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1.
Chemistry ; : e202401243, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38711202

RESUMEN

Axially chiral cycloalkylidenes are interesting but less developedaxially chiral molecules. Here, a bispidine-based chiral amine catalytic system was developed to promote efficiently the asymmetric Knoevenagel condensation ofN-protected oxindoles and benzofuranones with 4-substituted cyclohexanones. A variety of alkylidenecycloalkanes with stable axial chirality were obtained in good yields with high er. Based on the absolute configuration determination of product and DFT calculations, a possible mechanism of stereoselective induction was proposed.

2.
Artículo en Inglés | MEDLINE | ID: mdl-38602827

RESUMEN

OBJECTIVES: Individuals often automatically have more empathy for same-race members. However, there are no studies on racial bias in empathy (RBE) among Tibetan school-aged children. The present study aimed to examine the development of RBEs, including racial bias in cognitive empathy, affective empathy, and behavioral empathy, in Tibetan school-aged children. METHOD: In Experiment 1 (N = 108, aged 7-12), ethnic identity was primed using Tibetan and Han names. Then negative and neutral events were applied to measure the RBEs of Tibetan children. In Experiment 2 (N = 148, aged 7-12), negative events were replaced by pain events. In Experiment 3 (N = 60, aged 7-12), Tibetan children's ethnic identity and the awareness of the wrongfulness of ethnic intergroup bias were added to examine the underlying mechanism. RESULT: Results found that RBEs increased among Tibetan children aged 7-10 and decreased among those aged 11-12, Moreover, we analyzed age as a continuous variable and found that 10 years old was the inflection point in the development of RBEs in Tibetan children. Importantly, children aged 11-12 years old realized more wrongfulness of ethnic intergroup bias than children aged 7-10. The ethnic identity of Tibetan children aged 7-10 mediated the relation between age group and RBEs. And the wrongfulness of ethnic intergroup bias mediated the link between age group and RBEs in Tibetan children aged 9-12. CONCLUSION: Our study sheds light on the development of RBEs in Tibetan school-aged children and highlights the importance of identifying the appropriate timing for intervening in prejudice. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

3.
Front Pharmacol ; 15: 1337749, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38666026

RESUMEN

(R, S)- and (S)-ketamine have made significant progress in the treatment of treatment-resistant depression (TRD) and have become a research focus in recent years. However, they both have risks of psychomimetic effects, dissociative effects, and abuse liability, which limit their clinical use. Recent preclinical and clinical studies have shown that (R)-ketamine has a more efficient and lasting antidepressant effect with fewer side effects compared to (R, S)- and (S)-ketamine. However, a recent small-sample randomized controlled trial found that although (R)-ketamine has a lower incidence of adverse reactions in adult TRD treatment, its antidepressant efficacy is not superior to the placebo group, indicating its antidepressant advantage still needs further verification and clarification. Moreover, an increasing body of research suggests that (R)-ketamine might also have significant applications in the prevention and treatment of medical fields or diseases such as cognitive disorders, perioperative anesthesia, ischemic stroke, Parkinson's disease, multiple sclerosis, osteoporosis, substance use disorders, inflammatory diseases, COVID-19, and organophosphate poisoning. This article briefly reviews the mechanism of action and research on antidepressants related to (R)-ketamine, fully revealing its application potential and development prospects, and providing some references and assistance for subsequent expanded research.

