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1.
Cancer Sci ; 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39119813

RESUMO

Immune checkpoint inhibitors (ICIs) are effective against many advanced malignancies. However, many patients are nonresponders to immunotherapy, and overcoming this resistance to treatment is important. Boron neutron capture therapy (BNCT) is a local chemoradiation therapy with the combination of boron drugs that accumulate selectively in cancer and the neutron irradiation of the cancer site. Here, we report the first boron neutron immunotherapy (B-NIT), combining BNCT and ICI immunotherapy, which was performed on a radioresistant and immunotherapy-resistant advanced-stage B16F10 melanoma mouse model. The BNCT group showed localized tumor suppression, but the anti-PD-1 antibody immunotherapy group did not show tumor suppression. Only the B-NIT group showed strong tumor growth inhibition at both BNCT-treated and shielded distant sites. Intratumoral CD8+ T-cell infiltration and serum high mobility group box 1 (HMGB1) levels were higher in the B-NIT group. Analysis of CD8+ T cells in tumor-infiltrating lymphocytes (TILs) showed that CD62L- CD44+ effector memory T cells and CD69+ early-activated T cells were predominantly increased in the B-NIT group. Administration of CD8-depleting mAb to the B-NIT group completely suppressed the augmented therapeutic effects. This indicated that B-NIT has a potent immune-induced abscopal effect, directly destroying tumors with BNCT, inducing antigen-spreading effects, and protecting normal tissue. B-NIT, immunotherapy combined with BNCT, is the first treatment to overcome immunotherapy resistance in malignant melanoma. In the future, as its therapeutic efficacy is demonstrated not only in melanoma but also in other immunotherapy-resistant malignancies, B-NIT can become a new treatment candidate for advanced-stage cancers.

2.
J Pharmacol Exp Ther ; 390(1): 108-115, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38834354

RESUMO

Nonsteroidal anti-inflammatory drugs (NSAIDs) possess anti-inflammatory, antipyretic, and analgesic properties and are among the most commonly used drugs. Although the cause of NSAID-induced gastric ulcers is well understood, the mechanism behind small intestinal ulcers remains elusive. In this study, we examined the mechanism through which indomethacin (IM), a prominent NSAID, induces small intestinal ulcers, both in vitro and in vivo. In IEC6 cells, a small intestinal epithelial cell line, IM treatment elevated levels of LC3-II and p62. These expression levels remained unaltered after treatment with chloroquine or bafilomycin, which are vacuolar ATPase (V-ATPase) inhibitors. IM treatment reduced the activity of cathepsin B, a lysosomal protein hydrolytic enzyme, and increased the lysosomal pH. There was a notable increase in subcellular colocalization of LC3 with Lamp2, a lysosome marker, post IM treatment. The increased lysosomal pH and decreased cathepsin B activity were reversed by pretreatment with rapamycin (Rapa) or glucose starvation, both of which stabilize V-ATPase assembly. To validate the in vitro findings in vivo, we established an IM-induced small intestine ulcer mouse model. In this model, we observed multiple ulcerations and heightened inflammation following IM administration. However, pretreatment with Rapa or fasting, which stabilize V-ATPase assembly, mitigated the IM-induced small intestinal ulcers in mice. Coimmunoprecipitation studies demonstrated that IM binds to V-ATPase in vitro and in vivo. These findings suggest that IM induces small intestinal injury through lysosomal dysfunction, likely due to the disassembly of lysosomal V-ATPase caused by direct binding. Moreover, Rapa or starvation can prevent this injury by stabilizing the assembly. SIGNIFICANCE STATEMENT: This study elucidates the largely unknown mechanisms behind small intestinal ulceration induced by indomethacin and reveals the involvement of lysosomal dysfunction via vacuolar ATPase disassembly. The significance lies in identifying potential preventative interventions, such as rapamycin treatment or glucose starvation, offering pivotal insights that extend beyond nonsteroidal anti-inflammatory drugs-induced ulcers to broader gastrointestinal pathologies and treatments, thereby providing a foundation for novel therapeutic strategies aimed at a wide array of gastrointestinal disorders.


