Genome-wide Transcriptome Analysis Research Articles

White matter damage as a consequence of vascular dysfunction in a spontaneous mouse model of chronic mild chronic hypoperfusion with eNOS deficiency

Vascular cognitive impairment and dementia (VCID) is the second most common form of dementia after Alzheimer’s disease (AD). Currently, the mechanistic insights into the evolution and progression of VCID remain elusive. White matter change represents an invariant feature. Compelling clinical neuroimaging and pathological evidence suggest a link between white matter changes and neurodegeneration. Our prior study detected hypoperfused lesions in mice with partial deficiency of endothelial nitric oxide (eNOS) at very young age, precisely matching to those hypoperfused areas identified in preclinical AD patients. White matter tracts are particularly susceptible to the vascular damage induced by chronic hypoperfusion. Using immunohistochemistry, we detected severe demyelination in the middle-aged eNOS-deficient mice. The demyelinated areas were confined to cortical and subcortical areas including the corpus callosum and hippocampus. The intensity of demyelination correlated with behavioral deficits of gait and associative recognition memory performances. By Evans blue angiography, we detected blood–brain barrier (BBB) leakage as another early pathological change affecting frontal and parietal cortex in eNOS-deficient mice. Sodium nitrate fortified drinking water provided to young and middle-aged eNOS-deficient mice completely prevented non-perfusion, BBB leakage, and white matter pathology, indicating that impaired endothelium-derived NO signaling may have caused these pathological events. Furthermore, genome-wide transcriptomic analysis revealed altered gene clusters most related to mitochondrial respiratory pathways selectively in the white matter of young eNOS-deficient mice. Using eNOS-deficient mice, we identified BBB breakdown and hypoperfusion as the two earliest pathological events, resulting from insufficient vascular NO signaling. We speculate that the compromised BBB and mild chronic hypoperfusion trigger vascular damage, along with oxidative stress and astrogliosis, accounting for the white matter pathological changes in the eNOS-deficient mouse model. We conclude that eNOS-deficient mice represent an ideal spontaneous evolving model for studying the earliest events leading to white matter changes, which will be instrumental to future therapeutic testing of drug candidates and for targeting novel/specific vascular mechanisms contributing to VCID and AD.

Nuclear receptor estrogen-related receptor modulates antimicrobial peptide expression for host innate immunity in Tribolium castaneum

Antimicrobial peptides (AMPs) are core components of innate immunity to protect insects against microbial infections. Nuclear receptors (NRs) are ligand-dependent transcription factors that can regulate the expression of genes critical for insect development including molting and metamorphosis. However, the role of NRs in host innate immune response to microbial infection remains poorly understood in Tribolium castaneum (T. castaneum). Here, we show that estrogen-related receptor (ERR), an insect ortholog of the mammalian ERR family of NRs, is a novel transcriptional regulator of AMP genes for innate immune response of T. castaneum. Tribolium ERR (TcERR) expression was induced by immune deficiency (IMD)-Relish signaling in response to infection by Escherichia coli (E. coli), a Gram-negative bacterium, as demonstrated in TcIMD-deficient beetles. Interestingly, genome-wide transcriptome analysis of TcERR-deficient old larvae using RNA-sequencing analysis showed that TcERR expression was positively correlated with gene transcription levels of AMPs including attacins, defensins, and coleoptericin. Moreover, chromatin immunoprecipitation analysis revealed that TcERR could directly bind to ERR-response elements on promoters of genes encoding defensin3 and coleoptericin, critical for innate immune response of T. castaneum. Finally, TcERR-deficient old larvae infected with E. coli displayed enhanced bacterial load and significantly less host survival. These findings suggest that TcERR can coordinate transcriptional regulation of AMPs and host innate immune response to bacterial infection.

Genome-Wide Transcriptomic Analysis of the Effects of Infection with the Hemibiotrophic Fungus Colletotrichum lindemuthianum on Common Bean.

