RESUMO
The composite material PLGA compounded with ß-tricalcium phosphate (ß-TCP) was prepared by melt blending method, and the absorbable interface screw was prepared by injection molding process. Prepare PBS buffer that simulates human body, conduct in vitro degradation experiments on interface screws according to relevant national and industry standards, then test and characterize interface screws at different time points for degradation of intrinsic viscosity, average molecular weight distribution, mass loss, mechanical properties and thermal properties. According to the degradation performance-time curve, determine the time node at which the interface screw loses the mechanical properties. In this paper, the in vitro degradation behavior of interfacial screws prepared from PLGA and ß-TCP composites was studied in detail, providing a reference and basis for the degradation behavior of absorbable products prepared from PLGA and ß-TCP composites.
Assuntos
Fosfatos de Cálcio , Poliésteres , Humanos , Teste de Materiais , Implantes AbsorvíveisRESUMO
Overexpression of breast cancer resistance transporter (BCRP/ABCG2) in cancers has been explained for the failure of chemotherapy in clinic. Inhibition of the transport activity of BCRP during chemotherapy should reverse multidrug resistance. In this study, a triazole-bridged flavonoid dimer Ac15(Az8)2 was identified as a potent, nontoxic, and selective BCRP inhibitor. Using BCRP-overexpressing cell lines, its EC50 for reversing BCRP-mediated topotecan resistance was 3 nM in MCF7/MX100 and 72 nM in S1M180 in vitro. Mechanistic studies revealed that Ac15(Az8)2 restored intracellular drug accumulation by inhibiting BCRP-ATPase activity and drug efflux. It did not down-regulate the cell surface BCRP level to enhance drug retention. It was not a transport substrate of BCRP and showed a non-competitive relationship with DOX in binding to BCRP. A pharmacokinetic study revealed that I.P. administration of 45 mg/kg of Ac15(Az8)2 resulted in plasma concentration above its EC50 (72 nM) for longer than 24 h. It increased the AUC of topotecan by 2-fold. In an in vivo model of BCRP-overexpressing S1M180 xenograft in Balb/c nude mice, it significantly reversed BCRP-mediated topotecan resistance and inhibited tumor growth by 40% with no serious body weight loss or death incidence. Moreover, it also increased the topotecan level in the S1M180 xenograft by 2-fold. Our results suggest that Ac15(Az8)2 is a promising candidate for further investigation into combination therapy for treating BCRP-overexpressing cancers.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Antineoplásicos , Resistencia a Medicamentos Antineoplásicos , Animais , Humanos , Camundongos , Antineoplásicos/farmacologia , Antineoplásicos/química , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Linhagem Celular Tumoral , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Camundongos Nus , Proteínas de Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Topotecan/farmacologia , Flavonoides/farmacologia , Triazóis/farmacologiaRESUMO
OBJECTIVE: Many animal experiments and epidemiological studies have shown that the gut microbiota (GM) plays an important role in the development of obesity, but the specific biological mechanism involved in the pathogenesis of disease remain unknown. We aimed to examine the relationships and functional mechanisms of GM on obesity in peri- and post-menopausal women. METHODS: We recruited 499 Chinese peri- and post-menopausal women and performed comprehensive analyses of the gut microbiome, targeted metabolomics for short-chain fatty acids in serum, and host whole-genome sequencing by various association analysis methods. RESULTS: Through constrained linear regression analysis, we found that an elevated abundance of Bacteroides fragilis (B. fragilis) was associated with obesity. We also found that serum levels of acetic acid were negatively associated with obesity, and that B. fragilis was negatively associated with serum acetic acid levels by partial Spearman correlation analysis. Mendelian randomization analysis indicated that B. fragilis increases the risk of obesity and may causally down-regulate acetic acid levels. CONCLUSIONS: We found the gut with B. fragilis may accelerate obesity, in part, by suppressing acetic acid levels. Therefore, B. fragilis and acetic acid may represent important therapeutic targets for obesity intervention in peri- and post-menopausal women.
