Single-cell RNA sequencing of murine hearts for studying the development of the cardiac conduction system

The development of the cardiac conduction system (CCS) is essential for correct heart function. However, critical details on the cell types populating the CCS in the mammalian heart during the development remain to be resolved. Using single-cell RNA sequencing, we generated a large dataset of transcriptomes of ~0.5 million individual cells isolated from murine hearts at six successive developmental corresponding to the early, middle and late stages of heart development. The dataset provides a powerful library for studying the development of the heart's CCS and other cardiac components. Our initial analysis identified distinct cell types between 20 to 26 cell types across different stages, of which ten are involved in forming the CCS. Our dataset allows researchers to reuse the datasets for data mining and a wide range of analyses. Collectively, our data add valuable transcriptomic resources for further study of cardiac development, such as gene expression, transcriptional regulation and functional gene activity in developing hearts, particularly the CCS

A Review of Quadruped Robots: Structure, Control, and Autonomous Motion

With their unique point‐contact ability with the ground and exceptional adaptability to complex terrains, quadruped robots have become a focal point in the fields of automation and robotic engineering. Significant research progress has been made in aspects such as structural design, motion planning, and balance control of these robots. However, a primary challenge in current research lies in further enhancing the dynamic performance, environmental adaptability, and payload capacity. In this article, research achievements in key technical areas of quadruped robots, encompassing structural design, gait planning, traditional control strategies, intelligent control strategies, and autonomous movement, are comprehensively discussed. The focus of the article is on analyzing trends in intelligence and technological innovation within the aforementioned areas, aiming to provide robust theoretical support and forward‐looking technical guidance for quadruped robots research. Additionally, it offers valuable references for scholars engaged in this field

Single-cell RNA sequencing of murine hearts for studying the development of the cardiac conduction system

Abstract The development of the cardiac conduction system (CCS) is essential for correct heart function. However, critical details on the cell types populating the CCS in the mammalian heart during the development remain to be resolved. Using single-cell RNA sequencing, we generated a large dataset of transcriptomes of ~0.5 million individual cells isolated from murine hearts at six successive developmental corresponding to the early, middle and late stages of heart development. The dataset provides a powerful library for studying the development of the heart’s CCS and other cardiac components. Our initial analysis identified distinct cell types between 20 to 26 cell types across different stages, of which ten are involved in forming the CCS. Our dataset allows researchers to reuse the datasets for data mining and a wide range of analyses. Collectively, our data add valuable transcriptomic resources for further study of cardiac development, such as gene expression, transcriptional regulation and functional gene activity in developing hearts, particularly the CCS

ZL-mediated alleviation of MI/RI by inhibiting ferroptosis.

(A-E) The expression of Fe2+, ROS, MDA, SOD, and GSH were quantified (n = 4). (F-G) The expression of GPX4 and ACSL4 was detected by real-time quantitative polymerase chain reaction in cardiac tissue (n = 3). (H-J) The expression of GPX4 and ACSL4 was detected by western blot in cardiac tissue (n = 3). Data are shown as means ± S.E.D. **p < 0.01, *p < 0.05.</p

ZL promotion of Nrf2 expression and activation of the HO-1/GPX4 axis during MI/RI.

(A-C) Immunofluorescent staining visualized the expression of Nrf2 (green), HO-1 (red), and nuclei (blue) in myocardial tissues. Scale bars: 20 μm. Images captured at × 400 magnification. (D, E) RT-qPCR assessed the expression of Nrf2 and HO-1 in cardiac tissue. (F-H) The expression of Nrf2 and HO-1 was detected by western blot in cardiac tissue. Data are shown as means ± S.E.D (n = 3). **p < 0.01, *p < 0.05.</p

ZL protects mice from MI/RI.

(A-C) Left ventricular ejection fraction (EF, %) and shortening fraction (FS, %) in mice were assessed by cardiac ultrasound (n = 4). (D, E) LDH and CK-MB activities were detected by enzyme-linked immunosorbent assay in serum (n = 4). (F) Histopathological pictures of heart tissue sections were stained with H&E. Scale bars represent 20 μm. (G, I) Representative images of infarct size were detected using TTC staining (n = 3). Data are shown as means ± S.E.D. **p < 0.01, *p < 0.05.</p

S1_raw_images.

