{"id":{"repo_id":"sherbrooke","oai_identifier":"oai:usherbrooke.scholaris.ca:11143/18680"},"canonical_url":"https://search.dev.ndltd.org/etd/sherbrooke/oai:usherbrooke.scholaris.ca:11143/18680","repository":{"repo_id":"sherbrooke","name":"Université de Sherbrooke","base_url":"https://usherbrooke.scholaris.ca/server/oai/request"},"display":{"title":"The intrinsic role of SOCS1 in intestinal epithelial cells","abstract":"The SOCS1 protein negatively regulate cytokine signaling. To define its role in intestinal epithelial cells (IEC), our laboratory created a mouse model of Socs1 gene deletion in IEC lineages of the small and large intestines. Analysis of this Socs1ΔIEC mouse model suggests that lethal ulcerative colitis might be driven by Paneth and goblet cell defects, like those seen in inflammatory bowel disease patients and mouse models with defective genes regulating autophagy and endoplasmic reticulum (ER) stress response. Ensuing dysbiosis and bacteria invasion would then trigger immune responses for bacteria killing, whereas erosion of the colon epithelium in colitis Socs1ΔIEC mice seems driven by STAT1-dependent sensitization of Socs1- null IECs to apoptosis induced by immune cells-derived IFNγ in response to bacterial invasion. To define SOCS1 IEC-intrinsic role in the epithelium integrity and renewal, and for confirming that SOCS1 deficiency sensitizes IECs to IFNγ-driven cell death, crypt-derived colonoid populations from the WT, Ifng-/- and Socs1-/- x Ifng-/- (DKO) mouse models were produced. Morphological analysis, gene and/or protein expression profiling of markers of IEC populationages (Lg5, E-cadherin, Muc2 and Tff3), autophagy (P62), ER stress response (spliced Xbp1) and apoptosis (cleaved caspase 3 protein), as well as EdU incorporation proliferation assays were then performed. Our results indicate that the loss of Ifng and Socs1 is not affecting colonoid growth and renewal capacity of stem cells, goblet cell differentiation, or IEC proliferation. However, we detected Ifng expression in WT colonoids, which could explain the E-cadherin upregulation, P62 protein reduced levels, and enhanced Xpb1 splicing in the Ifng-/- colonoids. Likewise, DKO colonoids also displayed elevated E-cadherin protein expression, but Xbp1 splicing was further increased and P62 protein slightly restored when compared to Ifng-/- colonoids. These results indicate that loss of SOCS1 in IECs might promote deficiency in ER stress response and enhanced autophagy. Furthermore, the loss of IFNg or SOCS1 seems to increase STAT1 protein levels in IECs at steady state and upon IFNg treatment, but only simultaneous deletion of Ifng and Socs1 genes was found to boost IFNg-induced STAT1 phosphorylation. Importantly morphological assessment combined with measure of cleaved caspase 3 protein levels by WB and immunofluorescent microscopy strongly suggest that the loss of SOCS1 makes IECs more prone to death by a non-apoptotic mechanism at steady state and to apoptosis upon IFNg stimulation. Although our results are preliminary and need to be validated in independent colonoids s, they support that goblet cell dysfunction in Socs1ΔIEC mice could be linked to defects in autophagy and ER stress response, and that loss of SOCS1 sensitizes IECs to IFNγ-induced cell death in a STAT1-dependent manner.The SOCS1 protein negatively regulate cytokine signaling. To define its role in intestinal epithelial cells (IEC), our laboratory created a mouse model of Socs1 gene deletion in IEC lineages of the small and large intestines. Analysis of this Socs1ΔIEC mouse model suggests that lethal ulcerative colitis might be driven by Paneth and goblet cell defects, like those seen in inflammatory bowel disease patients and mouse models with defective genes regulating autophagy and endoplasmic reticulum (ER) stress response. Ensuing dysbiosis and bacteria invasion would then trigger immune responses for bacteria killing, whereas erosion of the colon epithelium in colitis Socs1ΔIEC mice seems driven by STAT1-dependent