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1.
Artigo em Inglês | MEDLINE | ID: mdl-38766682

RESUMO

BACKGROUND AND AIM: Reliable bowel preparation assessment is important in colonoscopy. However, current scoring systems are limited by laborious and time-consuming tasks and interobserver variability. We aimed to develop an artificial intelligence (AI) model to assess bowel cleanliness and evaluate its clinical applicability. METHODS: A still image-driven AI model to assess the Boston Bowel Preparation Scale (BBPS) was developed and validated using 2361 colonoscopy images. For evaluating real-world applicability, the model was validated using 113 10-s colonoscopy video clips and 30 full colonoscopy videos to identify "adequate (BBPS 2-3)" or "inadequate (BBPS 0-1)" preparation. The model was tested with an external dataset of 29 colonoscopy videos. The clinical applicability of the model was evaluated using 225 consecutive colonoscopies. Inter-rater variability was analyzed between the AI model and endoscopists. RESULTS: The AI model achieved an accuracy of 94.0% and an area under the receiver operating characteristic curve of 0.939 with the still images. Model testing with an external dataset showed an accuracy of 95.3%, an area under the receiver operating characteristic curve of 0.976, and a sensitivity of 100% for the detection of inadequate preparations. The clinical applicability study showed an overall agreement rate of 85.3% between endoscopists and the AI model, with Fleiss' kappa of 0.686. The agreement rate was lower for the right colon compared with the transverse and left colon, with Fleiss' kappa of 0.563, 0.575, and 0.789, respectively. CONCLUSIONS: The AI model demonstrated accurate bowel preparation assessment and substantial agreement with endoscopists. Further refinement of the AI model is warranted for effective monitoring of qualified colonoscopy in large-scale screening programs.

2.
Sci Rep ; 13(1): 13927, 2023 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-37626185

RESUMO

Protein disulfide isomerase (PDI) is a redox-active enzyme and also serves as a nitric oxide donor causing S-nitrosylation of cysteine residues in various proteins. Although PDI knockdown reduces α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR)-mediated neuronal activity, the underlying mechanisms are largely unknown. In the present study, we found that under physiological condition PDI knockdown increased CaMKII activity (phosphorylation) in the mouse hippocampus. However, PDI siRNA inhibited protein phosphatase (PP) 2A-mediated GluA2 S880 dephosphorylation by increasing PP2A oxidation, independent of S-nitrosylation. PDI siRNA also enhanced glutamate ionotropic receptor AMPA type subunit 1 (GluA1) S831 and GluA2 S880, but not GluA1 S845 and GluA2 Y869/Y873/Y876 phosphorylations, concomitant with the enhanced protein interacting with C kinase 1 (PICK1)-mediated AMPAR internalization. Furthermore, PDI knockdown attenuated seizure activity and neuronal damage in response to kainic acid (a non-desensitizing agonist of AMPAR). Therefore, these findings suggest that PDI may regulate surface AMPAR expression through PP2A-GluA2-PICK1 signaling pathway, and that PDI may be one of the therapeutic targets for epilepsy via AMPAR internalization without altering basal neurotransmission.


Assuntos
Ácido Caínico , Isomerases de Dissulfetos de Proteínas , Animais , Camundongos , Ácido Caínico/farmacologia , Receptores de AMPA/genética , Proteínas Adaptadoras de Transdução de Sinal , Ácidos Carboxílicos , Hipocampo
3.
BMC Gastroenterol ; 23(1): 210, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37322445

RESUMO

BACKGROUND/AIMS: Regression of liver fibrosis during antiviral therapy in chronic hepatitis B (CHB) patients has been demonstrated, but data on the influence of long-term treatment with tenofovir disoproxil fumarate (TDF) on liver stiffness (LS) measured by transient elastography are scarce. We aimed to investigate the changes in LS values during the 144-week TDF therapy in treatment-naïve CHB patients. METHODS: This prospective observational study was conducted from April 2015 to July 2020 at CHA Bundang Medical Center. Laboratory tests and LS measurements were performed at baseline and repeated at weeks 12, 24, 48, 96, and 144. A significant decline in LS was defined as ≥ 30% decrease in LS value at week 96 from baseline. RESULTS: A total of 48 treatment-naïve CHB patients initiating TDF therapy were screened, and 36 patients were included in the final analysis (median age, 46 [interquartile range, 34.5-55.8] years; 19 men [52.8%]). During TDF therapy, the median LS values decreased from 13.8 kPa at baseline to 8.7 kPa, 6.5 kPa, and 6.4 kPa at weeks 48, 96, and 144, respectively (all P < 0.001). At week 96, virological and biochemical responses were achieved in 34 (94.4%) patients and 20 (76.9%) patients, respectively. Moreover, 21 of 36 (58.3%) patients showed a significant decline in LS value. A higher baseline LS value was a single independent predictor for the reduction in LS value at week 96 from baseline (P < 0.001). CONCLUSIONS: During the 144-week TDF therapy, LS values declined significantly in treatment-naïve CHB patients.


