Role of inhibition of p38 mitogen-activated protein kinase in liver dysfunction after hemorrhagic shock and resuscitation.

BACKGROUND: The liver is one of the organs most frequently affected by trauma and hemorrhagic shock; the exact role of p38 mitogen-activated protein kinase (MAPK) activation in response to hepatic hemorrhagic shock/resuscitation (HS/R) remains unclear. MATERIALS AND METHODS: C57Bl/6 mice were divided into four groups: sham-operated group, SB-only group, control group, and SB + HS/R group. Hepatocellular injury (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]) and tumor necrosis factor (TNF-α) and interleukin (IL-1ß) messenger ribonucleic acid (mRNA) expression in the liver were assessed 6 h after resuscitation, p38 MAPK activation in the liver was assessed at 30 min after resuscitation. RESULTS: p38 MAPK activation was higher in the control group than other groups 30 min after resuscitation. p38 MAPK activation level in the SB + HS/R group did not change significantly compared with that of sham and SB-only groups, but was significantly lower than that in the control group. The TNF-α mRNA expression in the control group was significantly higher than that in the sham group. The TNF-α mRNA levels after HS/R in the SB + HS/R group were significantly lower than those in the control group and were roughly the same as those in the sham and SB-only groups. IL-1ß mRNA expression showed similar changes in the four groups. Serum ALT and AST levels in the control group were significantly higher than those in the sham group. The increase in serum ALT and AST levels after HS/R in the SB + HS/R group was significantly less pronounced than that in the control group and markedly higher than that in the sham group. CONCLUSIONS: p38 MAPK was phosphorylated during the HS/R process. Inhibiting the activation of p38 MAPK may attenuate HS/R injury to the liver.

TLR4 mediates lung injury and inflammation in intestinal ischemia-reperfusion.

BACKGROUND: Splanchnic ischemia is common in critically ill patients, and it can result in injury not only of the intestine but also in distant organs, particularly in the lung. Local inflammatory changes play a pivotal role in the development of acute lung injury after intestinal ischemia, but the underlying molecular mechanisms are not fully understood. We sought to examine the role of Toll-like receptor 4 (TLR4) in the mouse model of intestinal ischemia-reperfusion (I/R)-induced lung injury and inflammation. MATERIALS AND METHODS: Adult male TLR4 mutant (C3H/HeJ) mice and TLR4 wild-type (WT) (C3H/HeOuJ) mice were subjected to 40 min of intestinal ischemia by clamping the superior mesenteric artery followed by 6 h of reperfusion. Lung histology was assessed and parameters of pulmonary microvascular permeability, inflammatory cytokine expression, and neutrophil infiltration were measured. Activation of mitogen-activated protein kinases (MAPKs) and the transcription factors nuclear factor κB (NF-κB) and activator protein-1 (AP-1) in the lungs were also detected. RESULTS: After intestinal I/R, lungs from TLR4 mutant mice demonstrated a significantly lower histological injury, a marked reduction of epithelial apoptosis associated with the decreased level of cleaved caspase-3 and the increased ratio of Bcl-xL to Bax proteins, and a large reduction in pulmonary vascular permeability and myeloperoxidase (MPO) activity in comparison with WT mice. TLR4 mutant mice also displayed marked decreases in tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein-2 (MIP-2) expression. Following intestinal I/R, phosporylation of p38 MAPK and activation of NF-κB and AP-1 were significantly inhibited in lung tissue from TLR4 mutant mice compared with WT controls. CONCLUSIONS: These data suggest that TLR4 plays an important role in the pathogenesis of intestinal I/R-induced acute lung injury and inflammation and that p38 kinase and NF-κB may be involved in TLR4 signaling-mediated lung inflammatory processes during intestinal I/R.

Unplanned decannulation of tracheotomy tube in massive burn patients: a retrospective case series study.

