Astragalus Polysaccharides and Metformin May Have Synergistic Effects on the Apoptosis and Ferroptosis of Lung Adenocarcinoma A549 Cells.

Astragalus polysaccharides (APSs), the compounds extracted from the common herb Astragalus membranaceus, have been extensively studied for their antitumor properties. In this study, we investigated the effect of APS on lung adenocarcinoma A549 cells. The effects of APS and the anti-diabetic drug metformin on apoptosis and ferroptosis were compared. Furthermore, the combination treatment of APS and metformin was also investigated. We found that APS not only reduced the growth of lung cancer cells but also had a synergistic effect with metformin on A549 cells. The study results showed that it may be promising to use APS and metformin as a combination therapy for the treatment of lung adenocarcinoma.

iRhom2 regulates ERBB signalling to promote KRAS-driven tumour growth of lung cancer cells.

Dysregulation of the ERBB/EGFR signalling pathway causes multiple types of cancer. Accordingly, ADAM17, the primary shedding enzyme that releases and activates ERBB ligands, is tightly regulated. It has recently become clear that iRhom proteins, inactive members of the rhomboid-like superfamily, are regulatory cofactors for ADAM17. Here, we show that oncogenic KRAS mutants target the cytoplasmic domain of iRhom2 (also known as RHBDF2) to induce ADAM17-dependent shedding and the release of ERBB ligands. Activation of ERK1/2 by oncogenic KRAS induces the phosphorylation of iRhom2, recruitment of the phospho-binding 14-3-3 proteins, and consequent ADAM17-dependent shedding of ERBB ligands. In addition, cancer-associated mutations in iRhom2 act as sensitisers in this pathway by further increasing KRAS-induced shedding of ERBB ligands. This mechanism is conserved in lung cancer cells, where iRhom activity is required for tumour xenograft growth. In this context, the activity of oncogenic KRAS is modulated by the iRhom2-dependent release of ERBB ligands, thus placing the cytoplasmic domain of iRhom2 as a central component of a positive feedback loop in lung cancer cells. This article has an associated First Person interview with the first authors of the paper.

Integrated global proteomic and phosphoproteomic analysis of cisplatin-induced apoptosis in A549 cells.

Protein phosphorylation, a widely occurring and significant post-translational modification, is integral to various biological processes. We previously utilized a protein affinity probe to identify genes damaged by cisplatin, revealing that it inflicts substantial damage on protein kinase and protein phosphatase genes. In this study, we investigated cisplatin-induced alterations in the global proteome and phosphoproteome of A549 cells. Employing Fe-IMAC beads and tyrosine phosphorylation enrichment antibodies, we identified 6944 protein groups and 18,274 phosphorylation sites on 4915 proteins across three biological replicates of both cisplatin-treated A549 cells and control cells. Among these, 730 tyrosine phosphorylation sites were identified-marking the most substantial discovery of such sites in A549 cells following cisplatin treatment. Bioinformatics analysis indicated that the proteins exhibiting significant phosphorylation level changes predominantly involved in RNA processing, modification, transcription, translation, and the spliceosome. This suggests that cisplatin-induced damage to protein kinases and phosphatases may disrupt the normal function of these proteins, consequently impairing DNA replication, RNA translation, and shearing, ultimately culminating in tumor cell death. Moreover, we cross-referenced our proteomic data with our previously obtained cisplatin-damaged genes, observing that the majority of down-regulated proteins derived from cisplatin-induced gene damage. The data are available on ProteomeXchange under the identifier PXD053902.

Respiratory Syncytial Virus Infection Does Not Induce Epithelial-Mesenchymal Transition.

