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1.
BMC Pulm Med ; 21(1): 233, 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34256743

RESUMO

BACKGROUND: To explore the long-term trajectories considering pneumonia volumes and lymphocyte counts with individual data in COVID-19. METHODS: A cohort of 257 convalescent COVID-19 patients (131 male and 126 females) were included. Group-based multi-trajectory modelling was applied to identify different trajectories in terms of pneumonia lesion percentage and lymphocyte counts covering the time from onset to post-discharge follow-ups. We studied the basic characteristics and disease severity associated with the trajectories. RESULTS: We characterised four distinct trajectory subgroups. (1) Group 1 (13.9%), pneumonia increased until a peak lesion percentage of 1.9% (IQR 0.7-4.4) before absorption. The slightly decreased lymphocyte rapidly recovered to the top half of the normal range. (2) Group 2 (44.7%), the peak lesion percentage was 7.2% (IQR 3.2-12.7). The abnormal lymphocyte count restored to normal soon. (3) Group 3 (26.0%), the peak lesion percentage reached 14.2% (IQR 8.5-19.8). The lymphocytes continuously dropped to 0.75 × 109/L after one day post-onset before slowly recovering. (4) Group 4 (15.4%), the peak lesion percentage reached 41.4% (IQR 34.8-47.9), much higher than other groups. Lymphopenia was aggravated until the lymphocytes declined to 0.80 × 109/L on the fourth day and slowly recovered later. Patients in the higher order groups were older and more likely to have hypertension and diabetes (all P values < 0.05), and have more severe disease. CONCLUSIONS: Our findings provide new insights to understand the heterogeneous natural courses of COVID-19 patients and the associations of distinct trajectories with disease severity, which is essential to improve the early risk assessment, patient monitoring, and follow-up schedule.

2.
Int J Oncol ; 59(2)2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34278453

RESUMO

Leukemia is a group of malignant diseases of clonal hematopoietic stem­progenitor cells and its pathological mechanisms remain to be elucidated. Genetic and epigenetic abnormalities, as well as microenvironmental factors, including cytokines, serve critical roles in leukaemogenesis. Macrophage migration inhibitory factor (MIF) has been presented as one of the key regulators in tumorigenesis, angiogenesis and tumor metastasis. This article focuses on the functional role of MIF and its pathway in cancer, particularly in leukemia. MIF/CD74 interaction serves prominent roles in tumor cell survival, such as upregulating BCL­2 and CD84 expression, and activating receptor­type tyrosine phosphatase ζ. Furthermore, MIF upregulation forms a pro­tumor microenvironment in response to hypoxia­induced factors and promotes pro­inflammatory cytokine production. Additionally, polymorphisms of the MIF promoter sequence are associated with leukemia development. MIF signal­targeted early clinical trials show positive results. Overall, these efforts provide a promising means for intervention in leukemia.

3.
Insect Sci ; 2021 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-34288425

RESUMO

RNA interference (RNAi) has developed rapidly as a potential 'green' pest management strategy. At present, most studies have focused on the screening of aphid lethal genes, whereas only a few studies have been conducted on wing development, which is crucial for aphid migration and plant-virus dissemination. Here, the Myzus persicae genes vestigial (vg) and Ultrabithorax (Ubx) related to wing development, were cloned. These two genes were expressed in various tissues of 3rd-instar winged aphids. The mRNA level of vg was high in 3rd -instar nymphs, whereas the expression level of Ubx was high in adults. The nanocarrier-mediated delivery system delivered double-stranded RNAs for aphid RNAi using topical and root applications. The expression levels of vg and Ubx were down-regulated by 44.0% and 36.5% respectively, using the topical application. The simultaneous RNAi of the two target genes caused 63.3% and 32.2% wing aberration rates using topical and root applications, respectively. The current study provided a promising method for controlling aphid migration to alleviate the spread of insect transmitted plant diseases. This article is protected by copyright. All rights reserved.

