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Fulltext Burkholderia pseudomallei suppresses Caenorhabditis elegans immunity by specific degradation of a GATA transcription factor

Lee SH, Wong RR, Chin CY, Lim TY, Eng SA, Kong C, et al.

Proc Natl Acad Sci U S A, 2013 Sep 10;110(37):15067-72.
PMID: 23980181 DOI: 10.1073/pnas.1311725110

Burkholderia pseudomallei is a Gram-negative soil bacterium that infects both humans and animals. Although cell culture studies have revealed significant insights into factors contributing to virulence and host defense, the interactions between this pathogen and its intact host remain to be elucidated. To gain insights into the host defense responses to B. pseudomallei infection within an intact host, we analyzed the genome-wide transcriptome of infected Caenorhabditis elegans and identified ∼6% of the nematode genes that were significantly altered over a 12-h course of infection. An unexpected feature of the transcriptional response to B. pseudomallei was a progressive increase in the proportion of down-regulated genes, of which ELT-2 transcriptional targets were significantly enriched. ELT-2 is an intestinal GATA transcription factor with a conserved role in immune responses. We demonstrate that B. pseudomallei down-regulation of ELT-2 targets is associated with degradation of ELT-2 protein by the host ubiquitin-proteasome system. Degradation of ELT-2 requires the B. pseudomallei type III secretion system. Together, our studies using an intact host provide evidence for pathogen-mediated host immune suppression through the destruction of a host transcription factor.

Matched MeSH terms: GATA Transcription Factors/genetics
Fulltext Investigation of a PAX6 gene mutation in a Malaysian family with congenital aniridia

Lee PC, Lam HH, Ghani SA, Subrayan V, Chua KH

Genet. Mol. Res., 2014;13(2):3553-9.
PMID: 24737507 DOI: 10.4238/2014.March.24.15

Mutations in the PAX6 gene that cause aniridia have been identified in various ethnicities but not in the Malaysian population. Therefore, the objective of this study was to investigate the PAX6 mutation in a Malaysian family with congenital aniridia. In this study, a complete ophthalmic examination was performed on a Dusun ethnic family with aniridia. Genomic DNA was extracted from the peripheral blood of the subjects and screened for the PAX6 gene mutation using polymerase chain reaction amplification high-resolution melting curve analysis (PCR-HRM) followed by confirmation via direct DNA sequencing. A heterozygous G deletion (c.857delG) in exon 7 causing a frame shift in PAX6 was identified in all affected family members. Genotype-phenotype correlation analysis revealed congenital cataract and all affected family members showed a similar spectrum of aniridia with no phenotypic variability but with differences in severity that were age-dependent. In summary, by using a PCR-HRM approach, this study is the first to report a PAX6 mutation in a Malaysian family. This mutation is the cause of the aniridia spectra observed in this family and of congenital cataract.

Matched MeSH terms: Paired Box Transcription Factors/genetics*
Fulltext Divergence of iron metabolism in wild Malaysian yeast

Lee HN, Mostovoy Y, Hsu TY, Chang AH, Brem RB

G3 (Bethesda), 2013 Dec 09;3(12):2187-94.
PMID: 24142925 DOI: 10.1534/g3.113.008011

Comparative genomic studies have reported widespread variation in levels of gene expression within and between species. Using these data to infer organism-level trait divergence has proven to be a key challenge in the field. We have used a wild Malaysian population of S. cerevisiae as a test bed in the search to predict and validate trait differences based on observations of regulatory variation. Malaysian yeast, when cultured in standard medium, activated regulatory programs that protect cells from the toxic effects of high iron. Malaysian yeast also showed a hyperactive regulatory response during culture in the presence of excess iron and had a unique growth defect in conditions of high iron. Molecular validation experiments pinpointed the iron metabolism factors AFT1, CCC1, and YAP5 as contributors to these molecular and cellular phenotypes; in genome-scale sequence analyses, a suite of iron toxicity response genes showed evidence for rapid protein evolution in Malaysian yeast. Our findings support a model in which iron metabolism has diverged in Malaysian yeast as a consequence of a change in selective pressure, with Malaysian alleles shifting the dynamic range of iron response to low-iron concentrations and weakening resistance to extreme iron toxicity. By dissecting the iron scarcity specialist behavior of Malaysian yeast, our work highlights the power of expression divergence as a signpost for biologically and evolutionarily relevant variation at the organismal level. Interpreting the phenotypic relevance of gene expression variation is one of the primary challenges of modern genomics.

