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1.
Nucleic Acids Res ; 52(10): 5732-5755, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38597682

ABSTRACT

Expansion of a G4C2 repeat in the C9orf72 gene is associated with familial Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal Dementia (FTD). To investigate the underlying mechanisms of repeat instability, which occurs both somatically and intergenerationally, we created a novel mouse model of familial ALS/FTD that harbors 96 copies of G4C2 repeats at a humanized C9orf72 locus. In mouse embryonic stem cells, we observed two modes of repeat expansion. First, we noted minor increases in repeat length per expansion event, which was dependent on a mismatch repair pathway protein Msh2. Second, we found major increases in repeat length per event when a DNA double- or single-strand break (DSB/SSB) was artificially introduced proximal to the repeats, and which was dependent on the homology-directed repair (HDR) pathway. In mice, the first mode primarily drove somatic repeat expansion. Major changes in repeat length, including expansion, were observed when SSB was introduced in one-cell embryos, or intergenerationally without DSB/SSB introduction if G4C2 repeats exceeded 400 copies, although spontaneous HDR-mediated expansion has yet to be identified. These findings provide a novel strategy to model repeat expansion in a non-human genome and offer insights into the mechanism behind C9orf72 G4C2 repeat instability.


Subject(s)
C9orf72 Protein , DNA Repeat Expansion , Genomic Instability , Animals , Humans , Mice , Amyotrophic Lateral Sclerosis/genetics , C9orf72 Protein/genetics , Disease Models, Animal , DNA Breaks, Double-Stranded , DNA Repeat Expansion/genetics , Frontotemporal Dementia/genetics , Gene Knock-In Techniques , Genomic Instability/genetics , MutS Homolog 2 Protein/genetics
2.
PLoS Genet ; 17(3): e1009461, 2021 03.
Article in English | MEDLINE | ID: mdl-33739974

ABSTRACT

Long noncoding RNAs (lncRNAs) are emerging as important regulators in plant development, but few of them have been functionally characterized in fruit ripening. Here, we have identified 25,613 lncRNAs from strawberry ripening fruits based on RNA-seq data from poly(A)-depleted libraries and rRNA-depleted libraries, most of which exhibited distinct temporal expression patterns. A novel lncRNA, FRILAIR harbours the miR397 binding site that is highly conserved in diverse strawberry species. FRILAIR overexpression promoted fruit maturation in the Falandi strawberry, which was consistent with the finding from knocking down miR397, which can guide the mRNA cleavage of both FRILAIR and LAC11a (encoding a putative laccase-11-like protein). Moreover, LAC11a mRNA levels were increased in both FRILAIR overexpressing and miR397 knockdown fruits, and accelerated fruit maturation was also found in LAC11a overexpressing fruits. Overall, our study demonstrates that FRILAIR can act as a noncanonical target mimic of miR397 to modulate the expression of LAC11a in the strawberry fruit ripening process.


Subject(s)
Fragaria/growth & development , Fragaria/genetics , Fruit/genetics , Gene Expression Regulation, Plant , RNA, Long Noncoding , RNA, Plant , Gene Editing , Genetic Association Studies , MicroRNAs/genetics , Models, Biological , Phenotype , RNA, Guide, Kinetoplastida , RNA, Messenger/genetics
3.
J Xray Sci Technol ; 2024 Jul 12.
Article in English | MEDLINE | ID: mdl-39031429

ABSTRACT

X-ray communication is a kind of space communication technology which uses X-ray as information carrier. In order to improve the information transmission capacity, communication rate and anti-interference ability of X-ray communication, we proposes to design a novel multi-target X-ray source. The source is composed of a fast switching module of light channels based on FPGA technology and four photoelectric X-ray tubes with different target materials: Cr, Fe, Ni, and Cu. Using Geant4 software, we determined the optimal target thickness for each material, which enabled us to fully leverage the characteristic X-rays for multi-channel signal modulation transmission. Moreover, using CST software for particle trajectory simulation and optimization of the electron beam revealed that at a tube voltage of 20 kV, the focus area measures approximately 1.2 mm×1.2 mm. The simulations show that four kinds of spectra with high distinctiveness can be generated from the Cr, Fe, Ni, and Cu targets. Within a single modulation period, these spectra can be combined in various ways to create 16 different X-ray spectra signals, thereby increasing the number of communication elements and enhancing the information transmission rate.