4.
Circulation ; 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38686562

RESUMEN

BACKGROUND: Myocardial mitochondrial dysfunction underpins the pathogenesis of heart failure (HF), yet therapeutic options to restore myocardial mitochondrial function are scarce. Epigenetic modifications of mitochondrial DNA (mtDNA), such as methylation, play a pivotal role in modulating mitochondrial homeostasis. However, their involvement in HF remains unclear. METHODS: Experimental HF models were established through continuous angiotensin II and phenylephrine (AngII/PE) infusion or prolonged myocardial ischemia/reperfusion injury. The landscape of N6-methyladenine (6mA) methylation within failing cardiomyocyte mtDNA was characterized using high-resolution mass spectrometry and methylated DNA immunoprecipitation sequencing. A tamoxifen-inducible cardiomyocyte-specific Mettl4 knockout mouse model and adeno-associated virus vectors designed for cardiomyocyte-targeted manipulation of METTL4 (methyltransferase-like protein 4) expression were used to ascertain the role of mtDNA 6mA and its methyltransferase METTL4 in HF. RESULTS: METTL4 was predominantly localized within adult cardiomyocyte mitochondria. 6mA modifications were significantly more abundant in mtDNA than in nuclear DNA. Postnatal cardiomyocyte maturation presented with a reduction in 6mA levels within mtDNA, coinciding with a decrease in METTL4 expression. However, an increase in both mtDNA 6mA level and METTL4 expression was observed in failing adult cardiomyocytes, suggesting a shift toward a neonatal-like state. METTL4 preferentially targeted mtDNA promoter regions, which resulted in interference with transcription initiation complex assembly, mtDNA transcriptional stalling, and ultimately mitochondrial dysfunction. Amplifying cardiomyocyte mtDNA 6mA through METTL4 overexpression led to spontaneous mitochondrial dysfunction and HF phenotypes. The transcription factor p53 was identified as a direct regulator of METTL4 transcription in response to HF-provoking stress, thereby revealing a stress-responsive mechanism that controls METTL4 expression and mtDNA 6mA. Cardiomyocyte-specific deletion of the Mettl4 gene eliminated mtDNA 6mA excess, preserved mitochondrial function, and mitigated the development of HF upon continuous infusion of AngII/PE. In addition, specific silencing of METTL4 in cardiomyocytes restored mitochondrial function and offered therapeutic relief in mice with preexisting HF, irrespective of whether the condition was induced by AngII/PE infusion or myocardial ischemia/reperfusion injury. CONCLUSIONS: Our findings identify a pivotal role of cardiomyocyte mtDNA 6mA and the corresponding methyltransferase, METTL4, in the pathogenesis of mitochondrial dysfunction and HF. Targeted suppression of METTL4 to rectify mtDNA 6mA excess emerges as a promising strategy for developing mitochondria-focused HF interventions.

5.
ACS Nano ; 18(17): 11474-11486, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38632861

RESUMEN

Cobalt-nitrogen-carbon (Co-N-C) catalysts with a CoN4 structure exhibit great potential for oxygen reduction reaction (ORR), but the imperfect adsorption energy toward oxygen species greatly limits their reduction efficiency and practical application potential. Here, F-coordinated Co-N-C catalysts with square-pyramidal CoN4-F1 configuration are successfully synthesized using F atoms to regulate the axial coordination of Co centers via hydrothermal and chemical vapor deposition methods. During the synthesis process, the geometry structure of the Co atom converts from six-coordinated Co-F6 to square-pyramidal CoN4-F1 in the coordinatively unsaturated state, which provides an open binding site for the O2. The introduction of axial F atoms into the CoN4 plane alters the local atomic environment around Co, significantly improving the ORR activity and Zn-air batteries performance. In situ spectroscopy proves that CoN4-F1 sites strongly combine with the OOH* intermediate and facilitate the splitting of O-O bond, making OOH* readily decompose into O* and OH* via a dissociative pathway. Theoretical calculations confirm that the axial F atom effectively reduces the electronic density of the Co centers and facilitates the desorption of the OH* intermediate, efficiently accelerating the overall ORR kinetics. This work advances a feasible synthesis mechanism of axial ligands and provides a route to construct efficient high-coordination catalysts.

