In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric s...In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach.The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied.It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction.The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined,and a recommendation was given to promote the degree of thermobaric destruction of quartz particles,which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.展开更多
Helicobacter pylori(H.pylori)are resistant to hostile gastric environments and antibiotic therapy,reflecting the possibility that they are protected by an ecological niche,such as inside the vacuoles of human epitheli...Helicobacter pylori(H.pylori)are resistant to hostile gastric environments and antibiotic therapy,reflecting the possibility that they are protected by an ecological niche,such as inside the vacuoles of human epithelial and immune cells.Candida yeast may also provide such an alternative niche,as fluorescently labeled H.pylori were observed as fast-moving and viable bacterium-like bodies inside the vacuoles of gastric,oral,vaginal and foodborne Candida yeasts.In addition,H.pylori-specific genes and proteins were detected in samples extracted from these yeasts.The H.pylori present within these yeasts produce peroxiredoxin and thiol peroxidase,providing the ability to detoxify oxygen metabolites formed in immune cells.Furthermore,these bacteria produce urease and VacA,two virulence determinants of H.pylori that influence phago-lysosome fusion and bacterial survival in macrophages.Microscopic observations of H.pylori cells in new generations of yeasts along with amplification of H.pylori-specific genes from consecutive generations indicate that new yeasts can inherit the intracellular H.pylori as part of their vacuolar content.Accordingly,it is proposed that yeast vacuoles serve as a sophisticated niche that protects H.pylori against the environmental stresses and provides essential nutrients,including ergosterol,for its growth and multiplication.This intracellular establishment inside the yeast vacuole likely occurred long ago,leading to the adaptation of H.pylori to persist in phagocytic cells.The presence of these bacteria within yeasts,including foodborne yeasts,along with the vertical transmission of yeasts from mother to neonate,provide explanations for the persistence and propagation of H.pylori in the human population.This Topic Highlight reviews and discusses recent evidence regarding the evolutionary adaptation of H.pylori to thrive in host cell vacuoles.展开更多
Glucose deprivation induces the synthesis of pivotagluconeogenic enzymes such as fructose-1,6-bisphos-phatase, malate dehydrogenase, phosphoenolpyruvatecarboxykinase and isocitrate lyase in Saccharomycescerevisiae. Ho...Glucose deprivation induces the synthesis of pivotagluconeogenic enzymes such as fructose-1,6-bisphos-phatase, malate dehydrogenase, phosphoenolpyruvatecarboxykinase and isocitrate lyase in Saccharomycescerevisiae. However, following glucose replenishment,these gluconeogenic enzymes are inactivated and de-graded. Studies have characterized the mechanismsby which these enzymes are inactivated in response toglucose. The site of degradation of these proteins hasalso been ascertained to be dependent on the dura-tion of starvation. Glucose replenishment of short-termstarved cells results in these proteins being degradedin the proteasome. In contrast, addition of glucose tocells starved for a prolonged period results in theseproteins being degraded in the vacuole. In the vacuoledependent pathway, these proteins are sequestered inspecialized vesicles termed vacuole import and degra-dation (Vid). These vesicles converge with the endo-cytic pathway and deliver their cargo to the vacuolefor degradation. Recent studies have identified thatinternalization, as mediated by actin polymerization, isessential for delivery of cargo proteins to the vacuolefor degradation. In addition, components of the targetof rapamycin complex 1 interact with cargo proteins during glucose starvation. Furthermore, Tor1p dissoci-ates from cargo proteins following glucose replenish-ment. Future studies will be needed to elaborate on the importance of internalization at the plasma membrane and the subsequent import of cargo proteins into Vid vesicles in the vacuole dependent degradation pathway.展开更多
Glucose(Glu) is involved in not only plant physiological and developmental events but also plant responses to abiotic stresses. Here, we found that the exogenous Glu improved root and shoot growth, reduced shoot cadmi...Glucose(Glu) is involved in not only plant physiological and developmental events but also plant responses to abiotic stresses. Here, we found that the exogenous Glu improved root and shoot growth, reduced shoot cadmium(Cd) concentration, and rescued Cdinduced chlorosis in Arabidopsis thaliana(Columbia ecotype,Col-0) under Cd stressed conditions. Glucose increased Cd retained in the roots, thus reducing its translocation from root to shoot signi fi cantly. The most Cd retained in the roots was found in the hemicellulose 1. Glucose combined with Cd(Glu t Cd) treatment did not affect the content of pectin and its binding capacity of Cd while it increased the content of hemicelluloses 1 and the amount of Cd retained in it signi fi cantly. Furthermore, Leadmium Green staining indicated that more Cd was compartmented into vacuoles in Glu t Cd treatment compared with Cd treatment alone, which was in accordance with the R e ssigni fi cant upregulation of the expression of tonoplastlocalized metal transporter genes, suggesting that compartmentation of Cd into vacuoles also contributes to the Glu-alleviated Cd toxicity. Taken together, we demonstrated that Glu-alleviated Cd toxicity is mediated through increasing Cd fi xation in the root cell wall and sequestration into the vacuoles.展开更多
Vacuoles are organelles in plant cells that play pivotal roles in growth and developmental regulation.The main functions of vacuoles include maintaining cell acidity and turgor pressure,regulating the storage and tran...Vacuoles are organelles in plant cells that play pivotal roles in growth and developmental regulation.The main functions of vacuoles include maintaining cell acidity and turgor pressure,regulating the storage and transport of substances,controlling the transport and localization of key proteins through the endocytic and lysosomal-vacuolar transport pathways,and responding to biotic and abiotic stresses.Further,proteins localized either in the tonoplast(vacuolar membrane)or inside the vacuole lumen are critical for fruit quality.In this review,we summarize and discuss some of the emerging functions and regulatory mechanisms associated with plant vacuoles,including vacuole biogenesis,vacuole functions in plant growth and development,fruit quality,and plant-microbe interaction,as well as some innovative research technology that has driven advances in the field.Together,the functions of plant vacuoles are important for plant growth and fruit quality.The investigation of vacuole functions in plants is of great scientific significance and has potential applications in agriculture.展开更多
