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1.
J Biol Chem ; 299(3): 102973, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36738789

RESUMO

Although cell size regulation is crucial for cellular functions in a variety of organisms from bacteria to humans, the underlying mechanisms remain elusive. Here, we identify Rim21, a component of the pH-sensing Rim101 pathway, as a positive regulator of cell size through a flow cytometry-based genome-wide screen of Saccharomyces cerevisiae deletion mutants. We found that mutants defective in the Rim101 pathway were consistently smaller than wildtype cells in the log and stationary phases. We show that the expression of the active form of Rim101 increased the size of wildtype cells. Furthermore, the size of wildtype cells increased in response to external alkalization. Microscopic observation revealed that this cell size increase was associated with changes in both vacuolar and cytoplasmic volume. We also found that these volume changes were dependent on Rim21 and Rim101. In addition, a mutant lacking Vph1, a component of V-ATPase that is transcriptionally regulated by Rim101, was also smaller than wildtype cells, with no increase in size in response to alkalization. We demonstrate that the loss of Vph1 suppressed the Rim101-induced increase in cell size under physiological pH conditions. Taken together, our results suggest that the cell size of budding yeast is regulated by the Rim101-V-ATPase axis under physiological conditions as well as in response to alkaline stresses.


Assuntos
Proteínas Repressoras , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Concentração de Íons de Hidrogênio , Proteínas Repressoras/metabolismo , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , ATPases Vacuolares Próton-Translocadoras/metabolismo , Deleção de Sequência
2.
J Cell Sci ; 135(17)2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35912799

RESUMO

Target of rapamycin (TOR) forms two distinct complexes, TORC1 and TORC2, to exert its essential functions in cellular growth and homeostasis. TORC1 signaling is regulated in response to nutrients such as amino acids and glucose; however, the mechanisms underlying the activation of TORC2 signaling are still poorly understood compared to those for TORC1 signaling. In the budding yeast Saccharomyces cerevisiae, TORC2 targets the protein kinases Ypk1 and Ypk2 (hereafter Ypk1/2), and Pkc1 for phosphorylation. Plasma membrane stress is known to activate TORC2-Ypk1/2 signaling. We have previously reported that methylglyoxal (MG), a metabolite derived from glycolysis, activates TORC2-Pkc1 signaling. In this study, we found that MG activates the TORC2-Ypk1/2 and TORC2-Pkc1 signaling, and that phosphatidylserine is involved in the activation of both signaling pathways. We also demonstrated that the Rho family GTPase Cdc42 contributes to the plasma membrane stress-induced activation of TORC2-Ypk1/2 signaling. Furthermore, we revealed that phosphatidylinositol-specific phospholipase C, Plc1, contributes to the activation of both TORC2-Ypk1/2 and TORC2-Pkc1 signaling.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Fosfatidilserinas/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Sirolimo , Fosfolipases Tipo C/genética , Fosfolipases Tipo C/metabolismo
3.
Kyobu Geka ; 77(3): 213-216, 2024 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-38465494

RESUMO

Formation of a pseudoaneurysm due to blood leakage from the anastomotic site of the vascular graft in large-diameter vessels is often seen, but formation of a pseudoaneurysm from the non-anastomotic site is extremely rare. A 68-year-old woman presented with a history of double valve replacement for combined valvular disease at 37 years old and hemiarch replacement for thoracic aortic dilatation at 65 years old. She visited the emergency room with a 2-week history of chest pain. Contrast-enhanced computed tomography (CT) revealed a 5-cm-diameter pseudoaneurysm and extravasation from the ascending aorta, so emergency surgery was performed. Around the ascending aorta area, we confirmed bleeding from a 5-mm dehiscence in the non-anastomotic part of the graft prosthesis, so hemostasis was performed with a cross-stitch mattress suture over a felt strip. Initially, the cause of the pseudoaneurysm was unknown, but re-examination of CT images from after the previous hemiarch replacement confirmed contact between the sternal wire and graft prosthesis. The wire was thus considered to have caused damage and bleeding. The patient was discharged from the hospital with a good postoperative course and is being followed-up in the outpatient department.


