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1.
Artículo en Inglés | MEDLINE | ID: mdl-38953940

RESUMEN

Intact executive functions are required for proper performance of cognitive tasks and relies on balance of excitatory and inhibitory (E/I) transmission in the medial prefrontal cortex (mPFC). Hypofrontality is a state of decreased activity in the mPFC and is seen in several neuropsychiatric conditions, including substance use disorders. People who chronically use methamphetamine (meth) develop hypofrontality and concurrent changes in cognitive processing across several domains. Despite the fact that there are sex difference in substance use disorders, few studies have considered sex as a biological variable regarding meth-mediated hypoactivity in mPFC and concurrent cognitive deficits. Hypofrontality along with changes in cognition are emulated in rodent models following repeated meth administration. Here, we used a meth sensitization regimen to study sex differences in a Temporal Order Memory (TOM) task following short (7 days) or prolonged (28 days) periods of abstinence. GABAergic transmission, GABAA receptor (GABAAR) and GABA Transporter (GAT) mRNA expression in the mPFC were evaluated with patch-clamp recordings and RT-qPCR, respectively. Both sexes sensitized to the locomotor activating effects of meth, with the effect persisting in females. After short abstinence, males and females had impaired TOM and increased GABAergic transmission. Female rats recovered from these changes after prolonged abstinence, whereas male rats showed enduring changes. In general, meth appears to elicit an overall decrease in GABAAR expression after short abstinence; whereas GABA transporters are decreased in meth female rats after prolonged abstinence. These results show sex differences in the long-term effects of repeated meth exposure and suggest that females have neuroprotective mechanisms that alleviate some of the meth-mediated cognitive deficits.

2.
Microorganisms ; 12(5)2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38792783

RESUMEN

The present study involves the precise identification and safety evaluation of Enterococcus casseliflavus KB1733, previously identified using 16S rRNA analysis, through whole-genome sequencing, phenotypic analysis, and preclinical toxicity studies. Analyses based on the genome sequencing data confirm the identity of KB1733 as E. casseliflavus and show that the genes related to vancomycin resistance are only present on the chromosome, while no virulence factor genes are present on the chromosome or plasmid. Phenotypic analyses of antibiotic resistance and hemolytic activity also indicated no safety concerns. A bacterial reverse mutation test showed there was no increase in revertant colonies of heat-killed KB1733. An acute toxicity test employing heat-killed KB1733 at a dose of 2000 mg/kg body weight in rats resulted in no deaths and no weight gain or other abnormalities in the general condition of the animals, with renal depression foci and renal cysts only occurring at the same frequency as in the control. Taking the background data into consideration, the effects on the kidneys observed in the current study were not caused by KB1733. Our findings suggest that KB1733 is non-pathogenic to humans/animals, although further studies involving repeated oral toxicity tests and/or clinical tests are required.

3.
Microbiol Resour Announc ; 12(12): e0070723, 2023 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-37943041

RESUMEN

We isolated a Vibrio fluvialis strain (IDH5335) from a stool sample collected from a patient with diarrhea. In this announcement, we report the complete genomic sequence of this organism, which was obtained by combining Illumina and Oxford Nanopore sequencing data.

4.
bioRxiv ; 2023 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-37873212

RESUMEN

Type-2 ryanodine receptor (RyR2) ion channels facilitate the release of Ca 2+ from stores and serve an important function in neuroplasticity. The role for RyR2 in hippocampal-dependent learning and memory is well established and chronic hyperphosphorylation of RyR2 (RyR2P) is associated with pathological calcium leakage and cognitive disorders, including Alzheimer's disease. By comparison, little is known about the role of RyR2 in the ventral medial prefrontal cortex (vmPFC) circuitry important for working memory, decision making, and reward seeking. Here, we evaluated the basal expression and localization of RyR2 and RyR2P in the vmPFC. Next, we employed an operant model of sucrose, cocaine, or morphine self-administration (SA) followed by a (reward-free) recall test, to reengage vmPFC neurons and reactivate reward-seeking and re-evaluated the expression and localization of RyR2 and RyR2P in vmPFC. Under basal conditions, RyR2 was expressed in pyramidal cells but not regularly detected in PV/SST interneurons. On the contrary, RyR2P was rarely observed in PFC somata and was restricted to a different subcompartment of the same neuron - the apical dendrites of layer-5 pyramidal cells. Chronic SA of drug (cocaine or morphine) and nondrug (sucrose) rewards produced comparable increases in RyR2 protein expression. However, recalling either drug reward impaired the usual localization of RyR2P in dendrites and markedly increased its expression in somata immunoreactive for Fos, a marker of highly activated neurons. These effects could not be explained by chronic stress or drug withdrawal and instead appeared to require a recall experience associated with prior drug SA. In addition to showing the differential distribution of RyR2/RyR2P and affirming the general role of vmPFC in reward learning, this study provides information on the propensity of addictive drugs to redistribute RyR2P ion channels in a neuronal population engaged in drug-seeking. Hence, focusing on the early impact of addictive drugs on RyR2 function may serve as a promising approach to finding a treatment for substance use disorders.

