Riikka E Mäkitie1, Matthias Hackl2, Riitta Niinimäki3, Sakari Kakko4, Johannes Grillari5, Outi Mäkitie1,6,7. 1. Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland. 2. TAmiRNA GmbH, Vienna, Austria. 3. Department of Children and Adolescents, Oulu University Hospital, and PEDEGO Research Unit, University of Oulu, Oulu, Finland. 4. Internal Medicine and Clinical Research Center, University of Oulu, Oulu, Finland. 5. Christian Doppler Laboratory on Biotechnology of Skin Aging, Department of Biotechnology, University of Natural Resources and Life Sciences Vienna, Vienna, Austria. 6. Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland. 7. Center for Molecular Medicine, Karolinska Institutet and Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.
Abstract
Context: WNT signaling is fundamental to bone health, and its aberrant activation leads to skeletal pathologies. The heterozygous missense mutation p.C218G in WNT1, a key WNT pathway ligand, leads to severe early-onset and progressive osteoporosis with multiple peripheral and spinal fractures. Despite the severe skeletal manifestations, conventional bone turnover markers are normal in mutation-positive patients. Objective: This study sought to explore the circulating microRNA (miRNA) pattern in patients with impaired WNT signaling. Design and Setting: A cross-sectional cohort study at a university hospital. Participants: Altogether, 12 mutation-positive (MP) subjects (median age, 39 years; range, 11 to 76 years) and 12 mutation-negative (MN) subjects (35 years; range, 9 to 59 years) from two Finnish families with WNT1 osteoporosis due to the heterozygous p.C218G WNT1 mutation. Methods and Main Outcome Measure: Serum samples were screened for 192 miRNAs using quantitative polymerase chain reaction. Findings were compared between WNT1 MP and MN subjects. Results: The pattern of circulating miRNAs was significantly different in the MP subjects compared with the MN subjects, with two upregulated (miR-18a-3p and miR-223-3p) and six downregulated miRNAs (miR-22-3p, miR-31-5p, miR-34a-5p, miR-143-5p, miR-423-5p, and miR-423-3p). Three of these (miR-22-3p, miR-34a-5p, and miR-31-5p) are known inhibitors of WNT signaling: miR-22-3p and miR-34a-5p target WNT1 messenger RNA, and miR-31-5p is predicted to bind to WNT1 3'UTR. Conclusions: The circulating miRNA pattern reflects WNT1 mutation status. The findings suggest that the WNT1 mutation disrupts feedback regulation between these miRNAs and WNT1, providing insights into the pathogenesis of WNT-related bone disorders. These miRNAs may have potential in the diagnosis and treatment of osteoporosis.
Context:WNT signaling is fundamental to bone health, and its aberrant activation leads to skeletal pathologies. The heterozygous missense mutation p.C218G in WNT1, a key WNT pathway ligand, leads to severe early-onset and progressive osteoporosis with multiple peripheral and spinal fractures. Despite the severe skeletal manifestations, conventional bone turnover markers are normal in mutation-positive patients. Objective: This study sought to explore the circulating microRNA (miRNA) pattern in patients with impaired WNT signaling. Design and Setting: A cross-sectional cohort study at a university hospital. Participants: Altogether, 12 mutation-positive (MP) subjects (median age, 39 years; range, 11 to 76 years) and 12 mutation-negative (MN) subjects (35 years; range, 9 to 59 years) from two Finnish families with WNT1 osteoporosis due to the heterozygous p.C218GWNT1 mutation. Methods and Main Outcome Measure: Serum samples were screened for 192 miRNAs using quantitative polymerase chain reaction. Findings were compared between WNT1 MP and MN subjects. Results: The pattern of circulating miRNAs was significantly different in the MP subjects compared with the MN subjects, with two upregulated (miR-18a-3p and miR-223-3p) and six downregulated miRNAs (miR-22-3p, miR-31-5p, miR-34a-5p, miR-143-5p, miR-423-5p, and miR-423-3p). Three of these (miR-22-3p, miR-34a-5p, and miR-31-5p) are known inhibitors of WNT signaling: miR-22-3p and miR-34a-5p target WNT1 messenger RNA, and miR-31-5p is predicted to bind to WNT1 3'UTR. Conclusions: The circulating miRNA pattern reflects WNT1 mutation status. The findings suggest that the WNT1 mutation disrupts feedback regulation between these miRNAs and WNT1, providing insights into the pathogenesis of WNT-related bone disorders. These miRNAs may have potential in the diagnosis and treatment of osteoporosis.
Authors: David Carro Vázquez; Lejla Emini; Martina Rauner; Christine Hofbauer; Johannes Grillari; Andreas B Diendorfer; Richard Eastell; Lorenz C Hofbauer; Matthias Hackl Journal: Int J Mol Sci Date: 2022-06-10 Impact factor: 6.208