Assuntos
Falso Aneurisma , Implante de Prótese Vascular , Idoso , Feminino , Humanos , Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/etiologia , Falso Aneurisma/cirurgia , Aorta/cirurgia , Substitutos Sanguíneos , Implante de Prótese Vascular/efeitos adversos
4.
Kyobu Geka ; 77(7): 533-539, 2024 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-39009552

RESUMO

OBJECTIVES: The extensibility of the aortic root after the remodeling procedure was evaluated using 4-dimentional computed tomography( 4D-CT). PATIENTS AND METHODS: Seventeen patients( 13 males/4 females), mean age 52 years, who had undergone the remodeling procedure in the last 3 years were included. To understand the dynamics of the aortic root after reconstruction, the R-R interval on the electrocardiogram was divided into 10 equal parts, and the percentage change in area of the basal ring/Valsalva sinus/sino-tubular junction (STJ) level was calculated to evaluate the extensibility of the aortic root. For the basal ring, changes in ellipticity and circumference were also compared. RESULTS: Basal ring, Valsalva sinus, and STJ area changes with cardiac cycle were similar to those in the control group. Basal ring showed a regular circle in systole and an oval in diastole, and its circumference was enlarged in systole. CONCLUSIONS: The use of 4D-CT made it possible to evaluate the extensibility of the aortic root after remodeling procedure. In particular, the mobility of the basal ring is large, suggesting that it guarantees the physiological opening and closing of the valve and contributes to its durability.


Assuntos
Tomografia Computadorizada Quadridimensional , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Idoso , Valva Aórtica/cirurgia , Valva Aórtica/diagnóstico por imagem
5.
Mol Microbiol ; 117(5): 1227-1244, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35383382

RESUMO

MCCs are linear invaginations of the yeast plasma membrane that form stable membrane microdomains. Although over 20 proteins are localized in the MCCs, it is not well understood how these proteins coordinately maintain normal MCC function. Pil1 is a core eisosome protein and is responsible for MCC-invaginated structures. In addition, six-tetraspan membrane proteins (6-Tsp) are localized in the MCCs and classified into two families, the Sur7 family and Nce102 family. To understand the coordinated function of these MCC proteins, single and multiple deletion mutants of Pil1 and 6-Tsp were generated and their MCC structure and growth under various stresses were investigated. Genetic interaction analysis revealed that the Sur7 family and Nce102 function in stress tolerance and normal eisosome assembly, respectively, by cooperating with Pil1. To further understand the role of MCCs/eisosomes in stress tolerance, we screened for suppressor mutants using the SDS-sensitive phenotype of pil1Δ 6-tspΔ cells. This revealed that SDS sensitivity is caused by hyperactivation of Tor kinase complex 2 (TORC2)-Ypk1 signaling. Interestingly, inhibition of sphingolipid metabolism, a well-known downstream pathway of TORC2-Ypk1 signaling, did not rescue the SDS-sensitivity of pil1Δ 6-tspΔ cells. These results suggest that Pil1 and 6-Tsp cooperatively regulate TORC2 signaling during the stress response.


Assuntos
Proteínas de Saccharomyces cerevisiae , Membrana Celular/metabolismo , Alvo Mecanístico do Complexo 2 de Rapamicina/metabolismo , Microdomínios da Membrana/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Fosfoproteínas/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
6.
Int J Mol Sci ; 24(7)2023 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-37047295

RESUMO

Previous works have shown the existence of protein partnership, belonging to a MultiStep Phosphorelay (MSP), potentially involved in osmosensing in Populus. The first actor of this signalling pathway belongs to the histidine-aspartate kinase (HK) family, which also includes the yeast osmosensor Sln1, as well as the Arabidopsis putative osmosensor AHK1. In poplar, the homologous AHK1 protein corresponds to a pair of paralogous proteins, HK1a and HK1b, exhibiting an extracellular domain (ECD), as in Sln1 and AHK1. An ECD alignment of AHK1-like proteins, from different plant species, showed a particularly well conserved ECD and revealed the presence of a cache domain. This level of conservation suggested a functional role of this domain in osmosensing. Thus, we tested this possibility by modelling assisted mutational analysis of the cache domain of the Populus HK1 proteins. The mutants were assessed for their ability to respond to different osmotic stress and the results point to an involvement of this domain in HK1 functionality. Furthermore, since HK1b was shown to respond better to stress than HK1a, these two receptors constituted a good system to search for osmosensing determinants responsible for this difference in efficiency. With domain swapping experiments, we finally demonstrated that the cache domain, as well as the second transmembrane domain, are involved in the osmosensing efficiency of these receptors.


