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BACKGROUND: Metagenomic next-generation sequencing (mNGS) was previously established as a method that can increase the pathogen identification rate in patients with severe community-acquired pneumonia (SCAP). RESEARCH QUESTION: What is the impact on clinical outcomes of mNGS of BALF in ICU patients with SCAP? STUDY DESIGN AND METHODS: A multicenter, randomized, open-label clinical trial was conducted in 10 ICUs. Patients were randomized in a 1:1 ratio to undergo BALF with the conventional microbiological tests (CMTs) only (CMT group) or both BALF with mNGS and CMTs (mNGS group). The primary outcome was the time to clinical improvement, defined as the time from randomization to either an improvement of two points on a six-category ordinal scale or discharge from the ICU, whichever occurred first. RESULTS: A total of 349 patients were randomized between January 1, 2021, to November 18, 2022, of whom 170 were assigned to the CMT group and 179 to the mNGS group. In the intention-to-treat analysis, the time to clinical improvement was better in the mNGS group than that in the CMT group (10 d vs. 13 d, difference: -2.0 [95% CI = -3.0 to 0.0]). Similar results were obtained in the per-protocol analysis. The proportion of patients with clinical improvement within 14 d was significantly higher in the mNGS group (62.0%) than that in the CMT group (46.5%). There was no significant difference in other secondary outcomes. CONCLUSION: MNGS combined with CMTs reduced the time to clinical improvement for patients with SCAP, compared to the use of CMTs alone.
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Insulin signaling to the glomerular podocyte via the insulin receptor (IR) is critical for kidney function. In this study we show that near-complete knockout of the closely related insulin-like growth factor 1 receptor (IGF1R) in podocytes is detrimental, resulting in albuminuria in vivo and podocyte cell death in vitro. In contrast, partial podocyte IGF1R knockdown confers protection against doxorubicin-induced podocyte injury. Proteomic analysis of cultured podocytes revealed that while near-complete loss of podocyte IGF1R results in the downregulation of mitochondrial respiratory complex I and DNA damage repair proteins, partial IGF1R inhibition promotes respiratory complex expression. This suggests that altered mitochondrial function and resistance to podocyte stress depends on the level of IGF1R suppression, the latter determining whether receptor inhibition is protective or detrimental. Our work suggests that the partial suppression of podocyte IGF1R could have therapeutic benefits in treating albuminuric kidney disease.
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Rice OsBBX17 encodes a B-box zinc finger transcription factor in which the N-terminal B-box structural domain interacts with OsMPK1. In addition, it directly binds to the G-box of OsHAK2 and OsHAK7 promoters and represses their transcription. Under saline-alkaline conditions, the expression of OsBBX17 was inhibited. Meanwhile, activation of the OsMPK1-mediated mitogen-activated protein kinase cascade pathway caused OsMPK1 to interact with OsBBX17 and phosphorylate OsBBX17 at the Thr-95 site. It reduced OsBBX17 DNA-binding activity and enhanced saline-alkaline tolerance by deregulating transcriptional repression of OsHAK2 and OsHAK7. Genetic assays showed that the osbbx17-KO had an excellent saline-alkaline tolerance, whereas the opposite was in OsBBX17-OE. In addition, overexpression of OsMPK1 significantly improved saline-alkaline tolerance, but knockout of OsMPK1 caused an increased sensitivity. Further overexpression of OsBBX17 in the osmpk1-KO caused extreme saline-alkaline sensitivity, even a quick death. OsBBX17 was validated in saline-alkaline tolerance from two independent aspects, transcriptional level and post-translational protein modification, unveiling a mechanistic framework by which OsMPK1-mediated phosphorylation of OsBBX17 regulates the transcription of OsHAK2 and OsHAK7 to enhance the Na+ /K+ homeostasis, which partially explains light on the molecular mechanisms of rice responds to saline-alkaline stress via B-box transcription factors for the genetic engineering of saline-alkaline tolerant crops.
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Oryza , Fatores de Transcrição , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Oryza/metabolismo , Fosforilação , Tolerância ao Sal/genética , Sistema de Sinalização das MAP Quinases , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de PlantasRESUMO
[This corrects the article DOI: 10.1371/journal.pone.0095259.].
