Genes and osteoporosis

Insights into the pleiotropic relationships between chronic back pain and inflammation-related musculoskeletal conditions: rheumatoid arthritis and osteoporotic abnormalities

ABSTRACT

The ageing process includes the development of debilitating musculoskeletal (MSK) conditions, including chronic back pain (CBP), rheumatoid arthritis (RA), and osteoporosis (OP). The mechanisms involved in the genetic-epidemiological relationships between these MSK phenotypes are controversial and limited and thus require clarification, in particular, between CBP and the other MSK phenotypes. A cross-sectional statistical analysis was conducted using Europeans from the UK Biobank data collection, including 73,794 CBP, 4883 RA, and 7153 OP cases as well as 242,216 calcaneus bone mineral density scores. C-reactive protein (CRP) was measured for 402,165 subjects in this sample. Genetic correlations were assessed to evaluate shared genetic background between traits. Mendelian randomization was performed to assess a causal relationship between CBP and RA and OP along with other risk factors, such as CRP. Colocalization analysis was conducted to identify shared pleiotropic regions between the examined traits. Bayesian modelling was performed to determine a potential pathway that may explain the interrelationships among these traits. Mendelian randomization analyses revealed that CRP causally predicts CBP only (β = 0.183, 95% CI = 0.077-0.290, P -value = 0.001). Horizontally pleiotropy appeared to explain the relationship between CBP and RA and OP. Through colocalization analysis, several genomic regions emerged describing common genetic influences between CBP and its proposed risk factors, including HLA-DQA1/HLA-DQB1, APOE , SOX5, and MYH7B as well as Histone 1 genes. We speculate that among other factors, CBP and its MSK comorbidities may arise from common inflammatory mechanisms. Colocalized identified genes may aid in advancing or improving the mode of treatment in patients with CBP.

Association between total cholesterol and total bone mineral density in US adults: National Health and Nutrition Examination Survey (NHANES), 2011-2018

BACKGROUND

Accumulated evidence indicates that cholesterol is offensive to bone metabolism. Therefore, we examined the real-world study among total cholesterol and total bone mineral density (BMD). We investigated the relationship between total cholesterol and total BMD among 10,039 US participants aged 20-59 years old over the period 2011-2018 from the NHANES.

METHODS

To analyze the relationship among total cholesterol and total BMD, multivariate linear regression models were used. Fitted smoothing curves, generalized additive models, and threshold effect analysis were also conducted.

RESULTS

After adjusting for additional covariates, weighted multivariable linear regression models indicated total cholesterol concentration levels exhibited a negative relationship with total BMD, particularly among participants aged 20-29 years. Concerning subgroup analysis, stratified by gender, race/ethnicity and age group, the negative correlation of total cholesterol with total BMD dwelled in both female and male as well as in whites and other races (including Hispanic and Multi-Racial), but not in non-Hispanic blacks and Mexican American. In other races, this relationship presented a nonlinear association (inflection point: 6.7 mmol/L) with a U-shaped curve. Among participants aged 40 to 49 years, this relationship also followed a nonlinear association (inflection point: 5.84 mmol/L), indicating a saturation effect. Moreover, the three types of diabetes status were found to have negative, U-shaped, and positive relationships. In participants with borderline diabetes status, the relationship of total cholesterol with total BMD was a U-shaped curve (inflection point: 4.65 mmol/L).

CONCLUSIONS

For US young adults (20-29 years old), our study revealed a negative relationship between total cholesterol and total BMD. This association followed a U-shaped curve (inflection point: 4.65 mmol/L) in borderline diabetes status participants, a saturation curve (inflection point: 5.84 mmol/L) in participants aged 40-49 years and a nonlinear curve (inflection point: 6.7 mmol/L) in other races (including Hispanic and Multi-Racial). Therefore, keeping total cholesterol concentration at a reasonable level for young adults and diabetic population might be an approach to prevent osteoporosis or osteopenia.