Pear has an S-RNase-based gametophytic selfincompatibility(SI)system.Nuclear DNA degradation is a typical feature of incompatible pollen tube death,and is among the many physiological functions of vacuoles.However,the...Pear has an S-RNase-based gametophytic selfincompatibility(SI)system.Nuclear DNA degradation is a typical feature of incompatible pollen tube death,and is among the many physiological functions of vacuoles.However,the specific changes that occur in vacuoles,as well as the associated regulatory mechanism in pear SI,are currently unclear.Although research in tobacco has shown that decreased activity of diacylglycerol kinase(DGK)results in the morphological change of pollen tube vacuole,whether DGK regulates the pollen tube vacuole of tree plants and whether it occurs in SI response,is currently unclear.We found that DGK activity is essential for pear pollen tube growth,and DGK4 regulates pollen tube vacuole morphology following its high expression and deposition at the tip and shank edge of the pollen tube of pear.Specifically,incompatible S-RNase may induce cytoplasmic acidification of the pollen tube by inhibiting V-ATPase V0 domain a1 subunit gene expression as early as 30 min after treatment,when the pollen tube is still alive.Cytoplasmic acidification induced by incompatible S-RNase results in reduced DGK4 abundance and deposition,leading to morphological change of the vacuole and fragmentation of nuclear DNA,which indicates that DGK4 is a key factor in pear SI response.展开更多
Subject Code:C02With the support by the National Natural Science Foundation of China,the research team led by Prof.Lin Jinxing(林金星)at the College of Biological Sciences&Biotechnology,Beijing Forestry University...Subject Code:C02With the support by the National Natural Science Foundation of China,the research team led by Prof.Lin Jinxing(林金星)at the College of Biological Sciences&Biotechnology,Beijing Forestry University,overcame the limitations of existing techniques and expanded the study of protein characteristics from the plasma membrane to the vacuole membranes.This study was published in Molecular Plant(2016,DOI:展开更多
BACKGROUND In recent years,associations between specific virulence markers of Helicobacter pylori(H.pylori)and gastrointestinal disorders have been suggested.AIM To investigate the presence of virulence factors includ...BACKGROUND In recent years,associations between specific virulence markers of Helicobacter pylori(H.pylori)and gastrointestinal disorders have been suggested.AIM To investigate the presence of virulence factors including vacuolating cytotoxin A genotypes(s1m1,s1m2,s2m1,and s2m2),cytotoxin-associated gene A(CagA),and urease activity in H.pylori strains isolated from Arab and Jewish populations in northern Israel and to assess associations between these factors and patients’demographics and clinical outcomes.METHODS Patients(n=108)who underwent gastroscopy at the Baruch Padeh Medical Center,Poriya due to symptomatic gastroduodenal pathologies as part of H.pylori diagnosis were enrolled in the study.Gastric biopsy specimens were collected from the antrum of the stomach.Clinical condition was assessed by clinical pathology tests.Bacteria were isolated on modified BD Helicobacter Agar(BD Diagnostics,Sparks,MD,United States).Bacterial DNA was extracted,and PCR was performed to detect CagA and vacuolating cytotoxin A genes.Urease activity was assessed using a rapid urease test.RESULTS A significant correlation was found between disease severity and patient ethnicity(P=0.002).A significant correlation was found between CagA presence and the s1m1 genotype(P=0.02),which is considered the most virulent genotype.Further,a higher level of urease activity was associated with isolates originating from the Jewish population.Moreover,higher urease activity levels were measured among CagA-/s1m1 and CagA-/s2m2 isolates.CONCLUSION Our study highlights the importance of incorporating molecular methods for detection of virulence markers of H.pylori in order to tailor optimal treatments for each patient.Further investigation should be performed regarding associations between H.pylori virulence factors and ethnicity.展开更多
The Helicobacter pylori vacuolating cytotoxin (VacA) is an intracellular, mitochondrial-targeting exotoxin that rapidly causes mitochondrial dysfunction and fragmentation. Although VacA targeting of mitochondria has b...The Helicobacter pylori vacuolating cytotoxin (VacA) is an intracellular, mitochondrial-targeting exotoxin that rapidly causes mitochondrial dysfunction and fragmentation. Although VacA targeting of mitochondria has been reported to alter overall cellular metabolism, there is little known about the consequences of extended exposure to the toxin. Here, we describe studies to address this gap in knowledge, which have revealed that mitochondrial dysfunction and fragmentation are followed by a time-dependent recovery of mitochondrial structure, mitochondrial transmembrane potential, and cellular ATP levels. Cells exposed to VacA also initially demonstrated a reduction in oxidative phosphorylation, as well as increase in compensatory aerobic glycolysis. These metabolic alterations were reversed in cells with limited toxin exposure, congruent with the recovery of mitochondrial transmembrane potential and the absence of cytochrome c release from the mitochondria. Taken together, these results are consistent with a model that mitochondrial structure and function are restored in VacA-intoxicated cells.展开更多
Trypanosoma cruzi is the causative agent of Chagas disease.This parasite requires the intracellular niche in order to proliferate and disseminate the infection.After invasion,T.cruzi resides temporarily in an acidic v...Trypanosoma cruzi is the causative agent of Chagas disease.This parasite requires the intracellular niche in order to proliferate and disseminate the infection.After invasion,T.cruzi resides temporarily in an acidic vacuole which is lysed by a not well-understood mechanism.Transmission electron microscopy was used to describe the process of T.cruzi escape from the parasitophorous vacuole over the time.Using HeLa(non-professional phagocytic cells)as host cell,we observed that recently internalized parasites reside in a membrane-bounded vacuole.A few hours later,the first sign of vacuole disruption appeared as membrane discontinuities.This observation was followed by a progressive vacuole swelling as evidenced by an electron-lucent halo between the parasite and the vacuole membrane.Apparently,the vacuole membrane remnants reorganized as small vesicles that eventually disappeared from the vicinity of the parasites.Finally,parasites reach the host cell cytosol where replication takes place.The thorough ultrastructural description of this process set the base for a comprehensive understanding of the parasite-host cell interaction and,thus open the possibility of new therapeutic intervention strategies.展开更多
Objective:To evaluate the impact of freezing–thawing on the human sperm head vacuoles and the potential value of motile sperm organelle morphology examination for selection of frozen-thaw spermatozoa.Methods: In 30 s...Objective:To evaluate the impact of freezing–thawing on the human sperm head vacuoles and the potential value of motile sperm organelle morphology examination for selection of frozen-thaw spermatozoa.Methods: In 30 sperm samples from infertile men, analysis for conventional sperm parameters (motility, vitality, and normal morphology) and a morphological analysis at high magnification for vacuoles examination were done before cooling and after warming. For description of sperm head vacuoles, two hundred spermatozoa were examined and were classified into three groups according to presence and vacuole areas including no vacuole group (free of any vacuole), small vacuole group (occupy not more than 4% of the nuclear area), and large vacuole group (occupy more than 4% of the normal nuclear area).Results:Significant reduction of progressive motility and vitality was observed following cryopreservation (P<0.001). Also, normal morphology decreased significantly after cryopreservation (P<0.05). Spermatozoa with a vacuole-free head had a significant reduction in cryopreservation group (P=0.013). The percentage of spermatozoa with small vacuoles increased slightly, but not significantly after cryopreservation (P=0.296).Conclusions:Motile sperm organelle morphology examination is a powerful research tool for investigating spermatozoa abnormalities such as vacuoles that are increased post cryopreservation.展开更多