Assuntos
Técnicas de Imagem por Elasticidade , Hepatite B Crônica , Masculino , Humanos , Pessoa de Meia-Idade , Tenofovir/uso terapêutico , Hepatite B Crônica/diagnóstico por imagem , Hepatite B Crônica/tratamento farmacológico , Antivirais , Vírus da Hepatite B/genética , Resultado do Tratamento , Antígenos E da Hepatite B , DNA Viral
4.
J Neuroinflammation ; 20(1): 99, 2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37118736

RESUMO

BACKGROUND: Pyridoxal-5'-phosphate phosphatase/chronophin (PLPP/CIN) selectively dephosphorylates serine (S) 10 site on neurofibromin 2 (NF2, also known as merlin (moesin-ezrin-radixin-like protein) or schwannomin). p21-activated kinase 1 (PAK1) is a serine/threonine protein kinase, which is involved in synaptic activity and plasticity in neurons. NF2 and PAK1 reciprocally regulate each other in a positive feedback manner. Thus, the aim of the present study is to investigate the effects of PLPP/CIN-mediated NF2 S10 dephosphorylation on PAK1-related signaling pathways under physiological and neuroinflammatory conditions, which are largely unknown. METHODS: After kainate (KA) injection in wild-type, PLPP/CIN-/- and PLPP/CINTg mice, seizure susceptibility, PAK1 S204 autophosphorylation, nuclear factor-κB (NF-κB) p65 S276 phosphorylation, cyclooxygenase-2 (COX-2) upregulation, prostaglandin E synthase 2 (PTGES2) induction and neuronal damage were measured. The effects of 1,1'-dithiodi-2-naphthtol (IPA-3, a selective inhibitor of PAK1) pretreatment on these responses to KA were also validated. RESULTS: PLPP/CIN overexpression increased PAK1 S204 autophosphorylation concomitant with the enhanced NF2 S10 dephosphorylation in hippocampal neurons under physiological condition. Following KA treatment, PLPP/CIN overexpression delayed the seizure on-set and accelerated PAK1 S204 phosphorylation, NF-κB p65 S276 phosphorylation, COX-2 upregulation and PTGES2 induction, which were ameliorated by PLPP/CIN deletion or IPA-3. Furthermore, IPA-3 pretreatment shortened the latency of seizure on-set without affecting seizure severity (intensity) and ameliorated CA3 neuronal death induced by KA. CONCLUSIONS: These findings indicate that PLPP/CIN may regulate seizure susceptibility (the latency of seizure on-set) and CA3 neuronal death in response to KA through NF2-PAK1-NF-κB-COX-2-PTGES2 signaling pathway.


Assuntos
NF-kappa B , Neurofibromina 2 , Camundongos , Animais , NF-kappa B/metabolismo , Neurofibromina 2/metabolismo , Neurofibromina 2/farmacologia , Ciclo-Oxigenase 2/metabolismo , Quinases Ativadas por p21/metabolismo , Ácido Caínico/toxicidade , Prostaglandina-E Sintases/metabolismo , Fosfatos , Transdução de Sinais , Convulsões/induzido quimicamente , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilação
5.
Toxins (Basel) ; 15(3)2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36977122

RESUMO

Ptaquiloside, a naturally occurring cancer-causing substance in bracken fern, has been detected in the meat and milk of cows fed a diet containing bracken fern. A rapid and sensitive method for the quantitative analysis of ptaquiloside in bracken fern, meat, and dairy products was developed using the QuEChERS method and liquid chromatography-tandem mass spectrometry. The method was validated according to the Association of Official Analytical Chemists guidelines and met the criteria. A single matrix-matched calibration method with bracken fern has been proposed, which is a novel strategy that uses one calibration for multiple matrices. The calibration curve ranged from 0.1 to 50 µg/kg and showed good linearity (r2 > 0.99). The limits of detection and quantification were 0.03 and 0.09 µg/kg, respectively. The intraday and interday accuracies were 83.5-98.5%, and the precision was <9.0%. This method was used for the monitoring and exposure assessment of ptaquiloside in all routes of exposure. A total of 0.1 µg/kg of ptaquiloside was detected in free-range beef, and the daily dietary exposure of South Koreans to ptaquiloside was estimated at up to 3.0 × 10-5 µg/kg b.w./day. The significance of this study is to evaluate commercially available products in which ptaquiloside may be present, to monitor consumer safety.