BACKGROUND: Unplanned extubation is associated with adverse outcomes in intensive care unit. The massive burn patient differs from other critically ill patients in many ways. However, little is known about the unplanned decannulation (UD) in Burn Intensive Care Unit. This paper describes the special features of the circumstances and outcome of UD of tracheotomy tube in massive burn patients. METHODS: A case series study was performed between January 1999 and December 2008 and UD of tracheotomy tube was analyzed retrospectively. A total of 21 patients with 29 UD events were identified. Demographic data, diagnosis, intervention, UD events and outcome of UD patients were collected. Differences in proportions were compared using the chi-square (χ(2)) or Fisher's exact test. RESULTS: Patients with UD were often burned with head and neck (67%) and combined with inhalation injury (62%). The majority of them (76%) were transferred patients, occurred early (55%) and were accidental UD (79%). UD events tended to happen in day shift (90%) and to be associated with the medical procedure that was performing by caregivers at besides (79%). Loose of the stabilizing rope, medical procedure and tracheotomy malposition were the main causes of UD. Early UD and reintubation failure were associated with patients' death. CONCLUSIONS: UD happened to massive burn patients can lead to patient death. Careful management of respiratory tract was essential for massive burn patients.

Effects of early excision and grafting on cytokines and insulin resistance in burned rats.

UNLABELLED: Burn wound excision and grafting is a common clinical practice that decreases patient morbidity and mortality. It is not known, however, if the salutary effects of this procedure are related to effects on interleukin 6 (IL-6) and tumor necrosis factor (TNF-) α, and to reducing insulin resistance after burn. Sprague-Dawley rats were randomly divided into three groups: control, burn, burn ± excision groups. Rats in burn group were given a third-degree scald burn covering 30% total body surface area (TBSA) and no wound excision. Rats in burn ± excision group were subjected to a 30% third-degree burn followed by complete excision and allografting of the injury site within 15 min after burn. The rats in control group were treated in the same manner as the burn group, except that they were immersed in a room-temperature water. Glucose tolerance tests (GTT) were observed at 3 days after burn, euglycemic-hyperinsulinemic glucose clamps were performed at 4 days after burn and interleukin 6 (IL-6) and tumor necrosis factor (TNF-) α were determined after euglycemic-hyperinsulinemic glucose clamps. The levels of IL-6 and TNF-α increased after burn. Significant differences in GTT were observed between control and burn groups, and the rate of glucose infused measured in burned rats was significantly decreased compared with that in control at 4 days after burn. Early excision and grafting significantly decreased levels of IL-6 and TNF-α, and further reduced insulin resistance following thermal injury compared with burn group. CONCLUSION: Early excision and grafting appeared to have an effect on inflammatory mediators and further reduced insulin resistance induced by major burns.

Burn injuries caused by ship fire: a 12-year study in Shanghai.

UNLABELLED: The 105 patients admitted to our Burn Institute from 1st January 1996 to 31st December 2007, with ship fire-related burns were studied retrospectively. The mean age was 30.2+/-12.6 years with a range of 1-58. One hundred and three patients (98.1%) were men and 2 (1.9%) women. The mean total burn surface area (TBSA) was 46.5%, mostly deep burns. The most common areas of burn were the head, neck and upper limb. Summer months July, August, June and September were times of highest incidence. Fifty-seven (54.3%) patients had inhalation injury, 42 received tracheotomy, and 38 received mechanical ventilation. The treatment was complex, difficult, long, and costly. The interval between burn and start of resuscitation ranged from 2.1 to 67 h with a mean of (5.9+/-4.4)h. Forty-two patients (40%) started intravenous fluid resuscitation 6h after burn. Twenty-four patients (23%) received insufficient fluid resuscitation developed hypotension and severe shock at admission. Ninety-two (87.6%) patients required operations including tracheotomy, debridement and grafting, per patient was 5.2. The mean length of hospital stay was 44.2 days. Pulmonary edema was the most common complication during the early post-burn period (within 7 days), and sepsis during the later period (>7 days). Nine patients died of MODS or sepsis, giving a mortality rate of 8.57%. CONCLUSION: Caution and preventive measures are needed for persons in ships for fire-related burns.

