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Brain-derived neurotrophic factor regulates TRPC3/6 channels and protects against myocardial infarction in rodents.

Hang P, Zhao J, Cai B, Tian S, Huang W, Guo J, Sun C, Li Y, Du Z - Int. J. Biol. Sci. (2015)

Bottom Line: Meanwhile, echocardiography indicated that BDNF significantly improved cardiac function of MI mice.Furthermore, protective role of BDNF against hypoxia-induced apoptosis was reversed by 2-APB and TRPC3/6 siRNAs.BDNF/TrkB alleviated cardiac ischemic injury and inhibited cardiomyocytes apoptosis by regulating TRPC3/6 channels, which provides a novel potential therapeutic candidate for MI.

View Article: PubMed Central - PubMed

Affiliation: 1. Institute of Clinical Pharmacology of the Second Affiliated Hospital (Key Laboratory of Drug Research, Heilongjiang Higher Education Institutions), Harbin Medical University, Harbin 150086, China.

ABSTRACT

Background: Brain-derived neurotrophic factor (BDNF) is associated with coronary artery diseases. However, its role and mechanism in myocardial infarction (MI) is not fully understood.

Methods: Wistar rat and Kunming mouse model of MI were induced by the ligation of left coronary artery. Blood samples were collected from MI rats and patients. Plasma BDNF level, protein expression of BDNF, tropomyosin-related kinase B (TrkB) and its downstream transient receptor potential canonical (TRPC)3/6 channels were examined by enzyme-linked immunosorbent assay and Western blot. Infarct size, cardiac function and cardiomyocyte apoptosis were measured after intra-myocardium injection with recombinant human BDNF. Protective role of BDNF against cardiomyocyte apoptosis was confirmed by BDNF scavenger TrkB-Fc. The regulation of TRPC3/6 channels by BDNF was validated by pretreating with TRPC blocker (2-Aminoethyl diphenylborinate, 2-APB) and TRPC3/6 siRNAs.

Results: Circulating BDNF was significantly enhanced in MI rats and patients. Protein expression of BDNF, TrkB and TRPC3/6 channels were upregulated in MI. 3 days post-MI, BDNF treatment markedly reduced the infarct size and serum lactate dehydrogenase activity. Meanwhile, echocardiography indicated that BDNF significantly improved cardiac function of MI mice. Furthermore, BDNF markedly inhibited cardiomyocyte apoptosis by upregulating Bcl-2 expression and downregulating caspase-3 expression and activity in ischemic myocardium. In neonatal rat ventricular myocytes, cell viability was dramatically increased by BDNF in hypoxia, which was restored by TrkB-Fc. Furthermore, protective role of BDNF against hypoxia-induced apoptosis was reversed by 2-APB and TRPC3/6 siRNAs.

Conclusion: BDNF/TrkB alleviated cardiac ischemic injury and inhibited cardiomyocytes apoptosis by regulating TRPC3/6 channels, which provides a novel potential therapeutic candidate for MI.

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Expression of BDNF/TrkB and downstream TRPC3/6 channels. (A) Representative bands of protein expression of proBDNF and mature BDNF by western blot analysis. (B) Representative bands of protein expression of TrkB. (C, D) Representative bands of protein expression of TRPC3 and 6 channels. Values given are normalized to band intensity of GADPH (anti-GAPDH antibody) used as internal control. *p<0.05, **p<0.01 vs. sham, n = 4 rats each group.
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Figure 3: Expression of BDNF/TrkB and downstream TRPC3/6 channels. (A) Representative bands of protein expression of proBDNF and mature BDNF by western blot analysis. (B) Representative bands of protein expression of TrkB. (C, D) Representative bands of protein expression of TRPC3 and 6 channels. Values given are normalized to band intensity of GADPH (anti-GAPDH antibody) used as internal control. *p<0.05, **p<0.01 vs. sham, n = 4 rats each group.

Mentions: It is recognized that 28 kDa Pro-BDNF form is cleaved extracellularly by proteases to generate an active mature 14 kDa BDNF form 25. To evaluate the time course of BDNF expression in the infarcted ventricles at 1, 6 and 24 h post-MI, we used an anti-BDNF antibody that recognizes both the 28 kDa proform and 14 kDa active form of BDNF. We found that both pro-BDNF and mature BDNF expression was upregulated in MI for 1 h and 6 h, and recovered after MI for 24 h (Fig. 3A). In parallel, protein expression of TrkB was also increased in MI for 1 h and 6 h, while reduced in MI for 24 h (Fig. 3B). Consistently, protein levels of TRPC3/6 channels were significantly increased after MI for 1 h and 6 h, then recovered after 24 h (Fig. 3C, D). Thus, these data together supported that BDNF/TrkB/TRPC3/6 axis was upregulated in MI.


