RESUMO
Given the serious neurological complications and deaths associated with enterovirus 71 (EV71) infection, there is an urgent need to develop effective antivirals against this viral infection. In this study, we demonstrated that two Cathelicidin-derived peptides, LL-18 and FF-18 were more potent against EV71 infection than the parent peptide LL-37, which is the mature and processed form of Cathelicidin. These peptides could directly bind to the EV71 virus particles, but not to coxsackievirus, indicative of their high specificity. The binding of peptides with the virus surface occupied the viral canyon region in a way that could block virus-receptor interactions and inhibit viral uncoating. In addition, these peptide analogues could also relieve the deleterious effect of EV71 infection in vivo. Therefore, Cathelicidin-derived peptides might be excellent candidates for further development of antivirals to treat EV71 infection.
Assuntos
Enterovirus Humano A , Infecções por Enterovirus , Enterovirus , Humanos , Catelicidinas/farmacologia , Internalização do Vírus , Antivirais/metabolismoRESUMO
Enterovirus 71 (EV71) is one of the major pathogens causing hand, foot, and mouth disease in children under 5 years old, which can result in severe neurological complications and even death. Due to limited treatments for EV71 infection, the identification of novel host factors and elucidation of mechanisms involved will help to counter this viral infection. N-terminal acetyltransferase 6 (NAT6) was identified as an essential host factor for EV71 infection with genome-wide CRISPR/Cas9 screening. NAT6 facilitates EV71 viral replication depending on its acetyltransferase activity but has little effect on viral release. In addition, NAT6 is also required for Echovirus 7 and coxsackievirus B5 infection, suggesting it might be a pan-enterovirus host factor. We further demonstrated that NAT6 is required for Golgi integrity and viral replication organelle (RO) biogenesis. NAT6 knockout significantly inhibited phosphatidylinositol 4-kinase IIIß (PI4KB) expression and PI4P production, both of which are key host factors for enterovirus infection and RO biogenesis. Further mechanism studies confirmed that NAT6 formed a complex with its substrate actin and one of the PI4KB recruiters-acyl-coenzyme A binding domain containing 3 (ACBD3). Through modulating actin dynamics, NAT6 maintained the integrity of the Golgi and the stability of ACBD3, thereby enhancing EV71 infection. Collectively, these results uncovered a novel mechanism of N-acetyltransferase supporting EV71 infection.IMPORTANCEEnterovirus 71 (EV71) is an important pathogen for children under the age of five, and currently, no effective treatment is available. Elucidating the mechanism of novel host factors supporting viral infection will reveal potential antiviral targets and aid antiviral development. Here, we demonstrated that a novel N-acetyltransferase, NAT6, is an essential host factor for EV71 replication. NAT6 could promote viral replication organelle (RO) formation to enhance viral replication. The formation of enterovirus ROs requires numerous host factors, including acyl-coenzyme A binding domain containing 3 (ACBD3) and phosphatidylinositol 4-kinase IIIß (PI4KB). NAT6 could stabilize the PI4KB recruiter, ACBD3, by inhibiting the autophagy degradation pathway. This study provides a fresh insight into the relationship between N-acetyltransferase and viral infection.
Assuntos
Enterovirus Humano A , Infecções por Enterovirus , Acetiltransferases N-Terminal , Fosfotransferases (Aceptor do Grupo Álcool) , Criança , Pré-Escolar , Humanos , 1-Fosfatidilinositol 4-Quinase/metabolismo , Actinas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Antivirais , Coenzima A/metabolismo , Infecções por Coxsackievirus , Enterovirus Humano A/fisiologia , Infecções por Enterovirus/metabolismo , Infecções por Enterovirus/virologia , Proteínas de Membrana/metabolismo , Acetiltransferases N-Terminal/metabolismo , Biogênese de Organelas , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Replicação Viral/fisiologiaRESUMO
Whereas thermal comfort and healthcare management during long-term wear are essentially required for wearable system, simultaneously achieving them remains challenge. Herein, a highly comfortable and breathable smart textile for personal healthcare and thermal management is developed, via assembling stimuli-responsive core-sheath dual network that silver nanowires(AgNWs) core interlocked graphene sheath induced by MXene. Small MXene nanosheets with abundant groups is proposed as a novel "dispersant" to graphene according to "like dissolves like" theory, while simultaneously acting as "cross-linker" between AgNWs and graphene networks by filling the voids between them. The core-sheath heterogeneous interlocked conductive fiber induced by MXene "cross-linking" exhibits a reliable response to various mechanical/electrical/light stimuli, even under large mechanical deformations(100%). The core-sheath conductive fiber-enabled smart textile can adapt to movements of human body seamlessly, and convert these mechanical deformations into character signals for accurate healthcare monitoring with rapid response(440 ms). Moreover, smart textile with excellent Joule heating and photothermal effect exhibits instant thermal energy harvesting/storage during the stimuli-response process, which can be developed as self-powered thermal management and dynamic camouflage when integrated with phase change and thermochromic layer. The smart fibers/textiles with core-sheath heterogeneous interlocked structures hold great promise in personalized healthcare and thermal management.