sensitization of Socs1- null IECs to apoptosis induced by immune cells-derived IFNγ in response to bacterial invasion. To define SOCS1 IEC-intrinsic role in the epithelium integrity and renewal, and for confirming that SOCS1 deficiency sensitizes IECs to IFNγ-driven cell death, crypt-derived colonoid populations from the WT, Ifng-/- and Socs1-/- x Ifng-/- (DKO) mouse models were produced. Morphological analysis, gene and/or protein expression profiling of markers of IEC populationages (Lg5, E-cadherin, Muc2 and Tff3), autophagy (P62), ER stress response (spliced Xbp1) and apoptosis (cleaved caspase 3 protein), as well as EdU incorporation proliferation assays were then performed. Our results indicate that the loss of Ifng and Socs1 is not affecting colonoid growth and renewal capacity of stem cells, goblet cell differentiation, or IEC proliferation. However, we detected Ifng expression in WT colonoids, which could explain the E-cadherin upregulation, P62 protein reduced levels, and enhanced Xpb1 splicing in the Ifng-/- colonoids. Likewise, DKO colonoids also displayed elevated E-cadherin protein expression, but Xbp1 splicing was further increased and P62 protein slightly restored when compared to Ifng-/- colonoids. These results indicate that loss of SOCS1 in IECs might promote deficiency in ER stress response and enhanced autophagy. Furthermore, the loss of IFNg or SOCS1 seems to increase STAT1 protein levels in IECs at steady state and upon IFNg treatment, but only simultaneous deletion of Ifng and Socs1 genes was found to boost IFNg-induced STAT1 phosphorylation. Importantly morphological assessment combined with measure of cleaved caspase 3 protein levels by WB and immunofluorescent microscopy strongly suggest that the loss of SOCS1 makes IECs more prone to death by a non-apoptotic mechanism at steady state and to apoptosis upon IFNg stimulation. Although our results are preliminary and need to be validated in independent colonoids s, they support that goblet cell dysfunction in Socs1ΔIEC mice could be linked to defects in autophagy and ER stress response, and that loss of SOCS1 sensitizes IECs to IFNγ-induced cell death in a STAT1-dependent manner.","abstract_html":"The SOCS1 protein negatively regulate cytokine signaling. To define its role in intestinal epithelial cells (IEC), our laboratory created a mouse model of Socs1 gene deletion in IEC lineages of the small and large intestines. Analysis of this Socs1ΔIEC mouse model suggests that lethal ulcerative colitis might be driven by Paneth and goblet cell defects, like those seen in inflammatory bowel disease patients and mouse models with defective genes regulating autophagy and endoplasmic reticulum (ER) stress response. Ensuing dysbiosis and bacteria invasion would then trigger immune responses for bacteria killing, whereas erosion of the colon epithelium in colitis Socs1ΔIEC mice seems driven by STAT1-dependent sensitization of Socs1- null IECs to apoptosis induced by immune cells-derived IFNγ in response to bacterial invasion. To define SOCS1 IEC-intrinsic role in the epithelium integrity and renewal, and for confirming that SOCS1 deficiency sensitizes IECs to IFNγ-driven cell death, crypt-derived colonoid populations from the WT, Ifng-/- and Socs1-/- x Ifng-/- (DKO) mouse models were produced. Morphological analysis, gene and/or protein expression profiling of markers of IEC populationages (Lg5, E-cadherin, Muc2 and Tff3), autophagy (P62), ER stress response (spliced Xbp1) and apoptosis (cleaved caspase 3 protein), as well as EdU incorporation proliferation assays were then performed. Our results indicate that the loss of Ifng and Socs1 is not affecting colonoid growth and renewal capacity of stem cells, goblet cell differentiation, or IEC proliferation. However, we detected Ifng expression in WT colonoids, which could explain the E-cadherin upregulation, P62 protein reduced levels, and enhanced Xpb1 splicing in the Ifng-/- colonoids. Likewise, DKO colonoids also displayed elevated E-cadherin