Assuntos
Bacteroides fragilis , Microbioma Gastrointestinal , Ácido Acético , Bacteroides fragilis/fisiologia , Feminino , Humanos , Obesidade , Pós-MenopausaRESUMO
The insulin receptor (IR) is a transmembrane protein that is activated by ligands in insulin signaling pathways. The IR has been considered as a novel therapeutic target for clinical intervention, considering the overexpression of its protein and A-isoform in multiple cancers, Alzheimer's disease, and Type 2 diabetes mellitus in humans. Meanwhile, it may also serve as a potential target in pest management due to its multiple physiological influences in insects. In this review, we provide an overview of the structural and molecular biology of the IR, functions of IRs in humans and insects, physiological and nonpeptide small molecule modulators of the IR, and the regulating mechanisms of the IR. Xenobiotic compounds and the corresponding insecticidal chemicals functioning on the IR are also discussed. This review is expected to provide useful information for a better understanding of human IR-related diseases, as well as to facilitate the development of novel small-molecule activators and inhibitors of the IR for use as medicines or pesticides.
Assuntos
Diabetes Mellitus Tipo 2 , Praguicidas , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Insulina/metabolismo , Proteínas Substratos do Receptor de Insulina/metabolismo , Praguicidas/farmacologia , Receptor de Insulina/metabolismoRESUMO
BACKGROUND: Berberine is a plant-derived herbicidal alkaloid. The herbicidal mechanism of berberine is still not clear. In this study, our aim is to clarify the mechanism of berberine inhibiting the root growth of Arabidopsis thaliana, aiming at providing new insight into identifying the molecular targets of berberine. RESULTS: The whole-genome RNA sequencing had revealed that 403 genes were down-regulated, and 422 genes were up-regulated in Arabidopsis roots with berberine treatment. According to KEGG and GO analysis, the expression of two genes AT5G48010 (Thas) and AT5G42600 (MRN1) which are in the sesquiterpenoid and triterpenoid biosynthesis pathway were affected most. These two genes belong to thalianol and marneral gene clusters. RT-PCR showed that Arabidopsis responds to berberine by inhibiting root growth through repressing the expression of thalianol and marneral gene clusters, which was independent of the upstream effectors ARP6 and HTA9-1. GC-MS analysis showed that berberine could inhibit THAH in the biosynthetic network of triterpenoid gene cluster in Arabidopsis and thus cause the accumulation of thalianol. CONCLUSION: Our study indicated the repression of the thalianol and marneral gene clusters as the primary mechanism of action of berberine in Arabidopsis, which may result in plant growth defects by interrupting the thalianol metabolic pathway. This provides novel clues as to the possible molecular herbicidal mechanism of berberine. © 2022 Society of Chemical Industry.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Berberina , Herbicidas , Triterpenos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Berberina/metabolismo , Berberina/farmacologia , Regulação da Expressão Gênica de Plantas , Herbicidas/metabolismo , Família Multigênica , Triterpenos/farmacologiaRESUMO
We synthesize various substituted triazole-containing flavonoids and identify potent, nontoxic, and highly selective BCRP inhibitors. Ac18Az8, Ac32Az19, and Ac36Az9 possess m-methoxycarbonylbenzyloxy substitution at C-3 of the flavone moiety and substituted triazole at C-4' of the B-ring. They show low toxicity (IC50 toward L929 > 100 µM), potent BCRP-inhibitory activity (EC50 = 1-15 nM), and high BCRP selectivity (BCRP selectivity over MRP1 and P-gp > 67-714). They inhibit the efflux activity of BCRP, elevate the intracellular drug accumulation, and restore the drug sensitivity of BCRP-overexpressing cells. Like Ko143, Ac32Az19 remarkably exhibits a 100% 5D3 shift, indicating that it can bind and cause a conformational change of BCRP. Moreover, it significantly reduces the abundance of functional BCRP dimers/oligomers by half to retain more mitoxantrone in the BCRP-overexpressing cell line and that may account for its inhibitory activity. They are promising candidates to be developed into combination therapy to overcome MDR cancers with BCRP overexpression.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Antineoplásicos/farmacologia , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Flavonoides/farmacologia , Proteínas de Neoplasias/antagonistas & inibidores , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/química , Anticorpos Monoclonais/imunologia , Antineoplásicos/química , Flavonoides/química , Células HEK293 , Humanos , Mitoxantrona/farmacologia , Proteínas de Neoplasias/química , Relação Estrutura-Atividade , Especificidade por SubstratoRESUMO
