Results of our study were selected for oral presentation on the most important meeting of European researchers of calcified tissues, which is organized annually by European Calcified Tissue Society. In the discovery stage we used Nanostring nCounter technology to obtain the expression profile of 800 miRNAs in bone samples from 5 osteoporotic patients (OP) and 5 patients with primary osteoarthrosis (OA). qPCR was used for the validation of differentially expressed miRNAs and their predicted targets. Nine miRNAs were differentially expressed in OP and OA groups in the discovery stage. miR-195-5p and miR-204-5p were selected for validation in the whole group of 103 patients. Additionally, their potential target genes relevant in bone metabolism were identified using three target prediction tools and were measured. There was a significant difference in miR-195-5p but not miR-204-5p levels among the tested groups (P(0.0001). Furthermore, there was a negative correlation between the levels of miR-195-5p and possible target genes ELOVL6 (P=0.001), GSTCD (P(0.0001) and MYB (P=0.035). Their gene expressions were also significantly different in the three groups with the lowest levels in OP followed by OA and C groups (P(0.0001 for all three genes). Our results are the first to identify miR-195-5p as a potential biomarker in OP and OA, which has only recently been demonstrated to inhibit osteoblast differentiation. Moreover, negative correlations with ELOVL6, GSTCD and MYB gene expression represent evidence of interaction. Further functional confirmations of predicted target genes are underway.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 4089969The project group is actively involved in the dissemination of new scientific discoveries and professional novelties in the field of bone diseases as well as their implementation in routine clinical practice. Three members of the project group were included in the organisational commitee of the 5th Osteologic days, a two-days interdisciplinary meeting with international participation intended for all profiles professionally engaged in bone diseases and their consequences. There were also three invited lectures presented during event by members of the project group. One of them focused specifically on micro RNAs, their physiological and pathophysiological roles as well as diagnostic and therapeutic potential and current challenges. The contents, results and the impact of our project in the field of bone diseases, where micro RNA studies are at an early stage were also presented.
B.04 Guest lecture
COBISS.SI-ID: 4036209Young researcher Peter Vrtačnik successfully defended his Ph.D. thesis in 2015. He used state-of- the-art methods and upgraded results from in vitro models with testing of bone samples from patients thus giving them larger clinical relevance. He was the first to study and demonstrate the influence of oxidative stress and hypoxia on expression of several genes ivolved in histone acetylation, DNA methylation and micro RNAs. Detected differences in their expression in bone samples of patients with osteoporosis and osteoarthrosis implicate their involvement in pathogenesis and range them among the potential targets for future generation of osteoanabolic drugs. During his Ph.D. study, he published 4 articles in international journals with impact factor and another one has been submitted. He is currently continuing with postdoctoral study at the eminent European Medical University (Karolinska Institutet). Four students defended their master thesis within the project and four more are in preparation, they have already finished the experimental part.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 278090496The effects of estrogens on miRNAs have so far mainly been studied in breast cancer, where miRNAs are emerging as novel biomarkers that can improve diagnosis and prognosis. Moreover, miRNAs were shown to be involved in tamoxifen and aromatase inhibitors resistance. There is only one study on animal model in which the effects of estrogen on bone miRNAs has been evaluated suggesting the likely role of miRNAs in the pathogenesis of postmenopausal osteoprosis. The study objective was to evaluate the effect of 17β-estradiol (E2) on miRNAs expression in cultured human osteoblasts. Osteobast cell line was transfected with a plasmid containing estrogen receptor α and the successful transfection was confirmed by Western blotting. Following 24 and 72 hours of E2 treatment total RNA was isolated. Simultaneous detection and quantification of 800 miRNAs was performed by using Nanostring nCounter technology. Gene expression of estrogen receptors: ERα, ERβ and GPER1 was measured by quantitative real-time PCR. There was a downregulation of miR-4516 following 24 hours of E2 treatment and downregulation of miR-520d-5p, miR-376a-3p, miR-518b, miR-593-3p and miR-338-3p following 72 hours of E2 treatment. Interestingly, miR-338-3p has already been shown to have an important role in osteoblast biology by decreasing osteoblast diferentiation through direct inhibition of transcription factor RUNX2. The results of our in vitro study support the role of miRNAs in epigenetic estrogen response in osteoblasts, which could be important also in vivo for example in hormone replacement therapy.
B.04 Guest lecture
COBISS.SI-ID: 4014449Osteoporotic fractures are extremely common, significantly impair the quality of life of patients who sustain these fractures, increase their mortality and cause enormous costs. Prof. Preželj as one of the leading experts in the field of clinical treatment of osteoporosis in the country, is also a coauthor of the current Slovenian guidelines for the diagnosis and treatment of osteoporosis. The guidelines have successfully implemented the computer derived model FRAX into our region. FRAX allows identification and treatment of individuals with high risk for fracture, which is the only way to effectively prevent osteoporotic fractures, improve the quality of life and survival of older people and to reduce the economic costs.
F.22 Improvement to existing health/diagnostic methods/procedures
COBISS.SI-ID: 4635711