miR-1-3p在食蟹猴心肌损伤中表达水平及其与CK-MB、cTnI和NT-proBNP的相关性

目的探讨循环miR-1-3p在多柔比星诱导食蟹猴心肌损伤模型中的表达水平和诊断价值。方法选取3~5岁普通级雄性食蟹猴17只,随机分为对照组(7只)和实验组(10只),静脉注射盐酸多柔比星注射液(2.5 mg/kg)4周,收集外周血浆标本和心脏组织标本,应用液相芯片技术测定肌酸激酶同工酶(CK-MB)、肌钙蛋白I(cTnI)和NT-proBNP表达水平,且应用实时定量PCR技术测定miR-1-3p表达的水平,并进行相关性分析。结果成功建立药物致食蟹猴心肌损伤模型;两组CK-MB、cTnI和NT-proBNP水平比较差异有统计学意义(P<0.05);实验组miR-1-3p的表达水平在给药4周后较给药前和对照组相比明显升高(P<0.05);miR-1-3p的表达水平与CK-MB、cTnI和NT-proBNP改变呈现了相同的升高趋势,且二者之间具有明显相关性。结论miR-1-3p可作为药物引起心肌损伤的生物学诊断标志物之一。     

干扰素α2b给药途径对小儿病毒性肺炎疗效、T淋巴细胞亚群与血清KL-6、ICAM-1、TNF-α的影响

目的探讨干扰素α2b给药途径治疗小儿病毒性肺炎的疗效及其对T淋巴细胞亚群与血清KL-6、ICAM-1、TNF-α的影响。方法选取我院2017年3月至2019年3月收治的92例病毒性肺炎患儿,随机分为雾化组与肌注组,每组46例。比较两组治疗1周后的总有效率,记录两组治疗前及治疗1 d、2 d、3 d、4 d、5 d、6 d、7 d后的临床症状总评分,比较两组治疗前与治疗7 d后的血清CD^+_3、CD^+_4、CD^+_8、CD^+_4/CD^+_8、KL-6、ICAM-1、TNF-α水平与不良反应。结果两组的整体疗效与总有效率比较差异无统计学意义(P>0.05)。两组治疗后的临床症状总评分均呈下降趋势,组内前后差异有统计学意义(P<0.05)。雾化组治疗4 d、5 d、6 d、7 d的临床症状总评分低于肌注组(P<0.05)。治疗7 d后,两组CD^+_3、CD^+_4和CD^+_4/CD^+_8升高,CD^+_8降低(P<0.05);雾化组治疗7 d后CD^+_3、CD^+_4和CD^+_4/CD^+_8高于肌注组,CD^+_8低于肌注组(P<0.05)。治疗7 d后,两组各项血清学指标均明显降低(P<0.05),雾化组治疗后的血清ICAM-1、TNF-α低于肌注组(P<0.05),两组KL-6比较差异无统计学意义(P>0.05)。结论干扰素α2b雾化吸入给药可取得与肌注给药相当的疗效,同时可加速患儿症状缓解,调节免疫,血清ICAM-1、TNF-α下降幅度大,安全性良好。     

Differentiation Effect of Pyruvate and Uridine on Cultured U937-ρ° Cells

ABSTRACT

The human pro-monocytic leukemia U937 cell line was previously reported to become ρ°cells after a long-term ethidium bromide exposure. In the authors' extensive PCR studies with different pairs of primers for the mtDNA molecule they showed that these U937-ρ° cells, after being cultured in their laboratory for a time, did replete their mtDNA. That the cells grew well in the normal medium (RPMI 1640 plus 10% fetal calf serum and 2 mM L-glutamine) as the parental cells also suggests that these cells contain functional mitochondria and mtDNA molecules. Further experiments showed that the cells cultured in the medium with pyruvate and uridine rather rapidly and strongly adhered on the culture flask walls while the cells cultured in the medium without pyruvate and uridine either floated or only very loosely covered the culture flask walls. Ultrastructural examination showed that the floating cells, which were often found in the culture without pyruvate and uridine, were rather similar to monocytes in nature, like the original U937 cells, while the attached larger cells appearing earlier in the culture with pyruvate and uridine demonstrated macrophage differentiation, indicating a differentiation effect of pyruvate and uridine on the cells.     

Effects of transmembrane region variability on cell surface expression and allorecognition of HLA-DP3

The functional relevance of polymorphisms outside the peptide binding groove of HLA molecules is poorly understood. Here we have addressed this issue by studying HLA-DP3, a common antigen relevant for functional matching algorithms of unrelated hematopoietic stem cell transplantation (HSCT) encoded by two transmembrane (TM) region variants, DPB1^*03:01 and DPB1^*104:01. The two HLA-DP3 variants were found at a overall allelic frequency of 10.4% in 201 volunteer stem cell donors, at a ratio of 4.2:1. No significant differences were observed in cell surface expression levels of the two variants on B lymphoblastoid cell lines (BLCL), primary B cells or monocytes. Three different alloreactive T cell lines or clones showed similar levels of activation marker CD107a and/or CD137 upregulation in response to HLA-DP3 encoded by DPB1^*03:01 and DPB1^*104:01, either endogenously on BLCL or after lentiveral-vector mediated transfer into the same cellular background. These data provide, for the first time, direct evidence for a limited functional role of a TM region polymorphism on expression and allorecognition of HLA-DP3 and are compatible with the notion that the two variants can be considered as a single functional entity for unrelated stem cell donor selection.     

Mutations in K-Ras linked to levels of osteoprotegerin and sensitivity to TRAIL-induced cell death in pancreatic ductal adenocarcinoma cells

Osteoprotegerin (OPG) is a soluble receptor expressed in the serum of patients with diabetes, arthritis and pancreatic cancer. While OPG has been considered a tumor survival factor for bone metastasizing breast and prostate cancers, the role of OPG in pancreatic cancer, which itself rarely metastasizes to bone, is not known. Pancreatic ductal adenocarcinoma (PDAC) cell lines were found to secrete OPG and the level of OPG production correlated with sensitivity to TRAIL-induced apoptosis. Silencing OPG sensitized cells to TRAIL-induced apoptosis. Interestingly, a positive correlation was noted between OPG production level and K-Ras mutation status. Earlier studies implicated K-Ras in conferring resistance to TRAIL-induced apoptosis in pancreatic cells and this study demonstrates that K-Ras mediated TRAIL resistance in pancreatic cancer cells occurs due to increased OPG production. Silencing K-Ras in pancreatic cancer cells decreased OPG levels and increased sensitivity to TRAIL-induced apoptosis. These observations indicate that OPG can play a role in both cell survival and in PDAC cell sensitivity to TRAIL-induced apoptosis, which may contribute to metastasis. Targeted inhibition of OPG binding to TRAIL may represent a therapeutic approach in the treatment of pancreatic cancer.     

Costamere remodeling with muscle loading and unloading in healthy young men

Costameres are mechano-sensory sites of focal adhesion in the sarcolemma that provide a structural anchor for myofibrils. Their turnover is regulated by integrin-associated focal adhesion kinase (FAK). We hypothesized that changes in content of costamere components (beta 1 integrin, FAK, meta-vinculin, gamma-vinculin) with increased and reduced loading of human anti-gravity muscle would: (i) relate to changes in muscle size and molecular parameters of muscle size regulation [p70S6K, myosin heavy chain (MHC)1 and MHCIIA]; (ii) correspond to adjustments in activity and expression of FAK, and its negative regulator, FRNK; and (iii) reflect the temporal response to reduced and increased loading. Unloading induced a progressive decline in thickness of human vastus lateralis muscle after 8 and 34 days of bedrest (−4% and −14%, respectively; n = 9), contrasting the increase in muscle thickness after 10 and 27 days of resistance training (+5% and +13%; n = 6). Changes in muscle thickness were correlated with changes in cross-sectional area of type I muscle fibers (r = 0.66) and beta 1 integrin content (r = 0.76) at the mid-point of altered loading. Changes in meta-vinculin and FAK-pY397 content were correlated (r = 0.85) and differed, together with the changes of beta 1 integrin, MHCI, MHCII and p70S6K, between the mid- and end-point of resistance training. By contrast, costamere protein level changes did not differ between time points of bedrest. The findings emphasize the role of FAK-regulated costamere turnover in the load-dependent addition and removal of myofibrils, and argue for two phases of muscle remodeling with resistance training, which do not manifest at the macroscopic level.     

Cigarette smoke disrupts the integrity of airway adherens junctions through the aberrant interaction of p120‐catenin with the cytoplasmic tail of MUC1

Adherens junctions (AJs) containing epithelial cadherin (E‐cad) bound to p120‐catenin (p120ctn) and β‐catenin (β‐ctn) play a crucial role in regulating cell–cell adhesion. Cigarette smoke abrogates cell–cell adhesion between epithelial cells by disrupting E‐cad, a hallmark of epithelial–mesenchymal transition (EMT), yet the underlying mechanism remains unknown. We used an organotypic culture of primary human bronchial epithelial (HBE) cells treated with smoke‐concentrated medium (Smk) to establish an essential role for the interaction between p120ctn and the cytoplasmic tail of MUC1 (MUC1‐CT) in regulating E‐cad disruption. Within the first 4 h of smoke exposure, apical MUC1‐CT repositioned to the basolateral membrane of pseudo‐stratified HBE cells, where it interacted with p120ctn. A time‐dependent increase in MUC1‐CT/p120ctn complexes occurred in conjunction with a time‐dependent dissociation of p120ctn/E‐cad/β‐ctn complexes, as well as the coordinated degradation of p120ctn and E‐cad. Interestingly, Smk induced a similar interaction between MUC1‐CT and β‐ctn, but this occurred 44 h after MUC1‐CT's initial interaction with p120ctn, and well after the AJs were destroyed. Blocking MUC1‐CT's interaction with p120ctn using a MUC1‐CT dominant‐negative peptide, PMIP, successfully abolished Smk's disruptive effects on AJs and recovered apical‐basolateral polarity of HBE cells. The MUC1‐CT/p120ctn interaction was highly dependent on EGFR/Src/Jnk‐mediated tyrosine phosphorylation (TyrP) of MUC1‐CT. Accordingly, EGFR, Src or Jnk inhibitors (AG1478, PP2, SP600125, respectively) abrogated Smk‐induced MUC1‐CT‐TyrP, MUC1‐CT/p120ctn interaction, AJ disruption, and loss of cellular polarity. Our work identified MUC1‐CT and p120ctn as important regulators of epithelial polarity and cell‐cell adhesion during a smoke‐induced EMT‐like process. Novel therapeutics designed to inhibit MUC1‐CT/p120ctn complex formation may prevent EMT in the smoker's airway. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.