[Hunyuan moxibustion for diarrhea-predominant irritable bowel syndrome of spleen and kidney yang deficiency: a randomized controlled trial].

OBJECTIVE: To compare the therapeutic effect between Hunyuan moxibustion and oral western medication on diarrhea-predominant irritable bowel syndrome（IBS-D）of spleen and kidney yang deficiency. METHODS: Sixty patients with IBS-D of spleen and kidney yang deficiency were randomly divided into a Hunyuan moxibustion group and a western medication group, 30 cases each group. The Hunyuan moxibustion group was treated with Hunyuan moxibustion at Guanyuan（CV 4），40 min each time, once a day; in the western medication group，loperamide hydrochloride capsules (2 mg each time, 3 times a day) and bacillus licheniformis live capsules (0.5 g each time, 3 times a day) were given orally.Both groups were treated for 20 days. The scores of irritable bowel syndrome（IBS）symptom severity scale（IBS-SSS）, IBS quality of life scale (IBS-QOL) and TCM symptom grading quantitative were observed before and after treatment, and the clinical efficacy and safety were evaluated in the two groups. RESULTS: After treatment，each item scores and total scores of IBS-SSS in the two groups were lower than those before treatment（P<0.05）, and the total scores of IBS-QOL were higher than those before treatment (P<0.05)；each item score and total score of IBS-SSS in the Hunyuan moxibustion group were lower than those in the western medication group (P<0.05), and the total score of IBS-QOL in the Hunyuan moxibustion group was higher than that in the western medication group (P<0.05).After treatment, each item score and total score of TCM symptom grading quantitative in the Hunyuan moxibustion group were lower than those before treatment (P<0.05), the abdominal pain, diarrhea, lack of appetite scores and total score in the western medication group were lower than those before treatment (P<0.05)；and the abdominal pain, soreness and weakness of waist and knees, fear to cold and cold limbs scores and total score in the Hunyuan moxibustion group were lower than those in the western medication group (P<0.05).The total effective rate was 90.0%（27/30）in the Hunyuan moxibustion group, which was higher than 73.3%（22/30）in the western medication group (P<0.05). No adverse reactions occurred in both groups during treatment. CONCLUSION: Hunyuan moxibustion can effectively improve the symptom severity and quality of life in patients with IBS-D of spleen and kidney yang deficiency, especially in improving the symptoms of abdominal pain, soreness and weakness of waist and knees, fear to cold and cold limbs.Its therapeutic effect is superior to western medication.

Frequency of prothrombin time-international normalized ratio monitoring and the long-term prognosis in patients with mechanical valve replacement.

BACKGROUND: The study aimed to assess the correlation between the monitoring frequency of PT-INR and the long-term prognosis in patients with mechanical heart valve (MHV) replacement after discharge. METHODS: This single-center, observational study enrolled patients who underwent MHV replacement and discharged from June 2015 to May 2018. Patients or their corresponding family members were followed with a telephone questionnaire survey in July-October 2020. Based on monitoring intervals, patients were divided into frequent monitoring (FM) group (≤ 1 month) and less frequent monitoring (LFM) group (> 1 month). The primary endpoint was the composite of thromboembolic event, major bleeding or all-cause death. The secondary endpoints were thromboembolic event, major bleeding or all-cause death, respectively. RESULTS: A total of 188 patients were included in the final analysis. The median follow-up duration was 3.6 years (Interquartile range: 2.6 to 4.4 years). 104 (55.3%) patients and 84 (44.7%) patients were classified into the FM group and the LFM group, respectively. The FM group had a significantly lower incidence of the primary endpoint than the LFM group (3.74 vs. 1.16 per 100 patient-years, adjusted HR: 3.31 [95% CI 1.05-10.42, P = 0.041]). Secondary analysis revealed that the risk of thromboembolic events and all-cause death were also reduced in the FM group. CONCLUSIONS: The management of warfarin treatment in patients after MHV replacement remains challenging. Patients with less frequent monitoring of PT-INR might have worse clinical prognosis than those with frequent PT-INR monitoring.