Assuntos
Indometacina , Lisossomos , Sirolimo , ATPases Vacuolares Próton-Translocadoras , Animais , Indometacina/toxicidade , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , ATPases Vacuolares Próton-Translocadoras/metabolismo , ATPases Vacuolares Próton-Translocadoras/antagonistas & inibidores , Sirolimo/farmacologia , Camundongos , Masculino , Ratos , Anti-Inflamatórios não Esteroides/farmacologia , Catepsina B/metabolismo , Camundongos Endogâmicos C57BL , Linhagem Celular , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/patologia , Intestino Delgado/metabolismo , Úlcera/induzido quimicamente , Úlcera/patologia , Úlcera/metabolismo
3.
Plant Cell Physiol ; 64(3): 284-290, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36331512

RESUMO

Shoot stem cells act as the source of the aboveground parts of flowering plants. A precise regulatory basis is required to ensure that plant stem cells show the right status during the stages of proliferation, senescence and cell death. Over the past few decades, the genetic circuits controlling stem cell fate, including the regulatory pathways of establishment, maintenance and differentiation, have been largely revealed. However, the morphological changes and molecular mechanisms of the final stages of stem cells, which are represented by senescence and cell death, have been less studied. The senescence and death of shoot stem cells are under the control of a complex series of pathways that integrate multiple internal and external signals. Given the crucial roles of shoot stem cells in influencing plant longevity and crop yields, researchers have attempted to uncover details of stem cell senescence and death. Recent studies indicate that stem cell activity arrest is controlled by the FRUITFULL-APETALA2 pathway and the plant hormones auxin and cytokinin, while the features of senescent and dead shoot apical stem cells have also been described, with dynamic changes in reactive oxygen species implicated in stem cell death. In this review, we highlight the recent breakthroughs that have enriched our understanding of senescence and cell death processes in plant stem cells.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Senescência Vegetal , Brotos de Planta , Células-Tronco , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Citocininas/genética , Citocininas/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Meristema/genética , Meristema/metabolismo , Reguladores de Crescimento de Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Senescência Vegetal/genética , Senescência Vegetal/fisiologia , Brotos de Planta/genética , Brotos de Planta/metabolismo , Brotos de Planta/fisiologia , Morte Celular Regulada/genética , Morte Celular Regulada/fisiologia , Células-Tronco/metabolismo , Células-Tronco/fisiologia
4.
Plant Cell Physiol ; 64(2): 234-247, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36440710

RESUMO

The glucosinolate-myrosinase defense system (GMDS), characteristic of Brassicales, is involved in plant defense. Previous single-cell transcriptomic analyses have reported the expression profiles of multiple GMDS-related cell types (i.e. myrosinase-rich myrosin idioblasts and multiple types of potential glucosinolate synthetic cells as well as a candidate S-cell for glucosinolate accumulation). However, differences in plant stages and cell-type annotation methods have hindered comparisons among studies. Here, we used the single-cell transcriptome profiles of extended Arabidopsis leaves and verified the distribution of previously used markers to refine the expression profiles of GMDS-associated cell types. Moreover, we performed beta-glucuronidase promoter assays to confirm the histological expression patterns of newly obtained markers for GMDS-associated candidates. As a result, we found a set of new specific reporters for myrosin cells and potential glucosinolate-producing cells.


Assuntos
Arabidopsis , Arabidopsis/genética , Glucosinolatos/metabolismo , Folhas de Planta/metabolismo , Glicosídeo Hidrolases/metabolismo , Glucuronidase/metabolismo , Plantas/metabolismo , Análise de Sequência de RNA
5.
Planta ; 258(6): 112, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37935872

RESUMO

MAIN CONCLUSION: Extracellular traps in the primary root of Pinus densiflora contribute to root-associated bacterial colonization. Trapped rhizobacteria induce the production of reactive oxygen species in root-associated, cap-derived cells. Ectomycorrhizal (ECM) woody plants, such as members of Pinaceae and Fagaceae, can acquire resistance to biotic and abiotic stresses through the formation of mycorrhiza with ECM fungi. However, germinated tree seedlings do not have mycorrhizae and it takes several weeks for ectomycorrhizae to form on their root tips. Therefore, to confer protection during the early growth stage, bare primary roots require defense mechanisms other than mycorrhization. Here, we attempted to visualize root extracellular traps (RETs), an innate root defense mechanism, in the primary root of Pinus densiflora and investigate the interactions with root-associated bacteria isolated from ECM and fine non-mycorrhizal roots. Histological and histochemical imaging and colony-forming unit assays demonstrated that RETs in P. densiflora, mainly consisting of root-associated, cap-derived cells (AC-DCs) and large amounts of root mucilage, promote bacterial colonization in the rhizosphere, despite also having bactericidal activity via extracellular DNA. Four rhizobacterial strains retarded the mycelial growth of a pathogenic strain belonging to the Fusarium oxysporum species complex in dual culture assay. They also induced the production of reactive oxygen species (ROS) from host tree AC-DCs without being excluded from the rhizosphere of P. densiflora. Applying three Paraburkholderia strains, especially PM O-EM8 and PF T-NM22, showed significant differences in the ROS levels from the control group. These results reveal the indirect contributions of rhizobacteria to host root defense and suggest that root-associated bacteria could be a component of RETs as a first line of defense against root pathogens in the early growth stage of ECM woody plants.


