糖尿病氧化应激环境中α-Klotho对巨噬细胞-血管内皮细胞串扰的影响

目的：探讨糖尿病氧化应激环境中过表达α-Klotho(KL)的小鼠单核巨噬细胞白血病细胞(RAW264.7)对人脐静脉内皮细胞(HUVECs)增生、迁移、管腔形成以及紧密连接的影响。

方法：将RAW264.7细胞分为对照组、4-羟壬二酸酯(4HNE)组、4HNE+KL组,采用免疫荧光实验检测RAW264.7细胞F4/80的表达。制备3组细胞的条件培养基用于培养HUVECs,分为Mø-NC组、Mø-4HNE组和Mø-4HNE+KL组。采用CCK8实验检测血管内皮细胞增生,采用划痕实验和Transwell实验检测迁移,采用管腔形成实验检测管腔形成,采用Western blot实验检测闭合蛋白5(Claudin 5)、咬合蛋白(Occludin)、带状闭合蛋白1(ZO 1)表达水平。

结果：免疫荧光实验结果显示,4HNE组RAW264.7细胞F4/80荧光强度较对照组明显增强,而4HNE+KL组F4/80荧光强度较4HNE组明显减弱(均P<0.05)。CCK8实验结果显示,相比于Mø-NC组,Mø-4HNE组HUVECs增生显著增加,而Mø-4HNE+KL组HUVECs增生较Mø-4HNE组显著下降(均P<0.01)。划痕实验和Transwell实验结果显示,相比于Mø-NC组,Mø-4HNE组HUVECs迁移显著增强,而Mø-4HNE+KL组HUVECs迁移较Mø-4HNE组显著减弱(均P<0.01)。管腔形成实验结果显示,相比于Mø-NC组,Mø-4HNE组HUVECs管腔数显著增加,而Mø-4HNE+KL组管腔数较Mø-4HNE组显著下降(均P<0.01)。Western blot实验结果显示,相比于 Mø-NC组,Mø-4HNE组HUVECs中Claudin 5、Occludin、ZO 1蛋白的相对表达量明显减少,而Mø-4HNE+KL组Claudin 5、Occludin、ZO 1蛋白的相对表达量较Mø-4HNE组明显增加(均P<0.01)。

结论：KL通过改变糖尿病氧化应激环境中巨噬细胞激活状态抑制了HUVECs的增生、迁移、管腔形成,并增强了HUVECs的紧密连接。     

Electrochemical Corrosion Behaviour of X70 Steel under the Action of Capillary Water in Saline Soils

In this paper, the electrochemical corrosion behavior of X70 steel in saline soil under capillary water was simulated by a Geo-experts one-dimensional soil column instrument. A volumetric water content sensor and conductivity test were used to study the migration mechanism of water and salt (sodium chloride) under the capillary water. The electrochemical corrosion behavior of the X70 steel in the corrosion system was analyzed by electrochemical testing as well as the macroscopic and microscopic corrosion morphology of the steel. The test results showed that the corrosion behavior of X70 steel was significantly influenced by the rise of capillary water. In particular, the wetting front during the capillary water rise meant that the X70 steel was located at the three-phase solid/liquid/gas interface at a certain location, which worsened its corrosion behavior. In addition, after the capillary water was stabilized, the salts were transported with the capillary water to the top of the soil column. This resulted in the highest salt content in the soil environment and the most severe corrosion of the X70 steel at this location.     

Mechanical coupling of supracellular stress amplification and tissue fluidization during exit from quiescence

Cellular quiescence is a state of reversible cell cycle arrest that is associated with tissue dormancy. Timely regulated entry into and exit from quiescence is important for processes such as tissue homeostasis, tissue repair, stem cell maintenance, developmental processes, and immunity. However, little is known about processes that control the mechanical adaption to cell behavior changes during the transition from quiescence to proliferation. Here, we show that quiescent human keratinocyte monolayers sustain an actinomyosin-based system that facilitates global cell sheet displacements upon serum-stimulated exit from quiescence. Mechanistically, exposure of quiescent cells to serum-borne mitogens leads to rapid amplification of preexisting contractile sites, leading to a burst in monolayer tension that subsequently drives large-scale displacements of otherwise motility-restricted monolayers. The stress level after quiescence exit correlates with the level of quiescence depth at the time of activation, and a critical stress magnitude must be reached to overcome the cell sheet displacement barrier. The study shows that static quiescent cell monolayers are mechanically poised for motility, and it identifies global stress amplification as a mechanism for overcoming motility restrictions in confined confluent cell monolayers.

