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Abstract Background Inflammatory diseases are often initiated by the activation of inflammasomes triggered by pathogen-associated molecular patterns (PAMPs) and endogenous damage-associated molecular patterns (DAMPs), which mediate pyroptosis. Although pyroptosis resulting from aberrant inflammasome triggering in thyroid follicular cells (TFCs) has been observed in Hashimoto's thyroiditis (HT) patients, the underlying mechanisms remain largely unknown. Given the extensive involvement of protein ubiquitination and deubiquitination in inflammatory diseases, we aimed to investigate how deubiquitinating enzymes regulate thyroid follicular cell pyroptosis and HT pathogenesis. Methods Our study specifically investigated the role of Ubiquitin-specific peptidase 1 (USP1), a deubiquitinase (DUB), in regulating the inflammasome components NLRP3 and AIM2, which are crucial in pyroptosis. We conducted a series of experiments to elucidate the function of USP1 in promoting pyroptosis associated with inflammasomes and the progression of HT. These experiments involved techniques such as USP1 knockdown or inhibition, measurement of key pyroptosis indicators including caspase-1, caspase-1 p20, and GSDMD-N, and examination of the effects of USP1 abrogation on HT using a mouse model. Furthermore, we explored the impact of USP1 on NLRP3 transcription and its potential interaction with p65 nuclear transportation. Results Our findings provide compelling evidence indicating that USP1 plays a pivotal role in promoting inflammasome-mediated pyroptosis and HT progression by stabilizing NLRP3 and AIM2 through deubiquitination. Furthermore, we discovered that USP1 modulates the transcription of NLRP3 by facilitating p65 nuclear transportation. Knockdown or inhibition of USP1 resulted in weakened cell pyroptosis, as evidenced by reduced levels of caspase-1 p20 and GSDMD-N, which could be restored upon AIM2 overexpression. Remarkably, USP1 abrogation significantly ameliorated HT in the mice model, likely to that treating mice with pyroptosis inhibitors VX-765 and disulfiram. Conclusions Our study highlights a regulatory mechanism of USP1 on inflammasome activation and pyroptosis in TFCs during HT pathogenesis. These findings expand our understanding of HT and suggest that inhibiting USP1 may be a potential treatment strategy for managing HT.

Background: Inflammatory diseases are often initiated by the activation of inflammasomes triggered by pathogen-associated molecular patterns (PAMPs) and endogenous damage-associated molecular patterns (DAMPs), which mediate pyroptosis. Although pyroptosis resulting from aberrant inflammasome triggering in thyroid follicular cells (TFCs) has been observed in Hashimoto's thyroiditis (HT) patients, the underlying mechanisms remain largely unknown. Given the extensive involvement of protein ubiquitination and deubiquitination in inflammatory diseases, we aimed to investigate how deubiquitinating enzymes regulate thyroid follicular cell pyroptosis and HT pathogenesis. Methods: Our study specifically investigated the role of Ubiquitin-specific peptidase 1 (USP1), a deubiquitinase (DUB), in regulating the inflammasome components NLRP3 and AIM2, which are crucial in pyroptosis. We conducted a series of experiments to elucidate the function of USP1 in promoting pyroptosis associated with inflammasomes and the progression of HT. These experiments involved techniques such as USP1 knockdown or inhibition, measurement of key pyroptosis indicators including caspase-1, caspase-1 p20, and GSDMD-N, and examination of the effects of USP1 abrogation on HT using a mouse model. Furthermore, we explored the impact of USP1 on NLRP3 transcription and its potential interaction with p65 nuclear transportation. Results: Our findings provide compelling evidence indicating that USP1 plays a pivotal role in promoting inflammasome-mediated pyroptosis and HT progression by stabilizing NLRP3 and AIM2 through deubiquitination. Furthermore, we discovered that USP1 modulates the transcription of NLRP3 by facilitating p65 nuclear transportation. Knockdown or inhibition of USP1 resulted in weakened cell pyroptosis, as evidenced by reduced levels of caspase-1 p20 and GSDMD-N, which could be restored upon AIM2 overexpression. Remarkably, USP1 abrogation significantly ameliorated HT in the mice model, likely to that treating mice with pyroptosis inhibitors VX-765 and disulfiram. Conclusions: Our study highlights a regulatory mechanism of USP1 on inflammasome activation and pyroptosis in TFCs during HT pathogenesis. These findings expand our understanding of HT and suggest that inhibiting USP1 may be a potential treatment strategy for managing HT. [ABSTRACT FROM AUTHOR]

