WRKY transcription factors and OBERON histone-binding proteins form complexes to balance plant growth and stress tolerance.

WRKY transcription factors in plants are known to be able to mediate either transcriptional activation or repression, but the mechanism regulating their transcriptional activity is largely unclear. We found that group IId WRKY transcription factors interact with OBERON (OBE) proteins, forming redundant WRKY-OBE complexes in Arabidopsis thaliana. The coiled-coil domain of WRKY transcription factors binds to OBE proteins and is responsible for target gene selection and transcriptional repression. The PHD finger of OBE proteins binds to both histones and WRKY transcription factors. WRKY-OBE complexes repress the transcription of numerous stress-responsive genes and are required for maintaining normal plant growth. Several WRKY and OBE mutants show reduced plant size and increased drought tolerance, accompanied by increased expression of stress-responsive genes. Moreover, expression levels of most of these WRKY and OBE genes are reduced in response to drought stress, revealing a previously uncharacterized regulatory mechanism of the drought stress response. These results suggest that WRKY-OBE complexes repress transcription of stress-responsive genes, and thereby balance plant growth and stress tolerance.

BCAR4 facilitates trastuzumab resistance and EMT in breast cancer via sponging miR-665 and interacting with YAP1.

Breast cancer antiestrogen resistance 4 (BCAR4) has been suggested that can modulate cell behavior, resulting in tumorigenesis and chemoresistance. However, the underlying mechanisms of BCAR4 in trastuzumab resistance (TR) is still elusive. Here, we explored the function and the underlying mechanism of BCAR4 involving in TR. We found that BCAR4 is significantly upregulated in trastuzumab-resistant BC cells. Knockdown of BCAR4 could sensitize the BC cells to trastuzumab and suppress epithelial-mesenchymal transition (EMT). Mechanically, BCAR4 promotes yes-associated protein 1 (YAP1) expression by competitively sponging miR-665, to activated TGF-ß signaling. Reciprocally, YAP1 could occupy the BCAR4 promoter to enhance its transcription, suggesting that there exists a positive feedback regulation between YAP1 and BCAR4. Targeting the BCAR4/miR-665/YAP1 axis may provide a novel insight of therapeutic approaches for TR in BC.

LC-MS/MS platform-based serum untargeted screening reveals the diagnostic biomarker panel and molecular mechanism of breast cancer.

BACKGROUND: Breast cancer (BC), the most common form of malignant cancer affecting women worldwide, was characterized by heterogeneous metabolic disorder and lack of effective biomarkers for diagnosis. The purpose of this study is to search for reliable metabolite biomarkers of BC as well as triple-negative breast cancer (TNBC) using serum metabolomics approach. METHODS: In this study, an untargeted metabolomics technique based on ultra-high performance liquid chromatography combined with mass spectrometry (UHPLC-MS) was utilized to investigate the differences in serum metabolic profile between the BC group (n = 53) and non-BC group (n = 57), as well as between TNBC patients (n = 23) and non-TNBC subjects (n = 30). The multivariate data analysis, determination of the fold change and the Mann-Whitney U test were used to screen out the differential metabolites. Additionally, machine learning methods including receiver operating curve analysis and logistic regression analysis were conducted to establish diagnostic biomarker panels. RESULTS: There were 36 metabolites found to be significantly different between BC and non-BC groups, and 12 metabolites discovered to be significantly different between TNBC and non-TNBC patients. Results also showed that four metabolites, including N-acetyl-D-tryptophan, 2-arachidonoylglycerol, pipecolic acid and oxoglutaric acid, were considered as vital biomarkers for the diagnosis of BC and non-BC with an area under the curve (AUC) of 0.995. Another two-metabolite panel of N-acetyl-D-tryptophan and 2-arachidonoylglycerol was discovered to discriminate TNBC from non-TNBC and produced an AUC of 0.965. CONCLUSION: This study demonstrated that serum metabolomics can be used to identify BC specifically and identified promising serum metabolic markers for TNBC diagnosis.

Single-cell sequencing reveals the impact of endothelial cell PIEZO1 expression on thoracic aortic aneurysm.