Bean anthracnose caused by the hemibiotrophic fungus Colletotrichum lindemuthianum is one of the most important diseases of common bean (Phaseolus vulgaris) in the world. In the present study, the whole transcriptome of common bean infected with C. lindemuthianum during compatible and incompatible interactions was characterized at 48 and 72 hpi, corresponding to the biotrophy phase of the infection cycle. Our results highlight the prominent role of pathogenesis-related (PR) genes from the PR10/Bet vI family as well as a complex interplay of different plant hormone pathways including Ethylene, Salicylic acid (SA) and Jasmonic acid pathways. Gene Ontology enrichment analysis reveals that infected common bean seedlings responded by down-regulation of photosynthesis, ubiquitination-mediated proteolysis and cell wall modifications. In infected common bean, SA biosynthesis seems to be based on the PAL pathway instead of the ICS pathway, contrarily to what is described in Arabidopsis. Interestingly, ~30 NLR were up-regulated in both contexts. Overall, our results suggest that the difference between the compatible and incompatible reaction is more a question of timing and strength, than a massive difference in differentially expressed genes between these two contexts. Finally, we used RT-qPCR to validate the expression patterns of several genes, and the results showed an excellent agreement with deep sequencing.

Clock-Controlled and Cold-Induced CYCLING DOF FACTOR6 Alters Growth and Development in Arabidopsis.

The circadian clock represents a critical regulatory network, which allows plants to anticipate environmental changes as inputs and promote plant survival by regulating various physiological outputs. Here, we examine the function of the clock-regulated transcription factor, CYCLING DOF FACTOR 6 (CDF6), during cold stress in Arabidopsis thaliana. We found that the clock gates CDF6 transcript accumulation in the vasculature during cold stress. CDF6 mis-expression results in an altered flowering phenotype during both ambient and cold stress. A genome-wide transcriptome analysis links CDF6 to genes associated with flowering and seed germination during cold and ambient temperatures, respectively. Analysis of key floral regulators indicates that CDF6 alters flowering during cold stress by repressing photoperiodic flowering components, FLOWERING LOCUS T (FT), CONSTANS (CO), and BROTHER OF FT (BFT). Gene ontology enrichment further suggests that CDF6 regulates circadian and developmental-associated genes. These results provide insights into how the clock-controlled CDF6 modulates plant development during moderate cold stress.

434 Molecular events in the epidermis upon aryl hydrocarbon receptor targeting: AHR-TFAP2A axis drives epidermal keratinocyte differentiation

The aryl hydrocarbon receptor (AHR) is an environmental sensor and ligand-activated transcription factor that is involved in epithelial homeostasis and barrier development of the skin. Through genome-wide transcriptomic and epigenomic analyses of human primary keratinocytes upon AHR activation using TCDD we identified early and late AHR responsive genes. The early responsive genes were enriched for canonical transcription factors known to promote keratinocyte differentiation, barrier development, and host defense, such as Transcription Factor AP-2α (TFAP2A).

Polaramycin B, and not physical interaction, is the signal that rewires fungal metabolism in the Streptomyces-Aspergillus interaction.

Co-culturing the bacterium Streptomyces rapamycinicus and the ascomycete Aspergillus nidulans has previously been shown to trigger the production of orsellinic acid (ORS) and its derivates in the fungal cells. Based on these studies it was assumed that direct physical contact is a prerequisite for the metabolic reaction that involves a fungal amino acid starvation response and activating chromatin modifications at the biosynthetic gene cluster (BGC). Here we show that not physical contact, but a guanidine containing macrolide, named polaramycin B, triggers the response. The substance is produced constitutively by the bacterium and above a certain concentration, provokes the production of ORS. In addition, several other secondary metabolites were induced by polaramycin B. Our genome-wide transcriptome analysis showed that polaramycin B treatment causes downregulation of fungal genes necessary for membrane stability, general metabolism and growth. A compensatory genetic response can be observed in the fungus that included upregulation of BGCs and genes necessary for ribosome biogenesis, translation and membrane stability. Our work discovered a novel chemical communication, in which the antifungal bacterial metabolite polaramycin B leads to the production of antibacterial defence chemicals and to the upregulation of genes necessary to compensate for the cellular damage caused by polaramycin B.

Nuclear receptor HR3 mediates transcriptional regulation of chitin metabolic genes during molting in Tribolium castaneum.

