Effects of early rehabilitation in improvement of paediatric burnt hands function.

BACKGROUND: Hands are one of the most common burn sites in children. Hypertrophic scar contractures in hands after wound healing result in further reductions in their range of motion (ROM), motility, and fine motor activities. Rehabilitation can improve the function of hands. But the optimal time of rehabilitation intervention is still unclear. Therefore, this study was designed to investigate the effects of early rehabilitation management of paediatric burnt hands and to compare the efficacy between early and later rehabilitation intervention. AIM: To investigate the effects of early rehabilitation management of paediatric burnt hands. METHODS: A total of 52 children with burnt hands were allocated into the early intervention group (≤ 1 mo from onset) and a late intervention group (> 1 mo from onset) between January 2016 and December 2017. The children received the same rehabilitation programme including skin care, scar massage, passive ROM exercises, active ROM exercises, compression therapy, orthotic devices wearing and game or music therapy. Rehabilitation assessments were performed before and after the rehabilitation treatment. RESULTS: In the early intervention group, the ROM of the hands was significantly improved after rehabilitation (P = 0.001). But in the late group the effect was not significant statistically (P = 0.142). In the early group, 38.5% of the patients showed significant improvement, while in the late group, 69.2% of the patients showed no significant improvement. The time from onset to posttraumatic rehabilitation (P = 0.0007) and length of hospital stay (P = 0.003) were negatively correlated with the hand function improvement. The length of rehabilitation stay was positively correlated with the hand function improvement (P = 0.005). CONCLUSION: These findings suggest that early rehabilitation might show better results in terms of ROM.

Process of Hypertrophic Scar Formation: Expression of Eukaryotic Initiation Factor 6.

BACKGROUND: Hypertrophic scar is one of the most common complications and often causes the disfigurement or deformity in burn or trauma patients. Therapeutic methods on hypertrophic scar treatment have limitations due to the poor understanding of mechanisms of hypertrophic scar formation. To throw light on the molecular mechanism of hypertrophic scar formation will definitely improve the outcome of the treatment. This study aimed to illustrate the negative role of eukaryotic initiation factor 6 (eIF6) in the process of human hypertrophic scar formation, and provide a possible indicator of hypertrophic scar treatment and a potential target molecule for hypertrophic scar. METHODS: In the present study, we investigated the protein expression of eIF6 in the human hypertrophic scar of different periods by immunohistochemistry and Western blot analysis. RESULTS: In the hypertrophic scar tissue, eIF6 expression was significantly decreased and absent in the basal layer of epidermis in the early period, and increased slowly and began to appear in the basal layer of epidermis by the scar formation time. CONCLUSIONS: This study confirmed that eIF6 expression was significantly related to the development of hypertrophic scar, and the eIF6 may be a target molecule for hypertrophic scar control or could be an indicator of the outcomes for other treatment modalities.

Eukaryotic initiation factor 6 modulates myofibroblast differentiation at transforming growth factor-ß1 transcription level via H2A.Z occupancy and Sp1 recruitment.

Eukaryotic initiation factor 6 (eIF6) is a pivotal regulator of ribosomal function, participating in translational control. Previously our data suggested that eIF6 acts as a key binding protein of P311 (a hypertrophic scar-related protein; also known as NREP). However, a comprehensive investigation of its functional role and the underlying mechanisms in modulation of myofibroblast (a key effector of hypertrophic scar formation) differentiation remains unclear. Here, we identified that eIF6 is a novel regulator of transforming growth factor-ß1 (TGF-ß1) expression at transcription level, which plays a key role in myofibroblast differentiation. Mechanistically, this effect is associated with eIF6 altering the occupancy of the TGF-ß1 promoter by H2A.Z (Swiss-Prot P0C0S6) and Sp1. Accordingly, modulation of eIF6 expression in myofibroblasts significantly affects their differentiation via the TGF-ß/Smad signaling pathway, which was verified in vivo by the observation that heterozygote eIF6(+/-) mice exhibited enhanced TGF-ß1 production coupled with increased α-smooth muscle actin (α-SMA)(+) myofibroblasts after skin injury. Overall, our data reveal a novel transcriptional regulatory mechanism of eIF6 that acts on facilitating Sp1 recruitment to TGF-ß1 promoter via H2A.Z depletion and thus results in increased TGF-ß1 transcription, which contributes to myofibroblast differentiation.