protein expression, but Xbp1 splicing was further increased and P62 protein slightly restored when compared to Ifng-/- colonoids. These results indicate that loss of SOCS1 in IECs might promote deficiency in ER stress response and enhanced autophagy. Furthermore, the loss of IFNg or SOCS1 seems to increase STAT1 protein levels in IECs at steady state and upon IFNg treatment, but only simultaneous deletion of Ifng and Socs1 genes was found to boost IFNg-induced STAT1 phosphorylation. Importantly morphological assessment combined with measure of cleaved caspase 3 protein levels by WB and immunofluorescent microscopy strongly suggest that the loss of SOCS1 makes IECs more prone to death by a non-apoptotic mechanism at steady state and to apoptosis upon IFNg stimulation. Although our results are preliminary and need to be validated in independent colonoids s, they support that goblet cell dysfunction in Socs1ΔIEC mice could be linked to defects in autophagy and ER stress response, and that loss of SOCS1 sensitizes IECs to IFNγ-induced cell death in a STAT1-dependent manner.The SOCS1 protein negatively regulate cytokine signaling. To define its role in intestinal epithelial cells (IEC), our laboratory created a mouse model of Socs1 gene deletion in IEC lineages of the small and large intestines. Analysis of this Socs1ΔIEC mouse model suggests that lethal ulcerative colitis might be driven by Paneth and goblet cell defects, like those seen in inflammatory bowel disease patients and mouse models with defective genes regulating autophagy and endoplasmic reticulum (ER) stress response. Ensuing dysbiosis and bacteria invasion would then trigger immune responses for bacteria killing, whereas erosion of the colon epithelium in colitis Socs1ΔIEC mice seems driven by STAT1-dependent sensitization of Socs1- null IECs to apoptosis induced by immune cells-derived IFNγ in response to bacterial invasion. To define SOCS1 IEC-intrinsic role in the epithelium integrity and renewal, and for confirming that SOCS1 deficiency sensitizes IECs to IFNγ-driven cell death, crypt-derived colonoid populations from the WT, Ifng-/- and Socs1-/- x Ifng-/- (DKO) mouse models were produced. Morphological analysis, gene and/or protein expression profiling of markers of IEC populationages (Lg5, E-cadherin, Muc2 and Tff3), autophagy (P62), ER stress response (spliced Xbp1) and apoptosis (cleaved caspase 3 protein), as well as EdU incorporation proliferation assays were then performed. Our results indicate that the loss of Ifng and Socs1 is not affecting colonoid growth and renewal capacity of stem cells, goblet cell differentiation, or IEC proliferation. However, we detected Ifng expression in WT colonoids, which could explain the E-cadherin upregulation, P62 protein reduced levels, and enhanced Xpb1 splicing in the Ifng-/- colonoids. Likewise, DKO colonoids also displayed elevated E-cadherin protein expression, but Xbp1 splicing was further increased and P62 protein slightly restored when compared to Ifng-/- colonoids. These results indicate that loss of SOCS1 in IECs might promote deficiency in ER stress response and enhanced autophagy. Furthermore, the loss of IFNg or SOCS1 seems to increase STAT1 protein levels in IECs at steady state and upon IFNg treatment, but only simultaneous deletion of Ifng and Socs1 genes was found to boost IFNg-induced STAT1 phosphorylation. Importantly morphological assessment combined with measure of cleaved caspase 3 protein levels by WB and immunofluorescent microscopy strongly suggest that the loss of SOCS1 makes IECs more prone to death by a non-apoptotic mechanism at steady state and to apoptosis upon IFNg stimulation. Although our results are preliminary and need to be validated in independent colonoids s, they support that goblet cell dysfunction in Socs1ΔIEC mice could be linked to defects in autophagy and ER stress response, and that loss of SOCS1 sensitizes IECs to IFNγ-induced cell death in a STAT1-dependent manner.","abstract_has_math":false,"creators":["Emami, Seyed