Chitin, a major component of insect cuticles, plays a critical role in insect molting and morphogenesis. Thus, coordination of chitin remodeling during insect development requires tight transcriptional control of the chitin metabolism genes involved in chitin synthesis, assembly and degradation. However, the molecular mechanism underlying transcriptional coordination of chitin metabolism genes during beetle development is not yet completely understood. We cloned the full-length cDNA encoding hormone receptor 3 (TcHR3) from Tribolium castaneum and showed a critical role of TcHR3 in modulating chitin metabolism gene expression during molting. Genome-wide transcriptome analysis of HR3-deficient old larvae using RNA sequencing analysis revealed a positive correlation between TcHR3 and transcription of chitin metabolism genes involved in chitin synthesis and degradation. In addition, HR3 overexpression significantly induced the gene promoter activity of N-acetylglucosaminidase 1 (NAG1) involved in chitin degradation and UDP-N-acetylglucosamine pyrophosphorylase 1 (UAP1) involved in chitin synthesis. Chromatin immunoprecipitation analysis revealed that HR3 could directly bind to HR3-response element of NAG1 and UAP1 promoters. Finally, HR3-deficient late instar larvae and prepupae exhibited defects in larval-larval and larval-pupal molting, respectively, leading to eventual larval death because developing larvae were trapped inside the old cuticle as a result of abnormal chitin metabolism. TcHR3 is a transcriptional regulator of chitin metabolic genes for molting of T.castaneum. Controlling the molting system by TcHR3 might be a new management strategy for selective control of red flour beetle infestation. © 2022 Society of Chemical Industry.

Inhibition of DYRK1A, via histone modification, promotes cardiomyocyte cell cycle activation and cardiac repair after myocardial infarction.

SummaryBackgroundWhile the adult mammalian heart undergoes only modest renewal through cardiomyocyte proliferation, boosting this process is considered a promising therapeutic strategy to repair cardiac injury. This study explored the role and mechanism of dual-specificity tyrosine regulated kinase 1A (DYRK1A) in regulating cardiomyocyte cell cycle activation and cardiac repair after myocardial infarction (MI).MethodsDYRK1A-knockout mice and DYRK1A inhibitors were used to investigate the role of DYRK1A in cardiomyocyte cell cycle activation and cardiac repair following MI. Additionally, we explored the underlying mechanisms by combining genome-wide transcriptomic, epigenomic, and proteomic analyses.FindingsIn adult mice subjected to MI, both conditional deletion and pharmacological inhibition of DYRK1A induced cardiomyocyte cell cycle activation and cardiac repair with improved cardiac function. Combining genome-wide transcriptomic and epigenomic analyses revealed that DYRK1A knockdown resulted in robust cardiomyocyte cell cycle activation (shown by the enhanced expression of many genes governing cell proliferation) associated with increased deposition of trimethylated histone 3 Lys4 (H3K4me3) and acetylated histone 3 Lys27 (H3K27ac) on the promoter regions of these genes. Mechanistically, via unbiased mass spectrometry, we discovered that WD repeat-containing protein 82 and lysine acetyltransferase 6A were key mediators in the epigenetic modification of H3K4me3 and H3K27ac and subsequent pro-proliferative transcriptome and cardiomyocyte cell cycle activation.InterpretationOur results reveal a significant role of DYRK1A in cardiac repair and suggest a drug target with translational potential for treating cardiomyopathy.FundingThis study was supported in part by grants from the National Natural Science Foundation of China (81930008, 82022005, 82070296, 82102834), National Key R&D Program of China (2018YFC1312700), Program of Innovative Research Team by the National Natural Science Foundation (81721001), and National Institutes of Health (5R01DK039308-31, 7R37HL023081-37, 5P01HL074940-11).

A novel long noncoding RNA CIL1 enhances cold stress tolerance in Arabidopsis

With the intensification of global warming, extreme weather events have occurred more frequently, among which cold stress has become one of the major environmental factors that restrict global crop yield and production. Multiple long noncoding RNAs (lncRNAs) have been predicted or recognized in the plant response to cold stress, however, the molecular biological functions of most of these RNAs are still poorly understood. Here, we identified a novel lncRNA, COLD INDUCED lncRNA 1 (CIL1), as a positive regulator of the plant response to cold stress in Arabidopsis. CIL1 was significantly induced when the plant was exposed to cold stress. Moreover, knockdown mutants showed more sensitivity to cold stress than the wild type did, accompanied by an increased content of endogenous ROS (reactive oxygen species) and reduced osmoregulatory substances. Genome-wide transcriptome analysis indicated that 256 genes were downregulated and 34 genes were upregulated in cil1 mutants under cold stress, which were mainly involved in hormone signal transduction, ROS homeostasis and glucose metabolism. Our study implies that CIL1 has a positive effect on the plant response to cold stress by regulating the expression of multiple stress-related genes during the seedling stage.

