Association between polymorphisms in tumor necrosis factor (TNF) and TNF receptor genes and circulating TNF, soluble TNF receptor levels, and bone mineral density in postmenopausal Korean women

Causal effect of polyunsaturated fatty acids on bone mineral density and fracture

Background

Polyunsaturated fatty acids (PUFAs) are closely related to osteoporosis. To test their causal relationship, we conducted a Mendelian randomization (MR) analysis.

Methods

We analyzed the causal relationship between four PUFAs measures, n-3 PUFAs (n-3), n-6 PUFAs (n-6), the ratio of n-3 PUFAs to total fatty acids (n-3 pct), and the ratio of n-6 PUFAs to n-3 PUFAs (n-6 to n-3), and five measures of osteoporosis, including estimated bone mineral density (eBMD), forearm (FA) BMD, femoral neck (FN) BMD, lumbar spine (LS) BMD, and fracture, using two-sample MR analysis. In order to verify the direct effect between PUFAs and BMD, we chose interleukin-6 (IL-6), tumor necrosis factor-β (TNF-β), and bone morphogenetic proteins 7 (BMP-7), three markers or cytokines strongly related to BMD, as possible confounding factors, and analyzed the possible causal relationships between them and PUFAs or BMD by MR. Inverse variance weighting (IVW), MR-Egger, weighted and weighted median were conducted. MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO) and MR-Egger regression methods were used to evaluate the potential pleiotropy of instrumental variables (IVs) and outliers were identified by MR-PRESSO. Cochran's Q statistic was used to detect the heterogeneity among IVs. Leave-one-out sensitivity analysis was used to find SNPs that have a significant impact on the results. All results were corrected by the Bonferroni correction.

Results

The IVW results showed that n-3 PUFAs (OR = 1.030, 95% CI: 1.013, 1.047, P = 0.001) and n-6 PUFAs (OR = 1.053, 95% CI: 1.034, 1.072, P < 0.001) were positively correlated with eBMD, while n-6 to n-3 (OR = 0.947, 95% CI: 0.924, 0.970, P < 0.001) were negatively correlated with eBMD. These casual relationships still existed after Bonferroni correction. There were positive effects of n-3 PUFAs on FA BMD (OR = 1.090, 95% CI: 1.011, 1.176, P = 0.025) and LS BMD (OR = 1.056, 95% CI: 1.011, 1.104, P = 0.014), n-3 pct on eBMD (OR = 1.028, 95% CI: 1.002, 1.055, P = 0.035) and FA BMD (OR = 1.090, 95% CI: 1.011, 1.174, P = 0.025), n-6 to n-3 on LS BMD (OR = 1.071, 95% CI: 1.021, 1.124, P = 0.005); negative effects of n-3 pct on fracture (OR = 0.953, 95% CI: 0.918, 0.988, P = 0.009) and n-6 to n-3 on FA BMD (OR = 0.910, 95% CI: 0.837, 0.988, P = 0.025). However, these causal effects all disappeared after Bonferroni correction (all P > 0.0025). None of IL-6, TNF-β, and BMP-7 had a causal effect on PUFA and BMD simultaneously (all P > 0.05).

Conclusion

Evidence from this MR study supports the genetically predicted causal effects of n-3, n-6, n-3 pct, and n-6 to n-3 on eBMD. In addition, n-3 not only associate with FA BMD and LS BMD through its own level and n-6 to n-3, but also link to fracture through n-3 pct.

TNFRSF1B and TNF variants are associated with differences in soluble TNF receptors' levels in patients with severe COVID-19

BACKGROUND

The impact of genetic variants in the expression of TNF-α and its receptors in COVID-19 severity has not been previously explored. We evaluated the association of TNF (rs1800629 and rs361525), TNFRSF1A (rs767455 and rs1800693), and TNFRSF1B (rs1061622 and rs3397) variants with COVID-19 severity, assessed as invasive mechanical ventilation (IMV) requirement, and the plasma levels of soluble TNF-α, TNFR1, and TNFR2 in patients with severe COVID-19.

METHODS

The genetic study included 1,353 patients. Taqman assays assessed the genetic variants. ELISA determined the soluble TNF, TNFR1, and TNFR2 in plasma samples from 334 patients.

