Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 299
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 121(16): e2311390121, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38593075

RESUMO

Many organisms that utilize the Calvin-Benson-Bassham (CBB) cycle for autotrophic growth harbor metabolic pathways to remove and/or salvage 2-phosphoglycolate, the product of the oxygenase activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). It has been presumed that the occurrence of 2-phosphoglycolate salvage is linked to the CBB cycle, and in particular, the C2 pathway to the CBB cycle and oxygenic photosynthesis. Here, we examined 2-phosphoglycolate salvage in the hyperthermophilic archaeon Thermococcus kodakarensis, an obligate anaerobe that harbors a Rubisco that functions in the pentose bisphosphate pathway. T. kodakarensis harbors enzymes that have the potential to convert 2-phosphoglycolate to glycine and serine, and their genes were identified by biochemical and/or genetic analyses. 2-phosphoglycolate phosphatase activity increased 1.6-fold when cells were grown under microaerobic conditions compared to anaerobic conditions. Among two candidates, TK1734 encoded a phosphatase specific for 2-phosphoglycolate, and the enzyme was responsible for 80% of the 2-phosphoglycolate phosphatase activity in T. kodakarensis cells. The TK1734 disruption strain displayed growth impairment under microaerobic conditions, which was relieved upon addition of sodium sulfide. In addition, glycolate was detected in the medium when T. kodakarensis was grown under microaerobic conditions. The results suggest that T. kodakarensis removes 2-phosphoglycolate via a phosphatase reaction followed by secretion of glycolate to the medium. As the Rubisco in T. kodakarensis functions in the pentose bisphosphate pathway and not in the CBB cycle, mechanisms to remove 2-phosphoglycolate in this archaeon emerged independent of the CBB cycle.


Assuntos
Archaea , Ribulose-Bifosfato Carboxilase , Ribulose-Bifosfato Carboxilase/genética , Ribulose-Bifosfato Carboxilase/metabolismo , Archaea/metabolismo , Fotossíntese , Glicolatos/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Oxigenases/metabolismo , Pentoses
2.
Nature ; 577(7789): 260-265, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31853061

RESUMO

Chronic inflammation is accompanied by recurring cycles of tissue destruction and repair and is associated with an increased risk of cancer1-3. However, how such cycles affect the clonal composition of tissues, particularly in terms of cancer development, remains unknown. Here we show that in patients with ulcerative colitis, the inflamed intestine undergoes widespread remodelling by pervasive clones, many of which are positively selected by acquiring mutations that commonly involve the NFKBIZ, TRAF3IP2, ZC3H12A, PIGR and HNRNPF genes and are implicated in the downregulation of IL-17 and other pro-inflammatory signals. Mutational profiles vary substantially between colitis-associated cancer and non-dysplastic tissues in ulcerative colitis, which indicates that there are distinct mechanisms of positive selection in both tissues. In particular, mutations in NFKBIZ are highly prevalent in the epithelium of patients with ulcerative colitis but rarely found in both sporadic and colitis-associated cancer, indicating that NFKBIZ-mutant cells are selected against during colorectal carcinogenesis. In further support of this negative selection, we found that tumour formation was significantly attenuated in Nfkbiz-mutant mice and cell competition was compromised by disruption of NFKBIZ in human colorectal cancer cells. Our results highlight common and discrete mechanisms of clonal selection in inflammatory tissues, which reveal unexpected cancer vulnerabilities that could potentially be exploited for therapeutics in colorectal cancer.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Colite Ulcerativa/genética , Taxa de Mutação , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Linhagem Celular Tumoral , Colite Ulcerativa/metabolismo , Colite Ulcerativa/patologia , Neoplasias Colorretais/genética , Humanos , Camundongos , Transdução de Sinais
3.
J Am Chem Soc ; 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38592076

RESUMO

The control of the selectivity is a central issue in the total synthesis of complex natural products. In this paper, we report the total synthesis of (±)-keramaphidin B and (±)-ingenamine. The key reaction is a DMAP-catalyzed Diels-Alder reaction in which the regioselectivity is completely controlled by dynamic crystallization. Our synthesis successfully demonstrates that dynamic crystallization can be an alternative when the selectivity is not controlled by either kinetic or thermodynamic approaches in solution.