Assuntos
Condutividade Elétrica , Têxteis , Humanos , Nanofios/química , Prata/química , Medicina de Precisão/métodos , Dispositivos Eletrônicos Vestíveis , Temperatura , Grafite/químicaRESUMO
CRISPR-Cas9 is widely used for genome editing, but its PAM sequence requirements limit its efficiency. In this study, we explore Faecalibaculum rodentium Cas9 (FrCas9) for plant genome editing, especially in rice. FrCas9 recognizes a concise 5'-NNTA-3' PAM, targeting more abundant palindromic TA sites in plant genomes than the 5'-NGG-3' PAM sites of the most popular SpCas9. FrCas9 shows cleavage activities at all tested 5'-NNTA-3' PAM sites with editing outcomes sharing the same characteristics of a typical CRISPR-Cas9 system. FrCas9 induces high-efficiency targeted mutagenesis in stable rice lines, readily generating biallelic mutants with expected phenotypes. We augment FrCas9's ability to generate larger deletions through fusion with the exonuclease, TREX2. TREX2-FrCas9 generates much larger deletions than FrCas9 without compromise in editing efficiency. We demonstrate TREX2-FrCas9 as an efficient tool for genetic knockout of a microRNA gene. Furthermore, FrCas9-derived cytosine base editors (CBEs) and adenine base editors (ABE) are developed to produce targeted C-to-T and A-to-G base edits in rice plants. Whole-genome sequencing-based off-target analysis suggests that FrCas9 is a highly specific nuclease. Expression of TREX2-FrCas9 in plants, however, causes detectable guide RNA-independent off-target mutations, mostly as single nucleotide variants (SNVs). Together, we have established an efficient CRISPR-FrCas9 system for targeted mutagenesis, large deletions, C-to-T base editing, and A-to-G base editing in plants. The simple palindromic TA motif in the PAM makes the CRISPR-FrCas9 system a promising tool for genome editing in plants with an expanded targeting scope.
Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Genoma de Planta , Oryza , Edição de Genes/métodos , Genoma de Planta/genética , Oryza/genética , Proteína 9 Associada à CRISPR/metabolismo , Proteína 9 Associada à CRISPR/genéticaRESUMO
EZH2 (enhancer of zeste homolog 2) is one of the most important histone methyltransferases (HMTs), and overexpression of EZH2 can lead to proliferation, migration and angiogenesis of tumor cells. But most of EZH2 inhibitors are only effective against some hematologic malignancies and have poor efficacy against solid tumors. Here, we report the design, synthesis, and evaluation of highly potent proteolysis targeting chimeric (PROTACs) small molecules targeting EZH2. We developed a potent and effective EZH2 degrader P4, which effectively induced EZH2 protein degradation and inhibited breast cancer cell growth. Further studies showed that P4 can significantly decrease the degree of H3K27me3 in MDA-MB-231 cell line, induce apoptosis and G0/G1 phase arrest in Pfeiffer and MDA-MB-231 cell lines. Therefore, P4 is a potential anticancer molecule for breast cancer treatment.