RESULTS

Patients carrying TT (TNFRSF1B rs3397) exhibited lower PaO2/FiO2 levels than those with CT+CC genotypes. Differences in plasma levels of TNFR1 and TNFR2 were observed according to the genotype of TNFRSF1B rs1061622, TNF rs1800629, and rs361525. According to the studied genetic variants, there were no differences in the soluble TNF-α levels. Higher soluble TNFR1 and TNFR2 levels were detected in patients with COVID-19 requiring IMV.

CONCLUSION

Genetic variants in TNF and TNFRSFB1 influence the plasma levels of soluble TNFR1 and TNFR2, implicated in the COVID-19 severity.

Ovariectomy Activates Chronic Low-Grade Inflammation Mediated by Memory T Cells, Which Promotes Osteoporosis in Mice

The loss of estrogen (E₂ ) initiates a rapid phase of bone loss leading to osteoporosis in one-half of postmenopausal women, but the mechanism is not fully understood. Here, we show for the first time how loss of E₂ activates low-grade inflammation to promote the acute phase of bone catabolic activity in ovariectomized (OVX) mice. E₂ regulates the abundance of dendritic cells (DCs) that express IL-7 and IL-15 by inducing the Fas ligand (FasL) and apoptosis of the DC. In the absence of E₂ , DCs become long-lived, leading to increased IL-7 and IL-15. We find that IL-7 and IL-15 together, but not alone, induced antigen-independent production of IL-17A and TNFα in a subset of memory T cells (T_MEM ). OVX of mice with T-cell-specific ablation of IL15RA showed no IL-17A and TNFα expression, and no increase in bone resorption or bone loss, confirming the role of IL-15 in activating the T_MEM and the need for inflammation. Our results provide a new mechanism by which E₂ regulates the immune system, and how menopause leads to osteoporosis. The low-grade inflammation is likely to cause or contribute to other comorbidities observed postmenopause. © 2020 American Society for Bone and Mineral Research.

The associations of TNF-α gene polymorphisms with bone mineral density and risk of osteoporosis: A meta-analysis

OBJECTIVE

Fracture is a common consequence of osteoporosis and is associated with high morbidity and mortality. Recently, increasing evidence has suggested that polymorphisms in tumor necrosis factor-α (TNF-α) gene were associated with osteoporosis risk and bone mineral density (BMD), but results remain conflicting. We herein performed a meta-analysis based on evidence currently available from the literature to make a more precise estimation of these relationships.

METHODS

The PubMed, EMBASE, Cochrane Library, CNKI (China National Knowledge Infrastructure) and Wan Fang databases were searched for eligible studies. Articles meeting the inclusion criteria were comprehensively reviewed and all available data were accumulated. The pooled odds ratios (ORs) or mean differences (MDs) and corresponding 95% confidence intervals (CIs) were applied to assess the strength of the relationships.

RESULTS

A total of 15 studies involving 5273 subjects were included in our meta-analysis. The GG genotype of TNF-α G308A was associated with an increased risk of osteoporosis under a mutant model (GG vs GA+AA: OR = 0.63, 95% CI: 0.51-0.77, P < 0.0001, I²  = 31%). Additionally, we also observed a significant association between G308A polymorphism and BMD of lumbar spine (AA vs GG: P = 0.01, I²  = 53%). However, TNF-α T1031C, C857T and C863A polymorphisms had no obvious impacts on osteoporosis risk.

CONCLUSIONS

The present meta-analysis demonstrated that TNF-α G308A polymorphism may act as a potential candidate biomarker for screening, diagnosis, and treatment of osteoporosis, which will help improve individualized therapy of osteoporosis patients in clinics.

