Alarmins from conjunctival fibroblasts up-regulate matrix metalloproteinases in corneal fibroblasts

AIM:To explore the effects of alarmins produced by necrotic human conjunctival fibroblasts on the release of matrix metalloproteinases(MMPs)by human corneal fibroblasts(HCFs).METHODS:A necrotic cell supernatant(NHCS)was prepared by subjecting human conjunctival fibroblasts to three cycles of freezing and thawing.The amounts of interleukin(IL)-1βand tumor necrosis factor(TNF)-αin NHCS were determined by enzyme-linked immunosorbent assays.HCFs exposed to NHCS or other agents in culture were assayed for the release of MMPs as well as for intracellular signaling by immunoblot analysis.The abundance of MMP m RNAs in HCFs was examined by reverse transcription and real-time polymerase chain reaction analysis.RESULTS:NHCS increased the release of MMP-1 and MMP-3 by HCFs as well as the amounts of the corresponding m RNAs in the cells.NHCS also induced activation of mitogen-activated protein kinase(MAPK)signaling pathways mediated by extracellular signal-regulated kinase(ERK),p38,and c-Jun NH2-terminal kinase(JNK)as well as elicited that of the nuclear factor(NF)-κB signaling pathway by promoting phosphorylation of the endogenous NF-κB inhibitor IκB-α.Inhibitors of MAPK and NF-κB signaling as well as IL-1 and TNF-αreceptor antagonists attenuated the NHCS-induced release of MMP-1 and MMP-3 by HCFs.Furthermore,IL-1βand TNF-αwere both detected in NHCS,and treatment of HCFs with these cytokines induced the release of MMP-1 and MMP-3 in a concentration-dependent manner.CONCLUSION:Alarmins,including IL-1βand TNF-α,produced by necrotic human conjunctival fibroblasts triggered MMP release in HCFs through activation of MAPK and NF-κB signaling.IL-1βand TNF-αare therefore potential therapeutic targets for the amelioration of corneal stromal degradation in severe ocular burns.

Hepatic Alarmins and Mitochondrial Dysfunction under Residual Hyperlipidemic Stress Lead to Irreversible NAFLD

Background and Aims:Nonalcoholic fatty liver disease(NAFLD)includes a range of progressive disorders generated by excess lipid accumulation in the liver leading to hepatic steatosis and eventually fibrosis.We aimed to identify by high performance mass spectrometry-based proteomics the main signaling pathways and liver proteome changes induced by hypercholesterolemia in a rabbit atherosclerotic model that induced high accumulation of lipids in the liver.Methods:The effect of combined lipid-lowering drugs(statins and anti-PCSK9 monoclonal antibody)were used after the interruption of the hypercholesterolemic diet to identify also the potential mediators,such as alarmins,responsible for the irreversible NAFLD build up under the hyperlipidemic sustained stress.Results:Proteomic analysis revealed a number of proteins whose abundance was altered.They were components of metabolic pathways including fatty-acid degradation,glycolysis/gluconeogenesis,and nonalcoholic fatty liver disease.Mitochondrial dysfunction indicated alteration at the mitochondrial respiratory chain level and down-regulation of NADH:ubiquinone oxidoreductase.The expression of a majority of cytochromes(P4502E1,b5,and c)were up-regulated by lipid-lowering treatment.Long-term hyperlipidemic stress,even with a low-fat diet and lipid-lowering treatment,was accompanied by alarmin release(annexins,galectins,HSPs,HMGB1,S100 proteins,calreticulin,and fibronectin)that generated local inflammation and induced liver steatosis and aggressive fibrosis(by high abundance of galectin 3,fibronectin,and calreticulin).Conclusions:The novel findings of this study were related to the residual effects of hyperlipidemic stress with consistent,combined lipid-lowering treatment with statin and inhibitor of PCSK9.

