Isolation of extracellular fluids reveals novel secreted bioactive proteins from muscle and fat tissues
Ontology highlight
ABSTRACT: Proteins are secreted from cells to send information to neighboring cells or distant tissues. Because of the highly integrated nature of energy balance systems, there has been particular interest in myokines and adipokines. These are challenging to study through proteomics because serum or plasma contain highly abundant proteins that limit the detection of proteins with lower abundance. We show here that extracellular fluid (EF) from muscle and fat tissues of mice show a different protein composition than either serum or tissues. Mass spectrometry analyses of EFs from mice with physiological perturbations, like exercise or cold exposure, allowed quantification of many potentially novel myokines and adipokines. Using this approach, we identify prosaposin as a secreted product of muscle and fat. Prosaposin expression stimulates thermogenic gene expression and induces mitochondrial respiration in primary fat cells. These studies together illustrate the utility of EF isolation as a discovery tool for adipokines and myokines.
Project description:Proteins are secreted from various cells to send information to neighboring cells or distant tissues. Because of the highly integrated nature of energy balance systems, there has been a great deal of interest in myokines and adipokines, proteins secreted from muscle and fat tissues, respectively. These have been challenging to study through proteomics because serum is loaded with super-abundant proteins that limit the detection of proteins that have a low, hormone-like abundance. We show here that interstitial fluids (IFs) can be harvested easily from muscle and fat tissues of mice by very low-speed centrifugation and these fluids show a very different protein constellation than that of plasma or tissues. Under several different perturbations in vivo, like exercise or cold, quantitative Mass Spectrometry of these IFs allowed for the identification of many novel myokines and adipokines, including factors both increased and decreased in abundance. Finally, we identify prosaposin, a well-known neurotrophic factor, as a secreted product of both muscle and fat tissues; recombinant prosaposin stimulates a gene program related to thermogenesis in primary fat cells, indicating one potential function for PSAP.
Project description:Proteins are secreted from various cells to send information to neighboring cells or distant tissues. Because of the highly integrated nature of energy balance systems, there has been a great deal of interest in myokines and adipokines, proteins secreted from muscle and fat tissues, respectively. These have been challenging to study through proteomics because serum is loaded with super-abundant proteins that limit the detection of proteins that have a low, hormone-like abundance. We show here that interstitial fluids (IFs) can be harvested easily from muscle and fat tissues of mice by very low-speed centrifugation and these fluids show a very different protein constellation than that of plasma or tissues. Under several different perturbations in vivo, like exercise or cold, quantitative Mass Spectrometry of these IFs allowed for the identification of many novel myokines and adipokines, including factors both increased and decreased in abundance. Finally, we identify prosaposin, a well-known neurotrophic factor, as a secreted product of both muscle and fat tissues; recombinant prosaposin stimulates a gene program related to thermogenesis in primary fat cells, indicating one potential function for PSAP.
Project description:Adipokines are proteins secreted by the adipose tissue and are associated with obesity-related metabolic disorders; however, most studies have focused on adipokines expressed by visceral adipose tissue. This study aimed to identify the adipokine potentially derived from subcutaneous adipose tissue and its clinical significance.
Project description:Obesity is a risk factor for osteoarthritis (OA), and leptin is among the adipokines implicated in obesity-induced OA. However, the specific role of leptin in OA severity and pain is not known. Using lipodystrophic (LD) mice, we show fat-secreted factors are required for knee OA development, implicating a fat-cartilage crosstalk. Fat pad implantation or systemic leptin restoration in LD mice reintroduced structural OA and pain, whereas implantation of leptin-deficient fat pad did not change OA susceptibility. Isochronic parabiosis and spatial transcriptomics confirmed that fat-joint crosstalk likely occurred via soluble mediators. Global unsupervised multiomics of conditioned media from fat implants revealed that leptin exerts a regulatory effect on adipsin (or complement factor D), the activity of which modulates contrastive OA structural and pain phenotype. These findings suggest adipokines influence OA pathogenesis, providing conclusive evidence of a fat-joint crosstalk and implicating OA as a systemic disease of adipose tissue.
Project description:The Skeletal muscle is a metabolic active tissue that secretes various proteins. These so called myokines act auto-, para- and endocrine affecting muscle physiology and exert systemic effects on other tissues and organs. Myokines are also described to play a crucial role in the pathophysiology of metabolic diseases. Combining three different mass spectrometry based non-targeted and one antibody based targeted approach we investigated the secretome of differentiated primary human skeletal muscle cells derived from adult donors. A total of 548 non-redundant proteins were detected by combined proteomic profiling. Expression was confirmed on mRNA level for 501. Stringent consecutive filtering recruiting several database, i.e. SignalP, SecretomeP and ER_retention signals, the computational analysis assigned 306 as secretory proteins including 33 potentially novel myokines. This comprehensive profiling study of the human skeletal muscle secretome expands our knowledge of the composition of the human myokinome and further highlights the pivotal role of myokines in the regulation of multiple biological processes. We performed gene expression microarray analysis of primary human myotubes derived from twelve healthy individuals
Project description:The Skeletal muscle is a metabolic active tissue that secretes various proteins. These so called myokines act auto-, para- and endocrine affecting muscle physiology and exert systemic effects on other tissues and organs. Myokines are also described to play a crucial role in the pathophysiology of metabolic diseases. Combining three different mass spectrometry based non-targeted and one antibody based targeted approach we investigated the secretome of differentiated primary human skeletal muscle cells derived from adult donors. A total of 548 non-redundant proteins were detected by combined proteomic profiling. Expression was confirmed on mRNA level for 501. Stringent consecutive filtering recruiting several database, i.e. SignalP, SecretomeP and ER_retention signals, the computational analysis assigned 306 as secretory proteins including 33 potentially novel myokines. This comprehensive profiling study of the human skeletal muscle secretome expands our knowledge of the composition of the human myokinome and further highlights the pivotal role of myokines in the regulation of multiple biological processes.