Inorganic polyphosphate (PolyP), a bioactive polymer with multiple functions, plays a key role in biomineralizaion and phosphorus homeostasis in yeasts. After phosphate starvation, the cells of Saccharomyces cerevisia...Inorganic polyphosphate (PolyP), a bioactive polymer with multiple functions, plays a key role in biomineralizaion and phosphorus homeostasis in yeasts. After phosphate starvation, the cells of Saccharomyces cerevisiae restored their pool of PolyP during the first 30 min of incubation in the media containing phosphate and carbon sources. The cells of parent strain accumulated PolyP both in glucose and ethanol-containing media. In the medium with glucose, the strain with inactivated PPX1 and PPN1 genes (encoding two major yeast polyphosphatases) accumulated 2-fold more PolyP than the parent strain. The PolyP in the mutant cells had a greater average chain length compared to the parent strain. The strain with inactivated exopolyphosphatase genes РРХ1 and PPN1 was incapable of PolyP synthesis in the medium with ethanol. The in vivo staining of cells with DAPI show that in the cells of parent strain PolyP appeared first in cytoplasm and mitochondria under cultivation in glucose-containing medium and in cytoplasm and vacuoles in the medium with ethanol. In the ΔPPX1ΔPPN1double mutant PolyP accumulated in cytoplasm and vacuoles under cultivation in glucose-contained medium.展开更多
The budding yeast Saccharomyces cerevisiae serves as an effective model organism for many cellular pathways including phosphate transport, accumulation, and storage. In S. cerevisiae, phosphate is actively transported...The budding yeast Saccharomyces cerevisiae serves as an effective model organism for many cellular pathways including phosphate transport, accumulation, and storage. In S. cerevisiae, phosphate is actively transported across the plasma membrane via several phosphate carriers and is then transported into the acidic vacuole (roughly equivalent to the mammalian lysosome with degradative functions but with additional storage functions, such as calcium) where it is synthesized into volutin, a storage form of polyphosphate, found in many organisms. We have been studying volutin granule formation in wild type cells to determine the physiological requirements for formation and in mutants to determine the pathway by which the volutin biosynthetic proteins are transported to the vacuole. Undertaking an analysis of volutin formation in yeast vacuoles by blocking vacuole function with pharmacological agents, such as ionomycin and CCCP, we see that vacuole pH as well as vacuolar calcium seems critical for volutin formation. Different blocks in vacuolar protein sorting have differential effects on volutin granule accumulation, with volutin granule formation seen in all mutant strains thus far tested, except for vps33, a mutant cell strain lacking all vacuolar structure. Our data are consistent with pleiotrophic effects of vacuolar physiological function blocks leading to a decrease in volutin formation.展开更多
AIM: To better understand the pathogenic role of Helicobacter pylori (H. pylori) in pre-eclampsia (PE), and whether it is associated or not with fetal growth retardation (FGR). METHODS: Maternal blood samples were col...AIM: To better understand the pathogenic role of Helicobacter pylori (H. pylori) in pre-eclampsia (PE), and whether it is associated or not with fetal growth retardation (FGR). METHODS: Maternal blood samples were collected from 62 consecutive pregnant women with a diagnosis of PE and/or FGR, and from 49 women with uneventful pregnancies (controls). Serum samples were evaluated by immunoblot assay for presence of specific antibodies against H. pylori antigens [virulence: cytotoxin-associated antigen A (CagA); ureases; heat shock protein B; flagellin A; persistence: vacuolating cytotoxin A (VacA)]. Maternal complete blood count and liver enzymes levels were assessed at delivery by an automated analyzer. RESULTS: A significantly higher percentage of H. pyloriseropositive women were found among PE cases (85.7%) compared to controls (42.9%, P < 0.001). There were no differences between pregnancies complicated by FGR without maternal hypertension (46.2%) and controls. Importantly, persistent and virulent infections (VacA/ CagA seropositive patients, intermediate leukocyte blood count and aspartate aminotransferase levels) were exclusively associated with pre-eclampsia complicated by FGR, while virulent but acute infections (CagA positive/ VacA negative patients, highest leukocyte blood count and aspartate aminotransferase levels) specifically correlated with PE without FGR. CONCLUSION: Our data strongly indicate that persistent and virulent H. pylori infections cause or contribute to PE complicated by FGR, but not to PE without feto-placental compromise.展开更多
AIM: To investigate into the potential involvement of pyrin containing 3 gene(NLRP3), a member of the nucleotide-binding oligomerization domain-like receptors with cytosolic pattern recognition, in the host defense of...AIM: To investigate into the potential involvement of pyrin containing 3 gene(NLRP3), a member of the nucleotide-binding oligomerization domain-like receptors with cytosolic pattern recognition, in the host defense of corneas against viruses.METHODS: The herpes viral keratitis model was utilized in BALB/c mice with inoculation of herpes simplex virus-1(HSV-1). Corneal tissues removed during therapy of patients with viral keratitis as well as a Simian vacuolating virus 40(SV40)-immortalized human corneal epithelial cell line were also examined.Immunohistochemistry was used to detect NLRP3 in these subjects, focusing on their distribution in tissue or cells. Western blot was used to measure the level of NLRP3 and another two related molecules in NLPR3 inflammasome, namely caspase-1 and IL-1β.RESULTS: The NLRP3 activation induced by HSV-1infection in corneas was accompanied with redistribution of NLRP3 from the cytoplasm to the nucleus in both murine and human corneal epithelial cells. Furthermore,in the SV40-immortalized human corneal epithelial cells,NLRP3 was exclusively located in the nucleus, and treatment of the cells with high concentration of extracellular potassium(known as an inhibitor of NLRP3activation) effectively drove NLRP3 back to the cytoplasm as reflected by both immunohistochemistry and Western blot.· CONCLUSION: It is proposed that herpes virus infection activates and causes redistribution of NLRP3 to nuclei. Whether this NLRP3 translocation occurs with other viral infections and in other cell types merit further study.展开更多
AIM: To test our hypothesis that activation of protein kinase A(PKA) signal pathway by β-adrenergic agonist plays an important role in the protecting of cultured retinal pigment epithelial(RPE) cells against the hydr...AIM: To test our hypothesis that activation of protein kinase A(PKA) signal pathway by β-adrenergic agonist plays an important role in the protecting of cultured retinal pigment epithelial(RPE) cells against the hydroxychloroquine(HCQ) toxicity. METHODS: Cultured human RPE cells were treated with 1) HCQ, 2) HCQ with salbutamol(a β2-adrenergic receptor agonist), and 3) HCQ with salbutamol and a PKA inhibitor, and compared these to 4) untreated cells(controls). After treated for 24 h, cell vacuolation, cells viability, PKA and PKA kinase activity levels were determined by the measurement of the size of vacuoles using Image J software, the cell counting with a dye-exclusion testing, Western blot and PKA kinase detection, respectively. RESULTS: Cell vacuolation and cell death of cultured RPE cells were significantly increased by the treatment of HCQ. Salbutamol significantly elevated PKA and PKA activity levels and this was associated with the inhibition of the vacuolation and cell death. The PKA inhibitor significantly decreased the PKA levels and eliminated the protective effects of salbutamol on HCQ-treated RPE cells. CONCLUSION: The PKA pathway plays an important role in the protective effects of β2-adrenergic agonist on the RPE cells against HCQ toxicity. These findings reveal a novel potential strategy against HCQ retinopathy by treatment with PKA activating medications.展开更多