Assuntos
Arabidopsis , Populus , Proteínas de Saccharomyces cerevisiae , Histidina Quinase/genética , Histidina Quinase/metabolismo , Ácido Aspártico/metabolismo , Histidina/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Populus/genética , Populus/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo
7.
Kyobu Geka ; 76(13): 1097-1100, 2023 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-38088074

RESUMO

Coronary artery fistula is a rare abnormality in the communication between a coronary artery and any of the cardiac chambers or major vessels. At present, there is no standard surgical treatment and the most appropriate method is selected on a case-by-case basis. We report one case of coronary artery fistulae in which pulmonary artery transection was required around the left main trunk (LMT). A 62-year-old man who had coronary artery fistulae with an aneurysm which increased from 12 mm to 16 mm in a two-year span. The fistula was located adjacent to the LMT. A complete aneurysm excision under cardiopulmonary bypass was performed, which required pulmonary artery transection. No postoperative complications occurred. Postoperative coronary computed tomography scan showed intact coronary arteries and complete aneurysm removal.


Assuntos
Fístula Artério-Arterial , Aneurisma Coronário , Doença da Artéria Coronariana , Masculino , Humanos , Pessoa de Meia-Idade , Aneurisma Coronário/complicações , Artéria Pulmonar/diagnóstico por imagem , Artéria Pulmonar/cirurgia , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/cirurgia , Fístula Artério-Arterial/diagnóstico por imagem , Fístula Artério-Arterial/cirurgia , Fístula Artério-Arterial/complicações , Doença da Artéria Coronariana/cirurgia , Angiografia Coronária
8.
Circ J ; 86(10): 1579-1585, 2022 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-35466157

RESUMO

BACKGROUND: The coronavirus disease (COVID-19) pandemic may have influenced the prehospital emergency care and deaths of individuals experiencing an out-of-hospital cardiac arrest (OHCA).Methods and Results: We analyzed the registry data of 2,420 and 2,371 OHCA patients in Osaka City, Japan in 2019 and 2020, respectively, according to the 3 waves of the COVID-19 pandemic. Patient outcomes were compared using multivariable logistic regression analyses with the 2019 data as the reference. Bystander cardiopulmonary resuscitation (CPR) was initiated significantly less frequently in 2020 than in 2019 (2019: 48.0%, 2020: 42.7%, P<0.001), particularly during the first wave (2019: 47.2%, 2020: 42.9%, P=0.046) and second wave (2019: 48.1%, 2020: 41.2%, P=0.010), but not during the third wave (2019: 49.2%, 2020: 44.1%, P=0.066). The public-access automated external defibrillator was less frequently applied during the first wave (2019: 12.6%, 2020: 9.9%, P=0.043), with no significant difference during the second wave (2019: 12.5%, 2020: 12.8%, P=0.863) and third wave (2019: 13.7%, 2020: 13.0%, P=0.722). There was a significant difference in 1-month survival with favorable neurological outcomes (2019: 4.6%, 2020: 3.3%, P=0.018), with a 28% reduction in the adjusted odds ratio in 2020 (0.72; 95% confidence interval: 0.52-0.99, P=0.044). CONCLUSIONS: Bystander CPR and neurologically favorable outcomes after OHCA decreased significantly during the COVID-19 pandemic in Japan.


Assuntos
COVID-19 , Reanimação Cardiopulmonar , Serviços Médicos de Emergência , Parada Cardíaca Extra-Hospitalar , COVID-19/epidemiologia , Reanimação Cardiopulmonar/métodos , Serviços Médicos de Emergência/métodos , Humanos , Japão/epidemiologia , Pandemias , Sistema de Registros
9.
Mol Cell ; 47(2): 242-52, 2012 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-22727621

