Notch Signaling Pathway Research Articles

The SWI/SNF nucleosome remodeler constrains enhancer activity during Drosophila wing development.

Chromatin remodeling is central to the dynamic changes in gene expression that drive cell fate determination. During development, the sets of enhancers that are accessible for use change globally as cells transition between stages. While transcription factors and nucleosome remodelers are known to work together to control enhancer accessibility, it is unclear how the short stretches of DNA that they individually unmask yield the kilobase-sized accessible regions characteristic of active enhancers. Here, we performed a genetic screen to investigate the role of nucleosome remodelers in control of dynamic enhancer activity. We find that the Drosophila Switch/Sucrose Non-Fermenting complex, BAP, is required for repression of a temporally dynamic enhancer, brdisc. Contrary to expectations, we find that the BAP-specific subunit Osa is dispensable for mediating changes in chromatin accessibility between the early and late stages of wing development. Instead, we find that Osa is required to constrain the levels of brdisc activity when the enhancer is normally active. Genome-wide profiling reveals that Osa directly binds brdisc as well as thousands of other developmentally dynamic regulatory sites, including multiple genes encoding components and targets of the Notch signaling pathway. Transgenic reporter analyses demonstrate that Osa is required for activation and for constraint of different sets of target enhancers in the same cells. Moreover, Osa loss results in hyperactivation of the Notch ligand Delta and development of ectopic sensory structures patterned by Notch signaling early in development. Together, these findings indicate that proper constraint of enhancer activity is necessary for regulation of dose-dependent developmental events.

IndiSPENsable for X Chromosome Inactivation and Gene Silencing.

For about 30 years, SPEN has been the subject of research in many different fields due to its variety of functions and its conservation throughout a wide spectrum of species, like worms, arthropods, and vertebrates. To date, 216 orthologues have been documented. SPEN had been studied for its role in gene regulation in the context of cell signaling, including the NOTCH or nuclear hormone receptor signaling pathways. More recently, SPEN has been identified as a major regulator of initiation of chromosome-wide gene silencing during X chromosome inactivation (XCI) in mammals, where its function remains to be fully understood. Dependent on the biological context, SPEN functions via mechanisms which include different domains. While some domains of SPEN are highly conserved in sequence and secondary structure, species-to-species differences exist that might lead to mechanistic differences. Initiation of XCI appears to be different between humans and mice, which raises additional questions about the extent of generalization of SPEN's function in XCI. In this review, we dissect the mechanism of SPEN in XCI. We discuss its subregions and domains, focusing on its role as a major regulator. We further highlight species-related research, specifically of mouse and human SPEN, with the aim to reveal and clarify potential species-to-species differences in SPEN's function.

CLL Cells within the Proliferation Centers of the Patient Lymph Nodes Are Enriched for Notch Signaling, Thus NOTCH a Viable Target for CLL Therapy