[Repair of deep burn and traumatic wounds in lower extremities with combined transplantation of multiple pedicled skin flaps].

OBJECTIVE: To summarize the clinical experience in repair of deep burn and traumatic wounds with combined transplantation of different types of pedicled skin flaps in lower extremities. METHODS: Two hundred and thirty-six patients with 271 deep wounds in lower extremities after burn or trauma were repaired with muscular skin flaps, local fascial flaps and island flaps with vascular pedicle (more than 20 types) in our department from Jan. 1998 to Sept. 2008. RESULTS: Complete necrosis of skin flaps occurred in 1 case, congestion and necrosis over the edge of skin flaps occurred in 3 cases, which were healed after grafting, and other skin flaps survived well with soft texture. Skin flaps were too bulky in 26 cases, among them 17 cases were thinned, and the appearance of other skin flaps were satisfactory. In 68 patients with functional region injury were recovered to certain extent without contracture. CONCLUSIONS: Skin flaps with pedicles, multiple transplantations if necessary, can repair deep wounds satisfactorily in lower extremities after deep burn or trauma injury.

Angiotensin II induces type I collagen gene expression in human dermal fibroblasts through an AP-1/TGF-beta1-dependent pathway.

Angiotensin II is critically involved in skin wound healing, but the underlying mechanism remains unclear. This study investigated the effect of angiotensin II on type I collagen gene activation in human dermal fibroblasts and the possible mechanism involved. Angiotensin II stimulated the mRNA and protein expression of type I collagen and TGF-beta1. Effects were abolished by the angiotensin AT1 receptor antagonist ZD7155 but not by the AT2 blocker PD123319. Blockade of TGF-beta1 markedly inhibited angiotensin II-induced type I collagen gene expression. Activator protein-1 (AP-1) decoy ODNs transfection suppressed angiotensin II-induced TGF-beta1 expression, and also, diminished type I collagen expression. These data indicated that angiotensin II induces collagen gene activation in human dermal fibroblasts through an AT1-mediated AP-1/TGF-beta1 signaling pathway.

[Treatment of severe crush syndrome caused by earthquake: a report of 35 cases].

OBJECTIVE: To discuss the diagnosis and treatment of the crush syndrome in the earthquake. METHODS: Thirty-five patients with crush syndrome caused by earthquake were involved the retrospective study. The role of nutritional support, active wound treatment and hemodialysis on the patients' recovery was observed. RESULTS: The function of the heart and kidneys were gradually improved by the planned removal of the necrotic tissue, which laid a foundation for the further repair of the wound. CONCLUSION: The removal of necrotic tissue, which can decrease the toxic absorption, will improve the success rate for treatment of the crush syndrome patients when being assisted with the hemodialysis.

Prevention and treatment of gastrointestinal dysfunction following severe burns: a summary of recent 30-year clinical experience.

AIM: To sum up the recent 30-year experience in the prevention and treatment of gastrointestinal dysfunction in severe burn patients, and propose practicable guidelines for the prevention and treatment of gastrointestinal (GI) dysfunction. METHODS: From 1980 to 2007, a total of 219 patients with large area and extraordinarily large area burns (LAB) were admitted, who were classified into three stages according the therapeutic protocols used at the time: Stage 1 from 1980 to 1989, stage 2 from 1990 to 1995, and stage 3 from 1996 to 2007. The occurrence and mortality of GI dysfunction in patients of the three stages were calculated and the main causes were analyzed. RESULTS: The occurrence of stress ulcer in patients with LAB was 8.6% in stage 1, which was significantly lower than that in stage 1 (P < 0.05). No massive hemorrhage from severe stress ulcer and enterogenic infections occurred in stages 2 and 3. The occurrence of abdominal distension and stress ulcer and the mortality in stage 3 patients with extraordinarily LAB was 7.1%, 21.4% and 28.5%, respectively, which were significantly lower than those in stage 1 patients (P < 0.05 or P < 0.01), and the occurrence of stress ulcer was also significantly lower than that in stage 2 patients (P < 0.05). CONCLUSION: Comprehensive fluid resuscitation, early excision of necrotic tissue, staged food ingestion, and administration of specific nutrients are essential strategies for preventing gastrointestinal complications and lowering mortality in severely burned patients.