Alireza"],"institution":"Université de Sherbrooke","degree_name":"M. Sc.","degree_level":"Maîtrise","degree_discipline":"Biologie cellulaire","degree_department":null,"school":null,"contributors":[],"advisors":["Saucier, Caroline"],"committee_chairs":[],"committee_members":[],"year":2021,"date_issued":"2021","date_published":"2021","updated_at":"2026-07-27T21:07:32Z","subjects":["SOCS1","Inflammatory bowel disease","IFNγ","Colonoid","Intestinal epithelial cells","Maladie inflammatoire de l'intestin","Colonoïde","Cellules épithéliales intestinales"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11143/18680","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Saucier, Caroline"]},{"key":"dc:creator","label":"Author","values":["Emami, Seyed Alireza"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2021-09-08T13:53:45Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2021-09-08T13:53:45Z"]},{"key":"dc:date.issued","label":"Date","values":["2021"]},{"key":"dc:publisher","label":"Institution","values":["Université de Sherbrooke"]},{"key":"dc:type","label":"Dc Type","values":["Mémoire de maîtrise"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biologie cellulaire"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Maîtrise"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M. Sc."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Faculté de médecine et des sciences de la santé"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["SOCS1","Inflammatory bowel disease","IFNγ","Colonoid","Intestinal epithelial cells","Maladie inflammatoire de l'intestin","Colonoïde","Cellules épithéliales intestinales"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11143/18680"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The SOCS1 protein negatively regulate cytokine signaling. To define its role in intestinal epithelial cells (IEC), our laboratory created a mouse model of Socs1 gene deletion in IEC lineages of the small and large intestines. Analysis of this Socs1ΔIEC mouse model suggests that lethal ulcerative colitis might be driven by Paneth and goblet cell defects, like those seen in inflammatory bowel disease patients and mouse models with defective genes regulating autophagy and endoplasmic reticulum (ER) stress response. Ensuing dysbiosis and bacteria invasion would then trigger immune responses for bacteria killing, whereas erosion of the colon epithelium in colitis Socs1ΔIEC mice seems driven by STAT1-dependent sensitization of Socs1- null IECs to apoptosis induced by immune cells-derived IFNγ in response to bacterial invasion. To define SOCS1 IEC-intrinsic role in the epithelium integrity and renewal, and for confirming that SOCS1 deficiency sensitizes IECs to IFNγ-driven cell death, crypt-derived colonoid populations from the WT, Ifng-/- and Socs1-/- x Ifng-/- (DKO) mouse models were produced. Morphological analysis, gene and/or protein expression profiling of markers of IEC populationages (Lg5, E-cadherin, Muc2 and Tff3), autophagy (P62), ER stress response (spliced Xbp1) and apoptosis (cleaved caspase 3 protein), as well as EdU incorporation proliferation assays were then performed. Our results indicate that the loss of Ifng and Socs1 is not affecting colonoid growth and renewal capacity of stem cells, goblet cell differentiation, or IEC proliferation. However, we detected Ifng expression in WT colonoids, which could explain the E-cadherin upregulation, P62 protein reduced levels, and enhanced Xpb1 splicing in the Ifng-/- colonoids. Likewise, DKO colonoids also displayed elevated E-cadherin protein expression, but Xbp1 splicing was further increased and P62 protein slightly restored when compared to Ifng-/- colonoids. These results indicate that loss of SOCS1 in IECs might promote deficiency in ER stress response and enhanced autophagy. Furthermore, the loss of IFNg or SOCS1 seems to increase STAT1 protein levels in IECs at steady state and upon IFNg treatment, but only simultaneous deletion of Ifng and Socs1 genes was found to boost