The homeostasis of bone metabolism depends on the coupling and precise regulation of various types of cells in bone tissue. However, the communication and interaction between bone tissue cells at the single-cell level remains poorly understood. Thus, we performed single-cell RNA sequencing (scRNA-seq) on the primary human femoral head tissue cells (FHTCs). Nine cell types were identified in 26,574 primary human FHTCs, including granulocytes, T cells, monocytes, B cells, red blood cells, osteoblastic lineage cells, endothelial cells, endothelial progenitor cells (EPCs) and plasmacytoid dendritic cells. We identified serine protease 23 (PRSS23) and matrix remodeling associated protein 8 (MXRA8) as novel bone metabolism-related genes. Additionally, we found that several subtypes of monocytes, T cells and B cells were related to bone metabolism. Cell-cell communication analysis showed that collagen, chemokine, transforming growth factor and their ligands have significant roles in the crosstalks between FHTCs. In particular, EPCs communicated with osteoblastic lineage cells closely via the "COL2A1-ITGB1" interaction pair. Collectively, this study provided an initial characterization of the cellular composition of the human FHTCs and the complex crosstalks between them at the single-cell level. It is a unique starting resource for in-depth insights into bone metabolism.
Assuntos
Cabeça do Fêmur/metabolismo , Análise de Sequência de RNA , Análise de Célula Única , Linfócitos B/metabolismo , Linhagem da Célula/genética , Perfilação da Expressão Gênica , Ontologia Genética , Redes Reguladoras de Genes , Humanos , Monócitos/metabolismo , Osteoblastos/citologia , Osteoblastos/metabolismo , Linfócitos T/metabolismoRESUMO
The present work describes the syntheses of diverse triazole bridged flavonoid dimers and identifies potent, nontoxic, and highly selective BCRP inhibitors. A homodimer, Ac22(Az8)2, with m-methoxycarbonylbenzyloxy substitution at C-3 of the flavone moieties and a bis-triazole-containing linker (21 atoms between the two flavones) showed low toxicity (IC50 toward L929, 3T3, and HFF-1 > 100 µM), potent BCRP-inhibitory activity (EC50 = 1-2 nM), and high BCRP selectivity (BCRP selectivity over MRP1 and P-gp > 455-909). Ac22(Az8)2 inhibits BCRP-ATPase activity, blocks the drug efflux activity of BCRP, elevates the intracellular drug accumulation, and finally restores the drug sensitivity of BCRP-overexpressing cells. It does not down-regulate the surface BCRP protein expression to enhance the drug retention. Therefore, Ac22(Az8)2 and similar flavonoid dimers appear to be promising candidates for further development into combination therapy to overcome MDR cancers with BCRP overexpression.
Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/antagonistas & inibidores , Antineoplásicos/farmacologia , Flavonoides/farmacologia , Proteínas de Neoplasias/antagonistas & inibidores , Triazóis/química , Células 3T3 , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/química , Animais , Antineoplásicos/química , Simulação por Computador , Cobre/química , Dimerização , Desenho de Fármacos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Flavonas/química , Flavonoides/química , Células HEK293 , Humanos , Camundongos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores , Proteínas Associadas à Resistência a Múltiplos Medicamentos/químicaRESUMO
A 300-member flavonoid dimer library of multidrug resistance-associated protein 1 (MRP1, ABCC1) modulators was rapidly assembled using "click chemistry". Subsequent high-throughput screening has led to the discovery of highly potent (EC50 ranging from 53 to 298 nM) and safe (selective indexes ranging from >190 to >1887) MRP1 modulators. Some dimers have potency about 6.5- to 36-fold and 64- to 358-fold higher than the well-known MRP1 inhibitors, verapamil, and MK571, respectively. They inhibited DOX efflux and restored intracellular DOX concentration. The most potent modulator, Ac3Az11, was predicted to bind to the bipartite substrate-binding site of MRP1 in a competitive manner. Moreover, it provided sufficient concentration to maintain its plasma level above its in vitro EC50 (53 nM for DOX) for about 90 min. Overall, we demonstrate that "click chemistry" coupled with high throughput screening is a rapid, reliable, and efficient tool in the discovery of compounds having potent MRP1-modualting activity.