Randomized, multicenter, double-blind, and placebo-controlled trial using topical recombinant human acidic fibroblast growth factor for deep partial-thickness burns and skin graft donor site.

Wound healing is a dynamic and complex biologic process that could be accelerated by growth factors. To investigate the efficacy of topical recombinant human acidic fibroblast growth factor (rh-aFGF) treatment in deep partial-thickness burn or skin graft donor sites, we designed a randomized, multicenter, double-blind, and placebo-controlled clinical trial. The healing rate, fully healed rate, and healing time were evaluated to assess the efficacy of rh-aFGF application. Laboratory examinations and abnormal signs were used to assess the side and toxic effects. The results showed that the healing rate of burn wounds and skin graft donor sites treated by rh-aFGF was significantly higher than that by placebo, and the mean healed time of burn wounds and skin graft donor sites in the rh-aFGF group was significantly the shorter than that in the placebo group. In conclusion, topical administration of rh-aFGF can accelerate the wound healing process and shorten the healed time. It is a potential therapeutic application for promoting healing of deep partial-thickness burns or skin graft donor sites.

[Role of c-Jun NH (2)-terminal kinase in insulin resistance after burn].

OBJECTIVE: To investigate the role of c-Jun NH (2)-terminal kinase (JNk) in insulin resistance after burn and its mechanism. METHODS: Twenty-four Sprague-Dawley rats were randomized to control, burn and burn + anisomycin groups. The rats in control group received sham burn trauma, and burn and burn + anisomycin groups received 30% total body surface area (TBSA) full thickness burn injury. Anisomycin (5 mg/kg) together with 250 microl dimethyl sulfoxide (DMSO) was injected to the rats in anisomycin group intravenously, and only 250 microl DMSO in the other two groups. Euglycemic-hyperinsulinemic glucose clamps was performed 2 hours after the injection. The changes of phospho-serine 307, phospho-tyrosine of insulin receptor substrate (IRS)-1 and phospho-JNK in muscle tissues were determined and compared using immunoprecipitation and Western blot analysis or immunohistochemistry in the three groups. RESULTS: The infusing rates of total 10% glucose (mg x kg(-1) x min(-1)) in control, burn and burn + anisomycin group were 12.3 +/- 0.4, 6.6 +/- 0.3, 6.5 +/- 0.4, respectively. The level of IRS-1 Serine 307 phosphorylation and phospho-JNK in muscle increased significantly, while insulin-induced tyrosine phosphorylation of IRS-1 decreased markedly after burn. CONCLUSIONS: The activation of JNK elevates the level of IRS-1 phospho-serine 307 and might play a role in insulin resistance after burn in rats.

[Interaction between p38 mitogen-activated protein kinase signal transduction pathway and NF-kappaB/IkappaB system on the proinflammatory cytokines release after burn trauma].