IFNg-induced STAT1 phosphorylation. Importantly morphological assessment combined with measure of cleaved caspase 3 protein levels by WB and immunofluorescent microscopy strongly suggest that the loss of SOCS1 makes IECs more prone to death by a non-apoptotic mechanism at steady state and to apoptosis upon IFNg stimulation. Although our results are preliminary and need to be validated in independent colonoids s, they support that goblet cell dysfunction in Socs1ΔIEC mice could be linked to defects in autophagy and ER stress response, and that loss of SOCS1 sensitizes IECs to IFNγ-induced cell death in a STAT1-dependent manner.The SOCS1 protein negatively regulate cytokine signaling. To define its role in intestinal epithelial cells (IEC), our laboratory created a mouse model of Socs1 gene deletion in IEC lineages of the small and large intestines. Analysis of this Socs1ΔIEC mouse model suggests that lethal ulcerative colitis might be driven by Paneth and goblet cell defects, like those seen in inflammatory bowel disease patients and mouse models with defective genes regulating autophagy and endoplasmic reticulum (ER) stress response. Ensuing dysbiosis and bacteria invasion would then trigger immune responses for bacteria killing, whereas erosion of the colon epithelium in colitis Socs1ΔIEC mice seems driven by STAT1-dependent sensitization of Socs1- null IECs to apoptosis induced by immune cells-derived IFNγ in response to bacterial invasion. To define SOCS1 IEC-intrinsic role in the epithelium integrity and renewal, and for confirming that SOCS1 deficiency sensitizes IECs to IFNγ-driven cell death, crypt-derived colonoid populations from the WT, Ifng-/- and Socs1-/- x Ifng-/- (DKO) mouse models were produced. Morphological analysis, gene and/or protein expression profiling of markers of IEC populationages (Lg5, E-cadherin, Muc2 and Tff3), autophagy (P62), ER stress response (spliced Xbp1) and apoptosis (cleaved caspase 3 protein), as well as EdU incorporation proliferation assays were then performed. Our results indicate that the loss of Ifng and Socs1 is not affecting colonoid growth and renewal capacity of stem cells, goblet cell differentiation, or IEC proliferation. However, we detected Ifng expression in WT colonoids, which could explain the E-cadherin upregulation, P62 protein reduced levels, and enhanced Xpb1 splicing in the Ifng-/- colonoids. Likewise, DKO colonoids also displayed elevated E-cadherin protein expression, but Xbp1 splicing was further increased and P62 protein slightly restored when compared to Ifng-/- colonoids. These results indicate that loss of SOCS1 in IECs might promote deficiency in ER stress response and enhanced autophagy. Furthermore, the loss of IFNg or SOCS1 seems to increase STAT1 protein levels in IECs at steady state and upon IFNg treatment, but only simultaneous deletion of Ifng and Socs1 genes was found to boost IFNg-induced STAT1 phosphorylation. Importantly morphological assessment combined with measure of cleaved caspase 3 protein levels by WB and immunofluorescent microscopy strongly suggest that the loss of SOCS1 makes IECs more prone to death by a non-apoptotic mechanism at steady state and to apoptosis upon IFNg stimulation. Although our results are preliminary and need to be validated in independent colonoids s, they support that goblet cell dysfunction in Socs1ΔIEC mice could be linked to defects in autophagy and ER stress response, and that loss of SOCS1 sensitizes IECs to IFNγ-induced cell death in a STAT1-dependent manner.","Afin de définir le rôle de la protéine SOCS1 dans les cellules épithéliales intestinales (CEI), notre labo a créé un modèle murin invalidé pour Socs1 dans les CEI. L’analyse des souris Socs1ΔIEC suggère que la colite létale serait déclenchée par des défauts des cellules de Paneth et caliciformes, comme ceux observés dans les maladies inflammatoires de l’intestin et les modèles murins de gènes défectueux régulant l’autophagie et la réponse au stress du réticulum endoplasmique (RE). La dysbiose