Assuntos
Armadilhas Extracelulares , Micorrizas , Pinus , Micorrizas/genética , Espécies Reativas de Oxigênio , Raízes de Plantas , Bactérias , Árvores/microbiologia
6.
Chem Pharm Bull (Tokyo) ; 71(1): 70-73, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36596514

RESUMO

In this study, we developed a water-soluble complex-hydrogel viscosity-controlled formulation of amphotericin B (AmB). AmB is insoluble in water, but borax makes it soluble by forming a complex with AmB. Borax also forms complexes with poly(vinyl alcohol) (PVA) to produce viscous hydrogels. Furthermore, boric acid interacts with mucin expressed in corneal epithelial cells. Accordingly, by utilizing these properties of borax simultaneously, we prepared a water-soluble AmB complex-hydrogel with poly(vinyl alcohol)/borate (PVA-B-AmB), which is suitable for eye drops. PVA-B-AmB was easily prepared by simply mixing aqueous AmB solution dissolved in borax, PVA solution, and water. The 11B-NMR results suggested that PVA-B-AmB existed by bonding PVA and AmB via boronic acid. PVA-B-AmB (gel ratio = 0.55) has a viscosity of 18.3 ± 0.5 mPa·s and is suitable for ophthalmic formulations. This formulation exhibited sustained release of AmB of approximately 45% at 24 h. It was also shown that this formulation interacts with mucin. These results suggest that PVA-B-AmB can be used as a water-soluble AmB preparation suitable for ophthalmic use.


Assuntos
Anfotericina B , Hidrogéis , Anfotericina B/química , Álcool de Polivinil/química , Boratos , Mucinas , Água
7.
Int J Mol Sci ; 23(7)2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-35409227

RESUMO

In monocarpic plants, stem cells are fated to die. However, the potential mechanism of stem cell death has remained elusive. Here, we reveal that the levels of two forms of reactive oxygen species (ROS), superoxide anion free radical (O2·-) and hydrogen peroxide (H2O2), show dynamic changes in the shoot apex during the plant life cycle of Arabidopsis thaliana. We found that the level of O2·- decreased and disappeared at four weeks after bolting (WAB), while H2O2 appeared at 3 WAB and showed a burst at 5 WAB. The timing of dynamic changes in O2·- and H2O2 was delayed for approximately three weeks in clv3-2, which has a longer lifespan. Moreover, exogenous application of H2O2 inhibited the expression of the stem cell determinant WUSCHEL (WUS) and promoted the expression of the developmentally programmed cell death (dPCD) marker gene ORESARA 1 (ORE1). These results indicate that H2O2 triggers an important signal inducing dPCD in stem cells. Given that O2·- plays roles in maintaining WUS expression and stem cell activity, we speculate that the dynamic shift from O2·- to H2O2 in the shoot apex results in stem cell death. Our findings provide novel insights for understanding ROS-mediated regulation during plant stem cell death.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Morte Celular , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio/metabolismo , Peróxido de Hidrogênio/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Células-Tronco/metabolismo
8.
Development ; 144(3): 499-506, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28087627

RESUMO

Stem cell polarization is a crucial step in asymmetric cell division, which is a universal system for generating cellular diversity in multicellular organisms. Several conventional genetics studies have attempted to elucidate the mechanisms underlying cell polarization in plants, but it remains largely unknown. In plants, stomata, which are valves for gas exchange, are generated through several rounds of asymmetric divisions. In this study, we identified and characterized a chemical compound that affects stomatal stem cell polarity. High-throughput screening for bioactive molecules identified a pyridine-thiazole derivative, named bubblin, which induced stomatal clustering in Arabidopsis epidermis. Bubblin perturbed stomatal asymmetric division, resulting in the generation of two identical daughter cells. Both cells continued to express the stomatal fate determinant SPEECHLESS, and then differentiated into mispatterned stomata. Bubblin-treated cells had a defect in the polarized localization of BREAKING OF ASYMMETRY IN THE STOMATAL LINEAGE (BASL), which is required for asymmetric cell fate determination. Our results suggest that bubblin induces stomatal lineage cells to divide without BASL-dependent pre-mitotic establishment of polarity. Bubblin is a potentially valuable tool for investigating cell polarity establishment in stomatal asymmetric division.


