scholarly journals Screening of Virulence-Related Transcriptional Regulators in Streptococcus suis

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 972
Author(s):  
Liang Liu ◽  
Qiang Zhang ◽  
Zhongmin Xu ◽  
Bo Chen ◽  
Anding Zhang ◽  
...  

Streptococcus suis (S.suis) is an important zoonotic pathogen that causes many severe diseases in pigs and humans. Virulence-related transcriptional regulators have been widely reported in pathogenic microorganisms, but only a few have been identified in S.suis. Our aim was to screen virulence-related transcriptional regulators in S.suis. A total of 89 such genes were predicted in the S.suis genome, of which 22 were up-regulated and 18 were down-regulated during S.suis infection in mice. To evaluate the roles of these differentially expressed factors in S.suis virulence, deletion mutants were constructed, and 10 mutants were successfully obtained. Among these genes, the deletion of comR, sitR, or sxvR caused significantly decreased virulence in mice, compared to that with the wild-type strain. Moreover, the survival of ΔcomR, ΔsitR, and ΔsxvR mutant strains in blood was significantly reduced both in vitro and in vivo. Furthermore, their pro-inflammatory abilities were also obviously decreased in vivo. The regulatory mechanisms of comR, sitR, and sxvR were then analyzed by whole transcriptome RNA sequencing (RNA-Seq). Results indicated that the absence of comR induced the down-regulation of 17 virulence factors or virulence-related factors, including genes involved in the synthesis of capsules, oxidative stress tolerance, immune evasion, and cell division. Furthermore, three and two virulence factors or virulence-related factors were down-regulated upon deletion of sitR and sxvR, respectively. Thus, this study reports the discovery of three virulence-associated transcriptional regulatory factors in S.suis. These factors could ultimately be targeted to control infection caused by these bacteria.

Author(s):  
Alexa N. Lauer ◽  
Rene Scholtysik ◽  
Andreas Beineke ◽  
Christoph Georg Baums ◽  
Kristin Klose ◽  
...  

Streptococcus suis (S. suis) is an important opportunistic pathogen, which can cause septicemia and meningitis in pigs and humans. Previous in vivo observations in S. suis-infected pigs revealed lesions at the choroid plexus (CP). In vitro experiments with primary porcine CP epithelial cells (PCPEC) and human CP epithelial papilloma (HIBCPP) cells demonstrated that S. suis can invade and traverse the CP epithelium, and that the CP contributes to the inflammatory response via cytokine expression. Here, next generation sequencing (RNA-seq) was used to compare global transcriptome profiles of PCPEC and HIBCPP cells challenged with S. suis serotype (ST) 2 infected in vitro, and of pigs infected in vivo. Identified differentially expressed genes (DEGs) were, amongst others, involved in inflammatory responses and hypoxia. The RNA-seq data were validated via quantitative PCR of selected DEGs. Employing Gene Set Enrichment Analysis (GSEA), 18, 28, and 21 enriched hallmark gene sets (GSs) were identified for infected HIBCPP cells, PCPEC, and in the CP of pigs suffering from S. suis ST2 meningitis, respectively, of which eight GSs overlapped between the three different sample sets. The majority of these GSs are involved in cellular signaling and pathways, immune response, and development, including inflammatory response and hypoxia. In contrast, suppressed GSs observed during in vitro and in vivo S. suis ST2 infections included those, which were involved in cellular proliferation and metabolic processes. This study suggests that similar cellular processes occur in infected human and porcine CP epithelial cells, especially in terms of inflammatory response.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Meng Yue ◽  
Tao Liu ◽  
Guoqiang Yan ◽  
Xiaofan Luo ◽  
Lei Wang