OBJECTIVE: To investigate the interaction between p38 mitogen-activated protein kinase signal transduction pathway and nuclear factor (NF)-kappaB/IkappaB system on the proinflammatory cytokines release after burn trauma. METHODS: Human monocyte line THP-1 were incubated with serum from eight healthy controls, burn sera, burn sera pretreatment with SB203580, and burn sera pretreatment with pyrrolidine dithiocarbamate (PDTC). After 24 hours incubation with serum, tumor necrosis factor (TNF)-alpha and interleukin-1beta (IL-1beta) levels in THP-1 culture supernatants were measured by ELISA. The activities of p38 MAPK and expressions of IkappaBalpha in THP-1 were measured by Western blot analysis. The EMSA method was used to characterize the binding activities of NF-kappaB and activating protein (AP)-1 in THP-1. RESULTS: In comparison with normal controls, burn sera resulted in a significant higher level release of TNF-alpha and IL-1beta in THP-1 [(7.30 +/- 0.84) ng/ml vs (2.20 +/- 0.28) ng/ml, P < 0.05; (2.88 +/- 0.38) ng/ml vs (0.81 +/- 0.14) ng/ml, P < 0.05], which were significantly inhibited by pretreatment with SB203580 or PDTC. Burn sera showed increased activities of p38 MAPK and AP-1 in THP-1 (4728 +/- 582 vs 1291 +/- 163, P < 0.05; 946 +/- 137 vs 361 +/- 40, P < 0.05), which were abolished by pretreatment with SB203580 but not PDTC. The expression of IkappaBalpha in THP-1 incubated with burn sera was significantly decreased than those incubated with control sera (1211 +/- 115 vs 2658 +/- 318, P < 0.05), which were abolished by pretreatment with PDTC but not SB203580. Burn sera also leaded to an increased activity of NF-kappaB in THP-1 (1636 +/- 170 vs 317 +/- 32, P < 0.05), which were abolished by pretreatment with PDTC but not SB203580. CONCLUSIONS: There are no direct interaction between p38 MAPK signal transduction pathway and NF-kappaB/IkappaB pathway. These two pathways, which regulate the production of TNF-alpha and IL-1beta in monocyte following burn trauma, are parallel and independent.

[Amelioration of insulin resistance after scald by c-Jun N-terminal kinase inhibitor in rat].

OBJECTIVE: To investigate the role and mechanism of c-Jun N-terminal kinase (JNk) inhibitor (SP600125) in amelioration of insulin resistance after scald. METHODS: Twenty-four Sprague-Dawley rats were randomized into sham (the process of scald was mimicked by water at room temperature) , scald, scald and SP600125 groups. The rats were inflicted with 30% TBSA full-thickness scald in the latter two groups. Euglycemic-hyperinsulinemic glucose clamp experiment was carried out 4 days after scald. SP600125 was administered to the rats in scald and SP600125 2 hrs before Euglycemic-hyperinsulinemic glucose clamp was performed. Changes in the phospho-Serine307 and phospho-tyrosine of IRS-1 activity, as well as expression of phospho-JNK in muscles were determined. RESULTS: Euglycemic-Hyperinsulinemic Glucose Clamps experiment showed that the infusion rate of 100 g/L glucose in sham, scald, scald and SP600125 groups were (12. 33 +/-0. 42) , (6. 61 +/-0. 27) , (11. 11 +/-0. 68) mgx kg(-1) x min(-1) , respectively ( P <0.01). The level of IRS-1 Serine307 phosphorylation and JNK activity in muscles were significantly increased, while insulin-induced tyrosine phosphorylation of IRS-1 decreased markedly after scald. Compared with scald group, the level of IRS-1 Serine307 phosphorylation and JNK activity in scald and SP600125 group were decreased but tyrosine phosphorylation was elevated. CONCLUSION: SP600125 can partially ameliorate insulin resistance after scald by inhibition of JNK activation, and decrease the level of IRS-1 phospho-serine307.

[Role of p38MAPK signal transduction pathway in Kupffer cells production of TNF-alpha and IL-1beta in severely burned rats].

