Gadd45a knockdown alleviates oxidative stress through suppressing the p38 MAPK signaling pathway in the pathogenesis of preeclampsia

Lactate promotes premature aging of preeclampsia placentas through histone lactylation-regulated GADD45A

BACKGROUND

Premature placental aging has been linked to preeclampsia (PE), with lactate identified as a promoter of cellular senescence in various cell types. In this study, we explored the role and underlying mechanisms of lactate in driving premature placental aging associated with PE.

METHODS

To evaluate senescence markers in placental samples or trophoblast cells, we conducted SA-β-Gal staining, western blotting, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and immunofluorescence assays. SiRNA transfection was used to reduce GADD45A expression in HTR-8/SVneo cells exposed to lactate. Additionally, chromatin immunoprecipitation-qPCR (ChIP-qPCR) was used to analyze histone lactylation at the GADD45A promoter region.

RESULTS

SA-β-Gal staining indicated a significant increase in senescent cell proportions in placentas from PE patients compared to controls. Treatment with lactate enhanced senescence in trophoblast cells, leading to an increase in P16 expression. RNA sequencing analysis showed that genes differentially expressed in lactate-treated cells were involved in pathways linked to cellular senescence. Additionally, lactate augmented GADD45A expression and increased histone lactylation at its promoter region, while knocking down GADD45A in trophoblast cells mitigated the senescence induced by lactate.

CONCLUSIONS

Lactate promotes trophoblast senescence through epigenetic upregulation of GADD45A expression, offering fresh perspectives on the molecular mechanisms and potential treatment targets for PE.

Bioinformatics-based Analysis and Verification of Chromatin Regulators and the Mechanism of Immune Infiltration Associated with Myocardial Infarction

BACKGROUND

Recent studies have shown that dysfunction in chromatin regulators (CRs) may be an important mechanism of myocardial infarction (MI). They are thus expected to become a new target in the diagnosis and treatment of MI. However, the diagnostic value of CRs in MI and the mechanisms are not clear.

METHODS

CRs-related differentially expressed genes (DEGs) were screened between healthy controls and patients with MI via GSE48060, GSE60993, and GSE66360 datasets. DEGs were further analyzed for enrichment analysis. Hub genes were screened by least absolute shrinkage and selection operator (LASSO) regression and weighted gene co-expression network analysis (WGCNA). GSE61144 datasets were further used to validate hub genes. RT-qPCR examined peripheral blood mononuclear cells (PBMCs) to verify expressions of hub genes. In addition, a correlation between hub genes and immune cell infiltration was identified by CIBERSORT and single-sample gene set enrichment analysis (ssGSEA). Finally, we constructed a diagnostic nomogram and ceRNA network and found possible therapeutic medicines which were based on hub genes.

RESULTS

Firstly, 16 CR-related DEGs were identified. Next, Dual-specificity phosphatase 1 (DUSP1), growth arrest and DNA damage-inducible 45 (GADD45A), and transcriptional regulator Jun dimerization protein 2 (JDP2) were selected as hub genes by LASSO and WGCNA. Receiver operating characteristic curves in the training and test data sets verified the reliability of hub genes. Results of RT-qPCR confirmed the upregulation of hub genes in MI. Subsequently, the immune infiltration analysis indicated that DUSP1, GADD45A, and JDP2 were correlated with plasmacytoid dendritic cells, natural killer cells, eosinophils, effector memory CD4 T cells, central memory CD4 T cells, activated dendritic cells, and activated CD8 T cells. Furthermore, a nomogram that included DUSP1, GADD45A, and JDP2 was created. The calibration curve, decision curve analysis, and the clinical impact curve indicated that the nomogram could predict the occurrence of MI with high efficacy. The results of the ceRNA network suggest that hub genes may be cross-regulated by various lncRNAs and miRNAs. In addition, 10 drugs, including 2H-1-benzopyran, Nifuroxazide, and Bepridil, were predicted to be potential therapeutic agents for MI.

CONCLUSION

Our study identifies three promising genes associated with the progression of chromatin regulators (CRs)-related myocardial infarction (MI) and immune cell infiltration, including Dual-specificity phosphatase 1 (DUSP1), growth arrest and DNA damage-inducible 45 (GADD45A), and Jun dimerization protein 2 (JDP2), which might be worthy of further study.

