Expression Of Downstream Genes Research Articles

Molecular evidence for enhancer-promoter interactions in light responses of soybean seedlings.

Interactions of enhancers with promoters and transcription factors mediate chromatin loop formation to regulate downstream gene expression in response to environmental stimuli such as light.

Aloe-emodin alleviates doxorubicin-induced cardiotoxicity via inhibition of ferroptosis.

Aloe-emodin (AE), a novel ferroptosis inhibitor, alleviates the doxorubicin (DOX)-induced cardiotoxicity in H9c2 rat cardiomyocytes. The inhibition of ferroptosis and the protective effect against cardiotoxicity were evaluated via MTT assay in H9c2 cells. The molecular mechanism of action (MOA) of nuclear factor erythroid 2-related factor 2 (Nrf2) activation, including transactivation of multiple downstream cytoprotective genes, were further assessed by Western blot, luciferase reporter assay and qRT-PCR analyses. Fluorescent imaging was performed to detect the change of intracellular reactive oxygen species, mitochondrial membrane potential and lipid peroxidation. In addition, an infrared spectroscopy was employed to detect the AE-Fe (II) complex. AE, alleviates oxidative stress in DOX-induced H9c2 cells by activating Nrf2 and increasing the expression of Nrf2 downstream antioxidant genes, SLC7A11 and GPX4. Furthermore, AE complexes bivalent iron and regulates the intracellular iron-related genes. In conclusion, the discovery of AE as a novel ferroptosis inhibitor and its MOA provides a new perspective for further exploration of cardio-protective agents in cancer patients during chemotherapy.

Identification, expression pattern and functional characterization of IFN-γ involved in activating JAK-STAT pathway in Sebastes schlegeli.

IFN-γ (interferon gamma) is a critical cytokine in the immune system involved both directly and indirectly in antiviral activity, stimulation of bactericidal activity, antigen presentation and activation of macrophages via the Janus kinase/signal transducer and activator of transcription (JAK-STAT) pathway. The IFN-γ function is best described in cell defense against intracellular pathogens in mammals, but IFN-γ cytokine-induced metabolic change and its role in anti-infection remain unknown in teleost fish. In this study, a novel IFN-γ (SsIFN-γ) was identified from black rockfish (Sebastes schlegeli) by rapid amplification of cDNA ends (RACE). The open reading frame (ORF) of SsIFN-γ encoded a putative protein of 215 amino acids and shares 60.2%-93.5% overall sequence identities with other teleost IFN-γ. SsIFN-γ was distributed ubiquitously in all the detected tissues and immune cells, which was highly expressed in the spleen, gills, head kidney by quantitative real-time PCR. The mRNA expression of SsIFN-γ was significantly upregulated in the spleen, head kidney, head kidney (HK) macrophages and peripheral blood lymphocytes (PBLs) during pathogen infection. Meanwhile, the recombinant protein (rSsIFN-γ) exhibited an immunomodulatory function to enhance respiratory burst activity and nitric oxide response of HK macrophages. Furthermore, rSsIFN-γ could effectively upregulate the expression of macrophage proinflammatory cytokine, the expression of JAK-STAT signaling pathway related genes and interferon-related downstream genes in the head kidney and spleen. Luciferase assays showed ISRE and GAS activity were obviously enhanced after rSsIFN-γ treatment. These results indicated that SsIFN-γ possessed apparent immunoregulatory properties and played a role in fighting pathogen infection which will be helpful to further understanding of the immunologic mechanism of teleosts IFN-γ in innate immunity.

Identification of long non-coding RNA MSTRG.5748.1 and MSTRG.7894.1 from Megalobrama amblycephala and their potential roles in innate immunity.

