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2.
Comput Biol Med ; 170: 108011, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38271838

RESUMO

While the average value measurement approach can successfully analyze and predict the general behavior and biophysical properties of an isogenic cell population, it fails when significant differences among individual cells are generated in the population by intracellular changes such as the cell cycle, or different cellular responses to certain stimuli. Detecting such single-cell differences in a cell population has remained elusive. Here, we describe an easy-to-implement and generalizable platform that measures the dielectrophoretic cross-over frequency of individual cells by decreasing measurement noise with a stochastic method and computing ensemble average statistics. This platform enables multiple, real-time, label-free detection of individual cells with significant dielectric variations over time within an isogenic cell population. Using a stochastic method in combination with the platform, we distinguished cell subpopulations from a mixture of drug-untreated and -treated isogenic cells. Furthermore, we demonstrate that our platform can identify drug-treated isogenic cells with different recovery rates.

4.
Sci Rep ; 13(1): 11975, 2023 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-37488184

RESUMO

Benign paroxysmal positional vertigo (BPPV), the most common vestibular disorder, is diagnosed by an examiner changing the posture of the examinee and inducing nystagmus. Among the diagnostic methods used to observe nystagmus, video-nystagmography has been widely used recently because it is non-invasive. A specialist with professional knowledge and training in vertigo diagnosis is needed to diagnose BPPV accurately, but the ratio of vertigo patients to specialists is too high, thus necessitating the need for automated diagnosis of BPPV. In this paper, a convolutional neural network-based nystagmus extraction system, ANyEye, optimized for video-nystagmography data is proposed. A pupil was segmented to track the exact pupil trajectory from real-world data obtained during field inspection. A deep convolutional neural network model was trained with the new video-nystagmography dataset for the pupil segmentation task, and a compensation algorithm was designed to correct pupil position. In addition, a slippage detection algorithm based on moving averages was designed to eliminate the motion artifacts induced by goggle slippage. ANyEye outperformed other eye-tracking methods including learning and non-learning-based algorithms with five-pixel error detection rate of 91.26%.


Assuntos
Inteligência Artificial , Nistagmo Patológico , Humanos , Técnicas de Diagnóstico Oftalmológico , Algoritmos , Redes Neurais de Computação , Vertigem Posicional Paroxística Benigna
6.
Cell Rep ; 39(8): 110861, 2022 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-35613594

RESUMO

N6-methyladenosine (m6A) is the most prevalent internal modification in eukaryotic mRNAs and affects RNA processing and metabolism. When YTHDF2, an m6A-recognizing protein, binds to m6A, it facilitates the destabilization of m6A-containing RNAs (m6A RNAs). Here, we demonstrate that upstream frameshift 1 (UPF1), a key factor for nonsense-mediated mRNA decay, interacts with YTHDF2, thereby triggering rapid degradation of m6A RNAs. The UPF1-mediated m6A RNA degradation depends on a specific interaction between UPF1 and N-terminal residues 101-168 of YTHDF2, UPF1 ATPase/helicase activities, and UPF1 interaction with proline-rich nuclear receptor coactivator 2 (PNRC2), a decapping-promoting factor preferentially involved in nonsense-mediated mRNA decay. Furthermore, transcriptome-wide analyses show that YTHDF2-bound mRNAs that are not substrates for HRSP12-RNase P/MRP-mediated endoribonucleolytic cleavage are destabilized with a higher dependency on UPF1. Collectively, our data indicate dynamic and multilayered regulation of the stability of m6A RNAs and highlight the multifaceted role of UPF1 in mRNA decay.


Assuntos
RNA Helicases , Transativadores , Degradação do RNAm Mediada por Códon sem Sentido , RNA/metabolismo , RNA Helicases/metabolismo , Estabilidade de RNA/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/metabolismo
7.
Cancer Sci ; 113(5): 1752-1762, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35243724