Assuntos
Arabidopsis/citologia , Arabidopsis/efeitos dos fármacos , Estômatos de Plantas/citologia , Estômatos de Plantas/efeitos dos fármacos , Tiazóis/farmacologia , Arabidopsis/genética , Divisão Celular Assimétrica/efeitos dos fármacos , Padronização Corporal/efeitos dos fármacos , Linhagem da Célula , Polaridade Celular/efeitos dos fármacos , Genes de Plantas , Ensaios de Triagem em Larga Escala , Estômatos de Plantas/genética , Plantas Geneticamente Modificadas , Relação Estrutura-Atividade , Tiazóis/química
9.
Kyobu Geka ; 73(8): 595-598, 2020 Aug.
Artigo em Japonês | MEDLINE | ID: mdl-32879287

RESUMO

Coronary aneurysms are relatively rare. However, myocardial infarction associated with thrombus formation in the aneurysm and rupture of the aneurysm are clinical problems. There are no specific guidelines for the treatment of coronary aneurysms. Here, we report a case of a 47-year-old female with acute myocardial infarction. She had a history of collagen disease, which was suspected to be Kawasaki disease. She underwent thrombus aspiration supported by intra-aortic balloon pumping( IABP) because of acute thrombosis of coronary aneurysms, followed by coronary artery bypass grafting on 2 stages. The operative course was uneventful.


Assuntos
Aneurisma Coronário , Síndrome de Linfonodos Mucocutâneos , Infarto do Miocárdio , Ponte de Artéria Coronária , Feminino , Humanos , Balão Intra-Aórtico , Pessoa de Meia-Idade
10.
Kyobu Geka ; 73(3): 197-201, 2020 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-32393702

RESUMO

Postoperative chylothorax is known as a possible complication after thoracic surgery, but no treatment strategy has been established. We report a case of successful surgical treatment for postoperative chylothorax after redo aortic arch replacement via median sternotomy. A 48-year-old man, who had undergone redo aortic arch replacement for aortic pseudoaneurysm due to prosthetic vascular graft infection, developed postoperative chylothorax. Despite the conservative treatment with fasting and administration of octreotide for 4 days, there was no effect on reduction in drainage. Surgical repair was performed on postoperative day 13. About 3 hours before surgery, milk was administered from the nasogastric tube to make the drainage milky. After median re-sternotomy, a stump of the thoracic duct was clearly identified and exposed in the posterior mediastinum, and the thoracic duct was easily closed by clipping. There was no recurrence of chylothorax and oral intake was re-started on day 2. Early operation might be effective against postoperative chylothorax.


Assuntos
Quilotórax , Aorta Torácica , Quilotórax/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Complicações Pós-Operatórias , Esternotomia
11.
Perfusion ; 34(2): 147-153, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30444180

RESUMO

BACKGROUND: Cerebrovascular disease (CVD) with brain hypoperfusion is a strong risk factor for stroke. However, how this pathology influences long-term outcomes after coronary artery bypass graft (CABG) surgery is not known. METHODS: Magnetic resonance imaging/angiography (MRI/A) of the neck and brain was performed in 318 out of 575 consecutive CABG patients between May 2005 and April 2018. Critical CVD with chronic hypoperfusion was defined as multiple severe stenoses (⩾70%) and/or occlusion in the carotid and/or vertebral systems associated with reduced collateral flow due to severe contralateral and/or circle of Willis lesion. Fifty patients were identified to have this pathology (early results were previously reported). The entire cohort was followed up for 83.6 ± 53.7 months. Carotid endarterectomy was considered for symptomatic patients. Propensity matching was performed to compare long-term outcomes between patients with and without critical CVD. RESULTS: Patients with critical CVD at follow-up displayed significantly higher incidences of stroke than those without critical CVD (p=0.007), with an extremely high final incidence (approximately 40% at 8 years). However, survival (p=0.623) and incidences of major adverse cardiac events (MACE: myocardial infarction, coronary revascularization and all causes of death) (p=0.881) were similar. The Cox hazard model revealed that critical CVD was the strongest risk factor for stroke (p=0.000; hazard ratio 6.572; 95% confidence interval 2.657-16.258) while not affecting survival and MACE. CONCLUSION: Critical CVD was the strongest risk factor for long-term stroke after CABG. However, survival and MACE-free rates were equivalent in patients with critical CVD and those without critical CVD.