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Podocytes are specialized epithelial cells that maintain the glomerular filtration barrier. These cells are susceptible to lipotoxicity in the obese state and irreversibly lost during kidney disease leading to proteinuria and renal injury. PPARγ is a nuclear receptor whose activation can be renoprotective. This study examined the role of PPARγ in the lipotoxic podocyte using a PPARγ knockout (PPARγKO) cell line and since the activation of PPARγ by Thiazolidinediones (TZD) is limited by their side effects, it explored other alternative therapies to prevent podocyte lipotoxic damage. Wild-type and PPARγKO podocytes were exposed to the fatty acid palmitic acid (PA) and treated with the TZD (Pioglitazone) and/or the Retinoid X receptor (RXR) agonist Bexarotene (BX). It revealed that podocyte PPARγ is essential for podocyte function. PPARγ deletion reduced key podocyte proteins including podocin and nephrin while increasing basal levels of oxidative and ER stress causing apoptosis and cell death. A combination therapy of low-dose TZD and BX activated both the PPARγ and RXR receptors reducing PA-induced podocyte damage. This study confirms the crucial role of PPARγ in podocyte biology and that their activation in combination therapy of TZD and BX may be beneficial in the treatment of obesity-related kidney disease.
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Nefropatias , Podócitos , Tiazolidinedionas , Humanos , PPAR gama/metabolismo , Pioglitazona/farmacologia , Tiazolidinedionas/metabolismo , Tiazolidinedionas/farmacologia , Tiazolidinedionas/uso terapêutico , Nefropatias/tratamento farmacológico , Bexaroteno/farmacologiaRESUMO
Vegetative phase change in plants is regulated by a gradual decline in the level of miR156 and a corresponding increase in the expression of its targets, SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes. Gibberellin (GA), jasmonic acid (JA), and cytokinin (CK) regulate vegetative phase change by affecting genes in the miR156-SPL pathway. However, whether other phytohormones play a role in vegetative phase change remains unknown. Here, we show that a loss-of-function mutation in the brassinosteroid (BR) biosynthetic gene, DWARF5 (DWF5), delays vegetative phase change, and the defective phenotype is primarily attributable to reduced levels of SPL9 and miR172, and a corresponding increase in TARGET OF EAT1 (TOE1). We further show that GLYCOGEN SYNTHASE KINASE3 (GSK3)-like kinase BRASSINOSTEROID INSENSITIVE2 (BIN2) directly interacts with and phosphorylates SPL9 and TOE1 to cause subsequent proteolytic degradation. Therefore, BRs function to stabilize SPL9 and TOE1 simultaneously to regulate vegetative phase change in plants.
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Proteínas de Arabidopsis , Arabidopsis , MicroRNAs , Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , MicroRNAs/genética , Proteínas Quinases/genética , Proteínas Quinases/metabolismoRESUMO
In rice, the Ca2+/calmodulin-dependent protein kinase OsDMI3 is an important positive regulator of abscisic acid (ABA) signaling. In ABA signaling, H2O2 is required for ABA-induced activation of OsDMI3, which in turn increase H2O2 production. However, how OsDMI3 regulates H2O2 production in ABA signaling remains unknown. Here we show that OsRbohB is the main NADPH oxidase involved in ABA-induced H2O2 production and ABA-mediated physiological responses. OsDMI3 directly interacts with and phosphorylates OsRbohB at Ser-191, which is OsDMI3-mediated site-specific phosphorylation in ABA signaling. Further analyses revealed that OsDMI3-mediated OsRbohB Ser-191 phosphorylation positively regulates the activity of NADPH oxidase and the production of H2O2 in ABA signaling, thereby enhancing the sensitivity of seed germination and root growth to ABA and plant tolerance to water stress and oxidative stress. Moreover, we discovered that the OsDMI3-mediated OsRbohB phosphorylation and H2O2 production is dependent on the sucrose non-fermenting 1-related protein kinases SAPK8/9/10, which phosphorylate OsRbohB at Ser-140 in ABA signaling. Taken together, these results not only reveal an important regulatory mechanism that directly activates Rboh for ABA-induced H2O2 production but also uncover the importance of this regulatory mechanism in ABA signaling.