Matched MeSH terms: Transcription Factors/genetics; Basic-Leucine Zipper Transcription Factors/genetics
Gene and protein expression profiles of JAK-STAT signalling pathway in the developing brain of the Ts1Cje down syndrome mouse model

Lee HC, Md Yusof HH, Leong MP, Zainal Abidin S, Seth EA, Hewitt CA, et al.

Int J Neurosci, 2019 Sep;129(9):871-881.
PMID: 30775947 DOI: 10.1080/00207454.2019.1580280

Aims: The JAK-STAT signalling pathway is one of the key regulators of pro-gliogenesis process during brain development. Down syndrome (DS) individuals, as well as DS mouse models, exhibit an increased number of astrocytes, suggesting an imbalance of neurogenic-to-gliogenic shift attributed to dysregulated JAK-STAT signalling pathway. The gene and protein expression profiles of JAK-STAT pathway members have not been characterised in the DS models. Therefore, we aimed to profile the expression of Jak1, Jak2, Stat1, Stat3 and Stat6 at different stages of brain development in the Ts1Cje mouse model of DS. Methods: Whole brain samples from Ts1Cje and wild-type mice at embryonic day (E)10.5, E15, postnatal day (P)1.5; and embryonic cortex-derived neurospheres were collected for gene and protein expression analysis. Gene expression profiles of three brain regions (cerebral cortex, cerebellum and hippocampus) from Ts1Cje and wild-type mice across four time-points (P1.5, P15, P30 and P84) were also analysed. Results: In the developing mouse brain, none of the Jak/Stat genes were differentially expressed in the Ts1Cje model compared to wild-type mice. However, Western blot analyses indicated that phosphorylated (p)-Jak2, p-Stat3 and p-Stat6 were downregulated in the Ts1Cje model. During the postnatal brain development, Jak/Stat genes showed complex expression patterns, as most of the members were downregulated at different selected time-points. Notably, embryonic cortex-derived neurospheres from Ts1Cje mouse brain expressed lower Stat3 and Stat6 protein compared to the wild-type group. Conclusion: The comprehensive expression profiling of Jak/Stat candidates provides insights on the potential role of the JAK-STAT signalling pathway during abnormal development of the Ts1Cje mouse brains.

Matched MeSH terms: STAT Transcription Factors/genetics*
Fulltext Cloning and characterization of short-chain N-acyl homoserine lactone-producing Enterobacter asburiae strain L1 from lettuce leaves

Lau YY, How KY, Yin WF, Chan KG

Microbiologyopen, 2018 Dec;7(6):e00610.
PMID: 29982994 DOI: 10.1002/mbo3.610

In gram-negative bacteria, bacterial communication or quorum sensing (QS) is achieved using common signaling molecules known as N-acyl homoserine lactones (AHL). We have previously reported the genome of AHL-producing bacterium, Enterobacter asburiae strain L1. In silico analysis of the strain L1 genome revealed the presence of a pair of luxI/R genes responsible for AHL-type QS, designated as easIR. In this work, the 639 bp luxI homolog, encoding 212 amino acids, have been cloned and overexpressed in Escherichia coli BL21 (DE3)pLysS. The purified protein (~25 kDa) shares high similarity to several members of the LuxI family among different E asburiae strains. Our findings showed that the heterologously expressed EasI protein has activated violacein production by AHL biosensor Chromobacterium violaceum CV026 as the wild-type E. asburiae. The mass spectrometry analysis showed the production of N-butanoyl homoserine lactone and N-hexanoyl homoserine lactone from induced E. coli harboring the recombinant EasI, suggesting that EasI is a functional AHL synthase. E. asburiae strain L1 was also shown to possess biofilm-forming characteristic activity using crystal violet binding assay. This is the first report on cloning and characterization of the luxI homolog from E. asburiae.