4.
Appl Environ Microbiol ; 90(7): e0081424, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-38888337

RESUMO

Tetrahydrofolate is a cofactor involved in C1 metabolism including biosynthesis pathways for adenine and serine. In the classical tetrahydrofolate biosynthesis pathway, the steps removing three phosphate groups from the precursor 7,8-dihydroneopterin triphosphate (DHNTP) remain unclear in many bacteria. DHNTP pyrophosphohydrolase hydrolyzes pyrophosphate from DHNTP and produces 7,8-dihydroneopterin monophosphate. Although two structurally distinct DHNTP pyrophosphohydrolases have been identified in the intestinal bacteria Lactococcus lactis and Escherichia coli, the distribution of their homologs is limited. Here, we aimed to identify a third DHNTP pyrophosphohydrolase gene in the intestinal lactic acid bacterium Limosilactobacillus reuteri. In a gene operon including genes involved in dihydrofolate biosynthesis, we focused on the lreu_1276 gene, annotated as Ham1 family protein or XTP/dITP diphosphohydrolase, as a candidate encoding DHNTP pyrophosphohydrolase. The Lreu_1276 recombinant protein was prepared using E. coli and purified. Biochemical analyses of the reaction product revealed that the Lreu_1276 protein displays significant pyrophosphohydrolase activity toward DHNTP. The optimal reaction temperature and pH were 35°C and around 7, respectively. Substrate specificity was relatively strict among 17 tested compounds. Although previously characterized DHNTP pyrophosphohydrolases prefer Mg2+, the Lreu_1276 protein exhibited maximum activity in the presence of Mn2+, with a specific activity of 28.2 ± 2.0 µmol min-1 mg-1 in the presence of 1 mM Mn2+. The three DHNTP pyrophosphohydrolases do not share structural similarity to one another, and the distribution of their homologs does not overlap, implying that the Lreu_1276 protein represents a third structurally novel DHNTP pyrophosphohydrolase in bacteria. IMPORTANCE: The identification of a structurally novel DHNTP pyrophosphohydrolase in L. reuteri provides valuable information in understanding tetrahydrofolate biosynthesis in bacteria that possess lreu_1276 homologs. Interestingly, however, even with the identification of a third family of DHNTP pyrophosphohydrolases, there are still a number of bacteria that do not harbor homologs for any of the three genes while possessing other genes involved in the biosynthesis of the pterin ring structure. This suggests the presence of an unrecognized DHNTP pyrophosphohydrolase gene in bacteria. As humans do not harbor DHNTP pyrophosphohydrolase, the high structural diversity of enzymes responsible for a reaction in tetrahydrofolate biosynthesis may provide an advantage in designing inhibitors targeting a specific group of bacteria in the intestinal microbiota.


Assuntos
Proteínas de Bactérias , Limosilactobacillus reuteri , Pirofosfatases , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Limosilactobacillus reuteri/genética , Limosilactobacillus reuteri/enzimologia , Limosilactobacillus reuteri/metabolismo , Pirofosfatases/genética , Pirofosfatases/metabolismo , Pterinas/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Neopterina/análogos & derivados
5.
Langmuir ; 40(8): 4077-4086, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38346388

RESUMO

Since microemulsions are usually low viscosity fluids, enhanced rheological properties while maintaining their structure-derived functionality have long been desired from an industrial application point of view. However, for instance, it is practically difficult to thicken bicontinuous microemulsions (BCMEs) without perturbing their alternating domain structure or to emulsify oils using BCME having ultralow interfacial tension as an external phase. In this study, a methodology called a BCLC emulsification technique has been constructed to obtain oil-in-water emulsions stabilized by coexisting BCME and liquid crystal (LC) phases. The produced emulsions based on polyglyceryl-10 diisostearate, polyglyceryl-6 dicaprate, cetyl ethylhexanoate, and water are structurally scrutinized by means of small- and wide-angle X-ray scattering (SWAXS), freeze fracture transmission electron microscopy (FF-TEM), and scanning electron assisted dielectric microscopy (SE-ADM). The data provide experimental evidence that this methodology enables one to control the bending elasticity of the interfacial membranes and consequent long-range order of the BCME domains. Moreover, closely correlated with the interfacial membrane properties, submicrometer-sized fine oil droplets are supported by the LC networks and agglomerated into spongy or network-like phase-separation patterns. The resulting nonfluidic, jelly emulsions are particularly useful in cosmetics because of combined BCME-derived high cleansing performance and excellent usability owing to the enhanced viscosity. The thickening mechanisms are essentially different from those of common lamellar-gel-stabilized oil-in-water emulsions, which utilize crystalline lamellar gel networks as oil droplet stabilizers.