RESUMO

We investigated the anticancer effect of the aptamer-conjugated gemcitabine-loaded atelocollagen patch in a pancreatic cancer patient-derived xenograft (PDX) model to propose a future potential adjuvant surgical strategy during curative pancreatic resection for pancreatic cancer. A pancreatic cancer PDX model was established. Animals were grouped randomly into a no-treatment control group; treatment group treated with intraperitoneal gemcitabine injection (IP-GEM) or aptamer-conjugated gemcitabine (APT:GEM); and transplant with three kinds of patches: atelocollagen-aptamer-gemcitabine (patch I), atelocollagen-inactive aptamer-gemcitabine (patch II), and atelocollagen-gemcitabine (patch III). Tumor volumes and response were evaluated based on histological analysis by H&E staining and Immunohistochemistry (IHC) was performed. Anticancer therapy-related toxicity was evaluated by hematologic findings. The patch I group showed the most significant reduction of tumor growth rate, compared with the no-treatment group (p < 0.05). However, other treatment groups were not found to show significant reduction in tumor growth rate (0.05 < p < 0.1). There was no microscopic evidence suggesting potential toxicity, such as inflammation, nor necrotic changes in liver, lung, kidney, and spleen tissue. In addition, no leukopenia, anemia, or neutropenia was observed in the patch I group. This implantable aptamer-drug conjugate system is thought to be a new surgical strategy to augment the oncologic significance of margin-negative resection in treating pancreatic cancer in near future.


Assuntos
Neoplasias Pancreáticas , Animais , Humanos , Linhagem Celular Tumoral , Colágeno , Desoxicitidina/análogos & derivados , Modelos Animais de Doenças , Gencitabina , Xenoenxertos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto , Neoplasias Pancreáticas
8.
Complement Ther Clin Pract ; 44: 101447, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34289443

RESUMO

BACKGROUND AND PURPOSE: Outpatient nursing is an occupation with high emotional labor and job stress. The purpose of this study was to examine the effects of auricular acupressure on stress, anxiety, and depression of outpatient nurses. MATERIALS AND METHODS: The study design was a randomized controlled trial. Participants were 54 outpatient nurses, divided into an experimental (n = 28) and a control group (n = 26). Auricular acupressure using vaccaria seeds was administered to the experimental group, while placebo auricular acupressure using vaccaria seeds was administered to the placebo group. Sessions continued for 5 weeks. Outcome measurements included blood tests such as cortisol and serotonin. RESULTS: There was a statistically significant difference in depression scores (t = 3.111, p = 0.002) and serotonin levels (t = 6.304, p < 0.001) between the experimental and placebo groups. Auricular acupressure decreased depression scores, and the depression-related physiological index, serotonin, also changed significantly. CONCLUSION: Auricular acupressure using vaccaria seeds was effective in decreasing depression in outpatient nurses.


Assuntos
Acupressão , Enfermeiras e Enfermeiros , Ansiedade/terapia , Humanos , Pacientes Ambulatoriais , República da Coreia
9.
J Clin Apher ; 36(1): 135-142, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33247855

RESUMO

BACKGROUND: Peripheral blood stem cell (PBSC) collection is important for successful hematopoietic stem cell transplantation. This study aimed to investigate the laboratory parameters associated with the optimal timing of autologous PBSC collection from lymphoma and multiple myeloma patients. METHODS: We retrospectively evaluated data from 1105 PBSC apheresis procedures performed on 379 adult patients at the National Cancer Center between June 2005 and December 2019. Laboratory parameters, including cutoff values for the number of hematopoietic progenitor cells (HPCs) and circulating CD34+ cells, were analyzed to determine their association with CD34+ cell yield. RESULTS: The pre-apheresis HPC and CD34+ cell count were statistically significant variables associated with harvested CD34+ cell in lymphoma and MM patients. The optimal cutoff values were 18 × 106 /L for pre-HPC count (66.8% sensitivity, 66.4% specificity) and 11/µL for pre-CD34+ cell count (85.8% sensitivity, 87.2% specificity), to achieve CD34+ cell yields ≥ 1.0 × 106 /kg for each apheresis procedure. Moreover, the optimal cutoff values were 23 × 106 /L for pre-HPC count (71.0% sensitivity, 69.0% specificity) and 18/µL for pre-CD34+ cell count (87.5% sensitivity, 86.3% specificity) to achieve CD34+ cell yields ≥ 2.0 × 106 /kg for each apheresis procedure. CONCLUSION: HPC count is a potential surrogate marker for monitoring the starting time for PBSC collection. Applying cutoff values for the number of HPC and CD34+ cells may be clinically useful for optimizing the timing of PBSC collection.


