Bone Abstracts

Loss of genomic maintenance contributes to aging, as exemplified by mutations in Ercc DNA repair proteins that lead to a plethora of progeroid syndromes of which some display accelerated bone loss. It is generally accepted that dietary restriction (DR) increases life span and improves organ function. We therefore assessed the impact of DR on life span and bone mass in WT and bona fide prematurely aging hypomorphic Ercc-deficient mice (Ercc1−/Δ).<...

Activins belong to the transforming growth factor-β superfamily, and they regulate bone formation by controlling both osteoclast and osteoblast behaviour. We have previously shown that activin-A strongly inhibited matrix mineralization in osteoblast cultures, and that activin A-signalling was most effective before the onset of mineralization.The aim of this study was therefore to investigate how an early activin-A pulse affected osteoblast mineraliz...

The mammalian circadian clock is tightly controlled by clock genes, which have been shown to regulate up to 20% of the transcriptome in any given tissue. Evidence is accumulating that light-modulation perpetually affects circadian clock performance. In accordance, shift work or chronic jet lag is associated with higher risk of disease later in life, including osteoporosis. In this study, we assessed whether gestational jet lag in mice reduces bone mass postnatally.<p class...

Transient receptor potential vanilloid channels (TRPVs) have been implicated in Ca2+ homeostasis and bone metabolism. In particular, TRPV4 deficiency was shown to cause sexual dimorphism in bone metabolism and osteoporotic fracture risk. Cortical bone structure was reported to be altered in male TRPV4 knock-out (TRPV4−/−) mice but not in female TRPV−/− mice compared to sex-matched wildtype (TRPV4+/+) animals.To gain knowledge on t...

In this case report, we present a brother and sister with hereditary vitamin D resistant rickets (HVDRR). Both children presented at the age of 18 months with severe rickets and elevated serum levels of 1,25-(OH)2D3. They differ from each other in that the girl presented with hypophosphatemia instead of hypocalcemia. Besides, she developed alopecia earlier than the boy and needed more 1,25-(OH)2D3 supplementation. Interestingly, the ...