RESUMO

The target of rapamycin complex 1 (TORC1) is a central kinase that coordinates nutrient availability with eukaryotic cell growth. Although TORC1 signaling is repressed by various stresses in yeast, the underlying mechanisms remain elusive. Here we report that TORC1 signaling upon heat stress is regulated by stress granules (SGs), which are cytoplasmic foci formed under certain stresses. Ectopic formation of SGs achieved by Pbp1 overexpression in unstressed cells sequesters TORC1 in this compartment, thereby blunting TORC1 signaling. Upon heat stress, a physiological SG-inducing condition, TORC1 is also recruited to SGs, which delays reactivation of TORC1 signaling during recovery from heat stress. Moreover, TORC1 reactivation is directed through SG disassembly, suggesting that SGs act as a key determinant for TORC1 reactivation during recovery from heat stress. Furthermore, this mechanism contributes to reduction of heat-induced mutations. Thus, TORC1 signaling is coupled to heat-induced SGs to protect cells from DNA damage.


Assuntos
Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Citoplasma/metabolismo , Grânulos Citoplasmáticos/genética , Dano ao DNA , Regulação Fúngica da Expressão Gênica , Temperatura Alta , Microscopia de Fluorescência/métodos , Modelos Genéticos , Mutação , Fosforilação , Biossíntese de Proteínas , Transdução de Sinais , Sirolimo/metabolismo
10.
Biochem Biophys Res Commun ; 511(2): 434-439, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30797551

RESUMO

Misfolded and aggregated proteins are eliminated to maintain protein homeostasis. Autophagy contributes to the removal of protein aggregates. However, if and how proteotoxic stress induces autophagy is poorly understood. Here we show that proteotoxic stress after treatment with azetidine-2-carboxylic acid (AZC), a toxic proline analog, induces autophagy in budding yeast. AZC treatment attenuated target of rapamycin complex 1 (TORC1) activity, resulting in the dephosphorylation of Atg13, a key factor of autophagy. By contrast, AZC treatment did not affect target of rapamycin complex 2 (TORC2). Proteotoxic stress also induced TORC1 inactivation and autophagy in fission yeast and human cells. This study suggested that TORC1 is a conserved key factor to cope with proteotoxic stress in eukaryotic cells.


Assuntos
Autofagia/efeitos dos fármacos , Ácido Azetidinocarboxílico/toxicidade , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Saccharomyces cerevisiae/efeitos dos fármacos , Schizosaccharomyces/efeitos dos fármacos , Proteínas Fúngicas/metabolismo , Células HEK293 , Humanos , Saccharomyces cerevisiae/citologia , Schizosaccharomyces/citologia
11.
Appl Environ Microbiol ; 85(1)2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30341081

RESUMO

Saccharomyces cerevisiae sake yeast strain Kyokai no. 7 (K7) and its relatives carry a homozygous loss-of-function mutation in the RIM15 gene, which encodes a Greatwall family protein kinase. Disruption of RIM15 in nonsake yeast strains leads to improved alcoholic fermentation, indicating that the defect in Rim15p is associated with the enhanced fermentation performance of sake yeast cells. In order to understand how Rim15p mediates fermentation control, we here focused on target-of-rapamycin protein kinase complex 1 (TORC1) and protein phosphatase 2A with the B55δ regulatory subunit (PP2AB55δ), complexes that are known to act upstream and downstream of Rim15p, respectively. Several lines of evidence, including our previous transcriptomic analysis data, suggested enhanced TORC1 signaling in sake yeast cells during sake fermentation. Fermentation tests of the TORC1-related mutants using a laboratory strain revealed that TORC1 signaling positively regulates the initial fermentation rate in a Rim15p-dependent manner. Deletion of the CDC55 gene, encoding B55δ, abolished the high fermentation performance of Rim15p-deficient laboratory yeast and sake yeast cells, indicating that PP2AB55δ mediates the fermentation control by TORC1 and Rim15p. The TORC1-Greatwall-PP2AB55δ pathway similarly affected the fermentation rate in the fission yeast Schizosaccharomyces pombe, strongly suggesting that the evolutionarily conserved pathway governs alcoholic fermentation in yeasts. It is likely that elevated PP2AB55δ activity accounts for the high fermentation performance of sake yeast cells. Heterozygous loss-of-function mutations in CDC55 found in K7-related sake strains may indicate that the Rim15p-deficient phenotypes are disadvantageous to cell survival.IMPORTANCE The biochemical processes and enzymes responsible for glycolysis and alcoholic fermentation by the yeast S. cerevisiae have long been the subject of scientific research. Nevertheless, the factors determining fermentation performance in vivo are not fully understood. As a result, the industrial breeding of yeast strains has required empirical characterization of fermentation by screening numerous mutants through laborious fermentation tests. To establish a rational and efficient breeding strategy, key regulators of alcoholic fermentation need to be identified. In the present study, we focused on how sake yeast strains of S. cerevisiae have acquired high alcoholic fermentation performance. Our findings provide a rational molecular basis to design yeast strains with optimal fermentation performance for production of alcoholic beverages and bioethanol. In addition, as the evolutionarily conserved TORC1-Greatwall-PP2AB55δ pathway plays a major role in the glycolytic control, our work may contribute to research on carbohydrate metabolism in higher eukaryotes.


