MK2 plays an important role for the increased vascular permeability that follows thermal injury

We previously reported Rho kinase is involved in vessel hyper-permeability caused by burns. Here we further explore the Rho kinase downstream signaling, it is found that its specific inhibitor Y27632 significantly diminishes the activation of JNK and p38 MAPKs but not ERK that induced by serum from burned rats (burn-serum). JNK activation was found involved in the expression of HUVEC adhesion molecules following thermal injury, although not in the process of stress fiber formation. Inhibition of various MAPKs by specific inhibitors showed that SB203580 (inhibitor of p38), but neither SP600125 (inhibitor of JNK) nor PD98059 (inhibitor of ERK), abolish activation of the p38 downstream kinase MK2. Demonstration of stress fibers by fluorescent-labeled phalloidin showed that inhibition of MK2, either by its specific inhibitor or by dominant negative adeno-viral-carried constructs, significantly reduced burn-serum-induced HUVEC stress-fiber formation, while inhibition of another downstream p38 MAPK kinase, PRAK, had no such effects. Transfection of dominant negative adeno-viral MK2 (Ad-MK2(A)) significantly inhibited thermal injury-induced blood vessel hyper-permeability in rats and, moreover, prolonged the survival of burned rats beyond 72 h following thermal injury. One of the mechanisms behind these phenomena is that Ad-MK2(A) causes a significant depression of burn-serum-induced HSP27-phosphorylation, while the adeno-viral transported dominant negative PRAK (Ad-PRAK(A)) does not block. Although the effect of blockade of MK2 through its adeno-viral approach requires further study and investigation of alternatives to know for sure, we may have found a new pathway behind thermal-injury-induced blood vessel hyper-permeability, namely: Rho kinase > p38 > MK2 > HSP27.     

Delayed wound healing in aged skin rat models after thermal injury is associated with an increased MMP-9, K6 and CD44 expression

Age-related differences in wound healing have been documented but little is known about the wound healing mechanism after burns. Our aim was to compare histological features and immunohistochemical expression of matrix metalloproteinase-9 (MMP-9), collagen IV, K6 and CD44 in the burn wound healing process in aged and young rats.     

Pretransplant Interferon‐γ Secretion by CMV‐Specific CD8+ T Cells Informs the Risk of CMV Replication After Transplantation

In this prospective study we analyzed pretransplant interferon‐γ secretion by cytomegalovirus (CMV)‐specific CD8+ T cells to assess its possible utility in determining the risk of CMV replication after solid organ transplantation. A total of 113 lung and kidney transplant patients were enrolled in the study but only 55 were evaluable. All CMV‐seronegative recipients were pretransplant “nonreactive” (IFNγ <0.2 IU/mL) (11/11), whereas 30/44 (68.2%) CMV‐seropositive (R+) recipients were “reactive” (IFNγ ≥0.2 IU/mL) and 14/44 (31.8%) were “nonreactive”. In the R(+) “nonreactive” group, 7/14 (50%) developed posttransplant CMV replication, whereas the virus replicated only in 4/30 (13.3%) of the R(+) “reactive” patients (p = 0.021). According to the best multivariate model, pretransplant “nonreactive” recipients receiving an organ from a CMV‐seropositive donor had a 10‐fold increased risk of CMV replication compared to pretransplant “reactive” recipients (adjusted OR 10.49, 95% CI 1.88–58.46). This model displayed good discrimination ability (AUC 0.80) and calibration (Hosmer–Lemeshow test, p = 0.92). Negative and positive predictive values were 83.7% and 75%, respectively. The accuracy of the model was 82%. Therefore, assessment of interferon‐γ secretion by cytomegalovirus (CMV)‐specific CD8+ T cells prior to transplantation is useful in informing the risk of posttransplant CMV replication in solid organ transplant patients.     

超高分子聚乙烯颗粒刺激单核细胞高表达CD147/EMMPRIN

目的探讨不同浓度磨损颗粒对单核细胞表达细胞外基质金属蛋白酶诱导剂（CD147/EMMPRIN）的影响。方法根据颗粒/细胞比值实验分为0、1、10、100、500、1000共6组,将不同浓度的超高分子聚乙烯（UHMWPE）颗粒与人单核细胞株THP-1共培养24h,台盼蓝染色检测THP-1细胞存活率,利用流式细胞术、Real-time PCR和Western blot检测THP-1细胞CD147/EMMPRIN的表达。结果加入UHMWPE颗粒前及共培养24h后THP-1细胞存活率均大于90%。流式细胞术、Real-timePCR和Westernblot结果均显示加入UHMWPE颗粒后,CD147/EMMPRIN表达较对照组（即颗粒/细胞比值为0）增加,当颗粒/细胞比值在1-100范围时,CD147/EMMPRIN表达与颗粒浓度正相关,颗粒/细胞比值大于或等于100时,CD147/EMMPRIN稳定保持在高表达水平,不随颗粒浓度升高而变化。结论 UHMWPE颗粒刺激单核细胞高表达CD147/EMMPRIN,并呈浓度依赖性。     