TNFα -857 C/T and TNFR2 +587 T/G polymorphisms are associated with cystic fibrosis in Iranian patients

Identification of modifier genes influencing phenotype of cystic fibrosis (CF) patients has become a challenge in CF pathophysiology, prognostic estimations and development of new therapeutic strategies. The aim of this study was to explore the association between four genetic polymorphisms of three modifier genes with CF, by comparing their alleles, genotypes and haplotype frequencies in patients and controls. In this favor, two regulatory polymorphic loci in TNFα promoter (-857C/T, rs1799724 and -238A/G, rs361525) and two functional polymorphic loci in TNFR1 (+36A/G, rs767455) and TNFR2 (+587T/G, rs1061622) were genotyped in 70 patients and 79 controls, using PCR-RFLP. Clinical pulmonary data were also recorded from all studied patients. Results indicated that an association was observed between both T allele and CT/TT genotypes of TNFα (P = 0.0005, OR = 7.06, 95% CI = 3.71-13.45) with CF under dominant model of inheritance. GG genotype of TNFR2 +587 (P = 0.0005, OR = 4.92, 95%CI = 2.34-10.34) was significantly associated with CF using recessive model. Consistently, more severe pulmonary disorder was found for patients carrying either T dominant allele of TNFα -857 or GG genotype of TNFR2 +587 polymorphic sites. Despite an association of A-T and G-T haplotypes with CF, no significant association was found between these haplotypes and clinical parameters of CF. Overall, TNFα -857 T allele and GG genotype of TNFR2 +587 were more frequent in CF patients compared to healthy controls and hence, they showed an association with CF and severe pulmonary phenotype in Iranian patients.

Genetic Variability of Tumor Necrosis Factor Receptors Type I and II in Lymphoproliferative Diseases in the Serbian Population –

TNF-alpha and LT-alpha are involved in the pathogenesis of established lymphoproliferative diseases. Both molecules bind to TNFRI and TNFRII. TNFRI is the major mediator of the TNF pro-apoptotic and proliferative effects and TNFRII might enhance these effects. TNF receptors I and II are normally present on hematopoetic cells. TNFR II is characteristic only on immune cells, especially on peripheral leukocytes. Neoplastic B cells and activated B lymphocytes have increased expression of surface TNFR I. In this study, we have analyzed polymorphisms in the TNFRI gene (TNFRI+36A/G SNP) and polymorphism in the TNFRII gene (TNFRII + 676 T/G). All these polymorphisms were studied in patients with chronic lymphocytic leukemia (CLL), patients with non-Hodkin’s lymphoma (NHL) and in healthy controls. The present study was undertaken to investigate the genetic association of these polymorphisms with lymproproliferative disease development.

A total of 68 patients (49-CLL, 19-HNL) were diagnosed at the Clinic of Hematology, Clinical centre Niš, Serbia, using clinical findings and conventional morphological, cytochemical and immunological tests. Genomic DNA was isolated from isolated lymphocytes by proteinase K/phenol/chloroform method, and genotyped for TNFR I (A36G) and TNFR II (T676G) using the PCR-RFLP method.

No significant differences in allele frequencies of TNFR1 polymorphism were found between the patients with lymphoproliferative disease and healthy individuals. In a group of healthy individuals, the study has revealed for the first time significantly higher TNFRI G/G genotype compared to the patients with lymphoproliferative disease (χ22 = 5.66; p = 0.017). Also, we reported the implication of TNFRII T allele in NHL pathogenesis, respectively (χ22 = 10.77; p = 0.001; Mantel-Haenszel: χ22 = 10.64; p = 0.0011).

Our data showed that TNFRII T676G polymorphisms have an important role in NHL pathogenesis but not in CLL patients. A/A polymorphism in TNFRI was not associated with CLL and NHL patients in the Serbian population. Investigated polymorphisms on TNFR genes in leukemic cells of CLL and NHL patients have not showed a correlation with increased proliferation of B lymphocytes and increased expression of TNF R II on B CLL lymphocytes.

TNF-α and IL10 gene polymorphisms in women with postmenopausal osteoporosis

OBJECTIVE

Postmenopausal osteoporosis is a common disorder characterized by decreased bone mineral density (BMD). Proinflammatory cytokines are among the significant factors involved in bone turnover. They are the stimulants of bone resorption, acting directly on osteoclasts and osteoclast precursors. In this study, we examined the TNF-α (-308G>A) (rs1800629) and IL10 (-1082G>A) (rs1800896), (-592C>A) (rs1800872) polymorphisms in postmenopausal women with BMD T-scores less than and greater than or equal to -2.5 SD.

