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1.
Int J Nanomedicine ; 19: 5381-5395, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38859950

RESUMO

Background: Current immunotherapies with unexpected severe side effects and treatment resistance have not resulted in the desired outcomes for patients with melanoma, and there is a need to discover more effective medications. Cytotoxin (CTX) from Cobra Venom has been established to have favorable cytolytic activity and antitumor efficacy and is regarded as a promising novel anticancer agent. However, amphiphilic CTX with excellent anionic phosphatidylserine lipid-binding ability may also damage normal cells. Methods: We developed pH-responsive liposomes with a high CTX load (CTX@PSL) for targeted acidic-stimuli release of drugs in the tumor microenvironment. The morphology, size, zeta potential, drug-release kinetics, and preservation stability were characterized. Cell uptake, apoptosis-promoting effects, and cytotoxicity were assessed using MTT assay and flow cytometry. Finally, the tissue distribution and antitumor effects of CTX@PSL were systematically assessed using an in vivo imaging system. Results: CTX@PSL exhibited high drug entrapment efficiency, drug loading, stability, and a rapid release profile under acidic conditions. These nanoparticles, irregularly spherical in shape and small in size, can effectively accumulate at tumor sites (six times higher than free CTX) and are rapidly internalized into cancer cells (2.5-fold higher cell uptake efficiency). CTX@PSL displayed significantly stronger cytotoxicity (IC50 0.25 µg/mL) and increased apoptosis in than the other formulations (apoptosis rate 71.78±1.70%). CTX@PSL showed considerably better tumor inhibition efficacy than free CTX or conventional liposomes (tumor inhibition rate 79.78±5.93%). Conclusion: Our results suggest that CTX@PSL improves tumor-site accumulation and intracellular uptake for sustained and targeted CTX release. By combining the advantages of CTX and stimuli-responsive nanotechnology, the novel CTX@PSL nanoformulation is a promising therapeutic candidate for cancer treatment.


Assuntos
Antineoplásicos , Venenos Elapídicos , Lipossomos , Lipossomos/química , Concentração de Íons de Hidrogênio , Animais , Venenos Elapídicos/química , Venenos Elapídicos/farmacologia , Humanos , Linhagem Celular Tumoral , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/farmacocinética , Camundongos , Apoptose/efeitos dos fármacos , Liberação Controlada de Fármacos , Citotoxinas/química , Citotoxinas/farmacologia , Citotoxinas/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Distribuição Tecidual , Microambiente Tumoral/efeitos dos fármacos , Nanopartículas/química
2.
Protein J ; 43(3): 603-612, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38734856

RESUMO

Disintegrins, a family of snake venom protein, which are capable of modulating the activity of integrins that play a fundamental role in the regulation of many physiological and pathological processes. The main purpose of this study is to obtain the recombinant disintegrin (r-DI) and evaluate its biological activity. In this study, we explored a high-level expression prokaryotic system and purification strategy for r-DI. Then, r-DI was treated to assay effects on cell growth, migration, and invasion. The affinity for the interactions of r-DI with integrin was determined using Surface plasmon resonance (SPR) analyses. The r-DI can be expressed in Escherichia coli and purified by one-step chromatography. The r-DI can inhibit B16F10 cells proliferation, migration, and invasion. Also, we found that r-DI could interact with the integrin αIIbß3 (GPIIb/IIIa). The r-DI can be expressed, purified, characterized through functional assays, and can also maintain strong biological activities. Thus, this study showed potential therapeutic effects of r-DI for further functional and structural studies.


Assuntos
Desintegrinas , Escherichia coli , Proteínas Recombinantes , Escherichia coli/genética , Escherichia coli/metabolismo , Animais , Desintegrinas/química , Desintegrinas/genética , Desintegrinas/isolamento & purificação , Desintegrinas/farmacologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/metabolismo , Camundongos , Viperidae/genética , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/genética , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/química , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Linhagem Celular Tumoral , Expressão Gênica , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Venenos de Crotalídeos/química , Venenos de Crotalídeos/genética , Crotalinae , Serpentes Peçonhentas
3.
Anim Reprod Sci ; 255: 107295, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37422950