4.
Int J Mol Sci ; 22(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206574

RESUMO

Sorafenib (Sor) is an oral multi-kinase inhibitor, but its water solubility is very low. To improve its solubility, sorafenib hydrochloride hydrate, sorafenib hydrobromide and sorafenib hydrobromide hydrate were prepared in the mixed solvent of the corresponding acid solution, and tetrahydrofuran (THF). The crystal structures of sorafenib hydrochloride trihydrate (Sor·HCl.3H2O), 4-(4-{3-[4-chloro-3-(trifluoro-methyl)phenyl]ureido}phenoxy)-2-(N-methylcarbamoyl) pyridinium hydrochloride trihydrate, C21H17ClF3N4O3+·Cl-.3H2O (I), sorafenib hydrochloride monohydrate (Sor·HCl.H2O), C21H17ClF3N4O3+·Cl-.H2O (II), its solvated form (sorafenib hydrochloride monohydrate monotetrahydrofuran (Sor·HCl.H2O.THF), C21H17ClF3N4O3+·Cl-.H2O.C4H8O (III)), sorafenib hydrobromide (Sor·HBr), 4-(4-{3-[4-chloro-3-(trifluoro-methyl)phenyl]ureido}phenoxy)-2-(N-methylcarbamoyl) pyridinium hydrobromide, C21H17ClF3N4O3+·Br- (IV) and sorafenib hydrobromide monohydrate (Sor·HBr.H2O), C21H17ClF3N4O3+·Br-.H2O (V) were analysed. Their hydrogen bond systems and topologies were investigated. The results showed the distinct roles of water molecules in stabilizing their crystal structures. Moreover, (II) and (V) were isomorphous crystal structures with the same space group P21/n, and similar unit cell dimensions. The predicted morphologies of these forms based on the BFDH model matched well with experimental morphologies. The energy frameworks showed that (I), and (IV) might have better tabletability than (II) and (V). Moreover, the solubility and dissolution rate data exhibited an improvement in the solubility of these salts compared with the free drug.

5.
Molecules ; 26(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200376

RESUMO

The dissolution rate is the rate-limiting step for Biopharmaceutics Classification System (BCS) class II drugs to enhance their in vivo pharmacokinetic behaviors. There are some factors affecting the dissolution rate, such as polymorphism, particle size, and crystal habit. In this study, to improve the dissolution rate and enhance the in vivo pharmacokinetics of sorafenib tosylate (Sor-Tos), a BCS class II drug, two crystal habits of Sor-Tos were prepared. A plate-shaped crystal habit (ST-A) and a needle-shaped crystal habit (ST-B) were harvested by recrystallization from acetone (ACN) and n-butanol (BuOH), respectively. The surface chemistry of the two crystal habits was determined by powder X-ray diffraction (PXRD) data, molecular modeling, and face indexation analysis, and confirmed by X-ray photoelectron spectroscopy (XPS) data. The results showed that ST-B had a larger hydrophilic surface than ST-A, and subsequently a higher dissolution rate and a substantial enhancement of the in vivo pharmacokinetic performance of ST-B.


Assuntos
Solubilidade/efeitos dos fármacos , Sorafenibe/química , Acetona/química , Biofarmácia/métodos , Química Farmacêutica/métodos , Cristalização/métodos , Interações Hidrofóbicas e Hidrofílicas , Tamanho da Partícula , Pós/química , Difração de Raios X/métodos
6.
Artigo em Inglês | MEDLINE | ID: mdl-34283576

RESUMO

The application of botanical pesticides is a good choice in organic agriculture. However, most botanical pesticides have limitations of slow action and short persistence for pest and disease management, which constrain their further application. With the objective of exploring a green pesticide for controlling strawberry pests and diseases simultaneously, a star polymer (SPc) with a low production cost was synthesized as a pesticide nanocarrier through simple reactions. The SPc complexed with osthole quickly through electrostatic interaction and hydrophobic association, which decreased the particle size of osthole down to the nanoscale (17.66 nm). With the help of SPc, more nano-sized osthole was delivered into cytoplasm through endocytosis, leading to the enhanced cytotoxicity against insect cells. As a green botanical pesticide, the control efficacy of the osthole/SPc complex was improved against main strawberry pests (green peach aphid and two-spotted spider mite) and disease (powdery mildew), which fulfilled the need of both pest and disease management in sustainable production of strawberry. Meanwhile, the introduction of SPc not only improved plant-uptake but also decreased the residue of osthole due to the higher degradation rate. Furthermore, the application of the osthole/SPc complex exhibited no influence on the strawberry fruit quality and nontarget predators. To our knowledge, it is the first success to control plant pests and diseases simultaneously for sustainable agriculture by only one pesticidal formulation based on nanoparticle-delivered botanical pesticides.

