A positive feedback loop promotes HIF-1α stability through miR-210-mediated suppression of RUNX3 in paraquat-induced EMT

CPEB2 Suppresses Hepatocellular Carcinoma Epithelial-Mesenchymal Transition and Metastasis through Regulating the HIF-1α/miR-210-3p/CPEB2 Axis

Hepatocellular carcinoma (HCC) is a prevalent and high-mortality cancer worldwide, and its complexity necessitates novel strategies for drug selection and design. Current approaches primarily focus on reducing gene expression, while promoting gene overexpression remains a challenge. In this work, we studied the effect of cytoplasmic polyadenylation element binding protein 2 (CPEB2) in HCC by constructing tissue microarrays (TAMs) from 90 HCC cases and corresponding para-cancerous tissues. Our analysis showed that CPEB2 expression was significantly reduced in HCC tissues, and its low expression was associated with a higher recurrence risk and poorer prognosis in patients with head and neck cancer. CPEB2 was found to regulate HCC epithelial-mesenchymal transition (EMT) and metastasis through the HIF-1α/miR-210-3p/CPEB2 feedback circuit. Using the RNA binding protein immunoprecipitation (RIP) assay, we demonstrated that miR-210 directly governs the expression of CPEB2. The inverse relationship between CPEB2 expression and miR-210-3p in HCC tissues suggested that this regulatory mechanism is directly linked to HCC metastasis, EMT, and clinical outcomes. Moreover, utilizing the SM2miR database, we identified drugs that can decrease miR-210-3p expression, consequently increasing CPEB2 expression and providing new insights for drug development. In conclusion, our findings illustrated a novel HIF-1α/miR-210-3p/CPEB2 regulatory signaling pathway in HCC and highlighted the potential of enhancing CPEB2 expression through targeting miR-210-3p as a novel predictive biomarker and therapeutic strategy in HCC, as it is modulated by the HIF-1α/miR-210-3p/CPEB2 feedback circuit.

High glucose induces an activated state of partial epithelial-mesenchymal transition in human primary tubular cell cultures

Tubulointerstitial fibrosis is observed in diabetic nephropathy. It is still debated whether tubular cells, undergoing epithelial-mesenchymal transition (EMT) in high glucose (HG) conditions, may contribute to interstitial fibrosis development. In this study, we investigated the phenotypic and molecular EMT-like changes and the alteration of inflammatory and fibrogenic secretome induced by HG in human primary tubular cell cultures. Taking advantage of this in vitro cell model composed of proximal and distal tubular cells, we showed that HG-treated tubular cells acquired a fibroblast-like morphology with increased cytoplasmic stress fibers, maintaining the expression of the epithelial markers specific of proximal and distal tubular cells. HG increased Snail1, miRNA210 and Vimentin mesenchymal markers, decreased N-cadherin expression and migration ability of primary tubular cells, while E-cadherin expression and focal adhesion distribution were not affected. Furthermore, HG treatment of tubular cells altered the inflammatory cytokine secretion creating a secretome able to enhance the proliferation and migration of fibroblasts. Our findings show that HG promotes an activated state of partial EMT in human tubular primary cells and induces a pro-inflammatory and pro-fibrogenic microenvironment, supporting the active role of tubular cells in diabetic nephropathy onset.

RUNX3 Meets the Ubiquitin-Proteasome System in Cancer

RUNX3 is a transcription factor with regulatory roles in cell proliferation and development. While largely characterized as a tumor suppressor, RUNX3 can also be oncogenic in certain cancers. Many factors account for the tumor suppressor function of RUNX3, which is reflected by its ability to suppress cancer cell proliferation after expression-restoration, and its inactivation in cancer cells. Ubiquitination and proteasomal degradation represent a major mechanism for the inactivation of RUNX3 and the suppression of cancer cell proliferation. On the one hand, RUNX3 has been shown to facilitate the ubiquitination and proteasomal degradation of oncogenic proteins. On the other hand, RUNX3 can be inactivated through the ubiquitin-proteasome system. This review encapsulates two facets of RUNX3 in cancer: how RUNX3 suppresses cell proliferation by facilitating the ubiquitination and proteasomal degradation of oncogenic proteins, and how RUNX3 is degraded itself through interacting RNA-, protein-, and pathogen-mediated ubiquitination and proteasomal degradation.