Comprehensive lung microbial gene and genome catalogs assist the mechanism survey of Mesomycoplasma hyopneumoniae strains causing pig lung lesions

Understanding the community structure of the lower respiratory tract microbiome is crucial for elucidating its roles in respiratory tract diseases. However, there are few studies about this topic due to the difficulty in obtaining microbial samples from both healthy and disease individuals. Here, using 744 high-depth metagenomic sequencing data of lower respiratory tract microbial samples from 675 well-phenotyped pigs, we constructed a lung microbial gene catalog containing the largest scale of 10,031,593 nonredundant genes to date, 44.8% of which are novel. We obtained 356 metagenome-assembled genomes (MAGs) which were further clustered into 256 species-level genome bins with 41.8% being first reported in the current databases. Based on these data sets and through integrated analysis of the isolation of the related bacterial strains, in vitro infection, and RNA sequencing, we identified and confirmed that Mesomycoplasma hyopneumoniae (M. hyopneumoniae) MAG_47 and its adhesion-related virulence factors (VFs) were associated with lung lesions in pigs. Differential expression levels of adhesion- and immunomodulation-related VFs likely determined the heterogenicity of adhesion and pathogenicity among M. hyopneumoniae strains. M. hyopneumoniae adhesion activated several pathways, including nuclear factor kappa-light-chain-enhancer of activated B, mitogen-activated protein kinase, cell apoptosis, T helper 1 and T helper 2 cell differentiation, tumor necrosis factor signaling, interleukin-6/janus kinase 2/signal transducer and activator of transcription signaling, and response to reactive oxygen species, leading to cilium loss, epithelial cell‒cell barrier disruption, and lung tissue lesions. Finally, we observed the similar phylogenetic compositions of the lung microbiome between humans with Mycoplasma pneumoniae and pigs infected with M. hyopneumoniae. The results provided important insights into pig lower respiratory tract microbiome and its relationship with lung health.

The neo-potential therapeutic strategy in preeclampsia: Downregulated miR-26a-2-3p motivates endothelial cell injury by targeting 15-LOX-1

Preeclampsia (PE) poses a life-threatening risk for both mothers and babies, and its onset and progression are linked to endothelial injury. The enzyme 15-lipoxygenase-1 (15-LOX-1), critical in arachidonic acid metabolism, is implicated in various diseases, yet its specific role and precise mechanisms in PE remain largely unknown. In this study, we found that 15-LOX-1 and its main metabolite, 15-HETE, were significantly increased in both the placenta and serum of PE patients. This increase was accompanied by elevated levels of endothelial injury markers, including intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). A positive correlation between 15-LOX-1 and those markers in the placenta. In Alox15-/- mice, Alox15 deficiency reduced endothelial cell injury in PE-like mice induced by L-NAME. In vitro studies showed that hypoxia-induced upregulation of 15-LOX-1 reduced the cell viability, migration, and angiogenesis of human umbilical vein endothelial cells (HUVECs), while increasing apoptosis and inflammatory cell adhesion. Mechanistically, the p38 MAPK pathway was identified as a downstream target of 15-LOX-1. Knocking down 15-LOX-1 or inhibiting p38 MAPK activation improved endothelial cell injury in hypoxia-treated HUVECs. Furthermore, downregulation of miR-26a-2-3p was found to correlate negatively and colocalize with 15-LOX-1 upregulation in the placenta of PE patients. Luciferase reporter assays further confirmed that miR-26a-2-3p directly bind to the 3'UTR of 15-LOX-1, targeting its expression. Moreover, miR-26a-2-3p agomir ameliorated the PE-like phenotype in mice through the 15-LOX-1/p38 MAPK axis, improving endothelial dysfunction. Therefore, our study provides novel insights into the pathogenesis of PE and highlight modulating the miR-26a-2-3p/15-LOX-1/p38 MAPK axis as a potential therapeutic target for PE.