Abstract Background Colorectal cancer (CC) is one of the major contributors to tumor-related death worldwide, and its main cause of death is distant metastasis. Dysregulation of long non-coding RNA (lncRNA) LINC01605 has been implicated in CC. However, its role in metastasis of CC remains elusive. The goal of the study is to uncover the biological function and molecular mechanism of LINC01605 in CC. Methods The differentially expressed lncRNAs were first screened from GSE97300, GSE84983, GSE110715, GSE70880, and GSE75970 microarrays. The correlation between the expression of LINC01605 and the clinical phenotypes of enrolled CC patients (n = 134) was subsequently analyzed. The upstream and downstream regulatory mechanisms of LINC01605 in CC were identified through bioinformatics and RNA-seq analyses. Finally, the effects of related factors on CC cell growth and metastasis were confirmed through functional validation experiments. Results LINC01605, significantly highly expressed in CC, was a prognostic factor for patients with CC. Functional experiments revealed that LINC01605 knockdown inhibited the proliferatory and metastatic potential of CC cells in vitro and in vivo. Moreover, LINC01605 was regulated by SMYD2-EP300-mediated modifications of histone H3K4me3 as well as H3K27ac. LINC01605 was found to bind to METTL3 and promote the m6A modification of SPTBN2 mRNA, thereby facilitating the translation of SPTBN2. Conclusions Overexpression of LINC01605, regulated by SMYD2-EP300-mediated H3K27ac and H3K4me3 modifications, bound to METTL3 protein to promote m6A modification of SPTBN2 mRNA, leading to the development of CC.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 566-566
Author(s):  
Arnav Mehta ◽  
Mati Mann ◽  
Monika Kowalczyk ◽  
Carl de Boer ◽  
Jun Wang ◽  
...  

Abstract Hematopoietic stem cells (HSCs) have the unique responsibility to produce balanced immune cell output throughout an organism's life. Importantly, they must do so robustly despite a plethora of external stress, including frequent inflammatory challenge. With age, the accumulation of these stresses leads to impaired HSC function and myeloid-biased output. Aged HSCs are also more prone to pathological hematopoiesis, such as myeloproliferative disorder, leukemia and autoimmune diseases. However, little is known about the subcellular mechanisms that govern the inflammatory response of HSCs with age, which in turn might contribute to pathologic transformation. We show that young hematopoietic stem and progenitor cells (HSPCs) demonstrate a robust transcriptional response to toll-like receptor (TLR) ligands. Interestingly, this response is similar to that of mature immune cell types such as dendritic cells. Using single-cell proteomic assays, we found that young HSPCs secrete a diverse array of myeloid and lymphoid cytokines. However, when challenged with TLR ligands in vivo, young mice acutely increase myeloid-biased output but return rapidly to baseline hematopoietic output of both lymphoid and myeloid cells. Moreover, inflammatory challenge of young long-term HSCs in vitro did not perturb the function and output of these cells in bone marrow reconstitution experiments. In contrast to their counterparts from young mice, we found HSPCs obtained from aged mice have a diminished ability to secrete cytokines in response to TLR ligands. Furthermore, they secrete a homogenous subset of myeloid-biased cytokines. When challenged with TLR ligands in vivo, aged mice acutely increased myeloid output and maintain elevated myeloid output for several months implying memory of the inflammatory challenge. Consistent with this, we also found that pre-stimulation of aged HSCs prior to bone marrow transplant results in a sustained increase in myeloid output compared to unstimulated aged HSCs. To elucidate the differential heterogeneity between young and aged HSPCs in response to TLR signaling, we next performed single-cell RNA sequencing (RNA-seq) experiments. We found that the sustained myeloid output in aged mice after TLR stimulation is largely due to expansion of a myeloid-biased HSC subset in the aged HSC pool. By characterizing the gene expression networks that define these myeloid-biased HSCs under stimulation conditions, we were then able to identify a myeloid-biased HSC subset in both the unperturbed young and aged HSC pools. Moreover, we found that these cells are more abundant in aged mice at steady-state, and that these HSCs demonstrate a unique response to inflammatory challenge. We further identify putative transcriptional regulators, including Klf4, Klf5, Ikzf1 and Stat3, among others, that define gene expression in these myeloid-biased HSCs. We further show that loss of function of these factors can differentially alter myeloid output in young and aged mice both in vitro and in vivo. Our results demonstrate that there is a differential response of young and aged HSCs to inflammatory signals. Using single-cell RNA-seq and protein secretion studies, we elucidate the molecular heterogeneity of the HSC pool at steady state and with TLR stimulation. By resolving heterogeneous subsets of cells in both the young and aged HSC pool, and by uncovering the transcriptional regulators that influence their function, we thus propose a new model of inflammatory hematopoiesis that may have implications to understanding age-related defects in immune development. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Junjun Li ◽  
Yuan Qian ◽  
Chao Zhang ◽  
Wei Wang ◽  
Yisheng Qiao ◽  
...  

AbstractLong noncoding RNAs (lncRNAs) and their crosstalks with other RNAs have been revealed to be closely related to tumorigenesis and development, but their role in invasive pituitary adenoma (IPA) remains largely unclear. In our study, LINC00473 was identified as the most upregulated lncRNA in IPA by whole transcriptome RNA sequencing (RNA-Seq). Further, its related signaling pathway LINC00473/miR-502-3p/KMT5A was obtained by constructing a competing endogenous RNA (ceRNA) regulatory network. Their expression in IPA and non-invasive pituitary adenoma (NIPA) tissues was verified by qRT-PCR. Then the effects and mechanisms of LINC00473 and its ceRNA network on the proliferation of pituitary adenoma (PA) cells were confirmed by gene overexpression or silencing techniques combined with CCK-8 assay, EdU staining, flow cytometry assay, and double luciferase reporter gene assay in PA cell lines AtT-20 and GT1-1 in vitro and in a xenograft model in vivo. LINC00473 is overexpressed in IPA and can promote PA cells proliferation. Mechanistically, overexpression of LINC00473 restricts miR-502-3p through the ceRNA mechanism, upregulates KMT5A expression, and promotes the expression of cyclin D1 and CDK2, which is conducive to the cell cycle process, thereby promoting the proliferation of PA cells, involving IPA progression.


2019 ◽  
Vol 476 (21) ◽  
pp. 3141-3159 ◽  
Author(s):  
Meiru Si ◽  
Can Chen ◽  
Zengfan Wei ◽  
Zhijin Gong ◽  
GuiZhi Li ◽  
...  

Abstract MarR (multiple antibiotic resistance regulator) proteins are a family of transcriptional regulators that is prevalent in Corynebacterium glutamicum. Understanding the physiological and biochemical function of MarR homologs in C. glutamicum has focused on cysteine oxidation-based redox-sensing and substrate metabolism-involving regulators. In this study, we characterized the stress-related ligand-binding functions of the C. glutamicum MarR-type regulator CarR (C. glutamicum antibiotic-responding regulator). We demonstrate that CarR negatively regulates the expression of the carR (ncgl2886)–uspA (ncgl2887) operon and the adjacent, oppositely oriented gene ncgl2885, encoding the hypothetical deacylase DecE. We also show that CarR directly activates transcription of the ncgl2882–ncgl2884 operon, encoding the peptidoglycan synthesis operon (PSO) located upstream of carR in the opposite orientation. The addition of stress-associated ligands such as penicillin and streptomycin induced carR, uspA, decE, and PSO expression in vivo, as well as attenuated binding of CarR to operator DNA in vitro. Importantly, stress response-induced up-regulation of carR, uspA, and PSO gene expression correlated with cell resistance to β-lactam antibiotics and aromatic compounds. Six highly conserved residues in CarR were found to strongly influence its ligand binding and transcriptional regulatory properties. Collectively, the results indicate that the ligand binding of CarR induces its dissociation from the carR–uspA promoter to derepress carR and uspA transcription. Ligand-free CarR also activates PSO expression, which in turn contributes to C. glutamicum stress resistance. The outcomes indicate that the stress response mechanism of CarR in C. glutamicum occurs via ligand-induced conformational changes to the protein, not via cysteine oxidation-based thiol modifications.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shuiyan Wu ◽  
You Jiang ◽  
Yi Hong ◽  
Xinran Chu ◽  
Zimu Zhang ◽  
...  

