0.006) and all-cause mortality (mediation proportion = 8.2, 95%CI: 1.6-20.0%, P = 0.006). CONCLUSIONS: HRV might be a modest mediator in the association between high levels of PA and the reduced risks of cardiac death and all-cause mortality in ICD/CRT-D recipients. This finding supports that enhanced cardiac autonomic function might be one of the underlying mechanisms by which regular PA contributes to cardiovascular benefits.

The positive correlation between drug addiction and drug dosage in vemurafenib-resistant melanoma cells is underpinned by activation of ERK1/2-FRA-1 pathway.

Malignant melanoma is a kind of highly invasive and deadly diseases. The BRAF inhibitor (BRAFi) such as vemurafenib could achieve a high response rate in melanoma patients with BRAF mutation. However, melanoma cells could easily develop resistance as well as addiction to BRAFi. Based on the drug addiction, intermittent treatment has been proposed to select against BRAFi-resistant melanoma cells. Because different dosages of BRAFi might be used in patients, it is necessary to know about the relationship between drug dosage and the degree of addiction. To address the problem, four drug-resistant melanoma cell sublines (A375/R0.5, A375/R2.0, M14/R0.5 and M14/R2.0) were established by continuously exposure of melanoma A375 or M14 cells to 0.5 or 2.0 µM vemurafenib. Vemurafenib withdrawal resulted in much stronger suppression on clone formation in A375/R2.0 and M14/R2.0, compared with A375/R0.5 and M14/R0.5, respectively. Meanwhile, stronger upregulation of ERK1/2-FRA-1 pathway could be observed in A375/R2.0 and M14/R2.0. Further detection showed that some proinflammatory cytokines downstream of ERK1/2-FRA-1 pathway were upregulated after drug withdrawal, and the conditioned medium collected from the resistant A375 cells could inhibit clone formation. Furthermore, vemurafenib withdrawal resulted in suppressed cell proliferation rather than cell senescence, with stronger effect on A375/R2.0 compared with A375/R0.5. This study suggested that the depth of vemurafenib addiction in resistant melanoma cells is positively correlated to the drug dosage, which might be underpinned by the ERK1/2-FRA-1 pathway and the related cytokines.

COMMD1 regulates cell proliferation and cell cycle progression by modulating p21 Cip1 levels.

Copper metabolism MURR1 domain-containing 1 (COMMD1) is a protein that participates in multiple cellular processes, including copper homeostasis and nuclear factor kappa B (NF-κB) and hypoxia-inducible factor 1α (HIF-1α) signaling. The COMMD1 upstream regulators X-linked inhibitor of apoptosis protein (XIAP) and p300 and downstream targets such as NF-κB and HIF-1α are involved in the regulation of cell proliferation and cell cycle progression. However, whether COMMD1 regulates cell proliferation and the cell cycle remains unclear. In the present study, we demonstrated that both overexpression and knockdown of COMMD1 affected the proliferation of HEK293 cells, and the cell cycle assay revealed that ectopic expression of COMMD1 arrested the cell cycle at the G1 phase. Furthermore, western blot analysis showed that COMMD1 affected p21 Cip1 levels. Taken together, these results suggest that COMMD1 regulates cell proliferation and cell cycle progression by modulating p21 Cip1 levels. Abbreviations COMMD1: Copper metabolism MURR1 domain containing 1; XIAP: X chromosome-linked inhibitor of apoptosis protein; FCS: Fetal calf serum; WCE: Whole cell extracts; RT-PCR: Reverse transcription-polymerase chain reaction; HEK293: Human embryonic kidney 293; ShRNA: Short hairpin RNA; NF-κB: Nuclear factor kappa-light-chain-enhancer of activated B cells; ARF: Alternate reading frame protein product of the CDKN2A locus.

Retinoid acid and taurine promote NeuroD1-induced differentiation of induced pluripotent stem cells into retinal ganglion cells.