Matched MeSH terms: Transcription Factors/genetics*
Fulltext Novel discovery of Averrhoa bilimbi ethanolic leaf extract in the stimulation of brown fat differentiation program in combating diet-induced obesity

Lau WK, Noruddin NAA, Ariffin AH, Mahmud MZ, Noor MHM, Amanah A, et al.

BMC Complement Altern Med, 2019 Sep 05;19(1):243.
PMID: 31488120 DOI: 10.1186/s12906-019-2640-3

BACKGROUND: Brown adipocytes are known to promote energy expenditure and limit weight gain to combat obesity. Averrhoa bilimbi, locally called belimbing buluh (DBB), is mainly used as an ethnomedicine in the treatment of metabolic disorders including diabetes mellitus, hypertension and obesity. The present study aims to investigate the browning activity on white adipocytes by A. bilimbi leaf extract and to evaluate the potential mechanisms.
METHODS: Ethanolic leaf extract of A. bilimbi was exposed to Myf5 lineage precursor cells to stimulate adipocyte differentiation. Protein expressions of brown adipocyte markers were determined through high content screening analysis and validated through western blotting. Mito Stress Test assay was conducted to evaluate the cellular oxygen consumption rate upon A. bilimbi treatment.
RESULTS: A. bilimbi ethanolic leaf extract exhibited an adipogenesis effect similar to a PPARgamma agonist. It also demonstrated brown adipocyte differentiation in myoblastic Myf5-positive precursor cells. Expression of UCP1 and PRDM16 were induced. The basal metabolic rate and respiratory capacity of mitochondria were increased upon A. bilimbi treatment.
CONCLUSIONS: The findings suggest that Averrhoa bilimbi ethanolic leaf extract induces adipocyte browning through PRDM16 activation and enhances mitochondria activity due to UCP1 up-regulation.

Matched MeSH terms: Transcription Factors/genetics
Fulltext dsRNA silencing of an R2R3-MYB transcription factor affects flower cell shape in a Dendrobium hybrid

Lau SE, Schwarzacher T, Othman RY, Harikrishna JA

BMC Plant Biol, 2015;15:194.
PMID: 26260631 DOI: 10.1186/s12870-015-0577-3

The R2R3-MYB genes regulate pigmentation and morphogenesis of flowers, including flower and cell shape, and therefore have importance in the development of new varieties of orchids. However, new variety development is limited by the long breeding time required in orchids. In this study, we identified a cDNA, DhMYB1, that is expressed during flower development in a hybrid orchid, Dendrobium hybrida (Dendrobium bobby messina X Dendrobium chao phraya) then used the direct application of dsRNA to observe the effect of gene silencing on flower phenotype and floral epidermal cell shape.

Matched MeSH terms: Transcription Factors/genetics*
Fulltext Advancements in reprogramming strategies for the generation of induced pluripotent stem cells

Lai MI, Wendy-Yeo WY, Ramasamy R, Nordin N, Rosli R, Veerakumarasivam A, et al.

J Assist Reprod Genet, 2011 Apr;28(4):291-301.
PMID: 21384252 DOI: 10.1007/s10815-011-9552-6

Direct reprogramming of somatic cells into induced pluripotent stem (iPS) cells has emerged as an invaluable method for generating patient-specific stem cells of any lineage without the use of embryonic materials. Following the first reported generation of iPS cells from murine fibroblasts using retroviral transduction of a defined set of transcription factors, various new strategies have been developed to improve and refine the reprogramming technology. Recent developments provide optimism that the generation of safe iPS cells without any genomic modification could be derived in the near future for the use in clinical settings. This review summarizes current and evolving strategies in the generation of iPS cells, including types of somatic cells for reprogramming, variations of reprogramming genes, reprogramming methods, and how the advancement iPS cells technology can lead to the future success of reproductive medicine.

