Project description:Signal Transducer and Activator of Transcription 3 (STAT3) is considered as an oncogene being constitutively activated in a wide variety of primary human tumours, which often become addicted to its activity. Using primary fibroblasts derived from a knock-in mouse expressing only the constitutively active form STAT3-C as well as STAT3-dependent tumor cell lines MDA-MB468, DU145 and SKBR3, we provide evidence that STAT3 can act as a central regulator of cell metabolism. STAT3C/C MEFs are resistant to apoptosis and senescence and they show reduced mitochondrial activity but activate aerobic glycolysis, as shown by enhanced expression of master regulators of glycolysis such as PDK-1 and HIF-1α, and by increased lactate production, glucose avidity and sensitivity to glycolysis inhibitors. HIF-1α is up-regulated in the STAT3C/C MEFs and is responsible for the glycolytic phenotype. Moreover, inhibition of STAT3 activity in STAT3-addicted tumour cell lines restores mitochondrial activity and down-regulates glycolytic metabolism, preceding the induction of massive apoptosis. Thus, the essential role observed for STAT3 in so many different cancer cell types may be partly explained by its ability to act as a molecular switch of cellular metabolism triggering abnormal cell survival/proliferation. Three biological replicates of MEFs from mice with constitutively active Stat3 are compared to three biological replicates of wild-type MEFs.
Project description:Transcription profiles of BV2 microglial cell lines: unstimulated, stimulated with LPS or transfected with constitutively active Stat1 and Stat3.
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:The transcription factor STAT3 is constitutively activated in tumors of different origin but the molecular bases for STAT3 addiction of tumor cells have not yet been clearly identified. We generated knock/in mice carrying the constitutively active Stat3 allele, Stat3C, and showed that Stat3C could enhance Neu oncogenic power, triggering the production of earlier onset, more invasive mammary tumors. Tumor-derived cell lines displayed higher migration and invasion and disrupted distribution of cell-cell junction markers. The tensin family member Cten (C-Terminal Tensin-like), known to mediate EGF-induced migration and highly expressed in inflammatory breast cancer, was up-regulated in both Neu;Stat3C cells and tumors. Both Cten expression and enhanced migration were strictly dependent on Stat3, and Cten silencing normalized cell migration and rescued cell-cell contact defects. Importantly, the pro-inflammatory cytokine IL-6 could mediate Cten induction in MCF10 cells, in an exquisitely Stat3-dependent way. This model allowed us to shed some light on the oncogenic role of Stat3 in the breast, suggesting moreover a mechanism through which inflammatory signals can cooperate with EGF receptors in inflammatory breast cancer.
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from Mus musculus tissues (Heart, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:SILAC based protein correlation profiling using size exclusion of protein complexes derived from seven Mus musculus tissues (Heart, Brain, Liver, Lung, Kidney, Skeletal Muscle, Thymus)
Project description:Signal Transducer and Activator of Transcription 3 (STAT3) is considered as an oncogene being constitutively activated in a wide variety of primary human tumours, which often become addicted to its activity. Using primary fibroblasts derived from a knock-in mouse expressing only the constitutively active form STAT3-C as well as STAT3-dependent tumor cell lines MDA-MB468, DU145 and SKBR3, we provide evidence that STAT3 can act as a central regulator of cell metabolism. STAT3C/C MEFs are resistant to apoptosis and senescence and they show reduced mitochondrial activity but activate aerobic glycolysis, as shown by enhanced expression of master regulators of glycolysis such as PDK-1 and HIF-1α, and by increased lactate production, glucose avidity and sensitivity to glycolysis inhibitors. HIF-1α is up-regulated in the STAT3C/C MEFs and is responsible for the glycolytic phenotype. Moreover, inhibition of STAT3 activity in STAT3-addicted tumour cell lines restores mitochondrial activity and down-regulates glycolytic metabolism, preceding the induction of massive apoptosis. Thus, the essential role observed for STAT3 in so many different cancer cell types may be partly explained by its ability to act as a molecular switch of cellular metabolism triggering abnormal cell survival/proliferation.
Project description:Translational research is commonly performed in the C57B6/J mouse strain, chosen for its genetic homogeneity and phenotypic uniformity. Here, we evaluate the suitability of the white-footed deer mouse (Peromyscus leucopus) as a model organism for aging research, offering a comparative analysis against C57B6/J and diversity outbred (DO) Mus musculus strains. Our study includes comparisons of body composition, skeletal muscle function, and cardiovascular parameters, shedding light on potential applications and limitations of P. leucopus in aging studies. Notably, P. leucopus exhibits distinct body composition characteristics, emphasizing reduced muscle force exertion and a unique metabolism, particularly in fat mass. Cardiovascular assessments showed changes in arterial stiffness, challenging conventional assumptions and highlighting the need for a nuanced interpretation of aging-related phenotypes. Our study also highlights inherent challenges associated with maintaining and phenotyping P. leucopus cohorts. Behavioral considerations, including anxiety-induced responses during handling and phenotyping assessment, pose obstacles in acquiring meaningful data. Moreover, the unique anatomy of P. leucopus necessitates careful adaptation of protocols designed for Mus musculus. While showcasing potential benefits, further extensive analyses across broader age ranges and larger cohorts are necessary to establish the reliability of P. leucopus as a robust and translatable model for aging studies.