4.
Hum Mol Genet ; 29(21): 3516-3531, 2021 01 06.
Article in English | MEDLINE | ID: mdl-33105479

ABSTRACT

Neurodevelopmental disorder with microcephaly, hypotonia and variable brain anomalies (NMIHBA) is an autosomal recessive neurodevelopmental and neurodegenerative disorder characterized by global developmental delay and severe intellectual disability. Microcephaly, progressive cortical atrophy, cerebellar hypoplasia and delayed myelination are neurological hallmarks in affected individuals. NMIHBA is caused by biallelic variants in PRUNE1 encoding prune exopolyphosphatase 1. We provide in-depth clinical description of two affected siblings harboring compound heterozygous variant alleles, c.383G > A (p.Arg128Gln), c.520G > T (p.Gly174*) in PRUNE1. To gain insights into disease biology, we biochemically characterized missense variants within the conserved N-terminal aspartic acid-histidine-histidine (DHH) motif and provide evidence that they result in the destabilization of protein structure and/or loss of exopolyphosphatase activity. Genetic ablation of Prune1 results in midgestational lethality in mice, associated with perturbations to embryonic growth and vascular development. Our findings suggest that NMIHBA results from hypomorphic variant alleles in humans and underscore the potential key role of PRUNE1 exopolyphoshatase activity in neurodevelopment.


Subject(s)
Acid Anhydride Hydrolases/deficiency , Intellectual Disability/pathology , Microcephaly/pathology , Muscle Hypotonia/pathology , Mutation , Neurodevelopmental Disorders/pathology , Phosphoric Monoester Hydrolases/genetics , Alleles , Animals , Child, Preschool , Female , Humans , Infant , Intellectual Disability/etiology , Intellectual Disability/metabolism , Male , Mice , Microcephaly/etiology , Microcephaly/metabolism , Muscle Hypotonia/etiology , Muscle Hypotonia/metabolism , Neurodevelopmental Disorders/etiology , Neurodevelopmental Disorders/metabolism , Pedigree , Phenotype
5.
Mol Ther ; 29(12): 3512-3524, 2021 12 01.
Article in English | MEDLINE | ID: mdl-34400331

ABSTRACT

Lysosomal diseases are a class of genetic disorders predominantly caused by loss of lysosomal hydrolases, leading to lysosomal and cellular dysfunction. Enzyme replacement therapy (ERT), where recombinant enzyme is given intravenously, internalized by cells, and trafficked to the lysosome, has been applied to treat several lysosomal diseases. However, current ERT regimens do not correct disease phenotypes in all affected organs because the biodistribution of enzyme uptake does not match that of the affected cells that require the enzyme. We present here targeted ERT, an approach that utilizes antibody-enzyme fusion proteins to target the enzyme to specific cell types. The antibody moiety recognizes transmembrane proteins involved in lysosomal trafficking and that are also preferentially expressed in those cells most affected in disease. Using Pompe disease (PD) as an example, we show that targeted ERT is superior to ERT in treating the skeletal muscle phenotypes of PD mice both as a protein replacement therapeutic and as a gene therapy.


Subject(s)
Glycogen Storage Disease Type II , Lysosomal Storage Diseases , Animals , Enzyme Replacement Therapy , Glycogen Storage Disease Type II/drug therapy , Glycogen Storage Disease Type II/genetics , Hydrolases/metabolism , Lysosomal Storage Diseases/drug therapy , Lysosomal Storage Diseases/genetics , Lysosomes/metabolism , Mice , Tissue Distribution , alpha-Glucosidases/genetics
6.
Hum Mol Genet ; 28(18): 3072-3090, 2019 09 15.
Article in English | MEDLINE | ID: mdl-31174210

ABSTRACT

X-linked juvenile retinoschisis (XLRS) is an early-onset inherited condition that affects primarily males and is characterized by cystic lesions of the inner retina, decreased visual acuity and contrast sensitivity and a selective reduction of the electroretinogram (ERG) b-wave. Although XLRS is genetically heterogeneous, all mouse models developed to date involve engineered or spontaneous null mutations. In the present study, we have studied three new Rs1 mutant mouse models: (1) a knockout with inserted lacZ reporter gene; (2) a C59S point mutant substitution and (3) an R141C point mutant substitution. Mice were studied from postnatal day (P15) to 28 weeks by spectral domain optical coherence tomography and ERG. Retinas of P21-22 mice were examined using biochemistry, single cell electrophysiology of retinal ganglion cells (RGCs) and by immunohistochemistry. Each model developed intraretinal schisis and reductions in the ERG that were greater for the b-wave than the a-wave. The phenotype of the C59S mutant appeared less severe than the other mutants by ERG at adult ages. RGC electrophysiology demonstrated elevated activity in the absence of a visual stimulus and reduced signal-to-noise ratios in response to light stimuli. Immunohistochemical analysis documented early abnormalities in all cells of the outer retina. Together, these results provide significant insight into the early events of XLRS pathophysiology, from phenotype differences between disease-causing variants to common mechanistic events that may play critical roles in disease presentation and progression.