Megalobrama amblycephala is one of the most economically important freshwater fish in China, and the bacterial septicemia caused by Aeromonas hydrophila is a serious threat to the breeding industry of M. amblycephala. Unfortunately, the characterization of long noncoding RNA (lncRNA) in response to A. hydrophila infection has not been performed in M. amblycephala. To better understand the biological significance of lncRNA in the immune system, we identified two lncRNA, named MSTRG.5748.1 and MSTRG.7894.1, as playing critical roles in the antibacterial response of M. amblycephala. After separating the nucleus and cytoplasm of the hepatocytes from M. amblycephala, cellular localization of MSTRG.5748.1 and MSTRG.7894.1 was performed to predict their functions. The results showed that MSTRG.5748.1 was mainly expressed in the nucleus, suggesting that its functions are mostly to regulate the expression of downstream genes through epistasis and transcription. MSTRG.7894.1 existed in both the nucleus and cytoplasm, which indicated that it has many regulatory modes. qPCR analysis showed that MSTRG.5748.1 and MSTRG.7894.1 were expressed in the immune-related organs of M. amblycephala, and significantly changed in the liver after A. hydrophila infection. RNA-seq analysis revealed that differentially expressed genes (DEGs) were mainly enriched in antigen processing and presentation via MHC class I, RIG-I-like receptor (RLR) signaling pathway, and IFN-related pathway, and a large number of pathway-related genes were significantly regulated after lncRNA overexpression in muscle cell of M. amblycephala. Overexpression of MSTRG.5748.1 and MSTRG.7894.1 significantly inhibited the expression of STING and IFN, significantly upregulated muscle cell viability, and promoted cell proliferation by targeting STING and IFN.

Structure and function analysis of a type III preQ1-I riboswitch from Escherichia coli reveals direct metabolite sensing by the Shine-Dalgarno sequence

Riboswitches are small noncoding RNAs found primarily in the 5' leader regions of bacterial messenger RNAs where they regulate expression of downstream genes in response to binding one or more cellular metabolites. Such noncoding RNAs are often regulated at the translation level, which is thought to be mediated by the accessibility of the Shine-Dalgarno sequence (SDS) ribosome-binding site. Three classes (I-III) of prequeuosine1 (preQ1)-sensing riboswitches are known that control translation. Class I is divided into three subtypes (types I-III) that have diverse mechanisms of sensing preQ1, which is involved in queuosine biosynthesis. To provide insight into translation control, we determined a 2.30 Å-resolution cocrystal structure of a class I type III preQ1-sensing riboswitch identified in Escherichia coli (Eco) by bioinformatic searches. The Eco riboswitch structure differs from previous preQ1 riboswitch structures because it has the smallest naturally occurring aptamer and the SDS directly contacts the preQ1 metabolite. We validated structural observations using surface plasmon resonance and invivo gene-expression assays, which showed strong switching in live E.coli. Our results demonstrate that the Eco riboswitch is relatively sensitive to mutations that disrupt noncanonical interactions that form the pseudoknot. In contrast to type II preQ1 riboswitches, a kinetic analysis showed that the type III Eco riboswitch strongly prefers preQ1 over the chemically similar metabolic precursor preQ0. Our results reveal the importance of noncanonical interactions in riboswitch-driven gene regulation and the versatility of the class I preQ1 riboswitch pseudoknot as a metabolite-sensing platform that supports SDS sequestration.

Comparative transcriptomic and plastid development analysis sheds light on the differential carotenoid accumulation in kiwifruit flesh.

Carotenoids are colorful lipophilic isoprenoids synthesized in all photosynthetic organisms which play roles in plant growth and development and provide numerous health benefits in the human diet (precursor of Vitamin A). The commercially popular kiwifruits are golden yellow-fleshed (Actinidia chinensis) and green fleshed (A. deliciosa) cultivars which have a high carotenoid concentration. Understanding the molecular mechanisms controlling the synthesis and sequestration of carotenoids in Actinidia species is key to increasing nutritional value of this crop via breeding. In this study we analyzed fruit with varying flesh color from three Actinidia species; orange-fleshed A. valvata (OF), yellow-fleshed A. polygama (YF) and green-fleshed A. arguta (GF). Microscopic analysis revealed that carotenoids accumulated in a crystalline form in YF and OF chromoplasts, with the size of crystals being bigger in OF compared to YF, which also contained globular substructures in the chromoplast. Metabolic profiles were investigated using ultra-performance liquid chromatography (UPLC), which showed that β-carotene was the predominant carotenoid in the OF and YF species, while lutein was the dominant carotenoid in the GF species. Global changes in gene expression were studied between OF and GF (both tetraploid) species using RNA-sequencing which showed higher expression levels of upstream carotenoid biosynthesis-related genes such as DXS, PSY, GGPPS, PDS, ZISO, and ZDS in OF species compared to GF. However, low expression of downstream pathway genes was observed in both species. Pathway regulatory genes (OR and OR-L), plastid morphology related genes (FIBRILLIN), chlorophyll degradation genes (SGR, SGR-L, RCCR, and NYC1) were upregulated in OF species compared to GF. This suggests chlorophyll degradation (primarily in the initial ripening stages) is accompanied by increased carotenoid production and localization in orange flesh tissue, a contrast from green flesh tissue. These results suggest a coordinated change in the carotenoid pathway, as well as changes in plastid type, are responsible for an orange phenotype in certain kiwifruit species.

