Molecular simplification of lipid A structure: TLR4-modulating cationic and anionic amphiphiles

A growing body of data suggests that therapies based on Toll-like receptors (TLR) targeting, in particular TLR4, holds promise in curing autoimmune and inflammatory pathologies still lacking specific treatment, included several rare diseases. While TLR4 activators (agonists) have already found successful clinical application as vaccine adjuvants, the use of TLR4 blockers (antagonists) as antisepsis agents or as agents against inflammatory diseases (including arthritis, multiple sclerosis, neuroinflammations) and cancer is still at a preclinical phase of development. This minireview focuses on recent achievements on the development of TLR4 modulators based on lipid A structure simplification, in particular on compounds having disaccharide or monosaccharide structures. As the TLR4 activity of natural TLR4 ligands (lipopolysaccharide, LPS and its biologically active part, the lipid A) depends on both the structure of endotoxin aggregates in solution and on single-molecule interaction with MD-2 and CD14 receptors, the rational design of TLR4 modulators should in principle take into account both these factors. In the light of the most recent advances in the field, in this minireview we discuss the structure–activity relationship in simplified lipid A analogs, with cationic or anionic amphiphilic structures.     

TLR9在不同胎龄新生儿脐血中的表达变化

目的 通过观察早产儿不同胎龄Toll样受体9（TLR9）的表达，探讨早产儿免疫功能低下的机制。方法 采集2010年7月至2014年6月在上海市嘉定区妇幼保健院产科出生的活产新生儿的脐血229份，按胎龄分为4组，28~31周组，31~34周组，34~37周组，≥37周组，采用流式细胞术和实时荧光定量PCR方法，分别检测其TLR9的蛋白和mRNA表达情况，了解其与胎龄之间的关系，并分析mRNA和蛋白表达间的相关性。结果 TLR9阳性细胞率在28~31周组，31~34周组，34~37周组，≥37周组分别为（15.93±6.23）%，（11.63±6.70）%，（13.66±6.88）%，（20.51±12.06）%；其在胎龄28~31周较高，至31~34周逐渐下降至最低，两组差异有统计学意义（P<0.05）；34~37周后TLR9阳性细胞率表达逐渐升高，至≥37周达最高，两胎龄组比较，差异具有统计学意义（P<0.05）。31~37周间新生儿脐血TLR9阳性细胞率与胎龄呈正相关（r=0.273，P=0.006）。TLR9 mRNA表达在28~31周组，31~34周组，34~37周组，≥37周组分别为（4.95±3.44）%，（8.89±8.49）%，（13.91±10.92）%，（7.19±7.11）%；其在28~36周逐渐升高，与胎龄呈正相关（r=0.355，P< 0.001）。≥37周TLR9 mRNA表达量下降，该值虽高于28~31周，但差异无统计学意义（P>0.05）。相关性分析表明，同胎龄时期同样本新生儿的TLR9 mRNA和TLR9阳性细胞率之间存在负相关（r=-0.227，P=0.011）。结论 TLR9阳性细胞率和TLR9 mRNA表达在不同胎龄组新生儿间有差异，TLR9阳性细胞率表达在31~37周间随着胎龄的增加而增加，TLR9 mRNA在28~36周间随着胎龄的增加而增加。     

miR-503靶向TLR4对前列腺癌多西他赛耐药的影响

背景与目的：在前列腺癌标准化疗方案中，多西他赛（docetaxel，DTX）引起的化疗耐药是引起患者死亡的重要原因之一，然而DTX引起的化疗耐药相关机制尚未知。探讨前列腺癌DTX耐药的作用机制。方法：收集2016年6月—2019年6月在武汉市第三医院进行化疗的40例患者，包括20例DTX耐药和20例DTX敏感患者。人前列腺癌细胞系PC-3在一系列逐渐增加的DTX浓度梯度处理下形成耐药株PC-3/DTX。采用实时荧光定量聚合酶链反应（real-time fluorescence quantitative polymerase chain reaction，RTFQ-PCR）检测miR-503和TLR4 mRNA的表达，采用蛋白质印迹法（Western blot）检测TLR4蛋白的水平，采用双荧光素酶报告基因检测miR-503和TLR4的相互作用，采用四甲基偶氮唑蓝（methyl thiazolyl tetrazolium，MTT）法检测细胞活力，采用流式细胞术检测细胞凋亡。结果：前列腺癌耐药患者组织和耐药细胞系中miR-503的表达较敏感组显著降低（P=0.013），而TLR4显著增加（P=0.005 6）。过表达miR-503显著抑制耐药细胞的增殖，促进凋亡，同时抑制耐药相关蛋白MDR-1的表达，而过表达TLR4则促进细胞的增殖，抑制凋亡，促进耐药相关蛋白MDR-1的表达。结论：miR-503通过靶向调控TLR4的表达影响前列腺癌的DTX耐药。     

Pharmacotherapeutic strategies for critical asthma syndrome: a look at the state of the art

ABSTRACT

Introduction

‘Critical Asthma Syndrome’ (CAS) is an umbrella term proposed to include several forms of asthma, responsible for acute and life-threatening exacerbations. CAS requires urgent and adequate supportive and pharmacological treatments to prevent serious outcomes.     

