The role of TGF-β pathway in immune regulation as a potential biomarker of immunotherapy across pan-cancer.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e15187-e15187
Author(s):  
Yongmei Yin ◽  
Yan Liang ◽  
Zhengyi Zhao ◽  
Yuzi Zhang ◽  
Jing Zhao ◽  
...  
Keyword(s):  
Overall Survival ◽  
Immune Regulation ◽  
Transforming Growth Factor ◽  
Expression Patterns ◽  
Group Versus ◽  
Chinese Patients ◽  
Wild Type ◽  
Potential Biomarker ◽  
Tumor Types

e15187 Background: The transforming growth factor beta (TGF-β) signaling pathway has been reported to be involved in both tumor suppression and tumor promotion. However, the role of TGF-β pathway in immune regulation for cancer patients and its influences on immunotherapy efficacy have not been systematically investigated. Methods: Available data of whole-exome sequencing, mRNA expression, baseline characterization and prognosis information of 10,912 pancancer patients were adopted from The Cancer Genome Altas (TCGA) to explore the role of TGF-β pathway in immune regulation. Formalin-fixed, paraffin-embedded tissue samples from 6,717 Chinese patients with over 17 tumor types were assayed by next-generation sequencing with a panel with 381 cancer related genes as a validation cohort (3DMed cohort). Datasets from the public MSK cohort (N = 1,610) was used to explore the association of TGF-β pathway in patient survival. Results: The highest prevalence of single nucleotide variation (SNVs) in TGF-β pathway fell in digestive system tumors in both TCGA and 3DMed cohorts, including colon adenocarcinoma pancreatic adenocarcinoma, rectum adenocarcinoma, and stomach adenocarcinoma. TGF-β pathway SNVs was significantly correlated with high microsatellite instability, high tumor mutational burden (TMB-H) status and high neoantigen burden (TNB-H) ( p< 0.001) across all tumor types. Notably, the correlation of pathway alternation and TMB or TNB remained significance in microsatellite stable patients ( p< 0.001). Alternations of the pathway genes were associated with significant different expression patterns of immune-related genes such as the up-regulation of CD28, CD40, and CCL5, etc. Consistently, significant higher levels of CD8 ( p< 0.001), dendritic cells ( p< 0.001), and neutrophil cells ( p< 0.001) were observed in the pathway mutated samples. Patients with TGF-β pathway mutations exhibited significant worse prognosis than the wild-type patients regardless of interventions (overall survival, HR 1.20, 95% CI 1.08-1.33; p= 0.001). However, when treated with immune checkpoint inhibitors, superior survival benefit was observed in patients in the mutation group versus the wild-type group (overall survival, HR 0.73, 95% CI 0.61-0.88; p= 0.001). Conclusions: Our study has provided clues for the role of TGF-β pathway in immune regulation in patients with solid tumors and revealed the potential predictive role of TGF-β pathway alternation in cancer immunotherapy.

Pax6 regulates specification of ventral neurone subtypes in the hindbrain by establishing progenitor domains

Development ◽  
2002 ◽  
Vol 129 (6) ◽  
pp. 1327-1338 ◽  
Author(s):  
Masanori Takahashi ◽  
Noriko Osumi
Keyword(s):  
Expression Patterns ◽  
Domain Formation ◽  
Wild Type ◽  
Whole Embryo Culture ◽  
Neuronal Markers ◽  
Signalling Molecules ◽  
Neuronal Progenitors ◽  
In The Wild ◽  
Mutant Rat