CLL cells within the Proliferation Centers of the Patient Lymph Nodes are enriched for Notch signaling, thus a Target for CLL Therapy. Shantaram S. Joshi, Michael Pitner, Matt Kling, Furqan Mehdi, Mamta Shukla, Ashima Shukla, Vipul Shukla, Nagendra Chaturvedi, Hamid Band , Javeed Iqbal The tissue microenvironment, particularly the lymph node (LN), plays a major role in regulating the leukemic progression and clinical heterogeneity of chronic lymphocytic leukemia (CLL). CLL cells proliferate in the patient lymph nodes, resulting in the formation of proliferation centers (PCs). The molecular basis of the CLL cell proliferation within PCs is not well known. Several reports have implicated the activated Notch signaling pathway in the pathogenesis of CLL. Using the IRF4 -/-Vh11 mouse model of CLL, we have previously shown that Notch signaling is indispensable for CLL development (Vipul Shukla et al, Oncotarget, 2016). Based on these studies, we hypothesized that CLL cell proliferation in the lymph node PCs involves activated NOTCH signaling. To this end, we have examined the expression levels of Notch signaling associated molecules namely IRF4, Notch 1, Notch 2, Nedd4, Fbxw7 and Itch1 on CLL cells within the patient lymph node proliferation centers (n=12) using immunohistochemistry and western blotting. Expression levels were scored based on the percentage of cells with positive staining: 5+ (>80%), 4+ (60-80%), 3+ (40-60%), 2+ (20-40%), 1+ (<20%) and 0 (No staining). IHC analyses showed that the expression levels of IRF4 to be 2+, Notch 1 was 4+, Notch 2 was -3 to 4+, Nedd4 was 1+, Fbxw7 was 3+ and ITCH1 was 1+. Western blotting of CLL cells from the lymph node proliferation centers (n=6) confirmed a similar pattern of expression of the Notch-associated genes. Together, these results validate the association of Notch signaling in CLL cells of the patient lymph node PCs similar to CLL cells from the IRF4 -/-Vh11 mouse model. Therefore, as a next logical step we treated the MEC-1 and OSU-CLL cells in culture and primary CLL cell from patients with NOTCH inhibitor RO4929097 (RO), a γ-secretase inhibitor for 24, 48 and 72 hours in vitro. There was a significant decrease in the expression NOTCH 1, NOTCH 2 in MEC-1, OSU-CLL and primary CLL cells determined using western blot technique. Also, we observed a significant decrease in proliferation of CLL cells from MEC-1 and OSU-CLL cell lines, following treatment with NOTCH inhibitor RO. In addition, NOTCH inhibitor combined with Bruton's Tyrosine Kinase (BTK) a member of the B-Cell Receptor signaling, showed a further significant decrease in the proliferation of CLL cells in culture. Together these experiments demonstrated that NOTCH targeting strategy is a viable therapy for aggressive CLL warranting further preclinical and clinical studies. This work was partially supported by bridge funding from the American Association of Hematology awarded to Dr. Runqing Lu, who passed away during the pursuit of this study.

Comparative analysis of alternative splicing events in skeletal muscle of different sheep

This paper aims to investigate the relationship between genes with alternative splicing (AS) events and breed-specific differences in muscle development in two breeds of sheep. RNA-seq was utilized to identify genes with AS between Small-tailed Han sheep and Dorset sheep. The gene lists of differentially spliced genes were identified, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were conducted on these genes. In this study, 299 genes with 356 AS indicated significant differences between two diffrerent breeds. There are differences in 31 genes with 35 AS. Cassette, alt5′ and alt3’ exhibited the highest levels of enrichment across various significant levels. GO and KEGG enrichment analysis demonstrated a significant correlation between Wnt, TGF-beta, Notch and MAPK signaling pathways and the development of muscle in sheep. These findings indicate that genes with AS are linked to variations in muscle development in sheep. These results offer significant scientific and practical implications for improving the quality of sheep meat.

RNA sequencing analysis reveals that missense mutation in SOX10 is associated with iris color phenotype in quail.

To investigate the molecular mechanisms underlying the differences in iris color in quail, the transcriptome of iris tissue from black quail and Korean quail at day 10 of hatching was RNA sequenced in this study. The differentially expressed genes (DEGs) were screened, functionally annotated and enriched after the quality control and mapping of the raw data. RT-qPCR validation was performed using EIF2S3 as an internal reference gene. The screened SNPs were studied by bioinformatics analysis and iris color correlation analysis. The results showed that there were 425 upregulated genes and 364 downregulated genes in 789 DEGs. Gene Ontology (GO) enrichment analysis revealed that 139 DEGs were significantly enriched in 154 GO terms. The Kyoto Encyclopedia of Genes and Genomes enrichment results showed that the Notch signaling pathway, melanogenesis and tyrosine metabolism were associated with pigment synthesis (p < 0.05). The expression levels of the ASIP, MLPH, PMEL, TYR and SOX10 genes were significantly different in black quail iris and Korean quail iris, as verified by RT-qPCR. The SOX10 gene c.324G>C mutation, which caused the replacement of p.Glu108Asp, had a highly significant correlation with iris color in black quail and Korean quail, which may be one of the reasons for different in iris color between these two quail species.

