Project description:Purpose: Idenfication of microRNA biomarkers of Chronic wasting disease in serum from infected elk Methods: Illumina next generation was used to profile abundance of serum miRNA in elk naturally infected with chronic wasting disease and Hamsters experimentally infected with the 263K scrapie prion strains Results: A signature of 21 miRNAs with diagnostic potential was found to be altered in abundance in serum from CWD infected elk. Of these, 6 were similarily altered in the serum from the 263K infected hamsters Conclusion: These altered miRNA signatures may serve as the basis for non-invasive diagnostic assays for chronic wasting disease and may shed light on the pathogenesis of prion infection
Project description:Cachexia, described as a syndrome of weight loss, muscle wasting, fat loss and insulin resistance has been described in patients with chronic liver disease. Whereas extensive work is being done to delineate these molecular pathways in adult patients with chronic liver or other disease, very little is known about these pathways in children with chronic liver disease. We used microarrays to detail the global programme of gene expression underlying the metabolic processes of cachexia in children with end stage liver disease udergoing liver transplantion. We included tissue from patients with Crigler-najjar syndrome as controls. We were able to identify distinct classes of differentially regulated genes related to these processes.
Project description:The maintenance of skeletal muscle tissue is of pivotal importance in health and disease, as its loss is often associated with chronic or progressive pathologies, generally worsening the prognosis. Increased levels of vitamin D binding protein (VDBP) in biological samples were reported to co-occur with several pathologies susceptible to muscle wasting, including various types of tumors. We, therefore, hypothesized that VDBP may participate in muscle wasting and investigated its direct effects on skeletal muscle homeostasis. Here we demonstrate that VDBP induces atrophy independently of vitamin D. In C2C12 myotubes, we identified the perturbation of the intracellular actin dynamic and subsequent mitochondrial dysfunction as the main molecular mechanisms at the basis of VDBP-induced atrophy. Coherently, the ectopic introduction of VDBP in mice lacking the protein (Gc-knockout mice; Gc-KO) induces muscle atrophy, the dismantling of neuromuscular junctions, and decreased force. Finally, we provide proof-of-concept evidence that VDBP contributes to cancer-associated muscle wasting. Altogether, these findings provide novel insights into the biological function of VDBP and have potential implications for the treatment of muscle wasting.
Project description:Parathyroid hormone (PTH) and PTH-related protein (PTHrP) are involved in cachexia associated with chronic kidney disease and cancer respectively. Tumor-derived PTHrP triggers adipose tissue browning and thereby leads to wasting of fat tissue in tumor-bearing mice. Similarly, elevated in 5/6 nephrectomized mice, PTH stimulates adipose tissue browning and wasting. Mice lacking the PTH/PTHrP receptor in their fat tissue are resistant to wasting of both adipose tissue and skeletal muscle. Therefore, the PTH/PTHrP signaling in adipocytes should activate various pathways that contribute to hypermetabolism and muscle wasting.
Project description:Skeletal muscle wasting is commonly associated with chronic kidney disease (CKD), resulting in increased morbidity and mortality. However, the link between kidney and muscle function remains poorly understood. Here, we took a complementary interorgan approach to investigate skeletal muscle wasting in CKD. We identified an increased production and elevated blood levels of soluble pro-cachectic factor Activin A, directly linking experimental and human CKD to skeletal muscle wasting programs. Systemic pharmacological blockade of Activin A using soluble activin receptor type IIB ligand trap prevented muscle wasting in a mouse model of experimental CKD.