Project description:We analyzed the proteomic changes that occur in a Fbxl4 knock-out 1-year mouse. We analyzed Liver tissue using a 6-plex TMT approach (3 KO and 3 controls). Since we observed a global decrease in mitochondrial proteins, we also explored mitoproteome changes in different tissues (liver, kidney and heart) using a label-free approach. Finally, we also did a 6-plex TMT to analize the proteomic changes in 3 patient-derived fibroblast lines compared to 3 control lines and correlated them with the results obtained in the mouse model. All together, these experiments revealed that Fbxl4 deficiency leads to a decreased mitochondrial content without major changes in mitochondria itself, pointing to an increased turnover.
Project description:We developed a novel approach, m6A-seq, for high-resolution mapping of the transcriptome-wide m6A landscape, based on antibody-mediated capture followed by massively parallel sequencing Identification of m6A modified sequences in mouse liver and human brain
Project description:Purpose: MetS consist of five risk factors: elevated blood pressure and fasting glucose, visceral obesity, dyslipidemia and hypercholesterinemia. The physiological impact of lipid metabolism indicated as visceral obesity and hepatic lipid accumulation is still under debate. One major cause of disturbed lipid metabolism might be dysfunction of cellular organelles controlling energy homeostasis, i.e. mitochondria and peroxisomes. Experimental design: The New Zealand Obese (NZO) mouse model exhibits a polygenic syndrome of obesity, insulin resistance, triglyceridemia and hypercholesterolemia that resembles human metabolic syndrome. We applied a combinatorial approach of lipidomics with liver transcriptomics, 2D-DIGETM and mass spectroscopy based organelle proteomics of highly purified mitochondria and peroxisomes in male mice, to investigate molecular mechanisms related to the impact of lipid metabolism in the pathophysiology of the metabolic syndrome. Conclusions and clinical relevance: Proteome analyses of liver organelles indicated differences in fatty acid metabolism, oxidative stress and response, mainly influenced by PG-C1α/PPARα mediated pathways. These results were in accordance with serum lipid profiles and elevated organelle functionality. These data emphasize that metabolic syndrome is accompanied with increased mitochondria and peroxisomal activity controlling directly cellular energy homeostasis to cope with dyslipidemia and hypercholesterinemia driven hepatic lipid overflow in developing a fatty liver.
Project description:Whilst 5-methylcytosine (5mC) is a major epigenetic mark in the nuclear DNA in mammals, whether or not mitochondrial DNA (mtDNA) receives 5mC modification remains controversial. Herein, we exhaustively analysed mouse mtDNA using three methods that are based upon different principles for detecting 5mC. Next-generation bisulfite sequencing did not give any significant signatures of methylation in mtDNAs of liver, brain and embryonic stem cells (ESCs). Also, treatment with methylated cytosine-sensitive endonuclease McrBC resulted in no substantial decrease of mtDNA band intensities in Southern hybridisation. Furthermore, mass spectrometric nucleoside analyses of highly purified liver mtDNA preparations did not detect 5-methyldeoxycytidine at the levels found in the nuclear DNA but at a range of only 0.3–0.5% of deoxycytidine. Taken together, we propose that 5mC is not present at any specific region(s) of mtDNA and that levels of the methylated cytosine are fairly low, provided the modification occurs. It is thus unlikely that 5mC plays a universal role in mtDNA gene expression or mitochondrial metabolism.
Project description:Tuberculosis is one of top causes of death among curable infectious diseases; it is an airborne infectious disease that kills 2 million people worldwide. Anti-tuberculosis drug-induced liver injury is the primary cause of drug-induced liver injury (DILI). Rifampicin is one of the most common anti-tuberculosis therapies and has well-known hepatotoxicity. To understand the mechanism of rifampicin-induced liver injury, we performed a global proteomic analysis of liver proteins by LC-MS/MS in a mouse model after the oral administration of 177 and 442.5 mg/kg rifampicin (LD10 and LD25) for 14 days. Based on the biochemical parameters in the plasma after rifampicin treatment, the hepatotoxic effect of rifampicin in the mouse liver was defined as a mixed liver injury. In the present study, we identified 1,101 proteins and quantified 1,038 proteins. A total of 29 and 40 proteins were up-regulated and 27 and 118 proteins were down-regulated in response to 177 and 442.5 mg/kg rifampicin, respectively.