7.
Molecules ; 26(11)2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-34198794

RESUMO

Cardiovascular diseases (CVDs) are the leading cause of death worldwide, causing approximately 17.9 million deaths annually, an estimated 31% of all deaths, according to the WHO. CVDs are essentially rooted in atherosclerosis and are clinically classified into coronary heart disease, stroke and peripheral vascular disorders. Current clinical interventions include early diagnosis, the insertion of stents, and long-term preventive therapy. However, clinical diagnostic and therapeutic tools are subject to a number of limitations including, but not limited to, potential toxicity induced by contrast agents and unexpected bleeding caused by anti-platelet drugs. Nanomedicine has achieved great advancements in biomedical area. Among them, cell membrane coated nanoparticles, denoted as CMCNPs, have acquired enormous expectations due to their biomimetic properties. Such membrane coating technology not only helps avoid immune clearance, but also endows nanoparticles with diverse cellular and functional mimicry. In this review, we will describe the superiorities of CMCNPs in treating cardiovascular diseases and their potentials in optimizing current clinical managements.

9.
Int J Med Sci ; 18(13): 3039-3049, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34220332

RESUMO

Small double-stranded RNAs (dsRNAs) have been proved to effectively up-regulate the expression of particular genes by targeting their promoters. These small dsRNAs were also termed small activating RNAs (saRNAs). We previously reported that several small double-stranded RNAs (dsRNAs) targeting the PRKC apoptosis WT1 regulator (PAWR) promoter can up-regulate PAWR gene expression effectively in human cancer cells. The present study was conducted to evaluate the antitumor potential of PAWR gene induction by these saRNAs in bladder cancer. Promisingly, we found that up-regulation of PAWR by saRNA inhibited the growth of bladder cancer cells by inducing cell apoptosis and cell cycle arrest which was related to inhibition of anti­apoptotic protein Bcl-2 and inactivation of the NF-κB and Akt pathways. The activation of the caspase cascade and the regulation of cell cycle related proteins also supported the efficacy of the treatment. Moreover, our study also showed that these saRNAs cooperated with cisplatin in the inhibition of bladder cancer cells. Overall, these data suggest that activation of PAWR by saRNA may have a therapeutic benefit for bladder cancer.

10.
Se Pu ; 39(7): 708-714, 2021 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-34227368

RESUMO

Lithospermum erythrorhizon has the functions of cooling blood, activating blood, as well as detoxifying and penetrating rash. Lithospermum oil extracted from Lithospermum erythrorhizon can prevent and treat diaper rash, skin ulceration, eczema, and other skin diseases. Supercritical fluid extraction is the optimal method for the extraction of active components from lithospermum. In this study, an analytical method was established for simultaneously determination of six active components in lithospermum oil with high performance liquid chromatography (HPLC), and the contents of the active components as the evaluation index were used to investigate several important factors in the preparation of lithospermum oil by supercritical fluid extraction. The optimized HPLC conditions were as follows: separation column, Diamonsil C18 (250 mm×4.6 mm, 5 µm); mobile phases, acetonitrile containing 0.1% (v/v) formic acid-0.1% (v/v) formic acid aqueous solution containing 5 mmol/L ammonium formate (75∶25, v/v); flow rate, 1 mL/min; injection volume, 15 µL; room temperature; photodiode array detector (PAD); detection wavelength, 275 nm. The supercritical fluid extraction was optimized for ensuring stability of the amounts of effective components and the reliability of the quality of lithospermum oil. This will serve as the basis for preparation and quality control processes. Three factors and three levels orthogonal tests were adopted to investigate the important factors, viz. the pressure, temperature and CO2 flow rate in the preparation of lithospermum oil. The results showed that the developed HPLC-PAD method can be used for the simultaneous determination of shikonin, acetylshikonin, ß-acetoxyisovaleryl akanin, isobutyryl shikonin, ß,ß-dimethylacryl shikonin, and 2-methylbutyryl shikonin in 30 min. The method has good precision, accuracy and repeatability. The contents of the active components were the highest when the extraction pressure, extraction temperature, and CO2 flow rate were 23 MPa, 40 ℃, and 27 L/h, respectively. The optimized conditions are suitable for the preparation and actual production of lithospermum oil. The HPLC-PAD method is simple, feasible, accurate, and reliable. It can be used for the preparation and quality control of lithospermum oil by supercritical fluid extraction. Thus, with this method, the stability of the contents of active ingredients and the reliability of the quality of lithospermum oil can be ensured; moreover, safe and effective drug use can be realized. The established method has obvious advantages over the traditional process and is a good candidate for widespread use.

