Online data supplement
Methods
Immunohistochemistry
Quantification
of leukocyte and neutrophil homing after CPR was performed on 7 µm paraffin
sections. The animals were perfused with 4% paraformaldehyde in phosphate
buffer (pH 7.4). Organs were removed and postfixed in phosphate buffered 4%
paraformaldehyde (pH 7.4) overnight prior to paraffin-embedding and sectioning.
Sections were deparaffinized with xylene and dehydrated in graded series of
ethanol. Endogenous peroxidase was quenched with 3% H202
in methanol for 30 minutes at RT. Sections were rinsed in 10 mM Tris, 150 mM
NaCL, pH 7.4 (TBS) blocked with 20% swine serum in TBS for 45 min at RT.
Neutrophils were detected with rat anti-neutrophils monoclonal antibodies,
clone MCA771G (Serotec, Oxford, England), diluted 1:500 in TBS supplemented
with 2% bovine serum albumin. Sections were incubated with primary antibodies
overnight in a humidified chamber. Primary antibodies were detected with the avidin biotin complex technique using the ABC Elite Kit according
to the manufacturer instructions (Vector Laboratories, Burlingame, CA, USA) and 3'-diamino benzidine
tetrahydrochloride as chromogenic substrate. Sections
were counterstained with Harris Hematoxylin and mounted in DPX (Serva, Heidelberg, Germany).
Serial sections were photographed with a Zeiss Axiophot II (Zeiss, Oberkochen, Germany)
equipped with a digital camera, colour view (SIS, Münster, Germany).
3 serial sections/mice were
used to quantify neutrophils/high power field 24 h and 48 h after surgery. Homing
of leukocytes and neutrophils was quantified using analySIS software (SIS, Münster, Germany).
Endothelial
cells and ICAM-1 were stained using indirect immunofluorescent technique.
Organs of Sham or CPR mice were snap-frozen in Tissue Freezing Medium (Leica
Instruments, Nussloch, Germany). 10 µM cryosections were
air dried overnight and fixed in cold acetone for 10 min. After blocking
sections with PBS, supplemented with 1% bovine serum albumine and 0,05% Tween
20, endothelial cells were detected with polyclonal rabbit anti-von Willebrand
Factor antisera (Dako, Glostrup, Denmark) diluted 1:200 in blocking buffer,
ICAM-1 was stained with rabbit anti-ICAM-1 IgGs (Santa Cruz Biotechnology, Heidelberg,
Germany)
diluted 1:100 in blocking buffer for 1 h. Primary antibodies were visualized by
incubating sections with Cy2-labeled goat anti-rabbit IgGs (Dianova, Hamburg,
Germany), diluted 1:100 in blocking buffer for 1h. Sections were counterstained
with DAPI Nucleic Acid Stain (Invitrogen, Carlsbad,
CA, USA)
and embedded in Fluorescent Mounting Medium (Dako, Glostrup, Denmark).
Western Blot
Snap
frozen tissue samples were pulverized and homogenized (Micro-Dismembrator U and
Homogenisator Modell 853202,
B. Braun Melsungen, Melsungen, Germany) in 2fold
concentrated reducing Laemmli gel loading buffer (2fold is: 120 mM Tris, 4%
SDS, 20% glycerol, 0,05% bromphenol blue, 200 mM dithiothreitol, pH6,8) and
separated by gel electrophoresis with 10% Tris/glycine SDS-polyacrylamide gels.
The amount of protein per lane was adjusted by densitometric analysis (Kodak
Image Station 1000 Kodak, New York, NY, USA) of
coomassie brilliant blue stained was gels performed in parallel. Proteins were
transferred from gel to PVDF-membranes (Millipore, Billerica, MA, USA) using the Mini Trans-Blot Cell (Biorad,
Hercules, CA, USA).
Membranes were blocked with 3% bovine serum albumin in PBS for 2h at RT and
then incubated with polyclonal goat anti-ICAM-1 antibody (Santa Cruz Biotechnology, Heidelberg,
Germany),
diluted 1:200 in PBS supplemented with 1% bovine serum albumin. Membranes were
washed with PBS with 0.1 % Tween 20 and incubated with horseradish
peroxidase-labeled anti-goat IgGs (Santa Cruz Biotechnology, Heidelberg, Germany),
diluted 1:4000 in PBS supplemented with 1% bovine serum albumin. Blots were
developed with Super Signal West Pico chemiluminescent substrate (Pierce Biotechnology, Rockford, IL,
USA) and the
Kodak Image Station 1000.