Respiratory syncytial virus (RSV) infection does not cause severe disease in most of us despite suffering from multiple RSV infections during our lives. However, infants, young children, older adults, and immunocompromised patients are unfortunately vulnerable to RSV-associated severe diseases. A recent study suggested that RSV infection causes cell expansion, resulting in bronchial wall thickening in vitro. Whether the virus-induced changes in the lung airway resemble epithelial-mesenchymal transition (EMT) is still unknown. Here, we report that RSV does not induce EMT in three different in vitro lung models: the epithelial A549 cell line, primary normal human bronchial epithelial cells, and pseudostratified airway epithelium. We found that RSV increases the cell surface area and perimeter in the infected airway epithelium, which is distinct from the effects of a potent EMT inducer, transforming growth factor ß1 (TGF-ß1), driving cell elongation-indicative of cell motility. A genome-wide transcriptome analysis revealed that both RSV and TGF-ß1 have distinct modulation patterns of the transcriptome, which suggests that RSV-induced changes are distinct from EMT. IMPORTANCE We have previously shown that RSV infects ciliated cells on the apical side of the lung airway. RSV-induced cytoskeletal inflammation contributes to an uneven increase in the height of the airway epithelium, resembling noncanonical bronchial wall thickening. RSV infection changes epithelial cell morphology by modulating actin-protein 2/3 complex-driven actin polymerization. Therefore, it is prudent to investigate whether RSV-induced cell morphological changes contribute to EMT. Our data indicate that RSV does not induce EMT in at least three different epithelial in vitro models: an epithelial cell line, primary epithelial cells, and pseudostratified bronchial airway epithelium.

Radiosensitization effect of quinoline-indole-schiff base derivative 10E on non-small cell lung cancer cells in vitro and in tumor xenografts.

Radioresistance is an inevitable obstacle in the clinical treatment of inoperable patients with non-small cell lung cancer (NSCLC). Combining treatment with radiosensitizers may improve the efficacy of radiotherapy. Previously, the quinoline derivative 10E as new exporter of Nur77 has shown superior antitumor activity in hepatocellular carcinoma. Here, we aimed to investigate the radiosensitizing activity and acting mechanisms of 10E. In vitro, A549 and H460 cells were treated with control, ionizing radiation (IR), 10E, and 10E + IR. Cell viability, apoptosis, and cycle were examined using CCK-8 and flow cytometry assays. Protein expression and localization were examined using western blotting and immunofluorescence. Tumor xenograft models were established to evaluate the radiosensitizing effect of 10E in vivo. 10E significantly inhibited cell proliferation and increased their radiosensitivity while reducing level of p-BCRA1, p-DNA-PKs, and 53BP1 involved in the DNA damage repair pathway, indicating that its radiosensitizing activity is closely associated with repressing DNA damage repair. A549 cells showed low level of Nur77 and a low response to IR but 10E-treated A549 cells showed high level of Nur77 indicating that Nur77 is a core radiosensitivity factor and 10E restores the expression of Nur77. Nur77 and Ku80 extranuclear co-localization in the 10E-treated A549 cells suggested that 10E-modulated Nur77 nuclear exportation inhibits DNA damage repair pathways and increases IR-triggered apoptosis. The combination of 10E and IR significantly inhibits tumor growth in a tumor xenograft model. Our findings suggest that 10E acts as a radiosensitizer and that combining 10E with radiotherapy may be a potential strategy for NSCLC treatment.

METTL14 enhances the m6A modification level of lncRNA MSTRG.292666.16 to promote the progression of non-small cell lung cancer.

BACKGROUND: m6A modification has close connection with the occurrence, development, and prognosis of tumors. This study aimed to explore the roles of m6A modification and its related mechanisms in non-small cell lung cancer (NSCLC). METHODS: NSCLC tissues and their corresponding para-cancerous tissues were collected to determine the m6A levels of total RNA/lncRNAs and the expression of m6A modification-related genes/lncRNAs. Then, A549 cells were transfected with si-METTL14 or oe-METTL14, and the cell transfection efficiency was assessed. Subsequently, the viability, apoptosis, cell colony formation, migration and invasion of the different cells were determined. Finally, the nude mouse tumorigenicity experiments were performed to observe the effects of METTL14 in vivo. RESULTS: Compared to the para-NSCLC tissues, the m6A level and METTL14 expression were both significantly increased in the NSCLC tissues (P < 0.05). Based on the expression of METTL14 in the different cell lines, A549 cells were chosen for further experiments. Then, the A549 cells with METTL14 knockdown and overexpression were successfully established, as well as it was found that METTL14 knockdown could inhibit the viability, colony formation, migration, and invasion of A549 cells, while facilitate their apoptosis. In vivo experiments also showed that METTL14 knockdown could inhibit tumor formation and growth. Additionally, the m6A level of MSTRG.292666.16 was higher in the NSCLC tissues; and after METTL14 knockdown, the expression and m6A level of MSTRG.292666.16 were both significantly reduced in A549 cells, and vice versa. CONCLUSION: METTL14 may promote the progression of NSCLC through up-regulating MSTRG.292666.16 and enhance its m6A modification level.

