Limits...
Ghrelin reduces liver impairment in a model of concanavalin A-induced acute hepatitis in mice.

Mao Y, Wang J, Yu F, Cheng J, Li H, Guo C, Fan X - Drug Des Devel Ther (2015)

Bottom Line: Inflammatory cytokines were significantly reduced by ghrelin pretreatment.However, the Akt kinase inhibitor reversed the decrease of Bax and caspase 3, 8, 9, and reduced the protein level of p-Akt and Bcl-2.These effects could be interrupted by an Akt kinase inhibitor.

View Article: PubMed Central - PubMed

Affiliation: Department of Gastroenterology and Hepatology, Jinshan Hospital of Fudan University, Shanghai, People's Republic of China.

ABSTRACT

Background and aims: Ghrelin is a 28-amino-acid gut hormone that was first discovered as a potent growth hormone secretagogue. Recently, it has been shown to exert a strong anti-inflammatory effect. The purpose of the study reported here was to explore the effect and mechanism of ghrelin on concanavalin (Con) A-induced acute hepatitis.

Methods: Balb/C mice were divided into four groups: normal control (NC) (mice injected with vehicle [saline]); Con A (25 mg/kg); Con A + 10 μg/kg ghrelin; and Con A + 50 μg/kg ghrelin (1 hour before Con A injection). Pro-inflammatory cytokine levels were detected. Protein levels of phosphoinositide 3-kinase (PI3K); phosphorylated Akt (p-Akt); caspase 3, 8, and 9; and microtubule-associated protein 1 light chain 3 (LC3) were also detected. Perifosine (25 mM) (an Akt inhibitor) was used to investigate whether the protective effect of ghrelin was interrupted by an Akt inhibitor. Protein levels of p-AKT; Bcl-2; Bax; and caspase 3, 8, and 9 were also detected.

Results: Aspartate aminotransferase, alanine aminotransferase, and pathological damage were significantly ameliorated by ghrelin pretreatment in Con A-induced hepatitis. Inflammatory cytokines were significantly reduced by ghrelin pretreatment. Bcl-2; Bax; and caspase 3, 8, and 9 expression were also clearly affected by ghrelin pretreatment, compared with the Con A-treated group. However, the Akt kinase inhibitor reversed the decrease of Bax and caspase 3, 8, 9, and reduced the protein level of p-Akt and Bcl-2. Ghrelin activated the PI3K/Akt/Bcl-2 pathway and inhibited activation of autophagy.

Conclusion: Our results demonstrate that ghrelin attenuates Con A-induced acute immune hepatitis by activating the PI3K/Akt pathway and inhibiting the process of autophagy, which might be related to inhibition of inflammatory cytokine release, and prevention of hepatocyte apoptosis. These effects could be interrupted by an Akt kinase inhibitor.

No MeSH data available.


Related in: MedlinePlus

Ghrelin pretreatment inhibits release of IL-1β, IL-6, and TNF-α in Con A-induced hepatitis.Notes: (A) The serum IL-1β, IL-6, and TNF-α levels are expressed as mean ± SD of six animals per group at 4, 8, and 24 h after Con A injection in mice and the effects of both low (10 μg/kg) and high (50 μg/kg) dose ghrelin pretreatment at the same time. (B) mRNA expression of IL-1β, IL-6, and TNF-α in the NC, Con A, Con A + 10 μg/kg ghrelin, and Con A + 50 μg/kg ghrelin groups was evaluated by real-time PCR. (C) Western blots showing the expression of IL-1β, IL-6, and TNF-α in liver tissues. (D) Immunohistochemistry staining (200×) showing the expression of IL-1β, IL-6, and TNF-α in liver tissue at 8 h. The ratio of brown area to total area was analyzed with Image-Pro® Plus (v 6.0); (n=6). *P<0.05 for NC vs Con A, #P<0.05 for Con A vs Con A + 10 μg/kg ghrelin, †P<0.05 for Con A + 50 μg/kg ghrelin vs Con A + 10 μg/kg ghrelin, and †,*P>0.05 for Con A + 50 μg/kg ghrelin vs Con A + 10 μg/kg ghrelin.Abbreviations: Con, concanavalin; h, hours; IL, interleukin; NC, normal control; TNF, tumor necrosis factor; PCR, polymerase chain reaction.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4592035&req=5