Reduced graphene oxide/carbon nitride composite sponge for interfacial solar water evaporation and wastewater treatment.

Interfacial solar-driven steam generation has been proposed as a cost-effective green sustainable technology to alleviate the freshwater crisis. However, the desire to produce clean water from water sources containing organic contaminants is still remains a challenge due to the limitations of the traditional wastewater treatment methods. Here, we constructed a g-C3N4-based composite sponge solar steam generator (rGCPP) by a simple hydrothermal reaction. Benefiting from its low cost and easy preparation, this evaporator can be expected to be a promising candidate for the alleviation of water shortages and water pollution in practical applications. By combination of the solar steam generation and the photocatalysis into the rGCPP-based interfacial solar-driven steam generation system, the resulted rGCPP-based solar steam generator performs outstanding solar absorption of 90.8%, which achieves high evaporation rate of 1.875 kg m-2 h-1 and solar-to-vapor efficiency of 81.07% under 1 sun irradiation. Meanwhile, organic pollutants in the water source can be completely removed by photocatalytic degradation and the degradation rates were measured to be 99.20% for methylene blue and 91.07% for rhodamine B, respectively. Consequently, the as-prepared composite sponge has promising applications in generating clean water and alleviating water pollution.

Atrial Lesions in a Pedigree With PRKAG2 Cardiomyopathy: Involvement of Disrupted AMP-Activated Protein Kinase Signaling.

PRKAG2 cardiomyopathy is a rare progressive disease characterized by increased ventricular wall thickness and preexcitation. Dysfunction of the protein 5'-AMP-activated protein kinase (AMPK) plays a decisive role in the progression of ventricular lesions. Although patients with the PRKAG2-R302Q mutation have a high incidence of atrial fibrillation (AF), the molecular mechanism contributing to the disease remains unclear. We carried out whole-genome sequencing with linkage analysis in three affected members of a family. Atrial samples were obtained from the proband via surgical intervention. Control atrium biopsies were obtained from patients with persistent AF. Pathological changes were analyzed using the hematoxylin and eosin (H&E), Masson, and periodic acid-Schiff (PAS) staining. The AMPK signaling pathway was investigated by western blot. A murine atrial cardiomyocyte cell line (HL-1) and human induced pluripotent stem derived atrial cardiomyocytes (hiPSC-ACMs) were transfected with an adenovirus carrying the same mutation. We used enzyme linked immunosorbent assay (ELISA) to determine the AMPK activity in HL-1 cells and hiPSC-ACMs overexpressing PRKAG2-R302Q. Pathological results showed a large quantity of glycogen accumulation and vacuolization in cardiomyocytes from the proband atrial tissue. Western blot analysis revealed that the AMPK activity was significantly downregulated compared with that of the controls. Furthermore, remarkable glycogen deposition and impairment of AMPK activity were reproduced in HL-1 cells overexpressing PRKAG2-R302Q. Taken together, PRKAG2-R302Q mutation directly impair atrial cardiomyocytes. PRKAG2-R302Q mutation lead to glycogen deposition and promote the growth of atrial lesions by disrupting the AMPK pathway.

CFP is a prognostic biomarker and correlated with immune infiltrates in Gastric Cancer and Lung Cancer.

Complement factor properdin (CFP), encodes plasma glycoprotein, is a critical gene that regulates the complement pathway of the innate immune system. However, correlations of CFP in cancers remain unclear. In this study, the expression pattern and prognostic value of CFP in pan-cancer were analyzed via the Oncomine, PrognoScan, GEPIA and Kaplan-Meier plotters. In addition, we used immunohistochemical staining to validate CFP expression in clinical tissue samples. Finally, we evaluated the correlations between CFP and cancer immune infiltrates particularly in stomach adenocarcinoma (STAD) and lung adenocarcinoma (LUAD) by using GEPIA and TIMER databases. The results of database analysis and immunohistochemistry showed that the expression level of CFP in STAD and LUAD was lower than that in normal tissues. Low expression level of CFP was associated with poorer overall survival (OS), first progression (FP), post progression survival (PPS) and was detrimental to the prognosis of STAD and LUAD, specifically in stage 3, stage T3, stage N2 and N3 of STAD (P<0.05). Moreover, expression of CFP had significant positive correlations with the infiltration levels of CD8+ T cells, CD4+ T cells, macrophages, neutrophils and dendritic cells (DCs) in STAD and LUAD. Furthermore, gene markers of infiltrating immune cells exhibited different CFP-related immune infiltration patterns such as tumor-associated-macrophages (TAMs). These results suggest that CFP can serve as a prognostic biomarker for determining prognosis and immune infiltration in STAD and LUAD.