HIF-1α promotes paraquat induced acute lung injury and implicates a role NF-κB and Rac2 activity

Paraquat (PQ) is a bipyridine herbicide and oral exposure is the main way of PQ exposure with a very high mortality. At present, it is believed that large number of oxygen free radicals are generated and cause lipid peroxidation of tissue and organ cell membranes after PQ is absorbed. PQ exposure could cause multiple organ dysfunction, among which acute lung injury is the most common and most serious. However, its specific mechanism is still unclear. In this study, the C57BL/6J mouse (alveolar epithelial cell-specific knockout HIF-1α) model of acute lung injury (40 mg/kg PQ) at several time pointes and a model of acute type II alveolar epithelial cell (A549, 800 μM PQ) injury constructed. The oxidative stress (ROS, MDA) and inflammatory response (IL-1β, IL-6, TNF-α) were significantly inhibited in the alveolar epithelial cell-specific knockout of HIF-1α mice and siRNA technology to inhibit HIF-1α in alveolar epithelial cells. Further proteomic analysis showed that the expression of Rac2 protein, which is closely related to oxidative stress, was significantly increased after PQ exposure. And the inhibition of Rac2 expression in vitro significantly alleviated PQ-induced oxidative stress and inflammatory response. The expression of Rac2 protein was regulated by HIF-1α. The above suggests that HIF-1α may promote oxidative stress and inflammatory response in alveolar epithelial cells by regulating the expression of Rac2, and then participate in the promotion of PQ exposure-induced acute lung injury.

miRNAs: A potentially valuable tool in pesticide toxicology assessment-current experimental and epidemiological data review

miRNAs are responsible for the regulation of many cellular processes such as development, cell differentiation, proliferation, apoptosis, and tumor growth. Several studies showed that they can also serve as specific, stable, and sensitive markers of chemical exposure. In this review, current experimental and epidemiological data evidencing deregulation in miRNA expression in response to fungicides, insecticides or herbicides were analyzed. As shown by Venn's diagrams, miR-363 and miR-9 deregulation is associated with fungicide exposure in vitro and in vivo, while let-7, miR-155, miR-181 and miR-21 were found to be commonly deregulated by at least three different insecticides. Furthermore, let-7, miR-30, miR-126, miR-181 and miR-320 were commonly deregulated by 3 different herbicides. Notably, these 5 miRNAs were also found to be deregulated by one or more insecticides, suggesting their participation in the cellular response to pesticides, regardless of their chemical structure. All these miRNAs have been proposed as potential biomarkers for fungicide, insecticide, or herbicide exposure. These results allow us to improve our understanding of the molecular mechanisms of toxicity upon pesticide exposure, although further studies are needed to confirm these miRNAs as definitive (not potential) biomarkers of pesticide exposure.

Advances in research on the effects of platelet activation in acute lung injury (Review)

Acute lung injury (ALI) is an acute hypoxic respiratory insufficiency or failure caused by various factors inside and outside the lungs. ALI is associated with high morbidity and a poor prognosis in hospitalized patients. The lungs serve as a reservoir for platelet precursor megakaryocytes and are closely associated with platelets. Platelets not only play a central role in hemostasis, coagulation and wound healing, but can also act as inflammatory cells capable of stimulating non-hemostatic immune functions under inflammatory conditions, participating in the progression of various inflammatory diseases, and can result in tissue damage. Therefore, it was speculated that platelets may play an important role in the pathogenesis of ALI. In this review, the latest research progress on secretion of bioactive mediators from platelets, platelet activation-related signaling pathways, and the direct contact reactions between platelets and neutrophils with endothelial cells that result in ALI are described, providing evidence to support the importance of the consideration of platelets in the search for ALI interventional targets.