6.
Microbiol Spectr ; 12(3): e0240223, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38299864

RESUMEN

Infectious bronchitis virus (IBV), the causative agent of infectious bronchitis, is responsible for major economic losses in the poultry industry worldwide. While IBVs can usually be passaged in primary chicken embryonic fibroblasts (CEFs), most of the wild ones cannot adapt to passaged cell lines. In this study, the wild strain CK/CH/MY/2020 was used to infect primary CEF and immortalize DF-1 CEF cells. Results indicated that IBV was able to cause lesions and pass onto CEF, but not DF-1. Indeed, the virus could enter DF-1 cells and synthesize the associated structural gene but could not assemble into complete viral particles for release. Furthermore, transcriptome sequencing analysis showed significant differences in gene expression between CEF and DF-1 cells after viral infection, although the corresponding antiviral responses could be activated in both cell types. The biggest difference was in terms of the amino acid biosynthesis pathway and the cytokine receptor interaction pathway, which were significantly and specifically activated in CEF. This could actually explain why intact viruses can be assembled but not in DF-1. In addition, SLBP and P2RX7 affect the replication of IBV's structural genes to some extent. Overall, IBV can enter CEF and DF-1 cells, but the complex intracellular cytokine interactions affect the assembly and release of viral particles. The insight will be useful for the study of IBV through in vitro transmission and pathogenesis. IMPORTANCE: Infectious bronchitis virus (IBV) is responsible for high morbidity and mortality as well as substantial economic losses worldwide. Transcriptome sequencing of IBV-infected chicken embryonic fibroblast and DF-1 cells revealed that the virus elicits antiviral immunity in cells after viral infection, but IBV cannot activate DF-1 cells to produce sufficient amounts of viral structures to assemble into complete virions, which may be caused by the interactions between cytokines. The study of IBV cellular adaptations is important for vaccine development and investigation of the pathogenesis of IBV.


Asunto(s)
Infecciones por Coronavirus , Virus de la Bronquitis Infecciosa , Enfermedades de las Aves de Corral , Virosis , Embrión de Pollo , Animales , Pollos , Virus de la Bronquitis Infecciosa/genética , Infecciones por Coronavirus/veterinaria , Citocinas/metabolismo , Fibroblastos/metabolismo
7.
Small ; : e2400564, 2024 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-38368264

RESUMEN

Developing efficient metal-free catalysts to directly synthesize hydrogen peroxide (H2 O2 ) through a 2-electron (2e) oxygen reduction reaction (ORR) is crucial for substituting the traditional energy-intensive anthraquinone process. Here, in-plane topological defects enriched graphene with pentagon-S and pyrrolic-N coordination (SNC) is synthesized via the process of hydrothermal and nitridation. In SNC, pentagon-S and pyrrolic-N originating from thiourea precursor are covalently grafted onto the basal plane of the graphene framework, building unsymmetrical dumbbell-like S─C─N motifs, which effectively modulates atomic and electronic structures of graphene. The SNC catalyst delivers ultrahigh H2 O2 productivity of 8.1, 7.3, and 3.9 mol gcatalyst -1  h-1 in alkaline, neutral, and acidic electrolytes, respectively, together with long-term operational stability in pH-universal electrolytes, outperforming most reported carbon catalysts. Theoretical calculations further unveil that defective S─C─N motifs efficiently optimize the binding strength to OOH* intermediate and substantially diminish the kinetic barrier for reducing O2 to H2 O2 , thereby promoting the intrinsic activity of 2e-ORR.

8.
Nat Commun ; 15(1): 396, 2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38195602

RESUMEN

Primary open-angle glaucoma (POAG), characterized by retinal ganglion cell death, is a leading cause of irreversible blindness worldwide. However, its molecular and cellular causes are not well understood. Elevated intraocular pressure (IOP) is a major risk factor, but many patients have normal IOP. Colocalization and Mendelian randomization analysis of >240 POAG and IOP genome-wide association study (GWAS) loci and overlapping expression and splicing quantitative trait loci (e/sQTLs) in 49 GTEx tissues and retina prioritizes causal genes for 60% of loci. These genes are enriched in pathways implicated in extracellular matrix organization, cell adhesion, and vascular development. Analysis of single-nucleus RNA-seq of glaucoma-relevant eye tissues reveals that the POAG and IOP colocalizing genes and genome-wide associations are enriched in specific cell types in the aqueous outflow pathways, retina, optic nerve head, peripapillary sclera, and choroid. This study nominates IOP-dependent and independent regulatory mechanisms, genes, and cell types that may contribute to POAG pathogenesis.