Assuntos
Neoplasias da Mama , Proteína Potenciadora do Homólogo 2 de Zeste , Quimera de Direcionamento de Proteólise , Feminino , Humanos , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células , Proteína Potenciadora do Homólogo 2 de Zeste/efeitos dos fármacos , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Inibidores Enzimáticos/farmacologia , Proteína Supressora de Tumor Von Hippel-Lindau/farmacologia , Quimera de Direcionamento de Proteólise/química , Quimera de Direcionamento de Proteólise/farmacologiaRESUMO
KEY MESSAGE: Cathepsin B plays an important role that degrades the Rubisco large subunit RbcL in freezing stress. Programmed cell death (PCD) has been well documented in both development and in response to environmental stresses in plants, however, PCD induced by freezing stress and its molecular mechanisms remain poorly understood. In the present study, we characterized freezing-induced PCD and explored its mechanisms in Arabidopsis. PCD induced by freezing stress was similar to that induced by other stresses and senescence in Arabidopsis plants with cold acclimation. Inhibitor treatment assays and immunoblotting indicated that cathepsin B mainly contributed to increased caspase-3-like activity during freezing-induced PCD. Cathepsin B was involved in freezing-induced PCD and degraded the large subunit, RbcL, of Rubisco. Our results demonstrate an essential regulatory mechanism of cathepsin B for Rubisco degradation in freezing-induced PCD, improving our understanding of freezing-induced cell death and nitrogen and carbohydrate remobilisation in plants.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Catepsina B/metabolismo , Congelamento , Ribulose-Bifosfato Carboxilase/metabolismo , Apoptose , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismoRESUMO
BACKGROUND: The therapeutic strategies for acute ischemic stroke were faced with substantial constraints, emphasizing the necessity to safeguard neuronal cells during cerebral ischemia to reduce neurological impairments and enhance recovery outcomes. Despite its potential as a neuroprotective agent in stroke treatment, Chikusetsu saponin IVa encounters numerous challenges in clinical application. RESULT: Brain-targeted liposomes modified with THRre peptides showed substantial uptake by bEnd. 3 and PC-12 cells and demonstrated the ability to cross an in vitro blood-brain barrier model, subsequently accumulating in PC-12 cells. In vivo, they could significantly accumulate in rat brain. Treatment with C-IVa-LPs-THRre notably reduced the expression of proteins in the P2RX7/NLRP3/Caspase-1 pathway and inflammatory factors. This was evidenced by decreased cerebral infarct size and improved neurological function in MCAO rats. CONCLUSION: The findings indicate that C-IVa-LPs-THRre could serve as a promising strategy for targeting cerebral ischemia. This approach enhances drug concentration in the brain, mitigates pyroptosis, and improves the neuroinflammatory response associated with stroke.
Assuntos
Barreira Hematoencefálica , AVC Isquêmico , Lipossomos , Fármacos Neuroprotetores , Piroptose , Ratos Sprague-Dawley , Saponinas , Animais , Saponinas/farmacologia , Saponinas/química , Piroptose/efeitos dos fármacos , Ratos , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/efeitos dos fármacos , Lipossomos/química , Masculino , AVC Isquêmico/tratamento farmacológico , AVC Isquêmico/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/química , Células PC12 , Ácido Oleanólico/farmacologia , Ácido Oleanólico/química , Ácido Oleanólico/análogos & derivados , Encéfalo/metabolismo , Encéfalo/efeitos dos fármacos , Peptídeos/química , Peptídeos/farmacologia , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismoRESUMO
Our previous studies showed that MAN3-mediated mannose plays an important role in plant responses to cadmium (Cd) stress. However, the underlying mechanisms and signaling pathways involved are poorly understood. In this study, we showed that an Arabidopsis MYB4-MAN3-Mannose-MNB1 signaling cascade is involved in the regulation of plant Cd tolerance. Loss-of-function of MNB1 (mannose-binding-lectin 1) led to decreased Cd accumulation and tolerance, whereas overexpression of MNB1 significantly enhanced Cd accumulation and tolerance. Consistently, expression of the genes involved in the GSH-dependent phytochelatin (PC) synthesis pathway (such as GSH1, GSH2, PCS1, and PCS2) was significantly reduced in the mnb1 mutants but markedly increased in the MNB1-OE lines in the absence or presence of Cd stress, which was positively correlated with Cd-activated PC synthesis. Moreover, we found that mannose is able to bind to the GNA-related domain of MNB1, and that mannose binding to the GNA-related domain of MNB1 is required for MAN3-mediated Cd tolerance in Arabidopsis. Further analysis showed that MYB4 directly binds to the promoter of MAN3 to positively regulate the transcript of MAN3 and thus Cd tolerance via the GSH-dependent PC synthesis pathway. Consistent with these findings, overexpression of MAN3 rescued the Cd-sensitive phenotype of the myb4 mutant but not the mnb1 mutant, whereas overexpression of MNB1 rescued the Cd-sensitive phenotype of the myb4 mutant. Taken together, our results provide compelling evidence that a MYB4-MAN3-Mannose-MNB1 signaling cascade regulates cadmium tolerance in Arabidopsis through the GSH-dependent PC synthesis pathway.