Induced pluripotent stem cells (iPSCs) possess the capacity to differentiate into multiple cell types including retinal neurons. Despite substantial progress in the transcriptional regulation of iPSC differentiation process, the efficiency of generation of retinal neurons from iPSCs is still low. In this study, we investigated the role of transcription factor NeuroD1 in the differentiation of iPSCs into retinal neurons. We observed that retrovirus-mediated NeuroD1 overexpression in iPSCs increased the efficiency of neuronal differentiation. Immunostaining analysis showed that NeuroD1 overexpression increased the expression of retina ganglion cell markers including Islet-1, Math5, Brn3b, and Thy1.2. Retinoid acid (RA) and taurine further improved the differentiation efficiency of iPSCs overexpressing NeuroD1. However, RA and taurine did not promote differentiation in the absence of NeuroD1 overexpression. Together, our study provides new evidence in transcription factor-regulated stem cell differentiation in vitro.

IL-1α inhibits proliferation and adipogenic differentiation of human adipose-derived mesenchymal stem cells through NF-κB- and ERK1/2-mediated proinflammatory cytokines.

Dysfunctional adipogenesis such as subcutaneous lipoatrophy is closely related to insulin resistance and metabolic disorders. Although the expression or release of the cytokine interleukin-1α (IL-1α) is known to increase in adipose tissue in response to cell death, cell senescence, aging, or solar radiation, the regulatory role of IL-1α in adipogenesis has not been sufficiently investigated. To investigate the problem, we explored the effect of IL-1α on the proliferation and adipogenic differentiation of human adipose-derived mesenchymal stem cells (ADSCs) using cell counting, alamarBlue assay, oil red O staining, Western blot, among others. The results showed that IL-1α evidently inhibited the proliferation and adipogenic differentiation of ADSCs, which might be related with the activated nuclear factor-κB (NF-κB) and extracellular signal-regulated kinase (ERK) 1/2 pathways. Early-stage adipogenic differentiation was more sensitive to IL-1α than late-stage differentiation. After differentiation of ADSCs into mature adipocytes, adding of IL-1α had no obvious influence on the cellular morphology, including lipid droplet accumulation. IL-1α enhanced the expression of proinflammatory cytokines, such as IL-8, IL-6, CCL2 (C-C motif chemokine ligand 2), and IL-1ß, when added into the adipogenic medium of ADSCs. Blocking IL-8 and IL-6 with neutralizing antibodies partially alleviated the inhibitory effect of IL-1α on the proliferation and adipogenic differentiation. The results suggest that IL-1α inhibits adipogenesis through activation of NF-κB and ERK1/2 pathways and subsequent upregulation of proinflammatory cytokines in ADSCs. IL-1α might play an important role in mediating lipoatrophy by regulation of ADSCs.

[Induction of robust senescence-associated secretory phenotype in mouse NIH-3T3 cells by mitomycin C].

Senescence-associated secretory phenotype (SASP) is often a concomitant result of cell senescence, embodied by the enhanced function of secretion. The SASP factors secreted by senescent cells include cytokines, proteases and chemokines, etc, which can exert great influence on local as well as systemic environment and participate in the process of cell senescence, immunoregulation, angiogenesis, cell proliferation and tumor invasion, etc. Relative to the abundance of SASP models in human cells, the in vitro SASP model derived from mouse cells is scarce at present. Therefore, the study aimed to establish a mouse SASP model to facilitate the research in the field. With this objective, we treated the INK4a-deficient mouse NIH-3T3 cells and the wildtype mouse embryonic fibroblasts (MEF) respectively with mitomycin C (MMC), an anticarcinoma drug which could induce DNA damage. The occurring of cell senescence was evaluated by cell morphology, ß-gal staining, integration ratio of EdU and Western blot. Quantitative RT-PCR and ELISA were used to detect the expression and secretion of SASP factors, respectively. The results showed that, 8 days after the treatment of NIH-3T3 cells with MMC (1 µg/mL) for 12 h or 24 h, the cells became enlarged and the ratios of ß-gal-positive (blue-stained) cells significantly increased, up to 77.4% and 90.4%, respectively. Meanwhile, the expression of P21 protein increased and the integration ratios of EdU significantly decreased (P < 0.01). Quantitative RT-PCR detection showed that the mRNA levels of several SASP genes, including IL-6, TNF-α, IL-1α and IL-1ß increased evidently. ELISA detection further observed an enhanced secretion of IL-6 (P < 0.01). On the contrary, although wildtype MEF could also be induced into senescence by MMC treatment for 12 h or 24 h, embodied by the enlarged cell volume, increased ratios of ß-gal-positive cells (up to 71.7% and 80.2%, respectively) and enhanced expression of P21 protein, the secretion of IL-6 displayed no significant change. Our study indicated that, although MMC could induce senescence in both mouse NIH-3T3 cells and wildtype MEF, only senescent NIH-3T3 cells displayed the canonical SASP phenomena. Current study suggested that senescent NIH-3T3 cells might be an appropriate in vitro SASP model of mouse cells.