GADD45A: With or without you

The growth arrest and DNA damage inducible (GADD)45 family includes three small and ubiquitously distributed proteins (GADD45A, GADD45B, and GADD45G) that regulate numerous cellular processes associated with stress signaling and injury response. Here, we provide a comprehensive review of the current literature investigating GADD45A, the first discovered member of the family. We first depict how its levels are regulated by a myriad of genotoxic and non-genotoxic stressors, and through the combined action of intricate transcriptional, posttranscriptional, and even, posttranslational mechanisms. GADD45A is a recognized tumor suppressor and, for this reason, we next summarize its role in cancer, as well as the different mechanisms by which it regulates cell cycle, DNA repair, and apoptosis. Beyond these most well-known actions, GADD45A may also influence catabolic and anabolic pathways in the liver, adipose tissue and skeletal muscle, among others. Not surprisingly, GADD45A may trigger AMP-activated protein kinase activity, a master regulator of metabolism, and is known to act as a transcriptional coregulator of numerous nuclear receptors. GADD45A has also been reported to display a cytoprotective role by regulating inflammation, fibrosis and oxidative stress in several organs and tissues, and is regarded an important contributor for the development of heart failure. Overall data point to that GADD45A may play an important role in metabolic, neurodegenerative and cardiovascular diseases, and also autoimmune-related disorders. Thus, the potential mechanisms by which dysregulation of GADD45A activity may contribute to the progression of these diseases are also reviewed below.

Tanshinol inhibits trophoblast cell migration and invasion by regulating Gadd45a in preeclampsia

OBJECTIVE

Tanshinol is an active constituent of Salvia miltiorrhiza that possesses anti-inflammatory, antioxidant, and antibacterial activities. Therefore, this study attempted to detect whether it has a role in the treatment of preeclampsia (PE).

METHODS

In this study, we explored the effect of tanshinol on the development of PE at the cellular level. The effect of tanshinol on cell proliferation was measured by colony formation and EdU assays. The migration, invasion, and in vitro angiogenesis of HTR-8/SVneo cells were detected by wound-healing, transwell, and tube formation assays, respectively. In addition, a PE cell model was established by overexpression of Gadd45a, and this cell model was assessed with the optimal concentration of tanshinol.

RESULTS

The results show that tanshinol enhanced proliferation, migration, invasion, and tube formation of HTR-8/SVneo cells in vitro. Furthermore, the reduction in proliferation, migration, invasion, and tube formation of cells by Gadd45a overexpression was partially reversed by tanshinol treatment. Tanshinol also inhibited the apoptosis of HTR-8/SVneo cells transfected with Gadd45a.

CONCLUSIONS

In summary, tanshinol promoted proliferation, migration, invasion, and tube formation and inhibited the apoptosis of HTR-8/SVneo cells. It may be a novel therapeutic compound to attenuate the development of PE.

Circ_0004904 suppresses trophoblast cell proliferation, invasion and migration in preeclampsia via upregulating the expression of DNA damage inducible alpha by interacting with miR-19a-3p

Preeclampsia (PE) is the most common complication in the pregnancy of women. PE progression was found to be associated with dysregulated circular RNAs (circRNAs), and we aimed to explore the pathological mechanism with circ_0004904 in PE. The circ_0004904, microRNA-19a-3p (miR-19a-3p) and DNA damage inducible alpha (GADD45A) were quantified via reverse transcription-quantitative polymerase chain reaction assay. Trophoblast cell behaviors were examined by cell viability using Cell Counting Kit-8 assay, cell proliferation using EdU assay, cell apoptosis using flow cytometry, cell invasion using transwell assay and migration using wound healing assay. Western blot was used for protein analysis of epithelial mesenchymal transition (EMT) and GADD45A. Dual-luciferase reporter assay and RNA immunoprecipitation assay were used for target interaction analysis. The circ_0004904 upregulation was detected in placenta tissues from PE patients. Trophoblast cell proliferation, invasion, migration and EMT were repressed but cell apoptosis was promoted after overexpression of circ_0004904. Circ_0004904 acted as a miR-19a-3p sponge in trophoblast cells, and all regulatory effects of circ_0004904 on trophoblast cell behaviors were reversed by miR-19a-3p upregulation. The miR-19a-3p directly targeted GADD45A and miR-19a-3p downregulation inhibited trophoblast cell development through elevating the GADD45A level. Moreover, circ_0004904 enhanced the expression of GADD45A via sponging miR-19a-3p. Our results elucidated that circ_0004904 reduced proliferation and cell motility of trophoblast cells via the miR-19a-3p-mediated GADD45A level elevation, indicating the involvement of circ_0004904/miR-19a-3p/GADD45A in PE progression.