Matched MeSH terms: Transcription Factors/genetics
Blastocystis sp. subtype 3 triggers higher proliferation of human colorectal cancer cells, HCT116

Kumarasamy V, Kuppusamy UR, Samudi C, Kumar S

Parasitol Res, 2013 Oct;112(10):3551-5.
PMID: 23933809 DOI: 10.1007/s00436-013-3538-5

Blastocystis sp. is a commonly found intestinal microorganism and was reported to cause many nonspecific gastrointestinal symptoms. Various subtypes have been previously reported, and the pathogenicity of different subtypes of Blastocystis is unclear and remains as a controversial issue. A recent study has shown that the Blastocystis antigen isolated from an unknown subtype could facilitate the proliferation of colon cancer cells. Current study was conducted to compare the effect of solubilized antigen isolated from five different subtypes of Blastocystis on colon cancer cells, HCT116. A statistically significant proliferation of these cells was observed when exposed to 1.0 μg/ml solubilized antigen isolated from subtype 3 Blastocystis (37.22%, p < 0.05). Real-time polymerase chain reaction demonstrated the upregulation of Th2 cytokines especially transforming growth factor beta in subtype 3-treated cancer cells (p < 0.01, 3.71-fold difference). Of interest, subtype 3 Blastocystis antigen also caused a significantly higher upregulation of cathepsin B (subtypes 1 and 2, p < 0.01; subtypes 4 and 5, p < 0.001; 6.71-fold difference) which lead to the postulation that it may enhance the exacerbation of existing colon cancer cells by weakening the cellular immune response. The dysregulation of IFN-γ and p53 expression also suggest Blastocystis as a proponent of carcinogenesis. Therefore, it is very likely for subtype 3 Blastocystis to have higher pathogenic potential as it caused an increased propagation of cancer cells and substantial amount of inflammatory reaction compared to other subtypes.

Matched MeSH terms: Transcription Factors/genetics
Molecular cloning and characterisation of peroxisome proliferator activated receptor gamma1 (PPARgamma1) cDNA gene from guinea pig (Cavia porcellus): tissue distribution

Khoo BY, Samian MR, Najimudin N, Tengku Muhammad TS

Comp Biochem Physiol B Biochem Mol Biol, 2003 Jan;134(1):37-44.
PMID: 12524031

The coding region of guinea pig peroxisome proliferator activated receptor gamma1 (gpPPARgamma1) cDNA was successfully cloned from adipose tissue by reverse transcription polymerase chain reaction (RT-PCR) using the designated primers based on the conserved regions of the other mammalian PPARgamma1 sequence. From RT-PCR, a combination of three cDNA fragments that comprised of the full length coding region PPARgamma1 cDNA gene were amplified, with the size of 498, 550 and 557 bp, respectively. All three fragments were then successfully assembled by utilising the internal restriction sites present at the overlapping regions to give rise to the full-length coding region of gpPPARgamma1 with the size of 1428 bp and consisting of 475 amino acids. Guinea pig PPARgamma1 is highly conserved with those of other species at protein and nucleotide levels. Gene expression studies showed that gpPPARgamma mRNA was predominantly expressed in adipose tissue followed by lung and spleen. However, at the protein level, PPARgamma was also found to be expressed in skeletal muscle.

Matched MeSH terms: Transcription Factors/genetics*
Fulltext DhMYB22 and DhMYB60 regulate pigment intensity and floral organ shape in Dendrobium hybrid

Khairul-Anuar MA, Mazumdar P, Othman RY, Harikrishna JA

Ann Bot, 2022 Sep 26;130(4):579-594.
PMID: 35980362 DOI: 10.1093/aob/mcac103

BACKGROUND: Flower pigment and shape are determined by the coordinated expression of a set of structural genes during flower development. R2R3-MYB transcription factors are known regulators of structural gene expression. The current study focused on two members of this large family of transcription factors that were predicted to have roles in pigment biosynthesis and organ shape development in orchids.
METHODS: Phylogenetic analysis was used to identify candidate Dendrobium catenatum R2R3-MYB (DcaMYB) sequences associated with pigment and cell shape development. Gene silencing of candidate DhMYBs in Dendrobium hybrid by direct application of dsRNA to developing flowers was followed by observation of gene expression level and flower phenotypes. Silencing of the structural gene chalcone synthase was used as a comparative control.
KEY RESULTS: Ten candidate flower-associated DcaMYBs were identified. Flowers treated with dsRNA of DhMYB22 and DhMYB60 sequences were less pigmented and had relatively low expression of anthocyanin biosynthetic genes (F3'H and DFR), lower total anthocyanin concentration and markedly lower levels of cyanidin-3-glucoside and cyanidin-3-rutinoside. Petals of DhMYB22-treated flowers and sepals of DhMYB60-treated flowers showed the greatest colour difference relative to the same organs in untreated flowers. DhMYB22-treated flowers had relatively narrow and constricted lips, while DhMYB60-treated flowers had narrow and constricted sepals. No significant difference in shape was observed for DhCHS-treated or untreated flowers.
CONCLUSIONS: Our results demonstrate that DhMYB22 and DhMYB60 regulate pigment intensity and floral organ shape in Dendrobium. This is a first report of MYB regulation of floral organ shape in orchids.

