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Kendomycin B is distinguished from other ansamycins by its unique, fully carbogenic ansa scaffold. We show here that FAD-dependent monooxygenase Kmy13 is solely responsible for installing the rare ansa structural framework; in vivo gene disruption/complementation experiments and in vitro enzymatic assays are described in detail. Moreover, the compound with a ß-keto ester, kendolactone A (2), was confirmed as the natural substrate of Kmy13 and a bona fide biosynthetic intermediate en route to kendomycin B. Further structural prediction and biochemical assays have provided significant insights into the catalytic mechanism of Kmy13.
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Postoperative neurocognitive disorders (pNCD) are a common neurological complication, especially in elderly following anesthesia and surgery. Yet, the underlying mechanisms of pNCD remain elusive. This study aimed to investigate the molecular mechanisms that compromise synaptic metaplasticity in pNCD development with a focus on the involvement of Nogo-66 receptor 1 (NgR1) in the pathogenesis of pNCD in aged mice. Aged mice subjected to anesthesia and laparotomy surgery exhibited anxiety-like behavior and contextual fear memory impairment. Moreover, the procedure significantly increased NogoA and NgR1 expressions, particularly in the hippocampal CA1 and CA3 regions. This increase led to the depolymerization of F-actin, attributed to the activation of the RhoA-GTPase, resulting in a reduction of dendritic spines and changes in their morphology. Additionally, these changes hindered the efficient postsynaptic delivery of the subunit GluA1 and GluA2 of AMPA receptors (AMPARs), consequently diminishing excitatory neurotransmission in the hippocampus. Importantly, administering the competitive NgR1 antagonist peptide NEP1-40 (Nogo-A extracellular peptide residues 1-40 amino acids of Nogo-66) and Fasudil (a Rho-kinase inhibitor) effectively mitigated synaptic impairments and reversed neurocognitive deficits in aged mice following anesthesia and surgery. Our work indicates that high hippocampal Nogo66-NgR1 signaling disrupts postsynaptic AMPA receptor surface delivery due to F-actin depolymerization in the pathophysiology of pNCD.
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Kirsten rat sarcoma virus (KRAS) mutation is associated with malignant tumor transformation and drug resistance. However, the development of clinically effective targeted therapies for KRAS-mutant cancer has proven to be a formidable challenge. Here, we report that tripartite motif-containing protein 21 (TRIM21) functions as a target of extracellular signal-regulated kinase 2 (ERK2) in KRAS-mutant colorectal cancer (CRC), contributing to regorafenib therapy resistance. Mechanistically, TRIM21 directly interacts with and ubiquitinates v-myc avian myelocytomatosis viral oncogene homolog (c-Myc) at lysine 148 (K148) via K63-linkage, enabling c-Myc to be targeted to the autophagy machinery for degradation, ultimately resulting in the downregulation of enolase 2 expression and inhibition of glycolysis. However, mutant KRAS (KRAS/MT)-driven mitogen-activated protein kinase (MAPK) signaling leads to the phosphorylation of TRIM21 (p-TRIM21) at Threonine 396 (T396) by ERK2, disrupting the interaction between TRIM21 and c-Myc and thereby preventing c-Myc from targeting autophagy for degradation. This enhances glycolysis and contributes to regorafenib resistance. Clinically, high p-TRIM21 (T396) is associated with an unfavorable prognosis. Targeting TRIM21 to disrupt KRAS/MT-driven phosphorylation using the antidepressant vilazodone shows potential for enhancing the efficacy of regorafenib in treating KRAS-mutant CRC in preclinical models. These findings are instrumental for KRAS-mutant CRC treatment aiming at activating TRIM21-mediated selective autophagic degradation of c-Myc.
