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。     

人巨细胞病毒活动性感染对早孕绒毛细胞ERK1/2蛋白活性的影响

目的人巨细胞病毒（human cytomegalovirus,HCMV）活动性感染对早孕绒毛细胞外信号调节激酶（extracellular signal regulated kinase1/2,ERK1/2）的信号通路的影响,探讨HCMV宫内感染的可能机制。方法选取既往有异常妊娠史并行人工流产术的早孕妇女139例,应用逆转录-聚合酶链反应技术检测其胎盘绒毛组织HCMV-mRNA的表达;酶联免疫吸附试验法测定其血清HCMV-IgM;免疫印迹法及免疫组化法检测其ERK1/2活性及蛋白表达水平并进行半定量分析。结果139例孕妇中有15例胎盘绒毛组织HCMV-mRNA阳性,32例血清HCMV-IgM阳性,阳性率为23.0%（32/139）。依据HCMV-mRNA与HCMV-IgM检测结果,139例孕妇分为3组：A组：HCMV-mRNA与HCMV-IgM均阳性14例,其宫内传播率为43.8%（14/32）;B组：HCMV-mRNA阴性而HCMV-IgM阳性18例;C组：HCMV-mRNA与HCMV-IgM均阴性106例。另有1例HCMV-IgM阴性者其胎盘绒毛组织HCMV2mRNA阳性;②在所有标本绒毛组织中均可见总ERK1/2的表达,主要位于细胞滋养细胞的胞浆中,三组中总ERK1/2表达相似,但A组pERK1/2的表达强度明显高于B组,B组与C组无明显的差异;A组与B组和C组pERK1与pERK2比较,差异有统计学意义（P〈0.01,P〈0.05）。结论ERK1/2的信号通路可能在HCMV宫内活动性感染中起重要作用。     

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。     

Altered Regulation of mRNA and miRNA Expression in Epithelial and Stromal Tissue of Keratoconus Corneas

PurposeEvaluation of mRNA and microRNA (miRNA) expression in epithelium and stroma of patients with keratoconus.MethodsThe epithelium and stroma of eight corneas of eight patients with keratoconus and eight corneas of eight non-keratoconus healthy controls were studied separately. RNA was extracted, and mRNA and miRNA analyses were performed using microarrays. Differentially expressed mRNAs and miRNAs in epithelial and stromal keratoconus samples compared to healthy controls were identified. Selected genes and miRNAs were further validated using RT-qPCR.ResultsWe discovered 170 epithelial and 1498 stromal deregulated protein-coding mRNAs in KC samples. In addition, in epithelial samples 180 miRNAs and in stromal samples 379 miRNAs were significantly deregulated more than twofold compared to controls. Pathway analysis revealed enrichment of metabolic and axon guidance pathways for epithelial cells and enrichment of metabolic, mitogen-activated protein kinase (MAPK), and focal adhesion pathways for stromal cells.ConclusionsThis study demonstrates significant differences in the expression and regulation of mRNAs and miRNAs in the epithelium and stroma of Patients with KC. Also, in addition to the well-known target candidates, we were able to identify further genes and miRNAs that may be associated with keratoconus. Signaling pathways influencing metabolic changes and cell contacts are affected in epithelial and stromal cells of patients with keratoconus.     

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.     

Extracellular ATP promotes angiogenesis and adhesion of TNBC cells to endothelial cells via upregulation of CTGF

Our previous works have indicated that extracellular ATP is an important prometastasis factor. However, the molecular mechanism involved needs to be further studied. We demonstrated that extracellular ATP treatment could upregulate the expression of connective tissue growth factor (CTGF) in both triple‐negative breast cancer (TNBC) cells and endothelial cells (ECs). Extracellular ATP stimulated the migration of TNBC cells and ECs, and angiogenesis of ECs via the P2Y2––YAP‐CTGF axis. Furthermore, we demonstrated that adenosine triphosphate (ATP) stimulated TNBC cell adhesion to ECs and transmigration through the EC layer via CTGF by upregulation of integrin β1 on TNBC cells and VCAM‐1 on ECs. Both apyrase (ATP‐diphosphohydrolase) and CTGF shRNA treatments could inhibit the metastasis of inoculated tumors to lung and liver in a mouse model, and these treated tumors had fewer blood vessels. Collectively, our data indicated that extracellular ATP promotes tumor angiogenesis and the interactions between TNBC cells and ECs through upregulation of CTGF, thereby stimulating TNBC metastasis. The pleiotropic effects of ATP in angiogenesis and cell adhesion suggest that extracellular ATP or CTGF could be an effective target for TNBC therapy.