Protein arginine N-methyltransferase 4 (PRMT4) contributes to lymphopenia in experimental sepsis.

Background: One hallmark of sepsis is the reduced number of lymphocytes, termed lymphopenia, that occurs from decreased lymphocyte proliferation or increased cell death contributing to immune suppression. Histone modification enzymes regulate immunity by their epigenetic and non-epigenetic functions; however, the role of these enzymes in lymphopenia remains elusive.

Methods: We used molecular biological approaches to investigate the high expression and function of a chromatin modulator protein arginine N-methyltransferase 4 (PRMT4)/coactivator-associated arginine methyltransferase 1 in human samples from septic patients and cellular and animal septic models.

Cigarette smoking is a secondary cause of folliculin loss.

Background: Birt-Hogg-Dubé syndrome (BHD) is a clinical syndrome manifesting with cystic lung disease and pneumothorax. Features of BHD result from the loss-of-function mutations of the folliculin () gene. Chronic obstructive pulmonary disease (COPD), characterised by an irreversible airflow limitation, is primarily caused by cigarette smoking.

Endotoxin stabilizes protein arginine methyltransferase 4 (PRMT4) protein triggering death of lung epithelia.

Lung epithelial cell death is a prominent feature of acute lung injury and acute respiratory distress syndrome (ALI/ARDS), which results from severe pulmonary infection leading to respiratory failure. Multiple mechanisms are believed to contribute to the death of epithelia; however, limited data propose a role for epigenetic modifiers. In this study, we report that a chromatin modulator protein arginine N-methyltransferase 4/coactivator-associated arginine methyltransferase 1 (PRMT4/CARM1) is elevated in human lung tissues with pneumonia and in experimental lung injury models.

Reciprocal Regulation between Primary Cilia and mTORC1.

In quiescent cells, primary cilia function as a mechanosensor that converts mechanic signals into chemical activities. This unique organelle plays a critical role in restricting mechanistic target of rapamycin complex 1 (mTORC1) signaling, which is essential for quiescent cells to maintain their quiescence. Multiple mechanisms have been identified that mediate the inhibitory effect of primary cilia on mTORC1 signaling.

Cigarette smoke extract modulates bacterial load via USP25/HDAC11 axis in lung epithelial cells.

Cigarette smoking increases susceptibility for microbial infection in respiratory system. However, the underlying molecular mechanism(s) is not fully elucidated. Here we report that cigarette smoking extract (CSE) increases bacterial load in lung epithelial cells via downregulation of the ubiquitin-specific protease 25 (USP25)/histone deacetylase 11 (HDAC11) axis.

LPS promotes HBO1 stability via USP25 to modulate inflammatory gene transcription in THP-1 cells.

The histone acetyltransferase HBO1 (Histone acetyltransferase binding to origin recognition complex 1, Myst2/Kat7) participates in a range of life processes including DNA replication and tumorigenesis. Recent studies revealed that HBO1 is involved in gene transcriptional activation. However, the molecular behavior of HBO1 in inflammation is yet to be studied.

Lipopolysaccharide modulates p300 and Sirt1 to promote PRMT1 stability via an SCF-recognized acetyldegron.

E3 ubiquitin ligase recognizes its protein substrates via specific molecular signatures for ubiquitin proteasomal degradation. However, the role of acetylation/deacetylation in the process of E3 ubiquitin ligase recognizing its protein substrates is not fully studied. Here, we report that a tandem IK motif in protein arginine methyltransferase 1 (PRMT1) forms an acetyldegron to recruit the F-box/LRR-repeat protein 17 (FBXL17), a component of the SKP1-CUL1-F-box protein (SCF)-type E3 ubiquitin ligase complex.

Oxidative stress destabilizes protein arginine methyltransferase 4 via glycogen synthase kinase 3β to impede lung epithelial cell migration.

Oxidative stress impacts normal cellular function leading to the pathogenesis of various diseases including pulmonary illnesses. Protein arginine methyltransferase 4 (PRMT4) is critical for normal lung alveolar epithelial cell development; however, the regulation of PRMT4 within such pulmonary diseases has yet to be elucidated. Using biochemical approaches, we uncovered that peroxide (HO) treatment decreases PRMT4 protein stability in murine lung epithelial (MLE12) cells to impede cell migration.

Functional role and mechanism of lncRNA LOC728228 in malignant 16HBE cells transformed by anti-benzopyrene-trans-7,8-dihydrodiol-9,10-epoxide.

Lung cancer is a major health problem, and is considered one of the deadliest cancers in humans. It is refractory to current treatments, and the mechanisms of lung cancer are unknown. Long noncoding RNAs (lncRNAs) are involved in various biological processes and human diseases.

PP2A-B56ϵ complex is involved in dephosphorylation of γ-H2AX in the repair process of CPT-induced DNA double-strand breaks.