Assuntos
Dimerização , Desenho de Fármacos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Flavonoides/química , Flavonoides/farmacologia , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Alcinos/química , Animais , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Azidas/química , Linhagem Celular Tumoral , Química Click , Doxorrubicina/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Flavonoides/metabolismo , Flavonoides/farmacocinética , Humanos , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Camundongos , Simulação de Acoplamento Molecular , Proteínas Associadas à Resistência a Múltiplos Medicamentos/química , Conformação ProteicaRESUMO
MRP1 overexpression in multidrug-resistant cancer cells has been shown to be responsible for collateral sensitivity to some flavonoids that stimulate a huge MRP1-mediated GSH efflux. This massive GSH depletion triggers the death of these cancer cells. We describe here that bivalent flavonoid dimers strikingly stimulate such MRP1-mediated GSH efflux and trigger a 50-100 fold more potent cell death than their corresponding monomers. This selective and massive cell death of MRP1-overexpressing cells (both transfected and drug-selected cell lines) is no longer observed either upon catalytic inactivation of MRP1 or its knockdown by siRNA. The best flavonoid dimer, 4e, kills MRP1-overexpressing cells with a selective ratio higher than 1000 compared to control cells and an EC50 value of 0.1 µM, so far unequaled as a collateral sensitivity agent targeting ABC transporters. This result portends the flavonoid dimer 4e as a very promising compound to appraise in vivo the therapeutic potential of collateral sensitivity for eradication of MRP1-overexpressing chemoresistant cancer cells in tumors.
Assuntos
Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Flavonoides/farmacologia , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Animais , Linhagem Celular Tumoral , Dimerização , Glutationa/metabolismo , Humanos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genéticaRESUMO
Protein phosphorylation regulates a wide variety of cellular processes. Thus, we hypothesize that single-nucleotide polymorphisms (SNPs) that may modulate protein phosphorylation could affect osteoporosis risk. Based on a previous conventional genome-wide association (GWA) study, we conducted a three-stage meta-analysis targeting phosphorylation-related SNPs (phosSNPs) for femoral neck (FN)-bone mineral density (BMD), total hip (HIP)-BMD, and lumbar spine (LS)-BMD phenotypes. In stage 1, 9593 phosSNPs were meta-analyzed in 11,140 individuals of various ancestries. Genome-wide significance (GWS) and suggestive significance were defined by α = 5.21 × 10(-6) (0.05/9593) and 1.00 × 10(-4), respectively. In stage 2, nine stage 1-discovered phosSNPs (based on α = 1.00 × 10(-4)) were in silico meta-analyzed in Dutch, Korean, and Australian cohorts. In stage 3, four phosSNPs that replicated in stage 2 (based on α = 5.56 × 10(-3), 0.05/9) were de novo genotyped in two independent cohorts. IDUA rs3755955 and rs6831280, and WNT16 rs2707466 were associated with BMD phenotypes in each respective stage, and in three stages combined, achieving GWS for both FN-BMD (p = 8.36 × 10(-10), p = 5.26 × 10(-10), and p = 3.01 × 10(-10), respectively) and HIP-BMD (p = 3.26 × 10(-6), p = 1.97 × 10(-6), and p = 1.63 × 10(-12), respectively). Although in vitro studies demonstrated no differences in expressions of wild-type and mutant forms of IDUA and WNT16B proteins, in silico analyses predicts that WNT16 rs2707466 directly abolishes a phosphorylation site, which could cause a deleterious effect on WNT16 protein, and that IDUA phosSNPs rs3755955 and rs6831280 could exert indirect effects on nearby phosphorylation sites. Further studies will be required to determine the detailed and specific molecular effects of these BMD-associated non-synonymous variants.
