Funkcijsko vrednotenje vpliva genov FUBP3, MPP7 in ANAPC1 na razvoj osteoporoze in osteoartroze

Malavašič, Petra (author), Marc, Janja (mentor)

Osteoporoza (OP) je pogosta sistemska bolezen skeleta, za katero sta značilni zmanjšana mineralna kostna gostota (BMD) in povečano tveganje za zlome. Nasprotno je osteoartroza (OA) primarno bolezen sklepov, povezana s povišano BMD v subhondralni kosti, zato v raziskavah predstavlja obratno patologijo oziroma nasprotni fenotip OP. OP sodi med kompleksne genetske bolezni, pri katerih na razvoj vplivajo številni okoljski in genetski dejavniki z majhnimi učinki, kar otežuje njihovo identifikacijo in vrednotenje. Pomemben napredek so prinesle vsegenomske asociacijske študije (GWAS), ki so identificirale številne lokuse in gene, povezane z BMD in zlomi, vendar brez funkcionalne potrditve njihove vloge. V svoji disertaciji smo se osredotočili na ocenjevanje funkcije treh genov – FUBP3, ANAPC1 in MPP7, saj so lokusi s temi geni pri GWAS izkazali močno značilno (p<10-8) povezanost z BMD in zlomi (FUBP3: p = 3,4 × 10?22, ANAPC1: p = 1,5 × 10?? in MPP7: p = 2,4 × 10?16). Zasnovali smo večnivojski eksperimentalni pristop, ki je vključeval: analizo izražanja genov v kostnem in mišičnem tkivu bolnikov z OP, OA ter kontrolnih oseb, spremljanje izražanja med diferenciacijo mezenhimskih stromalnih/matičnih celic (MSC) v osteoblaste, adipocite in miocite ter eksperimentalno manipulacijo izražanja (utišanje oziroma izbitje gena) v celičnih modelih. V kostnem tkivu bolnikov z OP smo dokazali znižano izražanje vseh treh genov, pri OA pa le gena FUBP3. V mišičnem tkivu je bilo izražanje pri OP prav tako znižano, kar nakazuje pleiotropno delovanje teh genov. Med osteogeno diferenciacijo MSC se izražanje FUBP3 in ANAPC1 značilno zviša, kar potrjuje njuno vlogo v osteogenezi. Pokazali smo, da utišanje ANAPC1 vpliva na zgodnje faze osteogeneze, izbitje MPP7 povzroči popolno blokado mineralizacije, izbitje FUBP3 pa vodi v oslabljeno mineralizacijo. Naši rezultati prvi potrjujejo vlogo genov FUBP3, ANAPC1 in MPP7 v kostni biologiji pri človeku ter njihovo povezavo z OP in OA. Raziskava prispeva k razumevanju genetske osnove OP in predstavlja korak k prepoznavanju novih biomarkerjev ter razvoju ciljnih terapij za personalizirano zdravljenje osteoporoze.

• Language: Slovenian
• Keywords: osteoporoza, GWAS, kandidatni geni, MSC, osteogena diferenciacija, FUBP3, ANAPC1, MPP7, kostna biologija
• Work type: Doctoral dissertation
• Organization: FFA - Faculty of Pharmacy
• Year: 2026
• PID: 20.500.12556/RUL-177873
• Publication date in RUL: 11.01.2026

Secondary language

• Language: English
• Title: Functional evaluation of FUBP3, MPP7 and ANAPC1 genes in the development of osteoporosis and osteoartrosis

Abstract

Osteoporosis (OP) is a common systemic skeletal disorder characterized by reduced bone mineral density (BMD) and an increased risk of fractures. In contrast, osteoarthrosis (OA) is primarily a joint disease associated with elevated BMD in the subchondral bone and therefore represents an opposite pathology, or a reverse phenotype, of OP in research studies. OP is a complex genetic disease influenced by numerous environmental and genetic factors with small individual effects, which makes their identification and evaluation challenging. Significant progress has been achieved through genome-wide association studies (GWAS), which have identified multiple loci and genes associated with BMD and fractures; however, these findings lack functional validation of gene roles. In this dissertation, we focused on evaluating the function of three genes – FUBP3, ANAPC1, and MPP7 – as GWAS loci containing these genes showed strong genome-wide significant associations (p < 10⁻⁸) with BMD and fractures (FUBP3: p = 3.4 × 10⁻²²; ANAPC1: p = 1.5 × 10⁻⁹; MPP7: p = 2.4 × 10⁻¹⁶). We designed a multi-level experimental approach that included: analysis of gene expression in bone and muscle tissue of patients with OP and OA as well as control subjects, monitoring of gene expression during differentiation of mesenchymal stromal/stem cells (MSC) into osteoblasts, adipocytes, and myocytes, and experimental manipulation of gene expression (silencing or knockout) in relevant cellular models. In bone tissue of patients with OP, the expression of all three genes was decreased, whereas in OA only FUBP3 expression was reduced. In muscle tissue, gene expression was also decreased in OP, indicating pleiotropic functions of these genes. During osteogenic differentiation of MSC, expression of FUBP3 and ANAPC1 significantly increased, confirming their involvement in osteogenesis. We demonstrated that silencing of ANAPC1 affects the early stages of osteogenesis, knockout of MPP7 results in complete inhibition of mineralization, and knockout of FUBP3 leads to impaired mineralization. Our results provide the first evidence of the roles of FUBP3, ANAPC1, and MPP7 in human bone biology and their association with OP and OA. This study contributes to the understanding of the genetic basis of osteoporosis and represents an important step toward the identification of novel biomarkers and the development of targeted therapies for personalized treatment of osteoporosis.

• Keywords: osteoporosis, GWAS, candidate genes, MSC, osteogenic differentiation, FUBP3, ANAPC1, MPP7, bone biology