[Therapeutic effect of long-snake moxibustion combined with western medication on diarrhea type irritable bowel syndrome of spleen and kidney yang deficiency].

OBJECTIVE: To compare the therapeutic effect between long-snake moxibustion combined with western medication and simple medication on diarrhea type irritable bowel syndrome (IBS-D) of spleen and kidney yang deficiency. METHODS: A total of 60 patients with IBS-D of spleen and kidney yang deficiency were randomized into an observation group and a control group, 30 cases in each one. In the control group, loperamide hydrochloride capsule (2.0 mg each time, 3 times a day) and bacillus licheniformis live capsule (0.5 mg each time, 3 times a day) were given orally. In the observation group, long-snake moxibustion was added on the basis of the treatment in the control group, ginger-partitioned moxibustion was applied from Dazhui (GV 14) to Yaoshu (GV 2) of governor vessel, once a week. The treatment was given for 8 weeks in both groups. The scores of main symptom and IBS quality of life questionnaire (IBS-QOL) were observed before and after treatment, and the therapeutic effect was evaluated in both groups. RESULTS: Compared before treatment, the symptom scores of abdominal pain, defecation frequency, mucous stool and appetite reduction were decreased (P<0.05), the scores of daily social intercourse, daily activity, diet, work, emotion, sleep quality, mental state and energy change were increased in both groups (P<0.05). After treatment, each sub-item score of main symptom in the observation group was lower than the control group (P<0.05), each sub-item score of IBS-QOL was higher than the control group (P<0.05). The total effective rate was 96.7% (29/30) in the observation group, which was superior to 73.3% (22/30) in the control group (P<0.05). CONCLUSION: Long-snake moxibustion combined with western medication can effectively treat the IBS-D of spleen and kidney yang deficiency, relieve the clinical symptoms and improve the quality of life, the effect is superior to the simple treatment of oral western medication.

Automatic Staging for Retinopathy of Prematurity With Deep Feature Fusion and Ordinal Classification Strategy.

Retinopathy of prematurity (ROP) is a retinal disease which frequently occurs in premature babies with low birth weight and is considered as one of the major preventable causes of childhood blindness. Although automatic and semi-automatic diagnoses of ROP based on fundus image have been researched, most of the previous studies focused on plus disease detection and ROP screening. There are few studies focusing on ROP staging, which is important for the severity evaluation of the disease. To be consistent with clinical 5-level ROP staging, a novel and effective deep neural network based 5-level ROP staging network is proposed, which consists of multi-stream based parallel feature extractor, concatenation based deep feature fuser and clinical practice based ordinal classifier. First, the three-stream parallel framework including ResNet18, DenseNet121 and EfficientNetB2 is proposed as the feature extractor, which can extract rich and diverse high-level features. Second, the features from three streams are deeply fused by concatenation and convolution to generate a more effective and comprehensive feature. Finally, in the classification stage, an ordinal classification strategy is adopted, which can effectively improve the ROP staging performance. The proposed ROP staging network was evaluated with per-image and per-examination strategies. For per-image ROP staging, the proposed method was evaluated on 635 retinal fundus images from 196 examinations, including 303 Normal, 26 Stage 1, 127 Stage 2, 106 Stage 3, 61 Stage 4 and 12 Stage 5, which achieves 0.9055 for weighted recall, 0.9092 for weighted precision, 0.9043 for weighted F1 score, 0.9827 for accuracy with 1 (ACC1) and 0.9786 for Kappa, respectively. While for per-examination ROP staging, 1173 examinations with a 4-fold cross validation strategy were used to evaluate the effectiveness of the proposed method, which prove the validity and advantage of the proposed method.