Assuntos
Remoção de Componentes Sanguíneos/métodos , Mobilização de Células-Tronco Hematopoéticas/métodos , Linfoma/terapia , Mieloma Múltiplo/terapia , Transplante de Células-Tronco de Sangue Periférico/métodos , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neutrófilos , Estudos Retrospectivos , Transplante Autólogo , Adulto Jovem
10.
J Clin Apher ; 36(1): 28-33, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32882095

RESUMO

INTRODUCTION: Autologous peripheral blood stem cell (PBSC) transplantation has become a standard treatment option for many oncology patients. The aim of this study was to evaluate the performance of two cell separators, Spectra Optia (Terumo BCT, Japan) and Amicus (Fresenius-Kabi) for autologous PBSC collection. METHODS: We retrospectively evaluated 56 apheresis by Spectra Optia with Continuous Mononuclear Cell Collection (cMNC) from 20 patients, and 50 apheresis by Amicus from 27 patients between December 2018 and December 2019. CD34+ collection efficiency (CE2) and platelet (PLT) loss were evaluated. RESULTS: There was no significant difference in CD34+ CE2 between Spectra Optia with cMNC (median, 28.8%) and Amicus (median, 33.1%; P = 0.537). PLT loss was significantly lower in Amicus (median, 28.6%) than in Spectra Optia with cMNC (median, 37.8%; P = 0.009). CONCLUSION: CD34+ CE2 was comparable between Spectra Optia and Amicus, and PLT loss was significantly lower in Amicus. To the best of our knowledge, this is the first report comparing autologous PBSC collection of the Spectra Optia and Amicus. These results may provide general guidance with regard to device selection to apheresis clinics that use both separators for optimal outcomes depending on each patient's characteristics.


Assuntos
Remoção de Componentes Sanguíneos/métodos , Mobilização de Células-Tronco Hematopoéticas/métodos , Células-Tronco de Sangue Periférico/citologia , Adulto , Remoção de Componentes Sanguíneos/instrumentação , Feminino , Mobilização de Células-Tronco Hematopoéticas/instrumentação , Humanos , Masculino , Pessoa de Meia-Idade , Transplante Autólogo , Adulto Jovem
11.
J Virol ; 94(24)2020 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-32967955

RESUMO

Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe respiratory illness and has a high mortality of ∼34%. However, since its discovery in 2012, an effective vaccine has not been developed for it. To develop a vaccine against multiple strains of MERS-CoV, we targeted spike glycoprotein (S) using prime-boost vaccination with DNA and insect cell-expressed recombinant proteins for the receptor-binding domain (RBD), S1, S2, SΔTM, or SΔER. Our S subunits were generated using an S sequence derived from the MERS-CoV EMC/2012 strain. We examined humoral and cellular immune responses of various combinations with DNA plasmids and recombinant proteins in mice. Mouse sera immunized with SΔER DNA priming/SΔTM protein boosting showed cross-neutralization against 15 variants of S-pseudovirions and the wild-type KOR/KNIH/002 strain. In addition, these immunizations provided full protection against the KOR/KNIH/002 strain challenge in human DPP4 knock-in mice. These findings suggest that vaccination with the S subunits derived from one viral strain can provide cross-protection against variant MERS-CoV strains with mutations in S. DNA priming/protein boosting increased gamma interferon production, while protein-alone immunization did not. The RBD subunit alone was insufficient to induce neutralizing antibodies, suggesting the importance of structural conformation. In conclusion, heterologous DNA priming with protein boosting is an effective way to induce both neutralizing antibodies and cell-mediated immune responses for MERS-CoV vaccine development. This study suggests a strategy for selecting a suitable platform for developing vaccines against MERS-CoV or other emerging coronaviruses.IMPORTANCE Coronavirus is an RNA virus with a higher mutation rate than DNA viruses. Therefore, a mutation in S-protein, which mediates viral infection by binding to a human cellular receptor, is expected to cause difficulties in vaccine development. Given that DNA-protein vaccines promote stronger cell-mediated immune responses than protein-only vaccination, we immunized mice with various combinations of DNA priming and protein boosting using the S-subunit sequences of the MERS-CoV EMC/2012 strain. We demonstrated a cross-protective effect against wild-type KOR/KNIH/002, a strain with two mutations in the S amino acids, including one in its RBD. The vaccine also provided cross-neutralization against 15 different S-pseudotyped viruses. These suggested that a vaccine targeting one variant of S can provide cross-protection against multiple viral strains with mutations in S. The regimen of DNA priming/Protein boosting can be applied to the development of other coronavirus vaccines.


