Tamoxifen treatment as a therapeutic approach in a murine model of X-linked myotubular myopathy (Mtm1-/y)
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE160083 | GEO | 2020/12/15
REPOSITORIES: GEO
Similar Datasets
Project description:Purpose: The goal of this study was to investigate the transcriptional profile of genes expressed in the quadriceps muscle of myotubularin deficient (Mtm1-/-) mice, and determine whether improvements in the pathophysiology of tamoxifen treated Mtm1-/- mice are a consequence of ER-dependent transcriptional modulation. Methods: Muscle mRNA profiles from quadriceps of 36-day-old wild-type (WT), myotubularin deficient (Mtm1-/-) mice, and tamoxifen treated WT and Mtm1-/- mice were generated by deep sequencing, in triplicate or quadruplicate, using Illumina HiSeq 2500. Read sets from each of the 14 samples across the four conditions were aligned to the reference genome (GRCm38/MM10 version of the Mus musculus genome) and transcriptome using STAR (Dobin et al. Bioinformatics 2013 PMID: 23104886) two-step alignment to generate a Binary Alignment Map file (BAM file). Coordinate sorted BAM files were used to quantify transcript abundance (count data) using HTSeq (Anders et al. Bioinformatics 2014, PMID: 25260700). Raw read counts generated were used as input for differential gene expression analysis, carried out using both DESeq (Anders and Huber 2010) and edgeR (Robinson, McCarthy, and Smyth 2010) R/Bioconductor packages. This was carried out in a pair-wise manner between any two conditions that were considered. FDR adjusted p-values from both edgeR and DESeq was used to determine genes that are significantly differentially expressed between the conditions tested. Finally, we used the GoSeq R/Bioconductor package (Young MD, et al Genome Biology, 11, pp. R14) to identify pathways that were significantly enriched for differentially expressed genes between any two conditions. Results: Using an established data analysis workflow, 65 million reads were aligned per sample (>90% exonic). We observed 849 differentially expressed transcripts in untreated mtm1-/-mice (p< 0.01) in comparison to wild-type (WT) controls. Furthermore, we identified 29 differentially expressed genes (p<0.01) between mtm1-/- mice and their TAM-treated mtm1-/- mice. In particular, we observed that the transcriptional profiles of mtm1 -/- mice and tamoxifen-treated mtm1-/- mice cluster together and are distinct from wild-type contros. Moreover, no significant changes were observed in the expression of estrogen-response genes that are known gene targets of tamoxifen; no significant transcriptional changes were observed in well-known MTM-related genes.This strongly indicates that, contrary to its well-established function as a transcriptional modulator, tamoxifen improves the pathophysiology of myotubular myopathy in a post-transcriptional manner. Concusions: Our study represents the first comprehensive analysis of the whole transcriptome of the Mtm1-/- and tamoxifen treated Mtm1-/- mouse, generated by RNA-seq technology. The data reported here provides a framework a comparative investigation of the expression profiles in Mtm1-/- mice and tamoxifen treated Mtm1-/- mice. Importantly, our results demonstrate that in our MTM murine model, tamoxifen does not appear to alter the transcriptional profile of many estrogen-receptor (ER) related genes, and moreover does not appear to alter the transcriptional profile of genes that are abnormally expressed in Mtm1-/- mice alone. This suggests that tamoxifen is acting to improve the pathophysiology of the MTM mouse model in a transcriptionally-indepedent manner.
2018-09-23 | GSE120336 | GEO
Project description:In this study, we performed RNA sequencing on tibialis anterior muscle of male mice. WT and Mtm1 deficient (Mtm1-/y) mice as well as on Dnm2+/- mice and on Mtm1-/y mice crossed with Dnm2+/- (Mtm1-/yDnm2+/-) were sequenced. A longitudinal follow up was established by sequencing all the genotypes at E18.5, 2w and 7w.
2020-12-15 | GSE160079 | GEO
Project description:In this study, we performed RNA sequencing on tibialis anterior muscle of male mice at 7 weeks of age. WT and Mtm1 deficient (Mtm1-/y) mice were sequenced. The rescued mice, Mtm1-/y mice crossed with TgBIN1 mice (Mmt1-/yTgBIN1) and the associated control mice TgBIN1 were also sequenced.
2020-12-15 | GSE160081 | GEO
Project description:In this study, we performed mass spectometry on tibialis anterior muscle of male mice. WT and Mtm1 deficient (Mtm1-/y) mice as well as on Dnm2+/- mice and on Mtm1-/y mice crossed with Dnm2+/- (Mtm1-/yDnm2+/-) were analyzed. A longitudinal follow up was established by analyzing all the genotypes at E18.5, 2w and 7w.