MiR-223-3p attenuates M1 macrophage polarization via suppressing the Notch signaling pathway and NLRP3-mediated pyroptosis in experimental autoimmune uveitis

Autoimmune uveitis is an intraocular inflammatory disease with a high blindness rate in developed countries such as the United States. It is pressing to comprehend the pathogenesis of autoimmune uveitis and develop novel schemes for its treatment. In the present research, we demonstrated that the Notch signaling pathway was activated, and the level of miR-223-3p was significantly reduced in rats with experimental autoimmune uveitis (EAU) compared with the level of normal rats. To investigate the relationship between miR-223-3p and Notch signaling, EAU rats received miR-223-3p-carrying lentivirus, miR-223-3p vector-carrying lentivirus (miR-223-3p-N), and γ-secretase inhibitor (DAPT), respectively. The results of Q-PCR, immunological experiments, and flow cytometry analysis all support the hypothesis that both miR-223-3p and DAPT, a Notch signaling pathway inhibitor, had similar inhibitory effects on the EAU pathological process. That is to say, they could both inhibit the activation of the Notch signaling pathway via modulating recombination signal binding protein-Jκ (RBPJ) to restore the polarization imbalance of M/M2 macrophages in EAU rats. In addition, miR-223-3p could also inhibit NLRP3 inflammasome activation and inflammasome-induced pyroptosis in ocular tissues. Taken together, our findings indicate that miR-223-3p serves as an important regulator in M1 macrophage polarization and pyroptosis, thereby alleviating the inflammatory response in uveitis.

FGL1 Promotes Tumor Immune Escape in Stomach Adenocarcinoma via the Notch Signaling Pathway.

Immune escape is the major reason for immunotherapy failure in stomach adenocarcinoma (STAD). We tried to reveal the underlying mechanism of FGL1 influencing STAD in this study. Bioinformatics analyses were conducted to analyze the expression of FGL1, the signaling pathways affected by FGL1, and the relation between FGL1 and immune cell infiltration. Quantitative real-time PCR (qRT-PCR), cell counting kit-8 assay, colony formation assay, flow cytometry and Transwell assay were adopted to analyze FGL1 expression, cell viability, cell proliferation, cell apoptosis, and cell invasion, respectively. Enzyme-linked immunosorbent assay, lactate dehydrogenase method, qRT-PCR and Western blot were adopted to reveal proinflammatory cytokine expression, cytotoxicity and mRNA and protein expression of the Notch signaling-related genes, respectively, after co-culture of STAD cells and CD8+T cells. Nude mice experiment was conducted to validate the results obtained above. FGL1 expressed highly in STAD and could activate the Notch signaling pathway, and it was negatively correlated with CD8+T cell infiltration. Cell experiments confirmed that high expression of FGL1 facilitated proliferation and hindered apoptosis of STAD cells. Knockdown of FGL1 could facilitate expression of pro-inflammatory factors and the cytotoxicity of CD8+T cells in co-culture system of STAD and CD8+ T cells. Knockdown of FGL1 could suppress the expression of the Notch signaling pathway-related genes, and the addition of Notch inhibitor proved that FGL1 promoted immune escape via the Notch signaling pathway. This study investigated the influence of FGL1 on STAD immune escape and demonstrated that FGL1 inhibited CD8+ T cell activation by activating the Notch signaling pathway and thus promoted tumor immune escape in STAD, providing a new potential diagnostic marker and therapeutic target for the immunotherapy of STAD patients.

Integrated analysis of histone lysine lactylation (Kla)-specific genes suggests that NR6A1, OSBP2 and UNC119B are novel therapeutic targets for hepatocellular carcinoma

