Reduction of PGRN increased fibrosis during skin wound healing in mice.

Progranulin (PGRN) is a multi-functional growth factor known to be involved in regulating of development, cell cycle progression, cell motility, tumorigenesis and angiogenesis. Research has revealed that PGRN is a crucial mediator of skin wound healing. Nonetheless, the role of PGRN in the fibrosis process of cutaneous wound healing has not been identified. In the present study, mice with excisional wounds were treated with si-m-PGRN or physiological saline. We observed the expression of PGRN in intact and post-injury skin by immunohistochemistry. Tissue sections of skin around the wound were performed by hematoxylin & eosin and masson's trichrome staining. After PGRN knockdown by siRNA, the expression of PGRN, collagen I (Col I), small mothers against decapentaplegic homolog 3 (Smad3), phosphorylated Smad3 (P-Smad3), transforming growth factor (TGF)-ß1 and TGF-ß receptor I (TßRI) were detected by real-time reverse transcription polymerase chain reaction (RT-qPCR) or Western blot. PGRN mRNA and protein expressions were increased after insult and remained above that of intact skin through day 20. Down-regulation of PGRN augmented fibrosis area, skin thickness and the expression of Col I. In addition, reduction of PGRN considerably increased the expression of TGF-ß1, TßRI, Smad3 and P-Smad3. These results indicate that PGRN knockdown enhances the fibrosis degree, probably via the TGF-ß/Smad signaling pathway.

[Expression of caspase-3 and HAX-1 after cerebral contusion in rat].

OBJECTIVE: To observe the expression pattern of caspase-3 and HCLS1-associated protein X-1 (HAX-1) at different time after cerebral contusion in rat, and explore the new method for estimating the injury interval. METHODS: The cerebral contusion model was established using adult SD male rats. Then the rats were randomly allocated into 8 groups: 2 h, 6 h, 12 h, 1 d, 3 d, and 7 d after cerebral contusion, sham-operation and normal control. Expression of caspase-3 and HAX-1 protein after cerebral contusion in rat was detected by Western blotting. Laser scanning confocal microscope was used to observe the number of HAX-1 positive cells and TUNEL-stained cells after cerebral contusion. RESULTS: The expression of caspase-3 increased parallelly with the time after cerebral contusion and reached the peak value on 3 d. The expression of caspase-3 decreased gradually and still maintained a high level expression on 7 d (P < 0.05). The expression of HAX-1 positive cell went up after injury, and reached the peak value at 6 h (P < 0.05), then turned down gradually after 12 h and went out of detection after 3 d. The number of TUNEL-stained cells increased obviously at 2 h and reached the peak value on 3 d. The number of TUNEL-stained apoptotic cells decreased gradually and still maintained a high level expression on 7 d (P < 0.05). CONCLUSION: The expression of caspase-3 and HAX-1 after cerebral contusion has time sequential regularity, which may provide new evidence for forensic diagnosis of cerebral contusion interval.

[Time-order expression of caspase-3 and iNOS in contused human brain tissue].

OBJECTIVE: To investigate the expression of caspase-3 and iNOS in different intervals and to provide evidence for estimation of injury intervals after brain contusion in human. METHODS: Thirty cases died of serious brain injury were included into the injury groups and 5 cases died of non-brain injury were served as control group. To analyze the changes of caspase-3 and iNOS expression in brain samples at different intervals (2h, 4-8h, 10-14h, 1-2d, 3-5d, 8-11d) by immunohistochemistry and auto-image analysis system. RESULTS: The level of caspase-3 expression started to increase in 2 hours after brain contusion compared to the control group (P<0.05). The level of caspase-3 expression continued to increase in 1-2 days and maintained high level in 3-5 days compared to the control group (P<0.05), then decreased gradually. There was no statistically significant difference between the expression level of iNOS in 2 hours with the control group (P>0.05). But the expression level of iNOS began to increase in 4-8 hours after brain contusion and reached its maximum in 1-2 days, then decreased. Weak expression of iNOS still could be detected in 8-11 days. CONCLUSION: The expression of caspase-3 and iNOS can be used as effective evidence for human brain contusion interval.