@article{MuenchAbdelilahSeyfried2021, author = {M{\"u}nch, Juliane and Abdelilah-Seyfried, Salim}, title = {Sensing and responding of cardiomyocytes to changes of tissue stiffness in the diseased heart}, series = {Frontiers in cell developmental biology}, volume = {9}, journal = {Frontiers in cell developmental biology}, publisher = {Frontiers Media}, address = {Lausanne}, issn = {2296-634X}, doi = {10.3389/fcell.2021.642840}, pages = {13}, year = {2021}, abstract = {Cardiomyocytes are permanently exposed to mechanical stimulation due to cardiac contractility. Passive myocardial stiffness is a crucial factor, which defines the physiological ventricular compliance and volume of diastolic filling with blood. Heart diseases often present with increased myocardial stiffness, for instance when fibrotic changes modify the composition of the cardiac extracellular matrix (ECM). Consequently, the ventricle loses its compliance, and the diastolic blood volume is reduced. Recent advances in the field of cardiac mechanobiology revealed that disease-related environmental stiffness changes cause severe alterations in cardiomyocyte cellular behavior and function. Here, we review the molecular mechanotransduction pathways that enable cardiomyocytes to sense stiffness changes and translate those into an altered gene expression. We will also summarize current knowledge about when myocardial stiffness increases in the diseased heart. Sophisticated in vitro studies revealed functional changes, when cardiomyocytes faced a stiffer matrix. Finally, we will highlight recent studies that described modulations of cardiac stiffness and thus myocardial performance in vivo. Mechanobiology research is just at the cusp of systematic investigations related to mechanical changes in the diseased heart but what is known already makes way for new therapeutic approaches in regenerative biology.}, language = {en} } @article{GrajaGarciaCarrizoJanketal.2018, author = {Graja, Antonia and Garcia-Carrizo, Francisco and Jank, Anne-Marie and Gohlke, Sabrina and Ambrosi, Thomas H. and Jonas, Wenke and Ussar, Siegfried and Kern, Matthias and Sch{\"u}rmann, Annette and Aleksandrova, Krasimira and Bluher, Matthias and Schulz, Tim Julius}, title = {Loss of periostin occurs in aging adipose tissue of mice and its genetic ablation impairs adipose tissue lipid metabolism}, series = {Aging Cell}, volume = {17}, journal = {Aging Cell}, number = {5}, publisher = {Wiley}, address = {Hoboken}, issn = {1474-9718}, doi = {10.1111/acel.12810}, pages = {13}, year = {2018}, abstract = {Remodeling of the extracellular matrix is a key component of the metabolic adaptations of adipose tissue in response to dietary and physiological challenges. Disruption of its integrity is a well-known aspect of adipose tissue dysfunction, for instance, during aging and obesity. Adipocyte regeneration from a tissue-resident pool of mesenchymal stem cells is part of normal tissue homeostasis. Among the pathophysiological consequences of adipogenic stem cell aging, characteristic changes in the secretory phenotype, which includes matrix-modifying proteins, have been described. Here, we show that the expression of the matricellular protein periostin, a component of the extracellular matrix produced and secreted by adipose tissue-resident interstitial cells, is markedly decreased in aged brown and white adipose tissue depots. Using a mouse model, we demonstrate that the adaptation of adipose tissue to adrenergic stimulation and high-fat diet feeding is impaired in animals with systemic ablation of the gene encoding for periostin. Our data suggest that loss of periostin attenuates lipid metabolism in adipose tissue, thus recapitulating one aspect of age-related metabolic dysfunction. In human white adipose tissue, periostin expression showed an unexpected positive correlation with age of study participants. This correlation, however, was no longer evident after adjusting for BMI or plasma lipid and liver function biomarkers. These findings taken together suggest that age-related alterations of the adipose tissue extracellular matrix may contribute to the development of metabolic disease by negatively affecting nutrient homeostasis.}, language = {en} }