RESUMO

The critical role of the G protein-coupled receptor 1 (GPER1), a member of the seven-transmembrane G protein-coupled receptor family, in the functional regulation of oocytes accumulated abundant theories in the early research on model animals. However, the full-length cDNA encoding GPER1 and its role in the folliculogenesis has not been illustrated in crocodilians. 0.5, 3, and 12 months old Alligator sinensis cDNA samples were used to clone the full-length cDNA encoding GPER1. Immunolocalization and quantitative analysis were performed using Immunofluorescence technique, RT-PCR and Western blot. Simultaneously, studies on GPER1's promoter deletion and cis-acting transcriptional regulation mechanism were conducted. Immunolocalization staining for the germline marker DDX4 and GPER1 demonstrated that DDX4-positive oocytes were clustered tightly together within the nests, whereas scarcely any detectable GPER1 was present in the oocytes nest in Stage I. After that, occasionally GPER1-positive immunosignal was observed in oocytes and somatic cells additional with the primordial follicles, and it was mainly located at the granulosa cells or thecal cells within the early PFs in the Stage III. The single mutation of the putative SP1 motif, double mutating of Ets/SP1 and SP1/CRE binding sites all depressed promoter activities. This result will help to investigate the role of GPER1 in the early folliculogenesis of A. sinensis.


Assuntos
Jacarés e Crocodilos , Feminino , Animais , Jacarés e Crocodilos/genética , DNA Complementar/metabolismo , Ovário/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Proteínas de Ligação ao GTP/metabolismo
4.
BMC Zool ; 8(1): 8, 2023 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-37403129

RESUMO

BACKGROUND: The precise mechanisms of hormone action responsible for the full course of events modulating folliculogenesis in crocodilian have not been determined, although histological features have been identified. RESULTS: The Alligator sinensis ovarian morphological characteristics observed at 1, 15, 30, 60, 90, and 300 days post hatching(dph) revealed that the dynamic changes in germ cells varied in different meiotic and developmental stages, confirming that the processes of folliculogenesis were protracted and asynchronous. The presence of endogenous follicle-stimulating hormone(FSH) mRNA and protein expression within the cerebrum at 1 dph, in parallel with the increase in germ cells within the germ cell nests(Nest) from 1 dph to 15 dph, suggested that endocrine regulation of the pituitary-gonad axis is an early event in oogonia division. Furthermore, the endogenous expression of FSH showed a trend of negative feedback augmentation accompanied by the exhaustion of maternal yolk E2 observed at 15 dph. Such significant elevation of endogenous FSH levels was observed to be related to pivotal events in the transition from mitosis to meiosis, as reflected by the proportion of oogonia during premeiosis interphase, with endogenous FSH levels reaching a peak at the earliest time step of 1 dph. In addition, the simultaneous upregulation of premeiotic marker STRA8 mRNA expression and the increase in endogenous FSH further verified the above speculation. The strongly FSHr-positive label in the oocytes within Pre-previtellogenic follicles was synchronized with the significant elevation of ovarian cAMP detected at 300 dph, which suggested that diplotene arrest maintenance during early vitellogenesis might be FSH dependent. In addition, preferential selection in asynchronous meiotic initiation has been supposed to act on somatic supportive cells and not directly on germ cells via regulation of FSH that in turn affects downstream estrogen levels. This suggestion was verified by the reciprocal stimulating effect of FSH and E2 on the accelerated meiotic marker SYCP3 and by the inhibited cell apoptosis demonstrated in ovarian cell culture in vitro. CONCLUSION: The corresponding results contribute an expansion of the understanding of physiological processes and shed some light on the specific factors responsible for gonadotropin function in the early folliculogenesis of crocodilians.

