BMAL1 regulates mitochondrial fission and mitophagy through mitochondrial protein BNIP3 and is critical in the development of dilated cardiomyopathy

Dysregulation of circadian rhythms associates with cardiovascular disorders. It is known that deletion of the core circadian gene Bmal1 in mice causes dilated cardiomyopathy. However, the biological rhythm regulation system in mouse is very different from that of humans. Whether BMAL1 plays a role in regulating human heart function remains unclear. Here we generated a BMAL1 knockout human embryonic stem cell (hESC) model and further derived human BMAL1 deficient cardiomyocytes. We show that BMAL1 deficient hESC-derived cardiomyocytes exhibited typical phenotypes of dilated cardiomyopathy including attenuated contractility, calcium dysregulation, and disorganized myofilaments. In addition, mitochondrial fission and mitophagy were suppressed in BMAL1 deficient hESC-cardiomyocytes, which resulted in significantly attenuated mitochondrial oxidative phosphorylation and compromised cardiomyocyte function. We also found that BMAL1 binds to the E-box element in the promoter region of BNIP3 gene and specifically controls BNIP3 protein expression. BMAL1 knockout directly reduced BNIP3 protein level, causing compromised mitophagy and mitochondria dysfunction and thereby leading to compromised cardiomyocyte function. Our data indicated that the core circadian gene BMAL1 is critical for normal mitochondria activities and cardiac function. Circadian rhythm disruption may directly link to compromised heart function and dilated cardiomyopathy in humans.

BMAL1 regulates mitochondrial fission and mitophagy through mitochondrial protein BNIP3 and is critical in the development of dilated cardiomyopathy

Dysregulation of circadian rhythms associates with cardiovascular disorders. It is known that deletion of the core circadian gene Bmal1 in mice causes dilated cardiomyopathy. However, the biological rhythm regulation system in mouse is very different from that of humans. Whether BMAL1 plays a role in regulating human heart function remains unclear. Here we generated a BMAL1 knockout human embryonic stem cell (hESC) model and further derived human BMAL1 deficient cardiomyocytes. We show that BMAL1 deficient hESC-derived cardiomyocytes exhibited typical phenotypes of dilated cardiomyopathy including attenuated contractility, calcium dysregulation, and disorganized myofilaments. In addition, mitochondrial fission and mitophagy were suppressed in BMAL1 deficient hESC-cardiomyocytes, which resulted in significantly attenuated mitochondrial oxidative phosphorylation and compromised cardiomyocyte function. We also found that BMAL1 binds to the E-box element in the promoter region of BNIP3 gene and specifically controls BNIP3 protein expression. BMAL1 knockout directly reduced BNIP3 protein level, causing compromised mitophagy and mitochondria dysfunction and thereby leading to compromised cardiomyocyte function. Our data indicated that the core circadian gene BMAL1 is critical for normal mitochondria activities and cardiac function. Circadian rhythm disruption may directly link to compromised heart function and dilated cardiomyopathy in humans.

BMAL1 regulates mitochondrial fission and mitophagy through mitochondrial protein BNIP3 and is critical in the development of dilated cardiomyopathy

Dysregulation of circadian rhythms associates with cardiovascular disorders. It is known that deletion of the core circadian gene Bmal1 in mice causes dilated cardiomyopathy. However, the biological rhythm regulation system in mouse is very different from that of humans. Whether BMAL1 plays a role in regulating human heart function remains unclear. Here we generated a BMAL1 knockout human embryonic stem cell (hESC) model and further derived human BMAL1 deficient cardiomyocytes. We show that BMAL1 deficient hESC-derived cardiomyocytes exhibited typical phenotypes of dilated cardiomyopathy including attenuated contractility, calcium dysregulation, and disorganized myofilaments. In addition, mitochondrial fission and mitophagy were suppressed in BMAL1 deficient hESC-cardiomyocytes, which resulted in significantly attenuated mitochondrial oxidative phosphorylation and compromised cardiomyocyte function. We also found that BMAL1 binds to the E-box element in the promoter region of BNIP3 gene and specifically controls BNIP3 protein expression. BMAL1 knockout directly reduced BNIP3 protein level, causing compromised mitophagy and mitochondria dysfunction and thereby leading to compromised cardiomyocyte function. Our data indicated that the core circadian gene BMAL1 is critical for normal mitochondria activities and cardiac function. Circadian rhythm disruption may directly link to compromised heart function and dilated cardiomyopathy in humans.