Assuntos
Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Proteção Cruzada , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Vacinas de DNA/imunologia , Vacinas Virais/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/virologia , Modelos Animais de Doenças , Feminino , Humanos , Imunidade Celular , Imunização Secundária , Imunogenicidade da Vacina , Camundongos , Plasmídeos/administração & dosagem , Plasmídeos/genética , Plasmídeos/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Vacinação , Vacinas de DNA/administração & dosagem , Vacinas Virais/administração & dosagem
12.
Comput Methods Programs Biomed ; 195: 105662, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32712504

RESUMO

BACKGROUND AND OBJECTIVE: The dielectrophoresis (DEP) technique is increasingly being recognised as a potentially valuable tool for non-contact manipulation of numerous cells as well as for biological single cell analysis with non-invasive characterisation of a cell's electrical properties. Several studies have attempted to track multiple cells to characterise their cellular DEP mobility. However, they encountered difficulties in simultaneously tracking the movement of a large number of individual cells in a bright-field image sequence because of interference from the background electrode pattern. Consequently, this present study aims to develop an automatic system for imaging-based characterisation of cellular DEP mobility, which enables the simultaneous tracking of several hundred of cells inside a microfluidic device. METHODS: The proposed method for segmentation and tracking of cells consists of two main stages: pre-processing and particle centre localisation. In the pre-processing stage, background subtraction and contrast enhancement were performed to distinguish the cell region from the background image. In the particle centre localisation stage, the unmarked cell was automatically detected via graph-cut algorithm-based K-means clustering. RESULTS: Our algorithm enabled segmentation and tracking of numerous Michigan Cancer Foundation-7 (MCF-7) cell trajectories while the DEP force was oscillated between positive and negative. The cell tracking accuracy and cell count capability was at least 90% of the total number of cells with the newly developed algorithm. In addition, the cross-over frequency was measured by analysing the segmented and tracked trajectory data of the cellular movements caused by the positive and negative DEP force. The measured cross-over frequency was compared with previous results. The multi-cellular movements investigation based on the measured cross-over frequency was repeated until the viability of cells was unchanged in the same environment as in a microfluidic device. The results were statistically consistent, indicating that the developed algorithm was reliable for the investigation of DEP cellular mobility. CONCLUSION: This study developed a powerful platform to simultaneously measure the DEP-induced trajectories of numerous cells, and to investigate in a robust, efficient, and accurate manner the DEP properties at both the single cell and cell ensemble level.


Assuntos
Algoritmos , Dispositivos Lab-On-A-Chip , Movimento Celular , Eletrodos , Eletroforese
13.
PLoS One ; 15(7): e0236172, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32726321

RESUMO

There are several broadly neutralizing monoclonal antibodies that neutralize influenza viruses with different mechanisms from traditional polyclonal antibodies induced by vaccination. CT149, which is one of the broadly neutralizing antibodies, was also previously reported to neutralize group 2 and some of group 1 influenza viruses (13 out of 13 tested group 2 viruses and 5 out of 11 group 1 viruses). In this study, we developed another antibody with the aim of compensating partial coverage of CT149 against group 1 influenza viruses. CT120 was screened among different antibody candidates and mixed with CT149. Importantly, although the binding sites of CT120 and CT149 are close to each other, the two antibodies do not interfere. The mixture of CT120 and CT149, which we named as CT-P27, showed broad efficacy by neutralizing 37 viruses from 11 different subtypes, of both group 1 and 2 influenza A viruses. Moreover, CT-P27 showed in vivo therapeutic efficacy, long prophylactic potency, and synergistic effect with oseltamivir in influenza virus-challenged mouse models. Our findings provide a novel therapeutic opportunity for more efficient treatment of influenza.