5.
Heliyon ; 9(10): e20401, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37780754

RESUMEN

Objective: Tube feeders are prone to membranous substance formation on the palate, and those with membranous substances have a risk of fever, with the probable involvement of their oral bacteria. However, the palatal microbiota of those with membranous substances has not been elucidated. Therefore, we evaluated the differences in palatal microbiota between tube-fed individuals with and without membranous substances to clarify the microbiota. Materials and methods: This study included 19 participants aged 65 years who required tube feeding. The participants' characteristics were collected from nursing records and oral examinations. If membranous materials were found on the palate, a specimen was collected. Membranous substances were defined as keratotic degeneration observed under a microscope. Additionally, we performed a comprehensive microbiome analysis by extracting DNA from the samples and performing 16 S rRNA gene sequencing. Finally, we compared the participant demographics and oral microbiota between patients with and without membranous substances. Results: A total of 11 participants had membranous substances associated with "mouth dryness" (p < 0.001) and "constant mouth opening" (p = 0.020). Palatal microbiota differed between those with and without membranous substances. Among the bacteria with a relative abundance greater than 1.0%, the abundance of Streptococcus (p = 0.007), Fusobacterium (p = 0.041), Streptococcus agalactiae (p = 0.009), and Fusobacterium nucleatum subsp. vincentii (p = 0.026) was significantly higher in the membranous substance group than in the non-membranous substance group. Conclusions: The palatal microbiota of individuals undergoing tube feeding differed depending on the presence or absence of membranous substances. Membrane substance formation associated with dry mouth purportedly alters the palatal microbiota. Streptococcus, Fusobacterium, S. agalactiae, and F. nucleatum subsp. vincentii were more abundant in the oral microbiota of patients with membranous substances. Thus, preventing this formation may help in controlling the growth of these microbes.

6.
Int J Neuropsychopharmacol ; 26(12): 817-827, 2023 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-37875346

RESUMEN

BACKGROUND: Little is known about the specific roles of cortical and accumbal oxytocin receptors in drug use disorders. To better understand the importance of the endogenous oxytocin system in cocaine relapse behavior, we developed an adeno-associated viral vector-expressing short hairpin (sh) RNAs to selectively degrade the rat oxytocin receptor (OxyR) mRNA in vivo. METHODS: Male (Sprague-Dawley) rats received bilateral infusions of the shRNA for the oxytocin receptor (shOxyR) or an shRNA control virus into the prefrontal cortex (PFC) or the nucleus accumbens core (NAc). Rats self-administered cocaine on an escalating FR ratio for 14 days, lever responding was extinguished, and rats were tested for cued and cocaine-primed reinstatement of drug seeking. RESULTS: OxyR knockdown in the PFC delayed the acquisition of lever pressing on an fixed ratio 1 schedule of reinforcement. All rats eventually acquired the same level of lever pressing and discrimination, and there were no differences in extinction. OxyR knockdown in the NAc had no effect during acquisition. In both the PFC and NAc, the shOxyR decreased cued reinstatement relative to shRNA control virus but was without effect during drug-primed reinstatement. OxyR knockdown in the PFC increased chamber activity during a social interaction task. CONCLUSIONS: This study provides critical new information about how endogenous OxyRs function to affect drug seeking in response to different precipitators of relapse. The tool developed to knockdown OxyRs in rat could provide important new insights that aid development of oxytocin-based therapeutics to reduce return-to-use episodes in people with substance use disorder and other neuropsychiatric disorders.