Assuntos
Densidade Óssea/genética , Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único , Proteínas Wnt/genética , Estudos de Coortes , Feminino , Colo do Fêmur/metabolismo , Humanos , Vértebras Lombares/metabolismo , Masculino , Fosforilação , Proteínas Wnt/metabolismoRESUMO
MicroRNAs (miRNAs) are critical post-transcriptional regulators. Based on a previous genome-wide association (GWA) scan, we conducted a polymorphism in microRNA target sites (poly-miRTS)-centric multistage meta-analysis for lumbar spine (LS)-, total hip (HIP)- and femoral neck (FN)-bone mineral density (BMD). In stage I, 41 102 poly-miRTSs were meta-analyzed in seven cohorts with a genome-wide significance (GWS) α = 0.05/41 102 = 1.22 × 10(-6). By applying α = 5 × 10(-5) (suggestive significance), 11 poly-miRTSs were selected, with FGFRL1 rs4647940 and PRR5 rs3213550 as top signals for FN-BMD (P = 7.67 × 10(-6) and 1.58 × 10(-5)) in gender-combined sample. In stage II in silico replication (two cohorts), FGFRL1 rs4647940 was the only signal marginally replicated for FN-BMD (P = 5.08 × 10(-3)) at α = 0.10/11 = 9.09 × 10(-3). PRR5 rs3213550 was also selected based on biological significance. In stage III de novo genotyping replication (two cohorts), FGFRL1 rs4647940 was the only signal significantly replicated for FN-BMD (P = 7.55 × 10(-6)) at α = 0.05/2 = 0.025 in gender-combined sample. Aggregating three stages, FGFRL1 rs4647940 was the single stage I-discovered and stages II- and III-replicated signal attaining GWS for FN-BMD (P = 8.87 × 10(-12)). Dual-luciferase reporter assays demonstrated that FGFRL1 3' untranslated region harboring rs4647940 appears to be hsa-miR-140-5p's target site. In a zebrafish microinjection experiment, dre-miR-140-5p is shown to exert a dramatic impact on craniofacial skeleton formation. Taken together, we provided functional evidence for a novel FGFRL1 poly-miRTS rs4647940 in a previously known 4p16.3 locus, and experimental and clinical genetics studies have shown both FGFRL1 and hsa-miR-140-5p are important for bone formation.
Assuntos
Regiões 3' não Traduzidas , Densidade Óssea/genética , Loci Gênicos , MicroRNAs/genética , Polimorfismo Genético , Receptor Tipo 5 de Fator de Crescimento de Fibroblastos/genética , Feminino , Estudo de Associação Genômica Ampla , Humanos , MasculinoRESUMO
Obesity is a major public health problem with strong genetic determination. Multiple genetic variants have been implicated for obesity by conducting genome-wide association (GWA) studies, primarily focused on body mass index (BMI). Fat body mass (FBM) is phenotypically more homogeneous than BMI and is more appropriate for obesity research; however, relatively few studies have been conducted on FBM. Aiming to identify variants associated with obesity, we carried out meta-analyses of seven GWA studies for BMI-related traits including FBM, and followed these analyses by de novo replication. The discovery cohorts consisted of 21 969 individuals from diverse ethnic populations and a total of over 4 million genotyped or imputed SNPs. The de novo replication cohorts consisted of 6663 subjects from two independent samples. To complement individual SNP-based association analyses, we also carried out gene-based GWA analyses in which all variations within a gene were considered jointly. Individual SNP-based association analyses identified a novel locus 1q21 [rs2230061, CTSS (Cathepsin S)] that was associated with FBM after the adjustment of lean body mass (LBM) (P = 3.57 × 10(-8)) at the genome-wide significance level. Gene-based association analyses identified a novel gene NLK (nemo-like kinase) in 17q11 that was significantly associated with FBM adjusted by LBM. In addition, we confirmed three previously reported obesity susceptibility loci: 16q12 [rs62033400, P = 1.97 × 10(-14), FTO (fat mass and obesity associated)], 18q22 [rs6567160, P = 8.09 × 10(-19), MC4R (melanocortin 4 receptor)] and 2p25 [rs939583, P = 1.07 × 10(-7), TMEM18 (transmembrane protein 18)]. We also found that rs6567160 may exert pleiotropic effects to both FBM and LBM. Our results provide additional insights into the molecular genetic basis of obesity and may provide future targets for effective prevention and therapeutic intervention.