HMGB1, IL-1α, IL-33 and S100 proteins： dual-function alarmins

Our immune system is based on the close collaboration of the innate and adaptive immune systems for the rapid detection of any threats to the host. Recognition of pathogen-derived molecules is entrusted to specific germline- encoded signaling receptors. The same receptors have now also emerged as efficient detectors of misplaced or altered self-molecules that signal tissue damage and cell death following, for example, disruption of the blood supply and subsequent hypoxia. Many types of endogenous molecules have been shown to provoke such sterile inflammatory states when released from dying cells. However, a group of proteins referred to as alarmins have both intracellular and extracellular functions which have been the subject of intense research. Indeed, alarmins can either exert beneficial cell housekeeping functions, leading to tissue repair, or provoke deleterious uncontrolled inflammation. This group of proteins includes the high-mobility group box 1 protein （HMGB1）, interleukin （IL）-1α, IL-33 and the Ca^2＋-binding S100 proteins. These dual-function proteins share conserved regulatory mechanisms, such as secretory routes, post-translational modifications and enzymatic processing, that govern their extracellular functions in time and space. Release of alarmins from mesenchymal cells is a highly relevant mechanism by which immune cells can be alerted of tissue damage, and alarmins play a key role in the development of acute or chronic inflammatory diseases and in cancer development.

Contributions of the receptor for advanced glycation end products axis activation in gastric cancer

Compelling shreds of evidence derived from both clinical and experimental research have demonstrated the crucial contribution of receptor for advanced glycation end products(RAGE)axis activation in the development of neoplasms,including gastric cancer(GC).This new actor in tumor biology plays an important role in the onset of a crucial and long-lasting inflammatory milieu,not only by supporting phenotypic changes favoring growth and dissemination of tumor cells,but also by functioning as a pattern-recognition receptor in the inflammatory response to Helicobacter pylori infection.In the present review,we aim to highlight how the overexpression and activation of the RAGE axis contributes to the proliferation and survival of GC cells as and their acquisition of more invasive phenotypes that promote dissemination and metastasis.Finally,the contribution of some single nucleotide polymorphisms in the RAGE gene as susceptibility or poor prognosis factors is also discussed.

克拉霉素通过抑制小鼠母胎炎症预防早产和降低新生小鼠死亡率的研究

目的 本研究旨在探讨克拉霉素是否能通过抑制高迁移率族蛋白B1(high-mobility group box 1,HMGB1)的活性来减轻炎症反应,进而影响小鼠早产和不良新生小鼠结局。方法 采用HMGB1羊膜给药的方式诱导雌鼠(n=40)自发性早产和分娩,有3只雌鼠死亡。将给药后雌鼠随机分为实验组(n=19)和对照组(n=18)。实验组的雌鼠在HMGB1羊膜给药后接受皮下注射克拉霉素治疗,而对照组则接受等量的二甲基亚砜(dimethyl sulfoxide,DMSO)皮下注射。随后,对2组雌鼠的妊娠和新生小鼠结局进行了详细记录,收集雌鼠的羊水、胎盘、子宫蜕膜、子宫颈和胎儿组织,并进行炎症状态的生化检测。结果克拉霉素处理显著延长了实验组雌鼠的妊娠期,并降低早产率至7.13%(1/14),远低于对照组的46.15%(6/13)。此外,实验组有更高比例的新生小鼠能够存活至3周龄。生化检测结果显示,实验组雌鼠的子宫、子宫颈、胎膜和子宫蜕膜中多种炎症因子[如白细胞介素(interleukin,IL)-1α、IL-1β、干扰素-γ(interferon-γ,IFNG)等]的基因表达明显降低(P<0.05)。克拉霉素还能通过下调多个炎症和趋化因子基因[如IL-6、肿瘤坏死因子(tumor necrosis factor,TNF)、IL-12B、趋化因子配体(chemokine ligands,CCL)3、CCL5等]以及胎儿各组织(如肺、肠、肝和脾)中的炎症因子基因[如核因子-κB2(nuclear factor kappa B2,NF-κB2)、趋化因子CXCL9、Toll样受体4(toll-like receptor 4,TLR4)等]来提高新生小鼠的存活率(P<0.05)。结论 在HMGB1诱导的无菌性羊膜腔内炎症小鼠模型中,克拉霉素有效地抑制了子宫内母体组织(如子宫蜕膜和子宫颈)和胎儿的炎症反应,从而降低了早产率并改善了新生小鼠的结局。