Assuntos
Pteridium , Sesquiterpenos , Animais , Bovinos , Sesquiterpenos/análise , Leite/química , Carne/análise
6.
Neuropharmacology ; 228: 109462, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36792029

RESUMO

Dopamine plays a central role in the regulation of psychomotor functions in the brain. Furthermore, the dopaminergic system is involved in the ictogenesis in human patients and animal models of epilepsy. Dopamine and cAMP-regulated phosphoprotein, 32 kDa (DARPP-32) plays an important role in the regulation of interactions between dopamine and glutamate receptors in neurons. Indeed, SKF 83822 (a specific D1 receptor agonist) facilitates DARPP-32-mediated protein phosphatase 1 (PP1) inhibition leading to the increase in phosphorylation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR), which potentiates channel activities and currents and thereby generates seizure activity. In the present study, we found that pyridoxal-5'-phosphate phosphatase/chronophin (PLPP/CIN), a selective phosphatase for serine (S) residues, attenuated seizure susceptibility in response to SKF 83822 by dephosphorylating DARPP-32 S97 site. Similarly, inhibition of DARPP-32 S97 phosphorylation by 2-[4,5,6,7-Tetrabromo-2-(dimethylamino)-1H-benzo[d]imidazole-1-yl]acetic acid (TMCB; a selective casein kinase 2 inhibitor) attenuated SKF 83822-induced seizure activity. These inhibitory effects of PLPP/CIN and TMCB were relevant to the regulations of DARPP-32-PP1-AMPAR signaling pathway. Therefore, our findings suggest that PLPP/CIN may be a modulator in dopaminergic neurotransmission as well as glutamatergic systems, and that the PLPP/CIN-mediated DARPP-32 regulation may be one of the potential therapeutic targets for medication of seizure or epilepsy induced by D1 receptor hyperactivation.


Assuntos
Dopamina , Fosfatos , Camundongos , Animais , Humanos , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Dopamina/metabolismo , Fosfatos/metabolismo , Transmissão Sináptica , Fosforilação , Convulsões/metabolismo , Receptores de Dopamina D1/metabolismo , Proteína Fosfatase 1/metabolismo , Hipocampo
7.
J Nutr Sci ; 12: e4, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36721723

RESUMO

During the initial wave of the COVID-19 pandemic, symptoms of infection varied widely among adults younger than 60 years. This cross-sectional investigation of adults ages 18-59 years explored associations between SARS-CoV-2 symptomatology and supplementation of micronutrients involved in immune function, such as multivitamins, vitamin D, vitamin C, vitamin E and zinc. Between August and December 2020, an online survey was completed by 287 respondents, averaging 33⋅3 ± 10⋅5 years, who recovered from SARS-CoV-2 infection within the previous 4 months. In regression models, intake of supplements over the previous year was not protective against number of symptoms or symptom severity. Despite higher rates of supplementation over the previous year, smokers experienced more symptoms and greater symptom severity than non-smokers. Micronutrient supplementation did not protect young adults from experiencing symptoms of SARS-CoV-2, but our results suggest that smoking cessation may be a more effective modifiable lifestyle factor.


Assuntos
COVID-19 , SARS-CoV-2 , Adulto Jovem , Humanos , Adolescente , Adulto , Pessoa de Meia-Idade , Autorrelato , COVID-19/epidemiologia , Pandemias , Estudos Transversais , Suplementos Nutricionais , Vitaminas
8.
Exp Mol Med ; 54(11): 2092-2103, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36446848