Abstract Background T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disease with a high risk of induction failure and poor outcomes, with relapse due to drug resistance. Recent studies show that bromodomains and extra-terminal (BET) protein inhibitors are promising anti-cancer agents. ARV-825, comprising a BET inhibitor conjugated with cereblon ligand, was recently developed to attenuate the growth of multiple tumors in vitro and in vivo. However, the functional and molecular mechanisms of ARV-825 in T-ALL remain unclear. This study aimed to investigate the therapeutic efficacy and potential mechanism of ARV-825 in T-ALL. Methods Expression of the BRD4 were determined in pediatric T-ALL samples and differential gene expression after ARV-825 treatment was explored by RNA-seq and quantitative reverse transcription-polymerase chain reaction. T-ALL cell viability was measured by CCK8 assay after ARV-825 administration. Cell cycle was analyzed by propidium iodide (PI) staining and apoptosis was assessed by Annexin V/PI staining. BRD4, BRD3 and BRD2 proteins were detected by western blot in cells treated with ARV-825. The effect of ARV-825 on T-ALL cells was analyzed in vivo. The functional and molecular pathways involved in ARV-825 treatment of T-ALL were verified by western blot and chromatin immunoprecipitation (ChIP). Results BRD4 expression was higher in pediatric T-ALL samples compared with T-cells from healthy donors. High BRD4 expression indicated a poor outcome. ARV-825 suppressed cell proliferation in vitro by arresting the cell cycle and inducing apoptosis, with elevated poly-ADP ribose polymerase and cleaved caspase 3. BRD4, BRD3, and BRD2 were degraded in line with reduced cereblon expression in T-ALL cells. ARV-825 had a lower IC50 in T-ALL cells compared with JQ1, dBET1 and OTX015. ARV-825 perturbed the H3K27Ac-Myc pathway and reduced c-Myc protein levels in T-ALL cells according to RNA-seq and ChIP. In the T-ALL xenograft model, ARV-825 significantly reduced tumor growth and led to the dysregulation of Ki67 and cleaved caspase 3. Moreover, ARV-825 inhibited cell proliferation by depleting BET and c-Myc proteins in vitro and in vivo. Conclusions BRD4 indicates a poor prognosis in T-ALL. The BRD4 degrader ARV-825 can effectively suppress the proliferation and promote apoptosis of T-ALL cells via BET protein depletion and c-Myc inhibition, thus providing a new strategy for the treatment of T-ALL.


Author(s):  
Jiongwei Pan ◽  
Gang Huang ◽  
Zhangyong Yin ◽  
Xiaoping Cai ◽  
Enhui Gong ◽  
...  

AbstractSignificantly high-expressed circFLNA has been found in various cancer cell lines, but not in lung cancer. Therefore, this study aimed to explore the role of circFLNA in the progression of lung cancer. The target gene of circFLNA was determined by bioinformatics and luciferase reporter assay. Viability, proliferation, migration, and invasion of the transfected cells were detected by CCK-8, colony formation, wound-healing, and transwell assays, respectively. A mouse subcutaneous xenotransplanted tumor model was established, and the expressions of circFLNA, miR-486-3p, XRCC1, CYP1A1, and related genes in the cancer cells and tissues were detected by RT-qPCR, Western blot, or immunohistochemistry. The current study found that miR-486-3p was low-expressed in lung cancer. MiR-486-3p, which has been found to target XRCC1 and CYP1A1, was regulated by circFLNA. CircFLNA was located in the cytoplasm and had a high expression in lung cancer cells. Cancer cell viability, proliferation, migration, and invasion were promoted by overexpressed circFLNA, XRCC1, and CYP1A1 but inhibited by miR-486-3p mimic and circFLNA knockdown. The weight of the xenotransplanted tumor was increased by circFLNA overexpression yet reduced by miR-486-3p mimic. Furthermore, miR-486-3p mimic reversed the effect of circFLNA overexpression on promoting lung cancer cells and tumors and regulating the expressions of miR-486-3p, XRCC1, CYP1A1, and metastasis/apoptosis/proliferation-related factors. However, overexpressed XRCC1 and CYP1A1 reversed the inhibitory effect of miR-486-3p mimic on cancer cells and tumors. In conclusion, circFLNA acted as a sponge of miR-486-3p to promote the proliferation, migration, and invasion of lung cancer cells in vitro and in vivo by regulating XRCC1 and CYP1A1.