5.
Life (Basel) ; 12(11)2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36362939

RESUMO

Significant advances have been made in the morphological observations of the dorsal gland (DG), an oval organ/tissue which lies on both sides of the dorsal midline of the crocodilian. In the current study, RNA sequencing (RNA-seq) was used to identify the changing patterns of Alligator sinesis DGs at different timepoints from the 31st embryonic day (E31) to the newly hatched 1st day (NH1). A comprehensive transcriptional changes of differentially expression gene (DEGs) involved in the melanogenesis, cholesterol metabolism, and cell apoptosis pathways suggested that the DG might serves as a functional secretory gland in formation, transport and deposition of pigment, and lipids secretion via lysosomal exocytosis. Furthermore, the remarkable immunohistochemical staining of proliferating cell nuclear antigen (PCNA) and B-cell lymphoma 2 (Bcl-2)-positive signals in the basilar cells, in parallel with the immuno-reactive TdT-mediated dUTP nick-End labeling(TUNEL) within suprabasal cells, provided direct molecular evidence supporting for the speculation that DG serves as a holocrine secretion mode. Finally, subsequent phylogenetic and immunohistochemical analysis for the PITX2, the identified DEGs in the RNA-seq, was helpful to further elucidate the transcriptional regulatory mechanism of candidate genes. In conclusion, the current results are of considerable importance in enriching our understanding of the intrinsic relationship between the skin derivatives and lifestyles of newborn Alligator sinesis.

6.
Reprod Fertil Dev ; 34(12): 819-832, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35577543

RESUMO

Although oviductal sperm storage are essential steps in reproduction for female animals with internal fertilisation, no systematic study on the identification of genes involving sperm storage has been performed in crocodilian species. In the present research, the relationship between morphological variation related to sperm storage in the oviduct and gene expression patterns derived from RNA sequencing analyses between active period (AP), breeding period (BP), and hibernation period (HP) were investigated. The corresponding results indicated that sperm were observed not only in the ciliated cells within infundibulum and mucosal layer of uterus during BP, but also been detected in the spermatosperm storage tube (SST) in the anterior uterus at HP stage. The further transmission electron microscopy analysis indicated that the differences in the number and activity of the secretory cells likely to attributed to the seasonal variation of microenvironment related to the sperm storage. Based on the RNA-sequecing, 13147 DEGs related to the Peroxisome proliferator-activated receptors (PPARs) and FOXO signalling were identified, including these, the down-regulated ATG12 and BCL2L11 in the HP group may thus constitute an important point of convergence between autophagy and apoptosis involving the FOXO1 pathway. The genes involved in the PPARs pathway might modulate the immune response and thereby contribute to prolong the life span of stored spermatozoa in Alligator sinensis . The outcomes of this study provide fundamental insights into the mechanism of sperm storage in A. sinensis .


Assuntos
Jacarés e Crocodilos , Oviductos , Jacarés e Crocodilos/fisiologia , Animais , China , Feminino , Expressão Gênica , Masculino , Oviductos/fisiologia , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Estações do Ano , Sêmen , Espermatozoides/fisiologia
7.
Onco Targets Ther ; 14: 2599-2610, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33880038

RESUMO

PURPOSE: To assess the value of macrophage-related biomarkers (CD163, CD68, MCSF, and CCL2) for predicting the response to neo-chemoradiotherapy (NCRT) and the prognosis of locally advanced rectal cancer (LARC). METHODS: We enrolled 191 patients who underwent neoadjuvant chemoradiotherapy and radical resection between 2011 and 2015. Tumor tissues were collected before NCRT with a colonoscope and post-surgery and were subjected to immunohistochemical analysis. RESULTS: The expression levels of macrophage-related biomarkers (CD163, CD68, MCSF, and CCL2) were lower in the pathological complete response (pCR) group when compared with the non-pCR group (all P<0.05). Based on X-tile plots, we divided the tumors in two groups and found that lower pre-NCRT/post-surgical CD163, CD68, MCSF, CCL2 scores correlated with improved DFS. Cox regression analysis demonstrated that pre-NCRT CD163 (HR=1.008, 95% CI 1.003-1.013, P=0.003) and MCSF (HR=2.187, 95% CI 1.343-3.564, P=0.002) scores were independent predictors of DFS. Based on Cox multivariate analysis, we constructed a risk score model with a powerful ability to predict pCR in LARC patients. Moreover, COX regression analysis was performed to explore the role of the risk score in LARC patients. The results demonstrated that tumor size (HR=1.291, P=0.041), worse pathological TNM stage (HR=1.789, P=0.005, and higher risk score (HR=1.084, P<0.001) were significantly associated with impaired disease-free survival. Based on the above results, a nomogram and decision curve analysis were generated. CONCLUSION: The expression levels of macrophage-related biomarkers CD163, CD68, MCSF, and CCL2 were associated with chemoradiotherapy resistance and prognosis in LARC patients following NCRT. A risk score model was constructed which could be used to predict LARC outcome.