et l’invasion bactérienne qui s’ensuivraient induiraient alors une réponse immune pour détruire les bactéries, tandis que l’érosion de l’épithélium colique chez les souris Socs1ΔIEC serait promue par la sensibilisation STAT1-dépendante des CEI à l’apoptose induite par l’IFNγ produit par les cellules immunes en réponse à l’invasion bactérienne. Pour définir le rôle de SOCS1 dans l’intégrité et le renouvellement de l’épithélium intestinal, des populations de colonoïdes de souris WT, Ifng-/- et Socs1-/- x Ifng-/- (DKO) ont été produites. L’analyse morphologique et de l’expression de marqueurs des CEI, de l’autophagie (P62), de la réponse au stress du RE (Xbp1 épissé) et de l’apoptose (caspase 3 clivée), ainsi que des essais de prolifération d’incorporation d’EdU ont ensuite été effectués. Nos résultats indiquent que la perte d’IFNg et de SOCS1 n’affecte pas la croissance des colonoïdes, le renouvellement des cellules souches, la différenciation des cellules caliciformes et la prolifération des CEI. Nous avons aussi détecté l’expression du gène de l’IFNg dans les colonoids WT, ce qui expliquerait l’augmentation de E-cadhérine, les niveaux réduits de la protéine P62, et l’épissage d’Xpb1 augmenté dans les colonoïdes Ifng-/-. Les colonoids DKO en comparaison avec ceux Ifng-/-, montraient aussi un niveau élevé de E-cadhérine, mais l’épissage d’Xbp1 était plus accru et un léger retour de la protéine P62 était observé. Nos résultats indiquent que la perte de SOCS1 dans les CEI induirait une réponse au stress du RE déficiente et augmenterait l’autophagie. La perte d’IFNg ou de SOCS1 semble augmenter le niveau protéique de STAT1 dans les CEI à l’état basal et lors d’un traitement à l’IFNg, mais seule la perte simultanée des gènes Ifng et Socs1 s’est avérée augmenter la phosphorylation de STAT1 IFNg-induite. L’évaluation morphologique et des niveaux du clivage de la caspase 3 suggèrent que la perte de SOCS1 sensibilisait les CEI à la mort nonapoptotique à l’état basal et à l’apoptose IFNg-induite. Quoique nos résultats doivent être validés dans des populations de colonoïdes indépendantes, ils soutiennent que le dysfonctionnement des cellules caliciformes chez les souris Socs1ΔIEC serait lié à des défauts d’autophagie et de la réponse au stress ER, et que la perte de SOCS1 sensibiliserait de façon STAT1-dépendant les CEI à la mort cellulaire induite par IFNg."]},{"key":"dc:title","label":"Title","values":["The intrinsic role of SOCS1 in intestinal epithelial cells"]}]}],"canonical_facts":{"dc:contributor.advisor":["Saucier, Caroline"],"dc:creator":["Emami, Seyed Alireza"],"dc:date.accessioned":["2021-09-08T13:53:45Z"],"dc:date.available":["2021-09-08T13:53:45Z"],"dc:date.issued":["2021"],"dc:description.abstract":["The SOCS1 protein negatively regulate cytokine signaling. To define its role in intestinal epithelial cells (IEC), our laboratory created a mouse model of Socs1 gene deletion in IEC lineages of the small and large intestines. Analysis of this Socs1ΔIEC mouse model suggests that lethal ulcerative colitis might be driven by Paneth and goblet cell defects, like those seen in inflammatory bowel disease patients and mouse models with defective genes regulating autophagy and endoplasmic reticulum (ER) stress response. Ensuing dysbiosis and bacteria invasion would then trigger immune responses for bacteria killing, whereas erosion of the colon epithelium in colitis Socs1ΔIEC mice seems driven by STAT1-dependent sensitization of Socs1- null IECs to apoptosis induced by immune cells-derived IFNγ in response to bacterial invasion. To define SOCS1 IEC-intrinsic role in the epithelium integrity and renewal, and for confirming that SOCS1 deficiency sensitizes IECs to IFNγ-driven cell death, crypt-derived colonoid populations from the WT, Ifng-/- and Socs1-/- x Ifng-/- (DKO) mouse models were produced. Morphological analysis, gene and/or protein expression profiling of markers of IEC populationages (Lg5, E-cadherin, Muc2 and Tff3), autophagy (P62), ER stress response (spliced