Genetics ◽  
1999 ◽  
Vol 152 (1) ◽  
pp. 73-87 ◽  
Author(s):  
Margaret K Shirra ◽  
Karen M Arndt

AbstractBinding of the TATA-binding protein (TBP) to the promoter is a pivotal step in RNA polymerase II transcription. To identify factors that regulate TBP, we selected for suppressors of a TBP mutant that exhibits promoter-specific defects in activated transcription in vivo and severely reduced affinity for TATA boxes in vitro. Dominant mutations in SNF4 and recessive mutations in REG1, OPI1, and RTF2 were isolated that specifically suppress the inositol auxotrophy of the TBP mutant strains. OPI1 encodes a repressor of INO1 transcription. REG1 and SNF4 encode regulators of the Glc7 phosphatase and Snf1 kinase, respectively, and have well-studied roles in glucose repression. In two-hybrid assays, one SNF4 mutation enhances the interaction between Snf4 and Snf1. Suppression of the TBP mutant by our reg1 and SNF4 mutations appears unrelated to glucose repression, since these mutations do not alleviate repression of SUC2, and glucose levels have little effect on INO1 transcription. Moreover, mutations in TUP1, SSN6, and GLC7, but not HXK2 and MIG1, can cause suppression. Our data suggest that association of TBP with the TATA box may be regulated, directly or indirectly, by a substrate of Snf1. Analysis of INO1 transcription in various mutant strains suggests that this substrate is distinct from Opi1.


Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3470
Author(s):  
Aubrey L. Miller ◽  
Patrick L. Garcia ◽  
Samuel C. Fehling ◽  
Tracy L. Gamblin ◽  
Rebecca B. Vance ◽  
...  

Gemcitabine is used to treat pancreatic cancer (PC), but is not curative. We sought to determine whether gemcitabine + a BET bromodomain inhibitor was superior to gemcitabine, and identify proteins that may contribute to the efficacy of this combination. This study was based on observations that cell cycle dysregulation and DNA damage augment the efficacy of gemcitabine. BET inhibitors arrest cells in G1 and allow increases in DNA damage, likely due to inhibition of expression of DNA repair proteins Ku80 and RAD51. BET inhibitors (JQ1 or I-BET762) + gemcitabine were synergistic in vitro, in Panc1, MiaPaCa2 and Su86 PC cell lines. JQ1 + gemcitabine was more effective in vivo than either drug alone in patient-derived xenograft models (P < 0.01). Increases in the apoptosis marker cleaved caspase 3 and DNA damage marker γH2AX paralleled antitumor efficacy. Notably, RNA-seq data showed that JQ1 + gemcitabine selectively inhibited HMGCS2 and APOC1 ~6-fold, compared to controls. These proteins contribute to cholesterol biosynthesis and lipid metabolism, and their overexpression supports tumor cell proliferation. IPA data indicated that JQ1 + gemcitabine selectively inhibited the LXR/RXR activation pathway, suggesting the hypothesis that this inhibition may contribute to the observed in vivo efficacy of JQ1 + gemcitabine.


2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii414-iii414
Author(s):  
Muh-Lii Liang ◽  
Tsung-Han Hsieh ◽  
Tai-Tong Wong

Abstract BACKGROUND Glial-lineage tumors constitute a heterogeneous group of neoplasms, comprising gliomas, oligodendrogliomas, and ependymomas, which account for 40%–50% of all pediatric central nervous system tumors. Advances in modern neuro-oncological therapeutics are aimed at improving neoadjuvant chemotherapy and deferring radiotherapy because radiation exposure may cause long-term side effects on the developing brain in young children. Despite aggressive treatment, more than half the high-grade gliomas (pHGGs) and one-third of ependymomas exhibit recurrence within 2 years of initial treatment. METHODS By using integrated bioinformatics and through experimental validation, we found that at least one gene among CCND1, CDK4, and CDK6 was overexpressed in pHGGs and ependymomas. RESULTS The use of abemaciclib, a highly selective CDK4/6 inhibitor, effectively inhibited cell proliferation and reduced the expression of cell cycle–related and DNA repair–related gene expression, which was determined through RNA-seq analysis. The efficiency of abemaciclib was validated in vitro in pHGGs and ependymoma cells and in vivo by using subcutaneously implanted ependymoma cells from patient-derived xenograft (PDX) in mouse models. Abemaciclib demonstrated the suppression of RB phosphorylation, downstream target genes of E2F, G2M checkpoint, and DNA repair, resulting in tumor suppression. CONCLUSION Abemaciclib showed encouraging results in preclinical pediatric glial-lineage tumors models and represented a potential therapeutic strategy for treating challenging tumors in children.


Sign in / Sign up

Export Citation Format

Share Document