Subject(s)
Genes, X-Linked , Genetic Association Studies , Genetic Predisposition to Disease , Genotype , Phenotype , Retinoschisis/genetics , Retinoschisis/pathology , Animals , Biomarkers , Cell Adhesion Molecules/genetics , Disease Models, Animal , Electroretinography , Eye Proteins/genetics , Genetic Association Studies/methods , Immunohistochemistry , Mice , Mutation , Photic Stimulation , Retinoschisis/diagnosis , Severity of Illness Index , Tomography, Optical Coherence
7.
Nucleic Acids Res ; 47(6): 3142-3157, 2019 04 08.
Article in English | MEDLINE | ID: mdl-30649456

ABSTRACT

In Drosophila, dosage compensation globally upregulates the expression of genes located on male single X-chromosome. Maleless (MLE) helicase plays an essential role to incorporate the roX lncRNA into the dosage compensation complex (MSL-DCC), and such function is essentially dependent on its dsRNA-binding domains (dsRBDs). Here, we report a 2.90Å crystal structure of tandem dsRBDs of MLE in complex with a 55mer stem-loop of roX2 (R2H1). MLE dsRBDs bind to R2H1 cooperatively and interact with two successive minor grooves and a major groove of R2H1, respectively. The recognition of R2H1 by MLE dsRBDs involves both shape- and sequence-specificity. Moreover, dsRBD2 displays a stronger RNA affinity than dsRBD1, and mutations of key residues in either MLE dsRBD remarkably reduce their affinities for roX2 both in vitro and in vivo. In Drosophila, the structure-based mle mutations generated using the CRISPR/Cas9 system, are partially male-lethal and indicate the inter-regulation among the components of the MSL-DCC at multiple levels. Hence, our research provides structural insights into the interactions between MLE dsRBDs and R2H1 and facilitates a deeper understanding of the mechanism by which MLE tandem dsRBDs play an indispensable role in specific recognition of roX and the assembly of the MSL-DCC in Drosophila dosage compensation.


Subject(s)
Chromosomal Proteins, Non-Histone/chemistry , DNA Helicases/chemistry , Dosage Compensation, Genetic , Drosophila Proteins/chemistry , RNA, Double-Stranded/genetics , Transcription Factors/chemistry , Animals , Chromosomal Proteins, Non-Histone/genetics , DNA Helicases/genetics , Drosophila Proteins/genetics , Drosophila melanogaster/genetics , RNA, Double-Stranded/chemistry , Transcription Factors/genetics , X Chromosome/genetics
8.
Surgeon ; 19(5): 287-296, 2021 Oct.
Article in English | MEDLINE | ID: mdl-32709425

ABSTRACT

BACKGROUND: It remains controversial on the optimal timing of cholecystectomy for patients with mild acute biliary pancreatitis. This study aimed at comparing the safety, feasibility, and cost-effectiveness of early laparoscopic cholecystectomy (ELC, within 72 h after admission) versus delayed laparoscopic cholecystectomy (DLC, beyond 72 h after admission) for patients with mild acute biliary pancreatitis. METHODS: We performed a systematic search in the following databases: PubMed, Embase, Web of Science, and Cochrane library. We only included articles from RCTs which designed to evaluate the complications, conversion to open cholecystectomy, recurrence of acute pancreatitis, the length of hospital stay, and costs between patients undergoing ELC and those undergoing DLC. We schemed to analyze data using STATA 15.0 with both the random-effects and the fixed-effect models. We computed relative risk (RR) and weighted mean difference (WMD) with 95% confidence intervals (CI) based on the intention-to-treat (ITT) analysis. RESULTS: A total of 4 studies involving 439 (215 vs 224) patients were included. The difference of complication rate [3.3% vs 3.2%; RR 1.03 (0.35, 3.01), P = 0.961] and rate of conversion to open cholecystectomy [3.8% vs 3.3%; RR 1.13 (0.37, 3.43), P = 0.830] are insignificant between patients who underwent ELC and ones who underwent DLC. The difference of rate of recurrence of acute pancreatitis is significant between ELC and DLC (2.17% vs 8.99%; RR 0.24 (0.08-0.70), P = 0.009). ELC does not shorten the length of hospital stay (random-effects model analysis: WMD -1.09 days (-2.67, 0.48), P = 0.173; fixed-effect model analysis: WMD -0.62 days (-1.00, -0.24), P = 0.001). CONCLUSION: Compared to DLC, ELC is equally safe and feasible both in complication rate and rate of conversion to open procedure, and significantly reduces the recurrence rate of acute pancreatitis. PROSPERO REGISTRATION NUMBER: CRD42018116239.


