Endoplasmic reticulum stress is involved in ventilator-induced lung injury in mice via the IRE1α-TRAF2-NF-κB pathway

Inflammation plays a critical role in the development of ventilator-induced lung injury (VILI). Endoplasmic reticulum (ER) stress is associated with a variety of diseases through the modulation of inflammatory responses. However, little is known about how ER stress is implicated in VILI. In this study, murine mechanical ventilation models were constructed. Total protein and inflammatory cytokines were measured in bronchoalveolar lavage fluid (BALF), and lung tissue injury was assessed by histology. Our data revealed that mice subjected to high tidal ventilation (TV) for 4 h showed more severe pulmonary edema and inflammation than those of mice with spontaneous breathing and low TV-treatment. In addition, the high TV-treated animals upregulated the ER stress markers GRP78, CHOP, p-IRE1α, TRAF2, and p-NF-κB expression at both the mRNA and protein levels in lung tissue. Administration of thapsigargin exacerbated the histological changes, inflammation and expression of GRP78 and CHOP after high TV, but treatment with ER stress and IRE1α kinase inhibitors attenuated the pathological damage and downregulated the high expression of GRP78, CHOP, p-IRE1α, TRAF2, and p-NF-κB, suggesting that ER stress is involved in VILI though the IRE1α/TRAF2/NF-κB signaling pathway in mice.     

Use of biomimetic microtissue spheroids and specific growth factor supplementation to improve tenocyte differentiation and adaptation to a collagen-based scaffold in vitro

Tenocytes represent a valuable source of cells for the purposes of tendon tissue engineering and regenerative medicine and as such, should possess a high degree of tenogenic differentiation prior to their use in vivo in order to achieve maximal efficacy. In the current report, we identify an efficient means by which to maintain differentiated tenocytes in vitro by employing the hanging drop technique in combination with defined growth media supplements. Equine tenocytes retained a more differentiated state when cultured as scaffold-free microtissue spheroids in low serum-containing medium supplemented with l-ascorbic acid 2-phosphate, insulin and transforming growth factor (TGF)-β1. This was made evident by significant increases in the expression levels of pro-tenogenic markers collagen type I (COL1A2), collagen type III (COL3A1), scleraxis (SCX) and tenomodulin (TNMD), as well as by enhanced levels of collagen type I and tenomodulin protein. Furthermore, tenocytes cultured under these conditions demonstrated a typical spindle-like morphology and when embedded in collagen gels, became highly aligned with respect to the orientation of the collagen structure following their migration out from the microtissue spheroids. Our findings therefore provide evidence to support the use of a biomimetic microtissue approach to culturing tenocytes and that in combination with the defined growth media described, can improve their differentiation status and functional repopulation of collagen matrix.     

补骨脂素抗增生性瘢痕作用机制研究

目的探讨补骨脂素抗增生性瘢痕的作用机制。方法体外培养成纤维细胞,按随机数字表法分为正常组(培养正常成纤维细胞)、瘢痕组(培养增生性瘢痕成纤维细胞)、TGF-β1组(10 ng/ml TGF-β1处理增生性瘢痕成纤维细胞5 min^12 h)、Smurf2 RNA干扰组[Smad泛素化调节因子2(Smad ubiquitin regulatory factor2,Smurf2)siRNA转染增生性瘢痕成纤维细胞72 h]、补骨脂素组(10μmol/L补骨脂素处理增生性瘢痕成纤维细胞继续培养72 h)、补骨脂素+TGF-β1组(增生性瘢痕成纤维细胞加入补骨脂素培养72 h后加入TGF-β1培养6 h)。采用Western blot法检测Smurf2、α-平滑肌肌动蛋白(α-actin SMA,α-SMA)蛋白表达;RT-PCR法检测Ⅰ型胶原蛋白mRNA表达;ELISA法检测TGF-β1蛋白分泌。结果与正常组比较,瘢痕组Smurf2蛋白[(0.83±0.08)比(0.38±0.07)]表达增加(P<0.05);与瘢痕组比较,Smurf2 RNA干扰组TGF-β1[(2.2±0.18)比(4.2±0.47)]表达降低(P<0.05);TGF-β1组Smurf2[(0.71±0.06)比(0.42±0.04)]、α-SMA[(1.42±0.12)比(0.91±0.09)]蛋白表达增加(P<0.05),Ⅰ型胶原蛋白mRNA[(0.72±0.09)比(0.41±0.07)]表达增加(P<0.05);补骨脂素组Smurf2[(0.05±0.01)比(0.42±0.04)]、α-SMA[(0.71±0.07)比(0.91±0.09)]蛋白表达降低(P<0.05),Ⅰ型胶原蛋白mRNA表达[(0.12±0.04)比(0.41±0.07)]降低(P<0.05)。结论补骨脂素可能通过TGF-β1/Smurf2信号通路抑制α-SMA蛋白表达,从而降低Ⅰ型胶原蛋白表达,起到抑制瘢痕形成的作用。     

Emodin attenuates acute lung injury in Cecal-ligation and puncture rats

Acute lung injury (ALI) is a major cause of sepsis-induced acute respiratory failure. Emodin has been considered to play a protective role for acute lung edema in cecal ligation and puncture (CLP)-induced sepsis model. In this study we aimed to investigate whether emodin could improve CLP-induced lung sepsis via regulating aquaporin (AQP) and tight junction (TJ), inflammatory factors, and pulmonary apoptosis. The results showed that sepsis-induced pulmonary pathological changes were significantly improved after emodin treatment. Emodin was found to upregulate AQP and TJ expression in the CLP model. Meanwhile, inflammatory cytokine release and pulmonary apoptosis was remarkably reduced after emodin treatment in lung sepsis. Our data demonstrated that emodin could suppresse inflammation, restore pulmonary epithelial barrier and reduce mortality in CLP-induced ALI, suggesting the potential therapeutic application of emodin in sepsis.     