Matched MeSH terms: Transcription Factors/genetics
Role of Epithelial-to-Mesenchymal Transition Markers in Different Stages of Endometriosis: Expression of the Snail, Slug, ZEB1, and Twist Genes

Kazmi I, Alharbi KS, Al-Abbasi FA, Almalki WH, G SK, Yasmeen A, et al.

Crit Rev Eukaryot Gene Expr, 2021;31(2):89-95.
PMID: 34347983 DOI: 10.1615/CritRevEukaryotGeneExpr.2021037996

Among various epithelial-to-mesenchymal transition (EMT)-related transcription factors (TFs), altered expression levels of Snail-1, Snail-2/Slug, Twist, and ZEB1 have shown a significant association in different cancers having a higher risk of metastasis. However, their role in the circulation of endometriosis patients is not well understood. Hence, the present study was designed to evaluate the crucial role of these TFs in defining the molecular pathogenesis for endometriosis progression and differentiation from control subjects. The qualitative and quantitative expression analysis of Snail-1, Snail-2/Slug, Twist, and ZEB1 were analyzed in peripheral blood samples of 75 different stages of endometriosis patients and compared with 50 control subjects. Total RNA was extracted and converted into complementary DNA (cDNA) for relative quantification of each gene transcript using SYBRGreen-based reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). The Livak method of relative quantification was used for calculating the fold change in each TF compared with endogenous control. All four selected TFs showed significantly upregulated expression levels in endometriosis patients compared with control subjects. A three-fold increase was observed for Snail-1 (p = 0.0001), and a two-fold increase was observed for Snail-2 (p = 0.01), Twist (p = 0.0002), and ZEB1 (p = 0.001) in stage III and IV compared with stage I and II of endometriosis patients. The present study revealed that EMT-related TFs play a crucial role in the pathogenesis and differentiating different stages of endometriosis patients through expression analysis of specific molecular cascades using non-invasive tools.

Matched MeSH terms: Snail Family Transcription Factors/genetics*
Genomic analyses in Cornelia de Lange Syndrome and related diagnoses: Novel candidate genes, genotype-phenotype correlations and common mechanisms

Kaur M, Blair J, Devkota B, Fortunato S, Clark D, Lawrence A, et al.

Am J Med Genet A, 2023 Aug;191(8):2113-2131.
PMID: 37377026 DOI: 10.1002/ajmg.a.63247

Cornelia de Lange Syndrome (CdLS) is a rare, dominantly inherited multisystem developmental disorder characterized by highly variable manifestations of growth and developmental delays, upper limb involvement, hypertrichosis, cardiac, gastrointestinal, craniofacial, and other systemic features. Pathogenic variants in genes encoding cohesin complex structural subunits and regulatory proteins (NIPBL, SMC1A, SMC3, HDAC8, and RAD21) are the major pathogenic contributors to CdLS. Heterozygous or hemizygous variants in the genes encoding these five proteins have been found to be contributory to CdLS, with variants in NIPBL accounting for the majority (>60%) of cases, and the only gene identified to date that results in the severe or classic form of CdLS when mutated. Pathogenic variants in cohesin genes other than NIPBL tend to result in a less severe phenotype. Causative variants in additional genes, such as ANKRD11, EP300, AFF4, TAF1, and BRD4, can cause a CdLS-like phenotype. The common role that these genes, and others, play as critical regulators of developmental transcriptional control has led to the conditions they cause being referred to as disorders of transcriptional regulation (or "DTRs"). Here, we report the results of a comprehensive molecular analysis in a cohort of 716 probands with typical and atypical CdLS in order to delineate the genetic contribution of causative variants in cohesin complex genes as well as novel candidate genes, genotype-phenotype correlations, and the utility of genome sequencing in understanding the mutational landscape in this population.