8.
J Cancer ; 12(4): 1085-1093, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33442406

RESUMO

Objectives: Cigarette smoking is involved in the pathogenesis of head and neck squamous cell carcinoma (HNSCC). However, the underlying molecular mechanisms of cigarette smoking-induced HNSCC carcinogenesis are unclear and may involve cancer stem-like cell generation. We examined the effects of cigarette smoke condensate (CSC) on the formation of cancer stem-like cells, which are rich in octamer-binding transcription factor (OCT)-4, inhibitor of differentiation 1 (ID1), nuclear factor (NF)-κB, and B lymphoma Mo-MLV insertion region 1 homolog (BMI-1). Materials and Methods: We used in vitro, in vivo, and archival human HNSCC tissue analysis to evaluate the effects of CSC on cancer stem-like cell formation. Results: We found that CSC regulated OCT-4 expression, which subsequently regulated ID1 and NF-κB, at the promoter, mRNA, and protein levels in vitro. Furthermore, OCT-4 knockdown with siRNA reduced ID1 expression. ID1 and NF-κB synergistically increased the expression of BMI-1 and stimulated keratinocyte sphere generation. In vivo, ID1 and NF-κB acted together to generate malignant xenograft tumors, which were aggressive locally and systemically metastatic. Clinical data confirmed that ID1- and NF-κB-positive patients had poor clinical outcomes and 5-year disease-free survival. Conclusion: Our data suggest that smoking cigarettes promoted cancer stem-like cell generation in the head and neck area via the OCT-4/ID1/NF-κB/BMI-1 signaling pathway.

9.
IEEE Trans Image Process ; 30: 822-837, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33226946

RESUMO

Currently, video text spotting tasks usually fall into the four-staged pipeline: detecting text regions in individual images, recognizing localized text regions frame-wisely, tracking text streams and post-processing to generate final results. However, they may suffer from the huge computational cost as well as sub-optimal results due to the interferences of low-quality text and the none-trainable pipeline strategy. In this article, we propose a fast and robust end-to-end video text spotting framework named FREE by only recognizing the localized text stream one-time instead of frame-wise recognition. Specifically, FREE first employs a well-designed spatial-temporal detector that learns text locations among video frames. Then a novel text recommender is developed to select the highest-quality text from text streams for recognizing. Here, the recommender is implemented by assembling text tracking, quality scoring and recognition into a trainable module. It not only avoids the interferences from the low-quality text but also dramatically speeds up the video text spotting. FREE unites the detector and recommender into a whole framework, and helps achieve global optimization. Besides, we collect a large scale video text dataset for promoting the video text spotting community, containing 100 videos from 21 real-life scenarios. Extensive experiments on public benchmarks show our method greatly speeds up the text spotting process, and also achieves the remarkable state-of-the-art.

10.
Cancer Biol Ther ; 21(2): 130-138, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31690181

RESUMO

Programmed death ligand-1 (PD-L1) expression and the presence of tumor-infiltrating lymphocytes (TILs) in tumor microenvironment were common in chronic inflammatory tumor types and frequently responded to the PD-L1 pathway immune checkpoint blockade in the clinic. Animal models to optimize such immunotherapeutics comprise an important strategy but often fail to predict the efficacy of clinical approaches. To address this, we aimed to establish new mouse models. In this study, we found that the expression of PD-L1was present at the beginning stage but a gradual decline over time in the in vitro cell culture and also in the mouse model. Based upon this finding, we established the IFN-γ-(human peripheral blood mononuclear cell) PBMC-CDX (cell line-derived xenograft) and IFN-γ-PBMC-PDX (patient-derived xenograft) mouse models, which recapitulate human tumor and human immune system interactions. IFN-γ was injected peritumorally to maintain the positivity of PD-L1 in the tumor microenvironment. Under this circumstance, the PD-1 molecule on the human T lymphocyte surface is in contact with the PD-L1 molecule on the human tumor cells and, thus, the formatin of the PD-L1/PD-1 pathway in the tumor microenvironment.Treatment with anti-PD-1 monoclonal antibody (mAb) significantly inhibited the growth of both CDX and PDX tumors, but not non-human NCG models (without allogeneic human PBMCs and IFN-γ) . These experimental data provide an important and promising platform for the development of drugs and the evaluation of the drug efficacy of immunotherapies with anti-PD-1 mAb as well as the basis of preclinical mAb drug research.


