Project description:Tibialis anterior and gastrocnemius muscle from Eif6 heterozygous mice and wild-type mice profiled using Agilent gene expression arrays
Project description:Gastrocnemius muscle from Eif6 heterozygous mice and wild-type mice was used in a polysome profiling experiment. Total RNA was extracted from the whole muscle and from monosome/polysome fractions and profiled using Agilent gene expression arrays.
Project description:A cohort of age-matched mice (eIF6+/+ and eIF6+/-) were fed with High-Fat Diet. All experimental mice were sacrificed after 16 weeks and the livers were recovered. RNA was isolated from liver biopsies of eIF6+/+ and eIF6+/- mice and RNAseq analysis was performed. The aim of the analysis is the investigation of the transcriptional changes driven by chronic depletion of eIF6 in the liver of mice upon High Fat Diet (HFD) feeding.
Project description:We show that Mustn1 (Musculoskeletal embryonic nuclear protein 1, also known as Mustang) is highly expressed in skeletal muscle during the early stages of hindlimb reloading. Mustn1 expression is transiently elevated in mouse and human skeletal muscle in response to intense exercise, resistance exercise, or injury. We find that Mustn1 expression is highest in smooth muscle-rich tissues, followed by skeletal muscle fibers. Muscle from heterozygous Mustn1-deficient mice exhibit differences in gene expression related to the extracellular matrix and cell adhesion, compared to wild-type littermates. Mustn1-deficient mice have normal muscle and aorta function and whole-body glucose metabolism. Loss of Mustn1 in vascular smooth muscle cells does not affect their proliferative or migratory functions. We show that Mustn1 can be secreted from smooth muscle cells, and that it is present in arterioles of the muscle microvasculature and in muscle interstitial fluid, in particular during the hindlimb reloading phase. Proteomics analysis of muscle from Mustn1-deficient mice confirms differences in extracellular matrix composition, and female mice display higher collagen content after chemically induced muscle injury compared to wild-type littermates.
Project description:In differentiated skeletal muscle, intracellular Ca2+ concentrations rise dramatically upon membrane depolarization, constituting the link between excitation and contraction (EC). Transient rises in [Ca2+]i mainly emerge from Ca2+ released by the type 1 ryanodine receptor (RYR1) and, in non-adult muscle, by the inositol 1,4,5-triphosphate receptor (IP3R) of the sarcoplasmic reticulum (SR), the dominant Ca2+ store in skeletal muscle. While the IP3R-mediated, slow Ca2+ transients, have been implicated in cell signaling and development, RYR1’s non-contractile role(s) remain obscure. We used a homozygous mouse RyR1 knockout model (dyspedic) to investigate the effects of the absence of a functional RYR1 and, consequently, the lack of RyR1-mediated Ca2+ signaling during embryogenesis. While heterozygous mice of the model are undistinguishable from WT littermates, homozygous dyspedic mice die at birth from asphyxia, since their skeletal muscle does not support EC coupling. Furthermore, they display abnormal spine curvature, subcutaneous hematomas, small limbs, and enlarged neck. Skeletal muscles from front and hind limbs of dyspedic embryos (day E18.5) were subjected to microarray analyses, revealing 318 genes, significantly regulated by at least 50 % compared to control heterozygous littermates.