Assuntos
Transtornos Cerebrovasculares/etiologia , Ponte de Artéria Coronária/efeitos adversos , Acidente Vascular Cerebral/etiologia , Idoso , Transtornos Cerebrovasculares/patologia , Ponte de Artéria Coronária/métodos , Feminino , Humanos , Masculino , Análise Multivariada , Pontuação de Propensão , Acidente Vascular Cerebral/patologia
12.
Plant Cell Physiol ; 59(7): 1309-1316, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29897512

RESUMO

Plant vacuoles display many versatile functions. Vacuoles in vegetative tissues are generally involved in protein degradation, and are called lytic vacuoles. However, vegetative vacuoles in specialized cells can accumulate large concentrations of proteins, such as those in idioblast myrosin cells along veins in the order Brassicales, which store large amounts of myrosinases (thioglucoside glucohydrolase and thioglucoside glucohydrolase). Myrosinases cleave the bond between sulfur and glucose in sulfur-rich compounds (glucosinolates) to produce toxic compounds (isothiocyanates) when plants are damaged by pests. This defense strategy is called the myrosinase-glucosinolate system. Recent studies identified atypical myrosinases, PENETRATION 2 (PEN2) and PYK10, along with key components for development of myrosin cells. In this review, we discuss three topics in the myrosinase-glucosinolate system. First, we summarize the complexity and importance of the myrosinase-glucosinolate system, including classical myrosinases, atypical myrosinases and the system that counteracts the myrosinase-glucosinolate system. Secondly, we describe molecular machineries underlying myrosin cell development, including specific reporters, cell lineage, cell differentiation and cell fate determination. The master regulators for myrosin cell differentiation, FAMA and SCREAM, are key transcription factors involved in guard cell differentiation. This indicates that myrosin cells and guard cells share similar transcriptional networks. Finally, we hypothesize that the myrosinase-glucosinolate system may have originated in stomata of ancestral Brassicales plants and, after that, plants co-opted this defense strategy into idioblasts near veins at inner tissue layers.


Assuntos
Brassicaceae/citologia , Brassicaceae/fisiologia , Glucosinolatos/metabolismo , Glicosídeo Hidrolases/metabolismo , Vacúolos/fisiologia , Animais , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Evolução Biológica , Brassicaceae/química , Diferenciação Celular , Herbivoria , Células Vegetais , Fatores de Transcrição/metabolismo , Vacúolos/química , Vacúolos/metabolismo
13.
PLoS Genet ; 11(5): e1005084, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26020919

RESUMO

The plant hormone auxin regulates many aspects of plant growth and development. Recent progress in Arabidopsis provided a scheme that auxin receptors, TIR1/AFBs, target transcriptional co-repressors, AUX/IAAs, for degradation, allowing ARFs to regulate transcription of auxin responsive genes. The mechanism of auxin-mediated transcriptional regulation is considered to have evolved around the time plants adapted to land. However, little is known about the role of auxin-mediated transcription in basal land plant lineages. We focused on the liverwort Marchantia polymorpha, which belongs to the earliest diverging lineage of land plants. M. polymorpha has only a single TIR1/AFB (MpTIR1), a single AUX/IAA (MpIAA), and three ARFs (MpARF1, MpARF2, and MpARF3) in the genome. Expression of a dominant allele of MpIAA with mutations in its putative degron sequence conferred an auxin resistant phenotype and repressed auxin-dependent expression of the auxin response reporter proGH3:GUS. We next established a system for DEX-inducible auxin-response repression by expressing the putatively stabilized MpIAA protein fused with the glucocorticoid receptor domain (MpIAA(mDII)-GR). Repression of auxin responses in (pro)MpIAA:MpIAA(mDII)-GR plants caused severe defects in various developmental processes, including gemmaling development, dorsiventrality, organogenesis, and tropic responses. Transient transactivation assays showed that the three MpARFs had different transcriptional activities, each corresponding to their phylogenetic classifications. Moreover, MpIAA and MpARF proteins interacted with each other with different affinities. This study provides evidence that pleiotropic auxin responses can be achieved by a minimal set of auxin signaling factors and suggests that the transcriptional regulation mediated by TIR1/AFB, AUX/IAA, and three types of ARFs might have been a key invention to establish body plans of land plants. We propose that M. polymorpha is a good model to investigate the principles and the evolution of auxin-mediated transcriptional regulation and its roles in land plant morphogenesis.