Asunto(s)
Glaucoma de Ángulo Abierto , Glaucoma , Humanos , Estudio de Asociación del Genoma Completo , Glaucoma de Ángulo Abierto/genética , Regulación de la Expresión Génica , Causalidad , Glaucoma/genética
9.
Talanta ; 271: 125719, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38281429

RESUMEN

The design of surface ligands is crucial for ligand-protected gold nanoparticles (AuNPs). Herein, following the principle of green synthesis, environmentally friendly gold nanoparticles (AuNPs@His@CC, AuHC) were fabricated based on dual ligands of histidine and carboxylated chitosan. AuHC showed the advantages of low toxicity, good photoluminescent stability and ideal biocompatibility. Compared with single histidine-coated gold nanoclusters (AuNCs@His, AuH), AuHC presented enhanced fluorescence attributed to the addition of chitosan. The blue-emitting AuHC has a unique response to Fe3+ with detection limits as low as 9.51 nM. Interestingly, the quenched fluorescence of AuHC-Fe3+ system could be restored through the introduction of PPi with a detection limit of 10.6 µM. So an "on-off-on" fluorescence sensing platform was achieved. Apart from good optical properties and sensing, the designed AuHC demonstrated outstanding photothermal conversion efficiency (27.8 %), which made it ideal material for thermal ablation of tumor. To be specific, after laser irradiation (660 nm, 0.78 W cm-2, 10 min) of AuHC, the survival rate of HeLa cells as a tumor cell model decreased to 12.7 %, indicating that AuHC has a significant tumor inhibition effect in vitro. Besides, AuHC also could be a befitting candidate for overcoming drug-resistant tumor cells such as MCF-7/ADR cells. Notably, AuHC can markedly ablate solid tumors in 4T1 tumor-bearing mice after laser irradiation (660 nm, 0.78 W cm-2, 10 min). Hence this work provides insight into the design of multifunctional AuNPs platform for simultaneously integrating the ion sensing and photothermal therapy of cancer.


Asunto(s)
Quitosano , Nanopartículas del Metal , Humanos , Animales , Ratones , Terapia Fototérmica , Oro , Fluorescencia , Células HeLa , Histidina
10.
J Mol Cell Cardiol ; 188: 1-14, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38246086

RESUMEN

Stem cells represent an attractive resource for cardiac regeneration. However, the survival and function of transplanted stem cells is poor and remains a major challenge for the development of effective therapies. As two main cell types currently under investigation in heart repair, mesenchymal stromal cells (MSCs) indirectly support endogenous regenerative capacities after transplantation, while induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) functionally integrate into the damaged myocardium and directly contribute to the restoration of its pump function. These two cell types are exposed to a common microenvironment with many stressors in ischemic heart tissue. This review summarizes the research progress on the mechanisms and challenges of MSCs and iPSC-CMs in post-MI heart repair, introduces several randomized clinical trials with 3D-mapping-guided cell therapy, and outlines recent findings related to the factors that affect the survival and function of stem cells. We also discuss the future directions for optimization such as biomaterial utilization, cell combinations, and intravenous injection of engineered nucleus-free MSCs.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Células Madre Pluripotentes Inducidas , Infarto del Miocardio , Humanos , Infarto del Miocardio/terapia , Trasplante de Células Madre , Miocitos Cardíacos
11.
Small Methods ; : e2301434, 2024 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-38237086