INTRODUCTION: Thoracic aortic aneurysm (TAA) is a severe vascular disease that threatens human life, characterized by focal dilatation of the entire aortic wall, with a diameter 1.5 times larger than normal. PIEZO1, a mechanosensitive cationic channel, monitors mechanical stimulations in the environment, transduces mechanical signals into electrical signals, and converts them into biological signals to activate intracellular signaling pathways. However, the role of PIEZO1 in TAA is still unclear. METHODS: We analyzed a single-cell database to investigate the expression level of PIEZO1 in TAA. We constructed a conditional knockout mouse model of Piezo1 and used the PIEZO1 agonist Yoda1 to intervene in the TAA model mice established by co-administration of BAPN and ANG-II. Finally, we explored the effect of Yoda1 on TAA in vitro. RESULTS AND DISCUSSION: We observed decreased PIEZO1 expression in TAA at both RNA and protein levels. Single-cell sequencing identified a specific reduction in Piezo1 expression in endothelial cells. Administration of PIEZO1 agonist Yoda1 prevented the formation of TAA. In PIEZO1 endothelial cell conditional knockout mice, Yoda1 inhibited TAA formation by interfering with PIEZO1. In vivo and in vitro experiments demonstrated that the effect of Yoda1 on endothelial cells involved macrophage infiltration, extracellular matrix degradation, and neovascularization. This study highlights the role of PIEZO1 in TAA and its potential as a therapeutic target, providing opportunities for clinical translation.

DACH1 Attenuates Airway Inflammation in Chronic Obstructive Pulmonary Disease by Activating NRF2 Signaling.

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease of the airways characterized by impaired lung function induced by cigarette smoke (CS). Reduced DACH1 (dachshund homolog 1) expression has a detrimental role in numerous disorders, but its role in COPD remains understudied. This study aimed to elucidate the role and underlying mechanism of DACH1 in airway inflammation in COPD by measuring DACH1 expression in lung tissues of patients with COPD. Airway epithelium-specific DACH1-knockdown mice and adenoassociated virus-transfected DACH1-overexpressing mice were used to investigate the role of DACH1 and the potential for therapeutic targeting in experimental COPD caused by CS. Furthermore, we discovered a potential mechanism of DACH1 in inflammation induced by CS extract stimulation in vitro. Compared with nonsmokers and smokers without COPD, patients with COPD had reduced DACH1 expression, especially in the airway epithelium. Airway epithelium-specific DACH1 knockdown aggravated airway inflammation and lung function decline caused by CS in mice, whereas DACH1 overexpression protected mice from airway inflammation and lung function decline. DACH1 knockdown and overexpression promoted and inhibited IL-6 and IL-8 secretion, respectively, in 16HBE human bronchial epidermal cells after CS extract stimulation. NRF2 (nuclear factor erythroid 2-related factor 2) was discovered to be a novel downstream target of DACH1, which binds directly to its promoter. By activating NRF2 signaling, DACH1 induction reduced inflammation. DACH1 levels are lower in smokers and nonsmoking patients with COPD than in nonsmokers. DACH1 has protective effects against inflammation induced by CS by activating the NRF2 signaling pathway. Targeting DACH1 is a potentially viable therapeutic approach for COPD treatment.

Juvenile hormone signal transducer hairy inhibits Krüppel homolog1 expression.

Hairy and Krüppel homolog 1 (Kr-h1) are transcriptional repressors that act synergistically to mediate the gene-repressive action of juvenile hormone (JH). However, whether a regulatory relationship exists between Hairy and Kr-h1 remains unclear. In this study, an inhibitory effect of Hairy on Kr-h1 expression was found. Genetic studies in Drosophila have shown that the simultaneous overexpression of Hairy and Kr-h1 can rescue the defective phenotypes caused by the overexpression of a single factor. Reduced expression of Kr-h1 was observed in Hairy-overexpressing flies and cells, whereas the expression levels of Hairy were unaffected in cells with ectopic expression of Kr-h1. The inhibitory effect of Hairy on Kr-h1 expression was found to occur at the transcriptional level, as Hairy bound directly to the B-box within the Kr-h1 promoter via the bHLH motif and recruited the corepressors C-terminal binding protein (CtBP) and Groucho (Gro) through the PLSLV and WRPW motifs, respectively. Our findings revealed a regulatory relationship between two JH response factors, which advances our understanding of the molecular mechanism of JH signaling.

