1.
Celiac Disease and Its Role in the Development of Metabolic Bone Disease.
Micic, D, Rao, VL, Semrad, CE
Journal of clinical densitometry : the official journal of the International Society for Clinical Densitometry. 2020;(2):190-199
Abstract
Celiac disease (CD) is an immune-mediated enteropathy that occurs in genetically susceptible hosts with the ingestion of gluten-containing products. Ongoing gluten consumption leads to intestinal damage, characterized by villous blunting and increased intraepithelial lymphocytes, resulting in malabsorption. Pertinent to the development of bone disease, malabsorption of calcium and vitamin D leads to secondary hyperparathyroidism and metabolic bone disease among individuals with CD. In this article, we review the pathogenesis of CD and the effects of malabsorption on bone health. Imbalances in bone resorption and formation particularly in individuals with CD and persistent disease activity ultimately lead to a state of bone loss and impaired mineralization. Initiation of a gluten-free diet is critical in the management of CD-related metabolic bone disease, demonstrating improvements in bone mineral density within the first year of dietary adherence.
2.
Microbial osteoporosis: The interplay between the gut microbiota and bones via host metabolism and immunity.
Li, L, Rao, S, Cheng, Y, Zhuo, X, Deng, C, Xu, N, Zhang, H, Yang, L
MicrobiologyOpen. 2019;(8):e00810
Abstract
The complex relationship between intestinal microbiota and host is a novel field in recent years. A large number of studies are being conducted on the relationship between intestinal microbiota and bone metabolism. Bone metabolism consisted of bone absorption and formation exists in the whole process of human growth and development. The nutrient components, inflammatory factors, and hormone environment play important roles in bone metabolism. Recently, intestinal microbiota has been found to influence bone metabolism via influencing the host metabolism, immune function, and hormone secretion. Here, we searched relevant literature on Pubmed and reviewed the effect of intestinal microbiota on bone metabolism through the three aspects, which may provide new ideas and targets for the clinical treatment of osteoporosis.
3.
R516Q mutation in Melanoma differentiation-associated protein 5 (MDA5) and its pathogenic role towards rare Singleton-Merten syndrome; a signature associated molecular dynamics study.
Raghuraman, P, Sudandiradoss, C
Journal of biomolecular structure & dynamics. 2019;(3):750-765
Abstract
Singleton-Merten syndrome, a critical and rare multifactorial disorder that is closely linked to R516Q mutation in MDA5 protein associated with an enhanced interferon response in the affected individual. In the present study, we provide conclusive key evidence on R516Q mutation and their connectivity towards sequence-structural basis dysfunction of MDA5 protein. Among the various mutations, we found R516Q is the most pathogenic mutation based on mutational signature Q-A-[RE]-G-R-[GA]-R-A-[ED]-[DE]-S-[ST]-Y-[TSAV]-L-V designed from our work. Further, we derived a distant ortholog for this mutational signature from which we identified 343 intra-residue interactions that fall communally in the position required to maintain the structural and functional integration of protein architecture. This identification served us to understand the critical role of hot spots in residual aggregation that holds a native form of folding conformation in the functional region. In addition, the long-range molecular dynamics simulation demarcated the residual dependencies of conformational transition in distinct regions (L29360-370α18, α19380-410L31, α21430-480L33-α22-L35 and α24510-520L38) occurring upon R516Q mutation. Together, our results emphasise that the dislocation of functional hot spots Pro229, Arg414, Val498, Met510, Ala513, Gly515 and Arg516 in MDA5 protein which is important for interior structural packing and fold arrangements. In a nutshell, our findings are perfectly conceded with other experimental reports and will have potential implications in immune therapeutical advancement for rare singleton-merten syndrome.
4.
[Vitamin D metabolism and osteoporosis in systemic sclerosis].
Szamosi, S, Horváth, Á, Szekanecz, Z, Szűcs, G
Orvosi hetilap. 2017;(32):1252-1258
Abstract
In the past few years more and more data have become available on the important role of vitamin D in immunological processes and inflammation. The role of vitamin D deficiency in the pathogenesis as well as in disease progression of different autoimmune and inflammatory conditions is suspected. Vitamin D deficiency is prevalent in several autoimmune diseases, including systemic sclerosis. Hypovitaminosis has been found to be associated with low bone mineral density and higher prevalence of osteoporosis in this group of patients. Determinants of low bone density in SSc are poorly understood. Studies have shown the importance of both traditional osteoporotic as well as disease-specific factors (extent of skin involvement, presence of internal organ manifestation, malabsorption, systemic sclerosis subtype, serological profile, medication) in the development of low bone mineral density. The relationship between low bone density in systemic sclerosis patients and the above mentioned risk factors may be more complex and the real role of each factor is unclear. Yet very few studies reported clinically relevant low bone mass outcomes such as fracture risk assessment and fracture associated mortality in scleroderma. This review aims to synthesize data about the essential role of vitamin D in immune homeostasis as well as the prevalence of hypovitaminosis, low bone density, changes in bone turnover markers and presence of osteoporosis in scleroderma patients. Orv Hetil. 2017; 158(32): 1252-1258.