AGE challenge: Angle Closure Glaucoma Evaluation in Anterior Segment Optical Coherence Tomography.

Angle closure glaucoma (ACG) is a more aggressive disease than open-angle glaucoma, where the abnormal anatomical structures of the anterior chamber angle (ACA) may cause an elevated intraocular pressure and gradually lead to glaucomatous optic neuropathy and eventually to visual impairment and blindness. Anterior Segment Optical Coherence Tomography (AS-OCT) imaging provides a fast and contactless way to discriminate angle closure from open angle. Although many medical image analysis algorithms have been developed for glaucoma diagnosis, only a few studies have focused on AS-OCT imaging. In particular, there is no public AS-OCT dataset available for evaluating the existing methods in a uniform way, which limits progress in the development of automated techniques for angle closure detection and assessment. To address this, we organized the Angle closure Glaucoma Evaluation challenge (AGE), held in conjunction with MICCAI 2019. The AGE challenge consisted of two tasks: scleral spur localization and angle closure classification. For this challenge, we released a large dataset of 4800 annotated AS-OCT images from 199 patients, and also proposed an evaluation framework to benchmark and compare different models. During the AGE challenge, over 200 teams registered online, and more than 1100 results were submitted for online evaluation. Finally, eight teams participated in the onsite challenge. In this paper, we summarize these eight onsite challenge methods and analyze their corresponding results for the two tasks. We further discuss limitations and future directions. In the AGE challenge, the top-performing approach had an average Euclidean Distance of 10 pixels (10 µm) in scleral spur localization, while in the task of angle closure classification, all the algorithms achieved satisfactory performances, with two best obtaining an accuracy rate of 100%. These artificial intelligence techniques have the potential to promote new developments in AS-OCT image analysis and image-based angle closure glaucoma assessment in particular.

The Clinical Effectiveness of Cognitive Behavioral Therapy for Patients with Insomnia and Depression: A Systematic Review and Meta-Analysis.

BACKGROUND: Insomnia and depression often co-occurr. However, there is lack of effective treatment for such comorbidity. CBT-I has been recommended as the first-line treatment for insomnia; whether it is also effective for comorbidity of insomnia and depression is still unknown. Therefore, we conducted this meta-analysis of randomized controlled trials to assess the clinical effectiveness and safety of CBT-I for insomnia comorbid with depression. Data Sources. Seven electronic databases, including China National Knowledge Infrastructure (CNKI), Wanfang Database, China Science Technology Journal Database, SinoMed Database, PubMed, the Cochrane Library, and EMBASE, as well as grey literature, were searched from the beginning of each database to July 1, 2019. Study Eligibility Criteria. Randomized controlled trials that compared CBT-I to no treatment or hypnotics (zopiclone, estazolam, and benzodiazepine agonist) for insomnia comorbid with depression and reported both insomnia scales and depression scales. Study Assessment and Synthesis Methods. Cochrane Reviewer's Handbook was used for evaluating the risk of bias of included studies. Review Manager 5.3 software was used for meta-analysis. Online GRADEpro was used to assess the quality of evidence. RESULTS: The pooled data showed that CBT-I was superior to no treatment for insomnia, while it was unsure whether CBT-I was better than no treatment for depression. And the effectiveness of CBT-I was comparable to hypnotics for both insomnia and depression. CBT-I was likely to be safe due to its noninvasive nature. The methodological quality varied across these trials. The evidence quality varied from moderate to very low, and the recommendation level was low. CONCLUSIONS: Currently, findings support that CBT-I seems to be effective and safe for insomnia comorbid with depression to improve the insomnia condition, while it is unsure whether CBT-I could improve depression condition. More rigorous trials are needed to confirm our findings.

[Clinical effect of long-snake moxibustion on lumbago of cold-dampness type].