Cytotoxic test in vitro combined with cytochemical stain, fluorescent stain, transmission electronmicrograph was used to study the vacuolated effect by helicobacter pylori (H.pylori) (Toxin+) and its pathological mech...Cytotoxic test in vitro combined with cytochemical stain, fluorescent stain, transmission electronmicrograph was used to study the vacuolated effect by helicobacter pylori (H.pylori) (Toxin+) and its pathological mechanism. 78..26 % patients with peptic ulcer associated with H.pylori was infected with H.pylori (Toxin+), while 42.86 % patients with gastritis was infected with H.pylori (Toxin+). It was positive in vacuole with acridine orange and acid phosphatase stain. Transmission electronmicrograph of vacuole revealed the presence of abounding membrane. There was a closed relationship between infection with H.pylori (Toxin+) and peptic ulcer disease. The vacuole induced by H.pylori (Toxin+) was autophagosome, which was pathological phenomenon induced by toxin.展开更多
Bacteroides species are nearly half of the fecal flora community and some are host symbionts crucial to host nutrition and systemic immunity. Among Bacteroides species B. fragilis strains are considered to be the oppo...Bacteroides species are nearly half of the fecal flora community and some are host symbionts crucial to host nutrition and systemic immunity. Among Bacteroides species B. fragilis strains are considered to be the opportunistic ones, being the most isolated anaerobic bacteria in clinical samples. Cell-free supernatants of 65 B. fragilis strains were assayed and they were capable of inducing vacuolating phenotype on Vero cells lineage. The supernatant of the Bacteroides fragilis ATCC 23745 strain was elicited to have the strongest vacuolating effect on Vero cells monolayers and peritoneal macrophages. Some drastic cell alterations were observed, such as a general disorganization of cytoplasm and chromatin condensation, evidencing cell death. By transmission electron microscopy it was confirmed that the vacuoles observed were, in fact, swollen mitochondria. An immunocytochemical assay, TUNEL, was used to confirm this hypothesis and showed that Vero cells and peritoneal macrophages were dying by apoptotic process after exposition of B. fragilis cell-free supernatant. Physical analysis of the apoptotic factor has revealed properties similar to short-chain fatty acids. After gas chromatography and mass spectrometry analysis, phenylacetic acid (PA) was characterized as the major compound present in the most purified active fraction. We believe that the PA is responsible for the pro-apoptotic effect elicited by the supernatant of B. fragilis cultures.展开更多
CGG repeat expansions in LOC642361/NUTM2B-AS1 have recently been identified as a cause of oculopharyngeal myopathy with leukoencephalopathy.However,since only three patients from a single family were reported,it remai...CGG repeat expansions in LOC642361/NUTM2B-AS1 have recently been identified as a cause of oculopharyngeal myopathy with leukoencephalopathy.However,since only three patients from a single family were reported,it remains unknown whether their clinicopathological features are typical for CGG repeat expansions in LOC642361/NUTM2B-AS1.Here,using repeat-primed-polymerase chain reaction and long-read sequencing,we identify 12 individuals from 3 unrelated families with CGG repeat expansions in LOC642361/NUTM2B-AS1,typically presenting with oculopharyngodistal myopathy.The CGG repeat expansions range from 161 to 669 repeat units.Most of the patients present with ptosis,restricted eye movements,dysphagia,dysarthria,and diffuse limb muscle weakness.Only one patient shows T2-weighted hyperintensity in the cerebellar white matter surrounding the deep cerebellar nuclei on brain magnetic resonance imaging.Muscle biopsies from three patients show a myopathic pattern and rimmed vacuoles.Analyses of muscle biopsies suggest that CGG repeat expansions in LOC642361/NUTM2B-AS1 may deleteriously affect aggrephagic capacity,suggesting that RNA toxicity and mitochondrial dysfunction may contribute to pathogenesis.Our study thus expands the phenotypic spectrum for the CGG repeat expansion of LOC642361/NUTM2B-AS1 and indicates that this genetic variant typically manifests as oculopharyngodistal myopathy with chronic myopathic changes with rimmed vacuoles and filamentous intranuclear inclusions in muscle fibers.展开更多
Brassinosteroid(BR)is a vital plant hormone that regulates plant growth anddevelopment.BRASSINAZOLE RESISTANT1(BZR1)is a key transcription factor in BR signaling,and its nucleocytoplasmic localization is crucial for B...Brassinosteroid(BR)is a vital plant hormone that regulates plant growth anddevelopment.BRASSINAZOLE RESISTANT1(BZR1)is a key transcription factor in BR signaling,and its nucleocytoplasmic localization is crucial for BR signaling.However,the mechanisms that regulate BzR1 nucleocytoplasmic distribution and thus the homeostasis of BR signaling remain largely unclear.The vacuole is the largest organelle in mature plantcells and plays a key role in maintenance of cell ular pH,storage of intracellular substances,and transport ofions.In this study,weuncovered anovel mechanismof BR signaling homeostasis regulatedbythe vacuolar H+-ATPase(V-ATPase)and BZR1 feedback loop.Our results revealed that the vha-a2 vha-a3 mutant(vha2,lacking V-ATPase activity)exhibits enhanced BR signaling with increased total amount of BZR1,nuclearlocalized BZR1,and the ratio of BZR1/phosphorylated BZR1 in the nucleus.Further biochemical assays revealed that VHA-a2 and VHA-a3 of V-ATPase interact with the BZR1 protein through a domain that is conserved across multiple species.VHA-a2 and VHA-a3 negatively regulate BR signaling by interacting with BzR1 and promoting its retention in the tonoplast.Interestingly,a series of molecular analyses demonstrated that nuclear-localized BZR1 could bind directlyto specific motifs in the promoters of VHA-a2 andVHAa3topromote their expression.Taken together,these results suggest that V-ATPase and BzR1 mayforma feedback regulatory loop to maintain thehomeostasis of BR signaling in Arabidopsis,providing new insights into vacuole-mediated regulation of hormone signaling.展开更多
基金supported by National Natural Science Foundation of China(Nos.52202460,52177128)National Key R&D Program of China(Nos.2020YFC2201100,2021YFC2202804)+2 种基金China Postdoctoral Science Foundation(Nos.2021M690392,2021TQ0036)Science Foundation for Youth Scholars of the Beijing Institute of TechnologyAdvanced Space Propulsion Laboratory of BICE and the Beijing Engineering Research Centre of Efficient and Green Aerospace Propulsion Technology(No.LabASP-2021-04)。
文摘In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach.The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied.It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction.The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined,and a recommendation was given to promote the degree of thermobaric destruction of quartz particles,which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.