体外转染Cyclin A2基因对原代大鼠心肌细胞增殖的影响

目的探讨体外转染细胞周期素A2(Cyclin A2)基因对原代大鼠心肌细胞增殖的影响,为心脏再生提供细胞学依据。方法 SD乳鼠12只,分离、培养、鉴定原代乳鼠心肌细胞并分为3组,实验组:转染带有强化绿色荧光蛋白(GFP)和Cyclin A2基因的重组腺病毒(Ad-Cyclin A2-GFP);空病毒组:转染不含目的基因带有GFP的重组腺病毒(Ad-Null-GFP);阴性对照组:未做转染处理,仅加入等量的培养基。利用GFP示踪技术,评估原代心肌细胞转染效率;转染后的细胞继续体外培养3~5d,利用免疫荧光技术分别检测Cyclin A2、磷酸化组蛋白H3(H3P)、心肌肌钙蛋白-T(c Tn T)。结果 1.荧光GFP示踪表明原代心肌细胞的转染效率高达(97±0.74)%;2.免疫荧光标记显示,空病毒组和对照组结果相似;心肌细胞特异性标记蛋白c Tn T分布于细胞质,原代心肌细胞纯度高达(95±0.62)%;心肌细胞Cyclin A2主要在胞核内聚集,少数分布于细胞质。H3P为核蛋白在细胞核内分布。3.转染Cyclin A2后,实验组H3P阳性率明显高于空病毒组和对照组,差异具有统计学意义(P0.05);实验组可见大量多核细胞,以双核为主,伴少量3核细胞。结论腺病毒作为转染载体对原代心肌细胞有很好的侵染效率;Cyclin A2超表达促进原代心肌细胞形成双核。     

Tau Accumulation via Reduced Autophagy Mediates GGGGCC Repeat Expansion-Induced Neurodegeneration in Drosophila Model of ALS

Expansions of trinucleotide or hexanucleotide repeats lead to several neurodegenerative disorders, including Huntington disease [caused by expanded CAG repeats (CAGr) in the HTT gene], and amyotrophic lateral sclerosis [ALS, possibly caused by expanded GGGGCC repeats (G4C2r) in the C9ORF72 gene], of which the molecular mechanisms remain unclear. Here, we demonstrated that lowering the Drosophila homologue of tau protein (dtau) significantly rescued in vivo neurodegeneration, motor performance impairments, and the shortened life-span in Drosophila expressing expanded CAGr or expanded G4C2r. Expression of human tau (htau4R) restored the disease-related phenotypes that had been mitigated by the loss of dtau, suggesting an evolutionarily-conserved role of tau in neurodegeneration. We further revealed that G4C2r expression increased tau accumulation by inhibiting autophagosome–lysosome fusion, possibly due to lowering the level of BAG3, a regulator of autophagy and tau. Taken together, our results reveal a novel mechanism by which expanded G4C2r causes neurodegeneration via an evolutionarily-conserved mechanism. Our findings provide novel autophagy-related mechanistic insights into C9ORF72-ALS and possible entry points to disease treatment.Electronic supplementary materialThe online version of this article (10.1007/s12264-020-00518-2) contains supplementary material, which is available to authorized users.     

低密度脂蛋白在2型糖尿病骨质疏松中的作用研究进展

2型糖尿病及骨质疏松已成为我国最主要的慢性代谢性疾病。2型糖尿病常伴有血脂紊乱，常表现为低密度脂蛋白升高，而越来越多的研究表明血脂通过不同的方式影响骨代谢，其机制可能是通过抑制骨髓间充质干细胞成骨分化，通过RANK/RNAKL/OPG信号通路及炎症反应调节破骨细胞等方式调节骨代谢。     

Dissecting the biological heterogeneity of HER2-positive breast cancer

HER2-positive (HER2+) breast cancer (BC) is a heterogenous and multifaceted disease, with interesting therapeutic implications. First, all intrinsic molecular subtypes can be identified in HER2+ tumors, with the HER2-enriched being the most frequent. Such subtypes do not differ much from their counterparts in HER2-negative disease, apart for the high expression of genes in/near the HER2 amplicon on chromosome 17. Intrinsic subtyping, along with the quantification of ERBB2 mRNA levels, is associated with higher rates of pathologic complete response across neoadjuvant trials of dual HER2 blockade and might help select patients for de-escalation and escalation treatment strategies. Secondly, HER2+ tumors have a broad range of DNA alterations. ERBB2 mutations and alterations in the PI3K/Akt/mTOR pathway are among the most frequent and might predict benefit from potent pan-HER, PI3K and mTOR inhibitors. Moreover, HER2+ tumors are usually infiltrated by lymphocytes. These tumor infiltrating-lymphocytes (TILs) predict response to neoadjuvant anti-HER2-based treatment and exert a prognostic role. PD-L1, detected in ∼42 % of HER2+ BC, might also be useful to define patients responding to novel anti-PD1/PD-L1 immunotherapies. New multiparametric clinicopathologic and genomic tools accounting for this complexity, such as HER2DX, are under development to define more tailored treatment approaches. Finally, HER2-targeted antibody-drug conjugates (ADC) such as trastuzumab deruxtecan might be active in tumors with low expression of HER2. Overall, there is a need to molecularly characterize and develop novel targeted therapies for HER2+ disease.