Effect of ATG8 or SAC1 deficiency on the cell proliferation and lifespan of the long-lived PMT1 deficiency yeast cells.

Autophagy is pivotal in maintaining intracellular homeostasis, which involves various biological processes, including cellular senescence and lifespan modulation. Being an important member of the protein O-mannosyltransferase (PMT) family of enzymes, Pmt1p deficiency can significantly extend the replicative lifespan (RLS) of yeast cells through an endoplasmic reticulum (ER) unfolded protein response (UPR) pathway, which is participated in protein homeostasis. Nevertheless, the mechanisms that Pmt1p regulates the lifespan of yeast cells still need to be explored. In this study, we found that the long-lived PMT1 deficiency strain (pmt1Δ) elevated the expression levels of most autophagy-related genes, the expression levels of total GFP-Atg8 fusion protein and free GFP protein compared with wild-type yeast strain (BY4742). Moreover, the long-lived pmt1Δ strain showed the greater dot-signal accumulation from GFP-Atg8 fusion protein in the vacuole lumen through a confocal microscope. However, deficiency of SAC1 or ATG8, two essential components of the autophagy process, decreased the cell proliferation ability of the long-lived pmt1Δ yeast cells, and prevented the lifespan extension. In addition, our findings demonstrated that overexpression of ATG8 had no potential effect on the RLS of the pmt1Δ yeast cells, and the maintained incubation of minimal synthetic medium lacking nitrogen (SD-N medium as starvation-induced autophagy) inhibited the cell proliferation ability of the pmt1Δ yeast cells with the culture time, and blocked the lifespan extension, especially in the SD-N medium cultured for 15 days. Our results suggest that the long-lived pmt1Δ strain enhances the basal autophagy activity, while deficiency of SAC1 or ATG8 decreases the cell proliferation ability and shortens the RLS of the long-lived pmt1Δ yeast cells. Moreover, the maintained starvation-induced autophagy impairs extension of the long-lived pmt1Δ yeast cells, and even leads to the cell death.

Differentiation of mouse induced pluripotent stem cells into corneal epithelial-like cells.

Somatic cells can be reprogrammed into a pluripotent ES-cell-like state (termed induced pluripotent stem cells, iPS) by transcription factors, which have enormous therapeutic potential for regenerative medicine. We have investigated whether iPS can directly differentiate into corneal epithelium-like cells. Mouse iPS cells were co-cultured with corneal limbal stroma. RT-PCR, immunohistochemistry and scanning electron microscopy analysis were used to detect differentiated iPS. Undifferentiated iPS cells expressed ES cells related genes. Co-culture with corneal limbal stroma, in the presence of additional factors bFGF, EGF and NGF, activated keratin expression 12 (K12, a marker of corneal epithelial cells) and downregulated Nanog. These data suggest that mouse iPS cells can differentiate into corneal epithelial-like cells by replication of a corneal epithelial stem cell niche.

A simple and effective pressure culture system modified from a transwell cell culture system.