Asunto(s)
Trastornos Relacionados con Cocaína , Cocaína , Humanos , Ratas , Masculino , Animales , Núcleo Accumbens/metabolismo , Ratas Sprague-Dawley , Receptores de Oxitocina/genética , Receptores de Oxitocina/metabolismo , Oxitocina/farmacología , Cocaína/farmacología , Corteza Prefrontal/metabolismo , Trastornos Relacionados con Cocaína/metabolismo , Recurrencia , ARN Interferente Pequeño/farmacología , Autoadministración , Extinción Psicológica
7.
Arch Microbiol ; 205(10): 346, 2023 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-37773547

RESUMEN

Strain KK2020170T, a Gram-stain negative, yellow colony-forming bacterium, was isolated from surface seawater sampled in Kojima Bay, Okayama, Japan. Phylogenetic analysis based on the 16S rRNA gene revealed that strain KK2020170T belongs to the genus Flavobacterium, with Flavobacterium haoranii LQY-7T (98.1% similarity) being its closest relative, followed by Flavobacterium sediminis MEBiC07310T (96.9%) and Flavobacterium urocaniciphilum YIT 12746T (96.0%). Whole-genome shotgun sequencing showed that strain KK2020170T, when paralleled with F. haoranii LQY-7 T, had 81.3% average nucleotide identity, and 24.6% in silico DNA-DNA hybridization values, respectively. The DNA G + C content of strain KK2020170T was 31.1 mol%. The most abundant fatty acids (> 10%) of strain KK2020170T were iso-C15: 0, iso-C17: 0 3-OH and iso-C15: 1 G. The dominant respiratory quinone of the strain was menaquinone MK-6. Based on the phylogenetic and phenotypic analysis results, we propose that strain KK2020170T represents a novel species, for which the name Flavobacterium okayamense sp. nov. has been proposed. The type strain is KK2020170T (= ATCC TSD-280 T = NBRC 115344 T).


Asunto(s)
Flavobacterium , Agua de Mar , Filogenia , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Análisis de Secuencia de ADN , Técnicas de Tipificación Bacteriana , Agua de Mar/microbiología , Ácidos Grasos/análisis , Vitamina K 2
8.
iScience ; 26(4): 106508, 2023 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-37123221

RESUMEN

The zebrafish is a unique model to understand hematopoietic niches as hematopoietic stem/progenitor cells are maintained in the kidney. However, little is known about which cell types in the kidney play a role in hematopoietic niches. Here, we demonstrate that the sinusoidal endothelium is an essential and conserved niche component in the zebrafish kidney. Histological analysis revealed that runx1:mCherry + hematopoietic cells were predominantly detected in the dorsolateral region of the kidney where sinusoids are highly developed. Loss of Junctional adhesion molecule 1a (Jam1a), which is expressed in both sinusoidal endothelial cells and hematopoietic cells, resulted in a remarkable reduction in sinusoids and a defect in hematopoietic niches. We found that Jam1a regulates jagged-1a expression in vascular endothelial cells to form a sinusoidal structure in the kidney. Collectively, these data suggest that sinusoids are formed by Jam1a via endothelial Notch signaling to provide hematopoietic niches in the zebrafish kidney.

9.
Cell Rep ; 42(5): 112404, 2023 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-37083325

RESUMEN

Cocaine blocks dopamine reuptake, thereby producing rewarding effects that are widely studied. However, cocaine also blocks serotonin uptake, which we show drives, in rats, individually variable aversive effects that depend on serotonin 2C receptors (5-HT2CRs) in the rostromedial tegmental nucleus (RMTg), a major GABAergic afferent to midbrain dopamine neurons. 5-HT2CRs produce depolarizing effects in RMTg neurons that are particularly strong in some rats, leading to aversive effects that reduce acquisition of and relapse to cocaine seeking. In contrast, 5-HT2CR signaling is largely lost after cocaine exposure in other rats, leading to reduced aversive effects and increased cocaine seeking. These results suggest a serotonergic biological marker of cocaine-seeking vulnerability that can be targeted to modulate drug seeking.