2022-10-13 | PXD021725 | Pride
Project description:X-linked myotubular myopathy (XLMTM) is a severe monogenetic disorder of the skeletal muscle. It is caused by loss-of-expression/function mutations in the myotubularin (MTM1) gene. Much of what is known about the disease, as well as the treatment strategies, has been uncovered through experimentation in pre-clinical models, particularly the Mtm1 gene knockout mouse line (Mtm1 KO). Despite this understanding, and the identification of potential therapies, much remains to be understood about XLMTM disease pathomechanisms, and about the normal functions of MTM1 in muscle development. To lay the groundwork for addressing these knowledge gaps, we performed a natural history study of Mtm1 KO mice. This included longitudinal comparative analyses of motor phenotype, transcriptome and proteome profiles, muscle structure and targeted molecular pathways.We identified age-associated changes in gene expression, mitochondrial function, myofiber size and key molecular markers, including DNM2. Importantly, some molecular and histopathologic changes preceded overt phenotypic changes, while others, such as triad structural alternations, occurred coincidentally with the presence of severe weakness. In total, this study provides a comprehensive longitudinal evaluation of the murine XLMTM disease process, and thus provides a critical framework for future investigations.
2022-07-08 | GSE207447 | GEO
Project description:X-linked myotubular myopathy (XLMTM) is a fatal congenital disorder caused by mutations in the MTM1 gene. Currently, there are no approved treatments, though AAV8-mediated gene transfer therapy has shown promise in animal models and preliminarily in patients. However, four patients with XLMTM treated with gene therapy have died from progressive liver failure, and hepatobiliary disease has now been recognized more broadly in association with XLMTM. In an attempt to understand whether loss of MTM1 itself is associated with liver pathology, we have characterized a novel liver phenotype in a zebrafish model of this disease. Specifically, we have found that loss-of-function mutations in mtm1 lead to severe liver abnormalities including impaired bile flux, structural abnormalities of the bile canaliculus, and improper endosomal-mediated trafficking of canalicular transporters. Using a reporter tagged Mtm1 zebrafish line, we have established localization of Mtm1 in the liver in association with Rab11 and canalicular transport proteins, and demonstrated that hepatocyte specific re-expression of Mtm1 can rescue the cholestatic phenotype. Lastly, we completed a targeted chemical screen, and found that Dynasore, a dynamin II inhibitor, is able to partially restore bile flow and transporter localization to the canalicular membrane. In summary, we demonstrate for the first time liver abnormalities that are directly caused by MTM1 mutation in a pre-clinical model, thus establishing the critical framework for better understanding and comprehensive treatment of the human disease.
2023-08-10 | GSE235571 | GEO
Project description:X-linked myotubular myopathy (XLMTM) is a fatal neuromuscular disorder caused by loss of function mutations in MTM1 . At present, there are no directed therapies for XLMTM, and incomplete understanding of disease pathomechanisms. To address these knowledge gaps, we performed a drug screen in mtm1 mutant zebrafish andidentified four positive hits, including valproic acid, which functions as a potent suppressor of the mtm1 zebrafish phenotype via HDAC inhibition. We translated these findings to a mouse XLMTM model, and showed that valproic acid ameliorates the murine phenotype.
2022-08-08 | GSE210642 | GEO
Project description:Tamoxifen treatment as a therapeutic approach in a murine model of X-linked myotubular myopathy (Mtm1-/y)
| PRJNA671753 | ENA
Project description:X-linked myotubular myopathy (XLMTM, also known as XLCNM) is a severe congenital muscular disorder due to mutations in the myotubularin gene, MTM1. It is characterized by generalized hypotonia, leading to neonatal death of most patients. No specific treatment exists. Here, we show that tamoxifen, a well-known drug used against breast cancer, rescues the phenotype of Mtm1-deficient mice. Tamoxifen increases lifespan several-fold while improving overall motor function and preventing disease progression including lower limb paralysis. Tamoxifen corrects functional, histological and molecular hallmarks of XLMTM, with improved force output, myonuclei positioning, myofibrillar structure, triad number, and excitation-contraction coupling. Tamoxifen normalizes the expression level of the XLMTM disease modifiers DNM2 and PI3KC2B, likely contributing to the phenotypic rescue. Our findings demonstrate that tamoxifen is a promising candidate for clinical evaluation in XLMTM patients.
| S-EPMC6243013 | biostudies-literature
Project description:Myotubular myopathy (MTM) is a severe X-linked disease without existing therapies. Here, we show that tamoxifen ameliorates MTM-related histopathological and functional abnormalities in mice, and nearly doubles survival. The beneficial effects of tamoxifen are mediated primarily via estrogen receptor signaling, as demonstrated through in vitro studies and in vivo phenotypic rescue with estradiol. RNA sequencing and protein expression analyses revealed that rescue is mediated in part through post-transcriptional reduction of dynamin-2, a known MTM modifier. These findings demonstrate an unexpected ability of tamoxifen to improve the murine MTM phenotype, providing preclinical evidence to support clinical translation.
| S-EPMC6242823 | biostudies-literature