Periodic Reporting for period 1 - CHANGE (Cellular Homeostasis ANd AGing in Connective TissuE Disorders)
Reporting period: 2022-09-01 to 2024-08-31
The increased longevity in developed countries is a reality that the national health systems need to face since not necessarily longer lifespan is associated with the amelioration of health and quality of life. Furthermore, musculoskeletal, cardiovascular and neurodegenerative failure present in elderly are also described in several early-onset hereditary connective tissue (CT) disorders. Thus, such disorders represent a powerful tool for the molecular investigation of age-related pathologies due to the specific genetic disturbance of cellular homeostasis. The overall objective of CHANGE is to define the molecular pathways in genetic disorders of cartilage, bone, muscle and vasculature that represent premature signature of common late onset ageing diseases. This will identify drivers of the ageing and disease process to develop innovative prognostic and/or diagnostic biomarkers and therapeutic approaches. By using molecularly well-characterized CT diseases CHANGE aims: 1. to combine several cutting edge techniques to deeply phenotype in vitro and in vivo models of rare CT disorders, associated to signs of premature ageing affecting tissues/organs severely compromised in frailty and specific common age-related disorders; 2. to combine molecular, biochemical and imaging data to identify age-related changes in signalling and gene expression that are linked to and/or explain the observed precocious ageing defects associated with early onset CT diseases; 3. to exploit the acquired knowledge of cellular- and patho-biology to define the molecular pathways compromised during ageing with the aim to pursue drug targetable molecules for amelioration of cartilage, bone, muscle and vascular health.
Accordingly with the WP1 main objective of characterizing the early signs of ageing associated to cartilage and joint defects, the DCs involved in the project successfully: 1. obtained valuable insights into underlying disease mechanisms of specific monogenic diseases, namely diastrophic dysplasia (DTD) and spondylo-epimetaphyseal dysplasia with joint laxity type2 (SEMD JL2). The progression of alterations in cartilage and bone during ageing has been reported. A cartilage damage model by means of overloading osteochondral explants with a combination of static compression and shear has been developed and currently is being further optimized and validated. Accordingly, with the WP2 main goal of identifying the early signs of ageing associated to bone defects, the DCs involved in the project successfully characterized in adult and aged mice the skeletal and cellular phenotype of mutant mice carrying a dominant negative mutation in type I collagen (Brtl) and a gain-of-function mutation in FGFR3. Early signs of aging were identified in bone of both models. A bone phenotype has also been identified in a murine model of chondrodysplasia and in a murine and a zebrafish model for myopathy supporting the involvement of other tissues beyond the most affected one in different diseases during aging. In compliance with the WP3 main objective to identify early signs of ageing associated to muscular, cardiac and vascular defects, the DCs involved in the project successfully demonstrated altered vertebrae angles, correlating with stiff spine characteristics, in the col6a1∆ex14 mutant zebrafish. A worsening phenotype was observed in adult fish, leading to severe muscle integrity damage. In a knockout mouse for collagen VI, changes in cardiomiocytes ultrasctructure was observed during aging. A potential pro inflammatory role of extracellular vesicles derived from immortalized Ulrich congenital muscular dystrophy patients was proposed. More than 12 senescence markers in human brain endothelial cells and patient fibroblasts were successfully studied. The phenotypic characterization of a mutant Col4a2 mouse line during ageing was achieved. In accordance with the WP4 main goal to develop new tools to target cellular senescence as a treatment strategy for connective tissue disorders, the DCs involved in the project successfully accomplished already relevant results. The presence of primary cilium defects in immortalized cells derived from UCMD patients was described and was partially rescued by treating the cells with a direct inducer of adenilate cyclase or prostaglandin receptor targeting compounds. Also, the therapeutic potential of EP2 agonists in restoring primary cilia function and modulating senescence in the chondrocyte models was achieved. Defect in primary cilium was also found in presence of COL4 mutations and investigation of cell senescence in these cells supports activation of senescence.
The results of the project so far achieved build up on the already available in vitro and in vivo CT models within the consortium. The identification of early signs of aging-related processes in cartilage, bone, muscle and vasculature in the several CT models obtained by molecular techniques including -omics, imaging and functional assays allowed a step foward in the identification of specific biological changes in the intracellular pathways involved in cellular homeostasis and in extracellular matrix components during life. The identification of specific changes in tissue, matrix composition and quality, ageing-related cellular processes and downstream signalling in disease-relevant mouse and zebrafish models of chondrodysplasias, osteoarthritis, OI, myopathies and cerebral small vessel disease including stroke will impact on the identification of new targets not only for the afore mentioned diseases, but for common aging related morbidity.
Additionally, the validation of the biological alterations detected in monogenic disorders will be a powerful tool to improve diagnosis and prognosis of rare as well as common disease. The identification of abnormal ciliogenesis as shared senescence cell signature/biomarkers will likely also be of impact in defining target for therapy as well as early biomarker signature for aging.
Additionally, the validation of the biological alterations detected in monogenic disorders will be a powerful tool to improve diagnosis and prognosis of rare as well as common disease. The identification of abnormal ciliogenesis as shared senescence cell signature/biomarkers will likely also be of impact in defining target for therapy as well as early biomarker signature for aging.