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A J Harrold 《BMJ (Clinical research ed.)》1982,285(6353):1446
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Anke Wesselius Martijn JL Bours Niklas R Jørgensen James Wiley Ben Gu Svenjhalmar van Helden Lodewijk van Rhijn Pieter C Dagnelie 《Purinergic signalling》2013,9(1):123-130
In the present study we investigated whether single nucleotide polymorphisms (SNPs) in the P2RX4, which alter the P2X4R function, are associated with the development of osteoporosis and whether an interaction between the P2X4R and P2X7R confer a synergistic effect of these two receptors on osteoporosis risk. Patients with fracture (690 females and 231 males, aged ≥50 years) were genotyped for three non-synonymous P2X4R SNPs. Bone mineral density (BMD) was measured at the total hip, lumbar spine, and femoral neck. Subject carrying the variant allele of the Tyr315Cys polymorphism showed a 2.68-fold (95 % CI, 1.20–6.02) higher risk of osteoporosis compared with wild-type subject. Furthermore, significant lower lumbar spine BMD values were observed in subjects carrying the Cys315 allele as compared with wild-type (0.85 ± 0.17 and 0.93 ± 0.17 g/cm2, respectively; p < 0.001). Assuming a recessive model, carriers of the variant allele of the Ser242Gly polymorphism showed increased BMD values at the lumbar spine compare to wild-type subject (1.11 ± 0.35 and 0.92 ± 0.17 g/cm2, respectively; p = 0.0045). This is the first study demonstrating an association of non-synonymous polymorphisms in the P2RX4 and the risk of osteoporosis, suggesting a role of the P2X4R in the regulation of bone mass.
Electronic supplementary material
The online version of this article (doi:10.1007/s11302-012-9337-0) contains supplementary material, which is available to authorized users. 相似文献114.
Aquaporins (AQP) 1, 2, 3 and 4 belong to the aquaporin water channel family and play an important role in urine concentration by reabsorption of water from renal tubule fluid. Renal AQPs have not been reported in the yak (Bos grunniens), which resides in the Qinghai Tibetan Plateau. We investigated AQPs 1?4 expressions in the kidneys of Yak using immunohistochemical staining. AQP1 was expressed mainly in the basolateral and apical membranes of the proximal tubules and descending thin limb of the loop of Henle. AQP2 was detected in the apical plasma membranes of collecting ducts and distal convoluted tubules. AQP3 was located in the proximal tubule, distal tubule and collecting ducts. AQP4 was located in the collecting ducts, distal straight tubule, glomerular capillaries and peritubular capillaries. The expression pattern of AQPs 1?4 in kidney of yak was different from other species, which possibly is related to kidney function in a high altitude environment. 相似文献
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Investigating the biochemistry, resilience and environmental interactions of bacterial endospores often requires a pure endospore biomass free of vegetative cells. Numerous endospore isolation methods, however, neglect to quantify the purity of the final endospore biomass. To ensure low vegetative cell contamination we developed a quality control technique that enables rapid quantification of endospore harvest purity. This method quantifies spore purity using bright-field and fluorescence microscopy imaging in conjunction with automated cell counting software. We applied this method to Bacillus subtilis endospore harvests isolated using a two-phase separation method that utilizes mild chemicals. The average spore purity of twenty-two harvests was 88 ± 11% (error is 1σ) with a median value of 93%. A spearman coefficient of 0.97 correlating automated and manual bacterial counts confirms the accuracy of software generated data. 相似文献
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van den Burg HA Westerink N Francoijs KJ Roth R Woestenenk E Boeren S de Wit PJ Joosten MH Vervoort J 《The Journal of biological chemistry》2003,278(30):27340-27346
The extracellular AVR4 elicitor of the pathogenic fungus Cladosporium fulvum induces defense responses in the tomato genotype Cf-4. Here, the four disulfide bonds of AVR4 were identified as Cys-11-41, Cys-21-27, Cys-35-80, and Cys-57-72 by partial reduction with Tris-(2-carboxyethyl)-phosphine hydrochloride, subsequent cyanylation, and base-catalyzed chain cleavage. The resulting peptide fragments were analyzed by mass spectrometry. Sequence homology and the disulfide bond pattern revealed that AVR4 contains an invertebrate (inv) chitin-binding domain (ChBD). Binding of AVR4 to chitin was confirmed experimentally. The three disulfide bonds encompassing the inv ChBD motif are also required for protein stability of AVR4. Independent disruption of each of the three conserved disulfide bonds in AVR4 resulted in a protease-sensitive protein, whereas the fourth disulfide bond appeared not to be required for protein stability. Most strains of C. fulvum virulent on Cf-4 tomato contain Cys to Tyr substitutions in AVR4 involving two (Cys-11-41, Cys-35-80) of the three disulfide bonds present in the inv ChBD motif. These natural Cys to Tyr mutant AVR4 proteins did retain their chitin binding ability and when bound to chitin were less sensitive to proteases. Thus, the widely applied tomato Cf-4 resistance gene is circumvented by C. fulvum by amino acid substitutions affecting two disulfide bonds in AVR4 resulting in the absence of the corresponding AVR4 isoforms in apoplastic fluid. However, these natural isoforms of AVR4 appear to have retained their intrinsic function, i.e. binding to chitin present in the cell wall of C. fulvum, most likely to protect it against the deleterious effects of plant chitinases. 相似文献