Assuntos
Evolução Molecular , Ácidos Indolacéticos/metabolismo , Marchantia/genética , Transcrição Gênica , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Ligação a DNA/genética , Proteínas F-Box/genética , Regulação da Expressão Gênica de Plantas , Estágios do Ciclo de Vida , Marchantia/crescimento & desenvolvimento , Dados de Sequência Molecular , Morfogênese/genética , Mutação , Proteínas Nucleares/genética , Filogenia , Plantas Geneticamente Modificadas , Receptores de Superfície Celular/genética
14.
Plant Physiol ; 170(1): 211-9, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26546666

RESUMO

Adaptor protein (AP) complexes play critical roles in protein sorting among different post-Golgi pathways by recognizing specific cargo protein motifs. Among the five AP complexes (AP-1-AP-5) in plants, AP-4 is one of the most poorly understood; the AP-4 components, AP-4 cargo motifs, and AP-4 functional mechanism are not known. Here, we identify the AP-4 components and show that the AP-4 complex regulates receptor-mediated vacuolar protein sorting by recognizing VACUOLAR SORTING RECEPTOR1 (VSR1), which was originally identified as a sorting receptor for seed storage proteins to target protein storage vacuoles in Arabidopsis (Arabidopsis thaliana). From the vacuolar sorting mutant library GREEN FLUORESCENT SEED (GFS), we isolated three gfs mutants that accumulate abnormally high levels of VSR1 in seeds and designated them as gfs4, gfs5, and gfs6. Their responsible genes encode three (AP4B, AP4M, and AP4S) of the four subunits of the AP-4 complex, respectively, and an Arabidopsis mutant (ap4e) lacking the fourth subunit, AP4E, also had the same phenotype. Mass spectrometry demonstrated that these four proteins form a complex in vivo. The four mutants showed defects in the vacuolar sorting of the major storage protein 12S globulins, indicating a role for the AP-4 complex in vacuolar protein transport. AP4M bound to the tyrosine-based motif of VSR1. AP4M localized at the trans-Golgi network (TGN) subdomain that is distinct from the AP-1-localized TGN subdomain. This study provides a novel function for the AP-4 complex in VSR1-mediated vacuolar protein sorting at the specialized domain of the TGN.


Assuntos
Complexo 4 de Proteínas Adaptadoras/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Transporte Proteico/fisiologia , Rede trans-Golgi/metabolismo , Complexo 4 de Proteínas Adaptadoras/genética , Motivos de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Mutação , Plantas Geneticamente Modificadas , Sementes/genética , Sementes/metabolismo , Vacúolos/metabolismo
15.
Plant Cell ; 26(11): 4448-61, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25428982

RESUMO

Myrosin cells, which accumulate myrosinase to produce toxic compounds when they are ruptured by herbivores, form specifically along leaf veins in Arabidopsis thaliana. However, the mechanism underlying this pattern formation is unknown. Here, we show that myrosin cell development requires the endocytosis-mediated polar localization of the auxin-efflux carrier PIN1 in leaf primordia. Defects in the endocytic/vacuolar SNAREs (syp22 and syp22 vti11) enhanced myrosin cell development. The syp22 phenotype was rescued by expressing SYP22 under the control of the PIN1 promoter. Additionally, myrosin cell development was enhanced either by lacking the activator of endocytic/vacuolar RAB5 GTPase (VPS9A) or by PIN1 promoter-driven expression of a dominant-negative form of RAB5 GTPase (ARA7). By contrast, myrosin cell development was not affected by deficiencies of vacuolar trafficking factors, including the vacuolar sorting receptor VSR1 and the retromer components VPS29 and VPS35, suggesting that endocytic pathway rather than vacuolar trafficking pathway is important for myrosin cell development. The phosphomimic PIN1 variant (PIN1-Asp), which is unable to be polarized, caused myrosin cells to form not only along leaf vein but also in the intervein leaf area. We propose that Brassicales plants might arrange myrosin cells near vascular cells in order to protect the flux of nutrients and water via polar PIN1 localization.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Endocitose , Regulação da Expressão Gênica de Plantas , Proteínas de Membrana Transportadoras/metabolismo , Arabidopsis/citologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Polaridade Celular , Proteínas de Membrana Transportadoras/genética , Fenótipo , Folhas de Planta/citologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Feixe Vascular de Plantas/citologia , Feixe Vascular de Plantas/genética , Feixe Vascular de Plantas/crescimento & desenvolvimento , Feixe Vascular de Plantas/metabolismo , Plantas Geneticamente Modificadas , Transporte Proteico
16.
Plant Cell ; 26(10): 4039-52, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25304202

