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Proteomic analysis of regenerating mouse liver following 50% partial hepatectomy.

Cao H, Yu J, Xu W, Jia X, Yang J, Pan Q, Zhang Q, Sheng G, Li J, Pan X, Wang Y, Li L - Proteome Sci (2009)

Bottom Line: Remarkably, over 25 differentially expressed proteins were located at mitochondria.Several of the mitochondria-resident proteins which play important roles in citric acid cycle, oxidative phosphorylation and ATP production were found to be down-regulated, consistent with the recently-proposed model in which the reduction of ATP content in the remnant liver gives rise to early stress signals that contribute to the onset of liver regeneration.Our study provides novel evidence for mitochondria as a pivotal organelle that is connected to liver regeneration, and lays the foundation for further studies on key factors and pathways involved in liver regeneration following 50% PH, a condition frequently used for partial liver transplantation and conservative liver resection.

View Article: PubMed Central - HTML - PubMed

Affiliation: State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, 1st Affiliated Hospital, College of Medicine, Zhejiang University, 79 Qingchun Road, Hangzhou, 310003, PR China.

ABSTRACT

Background: Although 70% (or 2/3) partial hepatectomy (PH) is the most studied model for liver regeneration, the hepatic protein expression profile associated with lower volume liver resection (such as 50% PH) has not yet been reported. Therefore, the aim of this study was to determine the global protein expression profile of the regenerating mouse liver following 50% PH by differential proteomics, and thereby gaining some insights into the hepatic regeneration mechanism(s) under this milder but clinically more relevant condition.

Results: Proteins from sham-operated mouse livers and livers regenerating for 24 h after 50% PH were separated by SDS-PAGE and analyzed by nanoUPLC-Q-Tof mass spectrometry. Compared to sham-operated group, there were totally 87 differentially expressed proteins (with 50 up-regulated and 37 down-regulated ones) identified in the regenerating mouse livers, most of which have not been previously related to liver regeneration. Remarkably, over 25 differentially expressed proteins were located at mitochondria. Several of the mitochondria-resident proteins which play important roles in citric acid cycle, oxidative phosphorylation and ATP production were found to be down-regulated, consistent with the recently-proposed model in which the reduction of ATP content in the remnant liver gives rise to early stress signals that contribute to the onset of liver regeneration. Pathway analysis revealed a central role of c-Myc in the regulation of liver regeneration.

Conclusions: Our study provides novel evidence for mitochondria as a pivotal organelle that is connected to liver regeneration, and lays the foundation for further studies on key factors and pathways involved in liver regeneration following 50% PH, a condition frequently used for partial liver transplantation and conservative liver resection.

No MeSH data available.


Related in: MedlinePlus

Representative mass spectra of triplicate samples on nanoLC-Q-Tof Fig.5 (A-C) Individual mass spectrum of each of the triplicate samples shown in different colors. Fig.5 (D) An overlay of the mass spectrum of the triplicate samples. The high degree of overlapping of most peaks present in the triplicate samples demonstrated good reproducibility of the method. The protein identification was conducted separately with the triplicate samples, and only an identification observed in at least two of the three replicates was taken to be valid. In those cases, at least two out of the three mass spectra exhibited high degree of overlapping as shown in this figure.
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Figure 5: Representative mass spectra of triplicate samples on nanoLC-Q-Tof Fig.5 (A-C) Individual mass spectrum of each of the triplicate samples shown in different colors. Fig.5 (D) An overlay of the mass spectrum of the triplicate samples. The high degree of overlapping of most peaks present in the triplicate samples demonstrated good reproducibility of the method. The protein identification was conducted separately with the triplicate samples, and only an identification observed in at least two of the three replicates was taken to be valid. In those cases, at least two out of the three mass spectra exhibited high degree of overlapping as shown in this figure.

Mentions: The continuum LC-MS data were processed and searched against the ipi.MOUSE.v3.40.fasta protein database http://www.ebi.ac.uk/IPI/IPImouse.html using ProteinLynx Global Server (PLGS) version 2.3, a fully automatic and integrated Mass-Informatics™ platform for quantitative and qualitative proteomics research[69]. Stringent search criteria were set so that each protein identification was collectively determined by at least 7 tryptic fragments and a matching peptide whose identification was determined by at least 3 tryptic fragments. Protein identification scores were calculated by the software and reported in the tables which provide a measure of confidence for the proteins identified. Since the LC-MS was performed in triplicate, the triplicate data were processed separately, and only an identification observed in at least two of the three replicates was taken to be valid (Fig. 5). The average MS signal of the three most intense tryptic peptides from each protein was taken as a measure for the relative quantity of that protein[70], and the ratio of this signal in 50% PH samples versus that in sham control sample was calculated and used to determine up or down-regulation of the specific protein upon 50% PH treatment. The gel equal loading validation/correction, and the triplicate MS identification, collectively ensured the authenticity of the results.