6.
Diabetes Obes Metab ; 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39192522

RESUMO

AIM: Normoglycaemia was achieved in a significant proportion of Japanese participants with type 2 diabetes in two phase 3 studies of tirzepatide. This post hoc exploratory analysis aimed to identify predictive factors associated with normoglycaemia achievement. MATERIALS AND METHODS: SURPASS J-mono and SURPASS J-combo study data were pooled for this analysis. Characteristics of participants in whom normoglycaemia [glycated haemoglobin (HbA1c) <5.7%] was achieved were summarized. Logistic regression analyses were performed with HbA1c <5.7% achievement as the target variable. RESULTS: Of 912 participants, normoglycaemia was achieved in 553 (60.6%) following 52 weeks of tirzepatide treatment. Overall, the mean (SD) age was 56.7 (10.6) years and mean diabetes duration was 7.7 (6.0) years, and 76% of participants were men. Mean (SD) change from baseline in HbA1c and bodyweight was -2.87% (0.95) versus -2.47% (1.1) and -10.30 (5.8) kg versus -3.75 (4.3) kg for participants in whom normoglycaemia was and was not reached, respectively. Multivariate regression analyses showed that lower baseline body mass index, shorter disease duration and lower baseline HbA1c were significantly associated with higher rates of normoglycaemia achievement (p = 0.009, p = 0.008, p < 0.001, respectively) as was a tirzepatide dose of 10 or 15 mg compared with 5 mg (p < 0.001). The highest percentage of participants in whom normoglycaemia (94%) was achieved were those with lower baseline HbA1c (<8%) and the greatest weight reduction (≥15%). CONCLUSIONS: Baseline HbA1c and body mass index, disease duration and the tirzepatide treatment group were shown to be predictive factors for achieving normoglycaemia. A lower baseline HbA1c was most strongly associated with normoglycaemia achievement.

7.
Org Biomol Chem ; 22(16): 3230-3236, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38564238

RESUMO

Natural linear polyamines play diverse roles in physiological processes by interacting with receptors at the cellular level. Herein, we describe the stereodivergent synthesis of oligopyrrolidines, which are conformationally constrained polyamines. We synthesized dimeric and trimeric 2-oxo-oligopyrrolidines using an iterative coupling strategy. The key to our success is an iridium-catalyzed trans/cis-selective nucleophilic addition and subsequent threo/erythro-stereoselective reduction. The synthesized pyrrolidines show varying cytotoxicities against a human cancer cell line depending on the number of rings and their stereochemistry.

8.
Heart Vessels ; 39(7): 646-653, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38502318

RESUMO

Epicardial adipose tissue (EAT) have been shown to be associated with several heart disease, including coronary artery disease (CAD), atrial fibrillation (AF), and heart failure (HF). It is reported that the quality of EAT, represented by fat attenuation determined using computed tomography (CT) imaging, can detect the histologically-assessed remodeled EAT. We tested the hypothesis that quality of EAT would predict major adverse cerebral and cardiovascular events (MACCE) following transcatheter aortic valve implantation (TAVI) in patients with aortic stenosis (AS). A total of 125 consecutive severe AS patients who underwent TAVI were enrolled (39 male, mean 85.4 ± 4.0 years). Using CT imaging before TAVI, we measured the average CT fat attenuation of EAT (EAT attenuation) and investigated the association with MACCE. During the mean follow up period of 567 ± 371 days, 21 cases of MACCE were observed. Patients with MACCE had greater levels of EAT attenuation compared to those without (- 74 ± 3.7 Hounsfield Units (HU) vs - 77 ± 5.5 HU, p = 0.010). Based on the ROC curves, the high EAT attenuation was defined as > - 74.3 HU. According to this cut-off index, 44 patients were classified into the high EAT attenuation group (28 female, mean age 87 ± 3.6 years), whereas 81 patients were classified into the low EAT attenuation group (13 female, 85 ± 4.1 years). Kaplan-Meier survival curve demonstrated that the patients in the high EAT attenuation group showed greater prevalence of MACCE (log-rank 6.64, p = 0.010). Cox proportional hazards regression analysis revealed that EAT attenuation and Logistic EuroSCORE were independently associated with the incidence of MACCE. Our results suggest that quality of EAT, assessed by EAT attenuation detected by CT imaging, can predict the cerebral and cardiovascular events after TAVI in patients with AS.


