Polymorphisms of FDPS, LRP5, SOST and VKORC1 genes and their relation with osteoporosis in postmenopausal Romanian women

Cyclin A1 (CCNA1) inhibits osteoporosis by suppressing transforming growth factor-beta (TGF-beta) pathway in osteoblasts

BACKGROUND

Osteoporosis is a genetic disease caused by the imbalance between osteoblast-led bone formation and osteoclast-induced bone resorption. However, further gene-related pathogenesis remains to be elucidated.

METHODS

The aberrant expressed genes in osteoporosis was identified by analyzing the microarray profile GSE100609. Serum samples of patients with osteoporosis and normal group were collected, and the mRNA expression of candidate genes was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The mouse cranial osteoblast MC3T3-E1 cells were treated with dexamethasone (DEX) to mimic osteoporosis in vitro. Alizarin Red staining and alkaline phosphatase (ALP) staining methods were combined to measure matrix mineralization deposition of MC3T3-E1 cells. Meanwhile, the expression of osteogenesis related genes including alkaline phosphatase (ALP), osteocalcin (OCN), osteopontin (OPN), Osterix, and bone morphogenetic protein 2 (BMP2) were evaluated by qRT-PCR and western blotting methods. Then the effects of candidate genes on regulating impede bone loss caused by ovariectomy (OVX) in mice were studied.

RESULTS

Cyclin A1 (CCNA1) was found to be significantly upregulated in serum of osteoporosis patients and the osteoporosis model cells, which was in line with the bioinformatic analysis. The osteogenic differentiation ability of MC3T3-E1 cells was inhibited by DEX treatment, which was manifested by decreased Alizarin Red staining intensity, ALP staining intensity, and expression levels of ALP, OCN, OPN, Osterix, and BMP2. The effects of CCNA1 inhibition on regulating osteogenesis were opposite to that of DEX. Then, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis demonstrated that genes negatively associated with CCNA1 were enriched in the TGF-beta signaling pathway. Inhibitor of TGF-beta signaling pathway partly reversed osteogenesis induced by suppressed CCNA1. Furthermore, suppressed CCNA1 relieved bone mass of OVX mice in vivo.

CONCLUSION

Downregulation of CCNA1 could activate TGF-beta signaling pathway and promote bone formation, thus playing a role in treatment of osteoporosis.

Farnesyl diphosphate synthase promotes cell proliferation by regulating gene expression and alternative splicing profiles in HeLa cells

Farnesyl diphosphate synthase (FDPS), an essential enzyme involved in the mevalonate pathway, is implicated in various diseases, including multiple types of cancer. As an RNA-binding protein (RBP), FDPS is also involved in transcriptional and post-transcriptional regulation. However, to the best of our knowledge, transcriptome-wide targets of FDPS still remain unknown. In the present study, FDPS expression patterns in pan-cancer were analyzed. In addition, it was investigated how FDPS overexpression (FDPS-OE) regulates the transcriptome in HeLa cells. FDPS-OE increased the proliferation rate in HeLa cells by MTT assay. Using transcriptome-wide high throughput sequencing and bioinformatics analysis, it was found that FDPS upregulated the expression levels of genes enriched in cell proliferation and extracellular matrix organization, including the laminin subunit γ2, interferon-induced proteins with tetratricopeptide repeats 2 and matrix metallopeptidase 19 genes. According to alternative splicing (AS) analysis, FDPS modulated the splicing patterns of the bone morphogenic protein 1, semaphorin 4D, annexin A2 and sirtuin 2 genes, which are enriched in the cell cycle and DNA repair, and are related to cell proliferation. To corroborate the FDPS-regulated transcriptome findings, FDPS was overexpressed in human osteosarcoma cells. Differentially expressed genes and regulated AS genes in the cells were both validated by reverse transcription-quantitative PCR. The results suggested that, as an emerging RBP, FDPS may serve an important role in transcriptome profiles by altering gene expression and regulating AS. FDPS also affected the cell proliferation rate. These findings broaden the understanding of the molecular functions of FDPS, and the potential of FDPS as a target in therapy should be investigated.