f3-dddt-9-5385: Ghrelin pretreatment inhibits release of IL-1β, IL-6, and TNF-α in Con A-induced hepatitis.Notes: (A) The serum IL-1β, IL-6, and TNF-α levels are expressed as mean ± SD of six animals per group at 4, 8, and 24 h after Con A injection in mice and the effects of both low (10 μg/kg) and high (50 μg/kg) dose ghrelin pretreatment at the same time. (B) mRNA expression of IL-1β, IL-6, and TNF-α in the NC, Con A, Con A + 10 μg/kg ghrelin, and Con A + 50 μg/kg ghrelin groups was evaluated by real-time PCR. (C) Western blots showing the expression of IL-1β, IL-6, and TNF-α in liver tissues. (D) Immunohistochemistry staining (200×) showing the expression of IL-1β, IL-6, and TNF-α in liver tissue at 8 h. The ratio of brown area to total area was analyzed with Image-Pro® Plus (v 6.0); (n=6). *P<0.05 for NC vs Con A, #P<0.05 for Con A vs Con A + 10 μg/kg ghrelin, †P<0.05 for Con A + 50 μg/kg ghrelin vs Con A + 10 μg/kg ghrelin, and †,*P>0.05 for Con A + 50 μg/kg ghrelin vs Con A + 10 μg/kg ghrelin.Abbreviations: Con, concanavalin; h, hours; IL, interleukin; NC, normal control; TNF, tumor necrosis factor; PCR, polymerase chain reaction.

Mentions: Hepatitis is associated with changes in the levels of inflammatory cytokines. Serum levels of IL-1β, IL-6, and TNF-α were significantly increased in the Con A-treated group and peaked at 8 hours after Con A injection. As expected, pretreatment with both doses of ghrelin significantly lowered the Con A-induced increase of serum levels of IL-1β, IL-6, and TNF-α, especially at 8 hours (Figure 3A). To confirm our observations, mRNA transcription and protein expression of the cytokines were also reduced by ghrelin pretreatment (Figures 3B and C). In addition, immunohistochemical staining was used to detect the expression of the inflammatory cytokines in liver tissues in the control, Con A, Con A + 10 μg/kg ghrelin, and Con A + 50 μg/kg ghrelin groups (Figure 3D). These results showed that ghrelin pretreatment reduced inflammatory cytokines in Con A-induced hepatitis.


Ghrelin reduces liver impairment in a model of concanavalin A-induced acute hepatitis in mice.

Mao Y, Wang J, Yu F, Cheng J, Li H, Guo C, Fan X - Drug Des Devel Ther (2015)

Ghrelin pretreatment inhibits release of IL-1β, IL-6, and TNF-α in Con A-induced hepatitis.Notes: (A) The serum IL-1β, IL-6, and TNF-α levels are expressed as mean ± SD of six animals per group at 4, 8, and 24 h after Con A injection in mice and the effects of both low (10 μg/kg) and high (50 μg/kg) dose ghrelin pretreatment at the same time. (B) mRNA expression of IL-1β, IL-6, and TNF-α in the NC, Con A, Con A + 10 μg/kg ghrelin, and Con A + 50 μg/kg ghrelin groups was evaluated by real-time PCR. (C) Western blots showing the expression of IL-1β, IL-6, and TNF-α in liver tissues. (D) Immunohistochemistry staining (200×) showing the expression of IL-1β, IL-6, and TNF-α in liver tissue at 8 h. The ratio of brown area to total area was analyzed with Image-Pro® Plus (v 6.0); (n=6). *P<0.05 for NC vs Con A, #P<0.05 for Con A vs Con A + 10 μg/kg ghrelin, †P<0.05 for Con A + 50 μg/kg ghrelin vs Con A + 10 μg/kg ghrelin, and †,*P>0.05 for Con A + 50 μg/kg ghrelin vs Con A + 10 μg/kg ghrelin.Abbreviations: Con, concanavalin; h, hours; IL, interleukin; NC, normal control; TNF, tumor necrosis factor; PCR, polymerase chain reaction.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4592035&req=5

