Mammals exhibit limited heart regeneration ability, which can lead to heart failure after myocardial infarction. In contrast, zebrafish exhibit remarkable cardiac regeneration capacity. Several cell types and signaling pathways have been reported to participate in this process. However, a comprehensive analysis of how different cells and signals interact and coordinate to regulate cardiac regeneration is unavailable. We collected major cardiac cell types from zebrafish and performed high-precision single-cell transcriptome analyses during both development and post-injury regeneration. We revealed the cellular heterogeneity as well as the molecular progress of cardiomyocytes during these processes, and identified a subtype of atrial cardiomyocyte exhibiting a stem-like state which may transdifferentiate into ventricular cardiomyocytes during regeneration. Furthermore, we identified a regeneration-induced cell (RIC) population in the epicardium-derived cells (EPDC), and demonstrated Angiopoietin 4 (Angpt4) as a specific regulator of heart regeneration. angpt4 expression is specifically and transiently activated in RIC, which initiates a signaling cascade from EPDC to endocardium through the Tie2-MAPK pathway, and further induces activation of cathepsin K in cardiomyocytes through RA signaling. Loss of angpt4 leads to defects in scar tissue resolution and cardiomyocyte proliferation, while overexpression of angpt4 accelerates regeneration. Furthermore, we found that ANGPT4 could enhance proliferation of neonatal rat cardiomyocytes, and promote cardiac repair in mice after myocardial infarction, indicating that the function of Angpt4 is conserved in mammals. Our study provides a mechanistic understanding of heart regeneration at single-cell precision, identifies Angpt4 as a key regulator of cardiomyocyte proliferation and regeneration, and offers a novel therapeutic target for improved recovery after human heart injuries.
Humans ; Mice ; Rats ; Cell Proliferation ; Heart/physiology* ; Mammals ; Myocardial Infarction/metabolism* ; Myocytes, Cardiac/metabolism* ; Pericardium/metabolism* ; Single-Cell Analysis ; Zebrafish/metabolism*

In the present study, the performance of the liquid nitrogen frozen and thinned bovine pericardium was studied and compared with the porcine pericardium. The microstructure and mechanical properties of the bovine pericardium were observed and tested by hematoxylin-eosin (HE) staining and tensile test respectively. In all conditions, porcine pericardium was selected as a control group. The results showed that there was little difference in the performance of bovine pericardium after being frozen by liquid nitrogen. The secant modulus and ultimate strength of the thinned bovine pericardium were similar to those of porcine pericardium, however, the elastic modulus was a little higher than porcine pericardium. The study suggested that the performance of the thinned bovine pericardium was similar to those of porcine pericardium. It was easy for the thinned bovine pericardium to obtain a relatively ideal thickness and expected performance, therefore, the thinned bovine pericardium can be used as the materials of transcatheter aortic valve leaflets.
Animals ; Aortic Valve ; Bioprosthesis ; Cattle ; Elastic Modulus ; Freezing ; Heart Valve Prosthesis ; Nitrogen ; Pericardium ; physiology ; Swine

BACKGROUND: The aim of this study was to analyze the preoperative attributes and clinical impacts of complete pericardiectomy in chronic constrictive pericarditis. METHODS: A total of 26 patients were treated from January 2001 to December 2013. The pericardium was resected as widely as possible. When excessive bleeding or hemodynamic instability occurred intraoperatively, a cardiopulmonary bypass (CPB; n=3, 11.5%) or an apical suction device (n=8, 30.8%) was used. Patients were divided into 2 groups: those who underwent ≥ 80% resection of the pericardium (group A, n=18) and those who underwent <80% resection of the pericardium (group B, n=8). RESULTS: The frequency of CPB use was not significantly different between groups A and B (n=2, 11.1% vs. n=1, 12.5%; p=1.000). However, the apical suction device was more frequently applied in group A than group B (n=8, 30.8% vs. n=0, 0.0%; p=0.031). The postoperative New York Heart Association functional classification improved more in group A (p=0.030). Long-term follow-up echocardiography also showed a lower frequency of unresolved constriction in group A than in group B (n=1, 5.60% vs. n=5, 62.5%; p=0.008). CONCLUSION: Patients with chronic constrictive pericarditis demonstrated symptomatic improvement through complete pericardiectomy. Aggressive resection of the pericardium may correct constrictive physiology and an apical suction device can facilitate the approach to the posterolateral aspect of the left ventricle and atrioventricular groove area without the aid of CPB.
Cardiopulmonary Bypass ; Classification ; Constriction ; Echocardiography ; Follow-Up Studies ; Heart ; Heart Ventricles ; Hemodynamics ; Hemorrhage ; Humans ; Pericardiectomy* ; Pericarditis, Constrictive* ; Pericardium ; Physiology ; Suction*