[Effects of P 311 on the migration of epidermal stem cells in mice with superficial partial-thickness burn and injured cell model in vitro].

OBJECTIVE: To study effects of P311 on the migration of epidermal stem cells (ESCs) in mice with superficial partial-thickness burn and injured cell model in vitro and to explore the mechanism. METHODS: (1) Eighteen male C(57) BL/6 mice were used. Fifteen of them were inflicted with superficial partial-thickness burn on the back. In three injured mice wound tissue and skin of wound edge were obtained at post burn hour (PBH) 6, 12, 24, 48, 72 respectively. The rest three mice were used as normal control, and samples were harvested with the same method as above. The expressions of P311 in harvested samples were assessed with biotin-streptavidin-peroxidase (SP) staining. (2) Six newly born C(57) BL/6 mice were intraperitoneally injected with 50 µg/g BrdU (two times a day) for three days for ESCs-labelling. Seven weeks later, the mice were inflicted with superficial partial-thickness burn on the back. Serial slices of burn wound tissue were prepared at PBH 72 and immunohistochemically stained with SP for observation of the co-localization of BrdU-positive ESCs and P311-positive cells. (3) The empty vector pAdEasy-enhanced green fluorescence protein (EGFP) and the adenovirus P311-expressing vector named pAdEasy-EGFP-P311 were constructed and packed. Human ESCs were isolated by the method of rapid adhesion to collagen IV. After being divided into P311 high-expressing group (n = 3) and EGFP control group (n = 3), the ESCs in two groups were respectively infected by pAdEasy-EGFP-P311 and pAdEasy-EGFP. Scratching assay was performed on ESCs in both groups after they were treated by mitomycin C for 2 hours. The remaining area within the fixed range was measured at post scratching hour (PSH) 0, 24, 48, and 72, and the wound-area healing rate was calculated. Data were processed with independent samples t test. RESULTS: (1) Expression amount of P311 was different in different parts of wound at different time points after burn. Expression amount of P311 in the newly formed epidermis and hair follicle of wound increased along with prolongation of time. Expression amount of P311 in the epidermis and hair follicle of wound edge peaked at PBH 12 and then decreased to normal levels at PBH 72. (2) Co-localization of BrdU-positive ESCs and P311-positive cells was observed in the new epidermal layer of wound tissue of mice, where ESCs were labeled by BrdU. (3) At PSH 48 and 72, wound-area healing rate was obviously higher in P311 high-expressing group [(69 ± 31)%, (89 ± 26)%] than in EGFP control group [(35 ± 12)%, (46 ± 31)%, with t values respectively -2.336, -2.611, P values all below 0.05]. CONCLUSIONS: P311 may promote the migration of ESCs both in rats with superficial partial-thickness burns and in injured cell model in vitro, and it may play an important role in wound healing.

[Biologic effect of nitric oxide on human epidermal stem cells in vitro].