Immunohistochemical analysis of CD45RO+ T cells and vascular endothelial growth factor expression in cyclosporin A-induced rat gingival tissue

Background: The aim of this study is to evaluate CD4⁺, CD8⁺, and CD45RO⁺ T cells, and vascular endothelial growth factor (VEGF) expression in cyclosporin A (CsA)–induced rat overgrown gingival tissue during an 8‐week period. Methods: Sixty male Sprague‐Dawley rats weighing 200 to 250 g were used in this study. Mandibular first molars were ligated with 3–0 silk suture. The rats received daily doses of 0.09% NaCl (control group) or 10 mg/kg body weight of CsA (test group) by intraperitoneal injections. Five rats from the control group and 10 rats from the test group were sacrificed at each experimental period (2, 4, 6, and 8 weeks after the beginning of CsA treatment). The specimens were examined immunohistochemically. Results: CD4⁺, CD8⁺, and CD45RO⁺ T cells, and VEGF expression were more prevalent in the CsA‐treated group than in the control group (P <0.05). VEGF was significantly correlated with CD4⁺ T cells, CD4⁺/CD8⁺ ratio, and CD45RO⁺ cells (P <0.05). Conclusion: Based on our findings, we conclude that VEGF, a major regulator of angiogenesis, and CD4⁺, CD8⁺, and CD45RO⁺ memory T cells play a key role in CsA‐induced gingival overgrowth.     

Magnetic resonance spectroscopy and molecular studies in ornithine transcarbamylase deficiency novel mutation c.802A>G in exon 8 (p.Met268Val)

Ornithine transcarbamylase (OTC) deficiency, an X-linked, semidominant disorder, is the most common inherited defect in ureagenesis, resulting in hyperammonaemia type II. The OTC gene, localised on chromosome X, has been mapped to band Xp21.1, proximate to the Duchenne muscular dystrophy (DMD) gene. More than 350 different mutations, including missense, nonsense, splice-site changes, small deletions or insertions and gross deletions, have been described so far. Almost all mutations in consensus splicing sites confer a neonatal phenotype. Most mutations in the OTC gene are ‘private’ and are distributed throughout the gene with a paucity of mutation in the sequence encoding the leader peptide (exon 1 and beginning of exon 2) and in exon 7. They have familial origin or occur de novo. Even with sequencing of the entire reading frame and exon/intron boundaries, only about 80% of the mutations are detected in patients with proven OTC deficiency. The remainder probably occur within the introns or in regulatory domains. The authors present a 4-year-old boy with the unreported missense mutation c.802A>G. The nucleotide transition leads to amino acid substitution Met to Val at codon 268 of the OTC protein.     

Increased hippocampal CD38 and systemic inflammation after partial hepatectomy does not induce impairment of spatial cognition

Objective: The role of inflammation in cognitive alterations in a post-operative setting is still not fully understood. Surgical interventions can cause systemic inflammations which eventually can induce neuroinflammation. However, the main causes of functional changes after surgery are still elusive. In this study, we investigated the role of CD38, a TNFα-inducible NADH⁺ cyclase and hydrolase. We assume that CD38 overexpression impairs mitochondrial ATP synthesis. Within the hippocampus, the resulting cellular death could lead to cognitive impairment.

Methods: Seventy-nine Wistar-HAN rats were subjected for three hours either to partial hepatectomy under sevoflurane anaesthesia (‘surgery’), sevoflurane anaesthesia alone (‘anaesthesia’) or control. Rats were randomly selected to determine levels of CD38, TNFα, IL-6, and ATP, for GFAP immunohistochemistry and for Morris Water Maze testing.

Results: Plasma TNFα and IL-6 levels were significantly higher in the surgery group in the immediate post-operative phase. GFAP expression and hippocampal CD38 concentration were significantly elevated 24 h after the intervention in the surgery group as compared to anaesthesia alone and controls. ATP levels did not differ significantly between the three groups. No treatment differences in spatial cognition parameters were found.

Conclusions: Surgery in the form of partial hepatectomy activated the peripheral immune system and induced hippocampal glial activation and a CD38 increase. These changes, however, were not associated with rats’ cognitive impairment ≥24 h after surgery.