OBJECTIVETo explore the characteristics of light propagation along the Pericardium Meridian and its surrounding areas at human wrist by using optical experiment and Monte Carlo method.

METHODSAn experiment was carried out to obtain the distribution of diffuse light on Pericardium Meridian line and its surrounding areas at the wrist, and then a simplified model based on the anatomical structure was proposed to simulate the light transportation within the same area by using Monte Carlo method.

RESULTSThe experimental results showed strong accordance with the Monte Carlo simulation that the light propagation along the Pericardium Meridian had an advantage over its surrounding areas at the wrist.

CONCLUSIONThe advantage of light transport along Pericardium Merdian line was related to components and structure of tissue, also the anatomical structure of the area that the Pericardium Meridian line runs.

Diffusion ; Humans ; Light ; Meridians ; Models, Theoretical ; Monte Carlo Method ; Optics and Photonics ; methods ; Pericardium ; physiology ; Wrist ; physiology

OBJECTIVETo observe the effect of acupuncture at the whole points of Hand Jueyin pericardium meridian on the amplitude of low frequency fluctuations (ALFF) of healthy people in resting state (R1) functional magnetic resonance imaging (fMRI).

METHODSTotally 16 healthy subjects received structure scan of T1 and T2. Then two fMRI scans were conducted for each participant. fMRI included the resting-state scan (R1; the scanning time was 8 min 6 s), the stimulating-acupoint scan (AP; the scanning time was 8 min 6 s). fMRI data acquisition from structure scanning and function scanning were processed with format conversion and statistical analysis.

RESULTSUnder R1 state, brain regions with activated ALFF signals included bilateral superior frontal gyrus, medial frontal gyrus, middle occipital gyrus, precuneus, superior temporal gyrus, and cingulate gyrus. Under the AP state, brain regions with activated ALFF signals were bilateral superior frontal gyrus, medial frontal gyrus, middle temporal gyrus, left fusiform gyrus, precuneus, posterior cingulate, and declivis. Compared with R1 state, obvious difference of ALFF signal areas of the brain caused by acupuncture at pericardium were: bilateral cuneus, precuneus, left posterior cingulate gyrus, right middle occipital gyrus, and right occipital lingual gyrus.

CONCLUSIONAcupuncture at the whole points of Hand Jueyin pericardium meridian could significantly change inherent activity states of the cerebral cortex, especially in bilateral superior frontal gyrus, medial frontal gyrus, and precuneus.

Acupuncture ; Acupuncture Points ; Brain ; physiology ; Brain Mapping ; Frontal Lobe ; Humans ; Magnetic Resonance Imaging ; methods ; Pericardium

Adipose Tissue ; physiology ; Humans ; Iran ; Medicine, Traditional ; methods ; Pericardium ; physiology

OBJECTIVETo observe the descending modulation of cardiac nociception by the rostral ventromedial medulla (RVM) in rats.

