285 research outputs found

    Association of bone morphogenetic protein-2 gene polymorphisms with susceptibility to ossification of the posterior longitudinal ligament of the spine and its severity in Chinese patients

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    A case–control study was conducted to examine the association between two single nucleotide polymorphisms (SNPs) in exon 2 of the bone morphogenetic protein-2 gene (BMP-2) and ossification of the posterior longitudinal ligament (OPLL), and to investigate whether SNPs of the Ser37Ala (T/G) and the Ser87Ser (A/G) in the BMP-2 gene are associated with genetic susceptibility to OPLL and its severity in Chinese subjects. The Ser87Ser (A/G) SNP has been implicated in bone mineral density (BMD) and increases the risk of OA in women. The Ser37Ala (T/G) SNP is associated with BMD and the rate of bone loss in osteoporosis and osteoporosis fractures. A total of 57 OPLL patients and 135 non-OPLL controls were studied. Radiographs of the cervical spine were analyzed to determine the presence and the severity of OPLL. The association of two SNPs with the occurrence and the extent of OPLL were statistically evaluated. There was a significant association between the Ser37Ala (T/G) polymorphism and the occurrence of OPLL in the cervical spine. However, no significant association was found between the Ser37Ala (T/G) polymorphism and the more number of ossified cervical vertebrae in OPLL patients. There was a significant association between the Ser87Ser (A/G) polymorphism and the more number of ossified cervical vertebrae in OPLL patients. However, there was no statistical difference between the Ser87Ser (A/G) SNP and the occurrence of OPLL in the cervical spine. In addition, the Ser87Ser (A/G) polymorphism in male patients and in female patients showed no statistical difference between cases and controls. The present results demonstrate that BMP-2 Gene is not only a factor associated with the occurrence of OPLL, but also a factor related to more extensive OPLL. The “G” allele in the Ser37Ala (T/G) polymorphism is associated with the occurrence of OPLL, but not more extensive OPLL in the cervical spine. The “G” allele in the Ser87Ser (A/G) polymorphism promotes the extent of OPLL, whereas the “A” allele in the Ser87Ser (A/G) polymorphism restricts ectopic ossification in the cervical spine at least in Chinese subjects

    Comparison of plasma endothelin levels between osteoporotic, osteopenic and normal subjects

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    BACKGROUND: It has been demonstrated that endothelins (ET) have significant roles in bone remodeling, metabolism and physiopathology of several bone diseases. We aimed to investigate if there was any difference between the plasma ET levels of osteoporotic patients and normals. METHODS: 86 patients (70 women and 16 men) with a mean age of 62.6 (ranges: 51–90) years were included in this study. Patients were divided into groups of osteoporosis, osteopenia and normal regarding reported T scores of DEXA evaluation according to the suggestions of World Health Organization. According to these criteria 19, 43 and 24 were normal, osteopenic and osteoporotic respectively. Then total plasma level of ET was measured in all patients with monoclonal antibody based sandwich immunoassay (EIA) method. One-way analysis of variance test was used to compare endothelin values between normals, osteopenics and osteoporotics. RESULTS: Endothelin total plasma level in patients was a mean of 98.36 ± 63.96, 100.92 ± 47.2 and 99.56 ± 56.6 pg/ml in osteoporotic, osteopenic and normal groups respectively. The difference between groups was not significant (p > 0.05). CONCLUSION: No significant differences in plasma ET levels among three groups of study participants could be detected in this study

    Airway smooth muscle relaxation results from a reduction in the frequency of Ca(2+ )oscillations induced by a cAMP-mediated inhibition of the IP(3 )receptor