STUDY DESIGN

This study included 224 postmenopausal women with BMD T-scores lower than -2.5 SD (mean: -3.02±0.53) and 238 postmenopausal women with BMD T-scores -2.5 SD and greater (mean: -1.33±0.51).

RESULTS

There was a decrease in the frequency of IL10 1082 G allele carriers (GG and GA genotypes) in women with T-scores below -2.5 SD (GG+GA vs AA: OR=0.65, 95% CI=0.44-0.97, p=0.037). With regard to the TNF-α -308 G>A polymorphism, in the women with T-scores below -2.5 SD, the increased frequency of GG homozygotes and G allele carriers was detected (AA+GA vs GG: OR=0.54, 95% CI=0.35-0.82, p=0.004).

CONCLUSIONS

The results of our study suggest an association between TNF-α -308G>A and IL10 -1082G>A polymorphisms and postmenopausal osteoporosis.

Cannabinoid receptor gene polymorphisms and bone mineral density in Korean postmenopausal women

OBJECTIVE

We investigated the association between single nucleotide polymorphisms in cannabinoid receptor (CNR) genes and bone mineral density (BMD) in Korean postmenopausal women.

METHODS

Seven polymorphisms (rs2023239, rs806379, rs12720071, rs1049353, rs806368, rs2180619, and rs7766029) in the cannabinoid receptor type 1 (CNR1) gene and 16 polymorphisms (rs2501432, rs2502992, rs2501431, rs3003336, rs4649124, rs2502993, rs2229579, rs2229580, rs2229581, rs2229583, rs2229584, rs2229585, rs2229586, rs4237, rs7530595, and rs16828926) in the cannabinoid receptor type 2 (CNR2) gene were analyzed in 405 Korean postmenopausal women. Serum levels of bone turnover markers, osteoprotegerin (OPG), and soluble receptor activator of nuclear factor-κB ligand (sRANKL) were measured, and BMD at the lumbar spine and femoral neck was examined.

RESULTS

The CNR2 rs2501431, rs3003336, rs2229579, and rs4237 polymorphisms in CNR genes were associated with lumbar spine BMD. Women with the AA genotype of rs3003336 and rs4237 polymorphisms had significantly lower lumbar spine BMD compared with women with the non-AA genotype. Lumbar spine BMD in women with the TT genotype of CNR2 rs2501431 and rs2229579 polymorphisms was significantly lower than that in women with the non-TT genotype. Significantly higher odds for osteoporosis of the lumbar spine and/or femoral neck were observed in women with the TT genotype of rs2229579 polymorphisms (odds ratio, 3.43; 95% CI, 1.28-9.19) and with the AA genotype of rs4237 polymorphisms (odds ratio, 1.74; 95% CI, 1.03-2.95) compared with those not carrying the genotypes. The adjusted serum levels of bone turnover markers, OPG, sRANKL, or sRANKL × 1,000-to-OPG ratios were not associated with CNR gene polymorphisms.

CONCLUSIONS

Our results suggest that rs2501431, rs3003336, rs2229579, and rs4237 polymorphisms in CNR genes may be genetic factors affecting BMD in Korean postmenopausal women.

Bone Density in Patients with Cervical Cancer or Endometrial Cancer in comparison with Healthy Control; According to the stages

Objective: To evaluate the bone mineral density (BMD) in the lumbar spine and femur in postmenopausal women with cervical cancer and endometrial cancer without bone metastasis in comparison with that in healthy control postmenopausal women, and to assess the loss of BMD according to the cancer stage.

Materials and methods: We analyzed the BMD of the lumbar spine and femur using dual-energy X-ray absorptiometry (DXA) in 218 patients with cervical cancer, 85 patients with endometrial cancer, and 259 healthy controls. The serum levels of calcium (Ca), phosphorus (P), osteocalcin (OSC), and total alkaline phosphatase (ALP), and urine deoxypyridinoline(DPL) were measured in all participants.

Results: Age, body mass index, parity, and time since menopause were not significantly different between the three groups. Serum Ca level was higher in the cervical cancer group (p = 0.000), however, urine DPL was lower in endometrial cancer group (p = 0.000). The T-scores of basal BMD at the second and fourth lumbar vertebra (L2, L4) were significantly lower in patients with cervical cancer (p = 0.038, 0.000, respectively) compared to those in the healthy control groups. Additionally, the incidence of osteoporosis and osteopenia basal status of bone mass was significantly higher in patients with cervical cancer compared to that in controls (p = 0.016). No differences in basal BMD of the lumbar spine and femur were observed between patients with cervical cancer according to their stages.