Regulation of epithelial-to-mesenchymal transition in hypoxia by the HIF-1α network

Epithelial-to-mesenchymal transition (EMT) plays a significant role in cancer metastasis. A series of models have focused on EMT regulation by TGF-β network. However, how EMT is regulated under hypoxia is less understood. We developed a model of HIF-1α network to explore the potential link between EMT and the network topology. Our results revealed that three positive feedback loops, composed of HIF-1α and its three targets SNAIL, TWIST, and miR-210, should be sequentially activated to induce EMT under aggravating hypoxia. We suggested that the number of the positive feedback loops is critical for determining the number of stable states in EMT. Our work may advance the understanding of the significance of network topology in the regulation of EMT.

MiR-210-5p regulates STAT3 activation by targeting STAT5A in the differentiation of dermal fibroblasts

Elucidating the molecular mechanism of the microRNAs in skin fibrosis is critical for identifying a novel therapeutic strategy for hypertrophic scar (HS). In this study, it was shown that miR-210-5p is induced by TGFβ, and that overexpression of miR-210-5p promoted the differentiation of human dermal fibroblasts (HDFs) into myofibroblasts. STAT5A is required for TGFβ-induced STAT3 activity. Here, we show that miR-210-5p attenuated TGFβ-induced STAT3 signaling pathway by suppressing the expression of STAT5A. Taken together, the present study suggests that TGFβ-induced miR-210-5p reduced STAT5A expression, leading to aberrant activation of STAT3, and facilitate skin fibrosis in HDFs.

The herbicide paraquat-induced molecular mechanisms in the development of acute lung injury and lung fibrosis

The herbicide paraquat (PQ; 1,1'-dimethyl-4,4'-bipyridylium dichloride) is a highly toxic organic heterocyclic herbicide that has been widely used in agricultural settings. Since its commercial introduction in the early 1960s, numerous cases of fatal PQ poisonings attributed to accidental and/or intentional ingestion of PQ concentrated formulations have been reported. The clinical manifestations of the respiratory system during the acute phase of PQ poisoning mainly include acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), followed by pulmonary fibrosis in a later phase. The focus of this review is to summarize the most recent publications related to PQ-induced lung toxicity as well as the underlying molecular mechanisms for PQ-mediated pathologic processes. Growing sets of data from in vitro and in vivo models have demonstrated the involvement of the PQ in regulating lung oxidative stress, inflammatory response, epigenetics, apoptosis, autophagy, and the progression of lung fibrosis. The article also summarizes novel therapeutic avenues based on a literature review, which can be explored as potential means to combat PQ-induced lung toxicity. Finally, we also presented clinical studies on the association of PQ exposure with the incidence of lung injury and pulmonary fibrosis.

Role of epithelial-to-mesenchymal transition in the pulmonary fibrosis induced by paraquat in rats

BACKGROUND

This study aims to explore the characteristics of the epithelial-to-mesenchymal transition (EMT) process and its underlying molecular mechanisms in the period of paraquat (PQ)-induced pulmonary fibrosis (PF).

METHODS

Picrosirius red staining and collagen volume fraction were utilized to evaluate the pathological changes of PQ-induced PF in rats. Immunohistochemistry, Western blot, and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) were used to measure the protein and gene expression of EMT markers, EMT-associated transcription factors, and regulators of EMT-related pathways, respectively.