Antimicrobial and antitumor properties of anuran peptide temporin-SHf induce apoptosis in A549 lung cancer cells.

Temporin-SHf is a linear, ultra-short, hydrophobic, α-helix, and phe-rich cationic antimicrobial peptide. The antitumor activities and mechanism of temporin-SHf-induced cancer cell death are unknown. The temporin-SHf was synthesized by solid-phase Fmoc chemistry and antimicrobial and antitumor activities were investigated. Temporin-SHf was microbiocidal, non-hemolytic, and cytotoxic to human cancer cells but not to non-tumorigenic cells. It affected the cancer cells' lysosomal integrity and caused cell membrane damage. The temporin-SHf inhibited A549 cancer cell proliferation and migration. It is anti-angiogenic and causes cancer cell death through apoptosis. The molecular mechanism of action of temporin-SHf confirmed that it kills cancer cells by triggering caspase-dependent apoptosis through an intrinsic mitochondrial pathway. Owing to its short length and broad spectrum of antitumor activity, temporin-SHf is a promising candidate for developing a new class of anticancer drugs.

Photosensitizing effects and physicochemical properties of chlorophyll a derivatives with hydrophilic oligoethylene glycol fragments at the macrocycle periphery.

In this work, screening studies of the cytotoxic effect of chlorins with fragments of di-, tri-, and pentaethylene glycol at the macrocycle periphery in relation to HeLa, A549, and HT29 cells were performed. It is shown that, despite different hydrophobicity, all the compounds studied have a comparable photodynamic effect. The conjugate of chlorin e6 with pentaethylene glycol, which has the lowest tendency to association among the studied compounds with tropism for low density lipoproteins and the best characteristics of the formation of molecular complexes with Tween 80, has a significant difference in dark and photoinduced toxicity (ratio IC50(dark)/IC50(photo) approximately 2 orders of magnitude for all cell lines), which allows to hope for a sufficiently large "therapeutic window". A study of the interaction of this compound with HeLa cells shows that the substance penetrates the cell and, after red light irradiation induces ROS appearance inside the cell, associated, apparently, with the photogeneration of singlet oxygen. These data indicate that photoinduced toxic effects are caused by damage to intracellular structures as a result of oxidative stress. Programmed type of cell death characterized with caspase-3 induction is prevailing. So, the conjugate of chlorin e6 with pentaethylene glycol is a promising antitumor PS that can be successfully solubilized with Tween 80, which makes it suitable for further in vivo studies.

Comparison of the adherence of nontypeable haemophilus influenzae to lung epithelial cells.

OBJECTIVE: Nontypeable Haemophilus influenzae (NTHi) plays an important role in respiratory tract infections, and adherence to lung epithelial cells is the first step in lung infections. To explore the role of NTHi in childhood lung infections, a comparative study was conducted on the adherence of strains isolated from sputum culture and bronchoalveolar lavage fluid to A549 lung epithelial cells. METHODS: Haemophilus influenzae strains were obtained from the sample bank of Shenzhen Children's Hospital, and identified as NTHi via PCR detection of the capsule gene bexA. NTHi obtained from healthy children's nasopharyngeal swabs culture were selected as the control group, and a comparative study was conducted on the adherence of strains isolated from sputum culture or bronchoalveolar lavage fluid of patients to A549 cells. RESULTS: The adherence bacterial counts of NTHi isolated from the nasopharyngeal cultures of healthy children to A549 cells was 58.2 CFU. In patients with lung diseases, NTHi isolated from bronchoalveolar lavage fluid was 104.3 CFU, and from sputum cultures was 115.1 CFU, both of which were significantly higher in their adherence to A549 cells compared to the strains isolated from the healthy control group. There was no significant difference in adherence between the strains isolated from sputum cultures and bronchoalveolar lavage fluid (t = 0.5217, p = 0.6033). CONCLUSION: NTHi played an important role in childhood pulmonary infections by enhancing its adherence to lung epithelial cells.