Functional analysis of Notch gene in the white-backed planthopper Sogatella furcifera (Hemiptera: Delphacidae)

Insect wing development is a complex process controlled by a series of genes. Notch is a key gene that regulates insect wing development. It is a receptor protein in the Notch signaling pathway that regulates the expression of downstream target genes after binding with ligands. In this study, we obtained the Notch gene from Sogatella furcifera (SfNotch) and analyzed its mRNA expression levels in different developmental stages and tissues. We also used RNA interference(RNAi) to investigate the biological function of SfNotch. Our results showed that SfNotch expression increased toward the end of the 3rd–5th instars, reaching its highest expression in the adult stage, and was especially high in the thorax and wing tissues. In addition, knockdown of SfNotch resulted in notched wings in 68.5% of S. furcifera. Our findings provide insight into the regulation of insect wing development and contribute to the molecular understanding of this process.

TMED2 Induces Cisplatin Resistance in Breast Cancer via Targeting the KEAP1-Nrf2 Pathway.

Cisplatin is the first-line treatment for breast cancer, but it faces challenges of drug resistance. This study investigated new molecular mechanisms underlying cisplatin resistance in breast cancer. We analyzed sequencing data from the TCGA database to identify potential associations between transmembrane emp24 protein transport domain containing 2 (TMED2) and breast cancer. Western blotting, real-time PCR, CCK-8, and TUNEL assays were used to measure the effects and molecular mechanism of TMED2 on cisplatin resistance in MCF-7 and MDA-MB-231 cell lines. TMED2 was overexpressed in breast cancer and associated with poor prognosis. TMED2 increased cisplatin resistance in breast cancer cells in vitro via promoting ubiquitination of Kelch-like ECH-associated protein 1 (KEAP1), relieving inhibition of KEAP1 on nuclear factor erythroid 2-related factor 2 (Nrf2), and increasing expression of downstream drug resistance related genes, such as heme oxygenase 1 (HO-1) and NAD (P) H quinone oxidoreductase 1 (NQO1). We identified a new molecular mechanism by which TMED2 affects cisplatin resistance in breast cancer. Our results provide theoretical guidance for future clinical applications.

GR5 acts in the G protein pathway to regulate grain size in rice

Grain size is an important determinant of grain yield in rice. Although dozens of grain size genes have been reported, the molecular mechanisms that control grain size remain to be fully clarified. Here, we report the cloning and characterization of GR5 (GRAIN ROUND 5), which is allelic to SMOS1/SHB/RLA1/NGR5 and encodes an AP2 transcription factor. GR5 acts as a transcriptional activator and determines grain size by influencing cell proliferation and expansion. We demonstrated that GR5 physically interacts with five Gγ subunit proteins (RGG1, RGG2, DEP1, GS3, and GGC2) and acts downstream of the G protein complex. Four downstream target genes of GR5 in grain development (DEP2, DEP3, DRW1, and CyCD5;2) were revealed and their core T/CGCAC motif identified by yeast one-hybrid, EMSA, and ChIP–PCR experiments. Our results revealed that GR5 interacts with Gγ subunits and cooperatively determines grain size by regulating the expression of downstream target genes. These findings provide new insight into the genetic regulatory network of the G protein signaling pathway in the control of grain size and provide a potential target for high-yield rice breeding.