RESUMO

The Pim (proviral integration site for Moloney murine leukemia virus) proteins compose a serine threonine kinase family whose members regulate cell proliferation, migration and cell survival. However, whether Pim kinases participate in innate immune responses is unclear. Here, we show for the first time that Pim1 plays an essential role in the production of interferon (IFN)-ß by macrophages after their Toll-like receptor (TLR) pathway is activated by pathogen-associated molecular patterns (PAMPs). Specifically, Pim1 was quickly upregulated in an NF-κB-dependent manner after TLR stimulation with PAMPs. Pim1 deficiency reduced TLR3- or TLR4-stimulated IFN-ß and IFN-stimulated gene (ISG) expression but not proinflammatory cytokine expression in macrophages. Mechanistically, Pim1 specifically upregulates IRF3 phosphorylation and nuclear translocation. However, this role is not dependent on Pim1 kinase activity. Rather, Pim1 appears to promote IRF3 phosphorylation by enhancing the formation of IFN-ß signaling complexes composed of TRIF, TRAF3, TBK1, and IRF3. Poly (I:C)-treated Pim1-/- mice produced less serum IFN-ß and were less likely to survive than wild-type mice. These findings show for the first time that Pim1 participates in TLR-mediated IFN-ß production, thus revealing a novel target for controlling antiviral innate immune responses.


Assuntos
Interferon beta , Moléculas com Motivos Associados a Patógenos , Animais , Camundongos , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/metabolismo , Interferon beta/metabolismo , Moléculas com Motivos Associados a Patógenos/metabolismo , Fosforilação , Poli I-C , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais/genética
9.
Biochem Biophys Res Commun ; 632: 173-180, 2022 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-36209586

RESUMO

The presence of circulating cancer cells in the bloodstream is positively correlated with metastasis. We hypothesize that fluid shear stress (FSS) occurring during circulation alters mitochondrial function, enhancing metastatic behaviors of cancer cells. MCF7 and MDA-MB-231 human breast cancer cells subjected to FSS exponentially increased proliferation. Notably, FSS-treated cells consumed more oxygen but were resistant to uncoupler-mediated ATP loss. We found that exposure to FSS downregulated the F1FO ATP synthase c-subunit and overexpression of the c-subunit arrested cancer cell migration. Approaches that regulate c-subunit abundance may reduce the likelihood of breast cancer metastasis.


Assuntos
Neoplasias da Mama , ATPases Mitocondriais Próton-Translocadoras , Humanos , Feminino , ATPases Mitocondriais Próton-Translocadoras/genética , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Regulação para Baixo , Trifosfato de Adenosina , Proliferação de Células , Oxigênio
10.
Neuropharmacology ; 219: 109238, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36055413

RESUMO

Dopamine and cAMP-regulated phosphoprotein, 32 kDa (DARPP-32)-mediated protein phosphatase 1 (PP1) inhibition leads to the increase in phosphorylation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptor (AMPAR), which potentiates channel activity and current and thereby may facilitate seizure activity. In the present study, we found that pyridoxal-5'-phosphate phosphatase/chronophin (PLPP/CIN) transiently dephosphorylated DARPP-32 serine (S) 97 site in the early time window, and casein kinase 2 (CK2) subsequently phosphorylated this site in the later time points after kainic acid (KA) injection, which increased the latency of seizure onset in response to KA, but exacerbated the intensity (severity), duration and progression of seizures. TMCB (a CK2 inhibitor) delayed the seizure onset in response to KA, concomitant with the reduced DARPP-32 S97 phosphorylation. Therefore, our findings suggest that PLPP/CIN may play an important role in the latency of seizure onset via DARPP-32-PP1-AMPAR signaling pathway, and may be one of the potential therapeutic targets for medication of seizure or epilepsy.


Assuntos
Ácido Caínico , Serina , Animais , Caseína Quinase II/metabolismo , Dopamina/metabolismo , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Hipocampo/metabolismo , Ácido Caínico/farmacologia , Camundongos , Fosfatos/metabolismo , Fosfoproteínas/metabolismo , Fosforilação , Proteína Fosfatase 1/metabolismo , Piridoxal , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico , Convulsões/metabolismo , Serina/metabolismo , Serina/farmacologia
11.
Int J Mol Sci ; 23(9)2022 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-35562960

