Fahr’s disease

The scientific review based on an analysis of the literature examines key points in the etiology, pathomorphology and clinical picture of basal ganglia calcification. It also involves the so-called physiological calcification of the central nervous system. Juvenile and senile forms of a disease and frequency of occurrence of this nosological form are described. The historical information and modes of inheritance are briefly provided. The article considers the numerous synonyms of this disease and the causes of secondary calcification of the brain (Fahr’s syndrome). Four genes are described associated with primary calcification of the basal ganglia: SLC20A2 and XPR1 coding transmembrane conveyors of inorganic phosphate; PDGFB and PDGFRB which are involved in integrity of a blood-brain barrier and survival of pericytes. Pathogenetic mechanisms of clinical displays of a disease are presented. The article displays the features of macro- and microscopic changes in the brain with this nosology. The characteristic signs of the initial and advanced forms of the disease are described in detail, taking into account the age of the debut of calcification of the basal ganglia. The main and auxiliary instrumental methods for diagnosing this disease are also considered, the results of positron emission tomography and magnetic resonance spectroscopy are described, which confirm the pathophysiological mechanism of neurological manifestations of the disease associated with the disorganization of the front-striatal pathways in the area of ​​calcified basal ganglia. A number of additional general clinical laboratory and functional studies are listed to confirm or exclude the diagnosis of primary family idiopathic ferrocalcinosis (Fahr’s diseases). The main directions in the treatment of the described pathology are given.

MicroRNAs are central to osteogenesis: a review with a focus on cardiovascular calcification

Cardiovascular calcification, manifested by coronary artery calcification and aortic valve stenosis, is a widespread condition that is becoming more common with the aging of the general population. No disease-modifying therapies currently exist for any forms of cardiovascular calcification. A number of similarities exist between pathological calcification in cardiovascular tissue and physiological calcification in bone, termed osteogenesis. MicroRNAs are small noncoding RNAs that have been shown to have multiple effects throughout the cardiovascular system. In this review, we discuss the pre-clinical evidence supporting a role for microRNAs in osteogenesis, with a focus on cardiovascular calcification. The microRNAs with most evidence implicating them in the disease process are the miR-17~92 cluster, miR-23a/27a/24-2 family, miR-26a, miR-29b, the miR-30 family, miR-31, miR-125b, miR-133a, miR-143/145, miR-155, and miR-221/222. We also highlight the limitations of current evidence in this field, such as the lack of studies using high-throughput technologies.

Osteoprotegerin Reverses Osteoporosis by Inhibiting Endosteal Osteoclasts and Prevents Vascular Calcification by Blocking a Process Resembling Osteoclastogenesis

High systemic levels of osteoprotegerin (OPG) in OPG transgenic mice cause osteopetrosis with normal tooth eruption and bone elongation and inhibit the development and activity of endosteal, but not periosteal, osteoclasts. We demonstrate that both intravenous injection of recombinant OPG protein and transgenic overexpression of OPG in OPG−/2 mice effectively rescue the osteoporotic bone phenotype observed in OPG-deficient mice. However, intravenous injection of recombinant OPG over a 4-wk period could not reverse the arterial calcification observed in OPG−/− mice. In contrast, transgenic OPG delivered from mid-gestation through adulthood does prevent the formation of arterial calcification in OPG−/− mice. Although OPG is normally expressed in arteries, OPG ligand (OPGL) and receptor activator of NF-κB (RANK) are not detected in the arterial walls of wild-type adult mice. Interestingly, OPGL and RANK transcripts are detected in the calcified arteries of OPG−/− mice. Furthermore, RANK transcript expression coincides with the presence of multinuclear osteoclast-like cells. These findings indicate that the OPG/OPGL/RANK signaling pathway may play an important role in both pathological and physiological calcification processes. Such findings may also explain the observed high clinical incidence of vascular calcification in the osteoporotic patient population.