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Profilin modulates sarcomeric organization and mediates cardiomyocyte hypertrophy.

Kooij V, Viswanathan MC, Lee DI, Rainer PP, Schmidt W, Kronert WA, Harding SE, Kass DA, Bernstein SI, Van Eyk JE, Cammarato A - Cardiovasc. Res. (2016)

Bottom Line: Mechanistically, we found that profilin-1 regulates hypertrophy, in part, through activation of the ERK1/2 signalling cascade.Elevated profilin levels resulted in elongated sarcomeres, myofibrillar disorganization, and sarcomeric disarray, which correlated with impaired muscle function.Our results identify novel roles for profilin as an important mediator of cardiomyocyte hypertrophy.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, USA National Heart and Lung Institute, Imperial College London, 4th floor, ICTEM, Hammersmith Campus, Du Cane Road, London W12 0NN, UK v.kooij@imperial.ac.uk.

No MeSH data available.


Related in: MedlinePlus

Silencing of Pfn1 attenuates hypertrophic signalling in NRVMs. (A) Representative confocal images of control and PE-stimulated NRVMs. NRVMs were treated with control siRNA or Pfn1 siRNA. Nuclei were stained with DAPI (blue). Profilin-1 was dramatically reduced in response to Pfn1 siRNA. Scale bar, 10 μm. (B) Western blot analysis showed significantly decreased profilin-1 levels after the treatment of NRVMs with Pfn1 siRNA (n = 3, ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). (C) Transcript levels of Pfn1 in PE-stimulated NRVMs were increased compared with control, and treatment with Pfn1 siRNA significantly reduced mRNA levels (n = 4, *P < 0.05, **P < 0.01, and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). Cell surface area increased significantly upon treatment with PE and was diminished upon profilin-1 silencing (n = 20–29, *P < 0.05 and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). Transcription of the hypertrophic markers ANP, BNP, and skeletal muscle actin was significantly reduced after Pfn1 silencing in PE treated cells (n = 4, *P < 0.05, **P < 0.01, and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). (D) NRVMs that were treated with Pfn1 siRNA and stimulated with ET1 exhibited significantly reduced ANP, BNP, and skeletal α-actin mRNA levels compared with control siRNA-treated cells (n = 3, *P < 0.05, **P < 0.01, and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test).
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CVW050F6: Silencing of Pfn1 attenuates hypertrophic signalling in NRVMs. (A) Representative confocal images of control and PE-stimulated NRVMs. NRVMs were treated with control siRNA or Pfn1 siRNA. Nuclei were stained with DAPI (blue). Profilin-1 was dramatically reduced in response to Pfn1 siRNA. Scale bar, 10 μm. (B) Western blot analysis showed significantly decreased profilin-1 levels after the treatment of NRVMs with Pfn1 siRNA (n = 3, ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). (C) Transcript levels of Pfn1 in PE-stimulated NRVMs were increased compared with control, and treatment with Pfn1 siRNA significantly reduced mRNA levels (n = 4, *P < 0.05, **P < 0.01, and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). Cell surface area increased significantly upon treatment with PE and was diminished upon profilin-1 silencing (n = 20–29, *P < 0.05 and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). Transcription of the hypertrophic markers ANP, BNP, and skeletal muscle actin was significantly reduced after Pfn1 silencing in PE treated cells (n = 4, *P < 0.05, **P < 0.01, and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). (D) NRVMs that were treated with Pfn1 siRNA and stimulated with ET1 exhibited significantly reduced ANP, BNP, and skeletal α-actin mRNA levels compared with control siRNA-treated cells (n = 3, *P < 0.05, **P < 0.01, and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test).

Mentions: Profilin-1 protein and mRNA levels are increased compared to appropriate controls following TAC, in Gαq-overexpressing mouse hearts, and in PE/ET1-stimulated NRVMs, respectively (Figure 1A–C). Likewise, when overexpressed exclusively in Drosophila cardiomyocytes, profilin promoted eccentric hypertrophy (Figure 2). To further test if increased profilin-1 is vital to the cardiac hypertrophic response, we expressed Pfn1 siRNA in NRVMs and subsequently exposed the cells to PE or ET1. siRNA-directed Pfn1 silencing was confirmed by confocal microscopy (Figure 6A) and western blot analysis (Figure 6B). In addition, reduced and elevated Pfn1 mRNA levels verified the cellular responses to Pfn1 siRNA and post PE treatment, respectively (Figure 6C). PE resulted in significantly larger cells (3372 ± 266 µm2, n = 20) compared with control (1790 ± 138 µm2, n = 26; Figure 6C). Myocytes treated with Pfn1 siRNA and then PE had an increased surface area/size (2308 ± 135 µm2, n = 21) compared with unstimulated Pfn1 siRNA cells (1668 ± 122 µm2, n = 29). However, they were significantly smaller than PE-stimulated controls (3372 ± 266 µm2, n = 20). Moreover, ANP, BNP, and skeletal muscle actin were significantly decreased in cells treated with Pfn1 siRNA followed by PE stimulation compared with control cells. These findings were corroborated using ET1 stimulation of NRVMs in conjunction with Pfn1 silencing (Figure 6D). Our results indicate that profilin-1 contributes to hypertrophy-induced cell growth.Figure 6


Profilin modulates sarcomeric organization and mediates cardiomyocyte hypertrophy.

