Searchable abstracts of presentations at key conferences on calcified tissues

ba0005p163 | Cell biology: osteoblasts and bone formation | ECTS2016

Inhibition of histone demethylase LSD1 suppresses osteoblast differentiation

Al Majidi Rana , Tarkkonen Kati , Kiviranta Riku

Post-translational modifications of histone N-terminal tail domains affect the local chromatin conformation and serve as a dynamic regulatory layer for controlling gene transcription during cell differentiation. However, the role of epigenetic modifications in the regulation of osteoblast differentiation is still not fully understood. Recently, we identified RCOR2 as a novel regulator of osteoblast differentiation in a genome-wide transcription profiling of mouse MC3T3-E1 cell...

ba0001oc2.1 | Bone quality and fracture repair - animal models | ECTS2013

Treatment with soluble activin type IIB-receptor improves bone mass and strength in a mouse model of duchenne muscular dystrophy

Puolakkainen Tero , Ma Hongqiang , Pasternack Arja , Kainulainen Heikki , Ritvos Olli , Heikinheimo Kristiina , Hulmi Juha , Kiviranta Riku

Patients with Duchenne muscular dystrophy (DMD) carry a mutation in the dystrophin gene that leads to progressive muscle degeneration. In addition, DMD patients develop low bone mass especially in long bones and have high incidence of fractures. The underlying mechanisms for decreased bone mass remain unclear but muscle weakness and increased IL6 levels may play a role. Inhibition of activin/myostatin pathway has emerged as a novel approach to increase muscle mass and strength...

ba0001pp467 | Other diseases of bone and mineral metabolism | ECTS2013

Bone marrow fat is metabolically distinct fat depot

Kiviranta Riku , Pham Tam , Hannukainen Jarna , Jarvelin Juho , Karmi Anna , Soinio Minna , Salminen Pauliina , Nuutila Pirjo

In adults, majority of bone marrow (BM) space of long bones is filled with fat tissue. Adipocytes are also present within trabecular bone areas such as vertebral bodies. Despite its prevalence the roles of BM fat in energy and bone metabolism have been largely overlooked. To characterize bone marrow metabolic activity we measured regional glucose uptake in femoral and vertebral bone marrow during fasting and insulin stimulation in normal weight healthy subjects.<p class="a...

ba0005p162 | Cell biology: osteoblasts and bone formation | ECTS2016

RCOR2 is a novel regulator of osteoblast differentiation

Tarkkonen Kati , Al Majidi Rana , Valensisi Cristina , Saastamoinen Lauri , Hawkins David , Kiviranta Riku

Epigenetic mechanisms regulating osteoblast differentiation are still inadequately described. In a genome wide transcriptional profiling of MC3T3-E1 osteoblastic cell line, we identified RCOR2 as a significantly upregulated gene during a differentiation time-course from proliferative to mature osteoblasts. Similar expression profile of RCOR2 was found in mouse calvarial osteoblasts. RCOR2 belongs to CoREST/RCOR family of proteins that regulate action of lysine-specific histone...

ba0005oc2.1 | Bone mass and bone strength Wnt signalling | ECTS2016

Targeted deletion of Wnt1 in mesenchymal cells results in decreased bone mass and spontaneous fractures

Wang Fan , Tarkkonen Kati , Nieminen-Pihala Vappu , Rummukainen Petri , Lehto Jemina , Nagano Kenichi , Baron Roland , Makitie Outi , Kiviranta Riku

Wnt signaling is a major regulator of bone metabolism. We recently reported that mutations in WNT1 gene in humans cause early onset osteoporosis and severe osteogenesis imperfecta. To identify the cellular source and the mechanisms causing these severe phenotypes we generated and analyzed global and conditional Wnt1 knockout mice.Heterozygous Wnt1+/− mice were viable and fertile but Wnt1−/− embryos were lost in ute...

ba0002lb2 | (1) | ICCBH2013

WNT1 mutations in early-onset osteoporosis and osteogenesis imperfecta identify a key WNT ligand regulating bone mass

Laine Christine , Joeng Kyu Sang , Campeau Philippe , Kiviranta Riku , Tarkkonen Kati , Grover Monica , Lu James , Pekkinen Minna , Wessman Maija , Heino Terhi , Nieminen-Pihala Vappu , Laine Tero , Kroger Heikki , Cole William , Lehesjoki Anna-Elina , Krakow Deborah , Curry Cynthia , Cohn Daniel , Gibbs Richard , Lee Brendan , Makitie Outi

The role of the WNT pathway in skeletal maintenance has been extensively studied since the identification of mutations in key signaling WNT mediators (LRP5 and sclerostin) in high and low bone mass phenotypes. However, the identity of the key WNT ligand that signals via LRP5/6 has remained unknown. We aimed to identify genes with a major effect on the skeleton by studying individuals and families with early-onset osteoporosis or osteogenesis imperfecta (OI).<p class="abste...