Assuntos
Proteínas de Ciclo Celular/genética , Etanol/metabolismo , Nutrientes/metabolismo , Proteínas Quinases/genética , Proteína Fosfatase 2/genética , Bombas de Próton/genética , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiologia , Transdução de Sinais , Bebidas Alcoólicas/análise , Proteínas de Ciclo Celular/metabolismo , Fermentação , Proteínas Quinases/metabolismo , Proteína Fosfatase 2/metabolismo , Bombas de Próton/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
12.
J Biol Chem ; 291(4): 1826-1840, 2016 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-26620562

RESUMO

The transcription factor Bach2 regulates the immune system at multiple points, including class switch recombination (CSR) in activated B cells and the function of T cells in part by restricting their terminal differentiation. However, the regulation of Bach2 expression and its activity in the immune cells are still unclear. Here, we demonstrated that Bach2 mRNA expression decreased in Pten-deficient primary B cells. Bach2 was phosphorylated in primary B cells, which was increased upon the activation of the B cell receptor by an anti-immunoglobulin M (IgM) antibody or CD40 ligand. Using specific inhibitors of kinases, the phosphorylation of Bach2 in activated B cells was shown to depend on the phosphatidylinositol 3-kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) pathway. The complex of mTOR and Raptor phosphorylated Bach2 in vitro. We identified multiple new phosphorylation sites of Bach2 by mass spectrometry analysis of epitope-tagged Bach2 expressed in the mature B cell line BAL17. Among the sites identified, serine 535 (Ser-535) was critical for the regulation of Bach2 because a single mutation of Ser-535 abolished cytoplasmic accumulation of Bach2, promoting its nuclear accumulation in pre-B cells, whereas Ser-509 played an auxiliary role. Bach2 repressor activity was enhanced by the Ser-535 mutation in B cells. These results suggest that the PI3K-Akt-mTOR pathway inhibits Bach2 by both repressing its expression and inducing its phosphorylation in B cells.


Assuntos
Linfócitos B/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Núcleo Celular/metabolismo , Motivos de Aminoácidos , Animais , Fatores de Transcrição de Zíper de Leucina Básica/química , Fatores de Transcrição de Zíper de Leucina Básica/genética , Núcleo Celular/genética , Células Cultivadas , Feminino , Ativação Linfocitária , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Células Precursoras de Linfócitos B/metabolismo , Transporte Proteico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo
13.
Prostate ; 77(15): 1489-1498, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28905415

RESUMO

BACKGROUND: Neuroendocrine-differentiated prostate cancer (NEPCa) is refractory to androgen deprivation therapy and shows a poor prognosis. The underlying mechanisms responsible for neuroendocrine differentiation (NED) are yet to be clarified. In this study, we investigated the role of mammalian target of rapamycin (mTOR) in NEPCa. METHODS: We utilized a gain-of-function analysis by establishing a human PCa LNCaP stable line that expresses hyperactive mTOR (LNCaP-mTOR). Then, we employed a comprehensive mass spectrometric analysis to identify a key transcription factor in LNCaP-mTOR, followed by a loss-of-function analysis using CRISPR/Cas system. RESULTS: The activation of mTOR induced NED. We observed significant cell growth arrest in NED of LNCaP-mTOR, which accompanied increased expression of p21WAF1/CIP1 . A comprehensive mass spectrometric analysis identified interferon regulatory factor 1 (IRF1) as a key transcription factor in growth arrest of LNCaP-mTOR. The disruption of IRF1 gene in LNCaP-mTOR reversed cell growth arrest along with the suppression of its target p21WAF1/CIP1 . These results indicate that the growth arrest in NED is at least in part dependent on IRF1 through the induction of p21WAF1/CIP1 . CONCLUSIONS: We identified active mTOR as a novel inducer of NED, and elucidated a mechanism underlying the malignant transformation of NEPCa by recapitulating NED in vitro.


