Functional Assessment of Disease-Associated Regulatory Variants <i>In Vivo</i> Using a Versatile Dual Colour Transgenesis Strategy in Zebrafish

Disruption of gene regulation by sequence variation in non-coding regions of the genome is now recognised as a significant cause of human disease and disease susceptibility. Sequence variants in cis-regulatory elements (CREs), the primary determinants of spatio-temporal gene regulation, can alter transcription factor binding sites. While technological advances have led to easy identification of disease-associated CRE variants, robust methods for discerning functional CRE variants from background variation are lacking. Here we describe an efficient dual-colour reporter transgenesis approach in zebrafish, simultaneously allowing detailed in vivo comparison of spatio-temporal differences in regulatory activity between putative CRE variants and assessment of altered transcription factor binding potential of the variant. We validate the method on known disease-associated elements regulating SHH, PAX6 and IRF6 and subsequently characterise novel, ultra-long-range SOX9 enhancers implicated in the craniofacial abnormality Pierre Robin Sequence. The method provides a highly cost-effective, fast and robust approach for simultaneously unravelling in a single assay whether, where and when in embryonic development a disease-associated CRE-variant is affecting its regulatory function

Place de l'étude pharmacogénétique des cytochromes CYP2D6 et CYP2C19 dans la prise en charge du patient psychotique : revue de la littérature

La schizophrénie est une pathologie psychiatrique sévère dont la prévalence mondiale est d'environ 1% et dont les coûts de prise en charge sont élevés notamment en raison d'hospitalisations fréquentes. La première ligne de prise en charge repose principalement sur le traitement médicamenteux par antipsychotiques mais, malgré un large éventail thérapeutique, la pathologie reste incontrôlée pour environ 30% des patients. De plus, les effets secondaires associés à ces traitements peuvent être invalidants et entraîner une mauvaise observance du traitement. La variabilité inter et intra individuelle dans la réponse au traitement est multifactorielle et possède une composante génétique. La pharmacogénétique est une discipline qui s'intéresse à identifier des variantes génétiques mis en cause dans la variabilité de la réponse au traitement ou dans l'apparition et la sévérité des effets secondaires. Dans le cas des antipsychotiques, identifier ces gènes est un challenge important pour améliorer la prise en charge des patients schizophrènes, pour le bénéfice direct du patient mais aussi sur le plan économique. Les gènes codant les enzymes du métabolisme des médicaments (cytochromes CYP2D6 et CYP2C19) sont soumis à des polymorphismes impactant les capacités métaboliques de l'enzyme finale et modifiant ainsi les paramètres pharmacocinétiques des médicaments. Ce travail consiste en une revue de la littérature des études réalisées concernant la pharmacogénétique des CYP2D6 et CYP2C19 en lien avec un traitement antipsychotique, ainsi qu'une discussion sur les implications actuelles de ce génotypage en pratique clinique courante et sur ses aspects pharmaco-économiques

Réflexion sur les motifs de consultation des patients de plus de 75 ans aux urgences du CHU de Reims en 2011

REIMS-BU Santé (514542104) / SudocSudocFranceF

Dual-fluorescence transgenic analysis of a SHH enhancer SBE2 where a C>T change in a Six3 binding site has been identified in a patient with holoprosencephaly.

<p><b>(A)</b> Regulatory landscape of SHH, depicting the location of the SBE2 enhancer. The sequence conservation plot on the right shows the low level of sequence conservation for SBE2 in the zebrafish genome. <b>(B)</b> SHH-SBE2 enhancer-driven F1 reporter transgenics. The wild-type allele Wt(C) drives expression in the rostral and caudal hypothalamus (long green or red bar) independent of the associated fluorophore (eGFP or mCherry). Expression from the mutant allele, Mut(T), is retained in the caudal hypothalamus (short green or red bar) but lost in the rostral hypothalamus (short green or red bar). Additional expression of the SBE2 Wt(C) allele in the rostral forebrain of later stage (96hpf) zebrafish embryos is also lost by the Mut(T) allele. <b>(C)</b> RNA <i>in situ</i> hybridisation analysis of <i>shha</i> and <i>shhb</i> expression at 48hpf and 96hpf of zebrafish embryonic development. The reporter gene expression pattern driven by Wt(C) allele significantly overlaps with the <i>shha</i> expression domain in the hypothalamus. <b>(D)</b> Morpholino knock-down of Six3 in SHH-SBE2 transgenic embryos mimics the effect of the Six3 binding site mutation in SBE2. F2 embryos bearing both SHH-SBE2 Wt(C) and Mut(T) alleles injected with either control morpholino (Control MO) or morpholino against both six3A and six3B (six3 AMO). Upon knockdown of six3, the hypothalamus expression driven by the Wt allele shrinks to overlap completely with the expression driven by the mutant allele (bearing a mutant six3 binding site). Wt: wild-type; Mut: mutant; hpf: hours post fertilization; MO: morpholino, RH: Rostral hypothalamus; CH: Caudal hypothalamus; rFB: Rostral forebrain.</p

New enhancers from the SOX9 region with PRS-associated single nucleotide variants.