Asunto(s)
Cocaína , Ratas , Animales , Ratas Sprague-Dawley , Cocaína/farmacología , Serotonina/farmacología , Tegmento Mesencefálico , Neuronas Dopaminérgicas/fisiología , Serotoninérgicos/farmacología , Área Tegmental Ventral/fisiología
10.
Prog Disaster Sci ; 17: 100276, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36748009

RESUMEN

This study proposes a novel typology of adaptation to hazards-a conversion strategy as a countermeasure to manage risks in interconnected supply chains. Conversion strategies are intended to transform one or multiple supply chain functions for a different one to manage the changing environment. Supply chain disruptions due to natural hazards have been researched in key manufacturing-based economies like Thailand, the US, Japan, and China. Limited studies, however, have looked at the nature of interconnected risks and its effective countermeasures that arise when the COVID-19 pandemic disrupt supply chains. Here, we examine systemic risks by contrasting supply chain disruptions caused by natural hazards and the pandemic. Our study investigates whether businesses can manage systemic risks brought on by the pandemic by learning from dealing with disruptions caused by natural hazards. We offer a typology of conversion strategies to demonstrate how conversion strategies can be a successful response to pandemic scenarios. Specifically, we propose six conversion types: production location, production line, storage, usage, distributional channel, and workforce skill set. Then, we conclude with the future research directions as well as the kinds of policy supports required to assist businesses in implementing conversion measures by drawing on prior work addressing natural hazards.

11.
Proc Natl Acad Sci U S A ; 120(7): e2210953120, 2023 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-36745812

RESUMEN

Opioid use produces enduring associations between drug reinforcement/euphoria and discreet or diffuse cues in the drug-taking environment. These powerful associations can trigger relapse in individuals recovering from opioid use disorder (OUD). Here, we sought to determine whether the epigenetic enzyme, histone deacetylase 5 (HDAC5), regulates relapse-associated behavior in an animal model of OUD. We examined the effects of nucleus accumbens (NAc) HDAC5 on both heroin- and sucrose-seeking behaviors using operant self-administration paradigms. We utilized cre-dependent viral-mediated approaches to investigate the cell-type-specific effects of HDAC5 on heroin-seeking behavior, gene expression, and medium spiny neuron (MSN) cell and synaptic physiology. We found that NAc HDAC5 functions during the acquisition phase of heroin self-administration to limit future relapse-associated behavior. Moreover, overexpressing HDAC5 in the NAc suppressed context-associated and reinstated heroin-seeking behaviors, but it did not alter sucrose seeking. We also found that HDAC5 functions within dopamine D1 receptor-expressing MSNs to suppress cue-induced heroin seeking, and within dopamine D2 receptor-expressing MSNs to suppress drug-primed heroin seeking. Assessing cell-type-specific transcriptomics, we found that HDAC5 reduced expression of multiple ion transport genes in both D1- and D2-MSNs. Consistent with this observation, HDAC5 also produced firing rate depression in both MSN classes. These findings revealed roles for HDAC5 during active heroin use in both D1- and D2-MSNs to limit distinct triggers of drug-seeking behavior. Together, our results suggest that HDAC5 might limit relapse vulnerability through regulation of ion channel gene expression and suppression of MSN firing rates during active heroin use.


Asunto(s)
Cocaína , Heroína , Ratones , Animales , Ratones Transgénicos , Heroína/metabolismo , Heroína/farmacología , Cocaína/farmacología , Refuerzo en Psicología , Comportamiento de Búsqueda de Drogas/fisiología , Epigénesis Genética , Núcleo Accumbens/fisiología , Autoadministración
12.
Methods Mol Biol ; 2632: 31-39, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36781719

RESUMEN

Microbial genomes are typically several million base pairs in length and are relatively easy to sequence and assemble into a single chromosome, given the advances in long-read sequencing platforms such as that of Oxford Nanopore Technologies. This chapter describes the experimental as well as computational steps in the sequencing and assembly of microbial genomes.


Asunto(s)
Nanoporos , Análisis de Secuencia de ADN , Genoma Bacteriano , Secuenciación de Nucleótidos de Alto Rendimiento , Genoma Microbiano
13.
Elife ; 122023 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-36780219

RESUMEN

Chronic stress can produce reward system deficits (i.e., anhedonia) and other common symptoms associated with depressive disorders, as well as neural circuit hypofunction in the medial prefrontal cortex (mPFC). However, the molecular mechanisms by which chronic stress promotes depressive-like behavior and hypofrontality remain unclear. We show here that the neuronal activity-regulated transcription factor, NPAS4, in the mPFC is regulated by chronic social defeat stress (CSDS), and it is required in this brain region for CSDS-induced changes in sucrose preference and natural reward motivation in the mice. Interestingly, NPAS4 is not required for CSDS-induced social avoidance or anxiety-like behavior. We also find that mPFC NPAS4 is required for CSDS-induced reductions in pyramidal neuron dendritic spine density, excitatory synaptic transmission, and presynaptic function, revealing a relationship between perturbation in excitatory synaptic transmission and the expression of anhedonia-like behavior in the mice. Finally, analysis of the mice mPFC tissues revealed that NPAS4 regulates the expression of numerous genes linked to glutamatergic synapses and ribosomal function, the expression of upregulated genes in CSDS-susceptible animals, and differentially expressed genes in postmortem human brains of patients with common neuropsychiatric disorders, including depression. Together, our findings position NPAS4 as a key mediator of chronic stress-induced hypofrontal states and anhedonia-like behavior.