OBJECTIVE: To observe the effect of long-snake moxibustion on pain, functional disorder and body constitution in the patients with lumbago of cold-dampness type. METHODS: A total of 90 patients with lumbago of cold-dampness type were randomized into long-snake moxibustion, acupuncture and medication groups, 30 cases in each group. In the long-snake moxibustion group, long-snake moxibustion was exerted on the spinal (between Dazhui[GV14] and Yaoshu[GV2]) with the self-prepared moxa powder formula combined with fresh ginger and moxa wool, once a week, for 4 weeks. Regular acupuncture was given to the acupuncture group, 30 min each time, once a day, 8 times as a treatment course, at the interval of 2 days between the courses. The duration of treatment was 1 month. In the medication group, Diclofenac Sodium was prescribed for oral administration, 25 mg each time, three times a day, and Mecobalamine tablets, 0.5 mg each time, 3 times a day. The duration of medication was 1 month. Before and after treatment, the differences were evaluated in the scores of visual analog scale (VAS), the present pain intensity(PPI), Oswestry disability index (ODI) and the scale of yang-deficiency body constitution among the 3 groups. RESULTS: After the treatment, VAS and PPI score and ODI were significantly reduced in the patients of the 3 groups as compared with those before treatment (all P<0.05). Compared with the medication group, ODI score was significantly reduced in the long-snake moxibustion group and the acupuncture group (P<0.05). After the treatment, the scores of the scale of yang-deficiency body constitution were significantly reduced in the long-snake moxibustion group and the acupuncture group (P<0.05) as compared with those before the treatment, but not statistically significant in the medication group in comparison before and after the treatment (P>0.05). The score of the scale of yang-deficiency body constitution in the long-snake moxibustion group was significantly lower than that in the acupuncture group and the medication group (P<0.05). Regarding the clinical effect, the effective rate was 93.33% (28/30) in the long-snake moxibustion group and it was 86.67% (26/30) in the acupuncture group and 73.33% (22/30) in the medication group after the treatment. The effective rate in the long-snake moxibustion group was significantly higher than those in the acupuncture group and the medication group (P<0.05). CONCLUSION: The long-snake moxibustion therapy can achieve significant effect on lumbago of cold-dampness type. This therapy can alleviate pain, relieve the functional disorders and improve the conditions of body constitution in the patients. Hence, it is applicable for the clinical promotion.

