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Probiotic Lactobacillus rhamnosus GG mono-association suppresses human rotavirus-induced autophagy in the gnotobiotic piglet intestine.

Wu S, Yuan L, Zhang Y, Liu F, Li G, Wen K, Kocher J, Yang X, Sun J - Gut Pathog (2013)

Bottom Line: We found that LGG feeding did not increase autophagy, whereas virus infection induced autophagy in the piglet intestine.LGG treatment during viral gastroenteritis reduced autophagy marker expression to normal levels, induced apoptosis and partially prevented virus-induced tissue damage.A better understanding of the antiviral activity of LGG will lead to novel therapeutic strategies for infant infectious diseases.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry, Rush University, Cohn Research Building, 1735 W, Harrison Street, Chicago, IL 60612, USA. jun_sun@rush.edu.

ABSTRACT

Background: Human rotavirus (HRV) is the most important cause of severe diarrhea in infants and young children. Probiotic Lactobacillus rhamnosus GG (LGG) reduces rotavirus infection and diarrhea. However, the molecular mechanisms of LGG-mediated protection from rotavirus infection are poorly understood. Autophagy plays an essential role in responses to microbial pathogens. However, the role of autophagy in HRV infection and LGG treatment is unknown. We hypothesize that rotavirus gastroenteritis activates autophagy and that LGG suppresses virus-induced autophagy and prevents intestinal damage in infected piglets.

Methods: We used LGG feeding to combat viral gastroenteritis in the gnotobiotic pig model of virulent HRV infection.

Results: We found that LGG feeding did not increase autophagy, whereas virus infection induced autophagy in the piglet intestine. Virus infection increased the protein levels of the autophagy markers ATG16L1 and Beclin-1 and the autophagy regulator mTOR. LGG treatment during viral gastroenteritis reduced autophagy marker expression to normal levels, induced apoptosis and partially prevented virus-induced tissue damage.

Conclusion: Our study provides new insights into virus-induced autophagy and LGG suppression of uncontrolled autophagy and intestinal injury. A better understanding of the antiviral activity of LGG will lead to novel therapeutic strategies for infant infectious diseases.

No MeSH data available.


Related in: MedlinePlus

LGG stimulates apoptosis in Gn pig ileum treated with HRV. (A) LGG increases the expression of p53 protein and decreases Bcl-2 and Bcl-xl protein in the ilea of HRV-infected pigs. Ileum epithelia were scraped on PID 2. Relative protein band intensities of P53 in pig ileum were analyzed with NIH image. Data are reported as the mean ± SD. ANOVA * P<0.05. (B) LGG increases the expression of cleaved caspase-3 in the ilea of HRV-infected pigs. Densitometry analysis of caspase-3 activation. Values are the ratio of cleaved caspase-3 to pro-caspase-3. The results were normalized to mock (densitometer value = 1). * P<0.05. (C) Detection of p53 and cleaved caspase-3 by immunofluorescence in pig ileum (Magnification 20×, scale bar 100 μm).
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Figure 4: LGG stimulates apoptosis in Gn pig ileum treated with HRV. (A) LGG increases the expression of p53 protein and decreases Bcl-2 and Bcl-xl protein in the ilea of HRV-infected pigs. Ileum epithelia were scraped on PID 2. Relative protein band intensities of P53 in pig ileum were analyzed with NIH image. Data are reported as the mean ± SD. ANOVA * P<0.05. (B) LGG increases the expression of cleaved caspase-3 in the ilea of HRV-infected pigs. Densitometry analysis of caspase-3 activation. Values are the ratio of cleaved caspase-3 to pro-caspase-3. The results were normalized to mock (densitometer value = 1). * P<0.05. (C) Detection of p53 and cleaved caspase-3 by immunofluorescence in pig ileum (Magnification 20×, scale bar 100 μm).

Mentions: Autophagy is a programmed survival strategy, whereas apoptosis is programmed cell death. We further examined the expression of apoptosis markers in the pig intestine (Figure 4A). p53 limits cellular proliferation by inducing cell cycle arrest and apoptosis in response to cellular stress [16,17]. LGG feeding with HRV infection led to higher p53 in the intestine of LGG+HRV pigs than in the other groups (Figure 4A). p53 staining showed an increased number of p53-positive cells in the ilea of the LGG+HRV group (Figure 4C). HRV infection also induced expression of the anti-apoptotic protein Bcl-2 and the pro-survival marker Bcl-xl, and these proteins were significantly decreased by LGG feeding (Figure 4A).


Probiotic Lactobacillus rhamnosus GG mono-association suppresses human rotavirus-induced autophagy in the gnotobiotic piglet intestine.

Wu S, Yuan L, Zhang Y, Liu F, Li G, Wen K, Kocher J, Yang X, Sun J - Gut Pathog (2013)

LGG stimulates apoptosis in Gn pig ileum treated with HRV. (A) LGG increases the expression of p53 protein and decreases Bcl-2 and Bcl-xl protein in the ilea of HRV-infected pigs. Ileum epithelia were scraped on PID 2. Relative protein band intensities of P53 in pig ileum were analyzed with NIH image. Data are reported as the mean ± SD. ANOVA * P<0.05. (B) LGG increases the expression of cleaved caspase-3 in the ilea of HRV-infected pigs. Densitometry analysis of caspase-3 activation. Values are the ratio of cleaved caspase-3 to pro-caspase-3. The results were normalized to mock (densitometer value = 1). * P<0.05. (C) Detection of p53 and cleaved caspase-3 by immunofluorescence in pig ileum (Magnification 20×, scale bar 100 μm).
© Copyright Policy - open-access
Related In: Results  -  Collection

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Figure 4: LGG stimulates apoptosis in Gn pig ileum treated with HRV. (A) LGG increases the expression of p53 protein and decreases Bcl-2 and Bcl-xl protein in the ilea of HRV-infected pigs. Ileum epithelia were scraped on PID 2. Relative protein band intensities of P53 in pig ileum were analyzed with NIH image. Data are reported as the mean ± SD. ANOVA * P<0.05. (B) LGG increases the expression of cleaved caspase-3 in the ilea of HRV-infected pigs. Densitometry analysis of caspase-3 activation. Values are the ratio of cleaved caspase-3 to pro-caspase-3. The results were normalized to mock (densitometer value = 1). * P<0.05. (C) Detection of p53 and cleaved caspase-3 by immunofluorescence in pig ileum (Magnification 20×, scale bar 100 μm).
Mentions: Autophagy is a programmed survival strategy, whereas apoptosis is programmed cell death. We further examined the expression of apoptosis markers in the pig intestine (Figure 4A). p53 limits cellular proliferation by inducing cell cycle arrest and apoptosis in response to cellular stress [16,17]. LGG feeding with HRV infection led to higher p53 in the intestine of LGG+HRV pigs than in the other groups (Figure 4A). p53 staining showed an increased number of p53-positive cells in the ilea of the LGG+HRV group (Figure 4C). HRV infection also induced expression of the anti-apoptotic protein Bcl-2 and the pro-survival marker Bcl-xl, and these proteins were significantly decreased by LGG feeding (Figure 4A).

Bottom Line: We found that LGG feeding did not increase autophagy, whereas virus infection induced autophagy in the piglet intestine.LGG treatment during viral gastroenteritis reduced autophagy marker expression to normal levels, induced apoptosis and partially prevented virus-induced tissue damage.A better understanding of the antiviral activity of LGG will lead to novel therapeutic strategies for infant infectious diseases.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biochemistry, Rush University, Cohn Research Building, 1735 W, Harrison Street, Chicago, IL 60612, USA. jun_sun@rush.edu.

ABSTRACT

Background: Human rotavirus (HRV) is the most important cause of severe diarrhea in infants and young children. Probiotic Lactobacillus rhamnosus GG (LGG) reduces rotavirus infection and diarrhea. However, the molecular mechanisms of LGG-mediated protection from rotavirus infection are poorly understood. Autophagy plays an essential role in responses to microbial pathogens. However, the role of autophagy in HRV infection and LGG treatment is unknown. We hypothesize that rotavirus gastroenteritis activates autophagy and that LGG suppresses virus-induced autophagy and prevents intestinal damage in infected piglets.

Methods: We used LGG feeding to combat viral gastroenteritis in the gnotobiotic pig model of virulent HRV infection.

Results: We found that LGG feeding did not increase autophagy, whereas virus infection induced autophagy in the piglet intestine. Virus infection increased the protein levels of the autophagy markers ATG16L1 and Beclin-1 and the autophagy regulator mTOR. LGG treatment during viral gastroenteritis reduced autophagy marker expression to normal levels, induced apoptosis and partially prevented virus-induced tissue damage.

Conclusion: Our study provides new insights into virus-induced autophagy and LGG suppression of uncontrolled autophagy and intestinal injury. A better understanding of the antiviral activity of LGG will lead to novel therapeutic strategies for infant infectious diseases.

No MeSH data available.


Related in: MedlinePlus