Histone lysine lactylation (Kla) plays a vital role in the tumorigenesis of hepatocellular carcinoma (HCC). Hence, we focused on Kla-specific genes to select novel therapeutic targets. Differentially expressed Kla-specific genes (DEKlaGs) were identified from TCGA with the cut-off criteria |log2(FlodChange (FC))| > 2, p-value < 0.05, following investigating the prognostic value. The correlation between lactate accumulation and prognostic DEKlaGs expression was further investigated. On the other hand, we explored the roles of Kla activation in the immune microenvironment, immunotherapy, and drug resistance. We conducted gene set enrichment analysis (GSEA) to predict the pathways influenced by Kla. The predictive power of Cox model was further identified in ICGC and GEO databases. A total of 129 DEKlaGs were identified, and 32 molecules might be potential prognostic biomarkers. A Cox model including ARHGEF37, MTFR2, NR6A1, NT5DC2, OSBP2, RNASEH2A, SFN, and UNC119B was constructed, which suggested unfavorable overall survival in high-risk score group, and risk score could serve as an indicator for large tumor size, poor pathological grade and advanced stage. NR6A1, OSBP2 and UNC119B could inhibit NK cell as well as TIL cell infiltration, and impair Type-I and II IFN responses in HCC, thereby contributing to unsatisfactory prognosis and immunotherapy resistance. OSBP2 and UNC119B were identified to be related to chemotherapy resistance. GSEA showed that WNT, MTOR, MAPK and NOTCH signaling pathways were activated, indicating that these pathways might play a crucial role during the Kla process. On the other hand, we showed that NR6A1 and OSBP2 were overexpressed in GEO. OSBP2 and UNC119B contributed to poor survival and advanced stage in ICGC. In summary, histone Kla was related to HCC prognosis and might serve as an independent biomarker. NR6A1, OSBP2 and UNC119B were associated with the prognosis, immunotherapy, and chemotherapy resistance, suggesting that NR6A1, OSBP2 and UNC119B might be novel candidate therapeutic targets for HCC.

24 Intestinal Function and Integrity in Health and Disease: Current Knowledge in Swine

Abstract Optimal lean tissue accretion is contingent on the ability of the pig to efficiently establish and maintain host defenses, and to digest and absorb nutrients and water. Epithelial cells in the mucosa of the gastrointestinal tract interconnect with each other by tight junctions, adherens junctions, and desmosomes, forming a complete intestinal barrier. Of the secretory cells in this epithelial barrier, mucus secreting goblet cells and hormone producing enteroendocrine cells can be found interspersed, while Paneth cells lie in the base of the crypts and secrete antimicrobial proteins/peptides into the mucus layer. In the small intestine, enterocytes lining the villi allow for efficient nutrient transport. Maintenance of the epithelial barrier and its function is dependent on intestinal stem cells residing at the crypt base. Two major signaling pathways controlling intestinal stem cell proliferation and differentiation are the β-catenin/Wnt and Notch signaling pathways. Thus, achieving and maintaining optimal nutrient absorptive capacity requires an intricate balance amongst β-catenin/Wnt and Notch signaling pathways, wherein dysregulation of either can result in inefficiency of nutrient absorption. Weaning transition, off-feed events, hypophagia, and enteric and respiratory diseases can all compromise the structural and secretory barrier of the gastrointestinal tract mucosa via changes in tight and adherens junction proteins and mucin production. As a result, these stressors can increase the incidence of gastric ulcers, villous atrophy, and colitis in pigs. Depending on the severity and duration of the mucosal damage, repair and restitution occurs due to increased stem cell proliferation, migration, and repolarization. Thus, efficiency of digestive and absorptive function depends on several factors, including the types of epithelial cells present and their functionality, the rate of cell renewal, and epithelial surface area. This paper will discuss what we know about the regulation and repair of the mucosal epithelium in growing pigs during health, stress, and disease.

Bovine oviductal organoids: a multi-omics approach to capture the cellular and extracellular molecular response of the oviduct to heat stress