RESUMEN

Designing a multifunctional electrocatalyst to produce H2 from water, urea, urine, and wastewater, is highly desirable yet challenging because it demands precise Fermi-engineering to realize stronger π-donation from O 2p to electron(e- )-deficient metal (t2g ) d-orbitals. Here a Sr-induced phase transformed ß-FeOOH/α-Ni(OH)2 catalyst anchored on Ni-foam (designated as pt-NFS) is introduced, where Sr produces plenteous Fe4+ (Fe3+ → Fe4+ ) to modulate Fermi level and e- -transfer from e- -rich Ni3+ (t2g )-orbitals to e- -deficient Fe4+ (t2g )-orbitals, via strong π-donation from the π-symmetry lone-pair of O bridge. pt-NFS utilizes Fe-sites near the Sr-atom to break the H─O─H bonds and weakens the adsorption of *O while strengthening that of *OOH, toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. Invaluably, Fe-sites of pt-NFS activate H2 -production from urea oxidation reaction (UOR) through a one-stage pathway which, unlike conventional two-stage pathways with two NH3 -molecules, involves only one NH3 -molecule. Owing to more suitable kinetic energetics, pt-NFS requires 133 mV (negative potential shift), 193 mV, ≈1.352 V, and ≈1.375 V versus RHE for HER, OER, UOR, and human urine oxidation, respectively, to reach the benchmark 10 mA cm-2 and also demonstrates remarkable durability of over 25 h. This work opens a new corridor to design multifunctional electrocatalysts with precise Fermi engineering through d-band modulation.

12.
Nature ; 626(7999): 574-582, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38086421

RESUMEN

The intrinsic mechanisms that regulate neurotoxic versus neuroprotective astrocyte phenotypes and their effects on central nervous system degeneration and repair remain poorly understood. Here we show that injured white matter astrocytes differentiate into two distinct C3-positive and C3-negative reactive populations, previously simplified as neurotoxic (A1) and neuroprotective (A2)1,2, which can be further subdivided into unique subpopulations defined by proliferation and differential gene expression signatures. We find the balance of neurotoxic versus neuroprotective astrocytes is regulated by discrete pools of compartmented cyclic adenosine monophosphate derived from soluble adenylyl cyclase and show that proliferating neuroprotective astrocytes inhibit microglial activation and downstream neurotoxic astrocyte differentiation to promote retinal ganglion cell survival. Finally, we report a new, therapeutically tractable viral vector to specifically target optic nerve head astrocytes and show that raising nuclear or depleting cytoplasmic cyclic AMP in reactive astrocytes inhibits deleterious microglial or macrophage cell activation and promotes retinal ganglion cell survival after optic nerve injury. Thus, soluble adenylyl cyclase and compartmented, nuclear- and cytoplasmic-localized cyclic adenosine monophosphate in reactive astrocytes act as a molecular switch for neuroprotective astrocyte reactivity that can be targeted to inhibit microglial activation and neurotoxic astrocyte differentiation to therapeutic effect. These data expand on and define new reactive astrocyte subtypes and represent a step towards the development of gliotherapeutics for the treatment of glaucoma and other optic neuropathies.


Asunto(s)
Astrocitos , Neuroprotección , Adenilil Ciclasas/metabolismo , Astrocitos/citología , Astrocitos/enzimología , Astrocitos/metabolismo , Diferenciación Celular , Núcleo Celular/metabolismo , Supervivencia Celular , AMP Cíclico/metabolismo , Citoplasma/metabolismo , Macrófagos/metabolismo , Macrófagos/patología , Microglía/metabolismo , Microglía/patología , Traumatismos del Nervio Óptico/metabolismo , Traumatismos del Nervio Óptico/patología , Traumatismos del Nervio Óptico/terapia , Células Ganglionares de la Retina/citología , Células Ganglionares de la Retina/metabolismo , Sustancia Blanca/metabolismo , Sustancia Blanca/patología , Glaucoma/patología , Glaucoma/terapia
13.
Macromol Biosci ; 24(2): e2300302, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37815522

RESUMEN

Cardiovascular diseases (CVDs) have become the leading global burden of diseases in recent years and are the primary cause of human mortality and loss of healthy life expectancy. Myocardial infarction (MI) is the top cause of CVDs-related deaths, and its incidence is increasing worldwide every year. Recently, hydrogels have garnered great interest from researchers as a promising therapeutic option for cardiac tissue repair after MI. This is due to their excellent properties, including biocompatibility, mechanical properties, injectable properties, anti-inflammatory properties, antioxidant properties, angiogenic properties, and conductive properties. This review discusses the advantages of hydrogels as a novel treatment for cardiac tissue repair after MI. The design strategies of various hydrogels in MI treatment are then summarized, and the latest research progress in the field is classified. Finally, the future perspectives of this booming field are also discussed at the end of this review.