Assuntos
Adaptação Fisiológica/genética , Arabidopsis/genética , Lectinas de Ligação a Manose/genética , Manose/metabolismo , Proteínas Repressoras/genética , beta-Manosidase/genética , Aminoaciltransferases/genética , Aminoaciltransferases/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cádmio/toxicidade , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Glutamato-Cisteína Ligase/genética , Glutamato-Cisteína Ligase/metabolismo , Glutationa Sintase/genética , Glutationa Sintase/metabolismo , Lectinas de Ligação a Manose/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Repressoras/metabolismo , Transdução de Sinais , Poluentes do Solo/toxicidade , beta-Manosidase/metabolismoRESUMO
Urethane hydrolase can degrade the carcinogen ethyl carbamate (EC) in fermented food, but its stability and activity limit its application. In this study, a mutant G246A and a double mutant N194V/G246A with improved cpUH activity and stability of Candida parapsilosis were obtained by site-directed mutagenesis. The catalytic efficiency (Kcat/Km) of mutant G246A and double mutant N194V/G246A are 1.95 times and 1.88 times higher than that of WT, respectively. In addition, compared with WT, the thermal stability and pH stability of mutant G246A and double mutant N194V/G246A were enhanced. The ability of mutant G246A and double mutant N194V/G246A to degrade EC in rice wine was also stronger than that of WT. The mutation increased the stability of the enzyme, as evidenced by decreased root mean square deviation (RMSD) and increased hydrogen bonds between the enzyme and substrate by molecular dynamics simulation and molecular docking analysis. The molecule modification of new cpUH promotes the industrial process of EC degradation.
Assuntos
Candida parapsilosis , Etanol , Oryza , Vinho , Concentração de Íons de Hidrogênio , Candida parapsilosis/efeitos dos fármacos , Candida parapsilosis/genética , Etanol/metabolismo , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Uretana/metabolismo , Simulação de Dinâmica Molecular , Biodegradação Ambiental , Mutação , Estabilidade Enzimática , População do Leste AsiáticoRESUMO
Diabetes patients with painful diabetic neuropathy (PDN) show severe spinal atrophy, suggesting pathological changes of the spinal cord contributes to central sensitization. However, the cellular changes and underlying molecular mechanisms within the diabetic spinal cord are less clear. By using a rat model of type 1 diabetes (T1D), we noted an extensive and irreversible spinal astrocyte degeneration at an early stage of T1D, which is highly associated with the chronification of PDN. Molecularly, acetylation of astrocytic signal transducer and activator of transcription-3 (STAT3) that is essential for maintaining the homeostatic astrocytes population was significantly impaired in the T1D model, resulting in a dramatic loss of spinal astrocytes and consequently promoting pain hypersensitivity. Mechanistically, class IIa histone deacetylase, HDAC5 were aberrantly activated in spinal astrocytes of diabetic rats, which promoted STAT3 deacetylation by direct protein-protein interactions, leading to the PDN phenotypes. Restoration of STAT3 signaling or inhibition of HDAC5 rescued astrocyte deficiency and attenuated PDN in the T1D model. Our work identifies the inhibitory axis of HDAC5-STAT3 induced astrocyte deficiency as a key mechanism underlying the pathogenesis of the diabetic spinal cord that paves the way for potential therapy development for PDN.
Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1 , Neuropatias Diabéticas , Animais , Ratos , Acetilação , Astrócitos/patologia , Neuropatias Diabéticas/patologia , Histona Desacetilases/genéticaRESUMO
In terms of cancer diagnoses and cancer-related deaths worldwide, colorectal cancer (CRC) is now the third most common malignancy. The drawbacks of current screening methods are their exorbitant costs, difficult procedures, and lengthy implementation timelines. The benefits of fecal screening for CRC are ease of operation, noninvasiveness, cost-effectiveness, and superior sensitivity. As a result of its enrichment in the malignant tissues and feces of CRC patients, Fusobacterium nucleatum (F. nucleatum) has emerged as a crucial biomarker for the incipient detection, identification, and prognostic prediction of CRC. Here, for the first time, the whole-bacterium SELEX method was used to screen the highly specific and affinity aptamers against F. nucleatum by 13 cycles of selection. The Apt-S-5 linear correlation equation is y = 0.7363x2.8315 (R2 = 0.9864) with a limit of detection (LOD) of 851 CFU/mL. The results of the experiment using fecal samples revealed a substantial disparity between the microorganisms in the CRC patients' feces and those in the feces of healthy individuals and were consistent with those of qPCR. The aptamers may therefore offer a crucial approach to identifying F. nucleatum and hold tremendous promise for CRC diagnosis and prognostic prediction.
Assuntos
Neoplasias Colorretais , Fusobacterium nucleatum , Humanos , Detecção Precoce de Câncer , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/patologia , Fezes/microbiologia , BiomarcadoresRESUMO
BACKGROUND: MYB transcription factors are widely distributed in the plant kingdom and play key roles in regulatory networks governing plant metabolism and biochemical and physiological processes. RESULTS: Here, we first determined the R2R3-MYB genes in five Euphorbiaceae genomes. The three Trp (W) residues from the first MYB domain (R2) were absolutely conserved, whereas the first W residue from the second MYB domain (R3) was preferentially mutated. The R2R3-MYBs were clustered into 48 functional subfamilies, of which 34 had both R2R3-MYBs of Euphorbiaceae species and AtMYBs, and four contained only Euphorbiaceae R2R3-MYBs. The whole-genome duplication (WGD) and/or segmental duplication (SD) played key roles in the expansion of the R2R3-MYB family. Unlike paralogous R2R3-MYB family members, orthologous R2R3-MYB members contained a higher selective pressure and were subject to a constrained evolutionary rate. VfMYB36 was specifically expressed in fruit, and its trend was consistent with the change in oil content, indicating that it might be involved in oil biosynthesis. Overexpression experiments showed that VfMYB36 could significantly provide linolenic acid (C18:3) content, which eventually led to a significant increase in oil content. CONCLUSION: Our study first provides insight into understanding the evolution and expression of R2R3-MYBs in Euphorbiaceae species, and also provides a target for the production of biomass diesel and a convenient way for breeding germplasm resources with high linolenic acid content in the future.
Assuntos
Genes myb , Fatores de Transcrição , Fatores de Transcrição/metabolismo , Ácido alfa-Linolênico , Proteínas de Plantas/metabolismo , Melhoramento Vegetal , Óleos de Plantas , Filogenia , Regulação da Expressão Gênica de PlantasRESUMO
Enterovirus 71 (EV71) is deemed a reemergent pathogen, with recent outbreaks worldwide. EV71 infection causes hand, foot, and mouth disease (HFMD) and has been associated with severe cardiac and central nervous system complications and even death. Viruses need host factors to complete their life cycle; therefore, the identification of the host factors for EV71 infection is pivotal to new antiviral research. Emerging evidence has highlighted the importance of protein acetylation during infection by various human viruses. The endoplasmic reticulum (ER), as the prominent organelle of EV71 replication, also has a unique acetylation regulation mechanism. However, the pathogenesis of EV71 and its relationship with the ER-based acetylation machinery are not fully understood. In this study, we demonstrated for the first time that the ER-resident acetyltransferase N-acetyltransferase 8 (NAT8) is a host factor for EV71 infection. Inhibiting NAT8 with CRISPR or a small compound significantly suppressed EV71 infection in SK-N-SH cells. NAT8 promoted EV71 replication in an acetyltransferase-activity-dependent manner. Additionally, we found that NAT8 facilitates EV71 infection by interacting with EV71 2B, 3AB, and 3C proteins and increasing the stability of these proteins. These results uncovered a novel function of NAT8 and elucidated a new mechanism underlying the regulation of EV71 replication. IMPORTANCE EV71 is one of the most common pathogens causing HFMD in young children, and some patients experience severe or fatal neurological consequences. To ensure efficient replication, the virus must hijack multiple host factors for its own benefit. Here, we show that the ER-resident acetyltransferase NAT8 is a host factor for EV71 infection. EV71 fails to complete its infection in various cells in the absence of NAT8. We further show that NAT8 benefits EV71 replication in an acetyltransferase-activity-dependent manner. Finally, we show that NAT8 facilitates EV71 infection by interacting with EV71 2B, 3AB, and 3C proteins and increasing the stability of these proteins. These results uncovered a novel function of NAT8 in EV71 infection and elucidated a new mechanism underlying the regulation of EV71 replication.