Transcriptome analysis of the transition from primary to secondary growth of vertical stem in Eucalyptus grandis.

Eucalyptus was one of the most cultivated hardwood species worldwide, with rapid growth, good wood properties and a wide range of adaptability. Eucalyptus stem undergoes primary growth (longitudinal growth) followed by secondary growth (radial growth), which produces biomass that is an important source of energy worldwide. In order to better understand the genetic regulation of secondary growth in Eucalyptus grandis, Transcriptome analyses in stem segments along a developmental gradient from the third internode to the eleventh internode of E. grandis that spanned primary to secondary growth were carried out. 5,149 genes that were differentially expressed during stem development were identified. Combining the trend analysis by the Mfuzz method and the module-trait correlation analysis by the Weighted Gene Co-expression Network Analysis method, a total of 70 differentially expressed genes (DEGs) selected from 868 DEGs with high connectivity were found to be closely correlated with secondary growth. Results revealed that the differential expression of these DEGs suggests that they may involve in the primary growth or secondary growth. AP1, YAB2 TFs and EXP genes are highly expressed in the IN3, whereas NAC, MYB TFs are likely to be important for secondary growth. These results will expand our understanding of the complex molecular and cellular events of secondary growth and provide a foundation for future studies on wood formation in Eucalyptus.

Juvenile hormone inhibits adult cuticle formation in Drosophila melanogaster through Kr-h1/Dnmt2-mediated DNA methylation of Acp65A promoter.

Differentiation of imaginal epidermal cells of Drosophila melanogaster to form adult cuticles occurs at approximately 40-93 h after puparium formation. Juvenile hormone (JH) given at pupariation results in formation of a second pupal cuticle in the abdomen instead of the adult cuticle. Although the adult cuticle gene Acp65A has been reported to be down-regulated following JH treatment, the regulatory mechanism remains unclear. Here, we found that the JH primary response gene Krüppel homologue 1 (Kr-h1) plays a vital role in the repression of adult cuticle formation through the mediation of JH action. Overexpression of Kr-h1 mimicked-while knocking down of Kr-h1 attenuated-the inhibitory action of JH on the formation of the adult abdominal cuticle. Further, we found that Kr-h1 inhibited the transcription of Acp65A by directly binding to the consensus Kr-h1 binding site (KBS) within the Acp65A promoter region. Moreover, the DNA methyltransferase Dnmt2 was shown to interact with Kr-h1, combined with the KBS to promote the DNA methylation of sequences around the KBS, in turn inhibiting the transcription of Acp65A. This study advances our understanding of the molecular basis of the "status quo" action of JH on the Drosophila adult metamorphosis.

Blood glucose and lipids are associated with sarcoidosis: findings from observational and mendelian randomization studies.

BACKGROUND: Several researches have demonstrated that patients with sarcoidosis accompanied with the abnormality in blood glucose and/or lipids, however, the causal relationship between them remains uncertain. To elucidate the potential association and causality of blood glucose and lipids with sarcoidosis, we conducted a propensity score matching (PSM)-based observational study combined with mendelian randomization (MR) analysis. METHODS: All subjects in this study were retrospectively collected from Tongji Hospital during 2010 and 2023. 1:1 PSM was employed to control the potential confounders as appropriate. Univariable and multivariable logistic regression analyses were performed to estimate the associations of sarcoidosis with fasting glucose, high density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC), total cholesterol (TC), and total triglyceride (TG). The further subtype analysis was also conducted. Afterwards, a bidirectional MR analysis based on public data deeply explored the causality among the 5 candidate traits and sarcoidosis, for which the inverse-variance weighted (IVW) method was utilized as the main inferring approach. RESULTS: In the observational study, a total number of 756 subjects were enrolled, with 162 sarcoidosis patients and 594 non-sarcoidosis participants, while 160 pairs of subjects were matched after PSM. Multivariable logistic regression analysis indicated that HDLC (OR: 0.151; 95% CI: 0.056-0.408; P < 0.001) and TC (OR: 3.942; 95% CI: 2.644-5.877; P < 0.001) were strongly associated with sarcoidosis. Subtype analysis showed that low HDLC was independently correlated to risk of lesions in bronchus and lungs, and mediastinal lymph nodes, while high TC was to cervical lymph nodes. In MR analysis, high fasting glucose, low HDLC, and high TC were identified as the causal factors of sarcoidosis. CONCLUSION: HDLC and TC had the potential to influence the risk of sarcoidosis, which could be regarded as predictors and may provide new diagnostic and therapeutic targets for sarcoidosis.