Assuntos
Anticorpos Monoclonais/farmacocinética , Anticorpos Neutralizantes/farmacologia , Vírus da Influenza A Subtipo H1N1/imunologia , Influenza Humana/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Especificidade de Anticorpos/imunologia , Antígenos Virais/imunologia , Hemaglutinação/imunologia , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Camundongos , Testes de Neutralização , Vacinação
14.
Transfus Apher Sci ; 59(2): 102679, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31831328

RESUMO

BACKGROUND: The collection of a sufficient number of stem cells is important for success of allogeneic hematopoietic stem cell transplantation (HSCT). This study aimed to investigate the factors associated with successful allogeneic peripheral stem cell (PBSC) collection in healthy donors. METHODS: We retrospectively reviewed clinical data of allogeneic PBSC collection in 175 donors from 2007 to 2017 at the National Cancer Center, Korea. This study analyzed factors associated with the CD34+ cell yield such as the characteristics of donors, including age, laboratory results before apheresis, and data of procedures on the first day. The CD34+ cell dose of ≥ 4.0 × 106/kg have recently been the accepted minimum recommended dose in allogeneic HSCT settings, and this was the target dose in our study. RESULTS: The factors associated with the CD34+ cell yield were age (p = 0.007), baseline platelet (PLT) (p = 0.014), and pre-collection hematopoietic progenitor cells (HPCs) (p = 0.001) by multivariate analysis. This study represented that age, baseline platelet count, and pre-collection HPC count are important predictive factors as shown in other previous studies. CONCLUSION: Our data suggest that young age, high baseline platelet counts and high HPC counts before collection might be useful for identifying successful mobilizers.


Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Condicionamento Pré-Transplante/métodos , Transplante Homólogo/métodos , Adolescente , Adulto , Idoso , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Doadores de Tecidos , Adulto Jovem
15.
Clin Exp Vaccine Res ; 7(2): 104-110, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30112349

RESUMO

PURPOSE: An oral cholera vaccine (OCV), Euvichol, with thimerosal (TM) as preservative, was prequalified by the World Health Organization (WHO) in 2015. In recent years, public health services and regulatory bodies recommended to eliminate TM in vaccines due to theoretical safety concerns. In this study, we examined whether TM-free Euvichol induces comparable immunogenicity to its TM-containing formulation in animal model. MATERIALS AND METHODS: To evaluate and compare the immunogenicity of the two variations of OCV, mice were immunized with TM-free or TM-containing Euvichol twice at 2-week interval by intranasal or oral route. One week after the last immunization, mice were challenged with Vibrio cholerae O1 and daily monitored to examine the protective immunity against cholera infection. In addition, serum samples were obtained from mice to measure vibriocidal activity and vaccine-specific IgG, IgM, and IgA antibodies using vibriocidal assay and enzyme-linked immunosorbent assay, respectively. RESULTS: No significant difference in immunogenicity, including vibriocidal activity and vaccine-specific IgG, IgM, and IgA in serum, was observed between mice groups administered with TM-free and -containing Euvichol, regardless of immunization route. However, intranasally immunized mice elicited higher levels of serum antibodies than those immunized via oral route. Moreover, intranasal immunization completely protected mice against V. cholerae challenge but not oral immunization. There was no significant difference in protection between two Euvichol variations. CONCLUSION: These results suggested that TM-free Euvichol could provide comparable immunogenicity to the WHO prequalified Euvichol containing TM as it was later confirmed in a clinical study. The pulmonary mouse cholera model can be considered useful to examine in vivo the potency of OCVs.