METHODSA rat model of cardiosomatic motor reflex (CMR) was established by injecting capsaicin into the pericardial sac to induce cardiac nociception, and the electromyogram (EMG) response of the dorsal spinotrapezius muscle was studied. The RVM was electrically stimulated (25, 75 and 100 µA) or destroyed to examine whether RVM exerted descending modulation on cardiac nociception.

RESULTSElectrical stimulation of the RVM at 8 sites produced intensity-dependent inhibition of EMG responses to noxious cardiac stimulus (F[2,21]=43.188, P=0.001). Electrical stimulation at 3 sites caused facilitated EMG responses, but the increased magnitude of the EMG was not dependent on stimulation intensity (F[2,6]=0.884, P=0.461). Stimulation at 11 sites produced biphasic effects: at a low intensity (25 µA), the elicited EMG magnitude was significantly larger than baseline (P<0.05), and at greater intensities (75/100 µA), the stimulation caused suppression of the EMG magnitude to a level significantly lower than the baseline (P<0.05). Electrolytic lesion of the RVM resulted in significantly increased EMG responses compared with the baseline and sham lesion group.

CONCLUSIONCardiac nociception evoked by capsaicin stimulation is subjected to descending biphasic modulation by the RVM, which produces predominantly descending inhibition on heart pain.

Animals ; Capsaicin ; pharmacology ; Electric Stimulation ; Electromyography ; drug effects ; Male ; Medulla Oblongata ; physiology ; Nociception ; Nociceptors ; drug effects ; physiology ; Pain ; physiopathology ; Pericardium ; drug effects ; physiology ; Rats ; Rats, Sprague-Dawley ; Sensory System Agents ; pharmacology

In order to control real-time sampling and achieve smooth scroll wave in the epicardial mapping system, which has 128 channels and a sampling rate of 2kHz/channel, we have designed a user interface using Direct-Draw in cooperation with multiple-thread technology and extracting method. This method has proven to be feasible in animal experiment.
Algorithms ; Animals ; Artificial Intelligence ; Body Surface Potential Mapping ; methods ; Electrophysiologic Techniques, Cardiac ; instrumentation ; methods ; Pericardium ; physiology ; Signal Processing, Computer-Assisted ; instrumentation ; Software

A new denoising method is presented in the paper, based on the independent component analysis(ICA) and the noise independent component selection measurement which is the dispersivity of the independent component's projection coefficients to each electrode. The results indicate that the method can denoise EPM signals with giving prominence to electrodes' true depolarization signals. So it' s fit well for the EPM system.
Electrodes ; Epicardial Mapping ; methods ; Membrane Potentials ; Pericardium ; physiology

To observe the growth of rat bone marrow mesenchymal cells (BMMCs) on decellular bovine pericardia in vitro and to investigate the effect of proteins pre-coating on cells retention and proliferation, bovine pericardia were decellularized using trypsin, DNase and Triton X-100 respectively. Then three proteins (fibronetin (FN), gelatin, collagen I) were coated on the surfaces of the bovine pericardia separately. BMMCs were harvested from rat thighbone marrow , then expanded and seeded onto decellular bovine pericardia with the proteins pre-coated . Decelluar bovine pericardia without coating were used as controls. The retention and growth of BMMSCs were observed by Hochest staining and analyzed by MTT method. It was shown that the retention and proliferation of BMMCs on FN group and gelatin group were significantly enhanced comparing with those on collagen I group and control group (P < 0.001). There was no significant difference between FN group and gelatin group (P > 0.05), nor between collagen I group and control group (P > 0.05). We conclude that the retention and proliferation of seeding cells on FN and gelatin could be significantly improved on decellular bovine pericardia (DBP) but not on collagen I.
Animals ; Bone Marrow Cells ; cytology ; Cattle ; Cells, Cultured ; Collagen Type I ; pharmacology ; Fibronectins ; pharmacology ; Gelatin ; pharmacology ; Mesenchymal Stromal Cells ; cytology ; physiology ; Pericardium ; cytology ; drug effects ; Rats ; Tissue Engineering ; methods ; Tissue Scaffolds