Identification of a potential diagnostic signature for postmenopausal osteoporosis via transcriptome analysis

Purpose: We aimed to establish the transcriptome diagnostic signature of postmenopausal osteoporosis (PMOP) to identify diagnostic biomarkers and score patient risk to prevent and treat PMOP.

Methods: Peripheral blood mononuclear cell (PBMC) expression data from PMOP patients were retrieved from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were screened using the “limma” package. The “WGCNA” package was used for a weighted gene co-expression network analysis to identify the gene modules associated with bone mineral density (BMD). Least absolute shrinkage and selection operator (LASSO) regression was used to construct a diagnostic signature, and its predictive ability was verified in the discovery cohort. The diagnostic values of potential biomarkers were evaluated by receiver operating characteristic curve (ROC) and coefficient analysis. Network pharmacology was used to predict the candidate therapeutic molecules. PBMCs from 14 postmenopausal women with normal BMD and 14 with low BMD were collected, and RNA was extracted for RT-qPCR validation.

Results: We screened 2420 differentially expressed genes (DEGs) from the pilot cohort, and WGCNA showed that the blue module was most closely related to BMD. Based on the genes in the blue module, we constructed a diagnostic signature with 15 genes, and its ability to predict the risk of osteoporosis was verified in the discovery cohort. RT-qPCR verified the expression of potential biomarkers and showed a strong correlation with BMD. The functional annotation results of the DEGs showed that the diagnostic signature might affect the occurrence and development of PMOP through multiple biological pathways. In addition, 5 candidate molecules related to diagnostic signatures were screened out.

Conclusion: Our diagnostic signature can effectively predict the risk of PMOP, with potential application for clinical decisions and drug candidate selection.

Traditional Uses, Bioactive Constituents, Biological Functions, and Safety Properties of Oviductus ranae as Functional Foods in China

Oviductus ranae is an animal-based traditional Chinese material widely used as tonics in China for hundreds of years. Various bioactive components are present in OR including proteins, amino acids, steroids, fatty acids, phospholipids, nucleosides, vitamins, hydantoins, and mineral elements. These constituents exert a myriad of biological functions such as immunomodulatory, antioxidant, antifatigue, antiaging, estrogen-like, hepatoprotective, hypolipidemic, antiosteoporotic, antidepressant, antitumor, antitussive, expectorant, anti-inflammatory, and antiasthmatic activities. Unlike other traditional Chinese crude drugs recorded in Chinese Pharmacopoeia, OR is seldom prescribed as medicine but often consumed as nutraceuticals to optimize health. In this review, the traditional uses, bioactive constituents, biological functions, and safety properties of OR as functional foods in China were summarized and discussed. It is expected that this review will provide useful information for anyone who is interested in OR.

Genetic control of estrogen-regulated transcriptional and cellular responses in mouse uterus

The uterotropic response of the uterus to 17β-estradiol (E2) is genetically controlled, with marked variation observed depending on the mouse strain studied. Previous genetic studies from our laboratory using inbred mice that are high [C57BL/6J (B6)] or low [C3H/HeJ (C3H)] responders to E2 led to the identification of quantitative trait (QT) loci associated with phenotypic variation in uterine growth and leukocyte infiltration. The mechanisms underlying differential responsiveness to E2, and the genes involved, are unknown. Therefore, we used a microarray approach to show association of distinct E2-regulated transcriptional signatures with genetically controlled high and low responses to E2 and their segregation in (C57BL/6J×C3H/HeJ) F1 hybrids. Among the 6664 E2-regulated transcripts, analysis of cellular functions of those that were strain specific indicated C3H-selective enrichment of apoptosis, consistent with a 7-fold increase in the apoptosis indicator CASP3, and a 2.4-fold decrease in the apoptosis inhibitor Naip1 (Birc1a) in C3H vs. B6 following treatment with E2. In addition, several differentially expressed transcripts reside within our previously identified QT loci, including the ERα-tethering factor Runx1, demonstrated to enhance E2-mediated transcript regulation. The level of RUNX1 in uterine epithelial cells was shown to be 3.5-fold greater in B6 compared to C3H. Our novel insights into the mechanisms underlying the genetic control of tissue sensitivity to estrogen have great potential to advance understanding of individualized effects in physiological and disease states.