Matched MeSH terms: Transcription Factors/genetics
Acute phenanthrene toxicity to juvenile diploid and triploid African catfish (Clarias gariepinus): Molecular, biochemical, and histopathological alterations

Karami A, Romano N, Hamzah H, Simpson SL, Yap CK

Environ Pollut, 2016 May;212:155-165.
PMID: 26845363 DOI: 10.1016/j.envpol.2016.01.055

Information on the biological responses of polyploid animals towards environmental contaminants is scarce. This study aimed to compare reproductive axis-related gene expressions in the brain, plasma biochemical responses, and the liver and gill histopathological alterations in diploid and triploid full-sibling juvenile African catfish (Clarias gariepinus). Fish were exposed for 96 h to one of the two waterborne phenanthrene (Phe) concentrations [mean measured (SD): 6.2 (2.4) and 76 (4.2) μg/L]. In triploids, exposure to 76 μg/L Phe increased mRNA level of fushi tarazu-factor 1 (ftz-f1). Expression of tryptophan hydroxylase2 (tph2) was also elevated in both ploidies following the exposure to 76 μg/L Phe compared to the solvent control. In triploids, 76 μg/L Phe increased plasma alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) levels compared to the other Phe-exposed group. It also elevated lactate and glucose contents relative to the other groups. In diploids, however, biochemical biomarkers did not change. Phenanthrene exposures elevated glycogen contents and the prevalence of histopathological lesions in the liver and gills of both ploidies. This study showed substantial differences between diploids and triploids on biochemical and molecular biomarker responses, but similar histopathological alterations following acute Phe exposures.

Matched MeSH terms: Fushi Tarazu Transcription Factors/genetics
Fulltext Network-Based Integration of GWAS and Gene Expression Identifies a HOX-Centric Network Associated with Serous Ovarian Cancer Risk

Kar SP, Tyrer JP, Li Q, Lawrenson K, Aben KK, Anton-Culver H, et al.

Cancer Epidemiol Biomarkers Prev, 2015 Oct;24(10):1574-84.
PMID: 26209509 DOI: 10.1158/1055-9965.EPI-14-1270

BACKGROUND: Genome-wide association studies (GWAS) have so far reported 12 loci associated with serous epithelial ovarian cancer (EOC) risk. We hypothesized that some of these loci function through nearby transcription factor (TF) genes and that putative target genes of these TFs as identified by coexpression may also be enriched for additional EOC risk associations.
METHODS: We selected TF genes within 1 Mb of the top signal at the 12 genome-wide significant risk loci. Mutual information, a form of correlation, was used to build networks of genes strongly coexpressed with each selected TF gene in the unified microarray dataset of 489 serous EOC tumors from The Cancer Genome Atlas. Genes represented in this dataset were subsequently ranked using a gene-level test based on results for germline SNPs from a serous EOC GWAS meta-analysis (2,196 cases/4,396 controls).
RESULTS: Gene set enrichment analysis identified six networks centered on TF genes (HOXB2, HOXB5, HOXB6, HOXB7 at 17q21.32 and HOXD1, HOXD3 at 2q31) that were significantly enriched for genes from the risk-associated end of the ranked list (P < 0.05 and FDR < 0.05). These results were replicated (P < 0.05) using an independent association study (7,035 cases/21,693 controls). Genes underlying enrichment in the six networks were pooled into a combined network.
CONCLUSION: We identified a HOX-centric network associated with serous EOC risk containing several genes with known or emerging roles in serous EOC development.
IMPACT: Network analysis integrating large, context-specific datasets has the potential to offer mechanistic insights into cancer susceptibility and prioritize genes for experimental characterization.