Safety of Electrotherapy Treatment in Patients with Knee Osteoarthritis and Cardiac Diseases

OBJECTIVE: To assess the safety of electrotherapy applied in the knee area in patients with known atrial arrhythmias or ischemic heart disease, as it is not known whether this treatment induces or aggravates arrhythmias during or immediately after therapy. MATERIAL AND METHODS: The analytical and transversal study involved 46 patients with degenerative knee osteoarthritis (OA), with or without cardiac diseases, from the Clinical Rehabilitation Hospital inpatient center, Cluj-Napoca, Romania. All patients underwent a 10-day physical therapy program for knee OA (electrotherapy, massage and kinesiotherapy). Heart rate and the total number of ventricular and supraventricular extrasystoles were evaluated before and after treatment, by 24 h Holter ECG monitoring. RESULTS: There was no significant increase in heart rate or in the number of ventricular or supraventricular extrasystoles before or after electrotherapy treatment, regardless of the positive or negative history of arrhythmia or ischemic heart disease (all p > 0.05). Mean values during day 1 were: 35.15 (95% CI [9.60−60.75]) for ventricular ones extrasystoles and 91.7 (95% CI [51.69−131.7]) for supraventricular ones, which during day 2 were 38.09 (95% CI [3.68−72.50]), 110.48 (95% CI [48.59−172.36]), respectively. CONCLUSION: One of the most important things to consider when dealing with an OA patient is that they are most likely older than 65 years, which increases the chance of having a cardiac disease. This raises the need for viable interventions regarding the management of this disease in patients that probably have multiple comorbidities, and where pharmacological and surgical management are not possible, limited or have multiple side effects. Electrotherapy used for treating knee OA did not cause a significant increase in heart rate or number of ventricular and supraventricular extrasystoles in this category of patients.

Sclerostin Suppression Facilitates Uveal Melanoma Progression Through Activating Wnt/β-Catenin Signaling Via Binding to Membrane Receptors LRP5/LRP6

Objective

Uveal melanoma (UM) is the most frequent primary eye cancer in adults with a 50% mortality rate. Characterizing the fundamental signaling pathways that drive UM is of importance for the development of targeted therapy. This study aims to probe the impact of sclerostin (SOST) on malignant progression of UM and regulation of Wnt/β-catenin signaling.

Methods

Epithelial-type (n=20) and spindle-type (n=16) UM tissues were collected for immunohistochemical staining of SOST, Wnt-1, and β-catenin expressions. SOST was silenced in three UM cell lines (primary spindle-type OCM-1 cells, metastatic epithelial Mum-2B cells, and metastatic spindle-type Mum-2C cells) through transfecting specific siRNA. RT-qPCR and Western blot were presented for examining the levels of SOST, and markers in Wnt/β-catenin signaling. Flow cytometry, MTT, EdU, transwell, and tube formation assays were conducted, respectively. By implanting BALB/c nude murine models in situ, the function of SOST on tumor growth was investigated, followed by immunofluorescence double staining of SOST and LRP5/6.

Results

Low SOST expression as well as high Wnt-1 and β-catenin expressions were found in epithelial-type (high malignancy) than spindle-type (low malignancy) UM tissues. Silencing SOST activated the markers in Wnt/β-catenin signaling as well as accelerated cell cycle progression, migration, invasion, angiogenesis, and reduced apoptosis in UM cells. In situ tumor formation in murine eyes showed that SOST knockdown promoted tumor growth. Moreover, SOST interacted with LRP5/LRP6.

Conclusion

SOST silencing may facilitate the malignant progression of UM cells through activating Wnt/β-catenin signaling. Mechanistically, SOST may exert this function by interacting with LRP5/LRP6 membrane receptors.

Clinical and Genetic Features of Chinese Adult Patients With Chronic Non-Bacterial Osteomyelitis: A Single Center Report

Objectives

Chronic non-bacterial osteomyelitis (CNO) is a rare polygenic autoinflammatory bone disease. We aimed to characterize the clinical manifestations and gene variants of Chinese adult patients with CNO.

Methods

By reviewing data of all CNO patients being diagnosed and followed up at the Center for Adult Autoinflammation Diseases, Department of Rheumatology, Peking Union Medical College Hospital, clinical and genetic features of these patients were evaluated and concluded.