RESUMO

Brassicales plants, including Arabidopsis thaliana, have an ingenious two-compartment defense system, which sequesters myrosinase from the substrate glucosinolate and produces a toxic compound when cells are damaged by herbivores. Myrosinase is stored in vacuoles of idioblast myrosin cells. The molecular mechanism that regulates myrosin cell development remains elusive. Here, we identify the basic helix-loop-helix transcription factor FAMA as an essential component for myrosin cell development along Arabidopsis leaf veins. FAMA is known as a regulator of stomatal development. We detected FAMA expression in myrosin cell precursors in leaf primordia in addition to stomatal lineage cells. FAMA deficiency caused defects in myrosin cell development and in the biosynthesis of myrosinases THIOGLUCOSIDE GLUCOHYDROLASE1 (TGG1) and TGG2. Conversely, ectopic FAMA expression conferred myrosin cell characteristics to hypocotyl and root cells, both of which normally lack myrosin cells. The FAMA interactors ICE1/SCREAM and its closest paralog SCREAM2/ICE2 were essential for myrosin cell development. DNA microarray analysis identified 32 candidate genes involved in myrosin cell development under the control of FAMA. This study provides a common regulatory pathway that determines two distinct cell types in leaves: epidermal guard cells and inner-tissue myrosin cells.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Folhas de Planta/metabolismo , Estômatos de Plantas/metabolismo , Feixe Vascular de Plantas/metabolismo , Sequência de Aminoácidos , Arabidopsis/citologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Hipocótilo/citologia , Hipocótilo/genética , Hipocótilo/metabolismo , Immunoblotting , Microscopia Confocal , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Folhas de Planta/citologia , Folhas de Planta/genética , Raízes de Plantas/citologia , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Estômatos de Plantas/citologia , Estômatos de Plantas/genética , Feixe Vascular de Plantas/citologia , Feixe Vascular de Plantas/genética , Plantas Geneticamente Modificadas , Ligação Proteica , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Vacúolos/enzimologia
17.
Plant Cell Physiol ; 57(2): 325-38, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26858289

RESUMO

In land plants, there are two types of male gametes: one is a non-motile sperm cell which is delivered to the egg cell by a pollen tube, and the other is a motile sperm cell with flagella. The molecular mechanism underlying the sexual reproduction with the egg and pollen-delivered sperm cell is well understood from studies using model plants such as Arabidopsis and rice. On the other hand, the sexual reproduction with motile sperm has remained poorly characterized, due to the lack of suitable models. Marchantia polymorpha L. is a model basal land plant with sexual reproduction involving an egg cell and bi-flagellated motile sperm. To understand the differentiation process of plant motile sperm, we analyzed the gene expression profile of developing antheridia of M. polymorpha. We performed RNA-sequencing experiments and compared transcript profiles of the male sexual organ (antheridiophore and antheridium contained therein), female sexual organ (archegoniophore) and a vegetative organ (thallus). Transcriptome analysis showed that the antheridium expresses nearly half of the protein-coding genes predicted in the genome, but it also has unique features. The antheridium transcriptome shares some common features with male gamete transcriptomes of angiosperms and animals, and homologs of genes involved in male gamete formation and function in angiosperms and animals were identified. In addition, we showed that some of them had distinct expression patterns in the spermatogenous tissue of developing antheridia. This study provides a transcriptional framework on which to study the molecular mechanism of plant motile sperm development in M. polymorpha as a model.