Xbp1) and apoptosis (cleaved caspase 3 protein), as well as EdU incorporation proliferation assays were then performed. Our results indicate that the loss of Ifng and Socs1 is not affecting colonoid growth and renewal capacity of stem cells, goblet cell differentiation, or IEC proliferation. However, we detected Ifng expression in WT colonoids, which could explain the E-cadherin upregulation, P62 protein reduced levels, and enhanced Xpb1 splicing in the Ifng-/- colonoids. Likewise, DKO colonoids also displayed elevated E-cadherin protein expression, but Xbp1 splicing was further increased and P62 protein slightly restored when compared to Ifng-/- colonoids. These results indicate that loss of SOCS1 in IECs might promote deficiency in ER stress response and enhanced autophagy. Furthermore, the loss of IFNg or SOCS1 seems to increase STAT1 protein levels in IECs at steady state and upon IFNg treatment, but only simultaneous deletion of Ifng and Socs1 genes was found to boost IFNg-induced STAT1 phosphorylation. Importantly morphological assessment combined with measure of cleaved caspase 3 protein levels by WB and immunofluorescent microscopy strongly suggest that the loss of SOCS1 makes IECs more prone to death by a non-apoptotic mechanism at steady state and to apoptosis upon IFNg stimulation. Although our results are preliminary and need to be validated in independent colonoids s, they support that goblet cell dysfunction in Socs1ΔIEC mice could be linked to defects in autophagy and ER stress response, and that loss of SOCS1 sensitizes IECs to IFNγ-induced cell death in a STAT1-dependent manner.The SOCS1 protein negatively regulate cytokine signaling. To define its role in intestinal epithelial cells (IEC), our laboratory created a mouse model of Socs1 gene deletion in IEC lineages of the small and large intestines. Analysis of this Socs1ΔIEC mouse model suggests that lethal ulcerative colitis might be driven by Paneth and goblet cell defects, like those seen in inflammatory bowel disease patients and mouse models with defective genes regulating autophagy and endoplasmic reticulum (ER) stress response. Ensuing dysbiosis and bacteria invasion would then trigger immune responses for bacteria killing, whereas erosion of the colon epithelium in colitis Socs1ΔIEC mice seems driven by STAT1-dependent sensitization of Socs1- null IECs to apoptosis induced by immune cells-derived IFNγ in response to bacterial invasion. To define SOCS1 IEC-intrinsic role in the epithelium integrity and renewal, and for confirming that SOCS1 deficiency sensitizes IECs to IFNγ-driven cell death, crypt-derived colonoid populations from the WT, Ifng-/- and Socs1-/- x Ifng-/- (DKO) mouse models were produced. Morphological analysis, gene and/or protein expression profiling of markers of IEC populationages (Lg5, E-cadherin, Muc2 and Tff3), autophagy (P62), ER stress response (spliced Xbp1) and apoptosis (cleaved caspase 3 protein), as well as EdU incorporation proliferation assays were then performed. Our results indicate that the loss of Ifng and Socs1 is not affecting colonoid growth and renewal capacity of stem cells, goblet cell differentiation, or IEC proliferation. However, we detected Ifng expression in WT colonoids, which could explain the E-cadherin upregulation, P62 protein reduced levels, and enhanced Xpb1 splicing in the Ifng-/- colonoids. Likewise, DKO colonoids also displayed elevated E-cadherin protein expression, but Xbp1 splicing was further increased and P62 protein slightly restored when compared to Ifng-/- colonoids. These results indicate that loss of SOCS1 in IECs might promote deficiency in ER stress response and enhanced autophagy. Furthermore, the loss of IFNg or SOCS1 seems to increase STAT1 protein levels in IECs at steady state and upon IFNg treatment, but only simultaneous deletion of Ifng and Socs1 genes was found to boost IFNg-induced STAT1 phosphorylation. Importantly morphological assessment combined with measure of cleaved caspase 3 protein levels by WB and