Dataset Information

Deciphering the molecular basis of invasiveness in Sdhb-deficient cells.

ABSTRACT: Metastatic pheochromocytomas and paragangliomas (PPGL) are malignant neuroendocrine tumors frequently associated with germline mutations in the SDHB gene. SDHB-mutated PPGL display a hypermethylator phenotype associated with hallmarks of epithelial-to-mesenchymal transition (EMT). In the present study, we report the characterization of a unique model of Sdhb knockout in mouse chromaffin cells. Sdhb deficient cells exhibit a metastatic phenotype as highlighted by increased individual cell migration (characterized by faster motility and increased persistence) as well as high invasive and adhesion abilities. This phenotype is associated with the modulation of Twist1, Twist2, Tcf3, Snai1, N-cadherin or Krt19 expression, reflecting an EMT-like reprogramming of cells. Krt19 is epigenetically silenced in Sdhb-deficient cells and re-expressed after treatment by the demethylating agent decitabine. Krt19 rescue by lentiviral transduction in Sdhb-deficient cells and Krt19 inhibition by RNA interference in wild-type cells were performed. Both studies revealed the involvement of KRT19 in the invasive phenotype by modulating collective and individual migration and cell/extra-cellular matrix adhesion properties. These findings underline the role of hypermethylation and EMT in the in vitro acquisition of metastatic properties, following SDHB loss of function.

SUBMITTER: Loriot C

PROVIDER: S-EPMC4741742 | biostudies-literature | 2015 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Deciphering the molecular basis of invasiveness in Sdhb-deficient cells.

Loriot Céline C Domingues Mélanie M Berger Adeline A Menara Mélanie M Ruel Maëva M Morin Aurélie A Castro-Vega Luis-Jaime LJ Letouzé Éric É Martinelli Cosimo C Bemelmans Alexis-Pierre AP Larue Lionel L Gimenez-Roqueplo Anne-Paule AP Favier Judith J

Oncotarget 20151001 32

Metastatic pheochromocytomas and paragangliomas (PPGL) are malignant neuroendocrine tumors frequently associated with germline mutations in the SDHB gene. SDHB-mutated PPGL display a hypermethylator phenotype associated with hallmarks of epithelial-to-mesenchymal transition (EMT). In the present study, we report the characterization of a unique model of Sdhb knockout in mouse chromaffin cells. Sdhb deficient cells exhibit a metastatic phenotype as highlighted by increased individual cell migrati ...[more]

PMID: 26460615

Similar Datasets

Project description:Objectiveγ-Aminobutyric acid type A (GABAA ) receptor subunit gene mutations are significant causes of epilepsy, which are often accompanied by various neuropsychiatric comorbidities, but the underlying mechanisms are unclear. It has been suggested that the comorbidities are caused by seizures, as the comorbidities often present in severe epilepsy syndromes. However, findings from both humans and animal models argue against this conclusion. Mutations in the GABAA receptor γ2 subunit gene GABRG2 have been associated with anxiety alone or with severe epilepsy syndromes and comorbid anxiety, suggesting that a core molecular defect gives rise to the phenotypic spectrum. Here, we determined the pathophysiology of comorbid anxiety in GABRG2 loss-of-function epilepsy syndromes, identified the central nucleus of the amygdala (CeA) as a primary site for epilepsy comorbid anxiety, and demonstrated a potential rescue of comorbid anxiety via neuromodulation of CeA neurons.MethodsWe used brain slice recordings, subcellular fractionation with Western blot, immunohistochemistry, confocal microscopy, and a battery of behavior tests in combination with a chemogenetic approach to characterize anxiety and its underlying mechanisms in a Gabrg2+/Q390X knockin mouse and a Gabrg2+/- knockout mouse, each associated with a different epilepsy syndrome.ResultsWe found that impaired GABAergic neurotransmission in CeA underlies anxiety in epilepsy, which is due to reduced GABAA receptor subunit expression resulting from the mutations. Impaired GABAA receptor expression reduced GABAergic neurotransmission in CeA, but not in basolateral amygdala. Activation or inactivation of inhibitory neurons using a chemogenetic approach in CeA alone modulated anxietylike behaviors. Similarly, pharmacological enhancement of GABAergic signaling via γ2 subunit-containing receptors relieved the anxiety.SignificanceTogether, these data demonstrate the molecular basis for a comorbidity of epilepsy, anxiety, and suggest that impaired GABAA receptor function in CeA due to a loss-of-function mutation could at least contribute to anxiety. Modulation of CeA neurons could cause or suppress anxiety, suggesting a potential use of CeA neurons as therapeutic targets for treatment of anxiety in addition to traditional pharmacological approaches.

Project description:BackgroundCyanobacteria constitute a serious threat to freshwater ecosystems by producing toxic secondary metabolites, e.g. microcystins. These microcystins have been shown to harm livestock, pets and humans and to affect ecosystem service and functioning. Cyanobacterial blooms are increasing worldwide in intensity and frequency due to eutrophication and global warming. However, Daphnia, the main grazer of planktonic algae and cyanobacteria, has been shown to be able to suppress bloom-forming cyanobacteria and to adapt to cyanobacteria that produce microcystins. Since Daphnia's genome was published only recently, it is now possible to elucidate the underlying molecular mechanisms of microcystin tolerance of Daphnia.ResultsDaphnia magna was fed with either a cyanobacterial strain that produces microcystins or its genetically engineered microcystin knock-out mutant. Thus, it was possible to distinguish between effects due to the ingestion of cyanobacteria and effects caused specifically by microcystins. By using RNAseq the differentially expressed genes between the different treatments were analyzed and affected KOG-categories were calculated. Here we show that the expression of transporter genes in Daphnia was regulated as a specific response to microcystins. Subsequent qPCR and dietary supplementation with pure microcystin confirmed that the regulation of transporter gene expression was correlated with the tolerance of several Daphnia clones.ConclusionsHere, we were able to identify new candidate genes that specifically respond to microcystins by separating cyanobacterial effects from microcystin effects. The involvement of these candidate genes in tolerance to microcystins was validated by correlating the difference in transporter gene expression with clonal tolerance. Thus, the prevention of microcystin uptake most probably constitutes a key mechanism in the development of tolerance and adaptation of Daphnia. With the availability of clear candidate genes, future investigations examining the process of local adaptation of Daphnia populations to microcystins are now possible.

Dataset Information

Deciphering the molecular basis of invasiveness in Sdhb-deficient cells.

Publications

Deciphering the molecular basis of invasiveness in Sdhb-deficient cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets