RG108 调控 TFPI-2 甲基化/TMPRSS4 表达对 NSCLC 细胞增殖和凋亡的影响

目的：探讨RG108对人非小细胞肺癌（non-small cell lung cancer, NSCLC）A549和H1299细胞增殖、凋亡的影响及其可能的作用机制。方法：体外培养A549和H1299细胞，经不同浓度RG108处理后，采用MTT法、流式细胞术分别检测细胞增殖率、细胞周期和凋亡水平；qPCR和Western blotting（WB）法检测细胞内TFPI-2 mRNA和蛋白的表达及TMPRSS4的表达量，以甲基化特异性PCR和比色法检测细胞中TFPI-2启动子区域甲基化的状态和程度；分别采用siRNA-TFPI-2和pcDNA3.0-TMPRSS4质粒敲减TFPI-2或过表达TMPRSS4，然后检测细胞增殖率及凋亡率的变化。结果：RG108处理后，A549和H1299细胞的增殖率显著降低（均P<0.05）、细胞周期阻滞于G1/S期（均P<0.05）而凋亡率显著增加（均P<0.01），细胞中TFPI-2 mRNA及蛋白表达水平均显著升高（P<0.01和P<0.05），同时细胞中TFPI-2启动子区域甲基化程度显著降低（均P<0.05）、TMPRSS4的表达也明显减少（P<0.05）。沉默TFPI-2表达后，A549和H1299细胞的增殖水平显著增加（均P<0.05），而转染pcDNA3.0-TMPRSS4质粒则显著降低细胞的凋亡率（均P<0.05）。结论：RG108能够通过抑制TFPI-2甲基化负向调控TMPRSS4表达进而抑制A549和H1299细胞的增殖，并促进其凋亡。     

Germline gain-of-function MMP11 variant results in an aggressive form of colorectal cancer

Matrix metalloproteinase-11 (MMP11) is an enzyme with proteolytic activity against matrix and nonmatrix proteins. Although most MMPs are secreted as inactive proenzymes and are later activated extracellularly, MMP11 is activated intracellularly by furin within the constitutive secretory pathway. It is a key factor in physiological tissue remodeling and its alteration may play an important role in the progression of epithelial malignancies and other diseases. TCGA colon and colorectal adenocarcinoma data showed that upregulation of MMP11 expression correlates with tumorigenesis and malignancy. Here, we provide evidence that a germline variant in the MMP11 gene (NM_005940: c.232C>T; p.(Pro78Ser)), identified by whole exome sequencing, can increase the tumorigenic properties of colorectal cancer (CRC) cells. P78S is located in the prodomain region, which is responsible for blocking MMP11's protease activity. This variant was detected in the proband and all the cancer-affected family members analyzed, while it was not detected in healthy relatives. In silico analyses predict that P78S could have an impact on the activation of the enzyme. Furthermore, our in vitro analyses show that the expression of P78S in HCT116 cells increases tumor cell invasion and proliferation. In summary, our results show that this variant could modify the structure of the MMP11 prodomain, producing a premature or uncontrolled activation of the enzyme that may contribute to an early CRC onset in these patients. The study of this gene in other CRC cases will provide further information about its role in CRC development, which might improve patient treatment in the future.     

Glutamate hypothesis in schizophrenia

Schizophrenia is a chronic and severe psychiatric disorder that has profound impact on an individual’s life and on society. Thus, developing more effective therapeutic interventions is essential. Over the past quarter‐century, an abundance of evidence from pharmacologic challenges, post‐mortem studies, brain imaging, and genetic studies supports the role of glutamatergic dysregulation in the pathophysiology of schizophrenia, and the results of recent randomized clinical trials based on this evidence have yielded promising results. In this article, we review the evidence that alterations in glutamatergic neurotransmission, especially focusing on the N‐methyl‐d ‐aspartate receptor (NMDAR) function, may be a critical causative feature of schizophrenia, how this contributes to pathologic circuit function in the brain, and how these insights are revealing whole new avenues for treatment development that could reduce treatment‐resistant symptoms, which account for persistent disability.     

丝氨酸/精氨酸富有剪接因子1、核因子κB在前列腺癌中的表达及与患者临床特征的关系

目的探讨前列腺癌组织中丝氨酸/精氨酸富有剪接因子1(SRSF1)、核因子κB(NF-κB)的表达情况及与患者临床特征的关系。方法选取前列腺癌患者和前列腺良性增生患者,各70例,取前列腺癌组织和前列腺良性增生组织。免疫组化法检测前列腺癌组织和前列腺良性增生组织SRSF1、NF-κB蛋白的阳性表达率,并分析不同临床特征前列腺癌患者前列腺癌组织中SRSF1、NF-κB蛋白的表达情况。结果前列腺癌组织中SRSF1、NF-κB蛋白的阳性表达率均高于前列腺良性增生组织,差异均有统计学意义(P﹤0.05)。不同前列腺特异性抗原(PSA)水平前列腺癌患者前列腺癌组织中SRSF1蛋白的阳性表达率比较,差异无统计学意义(P﹥0.05);不同TNM分期、淋巴结转移情况、Gleason评分前列腺癌患者前列腺癌组织中SRSF1蛋白的阳性表达率比较,差异均有统计学意义(P﹤0.05)。不同PSA水平、Gleason评分前列腺癌患者前列腺癌组织中NF-κB蛋白的阳性表达率比较,差异均无统计学意义(P﹥0.05);不同TNM分期、淋巴结转移情况前列腺癌患者前列腺癌组织中NF-κB蛋白的阳性表达率比较,差异均有统计学意义(P﹤0.05)。结论前列腺癌组织中的SRSF1、NF-κB蛋白表达水平和阳性表达率均较高,SRSF1蛋白的表达可能与TNM分期、淋巴结转移情况和Gleason评分,NF-κB蛋白的表达可能与TNM分期和淋巴结转移情况有关。     

