Laminar regulation of STAT1 and STAT3 in black walnut extract and carbohydrate overload induced models of laminitis.
BACKGROUND
STAT1 and STAT3 are important signaling molecules in disorders of systemic inflammation and are likely to be involved in laminitis, as laminar and systemic inflammation have been well documented in experimental models of laminitis.


OBJECTIVE
The STAT1 and STAT3 activation (via phosphorylation of tyrosine and serine moieties) is occurring in the laminar tissue during the developmental and onset of lameness time points in both the black walnut extract (BWE) and carbohydrate overload (CHO) models of laminitis.


METHODS
Archived laminar tissue from horses.


METHODS
Experimental studies of induced laminitis (BWE and CHO administration) in horses were conducted and laminar tissue samples archived. Western hybridization was performed to determine concentrations of Tyr- and Ser-phosphorylated STAT1 and STAT3 from these archived samples. The RT-qPCR was also performed to assess mRNA concentrations of target genes of STAT1 and STAT3.


RESULTS
Increases (P < .05) in phosphorylation of tyrosine705 and serine727 of STAT3, demonstrated by band intensity ratios, are present in laminar tissue from both the BWE and CHO models at the DEV and OG1 time points. No change in phosphorylation of tyrosine701 or serine727 of STAT1 was present in the laminar tissue from either the BWE or the CHO models. The SOCS3 mRNA concentrations were increased at the onset of lameness in both the CHO and BWE models.


CONCLUSIONS
The STAT3 activation likely plays a role in equine laminitis, similar to its reported involvement in organ injury/failure in human sepsis. Regulation of JAK-STAT, through STAT3 inhibitors, might serve as potential therapeutic target for controlling the inflammatory response in the septic horse.
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA.
B S
BS
Leise
M
M
Watts
E
E
Tanhoff
P J
PJ
Johnson
S J
SJ
Black
J K
JK
Belknap
D000818:Animals; D015153:Blotting, Western; D004195:Disease Models, Animal; D005534:Foot Diseases / Q000378:metabolism / Q000662:veterinary*; D006734:Horse Diseases / Q000378:metabolism*; D006736:Horses; D007150:Immunohistochemistry / Q000662:veterinary; D007249:Inflammation / Q000378:metabolism / Q000662:veterinary; D007794:Lameness, Animal / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D012189:Retrospective Studies; D050794:STAT1 Transcription Factor / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D050796:STAT3 Transcription Factor / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D018709:Statistics, Nonparametric
D012333:RNA, Messenger; D050794:STAT1 Transcription Factor; D050796:STAT3 Transcription Factor