Assuntos
Antígeno B7-H1/antagonistas & inibidores , Imunoterapia/métodos , Interferon gama/metabolismo , Leucócitos Mononucleares/metabolismo , Neoplasias/terapia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Microambiente Tumoral/imunologia , Animais , Apoptose , Proliferação de Células , Modelos Animais de Doenças , Feminino , Humanos , Linfócitos do Interstício Tumoral/imunologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Terapia de Alvo Molecular , Neoplasias/imunologia , Neoplasias/metabolismo , Neoplasias/patologia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Cancer Biol Ther ; 20(5): 666-679, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30572778

RESUMO

The programmed death (PD) pathway is frequently present in the tumor microenvironment (TME) and suppresses tumor immunity by inhibiting the activity of tumor-infiltrating lymphocytes (TILs), particularly, CD8+ lymphocytes. PD immunotherapy involves stimulation of the immune response in the region surrounding the tumor but is insufficient to prevent tumor progression. Therefore, in this study, we examined the effects of combined PD immunotherapy with fractionated radiotherapy (RT) on antitumor immunity and tumor growth in lymphoma. The immune cell profiles of the TME, blood, and secondary lymphoid organs were determined 7 days after treatment. Four combination therapies were compared. The synergistic effects of αPD-1 mAb and fractionated RT on increased CD8+ lymphocytes in the TME, blood, and secondary lymphoid organs led to substantial tumor regression in mouse EL4 lymphoma, both locally and systemically. Fractionated RT for 4 days followed by αPD-1 mAb therapy was significantly superior to other schemes in terms of overall survival rates and curative rates in xenograft model mice. Our data indicated that substantial immune responses occurred following combination therapy with fractionated RT and αPD-1 mAb immunotherapy. Our findings provide important insights into the use of RT plus αPD-1 mAb as an efficacious combinatorial therapy.


Assuntos
Antineoplásicos Imunológicos/farmacologia , Quimiorradioterapia/métodos , Fracionamento da Dose de Radiação , Linfoma/terapia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Animais , Antineoplásicos Imunológicos/uso terapêutico , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos da radiação , Linhagem Celular Tumoral/transplante , Modelos Animais de Doenças , Humanos , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/efeitos da radiação , Linfoma/patologia , Camundongos , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia , Microambiente Tumoral/efeitos da radiação
12.
Pain Physician ; 21(4): E307-E322, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-30045596