Assuntos
Predisposição Genética para Doença , Obesidade/genética , Polimorfismo de Nucleotídeo Único , Tecido Adiposo/fisiologia , Catepsinas/genética , Feminino , Estudo de Associação Genômica Ampla , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Masculino , Proteínas de Membrana/genética , Proteínas Serina-Treonina Quinases/genéticaRESUMO
Aiming to identify novel genetic variants and to confirm previously identified genetic variants associated with bone mineral density (BMD), we conducted a three-stage genome-wide association (GWA) meta-analysis in 27 061 study subjects. Stage 1 meta-analyzed seven GWA samples and 11 140 subjects for BMDs at the lumbar spine, hip and femoral neck, followed by a Stage 2 in silico replication of 33 SNPs in 9258 subjects, and by a Stage 3 de novo validation of three SNPs in 6663 subjects. Combining evidence from all the stages, we have identified two novel loci that have not been reported previously at the genome-wide significance (GWS; 5.0 × 10(-8)) level: 14q24.2 (rs227425, P-value 3.98 × 10(-13), SMOC1) in the combined sample of males and females and 21q22.13 (rs170183, P-value 4.15 × 10(-9), CLDN14) in the female-specific sample. The two newly identified SNPs were also significant in the GEnetic Factors for OSteoporosis consortium (GEFOS, n = 32 960) summary results. We have also independently confirmed 13 previously reported loci at the GWS level: 1p36.12 (ZBTB40), 1p31.3 (GPR177), 4p16.3 (FGFRL1), 4q22.1 (MEPE), 5q14.3 (MEF2C), 6q25.1 (C6orf97, ESR1), 7q21.3 (FLJ42280, SHFM1), 7q31.31 (FAM3C, WNT16), 8q24.12 (TNFRSF11B), 11p15.3 (SOX6), 11q13.4 (LRP5), 13q14.11 (AKAP11) and 16q24 (FOXL1). Gene expression analysis in osteogenic cells implied potential functional association of the two candidate genes (SMOC1 and CLDN14) in bone metabolism. Our findings independently confirm previously identified biological pathways underlying bone metabolism and contribute to the discovery of novel pathways, thus providing valuable insights into the intervention and treatment of osteoporosis.
Assuntos
Densidade Óssea/genética , Claudinas/genética , Osteonectina/genética , Osteoporose/genética , Idoso , Osso e Ossos/metabolismo , Feminino , Colo do Fêmur/fisiologia , Expressão Gênica , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Quadril/fisiologia , Humanos , Vértebras Lombares/fisiologia , Masculino , Pessoa de Meia-Idade , Osteoclastos/citologia , Osteogênese/genética , Osteoporose/terapia , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Bone mineral density (BMD) is a major index for diagnosing osteoporosis. PhosSNPs are nonsynonymous SNPs that affect protein phosphorylation. The relevance and significance of phosSNPs to BMD and osteoporosis is unknown. This study aimed to identify and characterize phosSNPs significant for BMD in humans. We conducted a pilot genomewide phosSNP association study for BMD in three independent population samples, involving â¼5000 unrelated individuals. We identified and replicated three phosSNPs associated with both spine BMD and hip BMD in Caucasians. Association with hip BMD for one of these phosSNPs, ie, rs6265 (major/minor allele: G/A) in BDNF gene, was also suggested in Chinese. Consistently in both ethnicities, individuals carrying the AA genotype have significantly lower hip BMD than carriers of the GA and GG genotypes. Through in vitro molecular and cellular studies, we found that compared to osteoblastic cells transfected with wild-type BDNF-Val66 (encoded with allele G at rs6265), transfection of variant BDNF-Met66 (encoded with allele A at rs6265) significantly decreased BDNF protein phosphorylation (at amino acid residue T62), expression of osteoblastic genes (OPN, BMP2, and ALP), and osteoblastic activity. The findings are consistent with and explain our prior observations in general human populations. We conclude that phosSNP rs6265, by regulating BDNF protein phosphorylation and osteoblast differentiation, influences hip BMD in humans. This study represents our first endeavor to dissect the functions of phosSNPs in bone, which might stimulate extended large-scale studies on bone or similar studies on other human complex traits and diseases.