RESULTS

The collagen deposition in the alveolar septum and increased PF markers were characteristics of pathological changes in PQ-induced PF, reached a peak on day 14 after PQ poisoning, and then decreased on day 21. The protein and gene expression of the fibrosis marker, EMT markers, transcription factors, and regulators of EMT-related signaling pathways significantly increased at different time points after PQ poisoning compared with corresponding controls (P<0.05), and most of them reached a peak on day 14, followed by a decrease on day 21. The gene expression of EMT markers was significantly correlated with PF markers, transcription factors, and regulators of EMT-related signaling pathways (P<0.05). The mRNA expression of transcription factors was significantly correlated with that of TGF-β1 and Smad2 (P<0.05 or P<0.01), instead of Wnt2 and β-catenin (P>0.05).

CONCLUSIONS

EMT process plays a role in the PQ-induced PF, in which most PF and EMT markers have a peak phenomenon, and its underlying molecular mechanisms might be determined by further studies.

Analysis of microRNA expression profiling during paraquat-induced injury of murine lung alveolar epithelial cells

Paraquat (PQ) as a non-selective heterocyclic herbicide, has been applied worldwide for over a few decades. But PQ is very harmful to humans and rodents. The lung is the main target organ of PQ poisoning. It is an important event that lung epithelial cells are injured during PQ-induced acute lung injury and pulmonary fibrosis. As a regulator of mRNA expression, microRNA (miRNA) may play an important role in the progress. Our study was to investigate the mechanisms of PQ-induced injury of pulmonary epithelial cells through analyzing the profiling of miRNAs and their target genes. As a result, 11 differentially expressed miRNAs were screened, including 1 upregulated miRNA and 10 downregulated miRNAs in PQ-treated murine lung alveolar epithelial cells (MLE-12 cells). The bioinformatic analyses suggested that the target genes of these miRNAs were involved in mitochondrial apoptosis pathway and DNA methylation, and participated in the regulation of PI3K-Akt, mTOR, RAS, TNF, MAPK and other signal pathways which related to oxidative stress and apoptosis. This indicated that miRNAs were an important regulator of oxidative stress and apoptosis during PQ-induced injury of murine lung alveolar epithelial cells. The findings would deepen our understanding of the mechanisms of PQ-induced pulmonary injury and might provide new treatment targets for this disease.

Hirudin Reduces the Expression of Markers of the Extracellular Matrix in Renal Tubular Epithelial Cells in a Rat Model of Diabetic Kidney Disease Through the Hypoxia-Inducible Factor-1α (HIF-1α)/Vascular Endothelial Growth Factor (VEGF) Signaling Pathway

BACKGROUND This study aimed to investigate the effects of hirudin on the production of extracellular matrix (ECM) factors by renal tubular epithelial cells in a rat model of diabetic kidney disease (DKD) and HK-2 human renal tubule epithelial cells. MATERIAL AND METHODS Sprague-Dawley rats were divided into the normal control group (n=10), the normal control+hirudin group (n=10), the DKD model group (n=12) and the DKD+hirudin group (n=12). At the end of the study, renal histopathology was undertaken, and the expression of type IV collagen, fibronectin, hypoxia-inducible factor-1alpha (HIF-1alpha), and vascular endothelial growth factor (VEGF) were evaluated using immunohistochemistry, Western blot, and quantitative real-time polymerase chain reaction (qRT-PCR). HK-2 cells were cultured in glucose and treated with hirudin. Protein and mRNA expression of fibronectin, type IV collagen, HIF-1alpha, and VEGF were evaluated following knockdown or overexpression of HIF-1alpha. RESULTS Hirudin significantly improved renal function in the rat model of DKD (P<0.01), and significantly down-regulated the expression of fibronectin, type IV collagen, HIF-1alpha, and VEGF proteins (P<0.05). The expression of ECM associated proteins was increased in HK-2 cells treated with high glucose and reduced in the high glucose+shRNA HIF-1alpha group (P<0.05). Compared with the control group, the expression of ECM associated proteins was increased in the HIF-1alpha over-expressed group, and decreased following treatment with hirudin (P<0.05). CONCLUSIONS Hirudin reduced the expression of markers of ECM by inhibiting the HIF-1alpha/VEGF signaling pathway in DKD renal tubular epithelial cells.

