Microbiome dysbiosis occurred in hypertrophic scars is dominated by S. aureus colonization.

Background: The mechanisms of hypertrophic scar formation and its tissue inflammation remain unknown. Methods: We collected 33 hypertrophic scar (HS) and 36 normal skin (NS) tissues, and detected the tissue inflammation and bacteria using HE staining, Gram staining, and transmission electronic microscopy (TEM), in situ hybridization and immunohistochemistry for MCP-1, TNF-α, IL-6 and IL-8. In addition, the samples were assayed by 16S rRNA sequencing to investigate the microbiota diversity in HS, and the correlation between the microbiota and the indices of Vancouver Scar Scale(VSS)score. Results: HE staining showed that a dramatically increased number of inflammatory cells accumulated in HS compared with NS, and an enhanced number of bacteria colonies was found in HS by Gram staining, even individual bacteria could be clearly observed by TEM. In situ hybridization demonstrated that the bacteria and inflammation cells co-localized in the HS tissues, and immunohistochemistry indicated the expression of MCP-1, TNF-α, IL-6, and IL-8 were significantly upregulated in HS than that in NS. In addition, there was a significantly different microbiota composition between HS and NS. At the phylum level, Firmicutes was significantly higher in HS than NS. At the genus level, S. aureus was the dominant species, which was significantly higher in HS than NS, and was strongly correlated with VSS indices. Conclusion: Microbiome dysbiosis, dominated by S. aureus, occurred in HS formation, which is correlated with chronic inflammation and scar formation, targeting the microbiome dysbiosis is perhaps a supplementary way for future scar management.

LPS induces SGPP2 to participate metabolic reprogramming in endothelial cells.

Sepsis often causes organ dysfunction and is manifested in increased endothelial cell permeability in blood vessels. Early-stage inflammation is accompanied by metabolic changes, but it is unclear how the metabolic alterations in the endothelial cells following lipopolysaccharide (LPS) stimulation affect endothelial cell function. In this study, the effects of 1 µg/ml of LPS on the metabolism of human umbilical vein endothelial cells (HUVECs) were investigated, and the metabolic changes after LPS stimulation were explained from the perspective of mRNA expression, chromatin openness and metabolic flux. We found changes in the central metabolism of endothelial cells after LPS stimulation, such as enhanced glycolysis function, decreased mitochondrial membrane potential, and increased production of reactive oxygen species (ROS). Sphingolipid metabolic pathways change at the transcriptome level, and sphingosine-1-phosphatase 2 (SGPP2) was upregulated in LPS-stimulated endothelial cells and zebrafish models. Overexpression of SGPP2 improved cell barrier function, enhanced mitochondrial respiration capacity, but also produced oxidative respiration chain uncoupling. In addition, SGPP2 overexpression inhibited the degradation of HIF-1α protein. The molecular and biochemical processes identified in this study are not only beneficial for understanding the metabolic-related mechanisms of LPS-induced endothelial injury, but also for the discovery of general therapeutic targets for inflammation and inflammation-related diseases.

Blocking CCR10 Expression Activates m6A Methylation and Alleviates Vascular Endothelial Cell Injury.