11.
J Med Internet Res ; 23(6): e17095, 2021 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-34137724

RESUMO

BACKGROUND: In China, significant emphasis and investment in health care reform since 2009 has brought with it increasing scrutiny of its public hospitals. Calls for greater accountability in the quality of hospital care have led to increasing attention toward performance measurement and the development of hospital ratings. Despite such interest, there has yet to be a comprehensive analysis of what performance information is publicly available to understand the performance of hospitals in China. OBJECTIVE: This study aims to review the publicly available performance information about hospitals in China to assess options for ranking hospital performance. METHODS: A review was undertaken to identify performance measures based on publicly available data. Following several rounds of expert consultation regarding the utility of these measures, we clustered the available options into three key areas: research and development, academic reputation, and quality and safety. Following the identification and clustering of the available performance measures, we set out to translate these into a practical performance ranking system to assess variation in hospital performance. RESULTS: A new hospital ranking system termed the China Hospital Development Index (CHDI) is thus presented. Furthermore, we used CHDI for ranking well-known tertiary hospitals in China. CONCLUSIONS: Despite notable limitations, our assessment of available measures and the development of a new ranking system break new ground in understanding hospital performance in China. In doing so, CHDI has the potential to contribute to wider discussions and debates about assessing hospital performance across global health care systems.

12.
Stem Cell Res ; 53: 102367, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34087996

RESUMO

Type 1 early infantile epileptic encephalopathy (EIEE1) is a severe early-onset epileptic encephalopathy with arrest of psychomotor development caused by hemizygous mutations in the ARX gene, which encodes a transcription factor in fundamental brain developmental processes. A human induced pluripotent stem cell (iPSC) line, termed as OGHFUi001-A, was generated using non-integrating episomal vector technique from peripheral blood mononuclear cells (PBMCs) of a 7-year-old male EIEE1 patient, who had a hemizygous (c.989G > T: p.R330L) mutation in the ARX gene. OGHFUi001-A offers a useful cell resource to investigate pathogenic mechanisms in EIEE1, as well as a cell-based model for drug development for EIEE1.


Assuntos
Células-Tronco Pluripotentes Induzidas , Espasmos Infantis , Criança , Proteínas de Homeodomínio/genética , Humanos , Leucócitos Mononucleares , Masculino , Mutação , Espasmos Infantis/genética , Fatores de Transcrição/genética
13.
J Cell Mol Med ; 25(14): 7028-7038, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34121317

RESUMO

Findings from recent studies have revealed that microRNAs (miRNAs) are related to numerous neurological disorders. However, whether miRNAs regulate neuronal anomalies involved in the pathogenesis of depression remain unclear. In the present study, we screened miRNA expression profiles in the CA1 hippocampus of a rat model of depression and found that a specific miRNA, microRNA-211-5p, was significantly down-regulated in depressed rats. When miR-211-5p was up-regulated in these rats, neuronal apoptosis within the CA1 area was suppressed, effects which were accompanied with an amelioration of depression-like behaviours in these rats. These neuroprotective effects of miR-211-5p in depressed rats appear to result through suppression of the Dyrk1A/ASK1/JNK signalling pathway within the CA1 area. In further support of this proposal are the findings that knock-down of miR-211-5p within the CA1 area of normal rats activated the Dyrk1A/ASK1/JNK pathway, resulting in the promotion of neuronal apoptosis and display of depression-like behaviours in these rats. Taken together, these results demonstrate that deficits in miR-211-5p contribute to neuronal apoptosis and thus depression-like behaviours in rats. Therefore, the miR-211-5p/Dyrk1A pathway may be critically involved in the pathogenesis of depression and serve as a potential therapeutic target for the treatment of depression.

14.
Adv Sci (Weinh) ; : e2002211, 2021 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-34145798

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) biofilm infections after orthopedic implant increase the risk of failure and potentially cause amputation of limbs or life-threatening sepsis in severe cases. Additionally, satisfactory bone-implant integration is another important indicator of an ideal implant. Here, an antibiotic-free antibacterial nanofilm based on oxide perovskite-type calcium titanate (CTO)/fibrous red phosphorus (RP) on titanium implant surface (Ti-CTO/RP) in which the P-N heterojunction and internal electric field are established at the heterointerface, is designed. Near-infrared light-excited electron-hole pairs are effectively separated and transferred through the synergism of the internal electric field and band offset, which strongly boosts the photocatalytic eradication of MRSA biofilms by reactive oxygen species with an efficacy of 99.42% ± 0.22% in vivo. Additionally, the charge transfer endows the heterostructure with hyperthermia to assist biofilm eradication. Furthermore, CTO/RP nanofilm provides a superior biocompatible and osteoconductive platform that enables the proliferation and osteogenic differentiation of mesenchymal stem cells, thus contributing to the subsequent implant-to-bone osseointegration after eradicating MRSA biofilms.