Recent studies have shown that generation of different kinds of neurones is controlled by combinatorial actions of homeodomain (HD) proteins expressed in the neuronal progenitors. Pax6 is a HD protein that has previously been shown to be involved in the differentiation of the hindbrain somatic (SM) motoneurones and V1 interneurones in the hindbrain and/or spinal cord. To investigate in greater depth the role of Pax6 in generation of the ventral neurones, we first examined the expression patterns of HD protein genes and subtype-specific neuronal markers in the hindbrain of the Pax6 homozygous mutant rat. We found that Islet2 (SM neurone marker) and En1 (V1 interneurone marker) were transiently expressed in a small number of cells, indicating that Pax6 is not directly required for specification of these neurones. We also observed that domains of all other HD protein genes (Nkx2.2, Nkx6.1, Irx3, Dbx2 and Dbx1) were shifted and their boundaries became blurred. Thus, Pax6 is required for establishment of the progenitor domains of the ventral neurones. Next, we performed Pax6 overexpression experiments by electroporating rat embryos in whole embryo culture. Pax6 overexpression in the wild type decreased expression of Nkx2.2, but ectopically increased expression of Irx3, Dbx1 and Dbx2. Moreover, electroporation of Pax6 into the Pax6 mutant hindbrain rescued the development of Islet2-positive and En1-positive neurones. To know reasons for perturbed progenitor domain formation in Pax6 mutant, we examined expression patterns of Shh signalling molecules and states of cell death and cell proliferation. Shh was similarly expressed in the floor plate of the mutant hindbrain, while the expressions of Ptc1, Gli1 and Gli2 were altered only in the progenitor domains for the motoneurones. The position and number of TUNEL-positive cells were unchanged in the Pax6 mutant. Although the proportion of cells that were BrdU-positive slightly increased in the mutant, there was no relationship with specific progenitor domains. Taken together, we conclude that Pax6 regulates specification of the ventral neurone subtypes by establishing the correct progenitor domains.

Role of the Hypoxia-Inducible Factor Pathway in Normal and Osteoarthritic Meniscus and in Mice after Destabilization of the Medial Meniscus

Cartilage ◽  
2020 ◽  
pp. 194760352095814
Author(s):  
Austin V. Stone ◽  
Richard F. Loeser ◽  
Michael F. Callahan ◽  
Margaret A. McNulty ◽  
David L. Long ◽  
...  
Keyword(s):  
Gene Expression ◽  
Target Genes ◽  
Medial Meniscus ◽  
Transforming Growth Factor ◽  
Hypoxia Inducible Factor ◽  
Early Time ◽  
Wild Type ◽  
Inflammatory Stimuli ◽  
Hif Pathway

Objective Meniscus injury and the hypoxia-inducible factor (HIF) pathway are independently linked to osteoarthritis pathogenesis, but the role of the meniscus HIF pathway remains unclear. We sought to identify and evaluate HIF pathway response in normal and osteoarthritic meniscus and to examine the effects of Epas1 (HIF-2α) insufficiency in mice on early osteoarthritis development. Methods Normal and osteoarthritic human meniscus specimens were obtained and used for immunohistochemical evaluation and cell culture studies for the HIF pathway. Meniscus cells were treated with pro-inflammatory stimuli, including interleukins (IL)-1β, IL-6, transforming growth factor (TGF)-α, and fibronectin fragments (FnF). Target genes were also evaluated with HIF-1α and HIF-2α (Epas1) overexpression and knockdown. Wild-type ( n = 36) and Epas1+/− ( n = 30) heterozygous mice underwent destabilization of the medial meniscus (DMM) surgery and were evaluated at 2 and 4 weeks postoperatively for osteoarthritis development using histology. Results HIF-1α and HIF-2α immunostaining and gene expression did not differ between normal and osteoarthritic meniscus. While pro-inflammatory stimulation significantly increased both catabolic and anabolic gene expression in the meniscus, HIF-1α and Epas1 expression levels were not significantly altered. Epas1 overexpression significantly increased Col2a1 expression. Both wild-type and Epas1+/− mice developed osteoarthritis following DMM surgery. There were no significant differences between genotypes at either time point. Conclusion The HIF pathway is likely not responsible for osteoarthritic changes in the human meniscus. Additionally, Epas1 insufficiency does not protect against osteoarthritis development in the mouse at early time points after DMM surgery. The HIF pathway may be more important for protection against catabolic stress.

scholarly journals Unique Role of Caffeine Compared to Other Methylxanthines (Theobromine, Theophylline, Pentoxifylline, Propentofylline) in Regulation of AD Relevant Genes in Neuroblastoma SH-SY5Y Wild Type Cells

2020 ◽  
Vol 21 (23) ◽  
pp. 9015
Author(s):  
Daniel Janitschke ◽  
Anna A. Lauer ◽  
Cornel M. Bachmann ◽  
Martin Seyfried ◽  
Heike S. Grimm ◽  
...  
Keyword(s):  
Gene Regulation ◽  
Transcriptional Regulation ◽  
Expression Patterns ◽  
Wild Type ◽  
Neuronal Function ◽  
Purine Base ◽  
Unique Role ◽  
Beneficial Effects ◽  
Other Substances

Methylxanthines are a group of substances derived from the purine base xanthine with a methyl group at the nitrogen on position 3 and different residues at the nitrogen on position 1 and 7. They are widely consumed in nutrition and used as pharmaceuticals. Here we investigate the transcriptional regulation of 83 genes linked to Alzheimer’s disease in the presence of five methylxanthines, including the most prominent naturally occurring methylxanthines—caffeine, theophylline and theobromine—and the synthetic methylxanthines pentoxifylline and propentofylline. Methylxanthine-regulated genes were found in pathways involved in processes including oxidative stress, lipid homeostasis, signal transduction, transcriptional regulation, as well as pathways involved in neuronal function. Interestingly, multivariate analysis revealed different or inverse effects on gene regulation for caffeine compared to the other methylxanthines, which was further substantiated by multiple comparison analysis, pointing out a distinct role for caffeine in gene regulation. Our results not only underline the beneficial effects of methylxanthines in the regulation of genes in neuroblastoma wild-type cells linked to neurodegenerative diseases in general, but also demonstrate that individual methylxanthines like caffeine mediate unique or inverse expression patterns. This suggests that the replacement of single methylxanthines by others could result in unexpected effects, which could not be anticipated by the comparison to other substances in this substance class.

Landmark Analyses of DNMT3A Mutations in Hematological Malignancies

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 407-407
Author(s):  
Vera Grossmann ◽  
Alexander Kohlmann ◽  
Claudia Haferlach ◽  
Tamara Alpermann ◽  
Melanie Wild ◽  
...  
Keyword(s):  
Overall Survival ◽  
Mutation Rate ◽  
Mutation Frequency ◽  
Cpg Methylation ◽  
Homozygous Mutation ◽  
Wild Type ◽  
Employment Equity ◽  
Acute Leukemias ◽  
Equity Ownership