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Autofagia , Neoplasias Colorrectales , Compuestos de Fenilurea , Proteínas Proto-Oncogénicas c-myc , Proteínas Proto-Oncogénicas p21(ras) , Piridinas , Ribonucleoproteínas , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Humanos , Autofagia/efectos de los fármacos , Compuestos de Fenilurea/farmacología , Animales , Proteínas Proto-Oncogénicas p21(ras)/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/genética , Piridinas/farmacología , Proteínas Proto-Oncogénicas c-myc/metabolismo , Proteínas Proto-Oncogénicas c-myc/genética , Ratones , Ribonucleoproteínas/metabolismo , Ribonucleoproteínas/genética , Línea Celular Tumoral , Resistencia a Antineoplásicos , Ensayos Antitumor por Modelo de Xenoinjerto , Proteolisis/efectos de los fármacos , Mutación , Ratones DesnudosRESUMEN
Bacterial keratitis is a major cause of blindness, hindered by the rising threat of antibiotic resistance. Although corneal bandage lenses (CBLs) are widely utilized in ophthalmic treatment, their effectiveness in treating bacterial keratitis remains limited due to risks of secondary infections, patient discomfort, and complications. In this study, we developed a novel biomimetic coating on CBLs by grafting Ag/Cu bimetallic nanoparticles (Ag/Cu-NPs) and thiol-functionalized heparin (Hep-SH) using a rapid polydopamine (PDA) deposition technique, effectively mimicking the ocular surface glycocalyx structure. The resulting Ag/Cu-NPs/Hep-SH coated CBLs (PNH-CBLs) exhibited significant antibacterial activity, with over 80 % reduction in Staphylococcus aureus (S. aureus) and 70 % in Escherichia coli (E. coli) due to the sustained release of Ag+ and Cu2+, along with displaying favorable in vitro biocompatibility. Animal experiments conducted on New Zealand white rabbits with bacterial keratitis demonstrated successful treatment therapeutic outcomes, with PNH-CBLs leading to a significant decrease in clinical score. These biomimetic lenses also exhibited selective anti-protein adsorption properties, minimizing inflammation and promoting surface lubrication. Overall, this innovative approach addresses critical challenges in antibiotic resistance and offers a promising therapeutic strategy for managing ophthalmic infectious diseases.
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Concentrated Growth Factor (CGF) is a highly effective biomaterial known for its ability to promote tissue regeneration. While it's been studied extensively in intraoral procedures and bone grafting, its benefits in maxillary sinus lifting lack substantial evidence. This review aimed to evaluate CGF's effectiveness in maxillary sinus augmentation, focusing on clinical, radiographic, and histological outcomes.A comprehensive literature search was conducted across PubMed, Scopus, Web of Science, Google Scholar, and Cochrane Library databases using specific mesh terms and keywords and adhered to PRISMA guidelines. Studies up to March 2024 involving transcrestal or lateral maxillary sinus floor elevation with CGF, either alone or in combination with grafting materials, were included.Out of 783 publications, 13 studies met the eligibility criteria. The review assessed CGF's role in minimizing postoperative complications, enhancing new bone formation, and improving implant survival. Despite data variability among studies, the majority reported that CGF positively influenced maxillary sinus augmentation outcomes.While more robust randomized clinical trials are required to draw definitive conclusions, initial results are promising, and the findings suggest that CGF utilization in maxillary sinus augmentation seems to enhance clinical outcomes by promoting vascularization and regeneration at the surgical sites and improving both the quality and quantity of newly formed sinus bone. Furthermore, it exhibits potential for improving postoperative sequelae and achieving high implant survival rates.
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Péptidos y Proteínas de Señalización Intercelular , Elevación del Piso del Seno Maxilar , Humanos , Elevación del Piso del Seno Maxilar/métodos , Péptidos y Proteínas de Señalización Intercelular/uso terapéutico , Trasplante Óseo/métodos , Seno Maxilar/cirugía , Regeneración Ósea/efectos de los fármacosRESUMEN
There are increasing concerns regarding the rapid expansion of polystyrene nanoplastics (PS-NPs), which could impact human health. Previous studies have shown that nanoplastics can be transferred from mothers to offspring through the placenta and breast milk, resulting in cognitive deficits in offspring. However, the neurotoxic effects of maternal exposure on offspring and its mechanisms remain unclear. In this study, PS-NPs (50 nm) were gavaged to female rats throughout gestation and lactation to establish an offspring exposure model to study the neurotoxicity and behavioral changes caused by PS-NPs on offspring. Neonatal rat hippocampal neuronal cells were used to investigate the pathways through which NPs induce neurodevelopmental toxicity in offspring rats, using iron inhibitors, autophagy inhibitors, reactive oxygen species (ROS) scroungers, P53 inhibitors, and NCOA4 inhibitors. We found that low PS-NPs dosages can cause ferroptosis in the hippocampus of the offspring, resulting in a decline in the cognitive, learning, and memory abilities of the offspring. PS-NPs induced NOCA4-mediated ferritinophagy and promoted ferroptosis by inciting ROS production to activate P53-mediated ferritinophagy. Furthermore, the levels of the antioxidant factors glutathione peroxidase 4 (GPX4) and glutathione (GSH), responsible for ferroptosis, were reduced. In summary, this study revealed that consumption of PS-NPs during gestation and lactation can cause ferroptosis and damage the hippocampus of offspring. Our results can serve as a basis for further research into the neurodevelopmental effects of nanoplastics in offspring.
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Ferroptosis , Hipocampo , Exposición Materna , Nanopartículas , Poliestirenos , Especies Reactivas de Oxígeno , Proteína p53 Supresora de Tumor , Animales , Femenino , Hipocampo/metabolismo , Hipocampo/efectos de los fármacos , Ferroptosis/efectos de los fármacos , Proteína p53 Supresora de Tumor/metabolismo , Ratas , Embarazo , Especies Reactivas de Oxígeno/metabolismo , Poliestirenos/toxicidad , Nanopartículas/toxicidad , Ferritinas/metabolismo , Efectos Tardíos de la Exposición Prenatal , Autofagia/efectos de los fármacos , Ratas Sprague-Dawley , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Glutatión/metabolismoRESUMEN
Alzheimer's Disease (AD), as the most common neurodegenerative disease worldwide, severely impairs patients' cognitive functions. Although its exact etiology remains unclear, the abnormal aggregations of misfolded ß-amyloid peptide and tau protein are considered pivotal in its pathological progression. Recent studies identify ubiquitin-specific protease 11 (USP11) as the key regulator of tau deubiquitination, exacerbating tau aggregation and AD pathology. Thereby, inhibiting USP11 function, via either blocking USP11 activity or lowering USP11 protein level, may serve as an effective therapeutic strategy against AD. Our research introduces IsoLiPro, a unique lithium isobutyrate-L-proline coordination compound, effectively lowers USP11 protein level and enhances tau ubiquitination in vitro. Additionally, long-term oral administration of IsoLiPro dramatically reduces total and phosphorylated tau levels in AD transgenic mice. Moreover, IsoLiPro also significantly lessens ß-amyloid deposition and synaptic damage, improving cognitive functions in these animal models. These results indicate that IsoLiPro, as a novel small-molecule USP11 inhibitor, can effectively alleviate AD-like pathologies and improve cognitive functions, offering promise as a potential multi-targeting therapeutic agent against AD.
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Resistance to gemcitabine in pancreatic ductal adenocarcinoma (PDAC) leads to ineffective chemotherapy and, consequently, delayed treatment, thereby contributing to poor prognosis. Glycolysis is an important intrinsic reason for gemcitabine resistance as it competitively inhibits gemcitabine activity by promoting deoxycytidine triphosphate accumulation in PDAC. However, biomarkers are lacking to determine which patients can benefit significantly from glycolysis inhibition under the treatment of gemcitabine activity, and a comprehensive understanding of the molecular mechanisms that promote glycolysis in PDAC will contribute to the development of a strategy to sensitize gemcitabine chemotherapy. In this study, we aimed to identify a biomarker that can robustly indicate the intrinsic resistance of PDAC to gemcitabine and guide chemotherapy sensitization strategies. After establishing gemcitabine-resistant cell lines in our laboratory and collecting pancreatic cancer and adjacent normal tissues from gemcitabine-treated patients, we observed that circRNA hsa_circ_0008383 (namely cNEK6) was highly expressed in the peripheral blood and tumor tissues of patients and xenografts with gemcitabine-resistant PDAC. cNEK6 enhanced resistance to gemcitabine by promoting glycolysis in PDAC. Specifically, cNEK6 prevented K48 ubiquitination of small ribonucleoprotein peptide A from the BTRC, a ubiquitin E3 ligase; thus, the accumulated SNRPA stopped PP2Ac translation by binding to its G-quadruplexes in 5' UTR of mRNA. mTORC1 pathway was aberrantly phosphorylated and activated owing to the absence of PP2Ac. The expression level of cNEK6 in the peripheral blood and tumor tissues correlated significantly and positively with the activation of the mTORC1 pathway and degree of glycolysis. Hence, the therapeutic effect of gemcitabine is limited in patients with high cNEK6 levels, and in combination with the mTORC1 inhibitor, rapamycin, can enhance sensitivity to gemcitabine chemotherapy.
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Carcinoma Ductal Pancreático , Desoxicitidina , Resistencia a Antineoplásicos , Gemcitabina , Glucólisis , Diana Mecanicista del Complejo 1 de la Rapamicina , Neoplasias Pancreáticas , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacología , Desoxicitidina/uso terapéutico , Humanos , Carcinoma Ductal Pancreático/tratamiento farmacológico , Carcinoma Ductal Pancreático/metabolismo , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patología , Glucólisis/efectos de los fármacos , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Resistencia a Antineoplásicos/efectos de los fármacos , Resistencia a Antineoplásicos/genética , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/genética , Animales , Ratones , Línea Celular Tumoral , Ratones Desnudos , Femenino , Pirofosfatasas/metabolismo , Pirofosfatasas/genética , Masculino , Ratones Endogámicos BALB C , Persona de Mediana Edad , Transducción de Señal/efectos de los fármacosRESUMEN
BACKGROUND: Previous studies have indicated that occlusal disharmony (OD) can promote anxiety-like behaviours. However, the specific molecules involved in the development of anxiety-like behaviours and their underlying mechanisms remain unknown. METHODS: OD was produced by anterior crossbite of female mice. We measured the anxiety levels of mice in each group and screened the hippocampal mRNA expression profiles of mice in the control group and OD group. The role of target mRNA in OD-induced anxiety-like behaviours was evaluated and we preliminarily explored the possible downstream pathways. RESULTS: The results suggested that OD can induce and promote anxiety-like behaviours with/without chronic unpredictable mild stress. We found that Sirt1 was significantly downregulated within the hippocampus in OD mice. In addition, the downregulation of Sirt1 within the hippocampus in OD and control mice promoted anxiety-like behaviours, increased acetylated histone H3 expression and decreased Dnah12 transcription levels. In contrast, in OD mice subjected to an injection of resveratrol, there was a remission of anxiety-like behaviours and an upregulation of Sirt1 in the hippocampus, the effects of which were accompanied by decreased acetylated histone H3 expression and increased Dnah12 transcription levels. CONCLUSIONS: OD leads to increased sensitivity to chronic stress in mice, resulting in anxiety-like behaviours. During this process, Sirt1 acts as an effective factor in the regulation of OD-induced anxiety-like behaviours. CLINICAL RELEVANCE: OD, as a stressor, could induce anxiety-like behaviours. It investigates the impact of OD (a stressor) on the molecular genetic of the pathophysiology of major neuropsychiatric disorders.
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Ansiedad , Conducta Animal , Modelos Animales de Enfermedad , Sirtuina 1 , Animales , Sirtuina 1/metabolismo , Ratones , Femenino , Maloclusión , Hipocampo/metabolismo , Resveratrol/farmacología , Regulación hacia Abajo , ARN Mensajero/metabolismoRESUMEN
BACKGROUND: Foodborne diseases are a growing public health concern worldwide and households are a common setting. This study aimed to explore the epidemiological characteristics of household foodborne disease outbreaks in Zhejiang Province and propose targeted prevention and control measures. METHODS: Descriptive statistical methods were used to analyze household foodborne disease outbreak data collected from the Foodborne Disease Outbreaks Surveillance System in Zhejiang Province from 2010 to 2022. RESULTS: Household foodborne disease outbreaks showed an upward trend during the study period (Cox-Staurt trend test, p = 0.01563 < 0.05). These outbreaks mainly occurred from June to September, with 62.08% (352/567) of all reported outbreaks. The number of reported outbreaks varied in 11 prefectures, with a maximum of 100 and a minimum of only 7. Household foodborne disease outbreaks had a wide spectrum of etiologic factors. Mushroom toxins accounted for the largest proportion of all etiologies (43.39 %) and caused the highest proportion of hospitalization (54.18%) and death (78.26%). Such outbreaks are caused by accidently eating wild poisonous mushrooms. Bacterial infection (16.23%) was the second most common etiology, with Salmonella spp. and Vibrio parahaemolyticus being the primary pathogens. These outbreaks were caused by improper storage, improper processing or a combination of factors, and the foods involved were mainly aquatic animals, eggs and cooked meat. Other identified etiologies included plant toxins (9.52%), chemicals (7.23%), animal toxins (3.70%), and viruses (1.76%). Among the above-mentioned etiologies, mushroom toxins, bacteria, and animal toxins had seasonal characteristics. Analysis of regions and etiologies revealed that the proportion of various etiologies was different in 11 prefectures. Wild mushrooms (43.39%), aquatic animals (9.88%), and toxic plants (8.47%) were the top three foods involved in these outbreaks. The most common factors contributing to household foodborne disease outbreaks were inedibility and misuse (59.08%), followed by multiple factors (7.58%), improper storage (7.41%), and improper processing (7.41%). CONCLUSIONS: Household foodborne disease outbreaks were closely related to the lack of knowledge regarding foodborne disease prevention. Therefore, public health agencies should strengthen residents' surveillance and health education to improve food safety awareness and effectively reduce foodborne diseases in households. In addition, timely publicity and early warning by relevant government departments, the introduction of standards to control the contamination of pathogenic bacteria in raw materials, and strengthened supervision of the sale of substances that may cause health hazards, such as poisonous mushrooms and nitrites, will also help reduce such outbreaks.
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Brotes de Enfermedades , Enfermedades Transmitidas por los Alimentos , China/epidemiología , Humanos , Enfermedades Transmitidas por los Alimentos/epidemiología , Enfermedades Transmitidas por los Alimentos/microbiología , Composición Familiar , Contaminación de Alimentos/análisis , Contaminación de Alimentos/estadística & datos numéricos , Vibrio parahaemolyticus/aislamiento & purificación , Salmonella/aislamiento & purificación , AnimalesRESUMEN
In bacteria, chromosome replication is achieved by the coordinations of more than a dozen replisome enzymes. Replication initiation protein DnaA melts DNA duplex at replication origin (oriC) and forms a replication bubble, followed by loading of helicase DnaB with the help of loader protein DnaC. Then the DnaB helicase unwinds the dsDNA and supports the priming of DnaG and the polymerizing of DNA polymerase. The DnaB helicase functions as a platform coupling unwinding, priming, and polymerizing events. The multiple roles of DnaB helicase are underlined by its distinctive architecture and dynamics conformations. In this review, we will discuss the assembling of DnaB hexamer and the conformational changes upon binding of various partners, DnaB in states of closed dilated (CD), closed constricted (CC), closed helical (CH), and open helical (OH) are discussed. These multiple interfaces among DnaB and partners are potential targets for inhibitors design and novel peptide antibiotics development.
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BACKGROUND: Bisphosphonates (BPs) are widely used to inhibit excessive osteoclast activity. However, the potential to compromise bone defect healing has limited their broader application. To better understand the influence of BPs on bone regeneration, we established a bone grafting model with Zoledronate administration, aiming to deepen the understanding of bone remodeling and mineralization processes. METHODS: A bone grafting model was established in the distal femurs of male Sprague-Dawley rats. The experimental group received systemic administration of Zoledronate (ZOL, 0.2 mg/kg, administered twice). Histological analysis and immunohistochemistry (IHC) were employed to assess osteoblastic and macrophage activity, tartrate-resistant acid phosphatase (TRAP) staining was used to evaluate osteoclastogenesis. Mineralization was assessed through Micro-CT analysis, Raman spectroscopy, and back-scatter scanning electron microscopy (BSE-SEM). Additionally, the in vitro effects of ZOL on osteoblast and osteoclast activity were investigated to further elucidate its impact on bone regeneration. RESULTS: In vivo, the ZOL group showed increased bone mass, as observed in histological and radiological assessments. However, Micro-CT, Raman spectroscopy, and BSE-SEM detection revealed lower mineralization levels in ZOL group's regenerated bone. Acid-etched SEM analysis showed abnormal osteocyte characteristics in ZOL-group's regenerated bone. Simultaneously, elevated osteopontin (OPN), F4/80 expression along with reduced TRAP expressing was found in the grafting region of ZOL group. In vitro, ZOL did not negatively impact osteogenetic activity (ALP, BMP4, OCN expression) at the tested concentrations (0.02-0.5 g/ml) but significantly impaired mineralization and inhibited osteoclast formation, even at the lowest concentration. CONCLUSIONS: This study highlights a less recognized negative effect of ZOL on bone mineralization during bone regeneration. More research is needed to elucidate the underlying mechanism.
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Conservadores de la Densidad Ósea , Regeneración Ósea , Calcificación Fisiológica , Difosfonatos , Osteoclastos , Ratas Sprague-Dawley , Microtomografía por Rayos X , Ácido Zoledrónico , Animales , Ácido Zoledrónico/farmacología , Masculino , Regeneración Ósea/efectos de los fármacos , Ratas , Calcificación Fisiológica/efectos de los fármacos , Difosfonatos/farmacología , Conservadores de la Densidad Ósea/farmacología , Osteoclastos/efectos de los fármacos , Osteoblastos/efectos de los fármacos , Imidazoles/farmacología , Espectrometría Raman , Microscopía Electrónica de Rastreo , Fémur/efectos de los fármacos , Fémur/diagnóstico por imagen , Trasplante Óseo/métodos , Densidad Ósea/efectos de los fármacos , InmunohistoquímicaRESUMEN
While amyloidopathy and tauopathy have been recognized as hallmarks in Alzheimer's disease (AD) brain, recently, increasing lines of evidence have supported the pathological roles of cerebrovascular changes in the pathogenesis and progression of AD. Restoring or ameliorating the impaired cerebrovascular function during the early phase of the disease may yield benefits against the cognitive decline in AD. In the present study, we evaluated the potential therapeutic effects of nicergoline [NG, a well-known α1 adrenergic receptor (ADR) blocker and vasodilator] against AD through ameliorating vascular abnormalities. Our in vitro data revealed that NG could reverse ß-amyloid1-42 (Aß1-42)-induced PKC/ERK1/2 activation, the downstream pathway of α1-ADR activation, in α1-ADR-overexpressed N2a cells. NG also blocked Aß1-42- or phenylephrine-induced constrictions in isolated rat arteries. All these in vitro data may suggest ADR-dependent impacts of Aß on vascular function and the reversal effect of NG. In addition, the ameliorating impacts of NG treatment on cerebral vasoconstriction, vasoremodeling, and cognitive decline were investigated in vivo in a PSAPP transgenic AD mouse model. Consistent with in vitro findings, the chronic treatment of NG significantly ameliorated the cerebrovascular dysfunctions and Aß plaque depositions in the brain. Moreover, an improved cognitive performance was also observed. Taken together, our findings supported the beneficial effects of NG on AD through adrenergic-related mechanisms and highlighted the therapeutic potential of α1-adrenergic vasomodulators against AD pathologies.
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Macroalgal biomass blooms, including those causing the green and golden tides, have been rising along Chinese coasts, resulting in considerable social impacts and economic losses. To understand the links between the ongoing climate changes (ocean warming and acidification) and algal tide formation, the effects of temperature (20 and 24 °C), pCO2 concentration (Partial Pressure of Carbon Dioxide, 410 ppm and 1000 ppm) and their interaction on the growth of Ulva prolifera and Ulva lactuca (green tide forming species), as well as Sargassum horneri (golden tide forming species) were investigated. The results indicate that the concurrent rises in temperature and pCO2 level significantly boosted the growth and nutrient uptake rates of U. lactuca. For U. prolifera, the heightened growth and photosynthetic efficiency under higher CO2 conditions are likely due to the increased availability of inorganic carbon. In contrast, S. horneri exhibited negligible responsiveness to the individual and combined effects of the increased temperature and CO2 concentration. These outcomes indicate that the progressive climate changes, characterized by ocean warming and acidification, are likely to escalate the incidence of green tides caused by Ulva species, whereas they are not anticipated to precipitate golden tides.
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A highly efficient, atom-economical α-allylation reaction of NH2-unprotected amino acid esters and alkynes is achieved by chiral aldehyde/palladium combined catalysis. A diverse range of α,α-disubstituted nonproteinogenic α-amino acid esters are produced in 31-92% yields and 84-97% ee values. The allylation products are utilized for the synthesis of drug molecule BMS561392 and other chiral molecules possessing complex structures. Mechanistic investigations reveal that this reaction proceeds via a chiral aldehyde-/palladium-mediated triple cascade catalytic cycle.
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Although enhanced fibroblast growth factor (FGF) signaling has been demonstrated to be crucial in many cases of syndromic cleft palate caused by tongue malposition in humans, animal models that recapitulate this phenotype are limited, and the precise mechanisms remain elusive. Mutations in FGF9 with the effect of either loss- or gain-of-function effects have been identified to be associated with cleft palate in humans. Here, we generated a mouse model with a transgenic Fgf9 allele specifically activated in cranial neural crest cells, aiming to elucidate the gain-of-function effects of Fgf9 in palatogenesis. We observed cleft palate with 100% penetrance in mutant mice. Further analysis demonstrated that no inherent defects in the morphogenic competence of palatal shelves could be found, but a passively lifted tongue prevented the elevation of palatal shelves, leading to the cleft palate. This tongue malposition was induced by posterior spatial confinement that was exerted by temporomandibular joint (TMJ) dysplasia characterized by a reduction in Sox9+ progenitors within the condyle and a structural decrease in the posterior dimension of the lower jaw. Our findings highlight the critical role of excessive FGF signaling in disrupting spatial coordination during palate development and suggest a potential association between palatal shelf elevation and early TMJ development.
