治伤巴布剂对大鼠急性软组织损伤模型P38MAPK、AKT信号通路的影响＊

目的 观察治伤巴布剂对急性软组织损伤（acute soft tissue injury， ASTI）模型p38丝裂原活化蛋白激酶（mitogen-activated protein kinase，MAPK）、丝/苏氨酸蛋白激酶（AKT）信号通路的影响，探讨治伤巴布剂干预ASTI的可能作用机制。方法 将40只雄性SD大鼠按照随机数字表法分为正常对照组、模型对照组、治伤巴布剂组、p38MAPK信号通路抑制剂组、AKT信号通路抑制剂组，每组8只。除正常对照组外，其余四组均予以左侧后肢小腿ASTI造模。造模成功后，治伤巴布剂组于标记部位立即予治伤巴布剂（修剪成1.5x3cm大小）外敷，并用胶布固定；其余四组均予等剂量赋形剂（修剪成1.5×3 cm大小）外敷处理，胶布固定；持续外敷，共持续24 h。p38MAPK信号通路抑制剂组在造模前30 min予腹腔注射p38MAPK信号通路抑制剂SB203580（400 μg/kg/天）1次；AKT信号通路抑制剂组在造模前30 min予腹腔注射AKT信号通路抑制剂perifosine（20 mg/kg/天）1次。分别于0（造模前）、2h、4h、8h、12h、24h测量受伤小腿肌肉处的周长，并计算肌肉肿胀率（muscle swelling rate，MSR）。24 h药物干预结束后，采用颈椎脱臼法处死大鼠。后将左侧后肢小腿损伤中心部位进行取材，分成三份。一部分用于观察组织病理学形态变化；一部分用于逆转录聚合酶链反应（RT-PCR）检测核因子-κB（nuclear factor kappa-B，NF-κB）p65 mRNA、肿瘤坏死因子-α（TNF-α）mRNA、白细胞介素-1β（IL-1β）mRNA表达水平；剩下部分用酶联免疫吸附试验（ELISA）法检测骨骼肌组织TNF-α、IL-1β含量水平及蛋白质免疫印迹（Western-blot）法测定p38MAPK、AKT、NF-κB p65、核因子抑制蛋白α（inhibitor kappa B alpha， IκBα）表达水平。结果 与正常对照组相比，模型对照组MSR显著增加（P<0.01）；病理形态学上，骨骼肌组织可见大面积肌细胞排列紊乱，肌细胞变性坏死，间质内可见红细胞聚集及大量炎症细胞浸润；骨骼肌组织TNF-α、IL-1β含量水平显著升高（P<0.01）；磷酸化p38MAPK（p-p38）/总p38MAPK（t-p38），磷酸化-AKT（p-AKT）/总-AKT（t-AKT）明显升高（P<0.01），NF-κB p65及NF-κB p65mRNA表达水平明显升高（P<0.01）。与模型对照组相比，治伤巴布剂组MSR在治疗第8 h、12 h、24 h显著下降（P<0.01），且在治疗第24 h，其MSR较p38MAPK、AKT信号通路抑制剂组下降更明显（P<0.05）；病理学评分显著下降（P<0.01），且较p38MAPK、AKT信号通路抑制剂组下降更显著（P<0.05）；骨骼肌组织TNF-α、IL-1β含量水平明显下降（P<0.01），且较p38MAPK、AKT信号通路抑制剂组更显著（P<0.05）；p-p38/t-p38及p-AKT/t-AKT明显下降（P<0.01），NF-κB p65及NF-κB p65 mRNA表达水平显著下降（P<0.01），且较p38MAPK、AKT信号通路抑制剂组在降低NF-κB p65及NF-κB p65 mRNA相对表达值方面更显著（P<0.01）。结论 治伤巴布剂可能同时对p38MAPK、AKT信号通路产生了一定的抑制作用，引起NF-κB活性下调，NF-κB p65蛋白的表达下调，进而引起骨骼肌组织TNF-α、IL-1β炎性细胞因子含量水平下调，减轻ASTI炎症反应，从而改善ASTI。     

Analysis of the correlation between P27 expression and Helicobacter pylori infection in gastric cancer