Amelioration of paraquat-induced pulmonary fibrosis in mice by regulating miR-140-5p expression with the fibrogenic inhibitor Xuebijing

Intravenous Xuebijing (XBJ) therapy suppresses paraquat (PQ)-induced pulmonary fibrosis. However, the mechanism underlying this suppression remains unknown. This work aimed to analyze the miR-140-5p-induced effects of XBJ injection on PQ-induced pulmonary fibrosis in mice. The mice were arbitrarily assigned to four groups. The model group was administered with PQ only. The PQ treatment group was administered with PQ and XBJ. The control group was administered with saline only. The control treatment group was administered with XBJ only. The miR-140-5p and miR-140-5p knockout animal models were overexpressed. The gene expression levels of miR-140-5p, transglutaminase-2 (TG2), β-catenin, Wnt-1, connective tissue growth factor (CTGF), mothers against decapentaplegic homolog (Smad), and transforming growth factor-β1 (TGF-β1) in the lungs were assayed with quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analysis. The levels of TGF-β1, CTGF, and matrix metalloproteinase-9 (MMP-9) in the bronchoalveolar lavage fluid were assessed by enzyme-linked immunosorbent assay (ELISA). Hydroxyproline (Hyp) levels and pulmonary fibrosis were also scored. After 14 days of PQ induction of pulmonary fibrosis, AdCMV-miR-140-5p, and XBJ upregulated miR-140-5p expression; blocked the expressions of TG2, Wnt-1, and β-catenin; and decreased p-Smad2, p-Smad3, CTGF, MMP-9, and TGF-β1 expressions. In addition, Hyp and pulmonary fibrosis scores in XBJ-treated mice decreased. Histological results confirmed that PQ-induced pulmonary fibrosis in XBJ-treated lungs was attenuated. TG2 expression and the Wnt-1/β-catenin signaling pathway were suppressed by the elevated levels of miR-140-5p expression. This inhibition was pivotal in the protective effect of XBJ against PQ-induced pulmonary fibrosis. Thus, XBJ efficiently alleviated PQ-induced pulmonary fibrosis in mice.

Mechanism of miR-210 involved in epithelial-mesenchymal transition of pancreatic cancer cells under hypoxia

Purpose: To investigate the possible mechanism of miR-210 involved in epithelial-mesenchymal transition (EMT) of pancreatic cancer cells under hypoxia. Methods: In this study, we used the following approaches. Hypoxic microenvironment was stimulated in vitro, and the CCK-8 assay was used to analyze cell viability. The MiRNA expression level was measured by qRT-PCR. HOXA9, EMT-related proteins, and NF-κB activities were examined by immunoblotting assay. Dual luciferase reporter assay was used to assess whether HOXA9 was a target of miR-210.Results: Under hypoxia condition, miR-210, HIF-1α and NF-κB were increased, and the HOXA9 was reduced in PANC-1 cells. When miR-210 was overexpressed in normoxic PANC-1 cells, EMT epithelial markers of E-cadherin and β-catenin were down-regulated, and mesenchymal markers of vimentin and N-cadherin were up-regulated to promote cell migration/invasive ability, and the HOXA9 level was decreased. After HOXA9 level decreased, the sensitivity to chemotherapeutic drug of gemcitabine was reduced, NF-κB expression level and cell migration/invasive ability was enhanced. Whereas, miR-210 antagonist into hypoxic PANC-1 cells, which up-regulated E-cadherin, β-catenin level, and down-regulated vimentin and N-cadherin levels to decrease cell migration/invasive ability, and increase the HOXA9. Furthermore, increasing HOXA9 level decreased NF-κB expression level and cell migration/invasive ability, enhanced the sensitivity to gemcitabine. At last, miRDB and TargetScan predicted that HOXA9 was a target of miR-210, and dual luciferase reporter assay verified this hypothesis.Conclusion: MiR-210 inhibited the expression of HOXA9 to activate the NF-κB signaling pathway and mediated the occurrence of EMT of pancreatic cancer cells induced by HIF-1α under hypoxia.