BACKGROUND: Cardiovascular disease, one of the most common types of disease in clinical practice today, carries a very high risk of disability and death. This research aims to examine genome-wide changes in injured human dermal microvascular endothelial cells (HDMECs) using the Ribonucleic Acid sequencing (RNA-Seq) technique, and to search for key genes influencing N6-methyladenosine (m6A) methylation, thus gaining new insights into future clinical diagnosis and treatment of cardiovascular diseases (CVDs) and laying a foundation for follow-up research. METHODS: Impaired HDMECs (injury group), established by endotoxin intervention, were analyzed by RNA-Seq for differentially expressed genes (DEGs) relative to normal HDMECs (control group). Then, DEGs that might be associated with m6A methylation were selected for expression blocking to observe m6A methylation alterations. The migration, angiogenesis, and inflammatory response of damaged HDMECs were detected by cell scratch assay, western blotting, and Enzyme-linked Immunosorbent Assay (ELISA) experiments, respectively. RESULTS: In this study, 20 DEGs were screened out from the two groups by RNA-Seq, of which 17 were up-regulated and 3 were down-regulated. The C-C motif chemokine receptor 10 (CCR10) was selected for subsequent analysis. Real-Time Quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) identified elevated CCR10 expression and reduced m6A methylation levels in the injury group (p < 0.05). After blocking CCR10 expression in damaged HDMECs by BI6901 (a CCR10 specific blocker) m6A methylation, cell activity, vascular endothelial growth factor A (VEGFA) and CD31 protein expression, as well as relative length and branches of tube formation were found to be increased compared with the injury group, while the levels of inflammatory factors interleukin-1 (IL-1), interleukin-1 (IL-6) and tumor necrosis factor-α (TNF-α) were decreased (p < 0.05). CONCLUSIONS: Blocking CCR10 expression can activate m6A methylation, promote cell activity, inhibit inflammatory reactions and alleviate HDMEC injury, which may become a breakthrough in future diagnosis and treatment of cardiovascular diseases.

GEF-H1/RhoA signaling pathway mediates pro-inflammatory effects of NF-κB on CD40L-induced pulmonary endothelial cells.

One of the key targets of the inflammatory response in acute lung injury (ALI) is the human pulmonary micro-vascular endothelial cells (HPMVECs). Owing to its role in the activation of endothelial cells (ECs), CD40L figures prominently in the pathogenesis of ALI. Increasing evidences have showed that CD40L mediates inflammatory effects on ECs, at least in part, by triggering NF-κB-dependent gene expression. However, the mechanisms of such signal transmission remain unknown. In this study, we found that CD40L stimulated the transactivation of NF-κB and expression of its downstream cytokines in a p38 MAPK-dependent mechanism in HPMVECs. In addition, CD40L-mediated inflammatory effects might be correlated with the activation of the IKK/IκB/NF-κB pathway and nuclear translocation of NF-κB, being accompanied by dynamic cytoskeletal changes. GEF-H1/RhoA signaling is best known for its role in regulating cytoskeletal rearrangements. An interesting finding was that CD40L induced the activation of p38 and IKK/IκB, and the subsequent transactivation of NF-κB via GEF-H1/RhoA signaling. The critical role of GEF-H1/RhoA in CD40L-induced inflammatory responses in the lung was further confirmed in GEF-H1 and RhoA knockout mouse models, both of which were established by adeno-associated virus (AAV)-mediated delivery of sgRNAs into mice with EC-specific Cas9 expression. These results taken together suggested that p38 and IKK/IκB-mediated signaling pathways, both of which lied downstream of GEF-H1/RhoA, may coordinately regulate the transactivation of NF-κB in CD40L-activated HPMVECs. These findings may help to determine key pharmacological targets of intervention for CD40L-activated inflammatory effects associated with ALI.

Comparative effectiveness analysis of deep low heat burns in the shin surgical approaches: Outcomes and cost for wound rehabilitation.

A variety of surgical techniques exist for deep burn wounds in the shin at low temperature reconstruction after appropriate debridement, but limited high-quality data exist to inform treatment strategies. Using multi-institutional data, the authors evaluated the length of healing time, cost, and outcomes of three common surgical reconstructive modalities. All subjects with deep burn wounds in the shin caused by low temperature who received direct suture repair, skin grafting, or local flap reconstruction were retrospectively reviewed (from 2015.01 to 2021.03). Mean operation time, mean blood loss in operation, postoperative healing time, whether there is scar depression after operation were the primary outcomes; patient satisfaction score, Vancouver scar scale (VSS) score and average costs were secondary outcomes. Two hundred subjects (68 suture, 87 skin-grafting, and 45 local flap coverage patients) were evaluated. Matched patients (n = 200; 3/groups) were analysed. The average operation time, average operation blood loss, and postoperative healing time were statistically significant differences (P < 0.05). Readmissions and reoperations were greater for direct suture and local flaps, if achievable, direct suture provided success at low cost. Skin grafting was effective with large burn wounds but at higher costs and longer length of stay. Local flaps successfully treated smaller burn wounds unable to suture directly, with less pigmentation and scars, even suitable for older patients. Deep low heat burn wounds in the shin healing can be performed effectively using multiple modalities with varying degrees of success and costs. Direct suture or local skin flap reconstruction, if achievable, provides successful coverage at minimal costs, no skin contractures, and reducing length of hospital stay.