Synthesis and characterization of organoselenium based BODIPY and its application in living cells.

Phenylselenide based BODIPY probe was successfully synthesized and characterized by NMR spectroscopic techniques (1H, 13C and 77Se NMR), mass spectrometry and single crystal XRD. Surprisingly, crystal packing diagram of the probe showed formation of 1-D strip through intermolecular F---H interaction. The probe was screened with various Reactive Oxygen Species (ROS) and found to be selective for superoxide ion over other ROS via "turn-on" fluorescence response. The probe selectively and sensitively detects superoxide with a lower detection limit (43.34 nM) without interfering with other ROS. The quantum yield of the probe was found to increase from 0.091 % to 30.4 % (334-fold) after oxidation. Theoretical calculations (DFT and TD-DFT) were also performed to understand the sensing mechanism of the probe. The probe was able to effectively detect superoxide inside living cells without any toxic effect.

Pelargonidin inhibits cell growth and promotes oxidative stress-mediated apoptosis in lung cancer A549 cells.

Lung cancer has the worst prognosis with an average 5-year survival rate of only 10%-20%. Lung cancer has the highest prevalence rate and a second most common cause of cancer-associated mortalities worldwide. The present study was planned to explore the anticancer effects of pelargonidin against the lung cancer A549 cells via analyzing oxidative stress-mediated apoptosis. The viability of both control and pelargonidin-treated A549 cells was analyzed using the MTT cytotoxicity assay at different time periods. The levels of endogenous ROS generation, mitochondrial membrane potential (Δψm), and apoptosis were assessed using corresponding fluorescent staining assays. The levels of oxidative stress biomarkers, including TBARS, SOD, CAT, and GSH, in the cell lysates of control and pelargonidin-treated A549 cells were examined using the assay kits. The pelargonidin treatment substantially suppressed the A549 cell growth. Further, pelargonidin promoted the ROS production and depleted the Δψm levels in the A549 cells. The fluorescent staining assays witnessed the occurrence of increased apoptosis in the pelargonidin-treated A549 cells. The pelargonidin also boosted the TBARS and reduced the antioxidant levels thereby promoted the oxidative stress-regulated apoptosis in the A549 cells. In summary, the findings' results of the current study demonstrated an anticancer activity of pelargonidin on A549 cells. The pelargonidin treatment substantially decreased the growth and encouraged the oxidative stress-regulated apoptosis in A549 cells. Therefore, it was evident that the pelargonidin could be employed as an effective anticancer candidate to treat the lung cancer.

Combining analytical techniques to assess the translocation of diesel particles across an alveolar tissue barrier in vitro.

BACKGROUND: During inhalation, airborne particles such as particulate matter ≤ 2.5 µm (PM2.5), can deposit and accumulate on the alveolar epithelial tissue. In vivo studies have shown that fractions of PM2.5 can cross the alveolar epithelium to blood circulation, reaching secondary organs beyond the lungs. However, approaches to quantify the translocation of particles across the alveolar epithelium in vivo and in vitro are still not well established. In this study, methods to assess the translocation of standard diesel exhaust particles (DEPs) across permeable polyethylene terephthalate (PET) inserts at 0.4, 1, and 3 µm pore sizes were first optimized with transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-VIS), and lock-in thermography (LIT), which were then applied to study the translocation of DEPs across human alveolar epithelial type II (A549) cells. A549 cells that grew on the membrane (pore size: 3 µm) in inserts were exposed to DEPs at different concentrations from 0 to 80 µg.mL- 1 ( 0 to 44 µg.cm- 2) for 24 h. After exposure, the basal fraction was collected and then analyzed by combining qualitative (TEM) and quantitative (UV-VIS and LIT) techniques to assess the translocated fraction of the DEPs across the alveolar epithelium in vitro. RESULTS: We could detect the translocated fraction of DEPs across the PET membranes with 3 µm pore sizes and without cells by TEM analysis, and determine the percentage of translocation at approximatively 37% by UV-VIS (LOD: 1.92 µg.mL- 1) and 75% by LIT (LOD: 0.20 µg.cm- 2). In the presence of cells, the percentage of DEPs translocation across the alveolar tissue was determined around 1% at 20 and 40 µg.mL- 1 (11 and 22 µg.cm- 2), and no particles were detected at higher and lower concentrations. Interestingly, simultaneous exposure of A549 cells to DEPs and EDTA can increase the translocation of DEPs in the basal fraction. CONCLUSION: We propose a combination of analytical techniques to assess the translocation of DEPs across lung tissues. Our results reveal a low percentage of translocation of DEPs across alveolar epithelial tissue in vitro and they correspond to in vivo findings. The combination approach can be applied to any traffic-generated particles, thus enabling us to understand their involvement in public health.

