从噬菌体展示肽库中筛选脂质A的结合肽

以脂质A为靶标,筛选噬菌体展示十二肽库,三轮后随机挑取14个噬菌体克隆进行结合活性鉴定,并对5个克隆进行序列分析。结果表明,14个克隆全部是阳性克隆,测序结果显示4个阳性克隆的序列完全一样。说明筛选到了一个脂质A的结合多肽。     

The emerging role of MIF in septic shock and infection

The protein mediator described originally as macrophage migration inhibitory factor (MIF) has been re-discovered recently to be both a novel pituitary hormone and a pro-inflammatory, macrophage-derived cytokine. Emerging studies indicate that MIF plays a pivotal role not only in endotoxic shock but also in the host response to a variety of acute and chronic infections.Abbreviations MIF Macrophage migration Inhibitory Factor     

Monophosphoryl lipid A induces pharmacologic ‘preconditioning’ in rabbit hearts without concomitant expression of 70-kDa heat shock protein

The purpose of this study was to evaluate the protective effect of a new endotoxin analogue, monophosphoryl lipid A (MLA) in a rabbit model of myocardial ischemia/reperfusion and to show if this protection was mediated via synthesis of 70 kDa heat shock protein (HSP 70). Three groups of New Zealand White rabbits underwent 30 min coronary occlusion, followed by 4 hours reperfusion. First group of rabbits (n = 6) were treated with 0.35 ml vehicle (40 % propylene glycol, 10 % ethanol in water). The second and third group of rabbits (n = 6–8) were treated with MLA (35 g/kg, i.v.) 12 and 24 hours prior to ischemia and reperfusion. MLA treatment either 12 or 24 h prior to ischemia/reperfusion demonstrated significantly reduced infarct size (12.5 ± 1.7 and 14.7 ± 2.1% for 12 and 24 h) when compared with vehicle control (40.4 ± 8.6%, mean ± S.E.M, p < 0.05). No significant differences in the infarct size was observed between the 12 and 24 h MLA treated groups. The area at risk was not significantly different between the three groups. Baseline values of heart rate, systolic and diastolic blood pressure were not significantly different between the control and MLA treated groups. However, the systolic as well as diastolic blood pressure during reperfusion were significantly lower in rabbits treated with MLA. Western blot analysis of the protein extracts of the hearts (n = 2/group) demonstrated no increase in the expression of the inducible form of HSP 70 following treatment with MLA. We conclude that MLA has significant anti-infarct effect in rabbit which is not mediated by the cardioprotective protein HSP 70. The anti-infarct effect of this drug is superior to the reported protective effects of delayed ischemic or heat stress preconditioning. We hypothesize that the pharmacologic preconditioning afforded by MLA is accomplished via a unique pathway that bypasses the usual intracellular signaling pathways which lead to the myocardial protection with the expression of heat shock proteins.A preliminary form of this paper was presented at the XV World Congress of the International Society for Heart Research held in Prague, Czech Republic [17].This work was supported in part by grants HL 46763 and 51045 from Natinal Institute of Health and a grant from RIBI ImmunoChem Research, Hamilton, Montana. JBS was supported from a training grant HL 07537 from National Institutes of Health.This article was published in Molecular and Cellular Biochemistry 156: 1–8, 1996. Kluwer Academic Publishers regret the publication of the incorrect version.     

Decrease in the glycosaminoglycan content in the skin of diabetic rats. The role of IGF-I, IGF-binding proteins and proteolytic activity

