Tec kinase mediating IL-8 transcription in monocytes stimulated with LPS.

The purpose of present study was to explore the possibility of Tec kinase as a mediator for IL-8 transcription in monocytes stimulated with LPS. Plasmids of mouse Tec kinase IV or Tec kinase IV with inactivating point mutations generated with QuikChange site-directed mutagenesis were co-transfected with IL-8 promoter driven luciferase construct into RAW264.7 cells, then luciferase activity was measured with a luminometer. The results shown Tec kinase could significantly enhance IL-8 transcription. Furthermore, point inactivating mutation in SH2, PH or PTK domain almost completely abolish the effects of Tec kinase on the transcription of IL-8. In the transfection experiment, PD98059, a MEK1 inhibitor, decreased the transcription of IL-8 in a dose dependent pattern. When siRNA for Tec kinase was transfected into THP-1 cells, it could efficiently block the production of IL-8 from THP-1 cells (p < 0.01) stimulated with LPS. In conclusion, Tec kinase may mediate the transcription of IL-8 in monocyte stimulated with LPS.

Transplantation of epidermis of scar tissue on acellular dermal matrix.

This study enrolled 22 participants with hypertrophic scarring after burn who received treatment with co-transplantation of acellular dermal matrix and epidermis of either normal skin or scar tissue. Scar thickness was evaluated with high frequency ultrasonography and the distribution of keratinocyte stem cells was detected by immunostaining. The results showed p63-positive keratinocyte stem cells throughout the epidermis of scar tissue. However, if co-transplanted on acellular dermal matrix, this effectively inhibited scar formation and pruritus, providing an alternative method to treat hypertrophic scarring.

[Reconstruction and transplantation of the composite skin comprising epithelial growth factor gene-transfected keratinocytes].

OBJECTIVE: To investigate the epithelial growth factor (EGF) expression of EGF gene-transfected keratinocytes and its effect on cell proliferation after grafting. METHODS: Newborn Balb/c mouse keratinocytes and gene transfected keratinocytes were seeded on the surface of acellular dermal matrix and cocultured in different ratios as follows: 1:1, 1:3, or 1:5 1 week after culture. The composite skin was grafted onto the full-thickness wound in Balb/c mouse. Specimen was harvested at interval after grafting and underwent the immunohistochemistry staining for EGF and proliferating cell nuclear antigen (PCNA). RESULTS: Immunohistochemical staining showed EGF was expressed in the newly generated epidermis 1-2 week after grafting of the composite skin comprising Balb/c mouse keratinocytes and gene-transfected keratinocytes (at the ratio of 1:5). One week after surgery, Anti-PCNA positive basal cells were more than that in composite skin containing Balb/c mouse keratinocytes alone (P<0.01). CONCLUSION: The gene-transfected keratinocytes expresses EGF and promotes the proliferation of keratinocytes in the early stage after transplantation.

[Role of p38 mitogen-activated protein kinase signal transduction pathway in the acute lung injury of severely burned rats].

OBJECTIVE: To investigate the role of p38 mitogen-activated protein kinase (MAPK) signal transduction pathway in the acute lung injury of severely burned rats. METHODS: Forty-eight adult healthy rats were randomly divided into three groups: sham group, burn control group, and burn + SB203580 group. A third-degree burns over 30% total body surface area rat model was used and pulmonary capillary permeability, lung water content, pulmonary histology and p38 MAPK activity were measured at 24 hours postburn. RESULTS: Burn trauma resulted in increased pulmonary capillary leakage permeability (42.5 +/- 4.7 vs. 12.1 +/- 1.4, P < 0.01), elevated lung water content (P < 0.05), and worsen histologic condition. There was a significant activation of p38 MAPK at 24 hours postburn compared with control. SB203580 inhibited the activation of p38 MAPK, reduced the pulmonary capillary leakage permeability (24.7 +/- 2.9 vs. 42.5 +/- 4.7, P < 0.01), decreased lung water content, and prevented burn-mediated lung injury. CONCLUSION: The activation of p38 MAPK is one important aspect of the signaling event that contributes to burn-induced lung injury.

Expression and regulation of vascular cell adhesion molecule-1 in human umbilical vein endothelial cells induced by sera from severely burned patients.

OBJECTIVE: The purpose of this study was to determine the expression and regulation of vascular cell adhesion molecule (VCAM)-1 in human umbilical vein endothelial cells (HUVECs) induced by sera from severely burned patients. DESIGN: Controlled laboratory study. SETTINGS: Research laboratory in a university hospital. SUBJECTS: HUVECs. INTERVENTIONS: HUVECs were incubated with serum from eight healthy controls and eight patients with thermal injuries of >50% total body surface area. The experiment was repeated after pretreatment with pyrrolidine dithiocarbamate, an inhibitory effect on nuclear factor-kappaB activation, SB203580, a specific p38 mitogen-activated protein kinase inhibitor, and PD98059, a mitogen-activated protein/extracellular signal-regulated kinase inhibitor. MEASUREMENTS AND MAIN RESULTS: Protein and messenger RNA expression of VCAM-1 was measured by flow cytometry and reverse transcription-polymerase chain reaction respectively. Soluble VCAM-1 level in HUVECs culture supernatants was measured by enzyme-linked immunosorbent assay. Sera from severely burned patients showed a stimulatory effect on VCAM-1 messenger RNA levels and an increased VCAM-1 expression on the endothelial cell surfaces. The soluble form of VCAM-1 molecules was also elevated by the stimulation of burn sera. In vitro peripheral blood mononuclear leukocytes adherence to HUVECs incubated with burn sera was significantly increased compared with those incubated with control sera. Finally, these events were significantly inhibited by pretreatment with antioxidants pyrrolidine dithiocarbamate or SB203580, whereas PD98059 had no significant effect. CONCLUSIONS: These findings suggest that sera from severely burned patients induced up-regulation of VCAM-1 expressions in HUVECs, and this process might be largely dependent on oxidant-mediated nuclear factor-kappaB activation and p38 mitogen-activated protein kinase pathways.