Prediction of the immunological and prognostic value of five signatures related to fatty acid metabolism in patients with cervical cancer.

A growing attention has been attached to the role of fatty acid metabolism (FAM) in the development of cancer, and cervical cancer (CC) is still the primary cause of cancer-associated death in women worldwide. Therefore, it is imperative to explore the possible prognostic significance of FAM in CC. In this study, CC samples and corresponding normal samples were acquired from the Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx). Single sample gene set enrichment analysis (ssGSEA) was conducted for calculating FAM-related scores (FAMRs) to screen FAM-related genes (FAMRGs). Two subtypes related to FAM were identified by consistent clustering. Among them, subtype C2 had a poor prognosis, and C1 had a high level of immune cell infiltration, while C2 had a high possibility of immune escape and was insensitive to chemotherapy drugs. Based on the differentially expressed genes (DEGs) in the two subtypes, a 5-gene signature (PLCB4, FBLN5, TSPAN8, CST6, and SERPINB7) was generated by the least absolute shrinkage and selection operator (LASSO) and Akaike information criterion (AIC). The model demonstrated a high prognostic accuracy (area under the curve (AUC)>0.7) in multiple cohorts and was one independent prognostic factor for CC patients. Accordingly, FAMRGs can be adopted as a biomarker for the prediction of CC patients' prognosis and help guide the immunotherapy of CC.

An Application of a Negative-Pressure Wound Dressing for Partial- or Full-Thickness Burn Wounds.

Negative-pressure wound therapy is widely used in burn populations. Traditionally, negative-pressure devices use persistent vacuum suction, requiring a longer hospital stay. In this study, we applied a novel negative-pressure wound dressing for burn wounds, which eliminates the hospital stay. The medical records of 39 patients with partial-/full-thickness burns treated by negative-pressure wound dressing were retrospectively analyzed. The average burn area, burn degree, healing duration, cost, and incidents during treatment were determined and compared with previous data for conventional therapies. In conclusion, for patients diagnosed with partial-thickness or full-thickness burns and a burn area <34.6 ± 2.21 cm2, the negative-pressure wound dressing is a reliable option, especially for burnt children. Moreover, the negative-pressure wound dressing treatment was not only much cheaper than conventional therapies, but also eliminated hospital stay in patients with small-area deep burn wounds.

Factors Influencing Length of Hospital Stay and Predictors Affecting Probability of Requiring Surgery in Severely Pediatric Burn Patients.