The purpose of this study was to evaluate the protective effect of a new endotoxin analogue, monophosphoryl lipid A (MLA) in a rabbit model of myocardial ischemia/reperfusion and to show if this protection was mediated via synthesis of 70 kDa heat shock protein (HSP 70). Three groups of New Zealand White rabbits underwent 30 min coronary occlusion, followed by 4 hours reperfusion. First group of rabbits (n = 6) were treated with 0.35 ml vehicle (40 % propylene glycol, 10% ethanol in water). The second and third group of rabbits (n = 6–8) were treated with MLA (35 g/kg, i.v.) 12 and 24 hours prior to ischemia and reperfusion. MLA treatment either 12 or 24 h prior to ischemia/reperfusion demonstrated significantly reduced infarct size (12.5 ± 1.7 and 14.7 ± 2.1 % for 12 and 24 h) when compared with vehicle control (40.4 ± 8.6%, mean ± S.E.M, p < 0.05). No significant differences in the infarct size was observed between the 12 and 24 h MLA treated groups. The area at risk was not significantly different between the three groups. Baseline values of heart rate, systolic and diastolic blood pressure were not significantly different between the control and MLA treated groups. However, the systolic as well as diastolic blood pressure during reperfusion were significantly lower in rabbits treated with MLA. Western blot analysis of the protein extracts of the hearts (n = 2/group) demonstrated no increase in the expression of the inducible form of HSP 70 following treatment with MLA. We conclude that MLA has significant anti-infarct effect in rabbit which is not mediated by the cardioprotective protein HSP 70. The anti-infarct effect of this drug is superior to the reported protective effects of delayed ischemic or heat stress preconditioning. We hypothesize that the pharmacologic preconditioning afforded by MLA is accomplished via a unique pathway that bypasses the usual intracellular signaling pathways which lead to the myocardial protection with the expression of heat shock proteins.A preliminary form of this paper was presented at the XV World Congress of the International Society for Heart Research held in Prague, Czech Republic [17]. This work was supported in part by grants HL 46763 and 51045 from National Institutes of Health and a grant from RIBI ImmunoChem Research, Hamilton, Montana. JBS was supported from a training grant HL 07537 from National Institutes of Health.     

Analysis of peripheral blood lymphocyte subsets and prognosis in patients with septic shock

The purpose of the study is to study the relationship between peripheral blood lymphocyte subset proportion and prognosis in patients with septic shock. Fifty‐two patients with septic shock, admitted to the intensive care unit between March 2007 and December 2010, were enrolled in this study. Peripheral blood lymphocyte subset proportions were measured using flow cytometry. The percentage of CD3⁺CD4⁺ T lymphocytes and CD19⁺ lymphocytes, CD4⁺/CD8⁺ T cell ratio were substantially lower in patients with septic shock compared to the control group (P < 0.01). The percentage of CD3⁺CD8⁺ T lymphocytes did not differ significantly between the two groups (P > 0.05). The percentage of CD16⁺CD56⁺ lymphocytes was higher in patients with septic shock than in the control group (P < 0.01). Compared with the survivor group, the percentage of CD3⁺CD4⁺ T lymphocytes and CD19⁺ lymphocytes, CD4⁺/CD8⁺ T cell ratio were clearly lower in the non‐survivor group (P < 0.01). There was no difference in the percentage of CD3⁺CD8⁺ T lymphocytes between the non‐survivor and survivor groups (P > 0.05). The percentage of CD16⁺CD56⁺ lymphocytes was higher in the non‐survivor group than in the survivor group (P < 0.05). The total maximum SOFA score and the delta SOFA score were much higher in the non‐survivor group than in the survivor group (P < 0.01). Immune imbalance occurs in patients with septic shock. Peripheral blood lymphocyte subset proportion and SOFA scores can be used to assess the treatment and prognosis of septic shock.     

LPS的胞内受体Caspase-11的研究进展

以往的研究认为,TLR4是内毒素(LPS)的胞膜受体.新近的研究发现含半胱氨酸的天冬氨酸蛋白水解酶11(Caspase-11,Casp11)可能在胞内LPS的识别中发挥关键作用.Caspase-11与胞内LPS结合后被激活.活化的Casp-11一方面剪切下游gasdermin D分子进而介导细胞焦亡(pyroptosis),另一方面激活NLRP3/ASC-Casp-1通路,使细胞分泌促炎因子IL-1β和IL-18等.Casp-11还能通过促进吞噬体和溶酶体融合,增强细胞对革兰氏阴性菌的杀灭.在严重内毒素血症过程中,由于Casp-11过度活化,大量细胞发生焦亡,致使大量胞内促炎介质被释放到胞外,导致机体出现难以调控的炎症反应,最终发展成内毒素休克.Casp-11是内毒素休克发生的关键分子.本文对Casp-11在LPS的识别、活化及效应方面的最新进展进行综述.     