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    BACKGROUND: It has been shown that the contractile state of airway smooth muscle cells (SMCs) in response to agonists is determined by the frequency of Ca(2+ )oscillations occurring within the SMCs. Therefore, we hypothesized that the relaxation of airway SMCs induced by agents that increase cAMP results from the down-regulation or slowing of the frequency of the Ca(2+ )oscillations. METHODS: The effects of isoproterenol (ISO), forskolin (FSK) and 8-bromo-cAMP on the relaxation and Ca(2+ )signaling of airway SMCs contracted with methacholine (MCh) was investigated in murine lung slices with phase-contrast and laser scanning microscopy. RESULTS: All three cAMP-elevating agents simultaneously induced a reduction in the frequency of Ca(2+ )oscillations within the SMCs and the relaxation of contracted airways. The decrease in the Ca(2+ )oscillation frequency correlated with the extent of airway relaxation and was concentration-dependent. The mechanism by which cAMP reduced the frequency of the Ca(2+ )oscillations was investigated. Elevated cAMP did not affect the re-filling rate of the internal Ca(2+ )stores after emptying by repetitive exposure to 20 mM caffeine. Neither did elevated cAMP limit the Ca(2+ )available to stimulate contraction because an elevation of intracellular Ca(2+ )concentration induced by exposure to a Ca(2+ )ionophore (ionomycin) or by photolysis of caged-Ca(2+ )did not reverse the effect of cAMP. Similar results were obtained with iberiotoxin, a blocker of Ca(2+)-activated K(+ )channels, which would be expected to increase Ca(2+ )influx and contraction. By contrast, the photolysis of caged-IP(3 )in the presence of agonist, to further elevate the intracellular IP(3 )concentration, reversed the slowing of the frequency of the Ca(2+ )oscillations and relaxation of the airway induced by FSK. This result implied that the sensitivity of the IP(3)R to IP(3 )was reduced by FSK and this was supported by the reduced ability of IP(3 )to release Ca(2+ )in SMCs in the presence of FSK. CONCLUSION: These results indicate that the relaxant effect of cAMP-elevating agents on airway SMCs is achieved by decreasing the Ca(2+ )oscillation frequency by reducing internal Ca(2+ )release through IP(3 )receptors

    Rare SLC13A1 variants associate with intervertebral disc disorder highlighting role of sulfate in disc pathology

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    Publisher Copyright: © 2022, The Author(s).Back pain is a common and debilitating disorder with largely unknown underlying biology. Here we report a genome-wide association study of back pain using diagnoses assigned in clinical practice; dorsalgia (119,100 cases, 909,847 controls) and intervertebral disc disorder (IDD) (58,854 cases, 922,958 controls). We identify 41 variants at 33 loci. The most significant association (ORIDD = 0.92, P = 1.6 × 10−39; ORdorsalgia = 0.92, P = 7.2 × 10−15) is with a 3’UTR variant (rs1871452-T) in CHST3, encoding a sulfotransferase enzyme expressed in intervertebral discs. The largest effects on IDD are conferred by rare (MAF = 0.07 − 0.32%) loss-of-function (LoF) variants in SLC13A1, encoding a sodium-sulfate co-transporter (LoF burden OR = 1.44, P = 3.1 × 10−11); variants that also associate with reduced serum sulfate. Genes implicated by this study are involved in cartilage and bone biology, as well as neurological and inflammatory processes.Peer reviewe

    PDGF in gliomas: more than just a growth factor?

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    Platelet-derived growth factor B (PDGF-B) is a growth factor promoting and regulating cell migration, proliferation, and differentiation, involved in both developmental processes and in maintaining tissue homeostasis under strict regulation. What are the implications of prolonged or uncontrolled growth factor signaling in vivo, and when does a growth factor such as PDGF-B become an oncogene? Under experimental conditions, PDGF-B induces proliferation and causes tumor induction. It is not known whether these tumors are strictly a PDGF-B-driven proliferation of cells or associated with secondary genetic events such as acquired mutations or methylation-mediated gene silencing promoting neoplasia. If PDGF-B-driven tumorigenesis was only cellular proliferation, associated changes in gene expression would thus be correlated with proliferation and not associated with secondary events involved in tumorigenesis and neoplastic transformation such as cycle delay, DNA damage response, and cell death. Changes in gene expression might be expected to be reversible, as is PDGF-B-driven proliferation under normal circumstances. Since PDGF signaling is involved in oligodendrocyte progenitor cell differentiation and maintenance, it is likely that PDGF-B stimulates proliferation of a pool of cells with that phenotype, and inhibition of PDGF-B signaling would result in reduced expression of oligodendrocyte-associated genes. More importantly, inhibition of PDGF signaling would be expected to result in reversion of genes induced by PDGF-B accompanied by a decrease in proliferation. However, if PDGF-B-driven tumorigenesis is more than simply a proliferation of cells, inhibition of PDGF signaling may not reverse gene expression or halt proliferation. These fundamental questions concerning PDGF-B as a potential oncogene have not been resolved
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