Assuntos
Acetiltransferases , Enterovirus Humano A , Infecções por Enterovirus , Proteínas não Estruturais Virais , Replicação Viral , Acetiltransferases/metabolismo , Enterovirus Humano A/fisiologia , Humanos , Proteínas não Estruturais Virais/metabolismoRESUMO
BACKGROUND & AIMS: Intestinal fibrosis is a common and severe complication of inflammatory bowel disease without clear pathogenesis. Abnormal expression of host genes and metabolic perturbations might associate with the onset of intestinal fibrosis. In this study, we aimed to investigate the relationship between the development of intestinal fibrosis and the dynamic alterations in both fecal metabolites and host gene expression. METHODS: We induced intestinal fibrosis in a murine model using 2,4,6-trinitrobenzene sulfonic acid (TNBS). TNBS-treated or control mice were sacrificed after 4 and 6 weeks of intervention; alterations in colonic genes and fecal metabolites were determined by transcriptomics and metabolomics, respectively. Differential, tendency, enrichment, and correlation analyses were performed to assess the relationship between host genes and fecal metabolites. RESULTS: RNA-sequencing analysis revealed that 679 differential genes with enduring changes were mainly enriched in immune response-related signaling pathways and metabolism-related biological processes. Among them, 15 lipid metabolism-related genes were closely related to the development of intestinal fibrosis. Moreover, the fecal metabolic profile was significantly altered during intestinal fibrosis development, especially the lipid metabolites. Particularly, dynamic perturbations in lipids were strongly associated with alterations in lipid metabolism-related genes expression. Additionally, six dynamically altered metabolites might serve as biomarkers to identify colitis-related intestinal fibrosis in the murine model. CONCLUSIONS: Intestinal fibrosis in colitis mice might be related to dynamic changes in gene expression and metabolites. These findings could provide new insights into the pathogenesis of intestinal fibrosis.