f3-dddt-9-5385: Ghrelin pretreatment inhibits release of IL-1β, IL-6, and TNF-α in Con A-induced hepatitis.Notes: (A) The serum IL-1β, IL-6, and TNF-α levels are expressed as mean ± SD of six animals per group at 4, 8, and 24 h after Con A injection in mice and the effects of both low (10 μg/kg) and high (50 μg/kg) dose ghrelin pretreatment at the same time. (B) mRNA expression of IL-1β, IL-6, and TNF-α in the NC, Con A, Con A + 10 μg/kg ghrelin, and Con A + 50 μg/kg ghrelin groups was evaluated by real-time PCR. (C) Western blots showing the expression of IL-1β, IL-6, and TNF-α in liver tissues. (D) Immunohistochemistry staining (200×) showing the expression of IL-1β, IL-6, and TNF-α in liver tissue at 8 h. The ratio of brown area to total area was analyzed with Image-Pro® Plus (v 6.0); (n=6). *P<0.05 for NC vs Con A, #P<0.05 for Con A vs Con A + 10 μg/kg ghrelin, †P<0.05 for Con A + 50 μg/kg ghrelin vs Con A + 10 μg/kg ghrelin, and †,*P>0.05 for Con A + 50 μg/kg ghrelin vs Con A + 10 μg/kg ghrelin.Abbreviations: Con, concanavalin; h, hours; IL, interleukin; NC, normal control; TNF, tumor necrosis factor; PCR, polymerase chain reaction.
Mentions: Hepatitis is associated with changes in the levels of inflammatory cytokines. Serum levels of IL-1β, IL-6, and TNF-α were significantly increased in the Con A-treated group and peaked at 8 hours after Con A injection. As expected, pretreatment with both doses of ghrelin significantly lowered the Con A-induced increase of serum levels of IL-1β, IL-6, and TNF-α, especially at 8 hours (Figure 3A). To confirm our observations, mRNA transcription and protein expression of the cytokines were also reduced by ghrelin pretreatment (Figures 3B and C). In addition, immunohistochemical staining was used to detect the expression of the inflammatory cytokines in liver tissues in the control, Con A, Con A + 10 μg/kg ghrelin, and Con A + 50 μg/kg ghrelin groups (Figure 3D). These results showed that ghrelin pretreatment reduced inflammatory cytokines in Con A-induced hepatitis.

Bottom Line: Inflammatory cytokines were significantly reduced by ghrelin pretreatment.However, the Akt kinase inhibitor reversed the decrease of Bax and caspase 3, 8, 9, and reduced the protein level of p-Akt and Bcl-2.These effects could be interrupted by an Akt kinase inhibitor.

View Article: PubMed Central - PubMed

Affiliation: Department of Gastroenterology and Hepatology, Jinshan Hospital of Fudan University, Shanghai, People's Republic of China.

ABSTRACT

Background and aims: Ghrelin is a 28-amino-acid gut hormone that was first discovered as a potent growth hormone secretagogue. Recently, it has been shown to exert a strong anti-inflammatory effect. The purpose of the study reported here was to explore the effect and mechanism of ghrelin on concanavalin (Con) A-induced acute hepatitis.

Methods: Balb/C mice were divided into four groups: normal control (NC) (mice injected with vehicle [saline]); Con A (25 mg/kg); Con A + 10 μg/kg ghrelin; and Con A + 50 μg/kg ghrelin (1 hour before Con A injection). Pro-inflammatory cytokine levels were detected. Protein levels of phosphoinositide 3-kinase (PI3K); phosphorylated Akt (p-Akt); caspase 3, 8, and 9; and microtubule-associated protein 1 light chain 3 (LC3) were also detected. Perifosine (25 mM) (an Akt inhibitor) was used to investigate whether the protective effect of ghrelin was interrupted by an Akt inhibitor. Protein levels of p-AKT; Bcl-2; Bax; and caspase 3, 8, and 9 were also detected.

Results: Aspartate aminotransferase, alanine aminotransferase, and pathological damage were significantly ameliorated by ghrelin pretreatment in Con A-induced hepatitis. Inflammatory cytokines were significantly reduced by ghrelin pretreatment. Bcl-2; Bax; and caspase 3, 8, and 9 expression were also clearly affected by ghrelin pretreatment, compared with the Con A-treated group. However, the Akt kinase inhibitor reversed the decrease of Bax and caspase 3, 8, 9, and reduced the protein level of p-Akt and Bcl-2. Ghrelin activated the PI3K/Akt/Bcl-2 pathway and inhibited activation of autophagy.

Conclusion: Our results demonstrate that ghrelin attenuates Con A-induced acute immune hepatitis by activating the PI3K/Akt pathway and inhibiting the process of autophagy, which might be related to inhibition of inflammatory cytokine release, and prevention of hepatocyte apoptosis. These effects could be interrupted by an Akt kinase inhibitor.

No MeSH data available.


Related in: MedlinePlus