MED1 Regulates BMP/TGF-ß in Endothelium: Implication for Pulmonary Hypertension.

BACKGROUND: Dysregulated BMP (bone morphogenetic protein) or TGF-ß (transforming growth factor beta) signaling pathways are imperative in idiopathic and familial pulmonary arterial hypertension (PAH) as well as experimental pulmonary hypertension (PH) in rodent models. MED1 (mediator complex subunit 1) is a key transcriptional co-activator and KLF4 (Krüppel-like factor 4) is a master transcription factor in endothelium. However, MED1 and KLF4 epigenetic and transcriptional regulations of the BMP/TGF-ß axes in pulmonary endothelium and their dysregulations leading to PAH remain elusive. We investigate the MED1/KLF4 co-regulation of the BMP/TGF-ß axes in endothelium by studying the epigenetic regulation of BMPR2 (BMP receptor type II), ETS-related gene (ERG), and TGFBR2 (TGF-ß receptor 2) and their involvement in the PH. METHODS: High-throughput screening involving data from RNA-seq, MED1 ChIP-seq, H3K27ac ChIP-seq, ATAC-seq, and high-throughput chromosome conformation capture together with in silico computations were used to explore the epigenetic and transcriptional regulation of BMPR2, ERG, and TGFBR2 by MED1 and KLF4. In vitro experiments with cultured pulmonary arterial endothelial cells (ECs) and bulk assays were used to validate results from these in silico analyses. Lung tissue from patients with idiopathic PAH, animals with experimental PH, and mice with endothelial ablation of MED1 (EC-MED1-/-) were used to study the PH-protective effect of MED1. RESULTS: Levels of MED1 were decreased in lung tissue or pulmonary arterial endothelial cells from idiopathic PAH patients and rodent PH models. Mechanistically, MED1 acted synergistically with KLF4 to transactivate BMPR2, ERG, and TGFBR2 via chromatin remodeling and enhancer-promoter interactions. EC-MED1-/- mice showed PH susceptibility. In contrast, MED1 overexpression mitigated the PH phenotype in rodents. CONCLUSIONS: A homeostatic regulation of BMPR2, ERG, and TGFBR2 in ECs by MED1 synergistic with KLF4 is essential for the normal function of the pulmonary endothelium. Dysregulation of MED1 and the resulting impairment of the BMP/TGF-ß signaling is implicated in the disease progression of PAH in humans and PH in rodent models.

Cut-off values of haemoglobin and clinical outcomes in incident peritoneal dialysis: the PDTAP study.