Subject(s)
Cholecystectomy, Laparoscopic , Cholecystitis, Acute , Pancreatitis , Acute Disease , Cholecystectomy, Laparoscopic/adverse effects , Cholecystitis, Acute/surgery , Cost-Benefit Analysis , Feasibility Studies , Humans , Pancreatitis/surgery , Time Factors
9.
Med Sci Monit ; 26: e922149, 2020 Apr 14.
Article in English | MEDLINE | ID: mdl-32284524

ABSTRACT

BACKGROUND Leonurine is an active component of the traditional Chinese medicine Leonurus japonicus. This study aimed to investigate the effects of overexpressed CYP450s on the metabolic activity of leonurine. MATERIAL AND METHODS BEAS-2B cells stably expressing CYP1A1, 1A2, 2A13, 2B6, and 3A4 were constructed. CYP450s expression was identified using reverse-transcription PCR and Western blot assay. CCK-8 assay was used to evaluate the effect of leonurine on cell activity. Leonurine was incubated in vitro with CYP1A1, 1A2, 2A13, 2B6, and 3A4 metabolic enzymes to evaluate the clearance rate of CYP450 enzymes for leonurine. UPLC-MS was used to detect changes of drug concentration and discover the main metabolic enzymes affecting leonurine. RESULTS BEAS-2B cells stably expressing CYP1A1, 1A2, 2A13, 2B6, and 3A4 were successfully constructed. According to primary mass spectra and secondary mass spectra of leonurine, the main metabolic enzymes were 312.1550 [H+] and 181.0484. Compared to the control group, residue of leonurine in CYP2A13 group was significantly reduced (F=5.307, p=0.024). Compared to the 0-min group, the clearance rate of leonurine in the CYP2A13-treated group was significantly decreased at 120 min after treatment (F=7.273, p=0.007). CCK-8 results also showed that activity of BEAS-2B cells that overexpress CYP2A13 gradually decreased with increased concentration of leonurine. Although CYP2A13 demonstrated good metabolic activity for leonurine, we found that CYP1A1, 1A2, 2B6, and 3A4 had no metabolic effects on leonurine. CONCLUSIONS Leonurine can be effectively activated through CYP2A13 enzyme metabolism, and further inhibits activity of human lung epithelial cells (BEAS-2B). Therefore, CYP2A13 is a main metabolic enzyme for leonurine in BEAS-2B cells.


Subject(s)
Aryl Hydrocarbon Hydroxylases/metabolism , Epithelial Cells/drug effects , Epithelial Cells/enzymology , Gallic Acid/analogs & derivatives , Bronchi/cytology , Cell Line , Gallic Acid/pharmacology , Humans , Inactivation, Metabolic
10.
J Clin Lab Anal ; 34(1): e23009, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31495979

ABSTRACT

BACKGROUND: The hepatocellular carcinoma (HCC) belongs to a common malignancy especially in China. Recent data have clarified important roles of long non-coding RNAs (lncRNAs) in HCC. However, the role of a novel intergenic lncRNA termed TGLC15 is still elusive. METHODS: We screened for novel lncRNAs using lncRNA profiling. TGLC15 expression was quantified by qRT-PCR. In vitro experiments such as migration and viability assays were performed. In vivo implantation experiments were conducted to investigate tumorigenic functions of TGLC15. Combined RNA immunoprecipitation (RIP) and mass spectrometry (MS) were utilized to uncover Sox4 as TGLC15 binding protein. RESULTS: TGLC15 is significantly overexpressed in tumor tissues and HCC cell lines. Higher TGLC15 levels correlated with advanced malignant characteristics such as TNM stages, tumor size, and metastasis. TGLC15 advanced HCC migration and viability. The in vivo experiments supported that xenograft tumor growth and proliferation were facilitated by TGLC15 overexpression. Mechanistic studies showed that TGLC15 interacted with Sox4 and interaction between TGLC15 and Sox4 could stabilize Sox4 via reduction in proteasome-mediated degradation. CONCLUSIONS: Collectively, our data have identified a novel lncRNA TGLC15 during HCC development. The TGLC15-Sox4 signaling might be a potential target for pharmaceutical intervention.