Assuntos
Gametogênese Vegetal/genética , Marchantia/genética , Transcrição Gênica , Transcriptoma/genética , Cromossomos de Plantas/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Histonas/metabolismo , Marchantia/anatomia & histologia , Marchantia/metabolismo , Fases de Leitura Aberta/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo
18.
Plant Cell ; 25(8): 2958-69, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23975897

RESUMO

The adaptor protein-2 (AP-2) complex is a heterotetramer involved in clathrin-mediated endocytosis of cargo proteins from the plasma membrane in animal cells. The homologous genes of AP-2 subunits are present in the genomes of plants; however, their identities and roles in endocytic pathways are not clearly defined in plants. Here, we reveal the molecular composition of the AP-2 complex of Arabidopsis thaliana and its dynamics on the plasma membrane. We identified all of the α-, ß-, σ-, and µ-subunits of the AP-2 complex and detected a weak interaction of the AP-2 complex with clathrin heavy chain. The µ-subunit protein fused to green fluorescent protein (AP2M-GFP) was localized to the plasma membrane and to the cytoplasm. Live-cell imaging using a variable-angle epifluorescence microscope revealed that AP2M-GFP transiently forms punctate structures on the plasma membrane. Homozygous ap2m mutant plants exhibited abnormal floral structures, including reduced stamen elongation and delayed anther dehiscence, which led to a failure of pollination and a subsequent reduction of fertility. Our study provides a molecular basis for understanding AP-2-dependent endocytic pathways in plants and their roles in floral organ development and plant reproduction.


Assuntos
Complexo 2 de Proteínas Adaptadoras/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Flores/crescimento & desenvolvimento , Flores/metabolismo , Arabidopsis/ultraestrutura , Membrana Celular/metabolismo , Flores/ultraestrutura , Proteínas de Fluorescência Verde/metabolismo , Homozigoto , Mutação/genética , Desenvolvimento Vegetal , Pólen/crescimento & desenvolvimento , Pólen/metabolismo , Pólen/ultraestrutura , Transporte Proteico , Tirosina/metabolismo
19.
Kyobu Geka ; 69(13): 1110-1113, 2016 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-27909282

RESUMO

A 77-year-old male with many comorbidities underwent off pump coronary artery bypass grafting. A severely atherosclerotic ascending aorta was revealed by preoperative computed tomography(CT) and epiaortic echography during operation. Therefore, V-composite saphenous vein grafting was adopted for non left anterior descending artery (LAD) coronary lesions in addition to left internal thoracic artery-left anterior descending artery bypass grafting. He was discharged with no complications and all grafts were confirmed to be patent by postoperative CT. V-composite saphenous vein grafting for avoiding cerebrovascular complications might be one of the useful options in coronary artery revascularization for non-LAD lesions in elderly patients or those with many comorbidities, especially with a severely atherosclerotic ascending aorta.


Assuntos
Aorta/cirurgia , Doença da Artéria Coronariana/cirurgia , Revascularização Miocárdica/métodos , Veia Safena/cirurgia , Idoso , Aorta/diagnóstico por imagem , Doença da Artéria Coronariana/diagnóstico por imagem , Humanos , Masculino , Tomografia Computadorizada por Raios X
20.
Plant J ; 76(5): 781-91, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24118572

RESUMO

In Arabidopsis thaliana, MAIGO 2 (MAG2) is involved in protein transport between the endoplasmic reticulum (ER) and the Golgi apparatus via its association with the ER-localized t-SNARE components SYP81/AtUfe1 and SEC20. To characterize the molecular machinery of MAG2-mediated protein transport, we explored MAG2-interacting proteins using transgenic A. thaliana plants expressing TAP-tagged MAG2. We identified three proteins, which were designated as MAG2-INTERACTING PROTEIN 1-3 [MIP1 (At2g32900), MIP2 (At5g24350) and MIP3 (At2g42700)]. Both MIP1 and MAG2 localized to the ER membrane. All of the mag2, mip1, mip2 and mip3 mutants exhibited a defect in storage protein maturation, and developed abnormal storage protein body (MAG body) structures in the ER of seed cells. These observations suggest that MIPs are closely associated with MAG2 and function in protein transport between the ER and Golgi apparatus. MIP1 and MIP2 contain a Zeste-White 10 (ZW10) domain and a Sec39 domain, respectively, but have low sequence identities (21% and 23%) with respective human orthologs. These results suggest that the plant MAG2-MIP1-MIP2 complex is a counterpart of the triple-subunit tethering complexes in yeast (Tip20p-Dsl1p-Sec39p) and humans (RINT1-ZW10-NAG). Surprisingly, the plant complex also contained a fourth member (MIP3) with a Sec1 domain. There have been no previous reports showing that a Sec1-containing protein is a subunit of ER-localized tethering complexes. Our results suggest that MAG2 and the three MIP proteins form a unique complex on the ER that is responsible for efficient transport of seed storage proteins.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas de Transporte/metabolismo , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Proteínas de Armazenamento de Sementes/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Transporte/genética , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Domínios e Motivos de Interação entre Proteínas , Transporte Proteico
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