靶向警报素单克隆抗体治疗哮喘的研究进展

哮喘是一种以慢性气道炎症为主要特征的异质性疾病。变应原、空气污染物等触发呼吸道上皮细胞产生的警报素——胸腺基质淋巴生成素、白细胞介素(IL)-33和IL-25在哮喘发病中发挥重要作用。警报素可直接激活2型固有淋巴细胞、嗜酸粒细胞、嗜碱粒细胞和肥大细胞,也可刺激树突状细胞驱动辅助性T细胞(Th细胞)0向Th2细胞表型转化,参与2型哮喘的发生发展。目前靶向警报素单克隆抗体治疗哮喘的研究已进入临床试验阶段。未来人源性抗警报素单克隆抗体或可成为哮喘治疗的有效方案,为疾病的治疗提供新思路。

高迁移率族蛋白B1--启动免疫应答的重要信号分子

高迁移率族蛋白B1(high mobility group box 1 protein,HMGB1)是核内一类非组蛋白染色体结合蛋白,参与核小体结构的重构;调控DNA重组、修复、复制和基因转录。HMGB1是细胞核内一种重要的预警素,启动固有免疫应答维持组织长期修复及防御过程,并能够促使树突状细胞成熟,进而使初始T细胞活化、增殖、分化为辅助性T淋巴细胞(Th)1。HMGB1也是一种内源性免疫佐剂,诱导适应性免疫应答。可以说,HMGB1是介于固有免疫和适应性免疫之间一种重要蛋白。

波形蛋白的警报素功能鉴定

目的:鉴定胞外可溶性波形蛋白(Vim)促进相关细胞增殖、活化、趋化的能力。方法:体外检测Vim刺激大鼠脾细胞的增殖情况。体内检测Vim免疫小鼠的外周血淋巴细胞数及Vim抗体水平。收集小鼠腹腔巨噬细胞与不同浓度Vim共培养,检测其对巨噬细胞吞噬鸡红细胞能力的影响。以Transwell小室法检测Vim对NIH3T3成纤维细胞的趋化作用。结果:体外实验Vim剂量依赖性地促进大鼠脾细胞增殖,16μg/ml浓度的Vim刺激预致敏或未致敏脾细胞增殖率分别高达(196.0±9.7)%、(208.9±4.6)%,且该二者无显著性差异。体内实验单用Vim免疫小鼠的外周血淋巴细胞浓度(10~9L^(-1))激增(5.74±0.51 vs.1.69±0.13),同时激发了Vim特异性抗体水平(OD值2.31±0.06 vs.0.19±0.08);且与Vim辅以佐剂免疫小鼠的相应指标均无显著性差异。体外实验Vim浓度依赖性地促进巨噬细胞吞噬鸡红细胞的能力,并能够对NIH3T3成纤维细胞产生趋化作用。结论:胞外可溶性Vim非特异性促进炎症反应相关细胞增殖、活化、趋化,具有警报素功能。

HMGB1在急性肺损伤/急性呼吸窘迫综合征中的研究进展

急性肺损伤(acute lung ingury,ALI)和急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)是ICU内危及患者生命的临床综合征。目前ARDS的病死率仍居高不下(>40%)[1]。其治疗和早期运用生物学标记诊断仍是重症医学领域的重大难题。高迁移率族蛋白B1(high mobility group box-1 protein,HMGB1)是一种新近发现的重要的晚期炎性介质,与脓毒症、恶性肿瘤、免疫性疾病等许多疾病相关。HMGB1作为一种警报素,其浓度的高低可以反映机体炎症及组织损伤的严重程度,并与疾病的预后密切相关。HMGB1可能会为阻断炎症通路的级联反应提供新的治疗靶点。本文就HMGB1在ALI/ARDS中的研究进展做一综述。

危险信号分子与原发性肝癌的研究进展

危险信号分子,是一大类细胞结构蛋白,病理情况下释放到细胞外,通过启动和介导炎症反应,传递着细胞损伤的危险信号.以HMGB1、HSPs和S100为代表的危险信号分子,在肝脏慢性炎症和肿瘤形成的微环境中持续存在,在原发性肝癌形成和进展过程中发挥着重要的作用.危险信号分子可以成为新的预测和监测原发性肝癌发生、转移和复发的标志物,下调这些危险信号分子表达及阻断其与受体结合的措施,有望成为新的抗肿瘤治疗方法.

