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F‑actin cytoskeleton reorganization is associated with hepatic stellate cell activation.

Cui X, Zhang X, Yin Q, Meng A, Su S, Jing X, Li H, Guan X, Li X, Liu S, Cheng M - Mol Med Rep (2014)

Bottom Line: Treatment with Jas resulted in thick actin bundles and a patchy appearance in the cytoplasm in HSC-T6 cells.Furthermore, the activation of HSC-T6 cells induced by the reorganization of the actin cytoskeleton was associated with the p38 mitogen-activated protein kinase (p38 MAPK) pathway.In conclusion, the present study suggests that the reorganization of the F-actin cytoskeleton is associated with HSC activation and that the p38 MAPK pathway is involved in this process.

View Article: PubMed Central - PubMed

Affiliation: Medical Research Center, Weifang Medical University, Weifang, Shandong 261053, P.R. China.

ABSTRACT
The activation of hepatic stellate cells (HSCs) is involved in the development of hepatic fibrosis. Previous studies have indicated that the acquisition of certain properties by activated HSCs is highly dependent on the reorganization of the actin cytoskeleton. However, direct evidence showing that the reorganization of the actin cytoskeleton is responsible for HSC activation is lacking. The aim of the present study was to investigate the role of cytoskeletal reorganization during HSC activation and to clarify the underlying mechanism. HSC-T6 cells were treated either with the F-actin stabilizer jasplakinolide (Jas) or the depolymerizer cytochalasin D (Cyto D). The actin cytoskeleton was evaluated via assessment of stress fiber formation. Furthermore, the activation properties of HSCs, including proliferation, adhesion, migration and the expression of α-smooth muscle actin (α-SMA) and collagen 1, were investigated in vitro. The results showed that Jas and Cyto D affected the actin distribution in HSC-T6 cells. Treatment with Jas resulted in thick actin bundles and a patchy appearance in the cytoplasm in HSC-T6 cells. In parallel, polymerization of actin microfilaments induced by Jas upregulated the expression of α-SMA and collagen 1, and also enhanced the migration and adhesion properties of HSC-T6 cells. Furthermore, the activation of HSC-T6 cells induced by the reorganization of the actin cytoskeleton was associated with the p38 mitogen-activated protein kinase (p38 MAPK) pathway. In conclusion, the present study suggests that the reorganization of the F-actin cytoskeleton is associated with HSC activation and that the p38 MAPK pathway is involved in this process. The inhibition of F-actin reorganization may thus be a potential key factor or molecular target for the control of liver fibrosis or cirrhosis.

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Effect of the actin cytoskeleton reorganization induced by Jas or Cyto D on the activation of HSC-T6 cells. (A) HSC-T6 cells were treated with dimethylsulfoxide, Jas or Cyto D, respectively. The gene expression of α-SMA and collagen type 1 was assessed by the quantitative polymerase chain reaction. Data were analyzed using the 2−ΔΔCt method. (B) The protein expression of α-SMA and collagen type 1 was assessed by western blot analysis. Following treatment, cell lysates were resolved using 12% SDS-PAGE, followed by transfer to a polyvinylidene fluoride membrane. Western blot analysis was performed with specific antibodies and each band was detected using enhanced chemoluminescence reagent. Data are expressed as the mean ± standard error of five experiments. *P<0.05. α-SMA, α-smooth muscle actin; IOD, integrated optical density; Cyto D, cytochalasin D; Jas, jasplakinolide.
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f3-mmr-09-05-1641: Effect of the actin cytoskeleton reorganization induced by Jas or Cyto D on the activation of HSC-T6 cells. (A) HSC-T6 cells were treated with dimethylsulfoxide, Jas or Cyto D, respectively. The gene expression of α-SMA and collagen type 1 was assessed by the quantitative polymerase chain reaction. Data were analyzed using the 2−ΔΔCt method. (B) The protein expression of α-SMA and collagen type 1 was assessed by western blot analysis. Following treatment, cell lysates were resolved using 12% SDS-PAGE, followed by transfer to a polyvinylidene fluoride membrane. Western blot analysis was performed with specific antibodies and each band was detected using enhanced chemoluminescence reagent. Data are expressed as the mean ± standard error of five experiments. *P<0.05. α-SMA, α-smooth muscle actin; IOD, integrated optical density; Cyto D, cytochalasin D; Jas, jasplakinolide.

Mentions: Increased expression levels of α-SMA and collagen type 1 are considered to be the major markers of HSC activation (12,13). Compared with the control group, treatment with Jas increased the mRNA levels of α-SMA and collagen type 1. By contrast, the gene expression of α-SMA in the Cyto D-treated group was lower than that in the control group (Fig. 3A). Similar results were obtained for the protein levels (Fig. 3B).