Recapitulating infection, thermal sensitivity and antiviral treatment of seasonal coronaviruses in human airway organoids

SummaryBackgroundHuman seasonal coronaviruses usually cause mild upper-respiratory tract infection, but severe complications can occur in specific populations. Research into seasonal coronaviruses is limited and robust experimental models are largely lacking. This study aims to establish human airway organoids (hAOs)-based systems for seasonal coronavirus infection and to demonstrate their applications in studying virus-host interactions and therapeutic development.MethodsThe infections of seasonal coronaviruses 229E, OC43 and NL63 in 3D cultured hAOs with undifferentiated or differentiated phenotypes were tested. The kinetics of virus replication and production was profiled at 33 °C and 37 °C. Genome-wide transcriptome analysis by RNA sequencing was performed in hAOs under various conditions. The antiviral activity of molnupiravir and remdesivir, two approved medications for treating COVID19, was tested.FindingsHAOs efficiently support the replication and infectious virus production of seasonal coronaviruses 229E, OC43 and NL63. Interestingly, seasonal coronaviruses replicate much more efficiently at 33 °C compared to 37 °C, resulting in over 10-fold higher levels of viral replication. Genome-wide transcriptomic analyses revealed distinct patterns of infection-triggered host responses at 33 °C compared to 37 °C temperature. Treatment of molnupiravir and remdesivir dose-dependently inhibited the replication of 229E, OC43 and NL63 in hAOs.InterpretationHAOs are capable of modeling 229E, OC43 and NL63 infections. The intriguing finding that lower temperature resembling that in the upper respiratory tract favors viral replication may help to better understand the pathogenesis and transmissibility of seasonal coronaviruses. HAOs-based innovative models shall facilitate the research and therapeutic development against seasonal coronavirus infections.FundingThis research is supported by funding of a VIDI grant (No. 91719300) from the Netherlands Organization for Scientific Research and the Dutch Cancer Society Young Investigator Grant (10140) to Q.P., and the ZonMw COVID project (114025011) from the Netherlands Organization for Health Research and Development to R.R.

Epicardial HDAC3 Promotes Myocardial Growth Through a Novel MicroRNA Pathway.

Establishment of the myocardial wall requires proper growth cues from nonmyocardial tissues. During heart development, the epicardium and epicardium-derived cells instruct myocardial growth by secreting essential factors including FGF (fibroblast growth factor) 9 and IGF (insulin-like growth factor) 2. However, it is poorly understood how the epicardial secreted factors are regulated, in particular by chromatin modifications for myocardial formation. The current study is to investigate whether and how HDAC (histone deacetylase) 3 in the developing epicardium regulates myocardial growth. Various cellular and mouse models in conjunction with biochemical and molecular tools were employed to study the role of HDAC3 in the developing epicardium. We deleted Hdac3 in the developing murine epicardium, and mutant hearts showed ventricular myocardial wall hypoplasia with reduction of epicardium-derived cells. The cultured embryonic cardiomyocytes with supernatants from Hdac3 knockout (KO) mouse epicardial cells also showed decreased proliferation. Genome-wide transcriptomic analysis revealed that Fgf9 and Igf2 were significantly downregulated in Hdac3 KO mouse epicardial cells. We further found that Fgf9 and Igf2 expression is dependent on HDAC3 deacetylase activity. The supplementation of FGF9 or IGF2 can rescue the myocardial proliferation defects treated by Hdac3 KO supernatant. Mechanistically, we identified that microRNA (miR)-322 and miR-503 were upregulated in Hdac3 KO mouse epicardial cells and Hdac3 epicardial KO hearts. Overexpression of miR-322 or miR-503 repressed FGF9 and IGF2 expression, while knockdown of miR-322 or miR-503 restored FGF9 and IGF2 expression in Hdac3 KO mouse epicardial cells. Our findings reveal a critical signaling pathway in which epicardial HDAC3 promotes compact myocardial growth by stimulating FGF9 and IGF2 through repressing miR-322 or miR-503, providing novel insights in elucidating the etiology of congenital heart defects and conceptual strategies to promote myocardial regeneration.