Asunto(s)
Hidrogeles , Infarto del Miocardio , Humanos , Hidrogeles/uso terapéutico , Infarto del Miocardio/terapia
14.
Adv Sci (Weinh) ; 11(5): e2304120, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38030565

RESUMEN

Designing next-generation molecular devices typically necessitates plentiful oxygen-bearing sites to facilitate multiple-electron transfers. However, the theoretical limits of existing materials for energy conversion and information storage devices make it inevitable to hunt for new competitors. Polyoxometalates (POMs), a unique class of metal-oxide clusters, have been investigated exponentially due to their structural diversity and tunable redox properties. POMs behave as electron-sponges owing to their intrinsic ability of reversible uptake-release of multiple electrons. In this review, numerous POM-frameworks together with desired features of a contender material and inherited properties of POMs are systematically discussed to demonstrate how and why the electron-sponge-like nature of POMs is beneficial to design next-generation water oxidation/reduction electrocatalysts, and neuromorphic nonvolatile resistance-switching random-access memory devices. The aim is to converge the attention of scientists who are working separately on electrocatalysts and memory devices, on a point that, although the application types are different, they all hunt for a material that could exhibit electron-sponge-like feature to realize boosted performances and thus, encouraging the scientists of two completely different fields to explore POMs as imperious contenders to design next-generation nanodevices. Finally, challenges and promising prospects in this research field are also highlighted.

15.
Dig Liver Dis ; 56(4): 663-671, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37813808

RESUMEN

BACKGROUND: Although propofol is widely used for gastrointestinal endoscopic sedation, cardiopulmonary adverse events remain common. Ciprofol is a new intravenous anaesthetic agent demonstrating respiratory and hemodynamic stability. AIMS: This study aimed to clarify the benefits of ciprofol combined with alfentanil in bidirectional endoscopy (esophagogastroduodenoscopy followed by colonoscopy) to reduce adverse events and improve post-endoscopic recovery. METHODS: A total of 185 patients scheduled to undergo bidirectional endoscopy were randomly divided into two groups: ciprofol combined with alfentanil or propofol combined with alfentanil. All patients received 7 µg/kg alfentanil intravenously before the study drugs were administered. The propofol group received a bolus of 1.2 mg/kg (0.12 ml/kg) propofol intravenously, whereas the ciprofol group received a bolus of 0.3 mg/kg (0.12 ml/kg) ciprofol intravenously. The primary outcome was the proportion of patients with cardiopulmonary adverse events (i.e., any one of the airway obstruction, apnoea, hypotension, hypertension, bradycardia, tachycardia or arrhythmias). RESULTS: Compared with propofol, ciprofol reduced cardiopulmonary adverse events by 43.51 % (34.4% vs. 60.9 %, P <0.001), mitigated respiratory adverse events by 54.74 % (17.2% vs. 38.0 %, P = 0.002) overall and by 59.05 % (12.9% vs. 31.5 %, P = 0.002) during the induction period. CONCLUSIONS: Ciprofol can significantly decrease respiratory depression events and provides a better sedative efficacy than propofol with higher recovery quality and satisfaction.


Asunto(s)
Propofol , Humanos , Propofol/efectos adversos , Alfentanilo/efectos adversos , Estudios Prospectivos , Anestésicos Intravenosos/efectos adversos , Endoscopía Gastrointestinal , Método Doble Ciego
16.
Nature ; 624(7991): 415-424, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38092908