RESUMO

Clasmatodendrosis is one of the irreversible astroglial degeneration, which is involved in seizure duration and its progression in the epileptic hippocampus. Although sustained heat shock protein 25 (HSP25) induction leads to this autophagic astroglial death, dysregulation of mitochondrial dynamics (aberrant mitochondrial elongation) is also involved in the pathogenesis in clasmatodendrosis. However, the underlying molecular mechanisms of accumulation of elongated mitochondria in clasmatodendritic astrocytes are elusive. In the present study, we found that clasmatodendritic astrocytes showed up-regulations of HSP25 expression, AKT serine (S) 473 and dynamin-related protein 1 (DRP1) S637 phosphorylations in the hippocampus of chronic epilepsy rats. 2-Cyano-3,12-dioxo-oleana-1,9(11)-dien-28-oic acid methyl ester (CDDO-Me; bardoxolone methyl or RTA 402) abrogated abnormal mitochondrial elongation by reducing HSP25 upregulation, AKT S473- and DRP1 S637 phosphorylations. Furthermore, HSP25 siRNA and 3-chloroacetyl-indole (3CAI, an AKT inhibitor) abolished AKT-DRP1-mediated mitochondrial elongation and attenuated clasmatodendrosis in CA1 astrocytes. These findings indicate that HSP25-AKT-mediated DRP1 S637 hyper-phosphorylation may lead to aberrant mitochondrial elongation, which may result in autophagic astroglial degeneration. Therefore, our findings suggest that the dysregulation of HSP25-AKT-DRP1-mediated mitochondrial dynamics may play an important role in clasmatodendrosis, which would have implications for the development of novel therapies against various neurological diseases related to astroglial degeneration.


Assuntos
Astrócitos , Epilepsia , Ácido Oleanólico , Animais , Astrócitos/metabolismo , Dinaminas/metabolismo , Epilepsia/genética , Epilepsia/metabolismo , Proteínas de Choque Térmico/metabolismo , Dinâmica Mitocondrial , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/metabolismo , Ácido Oleanólico/farmacologia , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos
12.
Nutr Res ; 101: 31-42, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35366596

RESUMO

Alpha-tocotrienol (α-TCT) is a member of the vitamin E family. It has been reported to protect the brain against various pathologies including cerebral ischemia and neurodegeneration. However, it is still unclear if α-TCT exhibits beneficial effects during brain development. We hypothesized that treatment with α-TCT improves intracellular redox homeostasis supporting normal development of neurons. We found that primary hippocampal neurons isolated from rat feti grown in α-TCT-containing media achieved greater levels of neurite complexity compared to ethanol-treated control neurons. Neurons were treated with 1 µM α-TCT for 3 weeks, and media were replaced with fresh α-TCT every week. Treatment with α-TCT increased α-TCT levels (26 pmol/mg protein) in the cells, whereas the control neurons did not contain α-TCT. α-TCT-treated neurons produced adenosine triphosphate (ATP) at a higher rate and increased ATP retention at neurites, supporting formation of neurite branches. Although treatment with α-TCT alone did not change neuronal viability, neurons grown in α-TCT were more resistant to death at maturity. We further found that messenger RNA and protein levels of B-cell lymphoma-extra large (Bcl-xL) are increased by α-TCT treatment without inducing posttranslational cleavage of Bcl-xL. Bcl-xL is known to enhance mitochondrial energy production, which improves neuronal function including neurite outgrowth and neurotransmission. Therefore α-TCT-mediated Bcl-xL upregulation may be the central mechanism of neuroprotection seen in the α-TCT-treated group. In summary, treatment with α-TCT upregulates Bcl-xL and increases ATP levels at neurites. This correlates with increased neurite branching during development and with protection of mature neurons against oxidative stress.


Assuntos
Linfoma de Células B , Neurônios , Trifosfato de Adenosina/metabolismo , Trifosfato de Adenosina/farmacologia , Animais , Hipocampo/metabolismo , Linfoma de Células B/metabolismo , Ratos , Tocotrienóis , Regulação para Cima , Proteína bcl-X/genética , Proteína bcl-X/metabolismo
13.
Cell Death Differ ; 29(9): 1874-1887, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35322203

RESUMO

Mitochondrial ATP synthase is vital not only for cellular energy production but also for energy dissipation and cell death. ATP synthase c-ring was suggested to house the leak channel of mitochondrial permeability transition (mPT), which activates during excitotoxic ischemic insult. In this present study, we purified human c-ring from both eukaryotic and prokaryotic hosts to biophysically characterize its channel activity. We show that purified c-ring forms a large multi-conductance, voltage-gated ion channel that is inhibited by the addition of ATP synthase F1 subcomplex. In contrast, dissociation of F1 from FO occurs during excitotoxic neuronal death suggesting that the F1 constitutes the gate of the channel. mPT is known to dissipate the osmotic gradient across the inner membrane during cell death. We show that ATP synthase c-subunit knock down (KD) prevents the osmotic change in response to high calcium and eliminates large conductance, Ca2+ and CsA sensitive channel activity of mPT. These findings elucidate the gating mechanism of the ATP synthase c-subunit leak channel (ACLC) and suggest how ACLC opening is regulated by cell stress in a CypD-dependent manner.