The CDR1as/miR-7/TGFBR2 Axis Modulates EMT in Silica-Induced Pulmonary Fibrosis

Silicosis is one of the typical forms of pneumoconiosis characterized by abnormal proliferation of fibroblasts and deposition of extracellular matrix. Recent findings have shown that microRNAs and circular RNAs (circRNAs) are implicated in many diseases. However, the function of noncoding RNAs in pulmonary fibrosis remain to be elucidated. Here, miR-7 was found significantly decreased in silica-treated pulmonary epithelial cells as well as in fibrotic lung tissues of mice. Elevated expression of miR-7 via agomir injection relieved lung fibrosis in vivo. Further molecular study showed that miR-7 played its role against pulmonary fibrosis by blocking epithelial-mesenchymal transition (EMT) progression of human bronchial epithelial cells and A549 cells. Notably, transforming growth factor beta receptor 2 (TGFBR2) was identified as a target gene of miR-7 with bioinformatics tools, which was verified by dual luciferase receptor gene assay in human bronchial epithelial cells and A549 cells. Silica induced elevation of TGFBR2 could be abolished by exogenous expression of miR-7. Furthermore, bioinformatics software indicated that circRNA CDR1as had several binding sites for miR-7. The inhibitory effects of miR-7 on EMT and its target TGFBR2 were suppressed by circRNA CDR1as, which contributed to pulmonary fibrosis. Our studies also revealed overexpressed miR-7 could repress fibrogenesis of lung fibroblasts induced by TGF-β1. Collectively, circRNA CDR1as stimulated by silica could sponge miR-7 to release TGFBR2, plays an important role during pulmonary fibrosis by promoting EMT process. These results indicated that the interaction between miR-7 and circRNA CDR1as may exert important functions and provide potential therapeutic targets in lung fibrotic diseases.

Emerging insights into the biology of metastasis: A review article

Metastasis means the dissemination of the cancer cells from one organ to another which is not directly connected to the primary site. Metastasis has a crucial role in the prognosis of cancer patients. A few theories, different types of cell and several molecular pathways have been proposed to explain the mechanism of metastasis. In this work, the related articles in the limited period of time, 2000-mid -2018 were reviewed, through search in PubMed, Google Scholar and Scopus database. The articles published in the last two decades related to the biology of cancer metastasis were selected and the most important factors were discussed. Metastasis is critical factor to predict survival in patients with advanced cancer and prognosis determines the treatment plan. Many different cell types and various signaling pathways control the metastatic process. Metastasis is a multistep process. Many signaling pathways and molecules are involved in metastasis. Increasing knowledge about the mechanism of metastasis can help in finding the promising targets of cancer therapy.

Low RUNX3 expression alters dendritic cell function in patients with systemic sclerosis and contributes to enhanced fibrosis

Objectives

Systemic sclerosis (SSc) is an autoimmune disease with unknown pathogenesis manifested by inflammation, vasculopathy and fibrosis in skin and internal organs. Type I interferon signature found in SSc propelled us to study plasmacytoid dendritic cells (pDCs) in this disease. We aimed to identify candidate pathways underlying pDC aberrancies in SSc and to validate its function on pDC biology.

Methods

In total, 1193 patients with SSc were compared with 1387 healthy donors and 8 patients with localised scleroderma. PCR-based transcription factor profiling and methylation status analyses, single nucleotide polymorphism genotyping by sequencing and flow cytometry analysis were performed in pDCs isolated from the circulation of healthy controls or patients with SSc. pDCs were also cultured under hypoxia, inhibitors of methylation and hypoxia-inducible factors and runt-related transcription factor 3 (RUNX3) levels were determined. To study Runx3 function, Itgax-Cre:Runx3f/f mice were used in in vitro functional assay and bleomycin-induced SSc skin inflammation and fibrosis model.