Mechanical pressure plays an important role in many physiological and pathological processes. Mimicking the mechanical pressure present in vitro is necessary for related research, but usually requires expensive and complicated equipment. In this study we created a simple pressure culture system based on the transwell culture system. By cutting off the top rim of the transwell insert, the cells were compressed between the insert membrane and the well floor. The new pressure culture system was proven effective in that it induced cell morphological change, integrin ß1 upregulation, actin polymerization and growth change in rat retinal ganglion cells, human nasopharyngeal carcinoma cells and mice embryonic fibroblasts. Though the pressure value is immeasurable and inhomogeneous, the easily available culture system still provides a choice for the laboratories that do not have access to the better, but much more expensive pressure culture equipment.

[Investigation of 5-bromo-2'-deoxyuridine labelling mice retinal progenitor cells].

BrdU (5-Bromo-2'-deoxyuridine) is usually used to label the mitotic cells as well as to trace reagent in cell transplation. However, BrdU could also exert some side effect on cellular biological characteristics upon inappropriate use. To explore the appropriate concentration of BrdU for labelling retinal progenitor cells (RPCs), we co-cultured Embryonic day (E) 17. 5 RPCs with different concentrations of BrdU, which were 0.2, 1, 5 and 10 micromol/L, respectively. After 48 hours, the RPCs were proliferation- or differentiation-cultured. Immunofluorescence was used to detect the BrdU-positive ratio and differentiation potential. Cell count was used to evaluate proliferation ability, and lactate dehydrogenase (LDH) release assay was used to monitor cytotoxicity. The results showed that 0.2 micromol/ L BrdU could not label RPCs clearly, while BrdU of 1, 5 or 10 micromol/L could label the RPCs with similar ratios. 1 micromol/L BrdU displayed no obvious cytotoxicity and showed no obvious effect on the proliferation and differentiation ability. However, 5 micromol/L or 10 micromol/L BrdU could evidently inhibit RPCs proliferation, partly due to the cytotoxicity effect. Furthermore, 10 micromol/L BrdU could inhibit the differentiation of RPCs towards MAP2-positive nerve cells, but showed no influence on the differentiation of RPCs towards GFAP- and glutamine synthetase positive glial cells. This study suggested that 1 micromol/L BrdU could be an appropriate concentration for RPCs labelling and could efficiently label RPCs without obvious side effect.

A novel role of Fas in delaying cellular senescence.

Fas-mediated apoptosis is a major player of many physiological and pathological cellular processes. Fas-regulated immune regulation exhibits either the beneficial or the harmful effects which is associated with the onset or development of immune disorders. Alterations in apoptosis may contribute to age-associated changes. However, the role of apoptosis in the ageing process remains ambiguous. Here we demonstrated Fas signaling-mediated premature senescence in young mouse embryonic fibroblast (MEF) cells. Activated Fas signaling by agonist Jo-2 resulted in declined senescence in young and aged MEFs. Premature senescence induced the early activation of senescence markers, including the increase in the percentage of SA-ß-galactosidase (SA-ß-gal) cells, the induction of p53 phosphorylation, and the enhanced expression of p16 and p21 protein and elevated IL-6 pro-inflammatory cytokine in the absence of Fas. The elevated production of reactive oxygen species (ROS) in Fas-deficient MEFs was associated with dysfunctional mitochondria. Further, we determined that the known ROS scavenger NAC (N-acetyl-l-cysteine) could reverse the process of premature senescence in absence of Fas. Therefore, this study signifies a novel role of Fas in the control of cellular senescence.

Effects of multi-organ crosstalk on the physiology and pathology of adipose tissue.

In previous studies, adipocytes were found to play an important role in regulating whole-body nutrition and energy balance, and are also important in energy metabolism, hormone secretion, and immune regulation. Different adipocytes have different contributions to the body, with white adipocytes primarily storing energy and brown adipocytes producing heat. Recently discovered beige adipocytes, which have characteristics in between white and brown adipocytes, also have the potential to produce heat. Adipocytes interact with other cells in the microenvironment to promote blood vessel growth and immune and neural network interactions. Adipose tissue plays an important role in obesity, metabolic syndrome, and type 2 diabetes. Dysfunction in adipose tissue endocrine and immune regulation can cause and promote the occurrence and development of related diseases. Adipose tissue can also secrete multiple cytokines, which can interact with organs; however, previous studies have not comprehensively summarized the interaction between adipose tissue and other organs. This article reviews the effect of multi-organ crosstalk on the physiology and pathology of adipose tissue, including interactions between the central nervous system, heart, liver, skeletal muscle, and intestines, as well as the mechanisms of adipose tissue in the development of various diseases and its role in disease treatment. It emphasizes the importance of a deeper understanding of these mechanisms for the prevention and treatment of related diseases. Determining these mechanisms has enormous potential for identifying new targets for treating diabetes, metabolic disorders, and cardiovascular diseases.