Matched MeSH terms: Transcription Factors/genetics
Characterization of mutations in the FOXE1 gene in a cohort of unrelated Malaysian patients with congenital hypothyroidism and thyroid dysgenesis

Kang IN, Musa M, Harun F, Junit SM

Biochem Genet, 2010 Feb;48(1-2):141-51.
PMID: 20094846 DOI: 10.1007/s10528-009-9306-7

The FOXE1 gene was screened for mutations in a cohort of 34 unrelated patients with congenital hypothyroidism, 14 of whom had thyroid dysgenesis and 18 were normal (the thyroid status for 2 patients was unknown). The entire coding region of the FOXE1 gene was PCR-amplified, then analyzed using single-stranded conformational polymorphism, followed by confirmation by direct DNA sequencing. DNA sequencing analysis revealed a heterozygous A>G transition at nucleotide position 394 in one of the patients. The nucleotide transition changed asparagine to aspartate at codon 132 in the highly conserved region of the forkhead DNA binding domain of the FOXE1 gene. This mutation was not detected in a total of 104 normal healthy individuals screened. The binding ability of the mutant FOXE1 protein to the human thyroperoxidase (TPO) promoter was slightly reduced compared with the wild-type FOXE1. The mutation also caused a 5% loss of TPO transcriptional activity.

Matched MeSH terms: Forkhead Transcription Factors/genetics*
Fulltext Mutated HRAS Activates YAP1-AXL Signaling to Drive Metastasis of Head and Neck Cancer

Jagadeeshan S, Prasad M, Badarni M, Ben-Lulu T, Liju VB, Mathukkada S, et al.

Cancer Res, 2023 Apr 04;83(7):1031-1047.
PMID: 36753744 DOI: 10.1158/0008-5472.CAN-22-2586

The survival rate for patients with head and neck cancer (HNC) diagnosed with cervical lymph node (cLN) or distant metastasis is low. Genomic alterations in the HRAS oncogene are associated with advanced tumor stage and metastasis in HNC. Elucidation of the molecular mechanisms by which mutated HRAS (HRASmut) facilitates HNC metastasis could lead to improved treatment options for patients. Here, we examined metastasis driven by mutant HRAS in vitro and in vivo using HRASmut human HNC cell lines, patient-derived xenografts, and a novel HRASmut syngeneic model. Genetic and pharmacological manipulations indicated that HRASmut was sufficient to drive invasion in vitro and metastasis in vivo. Targeted proteomic analysis showed that HRASmut promoted AXL expression via suppressing the Hippo pathway and stabilizing YAP1 activity. Pharmacological blockade of HRAS signaling with the farnesyltransferase inhibitor tipifarnib activated the Hippo pathway and reduced the nuclear export of YAP1, thus suppressing YAP1-mediated AXL expression and metastasis. AXL was required for HRASmut cells to migrate and invade in vitro and to form regional cLN and lung metastases in vivo. In addition, AXL-depleted HRASmut tumors displayed reduced lymphatic and vascular angiogenesis in the primary tumor. Tipifarnib treatment also regulated AXL expression and attenuated VEGFA and VEGFC expression, thus regulating tumor-induced vascular formation and metastasis. Our results indicate that YAP1 and AXL are crucial factors for HRASmut-induced metastasis and that tipifarnib treatment can limit the metastasis of HNC tumors with HRAS mutations by enhancing YAP1 cytoplasmic sequestration and downregulating AXL expression.
SIGNIFICANCE: Mutant HRAS drives metastasis of head and neck cancer by switching off the Hippo pathway to activate the YAP1-AXL axis and to stimulate lymphovascular angiogenesis.

Matched MeSH terms: Transcription Factors/genetics
Stem cell genes are poorly expressed in chondrocytes from microtic cartilage

Ishak MF, Chua KH, Asma A, Saim L, Aminuddin BS, Ruszymah BH, et al.

Int J Pediatr Otorhinolaryngol, 2011 Jun;75(6):835-40.
PMID: 21543123 DOI: 10.1016/j.ijporl.2011.03.021

This study was aimed to see the difference between chondrocytes from normal cartilage compared to chondrocytes from microtic cartilage. Specific attentions were to characterize the growth of chondrocytes in terms of cell morphology, growth profile and RT-PCR analysis.