文摘Helicobacter pylori(H.pylori)are resistant to hostile gastric environments and antibiotic therapy,reflecting the possibility that they are protected by an ecological niche,such as inside the vacuoles of human epithelial and immune cells.Candida yeast may also provide such an alternative niche,as fluorescently labeled H.pylori were observed as fast-moving and viable bacterium-like bodies inside the vacuoles of gastric,oral,vaginal and foodborne Candida yeasts.In addition,H.pylori-specific genes and proteins were detected in samples extracted from these yeasts.The H.pylori present within these yeasts produce peroxiredoxin and thiol peroxidase,providing the ability to detoxify oxygen metabolites formed in immune cells.Furthermore,these bacteria produce urease and VacA,two virulence determinants of H.pylori that influence phago-lysosome fusion and bacterial survival in macrophages.Microscopic observations of H.pylori cells in new generations of yeasts along with amplification of H.pylori-specific genes from consecutive generations indicate that new yeasts can inherit the intracellular H.pylori as part of their vacuolar content.Accordingly,it is proposed that yeast vacuoles serve as a sophisticated niche that protects H.pylori against the environmental stresses and provides essential nutrients,including ergosterol,for its growth and multiplication.This intracellular establishment inside the yeast vacuole likely occurred long ago,leading to the adaptation of H.pylori to persist in phagocytic cells.The presence of these bacteria within yeasts,including foodborne yeasts,along with the vertical transmission of yeasts from mother to neonate,provide explanations for the persistence and propagation of H.pylori in the human population.This Topic Highlight reviews and discusses recent evidence regarding the evolutionary adaptation of H.pylori to thrive in host cell vacuoles.
基金Supported by NIH grant R01GM 59480the PA Tobacco Settlement Fund to Hui-Ling Chiang
文摘Glucose deprivation induces the synthesis of pivotagluconeogenic enzymes such as fructose-1,6-bisphos-phatase, malate dehydrogenase, phosphoenolpyruvatecarboxykinase and isocitrate lyase in Saccharomycescerevisiae. However, following glucose replenishment,these gluconeogenic enzymes are inactivated and de-graded. Studies have characterized the mechanismsby which these enzymes are inactivated in response toglucose. The site of degradation of these proteins hasalso been ascertained to be dependent on the dura-tion of starvation. Glucose replenishment of short-termstarved cells results in these proteins being degradedin the proteasome. In contrast, addition of glucose tocells starved for a prolonged period results in theseproteins being degraded in the vacuole. In the vacuoledependent pathway, these proteins are sequestered inspecialized vesicles termed vacuole import and degra-dation (Vid). These vesicles converge with the endo-cytic pathway and deliver their cargo to the vacuolefor degradation. Recent studies have identified thatinternalization, as mediated by actin polymerization, isessential for delivery of cargo proteins to the vacuolefor degradation. In addition, components of the targetof rapamycin complex 1 interact with cargo proteins during glucose starvation. Furthermore, Tor1p dissoci-ates from cargo proteins following glucose replenish-ment. Future studies will be needed to elaborate on the importance of internalization at the plasma membrane and the subsequent import of cargo proteins into Vid vesicles in the vacuole dependent degradation pathway.
基金supported by Changjiang Innovation Research Team (IRT1185)Fundamental Research Funds for the Central Universities
文摘Glucose(Glu) is involved in not only plant physiological and developmental events but also plant responses to abiotic stresses. Here, we found that the exogenous Glu improved root and shoot growth, reduced shoot cadmium(Cd) concentration, and rescued Cdinduced chlorosis in Arabidopsis thaliana(Columbia ecotype,Col-0) under Cd stressed conditions. Glucose increased Cd retained in the roots, thus reducing its translocation from root to shoot signi fi cantly. The most Cd retained in the roots was found in the hemicellulose 1. Glucose combined with Cd(Glu t Cd) treatment did not affect the content of pectin and its binding capacity of Cd while it increased the content of hemicelluloses 1 and the amount of Cd retained in it signi fi cantly. Furthermore, Leadmium Green staining indicated that more Cd was compartmented into vacuoles in Glu t Cd treatment compared with Cd treatment alone, which was in accordance with the R e ssigni fi cant upregulation of the expression of tonoplastlocalized metal transporter genes, suggesting that compartmentation of Cd into vacuoles also contributes to the Glu-alleviated Cd toxicity. Taken together, we demonstrated that Glu-alleviated Cd toxicity is mediated through increasing Cd fi xation in the root cell wall and sequestration into the vacuoles.
基金This work is supported by National Natural Science Foundation of China(Grant No.32070342)the Project MDS-JF-2020-8 supported from SJTU JiRLMDS Joint Research Fund,the Agri-X Interdisciplinary Fund of Shanghai Jiao Tong University(20200204)+1 种基金the bio-X Interdisciplinary Fund of Shanghai Jiao Tong University(20CX-04)Shanghai Jiao Tong University Scientific and Technological Innovation Funds(19X160020009).