Receptor for advanced glycation end-products axis and coronavirus disease 2019 in inflammatory bowel diseases:A dangerous liaison?

Compelling evidence supports the crucial role of the receptor for advanced glycation end-products(RAGE)axis activation in many clinical entities.Since the beginning of the coronavirus disease 2019 pandemic,there is an increasing concern about the risk and handling of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection in inflammatory gastrointestinal disorders,such as inflammatory bowel diseases(IBD).However,clinical data raised during pandemic suggests that IBD patients do not have an increased risk of contracting SARS-CoV-2 infection or develop a more severe course of infection.In the present review,we intend to highlight how two potentially important contributors to the inflammatory response to SARS-CoV-2 infection in IBD patients,the RAGE axis activation as well as the cross-talk with the renin-angiotensin system,are dampened by the high expression of soluble forms of both RAGE and the angiotensin-converting enzyme(ACE)2.The soluble form of RAGE functions as a decoy for its ligands,and soluble ACE2 seems to be an additionally attenuating contributor to RAGE axis activation,particularly by avoiding the transactivation of the RAGE axis that can be produced by the virus-mediated imbalance of the ACE/angiotensin II/angiotensin II receptor type 1 pathway.

Inflammatory niche:Mesenchymal stromal cell priming by soluble mediators

Mesenchymal stromal/stem cells(MSCs)are adult stem cells of stromal origin that possess self-renewal capacity and the ability to differentiate into multiple mesodermal cell lineages.They play a critical role in tissue homeostasis and wound healing,as well as in regulating the inammatory microenvironment through interactions with immune cells.Hence,MSCs have garnered great attention as promising candidates for tissue regeneration and cell therapy.Because the inflammatory niche plays a key role in triggering the reparative and immunomodulatory functions of MSCs,priming of MSCs with bioactive molecules has been proposed as a way to foster the therapeutic potential of these cells.In this paper,we review how soluble mediators of the inflammatory niche(cytokines and alarmins)influence the regenerative and immunomodulatory capacity of MSCs,highlighting the major advantages and concerns regarding the therapeutic potential of these inflammatory primed MSCs.The data summarized in this review may provide a significant starting point for future research on priming MSCs and establishing standardized methods for the application of preconditioned MSCs in cell therapy.

Hip prosthetic loosening and periprosthetic osteolysis:A commentary

Prosthetic loosening and periprosthetic osteolysis have been debated for decades,both in terms of the timing and nature of the triggering events.The hypothesis of wear-particle-induced loosening states that wear particles cause a foreign-body response leading to periprosthetic osteolysis and ultimately to late prosthetic loosening,i.e.,that the osteolysis precedes the loosening.The theory of early loosening,on the other hand,postulates that the loosening is already initiated during or shortly after surgery,i.e.,that the osteolysis is secondary to the loosening.This commentary focuses on the causal relationship between prosthetic loosening and periprosthetic osteolysis.

基于CAN总线的微机控制船舶机舱监测报警系统

根据现场总线系统的结构和技术特点,论述了在船舶机舱监测报警系统中采用现场总线技术的优越性,探讨了利用CAN总线的可行性,提出了基于CAN总线的船舶机舱监测报警模拟系统构造方案,并对该监测报警系统的组成、功能等进行了论述。

Advanced-glycation end-products axis:A contributor to the risk of severe illness from COVID-19 in diabetes patients