Assuntos
Tecido Adiposo , Estenose da Valva Aórtica , Pericárdio , Substituição da Valva Aórtica Transcateter , Humanos , Masculino , Feminino , Substituição da Valva Aórtica Transcateter/efeitos adversos , Pericárdio/diagnóstico por imagem , Estenose da Valva Aórtica/cirurgia , Tecido Adiposo/diagnóstico por imagem , Idoso de 80 Anos ou mais , Fatores de Risco , Estudos Retrospectivos , Valva Aórtica/cirurgia , Valva Aórtica/diagnóstico por imagem , Medição de Risco/métodos , Idoso , Tomografia Computadorizada por Raios X , Índice de Gravidade de Doença , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/diagnóstico , Curva ROC , Japão/epidemiologia , Valor Preditivo dos Testes , Seguimentos , Resultado do Tratamento , Tomografia Computadorizada Multidetectores , Fatores de Tempo , Tecido Adiposo Epicárdico
9.
Clin Oral Investig ; 28(8): 463, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39090476

RESUMO

OBJECTIVES: The first aim of this study was to determine whether there is a difference in degree of conversion (DC) of touch-cure cements polymerized by self-curing with adhesive or dual-curing under reduced light. The second aim was to compare interfacial adaptation of zirconia restoration cemented using touch-cure cements self-cured or dual-cured by reduced light. METHODS: The DC of touch-cure resin cements with adhesive was measured continuously using Fourier transform infrared spectrometry. Experimental groups differed depending on touch-cure cement. Each group had three subgroups of polymerization method. For subgroup 1, the DC was measured by self-curing. For subgroups 2 and 3, the DCs were measured by dual-curing with reduced light penetrating 3 mm and 1 mm zirconia blocks, respectively. For interfacial adaptation evaluation, Class I cavity was prepared on an extracted third molar, and zirconia restoration was fabricated. The restoration was cemented using the same cement. Groups and subgroups for interfacial adaptation were the same as those of the DC measurement. After thermo-cycling, interfacial adaptation at the tooth-restoration interface was evaluated using swept-source optical coherence tomography imaging. RESULTS: The DC of touch-cure cement differed depending on the measurement time, resin cement, and polymerization method (p < 0.05). Interfacial adaptation was different depending on the resin cement and polymerization method (p < 0.05). CONCLUSION: For touch-cure cement, light-curing with higher irradiance presented a higher DC and superior interfacial adaptation than light-curing with lower irradiance or self-curing. CLINICAL RELEVANCE: Although some adhesives accelerate the self-curing of touch-cure cement, light-curing for touch-cure cement is necessary for zirconia cementation.


Assuntos
Teste de Materiais , Polimerização , Cimentos de Resina , Zircônio , Cimentos de Resina/química , Zircônio/química , Espectroscopia de Infravermelho com Transformada de Fourier , Autocura de Resinas Dentárias , Lâmpadas de Polimerização Dentária , Cura Luminosa de Adesivos Dentários , Propriedades de Superfície , Técnicas In Vitro , Humanos , Dente Serotino , Restauração Dentária Permanente/métodos
10.
Angew Chem Int Ed Engl ; 63(6): e202317290, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38088513

RESUMO

A reductive (3+2) annulation of lactams through iridium-catalyzed hydrosilylation and photoredox coupling with α-bromoacetic acid was developed. The iridium-catalyzed hydrosilylation of the lactam carbonyl group and subsequent elimination provide a transient cyclic enamine, which undergoes iridium-catalyzed photoredox coupling with α-bromoacetic acid in a one-pot process. The developed conditions show high functional-group tolerance and provide cyclic N,O-acetals containing a quaternary carbon center. The resulting N,O-acetals undergo a variety of acid-mediated nucleophilic addition reactions via iminium ions to give substituted cyclic amines. The developed sequence including reductive (3+2) annulation and acid-mediated nucleophilic addition was successfully applied to the four-step total synthesis of (±)-eburnamonine.