Assuntos
Colite , Transcriptoma , Animais , Camundongos , Modelos Animais de Doenças , Transcriptoma/genética , Metabolômica , Colite/induzido quimicamente , Colite/genética , Ácido TrinitrobenzenossulfônicoRESUMO
During photoperiodic growth, the light-dependent nature of chlorophyll synthesis in angiosperms necessitates robust control of the production of 5-aminolevulinic acid (ALA), the rate-limiting step in the initial stage of tetrapyrrole biosynthesis (TBS). We are interested in dissecting the post-translational control of this process, which suppresses ALA synthesis for chlorophyll synthesis in dark-grown plants. Using biochemical approaches for analysis of Arabidopsis wild-type (WT) and mutant lines as well as complementation lines, we show that the heme-synthesizing ferrochelatase 2 (FC2) interacts with protochlorophyllide oxidoreductase and the regulator FLU which both promote the feedback-controlled suppression of ALA synthesis by inactivation of glutamyl-tRNA reductase, thus preventing excessive accumulation of potentially deleterious tetrapyrrole intermediates. Thereby, FC2 stabilizes POR by physical interaction. When the interaction between FC2 and POR is perturbed, suppression of ALA synthesis is attenuated and photoreactive protochlorophyllide accumulates. FC2 is anchored in the thylakoid membrane via its membrane-spanning CAB (chlorophyll-a-binding) domain. FC2 is one of the two isoforms of ferrochelatase catalyzing the last step of heme synthesis. Although FC2 belongs to the heme-synthesizing branch of TBS, its interaction with POR potentiates the effects of the GluTR-inactivation complex on the chlorophyll-synthesizing branch and ensures reciprocal control of chlorophyll and heme synthesis.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Ácido Aminolevulínico/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Clorofila/metabolismo , Ferroquelatase/genética , Ferroquelatase/metabolismo , Heme/metabolismo , Protoclorifilida/metabolismo , Tetrapirróis/metabolismoRESUMO
The salt overly sensitive (SOS) pathway plays an important role in plant salt stress; however, the transcriptional regulation of the genes in this pathway is unclear. In this study, we found that Linker histone variant HIS1-3 and WRKY1 oppositely regulate the salt stress response in Arabidopsis (Arabidopsis thaliana) through the transcriptional regulation of SOS genes. The expression of HIS1-3 was inhibited by salt stress, and the disruption of HIS1-3 resulted in enhanced salt tolerance. Conversely, the expression of WRKY1 was induced by salt stress, and the loss of WRKY1 function led to increased salt sensitivity. The expression of SOS1, SOS2, and SOS3 was repressed and induced by HIS1-3 and WRKY1, respectively, and HIS1-3 regulated the expression of SOS1 and SOS3 by occupying the WRKY1 binding sites on their promoters. Moreover, WRKY1 and HIS1-3 acted upstream of the SOS pathway. Together, our results indicate that HIS1-3 and WRKY1 oppositely modulate salt tolerance in Arabidopsis through transcriptional regulation of SOS genes.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/metabolismo , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Histonas/genética , Histonas/metabolismo , Tolerância ao Sal/genéticaRESUMO
RabA4 subfamily proteins, the key regulators of intracellular transport, are vital for tip growth of plant polar cells, but their unique distribution in the apical zone and role in vesicle targeting and trafficking in the tips remain poorly understood. Here, we found that loss of Arabidopsis (Arabidopsis thaliana) AMINOPHOSPHOLIPID ATPASE 3 (ALA3) function resulted in a marked decrease in YFP-RabA4b/ RFP-RabA4d- and FM4-64-labeled vesicles from the inverted-cone zone of the pollen tube tip, misdistribution of certain intramembrane compartment markers, and an obvious increase in pollen tube width. Additionally, we revealed that phosphatidylserine (PS) was abundant in the inverted-cone zone of the apical pollen tube in wild-type Arabidopsis and was mainly colocalized with the trans-Golgi network/early endosome, certain post-Golgi compartments, and the plasma membrane. Loss of ALA3 function resulted in loss of polar localization of apical PS and significantly decreased PS distribution, suggesting that ALA3 is a key regulator for establishing and maintaining the polar localization of apical PS in pollen tubes. We further demonstrated that certain Rab GTPases colocalized with PS in vivo and bound to PS in vitro. Moreover, ALA3 and RabA4d collectively regulated pollen tube growth genetically. Thus, we propose that the tip-localized PS established by ALA3 is crucial for Rab GTPase-mediated vesicle targeting/trafficking and polar growth of pollen tubes in Arabidopsis.