Matched MeSH terms: SOXB1 Transcription Factors/genetics
Overexpression of AtWRKY50 is correlated with enhanced production of sinapic derivatives in Arabidopsis

Hussain RMF, Kim HK, Khurshid M, Akhtar MT, Linthorst HJM

Metabolomics, 2018 01 31;14(3):25.
PMID: 30830336 DOI: 10.1007/s11306-018-1317-0

INTRODUCTION: WRKY proteins belong to a plant-specific class of transcription factors. Seventy-four WKRY genes have been identified in Arabidopsis and many WRKY proteins are known to be involved in responses to stress, especially to biotic stress. They may act either as transcriptional activators or as repressors of genes that play roles in the stress response. A number of studies have proposed the connection of Arabidopsis WRKY transcription factors in induced pathogenesis-related (PR) gene expression, although no direct evidence has been presented for specific WRKY-PR promoter interactions.
OBJECTIVE: We previously identified AtWRKY50 as a transcriptional activator of SAR gene PR1. Although PR1 accumulates to high levels in plants after attack by pathogens, its function is still elusive. Here we investigated the effects of overexpression of several WRKY proteins, including AtWRKY50, on the metabolome of Arabidopsis thaliana.
METHODS: The influence of overexpression of WRKY proteins on the metabolites of Arabidopsis was investigated by using an NMR spectroscopy-based metabolomic approach. The 1H NMR data was analysed using the multivariate data analysis methods, such as principal component analysis, hierarchical cluster analysis and partial least square-discriminant analysis.
RESULTS: The results showed that the metabolome of transgenic Arabidopsis seedlings overexpressing AtWRKY50 was different from wild type Arabidopsis and transgenic Arabidopsis overexpressing other WRKY genes. Amongst other metabolites, sinapic acid and 1-O-sinapoyl-β-D-glucose especially appeared to be the most prominent discriminating metabolites, accumulating to levels 2 to 3 times higher in the AtWRKY50 overexpressor lines.
CONCLUSION: Our results indicate a possible involvement of AtWRKY50 in secondary metabolite production in Arabidopsis, in particular of hydroxycinnamates such as sinapic acid and 1-O-sinapoyl-β-D-glucose.

Matched MeSH terms: Transcription Factors/genetics
Fulltext CaWRKY30 Positively Regulates Pepper Immunity by Targeting CaWRKY40 against Ralstonia solanacearum Inoculation through Modulating Defense-Related Genes

Hussain A, Khan MI, Albaqami M, Mahpara S, Noorka IR, Ahmed MAA, et al.

Int J Mol Sci, 2021 Nov 08;22(21).
PMID: 34769521 DOI: 10.3390/ijms222112091

The WRKY transcription factors (TFs) network is composed of WRKY TFs' subset, which performs a critical role in immunity regulation of plants. However, functions of WRKY TFs' network remain unclear, particularly in non-model plants such as pepper (Capsicum annuum L.). This study functionally characterized CaWRKY30-a member of group III Pepper WRKY protein-for immunity of pepper against Ralstonia solanacearum infection. The CaWRKY30 was detected in nucleus, and its transcriptional expression levels were significantly upregulated by R. solanacearum inoculation (RSI), and foliar application ethylene (ET), abscisic acid (ABA), and salicylic acid (SA). Virus induced gene silencing (VIGS) of CaWRKY30 amplified pepper's vulnerability to RSI. Additionally, the silencing of CaWRKY30 by VIGS compromised HR-like cell death triggered by RSI and downregulated defense-associated marker genes, like CaPR1, CaNPR1, CaDEF1, CaABR1, CaHIR1, and CaWRKY40. Conversely, transient over-expression of CaWRKY30 in pepper leaves instigated HR-like cell death and upregulated defense-related maker genes. Furthermore, transient over-expression of CaWRKY30 upregulated transcriptional levels of CaWRKY6, CaWRKY22, CaWRKY27, and CaWRKY40. On the other hand, transient over-expression of CaWRKY6, CaWRKY22, CaWRKY27, and CaWRKY40 upregulated transcriptional expression levels of CaWRKY30. The results recommend that newly characterized CaWRKY30 positively regulates pepper's immunity against Ralstonia attack, which is governed by synergistically mediated signaling by phytohormones like ET, ABA, and SA, and transcriptionally assimilating into WRKY TFs networks, consisting of CaWRKY6, CaWRKY22, CaWRKY27, and CaWRKY40. Collectively, our data will facilitate to explicate the underlying mechanism of crosstalk between pepper's immunity and response to RSI.

Matched MeSH terms: Transcription Factors/genetics

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