Project description:Calorie restriction (CR) and exercise training (EX) are two critical lifestyles for the prevention and treatment of metabolic diseases, such as obesity and diabetes. Brown adipose tissue (BAT) and skeletal muscle (SkM) are two important organs to generate heat. Here we provide detailed transcriptional profiling of these two thermogenic tissues from mice treated with CR and/or EX. We demonstrate the transcriptional reprogramming of BAT and SkM according to CR, but little to EX. Consistent with this, CR induces genes encoding adipokines or myokines alteration in BAT and SkM, respectively. Deconvolution analysis implies differences of subpopulations of myogenic cells, mesothelial cells and endogenic cells in BAT, and demonstrates differences of subpopulations of satellite cells, immune cells and endothelial cells in SkM according to CR or EX. NicheNet analysis, exploring potential inter-organ communication, indicates that BAT and SkM can mutually regulate their fatty acid metabolism and thermogenesis by ligands and receptors. These data comprise an extensive resource for thermogenic tissues molecular responses to CR and/or EX in healthy state. Calorie restriction (CR) and exercise training (EX) are two critical lifestyles for the prevention and treatment of metabolic diseases, such as obesity and diabetes. Brown adipose tissue (BAT) and skeletal muscle (SkM) are two important organs to generate heat. Here we provide detailed transcriptional profiling of these two thermogenic tissues from mice treated with CR and/or EX. We demonstrate the transcriptional reprogramming of BAT and SkM according to CR, but little to EX. Consistent with this, CR induces genes encoding adipokines or myokines alteration in BAT and SkM, respectively. Deconvolution analysis implies differences of subpopulations of myogenic cells, mesothelial cells and endogenic cells in BAT, and demonstrates differences of subpopulations of satellite cells, immune cells and endothelial cells in SkM according to CR or EX. NicheNet analysis, exploring potential inter-organ communication, indicates that BAT and SkM can mutually regulate their fatty acid metabolism and thermogenesis by ligands and receptors. These data comprise an extensive resource for thermogenic tissues molecular responses to CR and/or EX in healthy state.
Project description:Interventions: CRA vs Control:No
Primary outcome(s): Rate of metabolic syndrome;adipokines;visceral fat;Values of metabolic syndrome elements
Study Design: Case-Control study
Project description:The underlying mechanism of how the atopic lipids in skeletal muscle affect muscle growth remains elusive. Here we chose miniature Bama swine as our model to mimick human obesity and co-associated metabolic disorders by long time diet induction and study how the atopic fat accumulation in skeletal muscle influence muscle function. After 23 months high-fat high-sucrose diet (HFHSD) fed, the model minipig model of obesity accompanied with metabolic disorders like human, and they had increased body weight and extensive lipids deposition in adipose tissues (AT) and non-AT, especially in skeletal muscle. Further more, the mass of skeletal reduced greatly and the small area (0-2000μm2) muscle reduced after diet induced. The average fiber area of Gastroc reduced 25.2%, but no significant changes appeared in the other skeletal muscles. Antioxidant capacity of skeletal muscle also reduced. Microarray profiles showed genes related to fat deposition promotion (Peroxisome proliferator activated receptor γ, CCAAT/enhancer-binding protein α and apolipoprotein E), muscle growth inhibition (myostatin and p21) up regulated, and some other muscle cell differentiation related genes (myoD) down regulated. Meanwhile, adipokines like adiponectin and 11b-hydroxysteroid dehydrogenase type 1 (11βHSD1) which partake in the crosstalk between AT and skeletal muscles rose up. We draw a clear potential crosstalk pathway that, increased 11βHSD1 secreted by excess AT will promote the expression of the major inhibitor MSTN by activating corticosterone to cortisol, leading to the growth inhibition of skeletal muscle. Overall, this research announces how obesity affects skeletal muscle growth in a crosstalk sight. Male and female Bama minipigs, aged 6 months at the start of the study, were divided into the following two groups for 23 months of treatment. Bama minipigon control (CD group, N=3) were fed standard pig chow. The experimental group (N=6) were fed high-fat high-sucrose diet (53% basal diet, 37% sucrose, 10% lard, HFHSD).