Asunto(s)
Anhedonia , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Derrota Social , Animales , Humanos , Ratones , Anhedonia/fisiología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Depresión , Ratones Endogámicos C57BL , Corteza Prefrontal/fisiología , Conducta Social , Estrés Psicológico/psicología , Sinapsis/metabolismo
14.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 79(3): 252-261, 2023 Mar 20.
Artículo en Japonés | MEDLINE | ID: mdl-36709971

RESUMEN

PURPOSE: The questionnaire survey investigated whether "Explainer videos about radiation therapy (RT-Video)", "Treatment of breast cancer patients by female radiation therapists (F-RTT)" and "Treating male patients while wearing underwear in pelvic radiation therapy (M-RTT)" can improve patient's satisfaction. METHODS: The RT-Video survey included questions regarding the impression of radiation therapy, improving its understanding, and anxiety reduction (102 patients received radiation therapy). Fifty-one breast cancer patients were asked whether they preferred an F-RTT treatment. Subsequently, the patients treated with F-RTT (41 patients) and M-RTT (50 patients) were surveyed about their treatment satisfaction on a five-point scale. RESULTS: RT-Video improved the understanding of radiation therapy for 86 out of 102 patients (84%). In all, 68 out of 102 patients (68%) had a negative impression of radiotherapy; among them, watching the RT-Video reduced anxiety in 63% of patients. A total of 14 out of 51 breast cancer patients (28%) preferred the F-RTT treatment. The percentage of patients who received treatment satisfaction by F-RTT and M-RTT was 95% and 84%, respectively. CONCLUSION: RT-Video, F-RTT and M-RTT treatments improved patients' satisfaction.


Asunto(s)
Neoplasias de la Mama , Oncología por Radiación , Humanos , Masculino , Femenino , Satisfacción del Paciente , Neoplasias de la Mama/radioterapia
15.
Int J Mol Sci ; 23(18)2022 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-36142562

RESUMEN

Ceramide levels controlled by the sphingomyelin (SM) cycle have essential roles in cancer cell fate through the regulation of cell proliferation, death, metastasis, and drug resistance. Recent studies suggest that exosomes confer cancer malignancy. However, the relationship between ceramide metabolism and exosome-mediated cancer malignancy is unclear. In this study, we elucidated the role of ceramide metabolism via the SM cycle in exosomes and drug resistance in human leukemia HL-60 and adriamycin-resistant HL-60/ADR cells. HL-60/ADR cells showed significantly increased exosome production and release compared with parental chemosensitive HL-60 cells. In HL-60/ADR cells, increased SM synthase (SMS) activity reduced ceramide levels, although released exosomes exhibited a high ceramide ratio in both HL-60- and HL-60/ADR-derived exosomes. Overexpression of SMS2 but not SMS1 suppressed intracellular ceramide levels and accelerated exosome production and release in HL-60 cells. Notably, HL-60/ADR exosomes conferred cell proliferation and doxorubicin resistance properties to HL-60 cells. Finally, microRNA analysis in HL-60 and HL-60/ADR cells and exosomes showed that miR-484 elevation in HL-60/ADR cells and exosomes was associated with exosome-mediated cell proliferation. This suggests that intracellular ceramide metabolism by SMS2 regulates exosome production and release, leading to acquisition of drug resistance and enhanced cell proliferation in leukemia cells.