11.
Angew Chem Int Ed Engl ; 63(17): e202402335, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38454885

RESUMO

The total synthesis of lobatamides A (1 a) and C (1 c) via a common bislactone intermediate is reported. The allylic aryl moiety including a trisubstituted Z-olefin was constructed by hydroboration of a 1,1-disubstituted allene and subsequent Migita-Kosugi-Stille coupling. Although the seco acid proved to be highly unstable even in the presence of weak bases, Zhao macrolactonization under acidic conditions via the α-acyloxyenamide successfully provided the common bislactone intermediate. Hydrozirconation-iodination of the terminal alkyne and subsequent copper-mediated coupling with primary amides proceeded successfully in the presence of the sensitive bislactone framework. The developed synthetic route enables the late-stage installation of enamide side chains, which are crucial structures for V-ATPase inhibition.

12.
Cancer Sci ; 114(10): 4020-4031, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37608343

RESUMO

Lipids are a major component of extracellular vesicles; however, their significance in tumorigenesis and progression has not been well elucidated. As we previously found that lipid profiles drastically changed in breast tumors upon progression, we hypothesized that lipid profiles of plasma-derived extracellular vesicles could be utilized as breast cancer biomarkers. Here, we adopted modified sucrose cushion ultracentrifugation to isolate plasma-derived extracellular vesicles from breast cancer (n = 105), benign (n = 11), and healthy individuals (n = 43) in two independent cohorts (n = 126 and n = 33) and conducted targeted lipidomic analysis. We established a breast cancer diagnostic model comprising three lipids that showed favorable performance with the area under the receiver operating characteristic curve of 0.759, 0.743, and 0.804 in the training, internal validation, and external test sets, respectively. Moreover, we identified several lipids that could effectively discriminate breast cancer progression and subtypes: phosphatidylethanolamines and phosphatidylserines were relatively higher in Stage III, whereas phosphatidylcholines and sphingomyelins were higher in Stage IV; phosphatidylcholines and ceramides were correspondingly concentrated in HER2-positive patients, while lysophosphatidylcholines and polyunsaturated triglycerides were concentrated in the triple-negative breast cancer subtype. Lipid profiling of plasma-derived extracellular vesicles is a non-invasive and promising approach for diagnosing, staging, and subtyping breast cancer.

13.
Stem Cells ; 40(4): 397-410, 2022 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-35385105

RESUMO

Somatic cell reprogramming proceeds through a series of events to generate induced pluripotent stem cells (iPSCs). The early stage of reprogramming of mouse embryonic fibroblasts is characterized by rapid cell proliferation and morphological changes, which are accompanied by downregulation of mesenchyme-associated genes. However, the functional relevance of their downregulation to reprogramming remains poorly defined. In this study, we have screened transcriptional regulators that are downregulated immediately upon reprogramming, presumably through direct targeting by reprogramming factors. To test if these transcriptional regulators impact reprogramming when expressed continuously, we generated an expression vector that harbors human cytomegalovirus upstream open reading frame 2 (uORF2), which reduces translation to minimize the detrimental effect of an expressed protein. Screening of transcriptional regulators with this expression vector revealed that downregulation of (odd-skipped related 2 [Osr2]) is crucial for efficient reprogramming. Using a cell-based model for epithelial-mesenchymal transition (EMT), we show that Osr2 is a novel EMT regulator that acts through induction of transforming growth factor-ß (TGF-ß) signaling. During reprogramming, Osr2 downregulation not only diminishes TGF-ß signaling but also allows activation of Wnt signaling, thus promoting mesenchymal-epithelial transition (MET) toward acquisition of pluripotency. Our results illuminate the functional significance of Osr2 downregulation in erasing the mesenchymal phenotype at an early stage of somatic cell reprogramming.


Assuntos
Transição Epitelial-Mesenquimal , Células-Tronco Pluripotentes Induzidas , Animais , Reprogramação Celular/genética , Regulação para Baixo/genética , Transição Epitelial-Mesenquimal/genética , Fibroblastos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Camundongos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fator de Crescimento Transformador beta/metabolismo
14.
J Org Chem ; 88(19): 13655-13665, 2023 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-37729096

RESUMO

An accurate understanding of conformations in transition states is a critical piece in the theoretical analysis of complex molecular reactions. In this study, we investigated conformationally diverse transition states during intramolecular aza-spiro ring formation with an allylsilane moiety and N-alkoxy iminium ion, a key reaction in the synthesis of fasicularin by Sato and Chida et al., and identified the origins of stereoselectivity of the cyclization. A large number of conformational isomers with forming C-C bonds were comprehensively analyzed using Cremer-Pople puckering parameters. It was found that the conformations of the transition states had different puckering preferences depending on the reactant's double-bond geometry and the product's stereochemical configuration. Furthermore, an asymmetric aza-spiro cyclization with a tolyl group as a chiral auxiliary was investigated, showing that conformational anchoring by both a CH-O hydrogen bond and the CH-π interaction was critical for the asymmetric induction.