F‑actin cytoskeleton reorganization is associated with hepatic stellate cell activation.

Cui X, Zhang X, Yin Q, Meng A, Su S, Jing X, Li H, Guan X, Li X, Liu S, Cheng M - Mol Med Rep (2014)

Effect of the actin cytoskeleton reorganization induced by Jas or Cyto D on the activation of HSC-T6 cells. (A) HSC-T6 cells were treated with dimethylsulfoxide, Jas or Cyto D, respectively. The gene expression of α-SMA and collagen type 1 was assessed by the quantitative polymerase chain reaction. Data were analyzed using the 2−ΔΔCt method. (B) The protein expression of α-SMA and collagen type 1 was assessed by western blot analysis. Following treatment, cell lysates were resolved using 12% SDS-PAGE, followed by transfer to a polyvinylidene fluoride membrane. Western blot analysis was performed with specific antibodies and each band was detected using enhanced chemoluminescence reagent. Data are expressed as the mean ± standard error of five experiments. *P<0.05. α-SMA, α-smooth muscle actin; IOD, integrated optical density; Cyto D, cytochalasin D; Jas, jasplakinolide.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4020483&req=5

f3-mmr-09-05-1641: Effect of the actin cytoskeleton reorganization induced by Jas or Cyto D on the activation of HSC-T6 cells. (A) HSC-T6 cells were treated with dimethylsulfoxide, Jas or Cyto D, respectively. The gene expression of α-SMA and collagen type 1 was assessed by the quantitative polymerase chain reaction. Data were analyzed using the 2−ΔΔCt method. (B) The protein expression of α-SMA and collagen type 1 was assessed by western blot analysis. Following treatment, cell lysates were resolved using 12% SDS-PAGE, followed by transfer to a polyvinylidene fluoride membrane. Western blot analysis was performed with specific antibodies and each band was detected using enhanced chemoluminescence reagent. Data are expressed as the mean ± standard error of five experiments. *P<0.05. α-SMA, α-smooth muscle actin; IOD, integrated optical density; Cyto D, cytochalasin D; Jas, jasplakinolide.
Mentions: Increased expression levels of α-SMA and collagen type 1 are considered to be the major markers of HSC activation (12,13). Compared with the control group, treatment with Jas increased the mRNA levels of α-SMA and collagen type 1. By contrast, the gene expression of α-SMA in the Cyto D-treated group was lower than that in the control group (Fig. 3A). Similar results were obtained for the protein levels (Fig. 3B).

Bottom Line: Treatment with Jas resulted in thick actin bundles and a patchy appearance in the cytoplasm in HSC-T6 cells.Furthermore, the activation of HSC-T6 cells induced by the reorganization of the actin cytoskeleton was associated with the p38 mitogen-activated protein kinase (p38 MAPK) pathway.In conclusion, the present study suggests that the reorganization of the F-actin cytoskeleton is associated with HSC activation and that the p38 MAPK pathway is involved in this process.

View Article: PubMed Central - PubMed

Affiliation: Medical Research Center, Weifang Medical University, Weifang, Shandong 261053, P.R. China.

ABSTRACT
The activation of hepatic stellate cells (HSCs) is involved in the development of hepatic fibrosis. Previous studies have indicated that the acquisition of certain properties by activated HSCs is highly dependent on the reorganization of the actin cytoskeleton. However, direct evidence showing that the reorganization of the actin cytoskeleton is responsible for HSC activation is lacking. The aim of the present study was to investigate the role of cytoskeletal reorganization during HSC activation and to clarify the underlying mechanism. HSC-T6 cells were treated either with the F-actin stabilizer jasplakinolide (Jas) or the depolymerizer cytochalasin D (Cyto D). The actin cytoskeleton was evaluated via assessment of stress fiber formation. Furthermore, the activation properties of HSCs, including proliferation, adhesion, migration and the expression of α-smooth muscle actin (α-SMA) and collagen 1, were investigated in vitro. The results showed that Jas and Cyto D affected the actin distribution in HSC-T6 cells. Treatment with Jas resulted in thick actin bundles and a patchy appearance in the cytoplasm in HSC-T6 cells. In parallel, polymerization of actin microfilaments induced by Jas upregulated the expression of α-SMA and collagen 1, and also enhanced the migration and adhesion properties of HSC-T6 cells. Furthermore, the activation of HSC-T6 cells induced by the reorganization of the actin cytoskeleton was associated with the p38 mitogen-activated protein kinase (p38 MAPK) pathway. In conclusion, the present study suggests that the reorganization of the F-actin cytoskeleton is associated with HSC activation and that the p38 MAPK pathway is involved in this process. The inhibition of F-actin reorganization may thus be a potential key factor or molecular target for the control of liver fibrosis or cirrhosis.

Show MeSH
Related in: MedlinePlus