Practice of and reflection on online medical education during COVID-19 epidemic / 中华医学教育探索杂志

This paper introduces various measures of actively developing online teaching in Shanghai Medical College of Fudan University, on the basis of in-depth analysis of the development trend of educational informatization and the large-scale online teaching in China during the COVID-19 epidemic. According to the requirement of Ministry of Education —— "Suspended Class, Ongoing Learning", our university has actively carried out online teaching, promoted the multi-platform blended online teaching, established a quality assurance system with multi-role linkage and regular feedback, focused on improving ideological and political education efficiency of online courses at the same time. By analyzing the characteristics of medical education, together with the benefits and limitations of online medical teaching, this paper demonstrates the application and development of online teaching resources and platforms in medical education, and looks into the future of online medical education as well.

Role of circadian gene Clock during differentiation of mouse pluripotent stem cells

Biological rhythms controlled by the circadian clock are absent in embryonic stem cells (ESCs). However, they start to develop during the differentiation of pluripotent ESCs to downstream cells. Conversely, biological rhythms in adult somatic cells disappear when they are reprogrammed into induced pluripotent stem cells (iPSCs). These studies indicated that the development of biological rhythms in ESCs might be closely associated with the maintenance and differentiation of ESCs. The core circadian gene Clock is essential for regulation of biological rhythms. Its role in the development of biological rhythms of ESCs is totally unknown. Here, we used CRISPR/CAS9-mediated genetic editing techniques, to completely knock out the Clock expression in mouse ESCs. By AP, teratoma formation, quantitative real-time PCR and Immunofluorescent staining, we did not find any difference between Clock knockout mESCs and wild type mESCs in morphology and pluripotent capability under the pluripotent state. In brief, these data indicated Clock did not influence the maintaining of pluripotent state. However, they exhibited decreased proliferation and increased apoptosis. Furthermore, the biological rhythms failed to develop in Clock knockout mESCs after spontaneous differentiation, which indicated that there was no compensational factor in most peripheral tissues as described in mice models before (DeBruyne et al., 2007b). After spontaneous differentiation, loss of CLOCK protein due to Clock gene silencing induced spontaneous differentiation of mESCs, indicating an exit from the pluripotent state, or its differentiating ability. Our findings indicate that the core circadian gene Clock may be essential during normal mESCs differentiation by regulating mESCs proliferation, apoptosis and activity.

The roles of Mesp family proteins: functional diversity and redundancy in differentiation of pluripotent stem cells and mammalian mesodermal development

Mesp family proteins comprise two members named mesodermal posterior 1 (Mesp1) and mesodermal posterior 2 (Mesp2). Both Mesp1 and Mesp2 are transcription factors and they share an almost identical basic helix-loop-helix motif. They have been shown to play critical regulating roles in mammalian heart and somite development. Mesp1 sits in the core of the complicated regulatory network for generation of cardiovascular progenitors while Mesp2 is central for somitogenesis. Here we summarize the similarities and differences in their molecular functions during mammalian early mesodermal development and discuss possible future research directions for further study of the functions of Mesp1 and Mesp2. A comprehensive knowledge of molecular functions of Mesp family proteins will eventually help us better understand mammalian heart development and somitogenesis as well as improve the production of specific cell types from pluripotent stem cells for future regenerative therapies.

Development of major of basic medical science and reflection on the talents cultivation / 中华医学教育探索杂志

Aiming at the cultivation of basic medical science talents, the paper introduced and summarized the background, characteristics and development trends (expand of the team, de-crease of the schooling and increase of the interdisciplinary course) of basic medical science major. Three cultivation models of this major in China were introduced and discussed in the article.

Focus on the Establishment of Communist Among Student,Promote the Cultivation of Medical Calibers / 中华医学教育探索杂志

Development of communist party among the students in the universities plays an important role through out the university educational process.Soundly based on the development of advancement of communist party and the party's self-further organization;with laying the stress on the inproving of the technical & moral standard of each party member,Fu Dan University Shanghai Medical College entirely improved the quality of the education on medical calibers through the means of closely connecting the activites of party establishment among the students and the cultivation of medical elite at the same time,which was guaranteed by the system building up through out the process of carrying out of the various activities.