Abstract Background Loss of the transcription factor GLI-Similar 3 (GLIS3) function causes congenital hypothyroidism (CH) in both humans and mice due to decreased expression of several thyroid hormone (TH) biosynthetic genes in thyroid follicular cells. Whether and to what extent, GLIS3 regulates thyroid gene transcription in coordination with other thyroid transcriptional factors (TFs), such as PAX8, NKX2.1 and FOXE1, is poorly understood. Methods PAX8, NKX2.1, and FOXE1 ChIP-Seq analysis with mouse thyroid glands and rat thyrocyte PCCl3 cells was performed and compared to that of GLIS3 to analyze the co-regulation of gene transcription in thyroid follicular cells by these TFs. Results Analysis of the PAX8, NKX2.1, and FOXE1 cistromes identified extensive overlaps between these TF binding loci and those of GLIS3 indicating that GLIS3 shares many of the same regulatory regions with PAX8, NKX2.1, and FOXE1, particularly in genes associated with TH biosynthesis, induced by thyroid stimulating hormone (TSH), and suppressed in Glis3KO thyroid glands, including Slc5a5 (Nis), Slc26a4, Cdh16, and Adm2. ChIP-QPCR analysis showed that loss of GLIS3 did not significantly affect PAX8 or NKX2.1 binding and did not cause major alterations in H3K4me3 and H3K27me3 epigenetic signals. Conclusions Our study indicates that GLIS3 regulates transcription of TH biosynthetic and TSH-inducible genes in thyroid follicular cells in coordination with PAX8, NKX2.1, and FOXE1 by binding within the same regulatory hub. GLIS3 does not cause major changes in chromatin structure at these common regulatory regions. GLIS3 may induce transcriptional activation by enhancing the interaction of these regulatory regions with other enhancers and/or RNA Polymerase II (Pol II) complexes.

Background: Loss of the transcription factor GLI-Similar 3 (GLIS3) function causes congenital hypothyroidism (CH) in both humans and mice due to decreased expression of several thyroid hormone (TH) biosynthetic genes in thyroid follicular cells. Whether and to what extent, GLIS3 regulates thyroid gene transcription in coordination with other thyroid transcriptional factors (TFs), such as PAX8, NKX2.1 and FOXE1, is poorly understood. Methods: PAX8, NKX2.1, and FOXE1 ChIP-Seq analysis with mouse thyroid glands and rat thyrocyte PCCl3 cells was performed and compared to that of GLIS3 to analyze the co-regulation of gene transcription in thyroid follicular cells by these TFs. Results: Analysis of the PAX8, NKX2.1, and FOXE1 cistromes identified extensive overlaps between these TF binding loci and those of GLIS3 indicating that GLIS3 shares many of the same regulatory regions with PAX8, NKX2.1, and FOXE1, particularly in genes associated with TH biosynthesis, induced by thyroid stimulating hormone (TSH), and suppressed in Glis3KO thyroid glands, including Slc5a5 (Nis), Slc26a4, Cdh16, and Adm2. ChIP-QPCR analysis showed that loss of GLIS3 did not significantly affect PAX8 or NKX2.1 binding and did not cause major alterations in H3K4me3 and H3K27me3 epigenetic signals. Conclusions: Our study indicates that GLIS3 regulates transcription of TH biosynthetic and TSH-inducible genes in thyroid follicular cells in coordination with PAX8, NKX2.1, and FOXE1 by binding within the same regulatory hub. GLIS3 does not cause major changes in chromatin structure at these common regulatory regions. GLIS3 may induce transcriptional activation by enhancing the interaction of these regulatory regions with other enhancers and/or RNA Polymerase II (Pol II) complexes. [ABSTRACT FROM AUTHOR]

The transcription factor CREB3L1 is expressed in a wide variety of tissues including cartilage, pancreas, and bone. It is located in the endoplasmic reticulum and upon stimulation is transported to the Golgi where is proteolytically cleaved. Then, the N-terminal domain translocates to the nucleus to activate gene expression. In thyroid follicular cells, CREB3L1 is a downstream effector of thyrotropin (TSH), promoting the expression of proteins of the secretory pathway along with an expansion of the Golgi volume. Here, we analyzed the role of CREB3L1 as a TSH-dependent transcriptional regulator of the expression of the sodium/iodide symporter (NIS), a major thyroid protein that mediates iodide uptake. We show that overexpression and inhibition of CREB3L1 induce an increase and decrease in the NIS protein and mRNA levels, respectively. This, in turn, impacts on NIS-mediated iodide uptake. Furthermore, CREB3L1 knockdown hampers the increase the TSH-induced NIS expression levels. Finally, the ability of CREB3L1 to regulate the promoter activity of the NIS-coding gene (Slc5a5) was confirmed. Taken together, our findings highlight the role of CREB3L1 in maintaining the homeostasis of thyroid follicular cells, regulating the adaptation of the secretory pathway as well as the synthesis of thyroid-specific proteins in response to TSH stimulation. [ABSTRACT FROM AUTHOR]

The transcription factor CREB3L1 is expressed in a wide variety of tissues including cartilage, pancreas, and bone. It is located in the endoplasmic reticulum and upon stimulation is transported to the Golgi where is proteolytically cleaved. Then, the N-terminal domain translocates to the nucleus to activate gene expression. In thyroid follicular cells, CREB3L1 is a downstream effector of thyrotropin (TSH), promoting the expression of proteins of the secretory pathway along with an expansion of the Golgi volume. Here, we analyzed the role of CREB3L1 as a TSH-dependent transcriptional regulator of the expression of the sodium/iodide symporter (NIS), a major thyroid protein that mediates iodide uptake. We show that overexpression and inhibition of CREB3L1 induce an increase and decrease in the NIS protein and mRNA levels, respectively. This, in turn, impacts on NIS-mediated iodide uptake. Furthermore, CREB3L1 knockdown hampers the increase the TSH-induced NIS expression levels. Finally, the ability of CREB3L1 to regulate the promoter activity of the NIS-coding gene (Slc5a5) was confirmed. Taken together, our findings highlight the role of CREB3L1 in maintaining the homeostasis of thyroid follicular cells, regulating the adaptation of the secretory pathway as well as the synthesis of thyroid-specific proteins in response to TSH stimulation.