Continual Exposure to Cigarette Smoke Extracts Induces Tumor-Like Transformation of Human Nontumor Bronchial Epithelial Cells in a Microfluidic Chip

IntroductionHeavy cigarette smoking-related chronic obstructive pulmonary disease is an independent risk factor for lung squamous carcinoma. However, the mechanisms underlying the malignant transformation of bronchial epithelial cells are unclear.MethodsIn our study, human tumor-adjacent bronchial epithelial cells were obtained from 10 cases with smoking-related chronic obstructive pulmonary disease and lung squamous carcinoma and cultured in an established microfluidic chip for continual exposure to cigarette smoke extracts (CSE) to investigate the potential tumor-like transformation and mechanisms. The integrated microfluidic chip included upstream concentration gradient generator and downstream cell culture chambers supplied by flowing medium containing different concentrations of CSE.ResultsOur results showed that continual exposure to low doses of CSE promoted cell proliferation whereas to high doses of CSE triggered cell apoptosis. Continual exposure to CSE promoted reactive oxygen species production in human epithelial cells in a dose-dependent manner. More importantly, continual exposure to low dose of CSE promoted the epithelial-to-mesenchymal transition process and anchorage-independent growth, and increased chromosome instability in bronchial epithelial cells, accompanied by activating the GRP78, NF-κB, and PI3K pathways.ConclusionsThe established microfluidic chip is suitable for primary culture of human tumor-adjacent bronchial epithelial cells to investigate the malignant transformation. Continual exposure to low doses of CSE promoted tumor-like transformation of human nontumor bronchial epithelial cells by inducing reactive oxygen species production and activating the relevant signaling

Investigation of Predictive Regulation Strategy of Secondary Loop in District Heating Systems

The urban energy system is greatly dependent on the District Heating System (DHS). However, many difficulties with regulation and control are caused by its large scale and numerous coupling variables. Additionally, reliance on manual experience means it can be challenging to guarantee heating comfort and effectiveness in the regulation of DHS. This paper proposes a data-driven temperature response prediction model to predict secondary loop supply temperature based on the heating substation’s historical operating status, valve opening degree, weather conditions, etc. Further, the XGBoost model was established in this article with different input and prediction steps. The results show that the XGBoost model with 72 input steps and 24 prediction steps has better performance. As an application example, the model was applied to an urban central heating system. Based on this data-driven model, different operation strategies on primary loop valve opening are compared for temperature response analysis. Operators can check the temperature responses of different valve control strategies before being applied. This paper guides the regulation behavior of the DHS, which is of great significance for the operation of the actual DHS

Autophagy Activated by Bluetongue Virus Infection Plays a Positive Role in Its Replication

Bluetongue virus (BTV) is an important pathogen of wild and domestic ruminants. Despite extensive study in recent decades, the interplay between BTV and host cells is not clearly understood. Autophagy as a cellular adaptive response plays a part in many viral infections. In our study, we found that BTV1 infection triggers the complete autophagic process in host cells, as demonstrated by the appearance of obvious double-membrane autophagosome-like vesicles, GFP-LC3 dots accumulation, the conversion of LC3-I to LC3-II and increased levels of autophagic flux in BSR cells (baby hamster kidney cell clones) and primary lamb lingual epithelial cells upon BTV1 infection. Moreover, the results of a UV-inactivated BTV1 infection assay suggested that the induction of autophagy was dependent on BTV1 replication. Therefore, we investigated the role of autophagy in BTV1 replication. The inhibition of autophagy by pharmacological inhibitors (3-MA, CQ) and RNA interference (siBeclin1) significantly decreased viral protein synthesis and virus yields. In contrast, treating BSR cells with rapamycin, an inducer of autophagy, promoted viral protein expression and the production of infectious BTV1. These findings lead us to conclude that autophagy is activated by BTV1 and contributes to its replication, and provide novel insights into BTV-host interactions

Study on invadopodia formation for lung carcinoma invasion with a microfluidic 3D culture device.

Invadopodia or invasive feet, which are actin-rich membrane protrusions with matrix degradation activity formed by invasive cancer cells, are a key determinant in the malignant invasive progression of tumors and represent an important target for cancer therapies. In this work, we presented a microfluidic 3D culture device with continuous supplement of fresh media via a syringe pump. The device mimicked tumor microenvironment in vivo and could be used to assay invadopodia formation and to study the mechanism of human lung cancer invasion. With this device, we investigated the effects of epidermal growth factor (EGF) and matrix metalloproteinase (MMP) inhibitor, GM6001 on invadopodia formation by human non-small cell lung cancer cell line A549 in 3D matrix model. This device was composed of three units that were capable of achieving the assays on one control group and two experimental groups' cells, which were simultaneously pretreated with EGF or GM6001 in parallel. Immunofluorescence analysis of invadopodia formation and extracellular matrix degradation was conducted using confocal imaging system. We observed that EGF promoted invadopodia formation by A549 cells in 3D matrix and that GM6001 inhibited the process. These results demonstrated that epidermal growth factor receptor (EGFR) signaling played a significant role in invadopodia formation and related ECM degradation activity. Meanwhile, it was suggested that MMP inhibitor (GM6001) might be a powerful therapeutic agent targeting invadopodia formation in tumor invasion. This work clearly demonstrated that the microfluidic-based 3D culture device provided an applicable platform for elucidating the mechanism of cancer invasion and could be used in testing other anti-invasion agents