Subject(s)
Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/pathology , Liver Neoplasms/genetics , Liver Neoplasms/pathology , RNA, Long Noncoding/metabolism , SOXC Transcription Factors/metabolism , Cell Line, Tumor , Cell Proliferation/genetics , Disease Progression , Humans , Protein Stability , Proteolysis , RNA, Long Noncoding/genetics
11.
J Biol Chem ; 291(32): 16709-19, 2016 08 05.
Article in English | MEDLINE | ID: mdl-27311713

ABSTRACT

ARAP3 (Arf-GAP with Rho-GAP domain, ANK repeat, and PH domain-containing protein 3) is unique for its dual specificity GAPs (GTPase-activating protein) activity for Arf6 (ADP-ribosylation factor 6) and RhoA (Ras homolog gene family member A) regulated by phosphatidylinositol 3,4,5-trisphosphate and a small GTPase Rap1-GTP and is involved in regulation of cell shape and adhesion. However, the molecular interface between the ARAP3-RhoGAP domain and RhoA is unknown, as is the substrates specificity of the RhoGAP domain. In this study, we solved the crystal structure of RhoA in complex with the RhoGAP domain of ARAP3. The structure of the complex presented a clear interface between the RhoGAP domain and RhoA. By analyzing the crystal structure and in combination with in vitro GTPase activity assays and isothermal titration calorimetry experiments, we identified the crucial residues affecting RhoGAP activity and substrates specificity among RhoA, Rac1 (Ras-related C3 botulinum toxin substrate 1), and Cdc42 (cell division control protein 42 homolog).


Subject(s)
Adaptor Proteins, Signal Transducing/chemistry , GTPase-Activating Proteins/chemistry , rhoA GTP-Binding Protein/chemistry , ADP-Ribosylation Factor 6 , ADP-Ribosylation Factors/chemistry , ADP-Ribosylation Factors/genetics , ADP-Ribosylation Factors/metabolism , Adaptor Proteins, Signal Transducing/genetics , Adaptor Proteins, Signal Transducing/metabolism , Crystallography, X-Ray , GTPase-Activating Proteins/genetics , GTPase-Activating Proteins/metabolism , Humans , Phosphatidylinositol Phosphates/chemistry , Phosphatidylinositol Phosphates/genetics , Phosphatidylinositol Phosphates/metabolism , Protein Domains , Shelterin Complex , Structure-Activity Relationship , Telomere-Binding Proteins/chemistry , Telomere-Binding Proteins/genetics , Telomere-Binding Proteins/metabolism , rhoA GTP-Binding Protein/genetics
12.
Arch Virol ; 161(7): 2033-6, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27068169

ABSTRACT

The genome of a potyvirus (isolate JaVT_FZ) recovered from jasmine (Jasminum sambac L.) showing yellow ringspot symptoms in Fuzhou, China, was sequenced. JaVT_FZ is closely related to seven other potyviruses with completely sequenced genomes, with which it shares 66-70 % nucleotide and 52-56 % amino acid sequence identity. However, the coat protein (CP) gene shares 82-92 % nucleotide and 90-97 % amino acid sequence identity with those of two partially sequenced potyviruses, named jasmine potyvirus T (JaVT-jasmine) and jasmine yellow mosaic potyvirus (JaYMV-India), respectively. This suggests that JaVT_FZ, JaVT-jasmine and JaYMV-India should be regarded as members of a single potyvirus species, for which the name "Jasmine virus T" has priority.