15.
Angew Chem Int Ed Engl ; 62(13): e202218655, 2023 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-36719065

RESUMO

Asparagine-linked protein glycosylations (N-glycosylations) are one of the most abundant post-translational modifications and are essential for various biological phenomena. Herein, we describe the isolation, structural determination, and chemical synthesis of the N-glycan from the hyperthermophilic archaeon Thermococcus kodakarensis. The N-glycan from the organism possesses a unique structure including myo-inositol, which has not been found in previously characterized N-glycans. In this structure, myo-inositol is highly glycosylated and linked with a disaccharide unit through a phosphodiester. The straightforward synthesis of this glycan was accomplished through diastereoselective phosphorylation and phosphodiester construction by SN 2 coupling. Considering the early divergence of hyperthermophilic organisms in evolution, this study can be expected to open the door to approaching the primitive function of glycan modification at the molecular level.


Assuntos
Thermococcus , Inositol/metabolismo , Polissacarídeos/metabolismo
16.
J Sports Sci Med ; 22(1): 98-110, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36876177

RESUMO

We developed a new Physical Score (PS) consisting of comprehensive physical fitness indicators and elucidated the association between the resultant PS and metabolic diseases, i.e., diabetes, hypertension, dyslipidemia, fatty liver, and metabolic syndrome (MetS), among Japanese. Analyzed were 49,850 persons (30,039 men) aged 30 to 69 y who underwent physical fitness tests. Principal component analysis was performed on the correlation matrix of the physical fitness test results (relative grip strength, single-leg balance with eyes closed, and forward bending) according to sex and age. We defined the PS as the first principal component score. A formula was developed for various age groups comprised of men and women from 30 to 69 years of age from which the PS for each age and sex was calculated. The PS for both men and women was normally distributed with a value of 0 ± 1.15-1.16. Multivariate logistic regression analysis showed that the risk of metabolic diseases increased approximately 1.1-1.6 times per each 1-point reduction in the PS. The association between PS and MetS was particularly strong in that a 1-point reduction in the PS increased the risk of MetS by 1.54 times (95% confidence interval 1.46 to 1.62) in men and by 1.21 times (1.15 to 1.28) in women. The association between a lower PS and disease risk was stronger in younger men for fatty liver and in older men for MetS. Conversely, in women, the association between a lower PS and disease risk was stronger in older women for fatty liver and in younger women for MetS. For diabetes, hypertension, and dyslipidemia, the change in the impact of PS reductions across age groups was small. The PS is a useful and simple non-invasive tool for screening Japanese people for metabolic diseases.


Assuntos
Fígado Gorduroso , Hipertensão , Síndrome Metabólica , Masculino , Feminino , Humanos , Idoso , Adulto , Pessoa de Meia-Idade , Aptidão Física , Exercício Físico , Doença Crônica
17.
Appl Environ Microbiol ; 88(13): e0064422, 2022 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-35736229