OBJECTIVE: To investigate the role of p38 mitogen-activated protein kinase (MAPK) signal transduction pathway in the Kupffer cells production of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta in severely burns rats. METHODS: Male health adult Sprague-Dawley rats were randomized into four groups: sham burn rats given vehicle, sham burn rats given the p38 MAP kinase inhibitor SB203580, rats given a 30% total body surface area (TBSA) full-thickness burn and fluid resuscitation plus vehicle, and burn rats given injury and fluid resuscitation plus SB203580. Rats from each group were killed at 24 h after burn or sham burn and Kupffer cells (KCs) were isolated. After 18 h incubation, KCs next were stimulated with 50 ng/ml of LPS for 18 h. After stimulation, supernatants were removed for analysis of TNF-alpha and IL-1beta levels by ELISA. The TNF-alpha and IL-1beta mRNA expressions (by quantitative real-time RT-PCR) and the activities of p38 MAPK and JNK (by Western blot analysis) in KCs were examined. RESULTS: Eighteen hours after 50 ng/ml LPS stimulation, KCs from burn rats released significantly higher levels of TNF-alpha and IL-1beta than did shams. The mRNA levels of TNF-alpha and IL-1beta in KCs increased significantly postburn. Western blot analysis suggested that expression of phosphorylated p38 MAPK and JNK were increased in KCs harvested from burn group after stimulation with LPS compared with those from sham group. In vivo administration of SB203580 markedly suppressed both the release of TNF-alpha and IL-1beta and the mRNA expressions of TNF-alpha and IL-1beta in KCs from both sham and burn rats. p38 MAPK activity in KCs was abolished by administration with SB203580, whereas JNK was not. CONCLUSIONS: p38 MAPK signal transduction pathway mediates KCs production of proinflammatory cytokines TNF-alpha and IL-1beta in severely burned rats.

p38 mitogen-activated protein kinase inhibition attenuates burn-induced liver injury in rats.

This study was made to evaluate the effect of SB203580, a specific p38 MAP kinase inhibitor, on burn-induced hepatic injury as well as the activation of nuclear factor (NF)-kappaB in severely burned rats. Sprague-Dawley rats were divided into three groups: (1) sham group, rats underwent sham burn; (2) burn group, rats given third-degree burns over 30% total body surface area (TBSA) and treated with vehicle plus lactated Ringer solution for resuscitation 4 ml/(kg% TBSA); and (3) burn plus SB203580 group, rats given burn injury and fluid resuscitation plus SB203580 (10 mg/kg i.v., 15 min and 12 h after burn). Hepatocellular injury (measured by serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT)) and hepatocellular function (determined by the indocyanine green dye retention rate (ICG R15)) were assessed at 24 h post-burn. Liver histologic changes were also analyzed. Burn trauma resulted in increased serum aminotransferases concentrations, decreased ICG R15, elevated serum tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta levels and hepatic TNF-alpha and IL-1beta mRNA expressions, and worsen histologic condition. The level of Nuclear Factor (kappa) inhibitor (IkappaBalpha) in liver was decreased and DNA-binding activity of Nuclear Factor-kappaB (NF-kappaB) was increased after thermal injury. p38 MAP kinase was more significantly activated in liver harvested from burn rats than from shams. SB203580 inhibited the activation of p38 MAP kinase, reduced the levels of TNF-alpha and IL-1beta, and prevented burn-mediated liver injury. Both the IkappaBalpha level and NF-kappaB activity in the liver following burns was not affected by administration with SB203580. These findings suggest that (1) 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 liver injury and (2) p38 MAP kinase does not influence the activation of NF-kappaB directly in the liver of severely burned rats.

[The modulating role of p38 mitogen-activated protein kinase in the expression of tumor necrosis factor-alpha in hepatic cells and its role in hepatic injury in severely burned rats].