Proteomic analysis of regenerating mouse liver following 50% partial hepatectomy.

Cao H, Yu J, Xu W, Jia X, Yang J, Pan Q, Zhang Q, Sheng G, Li J, Pan X, Wang Y, Li L - Proteome Sci (2009)

Representative mass spectra of triplicate samples on nanoLC-Q-Tof Fig.5 (A-C) Individual mass spectrum of each of the triplicate samples shown in different colors. Fig.5 (D) An overlay of the mass spectrum of the triplicate samples. The high degree of overlapping of most peaks present in the triplicate samples demonstrated good reproducibility of the method. The protein identification was conducted separately with the triplicate samples, and only an identification observed in at least two of the three replicates was taken to be valid. In those cases, at least two out of the three mass spectra exhibited high degree of overlapping as shown in this figure.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2813229&req=5

Figure 5: Representative mass spectra of triplicate samples on nanoLC-Q-Tof Fig.5 (A-C) Individual mass spectrum of each of the triplicate samples shown in different colors. Fig.5 (D) An overlay of the mass spectrum of the triplicate samples. The high degree of overlapping of most peaks present in the triplicate samples demonstrated good reproducibility of the method. The protein identification was conducted separately with the triplicate samples, and only an identification observed in at least two of the three replicates was taken to be valid. In those cases, at least two out of the three mass spectra exhibited high degree of overlapping as shown in this figure.
Mentions: The continuum LC-MS data were processed and searched against the ipi.MOUSE.v3.40.fasta protein database http://www.ebi.ac.uk/IPI/IPImouse.html using ProteinLynx Global Server (PLGS) version 2.3, a fully automatic and integrated Mass-Informatics™ platform for quantitative and qualitative proteomics research[69]. Stringent search criteria were set so that each protein identification was collectively determined by at least 7 tryptic fragments and a matching peptide whose identification was determined by at least 3 tryptic fragments. Protein identification scores were calculated by the software and reported in the tables which provide a measure of confidence for the proteins identified. Since the LC-MS was performed in triplicate, the triplicate data were processed separately, and only an identification observed in at least two of the three replicates was taken to be valid (Fig. 5). The average MS signal of the three most intense tryptic peptides from each protein was taken as a measure for the relative quantity of that protein[70], and the ratio of this signal in 50% PH samples versus that in sham control sample was calculated and used to determine up or down-regulation of the specific protein upon 50% PH treatment. The gel equal loading validation/correction, and the triplicate MS identification, collectively ensured the authenticity of the results.

Bottom Line: Remarkably, over 25 differentially expressed proteins were located at mitochondria.Several of the mitochondria-resident proteins which play important roles in citric acid cycle, oxidative phosphorylation and ATP production were found to be down-regulated, consistent with the recently-proposed model in which the reduction of ATP content in the remnant liver gives rise to early stress signals that contribute to the onset of liver regeneration.Our study provides novel evidence for mitochondria as a pivotal organelle that is connected to liver regeneration, and lays the foundation for further studies on key factors and pathways involved in liver regeneration following 50% PH, a condition frequently used for partial liver transplantation and conservative liver resection.

View Article: PubMed Central - HTML - PubMed

Affiliation: State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, 1st Affiliated Hospital, College of Medicine, Zhejiang University, 79 Qingchun Road, Hangzhou, 310003, PR China.

ABSTRACT

Background: Although 70% (or 2/3) partial hepatectomy (PH) is the most studied model for liver regeneration, the hepatic protein expression profile associated with lower volume liver resection (such as 50% PH) has not yet been reported. Therefore, the aim of this study was to determine the global protein expression profile of the regenerating mouse liver following 50% PH by differential proteomics, and thereby gaining some insights into the hepatic regeneration mechanism(s) under this milder but clinically more relevant condition.

Results: Proteins from sham-operated mouse livers and livers regenerating for 24 h after 50% PH were separated by SDS-PAGE and analyzed by nanoUPLC-Q-Tof mass spectrometry. Compared to sham-operated group, there were totally 87 differentially expressed proteins (with 50 up-regulated and 37 down-regulated ones) identified in the regenerating mouse livers, most of which have not been previously related to liver regeneration. Remarkably, over 25 differentially expressed proteins were located at mitochondria. Several of the mitochondria-resident proteins which play important roles in citric acid cycle, oxidative phosphorylation and ATP production were found to be down-regulated, consistent with the recently-proposed model in which the reduction of ATP content in the remnant liver gives rise to early stress signals that contribute to the onset of liver regeneration. Pathway analysis revealed a central role of c-Myc in the regulation of liver regeneration.

Conclusions: Our study provides novel evidence for mitochondria as a pivotal organelle that is connected to liver regeneration, and lays the foundation for further studies on key factors and pathways involved in liver regeneration following 50% PH, a condition frequently used for partial liver transplantation and conservative liver resection.

No MeSH data available.


Related in: MedlinePlus