Conclusion: Our results suggest that postmenopausal women with cervical cancer have a lower BMD and are at increased risk of osteoporosis in the lumbar spine before receiving anticancer treatment compared with postmenopausal women with endometrial cancer.

Association between polymorphisms in sclerostin, dickkopfs and secreted frizzled-related protein genes and bone mineral density in postmenopausal Korean women

BACKGROUND/AIMS

The purpose of this study was to investigate the association between single nucleotide polymorphisms (SNPs) in sclerostin (SOST), dickkopf (DKK), secreted frizzled-related protein (sFRP) genes and bone mineral density (BMD) in postmenopausal Korean women.

METHODS

The SOST, Wnt inhibitory factor 1 (WIF1), sFRP1,sFRP2,sFRP3, sFRP4, sFRP5, DKK1, DKK2 and DKK3 polymorphisms were analyzed in 399 postmenopausal Korean women. Serum levels of bone turnover markers were measured, and BMDs at the lumbar spine and femoral neck were also examined.

RESULTS

No significant differences in adjusted BMD at the lumbar spine and femoral neck were noted according to any single and combined polymorphisms measured in SOST, DKKs and sFRPs. However, osteoporosis at the femoral neck was 2.35 times more frequently observed in the AA genotype of the sFRP4 c.958C>A polymorphism compared to the non-AA genotype (95% CI 1.09-5.08, p = 0.03). Also, the CC genotype of the sFRP3 c.970C>G polymorphism had a higher rate of osteoporosis at the femoral neck compared to the GC genotype (OR 8.47, 95% CI 1.37-52.63, p = 0.049).

CONCLUSIONS

Our results suggest that the sFRP3 c.970C>G and sFRP4 c.958C>A polymorphisms may be genetic factors associated with the prevalence of osteoporosis at the femoral neck in postmenopausal Korean women.

Association between polymorphisms in leptin, leptin receptor, and β-adrenergic receptor genes and bone mineral density in postmenopausal Korean women

OBJECTIVE

The purpose of this study was to investigate the association between single nucleotide polymorphisms in leptin (LEP), leptin receptor (LEPR), and β-adrenergic receptor (ADRB) genes and bone mineral density (BMD) in postmenopausal Korean women.

METHODS

LEP c.280G>A, LEPR c.326A>G, LEPR c.668A>G, LEPR c.1968G>C, LEPR c.2096C>T, ADRB2 c.46A>G, ADRB2 c.79C>G, ADRB2 c.718T>C, ADRB2 c.741G>T, ADRB2 c.769G>A, and ADRB3 c.190T>C polymorphisms were analyzed in 592 postmenopausal Korean women. Serum levels of leptin, soluble leptin receptor, osteoprotegerin, soluble receptor activator of the nuclear factor-κB ligand, bone alkaline phosphatase, and carboxy-terminal telopeptide of type I collagen were measured, and BMDs at the lumbar spine and femoral neck were also examined.

RESULTS

Among the polymorphisms measured, only the LEPR c.1968G>C polymorphism was found to be associated with BMD at the femoral neck, and higher BMD was observed with increasing number of G alleles (P = 0.04). Osteoporosis at the femoral neck was 3.27 and 3.89 times more frequently observed in the AG and GG genotypes than in the AA genotype in the ADRB2 c.46A>G polymorphism (P = 0.024 and P = 0.015, respectively). However, no significant differences in serum levels of leptin, soluble leptin receptor, free leptin index, osteoprotegerin, soluble receptor activator of the nuclear factor-κB ligand, and bone turnover markers were detected among single and haplotype genotypes.

CONCLUSIONS

These results suggest that the LEPR c.1968G>C polymorphism may be one of the genetic factors affecting femoral neck BMD in postmenopausal Korean women and that an analysis of the ADRB2 c.46A>G polymorphism may be useful in identifying women at risk for osteoporosis at the femoral neck.