The attenuated African swine fever vaccine HLJ/18-7GD provides protection against emerging prevalent genotype II variants in China

ABSTRACTGenetic changes have occurred in the genomes of prevalent African swine fever viruses (ASFVs) in the field in China, which may change their antigenic properties and result in immune escape. There is usually poor cross-protection between heterogonous isolates, and, therefore, it is important to test the cross-protection of the live attenuated ASFV vaccines against current prevalent heterogonous isolates. In this study, we evaluated the protective efficacy of the ASFV vaccine candidate HLJ/18-7GD against emerging isolates. HLJ/18-7GD provided protection against a highly virulent variant and a lower lethal isolate, both derived from genotype II Georgia07-like ASFV and isolated in 2020. HLJ/18-7GD vaccination prevented pigs from developing ASF-specific clinical signs and death, decreased viral shedding via the oral and rectal routes, and suppressed viral replication after challenges. However, HLJ/18-7GD vaccination did not provide solid cross-protection against genotype I NH/P68-like ASFV challenge in pigs. HLJ/18-7GD vaccination thus shows great promise as an alternative strategy for preventing and controlling genotype II ASFVs, but vaccines providing cross-protection against different ASFV genotypes may be needed in China

Highly lethal genotype I and II recombinant African swine fever viruses detected in pigs

Abstract African swine fever virus (ASFV) poses a great threat to the global pig industry and food security. Currently, 24 ASFV genotypes have been reported but it is unclear whether recombination of different genotype viruses occurs in nature. In this study, we detect three recombinants of genotype I and II ASFVs in pigs in China. These recombinants are genetically similar and classified as genotype I according to their B646L gene, yet 10 discrete fragments accounting for over 56% of their genomes are derived from genotype II virus. Animal studies with one of the recombinant viruses indicate high lethality and transmissibility in pigs, and deletion of the virulence-related genes MGF_505/360 and EP402R derived from virulent genotype II virus highly attenuates its virulence. The live attenuated vaccine derived from genotype II ASFV is not protective against challenge of the recombinant virus. These naturally occurring recombinants of genotype I and II ASFVs have the potential to pose a challenge to the global pig industry

Thickness dependent properties of ultrathin perovskite nanosheets with Ruddlesden–Popper-like atomic stackings

Ruddlesden-Popper perovskites possess a rich variety of multiple phases due to their mixed organic cations and variable layer numbers. However, the direct observation of these phases and their optical performance in ultrathin nanosheets, have rarely been reported. Here we demonstrate, through a one-pot CVD synthesis method to incorporate MA(+) and NMA(+) cations into PbI2 simultaneously, that the stackings of Ruddlesden-Popper phases with a distribution of a number of layers n can be produced within a single perovskite nanosheet. As featured by the micro-, time-resolved and temperature-dependent photoluminescence measurements, the optical properties are highly dependent on the nanosheet thickness.The work was financially supported by the National Key R&D Program of China (Grant No. 2020YFA0308900), the National Natural Science Foundation of China (Grant No. 92064010, 61801210, 91833302), the Natural Science Foundation of Jiangsu Province (Grant No. BK20180686), the China postdoctoral Science Foundation (2020M683555), the funding for "Distinguished professors" and "High-level talents in six industries" of Jiangsu Province (Grant No. XYDXX-021), the Fundamental Research Funds for the Central Universities, the Key Research and Development Program of Shaanxi Province (2020GXLH-Z-020, 2020GXLH-Z-027) and the start-up foundation of Northwestern Polytechnical University and Nanjing Tech University

Illustration of medium flow direction in the microfluidic device.

<p>The blue, red and green indicators represented control group, EGF group, GM6001/EGF group respectively. These three indicators were perfused into microchannels from inlet A, B, C simultaneously and separately, while these indicators could spread out to cell chambers of both sides via oval microchannels uniformly and in parallel without crossing.</p

A microfluidic chip designed for the study of cancer cells invasion in 3D matrix.

<p>(A) Schematic representation of the microfluidic platform. Layout of the integrated microfluidic device is composed of three units sharing a common outlet, each of which contains an inlet, three parallel main channels, three cell culture chambers and an outlet. (B) A magnified illustration of one cell culture chamber. (C) Photograph of the microfluidic system.</p