文摘Vacuoles are organelles in plant cells that play pivotal roles in growth and developmental regulation.The main functions of vacuoles include maintaining cell acidity and turgor pressure,regulating the storage and transport of substances,controlling the transport and localization of key proteins through the endocytic and lysosomal-vacuolar transport pathways,and responding to biotic and abiotic stresses.Further,proteins localized either in the tonoplast(vacuolar membrane)or inside the vacuole lumen are critical for fruit quality.In this review,we summarize and discuss some of the emerging functions and regulatory mechanisms associated with plant vacuoles,including vacuole biogenesis,vacuole functions in plant growth and development,fruit quality,and plant-microbe interaction,as well as some innovative research technology that has driven advances in the field.Together,the functions of plant vacuoles are important for plant growth and fruit quality.The investigation of vacuole functions in plants is of great scientific significance and has potential applications in agriculture.
基金This work was supported by the National Key Research and Development Program of China(2018YFD1000107)National Natural Science Foundation of China(32001983).
文摘Pear has an S-RNase-based gametophytic selfincompatibility(SI)system.Nuclear DNA degradation is a typical feature of incompatible pollen tube death,and is among the many physiological functions of vacuoles.However,the specific changes that occur in vacuoles,as well as the associated regulatory mechanism in pear SI,are currently unclear.Although research in tobacco has shown that decreased activity of diacylglycerol kinase(DGK)results in the morphological change of pollen tube vacuole,whether DGK regulates the pollen tube vacuole of tree plants and whether it occurs in SI response,is currently unclear.We found that DGK activity is essential for pear pollen tube growth,and DGK4 regulates pollen tube vacuole morphology following its high expression and deposition at the tip and shank edge of the pollen tube of pear.Specifically,incompatible S-RNase may induce cytoplasmic acidification of the pollen tube by inhibiting V-ATPase V0 domain a1 subunit gene expression as early as 30 min after treatment,when the pollen tube is still alive.Cytoplasmic acidification induced by incompatible S-RNase results in reduced DGK4 abundance and deposition,leading to morphological change of the vacuole and fragmentation of nuclear DNA,which indicates that DGK4 is a key factor in pear SI response.
文摘Subject Code:C02With the support by the National Natural Science Foundation of China,the research team led by Prof.Lin Jinxing(林金星)at the College of Biological Sciences&Biotechnology,Beijing Forestry University,overcame the limitations of existing techniques and expanded the study of protein characteristics from the plasma membrane to the vacuole membranes.This study was published in Molecular Plant(2016,DOI:
基金The study was reviewed and approved by the Helsinki Committee of the Baruch Padeh Medical Center,Poriya(Approval No.POR 0007-20).
文摘BACKGROUND In recent years,associations between specific virulence markers of Helicobacter pylori(H.pylori)and gastrointestinal disorders have been suggested.AIM To investigate the presence of virulence factors including vacuolating cytotoxin A genotypes(s1m1,s1m2,s2m1,and s2m2),cytotoxin-associated gene A(CagA),and urease activity in H.pylori strains isolated from Arab and Jewish populations in northern Israel and to assess associations between these factors and patients’demographics and clinical outcomes.METHODS Patients(n=108)who underwent gastroscopy at the Baruch Padeh Medical Center,Poriya due to symptomatic gastroduodenal pathologies as part of H.pylori diagnosis were enrolled in the study.Gastric biopsy specimens were collected from the antrum of the stomach.Clinical condition was assessed by clinical pathology tests.Bacteria were isolated on modified BD Helicobacter Agar(BD Diagnostics,Sparks,MD,United States).Bacterial DNA was extracted,and PCR was performed to detect CagA and vacuolating cytotoxin A genes.Urease activity was assessed using a rapid urease test.RESULTS A significant correlation was found between disease severity and patient ethnicity(P=0.002).A significant correlation was found between CagA presence and the s1m1 genotype(P=0.02),which is considered the most virulent genotype.Further,a higher level of urease activity was associated with isolates originating from the Jewish population.Moreover,higher urease activity levels were measured among CagA-/s1m1 and CagA-/s2m2 isolates.CONCLUSION Our study highlights the importance of incorporating molecular methods for detection of virulence markers of H.pylori in order to tailor optimal treatments for each patient.Further investigation should be performed regarding associations between H.pylori virulence factors and ethnicity.
文摘The Helicobacter pylori vacuolating cytotoxin (VacA) is an intracellular, mitochondrial-targeting exotoxin that rapidly causes mitochondrial dysfunction and fragmentation. Although VacA targeting of mitochondria has been reported to alter overall cellular metabolism, there is little known about the consequences of extended exposure to the toxin. Here, we describe studies to address this gap in knowledge, which have revealed that mitochondrial dysfunction and fragmentation are followed by a time-dependent recovery of mitochondrial structure, mitochondrial transmembrane potential, and cellular ATP levels. Cells exposed to VacA also initially demonstrated a reduction in oxidative phosphorylation, as well as increase in compensatory aerobic glycolysis. These metabolic alterations were reversed in cells with limited toxin exposure, congruent with the recovery of mitochondrial transmembrane potential and the absence of cytochrome c release from the mitochondria. Taken together, these results are consistent with a model that mitochondrial structure and function are restored in VacA-intoxicated cells.
基金This work was financed by grants from Universidad Nacional de Cuyo to JAC and PSR(J043 and J481)Agencia Nacional de Promoción Científica y Tecnológica PICT 2013-2757 to PSR.
文摘Trypanosoma cruzi is the causative agent of Chagas disease.This parasite requires the intracellular niche in order to proliferate and disseminate the infection.After invasion,T.cruzi resides temporarily in an acidic vacuole which is lysed by a not well-understood mechanism.Transmission electron microscopy was used to describe the process of T.cruzi escape from the parasitophorous vacuole over the time.Using HeLa(non-professional phagocytic cells)as host cell,we observed that recently internalized parasites reside in a membrane-bounded vacuole.A few hours later,the first sign of vacuole disruption appeared as membrane discontinuities.This observation was followed by a progressive vacuole swelling as evidenced by an electron-lucent halo between the parasite and the vacuole membrane.Apparently,the vacuole membrane remnants reorganized as small vesicles that eventually disappeared from the vicinity of the parasites.Finally,parasites reach the host cell cytosol where replication takes place.The thorough ultrastructural description of this process set the base for a comprehensive understanding of the parasite-host cell interaction and,thus open the possibility of new therapeutic intervention strategies.