<p><b>(A) p300-PK17</b>, spatiotemporally altered expression: F1 dual-fluorescence reporter transgenic embryos shown at 48, 72 and 96 hpf. At 48 and 72 hpf the Wt(G) allele drives expression in the region around the oral cavity (OC) (white arrowhead). At 96 hpf Wt(G) drives expression in the palatoquadrate (PQ) (curved white arrow) and Meckel’s cartilage (MC) (open arrow). The Mut(A) allele is able to drive OC expression at 48 hpf, but this is lost by 72 hpf and at 96 hpf no PQ and MC expression is observed. <b>(B) hoc-CNE-D</b>, tissue-specific CRE with unaltered expression: F1 dual-fluorescence transgenic embryos at 72 and 96 hpf. The Wt(T) and the Mut(C) alleles both drive expression in olfactory placode (OP), brain (BR), and ceratobranchials (CB). <b>(C) p300-PK22</b>, craniofacial CRE with unaltered expression: F1 dual-fluorescence transgenic embryos at 72 hpf. The Wt(A) and Mut(C) allele both drive expression in the region around the oral cavity (OC). <b>(D-E)</b> RNA <i>in situ</i> hybridisation analysis of zebrafish <i>sox9a</i> and <i>sox9b</i> at 72hpf and 96hpf, showing overlap of reporter gene expression driven by the p300-Pk17, hoc-CNE-D and p300-Pk22 elements with the endogenous <i>sox9a</i> and <i>sox9b</i> expression pattern in the developing jaw. Wt: wild-type; Mut: mutant; hpf: hours post fertilization.</p

Dual-fluorescence transgenic analysis of IRF6 enhancer MCS-9.7 where a SNP (rs642961, G>A) in a TFAP2A (AP2α) binding site has been associated with cleft lip.

<p><b>(A)</b> Regulatory landscape of IRF6, depicting the location of MCS-9.7 enhancer. The conservation plot on the right shows the absence of sequence conservation for MCS-9.7 in the zebrafish genome. <b>(B)</b> IRF6-MCS-9.7 enhancer-driven F1 reporter transgenics. The Wt(G) allele drives expression in the first pharyngeal arch (PA1) (arrow) and in the developing ethmoid plate (EP) (curved arrow). Mut(A) has lost EP expression but maintains PA1 expression. <b>(C)</b> RNA <i>in situ</i> hybridisation analysis of zebrafish <i>irf6</i> at 72hpf showing overlap of the reporter gene expression domain driven by Wt(G) allele with the endogenous <i>irf6</i> expression pattern in the developing jaw. Wt: wild-type; Mut: mutant; hpf: hours post fertilization.</p

Dual-fluorescence transgenic analysis of established CREs with disease-associated point mutations.

<p><b>(A)</b> SHH-ZRS. (a) The regulatory landscape of SHH, depicting the location of ZRS enhancer. The conservation plot on the left shows the low level of sequence conservation for ZRS in the zebrafish genome. (b) SHH-ZRS enhancer-driven reporter expression is shown at 72 hpf and 96 hpf. The top row shows the Wt(G) allele driving both mCherry and eGFP expression to equal measure in a restricted region of the developing pectoral fin (PF), coinciding with the expression domain of both <i>shha</i> and <i>shhb</i> in the developing pectoral fin (c). The Mut(A) allele drives expression at an additional site on the opposite edge of the fin. The ectopic expression (arrowheads) is increased by 96 hpf. The double-headed arrow indicates the anterior (a)—posterior (p) axial plane of the developing pectoral fin. <b>(B)</b> PAX6-SIMO. <b>(a)</b> The regulatory landscape of PAX6, depicting the location of SIMO enhancer. The conservation plot on the right shows the presence of sequence conservation for SIMO in the zebrafish genome. (b) PAX6-SIMO enhancer-driven reporter expression is shown at 72 hpf. In contrast to the Wt(G) element, and irrespective of the fluorophore used, the Mut(T) allele consistently fails to drive reporter gene expression in the developing lens (L). (c) RNA <i>in situ</i> hybridisation analysis of zebrafish <i>pax6a</i> at 72hpf showing the endogenous <i>pax6a</i> expression pattern in the developing eye with strong retinal expression and weaker lens expression overlapping with the reporter domain driven by the Wt(G). Wt: wild-type; Mut: mutant; hpf: hours post fertilization.</p

Novel PRS-associated elements tested for enhancer function.

<p>Novel PRS-associated elements tested for enhancer function.</p