FOXA1 O-GlcNAcylation-mediated transcriptional switch governs metastasis capacity in breast cancer.

FOXA1, a transcription factor involved in epigenetic reprogramming, is crucial for breast cancer progression. However, the mechanisms by which FOXA1 achieves its oncogenic functions remain elusive. Here, we demonstrate that the O-linked β-N-acetylglucosamine modification (O-GlcNAcylation) of FOXA1 promotes breast cancer metastasis by orchestrating the transcription of numerous metastasis regulators. O-GlcNAcylation at Thr432, Ser441, and Ser443 regulates the stability of FOXA1 and promotes its assembly with chromatin. O-GlcNAcylation shapes the FOXA1 interactome, especially triggering the recruitment of the transcriptional repressor methyl-CpG binding protein 2 and consequently stimulating FOXA1 chromatin-binding sites to switch to chromatin loci of adhesion-related genes, including EPB41L3 and COL9A2. Site-specific depletion of O-GlcNAcylation on FOXA1 affects the expression of various downstream genes and thus inhibits breast cancer proliferation and metastasis both in vitro and in vivo. Our data establish the importance of aberrant FOXA1 O-GlcNAcylation in breast cancer progression and indicate that targeting O-GlcNAcylation is a therapeutic strategy for metastatic breast cancer.

HMGB1: a double-edged sword and therapeutic target in the female reproductive system.

HMGB1 that belongs to the High Mobility Group-box superfamily, is a nonhistone chromatin associated transcription factor. It is present in the nucleus of eukaryotes and can be actively secreted or passively released by kinds of cells. HMGB1 is important for maintaining DNA structure by binding to DNA and histones, protecting it from damage. It also regulates the interaction between histones and DNA, affecting chromatin packaging, and can influence gene expression by promoting nucleosome sliding. And as a DAMP, HMGB1 binding to RAGE and TLRs activates NF-κB, which triggers the expression of downstream genes like IL-18, IL-1β, and TNF-α. HMGB1 is known to be involved in numerous physiological and pathological processes. Recent studies have demonstrated the significance of HMGB1 as DAMPs in the female reproductive system. These findings have shed light on the potential role of HMGB1 in the pathogenesis of diseases in female reproductive system and the possibilities of HMGB1-targeted therapies for treating them. Such therapies can help reduce inflammation and metabolic dysfunction and alleviate the symptoms of reproductive system diseases. Overall, the identification of HMGB1 as a key player in disease of the female reproductive system represents a significant breakthrough in our understanding of these conditions and presents exciting opportunities for the development of novel therapies.

TAL1 hijacks MYCN enhancer that induces MYCN expression and dependence on mevalonate pathway in T-cell acute lymphoblastic leukemia.

A hallmark of T-cell acute lymphoblastic leukemia (T-ALL) is the dysregulated expression of oncogenic transcription factors (TFs), including TAL1, NOTCH1 and MYC. Rewiring of the transcriptional program disrupts the tightly controlled spatiotemporal expression of downstream target genes, thereby contributing to leukemogenesis. In this study, we first identify an evolutionarily conserved enhancer element controlling the MYCN oncogene (named enhMYCN) that is aberrantly activated by the TAL1 complex in T-ALL cells. TAL1-positive T-ALL cells are highly dependent on MYCN expression for their maintenance in vitro and in xenograft models. Interestingly, MYCN drives the expression of multiple genes involved in the mevalonate pathway, and T-ALL cells are sensitive to inhibition of HMG-CoA reductase (HMGCR), a rate-limiting enzyme of this pathway. Importantly, MYC and MYCN regulate the same targets and compensate for each other. Thus, MYCN-positive T-ALL cells display a dual dependence on the TAL1-MYCN and NOTCH1-MYC pathways. Together, our results demonstrate that enhMYCN-mediated MYCN expression is required for human T-ALL cells and implicate the TAL1-MYCN-HMGCR axis as a potential therapeutic target in T-ALL.

Turicibacter fermentation enhances the inhibitory effects of Antrodia camphorata supplementation on tumorigenic serotonin and Wnt pathways and promotes ROS-mediated apoptosis of Caco-2 cells.