Although many researches have explored the prognostic factors associated with length of hospital stay (LOS) of adult burn patients, fewer reports concerning pediatric burn patients have been conducted. The present study employed pediatric burn data to identify factors related to LOS and developed a novel model to assess the possibility of requiring surgery. A total of 750 children admitted for burns met the criteria for enrollment. We have analyzed the medical records using multivariable linear regression and logistic regression. The pediatric patients were stratified into medical (nonsurgical) and surgical groups, respectively. The median LOS was 27.11 ± 17.91 days (range: 6-107 days). Following multiple linear regression, surgery (P < .001; 95% confidence interval [CI]: 6.485, 11.918), percent total BSA (%TBSA) (P < .001; 95% CI: 0.271, 0.459), days to surgery (P < .001; 95% CI: 0.349, 0.648), etiology (P < .001; 95% CI: -15.801, -9.422), infection (P < .001; 95% CI: 4.163, 8.329), and erythrocyte loss (P < .001; 95% CI: 1.923, 4.017) were significantly associated with LOS. After logistic regression, the percent full thickness (%FT) (P < .001; odds ratio [OR]: 2.358; 95% CI: 1.680, 3.311), infection (P < .001; OR: 2.935; 95% CI: 2.014, 4.278), and erythrocyte loss (P < .001; OR: 0.572; 95% CI: 0.470, 0.696) within 5 days postadmission were independently related to the probability of requiring surgery. In conclusion, in pediatric patients admitted with burn size of TBSA ≥20%, factors independently influencing LOS were surgery, %TBSA, days to surgery, etiology, erythrocyte loss, and infection. Furthermore, the pivotal predictors of probability requiring surgery were %FT, infection, and erythrocyte loss.

Genistein-3'-sodium sulphonate protects against lipopolysaccharide-induced lung vascular endothelial cell apoptosis and acute lung injury via BCL-2 signalling.

Under septic conditions, Lipopolysaccharide (LPS)-induced apoptosis of lung vascular endothelial cells (ECs) triggers and aggravates acute lung injury (ALI), which so far has no effective therapeutic options. Genistein-3'-sodium sulphonate (GSS) is a derivative of native soy isoflavone, which has neuro-protective effects through its anti-apoptotic property. However, whether GSS protects against sepsis-induced lung vascular endothelial cell apoptosis and ALI has not been determined. In this study, we found that LPS-induced Myd88/NF-κB/BCL-2 signalling pathway activation and subsequent EC apoptosis were effectively down-regulated by GSS in vitro. Furthermore, GSS not only reversed the sepsis-induced BCL-2 changes in expression in mouse lungs but also blocked sepsis-associated lung vascular barrier disruption and ALI in vivo. Taken together, our results demonstrated that GSS might be a promising candidate for sepsis-induced ALI via its regulating effects on Myd88/NF-κB/BCL-2 signalling in lung ECs.

Exosome-delivered syndecan-1 rescues acute lung injury via a FAK/p190RhoGAP/RhoA/ROCK/NF-κB signaling axis and glycocalyx enhancement.

Acute lung injury (ALI) is characterized by protein-rich pulmonary edema, critical hypoxemia, and influx of pro-inflammatory cytokines and cells. There are currently no effective pharmacon therapies in clinical practice. Syndecan-1 in endothelial cells has potential to protect barrier function of endothelium and suppress inflammation response. Thus, the present study was to identify whether exosomes with encapsulation of syndecan-1 could achieve ideal therapeutic effects in ALI. Exosomes were isolated from the conditional medium of lentivirus-transfected mouse pulmonary microvascular endothelial cells (MPMVECs) and characterized by nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), and western blotting. ALI mouse models were induced via intratracheal administration of lipopolysaccharide (LPS) and treated with exosomes. Lung edema, inflammation, and glycocalyx thickness were examined. The possible mechanism was verified by immunoblotting in MPMVECs. The purified exosomes included SDC1-high-Exos and SDC1-low-Exos which loaded with up-regulated syndecan-1 and down-regulated syndecan-1 respectively. Compared with SDC1-low-Exos, administration of SDC1-high-Exos could ameliorate lung edema and inflammation, attenuate number of cells and protein levels in bronchoalveolar lavage fluid (BALF), and preserve glycocalyx. Furthermore, SDC1-high-Exos also mitigated the expression of pro-inflammatory cytokines such as IL-1ß, TNF-α, and IL-6 following LPS challenge. In MPMVECs, SDC1-high-Exos decreased stress fiber formation and ameliorated monolayer hyper-permeability after LPS stimulation. Western blotting analysis demonstrated that FAK/p190RhoGAP/RhoA/ROCK/NF-κB signaling pathway may be involved in LPS-induced ALI. In conclusion, SDC1-high-Exos play a pivotal role in ameliorating LPS-stimulated ALI models and may be served as a potential therapeutic agent for clinical application in the future.