文摘Objective:To evaluate the impact of freezing–thawing on the human sperm head vacuoles and the potential value of motile sperm organelle morphology examination for selection of frozen-thaw spermatozoa.Methods: In 30 sperm samples from infertile men, analysis for conventional sperm parameters (motility, vitality, and normal morphology) and a morphological analysis at high magnification for vacuoles examination were done before cooling and after warming. For description of sperm head vacuoles, two hundred spermatozoa were examined and were classified into three groups according to presence and vacuole areas including no vacuole group (free of any vacuole), small vacuole group (occupy not more than 4% of the nuclear area), and large vacuole group (occupy more than 4% of the normal nuclear area).Results:Significant reduction of progressive motility and vitality was observed following cryopreservation (P<0.001). Also, normal morphology decreased significantly after cryopreservation (P<0.05). Spermatozoa with a vacuole-free head had a significant reduction in cryopreservation group (P=0.013). The percentage of spermatozoa with small vacuoles increased slightly, but not significantly after cryopreservation (P=0.296).Conclusions:Motile sperm organelle morphology examination is a powerful research tool for investigating spermatozoa abnormalities such as vacuoles that are increased post cryopreservation.
文摘Inorganic polyphosphate (PolyP), a bioactive polymer with multiple functions, plays a key role in biomineralizaion and phosphorus homeostasis in yeasts. After phosphate starvation, the cells of Saccharomyces cerevisiae restored their pool of PolyP during the first 30 min of incubation in the media containing phosphate and carbon sources. The cells of parent strain accumulated PolyP both in glucose and ethanol-containing media. In the medium with glucose, the strain with inactivated PPX1 and PPN1 genes (encoding two major yeast polyphosphatases) accumulated 2-fold more PolyP than the parent strain. The PolyP in the mutant cells had a greater average chain length compared to the parent strain. The strain with inactivated exopolyphosphatase genes РРХ1 and PPN1 was incapable of PolyP synthesis in the medium with ethanol. The in vivo staining of cells with DAPI show that in the cells of parent strain PolyP appeared first in cytoplasm and mitochondria under cultivation in glucose-containing medium and in cytoplasm and vacuoles in the medium with ethanol. In the ΔPPX1ΔPPN1double mutant PolyP accumulated in cytoplasm and vacuoles under cultivation in glucose-contained medium.
文摘The budding yeast Saccharomyces cerevisiae serves as an effective model organism for many cellular pathways including phosphate transport, accumulation, and storage. In S. cerevisiae, phosphate is actively transported across the plasma membrane via several phosphate carriers and is then transported into the acidic vacuole (roughly equivalent to the mammalian lysosome with degradative functions but with additional storage functions, such as calcium) where it is synthesized into volutin, a storage form of polyphosphate, found in many organisms. We have been studying volutin granule formation in wild type cells to determine the physiological requirements for formation and in mutants to determine the pathway by which the volutin biosynthetic proteins are transported to the vacuole. Undertaking an analysis of volutin formation in yeast vacuoles by blocking vacuole function with pharmacological agents, such as ionomycin and CCCP, we see that vacuole pH as well as vacuolar calcium seems critical for volutin formation. Different blocks in vacuolar protein sorting have differential effects on volutin granule accumulation, with volutin granule formation seen in all mutant strains thus far tested, except for vps33, a mutant cell strain lacking all vacuolar structure. Our data are consistent with pleiotrophic effects of vacuolar physiological function blocks leading to a decrease in volutin formation.
基金Supported by The Italian Ministry of Health, Programma per la Ricerca Sanitaria 2007, Programma Strategico, Salute della donna/Area materno infantile, No. RFPS-2007-4-638281
文摘AIM: To better understand the pathogenic role of Helicobacter pylori (H. pylori) in pre-eclampsia (PE), and whether it is associated or not with fetal growth retardation (FGR). METHODS: Maternal blood samples were collected from 62 consecutive pregnant women with a diagnosis of PE and/or FGR, and from 49 women with uneventful pregnancies (controls). Serum samples were evaluated by immunoblot assay for presence of specific antibodies against H. pylori antigens [virulence: cytotoxin-associated antigen A (CagA); ureases; heat shock protein B; flagellin A; persistence: vacuolating cytotoxin A (VacA)]. Maternal complete blood count and liver enzymes levels were assessed at delivery by an automated analyzer. RESULTS: A significantly higher percentage of H. pyloriseropositive women were found among PE cases (85.7%) compared to controls (42.9%, P < 0.001). There were no differences between pregnancies complicated by FGR without maternal hypertension (46.2%) and controls. Importantly, persistent and virulent infections (VacA/ CagA seropositive patients, intermediate leukocyte blood count and aspartate aminotransferase levels) were exclusively associated with pre-eclampsia complicated by FGR, while virulent but acute infections (CagA positive/ VacA negative patients, highest leukocyte blood count and aspartate aminotransferase levels) specifically correlated with PE without FGR. CONCLUSION: Our data strongly indicate that persistent and virulent H. pylori infections cause or contribute to PE complicated by FGR, but not to PE without feto-placental compromise.
基金Supported by National Natural Science Foundation of China(No.81273212,81100651)Project of Science and Technology of Shandong Province(No.2014GSF118044)
文摘AIM: To investigate into the potential involvement of pyrin containing 3 gene(NLRP3), a member of the nucleotide-binding oligomerization domain-like receptors with cytosolic pattern recognition, in the host defense of corneas against viruses.METHODS: The herpes viral keratitis model was utilized in BALB/c mice with inoculation of herpes simplex virus-1(HSV-1). Corneal tissues removed during therapy of patients with viral keratitis as well as a Simian vacuolating virus 40(SV40)-immortalized human corneal epithelial cell line were also examined.Immunohistochemistry was used to detect NLRP3 in these subjects, focusing on their distribution in tissue or cells. Western blot was used to measure the level of NLRP3 and another two related molecules in NLPR3 inflammasome, namely caspase-1 and IL-1β.RESULTS: The NLRP3 activation induced by HSV-1infection in corneas was accompanied with redistribution of NLRP3 from the cytoplasm to the nucleus in both murine and human corneal epithelial cells. Furthermore,in the SV40-immortalized human corneal epithelial cells,NLRP3 was exclusively located in the nucleus, and treatment of the cells with high concentration of extracellular potassium(known as an inhibitor of NLRP3activation) effectively drove NLRP3 back to the cytoplasm as reflected by both immunohistochemistry and Western blot.· CONCLUSION: It is proposed that herpes virus infection activates and causes redistribution of NLRP3 to nuclei. Whether this NLRP3 translocation occurs with other viral infections and in other cell types merit further study.