Introduction: Diet-induced obesity has been shown to decrease the abundance of Turicibacter, a genus known to play a role in the serotonin signaling system, which is associated with colorectal tumorigenesis, making the presence of Turicibacter potentially influential in the protection of intestinal tumorigenesis. Recently, Antrodia camphorata (AC), a medicinal fungus native to Taiwan, has emerged as a promising candidate for complementary and alternative cancer therapy. Small molecules and polysaccharides derived from AC have been reported to possess health-promoting effects, including anti-cancer properties. Methods: Bacterial culture followed with cell culture were used in this study to determine the role of Turicibacter in colorectal tumorigenesis and to explore the anti-cancer mechanism of AC with Turicibacter fermentation. Results: Turicibacter fermentation and the addition of AC polysaccharide led to a significant increase in the production of nutrients and metabolites, including α-ketoglutaric acid and lactic acid (p < 0.05). Treatment of Turicibacter fermented AC polysaccharide was more effective in inhibiting serotonin signaling-related genes, including Tph1, Htr1d, Htr2a, Htr2b, and Htr2c (p < 0.05), and Wnt-signaling related protein and downstream gene expressions, such as phospho-GSK-3β, active β-catenin, c-Myc, Ccnd1, and Axin2 (p < 0.05). Additionally, it triggered the highest generation of reactive oxygen species (ROS), which activated PI3K/Akt and MAPK/Erk signaling and resulted in cleaved caspase-3 expression. In comparison, the treatment of AC polysaccharide without Turicibacter fermentation displayed a lesser effect. Discussion: Our findings suggest that AC polysaccharide effectively suppresses the tumorigenic serotonin and Wnt-signaling pathways, and promotes ROS-mediated apoptosis in Caco-2 cells. These processes are further enhanced by Turicibacter fermentation.

Abstract PR003: PBRM1-deficient PBAF complexes target aberrant genomic loci to activate NF-κB pathway in clear cell renal cell carcinoma

Abstract PBRM1 encodes an accessory subunit of the PBAF subclass of the SWI/SNF chromatin remodeler and the inactivation of PBRM1 is the second most frequent mutational event in kidney cancer. However, the impact of PBRM1 loss on chromatin remodeling, especially pertaining to kidney tumorigenesis, has not been well examined. Here we show that in VHL-deficient renal tumors, PBRM1 deficiency results in ectopic PBAF complexes that localize to de novo genomic loci and activate the pro-tumorigenic NF-κB pathway. PBRM1-deficient PBAF complexes, despite retaining the association between SMARCA4 and ARID2, have loosely tethered BRD7. The PBAF complexes redistribute from promoter proximal regions to distal enhancers containing NF-κB motifs; subsequently, PBRM1-deficient cells display heightened NF-κB activity in multiple models and clinical samples. The ATPase function of SMARCA4 maintains chromatin occupancy of both pre-existing and newly acquired RELA specific to PBRM1 loss, and activates downstream target gene expression. Proteasome inhibitor bortezomib abrogates RELA occupancy, suppresses NF-κB activation and delays growth of PBRM1-deficient tumors. In conclusion, PBRM1 safeguards the chromatin by repressing aberrant liberation of pro-tumorigenic NF-κB target genes by residual PBRM1-deficient PBAF complexes. Citation Format: Xiaosai Yao, Jing Han Hong, Amrita Nargund, Michelle S.W. Ng, Bin Tean Teh. PBRM1-deficient PBAF complexes target aberrant genomic loci to activate NF-κB pathway in clear cell renal cell carcinoma [abstract]. In: Proceedings of the AACR Special Conference: Advances in Kidney Cancer Research; 2023 Jun 24-27; Austin, Texas. Philadelphia (PA): AACR; Cancer Res 2023;83(16 Suppl):Abstract nr PR003.

Honokiol attenuates high glucose-induced peripheral neuropathy via inhibiting ferroptosis and activating AMPK/SIRT1/PGC-1ɑ pathway in Schwann cells.

Schwann cells injury induced by high glucose (HG) contributes to the development of diabetic peripheral neuropathy (DPN). Honokiol has been reported to regulate glucose metabolism, however, its effect on DPN and the precise molecular mechanisms remain unclear. This study aimed to investigate the role of AMPK/SIRT1/PGC-1α axis in the protective effects of honokiol on DPN. The biochemical assay and JC-1 staining results demonstrated that honokiol reduced HG-induced oxidative stress and ferroptosis as well as mitochondrial dysfunction in Schwann cells. RT-qPCR and western blotting were utilized to investigate the mechanism of action of honokiol, and the results showed that HG-induced inhibition of AMPK/SIRT1/PGC-1α axis and changes of downstream gene expression profile were restored by honokiol. Moreover, silencing of Sirt1 by siRNA delivery markedly diminished the changes of gene expression profile induced by honokiol in HG-induced Schwann cells. More importantly, we found that administration of honokiol remarkably attenuated DPN via improving sciatic nerve conduction velocity and increasing thermal and mechanical sensitivity in streptozotocin-induced diabetic rats. Collectively, these results demonstrate that honokiol can attenuate HG-induced Schwann cells injury and peripheral nerve dysfunction, suggesting a novel potential strategy for treatment of DPN.

Mycobacterial phage TM4 requires a eukaryotic-like Ser/Thr protein kinase to silence and escape anti-phage immunity

In eukaryotic cells, serine/threonine protein kinases (StpKs) play important roles in limiting viral infections. StpKs are commonly activated upon infections, inhibiting the expression of genes central for viral replication. Here, we report that a eukaryotic-like StpK7 encoded by MSMEG_1200 in M.smegmatis is required for mycobacteriophage TM4 to escape bacterial defense. stpK7 is located within a gene island, MSMEG_1191-MSMEG_1200, containing multiple anti-phage genes resembling the BREX (bacteriophage exclusion) phage-resistance system. StpK7 negatively regulates the expression of this gene island. Following phage TM4 infection, StpK7 is induced, directly phosphorylating the transcriptional regulator MSMEG_1198 and inhibiting its positive regulatory activity, thus reducing the expression of multiple downstream genes in the BREX-like gene island. Further analysis showed that genes within this anti-phage island critically regulate mycobacterial lipid hemostasis and phage adsorption. Collectively, this work characterizes a regulatory network driven by StpK7, which is utilized by phage TM4 to escape from the host defense against mycobacteria.

The RNA-Splicing Ligase RTCB Promotes Influenza A Virus Replication by Suppressing Innate Immunity via Interaction with RNA Helicase DDX1.

The RNA-splicing ligase RNA 2',3'-cyclic phosphate and 5'-OH ligase (RTCB) is a catalytic subunit of the tRNA-splicing ligase complex, which plays an essential role in catalyzing tRNA splicing and modulating the unfolded protein response. However, the function of RTCB in influenza A virus (IAV) replication has not yet been described. In this study, RTCB was revealed to be an IAV-suppressed host factor that was significantly downregulated during influenza virus infection in several transformed cell lines, as well as in primary human type II alveolar epithelial cells, and its knockout impaired the propagation of the IAV. Mechanistically, RTCB depletion led to a robust elevation in the levels of type I and type III IFNs and proinflammatory cytokines in response to IAV infection, which was confirmed by RTCB overexpression studies. Lastly, RTCB was found to compete with DDX21 for RNA helicase DDX1 binding, attenuating the DDX21-DDX1 association and thus suppressing the expression of IFN and downstream IFN-stimulated genes. Our study indicates that RTCB plays a critical role in facilitating IAV replication and reveals that the RTCB-DDX1 binding interaction is an important innate immunomodulator for the host to counteract viral infection.