BACKGROUND: To explore the cut-off values of haemoglobin (Hb) on adverse clinical outcomes in incident peritoneal dialysis (PD) patients based on a national-level database. METHODS: The observational cohort study was from the Peritoneal Dialysis Telemedicine-assisted Platform (PDTAP) dataset. The primary outcomes were all-cause mortality, major adverse cardiovascular events (MACE) and modified MACE (MACE+). The secondary outcomes were the occurrences of hospitalization, first-episode peritonitis and permanent transfer to haemodialysis (HD). RESULTS: A total of 2591 PD patients were enrolled between June 2016 and April 2019 and followed up until December 2020. Baseline and time-averaged Hb <100 g/l were associated with all-cause mortality, MACE, MACE+ and hospitalizations. After multivariable adjustments, only time-averaged Hb <100 g/l significantly predicted a higher risk for all-cause mortality {hazard ratio [HR] 1.83 [95% confidence interval (CI) 1.19-281], P = .006}, MACE [HR 1.99 (95% CI 1.16-3.40), P = .012] and MACE+ [HR 1.77 (95% CI 1.15-2.73), P = .010] in the total cohort. No associations between Hb and hospitalizations, transfer to HD and first-episode peritonitis were observed. Among patients with Hb ≥100 g/l at baseline, younger age, female, use of iron supplementation, lower values of serum albumin and renal Kt/V independently predicted the incidence of Hb <100 g/l during the follow-up. CONCLUSION: This study provided real-world evidence on the cut-off value of Hb for predicting poorer outcomes through a nation-level prospective PD cohort.

Low-dose pegylated recombinant human granulocyte-colony stimulating factor as hematopoietic support for adjuvant chemotherapy in Chinese patients with breast cancer: An open-label, randomized, non-inferiority trial.

AIMS: The recommended dosage of pegylated recombinant human granulocyte-colony stimulating factor (PEG-rhG-CSF) for Western chemotherapy patients is 6 mg per cycle. However, for Eastern Asians, the optimal dose remains unknown. METHODS: This open-label, randomized, non-inferiority trial (NCT05283616) enrolled Chinese female breast cancer patients receiving adjuvant chemotherapy. Participants were randomized to receive either 3 or 6 mg of PEG-rhG-CSF per cycle, stratified by body weight (BW; ≤60 kg vs. >60 kg). The primary endpoint was timely absolute neutrophil count (ANC) recovery before the second cycle of chemotherapy. RESULTS: A total of 122 patients were randomized and 116 were included for efficacy analyses. The timely ANC recovery rate in the 3 mg arm was 89.8%, compared to 93.0% in the 6 mg arm (one-sided 95% confidence interval [CI] lower limit for difference: -11.7%), meeting the prespecified non-inferiority margin of 15%. The rate was 93.3% with PEG-rhG-CSF 3 mg and 96.6% with 6 mg in patients with BW ≤ 60 kg, and 86.2% and 89.3%, respectively, in those with BW > 60 kg. Although the incidence of severe neutropenia was similar across arms, the occurrence of excessively high ANC and white blood cell counts was higher in the 6 mg arm. No grade ≥3 adverse events related to PEG-rhG-CSF occurred. CONCLUSION: Three milligrams of PEG-rhG-CSF per cycle provided non-inferior neutrophil protection and attenuated neutrophil overshoot compared to 6 mg doses. This low-dose regimen could be a new supportive care option for Chinese breast cancer patients receiving anthracycline-based adjuvant chemotherapy.

Sex-specific association of serum dehydroepiandrosterone and its sulfate levels with osteoporosis in type 2 diabetes.

INTRODUCTION: This study is to investigate the relation between serum dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) levels and the risk of osteoporosis in patients with T2DM. MATERIALS AND METHODS: This cross-sectional study involved 938 hospitalized patients with T2DM. Linear regression models were used to explore the relationship between DHEA and DHEAS and the BMD at different skeletal sites. Multinominal logistic regression models and the restricted cubic spline (RCS) were used to evaluate the associations of DHEA and DHEAS with the risks of osteopenia and/or osteoporosis. RESULTS: In postmenopausal women with T2DM, after adjustment for confounders including testosterone and estradiol, DHEA showed a significant positive correlation with lumbar spine BMD (P = 0.013). Moreover, DHEAS exhibited significant positive correlations with BMD at three skeletal sites: including femoral neck, total hip, and lumbar spine (all P < 0.05). Low DHEA and DHEAS levels were associated with increased risk of osteopenia and/or osteoporosis (all P < 0.05) and the risk of osteoporosis gradually decreased with increasing DHEAS levels (P overall = 0.018, P-nonlinear = 0.559). However, DHEA and DHEAS levels in men over the age of 50 with T2DM were not associated with any of above outcomes. CONCLUSION: In patients with T2DM, independent of testosterone and estradiol, higher DHEA and DHEAS levels are associated with higher BMD and lower risk of osteopenia/osteoporosis in postmenopausal women but not men over the age of 50.