Assuntos
Fator Regulador 1 de Interferon/metabolismo , Tumores Neuroendócrinos/metabolismo , Neoplasias da Próstata/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Diferenciação Celular/fisiologia , Processos de Crescimento Celular/fisiologia , Linhagem Celular Tumoral , Técnicas de Inativação de Genes , Xenoenxertos , Humanos , Fator Regulador 1 de Interferon/genética , Masculino , Camundongos , Tumores Neuroendócrinos/genética , Tumores Neuroendócrinos/patologia , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Serina-Treonina Quinases TOR/genética , Regulação para Cima
14.
J Equine Sci ; 28(3): 111-115, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28955163

RESUMO

A three-year old Thoroughbred racehorse was anesthetized with sevoflurane and oxygen inhalation anesthesia combined with constant rate infusion (CRI) of alfaxalone-medetomidine for internal fixation of a third metacarpal bone fracture. After premedication with intravenous (IV) injections of medetomidine (6.0 µg/kg IV), butorphanol (25 µg/kg IV), and midazolam (20 µg/kg IV), anesthesia was induced with 5% guaifenesin (500 ml/head IV) followed immediately by alfaxalone (1.0 mg/kg IV). Anesthesia was maintained with sevoflurane and CRIs of alfaxalone (1.0 mg/kg/hr) and medetomidine (3.0 µg/kg/hr). The total surgical time was 180 min, and the total inhalation anesthesia time was 230 min. The average end-tidal sevoflurane concentration during surgery was 1.8%. The mean arterial blood pressure was maintained above 70 mmHg throughout anesthesia, and the recovery time was 65 min. In conclusion, this anesthetic technique may be clinically applicable for Thoroughbred racehorses undergoing a long-time orthopedic surgery.

15.
Eukaryot Cell ; 14(10): 976-82, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26150415

RESUMO

Yeast Bro1 and Rim20 belong to a family of proteins which possess a common architecture of Bro1 and V domains. Alix and His domain protein tyrosine phosphatase (HD-PTP), mammalian Bro1 family proteins, bind YP(X)nL (n = 1 to 3) motifs in their target proteins through their V domains. In Alix, the Phe residue, which is located in the hydrophobic groove of the V domain, is critical for binding to the YP(X)nL motif. Although the overall sequences are not highly conserved between mammalian and yeast V domains, we show that the conserved Phe residue in the yeast Bro1 V domain is important for binding to its YP(X)nL-containing target protein, Rfu1. Furthermore, we show that Rim20 binds to its target protein Rim101 through the interaction between the V domain of Rim20 and the YPIKL motif of Rim101. The mutation of either the critical Phe residue in the Rim20 V domain or the YPIKL motif of Rim101 affected the Rim20-mediated processing of Rim101. These results suggest that the interactions between V domains and YP(X)nL motif-containing proteins are conserved from yeast to mammalian cells. Moreover, the specificities of each V domain to their target protein suggest that unidentified elements determine the binding specificity.


Assuntos
Motivos de Aminoácidos/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Proteínas Repressoras/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Sequência de Aminoácidos , Complexos Endossomais de Distribuição Requeridos para Transporte/ultraestrutura , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Tirosina Fosfatases/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/ultraestrutura
16.
Int J Mol Sci ; 17(12)2016 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-27941652