文摘AIM: To test our hypothesis that activation of protein kinase A(PKA) signal pathway by β-adrenergic agonist plays an important role in the protecting of cultured retinal pigment epithelial(RPE) cells against the hydroxychloroquine(HCQ) toxicity. METHODS: Cultured human RPE cells were treated with 1) HCQ, 2) HCQ with salbutamol(a β2-adrenergic receptor agonist), and 3) HCQ with salbutamol and a PKA inhibitor, and compared these to 4) untreated cells(controls). After treated for 24 h, cell vacuolation, cells viability, PKA and PKA kinase activity levels were determined by the measurement of the size of vacuoles using Image J software, the cell counting with a dye-exclusion testing, Western blot and PKA kinase detection, respectively. RESULTS: Cell vacuolation and cell death of cultured RPE cells were significantly increased by the treatment of HCQ. Salbutamol significantly elevated PKA and PKA activity levels and this was associated with the inhibition of the vacuolation and cell death. The PKA inhibitor significantly decreased the PKA levels and eliminated the protective effects of salbutamol on HCQ-treated RPE cells. CONCLUSION: The PKA pathway plays an important role in the protective effects of β2-adrenergic agonist on the RPE cells against HCQ toxicity. These findings reveal a novel potential strategy against HCQ retinopathy by treatment with PKA activating medications.
文摘Cytotoxic test in vitro combined with cytochemical stain, fluorescent stain, transmission electronmicrograph was used to study the vacuolated effect by helicobacter pylori (H.pylori) (Toxin+) and its pathological mechanism. 78..26 % patients with peptic ulcer associated with H.pylori was infected with H.pylori (Toxin+), while 42.86 % patients with gastritis was infected with H.pylori (Toxin+). It was positive in vacuole with acridine orange and acid phosphatase stain. Transmission electronmicrograph of vacuole revealed the presence of abounding membrane. There was a closed relationship between infection with H.pylori (Toxin+) and peptic ulcer disease. The vacuole induced by H.pylori (Toxin+) was autophagosome, which was pathological phenomenon induced by toxin.
基金supported by grants from the following institutions:CAPES,CNPq,Faperj,Pronex and MCT-CNPq.
文摘Bacteroides species are nearly half of the fecal flora community and some are host symbionts crucial to host nutrition and systemic immunity. Among Bacteroides species B. fragilis strains are considered to be the opportunistic ones, being the most isolated anaerobic bacteria in clinical samples. Cell-free supernatants of 65 B. fragilis strains were assayed and they were capable of inducing vacuolating phenotype on Vero cells lineage. The supernatant of the Bacteroides fragilis ATCC 23745 strain was elicited to have the strongest vacuolating effect on Vero cells monolayers and peritoneal macrophages. Some drastic cell alterations were observed, such as a general disorganization of cytoplasm and chromatin condensation, evidencing cell death. By transmission electron microscopy it was confirmed that the vacuoles observed were, in fact, swollen mitochondria. An immunocytochemical assay, TUNEL, was used to confirm this hypothesis and showed that Vero cells and peritoneal macrophages were dying by apoptotic process after exposition of B. fragilis cell-free supernatant. Physical analysis of the apoptotic factor has revealed properties similar to short-chain fatty acids. After gas chromatography and mass spectrometry analysis, phenylacetic acid (PA) was characterized as the major compound present in the most purified active fraction. We believe that the PA is responsible for the pro-apoptotic effect elicited by the supernatant of B. fragilis cultures.
文摘CGG repeat expansions in LOC642361/NUTM2B-AS1 have recently been identified as a cause of oculopharyngeal myopathy with leukoencephalopathy.However,since only three patients from a single family were reported,it remains unknown whether their clinicopathological features are typical for CGG repeat expansions in LOC642361/NUTM2B-AS1.Here,using repeat-primed-polymerase chain reaction and long-read sequencing,we identify 12 individuals from 3 unrelated families with CGG repeat expansions in LOC642361/NUTM2B-AS1,typically presenting with oculopharyngodistal myopathy.The CGG repeat expansions range from 161 to 669 repeat units.Most of the patients present with ptosis,restricted eye movements,dysphagia,dysarthria,and diffuse limb muscle weakness.Only one patient shows T2-weighted hyperintensity in the cerebellar white matter surrounding the deep cerebellar nuclei on brain magnetic resonance imaging.Muscle biopsies from three patients show a myopathic pattern and rimmed vacuoles.Analyses of muscle biopsies suggest that CGG repeat expansions in LOC642361/NUTM2B-AS1 may deleteriously affect aggrephagic capacity,suggesting that RNA toxicity and mitochondrial dysfunction may contribute to pathogenesis.Our study thus expands the phenotypic spectrum for the CGG repeat expansion of LOC642361/NUTM2B-AS1 and indicates that this genetic variant typically manifests as oculopharyngodistal myopathy with chronic myopathic changes with rimmed vacuoles and filamentous intranuclear inclusions in muscle fibers.
基金the National Natural Science Foundation of China(32070342 and 32270339)the Agri-X Interdisciplinary Fund of Shanghai Jiao Tong University(Agri-X20200204)+1 种基金the Bio-X Interdisciplinary Fund of Shanghai Jiao Tong University(20CX-04)the Scientific and Technological Innovation Funds of Shanghai Jiao Tong University(19X160020009).
文摘Brassinosteroid(BR)is a vital plant hormone that regulates plant growth anddevelopment.BRASSINAZOLE RESISTANT1(BZR1)is a key transcription factor in BR signaling,and its nucleocytoplasmic localization is crucial for BR signaling.However,the mechanisms that regulate BzR1 nucleocytoplasmic distribution and thus the homeostasis of BR signaling remain largely unclear.The vacuole is the largest organelle in mature plantcells and plays a key role in maintenance of cell ular pH,storage of intracellular substances,and transport ofions.In this study,weuncovered anovel mechanismof BR signaling homeostasis regulatedbythe vacuolar H+-ATPase(V-ATPase)and BZR1 feedback loop.Our results revealed that the vha-a2 vha-a3 mutant(vha2,lacking V-ATPase activity)exhibits enhanced BR signaling with increased total amount of BZR1,nuclearlocalized BZR1,and the ratio of BZR1/phosphorylated BZR1 in the nucleus.Further biochemical assays revealed that VHA-a2 and VHA-a3 of V-ATPase interact with the BZR1 protein through a domain that is conserved across multiple species.VHA-a2 and VHA-a3 negatively regulate BR signaling by interacting with BzR1 and promoting its retention in the tonoplast.Interestingly,a series of molecular analyses demonstrated that nuclear-localized BZR1 could bind directlyto specific motifs in the promoters of VHA-a2 andVHAa3topromote their expression.Taken together,these results suggest that V-ATPase and BzR1 mayforma feedback regulatory loop to maintain thehomeostasis of BR signaling in Arabidopsis,providing new insights into vacuole-mediated regulation of hormone signaling.