Importin 7 enhances protective autophagy induced by nuclear translocation of homeobox A10 in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is a common malignant tumor. Importin7 (IPO7) is responsible for nucleoplasmic transport of RNAs and proteins, and it has been confirmed to be involved in the development of human cancers. This study aimed to explore the function and mechanism of IPO7 in OSCC. IPO7 expression in tissues and cells was determined by RT-qPCR. Cell proliferative, migratory, and invasive capabilities were detected through transwell assay and colony formation assay. Mice xenograft models were established for evaluating tumor growth. Autophagy was estimated by the LC3 levels in cells through western blot and immunofluorescence (IF). Western blot was utilized to detect the key proteins in PERK/EIF2AK3/ATF4 pathway for assessing the endoplasmic reticulum stress (ERS). The interaction of IPO7 and homeobox A10 (HOXA10) was tested by GST pull-down assay and Co-IP assay. ChIP assay and luciferase reporter assay were utilized to determine the combination of HOXA10 and EIF2AK3. We proved that IPO7 was upregulated in OSCC tissues and cells, and its depletion reduced cell proliferation, migration, invasion and tumor growth. Furthermore, LC3 expression in cells was found to be reduced by IPO7 knockdown. IPO7 promoted OSCC tumor metastasis by activating autophagy. Additionally, we discovered that IPO7 could regulate ERS by activating the PERK/ATF4 pathway. EIF2AK3 upregulation can promote cell autophagy. Furthermore, IPO7 was proven to promote nuclear translocation of HOXA10 in cells. EIF2AK3 promoter can bind to HOXA10. Rescue assay confirmed that HOXA10 upregulation can reverse the effect of IPO7 silencing on OSCC progression. IPO7 can enhance proliferation, migration, invasion, and autophagy by nuclear translocation of HOXA10 and the activation of EIF2AK3/ATF4 pathway in OSCC.

Zonation of bulk and rhizosphere soil bacterial communities and their covariation patterns along the elevation gradient in riparian zones of three Gorges reservoir, China.

Zonation is a typical pattern of soil distribution and species assembly across riparian habitats. Microorganisms are essential members of riparian ecosystems and whether soil microbial communities demonstrate similar zonation patterns and how bulk and rhizosphere soil microorganisms interact along the elevation (submergence stress) gradient remain largely unknown. In this study, bulk and rhizosphere (dominant plant) soil samples were collected and investigated across riparian zones where the submergence stress intensity increased as the elevation decreased. Results showed that the richness of bacterial communities in bulk and rhizosphere soil samples was significantly different and presented a zonation pattern along with the submergence stress gradient. Bulk soil at medium elevation that underwent moderate submergence stress had the most abundant bacterial communities, while the species richness of rhizobacteria at low elevation that experienced serious submergence stress was the highest. Additionally, principal coordinate analysis (PCoA) and significance tests showed that bulk and rhizosphere soil samples were distinguished according to the structure of bacterial communities, and so were bulk or rhizosphere soil samples from different elevations. Redundancy analysis (RDA) and Mantel test suggested that bacterial communities of bulk soil mainly relied on the contents of soil organic matter, total carbon (TC), total nitrogen (TN), sodium (Na), calcium (Ca) and magnesium (Mg). Contrastingly, the contents of Na and Mg were the main factors explaining the variation in rhizobacterial community composition. Correlation and microbial source tracking analyses showed thatthe relationship of bulk and rhizosphere soil bacteria became much stronger, and the rhizosphere soil may get more bacterial communities from bulk soil with the increase in submergence severity. Our results suggest that the abiotic and biotic components of the riparian ecosystem are closely covariant along the submergence stress gradient and imply that the bacterial community may be a key node linking soil physiochemical properties and vegetation communities.

Dynamics of Lotka-Volterra Competition Patch Models in Streams with Two Branches.

