Mitochondrial regulator PGC-1a in neuronal metabolism and brain aging
Ontology highlight
ABSTRACT: The brain is a high-energy tissue, and brain-resident cell types are distinct in function and in metabolic requirements. The basis for cell-type-specific metabolic status and metabolic adaptation with age has not been well established. This proteomics analysis allows us to better understand how the brain responds to age, which we then leverage as an intervention point throughout the study. This dataset was derived from male mice at three different ages (10 months, 20 months, and 30 months).
Project description:Pathogen-derived peptides presented by MHCII that are best able to activate cognate CD4+ T cells and initiate an adaptive immune response are termed immunodominant. The exact mechanisms and molecular determinants of antigen processing that contribute to immunodominance remain unclear. Recently, attention has been called to the events of proteolytic cleavage as a potential determinant. Here, we compare data generated through cleavage of hemagglutinin from influenza A, at varying pH and over a twenty-four hour time period in the presence of cathepsin B, H and S, to an immunodominant hierarchy previously established with an ex-vivo mouse model. We show that cleavage alone does not directly predict immunodominance, however resistance to digestion emerged as a determinant of immunodominance. Moreover, pH conditions contribute to shaping the peptidome available for MHCII binding and the size of the pools of unique peptides associated with immunodominance. These differences suggest the presence of multiple antigen processing pathways through which resistance to proteolytic cleavage and peptide redundancy may result in a more diverse peptidome for presentation.
Project description:The Human Silencing Hub (HuSH) complex is a complex that silences retrotransposable elements invertebrates. Here, we identify a second HuSH complex, designated HuSH2, which is centered aroundTASOR2, a paralog of the core TASOR protein in HuSH. Our findings reveal that HuSH and HuSH2 localize todistinct and non-overlapping genomic loci. Specifically, HuSH localizes to and represses LINE-1retrotransposons, whereas HuSH2 targets and represses KRAB-ZNFs and interferon signaling and responsegenes. We use in silico protein structure predictions to simulate MPP8 interactions with TASOR paralogs,guiding amino acid substitutions that disrupted binding to HuSH complexes. These MPP8 transgenes andother constructs reveal the importance of HuSH complex quantities in regulating LINE-1 activity. Furthermore,our results suggest that dynamic changes in TASOR and TASOR2 expression enable cells to finely tuneHuSH-mediated silencing. This study offers insights into the interplay of HuSH complexes, highlighting theirvital role in retrotransposon regulation.
Project description:Type I, II, III and V collagens were commonly identified in human, pig, and mouse breast ECM. Mammary epithelial cells were able to form acini on certain types or combinations of the four collagens at normal breast tissue stiffness levels. Comparison of the collagen species in mouse normal breast and breast tumor ECM revealed common and distinct sets of collagens within the two types of tissues. Elevated collagen type I alpha 1 chain expression was found in human breast cancers. Collagen type XXV alpha 1 chain was identified in mouse breast tumors but not in normal breast tissues. Our data provide insights into modeling human breast pathophysiological structures and functions using native tissue-derived hydrogels and potential contributions of different collagen types or their monomers in breast cancer development.
Project description:Type I, II, III and V collagens were commonly identified in human, pig, and mouse breast ECM. Mammary epithelial cells were able to form acini on certain types or combinations of the four collagens at normal breast tissue stiffness levels. Comparison of the collagen species in mouse normal breast and breast tumor ECM revealed common and distinct sets of collagens within the two types of tissues. Elevated collagen type I alpha 1 chain expression was found in human breast cancers. Collagen type XXV alpha 1 chain was identified in mouse breast tumors but not in normal breast tissues. Our data provide insights into modeling human breast pathophysiological structures and functions using native tissue-derived hydrogels and potential contributions of different collagen types or their monomers in breast cancer development.
Project description:ECM is the physicochemical support for the cells living in the tissue microenvironment. it is important to know the protein contents within the ECM that are critical for extra- and intracellular signaling, cell growth, migration, cell-cell/ECM interactions. The ECM gel derived from the Engelbreth-Holm-Swarm murine sarcoma (commonly known as Matrigel or lrECM) purchased from the Sigma Aldrich in the liquid concentration of 8-12 mg/ml (Lot # 064M4075V) was used for the LC-MS/MS analysis and to prepare the 3D scaffolds used for downstream experiments. The Matrigel mass spectrometry data will be used to compare with those of the decellularized mice mammary tissue ECM/DBT-TMS.