Assuntos
Densidade Óssea/genética , Diferenciação Celular/genética , Osteoblastos/citologia , Polimorfismo de Nucleotídeo Único/genética , Adulto , Alelos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Linhagem Celular , Genótipo , Humanos , Pessoa de Meia-Idade , Osteoblastos/enzimologia , Fosforilação/genética , Reprodutibilidade dos Testes , Especificidade por SubstratoRESUMO
Femoral neck geometric parameters (FNGPs), which include cortical thickness (CT), periosteal diameter (W), buckling ratio (BR), cross-sectional area (CSA), and section modulus (Z), contribute to bone strength and may predict hip fracture risk. Age at menarche (AAM) is an important risk factor for osteoporosis and bone fractures in women. Some FNGPs are genetically correlated with AAM. In this study, we performed a bivariate genome-wide association study (GWAS) to identify new candidate genes responsible for both FNGPs and AAM. In the discovery stage, we tested 760,794 SNPs in 1,728 unrelated Caucasian subject, followed by replication analyses in independent samples of US Caucasians (with 501 subjects) and Chinese (with 826 subjects). We found six SNPs that were associated with FNGPs and AAM. These SNPs are located in three genes (i.e. NRCAM, IDS and LOC148145), suggesting these three genes may co-regulate FNGPs and AAM. Our findings may help improve the understanding of genetic architecture and pathophysiological mechanisms underlying both osteoporosis and AAM.
Assuntos
Colo do Fêmur/metabolismo , Estudo de Associação Genômica Ampla , Menarca/genética , Adulto , Fatores Etários , Idoso , Povo Asiático/genética , Feminino , Colo do Fêmur/anatomia & histologia , Colo do Fêmur/crescimento & desenvolvimento , Genótipo , Humanos , Desequilíbrio de Ligação , Pessoa de Meia-Idade , Fenótipo , Polimorfismo de Nucleotídeo Único , População Branca/genética , Adulto JovemRESUMO
Compressive strength index (CSI) is a newly established index for predicting hip fracture, the most serious consequence of osteoporosis. Appendicular lean mass (ALM), which influences skeletal strength of the lower limbs, is another trait associated with the risk of hip fracture. In this study, we performed a bivariate genome-wide association study (GWAS) to identify new candidate genes responsible for both CSI and ALM. In our discovery sample of 1627 unrelated Chinese subjects (802 males and 825 females), we scanned 909,509 SNPs using the Affymetrix Human Genome SNP 6.0 genotyping array. We successfully replicated our results in a sample of 2286 Caucasian subjects (558 males and 1728 females). The results indicated that five SNPs (rs174583, rs174577, rs174549, rs174548, rs7672337) in the FADS1, FADS2, and DCHS2 genes had significant bivariate associations with CSI and ALM in male subjects for both the GWAS discovery (with P<8.42×10(-6)) and the Caucasian sample (with P<0.07). We performed further replication analysis in a 2nd Caucasian sample with 501 Caucasian male subjects, using Affymetrix 500k arrays, and found that two of the above SNPs (rs174548 and rs174549, P=0.07) had bivariate associations with both CSI and ALM in males; the other 3 SNPs were not typed with the 500k array. The above findings suggest that the 3 genes, FADS1, FADS2, and DCHS2, containing these SNPs might play dual roles influencing both CSI and ALM in males. Our findings provide new insights into our understanding of the genetic basis of bone metabolism and the pathogenesis of osteoporosis.
Assuntos
Caderinas/genética , Força Compressiva/fisiologia , Ácidos Graxos Dessaturases/genética , Estudo de Associação Genômica Ampla/métodos , Adulto , Povo Asiático , Dessaturase de Ácido Graxo Delta-5 , Fraturas do Quadril/genética , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único/genética , População Branca , Adulto JovemRESUMO
Lean body mass (LBM) and age at menarche (AAM) are two important complex traits for human health. The aim of this study was to identify pleiotropic genes for both traits using a powerful bivariate genome-wide association study (GWAS). Two studies, a discovery study and a replication study, were performed. In the discovery study, 909622 single nucleotide polymorphisms (SNPs) were genotyped in 801 unrelated female Han Chinese subjects using the Affymetrix human genome-wide SNP array 6.0 platform. Then, a bivariate GWAS was performed to identify the SNPs that may be important for LBM and AAM. In the replication study, significant findings from the discovery study were validated in 1692 unrelated Caucasian female subjects. One SNP rs3027009 that was bivariately associated with left arm lean mass and AAM in the discovery samples (P=7.26×10(-6)) and in the replication samples (P=0.005) was identified. The SNP is located at the upstream of DARC (Duffy antigen receptor for chemokines) gene, suggesting that DARC may play an important role in regulating the metabolisms of both LBM and AAM.