16.
Autophagy ; 14(8): 1347-1358, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29929436

RESUMO

TRAF6 (TNF receptor associated factor 6) plays a pivotal role in NFKB activation and macroautphagy/autophagy activation induced by TLR4 (toll like receptor 4) signaling. The objective of this study was to determine the functional role of PRDX1 (peroxiredoxin 1) in NFKB activation and autophagy activation. PRDX1 interacted with the ring finger domain of TRAF6 and inhibited its ubiquitin-ligase activity. The inhibition on TRAF6 ubiquitin-ligase activity by PRDX1 induced the suppression of ubiquitination of an evolutionarily conserved signaling intermediate in Toll pathways (ECSIT) essential for NFKB activation and BECN1 (beclin 1) required for autophagy activation. An inhibitory effect of PRDX1 on TRAF6 was clearly evidenced in PRDX1-knockdown (PRDX1KD) THP-1, PRDX1KD MDA-MB-231, and PRDX1KD SK-HEP-1 cells. PRDX1KD THP-1 cells showed increases of NFKB activation, pro-inflammatory cytokine production, NFKB-dependent gene expression induced by TLR4 stimulation, and resistance against Salmonella typhimurium infection. Additionally, migration and invasion abilities of PRDX1KD MDA-MB-231 and PRDX1KD SK-HEP-1 cancer cells were significantly enhanced compared to those of control cancer cells. Taken together, these results suggest that PRDX1 negatively regulates TLR4 signaling for NFKB activation and autophagy functions such as bactericidal activity, cancer cell migration, and cancer cell invasion by inhibiting TRAF6 ubiquitin-ligase activity. ABBREVIATIONS: 3-MA: 3-methyladenine; BECN1: beclin 1; CHUK/IKKA: conserved helix-loop-helix ubiquitous kinase; ECSIT: ECSIT signalling integrator; ELISA: enzyme-linked immunosorbent assay; NFKB: nuclear factor kappa-light-chain-enhancer of activated B cells; IB: immunoblotting; IKBKB/IKKB: inhibitor of nuclear factor kappa B kinase subunit beta; IL1B: interleukin 1 beta; IL6: interleukin 6; IP: immunoprecipitation; LPS: lipopolysaccharide; MAP1LC3/LC3: microtuble associated protein 1 light chain 3; MAP3K7/TAK1: mitogen-activated protein kinase kinase kinase 7; MAPK14/p38: mitogen-activated protein kinase 14; mROS: mitochondrial reactive oxygen species; PRDX1: peroxiredoxin 1; PRDX6: peroxiredoxin 6; RELA/p65: RELA proto-oncogene, NF-kB subunit; TRAF6 TNF: receptor associated factor 6.


Assuntos
Autofagia , NF-kappa B/antagonistas & inibidores , Peroxirredoxinas/metabolismo , Fator 6 Associado a Receptor de TNF/antagonistas & inibidores , Proteína Beclina-1/metabolismo , Progressão da Doença , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Modelos Biológicos , NF-kappa B/metabolismo , Ligação Proteica , Proto-Oncogene Mas , Transdução de Sinais , Células THP-1 , Fator 6 Associado a Receptor de TNF/metabolismo , Receptor 4 Toll-Like/metabolismo , Ubiquitinação
17.
J Neurosci ; 38(6): 1351-1365, 2018 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-29279307

RESUMO

Injury to the peripheral axons of sensory neurons strongly enhances the regeneration of their central axons in the spinal cord. It remains unclear on what molecules that initiate such conditioning effect. Because ATP is released extracellularly by nerve and other tissue injury, we hypothesize that injection of ATP into a peripheral nerve might mimic the stimulatory effect of nerve injury on the regenerative state of the primary sensory neurons. We found that a single injection of 6 µl of 150 µm ATP into female rat sciatic nerve quadrupled the number of axons growing into a lesion epicenter in spinal cord after a concomitant dorsal column transection. A second boost ATP injection 1 week after the first one markedly reinforced the stimulatory effect of a single injection. Single ATP injection increased expression of phospho-STAT3 and GAP43, two markers of regenerative activity, in sensory neurons. Double ATP injections sustained the activation of phospho-STAT3 and GAP43, which may account for the marked axonal growth across the lesion epicenter. Similar studies performed on P2X7 or P2Y2 receptor knock-out mice indicate P2Y2 receptors are involved in the activation of STAT3 after ATP injection or conditioning lesion, whereas P2X7 receptors are not. Injection of ATP at 150 µm caused little Wallerian degeneration and behavioral tests showed no significant long-term adverse effects on sciatic nerve functions. The results in this study reveal possible mechanisms underlying the stimulation of regenerative programs and suggest a practical strategy for stimulating axonal regeneration following spinal cord injury.SIGNIFICANCE STATEMENT Injury of peripheral axons of sensory neurons has been known to strongly enhance the regeneration of their central axons in the spinal cord. In this study, we found that injection of ATP into a peripheral nerve can mimic the effect of peripheral nerve injury and significantly increase the number of sensory axons growing across lesion epicenter in the spinal cord. ATP injection increased expression of several markers for regenerative activity in sensory neurons, including phospho-STAT3 and GAP43. ATP injection did not cause significant long-term adverse effects on the functions of the injected nerve. These results may lead to clinically applicable strategies for enhancing neuronal responses that support regeneration of injured axons.