Modular air-liquid interface aerosol exposure system (MALIES) to study toxicity of nanoparticle aerosols in 3D-cultured A549 cells in vitro.

We present a novel lung aerosol exposure system named MALIES (modular air-liquid interface exposure system), which allows three-dimensional cultivation of lung epithelial cells in alveolar-like scaffolds (MatriGrids®) and exposure to nanoparticle aerosols. MALIES consists of multiple modular units for aerosol generation, and can be rapidly assembled and commissioned. The MALIES system was proven for its ability to reliably produce a dose-dependent toxicity in A549 cells using CuSO4 aerosol. Cytotoxic effects of BaSO4- and TiO2-nanoparticles were investigated using MALIES with the human lung tumor cell line A549 cultured at the air-liquid interface. Experiments with concentrations of up to 5.93 × 105 (BaSO4) and 1.49 × 106 (TiO2) particles/cm3, resulting in deposited masses of up to 26.6 and 74.0 µg/cm2 were performed using two identical aerosol exposure systems in two different laboratories. LDH, resazurin reduction and total glutathione were measured. A549 cells grown on MatriGrids® form a ZO-1- and E-Cadherin-positive epithelial barrier and produce mucin and surfactant protein. BaSO4-NP in a deposited mass of up to 26.6 µg/cm2 resulted in mild, reversible damage (~ 10% decrease in viability) to lung epithelium 24 h after exposure. TiO2-NP in a deposited mass of up to 74.0 µg/cm2 did not induce any cytotoxicity in A549 cells 24 h and 72 h after exposure, with the exception of a 1.7 fold increase in the low exposure group in laboratory 1. These results are consistent with previous studies showing no significant damage to lung epithelium by short-term treatment with low concentrations of nanoscale BaSO4 and TiO2 in in vitro experiments.

Effects of electromagnetic pulses, exosomes inhibition and their coaction on A549 cells.

Mounting literature indicates that electromagnetic pulses (EMP) is the promising modality to treat cancers with advantages such as noninvasiveness and few side-effects, but its appropriate parameters and underlying mechanisms such as its influence on tumor-derived exosomes (TDEs) are largely unknown. This study aimed to elucidate effects of EMP, exosome inhibition and their coaction on A549 lung adenocarcinoma cells. A549 cells were randomly divided into control group, GW4869 group treated by 20 µM GW4869, vehicle group treated by dimethyl sulfoxide, EMP group treated by EMP exposure, and EMPG group treated by EMP exposure combined with 20 µM GW4869. After EMP exposure, cell proliferation was determined by CCK8 assay, cell cycle and apoptosis was detected by flow cytometry, and cell migration was determined by transwell assay. The results showed that EMP or exosomes inhibition did not affect cell proliferation, cell cycle, apoptosis and cell migration (p > 0.05), but cell migration in EMPG group was significantly decreased compared with vehicle group (p < 0.05). We concluded that under the experimental condition, EMP or GW4869 alone had no effects on behaviors of A549 cells, but their coaction could effectively inhibit the migration of A549 cells.

Performance of 4,5-diphenyl-1H-imidazole derived highly selective 'Turn-Off' fluorescent chemosensor for iron(III) ions detection and biological applications.