BackgroundThe mammalian oviduct is a complex, fibromuscular organ known for its role in orchestrating a series of timely and dynamic changes to suitably support early embryogenesis. Climate change-induced heat stress (HS) is one of the largest single stressors compromising reproductive function in humans and farm animals via systemic changes in the redox status of the maternal environment, adversely affecting fertilization and early embryonic development. Oviductal organoids represent a unique 3-dimensional, biomimetic model to study the physiology of the oviduct and its subsequent impact on embryo development under various environmental conditions.ResultsOur study is the first to demonstrate an innovative approach to understanding the cascade of molecular changes sustained by bovine oviductal organoids under HS and the subsequent maternal signals harnessed within their secreted extracellular vesicles (EVs). Transcriptomic analysis of oviductal organoids exposed to HS revealed 2,570 differentially expressed genes (1,222 up‐ and 1,348 downregulated), while EV-coupled miRNome analysis disclosed 18 miRNAs with significant differential expression (12 up- and 6 downregulated) in EVs from thermally stressed organoids compared to EVs released from organoids cultured under thermoneutral conditions. Genes activated in oviductal organoids in response to thermal stress, include: COX1, ACTB, CST6, TPT1, and HSPB1, while miR-1246, miR-148a, miR21-5p, miR-451, and miR-92a represent the top highly abundant EV-coupled miRNAs released in response to HS. Pathway analysis of genes enriched in organoids exposed to thermal stress showed the enrichment of endocrine resistance, cellular senescence, and notch signaling pathways. Similarly, EV-coupled miRNAs released from thermally stressed organoids showed their potential regulation of genes involved in cellular senescence, p53 signaling, and TGF-beta signaling pathways.ConclusionsIn conclusion, the cellular and extracellular response of bovine oviductal organoids to in vitro HS conditions reveal the prospective impact of environmental HS on the physiology of the oviduct and the probable subsequent impacts on oocyte fertilization and early embryo development. Future studies elucidating the potential impact of HS-associated EVs from oviductal organoids on oocyte fertilization and preimplantation embryo development, would justify the use of an organoid model to optimally understand the oviduct-embryo communication under suboptimal environments.

Quantitative proteomics analysis reveals the key proteins related to semen quality in Niangya yaks

BackgroundProteins related to sperm motility and sperm morphology have an important impact on sperm function such as metabolism, motility and fertilisation etc. An understanding of the key proteins related to semen quality in Niangya yaks would help to provide support for breeding. However, the key proteins that affect semen quality in Niangya yaks remain unclear.MethodsHerein, we applied tandem mass tag (TMT) labeling and liquid chromatography-tandem mass spectrometry (LC‒MS/MS) to analyze the expression levels of sperm proteins in groups of high- and low-quality semen from Niangya yaks. And fifteen differentially expressed proteins (DEPs) were randomly selected for expression level validation by parallel reaction monitoring (PRM).ResultsOf the 2,092 quantified proteins, 280 were identified as DEPs in the high-quality group versus the low-quality group. Gene Ontology (GO) analysis revealed that in terms of biological pathways, the DEPs were mainly involved in metabolic processes, cell transformation processes, and single organism metabolic processes. In terms of cell composition, the DEPs were mainly located in the cell membrane, organelle, molecular complex. In terms of molecular functions, the most abundant functions of the DEPs were catalytic activity, binding activity, transport activity, and enzyme regulation activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that the DEPs were mainly involved in the cytokine and cytokine receptor interaction, notch signaling pathway, lysine biosynthesis, renal function-related protein and proteasome pathway. From protein-protein interaction (PPI) analysis of DEPs involved in important pathways, 6 related proteins affecting the semen quality of Niangya yaks were identified. And the results of the PRM and TMT analysis were consistent.ConclusionsThe differential sperm proteomic analysis of high- and low-quality semen from Niangya yaks, revealed 6 proteins (PSMC5, PSMD8, PSMB3, HSP90AA1, UGP2 and HSPB1), were mainly concentrated in energy production and metabolism, might play important roles in semen quality, which could serve as candidates for the selection and breeding of Niangya yaks.

ASH2L-mediated H3K4me3 drives diabetic nephropathy through HIPK2 and Notch1 pathway