RESUMEN

The basic plan of the retina is conserved across vertebrates, yet species differ profoundly in their visual needs1. Retinal cell types may have evolved to accommodate these varied needs, but this has not been systematically studied. Here we generated and integrated single-cell transcriptomic atlases of the retina from 17 species: humans, two non-human primates, four rodents, three ungulates, opossum, ferret, tree shrew, a bird, a reptile, a teleost fish and a lamprey. We found high molecular conservation of the six retinal cell classes (photoreceptors, horizontal cells, bipolar cells, amacrine cells, retinal ganglion cells (RGCs) and Müller glia), with transcriptomic variation across species related to evolutionary distance. Major subclasses were also conserved, whereas variation among cell types within classes or subclasses was more pronounced. However, an integrative analysis revealed that numerous cell types are shared across species, based on conserved gene expression programmes that are likely to trace back to an early ancestral vertebrate. The degree of variation among cell types increased from the outer retina (photoreceptors) to the inner retina (RGCs), suggesting that evolution acts preferentially to shape the retinal output. Finally, we identified rodent orthologues of midget RGCs, which comprise more than 80% of RGCs in the human retina, subserve high-acuity vision, and were previously believed to be restricted to primates2. By contrast, the mouse orthologues have large receptive fields and comprise around 2% of mouse RGCs. Projections of both primate and mouse orthologous types are overrepresented in the thalamus, which supplies the primary visual cortex. We suggest that midget RGCs are not primate innovations, but are descendants of evolutionarily ancient types that decreased in size and increased in number as primates evolved, thereby facilitating high visual acuity and increased cortical processing of visual information.


Asunto(s)
Evolución Biológica , Neuronas , Retina , Vertebrados , Visión Ocular , Animales , Humanos , Neuronas/clasificación , Neuronas/citología , Neuronas/fisiología , Retina/citología , Retina/fisiología , Células Ganglionares de la Retina/clasificación , Análisis de Expresión Génica de una Sola Célula , Vertebrados/fisiología , Visión Ocular/fisiología , Especificidad de la Especie , Células Amacrinas/clasificación , Células Fotorreceptoras/clasificación , Células Ependimogliales/clasificación , Células Bipolares de la Retina/clasificación , Percepción Visual
17.
Res Sq ; 2023 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-38014002

RESUMEN

Single-cell sequencing has revolutionized the scale and resolution of molecular profiling of tissues and organs. Here, we present an integrated multimodal reference atlas of the most accessible portion of the mammalian central nervous system, the retina. We compiled around 2.4 million cells from 55 donors, including 1.4 million unpublished data points, to create a comprehensive human retina cell atlas (HRCA) of transcriptome and chromatin accessibility, unveiling over 110 types. Engaging the retina community, we annotated each cluster, refined the Cell Ontology for the retina, identified distinct marker genes, and characterized cis-regulatory elements and gene regulatory networks (GRNs) for these cell types. Our analysis uncovered intriguing differences in transcriptome, chromatin, and GRNs across cell types. In addition, we modeled changes in gene expression and chromatin openness across gender and age. This integrated atlas also enabled the fine-mapping of GWAS and eQTL variants. Accessible through interactive browsers, this multimodal cross-donor and cross-lab HRCA, can facilitate a better understanding of retinal function and pathology.

18.
bioRxiv ; 2023 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-38014168

RESUMEN

The limited regenerative potential of the optic nerve in adult mammals presents a major challenge for restoring vision after optic nerve trauma or disease. The mechanisms of this regenerative failure are not fully understood1,2. Here, through small-molecule and genetic screening for epigenetic modulators3, we identify DNA methyltransferase 3a (DNMT3a) as a potent inhibitor of axon regeneration in mouse and human retinal explants. Selective suppression of DNMT3a in retinal ganglion cells (RGCs) by gene targeting or delivery of shRNA leads to robust, full-length regeneration of RGC axons through the optic nerve and restoration of vision in adult mice after nerve crush injury. Genome-wide bisulfite and transcriptome profiling in combination with single nucleus RNA-sequencing of RGCs revealed selective DNA demethylation and reactivation of genetic programs supporting neuronal survival and axonal growth/regeneration by DNMT3a deficiency. This was accompanied by the suppression of gene networks associated with apoptosis and inflammation. Our results identify DNMT3a as the central orchestrator of an RGC-intrinsic mechanism that limits optic nerve regeneration. Suppressing DNMT3a expression in RGCs unlocks the epigenetic switch for optic nerve regeneration and presents a promising therapeutic avenue for effectively reversing vision loss resulted from optic nerve trauma or diseases.