IntroductionZhilong Huoxue Tongyu Capsule (ZL) is a Chinese medicine used for the treatment of cardio-cerebral diseases. However, the pharmacological mechanisms underlying its regulation of myocardial ischemia/reperfusion injury (MI/RI) remain unclear.PurposeThis study aims to investigate the effects and mechanisms of ZL on MI/RI in mice.Materials and methodsC57BL/6J mice were randomly assigned to four groups: Sham group, I/R group, ZL group, and ZLY group. The MI/RI mouse model was established by ligation of the left anterior descending coronary artery for 30 minutes, followed by reperfusion for 120 minutes to restore blood perfusion. Cardiac function was evaluated using cardiac ultrasound. Histopathological changes and myocardial infarction area were assessed using Hematoxylin and eosin (H&E) staining and triphenyltetrazolium chloride (TTC) staining. The changes in oxidative stress- and ferroptosis-related markers were detected. RT-qPCR, Western blot, and ELISA were conducted to further explore the mechanism of ZL in improving MI/RI.ResultsOur findings demonstrated that ZL exerted a protective effect against MI/RI by inhibiting ferroptosis, evidenced by the upregulation of antioxidant enzymes such as GSH and GPX4, coupled with the downregulation of ACSL4, a pro-ferroptosis factor. Furthermore, ZL positively impacted the PI3K/AKT/Nrf2 pathway by promoting ATPase activities and enhancing the relative protein expression of its components. Notably, the administration of a PI3K/AKT inhibitor reversed the antioxidant and anti-ferroptosis effects of ZL to some extent, suggesting a potential role for this pathway in mediating ZL’s protective effects.ConclusionsZL protects against MI/RI-induced ferroptosis by modulating the PI3K/AKT signaling pathway, leading to increased Nrf2 expression and activation of the HO-1/GPX4 pathway. These findings shed light on the potential therapeutic mechanisms of ZL in the context of cardiovascular diseases.</div

ZL-promoted Nrf2 upregulation was mediated by the PI3K/AKT pathway.

(A-C) The expression of p-PI3K and p-AKT in myocardial tissue was detected by immunohistochemistry. Scale bars represent 20 μm. Images were captured at × 400 magnification. (D-F) The expression of p-PI3K and p-AKT was detected by western blot in cardiac tissue. Data are shown as means ± S.E.D (n = 3). **p < 0.01, *p < 0.05.</p

Material and reagents.

IntroductionZhilong Huoxue Tongyu Capsule (ZL) is a Chinese medicine used for the treatment of cardio-cerebral diseases. However, the pharmacological mechanisms underlying its regulation of myocardial ischemia/reperfusion injury (MI/RI) remain unclear.PurposeThis study aims to investigate the effects and mechanisms of ZL on MI/RI in mice.Materials and methodsC57BL/6J mice were randomly assigned to four groups: Sham group, I/R group, ZL group, and ZLY group. The MI/RI mouse model was established by ligation of the left anterior descending coronary artery for 30 minutes, followed by reperfusion for 120 minutes to restore blood perfusion. Cardiac function was evaluated using cardiac ultrasound. Histopathological changes and myocardial infarction area were assessed using Hematoxylin and eosin (H&E) staining and triphenyltetrazolium chloride (TTC) staining. The changes in oxidative stress- and ferroptosis-related markers were detected. RT-qPCR, Western blot, and ELISA were conducted to further explore the mechanism of ZL in improving MI/RI.ResultsOur findings demonstrated that ZL exerted a protective effect against MI/RI by inhibiting ferroptosis, evidenced by the upregulation of antioxidant enzymes such as GSH and GPX4, coupled with the downregulation of ACSL4, a pro-ferroptosis factor. Furthermore, ZL positively impacted the PI3K/AKT/Nrf2 pathway by promoting ATPase activities and enhancing the relative protein expression of its components. Notably, the administration of a PI3K/AKT inhibitor reversed the antioxidant and anti-ferroptosis effects of ZL to some extent, suggesting a potential role for this pathway in mediating ZL’s protective effects.ConclusionsZL protects against MI/RI-induced ferroptosis by modulating the PI3K/AKT signaling pathway, leading to increased Nrf2 expression and activation of the HO-1/GPX4 pathway. These findings shed light on the potential therapeutic mechanisms of ZL in the context of cardiovascular diseases.</div