Genetic influence of candidate osteoporosis genes in saudi arabian population: a pilot study

Background and Objectives. The purpose of the present study is to find the genes and SNP that influence BMD and postmenopausal Saudi women. Material and Methods. Two-hundred ethnic Saudi Arabian women with a diagnosis of postmenopausal osteoporosis were the subjects of this study. Baseline blood hematology, biochemistry, and bone panel were done. Blood was collected, and three TaqMan-MGB probes were used to analyze SNP variants in ALOX15 (rs7220870), LRP5 (C 25752205 10), and TNFRSF11B (C 11869235 10). Results. The variant of ALOX15 17p13 showed that the BMD of the spine was lower in the AA allele (P value <0.002) and fractures were highest at 50% compared to CC allele. In the TNFRSF11B gene, BMD of the hip and spine was significantly higher in the GG allele and the history of fractures was significantly higher in GG group. With regard to the LRP5 (C 25752205 10) gene, there was no significant difference between allele groups. Conclusion(s). This study shows that the genetic influence of osteoporosis in the Caucasian and Saudi Arabians population is similar. We believe that the same genetic markers that influence osteoporosis in the Caucasian race could be used for further studies in the Saudi Arabian population.

Genetic determinants of osteoporosis: common bases to cardiovascular diseases?

Osteoporosis is the most common and serious age-related skeletal disorder, characterized by a low bone mass and bone microarchitectural deterioration, with a consequent increase in bone fragility and susceptibility to spontaneous fractures, and it represents a major worldwide health care problem with important implications for health care costs, morbidity and mortality. Today is well accepted that osteoporosis is a multifactorial disorder caused by the interaction between environment and genes that singularly exert modest effects on bone mass and other aspects of bone strength and fracture risk. The individuation of genetic factors responsible for osteoporosis predisposition and development is fundamental for the disease prevention and for the setting of novel therapies, before fracture occurrence. In the last decades the interest of the Scientific Community has been concentrated in the understanding the genetic bases of this disease but with controversial and/or inconclusive results. This review tries to summarize data on the most representative osteoporosis candidate genes. Moreover, since recently osteoporosis and cardiovascular diseases have shown to share common physiopathological mechanisms, this review also provides information on the current understanding of osteoporosis and cardiovascular diseases common genetic bases.

A functional single nucleotide polymorphism in the vitamin-K-dependent gamma-glutamyl carboxylase gene (Arg325Gln) is associated with bone mineral density in elderly Japanese women

The vitamin-K-dependent gamma-glutamyl carboxylase (GGCX) carboxylates vitamin-K-dependent proteins including bone Gla protein (osteocalcin) and matrix Gla protein, which play important roles in bone metabolism. Therefore, GGCX polymorphism might explain in part individual susceptibility to osteoporosis. In the present study, polymorphisms in the exons of this gene were screened in Japanese elderly women and a non-synonymous single nucleotide polymorphisms (SNP) were found; c.8762 G>A; (Arg325Gln). When the kinetic parameters of GGCX325-Gln and GGCX325-Arg were compared in vitro, Vmax/Km was significantly higher for GGCX325-Gln (944.4+/-9.21 pmol/30 min/mg/mM FLEEL) than for GGCX325-Arg (671.9+10.79 pmol/30 min/mg/mM FLEEL) (p=0.018). Then, association study of this polymorphism with forearm bone mineral density (BMD) of Japanese postmenopausal women (n=500, age 73.6+/-5.74) was conducted. As a result, the body mass index (BMI)-adjusted Z score in the subpopulation older than 75 years (n=207) was higher in those with 325-Gln (0.650+/-0.883, mean+/-SD) than those with 325-Arg/Gln or 325-Arg (0.133+/-0.650) (p=0.0383). This is the first report to demonstrate the different activities of GGCX between the common genotypes and their association with BMD.