Subject(s)
Genome, Viral , Jasminum/virology , Plant Diseases/virology , Potyvirus/genetics , Potyvirus/isolation & purification , Base Sequence , China , Molecular Sequence Data , Open Reading Frames , Potyvirus/classification
13.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 36(2): 203-9, 2016 Feb.
Article in Zh | MEDLINE | ID: mdl-27078998

ABSTRACT

OBJECTIVE: To observe the intervention and mechanism of Qushi Huayu Recipe (QHR) on gene expression profiles in high lipid diet induced fatty liver rats. METHODS: Fatty liver model was prepared in 20 male SD rats using single high fat diet (88% common forage +2% cholesterol +10% lard). Four weeks after modeling they were divided into the model group and the QHR group according to random digit table, 10 in each group. QHR (at 0. 93 g crude drug/100 g body weight) and distilled water was respectively to rats in the QHR group and the model group by gastrogavage while modeling, once per day. Meanwhile, 10 SD male rats were recruited in a normal group, administered with equal volume of distilled water by gastrogavage. At the end of week 8 all rats were sacrificed, and blood and livers were collected for subsequent analysis. Contents of liver triglyceride (TG) and free fatty acid (FFA) , activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected using biochemical assay. Pathological changes of liver tissue were observed using H&E and oil red O stain. Liver gene expressions were detected by Affymetrix gene expression profiles. Differentially expressed genes were compared between the QHR group and the model group, functions of differentially expressed genes and signal pathways involved analyzed. Ten differentially expressed genes involved in glycolipid metabolism with fold change more than 2 were selected for verification by real-time PCR. RESULTS: (1) Compared with the normal group, contents of liver TG and FFA, and serum activities of ALT and AST obviously increased in the model group (P <0. 01). Compared with the model group, contents of liver TG and FFA, and activities of ALT and AST obviously decreased in the QHR group (P <0. 05, P <0. 01). QHR could reduce high fat induced fatty degeneration of liver cells , alleviate inflammation, and improve pathological changes of liver tissue. (2) Compared with the model group, there were 80 differentially expressed genes (with fold change > 2, P < 0.05) with clear functions and appointed gene names, including 44 up-regulated and 36 down-regulated genes. Eighty genes were involved in 27 signal pathways with statistical difference, including glycerolipid metabolism, adipocytokine signaling pathway, insulin signal pathway, drug metabolism signal pathway, etc (P < 0.05). (3) RT-PCR results of 10 glycolipids metabolism regulating genes such as Gk, Scd1, Gpat2, G6pc, Irs1, and so on showed that all RT-PCR genes were completely coincide with up-regulated or down-regulated tendency in results of gene chips. 80% genes had approximate fold change. CONCLUSION: QHR could regulate gene expressions related to fat metabolism, carbohydrate metabolism, anti-lipid peroxidation, and drug metabolism in high fat diet induced fatty liver rats, and its comprehensive pharmacological actions could be manifested.


Subject(s)
Drugs, Chinese Herbal/pharmacology , Fatty Liver/metabolism , Transcriptome/drug effects , Alanine Transaminase/metabolism , Animals , Aspartate Aminotransferases/metabolism , Carbohydrate Metabolism , Diet, High-Fat , Fatty Acids, Nonesterified/metabolism , Lipid Metabolism , Lipid Peroxidation , Male , Random Allocation , Rats , Rats, Sprague-Dawley , Triglycerides/metabolism
14.
Biochemistry ; 53(13): 2185-96, 2014 Apr 08.
Article in English | MEDLINE | ID: mdl-24611845

ABSTRACT

Glutaredoxins (Grxs) are wide-spread oxidoreductases that are found in all kingdoms of life. The yeast Saccharomyces cerevisiae encodes eight Grxs, among which, Grx8 shares a sequence identity of 30 and 23% with typical dithiol Grx1 and Grx2, respectively, but it exhibits a much lower GSH-dependent oxidoreductase activity. To elucidate its catalytic mechanism, we solved the solution structure of Grx8, which displays a typical Grx fold. Structural analysis indicated that Grx8 possesses a negatively charged CXXC motif (Cys(33)-Pro(34)-Asp(35)-Cys(36)) and a GSH-recognition site, which are distinct from Grx1 and Grx2. Subsequent structure-guided site mutations revealed that the D35Y single mutant and N80T/L81V double mutant possess increased activity of 10- and 11-fold, respectively; moreover, the D35Y/N80T/L81V triple mutant has increased activity of up to 44-fold, which is comparable to that of canonical Grx. Biochemical analyses suggested that the increase in catalytic efficiency resulted from a decreased pKa value of catalytic cysteine Cys33 and/or enhancement of the putative GSH-recognition site. Moreover, NMR chemical shift perturbation analyses combined with GSH analogue inhibition assays enabled us to elucidate that wild-type Grx8 and all mutants adopt a ping-pong mechanism of catalysis. All together, these findings provide structural insights into the catalytic mechanism of dithiol Grxs.