Assuntos
Trifosfato de Adenosina/farmacologia , Axônios/efeitos dos fármacos , Regeneração Nervosa/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Células Receptoras Sensoriais/efeitos dos fármacos , Medula Espinal/efeitos dos fármacos , Trifosfato de Adenosina/administração & dosagem , Animais , Comportamento Animal , Feminino , Proteína GAP-43/biossíntese , Proteína GAP-43/genética , Injeções , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Traumatismos dos Nervos Periféricos/genética , Traumatismos dos Nervos Periféricos/patologia , Ratos , Receptores Purinérgicos P2X7/genética , Receptores Purinérgicos P2Y2/genética , Fator de Transcrição STAT3/biossíntese , Fator de Transcrição STAT3/genética , Nervo Isquiático , Traumatismos da Medula Espinal/patologia , Degeneração Walleriana/genética , Degeneração Walleriana/fisiopatologia
19.
Front Immunol ; 8: 1827, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29326710

RESUMO

Ubiquitin-specific protease 14 (USP14), one of three proteasome-associated deubiquitinating enzymes, has multifunctional roles in cellular context. Here, we report a novel molecular mechanism and function of USP14 in regulating autophagy induction and nuclear factor-kappa B (NF-κB) activation induced by toll-like receptor (TLR) 4 (TLR4). USP14 interacted with tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) and interrupted the association of Beclin 1 with TRAF6, leading to inhibition of TRAF6-mediated ubiquitination of Beclin 1. Reduced expression of USP14 in USP14-knockdown (USP14KD) THP-1 cells enhanced autophagy induction upon TLR4 stimulation as shown by the increased conversion of cytosolic LC3-I to membrane-bound LC3-II. Moreover, USP14KD human breast carcinoma MDA-MB-231 cells and USP14KD human hepatic adenocarcinoma SK-HEP-1 cells showed increased cell migration and invasion, indicating that USP14 is negatively implicated in the cancer progression by the inhibition of autophagy induction. Furthermore, we found that USP14 interacted with TAK1-binding protein (TAB) 2 protein and induced deubiquitination of TAB 2, a key factor in the activation of NF-κB. Functionally, overexpression of USP14 suppressed TLR4-induced activation of NF-κB. In contrast, USP14KD THP-1 cells showed enhanced activation of NF-κB, NF-κB-dependent gene expression, and production of pro-inflammatory cytokines such as IL-6, IL-1ß, and tumor necrosis factor-α. Taken together, our data demonstrate that USP14 can negatively regulate autophagy induction by inhibiting Beclin 1 ubiquitination, interrupting association between TRAF6 and Beclin 1, and affecting TLR4-induced activation of NF-κB through deubiquitination of TAB 2 protein.

20.
Immune Netw ; 16(6): 373-380, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28035213

RESUMO

Peroxiredoxin-3 (Prdx3) is a mitochondrial protein of the thioredoxin family of antioxidant peroxidases and is the principal peroxidase responsible for metabolizing mitochondrial hydrogen peroxide. Recent reports have shown that mitochondrial reactive oxygen species (mROS) contribute to macrophage-mediated bactericidal activity in response to Toll-like receptors. Herein, we investigated the functional effect of Prdx3 in bactericidal activity. The mitochondrial localization of Prdx3 in HEK293T cells was confirmed by cell fractionation and confocal microscopy analyses. To investigate the functional role of Prdx3 in bactericidal activity, Prdx3-knockdown (Prdx3KD) THP-1 cells were generated. The mROS levels in Prdx3KD THP-1 cells were significantly higher than those in control THP-1 cells. Moreover, the mROS levels were markedly increased in response to lipopolysaccharide. Notably, the Salmonella enterica serovar Typhimurium infection assay revealed that the Prdx3KD THP-1 cells were significantly resistant to S. Typhimurium infection, as compared with control THP-1 cells. Taken together, these results indicate that Prdx3 is functionally important in bactericidal activity through the regulation of mROS.

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