RESUMO

BACKGROUND: Interferon regulatory factor 8 (IRF8), which is induced by peripheral nerve injury (PNI), plays a key role in activating spinal microglia to release inflammatory cytokines in a p38-dependent way, thereafter results in formation of central sensitization. Pulsed radiofrequency (PRF) on dorsal root ganglion (DRG) alleviates neuropathic pain and inhibits the microglial activation in chronic constriction injury (CCI) rats. However, the consequences of PRF on spinal IRF8 of CCI rats remains unknown. OBJECTIVE: We explore if PRF on DRG of rats with CCI could restrain IRF8, microglia, and p38 hyperactivity in the spinal cord to alleviate neuropathic pain. STUDY DESIGN: A randomized, controlled animal study. SETTING: Department of Pain Management, Fujian Provincial Hospital, Fujian Key Laboratory of Geriatrics, Provincial Clinic College of Fujian Medical University. METHODS: The changes in pain behaviors and the expressions of IRF8, Iba1 and p-p38 in the spinal cord of CCI rats which were administrated with antisense/ mismatch oligodeoxynucleotide of IRF8 were studied. Rats in CCI+AS ODN group, CCI+MM ODN group or CCI+NS group were intrathecally treated with antisense oligodeoxynucleotide of IRF8, mismatch oligodeoxynucleotide of IRF8 or same volume 0.9% NaCl once daily respectively, beginning from the day after nerve transection 12 hours and lasting for 7 days. The effects of PRF on L4-5 DRG of rats with CCI were investigated. PRF was applied adjacent to the L4-5 DRG at an intensity of 45 V for 6 minutes after CCI, whereas the control rats were treated without radiofrequency current. The withdrawal thresholds were studied and the spinal levels of IRF8, ionized calcium-binding adapter molecule 1 (Iba1, microglia characteristic marker) and p-p38 were calculated by ELISA, western blot, RT-PCR, and immunofluorescence. RESULTS: Intrathecal administration of antisense oligodeoxynucleotide of IRF8 led to the reversal of CCI-induced allodynia, lower activation of spinal microglia and p-p38. Withdrawal thresholds were partially recovered after a single PRF treatment for 14 days. CCI-induced IRF8 upregulation, microglia hyperactivity, and p38 phosphorylation in the spinal cord were reduced due to PRF treatment. However, PRF did not alter pain behaviors and pain signals in normal rats. LIMITATIONS: In our study, one time point was selected just to assess the levels of microglia, and p-p38. The changes of IRF8, microglia, p-p38 in the ipsilateral DRG were not investigated. A more detailed study on how PRF on the DRG could further relieve NP is needed. CONCLUSIONS: Restraining IRF8, microglia and p38 hyperactivity in the spinal cord of CCI rats involved in the contribution to the long-lasting analgesia of PRF. KEY WORDS: Neuropathic pain, pulsed radiofrequency, dorsal root ganglion, microglia, p38MAPK, Interferon regulatory factor 8, chronic constriction injury of sciatic nerve.


Assuntos
Gânglios Espinais/metabolismo , Fatores Reguladores de Interferon/biossíntese , Neuralgia/metabolismo , Tratamento por Radiofrequência Pulsada/métodos , Proteínas Quinases p38 Ativadas por Mitógeno/biossíntese , Animais , Regulação para Baixo , Gânglios Espinais/fisiopatologia , Gânglios Espinais/efeitos da radiação , Hiperalgesia/metabolismo , Hiperalgesia/fisiopatologia , Masculino , Microglia/metabolismo , Microglia/efeitos da radiação , Neuralgia/fisiopatologia , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/fisiopatologia , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/lesões
13.
Oncol Lett ; 15(5): 8039-8045, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29849806

RESUMO

Neddylation is a ubiquitination-like pathway. It has been reported that neddylation inhibition with the pharmacological agent MLN4924 potently uppresses lipopolysaccharide (LPS)-induced proinflammatory cytokine production, including tumor necrosis factor (TNF)-α and interleukin (IL)-6, by preventing the degradation of phosphorylated inhibitor of κB (p-IκB) in macrophages. However, whether neddylation serves a similar role in neutrophils remains unknown. In the present study MLN4924 treatment led to the accumulation of P-IκBα in neutrophils as well as the decreased production of TNF-α, IL-6 and IL-1ß in response to LPS, in a dose-dependent manner. The viability of neutrophils was only marginally affected in the same conditions, without statistical significance. Furthermore, the nuclear factor (NF)-κB inhibitor JSH-23 mimicked the effects of MLN4924 in neutrophils, and the inhibitory effects of MLN4924 on LPS-induced proinflammatory cytokine production diminished in the presence of JSH-23. Thus, the results of the present study suggest that neddylation inhibition suppresses neutrophil function by suppressing the NF-κB signaling pathway.