RESUMO

Lipoic acid is an organosulfur cofactor essential for several key enzyme complexes in oxidative and one-carbon metabolism. It is covalently bound to the lipoyl domain of the E2 subunit in some 2-oxoacid dehydrogenase complexes and the H-protein in the glycine cleavage system. Lipoate-protein ligase (Lpl) is involved in the salvage of exogenous lipoate and attaches free lipoate to the E2 subunit or the H-protein in an ATP-dependent manner. In the hyperthermophilic archaeon Thermococcus kodakarensis, TK1234 and TK1908 are predicted to encode the N- and C-terminal regions of Lpl, respectively. TK1908 and TK1234 recombinant proteins form a heterodimer and together displayed significant ligase activity toward octanoate in addition to lipoate when a chemically synthesized octapeptide was used as the acceptor. The proteins also displayed activity toward other fatty acids, indicating broad fatty acid specificity. On the other hand, lipoyl synthase from T. kodakarensis only recognized octanoyl-peptide as a substrate. Examination of individual proteins indicated that the TK1908 protein alone was able to catalyze the ligase reaction although with a much lower activity. Gene disruption of TK1908 led to lipoate/serine auxotrophy, whereas TK1234 gene deletion did not. Acyl carrier protein homologs are not found on the archaeal genomes, and the TK1908/TK1234 protein complex did not utilize octanoyl-CoA, raising the possibility that the substrate of the ligase reaction is octanoic acid itself. Although Lpl has been considered as an enzyme involved in lipoate salvage, the results imply that in T. kodakarensis, the TK1908 and TK1234 proteins function in de novo lipoyl-protein biosynthesis. IMPORTANCE Based on previous studies in bacteria and eukaryotes, lipoate-protein ligases (Lpls) have been considered to be involved exclusively in lipoate salvage. The genetic analyses in this study on the lipoate-protein ligase in T. kodakarensis, however, suggest otherwise and that the enzyme is additionally involved in de novo protein lipoylation. We also provide biochemical evidence that the lipoate-protein ligase displays broad substrate specificity and is capable of ligating acyl groups of various chain-lengths to the peptide substrate. We show that this apparent ambiguity in Lpl is resolved by the strict substrate specificity of the lipoyl synthase LipS in this organism, which only recognizes octanoyl-peptide. The results provide relevant physiological insight into archaeal protein lipoylation.


Assuntos
Thermococcus , Peptídeo Sintases/genética , Biossíntese de Proteínas , Especificidade por Substrato
18.
Cardiovasc Diabetol ; 21(1): 90, 2022 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-35655263

RESUMO

BACKGROUND: To determine the impact of metabolic syndrome (MetS) and/or metabolic dysfunction-associated fatty liver disease (MAFLD), which are pathophysiologically similar and include insulin resistance, on the development of new-onset cardiovascular disease with and without type 2 diabetes and according to sex. METHODS: This study included 570,426 individuals without a history of cardiovascular disease who were enrolled in a nationwide claims database from 2008 to 2016 and were classified by the presence or absence of MetS and/or MAFLD stratified by the presence or absence of type 2 diabetes and sex. The fatty liver index was used to determine the presence or absence of fatty liver that required a diagnosis of MAFLD. Risks of developing coronary artery disease (CAD) and cerebrovascular disease (CVD) in each category were analyzed using a multivariate Cox proportional hazard model. RESULTS: During a median follow-up of 5.2 years, 2252 CAD and 3128 CVD events occurred. Without type 2 diabetes the hazard ratio (HR) (95% CI) for CAD/CVD compared with neither MAFLD nor MetS was 1.32 (1.17-1.50)/1.41(1.28-1.57) for MAFLD only (without MetS), 1.78 (1.22-2.58)/1.66 (1.34-2.06) for MetS only (without MAFLD), and 2.10 (1.84-2.39)/1.73 (1.54-1.95) for MAFLD + MetS. For those with type 2 diabetes, the HR for CAD for MAFLD only (compared with neither MAFLD nor MetS) was 1.29 (1.06-1.58), for MetS only 1.34 (0.84-2.13), and for MAFLD + MetS 1.22 (1.02-1.47). For CVD, there was a significant increase in HR only in MAFLD + MetS [1.44 (1.18-1.76)]. The results of the analysis stratified by sex showed that MAFLD had a greater impact in men, and MetS had a greater impact in women regarding the development of CAD. CONCLUSIONS: Distinguishing between MetS and/or MAFLD in the presence or absence of type 2 diabetes and according to sex may aid in accurately identifying patients at high risk of cardiovascular disease.


