239 research outputs found

    Role of the HPRG Component of Striated Muscle AMP Deaminase in the Stability and Cellular Behaviour of the Enzyme

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    Multiple muscle-specific isoforms of the Zn2+ metalloenzyme AMP deaminase (AMPD) have been identified based on their biochemical and genetic differences. Our previous observations suggested that the metal binding protein histidine-proline-rich glycoprotein (HPRG) participates in the assembly and maintenance of skeletal muscle AMP deaminase (AMPD1) by acting as a zinc chaperone. The evidence of a role of millimolar-strength phosphate in stabilizing the AMPD-HPRG complex of both AMPD1 and cardiac AMP deaminase (AMPD3) is suggestive of a physiological mutual dependence between the two subunit components with regard to the stability of the two isoforms of striated muscle AMPD. The observed influence of the HPRG content on the catalytic behavior of the two enzymes further strengthens this hypothesis. Based on the preferential localization of HPRG at the sarcomeric I-band and on the presence of a Zn2+ binding motif in the N-terminal regions of fast TnT and of the AMPD1 catalytic subunit, we advance the hypothesis that the Zn binding properties of HPRG could promote the association of AMPD1 to the thin filament

    Avaliação de sistemas de tratamento de águas em recirculação no processamento dos frutos do cafeeiro

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    This study was carried out in order to evaluate treatment systems for removal of solids and organic material of the water (ARC) in way to make possible its recirculation in the coffee fruits processing. The recirculation of ARC was operated in four circuits: short circuit, without screen (CC-SP), when the ARC was recirculated without any treatment; short circuit, with screen (CC-CP), when the ARC went by a pressurized mesh screen; long circuit, without screen (CL-SP), when the ARC went by a decantation tank; and long circuit, with screen (CL-CP), when the ARC went by pressurized mesh screen and later for the decantation tank. The screen, included to ARC treatment system, showed low efficiency in removing CE, ST, SS, DBO and DQO, not resulting in significant effects in the quality of the water in recirculation. However, the decantation tank was more efficient in the removal of the analyzed variables. The circuit CL-CP presented small increment in the removal efficiencies, compared to CL-SP, not justifying the inclusion of the screen in the process. Thus the obtained data evidence the application only the decantation tank is sufficient in the ARC treatment for recirculation in the coffee fruits (Coffea arabica L.) processing.Objetivou-se, com a realização deste trabalho, avaliar a eficiência de sistemas de tratamento na remoção de sólidos e material orgânico da água utilizada no processamento de frutos do cafeeiro (ARC), de modo a possibilitar sua recirculação. O sistema de recirculação da ARC foi operado em quatro circuitos: circuito curto, sem peneira (CC-SP), no qual a ARC era recirculada sem nenhum tratamento; circuito curto, com peneira (CC-CP), no qual a ARC passava por uma peneira pressurizada de malha; circuito longo, sem peneira (CL-SP), no qual a ARC passava por um tanque de decantação; e circuito longo, com peneira (CL-CP), no qual a ARC passava pela peneira de malha e depois pelo tanque de decantação. A peneira, incluída ao sistema de tratamento da ARC, apresentou baixa eficiência na remoção de CE, ST, SS, DBO e DQO, não resultando em efeitos significativos na qualidade da água em recirculação. Entretanto, o tanque de decantação foi eficiente na remoção das variáveis analisadas. O circuito CL-CP apresentou pequeno acréscimo nas eficiências de remoção, quando comparado ao CL-SP, não justificando a inclusão da peneira de malha no processo. Com base nos resultados obtidos, verificou-se que apenas o tanque de decantação é suficiente no tratamento da ARC, para fins de sua recirculação no processamento dos frutos do cafeeiro (Coffea arabica L.)

    Immunohistochemical localization of histidine-rich glycoprotein in human skeletal muscle: preferential distribution of the protein at the sarcomeric I-band

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    Histidine-rich glycoprotein (HRG) is a relatively abundant plasma protein that is synthesized by parenchymal liver cells. Using Western blot analysis and immunoperoxidase techniques, we have previously shown the presence of HRG in human skeletal muscle. This paper reports the results of immunofluorescence experiments carried out on sections of human normal skeletal muscle biopsies to investigate the subcellular localization of HRG. The HRG localization was also compared with that of skeletal muscle AMP deaminase (AMPD1), since we have previously described an association of the enzyme with the protein. The obtained results give evidence for a preferential localization of HRG at the I-band level, where it shows the same distribution of actin and where AMPD1 is present in major concentration

    A network of stress-related genes regulates hypocotyl elongation downstream of selective auxin perception