Clinical effectiveness of Tui Na for insomnia compared with estazolam: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: The purpose of this systematic review (SR) is to evaluate the effectiveness and safety of Tui Na therapy for insomnia. METHODS: Two authors separately searched PubMed, the Cochrane Library, EMBASE, SinoMed Database, China National Knowledge Infrastructure (CNKI), Wanfang Database, China Science Technology Journal Database, related SR and published protocols at the same time to find randomized controlled trials (RCTs), which compared Tui Na therapy with estazolam therapy for insomnia, from their inception to January1st 2019. Screening documents, data extraction, quality assessment of methodology and quality assessment of evidence were also conducted by two authors separately at the same time. We used Cochrane Risk of Bias tool to assess the methodological quality of included RCTs. The results of meta-analysis were made via RevMan software (5.3). The quality of evidence was assessed by on-line GRADEpro. The primary outcome: Pittsburgh Sleep Quality Index (PSQI) score, the secondary outcome: clinical effectiveness rate and the safety index: adverse events. The clinical effectiveness of these included RCTs all focused on the improvement of patients' satisfaction with sleep time and sleep quality. RESULTS: We included 22 RCTs(1,999 participants), meeting the inclusion and exclusion criteria. The assessment of methodological quality was not satisfied, in which "high risk", "unclear risk" and "low risk" all existed. The results of meta-analysis demonstrated that (1)for primary outcome, the PSQI score of Tui Na therapy was lower than that of estazolam therapy after treatment in subgroup1(Head)(MD-2.39,95%CI[-3.79,-0.98],I2 = 82%,n = 291,3 trials) and subgroup4(Abdomen)(MD-1.7,95%CI[-2.53,-0.87],I2 = 0%,n = 120,2 trials);while there was no significant difference between Tui Na therapy and estazolam therapy in subgroup2(Head and trunk)(MD-1.39,95%CI[-3.03,0.24],I2 = 90%,n = 200, 2 trials) and subgroup3(Head, trunk and extremities)(MD-0.51,95%CI[-1.53,0.5],I2 = 30%,n = 126,2 trials).(2) for secondary outcomes(the clinical effectiveness rate and safety index),the clinical effectiveness rate of Tui Na therapy was higher than that of estazolam therapy after treatment in subgroup1(Head)(RR1.21,95%CI[1.05,1.39],I2 = 26%,n = 239,3 trials), subgroup2(Head and trunk)(RR1.15,95%CI[1.08,1.23],I2 = 33%,n = 1024,10 trials) and subgroup4(Abdomen)(RR1.12,95%CI[1.01,1.23],I2 = 0%,n = 180,3 trials); while there was no significant difference between Tui Na therapy and estazolam therapy in subgroup3(Head, trunk and extremities)(RR1.03,95%CI[0.94,1.13],I2 = 28%,n = 346,4 trials).Safety index, 5 RCTs reported adverse events. Among them, only 1 RCT reported adverse event in Tui Na therapy, which was daytime drowsiness; all 5 RCTs reported adverse events in estazolam therapy, which were dry mouth, dizziness, daytime drowsiness etc. The evidence quality was generally low to very low. CONCLUSION: Tui Na therapy appeared to be superior to estazolam therapy in treating areas(head; abdomen), while there was no significant difference between Tui Na therapy and estazolam therapy in treating areas(head and trunk; head, trunk and extremities). No serious adverse event was reported in Tui Na therapy. However the methodological quality and evidence quality were not satisfied. Therefore we could not make a convincing conclusion on the effectiveness and safety of Tui Na therapy for insomnia. Practitioners should combine their experience, evidence of our review and patients' preferences to make a proper treatment. And more high quality RCTs and well-designed protocols of Tui Na therapy for insomnia are needed in the future.

[Ginger-separated Snake Moxibustion Improves Yang Deficiency Constitution by Up-regulating Serum Adrenocorticotropic Hormone and Cortisol Levels in Yang Deficiency Constitution Volunteers].

OBJECTIVE: Yang deficiency constitution may bring with different types of illnesses in many people. The present study was designed to observe the effect of ginger-separated snake moxibustion on yang deficiency symptom, and serum adrenocorticotropic hormone (ACTH) and cortisol (CORT) contents in yang deficiency constitution subjects, so as to explore its mechanism underlying improvement of yang deficiency constitution. METHODS: Ninety subjects with yang deficiency type constitution were equally and randomly assigned to control A group (19 men and 26 women, 18－60 years in age) and moxibustion group (16 men and 29 women, 18－60 years in age) and 45 normal subjects with mild constitution (18 men and 27 women, 18－60 years in age) were assigned to control B group. An snake-like moxa-cone was placed at a moxa-holder covering the middle back of human body from Dazhui (GV 14) to Yaoshu (GV 2) after paving a layer (about 1 cm thick) of fresh ginger in the holder, and then ignited, followed by the next moxa-cone, 3 cones altogether every time for each participant. The treatment was conducted once a week, 12 times in total. The subjects' constitution was scored according to the "Classification and Evaluation of Constitution of Traditional Chinese Medicine" formulated by China Association of Chinese Medicine. The serum ACTH and CORT contents were measured by radioimmunoassay before and at the end of the treatment and 6 months after the treatment. RESULTS: The constitation scores of the moxibustion group and control A group were significantly higher than that of the control B group before treatment (P<0.01). At the end of the treatment, the constitution score was significantly decreased in the moxibustion group (P<0.01) rather than in the control A group relevant to its own pre-treatment (P>0.05). The serum CORT and ACTH contents were significantly decreased in both the moxibustion and control A groups in comparison to the control B group before treatment (P<0.01), and obviously increased at the end of treatment in the moxibustion group compared with its own pre-treatment (P<0.01). No significant differences were found among the three groups in the constitution score, and serum CORT and ACTH levels at the 6th month after the treatment compared with their own post-treatment (P>0.05)．. CONCLUSION: The ginger-separated snake moxibustion treatment may improve the constitution of yang deficiency participants by increasing the levels of serum ACTH and CORT, which may be helpful in resisting diseases.