Compelling pieces of evidence derived from both clinical and experimental research has demonstrated the crucial role of the receptor for advanced-glycation end-products(RAGE)in orchestrating a plethora of proinflammatory cellular responses leading to many of the complications and end-organ damages reported in patients with diabetes mellitus(DM).During the coronavirus disease 2019(COVID-19)pandemic,many clinical reports have pointed out that DM increases the risk of COVID-19 complications,hospitalization requirements,as well as the overall severe acute respiratory syndrome coronavirus 2 case-fatality rate.In the present review,we intend to focus on how the basal activation state of the RAGE axis in common preexisting conditions in DM patients such as endothelial dysfunction and hyperglycemia-related prothrombotic phenotype,as well as the contribution of RAGE signaling in lung inflammation,may then lead to the increased mortality risk of COVID-19 in these patients.Additionally,the crosstalk between the RAGE axis with either another severe acute respiratory syndrome coronavirus 2 receptor molecule different of angiotensin-converting enzyme 2 or the renin-angiotensin system imbalance produced by viral infection,as well as the role of this multi-ligand receptor on the obesity-associated lowgrade inflammation in the higher risk for severe illness reported in diabetes patients with COVID-19,are also discussed.

IL-33/ST2比值与红斑狼疮肾脏慢性损伤严重程度的相关性研究

目的:探讨新型内源性警报素白细胞介素33(interleukin-33,IL-33)/致癌性抑制因子2(suppression of tumorigenicity 2,ST2)途径与系统性红斑狼疮(systemic lupus erythematosus,SLE)肾脏损害及疾病活动度的相关性。方法:ELISA检测50例SLE患者和30例健康对照者(healthy control,HC)血清的可溶性ST2(soluble ST2,s ST2)和IL-33浓度。结果:SLE患者的血清sST2、IL-33浓度及IL-33/sST2比值均显著高于HC。SLE患者的血清s ST2浓度与红细胞沉降率(erythrocyte sedimentation rate,ESR)、SLE疾病活动度指数(SLE disease activity index,SLEDAI)、24 h尿蛋白、甘油三酯呈正相关,与补体C3呈负相关,线性回归示SLEDAI及甘油三酯作为主要因素影响sST2水平升高(R^2=0.432)。SLE患者血清IL-33浓度与SLEDAI、ESR、24 h尿蛋白、慢性肾脏病(chronic kidney disease,CKD)分期、甘油三酯呈正相关,与C3、C4、估算的肾小球滤过率(estimated glomerular filtration rate,eGFR)、白蛋白呈负相关,线性回归示SLEDAI、C3及e GFR作为主要因素影响IL-33水平升高(R^2=0.380)。SLE患者的血清IL-33/s ST2比值与SLEDAI、eGFR呈正相关,与病程、起病年龄、激素用量、CKD分期、血肌酐、C3、C4、白蛋白呈负相关,回归分析提示IL-33/s ST2比值与CKD分期及白蛋白水平相关(R2=0.442),尤以CKD的相关性较强,该比值随CKD分期的加重而降低,当CKD分期为3级以上时IL-33/s ST2比值显著下降。结论:IL-33/ST2参与SLE发病,血清IL-33和s ST2均能一定程度地反映病情,s ST2较IL-33与疾病活动度关联性更强;IL-33和s ST2不能直接反映SLE的肾脏受累,但与间接反映SLE肾损伤的24 h尿蛋白及其它危险因素有关;IL-33/s ST2比值的降低提示SLE肾脏的慢性、中重度损害。