RESUMO

Previous works have shown the existence of protein partnerships belonging to a MultiStep Phosphorelay (MSP) in Populus putatively involved in osmosensing. This study is focused on the identification of a histidine-aspartate kinase, HK1b, paralog of HK1a. The characterization of HK1b showed its ability to homo- and hetero-dimerize and to interact with a few Histidine-containing Phosphotransfer (HPt) proteins, suggesting a preferential partnership in poplar MSP linked to drought perception. Furthermore, determinants for interaction specificity between HK1a/1b and HPts were studied by mutagenesis analysis, identifying amino acids involved in this specificity. The HK1b expression analysis in different poplar organs revealed its co-expression with three HPts, reinforcing the hypothesis of partnership participation in the MSP in planta. Moreover, HK1b was shown to act as an osmosensor with kinase activity in a functional complementation assay of an osmosensor deficient yeast strain. These results revealed that HK1b showed a different behaviour for canonical phosphorylation of histidine and aspartate residues. These phosphorylation modularities of canonical amino acids could explain the improved osmosensor performances observed in yeast. As conserved duplicates reflect the selective pressures imposed by the environmental requirements on the species, our results emphasize the importance of HK1 gene duplication in poplar adaptation to drought stress.


Assuntos
Ácido Aspártico/metabolismo , Pressão Osmótica , Populus/enzimologia , Homologia de Sequência de Aminoácidos , Estresse Fisiológico , Aminoácidos/metabolismo , Duplicação Gênica , Regulação da Expressão Gênica de Plantas , Teste de Complementação Genética , Histidina Quinase , Proteínas Mutantes/metabolismo , Mutação/genética , Filogenia , Populus/genética , Ligação Proteica , Multimerização Proteica , Reprodutibilidade dos Testes , Estresse Fisiológico/genética , Especificidade por Substrato , Técnicas do Sistema de Duplo-Híbrido
17.
iScience ; 27(9): 110814, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39297172

RESUMO

Target of rapamycin complex 1 (TORC1) integrates nutrient availability, growth factors, and stress signals to regulate cellular metabolism according to its environment. Similar to mammals, amino acids have been shown to activate TORC1 in plants. However, as the Rag complex that controls amino acid-responsive TORC1 activation mechanisms in many eukaryotes is not conserved in plants, the amino acid-sensing mechanisms upstream of TORC1 in plants remain unknown. In this study, we report that Arabidopsis FYVE1/FREE1 is involved in glutamine-induced TORC1 activation, independent of its previously reported function in ESCRT-dependent processes. FYVE1/FREE1 has a domain structure similar to that of the yeast glutamine sensor Pib2 that directly activates TORC1. Similar to Pib2, FYVE1/FREE1 interacts with TORC1 in response to glutamine. Furthermore, overexpression of a FYVE1/FREE1 variant lacking the presumptive TORC1 activation motif hindered the glutamine-responsive activation of TORC1. Overall, these observations suggest that FYVE1/FREE1 acts as an intracellular amino acid sensor that triggers TORC1 activation in plants.

18.
Phys Med Biol ; 69(7)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38452379

RESUMO

Objective.The purpose of this study is to propose a novel blurring correction method that enables accurate quantitative analysis of the object edge when using energy-resolving photon counting detectors (ERPCDs). Although the ERPCDs have the ability to generate various quantitative analysis techniques, such as the derivations of effective atomic number (Zeff) and bone mineral density values, at the object edge in these quantitative images, accurate quantitative information cannot be obtained. This is because image blurring prevents the gathering of accurate primary x-ray attenuation information.Approach.We developed the following procedure for blurring correction. A 5 × 5 pixels masking region was set as the processing area, and the pixels affected by blurring were extracted from the analysis of pixel value distribution. The blurred pixel values were then corrected to the proper values estimated by analyzing minimum and/or maximum values in the set mask area. The suitability of our correction method was verified by a simulation study and an experiment using a prototype ERPCD.Main results. WhenZeffimage of aluminum objects (Zeff= 13) were analyzed without applying our correction method, regardless of raw data or correction data applying a conventional edge enhancement method, the properZeffvalues could not be derived for the object edge. In contrast, when applying our correction method, 82% of pixels affected by blurring were corrected and the properZeffvalues were calculated for those pixels. As a result of investigating the applicability limits of our method through simulation, it was proven that it works effectively for objects with 4 × 4 pixels or more.Significance. Our method is effective in correcting image blurring when the quantitative image is calculated based on multiple images. It will become an in-demand technology for putting a quantitative diagnosis into actual medical examinations.