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Oryza , Proteínas Quinases , Proteínas Quinases/metabolismo , Fosforilação , Peróxido de Hidrogênio/metabolismo , Oryza/metabolismo , Ácido Abscísico/metabolismo , NADPH Oxidases/metabolismoRESUMO
Model-informed drug development (MIDD) is a process that integrates drug exposure-based, biological, and statistical models to enhance the benefit-risk balance in drug development. The US Food and Drug Administration (FDA) MIDD Paired Meeting Pilot Program provides a platform to apply MIDD approaches to drug development and to seek regulatory feedback in a collaborative and streamlined process prior to submission for approval. Eli Lilly and Company (Lilly) participated in the Pilot Program to seek agency alignment to enhance the initial approved dosing regimens of cetuximab (Erbitux; Eli Lilly and Company, Indianapolis, IN) and ramucirumab (Cyramza; Eli Lilly and Company) without conducting additional clinical trials. Here, we describe the overall MIDD strategy at Lilly, the process with the FDA, and the impact of implementing the approach.
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Anticorpos Monoclonais Humanizados , Desenvolvimento de Medicamentos , Humanos , Preparações Farmacêuticas , Cetuximab , RamucirumabRESUMO
Overly Na+ ion in soil caused by salt stress has a significant negative impact on the growth and production of crops, especially rice (Oryza sativa L.). Therefore, it is vital for us to clarify how salt stress tolerance in rice is caused by Na+ ion toxicity. The UDP-glucuronic acid decarboxylase (UXS) is a critical enzyme in the biosynthesis of UDP-xylose, which is the key substrate of cytoderm synthesis in plants. In this study, we found that OsUXS3, a rice UXS, is a positive regulator to regulate Na+ ion toxicity under salt stress by interacting with OsCATs (Oryza sativa catalase; OsCAT). The expression of OsUXS3 was significantly up-regulated under NaCl and NaHCO3 treatments of rice seedlings. Meanwhile, by the genetic and biochemical evidence, knockout of OsUXS3 significantly increased reactive oxygen species (ROS) levels and decreased CAT activity under NaCl and NaHCO3 treatments in tissue. Furthermore, knockout of OsUXS3 caused excessive accumulation of Na + ion and rapid loss of K+ ion and disrupts Na+/K+ homeostasis under NaCl and NaHCO3 treatments. Based on the results above, we can conclude that OsUXS3 might regulate CAT activity by interacting with OsCATs, which is not only characterized for the first time but also regulating Na+/K+ homeostasis, positively regulating the Na+ ion toxicity tolerance under salt stress in rice.
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Oryza , Oryza/metabolismo , Cloreto de Sódio/farmacologia , Cloreto de Sódio/metabolismo , Estresse Salino , Sódio/metabolismoRESUMO
About 30% of patients who have a kidney transplant with underlying nephrotic syndrome (NS) experience rapid relapse of disease in their new graft. This is speculated to be due to a host-derived circulating factor acting on podocytes, the target cells in the kidney, leading to focal segmental glomerulosclerosis (FSGS). Our previous work suggests that podocyte membrane protease receptor 1 (PAR-1) is activated by a circulating factor in relapsing FSGS. Here, the role of PAR-1 was studied in human podocytes in vitro, and using a mouse model with developmental or inducible expression of podocyte-specific constitutively active PAR-1, and using biopsies from patients with nephrotic syndrome. In vitro podocyte PAR-1 activation caused a pro-migratory phenotype with phosphorylation of the kinase JNK, VASP protein and docking protein Paxillin. This signaling was mirrored in podocytes exposed to patient relapse-derived NS plasma and in patient disease biopsies. Both developmental and inducible activation of transgenic PAR-1 (NPHS2 Cre PAR-1Active+/-) caused early severe nephrotic syndrome, FSGS, kidney failure and, in the developmental model, premature death. We found that the non-selective cation channel protein TRPC6 could be a key modulator of PAR-1 signaling and TRPC6 knockout in our mouse model significantly improved proteinuria and extended lifespan. Thus, our work implicates podocyte PAR-1 activation as a key initiator of human NS circulating factor and that the PAR-1 signaling effects were partly modulated through TRPC6.