[Mechanism of p38 mitogen-activated protein kinase in postburn acute pulmonary injury in scalded rats].

OBJECTIVE: To investigate the role of p38 mitogen-activated protein kinase (MAPK) signal transduction pathway in the production of the proinflammatory factors such as tumor necrosis factor (TNF-alpha) and interleukin 1beta (IL-1beta) in lungs and in the pulmonary endothelial cell injury in severely scalded rats. METHODS: Forty eight adult healthy SD rats were randomly divided into three groups with 16 rats in each group, i.e. sham, burn and burn with SB203580 treatment groups. The changes in the TNF-alpha and IL-1beta contents in serum and bronchoalveolar lavage fluid (BALF), the von Willebrand factor (vWF) contents in plasma and pulmonary microvessels and pulmonary activating protein (AP-1) activity were determined at 24 postburn hours (PBH). RESULTS: Compared with those in sham group, the TNF-alpha and IL-1beta contents in serum and BALF and the vWF content in plasma (194.2% +/- 28.3% vs 93.2% +/- 14.3%) at 24 PBH in burn group increased significantly (P < 0.01), whereas vWF content in pulmonary microvessel decreased obviously (1.1 +/- 0.3 vs 3.3 +/- 0.4, P < 0.01). In addition, the pulmonary AP-1 activity also increased at 24 PBH. Nevertheless, all the above indices improved obviously in burn with SB203580 (inhibitor of p38 MAPK signal transduction pathway) treatment group when compared with those in burn group. CONCLUSION: AP-1 might mediate the production of proinflammatory factors, such as TNF-alpha and IL-1beta in lungs leading to pulmonary vascular endothelial injury, after being activated by activated p38 MAPK.

Role of p38 mitogen-activated protein kinase in Kupffer cell secretion of the proinflammatory cytokines after burn trauma.

This study was designed to investigate the role of p38 mitogen-activated protein (MAP) kinase on Kupffer cells (KCs) secretion of proinflammatory cytokines such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta and hepatic injury following burn trauma. Sprague-Dawley rats were randomized into four groups: (1) sham burn rats given vehicle, (2) sham burn rats given the p38 MAP kinase inhibitor SB203580 (10mg/kg i.v., 15min and 12h after sham burn), (3) rats given a 30% total body surface area (TBSA) full-thickness burn and fluid resuscitation plus vehicle, and (4) burn rats given injury and fluid resuscitation plus SB203580. Rats from each group were killed at 24h post-burn to examine plasma aspartate transaminase (AST) and alanine transaminase (ALT) and KCs were isolated. The KCs secretion of TNF-alpha and IL-1beta and p38 MAP kinase activity (by Western blot analysis) were also examined. These studies showed by more significant activation of p38 MAP kinase in KCs harvested from burn rats than from shams. Burn trauma resulted in hepatic dysfunction and promoted KCs secretion of TNF-alpha and IL-1beta. SB203580 inhibited p38 MAP kinase activity, reduced KCs secretion of proinflammatory cytokines, and alleviated burn-mediated hepatic dysfunction. These data suggest p38 MAP kinase activation is one important aspect of the signaling event that may mediate the KCs secretion of proinflammatory cytokines TNF-alpha and IL-1beta following burn trauma.

Role of p38 mitogen-activated protein kinase in lung injury after burn trauma.

This study was undertaken to evaluate the effect of SB203580, a specific p38 mitogen-activated protein (MAP) kinase inhibitor, on burn-induced lung injury as well as the release of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta in rats to characterize the role of p38 MAP kinase in lung injury after burn trauma. Sprague-Dawley rats were divided into three groups: 1) sham group, or rats who underwent sham burn; 2) control group, or rats given third-degree burns over 30% total body surface area (TBSA) and lactated Ringer solution for resuscitation; and 3) SB203580 group, or rats given burn injury and lactated Ringers solution with SB203580 inside for resuscitation. Pulmonary injury was assessed at 24 h by pulmonary capillary permeability determined with fluorescein isothiocyanate-labeled albumin and lung histologic analysis. TNF-alpha and IL-1beta protein in bronchoalveolar lavage fluid and serum were measured by enzyme-linked immunosorbent assay and p38 MAP kinase was activity determined in lung by Western blot analysis. These studies showed that significant activation of p38 MAP kinase at 24 h postburn compared with control. Burn trauma resulted in increased pulmonary capillary leakage permeability, elevated levels of TNF-alpha and IL-1beta in bronchoalveolar lavage fluid and serum, and worsened histologic condition. SB203580 inhibited the activation of p38 MAP kinase, reduced the levels of TNF-alpha and IL-1beta, and prevented burn-mediated lung injury. These data suggest that p38 MAP kinase activation is one important aspect of the signaling event that may mediate the release of TNF-alpha and IL-1beta and contributes to burn-induced lung injury.