Abstract 2946: Perturb-seq analysis of TNFα-induced transcriptional response

Abstract We performed a single-cell Perturb-seq screen on HEK293 cells with a ~100 sgRNA pooled library, aimed at identifying genes involved in TNFα-induced transcriptional response. As a reference, a parallel screen was performed with cells transduced in arrayed format with the same set of sgRNAs as the pooled library. For the pooled library screen, cells were transduced with the pooled sgRNA library, selected and expanded for 10 days, split into 2 samples for 72h TNFα treatment/mock-treatment. After treatment, cells were loaded on the 10X Genomics instrument according to manufacturer’s specifications at 2000, 7500 and 15,000 cells/sample/lane. For the arrayed screen, cells were transduced with individual sgRNAs in arrayed format, selected and expanded for 10 days, split into 2 samples for 72h TNFα treatment/mock treatment. After treatment ~10,000 from each sample were harvested for RNA purification. For both pooled library single-cell and arrayed screens, genome-wide transcriptome analysis was assayed using the DriverMap Targeted RNA-Seq assay. Both screens identified TNFRSF1A and IKBKG as top mediators of TFNα transcriptional response. Citation Format: Donato Tedesco, Alex Chenchik, Tianbing Liu, Dongfang Hu, Nadya Isachenko, Nadia Dolganov. Perturb-seq analysis of TNFα-induced transcriptional response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2946.

Abstract 898: Metformin and ICG-001 act synergistically to abrogate cancer stem cell-mediated chemoresistance in colorectal cancer by promoting apoptosis and autophagy

Abstract Background: Colorectal cancer (CRC) remains the third most frequently diagnosed cancers in the United States. Current treatment modalities for patients with CRC include surgery, which is often followed with 5-fluorouracil (5FU) based adjuvant chemotherapy. While such treatment regimens are effective at improving disease outcomes, their clinical usefulness is often hampered due to emergence of chemotherapeutic resistance. Presence of cancer stem cells (CSCs) have been attributed towards 5FU-mediated drug resistance which subsequently leads to poor prognosis in CRC patients. In this study we investigated a novel therapeutic strategy by using metformin along with ICG-001, a Wnt signaling inhibitor, as an approach to abrogate CSC mediated chemoresistance in 5FU resistant (5FUR) and parental CRC cells, as well as CRC patient derived tumor organoids. Methods: Two 5FU resistant (5FUR)-CRC cell lines previously generated and characterized in our lab were used in this study. First, we performed genome-wide transcriptomic profiling followed by pathway enrichment analysis to identify differentially expressed genes and its associated pathways between parental and 5FUR CRC cells. Next, we determine the anti-tumor effects of metformin and ICG-001 by performing cell viability, colony formation, migration, and invasion analysis. Next, we explore the possible mechanism of action of these two drugs by performing gene and protein expression analysis of CSC, autophagy and apoptotic markers. We also evaluated the anti-tumor activity of metformin and ICG-001 in CRC patient derived tumor organoids. Results: We observed that 5FUR-CRC cells exhibited increased expression of CSC markers and increased spheroid forming ability. Genome-wide transcriptomic analysis followed by pathway analysis revealed that Wnt signaling pathway, pathways regulating pluripotency of stem cells etc. were enriched between parental and 5FUR CRC cells. These findings prompted us to use ICG-001 which selectively targets Wnt signaling along with metformin in abrogating CSC mediated chemoresistance in CRC. We observed that a combined treatment of metformin and ICG-001 exert anti-tumor activity in by decreasing cell viability (p<0.01), colony formation (p<0.001), migration (p<0.01), and invasion ability (p<0.01) in synergistic manner. We also observed that combined treatment decreases the expression of CSC markers and promote autophagy and apoptosis. In accordance with our in vitro studies, we observed that metformin and ICG-001 exhibited anti-tumor activity in patient derived CRC organoid models in combination (p<0.001). Conclusion: We conclude that metformin and ICG-001 act synergistically, which can be used as a therapeutic strategy to overcome 5FU mediated therapeutic resistance in CRC. Citation Format: Souvick Roy, Yinghui Zhao, Yate-Ching Yuan, Ajay Goel. Metformin and ICG-001 act synergistically to abrogate cancer stem cell-mediated chemoresistance in colorectal cancer by promoting apoptosis and autophagy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 898.

WHIRLY1 recruits the histone deacetylase HDA15 repressing leaf senescence and flowering in Arabidopsis.