程序性细胞死亡蛋白配体1在结直肠癌免疫治疗中的研究进展

近年来,抗程序性细胞死亡蛋白1(PD-1)药物在转移性结直肠癌患者错配修复缺陷治疗中的成功使得该疾病的免疫治疗得以重视。然而,失配修复缺陷的结直肠癌患者仅占结肠癌患者的一部分。目前的研究重点是将免疫治疗应用到疾病的早期阶段,包括辅助一线治疗,以及检测免疫检查点抑制剂治疗的敏感性。然而,哪些患者能够从该免疫治疗中获益仍是值得商榷的问题,因为这类药物具有自身免疫毒性。PD-1的配体之一程序性细胞死亡蛋白配体1(PD-L1)作为一种检测生物标记物,其检测可以通过免疫组化来实现。但其免疫组化的检测存在一些混杂因素,包括应用不同的检测抗体、不同的免疫组化临界值、肿瘤组织的采集准备方式不同、处理过程的不同、原发与继发的活检标本、肿瘤源性或诱导的PD-L1表达,以及肿瘤与免疫细胞的染色等。目前的结果表明,免疫组化检测肿瘤过表达PD-L1的患者在接受抗PD-L1治疗时临床效果更理想,而有些低表达的肿瘤也对该治疗有所缓解,这使PD-L1的分析中存在复杂性。阐明宿主免疫系统与肿瘤微环境的机制则能够更好地解释针对PD-L1药物是否让患者受益。     

The prognostic role of tumour‐infiltrating lymphocytes in oral squamous cell carcinoma: A meta‐analysis

It has been suggested that tumour‐infiltrating lymphocytes (TILs) are associated with the progression of oral squamous cell carcinoma (OSCC). However, the prognostic value of TILs is inconclusive due to the heterogeneity of immune cells within the tumour microenvironment. In this meta‐analysis, we aimed to assess the prognostic value of TILs in OSCC. The PubMed, Cochrane, Embase, Scopus and Web of Science databases were searched up to April 20, 2019, and 33 studies were ultimately included in this meta‐analysis. Our pooled meta‐analysis showed that high infiltration of CD8⁺ TILs, CD45RO⁺ TILs and CD57⁺ TILs favoured better overall survival (OS). However, high infiltration of CD68⁺ macrophages and CD163⁺ macrophages was associated with poor prognosis in OSCC. These findings suggest that CD8⁺ TILs, CD45RO⁺ TILs, CD57⁺ TILs, CD68⁺ macrophages and CD163⁺ macrophages might serve as novel prognostic factors and therapeutic targets in OSCC.     

Antimicrobial activities of novel bipyridine compounds produced by a new strain of Saccharothrix isolated from Saharan soil

The actinobacterium strain ABH26 closely related to Saccharothrix xinjiangensis, isolated from an Algerian Saharan soil sample, exhibited highly antagonist activity against Gram-positive bacteria, yeasts and filamentous fungi. Its ability to produce antimicrobial compounds was investigated using several solid culture media. The highest antimicrobial activity was obtained on Bennett medium. The antibiotics secreted by strain ABH26 on Bennett medium were extracted by methanol and purified by reverse-phase HPLC using a C18 column. The chemical structures of the compounds were determined after spectroscopic (¹H NMR, ¹³C NMR, ¹H-¹H COSY and ¹H-¹³C HMBC spectra), and spectrometric (mass spectrum) analyses. Two new cyanogriside antibiotics named cyanogriside I (1) and cyanogriside J (2), were characterized along with three known caerulomycins, caerulomycin A (3), caerulomycin F (4) and caerulomycinonitrile (5). This is the first report of cyanogrisides and caerulomycins production by a member of the Saccharothrix genus. The minimum inhibitory concentrations (MIC) of these antibiotics were determined against pathogenic microorganisms.     

以肺动脉高压为首发表现的先天性中枢性低通气综合征临床特征和基因分析

目的探讨先天性中枢性低通气综合征(CCHS)的临床和基因变异特征。方法分析1例首发表现为不明原因肺动脉高压的CCHS患儿的临床资料,并总结国内外文献中CCHS病例的临床特点、致病机制和基因变异情况。结果11月龄女婴,主要表现为浮肿、尿少、低血压、嗜睡、发绀、抽搐及颅内压增高。B型脑利钠肽、丙氨酸氨基转移酶升高,凝血酶原时间延长。颅脑磁共振示右侧额叶出血;超声心动图示中重度肺动脉高压。靶向捕获二代测序未发现可能的致病基因。采用Sanger法验证示患儿PHOX 2 B基因第3外显子存在多聚丙氨酸重复扩展变异,基因型为20/25。患儿入院后采用无创通气,睡眠时呼吸浅慢、微弱,伴血氧下降;血气分析提示二氧化碳潴留。随后改用夜间无创通气、降肺压药物治疗。复查肺动脉压力明显下降,生命体征稳定。随访至24月龄,夜间只需较低压力水平的无创通气,生长发育无异常。结论对于不明原因的肺动脉高压伴撤机困难患儿,需警惕CCHS。疑诊者应尽早针对CCHS相关基因进行靶向捕获二代测序及PHOX 2 B基因Sanger法验证。早期给予无创通气有望改善预后。