甘草甜素对角膜上皮损伤愈合中炎症反应的抑制作用

目的探讨甘草甜素对角膜上皮损伤愈合中炎症反应的抑制作用。方法取SPF级健康8周龄的雄性C57BL/6J小鼠60只,随机分为治疗组和对照组,每组30只,两组小鼠右眼建立角膜上皮损伤模型,左眼不做处理。治疗组用甘草甜素溶液滴眼,对照组用PBS滴眼,连续滴眼3 d。造模后0 h、24 h、48 h、72 h,使用100 g·L^-1荧光素钠溶液染色观察两组小鼠的角膜上皮缺损面积;通过HE染色观察两组角膜组织结构变化;采用免疫组织化学染色法检测角膜基质层中白细胞介素-1(interleukin-1,IL-1)β的表达以及中性粒细胞的浸润情况。结果造模后24 h、48 h、72 h,治疗组角膜上皮缺损率分别为(78.75±5.81)%、(21.58±4.53)%、(0.83±0.72)%,明显低于对照组的(87.74±3.57)%、(32.21±4.02)%、(3.80±1.86)%,差异均有统计学意义(均为P<0.01)。造模后72 h,HE染色结果显示:治疗组角膜上皮生长2~3层,上皮细胞排列欠规则;对照组角膜上皮生长0~2层,上皮细胞排列紊乱。造模后72 h,免疫组织化学染色结果显示:两组角膜基质层中IL-1β的阳性表达均降低,治疗组角膜基质层中IL-1β的平均光密度值为0.21±0.03,明显低于对照组(0.31±0.03),差异有统计学意义(P<0.01)。另外,造模后72 h,两组角膜基质层的中性粒细胞数量大幅度减少,治疗组为每200倍视野(10.66±5.13)个,较对照组[(40.00±6.08)个]明显减少,差异有统计学意义(P<0.01)。结论角膜上皮损伤时,甘草甜素能有效降低角膜基质层中IL-1β的表达和中性粒细胞浸润,从而减轻炎症反应,促进角膜上皮愈合。

白介素-33在急性呼吸窘迫综合征中的研究进展

急性呼吸窘迫综合征（acute respiratory distress syndrome,ARDS）是以顽固性低氧血症和进行性呼吸困难为主要临床特点的综合征,是危重症患者死亡的主要原因之一。尽管,近年来医疗技术的迅猛发展和新的药物的应用使ARDS的预后有所改善,但其病死率仍高达40%~50%。因此,更充分的了解ARDS的发病机制,实现早期诊断,为临床上ARDS的防治提供指导仍是呼吸和重症医学界研究的重点和热点。白介素（interleukin,IL）-33是新近发现的IL-1家族成员,在炎症、感染、自身免疫性疾病等多种疾病中发挥重要的警报素作用,促进机体的炎症反应,加重机体组织的损伤。故IL-33及其信号通路可能成为阻断炎症通路的级联反应的一个潜在的分子靶点。本文就IL-33在ARDS中的研究进展做一综述。

警报素既是免疫警报又是疾病警报

警报素(Alarmins)是机体处于组织损伤和炎症反应状态或生理应激时,由白细胞和上皮细胞等释放到胞外的内源性生物介质,也称为危险相关分子模式(Danger-associated molecular patterns,DAMPs)。通过趋化和激活抗原递呈细胞(Antigen presenting cells,APC)等免疫细胞从而增强固有免疫和适应性免疫应答。它与疾病的产生发展及转归密切相关,对于临床诊疗具有重要的指导意义。

结膜成纤维细胞由来的警报素对角膜成纤维细胞的促炎作用

目的严重烧伤可致眼表结膜组织大量坏死,并导致角膜基质持续性炎症反应及溃疡形成。本研究探讨结膜成纤维细胞坏死上清产生的警报素(alarmins)对人角膜基质成纤维细胞(HCFs)释放促炎因子及粘附分子的影响。方法通过冻融方法制备结膜成纤维细胞坏死上清(NHCS),用NHCS、IKK2抑制剂、IL-1及TNF-α受体拮抗剂对HCFs进行处理。ELISA检测IL-6、IL-8及MCP-1的表达,Western blot分析ICAM-1表达及IκB-α磷酸化,免疫荧光染色检测NF-κB p65亚基定位。结果 NHCS可刺激HCFs表达IL-6、IL-8、MCP-1和ICAM-1,激活IκB-α磷酸化,并介导NF-κB p65亚基的核内转移。此外,IKK2抑制剂、IL-1及TNF-α受体拮抗剂可抑制NHCS诱导的上述炎性介质的表达。结论由结膜成纤维细胞坏死上清产生的警报素包括IL-1和TNF-α,可通过激活NF-κB信号通路促进角膜基质成纤维细胞表达促炎因子和粘附分子。IL-1和TNF-α可能成为改善严重眼烧伤角膜基质炎症反应的潜在治疗靶点。