Fournier's Gangrene With Septic Shock and Multiple Organ Dysfunction Syndrome.

Fournier's gangrene is a rare, rapidly progressing, and life-threatening infection associated with necrotizing fasciitis in the perineal, genital, and/or lower abdominal regions. Septic shock and multiple organ dysfunction syndrome due to the condition are even rarer events. We describe the case of a 58-year-old man who visited the emergency department with severely painful swelling in the scrotal, perianal, and lower abdominal regions. Physical examination combined with computed tomography and clinical findings led to the diagnosis of Fournier's gangrene with septic shock and multiple organ dysfunction syndrome. Broad-spectrum antibiotics, fluid resuscitation, sedative administration, and several surgeries that included perineum reconstruction were performed successfully, and the patient fully recovered. Comprehensive, timely treatments are critical for treating Fournier's gangrene.

Relation between dynamic changes of platelet counts and 30-day mortality in severely burned patients.

Thrombocytopenia is a common event in severely burned patients and associated with adverse outcome. The underlying relationship between the dynamic changes of platelet counts and mortality has not been well defined. We performed a 6-year retrospective chart of adult patients with a burn index of 50 or greater admitted to two burn centers and collected data on patient demographics, laboratory results, and patient outcomes. The mean daily increase in the platelet count (∆PC/∆t) from day 3 to day 10 was calculated, and 30-day mortality was determined. For the study, 141 survivors and 65 nonsurvivors were enrolled. The sequential changes in PCs presented a biphasic pattern after admission, with a slump to the nadir during the first 3 days and a subsequent recovery. With respect to 30-day mortality, compared with the AUC of APACHE-Ⅱ score (0.841), no significant difference was noted between ΔPC/ΔT and APACHE-Ⅱ score (p = 0.0648). The ΔPC/ΔT associated with the best discrimination between survivors and nonsurvivors was 20.57 × 109/L due to the cutoff with optimal Youden index (0.453). By multiple logistic regression, ΔPC/ΔT ＜ 20.57 × 109/L was one of the prognostic predictors of 30-day mortality. Furthermore, Kaplan-Meier estimates of hospital survival according to the size of ΔPC/ΔT revealed that a blunted increase with ΔPC/ΔT ＜ 20.57 × 109/L was associated with increased 30-day mortality. A blunted daily increase in PCs, especially ΔPC/ΔT < 20.57 × 109/L, is associated with increased 30-day mortality, which provides prognostic information for mortality risk assessment in severely burned patients.

Suppressive Effects of GSS on Lipopolysaccharide-Induced Endothelial Cell Injury and ALI via TNF-α and IL-6.

Background. Under septic conditions, LPS induced lung vascular endothelial cell (EC) injury, and the release of inflammatory mediator launches and aggravates acute lung injury (ALI). There are no effective therapeutic options for ALI. Genistein-3'-sodium sulfonate (GSS) is a derivative of native soy isoflavone, which exhibits neuroprotective effects via its antiapoptosis property. However, whether GSS protect against sepsis-induced EC injury and release of inflammatory mediators has not been determined. In this study, we found that GSS not only downregulated the levels of TNF-α and IL-6 in the lung and serum of mice in vivo but also inhibited the expression and secretion of TNF-α and IL-6 in ECs. Importantly, we also found that GSS blocked LPS-induced TNF-α and IL-6 expression in ECs via the Myd88/NF-κB signaling pathway. Taken together, our results demonstrated that GSS might be a promising candidate for sepsis-induced ALI via its regulating effects on inflammatory response in lung ECs.

HBP induces the expression of monocyte chemoattractant protein-1 via the FAK/PI3K/AKT and p38 MAPK/NF-κB pathways in vascular endothelial cells.

