Neuronal loss and neurofibrillary degeneration in the hippocampal cortex in late-onset sporadic Alzheimer's disease

To explore more fully the relationship between neuronal death and neurofibrillary degeneration, unaffected neurons, intracellular neurofibrillary tangles (i-NFT) and extracellular NFT (e-NFT) in 22 patients with late-onset sporadic Alzheimer's disease (AD) were morphometrically evaluated in eight subdivisions of the hippocampal cortex, using the Gallyas hematoxylin-eosin stain. The subdivisions examined included CA4, CA3, CA2, CA1 (CA: cornu ammonis), prosubiculum (PRO), subiculum and presubiculum (PRE), parasubiculum (PARA) and the entorhinal cortex (ENT). The unaffected neuron density was significantly lower and both i-NFT and e-NFT densities were significantly higher in subdivisions other than CA4 and CA3 in AD patients compared with those in the aged controls. Unaffected neuron density was significantly, inversely correlated with e-NFT density and with total NFT density in all subdivisions except for PRE in AD patients. Especially in CA2, CA1, PRO and ENT, there were strong correlations between the neuron density and these NFT densities. Both unaffected neuron and e-NFT densities in CA1 and ENT were significantly correlated with the disease duration. The i/e-NFT ratio, an index of the degree and/or rate of progress of neuronal death via neurofibrillary degeneration, showed the lowest value in ENT in AD patients. The findings suggest that neuronal death via neurofibrillary degeneration starts earliest and/or most rapidly progresses in ENT. Furthermore, the i/e-NFT ratios in both ENT and CA1 were significantly correlated with the disease duration, suggesting that the neuronal death pattern in the two subdivisions parallels disease progression.     

Identification of Potential mRNA Biomarkers in Milk Small Extracellular Vesicles of Enzootic Bovine Leukosis Cattle

Enzootic bovine leukosis (EBL) is a disease caused by bovine leukemia virus (BLV); only a small percentage of BLV-infected cattle develop EBL and present with B-cell lymphosarcoma. There is no vaccine against BLV, treatment for EBL, or method for predicting the possibility of EBL onset, thus making EBL control difficult. Herein, to explore biomarkers for EBL in milk, we examined the mRNA profiles of small extracellular vesicles (sEVs) in milk from four BLV-uninfected and four EBL cattle by microarray analysis. It was revealed that 14 mRNAs were encapsulated in significantly higher quantities, and these mRNAs were therefore selected as biomarker candidates. Primers for these mRNAs were designed, and nine primer sets were available for quantitative real-time PCR. Nine mRNAs were evaluated for their availability as biomarkers for EBL using sEVs from newly-collected milk of 7 uninfected and 10 EBL cattle. The quantities of eight mRNAs (TMEM156, SRGN, CXCL8, DEFB4A, FABP5, LAPTM5, LGALS1, and VIM) were significantly higher in milk sEVs of EBL cattle than in those of uninfected cattle. Therefore, our findings indicate that these eight mRNAs in milk sEVs can be used as potential EBL biomarkers with combination use, although single mRNA use is not enough. Consequently, cattle at risk of EBL onset can be identified by monitoring the fluctuation in quantities of these mRNAs in milk before they develop EBL.     

Pivoting Novel Exosome-Based Technologies for the Detection of SARS-CoV-2

The National Institutes of Health (NIH) launched the Rapid Acceleration of Diagnostics (RADx) initiative to meet the needs for COVID-19 diagnostic and surveillance testing, and to speed its innovation in the development, commercialization, and implementation of new technologies and approaches. The RADx Radical (RADx-Rad) initiative is one component of the NIH RADx program which focuses on the development of new or non-traditional applications of existing approaches, to enhance their usability, accessibility, and/or accuracy for the detection of SARS-CoV-2. Exosomes are a subpopulation of extracellular vesicles (EVs) 30–140 nm in size, that are critical in cell-to-cell communication. The SARS-CoV-2 virus has similar physical and molecular properties as exosomes. Therefore, the novel tools and technologies that are currently in development for the isolation and detection of exosomes, may prove to be invaluable in screening for SARS-CoV-2 viral infection. Here, we describe how novel exosome-based technologies are being pivoted for the detection of SARS-CoV-2 and/or the diagnosis of COVID-19. Considerations for these technologies as they move toward clinical validation and commercially viable diagnostics is discussed along with their future potential. Ultimately, the technologies in development under the NIH RADx-Rad exosome-based non-traditional technologies toward multi-parametric and integrated approaches for SARS-CoV-2 program represent a significant advancement in diagnostic technology, and, due to a broad focus on the biophysical and biochemical properties of nanoparticles, the technologies have the potential to be further pivoted as tools for future infectious agents.     

葛根素减轻PM2.5对血管内皮细胞损伤的机制研究

探讨PM2.5对EA.hy926型人脐静脉内皮细胞损伤的影响及葛根素的保护作用及机制。采集大气PM2.5分别以0,20,200,400 mg·L~(-1)染毒EA.hy926细胞24 h,MTT法测细胞存活率,流式细胞术测细胞凋亡,Western blot法测p-ERK1/2,Bax,Bcl-2蛋白水平,ELISA法测肿瘤坏死因子-α(TNF-α)及白细胞介素-6(IL-6)含量,并测细胞丙二醛(MDA)含量、超氧化物歧化酶(SOD)及乳酸脱氢酶(LDH)活性;分别加入葛根素(10,50,100μmol·L~(-1))和ERK1/2通路特异性阻滞剂PD98059 20μmol·L~(-1)检测葛根素的干预作用及机制。检测发现与对照组比较,PM2.5染毒后呈剂量依赖性降低EA.hy926细胞存活率,上调p-ERK1/2蛋白水平及Bax/Bcl-2蛋白比率以促进细胞凋亡,诱导分泌TNF-α及IL-6含量增高,降低SOD活性,增加MDA含量及LDH活性(P0.05);葛根素呈剂量依赖性增加EA.hy926细胞的存活率,下调p-ERK1/2蛋白水平及Bax/Bcl-2蛋白比率以抑制细胞凋亡,降低TNF-α及IL-6含量,增加SOD活性,降低MDA含量及LDH活性(P0.05)。研究显示葛根素可能通过抑制ERK1/2通路减轻PM2.5对EA.hy926细胞的损伤。     

唾液外泌体与口腔疾病相关研究进展

唾液外泌体是指存在于唾液中的直径在30～150 nm的细胞外囊泡。随着近年来技术手段的发展,大量研究揭示唾液外泌体在多种口腔疾病的发生发展中发挥重要作用,如唾液外泌体CD9及CD81通过调控细胞粘附及运动促进肿瘤细胞转移、唾液外泌体miR-24-3p通过作用于PER1促进肿瘤细胞增殖、唾液外泌体程序性细胞死亡配体-1(programmed cell death-ligand 1,PD-L1)mRNA抑制炎症组织的破坏等,具有作为诊断口腔癌、牙周炎等口腔疾病的生物标志物的潜能。因此,唾液外泌体可作为口腔疾病潜在的预后和诊断标志物。唾液外泌体除与口腔疾病,如口腔癌、牙周炎、口腔扁平苔藓、干燥综合征等有关外,还同远处部位肿瘤如胰腺癌、肺癌等及系统性疾病如帕金森综合征、炎症性肠病等密切相关;深入研究唾液外泌体对口腔、全身系统性疾病的诊断与治疗作用,开发唾液外泌体作为疾病诊断的生物标志物的潜力具有重要意义。     

酸性成纤维细胞生长因子在宫颈癌中的表达及其信号传导途径

目的探讨酸性成纤维细胞生长因子(aFGF)在宫颈癌发生发展中的作用及其信号传导机制.方法应用逆转录-聚合酶链反应技术(RT-PCR)对36例宫颈癌组织aFGF 及其受体FGFR1的表达进行了分析;并以不同浓度的aFGF 和酪氨酸蛋白激酶(TPK)抑制剂genistein诱导宫颈癌细胞株HeLa细胞,[γ-32P]ATP掺入外源性底物的方法,液体闪烁测定蛋白激酶C(PKC)及细胞外信号调节激酶(ERK)的活性.结果 aFGF mRNA 和FGFR1 mRNA在宫颈癌组织中的半定量检测结果分别为(1.233±0.064)和(1.168±0.103),与正常宫颈组织相比,差异有显著性(P<0.05),且在Ⅲ～Ⅳ期宫颈癌中的表达水平明显高于Ⅰ～Ⅱ期(P<0.05);随着aFGF浓度的增加,HeLa细胞PKC及ERK 活性随之升高,与aFGF浓度呈剂量依赖效应;genistein抑制细胞内PKC及ERK 活性,与genistein 浓度亦呈剂量依赖效应.结论提示aFGF 与宫颈癌的发生、发展、浸润呈正相关,其受体具有TPK活性,TPK激活后可进一步激活PKC和ERK,进一步证明PKC及ERK确是TPK的下游信号分子.     