Results

The median age of disease onset was 19 (6-64) years old, and adult-onset was observed in 6 (60%) patients. The mean time of diagnosis delay was 92 ± 78 months. The common symptoms were bone pain (10, 100%), fever (9, 90%), and arthritis (6, 60%). In total, there were 54 skeletal lesions, and each patient had no less than 2 lesions. The most frequently affected sites included lower limbs (20.5%), mandible, vertebrae and pelvis (17.5%, separately). Variants of 4 genes were detected in our study including COL1A1, PSTPIP1, LRP5 and CLCN7. In seven patients who were treated with combination therapy containing tumor necrosis factor (TNF) α inhibitors, five (55.6%) had a complete response and 2 (44.4%) had a partial response.

Conclusion

This is the first and largest case series of CNO in the Chinese adult patients. Four novel genetic mutations potentially associated with CNO were identified. Notably, CNO should be considered in the differential diagnosis of adult patients with long disease course and recurrent multifocal osteomyelitis of unknown cause, and these patients might benefit from combination therapy containing TNFα inhibitors.

Influence of melatonin on systemic inflammatory status and bone histopathological modifications in female rats with surgically induced menopause

Background. Melatonin, N-acetyl-5-methoxy-tryptamine is the major secretion product of the pineal gland with important anti-inflammatory and antioxidant properties, also being an im-portant marker of bone remodelling associated with menopause. Objectives. The aim of our study was to evaluate the effect of the co-administration of melatonin and estrogen on systemic inflammatory status and bone histopathological modifications in surgically induced menopau-sal female rats. Materials and methods. The study was performed on a number of 40 female rats, Wistar breed, which underwent bilateral surgical ovariectomy. Within 14 days postoperative, hormone replacement therapy with estrogen or estrogen with melatonin was initiated, in differ-ent doses. The treatment was administered for 12 consecutive weeks. At the end of the treatment we measured the serum levels of IL-6 and TNF-α. The femoral bones were harvested after sacri-ficing the animals and the thickness of the cortical bones was measured and histologically ana-lysed. Results. Serum values of inflammatory markers were negatively correlated with melatonin ad-ministration, the differences being more important at higher doses of melatonin (for both IL-6 and TNF-α the difference between group E_2M with estrogen substitution and melatonin in double dose and control group W, without hormone replacement, was highly statistically signif-icant with p <0.0001). Bone diameters improved in the case of female rats that received hormone replacement with estrogen and higher dose of melatonin (p = 0.0004 between group E_2M, with hormone replacement and group W, control group). Conclusions. Melatonin improved inflam-matory status and bone histopathological changes in ovariectomized female rats. Keywords: melatonin, estrogen replacement therapy, inflammation, low bone density

Genotypic Analyses of the Sclerostin rs851056 and Dickkopf rs1569198 Polymorphisms in Mexican-Mestizo Postmenopausal Osteoporosis: A Case-Control Study

Background: The Wnt/β catenin pathway promotes bone mineralization stimulating proliferation, differentiation, and survival of osteoblasts; it also inhibits osteoclast differentiation and osteocyte activity. Sclerostin (SOST) and Dickkopf 1 (DKK1) are Wnt/β catenin pathway inhibitors. Genetic variability in the expression of SOST and DKK1 might be involved in the development of postmenopausal osteoporosis (OP). Aim: To determine whether the SOST rs851056 and DKK1 rs1569198 polymorphisms are associated with OP in Mexican-Mestizo postmenopausal women. Materials and Methods: Two hundred and eighty Mexican-Mestizo postmenopausal women were assessed for their bone mineral density by dual-energy X-ray absorptiometry (DXA). Patients were classified as OP or non-OP. Genomic DNA was extracted from peripheral blood leukocytes. Genetic polymorphisms were analyzed by quantitative polymerase chain reaction using TaqMan probes. Results: The frequency of OP was 40% among the study population. Osteoporotic patients were older (p < 0.001), had a higher frequency of smoking (p = 0.01), and lower body mass index (p < 0.001) compared with the non-osteoporotic patients. The genotypic frequencies of the rs851056 locus of the SOST gene were GG 19%, GC 45%, and CC 35%, whereas the genotypic frequencies of the rs1569198 locus of the DKK1 gene were GG 15%, GA 40%, and AA 44%. In relation to rs851056 locus of the SOST gene, no differences were observed between the OP and non-OP cohorts in the frequencies of the GC polymorphism (48.7% vs. 43.1%). Similarly, analyses of the DKK1 rs1569198 does not demonstrate differences in the GA genotypic frequencies between the OP and non-OP cohorts (42.5% vs. 38.9%). Conclusion: Polymorphisms SOST rs851056 and DKK1 rs1569198 polymorphisms are not associated with OP in Mexican-Mestizo postmenopausal women.