Rapid Electrical Stimulation Increased Cardiac Apoptosis Through Disturbance of Calcium Homeostasis and Mitochondrial Dysfunction in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

BACKGROUND/AIMS: Heart failure induced by tachycardia, the most common arrhythmia, is frequently observed in clinical practice. This study was designed to investigate the underlying mechanisms. METHODS: Rapid electrical stimulation (RES) at a frequency of 3 Hz was applied on human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) for 7 days, with 8 h/day and 24 h/day set to represent short-term and long-term tachycardia, respectively. Age-matched hiPSC-CMs without electrical stimulation or with slow electrical stimulation (1 Hz) were set as no electrical stimulation (NES) control or low-frequency electrical stimulation (LES) control. Following stimulation, JC-1 staining flow cytometry analysis was performed to examine mitochondrial conditions. Apoptosis in hiPSC-CMs was evaluated using Hoechst staining and Annexin V/propidium iodide (AV/PI) staining flow cytometry analysis. Calcium transients and L-type calcium currents were recorded to evaluate calcium homeostasis. Western blotting and qPCR were performed to evaluate the protein and mRNA expression levels of apoptosis-related genes and calcium homeostasis-regulated genes. RESULTS: Compared to the controls, hiPSC-CMs following RES presented mitochondrial dysfunction and an increased apoptotic percentage. Amplitudes of calcium transients and L-type calcium currents were significantly decreased in hiPSC-CMs with RES. Molecular analysis demonstrated upregulated expression of Caspase3 and increased Bax/Bcl-2 ratio. Genes related to calcium re-sequence were downregulated, while phosphorylated Ca2+/calmodulin-dependent protein kinase II (CaMKII) was significantly upregulated following RES. There was no significant difference between the NES control and LES control groups in these aspects. Inhibition of CaMKII with 1 µM KN93 partly reversed these adverse effects of RES. CONCLUSION: RES on hiPSC-CMs disturbed calcium homeostasis, which led to mitochondrial stress, promoted cell apoptosis and caused electrophysiological remodeling in a time-dependent manner. CaMKII played a central role in the damages induced by RES, pharmacological inhibition of CaMKII activity partly reversed the adverse effects of RES on both structural and electrophysiological properties of cells.

Structural and electrophysiological dysfunctions due to increased endoplasmic reticulum stress in a long-term pacing model using human induced pluripotent stem cell-derived ventricular cardiomyocytes.

BACKGROUND: Long-term ventricular pacing has deleterious effects and becomes more significant when cumulative percent ventricular pacing (Cum%VP) exceeds 40% of time. However, cellular disturbances and pathways by which pacing leads to myocardial disorders are not well understood. Attempts to resolve these questions have been hampered by difficulties in obtaining human cardiac tissue and the inability to build a longer-lasting (lasting longer than weeks) pacing model in vitro. METHODS: Human induced pluripotent stem cell-derived ventricular cardiomyocytes (VCMs) were cultured in the presence of electrical stimulation for 2 weeks. Quantitative structural and electrophysiological analyses were used to define the functional disturbances of pacing. RESULTS: Compared to controls, paced VCMs exhibited a remarkable reduction in the contractile protein expression, an increased apoptosis ratio and electrophysiological remodelling in a Cum%VP-dependent manner. Investigation of the protein expression levels revealed that long-term pacing universally activated both ER stress and downstream calpain. Moreover, the inhibition of calpain attenuated the adverse effects on the structural remodelling and increased the ICa, L in paced VCMs. CONCLUSIONS: The results demonstrated that pacing VCMs for 2 weeks in vitro led to a series of structural and electrophysiological dysfunctions. The increased ER stress and downstream calpain could be a central mechanism underlying the disease pathogenesis. This finding could represent a new therapeutic target in the management of long-term pacing patients.