Transmembrane and PAS domains of the histidine kinase Hik33 as regulators of cold and light responses in the cyanobacterium Synechocystis sp. PCC 6803

The PAS (Per-ARNT-Sim) domain is a sensory protein regulatory module found in archaea, prokaryotes, and eukaryotes. Histidine and serine/threonine protein kinases, chemo- and photoreceptors, circadian rhythm regulators, ion channels, phosphodiesterases, and other cellular response regulators are among these proteins. Hik33 is a multifunctional sensory histidine kinase that is implicated in cyanobacterial responses to cold, salt, hyperosmotic, and oxidative stressors. The functional roles of individual Hik33 domains in signal transduction were investigated in this study. Synechocystis Hik33 deletion variants were developed, in which either both or a portion of the transmembrane domains and/or the PAS domain were deleted. Cold stress was applied to the mutant strains either under illumination or in the dark. The findings show that the transmembrane domains govern temperature responses, whereas PAS domain may be involved in regulation of downstream gene expression in light-dependent manner.

Repeated mechanical damage enhanced Aquilaria sinensis resistance to Heortia vitessoides through jasmonic acid.

The leaf-chewing pest Heortia vitessoides severely threatens the growth and development of Aquilaria sinensis. In our previous study, we found that mechanical damage (MD) to stem enhanced A. sinensis sapling resistance to H. vitessoides larvae. To reveal the defense mechanisms underlying this observation, we analyzed the types and contents of volatile organic compounds (VOCs), phytohormone contents, and expression of phytohormone-related genes in response to MD and herbivory wounding(HW). Here, we identified several VOCs, such as the pesticides fenobucarb and 2,4-di-tert-butylphenol, in mature leaf (ML) of MD-treated plants. Compared with salicylic acid (SA) or the ethylene (ET) pathway, jasmonic acid (JA) content and JA-related genes were more strongly upregulated. Interestingly, we found a dramatic difference between JA-related upstream and downstream genes expression in YL and ML, which confirmed that JA-Ile accumulation in MD-ML and HW-ML could be derived from local damaged site. Taken together, we provide evidence that the JA pathway plays a dominant role in the A. sinensis response to MD and HW.

Abstract P2061: The Intersection Of O-GlcNAc And Yap - A Novel Molecular Axis In Heart Failure

Introduction: Heart failure (HF) and pathological myocardial hypertrophy continue to grow world-wide and are strongly tied to obesity, hyperglycemia, and ischemia. These stressors lead to increased levels of O-beta-N-Acetylglucosamine modified proteins (OGN) in the heart. OGN levels are determined by the net activity of two enzymes, OGT and OGA. Our recent work showed excessive OGN was sufficient to cause HF and pathological myocardial hypertrophy. Here we test the relationship between OGN and Yes Associated Protein (YAP), a known promoter of cardiac hypertrophy. Objectives: Test if OGN modifies YAP in the heart and evaluate the role of OGN modified YAP in the development of pathologic cardiac hypertrophy and heart failure. Methods: We have shown that mouse models with myocardial OGT overexpression (OGT TG) developed pathological cardiac hypertrophy and HF. We found these animals have increased YAP activity. Myocardial OGA overexpression (OGA TG) attenuated OGN following transaortic constriction(TAC) and were protected against cardiac hypertrophy and HF. Interbreeding OGT TG with OGA TG rescued animals from pathological hypertrophy, HF and normalized YAP activity . We quantified levels of activated YAP protein/gene expression in hearts from WT, OGT, OGA and OGT x OGA mice. We evaluated YAP/TEAD1 target gene expression levels in OGA TG mice protected against TAC. We used an adenoviral YAP/TEAD expression reporter to quantify YAP/TEAD1 activity in cardiac myocytes, in the presence and absence of increased O-GlcNAcylation. Results: We found WT levels of activated (nuclear) YAP in OGA TG, increased active YAP in OGT TG and normal levels in OGT x OGA mice. YAP/TEAD1 target genes are upregulated in OGT TG hearts but interbred OGT x OGA animals have normal cardiac function and YAP/TEAD1 target gene expression. OGA TG mice who are protected against TAC induced heart failure/hypertrophy and have decreased myocardial levels of YAP/TEAD1 gene targets involved in pathological hypertrophy. Increased O-GlcNAcylation in cardiac myocytes activates YAP/TEAD activity and YAP/TEAD downstream gene expression. Conclusion: These preliminary data suggest a novel pathway for promoting pathological hypertrophy and HF via activation of the O-GlcNAc -YAP/TEAD1 axis.