OBJECTIVE: To investigate The modulating role of p38 mitogen-activated protein kinase (MAPK) in the expression of tumor necrosis factor-alpha in hepatic cells and its role in hepatic injury in severely burned rats. METHODS: Twenty-four adult healthy male SD rats were randomly divided into three groups (8 rats in each group): sham group, burn group, and burn with SB203580 group. A rat model of full-thickness burn injury covering 30% total body surface area (TBSA) was reproduced. The specific inhibitor of p38MAPK (SB203580 in 10 mg/kg) was given to the rats in the burn with SB203580 group at 15 minutes and 12 hours after burn. The serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured at 24 postburn hours (PBHs). The TNF-alpha mRNA expression in the liver was determined by real-time reverse transcription polymerase chain reaction, and the expression levels of p38MAPK and phosphor-p38MAPK in the liver were determined by Western blot analysis. RESULTS: The serum levels of AST and ALT, and the expression of TNF-alpha mRNA in liver cells were significantly higher in burn group than those in sham and SB203580 groups (P < 0.05 or 0.01), but there was no difference between the two latter groups. It was indicated by Western blot results that there was no difference of p38MAPK expression in rat liver among the three groups (P > 0.05). The phospho-p38MAPK expression ratio among sham, burn and burn with SB203580 groups was 1.00:3.90:1.10. The phospho-p38MAPK expression was significantly lower in burn with SB203580 group than that in burn group (P < 0.01), but there was no significant difference compared with that in sham group (P > 0.05). CONCLUSION: The postburn activated p38MAPK in rat liver after severe burn injury enhances the expression of TNF-alpha mRNA and participates in the development of postburn hepatic injury.

[Activation of p38 MAPK signal transduction pathway by burn serum and the expression of VCAM-1 in HUVECs induced by NF-kappaB].

OBJECTIVE: To investigate the influence of burn serum on the expression of vascular cell adhesion molecule-1 (VCAM-1) of human umbilical vein endothelial cells (HUVECs) andits signal transduction mechanism. METHODS: HUVECs cultured in vitro were employed for the experiment, and were divided into normal control (NC, with addition of normal serum), burn serum (BS, with addition of burn serum), SB203580 (with addition of 10 micromol/L SB203580 treatment 1 hour before burn serum treatment) and PDTC [with 10 mmol/L pyrrolidine dithiocarbamate (PDTC) 1 hour before burn serum treatment] groups. Protein and mRNA expression of VCAM-1 in HUVECs was measured by flow cytometry and reverse transcription polymerase chain reaction (RT-PCR) respectively at 0, 6, 12, 24 and 36 hours after burn serum treatment. The expression of VCAM-1 on HUVEC surface and the soluble VCAM-1 (sVCAM-1) content in HUVECs culture supernatants were measured by ELISA at 24 hours after the serum stimulation. Adherence of peripheral blood mononuclear leukocytes (PBMC) adherence to HUVECs was also observed in vitro. RESULTS: The expression of VCAM-1 mRNA increased obviously in BS group after the burn serum stimulation and reached peak level at 24 post stimulation hour (PSH), and it decreased thereafter. The above expression was significantly decreased in SB203580 and PDTC groups at 24 PSH, but there was no difference compared with normal control (P > 0.05). The VCAM-1 expression on the membrane of HUVEC was evidently higher in BS group (66.5 +/- 6.2) than that in NC group (19.1 +/- 1.9, P < 0.05) at 24 PSH, but it was decreased significantly in SB203580 (21.7 +/- 2.3) and PDTC (23.1 +/- 2.4) groups and there was no significant difference compared with NC group (P > 0.05), and which was evidently lower than that in BS group (P < 0.05). The VCAM-1 content in the supernatant of BS group (125 +/- 10 ng/L) was obviously higher than that in NC (23 +/- 3 ng/L), SB203580 (27 +/- 5 ng/L) and PDTC (29 +/- 5 ng/L) groups. (P < 0.05). The number of PBMCs adherent to HUVECs in BS group [(197 +/- 11)%] was much larger than that in NC group [(100 +/- 4)%], SB203580 group [(113 +/- 7)%] or PDTC group [(97 +/- 112)%] at 24 PSH (P < 0.05), but no difference between NC group and SB203580, PDTC groups (P > 0.05). CONCLUSION: Burn serum can enhance the expression of VCAM-1 in HUVECs through p38 MAPK signaling pathway, and the activation of NF-kappaB was also involved in this process.

[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.