Assuntos
Proteínas de Transporte da Membrana Mitocondrial , ATPases Mitocondriais Próton-Translocadoras , Trifosfato de Adenosina/metabolismo , Morte Celular , Humanos , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Poro de Transição de Permeabilidade Mitocondrial , ATPases Mitocondriais Próton-Translocadoras/genética , ATPases Mitocondriais Próton-Translocadoras/metabolismo , ATPases Translocadoras de Prótons/metabolismo
14.
Sci Rep ; 12(1): 3874, 2022 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-35264673

RESUMO

Mitochondrial dysfunction is a key element in the progression of Parkinson's disease (PD). The inefficient operation of the electron transport chain (ETC) impairs energy production and enhances the generation of oxidative stress contributing to the loss of dopaminergic cells in the brain. ATPase inhibitory factor 1 (IF1) is a regulator of mitochondrial energy metabolism. IF1 binds directly to the F1Fo ATP synthase and prevents ATP wasting during compromised energy metabolism. In this study, we found treatment with IF1 protects mitochondria against PD-like insult in vitro. SH-SY5Y cells treated with IF1 were resistant to loss of ATP and mitochondrial inner membrane potential during challenge with rotenone, an inhibitor of complex I in the ETC. We further demonstrated that treatment with IF1 reversed rotenone-induced superoxide production in mitochondria and peroxide accumulation in whole cells. Ultimately, IF1 decreased protein levels of pro-apoptotic Bax, cleaved caspase-3, and cleaved PARP, rescuing SH-SY5Y cells from rotenone-mediated apoptotic death. Administration of IF1 significantly improved the results of pole and hanging tests performed by PD mice expressing human α-synuclein. This indicates that IF1 mitigates PD-associated motor deficit. Together, these findings suggest that IF1 exhibits a neuroprotective effect preventing mitochondrial dysfunction in PD pathology.


Assuntos
Fármacos Neuroprotetores , Doença de Parkinson , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Camundongos , Mitocôndrias/metabolismo , Fármacos Neuroprotetores/metabolismo , Fármacos Neuroprotetores/farmacologia , Doença de Parkinson/metabolismo , Rotenona/metabolismo , Rotenona/farmacologia
15.
Biology (Basel) ; 10(8)2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34440004

RESUMO

B-cell lymphoma-extra large (Bcl-xL) is a mitochondrial protein known to inhibit mitochondria-dependent intrinsic apoptotic pathways. An increasing number of studies have demonstrated that Bcl-xL is critical in regulating neuronal energy metabolism and has a protective role in pathologies associated with an energy deficit. However, it is less known how Bcl-xL regulates physiological processes of the brain. In this study, we hypothesize that Bcl-xL is required for neurite branching and maturation during neuronal development by improving local energy metabolism. We found that the absence of Bcl-xL in rat primary hippocampal neurons resulted in mitochondrial dysfunction. Specifically, the ATP/ADP ratio was significantly decreased in the neurites of Bcl-xL depleted neurons. We further found that neurons transduced with Bcl-xL shRNA or neurons treated with ABT-263, a pharmacological inhibitor of Bcl-xL, showed impaired mitochondrial motility. Neurons lacking Bcl-xL had significantly decreased anterograde and retrograde movement of mitochondria and an increased stationary mitochondrial population when Bcl-xL was depleted by either means. These mitochondrial defects, including loss of ATP, impaired normal neurite development. Neurons lacking Bcl-xL showed significantly decreased neurite arborization, growth and complexity. Bcl-xL depleted neurons also showed impaired synapse formation. These neurons showed increased intracellular calcium concentration and were more susceptible to excitotoxic challenge. Bcl-xL may support positioning of mitochondria at metabolically demanding regions of neurites like branching points. Our findings suggest a role for Bcl-xL in physiological regulation of neuronal growth and development.

