Focal adhesion kinase signaling is decreased 56 days following spinal cord injury in rat gastrocnemius.
METHODS
Descriptive study.


OBJECTIVE
The goal of this study was to determine the effects of spinal cord injury (SCI) on aspects of the focal adhesion kinase (FAK) signaling pathway 56 days post injury in rat gastrocnemius.


METHODS
This study was conducted in Bronx, NY, USA.


METHODS
Three-month-old male Wistar rats were exposed to either a sham surgery (n=10) or complete T4 spinal cord transection (n=10). Rats were killed 56 days following surgery and the muscle was collected. Following homogenization, proteins of the FAK pathway were analyzed by western immunoblotting or reverse transcription-qPCR. In addition, cellular markers for proteins that target the degradation of FAK were investigated.


RESULTS
SCI resulted in significantly lower levels of total and phosphorylated FAK, cSrc and p70S6k, and a trend for increased FRNK protein expression. SCI did not change levels of the α7 or β1 integrin subunits, total or phosphorylated ERK1/2, phosphorylated Akt and TSC2 or total p70S6k. SCI resulted in a greater expression of total Akt. mRNA expression of FAK and the α7 or β1 integrins remained unchanged between sham and SCI groups. Caspase-3/7 activity and Trim72 mRNA and protein expression remained unchanged following SCI.


CONCLUSIONS
SCI results in diminished FAK signaling and is independent of ERK1/2 and Akt. SCI has no effect on mRNA levels for genes encoding components of the focal adhesion 56 days after injury.
James J. Peters Veterans Affairs Medical Center, National Center of Excellence for the Medical Consequences of Spinal Cord Injury, Bronx, NY, USA.|Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Z A
ZA
Graham
James J. Peters Veterans Affairs Medical Center, National Center of Excellence for the Medical Consequences of Spinal Cord Injury, Bronx, NY, USA.|Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
W
W
Qin
James J. Peters Veterans Affairs Medical Center, National Center of Excellence for the Medical Consequences of Spinal Cord Injury, Bronx, NY, USA.
L C
LC
Harlow
James J. Peters Veterans Affairs Medical Center, National Center of Excellence for the Medical Consequences of Spinal Cord Injury, Bronx, NY, USA.
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NH
Ross
James J. Peters Veterans Affairs Medical Center, National Center of Excellence for the Medical Consequences of Spinal Cord Injury, Bronx, NY, USA.|Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.|Department of Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
W A
WA
Bauman
Applied Physiology Laboratory, University of Kansas, Lawrence, KS, USA.
P M
PM
Gallagher
James J. Peters Veterans Affairs Medical Center, National Center of Excellence for the Medical Consequences of Spinal Cord Injury, Bronx, NY, USA.|Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.|Department of Rehabilitation Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA.|Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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CP
Cardozo
D000818:Animals; D020169:Caspases / Q000378:metabolism; D004195:Disease Models, Animal; D051417:Focal Adhesion Kinase 1 / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D020935:MAP Kinase Signaling System / Q000502:physiology; D008297:Male; D018482:Muscle, Skeletal / Q000201:enzymology*; D051058:Oncogene Protein v-akt / Q000378:metabolism; D010766:Phosphorylation; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000378:metabolism / Q000473:pathology*
D012333:RNA, Messenger; D051417:Focal Adhesion Kinase 1; C496052:Ptk2 protein, rat; D051058:Oncogene Protein v-akt; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D020169:Caspases