Bavachin induces apoptosis in colorectal cancer cells through Gadd45a via the MAPK signaling pathway

Bavachin is a dihydroflavonoid compound isolated from Psoralea corylifolia, and exhibits anti-bacterial, anti-inflammatory, anti-tumor and lipid-lowering activities. Recent attention has gradually drawn on bavachin-induced apoptosis in many human cancer cell lines. However, the anti-cancer effects and related mechanisms in colorectal cancer remain unknown. Here, we investigated the effects of bavachin on colorectal cancer in vivo and in vitro. The results showed that bavachin inhibited the proliferation of human colorectal cancer cells and induce apoptosis. These changes were mediated by activating the MAPK signaling pathway, which significantly up-regulated the expression of Gadd45a. Furthermore, Gadd45a silencing obviously attenuated bavachin-mediated cell apoptosis. Inhibition of the MAPK signaling pathway by JNK/ERK/p38 inhibitors also weakened the up-regulation of Gadd45a by bavachin. The anticancer effect of bavachin was also validated using a mouse xenograft model of human colorectal cancer. In conclusion, these findings suggest that bavachin induces the apoptosis of colorectal cancer cells through activating the MAPK signaling pathway.

The preventive effects of aspirin on preeclampsia based on network pharmacology and bioinformatics

This study aimed to reveal the key targets and molecular mechanisms of aspirin in preventing preeclampsia. We used bioinformatics databases to collect the candidate targets for aspirin and preeclampsia. The biological functions and signaling pathways of the intersecting targets were analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Then, the hub targets were identified by cytoscape plugin cytoHubba from the protein-protein interaction network. We collected 90 targets for aspirin in preventing preeclampsia. The biological processes of the intersecting targets are mainly involved in xenobiotic metabolic process, inflammatory response, negative regulation of apoptotic process, and protein phosphorylation. The highly enriched pathways were FoxO signaling pathway, circadian rhythm, insulin resistance, arachidonic acid metabolism, and drug metabolism-cytochrome P450. The hub targets for aspirin in preventing preeclampsia were tumor protein p53 (TP53), C-X-C motif chemokine ligand 8 (CXCL8), mitogen-activated protein kinase 3 (MAPK3), mitogen-activated protein kinase 1 (MAPK1), mitogen-activated protein kinase 14 (MAPK14), epidermal growth factor receptor (EGFR), estrogen receptor (ESR1), and prostaglandin-endoperoxide synthase 2 (PTGS2). Molecular docking results showed good bindings between the proteins and aspirin. In conclusion, these findings highlight the key targets and molecular mechanisms of aspirin in preventing preeclampsia.

EZH2 enhances proliferation and migration of trophoblast cell lines by blocking GADD45A-mediated p38/MAPK signaling pathway

Impaired activity of the trophoblasts is a major contributor to the progression of pregnancy pathologies including preeclampsia (PE). This research probed the function of enhancer of zeste homolog 2 (EZH2) in activity of trophoblast cells and its correlation with growth arrest and DNA damage inducible alpha (GADD45A). EZH2 was predicted to be downregulated in placental tissues in PE according to a gene chip analysis, and reduced expression of EZH2 was detected in the placental tissues of patients with PE. Overexpression of EZH2 augmented proliferation and invasiveness of two trophoblast cell lines HTR-8/SVneo and JEG3 cells. EZH2 catalyzed trimethylation of lysine 27 on histone 3 (H3K27me3) in GADD45A promoter to suppress its transcription. GADD45A silencing increased the activity of the trophoblast cell lines and inactivated the p38/mitogen-activated protein kinase (MAPK) signaling pathway. Rescue experiments confirmed that either inhibition of GADD45A or p38 restored the proliferation, migration, and invasiveness of the trophoblast cell lines suppressed by EZH2 silencing. In conclusion, this work suggests that EZH2 enhances activity of trophoblast cell lines by suppressing GADD45A-mediated p38/MAPK signaling pathway.

