Administration of Human Protein-C concentrate prevents apoptotic brain cell death after experimental sepsis.
Activated Protein C renders anti-apoptotic properties in neurons and endothelial cells. The aim of the present study was to evaluate the in vivo cytoprotective role of Protein C zymogen (PC) administration in septic rat brain. Male Wistar rats (n=60) were subjected to sepsis via Cecal Ligation and Puncture (CLP). Animals were randomly divided either to receive 100 IU/kg human PC concentrate at 1, 7 and 13 h post CLP (CLP+PC group) or placebo treatment (CLP group). At pre-specified time points (6, 12, 24, 36, 48 and 60 h post CLP) five animals from either group were euthanized and the brain tissue was removed. Apoptosis in both neurons (Neu-N+) and astroglia (GFAP+) was assessed by flow cytometry using 7-aminoactinomycin D (7AAD). Immunohistochemical detection of cleaved caspase 3, bax, bcl-2, cytochrome c and caspase 8 was also performed. PC treated animals had significantly reduced apoptosis in neurons at 6 and 24 h post CLP (p=0.04 and p=0.016 respectively) and necrosis at 6, 12 and 60 h post CLP (p=0.008, p=0.012 and p=0.032 respectively). Astrocyte necrosis was also decreased in septic rats receiving PC (6, 12 and 60 h post CLP p=0.008, p=0.016 and p=0.008 respectively). In addition, active caspase 3, bax, cytochrome c and caspase 8 expression was significantly decreased during early sepsis (6-36 h) while bcl-2 expression was increased (24 h p=0.001 and 60 h p=0.001) in the PC treated animals compared to placebo. PC concentrate administration in experimental sepsis produced a time dependent inhibition of apoptosis in rat neurons and astrocytes. The inhibition of sepsis related apoptosis concerned both the mitochondrial and caspase 8 dependent pathways.
First Department of Propaedeutic Surgery, Athens University Medical School, Hippocration General Hospital, Athens, Greece.
Nikolaos
N
Memos
Alex
A
Betrosian
Evangelos
E
Messaris
Maria
M
Boutsikou
Agapi
A
Kataki
Emmy
E
Chatzigianni
Marilena
M
Nikolopoulou
Emmanuel
E
Leandros
Manousos
M
Konstadoulakis
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D001921:Brain / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D020169:Caspases / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D019610:Cytoprotection; D005434:Flow Cytometry; D007150:Immunohistochemistry; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D011486:Protein C / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D018805:Sepsis / Q000378:metabolism / Q000473:pathology*; D013997:Time Factors; D051028:bcl-2-Associated X Protein / Q000378:metabolism
D011486:Protein C; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D045304:Cytochromes c; D020169:Caspases