Inflammation is characterized by early influx of polymorphonuclear neutrophils (PMNs), followed by a second wave of monocyte recruitment. PMNs mediate monocyte recruitment via their release of heparin binding protein (HBP), which activates CCR2 (CC-chemokine receptor 2) on monocytes. However, the pathways for such signal transmission remain unknown. Accumulating evidences have highlighted the importance of leukocyte-endothelial cell interactions in the initiation of inflammation. In this study, an interesting finding is that HBP enhances the secretion of monocyte chemotactic protein 1(MCP-1), ligand of CCR2, from a third party, the endothelial cells (ECs). HBP-induced increase in MCP-1 production was demonstrated at the protein, mRNA and secretion levels. Exposure of ECs to HBP elicited rapid phosphorylation of FAK/PI3K/AKT and p38 MAPK/NF-κB signaling. MCP-1 levels were attenuated during the response to HBP stimulation by pretreatment with a FAK inhibitor (or siRNA), a PI3K inhibitor, an AKT inhibitor, a p38 inhibitor (or siRNA) and two NF-κB inhibitors. Additionally, pretreatment with inhibitors to FAK, PI3K and AKT led to a decrease in HBP-induced phosphorylation of p38/NF-κB axis. These results showed that HBP induced MCP-1 expression via a sequential activation of the FAK/PI3K/AKT pathway and p38 MAPK/NF-κB axis. Interestingly, the patterns of HBP regulation of the expression of the adhesion molecular VCAM-1 were similar to those seen in MCP-1 after pretreatment with inhibitors (or not). These findings may help to determine key pharmacological points of intervention, thus slowing the progress of inflammatory-mediated responses in certain diseases where inflammation is detrimental to the host.

GSK-3Beta-Dependent Activation of GEF-H1/ROCK Signaling Promotes LPS-Induced Lung Vascular Endothelial Barrier Dysfunction and Acute Lung Injury.

The bacterial endotoxin or lipopolysaccharide (LPS) leads to the extensive vascular endothelial cells (EC) injury under septic conditions. Guanine nucleotide exchange factor-H1 (GEF-H1)/ROCK signaling not only involved in LPS-induced overexpression of pro-inflammatory mediator in ECs but also implicated in LPS-induced endothelial hyper-permeability. However, the mechanisms behind LPS-induced GEF-H1/ROCK signaling activation in the progress of EC injury remain incompletely understood. GEF-H1 localized on microtubules (MT) and is suppressed in its MT-bound state. MT disassembly promotes GEF-H1 release from MT and stimulates downstream ROCK-specific GEF activity. Since glycogen synthase kinase (GSK-3beta) participates in regulating MT dynamics under pathologic conditions, we examined the pivotal roles for GSK-3beta in modulating LPS-induced activation of GEF-H1/ROCK, increase of vascular endothelial permeability and severity of acute lung injury (ALI). In this study, we found that LPS induced human pulmonary endothelial cell (HPMEC) monolayers disruption accompanied by increase in GSK-3beta activity, activation of GEF-H1/ROCK signaling and decrease in beta-catenin and ZO-1 expression. Inhibition of GSK-3beta reduced HPMEC monolayers hyper-permeability and GEF-H1/ROCK activity in response to LPS. GSK-3beta/GEF-H1/ROCK signaling is implicated in regulating the expression of beta-catenin and ZO-1. In vivo, GSK-3beta inhibition attenuated LPS-induced activation of GEF-H1/ROCK pathway, lung edema and subsequent ALI. These findings present a new mechanism of GSK-3beta-dependent exacerbation of lung micro-vascular hyper-permeability and escalation of ALI via activation of GEF-H1/ROCK signaling and disruption of intracellular junctional proteins under septic condition.

Acinetobacter baumannii quorum-sensing signalling molecule induces the expression of drug-resistance genes.