Kooij V, Viswanathan MC, Lee DI, Rainer PP, Schmidt W, Kronert WA, Harding SE, Kass DA, Bernstein SI, Van Eyk JE, Cammarato A - Cardiovasc. Res. (2016)

Silencing of Pfn1 attenuates hypertrophic signalling in NRVMs. (A) Representative confocal images of control and PE-stimulated NRVMs. NRVMs were treated with control siRNA or Pfn1 siRNA. Nuclei were stained with DAPI (blue). Profilin-1 was dramatically reduced in response to Pfn1 siRNA. Scale bar, 10 μm. (B) Western blot analysis showed significantly decreased profilin-1 levels after the treatment of NRVMs with Pfn1 siRNA (n = 3, ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). (C) Transcript levels of Pfn1 in PE-stimulated NRVMs were increased compared with control, and treatment with Pfn1 siRNA significantly reduced mRNA levels (n = 4, *P < 0.05, **P < 0.01, and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). Cell surface area increased significantly upon treatment with PE and was diminished upon profilin-1 silencing (n = 20–29, *P < 0.05 and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). Transcription of the hypertrophic markers ANP, BNP, and skeletal muscle actin was significantly reduced after Pfn1 silencing in PE treated cells (n = 4, *P < 0.05, **P < 0.01, and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). (D) NRVMs that were treated with Pfn1 siRNA and stimulated with ET1 exhibited significantly reduced ANP, BNP, and skeletal α-actin mRNA levels compared with control siRNA-treated cells (n = 3, *P < 0.05, **P < 0.01, and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test).
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CVW050F6: Silencing of Pfn1 attenuates hypertrophic signalling in NRVMs. (A) Representative confocal images of control and PE-stimulated NRVMs. NRVMs were treated with control siRNA or Pfn1 siRNA. Nuclei were stained with DAPI (blue). Profilin-1 was dramatically reduced in response to Pfn1 siRNA. Scale bar, 10 μm. (B) Western blot analysis showed significantly decreased profilin-1 levels after the treatment of NRVMs with Pfn1 siRNA (n = 3, ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). (C) Transcript levels of Pfn1 in PE-stimulated NRVMs were increased compared with control, and treatment with Pfn1 siRNA significantly reduced mRNA levels (n = 4, *P < 0.05, **P < 0.01, and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). Cell surface area increased significantly upon treatment with PE and was diminished upon profilin-1 silencing (n = 20–29, *P < 0.05 and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). Transcription of the hypertrophic markers ANP, BNP, and skeletal muscle actin was significantly reduced after Pfn1 silencing in PE treated cells (n = 4, *P < 0.05, **P < 0.01, and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test). (D) NRVMs that were treated with Pfn1 siRNA and stimulated with ET1 exhibited significantly reduced ANP, BNP, and skeletal α-actin mRNA levels compared with control siRNA-treated cells (n = 3, *P < 0.05, **P < 0.01, and ***P < 0.001; two-way ANOVA with the Bonferroni post hoc test).
Mentions: Profilin-1 protein and mRNA levels are increased compared to appropriate controls following TAC, in Gαq-overexpressing mouse hearts, and in PE/ET1-stimulated NRVMs, respectively (Figure 1A–C). Likewise, when overexpressed exclusively in Drosophila cardiomyocytes, profilin promoted eccentric hypertrophy (Figure 2). To further test if increased profilin-1 is vital to the cardiac hypertrophic response, we expressed Pfn1 siRNA in NRVMs and subsequently exposed the cells to PE or ET1. siRNA-directed Pfn1 silencing was confirmed by confocal microscopy (Figure 6A) and western blot analysis (Figure 6B). In addition, reduced and elevated Pfn1 mRNA levels verified the cellular responses to Pfn1 siRNA and post PE treatment, respectively (Figure 6C). PE resulted in significantly larger cells (3372 ± 266 µm2, n = 20) compared with control (1790 ± 138 µm2, n = 26; Figure 6C). Myocytes treated with Pfn1 siRNA and then PE had an increased surface area/size (2308 ± 135 µm2, n = 21) compared with unstimulated Pfn1 siRNA cells (1668 ± 122 µm2, n = 29). However, they were significantly smaller than PE-stimulated controls (3372 ± 266 µm2, n = 20). Moreover, ANP, BNP, and skeletal muscle actin were significantly decreased in cells treated with Pfn1 siRNA followed by PE stimulation compared with control cells. These findings were corroborated using ET1 stimulation of NRVMs in conjunction with Pfn1 silencing (Figure 6D). Our results indicate that profilin-1 contributes to hypertrophy-induced cell growth.Figure 6

Bottom Line: Mechanistically, we found that profilin-1 regulates hypertrophy, in part, through activation of the ERK1/2 signalling cascade.Elevated profilin levels resulted in elongated sarcomeres, myofibrillar disorganization, and sarcomeric disarray, which correlated with impaired muscle function.Our results identify novel roles for profilin as an important mediator of cardiomyocyte hypertrophy.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Division of Cardiology, The Johns Hopkins University, Baltimore, MD, USA National Heart and Lung Institute, Imperial College London, 4th floor, ICTEM, Hammersmith Campus, Du Cane Road, London W12 0NN, UK v.kooij@imperial.ac.uk.

No MeSH data available.


Related in: MedlinePlus