Phosphorylation of histone H2AX (γ-H2AX) in response to DNA double-strand breaks (DSBs) should be eliminated from the sites of DNA damage to fulfill the DNA repair and release cells from the growth arrest. Previous study showed that protein phosphatase 2A (PP2A) interact with γ-H2AX that lead to the dephosphorylation of γ-H2AX. Here, we examined the effects of suppression of PP2A regulatory subunits on dephosphorylation of γ-H2AX in human embryonic kidney epithelial cells (HEK) treated by topoisomerase I inhibitor camptothecin (CPT).

Co-expression of perforin and granzyme B genes induces apoptosis and inhibits the tumorigenicity of laryngeal cancer cell line Hep-2.

Granzyme B and perforin, two of the most important components, have shown anticancer properties in various cancers, but their effects in laryngeal cancer remain unexplored. Here we decided to examine the effects of Granzyme B and perforin in Hep-2 cells and clarify the role of perforin and granzyme B in the tumorigenicity of laryngeal cancer cell line. Hep-2 cells were transfected with pVAX1-PIG co-expression vector (comprising perforin and granzyme B genes), and then the growth and apoptosis of these Hep-2 cells were evaluated.

Expression, purification and anticancer analysis of GST-tagged human perforin and granzyme B proteins in human laryngeal cancer Hep-2 cells.

Granzyme B and perforin, two major effector molecules in the granule-mediated cytolytic pathway, are thought to be involved in suppression of tumor progression. In this study, the pGEX-4T-1 expression vector was used to express full-length human perforin or granzyme B as a GST-tagged fusion protein in Escherichia coli (E. coli).

LncRNA-DQ786227-mediated cell malignant transformation induced by benzo(a)pyrene.

It has recently been found that the new class of transcripts, long non-coding RNAs (lncRNAs), are pervasively transcribed in the genome. LncRNAs are a large family of non-coding RNAs and regulate many protein-coding genes. Growing evidence indicates that lncRNAs may play an important functional role in cancer biology.

[Metabolic activation of benzo(a)pyrene enhanced transformation of human bronchial epithelium cell HBETR].

Objective: To study the application of different metabolic activation systems in benzo(a)pyrene [B(a)P]-induced human bronchial epithelium cell HBETR transformation.

Methods: In vitro metabolic activations of B(a)P were compared with rat liver S9 fraction mix, overexpression of a key enzyme (P450 CYP1A1), and prior low dose B(a)P (1 micromol/L) induction. Using soft agar assay and tumorigenicity assay, the different metabolic activation systems were compared to the influence on transformation of human bronchial epithelium cell HBETR.

[Establishment and application of oncogene over expressed human epithelial cell transformation model].

Objective: To establish human bronchial epithelial cell lines over expressing oncogene and to investigate its application in detection of carcinogen-induced cell transformation.

Methods: Mediated by retrovirus infection, human telomerase catalytic subunit, hTERT was introduced into immortal human bronchial epithelial cells (16HBE) and followed by introduction of the oncogenic allele H-Ras(V12), or c-Myc or empty vector, creating cell lines 16HBETR, 16HBETM and 16HBETV, respectively. Biological characteristics of these cell lines including morphology, proliferation, and chromosomal aberration were examined to access whether they were transformed.

Development of human cell models for assessing the carcinogenic potential of chemicals.

To develop human cell models for assessing the carcinogenic potential of chemicals, we established transgenic human cell lines and tested the sensitivity of known carcinogens using a cell transformation assay. A retroviral vector encoding an oncogenic allele of H-Ras (HBER) or c-Myc (HBEM) was introduced into human bronchial epithelial cells (HBE) immortalized by SV40 large T (LT) antigen, leading to increased cell proliferation but failing to confer a transformed phenotype characterized by anchorage-independent cell growth and tumor formation of immunodeficient mice. When these pre-transformed cells were treated with nickel sulfate (NiSO4), we found that it shortened the latency of malignant transformation at least by 19 wk in HBER cells or 16 wk in HBEM cells compared to vector control cells.

[Screening of aryl hydrocarbon receptor gene specific RNA interference fragment by quantitative competitive RT-PCR].

Objective: To evaluate and screen the specific RNAi fragments which can effectively inhibit Aryl hydrocarbon receptor(AHR) gene mRNA expression in human bronchial epithelial cell line (16HBE).

Methods: AHR mRNA of 16HBE cells transfected 4 different AHR gene interfere sites were determined quantitatively with the quantitative competitive RT-PCR by using self-prepared internal standard as competitive templates, and the RNA interfere effect wasevaluated.

Results: AHR mRNA average expression per 40ng total RNA of 16HBE cells transfected 4 different AHR gene interfere fragments were 5.

[Construction of carcinoembryonic antigen (CEA) gene vaccine and stable coexpression with an immune adjuvant].

Background & Objective: Carcinoembryonic antigen (CEA) positive cancers are poorly responded to different kinds of treatments. Gene vaccines are promising in research of gene immunotherapy for these tumors. In this study, a CEA gene vaccine with hIL-2 as an immune adjuvant was constructed into a pVAX1 vector for synchronous expression, so as to explore experimentally a new biotherapy strategy against tumors.