16.
Int J Mol Sci ; 22(5)2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33668863

RESUMO

Lon protease 1 (LONP1) is a highly conserved serine peptidase that plays an important role in the protein quality control system in mammalian mitochondria. LONP1 catalyzes the degradation of oxidized, dysfunctional, and misfolded matrix proteins inside mitochondria and regulates mitochondrial gene expression and genome integrity. Therefore, LONP1 is up-regulated and suppresses cell death in response to oxidative stress, heat shock, and nutrient starvation. On the other hand, translocation of high mobility group box 1 (HMGB1) and active caspase-3 into mitochondria is involved in apoptosis of parvalbumin (PV) cells (one of the GABAergic interneurons) and necrosis of CA1 neurons in the rat hippocampus, respectively, following status epilepticus (SE). In the present study, we investigated whether LONP1 may improve neuronal viability to prevent or ameliorate translocation of active caspase-3 and HMGB1 in mitochondria within PV and CA1 neurons. Following SE, LONP1 expression was up-regulated in mitochondria of PV and CA1 neurons. LONP1 knockdown deteriorated SE-induced neuronal death with mitochondrial accumulation of active caspase-3 and HMGB1 in PV cells and CA1 neurons, respectively. LONP1 knockdown did not affect the aberrant mitochondrial machinery induced by SE. Therefore, our findings suggest, for the first time, that LONP1 may contribute to the alleviation of mitochondrial overloads of active caspase-3 and HMGB1, and the maintenance of neuronal viability against SE.


Assuntos
Proteases Dependentes de ATP/metabolismo , Região CA1 Hipocampal/patologia , Caspase 3/metabolismo , Proteína HMGB1/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Neurônios/metabolismo , Parvalbuminas/metabolismo , Animais , Morte Celular , Técnicas de Silenciamento de Genes , Masculino , Dinâmica Mitocondrial , Pilocarpina , Transporte Proteico , RNA Interferente Pequeno/metabolismo , Ratos Sprague-Dawley , Estado Epiléptico
17.
Cell Death Dis ; 12(1): 37, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33414453

RESUMO

Neurofibromin 2 (NF2, also known as merlin) is a tumor suppressor protein encoded by the neurofibromatosis type 2 gene NF2. NF2 is also an actin-binding protein that functions in an intrinsic signaling network critical for actin dynamics. Although protein kinase A (PKA)-mediated NF2-serin (S) 10 phosphorylation stabilizes filamentous actin (F-actin), the underlying mechanisms of NF2-S10 dephosphorylation and the role of NF2 in seizures have been elusive. Here, we demonstrate that pyridoxal-5'-phosphate phosphatase/chronophin (PLPP/CIN) dephosphorylated NF2-S10 site as well as cofilin-S3 site. In addition, NF2-S10 dephosphorylation reversely regulated murine double minute-2 (Mdm2) and postsynaptic density 95 (PSD95) degradations in an activity-dependent manner, which increased seizure intensity and its progression in response to kainic acid (KA). In addition, NF2 knockdown facilitated seizure intensity and its progress through F-actin instability independent of cofilin-mediated actin dynamics. Therefore, we suggest that PLPP/CIN may be a potential therapeutic target for epileptogenesis and NF2-associated diseases.


Assuntos
Actinas/metabolismo , Neurofibromina 2/metabolismo , Fosfoproteínas Fosfatases/fisiologia , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Convulsões/metabolismo , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosforilação
18.
Gut Liver ; 15(3): 410-419, 2021 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32893194

RESUMO

Background/Aims: This study was performed to evaluate the efficacy of direct-acting antivirals (DAAs) in Korean patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) and to investigate the risk factors associated with HCC recurrence. Methods: A total of 100 patients with HCV-related HCC, who were treated with DAAs between May 2015 and December 2016, were recruited from seven university hospitals in Korea. Claim data of 526 patients with HCC obtained from the Health Insurance Review and Assessment Service in South Korea were used for external validation of the results. Results: Among the 100 patients, 88% achieved a sustained virological response (SVR) 12 weeks after the end of DAA therapy (SVR12), and 37% experienced HCC recurrence after DAA therapy. Short last HCC treatment durability (<12 months) before DAA commencement was independently associated with HCC recurrence (hazard ratio [HR], 2.89; p=0.011). In the nationwide validation cohort, 20.3% of the patients experienced HCC recurrence. The last HCC treatment with a noncurative method, a short last HCC treatment durability (<12 months), and a longer total duration of HCC treatment (≥18 months) were independently related with HCC recurrence (HR 3.73, p<0.001; HR 3.34, p<0.001; and HR 1.74, p=0.006; respectively). Conclusions: DAA therapy showed an acceptable SVR12 rate in patients with HCV-related HCC. Short last HCC treatment durability (<12 months) was associated with HCC recurrence after DAA therapy. This finding suggests that the last HCC treatment durability is an important predictor of HCC recurrence after DAA therapy.