Two fluorescent chemosensors, denoted as chemosensor 1 and chemosensor 2, were synthesized and subjected to comprehensive characterization using various techniques. The characterization techniques employed were Fourier-transform infrared (FTIR), proton (1 H)- and carbon-13 (13 C)-nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization (ESI) mass spectrometry, and single crystal X-ray diffraction analysis. Chemosensor 1 is composed of a 1H-imidazole core with specific substituents, including a 4-(2-(4,5-c-2-yl)naphthalene-3-yloxy)butoxy)naphthalene-1-yl moiety. However, chemosensor 2 features a 1H-imidazole core with distinct substituents, such as 4-methyl-2-(4,5-diphenyl-1H-imidazole-2-yl)phenoxy)butoxy)-5-methylphenyl. Chemosensor 1 crystallizes in the monoclinic space group C2/c. Both chemosensors 1 and 2 exhibit a discernible fluorescence quenching response selectively toward iron(III) ion (Fe3+ ) at 435 and 390 nm, respectively, in dimethylformamide (DMF) solutions, distinguishing them from other tested cations. This fluorescence quenching is attributed to the established mechanism of chelation quenched fluorescence (CHQF). The binding constants for the formation of the 1 + Fe3+ and 2 + Fe3+ complexes were determined using the modified Benesi-Hildebrand equation, yielding values of approximately 2.2 × 103 and 1.3 × 104 M-1 , respectively. The calculated average fluorescence lifetimes for 1 and 1 + Fe3+ were 2.51 and 1.17 ns, respectively, while for 2 and 2 + Fe3+ , the lifetimes were 1.13 and 0.63 ns, respectively. Additionally, the applicability of chemosensors 1 and 2 in detecting Fe3+ in live cells was demonstrated, with negligible observed cell toxicity.

Tris(1,3-dichloro-2-propyl) phosphate-induced cytotoxicity and its associated mechanisms in human A549 cells.

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is a widely used organophosphorus flame retardant and has been detected in various environmental matrices including indoor dust. Inhalation of indoor dust is one of the most important pathways for human exposure to TDCIPP. However, its adverse effects on human lung cells and potential impacts on respiratory toxicity are largely unknown. In the current study, human non-small cell carcinoma (A549) cells were selected as a cell model, and the effects of TDCIPP on cell viability, cell cycle, cell apoptosis, and underlying molecular mechanisms were investigated. Our data indicated a concentration-dependent decrease in the cell viability of A549 cells after exposure to TDCIPP for 48 h, with half lethal concentration (LC50) being 82.6 µM. In addition, TDCIPP caused cell cycle arrest mainly in the G0/G1 phase by down-regulating the mRNA expression of cyclin D1, CDK4, and CDK6, while up-regulating the mRNA expression of p21 and p27. In addition, cell apoptosis was induced via altering the expression levels of Bcl-2, BAX, and BAK. Our study implies that TDCIPP may pose potential health risks to the human respiratory system and its toxicity should not be neglected.

Stilbene Treatment Reduces Stemness Features in Human Lung Adenocarcinoma Model.

Lung cancer is among the most clinically challenging tumors because of its aggressive proliferation, metastasis, and the presence of cancer stem cells (CSCs). Natural bioactive substances have been used for cancer prevention, and, in particular, resveratrol (RSV), a stilbene-based compound with wide biological properties, has been proposed for chemoprevention. Its lesser-known analogue 4,4'-dihydroxy-trans-stilbene (DHS) has demonstrated superior activity both in cell-based assays and in mouse and zebrafish in vivo models. The present study analyzed the effects of DHS and RSV on A549 lung cancer cells, with a particular focus on stemness features and CSCs, isolated by sorting of the side population (SP). The results show that both stilbenes, especially DHS, strongly inhibited cell cycle progression. A reduction in the S phase was induced by DHS, whereas an increase in this phase was obtained with RSV. In addition, 50% reductions in the clonogenicity and soft agar colony formation were observed with the DHS treatment only. Finally, both stilbenes, especially DHS, reduced stemness marker expression in A549 cells and their sorted SP fraction. Spheroid formation, higher in SP cells than in the main population (MP), was significantly reduced after pretreatment with DHS, which was found to decrease SOX2 levels more than RSV. These findings indicate that stilbenes, and particularly DHS, affect stemness features of A549 cells and the SP fraction, suggesting their potential utility as anticancer agents, either alone or combined with chemotherapeutic drugs.

Effect of LRRC15 on autophagy in A549 cells.