RETRACTED: Bone mineral density of lumbar spine and femur in patients with gynecologic cancer

Objective To compare the bone mineral density (BMD) of the lumbar spine and femur in postmenopausal women with cervical and endometrial cancer without bone metastasis with that in normal control postmenopausal women Methods We retrospectively analyzed the BMD of the lumbar spine and femur using dual-energy X-ray absorptiometry in 130 patients with cervical cancer, 68 patients with endometrial cancer, and 225 healthy controls. Results The serum levels of calcium, phosphorus, osteocalcin, total alkaline phosphatase and urine deoxypyridinoline were measured in all participants. Age, body mass index, parity and time since menopause were not significantly different between the three groups. The T-scores of basal BMD at the fourth lumbar vertebra (L4) were significantly lower in patients with cervical cancer (- 0.68 ± 0.10) compared to those in the other two groups. Additionally, the incidence of osteoporosis at L4 according to the basal status of bone mass was significantly higher in patients with cervical cancer (10.0%) compared to that in controls (0.4%). Urine deoxypyridinoline levels were significantly higher in patients with cervical cancer compared to those in controls. No differences in basal BMD of the lumbar spine and femur were observed between patients with endometrial cancer and controls, and no significant differences in biochemical markers were detected between patients with endometrial cancer and controls. Conclusion Our results suggest that postmenopausal women with cervical cancer have a lower BMD and are at increased risk of osteoporosis in the lumbar spine before receiving anticancer treatment compared with postmenopausal women with endometrial cancer.

Systems-level analysis of genome-wide association data

Genome-wide association studies (GWAS) have emerged as the method of choice for identifying common variants affecting complex disease. In a GWAS, particular attention is placed, for obvious reasons, on single-nucleotide polymorphisms (SNPs) that exceed stringent genome-wide significance thresholds. However, it is expected that many SNPs with only nominal evidence of association (e.g., P < 0.05) truly influence disease. Efforts to extract additional biological information from entire GWAS datasets have primarily focused on pathway-enrichment analyses. However, these methods suffer from a number of limitations and typically fail to lead to testable hypotheses. To evaluate alternative approaches, we performed a systems-level analysis of GWAS data using weighted gene coexpression network analysis. A weighted gene coexpression network was generated for 1918 genes harboring SNPs that displayed nominal evidence of association (P ≤ 0.05) from a GWAS of bone mineral density (BMD) using microarray data on circulating monocytes isolated from individuals with extremely low or high BMD. Thirteen distinct gene modules were identified, each comprising coexpressed and highly interconnected GWAS genes. Through the characterization of module content and topology, we illustrate how network analysis can be used to discover disease-associated subnetworks and characterize novel interactions for genes with a known role in the regulation of BMD. In addition, we provide evidence that network metrics can be used as a prioritizing tool when selecting genes and SNPs for replication studies. Our results highlight the advantages of using systems-level strategies to add value to and inform GWAS.

Chronic inflammation and pain in a tumor necrosis factor receptor (TNFR) (p55/p75-/-) dual deficient murine model

