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.     

藿香正气汤抑制新型冠状病毒复制过程的有效成分及机制初探＊

目的 收集藿香正气汤的主要活性成分，通过分子对接及网络药理学探讨其防控新型冠状病毒肺炎（COVID-19）的有效成分及治疗机制。方法 通过基于配体-蛋白质相互作用的计算方法，以瑞德西韦为对照，探索藿香正气汤潜在治疗COVID-19的成分，并选出对接较好成分进行药理学机制预测，初探其药理学机制。结果 本研究筛选出5种与新冠病毒3CLpro结合能力强于瑞德西韦的小分子成分。网络药理学初步预测抗病毒途径可能是通过PI3K-Akt 信号通路影响病毒复制。结论 成分C1-C5与3CLpro结合良好，推测其可能是潜在的3CLpro的抑制剂，为抗病毒天然药物的开发提供了理论依据。     

Lack of ceramide synthase 2 suppresses the development of experimental autoimmune encephalomyelitis by impairing the migratory capacity of neutrophils

Ceramide synthases (CerS) synthesise ceramides of defined acyl chain lengths, which are thought to mediate cellular processes in a chain length-dependent manner. In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), we observed a significant elevation of CerS2 and its products, C24-ceramides, in CD11b⁺ cells (monocytes and neutrophils) isolated from blood. This result correlates with the clinical finding that CerS2 mRNA expression and C24-ceramide levels were significantly increased by 2.2- and 1.5-fold, respectively, in white blood cells of MS patients. The increased CerS2 mRNA/C24-ceramide expression in neutrophils/monocytes seems to mediate pro-inflammatory effects, since a specific genetic deletion of CerS2 in blood cells or a total genetic deletion of CerS2 significantly delayed the onset of clinical symptoms, due to a reduced infiltration of immune cells, in particular neutrophils, into the central nervous system. CXCR2 chemokine receptors, expressed on neutrophils, promote the migration of neutrophils into the central nervous system, which is a prerequisite for the recruitment of further immune cells and the inflammatory process that leads to the development of MS. Interestingly, neutrophils isolated from CerS2 null EAE mice, as opposed to WT EAE mice, were characterised by significantly lower CXCR2 receptor mRNA expression resulting in their reduced migratory capacity towards CXCL2. Most importantly, G-CSF-induced CXCR2 expression was significantly reduced in CerS2 null neutrophils and their migratory capacity was significantly impaired. In conclusion, our data strongly indicate that G-CSF-induced CXCR2 expression is regulated in a CerS2-dependent manner and that CerS2 thereby promotes the migration of neutrophils, thus, contributing to inflammation and the development of EAE and MS.     

冠状病毒感染对心血管系统的损伤及可能机制

冠状病毒(coronavirus,CoVs)感染主要累及肺部,但对心血管系统损伤作用也不容忽视。CoVs感染引起的心脏损伤并非罕见,其发生与病情的严重程度密切相关。本文首先从CoVs引起心血管损伤的证据入手,进一步探讨了CoVs对心肌的直接损伤,以及肾素血管紧张素(RAS)系统激活和细胞因子风暴与炎症反应对心血管损伤的可能作用机制。相关心血管损伤的可能机制包括,(1)病毒直接作用:CoVs在心肌细胞复制,损伤心肌;(2)RAS系统激活:感染CoVs后,心脏血管紧张素转化酶2(angiotensin-converting enzyme 2,ACE2)的表达下调,激活RAS系统,使得血管紧张素Ⅱ(AngiotensinⅡ,AngⅡ)收缩血管功能增强,Ang1-7保护心脏效应减弱;(3)诱发细胞因子风暴:循环细胞因子和全身炎症反应引起心脏损伤;(4)其他:包括低氧血症和儿茶酚胺心脏毒性。本文就相关内容作一综述,为后续的详尽机制和治疗策略研究提供思路。     

普通变异型免疫缺陷病合并肝硬化1例并文献复习

目的:讨论普通变异型免疫缺陷病(common variable immunodeficiency disease,CVID)的发病机制、临床表现及治疗方法。方法:报道1例普通变异型免疫缺陷病合并肝硬化患者并复习相关文献。结果:普通变异型免疫缺陷病是临床少见病,易误诊,病因不清,临床表现复杂,部分患者病程中可出现肝功能异常,甚至并发肝硬化。结论:临床反复感染的患者应考虑CVID的可能,须进一步作血浆免疫球蛋白的检测确诊。对已经确诊患者定期补充静脉丙种球蛋白,同时还应定期检查肝功能。