Leaf senescence is controlled by a complex regulatory network in which robustness is ensured by the activity of transcription factors and epigenetic regulators. However, how these coordinate the process of leaf senescence remains poorly understood. We found that WHIRLY1 interacts with Histone Deacetylase (HDA)15, a Reduced Potassium Dependence3 (RPD3)/HDA1-type HDA, by using green fluorescent protein-nanotrap-mass spectrum assays. The development-dependent interaction between WHIRLY1 and HDA15 was further confirmed by bimolecular fluorescence complementation assays and co-immunoprecipitation assays in Arabidopsis. Multi-omics genome-wide transcriptome and H3K9 acetylome enrichment analysis showed that HDA15 delays leaf senescence and flowering by repressing the expression of the positive regulators of leaf senescence and flowering, such as LOX2 and LARP1C, and reducing H3K9ac levels at these loci; WHIRLY1 and HDA15 co-target to the region near the transcription start site of a subset of nutrient recycling-related genes (e.g., Glutathione S-transferases 10, non-coding RNA, and photosystem II protein D1 synthesizer attenuator PDIL1-2), as well as WRKY53 and ELF4, and co-repress their expression by removing H3K9 acetylation. Our study revealed a key transcription regulatory node of nutrient recycling and senescence-associated genes involved in leaf senescence and flowering via the recruitment of HDA15 by the single-stranded DNA/RNA-binding protein WHIRLY1.

Abstract 3277: SWI/SNF inactivation vulnerability

Abstract Genetic inactivation in specific SWI/SNF complex members induce sensitivity to the inhibition of KDM6A/UTX and KDM6B/JMJD3 in cancer. Despite the genetic inactivation of the tumor suppressor SMARCA4 is frequently found in cancer, there are no therapies that effectively target SMARCA4-deficient tumors. In our previous work, we reported that unlike the cells with activated MYC oncogene, cells with SMARCA4 inactivation are refractory to the histone deacetylase inhibitor, SAHA, leading to the aberrant accumulation of H3K27me3. In this context, SMARCA4 deficient cells showed an impaired transactivation and significantly reduced levels of the histone H3K27me3 specific demethylases, KDM6A/UTX and KDM6B/JMJD3, and their inhibition compromises cell viability specifically in SMARCA4 mutant cells. Furthermore, the in vivo administration of KDM6s inhibitor (GSK-J4) to mice orthotopically implanted with SMARCA4 mutant lung cancer cell lines or primary tumors of small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), showed a strong anti-tumor effect, highlighting the vulnerability of the SMARCA4 deficient tumors to KDM6s inhibition as a biomarker that could be exploited for treating SMARCA4-mutant cancer patients (Romero OA, Vilarrubi A, et al. SMARCA4 deficient tumors are vulnerable to KDM6A/UTX and KDM6B/JMJD3 blockade. Nat Comm 12, 4319, 2021). Considering our previous observations, and due to the biological role of SMARCA4 as a core component of the SWI/SNF chromatin-remodeling complex, whose members are genetically inactivated in approximately 20% of all human cancers, we wanted to determine the potential response to KDM6s inhibitors in a context of genetic alterations in genes encoding for the other subunits of this remodeling complex. For this propose, we have integrated state of the art technology like genome-wide chromatin modification analysis (ChIP-seq) and transcriptome analysis (RNA-seq), using human cancer cell lines and preclinical models of different cancer types with genetic inactivation at different SWI/SNF-complex members, including mouse models such as orthoxenografts, to design a personalized epigenetic treatment based on the genetic background. Our results showed that, like SMARCA4 deficient cells, specific mutations at some, but not all, SWI/SNF components induce refractoriness to SAHA, aberrant increase of H3K27me3 mark and sensitizes cancer cells to KDM6 inhibitor accompanied with significantly reduced levels of KDM6A and KDM6B expression. These results suggest a strong functional relationship between KDM6A/6B activity and the SWI/SNF-complex, in the control of gene expression and cancer development. These results will be of great value for the stratification of tumors according to their genetic background for tailored treatments, opening the possibility to use SWI/SNF mutations as potential biomarkers for personalized epigenetic-based therapeutics in cancer. Citation Format: Andrea Vilarrubi, Fernando Setien, Eva Pros, Pedro P. Medina, Antonio Gomez, Alberto Villanueva, Octavio A. Romero, Montse Sanchez-Cespedes. SWI/SNF inactivation vulnerability [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3277.

Abstract 3389: An exosomal miRNA-based liquid biopsy signature for the noninvasive early detection of pancreatic ductal adenocarcinoma