Abstract Abstract 407 CpG methylation is an epigenetic modification that is important for cellular development. The DNMT3A gene, located on chromosome 2p23.3, encodes for a DNA methyltransferase and plays a central role in de novo CpG methylation. Recently, DNMT3A has been reported to be mutated in 22% of AML and 8% of MDS (Ley et al., N Engl J Med, 2010; Walter et al., Leukemia, 2011). Further, DNMT3A mutations were observed to be associated with a short overall survival in both diseases, respectively. In order to determine the role of DNMT3A mutations in leukemia we investigated two different entities by next-generation sequencing: 145 AML patients and 83 cases harboring a T-cell acute lymphoblastic leukemia (T-ALL). We applied an amplicon based deep-sequencing assay (454 Life Sciences, Branford, CT) in combination with the 48.48 Access Array technology (Fluidigm, South San Francisco, CA). The peripheral blood or bone marrow samples were obtained from untreated patients. The AML cohort was restricted to cases with normal karyotype (CN-AML). 87/145 (60%) cases were specifically selected to be wild-type for NPM1, FLT3-ITD, CEBPA, and MLL-PTD, whereas 58/145 (40%) samples were mutated in NPM1 (n=33) or double-mutated in NPM1 and FLT3-ITD (n=25). In our cohort of AML cases without mutations in NPM1, FLT3-ITD, CEBPA, and MLL-PTD, we observed a DNMT3A mutation frequency of 17.2% (15/87 cases). The DNMT3A mutation rate in the NPM1 mutated/FLT3 wild-type cases (16/33, 48.5%, P=0.001) and NPM1/FLT3-ITD mutated cases (19/25, 76%, P<0.001) was significantly higher, confirming the association of DNMT3A mutations with NPM1 and FLT3-ITD mutations that had been reported previously (Ley et al.). Interestingly, also in the cohort of T-ALL we detected patients that carried a DNMT3A mutation (16/83, 19.3%), which is very similar to the mutation frequency in AML, and has not been described yet. To further address the biology of DNMT3A mutations in acute leukemias we combined the AML and T-ALL cohorts and identified in total 31 distinct missense mutations in 65 patients (49 AML, 16 T-ALL). Most frequently, amino acid R882 located in exon 23 was mutated (n=29 cases). In addition, we identified 7 frame-shift alterations, 5 nonsense and 2 splice-site mutations. Moreover, 9 of the 65 mutated cases had two independent mutations. Focusing on AML, only three (6.1%) of the 49 DNMT3A-mutated cases were observed to harbor two different mutations concomitantly. In contrast, in the cohort of T-ALL we detected two different mutations in 6/16 (37.5%, P=0.003) cases. Further, in the cohort of AML, no homozygous mutation was detected, however, in the T-ALL group, two cases harbored a homozygous mutation. Therefore, only 3/49 AML (6.1%) cases, but 8/16 T-ALL (50%) cases showed biallelic mutation status (P<0.001). With respect to overall survival, no association was seen in the complete cohort of CN-AML cases (n=145). After limiting this cohort to the cases without mutations in NPM1, FLT3-ITD, CEBPA and MLL-PTD (n=87), an inferior survival was observed for DNMT3A-mutated patients as compared to DNMT3A wild-type patients (n=15 vs. n=72; alive at 2 years: 27.9% vs. 56.6%; P=0.048). Remarkably, also in the cohort of T-ALL a worse survival for patients with DNMT3A mutations was seen which has not been reported thus far (n=13 vs. n=64; alive at 1 years: 28.6% vs. 80.9%; P=0.001). Subsequently, we were interested whether gain-of-function mutations of the DNMT3A gene were associated with trisomy 2 and acquired uniparental disomy (aUPDs) of the short arm of chromosome 2 where DNMT3A is located. As such, we investigated 9 cases harboring a trisomy 2 (AML n=4, MDS n=4, and CMML n=1) and one MDS patient harboring an aUPD 2p, as confirmed by SNP microarray analyses (SNP Array 6.0, Affymetrix, Santa Clara, CA). Not all, but 3/9 cases with trisomy 2 harbored a DNMT3A mutation (one AML, MDS, and CMML case each), suggesting that duplication of DNMT3A mutations can enhance the effect of the mutation. Moreover, the single case with aUPD 2p also showed a mutation, further suggesting that LOH leading to loss of the wild-type DNMT3A may be another mechanism of disease leading to progression of leukemia. In conclusion, we here report on a high mutation rate of DNMT3A in both AML and T-ALL and independently confirmed an inferior overall survival in these two entities, respectively. This indicates a significant role of DNMT3A alterations in myeloid as well as in lymphoid neoplasms. Disclosures: Grossmann: MLL Munich Leukemia Laboratory: Employment. Kohlmann:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Alpermann:MLL Munich Leukemia Laboratory: Employment. Wild:MLL Munich Leukemia Laboratory: Employment. Weissmann:MLL Munich Leukemia Laboratory: Employment. Eder:MLL Munich Leukemia Laboratory: Employment. Dicker:MLL Munich Leukemia Laboratory: Employment. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Schnittger:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership.

Germline and somatic DNA damage repair gene mutations potentially predict the efficacy of relevant treatment in Chinese patients with pancreatic ductal adenocarcinoma.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e16732-e16732
Author(s):  
Lin Shui ◽  
Yang Peng ◽  
Shuangshuang Li ◽  
Jiangfang Tian ◽  
Dan Cao
Keyword(s):  
Dna Damage ◽  
Dna Damage Repair ◽  
Chinese Patients ◽  
Ductal Adenocarcinoma ◽  
Molecular Heterogeneity ◽  
Genetic Characteristics ◽  
Damage Repair ◽  
Potential Biomarker ◽  
Platinum Based Chemotherapy