Streams may have many branches and form complex river networks. We investigate two competition patch models associated with two different river network modules, where one is a distributary stream with two branches at the downstream end, and the other is a tributary stream with two branches at the upstream end. Treating one species as resident species and the other one as mutant species, it is shown that, for each model, there exists a invasion curve such that the mutant species can invade when rare if and only if its dispersal strategy is below this curve, but the shapes of the invasion curves are different. Moreover, we show that the global dynamics of the two models can be similar or different depending on river networks. Especially, if the drift rates of the two species are equal, then the global dynamics are similar for small drift rate and different for large drift rate. Our results also confirm a conjecture in Jiang et al. (Bull Math Biol 82:131, 2020).

DUSP1 interacts with and dephosphorylates VCP to improve mitochondrial quality control against endotoxemia-induced myocardial dysfunction.

Dual specificity phosphatase 1 (DUSP1) and valosin-containing protein (VCP) have both been reported to regulate mitochondrial homeostasis. However, their impact on mitochondrial quality control (MQC) and myocardial function during LPS-induced endotoxemia remains unclear. We addressed this issue by modeling LPS-induced endotoxemia in DUSP1 transgenic (DUSP1TG) mice and in cultured DUSP1-overexpressing HL-1 cardiomyocytes. Accompanying characteristic structural and functional deficits, cardiac DUSP1 expression was significantly downregulated following endotoxemia induction in wild type mice. In contrast, markedly reduced myocardial inflammation, cardiomyocyte apoptosis, cardiac structural disorder, cardiac injury marker levels, and normalized systolic/diastolic function were observed in DUSP1TG mice. Furthermore, DUSP1 overexpression in HL-1 cells significantly attenuated LPS-mediated mitochondrial dysfunction by preserving MQC, as indicated by normalized mitochondrial dynamics, improved mitophagy, enhanced biogenesis, and attenuated mitochondrial unfolded protein response. Molecular assays showed that VCP was a substrate of DUSP1 and the interaction between DUSP1 and VCP primarily occurred on the mitochondria. Mechanistically, DUSP1 phosphatase domain promoted the physiological DUSP1/VCP interaction which prevented LPS-mediated VCP Ser784 phosphorylation. Accordingly, transfection with a phosphomimetic VCP mutant abolished the protective actions of DUSP1 on MQC and aggravated inflammation, apoptosis, and contractility/relaxation capacity in HL-1 cardiomyocytes. These findings support the involvement of the novel DUSP1/VCP/MQC pathway in the pathogenesis of endotoxemia-caused myocardial dysfunction.

Characterization of an autonomous pathway complex that promotes flowering in Arabidopsis.

Although previous studies have identified several autonomous pathway components that are required for the promotion of flowering, little is known about how these components cooperate. Here, we identified an autonomous pathway complex (AuPC) containing both known components (FLD, LD and SDG26) and previously unknown components (EFL2, EFL4 and APRF1). Loss-of-function mutations of all of these components result in increased FLC expression and delayed flowering. The delayed-flowering phenotype is independent of photoperiod and can be overcome by vernalization, confirming that the complex specifically functions in the autonomous pathway. Chromatin immunoprecipitation combined with sequencing indicated that, in the AuPC mutants, the histone modifications (H3Ac, H3K4me3 and H3K36me3) associated with transcriptional activation are increased, and the histone modification (H3K27me3) associated with transcriptional repression is reduced, suggesting that the AuPC suppresses FLC expression at least partially by regulating these histone modifications. Moreover, we found that the AuPC component SDG26 associates with FLC chromatin via a previously uncharacterized DNA-binding domain and regulates FLC expression and flowering time independently of its histone methyltransferase activity. Together, these results provide a framework for understanding the molecular mechanism by which the autonomous pathway regulates flowering time.

OxLDL-Stimulated Macrophages Transmit Exosomal MicroRNA-320b to Aggravate Viability, Invasion, and Phenotype Switching via Regulating PPARGC1A-Mediated MEK/ERK Pathway in Proatherogenic Vascular Smooth Muscle Cells.