immunofluorescent microscopy strongly suggest that the loss of SOCS1 makes IECs more prone to death by a non-apoptotic mechanism at steady state and to apoptosis upon IFNg stimulation. Although our results are preliminary and need to be validated in independent colonoids s, they support that goblet cell dysfunction in Socs1ΔIEC mice could be linked to defects in autophagy and ER stress response, and that loss of SOCS1 sensitizes IECs to IFNγ-induced cell death in a STAT1-dependent manner.","Afin de définir le rôle de la protéine SOCS1 dans les cellules épithéliales intestinales (CEI), notre labo a créé un modèle murin invalidé pour Socs1 dans les CEI. L’analyse des souris Socs1ΔIEC suggère que la colite létale serait déclenchée par des défauts des cellules de Paneth et caliciformes, comme ceux observés dans les maladies inflammatoires de l’intestin et les modèles murins de gènes défectueux régulant l’autophagie et la réponse au stress du réticulum endoplasmique (RE). La dysbiose et l’invasion bactérienne qui s’ensuivraient induiraient alors une réponse immune pour détruire les bactéries, tandis que l’érosion de l’épithélium colique chez les souris Socs1ΔIEC serait promue par la sensibilisation STAT1-dépendante des CEI à l’apoptose induite par l’IFNγ produit par les cellules immunes en réponse à l’invasion bactérienne. Pour définir le rôle de SOCS1 dans l’intégrité et le renouvellement de l’épithélium intestinal, des populations de colonoïdes de souris WT, Ifng-/- et Socs1-/- x Ifng-/- (DKO) ont été produites. L’analyse morphologique et de l’expression de marqueurs des CEI, de l’autophagie (P62), de la réponse au stress du RE (Xbp1 épissé) et de l’apoptose (caspase 3 clivée), ainsi que des essais de prolifération d’incorporation d’EdU ont ensuite été effectués. Nos résultats indiquent que la perte d’IFNg et de SOCS1 n’affecte pas la croissance des colonoïdes, le renouvellement des cellules souches, la différenciation des cellules caliciformes et la prolifération des CEI. Nous avons aussi détecté l’expression du gène de l’IFNg dans les colonoids WT, ce qui expliquerait l’augmentation de E-cadhérine, les niveaux réduits de la protéine P62, et l’épissage d’Xpb1 augmenté dans les colonoïdes Ifng-/-. Les colonoids DKO en comparaison avec ceux Ifng-/-, montraient aussi un niveau élevé de E-cadhérine, mais l’épissage d’Xbp1 était plus accru et un léger retour de la protéine P62 était observé. Nos résultats indiquent que la perte de SOCS1 dans les CEI induirait une réponse au stress du RE déficiente et augmenterait l’autophagie. La perte d’IFNg ou de SOCS1 semble augmenter le niveau protéique de STAT1 dans les CEI à l’état basal et lors d’un traitement à l’IFNg, mais seule la perte simultanée des gènes Ifng et Socs1 s’est avérée augmenter la phosphorylation de STAT1 IFNg-induite. L’évaluation morphologique et des niveaux du clivage de la caspase 3 suggèrent que la perte de SOCS1 sensibilisait les CEI à la mort nonapoptotique à l’état basal et à l’apoptose IFNg-induite. Quoique nos résultats doivent être validés dans des populations de colonoïdes indépendantes, ils soutiennent que le dysfonctionnement des cellules caliciformes chez les souris Socs1ΔIEC serait lié à des défauts d’autophagie et de la réponse au stress ER, et que la perte de SOCS1 sensibiliserait de façon STAT1-dépendant les CEI à la mort cellulaire induite par IFNg."],"dc:identifier.uri":["http://hdl.handle.net/11143/18680"],"dc:language.iso":["en"],"dc:publisher":["Université de Sherbrooke"],"dc:subject":["SOCS1","Inflammatory bowel disease","IFNγ","Colonoid","Intestinal epithelial cells","Maladie inflammatoire de l'intestin","Colonoïde","Cellules épithéliales intestinales"],"dc:title":["The intrinsic role of SOCS1 in intestinal epithelial cells"],"dc:type":["Mémoire de maîtrise"],"thesis:degree_discipline":["Biologie cellulaire"],"thesis:degree_level":["Maîtrise"],"thesis:degree_name":["M. Sc."],"thesis:institution_name":["Faculté de médecine et des sciences de la santé"]},"updated_at":"2026-07-27T21:07:32Z"}