e16732 Background: PDAC is a fatal disease with molecular heterogeneity, inducing differences in biological behaviour and therapeutic strategy. We conducted a study to reveal the mutation landscape of Chinese PDAC patients, and investigate the predictive role of germline and somatic DNA damage repair (DDR) status in precise treatment. Methods: 195 PDAC patients were enrolled from multiple medical centers of China between Jan 2016 to Nov 2019. Baseline clinical or genetic characteristics, and survival status were collected. NGS were performed on paraffin-embedded resected tissues or peripheral blood using a panel of 417 genes, including 50 DDR-related genes. Survival analysis was conducted using Kaplan-Meier, and Cox proportional hazard regression model. Results: The main driver genes were KRAS, TP53, CDKN2A, and SMAD4. Patients with KRAS mutation showed worse OS than those without (p = 0.048). DDR deficiency were identified in 15.38% of overall patients, mainly occurred in BRCA2 (4.62%), ATM (4.10%), RAD50 (1.54%) and MLH1 genes (1.03%). No significant improvement of OS existed between patients with or without DDR mutations (p = 0.88). Treatment with olaparib (adjusted HR, 0.2550; P = 0.0720) or platinum-based chemotherapy (adjusted HR, 0.1308; P = 0.0185) respectively decreased hazard of death in patients with DDR mutation. Besides BRCA gene, ATM mutant patients treated with olaparib harbored prolonged median OS than those without olaparib treatment (22.25 vs 15.2 month). Despite a little higher PD-L1 expression rate were seen in DDR mutant patients (29.17% vs 20.51%), no statistical correlation between tumor mutation burden level and DDR mutation was identified. And in patients treated with PD-1 blockade, 2 patients of DDR wild-type group both had SD, whereas of the remaining 5 patients with DDR deficiency, 1 was evaluated as PR, 3 as SD, and 1 as PD (ORR, 0 wt vs 20% mut). Conclusions: In this multi-center retrospective study, we deciphered the intra-tumoral genetic heterogeneity in Chinese PDAC population, which differs from western patients cohort to some extent. We found the potential role of germline and somatic DDR mutation status in predicting the response to olaparib and platinum-based chemotherapy, especially with BRCA or ATM mutation. However, DDR alteration was limited in prediction of hypermutational status and sensitivity to PD-1 blockade. Our study may provide a valuable evidence for clinical application of DDR mutation as a potential biomarker for precise treatment.

scholarly journals Usp14 is required for spermatogenesis and ubiquitin stress responses in Drosophila melanogaster

2019 ◽  
Author(s):  
Levente Kovács ◽  
Ágota Nagy ◽  
Margit Pál ◽  
Peter Deák
Keyword(s):  
Male Sterility ◽  
Stress Responses ◽  
Expression Patterns ◽  
Loss Of Function ◽  
Wild Type ◽  
Cellular Processes ◽  
Protein Conjugates ◽  
Covalently Linked ◽  
Mutant Phenotypes

ABSTRACTDeubiquitinating (DUB) enzymes free covalently linked ubiquitins from ubiquitin-ubiquitin and ubiquitin-protein conjugates, and thereby maintain the equilibrium between free and conjugated ubiquitins and regulate ubiquitin-mediated cellular processes. The present genetic analyses of mutant phenotypes demonstrate that loss of Usp14 function results in male sterility, with defects in spermatid individualization and reduced testicular free monoubiquitin levels. These phenotypes were rescued by germline specific overexpression of wild type Usp14. Synergistic genetic interactions with Ubi-p63E and cycloheximide sensitivity suggest that ubiquitin shortage is a primary cause of male sterility. In addition, Usp14 is predominantly expressed in testes in Drosophila, and differential expression patterns may be causative of testis-specific loss of function Usp14 phenotypes. Collectively, these results suggest a major role of Usp14 in maintaining normal steady state free monoubiquitin levels during the later stages of Drosophila spermatogenesis.

Abstract 41: Postnatal Deletion of Vascular Smooth Muscle Cell Transforming Growth Factor beta Receptor 2 in Mice Exacerbates Marfan-syndrome-associated Aortic Dilation

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Hao Wei ◽  
Stoyan N Angelov ◽  
Jie Hong Hu ◽  
David A Dichek
Keyword(s):  
Smooth Muscle ◽  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Intramural Hematoma ◽  
Ascending Aorta ◽  
Wild Type ◽  
Aortic Pathology ◽  
Growth Factor Beta

