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Mitochondrial Damage-Associated Molecular Patterns (MTDs) Are Released during Hepatic Ischemia Reperfusion and Induce Inflammatory Responses.

Hu Q, Wood CR, Cimen S, Venkatachalam AB, Alwayn IP - PLoS ONE (2015)

Bottom Line: Using in vitro models we observed that levels of MTDs were significantly higher in both transplantation-associated and warm IR, and that co-culture of MTDs with human and rat hepatocytes significantly increased cell death.MTDs were also released in an in vivo rat model of hepatic IRI and associated with increased secretion of inflammatory cytokines (TNF-α, IL-6, and IL-10) and increased liver injury compared to the sham group.Our results suggest that hepatic IR results in a significant increase of MTDs both in vitro and in vivo suggesting that MTDs may serve as a novel marker in hepatic IRI.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada.

ABSTRACT
Ischemia / reperfusion injury (IRI) during the course of liver transplantation enhances the immunogenicity of allografts and thus impacts overall graft outcome. This sterile inflammatory insult is known to activate innate immunity and propagate organ damage through the recognition of damage-associate molecular pattern (DAMP) molecules. The purpose of the present study was to investigate the role of mitochondrial DAMPs (MTDs) in the pathogenesis of hepatic IRI. Using in vitro models we observed that levels of MTDs were significantly higher in both transplantation-associated and warm IR, and that co-culture of MTDs with human and rat hepatocytes significantly increased cell death. MTDs were also released in an in vivo rat model of hepatic IRI and associated with increased secretion of inflammatory cytokines (TNF-α, IL-6, and IL-10) and increased liver injury compared to the sham group. Our results suggest that hepatic IR results in a significant increase of MTDs both in vitro and in vivo suggesting that MTDs may serve as a novel marker in hepatic IRI. Co-culture of MTDs with hepatocytes showed a decrease in cell viability in a concentration dependent manner, which indicates that MTDs is a toxic mediator participating in the pathogenesis of liver IR injury.

No MeSH data available.


Related in: MedlinePlus

Total hepatic IR causes apoptosis in vivo.Liver sections were obtained from IR and sham control rats at 120 minutes post reperfusion. (A) and (B) the intensity of immunostaining of pro-caspase 3 significantly decreased after IRI compared with the sham group. (C) and (D) the intensity of immunostaining of cleaved-caspase 3 significantly increased after IRI compared with the sham group.
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pone.0140105.g008: Total hepatic IR causes apoptosis in vivo.Liver sections were obtained from IR and sham control rats at 120 minutes post reperfusion. (A) and (B) the intensity of immunostaining of pro-caspase 3 significantly decreased after IRI compared with the sham group. (C) and (D) the intensity of immunostaining of cleaved-caspase 3 significantly increased after IRI compared with the sham group.

Mentions: We next sought to confirm that total hepatic IR leads to injury of hepatocytes in vivo. We measured significantly more liver injury in the IR treatment group compared to Sham animals (Fig 6A and 6B). There were more necrotic cells with cell membrane disruption as indicated by the yellow arrows in Fig 6A. Liver enzyme levels remained within the normal range in the control, sham operated group for the duration of the study. A statistically significant difference was noted in mean serum ALT and AST levels following the induction of IR, compared with sham operated rats (Fig 7). Pro-caspase-3 is an intrinsic protein that is cleaved to segments when a cell undergoes apoptosis. Cleaved-caspase-3 is commonly used as an apoptotic marker [35]. We also assessed apoptosis in these groups with cleaved-caspase-3/ pro-caspase-3 immunohistochemistry (IHC). Liver sections from the IR group were highly positively for the cleaved form of caspase-3 compared to the sham group (Fig 8). In addition, we observed a trend that cleaved-caspase-3 accumulated while pro-caspase-3 reduced in the livers of the IR group, suggesting more apoptotic cells in these livers.


Mitochondrial Damage-Associated Molecular Patterns (MTDs) Are Released during Hepatic Ischemia Reperfusion and Induce Inflammatory Responses.

Hu Q, Wood CR, Cimen S, Venkatachalam AB, Alwayn IP - PLoS ONE (2015)

Total hepatic IR causes apoptosis in vivo.Liver sections were obtained from IR and sham control rats at 120 minutes post reperfusion. (A) and (B) the intensity of immunostaining of pro-caspase 3 significantly decreased after IRI compared with the sham group. (C) and (D) the intensity of immunostaining of cleaved-caspase 3 significantly increased after IRI compared with the sham group.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4599831&req=5

pone.0140105.g008: Total hepatic IR causes apoptosis in vivo.Liver sections were obtained from IR and sham control rats at 120 minutes post reperfusion. (A) and (B) the intensity of immunostaining of pro-caspase 3 significantly decreased after IRI compared with the sham group. (C) and (D) the intensity of immunostaining of cleaved-caspase 3 significantly increased after IRI compared with the sham group.
Mentions: We next sought to confirm that total hepatic IR leads to injury of hepatocytes in vivo. We measured significantly more liver injury in the IR treatment group compared to Sham animals (Fig 6A and 6B). There were more necrotic cells with cell membrane disruption as indicated by the yellow arrows in Fig 6A. Liver enzyme levels remained within the normal range in the control, sham operated group for the duration of the study. A statistically significant difference was noted in mean serum ALT and AST levels following the induction of IR, compared with sham operated rats (Fig 7). Pro-caspase-3 is an intrinsic protein that is cleaved to segments when a cell undergoes apoptosis. Cleaved-caspase-3 is commonly used as an apoptotic marker [35]. We also assessed apoptosis in these groups with cleaved-caspase-3/ pro-caspase-3 immunohistochemistry (IHC). Liver sections from the IR group were highly positively for the cleaved form of caspase-3 compared to the sham group (Fig 8). In addition, we observed a trend that cleaved-caspase-3 accumulated while pro-caspase-3 reduced in the livers of the IR group, suggesting more apoptotic cells in these livers.

Bottom Line: Using in vitro models we observed that levels of MTDs were significantly higher in both transplantation-associated and warm IR, and that co-culture of MTDs with human and rat hepatocytes significantly increased cell death.MTDs were also released in an in vivo rat model of hepatic IRI and associated with increased secretion of inflammatory cytokines (TNF-α, IL-6, and IL-10) and increased liver injury compared to the sham group.Our results suggest that hepatic IR results in a significant increase of MTDs both in vitro and in vivo suggesting that MTDs may serve as a novel marker in hepatic IRI.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada.

ABSTRACT
Ischemia / reperfusion injury (IRI) during the course of liver transplantation enhances the immunogenicity of allografts and thus impacts overall graft outcome. This sterile inflammatory insult is known to activate innate immunity and propagate organ damage through the recognition of damage-associate molecular pattern (DAMP) molecules. The purpose of the present study was to investigate the role of mitochondrial DAMPs (MTDs) in the pathogenesis of hepatic IRI. Using in vitro models we observed that levels of MTDs were significantly higher in both transplantation-associated and warm IR, and that co-culture of MTDs with human and rat hepatocytes significantly increased cell death. MTDs were also released in an in vivo rat model of hepatic IRI and associated with increased secretion of inflammatory cytokines (TNF-α, IL-6, and IL-10) and increased liver injury compared to the sham group. Our results suggest that hepatic IR results in a significant increase of MTDs both in vitro and in vivo suggesting that MTDs may serve as a novel marker in hepatic IRI. Co-culture of MTDs with hepatocytes showed a decrease in cell viability in a concentration dependent manner, which indicates that MTDs is a toxic mediator participating in the pathogenesis of liver IR injury.

No MeSH data available.


Related in: MedlinePlus