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:Angiogenesis-inhibitor (AI) drugs targeting vascular endothelial growth factor (VEGF) signalling to the endothelial cell (EC) are used to treat various cancers types. However, primary or secondary resistance to therapy is common. Clinical and pre-clinical studies suggest that other alternative pro-angiogenic factors are up-regulated after VEGF-pathway inhibition. Therefore, identification alternative pro-angiogenic pathway(s) is critical for the development of more effective anti-angiogenic therapy. Here we study the role of apelin as a pro-angiogenic G-protein coupled receptor (GPCR) ligand in tumor growth and angiogenesis. We applied single-cell RNA-sequencing to Mouse Lewis lung carcinoma (LLC1) or B16F10 mouse melanoma cell lines (1 X 106) implanted subcutaneously into the flanks of 12 weeks old Apln-/y or littermate control mice in combination with sunitinib or control (vehicle) treatment. We found apelin loss reduced angiogenic sprouting and tip cell marker gene expression in comparison to the sunitinib-alone treated mice and prevented EC tip cell differentiation.
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.
Project description:Resistance towards anti-angiogenic therapy (AAT) still represents a substantial clinical challenge. We report here that tumor-infiltrating mast cells (MC) are powerful mediators decreasing efficacy of AAT in mice and cancer patients. They act in a cell-extrinsic manner by secreting granzyme B, which liberates pro-angiogenic mediators from the extracellular matrix. In addition, MC also diminish efficacy of anti-angiogenic agents in a cell-autonomous way, which can be blocked by the mast cell degranulation inhibitor cromolyn. Our findings are relevant in humans because patients harboring higher numbers of MC in their tumors have an inferior outcome after anti-angiogenic treatment in the Gepar Quinto randomized Phase 3 clinical trial. Thus, MC-targeting might represent a novel promising approach to increase efficacy of AAT.
Project description:Purpose: Advanced melanoma patients have poor prognosis. Although immune checkpoint blockade has revolutionized treatment for melanoma patients, majority of patients do not respond. The goal of this research is to evaluate whether epigenetic therapy targeting KDM5B could overcome resistance to immunotherapy. Methods:RNA-Seq analysis of KDM5B KO mouse melanoma cell lines compared to control cells to evaluate whether KDM5B depletion induces activation of retroelements, which subsequently activates type I interferon responses. Mouse studies were conducted to evaluate whether anti-tumor immunity induced by KDM5B loss could overcome immunotherapy resistance. Results: We identified that KDM5B depletion derepress retroelement expression, which subsequently activates type I interferon response and enhances anti-tumor immunity. Loss of KDM5B could overcome resistance to anti-PD-1 immunotherapy. Conclusions: Our work characterized ablation of histone demethylase KDM5B in melanoma augments anti-tumor immunity through Upregulation of retroelements.
Project description:Purpose: Advanced melanoma patients have poor prognosis. Although immune checkpoint blockade has revolutionized treatment for melanoma patients, majority of patients do not respond. The goal of this research is to evaluate whether epigenetic therapy targeting KDM5B could overcome resistance to immunotherapy. Methods:RNA-Seq analysis of KDM5B KO mouse melanoma cell lines compared to control cells to evaluate whether KDM5B depletion induces activation of retroelements, which subsequently activates type I interferon responses. Mouse studies were conducted to evaluate whether anti-tumor immunity induced by KDM5B loss could overcome immunotherapy resistance. Results: We identified that KDM5B depletion derepress retroelement expression, which subsequently activates type I interferon response and enhances anti-tumor immunity. Loss of KDM5B could overcome resistance to anti-PD-1 immunotherapy. Conclusions: Our work characterized ablation of histone demethylase KDM5B in melanoma augments anti-tumor immunity through Upregulation of retroelements.