[Show abstract][Hide abstract] ABSTRACT: The expression of the cannabinoid receptor type 2 (CB2R) was investigated by immunohistochemistry, Western blotting, and RT-PCR during wound healing of contused skeletal muscle in rats with attempt of its applicability to skeletal muscle wound age estimation. Furthermore, Macrophage Marker (MAC387) was utilized to identify macrophages recruited into injured skeletal muscle tissue. Co-localization of CB2R with Macrophage Marker was detected by confocal laser scanning microscopy. A total of 50 Sprague-Dawley male rats were divided into control and contusion groups (3 h, 6 h, 12 h, 1 day, 3 days, 5 days, 7 days, 10 days, and 14 days post-injury). In the uninjured controls, immunoreactivity of CB2R was detected in the sarcolemma and sarcoplasm of normal myofibers. In the contusion groups, a few polymorphonulcear cells, a large number of macrophages, and spindle-shaped fibroblastic cells showed a positive staining for CB2R in wounded zones. By Western blotting analysis, the average of CB2R to GAPDH ratios in 5-7 days post-injury groups was highest, and all the samples had ratios of >2.60. In the other groups, no samples showed ratios of >2.60 and the CB2R to GAPDH ratios ranged from 1.19 to 2.59. The expression tendency was also confirmed by RT-PCR. From the viewpoint of forensic pathology, these observations suggested that the ratio markedly exceeding 2.60 strongly indicated a wound age of 5-7 days. In conclusion, dynamic distribution and expression of CB2R suggest that CB2R be involved in modulating macrophages in response to inflammatory event in rat skeletal muscle wound healing and CB2R be available as a marker for wound age determination.
Full-text · Article · Sep 2010 · Deutsche Zeitschrift für die Gesamte Gerichtliche Medizin
[Show abstract][Hide abstract] ABSTRACT: To investigate the expression of cannabinoid receptor I (CB1R) during mice skin incised wound healing course and time-dependent changes of CB1R in wound age determination.
The changes of CBIR expression in skin incised wound were detected by immunohistochemistry and Western blotting.
The control group showed a low expression of CB1R detected mainly in epidermis, hair follicles, sebaceous gland and dermomuscular layer. CB1R expression was undetectable in neutrophils in the wound specimens from 6h to 12h post-injury. CB1R positive cells were mostly mononuclear cells (MNCs) and fibroblastic cells (FBCs) from 1 d to 5 d post-injury. CB1R positive cells were mostly FBCs from 7 d to 14d post-injury. The ratio of the CB1R positive cells increased gradually in the wound specimens from 6 h to 3 d post-injury, reached peak level at 5 d, and then decreased gradually from 7d to 14 d post-injury. The positive bands of CB1R were observed in all time points of the wound healing course by Western blotting. The expression peak showed at 5 d post-injury.
CB1R is activated during the wound healing course. The expression of CB1R is found in mononuclear cells, which could be involved in inflammation reaction. CBIR is observed in fibroblastic cells, which could participate in the wound healing. CB1R may be a potentially useful marker for determination of wound healing age.
No preview · Article · Aug 2010 · Fa yi xue za zhi
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE To investigate the time-dependent expression of c-jun during the healing of incised wound in mice skin.
The expression of c-jun in different stages after the incised wound were detected by immunohistochemistry and Western blot.
There was a low level expression of c-jun in normal mice skin. Expression of c-jun was mainly detected in neutrophils from 3 h to 12h after injury. The c-jun positive cells were almost mononuclear cells (MNCs) and fibroblasts between 1 d and 5 d after injury. The c-jun positive cells were mostly fibroblasts between 7 d and 14 d after injury. The ratio of the c-jun positive cells increased in the wound specimens from 3 h to 12 h, peaked at 12 h, declined partially from 1 d to 5 d, and reached the peak secondly at 7 d, then decreased from 10 d to 14 d. The expression of c-jun was observed throughout the wound healing stages by Western blot with two peaks occurring at 12 h and 7 d after injury.
The c-jun may play a potential role in inducing apoptosis of neutrophils, MNCs and fibroblasts during skin wound healing, and it may be used as the marker for wound age determination.
No preview · Article · Dec 2009 · Fa yi xue za zhi
[Show abstract][Hide abstract] ABSTRACT: To investigate the changes of phospho-JNK (p-JNK) during the incised wound healing of the skin in mice and to explore the rule of the time-dependent change of p-JNK in wound age determination.
The changes of p-JNK expression in incised skin wound were detected by immunohistochemistry and Western blot.
There was a minimal baseline staining of p-JNK in control mouse skin. Changes of p-JNK expression were mainly detectable in neutrophils in the wound specimens from 3 hours to 12 hours after injury. Afterwards, the p-JNK positive cells were mostly mononuclear cells and fibroblasts between post-injury day 1 and day 5, whereas the p-JNK positive cells were mostly fibroblasts between post-injury day 7 and day 14. Morphometrically, the ratio of the p-JNK positive cells to the total increased gradually in the wound specimens from 3 hours to day 1, and maximized at day 1 with a slight decrease from post-injury day 3 to day 5. The ratio showed a second peak in the specimens of day 7, and then decreased gradually from post-injury day 10 to day 14. The changes of p-JNK expression were observed throughout the wound healing stages by Western blot as well, with a peak expression occurring between 12 hour and day 3 after injury.
p-JNK may play a pivotal role in inducing apoptosis of neutrophils, mononuclear cells, and fibroblasts during skin wound healing and meanwhile, p-JNK may be a potentially useful marker for wound age determination.
No preview · Article · Sep 2008 · Fa yi xue za zhi
[Show abstract][Hide abstract] ABSTRACT: To establish a new animal model of grading skeletal muscle contusions that could be controllable and repetitive.
The rats' gastrocnemius was injured by a new weight-dropping device designed. The force acting on gastrocnemius with a comparatively constant duration and inducing elastic deformation of the gastrocnemius was expressed with velocity (v) and deformation (DF). Instant velocity was changed to create gastrocnemius contusions. Pathological changes of gastrocnemius were graded by the gross and histological examinations of 39 rats.
At low level of impact (v: 2 m/s, DF: 5.5 mm), mild injuries were detected in epimysium and superficial layer of gastrocnemius. At moderate level of impact (v: 2.5 m/s, DF: 6.5 mm), the injuries were observed in epimysium and whole gastrocnemius. At high level of impact (v: 3 m/s, DF: 7.5 mm), severe injuries were seen deeper to soleus with more extensive skeletal muscle damage.
Grading of skeletal muscle blunt force contusion is created by parameter of velocity and muscle deformation. The model could be used for further research on skeletal muscle contusions.
No preview · Article · Jul 2008 · Fa yi xue za zhi