Brain-derived neurotrophic factor regulates TRPC3/6 channels and protects against myocardial infarction in rodents.

Hang P, Zhao J, Cai B, Tian S, Huang W, Guo J, Sun C, Li Y, Du Z - Int. J. Biol. Sci. (2015)

Expression of BDNF/TrkB and downstream TRPC3/6 channels. (A) Representative bands of protein expression of proBDNF and mature BDNF by western blot analysis. (B) Representative bands of protein expression of TrkB. (C, D) Representative bands of protein expression of TRPC3 and 6 channels. Values given are normalized to band intensity of GADPH (anti-GAPDH antibody) used as internal control. *p<0.05, **p<0.01 vs. sham, n = 4 rats each group.
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Related In: Results  -  Collection

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Figure 3: Expression of BDNF/TrkB and downstream TRPC3/6 channels. (A) Representative bands of protein expression of proBDNF and mature BDNF by western blot analysis. (B) Representative bands of protein expression of TrkB. (C, D) Representative bands of protein expression of TRPC3 and 6 channels. Values given are normalized to band intensity of GADPH (anti-GAPDH antibody) used as internal control. *p<0.05, **p<0.01 vs. sham, n = 4 rats each group.
Mentions: It is recognized that 28 kDa Pro-BDNF form is cleaved extracellularly by proteases to generate an active mature 14 kDa BDNF form 25. To evaluate the time course of BDNF expression in the infarcted ventricles at 1, 6 and 24 h post-MI, we used an anti-BDNF antibody that recognizes both the 28 kDa proform and 14 kDa active form of BDNF. We found that both pro-BDNF and mature BDNF expression was upregulated in MI for 1 h and 6 h, and recovered after MI for 24 h (Fig. 3A). In parallel, protein expression of TrkB was also increased in MI for 1 h and 6 h, while reduced in MI for 24 h (Fig. 3B). Consistently, protein levels of TRPC3/6 channels were significantly increased after MI for 1 h and 6 h, then recovered after 24 h (Fig. 3C, D). Thus, these data together supported that BDNF/TrkB/TRPC3/6 axis was upregulated in MI.

Bottom Line: Meanwhile, echocardiography indicated that BDNF significantly improved cardiac function of MI mice.Furthermore, protective role of BDNF against hypoxia-induced apoptosis was reversed by 2-APB and TRPC3/6 siRNAs.BDNF/TrkB alleviated cardiac ischemic injury and inhibited cardiomyocytes apoptosis by regulating TRPC3/6 channels, which provides a novel potential therapeutic candidate for MI.

View Article: PubMed Central - PubMed

Affiliation: 1. Institute of Clinical Pharmacology of the Second Affiliated Hospital (Key Laboratory of Drug Research, Heilongjiang Higher Education Institutions), Harbin Medical University, Harbin 150086, China.

ABSTRACT

Background: Brain-derived neurotrophic factor (BDNF) is associated with coronary artery diseases. However, its role and mechanism in myocardial infarction (MI) is not fully understood.

Methods: Wistar rat and Kunming mouse model of MI were induced by the ligation of left coronary artery. Blood samples were collected from MI rats and patients. Plasma BDNF level, protein expression of BDNF, tropomyosin-related kinase B (TrkB) and its downstream transient receptor potential canonical (TRPC)3/6 channels were examined by enzyme-linked immunosorbent assay and Western blot. Infarct size, cardiac function and cardiomyocyte apoptosis were measured after intra-myocardium injection with recombinant human BDNF. Protective role of BDNF against cardiomyocyte apoptosis was confirmed by BDNF scavenger TrkB-Fc. The regulation of TRPC3/6 channels by BDNF was validated by pretreating with TRPC blocker (2-Aminoethyl diphenylborinate, 2-APB) and TRPC3/6 siRNAs.

Results: Circulating BDNF was significantly enhanced in MI rats and patients. Protein expression of BDNF, TrkB and TRPC3/6 channels were upregulated in MI. 3 days post-MI, BDNF treatment markedly reduced the infarct size and serum lactate dehydrogenase activity. Meanwhile, echocardiography indicated that BDNF significantly improved cardiac function of MI mice. Furthermore, BDNF markedly inhibited cardiomyocyte apoptosis by upregulating Bcl-2 expression and downregulating caspase-3 expression and activity in ischemic myocardium. In neonatal rat ventricular myocytes, cell viability was dramatically increased by BDNF in hypoxia, which was restored by TrkB-Fc. Furthermore, protective role of BDNF against hypoxia-induced apoptosis was reversed by 2-APB and TRPC3/6 siRNAs.

Conclusion: BDNF/TrkB alleviated cardiac ischemic injury and inhibited cardiomyocytes apoptosis by regulating TRPC3/6 channels, which provides a novel potential therapeutic candidate for MI.

Show MeSH
Related in: MedlinePlus