Radiotherapy for the treatment of pulmonary hydatidosis in sheep

Hydatidosis is an endemic disease causing a severe threat to public health. Drugs and surgery have been utilized for treatment, but their efficiency is not adequate. Therefore, new methods are required for treating such diseases. In this study, we attempt to evaluate the efficiency of radiotherapy for hydatidosis in sheep. The sheep naturally infected with pulmonary hydatid were randomly divided into four groups, including the control group subjected to no irradiation and the other three groups subjected to 30, 45, and 60 Gy irradiation, respectively. Gene expression of caspase-3 and gadd45a and protein expression of BCL-2 and BAX in the lung tissues were evaluated after treatment. Our data showed that the irradiation with a dose of 30, 45, and 60 Gy significantly induced the expression of caspase-3 and gadd45a. Immunohistochemical staining showed that the BCL-2 protein was downregulated after exposure to 45 Gy of irradiation, whereas the BAX expression was downregulated after irradiation at a dose of 45 and 60 Gy, respectively. On this basis, we speculated that 45 Gy might be a safe and effective dose for treating pulmonary hydatidosis in sheep, which induced lower expression of caspase-3 and gadd45a in the cyst and a downregulation of BCL-2 and BAX in the adjacent lung tissues.

Glyoxal damages human aortic endothelial cells by perturbing the glutathione, mitochondrial membrane potential, and mitogen-activated protein kinase pathways

Background

Exposure to glyoxal, the smallest dialdehyde, is associated with several diseases; humans are routinely exposed to glyoxal because of its ubiquitous presence in foods and the environment. The aim of this study was to examine the damage caused by glyoxal in human aortic endothelial cells.

Methods

Cell survival assays and quantitative fluorescence assays were performed to measure DNA damage; oxidative stress was detected by colorimetric assays and quantitative fluorescence, and the mitogen-activated protein kinase pathways were assessed using western blotting.

Results

Exposure to glyoxal was found to be linked to abnormal glutathione activity, the collapse of mitochondrial membrane potential, and the activation of mitogen-activated protein kinase pathways. However, DNA damage and thioredoxin oxidation were not induced by dialdehydes.

Conclusions

Intracellular glutathione, members of the mitogen-activated protein kinase pathways, and the mitochondrial membrane potential are all critical targets of glyoxal. These findings provide novel insights into the molecular mechanisms perturbed by glyoxal, and may facilitate the development of new therapeutics and diagnostic markers for cardiovascular diseases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02418-3.

Silencing lncRNA-DGCR5 increased trophoblast cell migration, invasion and tube formation, and inhibited cell apoptosis via targeting miR-454-3p/GADD45A axis

Long noncoding RNA (lncRNA)-DGCR5 has been recognized as a potential tumor progression regulator, while its expression and specific functions in preeclampsia (PE) development remain unveiled. The expressions of miR-454-3p, lncRNA-DiGeorge syndrome critical region gene 5 (DGCR5) and growth arrest and DNA damage protein-inducible 45A (GADD45A) in placental tissues from PE patients or HTR-8/SVneo cells were assessed by Western blot or qRT-PCR. Dual-luciferase reporter assay determined the binding relations between miR-454-3p and GADD45A and between miR-454-3p and lncRNA-DGCR5. The viability, apoptosis, migration, invasiveness and tube formation of HTR-8/SVneo cell were evaluated using cell counting kit (CCK)-8, Annexin-V/Propidium iodide staining, wound healing, transwell and tube formation assays, respectively. miR-454-3p was low-expressed in PE tissue, and upregulation of miR-454-3p increased viability and promoted migration, invasion and tube formation in HTR-8/SVneo cells while inhibiting apoptosis. Then, miR-454-3p was found to directly target GADD45A which was high-expressed in PE tissues. Overexpressing GADD45A decreased the viability and inhibited the migration, invasion and tube formation of HTR-8/SVneo cells while enhancing apoptosis, and it neutralized the effect of miR-454-3p upregulation. In turn, miR-454-3p upregulation reversed the effect of GADD45A overexpression. Meanwhile, miR-454-3p could also target lncRNA-DGCR5. Silencing lncRNA-DGCR5 increased miR-454-3p expression and cell viability and promoted migration, invasion and tube formation in HTR-8/SVneo cells while inhibiting apoptosis, and it counteracted the effect of miR-454-3p downregulation. As usual, miR-454-3p downregulation reversed the effect of lncRNA-DGCR5 silencing. To conclude, silencing lncRNA-DGCR5 increased viability, promoted migration, invasion and tube formation, and inhibited apoptosis in HTR-8/SVneo cells by rescuing the inhibition of GADD45A expression caused by miR-454-3p.