Diabetic nephropathy (DN) is one of the complications of diabetes. Long-term hyperglycemia in the kidney results in renal insufficiency, and eventually leads to end-stage renal disease. Epigenetic factor ASH2L has long been identified as a transcriptional activator, and we previously indicated that ASH2L aggravated fibrosis and inflammation in high glucose-induced glomerular mesangial cells, but the pathophysiological relevance and the mechanism of ASH2L-mediated H3K4me3 in DN is not well understood. Here we demonstrated that ASH2L is upregulated in glomeruli isolated from db/db mice. Loss of ASH2L protected glomerular injury caused by hyperglycemia, as evidenced by reduced albuminuria, preserved structure, decreased glomerular extracellular matrix deposition, and lowered renal glomerular expression of proinflammatory and profibrotic markers in db/db mice. Furthermore, we demonstrated that enrichment of ASH2L-mediated H3K4me3 on the promoter regions of ADAM17 and HIPK2 triggered their transcription, leading to aberrant activation of Notch1 signaling pathway, thereby contributing to fibrosis and inflammation in DN. The findings of this study provide compelling evidence for targeting ASH2L as a potential therapeutic strategy to prevent or slow down the progression of DN.

The Special Role of JAK/STAT, and Notch Signaling Pathways in Cancer Pathogenesis

Cancer is essentially a genetic disease, characterized by unclear etiology in many cases, complex pathogenic mechanisms, since in the majority of cancer cases only risk or predisposing factors have been recognized, and unclarified observations concerning organs that are not often affected by malignant tumors such as the small intestine, spleen, heart, and the neurons of the Central Nervous System. A tumor’s appearance and progression presupposes a series of genetic and non-genetic alterations that characterize tumor cells, and are related to self-sufficiency in growth stimuli, insensitivity to anti-growth signals, unlimited replicative potential, angiogenesis promotion, ability to infiltrate surrounding tissues and induce distant metastases, and resistance to apoptosis. The mentioned characteristics are associated with signaling pathways that are involved in cell survival, cell death, cell growth and division, cell motility, and can be considered in the context of abnormalities of wider signaling networks that support cancer progression, such as tumor microenvironment alterations, angiogenesis, and inflammation. Among others, two signaling pathways, JAK/STAT and Notch, seem to play essential roles in tumorigenesis, despite the fact that are implicated in diverse cellular functions such as tissue formation and cell differentiation, proliferation, apoptosis, inflammation, self-renewal, antitumor immune response suppression, motility, stress response and other responses depending on the target tissue. Hyperactivation of those signaling pathways caused by mutations are able to transform cellular proto-oncogenes to oncogenes, whereas inactivation of tumor suppressor genes eradicates crucial negative regulators of signaling. Various anticancer agents target those signaling pathways in an attempt to inhibit those pathways including monoclonal antibodies and other agents in the context of targeted cancer therapy.

Prenatal exposure to acetaminophen at different doses, courses and time causes testicular dysplasia in offspring mice and its mechanism

Epidemiological investigation suggested that the use of acetaminophen during pregnancy may cause offspring testicular dysplasia, but no systematic study has been conducted. In this study, Kunming mice were given acetaminophen at different doses (100/200/400 mg/kg.d), courses (single/multiple), time (second/third trimester) during pregnancy. Fetal blood and testes were collected on gestaional day 18 for detection. The results indicated abnormal testicular development in the PAcE (prenatal acetaminophen exposure) groups. The maximum diameter/cross-sectional area decreased, the interstitial space widened, and decreased proliferation/increased apoptosis were observed, especially in the high-dose, multi-course and second-trimester groups. Meanwhile, the serum testosterone level decreased in PAcE groups, and the steroid synthesis function in Leydig cells, Sertoli and spermatogenic cell function were inhibited, it was more significant in high-dose, multi-course and second-trimester groups. Furthermore, Wnt signal pathway was activated but Notch signal pathway was inhibited in the PAcE groups. Finally, in vitro experiment, acetaminophen could inhibit spermatogonial cell proliferation, enhance apoptosis, and change Wnt/Notch signal pathway. In conclusion, this study confirmed that PAcE can change fetal testicular development in a dose, course and time-dependent manner, and found that multicellular function impaired. This study provides theoretical and experimental basis for systematically elucidating the developmental toxicity of acetaminophen in testis.

Effects of different signaling pathways on odontogenic differentiation of dental pulp stem cells: a review.