15.
BMC Immunol ; 22(1): 39, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34172011

RESUMO

BACKGROUND: Health care workers (HCWs) are at risk for occupationally acquired Mycobacterium tuberculosis infection and tuberculosis (TB) disease due to repeated exposure to workplace tubercle bacilli. To determine whether continual mycobacterial stimulation correlates with increased expression of inhibitory T cell receptors, here we compared PD-1 receptor expression on surfaces of circulating T cells between naïve (uninfected) HCWs and HCWs with latent TB infection (LTBI). RESULT: Data collected from 133 medical workers who met study selection criteria were included in the final analysis. QuantiFERON-TB Gold In-​Tube (QFT-GIT) testing yielded positive results for 32 HCWs, for an overall LTBI rate of 24.1%. Multivariate analysis identified HCW length of service > 15 years as an independent risk factor for a positive QFT-GIT result. In addition, comparisons of blood T cell subgroup profiles between QFT- and QFT+ groups indicated QFT+ subjects possessed greater proportions of mature (TM), transitional memory (TTM) and effector memory (TEM) CD4+ T cell subgroups and lower proportions of naïve T cells (TN). Moreover, the QFT+ group percentage of CD8+ T cells with detectable surface PD-1 was significantly higher than the corresponding percentage for the QFT- group. Meanwhile, no statistical intergroup difference was observed in percentages of CD4+ T cells with detectible surface PD-1. CONCLUSIONS: Our data demonstrated that upregulated PD-1 expression on circulating CD8+, but not CD4+ T cells, was associated with latent TB infection of HCWs. As compared to other hospitals, occupational TB infection risk in our hospital was substantially mitigated by implementation of multitiered infection control measures.

16.
AAPS PharmSciTech ; 22(5): 193, 2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-34184163

RESUMO

The human immunodeficiency virus (HIV) impacts up to 37 million people globally, of which 1.8 million are children. To date, there is no cure for HIV, although treatment options such as antiretroviral therapy (ART) are available. ART, which involves a patient taking a combination of antiretrovirals, is being used to treat HIV clinically. Despite the effectiveness of ART, there is currently no palatable pediatric formulation to treat HIV in children, which has hindered patient compliance and overall treatment efficacy. In addition, anti-HIV therapeutics are often poorly water-soluble, and hence have poor bioavailability. In the present study, we developed a pediatric-friendly formulation for anti-HIV therapeutics with improved dissolution characteristics of the therapeutic agents. Lopinavir (LPV) and ritonavir (RTV), available as FDA-approved fixed-dose combination products, were chosen as model ART drugs, and the formulation and processing parameters of spray-dried cyclodextrin (CD)-based LPV and RTV complexes were studied. Results showed that the spray-dried complexes exhibited enhanced dissolution profiles in comparison to pure drugs, particularly spray-dried ß-CD complexes, which showed the most favorable dissolution profiles. This current formulation with enhanced dissolution and taste-masking ability through the use of cyclodextrin has the potential to address the unmet need for the development of suitable pediatric formulations.


Assuntos
Fármacos Anti-HIV/análise , Fármacos Anti-HIV/síntese química , Ciclodextrinas/análise , Ciclodextrinas/síntese química , Desenvolvimento de Medicamentos/métodos , Secagem por Atomização , Fármacos Anti-HIV/uso terapêutico , Criança , Ciclodextrinas/uso terapêutico , Composição de Medicamentos/métodos , Infecções por HIV/tratamento farmacológico , Humanos , Espectroscopia de Ressonância Magnética/métodos , Pediatria/métodos , Difração de Raios X/métodos
17.
AAPS J ; 23(4): 87, 2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34145513

RESUMO

3D printing has emerged as an advanced manufacturing technology in the field of pharmaceutical sciences. Despite much focus on enteral applications, there has been a lack of research focused on potential benefits of 3D printing for parenteral applications such as wound dressings, biomedical devices, and regenerative medicines. 3D printing technologies, including fused deposition modeling, vat polymerization, and powder bed printing, allow for rapid prototyping of personalized medications, capable of producing dosage forms with flexible dimensions based on patient anatomy as well as dosage form properties such as porosity. Considerations such as printing properties and material selection play a key role in determining overall printability of the constructs. These parameters also impact drug release kinetics, and mechanical properties of final printed constructs, which play a role in modulating immune response upon insertion in the body. Despite challenges in sterilization of printed constructs, additional post-printing processing procedures, and lack of regulatory guidance, 3D printing will continue to evolve to meet the needs of developing effective, personalized medicines for parenteral applications.