Objectives: Thoracic aortic aneurysms (TAA) are an important cause of cardiovascular death and are often part of an autosomal dominant syndrome (e.g., Marfan syndrome; MFS). The role of transforming growth factor beta (TGF-β) signaling in TAA is controversial. Excessive TGF-β signaling in aortic smooth muscle cells (SMC) is proposed to cause TAA formation; however, much data support a protective role for aortic SMC TGF-β signaling. We investigated the role of SMC TGF-β signaling in the development of MFS-associated TAA by superimposing SMC-specific deletion of Tgfbr2 on MFS-related aortic pathology of Fbn1 C1039G/+ mice. Methods: We crossed Tgfbr2 flox/flox mice with Acta2 -CreERT2 mice (Tamoxifen-inducible Cre driven by the SMC-specific Acta 2 promoter) to generate mice with inducible deletion of Tgfbr 2 in SMCs. 4 groups of mice were studied: 1) Fbn1 +/+ , Acta2 -CreERT2 o/o , Tgfbr2 flox/flox mice received Tamoxifen (wild-type control); 2) Fbn1 C1039G /+ , Acta2 -CreERT2 o/o , Tgfbr2 flox/flox mice received Tamoxifen (MFS; controlled for Tamoxifen); 3) Fbn1 C1039G /+ , Acta2 -CreERT2 +/o , Tgfbr2 flox/flox mice received vehicle (MFS; controlled for Acta2 -CreERT2 +/o ); 4) Fbn1 C1039G /+ , Acta2 -CreERT2 +/o , Tgfbr2 flox/flox mice received Tamoxifen (SMC- Tgfbr2 -/- superimposed on MFS). All mice received Tamoxifen or vehicle at 6 wk of age; ascending aortic anatomy was assessed at 16 wk of age. Results: Compared to wild-type mice, both groups of MFS mice had significantly increased ascending aortic diameter (~30%; p<0.05; ANOVA). Both groups of mice with MFS alone (Tamoxifen- and Acta2 -CreERT2 +/o -controls) showed comparable ascending aorta dilation and similar prevalence of aortic intramural hematoma. Superimposing the SMC- Tgfbr2 -/- genotype on the Fbn1 C1039G /+ genotype mice further increased both ascending aorta diameter (>40%; p<0.05; ANOVA) and intramural hematoma rate (~4-fold; p<0.05, X ° test) compared to mice with MFS alone. Studies are under way to delineate the alterations of vascular SMC TGF-β signaling in these models. Conclusions: Our data suggest that loss of TGF-β signaling in vascular SMC exacerbates aortic pathology in MFS mice and that vascular SMC TGF-β signaling protects against TAA formation induced by fibrillin deficiency.

scholarly journals Characterization of the Mycobacterium tuberculosis Sigma Factor SigM by Assessment of Virulence and Identification of SigM-Dependent Genes

2006 ◽  
Vol 75 (1) ◽  
pp. 452-461 ◽  
Author(s):  
Nisheeth Agarwal ◽  
Samuel C. Woolwine ◽  
Sandeep Tyagi ◽  
William R. Bishai
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mouse Model ◽  
Consensus Sequence ◽  
Expression Patterns ◽  
Wild Type ◽  
Time To Death ◽  
Small Set ◽  
Genomic Microarray

ABSTRACT Alternate sigma factors have been implicated in the survival of mycobacteria in response to specific stresses. To characterize the role of SigM in Mycobacterium tuberculosis, a sigM deletion mutant was generated by allelic exchange in the virulent CDC1551 strain. Comparing the wild-type and ΔsigM strains by complete genomic microarray, we observed a low level of baseline expression of sigM in wild-type M. tuberculosis and no significant differences in the gene expression patterns between these two strains. Alternatively, a SigM-overexpressing M. tuberculosis strain was constructed and microarray profiling revealed SigM-dependent expression of a relatively small group of genes, which included four esat-6 homologues: esxE, esxF, esxT, and esxU. An assessment of SigM-dependent promoters from the microarray analysis revealed a putative consensus sequence for M. tuberculosis SigM of −35 GGAAC and −10 CGTCR. In vitro expression studies showed that M. tuberculosis sigM transcripts accumulate slightly in stationary phase and following heat shock. To understand the role of SigM in pathogenesis, the M. tuberculosis sigM deletion strain was compared with the isogenic wild-type strain and the complemented mutant strain for survival in murine macrophages and in the mouse model. The mutant was found to have similar abilities to survive in both the resting and activated J774A.1 macrophages. Mouse organ bacterial burdens indicated that the mutant proliferated and persisted at the same level as that of the wild-type and complemented strains in lung and spleen tissues. In time-to-death experiments in the mouse model, the ΔsigM mutant exhibited lethality times comparable to those observed for the wild-type and complemented strains. These data indicate that M. tuberculosis SigM governs the expression of a small set of genes, including four esat-6 homologues, and that the loss of sigM does not confer a detectable virulence defect in the macrophages and mouse models of infection.