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Glomerulosclerose Segmentar e Focal , Síndrome Nefrótica , Podócitos , Animais , Humanos , Podócitos/patologia , Síndrome Nefrótica/patologia , Glomerulosclerose Segmentar e Focal/patologia , Canal de Cátion TRPC6/metabolismo , Receptor PAR-1/genética , Receptor PAR-1/metabolismo , Modelos Animais de Doenças , RecidivaRESUMO
LAY ABSTRACT: Raising an autistic child can affect many aspects of families' lives. Parents are responsible for many decisions, from initiating evaluation to selecting and implementing treatments. How parents conceptualize the course and nature of their child's diagnosis influences these processes and parents' own well-being. Parents' perceptions about their children's autism are also affected by cultural contexts and understanding of autism. The Illness Perception Questionnaire-Revised (IPQ-R) is widely used to study cognitions in chronic health research and has been adapted and validated to measure parents' perceptions and beliefs about their children's ASD (IPQ-R-ASD). However, such studies are mostly conducted in high-income countries (HICs) with western, individualistic cultural values (e.g. United States, Canada). Therefore, it is unclear whether the IPQ-R-ASD is a useful instrument in understanding parents' perceptions of autism in Vietnam, a lower- and middle-income country (LMIC) with collectivistic Asian cultural values. These differences suggest that parents in Vietnam may have cognitive representations of their children's autism that differ from those of parents living in HIC, western countries. The purpose of this study was to examine the usability of the translated Vietnamese IPQ-R-ASD that may, ultimately, help explore Vietnamese parents' autism perceptions. While the study's result indicated the usability of the translated measure in Vietnam, when interpreted with Vietnamese norms, results also highlighted notable differences between Vietnamese and North American parents' perceptions of autism that warrant further research.
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Transtorno do Espectro Autista , Transtorno Autístico , Criança , Humanos , Estados Unidos , Comparação Transcultural , Vietnã , Transtorno do Espectro Autista/psicologia , Pais/psicologiaRESUMO
Calcium (Ca2+ )/calmodulin (CaM)-dependent protein kinase (CCaMK) is an important positive regulator of antioxidant defenses and tolerance against oxidative stress. However, the underlying molecular mechanisms are largely unknown. Here, we report that the rice (Oryza sativa) CCaMK (OsDMI3) physically interacts with and phosphorylates OsUXS3, a cytosol-localized UDP-xylose synthase. Genetic and biochemical evidence demonstrated that OsUXS3 acts downstream of OsDMI3 to enhance the oxidative stress tolerance conferred by higher catalase (CAT) activity. Indeed, OsUXS3 interacted with CAT isozyme B (OsCATB), and this interaction was required to increase OsCATB protein abundance under oxidative stress conditions. Furthermore, we showed that OsDMI3 phosphorylates OsUXS3 on residue Ser-245, thereby further promoting the interaction between OsUXS3 and OsCATB. Our results indicate that OsDMI3 promotes the association of OsUXS3 with OsCATB to enhance CAT activity under oxidative stress. These findings reveal OsUXS3 as a direct target of OsDMI3 and demonstrate its involvement in antioxidant defense.
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Oryza , Antioxidantes/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/genética , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/metabolismo , Estresse Oxidativo , Fosforilação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismoRESUMO
Tissue remodeling/fibrosis is a main feature of idiopathic pulmonary fibrosis (IPF), which results in the replacement of normal lung parenchyma with a collagen-rich extracellular matrix produced by fibroblasts and myofibroblasts. Epithelial-mesenchymal transition (EMT) in type 2 lung epithelial cells is a key process in IPF, which leads to fibroblasts and myofibroblasts accumulation and excessive collagen deposition. DEC1, a structurally distinct class of basic helix-loop-helix proteins, is associated with EMT in cancer. However, the functional role of DEC1 in pulmonary fibrosis (PF) remains elusive. Herein, we aimed to explore DEC1 expression in IPF and bleomycin (BLM)-induced PF in mice and the mechanisms underlying the fibrogenic effect of DEC1 in PF in vivo and in vitro by Dec1-knockout (Dec1 -/-) mice, knockdown and overexpression of DEC1 in alveolar epithelial cells (A549 cells). We found that the expression of DEC1 was increased in IPF and BLM-injured mice. More importantly, Dec1 -/- mice had reduced PF after BLM challenge. Additionally, DEC1 deficiency relieved EMT development and repressed the PI3K/AKT/GSK-3ß/ß-catenin integrated signaling pathway in mice and in A549 cells, whereas DEC1 overexpression in vitro had converse effects. Moreover, the PI3K/AKT and Wnt/ß-catenin signaling inhibitors, LY294002 and XAV-939, ameliorated BLM-meditated PF in vivo and relieved EMT in vivo and in vitro. These pathways are interconnected by the GSK-3ß phosphorylation status. Our findings indicated that during PF progression, DEC1 played a key role in EMT via the PI3K/AKT/GSK-3ß/ß-catenin integrated signaling pathway. Consequently, targeting DEC1 may be a potential novel therapeutic approach for IPF.
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Currently, multiplex-PCR with genotype-specific primers is widely used for preliminary screening of hepatitis B virus (HBV) genotypes, despite its relatively lower accuracy compared with whole genome sequencing. Here, we present the discrepant results of HBV genotyping by PCR and full-length sequencing. HBV DNA was isolated from chronic hepatitis B serum and the HBV genotype was detected by PCR using genotype-specific primers and full-length genome sequencing. As a result, the determination of genotype B by the PCR method was consistent with the DNA sequencing results; however, PCR revealed that genotype C showed a mix of B and C genotypes in the current study. In conclusion, the PCR-based genotyping may not provide accurate information of the HBV genotype and whole genome sequencing remains the "gold standard" for HBV genotyping.
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Hepatite B Crônica , Hepatite B , DNA Viral/genética , Genótipo , Vírus da Hepatite B/genética , Humanos , Reação em Cadeia da Polimerase Multiplex , Análise de Sequência de DNARESUMO
BACKGROUND: Depression is a common psychiatric disorder associated with defects in GABAergic (gamma-aminobutyric acidergic) neurotransmission. α-Dystroglycan (α-DG), a cell adhesion molecule known to be essential for skeletal muscle integrity, is also present at inhibitory synapses in the central nervous system and forms a structural element in certain synapses. However, the role of α-DG in the regulation of depressive-like behaviors remains largely unknown. METHODS: Depressive-like behaviors were induced by chronic social defeat stress in adult male mice. Surface protein was extracted by a biotin kit, and the expression of protein was detected by Western blotting. Intrahippocampal microinjection of the lentivirus or adeno-associated virus or agrin intervention was carried out using a stereotaxic instrument and followed by behavioral tests. Miniature inhibitory postsynaptic currents were recorded by whole-cell patch-clamp techniques. RESULTS: The expression of α-DG and glycosylated α-DG in the ventral hippocampus was significantly lower in chronic social defeat stress-susceptible male mice than in control mice, accompanied by a decreased surface expression of GABAA receptor γ2 subunit and reduced GABAergic neurotransmission. RNA interference-mediated knockdown of Dag1 increased the susceptibility of mice to subthreshold stress. Both in vivo administration of agrin and overexpression of like-acetylglucosaminyltransferase ameliorated depressive-like behaviors and restored the decrease in surface expression of GABAA receptor γ2 subunit and the amplitude of miniature inhibitory postsynaptic currents in chronic social defeat stress-exposed mice. CONCLUSIONS: Our findings demonstrate that glycosylated α-DG plays a role in the pathophysiological process of depressive-like behaviors by regulating the surface expression of GABAA receptor γ2 subunit and GABAergic neurotransmission in the ventral hippocampus.
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Distroglicanas , Receptores de GABA-A , Agrina/metabolismo , Animais , Distroglicanas/metabolismo , Hipocampo/metabolismo , Humanos , Masculino , Camundongos , Receptores de GABA/metabolismo , Receptores de GABA-A/metabolismo , Ácido gama-Aminobutírico/metabolismoRESUMO
Objectives: To evaluate the impact of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) on the inflammatory response and viral clearance in coronavirus disease 2019 (COVID-19) patients. Methods: We included 229 patients with confirmed COVID-19 in a multicenter, retrospective cohort study. Propensity score matching at a ratio of 1:3 was introduced to eliminate potential confounders. Patients were assigned to the ACEI/ARB group (n = 38) or control group (n = 114) according to whether they were current users of medication. Results: Compared to the control group, patients in the ACEI/ARB group had lower levels of plasma IL-1ß [(6.20 ± 0.38) vs. (9.30 ± 0.31) pg/ml, P = 0.020], IL-6 [(31.86 ± 4.07) vs. (48.47 ± 3.11) pg/ml, P = 0.041], IL-8 [(34.66 ± 1.90) vs. (47.93 ± 1.21) pg/ml, P = 0.027], and TNF-α [(6.11 ± 0.88) vs. (12.73 ± 0.26) pg/ml, P < 0.01]. Current users of ACEIs/ARBs seemed to have a higher rate of vasoconstrictive agents (20 vs. 6%, P < 0.01) than the control group. Decreased lymphocyte counts [(0.76 ± 0.31) vs. (1.01 ± 0.45)*109/L, P = 0.027] and elevated plasma levels of IL-10 [(9.91 ± 0.42) vs. (5.26 ± 0.21) pg/ml, P = 0.012] were also important discoveries in the ACEI/ARB group. Patients in the ACEI/ARB group had a prolonged duration of viral shedding [(24 ± 5) vs. (18 ± 5) days, P = 0.034] and increased length of hospitalization [(24 ± 11) vs. (15 ± 7) days, P < 0.01]. These trends were similar in patients with hypertension. Conclusions: Our findings did not provide evidence for a significant association between ACEI/ARB treatment and COVID-19 mortality. ACEIs/ARBs might decrease proinflammatory cytokines, but antiviral treatment should be enforced, and hemodynamics should be monitored closely. Since the limited influence on the ACEI/ARB treatment, they should not be withdrawn if there was no formal contraindication.
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Drought stress seriously limits crop productivity. Although studies have been carried out, it is still largely unknown how plants respond to drought stress. Here we find that drought treatment can enhance the phosphorylation activity of brassinosteroid-signaling kinase 1 (ZmBSK1) in maize (Zea mays). Our genetic studies reveal that ZmBSK1 positively affects drought tolerance in maize plants. ZmBSK1 localizes in plasma membrane, interacts with calcium/calmodulin (Ca2+ /CaM)-dependent protein kinase (ZmCCaMK), and phosphorylates ZmCCaMK. Ser-67 is a crucial phosphorylation site of ZmCCaMK by ZmBSK1. Drought stress enhances not only the interaction between ZmBSK1 and ZmCCaMK but also the phosphorylation of Ser-67 in ZmCCaMK by ZmBSK1. Furthermore, Ser-67 phosphorylation in ZmCCaMK regulates its Ca2+ /CaM binding, autophosphorylation and transphosphorylation activity, and positively affects its function in drought tolerance in maize. Our results reveal an important role for ZmBSK1 in drought tolerance and suggest a direct regulatory mode of ZmBSK1 phosphorylating ZmCCaMK.