Dental pulp stem cells (DPSCs) are a type of mesenchymal stem cells that can differentiate into odontoblast-like cells and protect the pulp. The differentiation of DPSCs can be influenced by biomaterials or growth factors that activate different signaling pathways in vitro or in vivo. In this review, we summarized six major pathways involved in the odontogenic differentiation of DPSCs, Wnt signaling pathways, Smad signaling pathways, MAPK signaling pathways, NF-kB signaling pathways, PI3K/AKT/mTOR signaling pathways, and Notch signaling pathways. Various factors can influence the odontogenic differentiation of DPSCs through one or more signaling pathways. By understanding the interactions between these signaling pathways, we can expand our knowledge of the mechanisms underlying the regeneration of the pulp-dentin complex.

Association of NOTCH3 With Elastic Fiber Dispersion in the Infrarenal Abdominal Aorta of Cynomolgus Monkeys.

The regional heterogeneity of vascular components and transcriptomes is an important determinant of aortic biology. This notion has been explored in multiple mouse studies. In the present study, we examined the regional heterogeneity of aortas in nonhuman primates. Aortic samples were harvested from the ascending, descending thoracic, suprarenal, and infrarenal regions of young control monkeys and adult monkeys with high fructose consumption for 3 years. The regional heterogeneity of aortic structure and transcriptomes was examined by histological and bulk RNA sequencing analyses, respectively. Immunostaining of CD31 and αSMA (alpha-smooth muscle actin) revealed that endothelial and smooth muscle cells were distributed homogeneously across the aortic regions. In contrast, elastic fibers were less abundant and dispersed in the infrarenal aorta compared with other regions and associated with collagen deposition. Bulk RNA sequencing identified a distinct transcriptome related to the Notch signaling pathway in the infrarenal aorta with significantly increased NOTCH3 mRNA compared with other regions. Immunostaining revealed that NOTCH3 protein was increased in the media of the infrarenal aorta. The abundance of medial NOTCH3 was positively correlated with the dispersion of elastic fibers. Adult cynomolgus monkeys with high fructose consumption displayed vascular wall remodeling, such as smooth muscle cell loss and elastic fiber disruption, predominantly in the infrarenal region. The correlation between NOTCH3 and elastic fiber dispersion was enhanced in these monkeys. Aortas of young cynomolgus monkeys display regional heterogeneity of their transcriptome and the structure of elastin and collagens. Elastic fibers in the infrarenal aorta are dispersed along with upregulation of medial NOTCH3.

Deregulation of TWIST1 expression by promoter methylation in gastrointestinal cancers

TWIST1, a basic helix-loop-helix transcription factor with versatile roles in cancer, is frequently deregulated in cancers, through established pathway perturbations. However. the significance of TWIST1 methylation in the deregulation of TWIST1 in gastrointestinal cancers is not fully clear. This study hypothesized that TWIST1 promoter methylation deregulates TWIST1 expression independent of established deregulators such as the WNT, TGFB, NOTCH and miRNA pathways. To prove this hypothesis, colon, gastric and rectal cancer genomic data comprising gene expression, DNA methylation, and miRNA data were retrieved from the Cancer Genome Atlas cohorts which are publicly available in cancer genomic databases, the Genome Data Commons and the cBioportal.org. About 217 variables comprising expression levels of genes of the WNT, TGFB, NOTCH and miRNA signalling pathways, as well as the beta values of 17 TWIST1 methylation loci were subjected to Principal Component Regression Analysis, and then standard Linear Regression Analysis. The results showed that TWIST1 methylation is a predictor of TWIST1 expression in the gastrointestinal cancers, independent of WNT, TGFB, and NOTCH signalling and miRNA deregulation. The results also showed that different TWIST1 methylation loci may deregulate TWIST1 expression in different cancer types. The inference that can be drawn from this study is that TWIST1 DNA methylation is an important TWIST1 deregulation mechanism in colon, rectal and gastric cancers.

Host factor TIMP1 sustains long-lasting myeloid-biased hematopoiesis after severe infection.