Interleukin-10 rs2227307 and CXCR2 rs1126579 polymorphisms modulate the predisposition to septic shock

Despite major improvements in its treatment and diagnosis, sepsis is still a leading cause of death and admittance to the intensive care unit (ICU). Failure to identify patients at high risk of developing septic shock contributes to an increase in the sepsis burden and rapid molecular tests are currently the most promising avenue to aid in patient risk determination and therapeutic anticipation. The primary goal of this study was to evaluate the genetic susceptibility that affects sepsis outcome in 72 sepsis patients admitted to the ICU. Seven polymorphisms were genotyped in key inflammatory response genes in sepsis, including tumour necrosis factor-α, interlelukin (IL)-1β, IL-10, IL-8, Toll-like receptor 4, CXCR1 and CXCR2. The primary finding showed that patients who were homozygous for the major A allele in IL-10 rs1800896 had almost five times higher chance to develop septic shock compared to heterozygotes. Similarly, selected clinical features and CXCR2 rs1126579 single nucleotide polymorphisms modulated septic shock susceptibility without affecting survival. These data support the hypothesis that molecular testing has clinical usefulness to improve sepsis prognostic models. Therefore, enrichment of the ICU portfolio by including these biomarkers will aid in the early identification of sepsis patients who may develop septic shock.     

The critical role played by endotoxin-induced liver autophagy in the maintenance of lipid metabolism during sepsis

Macroautophagy/autophagy is a central mechanism by which cells maintain integrity and homeostasis, and endotoxin-induced autophagy plays important roles in innate immunity. Although TLR4 stimulation mediated by lipopolysaccharide (LPS) also upregulates autophagy in hepatocytes and liver, its physiological role remains elusive. The objective of this study was to determine the role of LPS-induced autophagy in the regulation of liver lipid metabolism. LPS treatment (5 mg/kg) increased autophagy, as detected by LC3 conversion and transmission electron microscopy (TEM) analysis in C57BL6 mouse livers. AC2F hepatocytes also showed increased autophagic flux after LPS treatment (1 μg/ml). To investigate the role of LPS-induced autophagy further, liver lipid metabolism changes in LPS-treated mice and fasted controls were compared. Interestingly, LPS-treated mice showed less lipid accumulation in liver than fasted mice despite increased fatty acid uptake and lipid synthesis-associated genes. In vitro analysis using AC2F hepatocytes demonstrated LPS-induced autophagy influenced the degradation of lipid droplets. Inhibition of LPS-induced autophagy using bafilomycin A₁ or Atg7 knockdown significantly increased lipid accumulation in AC2F hepatocytes. In addition, pretreatment with chloroquine aggravated LPS-induced lipid accumulation and inflammation in C57BL6 mouse livers. The physiological importance of autophagy was verified in LPS-treated young and aged rats. Autophagic response was diminished in LPS-treated aged rats and lipid metabolism was impaired during sepsis, indicating autophagy response is important for regulating lipid metabolism after endotoxin challenge. Our findings demonstrate endotoxin-induced autophagy is important for the regulation of lipid metabolism, and suggest that autophagy helps maintain lipid metabolism homeostasis during sepsis.     

Soluble TREM-1 as a diagnostic and prognostic biomarker in patients with septic shock: an observational clinical study

Objectives: The impact of TREM-1-mediated inflammation was investigated in different inflammatory settings.

Methods: Secondary analyses of an observational clinical pilot study, including 60 patients with septic shock, 30 postoperative controls and 30 healthy volunteers.

Results: Plasma levels of sTREM-1 were found to identify patients with septic shock more effectively than procalcitonin and C-reactive protein. Moreover, sTREM-1 was identified to be an early predictor for survival in patients with septic shock.

Conclusion: Due to its diagnostic as well as prognostic value in sepsis syndrome, implementation of sTREM-1 measurements in routine diagnostics should be taken into account.