Assuntos
Fótons , Raios X , Radiografia , Simulação por Computador , Imagens de Fantasmas
19.
World J Radiol ; 16(8): 337-347, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39239242

RESUMO

BACKGROUND: Postoperative aortobronchial fistula (ABF) is a rare complication that can occur in 0.3%-5.0% of patients over an extended period of time after thoracic aortic surgery. Direct visualization of the fistula via imaging is rare. AIM: To investigate the relationship between computed tomography (CT) findings and the clinical signs/symptoms of ABF after thoracic aortic surgery. METHODS: Six patients (mean age 71 years, including 4 men and 2 women) with suspected ABF on CT (air around the graft) at our hospital were included in this retrospective study between January 2004 and September 2022. Chest CT findings included direct confirmation of ABF, peri-graft fluid, ring enhancement, dirty fat sign, atelectasis, pulmonary hemorrhage, and bronchodilation, and the clinical course were retrospectively reviewed. The proportion of each type of CT finding was calculated. RESULTS: ABF detection after surgery was found to have a mean and median of 14 and 13 years, respectively. Initial signs and symptoms were asymptomatic in 4 patients, bloody sputum was found in 1 patient, and fever was present in 1 patient. The complications of ABF included graft infection in 2 patients and graft infection with hemoptysis in 2 patients. Of the 6 patients, 3 survived, 2 died, and 1 was lost to follow-up. The locations of the ABFs were as follows: 1 in the ascending aorta; 1 in the aortic arch; 2 in the aortic arch leading to the descending aorta; and 2 in the descending aorta. ABFs were directly confirmed by CT in 4/6 (67%) patients. Peri-graft dirty fat (4/6, 67%) and peri-graft ring enhancement (3/6, 50%) were associated with graft infection, endoleaks and pseudoaneurysms were associated with hemoptysis (2/6, 33%). CONCLUSION: Asymptomatic ABF after thoracic aortic surgery can be confirmed on chest CT. CT is useful for the diagnosis of ABF and its complications.

20.
Med Phys ; 51(2): 1061-1073, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38103261

RESUMO

BACKGROUND: Many healthcare institutions have guidelines concerning the usage of protective procedures, and various x-ray shields have been used to reduce unwanted radiation exposure to medical staff and patients when using x-rays. Most x-ray shields are in the form of sheets and lack elasticity, which limits their effectiveness in shielding areas with movement, such as the thyroid. To overcome this limitation, we have developed an innovative elastic x-ray shield. PURPOSE: The purpose of this study is to explain the methodology for developing and evaluating a novel elastic x-ray shield with sufficient x-ray shielding ability. Furthermore, valuable knowledge and evaluation indices are derived to assess our shield's performance. METHODS: Our x-ray shield was developed through a process of embedding Bi2 O3 particles into porous polyurethane. Porous polyurethane with a thickness of 10 mm was dipped into a solution of water, metal particles, and chemical agents. Then, it was air-dried to fix the metal particles in the porous polyurethane. Thirteen investigational x-ray shields were fabricated, in which Bi2 O3 particles at various mass thicknesses (ranging from 585 to 2493 g/m2 ) were embedded. To determine the performance of the shielding material, three criteria were evaluated: (1) Dose Reduction Factor ( D R F $DRF$ ), measured using inverse broad beam geometry; (2) uniformity, evaluated from the standard deviation ( S D $SD$ ) of the x-ray image obtained using a clinical x-ray imaging detector; and (3) elasticity, evaluated by a compression test. RESULTS: The elastic shield with small pores, containing 1200 g/m2 of the metal element (Bi), exhibited a well-balanced performance. The D R F $DRF$ was approximately 80% for 70 kV diagnostic x-rays. This shield's elasticity was -0.62 N/mm, a loss of only 30% when compared to porous polyurethane without metal. Although the non-uniformity of the x-ray shield leads to poor shielding ability, it was found that the decrease in the shielding ability can be limited to a maximum of 6% when the shield is manufactured so that the S D $SD$ of the x-ray image of the shield is less than 10%. CONCLUSIONS: It was verified that an elastic x-ray shield that offers an appropriate reduction in radiation exposure can be produced by embedding Bi2 O3 particles into porous polyurethane. Our findings can lead to the development of novel x-ray shielding products that can reduce the physical and mental stress on users.


Assuntos
Poliuretanos , Tomografia Computadorizada por Raios X , Humanos , Raios X , Porosidade , Doses de Radiação , Tomografia Computadorizada por Raios X/métodos , Imagens de Fantasmas
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