We aimed to explore the correlation between P27 expression and Helicobacter pylori (H. pylori) infection in gastric cancer, so as to provide evidence for understanding the pathogenesis of gastric cancer caused by H. pylori infection. A total of 82 samples of gastric cancer tissues and 56 samples of tumor-adjacent normal tissues collected from the gastrectomy were enrolled in this study. Then, 14C-urease breathing test was carried out to evaluate the infection of H. pylori in gastric cancer tissues, the expression of P27 in the tissue samples was detected by the immunohistochemistry staining, and the correlation between the H. pylori infection and P27 expression in gastric cancer was analyzed. Of 82 gastric cancer patients, there were 53 patients with H. pylori infection (64.63%). Among the patients with highly or moderately differentiated gastric cancer, the expression of P27 was much higher than that of patients with poorly differentiated gastric cancer (p < 0.01). Besides, comparison of the P27 expression between males and females, among different age groups, tumor sizes, TNM stages, tumor infiltration degrees, or lymph node metastasis, showed no significant differences (p > 0.05). Analysis of the correlation revealed that P27 expression was negatively correlated with the infection of H. pylori (p < 0.01). Multifactorial logistics regression analysis indicated that tumor differentiation was a risk factor of P27-positive expression in gastric cancer tissues (p < 0.01). In addition, P27 expression in the gastric cancer tissues was lower than that in the tumor-adjacent normal tissues (p < 0.01). In gastric cancer patients, expression of P27 is correlated with H. pylori infection which, via downregulating P27, can cause the cancerization of gastric mucosa, and P27, for its role in the development and progression of gastric cancer, is a potential auxiliary indicator for clinical diagnosis whether gastric cancer is complicated with H. pylori infection. So, P27 is a key indicator for diagnosis, treatment, and prognostic evaluation of disease in the advanced stage.     

Metabolism of non-steroidal anti-inflammatory drugs (NSAIDs) by Streptomyces griseolus CYP105A1 and its variants

In the field of drug development, technology for producing human metabolites at a low cost is required. In this study, we explored the possibility of using prokaryotic water-soluble cytochrome P450 (CYP) to produce human metabolites. Streptomyces griseolus CYP105A1 metabolizes various non-steroidal anti-inflammatory drugs (NSAIDs), including diclofenac, mefenamic acid, flufenamic acid, tolfenamic acid, meclofenamic acid, and ibuprofen. CYP105A1 showed 4′-hydroxylation activity towards diclofenac, mefenamic acid, flufenamic acid, tolfenamic acid, and meclofenamic acid. It should be noted that this reaction specificity was similar to that of human CYP2C9. In the case of mefenamic acid, another metabolite, 3′-hydroxymethyl mefenamic acid, was detected as a major metabolite. Substitution of Arg at position 73 with Ala in CYP105A1 dramatically reduced the hydroxylation activity toward diclofenac, flufenamic acid, and ibuprofen, indicating that Arg73 is essential for the hydroxylation of these substrates. In contrast, substitution of Arg84 with Ala remarkably increased the hydroxylation activity towards diclofenac, mefenamic acid, and flufenamic acid. Recombinant Rhodococcus erythrocyte cells expressing the CYP105A1 variant R84A/M239A showed complete conversion of diclofenac into 4′-hydroxydiclofenac. These results suggest the usefulness of recombinant R. erythropolis cells expressing actinomycete CYP, such as CYP105A1, for the production of human drug metabolites.     

Preoperative comprehensive malignancy risk estimation for thyroid nodules: Development and verification of a network-based prediction model

BackgroundIn order to avoid excessive treatment of thyroid nodules in the clinic, it is necessary to find a simple and practical analysis method to comprehensively and accurately reflect benign or malignant thyroid nodules. This study aimed to construct and validate a comprehensive and reliable network-based predictive model using a variety of imaging and laboratory criteria for thyroid nodules to stratify the risk of malignancy prior to surgery.MethodsWe retrospectively analyzed data from patients who underwent surgical treatment for thyroid nodules at the Thyroid and Breast Diagnosis and Treatment Center of Weifang Hospital of Traditional Chinese Medicine between January 2018 and December 2020. Binary logical regression analysis was performed to predict whether nodules were malignant or benign. The developmental dataset included 457 patients (January 2018–December 2020). The validation set included separate data points (n = 225, January 2018–December 2020).ResultsIn this study, criteria that showed significant predictive value for malignant nodules included TI-RADS: 4b (p = 0.065); Bethesda IV, Bethesda V, Bethesda VI (P < 0.0001); BRAF^V600E mutation (P < 0.0001); Calcitonin>5 pg/ml (p = 0.0037); and FNA-Tg>30 ng/ml (p = 0.0003). A 10-grade risk scoring system was developed. The risk of malignancy risk ranged from 2.06% to 100% and was positively associated with increasing risk grade. The areas under the receiver-operating characteristic curve of the development and validation sets were 0.972 and 0.946, respectively.ConclusionA simple, comprehensive and reliable web-based predictive model was designed using a variety of imaging and laboratory criteria to stratify thyroid nodules by probability of malignancy.     