Assuntos
Carcinoma Hepatocelular , Hepatite C Crônica , Neoplasias Hepáticas , Antivirais/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/etiologia , Hepatite C Crônica/complicações , Hepatite C Crônica/tratamento farmacológico , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/etiologia , Recidiva Local de Neoplasia/epidemiologia , Fatores de Risco , Resposta Viral Sustentada
19.
Dig Dis Sci ; 66(7): 2427-2438, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-32856240

RESUMO

BACKGROUND AND AIMS: The influence of direct-acting antivirals (DAAs) on chronic hepatitis C (CHC)-related hepatocellular carcinoma (HCC) remains controversial. We investigated the effect of eradicating CHC using DAAs on treatment outcomes in patients with CHC-related HCC treated with transarterial chemoembolization (TACE). METHODS: This nationwide, multi-center, retrospective study recruited patients with CHC-related HCC treated with TACE as the first-line anti-cancer treatment, and who achieved a sustained virological response (SVR) using DAAs (DAA group) between 2006 and 2017. Patients achieving an SVR following interferon-based treatment (IFN group) and those without treatment (control group) were also recruited for comparison. RESULTS: A total of 425 patients were eligible for the study. Of these, 356 (83.8%), 26 (6.1%), and 43 (10.1%) were allocated to the control, IFN, and DAA groups, respectively. A multivariate analysis showed that liver cirrhosis, segmental portal vein thrombosis, and larger maximal tumor size independently predicted an increased risk of progression (all p < 0.05), whereas, the DAA group (vs. IFN and control groups) independently predicted a reduced risk of progression (hazard ratio (HR) = 0.630, 95% confidence interval 0.411-0.966, p = 0.034). The cumulative incidence rate of HCC progression in the DAA group was significantly lower than that in the IFN and control groups (p = 0.033, log-rank test). In addition, the DAA group (vs. IFN and control groups) was independently associated with a reduced risk of mortality (p = 0.042). CONCLUSIONS: DAA treatment provided significantly prolonged progression-free survival in patients with CHC-related HCC treated with TACE compared to that in patients administered IFN or no treatment.


Assuntos
Antivirais/uso terapêutico , Carcinoma Hepatocelular/terapia , Quimioembolização Terapêutica/métodos , Hepatite C/complicações , Hepatite C/tratamento farmacológico , Neoplasias Hepáticas/terapia , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
20.
Int J Mol Sci ; 21(24)2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33348808

RESUMO

Both α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor (AMPAR) and N-methyl-D-aspartate receptor (NMDAR) have been reported as targets for treatment of epilepsy. To investigate the roles and interactions of AMPAR and NMDAR in ictogenesis of epileptic hippocampus, we analyzed AMPAR antagonists (perampanel and GYKI 52466)-mediated phosphatase and tensin homolog deleted on chromosome 10 (PTEN) regulation and glutamate ionotropic receptor NMDA type subunit 2B (GluN2B) tyrosine (Y) 1472 phosphorylation in epilepsy rats. Both perampanel and GYKI 52466 increased PTEN expression and its activity (reduced phosphorylation), concomitant with decreased activities (phosphorylations) of Src family-casein kinase 2 (CK2) signaling pathway. Compatible with these, they also restored the upregulated GluN2B Y1472 and Ca2+/cAMP response element-binding protein (CREB) serine (S) 133 phosphorylations and surface expression of glutamate ionotropic receptor AMPA type subunit 1 (GRIA1) to basal level in the epileptic hippocampus. These effects of perampanel and GYKI 52466 are observed in responders (whose seizure activities are responsive to AMPAR antagonists), but not non-responders (whose seizure activities were uncontrolled by AMPAR antagonists). Therefore, our findings suggest that Src/CK2/PTEN-mediated GluN2B Y1472 and CREB S133 regulations may be one of the responsible signaling pathways for the generation of refractory seizures in non-responders to AMPAR antagonists.


Assuntos
Benzodiazepinas/farmacologia , Epilepsia/tratamento farmacológico , Regulação da Expressão Gênica/efeitos dos fármacos , Receptores de AMPA/antagonistas & inibidores , Animais , Caseína Quinase II/genética , Caseína Quinase II/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Epilepsia/induzido quimicamente , Epilepsia/metabolismo , Epilepsia/patologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Masculino , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Fosforilação , Ratos , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/genética , Receptores de N-Metil-D-Aspartato/metabolismo , Transdução de Sinais , Quinases da Família src/genética , Quinases da Família src/metabolismo
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