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Brassinosteroides , Zea mays , Cálcio/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Estresse Fisiológico , Zea mays/metabolismoRESUMO
Redox-altered plasticity refers to redox-dependent reversible changes in synaptic plasticity via altering functions of key proteins, such as N-methyl-d-aspartate receptor (NMDAR). Age-related cognitive disorders includes Alzheimer's disease (AD), vascular dementia (VD), and age-associated memory impairment (AAMI). Based on the critical role of NMDAR-dependent long-term potentiation (LTP) in memory, the increase of reactive oxygen species in cognitive disorders, and the sensitivity of NMDAR to the redox status, converging lines have suggested the redox-altered NMDAR-dependent plasticity might underlie the synaptic dysfunctions associated with cognitive disorders. In this review, we summarize the involvement of redox-altered plasticity in cognitive disorders by presenting the available evidence. According to reports from our laboratory and other groups, this "redox-altered plasticity" is more similar to functional changes rather than organic injuries, and strategies targeting redox-altered plasticity using pharmacological agents might reverse synaptic dysfunctions and memory abnormalities in the early stage of cognitive disorders. Targeting redox modifications for NMDARs may serve as a novel therapeutic strategy for memory deficits.
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Calcium (Ca2+)/calmodulin (CaM)-dependent protein kinase (CCaMK) is an important positive regulator of abscisic acid (ABA) and abiotic stress signaling in plants and is believed to act upstream of mitogen-activated protein kinase (MAPK) in ABA signaling. However, it is unclear how CCaMK activates MAPK in ABA signaling. Here, we show that OsDMI3, a rice (Oryza sativa) CCaMK, directly interacts with and phosphorylates OsMKK1, a MAPK kinase (MKK) in rice, in vitro and in vivo. OsDMI3 was found to directly phosphorylate Thr-25 in the N-terminus of OsMKK1, and this Thr-25 phosphorylation is OsDMI3-specific in ABA signaling. The activation of OsMKK1 and its downstream kinase OsMPK1 is dependent on Thr-25 phosphorylation of OsMKK1 in ABA signaling. Moreover, ABA treatment induces phosphorylation in the activation loop of OsMKK1, and the two phosphorylations, in the N-terminus and in the activation loop, are independent. Further analyses revealed that OsDMI3-mediated phosphorylation of OsMKK1 positively regulates ABA responses in seed germination, root growth, and tolerance to both water stress and oxidative stress. Our results indicate that OsMKK1 is a direct target of OsDMI3, and OsDMI3-mediated phosphorylation of OsMKK1 plays an important role in activating the MAPK cascade and ABA signaling.
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Ácido Abscísico/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Cálcio/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Oryza/enzimologia , Proteínas de Plantas/metabolismo , Ácido Abscísico/farmacologia , Quinases de Proteína Quinase Ativadas por Mitógeno/química , Modelos Biológicos , Oryza/efeitos dos fármacos , Oryza/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Fosfotreonina/metabolismo , Ligação Proteica/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos , ÁguaRESUMO
BACKGROUND: Deficiency in neuronal structural plasticity is involved in the development of major depressive disorder. TWIST1, a helix-loop-helix transcription factor that is essential for morphogenesis and organogenesis, is normally expressed at low levels in mature neurons. However, it is poorly understood what role TWIST1 plays in the brain and whether it is involved in the pathophysiology of depression. METHODS: Depressive-like behaviors in C57BL/6J mice were developed by chronic social defeat stress. Genetic and pharmacological approaches were used to investigate the role of the TWIST1-miR-214-PPAR-δ signaling pathway in depressive-like behaviors. Molecular biological and morphological studies were performed to define the molecular mechanisms downstream of TWIST1. RESULTS: The expression of TWIST1 was positively correlated with depressive behaviors in humans and mice. Chronic stress elevated TWIST1 expression in the medial prefrontal cortex of mice, which was reversed by fluoxetine treatment. While the overexpression of TWIST1 increased susceptibility to stress, the knockdown of TWIST1 prevented the defective morphogenesis of dendrites of pyramidal neurons in layer II/III of the medial prefrontal cortex and alleviated depressive-like behaviors. Mechanistically, this prodepressant property of TWIST1 was mediated, at least in part, through the repression of miR-214-PPAR-δ signaling and mitochondrial function, which was also mimicked by genetic and pharmacological inhibition of PPAR-δ. CONCLUSIONS: These results suggest that TWIST1 in the medial prefrontal cortex mediates chronic stress-induced dendritic remodeling and facilitates the occurrence of depressive-like behavior, providing new information for developing drug targets for depression therapy.