18.
Chemosphere ; 283: 131289, 2021 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-34182651

RESUMO

Microplastics, as a new type of pollution, have attracted global attention and have become a research focus in recent years. Given the small size of microplastics, they can be ingested by many organisms. In addition, microplastics can enter the human body through the food chain. So, the potential dangers of microplastics can't be ignored. This study took Drosophila as a model organism to delve the physiological effects of polyethylene terephthalate microplastics (PET-MPs). Here, we reported that the higher concentration of PET-MPs was, the more obvious the effect became. The amount of oviposition decreased in female flies exposed, indicating that microplastics affected reproduction. PET-MPs caused the decrease of triglyceride and glucose content in male flies, as well as the decrease of starvation resistance, suggesting the effect of microplastics on energy metabolism. In addition, the 24-h spontaneous activity of flies exposed to PET-MPs increased significantly. The experimental results can help understand the potential impact of microplastics on physiology.

19.
Mol Brain ; 14(1): 85, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-34034776

RESUMO

Mutations in the Presenilin genes are the major genetic cause of Alzheimer's disease (AD). Presenilin (PS) is highly expressed in the hippocampus, which is particularly vulnerable in AD. Previous studies of PS function in the hippocampus, however, focused exclusively on excitatory neurons. Whether PS regulates inhibitory neuronal function remained unknown. In the current study, we investigate PS function in GABAergic neurons by performing whole-cell and field-potential electrophysiological recordings using acute hippocampal slices from inhibitory neuron-specific PS conditional double knockout (IN-PS cDKO) mice at 2 months of age, before the onset of age-dependent loss of interneurons. We found that the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) is reduced in hippocampal CA1 neurons of IN-PS cDKO mice, whereas the amplitude of sIPSCs is normal. Moreover, the efficacy of inhibitory neurotransmission as assessed with synaptic input/output relations for evoked mono- and di-synaptic IPSCs is markedly lowered in hippocampal CA1 neurons of IN-PS cDKO mice. Consistent with these findings, IN-PS cDKO mice display enhanced paired-pulse facilitation, frequency facilitation and long-term potentiation in the Schaffer collateral-CA1 pathway. Interestingly, depletion of intracellular Ca2+ stores by inhibition of sarcoendoplasmic reticulum Ca2+ ATPase results in a reduction of IPSC amplitude in control hippocampal neurons but not in IN-PS cDKO neurons, suggesting that impaired intracellular calcium homeostasis in the absence of PS may contribute to the deficiencies in inhibitory neurotransmission. Furthermore, the amplitude of IPSCs induced by short trains of presynaptic stimulation and paired-pulse ratio are decreased in IN-PS cDKO mice. These findings show that inactivation of PS in interneurons results in decreased GABAergic responses and enhanced synaptic plasticity in the hippocampus, providing additional evidence for the importance of PS in the regulation of synaptic plasticity and calcium homeostasis.

20.
Cells Dev ; 165: 203664, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33993981

RESUMO

The Notch signaling pathway is highly conserved and regulates various fundamental development events. Activation of Notch signaling relies on production of the Notch intracellular domain (NICD), which assembles a transcription factor complex to turn on down-stream targets expression. The mastermind (mam) gene encodes an essential co-activator that permits NICD activity in the cell nucleus. During a somatic mosaic screen in Drosophila, an uncharacterized gene l(2)S9998 is identified as a positive regulator of the Notch signaling pathway. Genetic analysis demonstrates that l(2)S9998 functions at the level of transcriptional activation of Notch targets in the signal receiving cells. Whole genome sequencing reveals that l(2)S9998 is a novel allele of the mam gene, which is further confirmed by complementation tests. Along with three molecularly defined transposon insertions isolated from the screen, four mutants of mam are shown to modulate Notch signaling during fly wing development. Our analysis provides additional genetic resources for understanding mam function and Notch signaling regulation.

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