Gadd45α affects retinal ganglion cell injury in chronic ocular hypertension rats by regulating p38MAPK pathway

OBJECTIVE

To investigate the impact and the mechanism of Gadd45α mediating p38MAPK pathway on the retinal ganglion cells (RGCs) injury in chronic ocular hypertension (COH) rats.

METHODS

COH model in rats were established and intraocular pressure (IOP) was tested. Retrograde labeling was used for counting RGCs and TUNEL staining was performed for RGCs apoptosis. Western Blotting was conducted to examine the expression of Gadd45α and p38MAPK pathway. Besides, RGC-5 cells cultured in vitro were treated with H₂O₂. Cell viability was detected by CCK-8, ROS level tested by DCFH-DA assay, and cell apoptosis examined by flow cytometry.

RESULTS

COH rats had increased expression of Gadd45α and p-p38/p38 protein 1-4 weeks after surgery. Rats in COH group enhanced obviously in IOP, RGC apoptosis rate and the protein expression of Gadd45α, p-p38/p38, Bax/Bcl-2 and cleaved caspase-3, but declined appreciably in RGC counting. However, the above indicators of COH rats were effectively improved by Gadd45α shRNA treatment. Additionally, RGC-5 cells in H₂O₂ group reduced in cell viability and went up in ROS level and apoptosis rate. The H₂O₂-induced RGC-5 cells treated with Gadd45α shRNA were improved apparently in those indicators, and cells treated with pcDNA Gadd45α showed an opposite trend. Moreover, p38 MAPK inhibitor SB203580 can effectively reverse the damage of pcDNA Gadd45α from H₂O₂-induced RGC-5 cells.

CONCLUSION

Silencing Gadd45α can reduce the RGC damage in COH rats by inhibiting p38MAPK pathway and such a protective role may be associated with the suppression of RGC apoptosis and the mitigation of oxidative stress.

LIMD1 Increases the Sensitivity of Lung Adenocarcinoma Cells to Cisplatin via the GADD45α/p38 MAPK Signaling Pathway

Objective: To investigate the effect of LIM domain-containing protein 1 (LIMD1) on the sensitivity of lung adenocarcinoma cells to cisplatin and explore the mechanism.

Methods: A549 and H1299 cells were transfected with lentivirus to establish LIMD1-overexpressing cell lines and their respective controls. The protein expression of DNA damage-inducible 45 alpha (GADD45α) and p38 mitogen-activated protein kinase (MAPK) was detected by Western blot. The survival of A549-vec, A549-LIMD1, H1299-vec, and H1299-LIMD1 cells after cisplatin treatment was observed by CCK-8, and the viability was calculated accordingly. Then, SB203580 was used to inhibit the activity of the p38 MAPK signaling pathway, after which the survival of A549-vec, A549-LIMD1, H1299-vec, and H1299-LIMD1 cells in response to cisplatin was observed again by CCK-8, and the viability was calculated accordingly.

Results: When LIMD1 was overexpressed in A549 and H1299 cells, the levels of GADD45α and p-p38 MAPK were increased, but total p38 MAPK expression showed no significant change. After adding 30 μM cisplatin, the optical density (OD) values of A549-LIMD1 and H1299-LIMD1 cells were significantly lower than those of their respective controls at 24, 48, and 72 h. The viability of A549-LIMD1 and H1299-LIMD1 cells was significantly lower than that of their respective controls at all the times tested (p < 0.05). The Western blot results showed that the expression of apoptotic proteins cleaved caspase 3 and cleaved PARP in cisplatin-treated A549-LIDM1 and H1299-LIMD1 cells was significantly higher than that in their respective control cells. Flow cytometry showed that the apoptosis rates of A549-LIMD1 and H1299-LIMD1 cells were significantly higher than those of their respective controls (p < 0.05). SB203580 significantly inhibited the activation of the p38 MAPK signaling pathway in lung adenocarcinoma cells; however, neither the OD values nor the viability of A549-LIMD1 cells and H1299-LIMD1 cells showed no significant difference from those of their controls at 24, 48, and 72 h after cisplatin and SB203580 treatment (p > 0.05 for both). Western blot analysis showed that after SB203580 was added, the expression of cleaved caspase 3 and cleaved PARP in A549-LIMD1 and H1299-LIMD1 cells presented no significant difference compared with that in their respective controls.