Our previous study revealed oxidized-low density lipoprotein (oxLDL)-stimulated macrophages delivered exosomes to exacerbate vascular smooth muscle cell (VSMC) viability and invasion; and microRNA-320b was enriched in exosomes from oxLDL-stimulated macrophages. This study aimed to further explore molecular mechanisms of exosomal microRNA-320b from oxLDL-stimulated macrophages on cellular functions of VSMCs. Exosomes from oxLDL-stimulated macrophages with microRNA-320b mimic/inhibitor transfection were used to treat VSMCs. Next, microRNA-320b mimic/inhibitor, and microRNA-320b mimic with or without peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) overexpression vector were transfected into VSMCs. Viability, invasion, apoptosis, contractile/synthetic phenotype markers, and MEK/ERK pathway were detected in VSMCs. Exosomes from microRNA-320b mimic-treated macrophages promoted viability, invasion, and synthetic phenotype marker osteopontin, while suppressed apoptosis and contractile phenotype marker α-smooth muscle actin in VSMCs. Importantly, direct microRNA-320b mimic treatment aggravated viability, invasion, and synthetic phenotype transition in VSMCs. However, microRNA-320b inhibitor showed the opposite effects as microRNA-320b mimic. Next, luciferase reporter gene assay showed that microRNA-320b directly bound to PPARGC1A; microRNA-320b also inversely regulated PPARGC1A in VSMCs. Moreover, the effect of microRNA-320b mimic on cellular functions of VSMCs was hampered by PPARGC1A overexpression vector (all P < 0.05). Additionally, microRNA-320b activated MEK/ERKT pathway, which was also suppressed by PPARGC1A overexpression vector (all P < 0.05). OxLDL-stimulated macrophages deliver exosomal microRNA-320b to exacerbate viability, invasion, and synthetic phenotype transition in VSMCs via modulating PPARGC1A-mediated MEK/ERK pathway, thus participating in the progression of atherosclerosis.

Serum Exosomal MicroRNA-186-5p Positively Correlates with Lipid Indexes, Coronary Stenosis Degree, and Major Adverse Cardiovascular Events in Coronary Heart Disease.

Our previous study finds that exosomal microRNA (miR)-186-5p promotes viability and invasion of vascular smooth muscle cells to accelerate atherosclerosis via inactivating phosphoinositide 3 kinase/protein kinase B/mammalian target of rapamycin pathway. Subsequently, this study aimed to identify the linkage of serum exosomal miR-186-5p with clinical features and major adverse cardiovascular events (MACE) in coronary heart disease (CHD) patients. Serum exosomal miR-186-5p was quantified in 175 CHD patients and 50 healthy controls (HCs) via reverse transcription quantitative polymerase chain reaction. Our study revealed that serum exosomal miR-186-5p was enhanced in CHD patients vs. HCs (P < 0.001). In CHD patients, serum exosomal miR-186-5p was positively correlated with total cholesterol (P = 0.002) and low-density lipoprotein cholesterol (P = 0.003). Elevated serum exosomal miR-186-5p was linked with increased Gensini score (P = 0.028) and stenosis degree categorized by the Gensini score (P = 0.018). Regarding MACE, the 1-year and 2-year accumulating MACE rate was 6.6% and 15.6%, respectively. Serum exosomal miR-186-5p was elevated in CHD patients with MACE vs. those without (P = 0.042). By Kaplan-Meier curves and log-rank analyses, serum exosomal miR-186-5p > 1.000 (P = 0.404) and > 1.610 (P = 0.328) was not related to accumulating MACE. While serum exosomal miR-186-5p > 3.390 exhibited a correlative trend with increased accumulating MACE, but not achieving statistical significance (P = 0.071). The 1-year and 2-year accumulating MACE rate of patients with serum exosomal miR-186-5p > 3.390 was 11.5% and 21.5%, respectively; while the rate was 3.3% and 11.5% in patients with serum exosomal miR-186-5p ≤ 3.390, accordingly. Conclusively, serum exosomal miR-186-5p positively associates with lipid level, coronary stenosis degree, and the risk of MACE in CHD patients.