scholarly journals Genomic Expression Responses to DNA-damaging Agents and the Regulatory Role of the Yeast ATR Homolog Mec1p

2001 ◽  
Vol 12 (10) ◽  
pp. 2987-3003 ◽  
Author(s):  
Audrey P. Gasch ◽  
Mingxia Huang ◽  
Sandra Metzner ◽  
David Botstein ◽  
Stephen J. Elledge ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Damage ◽  
Ionizing Radiation ◽  
Cellular Response ◽  
Expression Patterns ◽  
Wild Type ◽  
Data Set ◽  
Genomic Expression ◽  
Dna Damaging Agents

Eukaryotic cells respond to DNA damage by arresting the cell cycle and modulating gene expression to ensure efficient DNA repair. The human ATR kinase and its homolog in yeast, MEC1, play central roles in transducing the damage signal. To characterize the role of the Mec1 pathway in modulating the cellular response to DNA damage, we used DNA microarrays to observe genomic expression inSaccharomyces cerevisiae responding to two different DNA-damaging agents. We compared the genome-wide expression patterns of wild-type cells and mutants defective in Mec1 signaling, includingmec1, dun1, and crt1 mutants, under normal growth conditions and in response to the methylating-agent methylmethane sulfonate (MMS) and ionizing radiation. Here, we present a comparative analysis of wild-type and mutant cells responding to these DNA-damaging agents, and identify specific features of the gene expression responses that are dependent on the Mec1 pathway. Among the hundreds of genes whose expression was affected by Mec1p, one set of genes appears to represent an MEC1-dependent expression signature of DNA damage. Other aspects of the genomic responses were independent of Mec1p, and likely independent of DNA damage, suggesting the pleiotropic effects of MMS and ionizing radiation. The complete data set as well as supplemental materials is available at http://www-genome.stanford.edu/mec1 .

Transforming Growth Factor-β Isoform Expression in the Perisutural Tissues of Craniosynostotic Rabbits

2004 ◽  
Vol 41 (4) ◽  
pp. 392-402 ◽  
Author(s):  
Elyane Poisson ◽  
James J. Sciote ◽  
Richard Koepsel ◽  
Gregory M. Cooper ◽  
Lynne A. Opperman ◽  
...  
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor ◽  
Expression Patterns ◽  
Rabbit Model ◽  
Transforming Growth Factor Β ◽  
Differential Staining ◽  
Wild Type ◽  
Opposite Pattern ◽  
Suture Fusion ◽  
Tgf Β1

Objective To describe the expression patterns of the various transforming growth factor-β (Tgf-β) isoforms, known to be involved in suture development, in the perisutural tissues of rabbits with naturally occurring craniosynostosis and relate such differential expression to the pathogenesis of premature suture fusion. Method Twenty-one coronal sutures were harvested from six wild-type control New Zealand White rabbits and five rabbits with familial coronal suture synostosis at 25 days of age for histomorphometric and immunohistochemical analyses. Tgf-β isoform immunoreactivity was assessed using indirect immunoperoxidase procedures with specific antibodies. Results Synostosed sutures had significantly (p < .01) greater bone area and relatively more osteoblasts and osteocytes in the osteogenic fronts, compared with wild-type sutures. Tgf-β isoform immunoreactivity showed differential staining patterns between wild-type and synostosed perisutural tissues. In wild-type sutures, Tgf-β1 and Tgf-β3 immunoreactivity was significantly (p < .001) greater than Tgf-β2 staining in all perisutural tissues. In synostosed sutures, the opposite pattern was observed, with Tgf-β2 immunoreactivity significantly (p < .001) greater than Tgf-β1 and Tgf-β3 in the osteogenic fronts, dura mater, and periosteum. Conclusions Findings from this study suggest that an overexpression of Tgf-β2, either in isolation or in association with an underexpression of Tgf-β1 and Tgf-β3, may be related to premature suture fusion (craniosynostosis) in this pathological rabbit model. These abnormal expression patterns may be involved in premature suture fusion either through increased cell proliferation, decreased apoptosis of the osteoblasts or both at the osteogenic fronts.

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