Subject(s)
Biocatalysis , Glutaredoxins/metabolism , Saccharomyces cerevisiae/enzymology , Enzyme Activation , Glutaredoxins/chemistry , Glutaredoxins/isolation & purification , Kinetics , Nuclear Magnetic Resonance, Biomolecular , Protein Conformation , Recombinant Proteins/chemistry , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism
15.
Nanotechnology ; 25(23): 235101, 2014 Jun 13.
Article in English | MEDLINE | ID: mdl-24849381

ABSTRACT

A novel quantum dots-based multifunctional nanovehicle (DOX-QD-PEG-FA) was designed for targeted drug delivery, fluorescent imaging, tracking, and cancer therapy, in which the GSH-CdTe quantum dots play a key role in imaging and drug delivery. To exert curative effects, the antineoplastic drug doxorubicin hydrochloride (DOX) was loaded on the GSH-CdTe quantum dots through a condensation reaction. Meanwhile, a polyethylene glycol (PEG) shell was introduced to wrap the DOX-QD, thus stabilizing the structure and preventing clearance and drug release during systemic circulation. To actively target cancer cells and prevent the nanovehicles from being absorbed by normal cells, the nanoparticles were further decorated with folic acid (FA), allowing them to target HeLa cells that express the FA receptor. The multifunctional DOX-QD-PEG-FA conjugates were simply prepared using the 'one pot' method. In vitro study demonstrated that this simple, multifunctional nanovehicle can deliver DOX to the targeted cancer cells and localize the nanoparticles. After reaching the tumor cells, the FA on the DOX-QD-PEG surface allowed folate receptor recognition and increased the drug concentration to realize a higher curative effect. This novel, multifunctional DOX-QD-PEG-FA system shows great potential for tumor imaging, targeting, and therapy.


Subject(s)
Antibiotics, Antineoplastic/chemical synthesis , Cadmium Compounds/chemistry , Doxorubicin/chemistry , Drug Delivery Systems/methods , Glutathione/chemistry , Quantum Dots/chemistry , Tellurium/chemistry , Antibiotics, Antineoplastic/therapeutic use , Doxorubicin/therapeutic use , Female , Folic Acid/chemistry , HeLa Cells , Humans , Polyethylene Glycols/chemistry , Quantum Dots/therapeutic use , Quantum Dots/ultrastructure
16.
Atten Percept Psychophys ; 86(3): 838-854, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38413503

ABSTRACT

Attention and memory are fundamental cognitive processes that closely interact. In the attentional boost effect (ABE), the stimuli that co-occur with targets are remembered better than those that co-occur with distractors in target detection tasks performed during memory encoding. In target detection tasks performed during retrieval, the stimuli that co-occur with targets are recognized as 'old' more easily than the stimuli that co-occur with distractors. This study mainly explored the internal mechanism of the effect of target detection on recognition. In Experiment 1, the full attention (FA; where participants performed only the memory task) condition was used to compare with divided attention (DA; where participants performed target detection while performing memory retrieval) condition to explore the impact of target detection and distraction inhibition on recognition. In Experiment 2, the proportion of old and new words in the retrieval stage was adjusted to 1:1 to eliminate the possible reaction tendency caused by the high proportion of old words. In Experiment 3, the presentation time of words was extended to 1.5 s and 3 s to eliminate the possible impact of rapid processing. The results indicated that the effect of target detection on recognition was attributed to both target detection and distraction rejection and is not affected by the ratio of old and new words and the word presentation time. The effect of target detection on recognition may be owing to temporal yoking of the dual tasks, which is different from the effect of target detection on memory encoding.


Subject(s)
Attention , Mental Recall , Pattern Recognition, Visual , Reaction Time , Recognition, Psychology , Humans , Pattern Recognition, Visual/physiology , Male , Young Adult , Female , Inhibition, Psychological , Semantics , Adult , Verbal Learning
17.
Plant Commun ; 5(5): 100823, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38243597

ABSTRACT

The inducible CRISPR activation (CRISPR-a) system offers unparalleled precision and versatility for regulating endogenous genes, making it highly sought after in plant research. In this study, we developed a chemically inducible CRISPR-a tool for plants called ER-Tag by combining the LexA-VP16-ER inducible system with the SunTag CRISPR-a system. We systematically compared different induction strategies and achieved high efficiency in target gene activation. We demonstrated that guide RNAs can be multiplexed and pooled for large-scale screening of effective morphogenic genes and gene pairs involved in plant regeneration. Further experiments showed that induced activation of these morphogenic genes can accelerate regeneration and improve regeneration efficiency in both eudicot and monocot plants, including alfalfa, woodland strawberry, and sheepgrass. Our study expands the CRISPR toolset in plants and provides a powerful new strategy for studying gene function when constitutive expression is not feasible or ideal.