Results

Here, we show downregulation of transcription factor RUNX3 in SSc pDCs. A higher methylation status of the RUNX3 gene, which is associated with polymorphism rs6672420, correlates with lower RUNX3 expression and SSc susceptibility. Hypoxia is another factor that decreases RUNX3 level in pDC. Mouse pDCs deficient of Runx3 show enhanced maturation markers on CpG stimulation. In vivo, deletion of Runx3 in dendritic cell leads to spontaneous induction of skin fibrosis in untreated mice and increased severity of bleomycin-induced skin fibrosis.

Conclusions

We show at least two pathways potentially causing low RUNX3 level in SSc pDCs, and we demonstrate the detrimental effect of loss of Runx3 in SSc model further underscoring the role of pDCs in this disease.

A-kinase-interacting protein 1 facilitates growth and metastasis of gastric cancer cells via Slug-induced epithelial-mesenchymal transition

A‐kinase‐interacting protein 1 (AKIP1) has previously been reported to act as a potential oncogenic protein in various cancers. The clinical significance and biological role of AKIP1 in gastric cancer (GC) is, however, still elusive. Herein, this study aimed to investigate the functional and molecular mechanism by which AKIP1 influences GC. AKIP1 mRNA and protein expressions in GC tissues were examined by quantitative real‐time PCR (qRT‐PCR), Western blot and immunohistochemistry. Other methods including stably transfected against AKIP1 into gastric cancer cells, wound healing, transwell assays, CCK‐8, colony formation, qRT‐PCR and Western blot in vitro and tumorigenesis in vivo were also performed. The up‐regulated expression of AKIP1 in GC specimens significantly correlated with clinical metastasis and poor prognosis in patients with GC. AKIP1 knockdown markedly suppressed GC cells proliferation, invasion and metastasis both in vitro and in vivo. In contrast, AKIP1 overexpression resulted in the opposite effects. Moreover, mechanistic analyses indicated that Slug‐induced epithelial‐mesenchymal transition (EMT) might be responsible for AKIP1‐influenced GC cells behaviour. Our findings demonstrated that high AKIP1 expression significantly correlated with clinical metastasis and unfavourable prognosis in patients with GC. Additionally, AKIP1 promoted GC cells proliferation, migration and invasion by activating Slug‐induced EMT.

Protective Effect of Anthocyanin on Paraquat-Induced Apoptosis and Epithelial-Mesenchymal Transition in Alveolar Type II Cells

BACKGROUND Paraquat (PQ) can over-accumulate in alveolar epithelial cells. Anthocyanin (An) can exert anti-oxidative properties. The role of An in PQ-induced toxicity is unclear, so we aimed to explore whether An could inhibit epithelial mesenchymal transition (EMT) induced by PQ in alveolar cells. MATERIAL AND METHODS lveolar epithelial cells were treated with PQ and An with concentration gradient for 12, 24, and 48 h. The cell viability, ROS level, and apoptosis rate were determined using the Cell Counting Kit-8 (CCK-8) and flow cytometry, respectively. The lactate dehydrogenase (LDH) leakage, methane dicarboxylic aldehyde (MDA) level, glutathione peroxidase (GPx), and superoxide dismutase (SOD) activities were determined by spectrophotometric method. The mRNA and protein expressions were detected using quantitative real-time PCR (qPCR) and Western blot, respectively. RESULTS An reduced the PQ-induced apoptosis in a dose-dependent manner. Moreover, An reduced the ratio of Bax/Bcl-2 to ROS level. We found that An suppressed the activity of LDH and MDA and improved SOD and GPX levels. Additionally, the level of PQ-induced E-cadherin was decreased by An while the expressions of vimentin, α-smooth muscle actin (α-SMA), and collagens type I (col-I) were increased. Furthermore, An inhibited the levels of transforming growth factor β1 (TGF-β1) and activin receptor-like kinase 5 (ALK5) and reduced the phosphorylation of smad2. CONCLUSIONS Our study shows newly discovered effects of anthocyanidins on EMT and supports their chemopreventive effects in paraquat-induced apoptosis in alveolar type II cells.