Many aspects of tissue damage after acute or chronic inflammatory reactions can be attributed directly to the concomitant biosynthesis and release of inducible early proinflammatory cytokine tumor necrosis factor alpha (TNFα). Conversely, systemic inflammation is impacted by the consequences of tissue damage. Dysregulated TNFα contributes to numerous pathophysiologic conditions including inflammatory bowel disease (IBD) and arthritis. Inflammatory stimuli trigger proteolytic cleavage and shedding of extracellular domains of TNFα receptors giving rise to 2 soluble fragments (p55 soluble tumor necrosis factor receptor 1 (sTNFR1) and p75 sTNFR2) that block the additional binding, activity, and synthesis of TNFα. We hypothesized that absence of sTNFR inhibitory feedback control would result in accumulated high levels of TNFα and other inflammatory factors promoting the cardinal signs of chronic inflammation and pain. The current study reports a translational murine model of chronic arthritis precipitated by 2 consecutive inflammatory insults. The "double hit" procedures provoke a chronic inflammatory response and pain-related behaviors in mice that are dually deficient in p55 (TNFR1) and p75 (TNFR2). The inflammation- and pain-related behaviors are transient in similarly treated wild-type (WT) mice. The complete Freund's adjuvant (CFA) method was used initially to induce knee joint inflammation, tactile mechanical and heat hypersensitivity, and gait disturbance. After these transient effects of the insult were resolved, a recrudescence persisting at least through 23 weeks was promoted by gastrointestinal (GI) insult with dilute intracolonic mustard oil (MO) only in the mutant mice and was reversed by a P2X7 antagonist. A serum proteome profiling analysis revealed high levels of serum inflammatory factors TNFα, regulated upon activation normally T-cell expressed and secreted (RANTES), chemokine (C-X-C motif) ligand 9 [CXCL9 (MIG)], chemokine (C-X-C motif) ligand 10 [CXCL10 (IP-10)], and chemokine (C-C motif) ligand 2 [CCL2 (MCP-1)]. These data suggest that impaired signaling of TNFα as a result of the deficit of the 2 protective soluble p55 and p75 sTNFR inhibitory factors plays a pivotal role in the reactivation of the immune response to GI insult that can produce recrudescence of inflammatory injury and a chronic pain state through promotion of high levels of serum inflammatory factors.

Association between polymorphisms in Wnt signaling pathway genes and bone mineral density in postmenopausal Korean women

OBJECTIVE

The purpose of this study was to investigate the association between single nucleotide polymorphisms in Wnt signal pathway genes and circulating osteoprotegerin (OPG), soluble receptor activator of the nuclear factor-κB ligand (sRANKL) levels, bone turnover markers, and bone mineral density (BMD) in postmenopausal Korean women.

METHODS

Wnt9a c256G>A; low-density lipoprotein receptor-related protein (LRP) 5 c266A>G, c2245C>G, c3893C>T, and c4099G>A; secreted frizzled-related protein (sFRP) 4 c1019G>A; axin II c148C>T and c1615G>A; glycogen synthase kinase binding protein (GBP) c455C>A; β-catenin c94G>T and c101G>T; T-cell factor 1 c663G>T, c734C>T, and c766G>A; and adenomatous polyposis coli c5465T>A polymorphisms were analyzed in 392 postmenopausal Korean women. Serum levels of OPG, sRANKL, and bone turnover markers were measured, and BMDs at the lumbar spine and femoral neck were examined.

RESULTS

Wnt9a c256G>A, LRP5 c2245C>G and c4099G>A, axin II c1615G>A, GBP c455C>A, β-catenin c94G>T and c101G>T, and T-cell factor 1 c663G>T and c734C>T single nucleotide polymorphisms were not observed. Among the genes showing polymorphisms, only the sFRP4 c1019G>A polymorphism was associated with BMD. The AA genotype in the sFRP4 c1019G>A polymorphism showed significantly lower lumbar spine BMD and a higher serum bone alkaline phosphatase level than did the GG genotype and showed a 6.39 times higher risk for osteoporosis at the lumbar spine compared with the GG genotype. No significant differences in bone turnover markers, OPG, and sRANKL were detected among the other single genotypes or the LRP haplotype genotype.

CONCLUSIONS

Our results suggest that the sFRP4 c1019G>A polymorphism may be one of the genetic factors affecting lumbar spine BMD in postmenopausal Korean women.

Molecular genetic studies of gene identification for osteoporosis: the 2009 update

Osteoporosis is a complex human disease that results in increased susceptibility to fragility fractures. It can be phenotypically characterized using several traits, including bone mineral density, bone size, bone strength, and bone turnover markers. The identification of gene variants that contribute to osteoporosis phenotypes, or responses to therapy, can eventually help individualize the prognosis, treatment, and prevention of fractures and their adverse outcomes. Our previously published reviews have comprehensively summarized the progress of molecular genetic studies of gene identification for osteoporosis and have covered the data available to the end of September 2007. This review represents our continuing efforts to summarize the important and representative findings published between October 2007 and November 2009. The topics covered include genetic association and linkage studies in humans, transgenic and knockout mouse models, as well as gene-expression microarray and proteomics studies. Major results are tabulated for comparison and ease of reference. Comments are made on the notable findings and representative studies for their potential influence and implications on our present understanding of the genetics of osteoporosis.