Dual- direction effect of crenulatin on apoptosis of cerebral microvascular endothelial cells and it's mechanism / 中国病理生理杂志

AIM: To study the effect and the mechanism of crenulatin, an effective constituent of Chinese traditional medicine, on apoptosis of cerebral microvascular endothelial cells. METHODS: The following terminal concentrations of crenulatin were used in the study: 25 mg/L and 100 mg/L. Apoptosis of mouse cerebral microvascular endothelial cells (bEnd. 3 cell line) was evaluated by flow cytometer, immunocytochemical assay (Fas, Bcl - 2) and Western blotting (caspase - 3) after culture for 24 h. RESULTS: Compared with control group, apoptosis of bEnd. 3 cells in 25 mg/L group was significantly inhibited ( P ＜0.05), but apoptosis in the 100 mg/L group was significantly increased (P ＜ 0.05). In apoptosis inhibited group, the Fas immunocytochemical staining was weaker, the positive cells were significantly decreased ( P ＜ 0.05) and caspase - 3 expression was decreased compared with control group; however, the Bcl - 2 staining was stronger and the positive cells were significantly increased ( P ＜ 0.05). On the other hand, in apoptosis increased group ( 100 mg/L group), the changes were just opposite. CONCLUSIONS: The effect of crenulatin on apoptosis of mouse cerebral microvascular endothelial cells possesses a dual - direction change, inhibitive effect in 25 mg/L and stimulative effect in 100 mg/L group, respectively. The mechanism is related to the alterations of Fas/Bcl - 2 expression and caspase - 3 activity.

Dual-direction effect of crenulatin on apoptosis of cerebral microvascular endothelial cells and it's mechanism / 中国病理生理杂志

] AIM: To study the effect and the mechanism of crenulatin, an effective constituent of Chinese traditional medicine, on apoptosis of cerebral microvascular endothelial cells. METHODS: The following terminal concentrations of crenulatin were used in the study: 25 mg/L and 100 mg/L. Apoptosis of mouse cerebral microvascular endothelial cells (bEnd.3 cell line) was evaluated by flow cytometer, immunocytochemical assay (Fas, Bcl-2) and Western blotting (caspase-3) after culture for 24 h. RESULTS: Compared with control group, apoptosis of bEnd.3 cells in 25 mg/L group was significantly inhibited (P

Role of protein kinase B in tryptase-induced gene expression / 中国病理生理杂志

AIM: To study the role of protein kinase B (PKB) in tryptase-induced gene expression on ECV304 cells. METHODS: The expression of PKB, transcript factor AP-1 and NF-?B P65, IL-8, JNK, p38MAPK, and the activity of PKB were measured using RT-PCR and Western blotting. RESULTS: Tryptase at concentration of 1 ?g/L increased the activity of PKB by promoting PKB phosphorylation, promoted the expression of PKB, chemokine IL-8, transcription factor AP-1 and NF-?B P65, however, no changes of JNK and p38MAPK was observed. PI3K specific inhibitor (LY294002) abolished the augment of PKB, NF-?B P65 and IL-8 expression. Antisense PKB cDNA transfection also abolished the augment of PKB, AP-1, NF-?B P65 and IL-8 expression. Though PAR2 antibody did not inhibit PKB expression, it did inhibit the phosphorylation by tryptase in ECV304 cells. CONCLUSION: These results indicate that tryptase can activate PKB through PAR2 receptor and subsequently NF-?B, AP1, IL-8 and PKB expression.

Relationship between the phospholipid content of BALL and lamellar body in septic rats / 中国病理生理杂志

The phospholipid content in BALL markedly increased (P0.01) in septic rats induced by cecal ligation plus punctures as compared with non-septic control. Meanwhile, the lamellar inclusion bodies in type Ⅱ alveolar epithelial cells were empty observed in electro-microscopic examination. Authors suggest that the changes mentioned above is a compensatory response related to stress in early stage of sepsis.