Subject(s)
Regeneration , Regeneration/genetics , CRISPR-Cas Systems , Clustered Regularly Interspaced Short Palindromic Repeats/genetics , Plants, Genetically Modified/genetics , Gene Expression Regulation, Plant
18.
Cell Rep Med ; 5(5): 101543, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38697101

ABSTRACT

Cognitive impairment in the elderly is associated with alterations in bile acid (BA) metabolism. In this study, we observe elevated levels of serum conjugated primary bile acids (CPBAs) and ammonia in elderly individuals, mild cognitive impairment, Alzheimer's disease, and aging rodents, with a more pronounced change in females. These changes are correlated with increased expression of the ileal apical sodium-bile acid transporter (ASBT), hippocampal synapse loss, and elevated brain CPBA and ammonia levels in rodents. In vitro experiments confirm that a CPBA, taurocholic acid, and ammonia induced synaptic loss. Manipulating intestinal BA transport using ASBT activators or inhibitors demonstrates the impact on brain CPBA and ammonia levels as well as cognitive decline in rodents. Additionally, administration of an intestinal BA sequestrant, cholestyramine, alleviates cognitive impairment, normalizing CPBAs and ammonia in aging mice. These findings highlight the potential of targeting intestinal BA absorption as a therapeutic strategy for age-related cognitive impairment.


Subject(s)
Aging , Ammonia , Bile Acids and Salts , Cognitive Dysfunction , Intestinal Absorption , Animals , Bile Acids and Salts/metabolism , Cognitive Dysfunction/metabolism , Cognitive Dysfunction/pathology , Intestinal Absorption/drug effects , Male , Female , Humans , Mice , Aging/metabolism , Ammonia/metabolism , Aged , Mice, Inbred C57BL , Cholestyramine Resin/pharmacology , Symporters/metabolism , Organic Anion Transporters, Sodium-Dependent/metabolism , Organic Anion Transporters, Sodium-Dependent/genetics , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Hippocampus/metabolism , Hippocampus/pathology , Rats , Aged, 80 and over
19.
Cell Metab ; 36(5): 1000-1012.e6, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38582087

ABSTRACT

The gut-brain axis is implicated in depression development, yet its underlying mechanism remains unclear. We observed depleted gut bacterial species, including Bifidobacterium longum and Roseburia intestinalis, and the neurotransmitter homovanillic acid (HVA) in individuals with depression and mouse depression models. Although R. intestinalis does not directly produce HVA, it enhances B. longum abundance, leading to HVA generation. This highlights a synergistic interaction among gut microbiota in regulating intestinal neurotransmitter production. Administering HVA, B. longum, or R. intestinalis to mouse models with chronic unpredictable mild stress (CUMS) and corticosterone (CORT)-induced depression significantly improved depressive symptoms. Mechanistically, HVA inhibited synaptic autophagic death by preventing excessive degradation of microtubule-associated protein 1 light chain 3 (LC3) and SQSTM1/p62 proteins, protecting hippocampal neurons' presynaptic membrane. These findings underscore the role of the gut microbial metabolism in modulating synaptic integrity and provide insights into potential novel treatment strategies for depression.


Subject(s)
Depression , Gastrointestinal Microbiome , Homovanillic Acid , Mice, Inbred C57BL , Animals , Gastrointestinal Microbiome/drug effects , Mice , Depression/drug therapy , Depression/metabolism , Male , Humans , Homovanillic Acid/metabolism , Synapses/metabolism , Synapses/drug effects , Hippocampus/metabolism , Hippocampus/drug effects , Neurons/metabolism , Neurons/drug effects , Female
20.
Plants (Basel) ; 12(2)2023 Jan 16.
Article in English | MEDLINE | ID: mdl-36679124

ABSTRACT

Non-coding RNAs play vital roles in the diverse biological processes of plants, and they are becoming key topics in horticulture research. In particular, miRNAs and long non-coding RNAs (lncRNAs) are receiving increased attention in fruit crops. Recent studies in horticulture research provide both genetic and molecular evidence that miRNAs and lncRNAs regulate biological function and stress responses during fruit development. Here, we summarize multiple regulatory modules of miRNAs and lncRNAs and their biological roles in fruit sets and stress responses, which would guide the development of molecular breeding techniques on horticultural crops.

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