Conclusion: LIMD1 increases the sensitivity of lung adenocarcinoma cells to cisplatin by activating the GADD45α/p38 MAPK signaling pathway.

Identifying Candidate Genes for Hypoxia Adaptation of Tibet Chicken Embryos by Selection Signature Analyses and RNA Sequencing

The Tibet chicken (Gallus gallus) lives on the Qinghai-Tibet Plateau and adapts to the hypoxic environment very well. The objectives of this study was to obtain candidate genes associated with hypoxia adaptation in the Tibet chicken embryos. In the present study, we used the fixation index (Fst) and cross population extended haplotype homozygosity (XPEHH) statistical methods to detect signatures of positive selection of the Tibet chicken, and analyzed the RNA sequencing data from the embryonic liver and heart with HISAT, StringTie and Ballgown for differentially expressed genes between the Tibet chicken and White leghorn (Gallus gallus, a kind of lowland chicken) embryos hatched under hypoxia condition. Genes which were screened out by both selection signature analysis and RNA sequencing analysis could be regarded as candidate genes for hypoxia adaptation of chicken embryos. We screened out 1772 genes by XPEHH and 601 genes by Fst, and obtained 384 and 353 differentially expressed genes in embryonic liver and heart, respectively. Among these genes, 89 genes were considered as candidate genes for hypoxia adaptation in chicken embryos. ARNT, AHR, GSTK1 and FGFR1 could be considered the most important candidate genes. Our findings provide references to elucidate the molecular mechanism of hypoxia adaptation in Tibet chicken embryos.

Prdx1 Reduces Intracerebral Hemorrhage-Induced Brain Injury via Targeting Inflammation- and Apoptosis-Related mRNA Stability

RNA-binding proteins (RBPs) have been shown to be involved in posttranscriptional regulation, which plays an important role in the pathophysiology of intracerebral hemorrhage (ICH). Peroxiredoxin 1 (Prdx1), an RBP, plays an important role in regulating inflammation and apoptosis. On the basis that inflammation and apoptosis may contribute to ICH-induced brain injury, in this study, we used ICH models coupled with in vitro experiments, to investigate the role and mechanism of Prdx1 in regulating inflammation and apoptosis by acting as an RBP after ICH. We first found that Prdx1 was significantly up-regulated in response to ICH-induced brain injury and was mainly expressed in astrocytes and microglia in ICH rat brains. After overexpressing Prdx1 by injecting adeno-associated virus (AAV) into the striatum of rats at 3 weeks, we constructed ICH models and found that Prdx1 overexpression markedly reduced inflammation and apoptosis after ICH. Furthermore, RNA immunoprecipitation combined with high-throughput sequencing (RIP-seq) in vitro revealed that Prdx1 affects the stability of inflammation- and apoptosis-related mRNA, resulting in the inhibition of inflammation and apoptosis. Finally, overexpression of Prdx1 significantly alleviated the symptoms and mortality of rats subjected to ICH. Our results show that Prdx1 reduces ICH-induced brain injury by targeting inflammation- and apoptosis-related mRNA stability. Prdx1 may be an improved therapeutic target for alleviating the brain injury caused by ICH.

The regulatory network of lncRNA DLX6-AS1/miR-149-5p/ERP44 is possibly related to the progression of preeclampsia

BACKGROUND

Long noncoding RNA DLX6 antisense RNA 1 (DLX6-AS1) has been reported to be involved in various human diseases, however, its potential role in the pathogenesis of preeclampsia (PE) has not been fully explored.

METHODS

The levels of DLX6-AS1, microRNA-149-5p (miR-149-5p) and endoplasmic reticulum protein 44 (ERP44) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Some clinicopathological parameters of PE were statistically analyzed. The cell proliferation, invasion and angiogenesis were assessed by methylthiazolyldiphenyl-tetrazolium bromide (MTT), transwell and tube formation assays, respectively. Levels of all protein were detected by western blot. The target relationship was predicted by StarBase v2.0 and confirmed by dual-luciferase reporter assay.