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is projected to become the second leading cause of cancer-related deaths in the United States by 2030. Most of the PDAC patients are diagnosed with advanced disease, and less than 20% of patients are resectable at the time of diagnosis. The current imaging tools and blood markers (e.g. CA 19-9), are inadequate for early disease detection due to their poor specificity and sensitivity. This highlights the need to develop robust, noninvasive biomarkers for early detection of PDAC. While a large body of literature supports the use of cell-free miRNAs (cf-miRNAs) as potential diagnostic biomarkers in cancer, their tumor specificity is often debatable. Given the emerging evidence that exosomal cargo is a more robust representation of individual tumor types, in this study we sought to explore the diagnostic potential of cf-miRNAs along with exosomal miRNAs (exo-miRNAs), to establish a non-invasive miRNA signature for the early detection of PDAC. Methods: As part of the NCI’s Pancreatic Cancer Detection Consortium (PCDC) funded project, in this study, small RNA-sequencing was performed in exosome and cell-free (cf) samples from a cohort of 57 PDAC cases and 57 non-disease controls. Using rigorous bioinformatic and biostatistical approaches, we prioritized a panel of cf- and exo-miRNAs and evaluated its diagnostic performance in the sequencing-based discovery and validation cohorts. Subsequently, the performance of the discovered miRNA panel was validated using qRT-PCR assays in an independent clinical validation cohort of PDAC patients and non-disease controls (n=48/each group). The results were examined by ROC curve analysis to determine the diagnostic power of the biomarker panel individually and in combination for their ability to discriminate PDAC from controls. Results: The genomewide transcriptomic analyses led to the identification of a panel of 13 cf-miRNA and 17 exo-miRNA candidates. Sequencing validation in an independent cohort revealed that a combined panel of cf and exo-miRNAs exhibited an area under curve (AUC) of 0.89. Subsequent risk score analysis demonstrated that our biomarker signature was also robust in the identification of PDAC patients with early-stage cancers (stage I & II) vs. controls (p <0.001). Moreover, when we combined the miRNA biomarker panel with CA19-9 values, the diagnostic performance was significantly superior when compared to the biomarker panel alone. Finally, the validation efforts in clinical cohorts by qRT-PCR revealed that the combined miRNA panel yielded an impressive accuracy with an AUC of 0.91, and a sensitivity of 0.88 and specificity of 0.87. Conclusions: In conclusion, we report a novel, exosome-based miRNA signature for the early detection of patients with PDAC; which could potentially improve early-detection efforts for this fatal malignancy. Citation Format: Kota Nakamura, Souvick Roy, Zhongxu Zhu, Eunsung Jun, Haiyong Han, Ruben M. Munoz, Satoshi Nishiwada, Geeta Sharma, Derek Cridebring, Frederic Zenhausern, Seungchan Kim, Denise Roe, Sourat Darabi, In Woong Han, Douglas Evans, Suguru Yamada, Michael Demure, Scott A. Celinski, Erkut Borazanci, Susan Tsai, John Bolton, Yasuhiro Kodera, Joon Oh Park, Song Cheol Kim, Xin Wang, Daniel Von Hoff, Ajay Goel. An exosomal miRNA-based liquid biopsy signature for the noninvasive early detection of pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3389.

Genome-Wide Transcriptome Analysis in Type 2 Diabetes Patients Treated by Sitagliptin.

ObjectiveIn this study, transcriptome sequencing was performed on patients with type 2 diabetes mellitus treated with different prognosis to explore the differential level genes of different hypoglycemic effects of sitagliptin.MethodsPatients with newly diagnosed T2DM (within six months of diagnosis) were selected as the study subjects. Patients were given sitagliptin 100 mg once a day orally. After 12 weeks of regular drug therapy, the reduction in glycated hemoglobin was compared before and after drug administration. The patients were then divided into two groups: the significantly effective group (M) and the less effective group (N). High-throughput sequencing of the transcriptome was conducted to detect the differential expression levels of genes in peripheral blood mononuclear cells. Expanded sample size validation of the candidate differential genes was conducted using reverse transcription-polymerase chain reaction (RT-PCR).ResultsAfter 12 weeks of treatment with sitagliptin, high-throughput sequencing of the transcriptome found that expression of the following genes was different when comparing the significantly effective group (M) and the less effective group (N): ghrelin (GHRL), insulin-like growth factor-1 receptor (IGF1R), mitogen-activated protein kinase-3 (MAPK3), phosphatidylinositol-4,5-bisphosphonate 3-kinase, catalytic subunit delta (PIK3CD), and the suppressor of cytokine signaling-3 (SOCS3). The validation results of RT-PCR showed that, in the significantly effective group (M), the expression of IGF1R was significantly increased (P = 0.034), the expression of MAPK3 was significantly reduced (P = 0.002), and the expression of SOCS3 was also significantly reduced (P < 0.001).ConclusionThere was a significant difference in gene level between patients with significant hypoglycemic effect and patients with poor hypoglycemic effect, and the expression of IGF1R increased and the expression of MAPK3 and SOCS3 decreased.