Project description:In higher plants, a P-type proton pumping ATPase generates the proton-motive force essential for the function of all other transporters and for proper growth and development. X-ray crystallographic studies of the plant plasma membrane proton pump have provided information on amino acids involved in ATP catalysis but provided no information on the structure of the C-terminal regulatory domain. Despite progress in elucidating enzymes involved in the signaling pathways that activate or inhibit this pump, the site of interaction of the C-terminal regulatory domain with the catalytic domains remains a mystery. Genetic studies have pointed to amino acids in various parts of the protein that may be involved but direct chemical evidence for which ones are specifically interacting with the C-terminus is lacking. In this study we used in vivo cross-linking experiments with a photo-reactive unnatural amino acid, p-benzoyl-phenylalanine (BPA) and tandem mass spectrometry, to obtain direct evidence that the carboxyl terminal regulatory domain directly interacts with amino acids located within the N-terminal actuator domain. Our observations are consistent with a mechanism in which intermolecular, rather than intramolecular, interactions are involved. Our model invokes a ‘head-to-tail’ organization of ATPase monomers in which the carboxyl terminal domain of one ATPase molecule interacts with the actuator domain of another ATPase molecule. This model serves to explain why cross-linked peptides are found only in dimers and trimers, and is consistent with prior studies suggesting that within the membrane, the protein can be organized as homopolymers, including dimers, trimers and hexamers.
Project description:Skeletal muscle has emerged as an endocrine organ secreting exercise-induced factors (exerkines), which play a pivotal role in inter-organ crosstalk. Via MS-based proteomics, we identified thymosin beta-4 (TMSB4X) to be the most upregulated secreted protein in the media of contracting C2C12 myotubes. TMSB4X was also acutely increased in the plasma of exercising humans and there was a net uptake of TMSB4X across the thigh during exercise. Chronic treatment of TMSB4X in mice did not ameliorate the metabolic disruptions associated with diet induced-obesity, nor did it enhance muscle regeneration in vivo. However, TMSB4X did increase osteoblast proliferation and neurite outgrowth, consistent with its WADA-classification as a prohibited growth factor. Thus, we report TMSB4X as a novel human exerkine with a potential role in cellular crosstalk.
Project description:To study the ontogeny of pharmacological relevant genes, such as, drug targets, transporters and metabolic enzymes, six wild-type C57BL/6JCrl female mice were sacrified at ten different age points, in order to capture potential transcriptomic switches as the mice progresses from newborn to infant, from infant to teenager, from teenager to adult, and finally from adult to old-adult (P1 - 1 day old; 1W - 1 week old; 2W - 2 weeks old; 3W - 3 weeks old; 1M - 1 month old; 2M - 2 months old; 3M - 3 months old; 6M - 6 months old; 1Y - 1 year old; and 2Y - 2 years old). Liver, heart, kidney, lungs and brain were extracted from all 60 females in the study, and liver samples were processed for RNA extraction. Overall, 8.3% of pharmacological relevant genes changed their expression with age, of which 57% were metabolic enzymes, like Cyp2c29 and Fmo3, and 22% were transporters.
Project description:We characterized the gene expression profile of brain regions at different stages of the AlzheimerM-bM-^@M-^Ys like neurodegeneration in the anti-NGF AD11 trangenic mouse model. Total RNA was extracted from hippocampus, cortex and basal forebrain of postnatal day 30 (P30, 1 month), P90 (3 months), P180 (6 months) and at 15 months of age. Expression profiles were studied by Agilent microarray analysis, followed by qRT-PCR validation of significant candidates. Wide changes in gene expression profiles occur already at the presymptomatic stage P30, with the most significantly affected clusters of mRNAs are linked to Inflammation and Immune Response. AD11 mice were compared to the trangenic VH controls. A total of 60 female AD11 mice and 59 female control VH (5 per group) mice were used for this study: 5 AD11 and 4-5 control VH mice for each time point (1,3,6,15 months of age) and brain area (HP, CTX, BFB).