Analysis of Molecular Mechanism of Erxian Decoction in Treating Osteoporosis Based on Formula Optimization Model

Osteoporosis (OP) is a highly prevalent orthopedic condition in postmenopausal women and the elderly. Currently, OP treatments mainly include bisphosphonates, receptor activator of nuclear factor kappa-B ligand (RANKL) antibody therapy, selective estrogen receptor modulators, teriparatide (PTH1-34), and menopausal hormone therapy. However, increasing evidence has indicated these treatments may exert serious side effects. In recent years, Traditional Chinese Medicine (TCM) has become popular for treating orthopedic disorders. Erxian Decoction (EXD) is widely used for the clinical treatment of OP, but its underlying molecular mechanisms are unclear thanks to its multiple components and multiple target features. In this research, we designed a network pharmacology method, which used a novel node importance calculation model to identify critical response networks (CRNs) and effective proteins. Based on these proteins, a target coverage contribution (TCC) model was designed to infer a core active component group (CACG). This approach decoded the mechanisms underpinning EXD's role in OP therapy. Our data indicated that the drug response network mediated by the CACG effectively retained information of the component-target (C-T) network of pathogenic genes. Functional pathway enrichment analysis showed that EXD exerted therapeutic effects toward OP by targeting PI3K-Akt signaling (hsa04151), calcium signaling (hsa04020), apoptosis (hsa04210), estrogen signaling (hsa04915), and osteoclast differentiation (hsa04380) via JNK, AKT, and ERK. Our method furnishes a feasible methodological strategy for formula optimization and mechanism analysis and also supplies a reference scheme for the secondary development of the TCM formula.

Associations of LRP5 Gene With Bone Mineral Density, Bone Turnover Markers, and Fractures in the Elderly With Osteoporosis

Objective: The study aimed to explore the associations of rs4988300 and rs634008 in the low-density lipoprotein receptor-related protein 5 (LRP5) gene with bone mineral density (BMD), bone turnover markers (BTM), and fractures in elderly patients with osteoporosis (OP). Methods: Our study included 328 unrelated OP patients with or without fractures. Genomic DNA was extracted for genotyping. BTM levels were assessed by electrochemiluminescence (ECL). Dual-energy X-ray absorptiometry (DXA) was employed to measure BMD in the lumbar spine (LS) and proximal femur. Basic features between the OP and fracture groups were analyzed using the t-test. The Chi-square test was performed to analyze the differences in allele and genotype frequencies. The associations of single-nucleotide polymorphisms (SNPs) with BMD and BTM in the subgroups were investigated by the analysis of covariance (ANCOVA) adjusted for confounding factors. Results: In both females and males, individuals with fractures exhibited higher BTM levels and lower BMD values than those with OP (P < 0.05). The allele and genotype frequencies of rs4988300 in the subgroups were significantly different (P < 0.05). In both females and males suffering from OP, participants with rs4988300 GG or rs634008 TT presented lower procollagen I N-terminal propeptide (PINP) levels (P < 0.05). Women with OP carrying rs4988300 GG exhibited lower BMD values at FN and TH (P < 0.05). In both females and males with fractures, individuals carrying rs4988300 GG genotype or rs634008 TT genotype exhibited lower PINP levels and BMD values at FN and TH than those with other genotypes (P < 0.05). Conclusions: Rs4988300 and rs634008 polymorphisms in the LRP5 gene are associated with bone phenotypes in the elderly with OP or fractures.