GDF5+ chondroprogenitors derived from human pluripotent stem cells preferentially form permanent chondrocytes.

It has been established in the mouse model that during embryogenesis joint cartilage is generated from a specialized progenitor cell type, distinct from that responsible for the formation of growth plate cartilage. We recently found that mesodermal progeny of human pluripotent stem cells gave rise to two types of chondrogenic mesenchymal cells in culture: SOX9+ and GDF5+ cells. The fast-growing SOX9+ cells formed in vitro cartilage that expressed chondrocyte hypertrophy markers and readily underwent mineralization after ectopic transplantation. In contrast, the slowly growing GDF5+ cells derived from SOX9+ cells formed cartilage that tended to express low to undetectable levels of chondrocyte hypertrophy markers, but expressed PRG4, a marker of embryonic articular chondrocytes. The GDF5+-derived cartilage remained largely unmineralized in vivo. Interestingly, chondrocytes derived from the GDF5+ cells seemed to elicit these activities via non-cell-autonomous mechanisms. Genome-wide transcriptomic analyses suggested that GDF5+ cells might contain a teno/ligamento-genic potential, whereas SOX9+ cells resembled neural crest-like progeny-derived chondroprogenitors. Thus, human pluripotent stem cell-derived GDF5+ cells specified to generate permanent-like cartilage seem to emerge coincidentally with the commitment of the SOX9+ progeny to the tendon/ligament lineage.

A MZB Cell Activation Profile Present in the Lacrimal Glands of Sjögren's Syndrome-Susceptible C57BL/6.NOD-Aec1Aec2 Mice Defined by Global RNA Transcriptomic Analyses.

The C57BL/6.NOD-Aec1Aec2 mouse has been extensively studied to define the underlying cellular and molecular basis for the onset and development of Sjögren’s syndrome (SS), a human systemic autoimmune disease characterized clinically as the loss of normal lacrimal and salivary gland functions leading respectively to dry eye and dry mouth pathologies. While an overwhelming majority of SS studies in both humans and rodent models have long focused primarily on pathophysiological events and the potential role of T lymphocytes in these events, recent studies in our murine models have indicated that marginal zone B (MZB) lymphocytes are critical for both development and onset of SS disease. Although migration and function of MZB cells are difficult to study in vivo and in vitro, we have carried out ex vivo investigations that use temporal global RNA transcriptomic analyses to track early cellular and molecular events in these exocrine glands of C57BL/6.NOD-Aec1Aec2 mice. In the present report, genome-wide transcriptome analyses of lacrimal glands indicate that genes and gene-sets temporally upregulated during early onset of disease define the Notch2/NF-kβ14 and Type1 interferon signal transduction pathways, as well as identify chemokines, especially Cxcl13, and Rho-GTPases, including DOCK molecules, in the cellular migration of immune cells to the lacrimal glands. We discuss how the current results compare with our recently published salivary gland data obtained from similar studies carried out in our C57BL/6.NOD-Aec1Aec2 mice, pointing out both similarities and differences in the etiopathogeneses underlying the autoimmune response within the two glands. Overall, this study uses the power of transcriptomic analyses to identify temporal molecular bioprocesses activated during the preclinical covert pathogenic stage(s) of SS disease and how these findings may impact future intervention therapies as the disease within the two exocrine glands may not be identical.

Identification of Metabolic Pathways Differentially Regulated in Somatic and Zygotic Embryos of Maritime Pine.

Embryogenesis is a complex phase of conifer development involving hundreds of genes, and a proper understanding of this process is critical not only to produce embryos with different applied purposes but also for comparative studies with angiosperms. A global view of transcriptome dynamics during pine somatic and zygotic embryogenesis is currently missing. Here, we present a genome-wide transcriptome analysis of somatic and zygotic embryos at three developmental stages to identify conserved biological processes and gene functions during late embryogenesis. Most of the differences became more significant as the developmental process progressed from early to cotyledonary stages, and a higher number of genes were differentially expressed in somatic than in zygotic embryos. Metabolic pathways substantially affected included those involved in amino acid biosynthesis and utilization, and this difference was already observable at early developmental stages. Overall, this effect was found to be independent of the line (genotype) used to produce the somatic embryos. Additionally, transcription factors differentially expressed in somatic versus zygotic embryos were analyzed. Some potential hub regulatory genes were identified that can provide clues as to what transcription factors are controlling the process and to how the observed differences between somatic and zygotic embryogenesis in conifers could be regulated.