Quiescence refers to a state of cell cycle arrest in which cells are retained in a standby mode, ready to re-enter the cell cycle upon activation by a given physiological stimuli. The pool of quiescent cells in the human body is typically represented by tissue-specific stem and progenitor cells, naive immune cells, fibroblasts, and epithelial cells (1, 2). In addition, certain cancer cells have the ability to evade cancer therapy by entering a dormant quiescence-like state (1, 2). Accordingly, careful regulation of entry into and exit out of quiescence is important for several physiological processes such as tissue homeostasis and repair, stem cell maintenance, immunity, reproduction, and development (1, 2).During homeostasis, the balance between quiescent and proliferating cells is controlled by constituents of the microenvironment such as soluble factors, extracellular matrix components, blood vessels, and neighboring cells. On the other hand, during episodes that require extensive tissue renewal and remodeling, for example after injury, coordinated stimulation of quiescent cells into proliferation is facilitated by increased exposure to blood-borne and cell-secreted mitogens through local inflammatory responses such as increased blood flow, increased vascular permeability (vasodilation), and immune cell recruitment (3, 4). Accordingly, a commonly used methodology for studies of quiescence in cultured mammalian cells involves consecutive treatments with serum-free and serum-containing growth medium (1).Quiescent cells are required to maintain a high level of preparedness in order to facilitate rapid activation of specialized cell functions once cell division is stimulated. In agreement with this, quiescent stem cells and naive immune cells have been shown to possess multiple epigenetic and posttranslation mechanisms that facilitate the rapid expression of linage-specific genes following stimulation of quiescence exit (2, 5–14). However, little is known about mechanical forces that facilitate adaptation to cell cycle–activated behaviors.Quiescence exit is frequently associated with activation of cell motility. For example, quiescent stem and naive immune cells migrate out of their niches in response to cell cycle activation in order to support tissue homeostasis, repopulate injured tissue, or to perform immune surveillance at distal locations (15–18). In addition, reawakening of dormant quiescent cancer cells can cause tumor relapse and formation of metastases years after remission (19). In multilayered epithelial tissue, like the skin, exit from quiescence during homeostasis is associated with lateral migration to suprabasal regions, while skin injury evokes massive reawakening of basally localized keratinocytes concomitant with activation of cell sheet displacement by collective migration to restore damaged epidermal surfaces (20–23). The strong correlation between quiescence exit and cell migration in multiple physiological settings suggests the existence of mechanisms that link quiescence exit to activation of cell motility.The dynamics of epithelial collectives is largely regulated by mechanical forces generated through cell–cell interactions as well as interactions between cells and the extracellular environment (24). Key components involved in controlling these forces are cytoskeletal components such as actinomyosin and adhesion complexes such as adherent junctions and focal adhesion complexes (25). Additional factors that have been reported to influence the dynamic behavior of epithelial monolayers include the presence of epithelial edges (24, 26), mechanical stretching or compression (27, 28), expression of the endosomal Rab5 protein (29), exposure of cells to growth factors (30–32), local changes in cell shape (33), and the ability of cells to undergo neighbor exchange (34, 35). In addition, recent studies have also identified a functional link between cell cycle progression and force fluctuation leading to dynamic behavior of cultured epithelial monolayers (36, 37).In this study, we have investigated a mechanical link between quiescence exit and activation of large-scale cell sheet displacements. Using traction force microscopy (TFM), we found that confluent cell monolayers install an actinomyosin-based system during quiescence that produces a coordinated burst of contractile forces and intercellular tension across the epithelial monolayer immediately following exposure to serum-borne mitogens. By combining experiments and theoretical modeling, we show that the amplified forces are essential for driving coordinated cell sheet displacements within otherwise motility-restricted cell monolayers. Furthermore, the magnitude of mechanical forces created during quiescence exit and the extent of cell sheet displacement correlate with quiescence depth. Our study provides evidence that quiescent keratinocyte monolayers possess mechanical preparedness for motility and establish monolayer stress amplification as a strategy for overcoming the motility barrier in confined cell sheets.     

中药“三宝素”对小白鼠细胞免疫功能的增强作用

三宝素经动物实验证明,具有显著增强小鼠细胞免疫功能的作用。本品还有抗疲劳、安神及镇静作用;而无毒、无致畸、无致癌等副作用     

LINC00941 promoted in vitro progression and glycolysis of laryngocarcinoma by upregulating PKM via activating the PI3K/AKT/mTOR signaling pathway