Comparison of P25 and nanobelts on Kruppel-like factor-mediated nitric oxide pathways in human umbilical vein endothelial cells

Recently, we reported that titanium dioxide (TiO₂) materials activated endothelial cells via Kruppel-like factor (KLF)-mediated nitric oxide (NO) dysfunction, but the roles of physical properties of materials are not clear. In this study, we prepared nanobelts from P25 particles and compared their adverse effects to human umbilical vein endothelial cells (HUVECs). TiO₂ nanobelts had belt-like morphology but comparable surface areas as P25 particles. When applied to HUVECs, P25 particles or nanobelts did not induce cytotoxicity, although nanobelts were much more effective to increase intracellular Ti element concentrations compared the same amounts of P25 particles. Only nanobelts significantly induced THP-1 adhesion onto HUVECs. Consistently, nanobelts were more significant to induce the expression of intracellular adhesion molecule-1 (ICAM1) and the release of soluble ICAM-1 (sICAM-1), indicating that nanobelts were more potent to induce endothelial activation in vitro. As the mechanisms for endothelial activation, both P25 and nanobelts reduced the generation of intracellular NO as well as the expression of NO regulators KLF2 and KLF4. Combined, the results from this study indicated that the different morphologies of P25 particles and nanobelts only changed their internalization into HUVECs but showed minimal impact on KLF-mediated NO signaling pathways.     

ε-聚赖氨酸对耐甲氧西林金黄色葡萄球菌USA300的作用机制

摘要：目的 研究ε-聚赖氨酸(ε-polylysine，ε-PL)对耐甲氧西林金黄色葡萄球菌(methicillin-resistant Staphylococcus aureus，MRSA)标准菌株USA300的抑菌作用及其机制。方法 依据CLSI微量肉汤稀释法测定最低抑菌浓度(minimum inhibitory concentration, MIC)和最低杀菌浓度(minimum bactericidal concentration, MBC)；绘制24 h内不同浓度ε-PL作用后USA300菌株时 间-抑菌曲线；SYBR Green I/PI检测ε-PL处理后USA300的生存情况；测定ε-PL处理后菌液电导率、胞外ATP含量、可溶性蛋白 含量的变化；利用扫描电镜(scanning electron microscopy，SEM)观察ε-PL对USA300形态的影响。结果 ε-PL对USA300的MIC、 MBC分别为5.12和10.24 mg/mL。ε-PL处理后细菌死/活比例，菌液电导率，胞外ATP含量，胞外可溶性蛋白含量均增加，表明菌 膜破损；经SEM进一步确证。结论 ε-PL对USA300生长有良好的抑制作用，且与ε-PL浓度呈正相关。ε-PL处理后细胞膜结构破 坏、通透性改变，导致细胞内容物大量渗出，其抑菌机制可能与破坏细菌菌体结构有关。     

Helicobacter pylori CagA oncoprotein interacts with SHIP2 to increase its delivery into gastric epithelial cells

Chronic infection with Helicobacter pylori cagA‐positive strains is causally associated with the development of gastric diseases, most notably gastric cancer. The cagA‐encoded CagA protein, which is injected into gastric epithelial cells by bacterial type IV secretion, undergoes tyrosine phosphorylation at the Glu‐Pro‐Ile‐Tyr‐Ala (EPIYA) segments (EPIYA‐A, EPIYA‐B, EPIYA‐C, and EPIYA‐D), which are present in various numbers and combinations in its C‐terminal polymorphic region, thereby enabling CagA to promiscuously interact with SH2 domain‐containing host cell proteins, including the prooncogenic SH2 domain‐containing protein tyrosine phosphatase 2 (SHP2). Perturbation of host protein functions by aberrant complex formation with CagA has been considered to contribute to the development of gastric cancer. Here we show that SHIP2, an SH2 domain‐containing phosphatidylinositol 5′‐phosphatase, is a hitherto undiscovered CagA‐binding host protein. Similar to SHP2, SHIP2 binds to the Western CagA‐specific EPIYA‐C segment or East Asian CagA‐specific EPIYA‐D segment through the SH2 domain in a tyrosine phosphorylation‐dependent manner. In contrast to the case of SHP2, however, SHIP2 binds more strongly to EPIYA‐C than to EPIYA‐D. Interaction with CagA tethers SHIP2 to the plasma membrane, where it mediates production of phosphatidylinositol 3,4‐diphosphate [PI(3,4)P₂]. The CagA‐SHIP2 interaction also potentiates the morphogenetic activity of CagA, which is caused by CagA‐deregulated SHP2. This study indicates that initially delivered CagA interacts with SHIP2 and thereby strengthens H. pylori‐host cell attachment by altering membrane phosphatidylinositol compositions, which potentiates subsequent delivery of CagA that binds to and thereby deregulates the prooncogenic phosphatase SHP2.