19.
J Neurosci ; 43(48): 8231-8242, 2023 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-37751999

RESUMEN

Dopamine is a key neurotransmitter in the signaling cascade controlling ocular refractive development, but the exact role and site of action of dopamine D1 receptors (D1Rs) involved in myopia remains unclear. Here, we determine whether retinal D1Rs exclusively mediate the effects of endogenous dopamine and systemically delivered D1R agonist or antagonist in the mouse form deprivation myopia (FDM) model. Male C57BL/6 mice subjected to unilateral FDM or unobstructed vision were divided into the following four groups: one noninjected and three groups that received intraperitoneal injections of a vehicle, D1R agonist SKF38393 (18 and 59 nmol/g), or D1R antagonist SCH39166 (0.1 and 1 nmol/g). The effects of these drugs on FDM were further assessed in Drd1-knock-out (Drd1-KO), retina-specific conditional Drd1-KO (Drd1-CKO) mice, and corresponding wild-type littermates. In the visually unobstructed group, neither SKF38393 nor SCH39166 affected normal refractive development, whereas myopia development was attenuated by SKF38393 and enhanced by SCH39166 injections. In Drd1-KO or Drd1-CKO mice, however, these drugs had no effect on FDM development, suggesting that activation of retinal D1Rs is pertinent to myopia suppression by the D1R agonist. Interestingly, the development of myopia was unchanged by either Drd1-KO or Drd1-CKO, and neither SKF38393 nor SCH39166 injections, nor Drd1-KO, affected the retinal or vitreal dopamine and the dopamine metabolite DOPAC levels. Effects on axial length were less marked than effects on refraction. Therefore, activation of D1Rs, specifically retinal D1Rs, inhibits myopia development in mice. These results also suggest that multiple dopamine D1R mechanisms play roles in emmetropization and myopia development.SIGNIFICANCE STATEMENT While dopamine is recognized as a "stop" signal that inhibits myopia development (myopization), the location of the dopamine D1 receptors (D1Rs) that mediate this action remains to be addressed. Answers to this key question are critical for understanding how dopaminergic systems regulate ocular growth and refraction. We report here the results of our study showing that D1Rs are essential for controlling ocular growth and myopia development in mice, and for identifying the retina as the site of action for dopaminergic control via D1Rs. These findings highlight the importance of intrinsic retinal dopaminergic mechanisms for the regulation of ocular growth and suggest specific avenues for exploring the retinal mechanisms involved in the dopaminergic control of emmetropization and myopization.


Asunto(s)
Dopamina , Miopía , Masculino , Ratones , Animales , Dopamina/metabolismo , 2,3,4,5-Tetrahidro-7,8-dihidroxi-1-fenil-1H-3-benzazepina/farmacología , Ratones Endogámicos C57BL , Miopía/genética , Miopía/metabolismo , Retina/metabolismo , Receptores de Dopamina D1/metabolismo
20.
Angew Chem Int Ed Engl ; 62(46): e202306896, 2023 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-37747767

RESUMEN

Developing efficient and robust hydrogen evolution reaction (HER) catalysts for scalable and sustainable hydrogen production through electrochemical water splitting is strategic and challenging. Herein, heterogeneous Mo8 O26 -NbNx Oy supported on N-doped graphene (defined as Mo8 O26 -NbNx Oy /NG) is synthesized by controllable hydrothermal reaction and nitridation process. The O-exposed Mo8 O26 clusters covalently confined on NbNx Oy nanodomains provide a distinctive interface configuration and appropriate electronic structure, where fully exposed multiple active sites give excellent HER performance beyond commercial Pt/C catalyst in pH-universal electrolytes. Theoretical studies reveal that the Mo8 O26 -NbNx Oy interface with electronic reconstruction affords near-optimal hydrogen adsorption energy and enhanced initial H2 O adsorption. Furthermore, the terminal O atoms in Mo8 O26 clusters cooperate with Nb atoms to promote the initial H2 O adsorption, and subsequently reduce the H2 O dissociation energy, accelerating the entire HER kinetics.

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