Pulsed field ablation of superior vena cava in paroxysmal atrial fibrillation: a case report.

Paroxysmal atrial fibrillation originates most commonly in the pulmonary veins. However, the superior vena cava has proved to be arrhythmogenic in some cases. Pulsed field ablation, an emerging ablation technology, selectively affects myocardial tissue. Herein, we present a case of paroxysmal atrial fibrillation in a 64-year-old man who was admitted to our hospital for pulsed field ablation. The tachycardia was recurrent despite four successful pulmonary vein isolations. The superior vena cava was determined to be involved in arrhythmogenesis. The atrial fibrillation terminated immediately after the pulsed field ablation discharge at the superior vena cava.

Association between nighttime heart rate and cardiovascular mortality in patients with implantable cardioverter-defibrillator: A cohort study.

BACKGROUND: Although studies have shown that an increased resting heart rate measured randomly at a single point of the day has been associated with adverse cardiovascular outcomes, the utility of continuous monitoring of nighttime heart rate (NTHR) has remained largely uninvestigated. OBJECTIVE: This study aimed to explore the association between NTHR and cardiovascular mortality. METHODS: The Study of Home Monitoring System Safety and Efficacy in Cardiac Implantable Electronic Device-implanted Patients, which is a prospective cohort study, enrolled patients with implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy defibrillator between 2010 and 2015. Baseline NTHR was measured during the programmed sleep period from 30 to 60 days after implantation. The primary outcome was cardiovascular mortality, fitted by a restricted cubic spline function. RESULTS: A total of 534 implantable cardioverter-defibrillator recipients with sinus rhythm during the detection window were included in the study. The mean baseline NTHR was 59.6 ± 8.0 beats/min. During the follow-up period of 60.4 ± 21.8 months, 88 (16.5%) patients experienced cardiovascular mortality. After considering potential confounders, a linear association was observed. Each 1 beat/min increase in NTHR was associated with a 7.8%, 10.1%, and 5.7% increase in the risk of cardiovascular mortality in the total population, patients with heart failure, and patients without heart failure, respectively. CONCLUSION: Continuous monitoring of NTHR may identify patients at high risk of cardiovascular mortality in a timely manner, with the potential for "preemptive" action. TRIAL REGISTRATION: No. ChiCTR-ONRC-13003695.

Vemurafenib induces a noncanonical senescence-associated secretory phenotype in melanoma cells which promotes vemurafenib resistance.

More than one half melanoma patients have BRAF gene mutation. BRAF inhibitor vemurafenib is an effective medication for these patients. However, acquired resistance is generally inevitable, the mechanisms of which are not fully understood. Cell senescence and senescence-associated secretory phenotype (SASP) are involved in extensive biological functions. This study was designed to explore the possible role of senescent cells in vemurafenib resistance. The results showed that vemurafenib treatment induced BRAF-mutant but not wild-type melanoma cells into senescence, as manifested by positive ß-galactosidase staining, cell cycle arrest, enlarged cellular morphology, and cyclin D1/p-Rb pathway inhibition. However, the senescent cells induced by vemurafenib (SenV) did not display DNA damage response, p53/p21 pathway activation, reactive oxygen species accumulation, decline of mitochondrial membrane potential, or secretion of canonical SASP cytokines. Instead, SenV released other cytokines, including CCL2, TIMP2, and NGFR, to protect normal melanoma cells from growth inhibition upon vemurafenib treatment. Xenograft experiments further confirmed that vemurafenib induced melanoma cells into senescence in vivo. The results suggest that vemurafenib can induce robust senescence in BRAFV600E melanoma cells, leading to the release of resistance-conferring cytokines. Both the senescent cells and the resistant cytokines could be potential targets for tackling vemurafenib resistance.