Infection is able to promote innate immunity by enhancing a long-term myeloid output even after the inciting infectious agent has been cleared. However, the mechanisms underlying such a regulation are not fully understood. Using a mouse polymicrobial peritonitis (sepsis) model, we show that severe infection leads to increased, sustained myelopoiesis after the infection is resolved. In post-infection mice, the tissue inhibitor of metalloproteinases 1 (TIMP1) is constitutively upregulated. TIMP1 antagonizes the function of ADAM10, an essential cleavage enzyme for the activation of the Notch signaling pathway, which suppresses myelopoiesis. While TIMP1 is dispensable for myelopoiesis under the steady state, increased TIMP1 enhances myelopoiesis after infection. Thus, our data establish TIMP1 as a molecular reporter of past infection in the host, sustaining hyper myelopoiesis and serving as a potential therapeutic target for modulating HSPC cell fate.

Cytokines as drivers: Unraveling the mechanisms of epithelial-mesenchymal transition in COVID-19 lung fibrosis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), like other viruses, can induce proliferation of myofibroblasts and even lead to fibrosis in the lung. Epithelial-mesenchymal transition (EMT) is thought to play an essential role in the pathogenesis of Coronavirus disease 19 (COVID-19). EMT is originally a critical process that regulates the development of different tissues in the embryo, but in inflammatory situations, EMT tries to be activated again to control inflammation or even heal inflammatory damage. However, in pathological situations, such as chronic viral infections (e.g., COVID-19) or pulmonary fibrosis initiation, this benign healing transforms into sinister nature, pushing the lung into the fibrotic process. Notably, the cytokines released by inflammatory cells and the chronic inflammatory microenvironment shared by fibrotic cells promote each other as critical factors in the induction of pathological EMT. In the induction of SARS-CoV-2 virus, cytokines are an essential mediator of EMT transformation, and a summary of whether COVID-19 patients, during the infection phase, have many persistent inflammatory mediators (cytokines) that are a causative factor of EMT has not yet appeared.The following common signaling drivers, including Transforming growth factor beta (TGF-β), cytokines, Notch signaling pathway, Wnt and hypoxia signaling pathways, drive the regulation of EMT. In this review, we will focus on 3 key EMT signaling pathways: TGF-β, Leucine zipper transcription factor like 1 (LZTFL1) and the common interleukin family expressed in the lung. TGF-β-induced SNAIL and LZTFL1 were identified as regulatory EMT in COVID-19. For cytokines, the interleukin family is a common inducer of EMT and plays an essential role in the formation of the microenvironment of fibrosis. We sought to demonstrate that cytokines act as "communicators" and build the "microenvironment" of fibrosis together with EMT as a "bridge" to induce EMT in fibrosis. The mechanisms utilized by these two pathways could serve as templates for other mesenchymal transformations and provide new potential therapeutic targets.

Prenatal prednisone exposure disturbs fetal kidney development and its characteristics

Prednisone is a synthetic glucocorticoid that is commonly used in both human and veterinary medication. Now, it is also recognized as an emerging environmental contaminant. Pregnant women may be exposed to prednisone actively or passively through multiple pathways and cause developmental toxicity to the fetus. However, the impact of prenatal prednisone exposure (PPE) on fetal kidney development remains unclear. In this study, pregnant mice were administered prednisone intragastrically during full-term pregnancy with different doses (0.25, 0.5, or 1 mg/(kg·day)), or at the dose of 1 mg/(kg·day) in different gestational days (GD) (GD0-9, GD10-18, or GD0-18). The pregnant mice were euthanized on GD18. HE staining revealed fetal kidney dysplasia, with an enlarged glomerular Bowman's capsule space and a reduced capillary network in the PPE groups. The expression of the podocyte and the mesangial cell marker genes was significantly reduced in the PPE groups. However, overall gene expression in renal tubules and collecting ducts were markedly increased. All of the above effects were more pronounced in high-dose, full-term pregnancy, and female fetuses. Studies on the mechanism of the female fetal kidney have revealed that PPE reduced the expression of Six2, increased the expression of Hnf1β, Hnf4α, and Wnt9b, and inhibited the expression of glial cell line-derived neurotrophic factor (GDNF) and Notch signaling pathways. In conclusion, this study demonstrated that there is a sex difference in the developmental toxicity of PPE to the fetal kidney, and the time effect is manifested as full-term pregnancy > early pregnancy > mid-late pregnancy.