OBJECTIVE: To observe the effect of nitric oxide (NO) on adhesion, proliferation, and migration of human epidermal stem cells (ESC) in vitro. METHODS: ESC were isolated and cultured by the modified method of rapid attachment to type IV collagen. (1) Morphology of cells was observed under inverted phase-contrast microscope. Expression levels of integrin ß(1) and cytokeratin 19 (CK19) of cells were determined by Western blotting and immunofluorescence staining. (2) After being treated with scratching, ESC adhered to the wall was respectively treated with nitric oxide (NO) donor S-nitroso-N-acetylpenicillamine (SNAP) in the concentration of 1, 10, 100, 500 µmol/L. ESC without treatment of SNAP was used as control. The migration rate of ESC was detected at post scratching hour (PSH) 12 and 24. The chemotaxis of ESC (treated with SNAP in above-mentioned concentration) was tested by Transwell assay, and the transferred cell number was counted. (3) ESC was respectively treated with SNAP in the concentration of 10, 100, 500 µmol/L for 1 h. ESC without treatment of SNAP was used as control. The adhesion of ESC was detected with adhesion test, and the inhibition rate of adhesion was calculated. The proliferation of ESC (denoted as absorbance value) was determined by microplate reader at post-treatment hour (PTH) 0, 12, 24, 48. Data were processed with one-way analysis of variance and Dunnett t test. RESULTS: (1) Small clone formed on post culture days (PCD) 5 to 9. On PCD 10 to 14, cell proliferation sped up. CK19 and integrin ß(1) were detected to be expressed in the isolated cells. The cells were identified as ESC. (2) Compared with that of ESC without treatment of SNAP [(35.7 ± 0.3)%, (45.7 ± 5.0)%], migration of ESC treated with SNAP in the concentration from 1 to 100 µmol/L was promoted at PSH 12 and 24. Migration rates of ESC treated with 100 µmol/L SNAP were the highest [respectively (48.8 ± 2.7)%, (82.1 ± 15.8)%, with t value respectively 8.34, 5.10, P values both below 0.01]. The number of ESC transferred to membrane after being treated with 100 µmol/L SNAP was significantly larger than that of ESC without treatment of SNAP (t = 9.24, P = 0.00). (3) Absorbance values of ESC treated with 100, 500 µmol/L SNAP were obviously higher than that of ESC without treatment of SNAP (with t value respectively 4.30, 4.67, P values both equal to 0.00). Proliferation of ESC treated with 100, 500 µmol/L SNAP was obviously stronger than that of cells without treatment of SNAP at PTH 24, 48 (with t values from 2.84 to 8.17, P values all below 0.05). CONCLUSIONS: Exogenous NO in suitable concentration can promote the migration of human ESC. Exogenous NO can inhibit the adhesion and promote the proliferation of human ESC in vitro.

[The therapeutic strategy for burn wounds].

Wound repair is the critical issue in burn injury management. Optimal coverage or regeneration of skin tissue is still a great challenge. In this review, we summarize the current achievements in the fields of immune tolerance induction, skin tissue regeneration, and hypertrophic scar control, which might provide new viewpoints and research direction for diagnosis and treatment of burn wounds.

[Study of xenotransplantation of fetal pig skin precursor tissue].

OBJECTIVE: To select the optimal pregnancy time window of embryonic pig skin precursor tissue for xenotransplantation and study its ability in wound repair. METHODS: Skin precursor tissues were obtained from pig fetus of fetal age of 35, 42, 56, 70 days, and were minced into microskin and transplanted to dorsal wounds of BALB/c nude mice, then they were covered with residual skin after plastic surgery of patients or adult pig skin (white). The characteristics of growth and development were observed after transplantation. Pathological examination was performed on 6 and 12 post operation weeks respectively to observe the tissue structure and tumorigenicity. RESULTS: Skin precursor tissues from fetal pig survived and developed after transplantation, and the microskin fused. New tissue area from skin precursor tissues with fetal age of 42 days was (47 +/- 6) mm2, which was higher than that of 35 days (18 +/- 8 mm2), 56 days (31 +/- 12 mm2), 70 days (20 +/- 8 mm2, P < 0.05). The skin precursor developed into "intact skin" with hair, sebaceous glands and sweat glands, and melanocytes were also detected in epidermis. The newly-grown skin tissue included epidermal and dermal layer, and obvious dermal papillae. Teratoma was not found after transplantation in skin precursor tissue with fetal age of 56, 70 days. CONCLUSION: Fetal pig skin precursor tissue with fetal age of 56 days can be used to repair wound as xenotransplantation.