Progression of Device-Detected Atrial High-Rate Episodes and the Risk of All-Cause Mortality.

Atrial high-rate episodes (AHREs) are prevalent in approximately 1/3 of patients with cardiac implanted electronic devices and are associated with an increased risk of several adverse outcomes. This study aimed to explore the factors associated with AHRE progression and the risk of all-cause mortality. At least 1 day with AHRE burden ≥15 minutes was identified in 124 of 343 recipients (36.2%) of an implantable cardioverter defibrillator or cardiac resynchronization therapy device. We included patients whose AHRE burden at the time of first detection was ≥15 minutes but <24 hours (n = 107). Various cut-off values (15 minutes, 6 hours, and 24 hours) of daily AHRE burden were analyzed. During an average follow-up of 4.2 years, 60 patients (56.1%) experienced ≥1 progression to greater AHRE burden. Patients with hypertension or greater AHRE burden at first detection were associated with faster progression. In addition, 27 deaths (45%) occurred among 60 patients with AHRE progression, compared with 25.5% (12 of 47) for those without progression. After multivariable adjustment, AHRE progression was independently associated with all-cause mortality (hazard ratio 2.56, 95% confidence interval 1.23 to 5.35, p = 0.012). Notably, AHRE progression within 1 month after their first detection was associated with an increased risk for all-cause mortality (hazard ratio 4.01, 95% confidence interval 1.76 to 9.16, p = 0.001) compared with patients without progression. However, a similar risk was not observed among patients with AHRE progression occurring after 1 month after their first detection. In conclusion, >1/2 of the patients with AHRE progressed to a greater burden over time. Continuous monitoring of the AHRE burden may help identify patients at great risk for death.

Recent advances of artificial intelligence in melanoma clinical practice.

Skin melanoma is a lethal cancer. The incidence of melanoma is increasing rapidly in all regions of the world. Despite significant breakthroughs in melanoma treatment in recent years, precise diagnosis of melanoma is still a challenge in some cases. Even specialized physicians may need time and effort to make accurate judgments. As artificial intelligence (AI) technology advances into medical practice, it may bring new solutions to this problem based on its efficiency, accuracy, and speed. This paper summarizes the recent progress of AI in melanoma-related applications, including melanoma diagnosis and classification, the discovery of new medication, guiding treatment, and prognostic assessment. The paper also compares the effectiveness of various algorithms in melanoma application and suggests future research directions for AI in melanoma clinical practice.

Volume-activated chloride currents in fetal human nasopharyngeal epithelial cells.

Volume-activated chloride channels have been studied by us extensively in human nasopharyngeal carcinoma cells. However, the chloride channels in the counterpart of the carcinoma cells have not been investigated. In this study, volume-activated chloride currents (I(cl,vol)) were characterized in normal fetal human nasopharyngeal epithelial cells using the whole-cell patch-clamp technique. Under isotonic conditions, nasopharyngeal epithelial cells displayed only a weak background current. Exposure to 47% hypotonic solution activated a volume-sensitive current. The reversal potential of the current was close to the calculated equilibrium potential for Cl(-). The peak values of the hypotonicity-activated current at +80 mV ranged from 0.82 to 2.71 nA in 23 cells. Further analysis indicated that the density of the hypotonicity-activated current in most cells (18/23) was smaller than 60 pA/pF. Only five cells presented a current larger than 60 pA/pF. The hypotonicity-activated current was independent of the exogenous ATP. Chloride channel inhibitors ATP, tamoxifen and 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB), inhibited the current dramatically. The anion permeability of the hypotonicity-activated chloride channels was I(-) > Br(-) > Cl(-) > gluconate. Unexpectedly, in isotonic conditions, ATP (10 mM) activated an inward-rectified current, which had not been observed in the nasopharyngeal carcinoma cells. These results suggest that, under hypotonic challenges, fetal human nasopharyngeal epithelial cells can produce I(cl,vol), which might be involved in cell volume regulation.