Quorum-sensing signalling molecules such as N­acyl homoserine lactones (AHLs) enable certain Gram­negative bacteria to respond to environmental changes through behaviours, such as biofilm formation and flagellar movement. The present study aimed to identify Acinetobacter baumannii AHLs and assess their influence on antibiotic resistance. A clinical isolate of A. baumannii strain S (AbS) was collected from the wound of a burn patient and high­performance liquid chromatography and tandem quadrupole or quadrupole time­of­flight high­resolution mass spectrometry was used to identify AbS AHLs. Antibiotic sensitivity was assessed in an AHL­deficient AbS mutant (AbS­M), and the expression of drug-resistance genes in the presence of meropenem in AbS, AbS­M and AbS­M treated with the AHL N-3-hydroxy-dodecanoyl-homoserine lactone (N­3­OH­C12­HSL). AbS­M was more sensitive to meropenem and piperacillin than wild­type AbS, but resistance was restored by supplementation with N­3­OH­C12­HSL. In addition, meropenem­treated AbS­M expressed lower levels of the drug­resistance genes oxacillinase 51, AmpC, AdeA and AdeB; treatment with N­3­OH­C12­HSL also restored the expression of these genes. Overall, the results of the present study indicate that N­3­OH­C12­HSL may be involved in regulating the expression of drug­resistance genes in A. baumannii. Therefore, this quorum­sensing signalling molecule may be an important target for treating multidrug­resistant A. baumannii infections.

Pseudomonas aeruginosa prevalence, antibiotic resistance and antimicrobial use in Chinese burn wards from 2007 to 2014.

Objective To assess the application of antibacterial agents, alongside pathogen prevalence and Pseudomonas aeruginosa drug resistance, with the aim of understanding the impact of inappropriate antibacterial use. Methods This retrospective study assessed bacteria from wounds, catheters, blood, faeces, urine and sputum of hospitalized patients in burn wards between 2007 and 2014. The intensity of use of antibacterial agents and resistance of P. aeruginosa to common anti-Gram-negative antibiotics were measured. Results Annual detection rates of Staphylococcus aureus were significantly decreased, whereas annual detection rates of P. aeruginosa and Klebsiella pneumoniae were significantly increased. Multidrug-resistant strains of P. aeruginosa were increased. The intensity of use of some anti-Gramnegative antibiotics positively correlated with resistance rates of P. aeruginosa to similar antimicrobials. Conclusion In burn wards, more attention should be paid to P. aeruginosa and K. pneumoniae. The use of ciprofloxacin, ceftazidime and cefoperazone/sulbactam should be limited to counter the related increase in resistance levels.

Lipopolysaccharide Induces Human Pulmonary Micro-Vascular Endothelial Apoptosis via the YAP Signaling Pathway.

Gram-negative bacterial lipopolysaccharide (LPS) induces a pathologic increase in lung vascular leakage under septic conditions. LPS-induced human pulmonary micro-vascular endothelial cell (HPMEC) apoptosis launches and aggravates micro-vascular hyper-permeability and acute lung injury (ALI). Previous studies show that the activation of intrinsic apoptotic pathway is vital for LPS-induced EC apoptosis. Yes-associated protein (YAP) has been reported to positively regulate intrinsic apoptotic pathway in tumor cells apoptosis. However, the potential role of YAP protein in LPS-induced HPMEC apoptosis has not been determined. In this study, we found that LPS-induced activation and nuclear accumulation of YAP accelerated HPMECs apoptosis. LPS-induced YAP translocation from cytoplasm to nucleus by the increased phosphorylation on Y357 resulted in the interaction between YAP and transcription factor P73. Furthermore, inhibition of YAP by small interfering RNA (siRNA) not only suppressed the LPS-induced HPMEC apoptosis but also regulated P73-mediated up-regulation of BAX and down-regulation of BCL-2. Taken together, our results demonstrated that activation of the YAP/P73/(BAX and BCL-2)/caspase-3 signaling pathway played a critical role in LPS-induced HPMEC apoptosis. Inhibition of the YAP might be a potential therapeutic strategy for lung injury under sepsis.

Yes-associated protein (YAP) signaling regulates lipopolysaccharide-induced tissue factor expression in human endothelial cells.