BackgroundLINC00941 has been proved to be related to various tumors, but its relationship with laryngocarcinoma remains vague.MethodsLINC00941 expression in laryngocarcinoma tumor and laryngocarcinoma cells was determined by real time‐quantitative polymerase chain reaction (RT‐qPCR). Besides, the five‐year survival of laryngocarcinoma patients with different LINC00941 expression was analyzed with Kaplan–Meier survival analysis, and the clinical characteristics of laryngocarcinoma patients were also recorded. After transfection, cell viability, cell proliferation, apoptosis, cell cycle, migration, and invasion were detected by cell counting kit‐8 (CCK‐8), colony formation, flow cytometry, cell scratch, and Transwell assays, respectively. Glycolysis was assessed by the colorimetric method. Expressions of proliferation‐associated proteins, migration‐associated proteins, glycolysis‐associated proteins, and phosphatidylinositol 3‐kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signal pathway‐associated proteins were detected by Western blot.ResultsIn laryngocarcinoma tumor tissues and cells, LINC00941 was highly expressed. High expression of LINC00941 decreased the 5‐year survival of laryngocarcinoma patients, and it was positively related to lymph node metastasis and clinical stages. LINC00941 overexpression decreased apoptosis but promoted cell viability, proliferation, cell‐cycle progression, migration, and invasion, and glucose consumption and lactate production in laryngocarcinoma cells. Moreover, LINC00941 overexpression elevated expressions of Ki‐67, PCNA, MMP2, N‐Cadherin, HK2, PFKFB4, and PKM, activated the PI3K/AKT/mTOR signal pathway but reduced E‐Cadherin expression, while LINC00941 silencing had the opposite effects. PKM overexpression reversed the effects of LINC00941 silencing on cellular and glycolytic phenotypes.ConclusionLINC00941 promoted in vitro progression and glycolysis of laryngocarcinoma cells by upregulating PKM via activating the PI3K/AKT/mTOR signaling pathway.     

补骨脂对体外黑素细胞黏附和迁移的作用

目的 :研究补骨脂对黑素细胞黏附和迁移的影响。方法 :用补骨脂处理黑素细胞 ,检测其黏附于牛血清纤维结合素和通过微孔滤膜的细胞数量并与生姜和未经药物处理的黑素细胞比较。结果 :补骨脂可显著促进黑素细胞黏附于牛血清纤维结合素和通过微孔滤膜并呈剂量依赖关系 ,但当补骨脂浓度超过 0.2mg·L^-1时这种作用未见增加。补骨脂浓度在 0.01mg·L^-1时 ,黑素细胞黏附并无显著增加 ,但对迁移的影响已可见统计学差异 (P <0.01)。生姜则不具有这样的作用。结论 :在体外 ,补骨脂能明显促进黑素细胞的黏附和迁移 ,这至少可以部分解释应用补骨脂治疗白癜风是有效的。     

Simply not there: the impact of international migration of nurses and midwives--perspectives from Guyana

The shortage of nurses and midwives across the world and the migratory trends of these scarce professionals--primarily from low-income countries to fill staffing needs in high-income countries--are critical international health care issues. This article reviews some of the demographic, educational, and socioeconomic factors driving this global trend, the impact on health care delivery in low-income countries, and the effect on the implementation of global public health initiatives. Nurses and midwives migrate from low-income nations while concurrently qualified applicants are rejected from educational programs in high-income countries. The impact of migration on the viability of the health care delivery system in Guyana, South America, is presented as an exemplar nation within the broader global context of ethical dilemmas, pressures on educational systems, and the anti- and pro-migration arguments.     

血小板衍生生长因子D通过ERK信号通路对肺癌H1299细胞增殖、迁移和侵袭的影响及其机制

目的:探讨血小板衍生生长因子D (PDGF-D)对人肺癌H1299细胞增殖、迁移和侵袭的影响,并阐明其可能的作用机制。方法:选用人肺癌H1299细胞,分为对照组(转染空载体)和PDGF-D组(转染GV230-PDGF-D质粒),同时设空白组,采用实时荧光定量PCR (RT-qPCR)法和Western blotting法检测各组细胞中PDGF-D mRNA表达水平和蛋白表达量。H1299细胞分为对照组(转染空载体)、PDGF-D组(转染GV230-PDGF-D质粒)、PDGF-D+PD98059组(转染GV230-PDGF-D质粒+ERK抑制剂PD98059)和PD98059组,PD98059终浓度为10μmol·L^-1。MTT法检测各组细胞增殖活性,划痕实验检测各组细胞迁移率,Transwell实验检测各组细胞中侵袭细胞数,Western blotting法检测各组细胞中磷酸化细胞外信号调节基酶(p-ERK)、细胞外信号调节基酶(ERK)、锌指转录因子Snail、基质金属蛋白酶1 (MMP-1)和跨膜黏附糖蛋白CD44的蛋白表达水平。结果:RT-qPCR法检测,...