Astrocytes in the damaged brain: Molecular and cellular insights into their reactive response and healing potential

Long considered merely a trophic and mechanical support to neurons, astrocytes have progressively taken the center stage as their ability to react to acute and chronic neurodegenerative situations became increasingly clear. Reactive astrogliosis starts when trigger molecules produced at the injury site drive astrocytes to leave their quiescent state and become activated. Distinctive morphological and biochemical features characterize this process (cell hypertrophy, upregulation of intermediate filaments, and increased cell proliferation). Moreover, reactive astrocytes migrate towards the injured area to constitute the glial scar, and release factors mediating the tissue inflammatory response and remodeling after lesion. A novel view of astrogliosis derives from the finding that subsets of reactive astrocytes can recapitulate stem cell/progenitor features after damage, fostering the concept of astroglia as a promising target for reparative therapies. But which biochemical/signaling pathways modulate astrogliosis with respect to both the time after injury and the type of damage? Are reactive astrocytes overall beneficial or detrimental for neuroprotection and tissue regeneration? This debate has been animating this research field for several years now, and an integrated view on the results obtained and the possible future perspectives is needed. With this Commentary article we have attempted to answer the above-mentioned questions by reviewing the current knowledge on the molecular mechanisms controlling and sustaining the reaction of astroglia to injury and its stem cell-like properties. Moreover, the cellular/molecular mechanisms supporting the detrimental or beneficial features of astrogliosis have been scrutinized to gain insights on possible pharmacological approaches to enhance astrocyte neuroprotective activities.     

氯沙坦抑制糖基化终末产物刺激培养的人内皮细胞外基质基因的表达

目的 探讨氯沙坦防治糖尿病血管病变的作用机理。方法 用反转录-聚合酶链反应(RT-PCR)和Northern印迹杂交方法测定了0.1～10 μmol·L^-1浓度的氯沙坦对经体外制备的糖基化终末代谢产物（AGEs）处理培养的人脐静脉内皮细胞（HUVECs）转化生长因子（TGF）-β₁和纤连蛋白（FN）基因表达的影响。结果 由AGEs处理的HUVECs TGF-β₁和FN mRNA表达较正常对照组明显增高；与AGEs组相比，TGF-β₁和FN mRNA的表达在氯沙坦1.0 μmol·L^-1时分别降低了29%和23%，10 μmol·L^-1时降低了56%和62%。结论 氯沙坦通过抑制AGEs刺激的内皮细胞TGF-β₁和FN mRNA表达，从而抑制细胞外基质的生成，防止血管重构可能是其防治糖尿病血管并发病的机理之一。     

依达拉奉对脑缺血再灌注损伤后p-ERK1/2表达的影响

目的:研究依达拉奉对脑缺血再灌注细胞损伤的影响及p-ERK1/2在此过程的作用。方法:将180只雄性ICR小鼠随机分为假手术组、生理盐水治疗组和依达拉奉治疗组。各组于缺血再灌注后分为30min、3h、6h、24h、48h等5个亚组。采用线栓法建立小鼠局灶性脑缺血再灌注模型。治疗组于脑缺血开始及再灌注后12h分别腹腔注射依达拉奉3mg/kg或等量生理盐水,于24h后进行小鼠神经功能学评分;应用免疫组织化学及Westernblot检测p-ERK1/2蛋白表达水平的变化;利用原位缺口末端标记法(TUNEL法)研究神经细胞凋亡的变化。结果:与生理盐水治疗组相比,依达拉奉治疗组小鼠神经行为学评分明显减少(P<0.05);p-ERK1/2免疫阳性细胞及蛋白表达明显减少(P<0.05);凋亡细胞也减少(P<0.05)。结论:依达拉奉能通过抑制与氧化应激有密切关系的p-ERK1/2信号通路显著减轻脑缺血再灌注损伤后神经细胞损伤。     

Extracellular PKCδ signals to epidermal growth factor receptor for tumor proliferation in liver cancer cells

Protein kinase C delta (PKCδ) is a multifunctional PKC family member and has been implicated in many types of cancers, including liver cancer. Recently, we have reported that PKCδ is secreted from liver cancer cells, and involved in cell proliferation and tumor growth. However, it remains unclear whether the extracellular PKCδ directly regulates cell surface growth factor receptors. Here, we identify epidermal growth factor receptor (EGFR) as a novel interacting protein of the cell surface PKCδ in liver cancer cells. Imaging studies showed that secreted PKCδ interacted with EGFR‐expressing cells in both autocrine and paracrine manners. Biochemical analysis revealed that PKCδ bound to the extracellular domain of EGFR. We further found that a part of the amino acid sequence on the C‐terminal region of PKCδ was similar to the putative EGFR binding site of EGF. In this regard, the point mutant of PKCδ in the binding site lacked the ability to bind to the extracellular domain of EGFR. Upon an extracellular PKCδ‐EGFR association, ERK1/2 activation, downstream of EGFR signaling, was apparently induced in liver cancer cells. This study indicates that extracellular PKCδ behaves as a growth factor and provides a molecular basis for extracellular PKCδ‐targeting therapy for liver cancer.