Assuntos
Doenças Cardiovasculares , Doença da Artéria Coronariana , Diabetes Mellitus Tipo 2 , Fígado Gorduroso , Síndrome Metabólica , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Doença da Artéria Coronariana/complicações , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , Fatores de Risco de Doenças Cardíacas , Humanos , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/epidemiologia , Fatores de Risco
19.
J Orthop Sci ; 27(6): 1185-1189, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34404611

RESUMO

BACKGROUND: Central sensitization is one cause of chronic low back pain. Lifestyle and psychosocial factors are involved in the exacerbation of central sensitization. However, the combined effects of these factors on central sensitization in patients with chronic low back pain are unclear. The objective of this study was to investigate the combined effects of lifestyle and psychosocial factors on central sensitization in patients with chronic low back pain. METHODS: This was a cross-sectional study. The participants were recruited from three orthopedic clinics for a total of 70 patients with chronic low back pain. Data were analyzed using hierarchical multiple regression analysis. In Model 1, lifestyle factors such as sleep quality, physical activity, sitting time, and perceived stress were included. Model 2 included psychosocial factors (pain catastrophizing, anxiety, and depression). RESULTS: The data showed that sleep (b = 0.30) and perceived stress (b = 0.47) were significantly correlated in Model 1, and anxiety (b = 0.41) and perceived stress (b = 0.27) were significantly correlated in Model 2. Furthermore, contributions from sleep (b = 0.14) decreased, and no significant correlations were observed. The coefficient of determination increased significantly from Model 1 to Model 2 (ΔR 2 = 0.12, p < 0.05). CONCLUSIONS: In this study, we clarified that perceived stress and anxiety were correlated with central sensitization in patients with chronic low back pain. In addition, sleep quality mediates anxiety and may be associated with central sensitization.


Assuntos
Dor Crônica , Dor Lombar , Humanos , Sensibilização do Sistema Nervoso Central , Dor Lombar/psicologia , Estudos Transversais , Catastrofização , Estilo de Vida , Dor Crônica/psicologia
20.
J Bacteriol ; 203(16): e0002521, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34096778

RESUMO

Serine kinase catalyzes the phosphorylation of free serine (Ser) to produce O-phosphoserine (Sep). An ADP-dependent Ser kinase in the hyperthermophilic archaeon Thermococcus kodakarensis (Tk-SerK) is involved in cysteine (Cys) biosynthesis and most likely Ser assimilation. An ATP-dependent Ser kinase in the mesophilic bacterium Staphylococcus aureus is involved in siderophore biosynthesis. Although proteins displaying various degrees of similarity with Tk-SerK are distributed in a wide range of organisms, it is unclear if they are actually Ser kinases. Here, we examined proteins from Desulfurococcales species in Crenarchaeota that display moderate similarity with Tk-SerK from Euryarchaeota (42 to 45% identical). Tk-serK homologs from Staphylothermus marinus (Smar_0555), Desulfurococcus amylolyticus (DKAM_0858), and Desulfurococcus mucosus (Desmu_0904) were expressed in Escherichia coli. All three partially purified recombinant proteins exhibited Ser kinase activity utilizing ATP rather than ADP as a phosphate donor. Purified Smar_0555 protein displayed activity for l-Ser but not other compounds, including d-Ser, l-threonine, and l-homoserine. The enzyme utilized ATP, UTP, GTP, CTP, and the inorganic polyphosphates triphosphate and tetraphosphate as phosphate donors. Kinetic analysis indicated that the Smar_0555 protein preferred nucleoside 5'-triphosphates over triphosphate as a phosphate donor. Transcript levels and Ser kinase activity in S. marinus cells grown with or without serine suggested that the Smar_0555 gene is constitutively expressed. The genes encoding Ser kinases examined here form an operon with genes most likely responsible for the conversion between Sep and 3-phosphoglycerate of central sugar metabolism, suggesting that the ATP-dependent Ser kinases from Desulfurococcales play a role in the assimilation of Ser. IMPORTANCE Homologs of the ADP-dependent Ser kinase from the archaeon Thermococcus kodakarensis (Tk-SerK) include representatives from all three domains of life. The results of this study show that even homologs from the archaeal order Desulfurococcales, which are the most structurally related to the ADP-dependent Ser kinases from the Thermococcales, are Ser kinases that utilize ATP, and in at least some cases inorganic polyphosphates, as the phosphate donor. The differences in properties between the Desulfurococcales and Thermococcales enzymes raise the possibility that Tk-SerK homologs constitute a group of kinases that phosphorylate free serine with a wide range of phosphate donors.


Assuntos
Proteínas Arqueais/metabolismo , Desulfurococcaceae/enzimologia , Proteínas Serina-Treonina Quinases/metabolismo , Trifosfato de Adenosina/metabolismo , Proteínas Arqueais/química , Proteínas Arqueais/genética , Desulfurococcaceae/classificação , Desulfurococcaceae/genética , Temperatura Alta , Cinética , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA