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1.
STAR Protoc ; 5(3): 103251, 2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39120976

RESUMEN

Midbrain organoids provide an innovative cellular source for transplantation therapies of neurodegenerative diseases. Here, we present a protocol for midbrain organoid-derived cell transplantation into a Parkinson's disease mouse model. We describe steps for midbrain organoid generation, single-cell suspension preparation, and cell transplantation. This approach is valuable for studying the efficacy of midbrain organoids as a potential cellular source for restoring motor function. For complete details on the use and execution of this protocol, please refer to Fu et al.1.

2.
Am J Pathol ; 194(5): 656-672, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38325552

RESUMEN

Idiopathic pulmonary fibrosis is a progressive interstitial lung disease for which there is no curative therapy available. Repetitive alveolar epithelial injury repair, myofibroblast accumulation, and excessive collagen deposition are key pathologic features of idiopathic pulmonary fibrosis, eventually leading to cellular hypoxia and respiratory failure. The precise mechanism driving this complex maladaptive process remains inadequately understood. WD repeat and suppressor of cytokine signaling box containing 1 (WSB1) is an E3 ubiquitin ligase, the expression of which is associated strongly with hypoxia, and forms a positive feedback loop with hypoxia-inducible factor 1α (HIF-1α) under anoxic condition. This study explored the expression, cellular distribution, and function of WSB1 in bleomycin (BLM)-induced mouse lung injury and fibrosis. WSB1 expression was highly induced by BLM injury and correlated with the progression of lung fibrosis. Significantly, conditional deletion of Wsb1 in adult mice ameliorated BLM-induced pulmonary fibrosis. Phenotypically, Wsb1-deficient mice showed reduced lipofibroblast to myofibroblast transition, but enhanced alveolar type 2 proliferation and differentiation into alveolar type 1 after BLM injury. Proteomic analysis of mouse lung tissues identified caveolin 2 as a potential downstream target of WSB1, contributing to BLM-induced epithelial injury repair and fibrosis. These findings unravel a vital role for WSB1 induction in lung injury repair, thus highlighting it as a potential therapeutic target for pulmonary fibrosis.


Asunto(s)
Fibrosis Pulmonar Idiopática , Lesión Pulmonar , Animales , Ratones , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Miofibroblastos/metabolismo , Lesión Pulmonar/patología , Proteómica , Pulmón/patología , Fibrosis , Hipoxia/patología , Fibrosis Pulmonar Idiopática/patología , Bleomicina/toxicidad , Regeneración , Péptidos y Proteínas de Señalización Intracelular
3.
Heliyon ; 10(2): e24234, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38293351

RESUMEN

Parkinson's disease (PD) is a neurodegenerative disease characterized by the degeneration of dopaminergic (DA) neurons in the substantia nigra and loss of DA transmission in the striatum, thus making cell transplantation an effective treatment strategy. Here, we develop a cellular therapy based on induced pluripotent stem cell (iPSC)-derived midbrain organoids. By transplanting midbrain organoid cells into the striatum region of a 6-OHDA-lesioned PD mouse model, we found that the transplanted cells survived and highly efficiently differentiated into DA neurons. Further, using a dopamine sensor, we observed that the differentiated human DA neurons could efficiently release dopamine and were integrated into the neural network of the PD mice. Moreover, starting from four weeks after transplantation, the motor function of the transplanted mice could be significantly improved. Therefore, cell therapy based on iPSC-derived midbrain organoids can be a potential strategy for the clinical treatment of PD.

4.
Angew Chem Int Ed Engl ; 63(5): e202318441, 2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38098269

RESUMEN

The construction of acyclic, non-adjacent 1,3-stereogenic centers, prevalent motifs in drugs and bioactive molecules, has been a long-standing synthetic challenge due to acyclic nucleophiles being distant from the chiral environment. In this study, we successfully synthesized highly valuable 1,2-bis(boronic) esters featuring acyclic and nonadjacent 1,3-stereocenters. Notably, this reaction selectively produces migratory coupling products rather than alternative deborylative allylation or direct allylation byproducts. This approach introduces a new activation mode for selective transformations of gem-diborylmethane in asymmetric catalysis. Additionally, we found that other gem-diborylalkanes, previously challenging due to steric hindrance, also successfully participated in this reaction. The incorporation of 1,2-bis(boryl)alkenes facilitated the diversification of the alkenyl and two boron moieties in our target compounds, thereby enabling access to a broad array of versatile molecules. DFT calculations were performed to elucidate the reaction mechanism and shed light on the factors responsible for the observed excellent enantioselectivity and diastereoselectivity. These were determined to arise from ligand-substrate steric repulsions in the syn-addition transition state.

5.
Angew Chem Int Ed Engl ; 62(32): e202307447, 2023 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-37316685

RESUMEN

Asymmetric cross-couplings based on 1,2-carbon migration from B-ate complexes have been developed efficiently to access valuable organoboronates. However, enantioselective reactions triggered by 1,2-boron shift have remained to be unaddressed synthetic challenge. Here, Ir-catalyzed asymmetric allylic alkylation enabled by 1,2-boron shift was developed. In this reaction, we disclosed that excellent enantioselectivities were achieved through an interesting dynamic kinetic resolution (DKR) process of allylic carbonates at the elevated temperature. Notably, the highly valuable (bis-boryl)alkenes have enabled an array of diversifications to access versatile molecules. Extensive experimental and computational studies were conducted to elucidate the reaction mechanism of DKR process and clarify the origin of excellent enantioselectivities.

6.
Cell Mol Life Sci ; 80(6): 145, 2023 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-37166489

RESUMEN

Alveolar epithelial type II cells (AT2s) together with AT1s constitute the epithelial lining of lung alveoli. In contrast to the large flat AT1s, AT2s are cuboidal and smaller. In addition to surfactant production, AT2s also serve as prime alveolar progenitors in homeostasis and play an important role during regeneration/repair. Based on different lineage tracing strategies in mice and single-cell transcriptomic analysis, recent reports highlight the heterogeneous nature of AT2s. These studies present compelling evidence for the presence of stable or transitory AT2 subpopulations with distinct marker expression, signaling pathway activation and functional properties. Despite demonstrated progenitor potentials of AT2s in maintaining homeostasis, through self-renewal and differentiation to AT1s, the exact identity, full progenitor potential and regulation of these progenitor cells, especially in the context of human diseases remain unclear. We recently identified a novel subset of AT2 progenitors named "Injury-Activated Alveolar Progenitors" (IAAPs), which express low levels of Sftpc, Sftpb, Sftpa1, Fgfr2b and Etv5, but are highly enriched for the expression of the surface receptor programmed cell death-ligand 1 (Pd-l1). IAAPs are quiescent during lung homeostasis but activated upon injury with the potential to proliferate and differentiate into AT2s. Significantly, a similar population of PD-L1 positive cells expressing intermediate levels of SFTPC are found to be expanded in human IPF lungs. We summarize here the current understanding of this newly discovered AT2 progenitor subpopulation and also try to reconcile the relationship between different AT2 stem cell subpopulations regarding their progenitor potential, regulation, and relevance to disease pathogenesis and therapeutic interventions.


Asunto(s)
Antígeno B7-H1 , Pulmón , Ratones , Humanos , Animales , Antígeno B7-H1/metabolismo , Pulmón/metabolismo , Células Epiteliales Alveolares , Alveolos Pulmonares/metabolismo , Alveolos Pulmonares/patología , Diferenciación Celular/fisiología
7.
J Org Chem ; 88(1): 261-271, 2023 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-36520655

RESUMEN

We report the first general and practical method for the addition of aryl halides and alkynes to norbornenes with palladium catalysis. Norbornenes have been used as the unsaturated acceptors of aryl and alkynyl groups to construct saturated bridged C-C bonds. The combination of Pd(OAc)2/PCy3HBF4 has been identified as the optimal system promoting difunctionalization of norbornenes via the C-X/C-H bond cleavage and highly selective C(sp3)-C(sp2)/C(sp3)-C(sp) bond formation. Broad substrate scope and excellent functional group tolerance have been achieved to show the high efficiency of this approach. Mechanism studies based on experiments and DFT have been performed to gain insights into the catalytic mechanism.

8.
Chinese Medical Journal ; (24): 1708-1718, 2023.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-980966

RESUMEN

BACKGROUND@#Currently, the effect of the 2022 nationwide coronavirus disease 2019 (COVID-19) wave on the perioperative prognosis of surgical patients in China is unclear. Thus, we aimed to explore its influence on postoperative morbidity and mortality in surgical patients.@*METHODS@#An ambispective cohort study was conducted at Xijing Hospital, China. We collected 10-day time-series data from December 29 until January 7 for the 2018-2022 period. The primary outcome was major postoperative complications (Clavien-Dindo class III-V). The association between COVID-19 exposure and postoperative prognosis was explored by comparing consecutive 5-year data at the population level and by comparing patients with and without COVID-19 exposure at the patient level.@*RESULTS@#The entire cohort consisted of 3350 patients (age: 48.5 ± 19.2 years), including 1759 females (52.5%). Overall, 961 (28.7%) underwent emergency surgery, and 553 (16.5%) had COVID-19 exposure (from the 2022 cohort). At the population level, major postoperative complications occurred in 5.9% (42/707), 5.7% (53/935), 5.1% (46/901), 9.4% (11/117), and 22.0% (152/690) patients in the 2018-2022 cohorts, respectively. After adjusting for potential confounding factors, the 2022 cohort (80% patients with COVID-19 history) had a significantly higher postoperative major complication risk than did the 2018 cohort (adjusted risk difference [aRD], 14.9% (95% confidence interval [CI], 11.5-18.4%); adjusted odds ratio [aOR], 8.19 (95% CI, 5.24-12.81)). At the patient level, the incidence of major postoperative complications was significantly greater in patients with (24.6%, 136/553) than that in patients without COVID-19 history (6.0% [168/2797]; aRD, 17.8% [95% CI, 13.6-22.1%]; aOR, 7.89 [95% CI, 5.76-10.83]). Secondary outcomes of postoperative pulmonary complications were consistent with primary findings. These findings were verified through sensitivity analyses using time-series data projections and propensity score matching.@*CONCLUSION@#Based on a single-center observation, patients with recent COVID-19 exposure were likely to have a high incidence of major postoperative complications.@*REGISTRATION@#NCT05677815 at https://clinicaltrials.gov/ .


Asunto(s)
Femenino , Humanos , Adulto , Persona de Mediana Edad , Anciano , Estudios de Cohortes , COVID-19/complicaciones , Pandemias , Estudios Retrospectivos , Complicaciones Posoperatorias/epidemiología
9.
Cell Mol Life Sci ; 79(12): 609, 2022 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-36445537

RESUMEN

The specification, characterization, and fate of alveolar type 1 and type 2 (AT1 and AT2) progenitors during embryonic lung development are poorly defined. Current models of distal epithelial lineage formation fail to capture the heterogeneity and dynamic contribution of progenitor pools present during early development. Furthermore, few studies explore the pathways involved in alveolar progenitor specification and fate. In this paper, we build upon our previously published work on the regulation of airway epithelial progenitors by fibroblast growth factor receptor 2b (FGFR2b) signalling during early (E12.5) and mid (E14.5) pseudoglandular stage lung development. Our results suggest that a significant proportion of AT2 and AT1 progenitors are lineage-flexible during late pseudoglandular stage development, and that lineage commitment is regulated in part by FGFR2b signalling. We have characterized a set of direct FGFR2b targets at E16.5 which are likely involved in alveolar lineage formation. These signature genes converge on a subpopulation of AT2 cells later in development and are downregulated in AT2 cells transitioning to the AT1 lineage during repair after injury in adults. Our findings highlight the extensive heterogeneity of pneumocytes by elucidating the role of FGFR2b signalling in these cells during early airway epithelial lineage formation, as well as during repair after injury.


Asunto(s)
Células Epiteliales Alveolares , Pulmón , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos , Células Madre , Animales , Ratones , Desarrollo Embrionario , Receptor Tipo 2 de Factor de Crecimiento de Fibroblastos/genética , Transducción de Señal , Pulmón/embriología , Linaje de la Célula
10.
J Org Chem ; 87(16): 11204-11217, 2022 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-35930660

RESUMEN

The α-methylene-γ-lactam offers promise as a complementary warhead for the development of targeted covalent inhibitors. However, an understanding of the factors governing its electrophilic reactivity is needed to promote the development of lead compounds utilizing this motif. Herein we synthesize a series of N-aryl-substituted α-methylene-γ-lactams installed within the framework of a bioactive guaianolide analog. To determine the effects of the guaianolide structure on the electrophilic reactivity, these compounds were reacted with glutathione under biomimetic conditions, and the rate constants were measured. A linear free-energy relationship was observed with the Hammett parameter of the N-aryl group within the cis- or trans-annulated isomeric series of compounds. However, the trans-annulated compounds exhibited a ca. 10-fold increase in reactivity relative to both the cis-annulated compounds and the corresponding N-arylated 3-methylene-2-pyrrolidinones. Density functional theory calculations revealed that the reactivity of the trans-annulated stereoisomers is promoted by the partial release of the ring strain of the fused seven-membered ring in the thio-Michael addition transition state.


Asunto(s)
Lactamas , Compuestos de Sulfhidrilo , Glutatión , Lactamas/química , Estructura Molecular , Estereoisomerismo , Compuestos de Sulfhidrilo/química
11.
Mol Med ; 28(1): 73, 2022 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-35764933

RESUMEN

BACKGROUND: Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), are devastating clinical disorders with high mortality, and for which more effective therapies are urgently needed. FGF1, the prototype member of the FGF family, is shown to exert protective effects against injurious stimuli in multiple disease models. Here we aimed to evaluate whether FGF1 pretreatment is protective against LPS-induced ALI and elucidate the potential underlying mechanisms. METHODS: For drug-treated groups, C57B/6 mice received a single i.p. injection of FGF1 (1 mg/kg) 1 h before the LPS challenge or not. To induce the ALI model, the mice were treated by intratracheal instillation of LPS (5 mg/kg). Then, histopathological changes in lung tissues were assessed by hematoxylin and eosin staining and transmission electron microscopy. ELISA and qPCR assays were used to detect pro-inflammatory cytokine levels in BALF and lung tissues, respectively. The total number of inflammatory cells (neutrophils and macrophages) in BALF were counted using the Wright-Giemsa method. The expressions of reactive oxygen species (ROS) and malondialdehyde (MDA) were measured using their respective kits. Western blot and immunostaining were used to evaluate the expressions of antioxidants (Nrf-2, HO-1, SOD2, GPX4, and Catalase), as well as the inflammatory and/or apoptosis-related factors (TLR4, NF-κB, and Cleaved- caspase 3). RESULTS: FGF1 pretreatment significantly ameliorated the LPS-induced histopathological changes, reduced lung wet/dry ratios, ROS and MDA levels, total BALF protein, inflammatory cell infiltration, proinflammatory cytokine levels, and significantly increased the expression of antioxidant proteins (Nrf-2, HO-1, Catalase, and SOD2). In addition, FGF1 pretreatment significantly reduced the expression of TLR4 and cleaved- caspase 3, inhibited NF-κB activation, and reduced LPS-induced cell apoptosis. CONCLUSIONS: Altogether, our results suggest that FGF1 pretreatment is protective against LPS-induced ALI through mediating anti-inflammatory and antioxidant effects, which may be attributed to the downregulation of TLR4 expression and inhibition of NF-κB activation, as well as promotion of antioxidant defenses. Therefore, FGF1 administration may prove beneficial in preventative strategies for ALI/ARDS.


Asunto(s)
Lesión Pulmonar Aguda , Factor 1 de Crecimiento de Fibroblastos/farmacología , Síndrome de Dificultad Respiratoria , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/tratamiento farmacológico , Lesión Pulmonar Aguda/metabolismo , Animales , Antioxidantes/metabolismo , Antioxidantes/farmacología , Caspasa 3/metabolismo , Catalasa/metabolismo , Catalasa/uso terapéutico , Citocinas/metabolismo , Factor 1 de Crecimiento de Fibroblastos/metabolismo , Inflamación/tratamiento farmacológico , Inflamación/patología , Lipopolisacáridos/efectos adversos , Ratones , FN-kappa B/metabolismo , Estrés Oxidativo , Especies Reactivas de Oxígeno , Receptor Toll-Like 4/metabolismo
13.
Front Pharmacol ; 13: 1019755, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36618911

RESUMEN

Introduction: Damage to alveolar epithelial cells caused by uncontrolled inflammation is considered to be the main pathophysiological change in acute lung injury. FGF10 plays an important role as a fibroblast growth factor in lung development and lung diseases, but its protective effect against acute lung injury is unclear. Therefore, this study aimed to investigate protective effect and mechanism of FGF10 on acute lung injury in mice. Methods: ALI was induced by intratracheal injection of LPS into 57BL/6J mice. Six hours later, lung bronchoalveolar lavage fluid (BALF) was acquired to analyse cells, protein and the determination of pro-inflammatory factor levels, and lung issues were collected for histologic examination and wet/dry (W/D) weight ratio analysis and blot analysis of protein expression. Results: We found that FGF10 can prevent the release of IL-6, TNF-α, and IL-1ß, increase the expression of BMP4 and autophagy pathway, promote the regeneration of alveolar epithelial type Ⅱ cells, and improve acute lung injury. BMP4 gene knockdown decreased the protective effect of FGF10 on the lung tissue of mice. However, the activation of autophagy was reduced after BMP4 inhibition by Noggin. Additionally, the inhibition of autophagy by 3-MA also lowered the protective effect of FGF10 on alveolar epithelial cells induced by LPS. Conclusions: These data suggest that the protective effect of FGF10 is related to the activation of autophagy and regeneration of alveolar epithelial cells in an LPS-induced ALI model, and that the activation of autophagy may depend on the increase in BMP4 expression.

14.
Front Cell Dev Biol ; 9: 671841, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34055804

RESUMEN

Fgf10 is a key gene during development, homeostasis and repair after injury. We previously reported a knock-in Fgf10 Cre-ERT2 line (with the Cre-ERT2 cassette inserted in frame with the start codon of exon 1), called thereafter Fgf10 Ki-v1, to target FGF10Pos cells. While this line allowed fairly efficient and specific labeling of FGF10Pos cells during the embryonic stage, it failed to target these cells after birth, particularly in the postnatal lung, which has been the focus of our research. We report here the generation and validation of a new knock-in Fgf10 Cre-ERT2 line (called thereafter Fgf10 Ki-v2) with the insertion of the expression cassette in frame with the stop codon of exon 3. Fgf10 Ki-v2/+ heterozygous mice exhibited comparable Fgf10 expression levels to wild type animals. However, a mismatch between Fgf10 and Cre expression levels was observed in Fgf10 Ki-v2/+ lungs. In addition, lung and limb agenesis were observed in homozygous embryos suggesting a loss of Fgf10 functional allele in Fgf10 Ki-v2 mice. Bioinformatic analysis shows that the 3'UTR, where the Cre-ERT2 cassette is inserted, contains numerous putative transcription factor binding sites. By crossing this line with tdTomato reporter line, we demonstrated that tdTomato expression faithfully recapitulated Fgf10 expression during development. Importantly, Fgf10 Ki-v2 mouse is capable of significantly targeting FGF10Pos cells in the adult lung. Therefore, despite the aforementioned limitations, this new Fgf10 Ki-v2 line opens the way for future mechanistic experiments involving the postnatal lung.

15.
Exp Ther Med ; 21(5): 466, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33763153

RESUMEN

Obese asthma is a phenotype of asthma whose occurrence is gradually increasing in both adults and children. The majority of studies have demonstrated that obesity is a major risk factor for asthma and the effect of obesity on the lungs is considerable. NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome has been previously demonstrated to serve a role in obese asthma mediated by mitochondrial reactive oxygen species (mtROS). The aim of the present in vitro study was to investigate the effect of leptin on airway epithelial cells and the protective effect of the mitochondrial-targeted antioxidant mitoquinone (mitoQ). Human normal bronchial epithelial cell lines BEAS-2 cells were used and divided into 6 groups: Control group (negative control), DMSO group (solvent control), lipopolysaccharide (LPS) group (positive control), LPS + mitoQ group, Leptin group and Leptin + mitoQ group. CCK8 assay was used to establish the optimal concentration and incubation time of the drugs. mitoTracker probe and mitoSOX reagent were used to detect the integrity of mitochondrial membranes and the content of mtROS. mRNA expression levels were detected by reverse transcription-quantitative PCR analysis. It was revealed that the mitochondrial membrane was disrupted in the Leptin group, which recovered after treatment with mitoQ. As a result, the production of mitochondrial reactive oxygen species (mtROS) in the Leptin group was significantly increased (P<0.01), but following treatment with mitoQ, this overproduction of mtROS was significantly decreased to normal levels (P<0.01). Furthermore, the expression levels of NOD-, LRR- and pyrin domain-containing protein 3 NLRP3 and caspase-1 mRNA in the leptin-pretreated BEAS-2 cells were significantly increased compared with those in the control group (P<0.01), while they were decreased following mitoQ treatment (P<0.01). Taken together, these data suggested that leptin may promote airway inflammation partially through upregulating the mtROS-NLRP3 inflammasome signaling pathway in airway epithelial cells and mitoQ may be a potential treatment for obese asthma.

16.
Proc Natl Acad Sci U S A ; 118(14)2021 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-33782126

RESUMEN

microRNA-218 (miR-218) has been linked to several cognition related neurodegenerative and neuropsychiatric disorders. However, whether miR-218 plays a direct role in cognitive functions remains unknown. Here, using the miR-218 knockout (KO) mouse model and the sponge/overexpression approaches, we showed that miR-218-2 but not miR-218-1 could bidirectionally regulate the contextual and spatial memory in the mice. Furthermore, miR-218-2 deficiency induced deficits in the morphology and presynaptic neurotransmitter release in the hippocampus to impair the long term potentiation. Combining the RNA sequencing analysis and luciferase reporter assay, we identified complement component 3 (C3) as a main target gene of miR-218 in the hippocampus to regulate the presynaptic functions. Finally, we showed that restoring the C3 activity in the miR-218-2 KO mice could rescue the synaptic and learning deficits. Therefore, miR-218-2 played an important role in the cognitive functions of mice through C3, which can be a mechanism for the defective cognition of miR-218 related neuronal disorders.


Asunto(s)
Complemento C3/genética , Hipocampo/metabolismo , Potenciación a Largo Plazo , MicroARNs/metabolismo , Vesículas Sinápticas/metabolismo , Regiones no Traducidas 3' , Animales , Células Cultivadas , Complemento C3/metabolismo , Exocitosis , Hipocampo/citología , Hipocampo/fisiología , Ratones , Ratones Endogámicos C57BL , MicroARNs/genética , Neuronas/metabolismo , Neuronas/fisiología
17.
Cell Rep ; 34(11): 108842, 2021 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-33730593

RESUMEN

Synaptic vesicle (SV) docking is a dynamic multi-stage process that is required for efficient neurotransmitter release in response to nerve impulses. Although the steady-state SV docking likely involves the cooperation of Synaptotagmin-1 (Syt1) and soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), where and how the docking process initiates remains unknown. Phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) can interact with Syt1 and SNAREs to contribute to vesicle exocytosis. In the present study, using the CRISPRi-mediated multiplex gene knockdown and 3D electron tomography approaches, we show that in mouse hippocampal synapses, SV docking initiates at ∼12 nm to the active zone (AZ) by Syt1. Furthermore, we demonstrate that PI(4,5)P2 is the membrane partner of Syt1 to initiate SV docking, and disrupting their interaction could abolish the docking initiation. In contrast, the SNARE complex contributes only to the tight SV docking within 0-2 nm. Therefore, Syt1 interacts with PI(4,5)P2 to loosely dock SVs within 2-12 nm to the AZ in hippocampal neurons.


Asunto(s)
Hipocampo/citología , Neuronas/metabolismo , Fosfatidilinositol 4,5-Difosfato/metabolismo , Vesículas Sinápticas/metabolismo , Sinaptotagmina I/metabolismo , Animales , Células HEK293 , Humanos , Ratones Endogámicos C57BL , Neuronas/ultraestructura , Unión Proteica , Proteínas SNARE/metabolismo , Vesículas Sinápticas/ultraestructura , Proteína 25 Asociada a Sinaptosomas/metabolismo , Sintaxina 1/metabolismo , Proteína 2 de Membrana Asociada a Vesículas/metabolismo
18.
Angew Chem Int Ed Engl ; 60(19): 10690-10699, 2021 05 03.
Artículo en Inglés | MEDLINE | ID: mdl-33596335

RESUMEN

Cooperative bimetallic catalysis is a fundamental approach in modern synthetic chemistry. We report bimetallic cooperative catalysis for the direct decarbonylative heteroarylation of ubiquitous carboxylic acids via acyl C-O/C-H coupling. This novel catalytic system exploits the cooperative action of a copper catalyst and a palladium catalyst in decarbonylation, which enables highly chemoselective synthesis of important heterobiaryl motifs through the coupling of carboxylic acids with heteroarenes in the absence of prefunctionalization or directing groups. This cooperative decarbonylative method uses common carboxylic acids and shows a remarkably broad substrate scope (>70 examples), including late-stage modification of pharmaceuticals and streamlined synthesis of bioactive agents. Extensive mechanistic and computational studies were conducted to gain insight into the mechanism of the reaction. The key step involves intersection of the two catalytic cycles via transmetallation of the copper-aryl species with the palladium(II) intermediate generated by oxidative addition/decarbonylation.