Assuntos
Composição Corporal/genética , Sistema do Grupo Sanguíneo Duffy/genética , Estudo de Associação Genômica Ampla/métodos , Menarca/genética , Receptores de Superfície Celular/genética , Adulto , Povo Asiático/genética , China , Feminino , Genótipo , Humanos , Modelos Lineares , Pessoa de Meia-Idade , Análise Multivariada , Polimorfismo de Nucleotídeo Único , Adulto JovemRESUMO
BACKGROUND: Alcohol dependence (AD) is a complex disorder characterized by impaired control over drinking. It is determined by both genetic and environmental factors. The recent approach of genome-wide association study (GWAS) is a powerful tool for identifying complex disease-associated susceptibility alleles, however, a few GWASs have been conducted for AD, and their results are largely inconsistent. The present study aimed to screen the loci associated with alcohol-related phenotypes using GWAS technology. METHODS: A genome-wide association study with the behavior of regular alcohol drinking and alcohol consumption was performed to identify susceptibility genes associated with AD, using the Affymetrix 500K SNP array in an initial sample consisting of 904 unrelated Caucasian subjects. Then, the initial results in GWAS were replicated in three independent samples: 1972 Caucasians in 593 nuclear families, 761 unrelated Caucasian subjects, and 2955 unrelated Chinese Hans. RESULTS: Several genes were associated with the alcohol-related phenotypes at the genome-wide significance level, with the ankyrin repeat domain 7 gene (ANKRD7) showing the strongest statistical evidence for regular alcohol drinking and suggestive statistical evidence for alcohol consumption. In addition, certain haplotypes within the ANKRD7 and cytokine-like1 (CYTL1) genes were significantly associated with regular drinking behavior, such as one ANKRD7 block composed of the SNPs rs6466686-rs4295599-rs12531086 (P = 6.51 × 10(-8)). The association of alcohol consumption was successfully replicated with rs4295599 in ANKRD7 gene in independent Caucasian nuclear families and independent unrelated Chinese Hans, and with rs16836497 in CYTL1 gene in independent unrelated Caucasians. Meta-analyses based on both the GWAS and replication samples further supported the observed significant associations between the ANKRD7 or CYTL1 gene and alcohol consumption. CONCLUSION: The evidence suggests that ANKRD7 and CYTL1 genes may play an important role in the variance in AD risk.
Assuntos
Consumo de Bebidas Alcoólicas/genética , Proteínas/genética , Receptores de Citocinas/genética , Adulto , Idoso , Proteínas Sanguíneas , Citocinas , Feminino , Estudo de Associação Genômica Ampla , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas Nucleares , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Alcohol dependence (AD) is a complex disorder characterized by psychiatric and physiological dependence on alcohol. AD is reflected by regular alcohol drinking, which is highly inheritable. In this study, to identify susceptibility genes associated with alcohol drinking, we performed a genome-wide association study of copy number variants (CNVs) in 2,286 Caucasian subjects with Affymetrix SNP6.0 genotyping array. We replicated our findings in 1,627 Chinese subjects with the same genotyping array. We identified two CNVs, CNV207 (combined p-value 1.91E-03) and CNV1836 (combined p-value 3.05E-03) that were associated with alcohol drinking. CNV207 and CNV1836 are located at the downstream of genes LTBP1 (870 kb) and FGD4 (400 kb), respectively. LTBP1, by interacting TGFB1, may down-regulate enzymes directly participating in alcohol metabolism. FGD4 plays a role in clustering and trafficking GABA(A) receptor and subsequently influence alcohol drinking through activating CDC42. Our results provide suggestive evidence that the newly identified CNV regions and relevant genes may contribute to the genetic mechanism of alcohol dependence.