[Expressions and time-dependent changes of FAK and phospho-FAK during skin incised wound healing in mouse].

OBJECTIVE: To study the expressions of focal adhesion kinase (FAK) and phospho-FAK( p-FAK) during skin incised wound healing and the applicability of time-dependent expressions of FAK and p-FAK. METHODS: The expression of FAK and p-FAK in cutaneous incised wound in mouse were investigated by immunohistochmeistry and Western blotting. RESULTS: FAK and p-FAK expression were detected in polymorphonuclear cells (PMNs) in the wound and adjacent regions 3 hours post-injury. The expressions of FAK and p-FAK were detected in a large number of infiltrating PMNs and some of mononuclear cells (MNCs) from 6 to 24 hours after injury. The MNCs and fibroblastic cells (FBCs) accounted for most part of the FAK and p-FAK positive cells from 3 to 14 days after injury. The numbers of FAK-positive cells increased continuously, reaching a peak at post-injury day 3, and then started to decrease from post-injury day 5 to 14. The changes of p-FAK-positive cells were similar to that of the FAKs, and reached a peak at 12 hours after injury. CONCLUSION: Both FAK and p-FAK displayed a time-dependent expression during skin incised wound healing in mouse, with p-FAK being superior to FAK. Both FAK and p-FAK may potentially be used as new markers for determination of the wound interval.

[Time-dependent expression of caspase-3 during contused skeletal muscle wound healing in rats].

OBJECTIVE: To investigate the expression of caspase-3 during contused skeletal muscle wound healing in rats and to explore the applicability of caspase-3 in wound age estimation. METHODS: Male Sprague-Dawley rats undergone anesthesia with 2% pentobarbital sodium (45 mg/kg) were struck by a single strike at the skeletal muscle of the right leg, then were sacrificed by cervical dislocation at different post-traumatic intervals. The changes of caspase-3 activity were assessed by imunohistochemistry, Western blot and caspase-3 colorimetric assay. The skeletal muscle of non-contusion rat's were used as controls. RESULTS: No caspase-3 was detected in skeletal muscle in the control group. The expression level of caspase-3 in the peripheral area of contused rat skeletal muscle increased gradually and maximized on the fifth day after injury, and then decreased gradually. Caspase-3 was also detected in the regenerated skeletal muscle within 7-14 days after injury. CONCLUSION: The expression of capase-3 in the peripheral area of contused rat skeletal muscle indicated that it may play a pivotal role in apoptosis of the wounded skeletal muscle and may be used as a marker for wound age estimation. The expression of capase-3 in regenerating skeletal muscle suggests that caspase-3 activity may be used for skeletal muscle differentiation.

[A study on the time-dependent expression of phospho-p38MAPK during the skin incised wound healing in mice].

OBJECTIVE: To investigate the expressions of phospho-p38MAPK(p-p38MAPK) during the incised wound healing of the skin in mice and to explore the applicability of the time-dependent expressions of p-p38MAPK in the determination of wound age. METHODS: The expression of p-p38MAPK in incised skin wound was detected by immunohistochemistry and Western blot. RESULTS: There was a minimal baseline expression of p-p38MAPK in control mouse skin. Expression of p-p38MAPK was mainly detectable in neutrophils in the wound specimens from 3hours to 12 hours after injury. Afterwards, the p-p38MAPK positive cells were mostly mononuclear cells and fibroblasts between post-injury day 1 and day 5, whereas the p-p38MAPK positive cells were mostly fibroblasts between post-injury day 7 and day 14. Morphometrically, the ratio of the p-p38MAPK positive cells to total number of the cells increased gradually in the wound specimens aged from 3 hours to 12 hours, and maximized in the wound specimens aged 12 hours with a slight decrease at 24 hours after injury. The ratio maintained at high level from post-injury day 3 to day 5, and then decreased gradually from post-injury day 7 to day 14. The expression of p-p38MAPK was observed throughout the wound healing stages by Western blot as well with a peak expression occurring between 12hour and day 3 after injury. CONCLUSION: Our data suggest that p-p38MAPK may play an important role in inducing apoptosis of neutrophils, mononuclear cells, and fibroblasts during skin wound healing and meanwhile, p-p38MAPK may be a potentially useful marker for wound age determination.