RESULTS

Higher levels of DLX6-AS1 and ERP44, lower level of miR-149-5p were observed in PE placenta tissues. Compared with PE group with low DLX6-AS1 expression, the systolic blood pressure, diastolic blood pressure and proteinuria levels in the group with high DLX6-AS1 expression were higher, and the infant body weight level was lower. The role of miR-149-5p on these clinicopathological parameters of PE patients was opposite to that of DLX6-AS1, while ERP44 had the same effect as DLX6-AS1. Besides, DLX6-AS1 directly targeted miR-149-5p and miR-149-5p targeted ERP44. The inhibitory impact of DLX6-AS1 overexpression or ERP44 overexpression on proliferation and invasion of trophoblast cells as well as angiogenesis of HUVEC cells was reversed by up-regulating miR-149-5p. We also found that DLX6-AS1 could enhance ERP44 expression by sponging miR-149-5p.

CONCLUSION

DLX6-AS1 inhibited proliferation and invasion of trophoblast cells, and suppressed angiogenesis of HUVEC cells by miR-149-5p/ERP44 pathway.

miR-141-5p regulate ATF2 via effecting MAPK1/ERK2 signaling to promote preeclampsia

OBJECTIVE

Preeclampsia is a pregnancy-specific syndrome characterized by hypertension and proteinuria. Impaired trophoblast invasion partly modulated by abnormal MAPK1/ERK2 signaling played important roles in the pathological process of preeclampsia. The objective of this study is to investigate miR-141-5p regulate ATF2 via effecting MAPK1/ERK2 signaling to promote preeclampsia.

STUDY DESIGN

The maternal placentae and clinical data of 30 patients with preeclampsia and 30 healthy pregnant women were collected in the Second Hospital of Shanxi Medical University from July 2015 to April 2016. Transcriptional levels of miR-141-5p in placentae were monitored using quantitative real-time reverse transcription-polymerase chain reaction. The target gene of miR-141-5p was analyzed with "TargetScanHuman Release 7.2″. To evaluate the pathways of this response, MAPK1 and ERK1/2 in placentae were detected using immunohistochemistry and Western Blot. Transfection experiment was used to verify the function of miR-141-5p regulating ATF2 to effect MAPK1/ERK2 signaling in JEG-3 cells.

RESULTS

miR-141-5p was significantly down-regulated in placentae of patients with preeclampsia, in comparison to the healthy pregnant women groups. There was no difference in MAPK1 expression between placentae of patients with preeclampsia and healthy pregnant women groups. While p-MAPK1 expression was lower in preeclampsia placentae, in comparison to the healthy pregnant women groups. Moreover, inhibition and activation experiments also validate the function of miR-141-5p in effecting p-MAPK1 level in JEG-3 cells. Bioinformatic analysis identified that ATF2 was a target gene of miR-141-5p, which was one DNA-binding protein to effect phosphatase DUSP1 transcription. DUSP1 effect MAPK1/ERK2 signaling in preeclampsia.

CONCLUSION

miR-141-5p up-regulated transcription factor ATF2 to promote phosphatase DUSP1 expression. DUSP1 expression reduces p-MAPK1 and ERK1/2 expression to promote preeclampsia.

Investigation of optimal pathways for preeclampsia using network-based guilt by association algorithm

This study investigated optimal pathways for preeclampsia (PE) utilizing the network-based guilt by association (GBA) algorithm. The inference method consisted of four steps: preparing differentially expressed genes (DEGs) between PE patients and normal controls from gene expression data; constructing co-expression network (CEN) for DEGs utilizing Spearman's correlation coefficient (SCC) method; and predicting optimal pathways by network-based GBA algorithm of which the area under the receiver operating characteristics curve (AUROC) was gained for each pathway. There were 351 DEGs and 61,425 edges in the CEN for PE. Subsequently, 53 pathways were obtained with a good classification performance (AUROC >0.5). AUROC for 9 was >0.9 and defined as optimal pathways, especially microRNAs in cancer (AUROC=0.9966), gap junction (AUROC=0.9922), and pathogenic Escherichia coli infection (AUROC=0.9888). Nine optimal pathways were identified through comprehensive analysis of data from PE patients, which might shed new light on uncovering molecular and pathological mechanism of PE.