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Fisura del Paladar , Factor 9 de Crecimiento de Fibroblastos , Cresta Neural , Transducción de Señal , Animales , Cresta Neural/metabolismo , Cresta Neural/patología , Fisura del Paladar/genética , Fisura del Paladar/patología , Fisura del Paladar/metabolismo , Ratones , Factor 9 de Crecimiento de Fibroblastos/metabolismo , Factor 9 de Crecimiento de Fibroblastos/genética , Ratones Transgénicos , Factor de Transcripción SOX9/metabolismo , Factor de Transcripción SOX9/genética , Hueso Paladar/metabolismo , Hueso Paladar/embriología , Hueso Paladar/patología , Articulación Temporomandibular/patología , Articulación Temporomandibular/metabolismo , Lengua/patología , Lengua/metabolismo , Modelos Animales de EnfermedadRESUMEN
Methylpyridines are a class of highly toxic pyridine derivatives. In this study, a novel degrading bacterium was isolated for 3-methylpyridine (3-MP) degradation (Gordonia rubripertincta ZJJ, GenBank accession NO. OP430847.1; CCTCC M 2022975). The maximum specific degradation rate, half-saturation constant and inhibition constant were fitted to be 0.48 h-1, 88.3 mg L-1 and 924.0 mg L-1, respectively. During 3-MP biodegradation, the lost total organic carbon was transformed into CO2 (67.4 %) and biomass (32.6 %), and ammonia nitrogen was almost the sole inorganic species with a conversion rate of 36.3 %. Three metabolic pathways were possibly involved in 3-MP degradation: I) methyl oxidation followed by ring hydroxylation and hydrogenation; II) rupture of C=C and C-N bonds after ring reduction; III) initial ring hydroxylation. The study not only provides a novel strain for the high-efficient degradation of 3-MP, but also contributes to an in-depth understanding of 3-MP biotransformation.
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Biodegradación Ambiental , Piridinas , Piridinas/metabolismo , Bacteria Gordonia/metabolismo , Filogenia , BiomasaRESUMEN
Netrin-G2 is a membrane-anchored protein known to play critical roles in neuronal circuit development and synaptic organization. In this study, we identify compound heterozygous mutations of c.547delC, p.(Arg183Alafs∗186) and c.605G > A, p.(Trp202X) in NTNG2 causing a syndrome exhibiting developmental delay, intellectual disability, hypotonia, and facial dysmorphism. To elucidate the underlying cellular and molecular mechanisms, CRISPR-Cas9 technology is employed to generate a knock-in mouse model expressing the R183Afs and W202X mutations. We report that the Ntng2R183Afs/W202X mice exhibit hypotonia and impaired learning and memory. We find that the levels of CaMKII and p-GluA1Ser831 are decreased, and excitatory postsynaptic transmission and long-term potentiation are impaired. To increase the activity of CaMKII, the mutant mice receive intraperitoneal injections of DCP-LA, a CaMKII agonist, and show improved cognitive function. Together, our findings reveal molecular mechanisms of how NTNG2 deficiency leads to impairments of cognitive ability and synaptic plasticity.
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Major depression is a complex psychiatric disorder that includes genetic, neurological, and cognitive factors. Early detection and intervention can prevent progression, and help select the best treatment. Traditional clinical diagnosis tends to be subjective and misdiagnosed. Based on this, this study leverages clinical scale assessments and sequencing data to construct disease prediction models. Firstly, data undergoes preprocessing involving normalization and other requisite procedures. Feature engineering is then applied to curate subsets of features, culminating in the construction of a model through the implementation of machine learning and deep learning algorithms. In this study, 18 features with significant differences between patients and healthy controls were selected. The depression recognition model was constructed by deep learning with an accuracy of 87.26 % and an AUC of 91.56 %, which can effectively distinguish patients with depression from healthy controls. In addition, 33 features selected by recursive feature elimination method were used to construct a prognostic effect model of patients after 2 weeks of treatment, with an accuracy of 75.94 % and an AUC of 83.33 %. The results show that the deep learning algorithm based on clinical and sequencing data has good accuracy and provides an objective and accurate method for the diagnosis and pharmacodynamic prediction of depression. Furthermore, the selected differential features can serve as candidate biomarkers to provide valuable clues for diagnosis and efficacy prediction.