Idiopathic pulmonary fibrosis (IPF) is a progressive, chronic, and irreversible interstitial lung disease with unknown cause. To explore the role and regulatory mechanism of leucine-rich repeat-containing protein 15 (LRRC15) in IPF, bleomycin (BLM)-induced pulmonary fibrosis in mouse and A549 cells were constructed, and the expression of LRRC15 were detected. Then, MTT, GFP-RFP-LC3 dual fluorescent labeling system and Western blotting were used to investigate the effects of LRRC15 on cell activity and autophagy after transfection of siLRRC15, respectively. The results indicated that the expression of LRRC15 was significantly increased after the BLM treatment in mouse lung tissue and A549 cells. The designed and synthesized siLRRC15 followed by transfection into A549 cells resulted in a dramatic reduction in LRRC15 expression and partially restored the cell damage induced by BLM. Moreover, the expression of LC3-II and P62 were up-regulated, the amount of autophagosome were increased by GFP-RFP-LC3 dual fluorescent labeling assay after BLM treatment. Meanwhile, this study also showed that the key autophagy proteins LC3-II, ATG5 and ATG7 were up-regulated, P62 was down-regulated and autophagic flux were enhanced after further treatment of A549 cells with siLRRC15. The above findings suggest that LRRC15 is an indicator of epithelial cell damage and may participate in the regulation of fibrosis through autophagy mechanism in IPF. This study provides necessary theoretical basis for further elucidating the mechanism of IPF.

Transcriptome-wide 5-methylcytosine modification profiling of long non-coding RNAs in A549 cells infected with H1N1 influenza A virus.

BACKGROUND: In recent years, accumulating evidences have revealed that influenza A virus (IAV) infections induce significant differential expression of host long noncoding RNAs (lncRNAs), some of which play important roles in the regulation of virus-host interactions and determining the virus pathogenesis. However, whether these lncRNAs bear post-translational modifications and how their differential expression is regulated remain largely unknown. In this study, the transcriptome-wide 5-methylcytosine (m5C) modification of lncRNAs in A549 cells infected with an H1N1 influenza A virus was analyzed and compared with uninfected cells by Methylated RNA immunoprecipitation sequencing (MeRIP-Seq). RESULTS: Our data identified 1317 upregulated m5C peaks and 1667 downregulated peaks in the H1N1 infected group. Gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that the differentially modified lncRNAs were associated with protein modification, organelle localization, nuclear export and other biological processes. Furthermore, conjoint analysis of the differentially modified (DM) and differentially expressed (DE) lncRNAs identified 143 'hyper-up', 81 'hypo-up', 6 'hypo-down' and 4 'hyper-down' lncRNAs. GO and KEGG analyses revealed that these DM and DE lncRNAs were predominantly associated with pathogen recognition and disease pathogenesis pathways, indicating that m5C modifications could play an important role in the regulation of host response to IAV replication by modulating the expression and/or stability of lncRNAs. CONCLUSION: This study presented the first m5C modification profile of lncRNAs in A549 cells infected with IAV and demonstrated a significant alteration of m5C modifications on host lncRNAs upon IAV infection. These data could give a reference to future researches on the roles of m5C methylation in virus infection.

Design, synthesis and SAR of novel 7-azaindole derivatives as potential Erk5 kinase inhibitor with anticancer activity.

The extracellular signal-regulated kinase 5 (Erk5) signaling plays a crucial role in cancer, and regulating its activity may have potential in cancer chemotherapy. In this study, a series of novel 7-azaindole derivatives (4a-5o) were designed and synthesized. Their antitumor activities on human lung cancer A549 cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 4',6-diamidino-2-phenylindole (DAPI) staining and colony formation assay. Among them, compounds 4a, 4 h, 5d and 5j exhibited good anti-proliferative activity with the IC50 values of 6.23 µg/mL, 8.52 µg/mL, 7.33 µg/mL and 4.56 µg/mL, respectively, equivalent to Erk5 positive control XMD8-92 (IC50 = 5.36 µg/mL). The results of structure-activity relationships (SAR) showed that double bond on the piperidine ring and N atoms at the N7 position of 7-azaindole was essential for their antiproliferative activity. Furthermore, compounds 4a and 5j exhibited good inhibition on Erk5 kinase through Western blot analysis and possible action site of compounds with Erk5 kinase was elucidated by molecular docking.