BACKGROUND: Sepsis-induced acute lung injury (ALI) is characterized by fibrin deposition, which indicates the local activation of coagulation. Tissue factor (TF), expressed in the pulmonary microvasculature, acts as a critical initiator of blood coagulation and ALI in sepsis. The molecular mechanism of lipopolysaccharide (LPS)-induced TF expression in endothelial cells (ECs), however, has not been determined. In this study, we implicate the Rho-associated protein kinase (ROCK)/Yes associated protein (YAP)/early growth response (Egr-1) signaling pathway in LPS-induced TF expression in vitro and in sepsis-induced ALI in vivo. METHODS: Human umbilical vein ECs incubated with LPS were pretreated with or without the ROCK inhibitor Y-27632, a YAP small, interfering RNA (siRNA) and an Egr-1 siRNA. ROCK, YAP and Egr-1 signaling-induced protein expression was investigated by Western blot. The LPS-induced activation of YAP was analyzed by an immunofluorescent assay. Furthermore, we intratracheally injected YAP siRNA to assess septic ALI in mice by hematoxylin and eosin staining. RESULTS: LPS rapidly induced ROCK activation and increased TF expression in ECs. LPS caused YAP shuttling into the nuclei of ECs and combined with Egr-1 via the activation of ROCK. Furthermore, the LPS-mediated TF expression increase was prevented by ROCK inactivation, YAP knockdown and Egr-1 depletion, suggesting that LPS-induced TF expression is closely associated with the ROCK/YAP/Egr-1 signaling pathway in ECs. Finally, an intratracheal injection of YAP siRNA relieved lung injury in septic mice. CONCLUSION: This study not only suggests that ROCK/YAP/Egr-1 signaling regulates TF expression after stimulation with LPS in ECs, but it also indicates that LPS-induced activation of YAP signaling plays an important role in septic ALI in mice. Our findings provide a new insight into the pathogenic mechanism of TF expression, which is closely linked to septic ALI, and YAP signaling is considered to be a novel target for therapeutic intervention under septic conditions.

The p38/mitogen-activated protein kinase pathway is implicated in lipopolysaccharide-induced microtubule depolymerization via up-regulation of microtubule-associated protein 4 phosphorylation in human vascular endothelium.

BACKGROUND: Microtubules (MTs) play an important role in lipopolysaccharide (LPS)-induced overexpression of inflammatory cytokines and vascular barrier dysfunction; however, the mechanisms behind MT dynamics changes in the vascular endothelium under septic conditions are still not well understood. METHODS: Human umbilical vein endothelial cells (HUVECs) stimulated with LPS were pretreated with or without the specific p38/mitogen-activated protein kinase (MAPK) inhibitor, SB203580. p38/MAPK cascade-induced signaling events and proteins expression were investigated by Western blotting assay. The interaction between p38/MAPK and microtubule-associated protein 4 (MAP4) was examined by immunoprecipitation. Furthermore, the effects of agonists on LPS-induced MT disruption and alteration of acetylated alpha-tubulin (Acet-tubulin) were analyzed by double-immunofluorescent assay and Western blotting analysis. RESULTS: In the present study, our results indicated that LPS induced MT depolymerization, but the effects of LPS could be reversed in endothelial cells pretreated with taxol. Furthermore, phosphor-p38 and MAP4 interacted to form a complex after exposure to LPS. LPS-induced MAP4 phosphorylation was greatly suppressed by SB203580, suggesting that activation of p38/MAPK signaling affected MAP4 phosphorylation linked to MT acetylation after stimulation with LPS. CONCLUSION: The present study demonstrated that the p38/MAPK signaling pathway might disrupt MT dynamics via phosphorylation of MAP4 in vascular endothelial cells challenged by LPS. Our findings provide novel insights into the pathogenic mechanism of MT disassembly and consider new targets for therapeutic intervention under sepsis or septic shock conditions.