Protein kinase C-zeta (PKC-zeta) regulates Kupffer cell apoptosis during experimental sepsis.
BACKGROUND
Kupffer cells play an important role in sepsis-mediated liver injury. We tested the hypothesis that PKC-zeta plays a critical role in Kupffer cell apoptosis during sepsis.


METHODS
Sepsis was induced in rats by cecal ligation and puncture (CLP); 12 h later, livers were assayed for PKC-zeta, IKKalpha, IKKbeta, IKKgamma, NF-kappaB, Fas/FasL, Caspase-3, and DNA fragmentation. Kupffer cells from control rats were infected with AdPKC-zeta DN to inhibit PKC-zeta, or transfected with pCMVPKC-zeta to overexpress PKC-zeta, and then treated with lipopolysaccharide (LPS). Cellular extracts were assayed for PKC-zeta, IKKalpha, IKKbeta, IKKgamma, NF-kappaB, Fas/FasL, Caspase-3, and DNA fragmentation.


RESULTS
During sepsis, PKC-zeta localized in cells positive for the macrophage marker (F4/80). CLP upregulated PKC-zeta protein and activity, IKKbeta, IKKgamma, NF-kappaB, Fas/FasL, Caspase-3, and increased DNA fragmentation in rat livers (all p<0.001). AdPKC-zeta DN attenuated the LPS-induced upregulation of PKC-zeta activity, IKKbeta, IKKgamma, NF-kappaB, Fas/FasL, Caspase-3, and DNA fragmentation in Kupffer cells (all p<0.001), whereas overexpression of PKC-zeta augmented LPS-induced upregulation of IKKbeta, IKKgamma, NF-kappaB, Caspase-3, and DNA fragmentation (p<0.001).


CONCLUSIONS
PKC-zeta plays an important role in sepsis-induced apoptosis of Kupffer cells via activation of NF-kappaB and Fas/FasL. Manipulating the response of Kupffer cells to cellular stress may have important therapeutic implications.
Peng
Yanhua
Y
Department of Surgery, James A. Haley Veterans Affairs Medical Center, University of South Florida Health Sciences Center, C/O Tampa General Hospital, Tampa, FL 33601, USA.
Sigua
Celia A
CA
Karsonovich
Cynthia
C
Murr
Michel M
MM
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D053938:DNA Fragmentation; D051550:I-kappa B Kinase / Q000502:physiology; D007728:Kupffer Cells / Q000502:physiology*; D008297:Male; D018832:Molecular Chaperones / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018805:Sepsis / Q000503:physiopathology*; D014178:Translocation, Genetic; D015854:Up-Regulation / Q000502:physiology; D000099221:Protein Kinase C zeta
D051550:I-kappa B Kinase; D018832:Molecular Chaperones; C490392:Prkcz protein, rat; D000099221:Protein Kinase C zeta