Asunto(s)
Ácidos Carboxílicos/química , Complejos de Coordinación/química , Compuestos Heterocíclicos/síntesis química , Paladio/química , Catálisis , Compuestos Heterocíclicos/química , Estructura Molecular
19.
J Thorac Dis ; 12(10): 6030-6038, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33209436

RESUMEN

BACKGROUND: To evaluate the efficacy of atrial fibrillation radiofrequency ablation (AFRA) in patients with chronic valvular atrial fibrillation (AF) with different left atrial sizes [left atrial diameter (LAD) >45 or ≤45 mm]. METHODS: Between May 2016 and January 2019, 264 patients who underwent cardiac operations with modified bipolar AFRA in the Department of Cardiovascular Surgery, PLA General Hospital, were enrolled. The clinical data of the patients were analysed, and inclusion and exclusion criteria were implemented. A propensity score was given for two groups of different left atrial sizes: group A (75 patients with LAD >45 mm) and group B (75 patients with LAD ≤45 mm). Preoperative general data, operative indicators, postoperative mortality, complications, and sinus rhythm recovery were analysed and compared between the two groups. RESULTS: The rates of sinus rhythm recovery in group A (LAD >45 mm) at 1 week, 6 months, 1 year, and 2 years after surgery were 84.0%, 81.33%, 73.33%, and 69.33%, respectively, compared with 90.67.0%, 88.00%, 86.67%, and 84.00% at 1 week, 6 months, 1 year, and 2 years after surgery, respectively, in group B (LAD ≤45 mm). The difference between the two groups was statistically significant at the two points in time of 1 year, and 2 years (P<0.05). Warfarin anticoagulation, the standard therapy, was applied after surgery. No new cerebrovascular events occurred in either group during short- and medium-term postoperative follow-up. CONCLUSIONS: Mitral valve surgery using improved Cox-Maze IV bipolar radiofrequency ablation was effective in treating chronic long-term persistent valvular AF and had an excellent sinus rhythm recovery rate. However, the larger the LAD, the less likely a patient was to maintain sinus rhythm as time passed after surgery.

20.
Proc Natl Acad Sci U S A ; 117(49): 31438-31447, 2020 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-33229564

RESUMEN

Synaptotagmin-7 (Syt7) probably plays an important role in bipolar-like behavioral abnormalities in mice; however, the underlying mechanisms for this have remained elusive. Unlike antidepressants that cause mood overcorrection in bipolar depression, N-methyl-d-aspartate receptor (NMDAR)-targeted drugs show moderate clinical efficacy, for unexplained reasons. Here we identified Syt7 single nucleotide polymorphisms (SNPs) in patients with bipolar disorder and demonstrated that mice lacking Syt7 or expressing the SNPs showed GluN2B-NMDAR dysfunction, leading to antidepressant behavioral consequences and avoidance of overcorrection by NMDAR antagonists. In human induced pluripotent stem cell (iPSC)-derived and mouse hippocampal neurons, Syt7 and GluN2B-NMDARs were localized to the peripheral synaptic region, and Syt7 triggered multiple forms of glutamate release to efficiently activate the juxtaposed GluN2B-NMDARs. Thus, while Syt7 deficiency and SNPs induced GluN2B-NMDAR dysfunction in mice, patient iPSC-derived neurons showed Syt7 deficit-induced GluN2B-NMDAR hypoactivity that was rescued by Syt7 overexpression. Therefore, Syt7 deficits induced mania-like behaviors in mice by attenuating GluN2B activity, which enabled NMDAR antagonists to avoid mood overcorrection.


Asunto(s)
Conducta Animal , Manía/patología , Receptores de N-Metil-D-Aspartato/metabolismo , Sinaptotagminas/deficiencia , Adulto , Anciano , Animales , Trastorno Bipolar/genética , Trastorno Bipolar/patología , Exocitosis , Femenino , Ácido Glutámico/metabolismo , Hipocampo/patología , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Masculino , Manía/fisiopatología , Ratones Noqueados , Persona de Mediana Edad , Neuronas/metabolismo , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Vesículas Sinápticas/metabolismo , Sinaptotagminas/genética , Sinaptotagminas/metabolismo , Adulto Joven
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