Asunto(s)
Exosomas , Leucemia , MicroARNs , Ceramidas/metabolismo , Doxorrubicina/farmacología , Resistencia a Antineoplásicos , Exosomas/metabolismo , Humanos , MicroARNs/genética , Esfingomielinas/metabolismo , Transferasas (Grupos de Otros Fosfatos Sustitutos)
16.
Front Mol Neurosci ; 15: 828055, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35813068

RESUMEN

Substance use induces long-lasting behavioral changes and drug craving. Increasing evidence suggests that epigenetic gene regulation contributes to the development and expression of these long-lasting behavioral alterations. Here we systematically review extensive evidence from rodent models of drug-induced changes in epigenetic regulation and epigenetic regulator proteins. We focus on histone acetylation and histone methylation in a brain region important for drug-related behaviors: the nucleus accumbens. We also discuss how experimentally altering these epigenetic regulators via systemically administered compounds or nucleus accumbens-specific manipulations demonstrate the importance of these proteins in the behavioral effects of drugs and suggest potential therapeutic value to treat people with substance use disorder. Finally, we discuss limitations and future directions for the field of epigenetic studies in the behavioral effects of addictive drugs and suggest how to use these insights to develop efficacious treatments.

17.
Microbiol Resour Announc ; 11(8): e0054122, 2022 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-35876570

RESUMEN

Actinomyces oris strain K20 was isolated from oral apical lesions. Here, we report the complete circular genome sequence of this strain, obtained by means of hybrid assembly using two next-generation sequencing datasets. The strain has a 3.1-Mb genome with 2,636 coding sequences.

18.
Clin Case Rep ; 10(4): e05725, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35449775

RESUMEN

The study aims to reveal the composition of subgingival bacteria in monozygotic twins with discordant in severity and progression risk of periodontitis. Microbiome analysis indicated that most bacteria were heritable but differed in their abundance and immune response. The dysbiotic bacteria can be considered as risk markers for periodontitis progression.

19.
Mol Pharmacol ; 101(5): 322-333, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35273080

RESUMEN

Ceramide is a bioactive sphingolipid that mediates ionizing radiation- and chemotherapy-induced apoptosis. Neocarzinostatin (NCS) is a genotoxic anti-cancer drug that induces apoptosis in response to DNA double-strand breaks (DSBs) through ataxia telangiectasia mutated (ATM) activation. However, the involvement of ceramide in NCS-evoked nuclear events such as DSB-activated ATM has not been clarified. Here, we found that nuclear ceramide increased by NCS-mediated apoptosis through the enhanced assembly of ATM and the meiotic recombination 11/double-strand break repair/Nijmengen breakage syndrome 1 (MRN) complex proteins in human lymphoblastoid L-39 cells. NCS induced an increase of ceramide production through activation of neutral sphingomyelinase (nSMase) and suppression of sphingomyelin synthase (SMS) upstream of DSB-mediated ATM activation. In ATM-deficient lymphoblastoid AT-59 cells compared with L-39 cells, NCS treatment showed a decrease of apoptosis even though ceramide increase and DSBs were observed. Expression of wild-type ATM, but not the kinase-dead mutant ATM, in AT-59 cells increased NCS-induced apoptosis despite similar ceramide accumulation. Interestingly, NCS increased ceramide content in the nucleus through nSMase activation and SMS suppression and promoted colocalization of ceramide with phosphorylated ATM and foci of MRN complex. Inhibition of ceramide generation by the overexpression of SMS suppressed NCS-induced apoptosis through the inhibition of ATM activation and assembly of the MRN complex. In addition, inhibition of ceramide increased by the nSMase inhibitor GW4869 prevented NCS-mediated activation of the ATM. Therefore, our findings suggest the involvement of the nuclear ceramide with ATM activation in NCS-mediated apoptosis. SIGNIFICANCE STATEMENT: This study demonstrates that regulation of ceramide with neutral sphingomyelinase and sphingomyelin synthase in the nucleus in double-strand break-mimetic agent neocarzinostatin (NCS)-induced apoptosis. This study also showed that ceramide increase in the nucleus plays a role in NCS-induced apoptosis through activation of the ataxia telangiectasia mutated/meiotic recombination 11/double-strand break repair/Nijmengen breakage syndrome 1 complex in human lymphoblastoid cells.


Asunto(s)
Ataxia Telangiectasia , Cinostatina , Apoptosis/genética , Ataxia Telangiectasia/genética , Proteínas de la Ataxia Telangiectasia Mutada/genética , Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Proteínas de Ciclo Celular/metabolismo , Ceramidas/farmacología , Reparación del ADN , Proteínas de Unión al ADN/metabolismo , Humanos , Proteínas Serina-Treonina Quinasas , Esfingomielina Fosfodiesterasa/genética , Esfingomielina Fosfodiesterasa/metabolismo , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Cinostatina/farmacología
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