Assuntos
Arabidopsis/crescimento & desenvolvimento , Fosfatidilserinas/metabolismo , Tubo Polínico/crescimento & desenvolvimento , Proteínas rab de Ligação ao GTP/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Parede Celular/química , Parede Celular/metabolismo , Mutação , Plantas Geneticamente Modificadas , Tubo Polínico/citologia , Tubo Polínico/genética , Tubo Polínico/metabolismo , Vesículas Secretórias/genética , Vesículas Secretórias/metabolismo , Proteínas rab de Ligação ao GTP/genéticaRESUMO
INTRODUCTION: The correlation between diabetes and stroke has been studied extensively in epidemiological research. Here we used bibliometric software to visualize and analyze the literature related to diabetic stroke to provide an overview of the current state of research, hot spots, and future trends in the field. METHODS: Based on the Web of Science Core Collection(WoSCC) database, we collected studies related to diabetic stroke from 2007 to May 2022. We used CiteSpace (version 6.1.R5), VOSviewer, and Sci-mago Graphica to create knowledge maps and conduct visual analyses on authors, countries, in-stitutions, cited references, and keywords, and Origin for statistical analysis. RESULTS: We included a total of 5171 papers on diabetic stroke from the WoSCC database. Overall, there was a steady increase in the number of publications, with a high number of emerging scientists. The United States was the most productive and influential country, which dominated national col-laborations. The most common subject category was "neurology". In total, 12 major clusters were generated from the cited references. Keywords analysis showed that keywords related to post-stroke injury and treatment are those with the highest burst intensity and latest burst time. CONCLUSIONS: Individual disease treatment remains a hot topic and how to balance acute stroke treatment and glycemic control is currently a difficult clinical problem. At the same time, the mechanism of their interaction and the prevention and treatment of related causative factors remain a hot topic of current and future research.
RESUMO
A simple and reliable method is developed to fabricate Ag-nanoparticle-decorated Co(OH)2 nanoflowers grafted on polyacrylonitrile (PAN) nanopillar arrays as uniform and sensitive surface-enhanced Raman scattering (SERS) substrates. First, Co(OH)2-nanosheet-assembled nanoflowers are achieved on the highly uniform PAN nanopillar arrays via electrochemical deposition. Then, Ag nanoparticles (Ag-NPs) are decorated onto the Au-nanoparticle-precoated Co(OH)2 nanoflowers based on a spontaneous redox reaction (SRR) between the silver ions and Co(OH)2 nanosheets at room temperature. Ag-NPs can be successfully in situ synthesized on the Co(OH)2 nanoflowers, and Au nanoparticles precoated on the surface of the Co(OH)2 nanosheets can ensure that the Co(OH)2 nanoflower structure does not collapse. Because of the highly uniform PAN nanopillar arrays and the high-density sub-10 nm gaps between the neighboring Ag-NPs on the surface of the Co(OH)2 nanoflowers, the hierarchical three-dimensional Ag@Co(OH)x grown on PAN nanopillar arrays can produce a reproducible and sensitive SERS effect. To verify the SERS performance of the substrate, 4-aminothiophenol (4-ATP) is used as the probe molecule, and the Ag@Co(OH)x grown on PAN nanopillar arrays is employed as the SERS substrate. As a result, 4-ATP concentrations as low as 10-10 M can still be identified, exhibiting high SERS activity. Additionally, the relative standard deviation value of the main characteristic peak of 10-5 M 4-ATP is 9.43%, indicating good uniformity of the SERS signal of the substrate. The SRR between silver ions and Co(OH)2 can provide a simple route to prepare heterostructures as SERS substrates, which has great potential for application in the field of analysis.
RESUMO
Iron (oxyhydr)oxides and organic matter (OM) are intimately associated in natural environments, and their fate might be linked to sulfur during sulfidation-reoxidation cycling. However, the coupling of DOM molecular fractionation with Fe and S transformations following a full sulfidation-reoxidation cycle remains poorly understood. Here, we reacted Fh and Fh-OM associations with S(-II) anaerobically and then exposed the sulfidic systems to air. S(-II) preferentially reacted with Fh to form inorganic S (e.g., mackinawite, S0, and S22-) over being incorporated into OM as organic S and therefore indirectly affected OM fate by altering Fe speciation. Fh sulfidation was inhibited by associated OM, and the main secondary Fe species were mackinawite, Fe(II)-OM compounds, and lepidocrocite. Concomitantly, organic molecules high in unsaturation, aromaticity, and molecular weight were detached from solid-phase Fe species due to their lower affinities for secondary Fe species than for Fh. During the reoxidation stage, the previously formed Fe(II) species were reoxidized to Fh with a stronger aggregation, which recaptured formerly released OM with higher selectivity. Additionally, â¢OH was generated from Fe(II) oxygenation and degraded a portion of the DOM molecules. Overall, these results have significant implications for Fe, C, and S cycling in S-rich environments characterized by oscillating redox conditions.