Atorvastatin attenuates paraquat poisoning-induced epithelial-mesenchymal transition via downregulating hypoxia-inducible factor-1 alpha

AIM

This study investigated the effects of atorvastatin (ATS) on the paraquat (PQ)-induced epithelial-mesenchymal transition (EMT) and the potential mechanism through hypoxia-inducible factor-1 alpha (HIF-1α).

MAIN METHODS

Sprague-Dawley (SD) rats were randomly divided into a control group (n = 5), PQ group (n = 20), PQ + ATS L group (n = 20, ATS 20 mg/kg daily) and PQ + ATS H group (n = 20, ATS 40 mg/kg daily). All treated rats were given a 20% PQ solution (50 mg/kg) once by gavage and then sacrificed 12, 24, 72 and 168 h after PQ exposure. The A549 and RLE-6TN cell lines were treated with ATS, PQ or both for 24 h. Mesenchymal (α-SMA and vimentin) and epithelial (E-cadherin and ZO-1) cell marker expression was tested both in vivo and in vitro. The effects of ATS on HIF-1α and β‑catenin expression were also evaluated.

KEY FINDINGS

ATS alleviated PQ poisoning-induced lung injury and pulmonary fibrosis in vivo. This effect was dose-dependent. ATS treatment attenuated the EMT by increasing the levels of the epithelial markers E-cadherin and ZO-1 and by decreasing the expression of the mesenchymal markers α-SMA and vimentin in both lung tissues and in vitro cell culture. In addition, ATS treatment may decrease the HIF-1α and β‑catenin levels both in vivo and in vitro.

SIGNIFICANCE

In conclusion, ATS can attenuate PQ-induced pulmonary fibrosis. The mechanism may involve the downregulation of the HIF-1α/β‑catenin pathway and the inhibition of the PQ-induced EMT by ATS. ATS may be considered as a therapeutic agent for PQ poisoning-induced pulmonary fibrosis.

The correlation between Runx3 and bronchial asthma

Runx3, a member of the Runt-related transcription factor family, has attracted extensive attention due to its important role in the development of immune systems, especially in the differentiation of T cells. Accumulated evidence indicated that altered expression of Runx3 regulates a variety of target genes in different tissues/cells. Studies in animal models suggested that Runx3 may regulate the development of T cell lineage including those of innate lymphoid cells, Treg cells and dendritic cells, which may contribute to the development of hypersensitivity and asthma. Specifically, Runx3 modulates Th1/Th2 balance and hence, the production of interleukins, which induce inflammatory responses. Understanding the roles and mechanisms of Runx3 in the regulation of immune function provides a basis for the design of novel preventive and treatment models for bronchial asthma. This article reviews published data from cell lines, animal models, and patients, concerning the relationship between Runx3 expression alteration and asthma. Epigenetic regulation of Runx3 by DNA hypermethylation and microRNA, and the implication of these pathways in asthma are also discussed.

A review of current studies on cellular and molecular mechanisms underlying pulmonary fibrosis induced by chemicals

Several studies showed that the inflammatory and fibrotic responses induced by polyhexamethylene guanidine phosphate (PHMG-p) were similar to those observed for idiopathic pulmonary fibrosis in South Korea in 2011. "Omic" technologies can be used to understand the mechanisms underlying chemical-induced diseases. Studies to determine the toxicity of chemicals may facilitate understanding of the mechanisms underlying the development of pulmonary fibrosis at a molecular level; thus, such studies may provide information about the toxic characteristics of various substances. In this review, we have outlined the cellular and molecular mechanisms underlying idiopathic pulmonary fibrosis and described pulmonary fibrosis induced by various chemicals, including bleomycin, paraquat, and PHMG-p, based on the results of studies performed to date.