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    The plant hormone auxin, a master coordinator of development, regulates hypocotyl elongation during seedling growth. We previously identified the synthetic molecule RubNeddin 1 (RN1), which induces degradation of the AUXIN/INDOLE-3-ACETIC ACID (AUX/IAA) transcriptional repressors INDOLE-3-ACETIC ACID-INDUCIBLE3 (IAA3) and IAA7 in planta and strongly promotes hypocotyl elongation. In the present study, we show that despite the structural similarity of RN1 to the synthetic auxin 2,4-dichlorophenoxyacetic-acid (2,4-D), direct treatments with these compounds in Arabidopsis (Arabidopsis thaliana) result in distinct effects, possibly due to enhanced uptake of RN1 and low-level, chronic release of 2,4-D from RN1 in planta. We confirm RN1-induced hypocotyl elongation occurs via specific TRANSPORT INHIBITOR RESISTANT1 (TIR1)/AUXIN SIGNALING F-BOX (AFB) receptor-mediated auxin signaling involving TIR1, AFB2, and AFB5. Using a transcriptome profiling strategy and candidate gene approach, we identify the genes ZINC FINGER OF ARABIDOPSIS THALIANA10 (ZAT10), ARABIDOPSIS TOXICOS EN LEVADURA31 (ATL31), and WRKY DNA-BINDING PROTEIN33 (WRKY33) as being rapidly upregulated by RN1, despite being downregulated by 2,4-D treatment. RN1-induced expression of these genes also occurs via TIR1/AFB-mediated auxin signaling. Our results suggest both hypocotyl elongation and transcription of these genes are induced by RN1 via the promoted degradation of the AUX/IAA transcriptional repressor IAA7. Moreover, these three genes, which are known to be stress-related, act in an inter-dependent transcriptional regulatory network controlling hypocotyl elongation. Together, our results suggest ZAT10, ATL31, and WRKY33 take part in a common gene network regulating hypocotyl elongation in Arabidopsis downstream of a selective auxin perception module likely involving TIR1, AFB2, and AFB5 and inducing the degradation of IAA7

    Effects of SNF472, a Novel Inhibitor of Hydroxyapatite Crystallization in Patients Receiving Hemodialysis - Subgroup Analyses of the CALIPSO Trial

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    Coronary artery calcium (CAC) is highly prevalent and linked with poor outcomes in patients receiving maintenance hemodialysis, and its reduction may improve patient prognosis. SNF472, a selective inhibitor of hydroxyapatite crystallization, slows CAC progression in patients receiving maintenance hemodialysis. In this analysis, we assessed the efficacy of SNF472 in prespecified patient subgroups. In a randomized clinical trial SNF472 300 mg, SNF472 600 mg, or placebo were infused thrice weekly in 91, 92, and 91 patients receiving maintenance hemodialysis and with CAC at baseline, respectively. In prespecified subanalyses, the percent change in CAC volume score (CACvs) from baseline to week 52 in modified intention-to-treat (mITT) and per-protocol (PP) populations was calculated in the following subgroups: age, sex, diabetes mellitus, dialysis vintage, prior atherosclerotic cardiovascular disease, baseline use of non-calcium and calcium-based phosphate binders, calcimimetics, activated vitamin D, warfarin, and statins. In the main trial, SNF472 significantly reduced CACvs progression compared with placebo (11% versus 20% mITT analyses; P = 0.016; 8% vs. 24% PP analyses; P < 0.001). Treatment differences for CACvs progression were similar across all subgroups, and all interaction P values were non-significant in mITT and PP analyses. SNF472 treatment for 52 weeks reduced CACvs progression compared with placebo in a broad range of patients receiving maintenance hemodialysis. Future studies will determine the impact of SNF472 on cardiovascular events in this population

    Trial design and baseline characteristics of CaLIPSO : a randomized, double-blind placebo-controlled trial of SNF472 in patients receiving haemodialysis with cardiovascular calcification

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    The objective of CaLIPSO, a Phase 2b, randomized, double-blind, placebo-controlled clinical trial, is to test the hypothesis that myo-inositol hexaphosphate (SNF472) attenuates the progression of cardiovascular calcification in patients receiving maintenance haemodialysis. Here we report the trial design and baseline characteristics of trial participants. Adult patients on maintenance haemodialysis (≥6 months) with an Agatston coronary artery calcium score, as measured by a multidetector computed tomography scanner, of 100-3500 U were enrolled. Patients were stratified by Agatston score (100-1000 U) and randomized in a 1:1:1 ratio to receive placebo, SNF472 300 mg or SNF472 600 mg administered intravenously three times weekly during each haemodialysis session. Overall, 274 patients were randomized. The mean age of trial participants was 63.6 (standard deviation 8.9) years and 39% were women. The coronary artery, aorta and aortic valve median (25th-75th percentile) Agatston scores at baseline were 730 U (315-1435), 1728 U (625-4978) and 103 U (31-262), respectively, and the median (25th-75th percentile) calcium volume scores at baseline were 666 (310-1234), 1418 (536-4052) and 107 (38-278), respectively. Older age and diabetes mellitus were associated with higher calcium scores at baseline. The CaLIPSO trial enrolled patients on haemodialysis with pre-existent cardiovascular calcification to test the hypothesis that SNF472 attenuates its progression in the coronary arteries, aorta and aortic valve
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