血管紧张素转换酶2对儿童2019冠状病毒病的作用研究进展

随着严重急性呼吸综合征冠状病毒2（SARS-CoV-2）在全球的肆虐，儿童感染者人数也越来越多。血管紧张素转换酶2（ACE2）是SARS-CoV-2感染人体的结合位点之一，可以与病毒尖峰蛋白结合，使得跨膜丝氨酸蛋白酶（TMPRSS2）启动S蛋白触发感染，引起白细胞介素-1、干扰素-γ、肿瘤坏死因子等多种炎性因子的产生。与成人相比，儿童的ACE2及TMPRSS2的表达水平较低，推测儿童症状较成人轻，发病人数较成人少均与此有关。该综述对SARS-CoV-2感染过程中ACE2的作用研究进展进行总结，有助于了解SARS-CoV-2的致病机制，为更好地开发药物及疫苗，防治儿童2019冠状病毒病提供参考。     

Targeting the membrane-anchored serine protease testisin with a novel engineered anthrax toxin prodrug to kill tumor cells and reduce tumor burden

The membrane-anchored serine proteases are a unique group of trypsin-like serine proteases that are tethered to the cell surface via transmembrane domains or glycosyl-phosphatidylinositol-anchors. Overexpressed in tumors, with pro-tumorigenic properties, they are attractive targets for protease-activated prodrug-like anti-tumor therapies. Here, we sought to engineer anthrax toxin protective antigen (PrAg), which is proteolytically activated on the cell surface by the proprotein convertase furin to instead be activated by tumor cell-expressed membrane-anchored serine proteases to function as a tumoricidal agent. PrAg''s native activation sequence was mutated to a sequence derived from protein C inhibitor (PCI) that can be cleaved by membrane-anchored serine proteases, to generate the mutant protein PrAg-PCIS. PrAg-PCIS was resistant to furin cleavage in vitro, yet cytotoxic to multiple human tumor cell lines when combined with FP59, a chimeric anthrax toxin lethal factor-Pseudomonas exotoxin fusion protein. Molecular analyses showed that PrAg-PCIS can be cleaved in vitro by several serine proteases including the membrane-anchored serine protease testisin, and mediates increased killing of testisin-expressing tumor cells. Treatment with PrAg-PCIS also potently attenuated the growth of testisin-expressing xenograft tumors in mice. The data indicates PrAg can be engineered to target tumor cell-expressed membrane-anchored serine proteases to function as a potent tumoricidal agent.     

IGF-1 mediated phosphorylation of specific IRS-1 serines in Ames dwarf fibroblasts is associated with longevity

Insulin/IGF-1 signaling involves phosphorylation/dephosphorylation of serine/threonine or tyrosine residues of the insulin receptor substrate (IRS) proteins and is associated with hormonal control of longevity determination of certain long-lived mice. The stimulation of serine phosphorylations by IGF-1 suggests there is insulin/IGF-1 crosstalk that involves the phosphorylation of the same serine residues. By this mechanism, insulin and IGF-1 mediated phosphorylation of specific IRS-1 serines could play a role in longevity determination.We used fibroblasts from WT and Ames dwarf mice to examine whether: (a) IGF-1 stimulates phosphorylation of IRS-1 serines targeted by insulin; (b) the levels of serine phosphorylation differ in WT vs. Ames fibroblasts; and (c) aging affects the levels of these serine phosphorylations which are altered in the Ames dwarf mutant. We have shown that IRS-1 is a substrate for IGF-1 induced phosphorylation of Ser³⁰⁷, Ser^612, Ser^636/639, and ^Ser1101; that the levels of phosphorylation of these serines are significantly lower in Ames vs. WT cells; that IGF-1 mediated phosphorylation of these serines increases with age in WT cells. We propose that insulin/IGF-1 cross talk and level of phosphorylation of specific IRS-1 serines may promote the Ames dwarf longevity phenotype.     

Extracts of Renealmia alpinia (Rottb.) MAAS Protect against Lethality and Systemic Hemorrhage Induced by Bothrops asper Venom: Insights from a Model with Extract Administration before Venom Injection

Renealmia alpinia (Rottb.) MAAS, obtained by micropropagation (in vitro) and wild forms have previously been shown to inhibit some toxic activities of Bothrops asper snake venom if preincubated before injection. In this study, assays were performed in a murine model in which extracts were administered for three days before venom injection. R. alpinia extracts inhibited lethal activity of B. asper venom injected by intraperitoneal route. Median Effective Dose (ED₅₀) values were 36.6 ± 3.2 mg/kg and 31.7 ± 5.4 mg/kg (p > 0.05) for R. alpinia wild and in vitro extracts, respectively. At a dose of 75 mg/kg, both extracts totally inhibited the lethal activity of the venom. Moreover, this dose prolonged survival time of mice receiving a lethal dose of venom by the intravenous route. At 75 mg/kg, both extracts of R. alpinia reduced the extent of venom-induced pulmonary hemorrhage by 48.0% (in vitro extract) and 34.7% (wild extract), in agreement with histological observations of lung tissue. R. alpinia extracts also inhibited hemorrhage in heart and kidneys, as evidenced by a decrease in mg of hemoglobin/g of organ. These results suggest the possibility of using R. alpinia as a prophylactic agent in snakebite, a hypothesis that needs to be further explored.