14.
Oncogenesis ; 7(1): 5, 2018 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-29358623

RESUMO

The oncogenic epidermal growth factor receptor (EGFR) is commonly overexpressed in solid cancers. The tyrosine kinase activity of EGFR has been a major therapeutic target for cancer; however, the efficacy of EGFR tyrosine kinase inhibitors to treat cancers has been challenged by innate and acquired resistance at the clinic. Accumulating evidence suggests that EGFR possesses kinase-independent pro-survival functions, and that cancer cells are more vulnerable to reduction of EGFR protein than to inhibition of its kinase activity. The molecular mechanism underlying loss-of-EGFR-induced cell death remains largely unknown. In this study, we show that, unlike inhibiting EGFR kinase activity that is known to induce pro-survival non-selective autophagy, downregulating EGFR protein, either by siRNA, or by a synthetic EGFR-downregulating peptide (Herdegradin), kills prostate and ovarian cancer cells via selective mitophagy by activating the mTORC2/Akt axis. Furthermore, Herdegradin induced mitophagy and inhibited the growth of orthotopic ovarian cancers in mice. This study identifies anti-mitophagy as a kinase-independent function of EGFR, reveals a novel function of mTORC2/Akt axis in promoting mitophagy in cancer cells, and offers a novel approach for pharmacological downregulation of EGFR protein as a potential treatment for EGFR-positive cancers.

15.
Arterioscler Thromb Vasc Biol ; 37(8): 1536-1547, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28642238

RESUMO

OBJECTIVE: Diabetic subjects are at higher risk of ischemic peripheral vascular disease. We tested the hypothesis that advanced glycation end products (AGEs) and their receptor (RAGE) block angiogenesis and blood flow recovery after hindlimb ischemia induced by femoral artery ligation through modulation of immune/inflammatory mechanisms. APPROACH AND RESULTS: Wild-type mice rendered diabetic with streptozotocin and subjected to unilateral femoral artery ligation displayed increased accumulation and expression of AGEs and RAGE in ischemic muscle. In diabetic wild-type mice, femoral artery ligation attenuated angiogenesis and impaired blood flow recovery, in parallel with reduced macrophage content in ischemic muscle and suppression of early inflammatory gene expression, including Ccl2 (chemokine [C-C motif] ligand-2) and Egr1 (early growth response gene-1) versus nondiabetic mice. Deletion of Ager (gene encoding RAGE) or transgenic expression of Glo1 (reduces AGEs) restored adaptive inflammation, angiogenesis, and blood flow recovery in diabetic mice. In diabetes mellitus, deletion of Ager increased circulating Ly6Chi monocytes and augmented macrophage infiltration into ischemic muscle tissue after femoral artery ligation. In vitro, macrophages grown in high glucose display inflammation that is skewed to expression of tissue damage versus tissue repair gene expression. Further, macrophages grown in high versus low glucose demonstrate blunted macrophage-endothelial cell interactions. In both settings, these adverse effects of high glucose were reversed by Ager deletion in macrophages. CONCLUSIONS: These findings indicate that RAGE attenuates adaptive inflammation in hindlimb ischemia; underscore microenvironment-specific functions for RAGE in inflammation in tissue repair versus damage; and illustrate that AGE/RAGE antagonism may fill a critical gap in diabetic peripheral vascular disease.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Angiopatias Diabéticas/metabolismo , Deleção de Genes , Inflamação/metabolismo , Isquemia/metabolismo , Músculo Esquelético/irrigação sanguínea , Neovascularização Fisiológica , Doença Arterial Periférica/metabolismo , Receptor para Produtos Finais de Glicação Avançada/deficiência , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Animais , Antígenos Ly/metabolismo , Velocidade do Fluxo Sanguíneo , Glicemia/metabolismo , Comunicação Celular , Células Cultivadas , Microambiente Celular , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/fisiopatologia , Angiopatias Diabéticas/genética , Angiopatias Diabéticas/fisiopatologia , Proteína 1 de Resposta de Crescimento Precoce/genética , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Células Endoteliais/metabolismo , Regulação da Expressão Gênica , Predisposição Genética para Doença , Produtos Finais de Glicação Avançada/metabolismo , Inflamação/genética , Inflamação/fisiopatologia , Isquemia/genética , Isquemia/fisiopatologia , Macrófagos/metabolismo , Camundongos Knockout , Camundongos Transgênicos , Monócitos/metabolismo , Músculo Esquelético/metabolismo , Doença Arterial Periférica/genética , Doença Arterial Periférica/fisiopatologia , Fenótipo , Receptor para Produtos Finais de Glicação Avançada/genética , Recuperação de Função Fisiológica , Fluxo Sanguíneo Regional , Transdução de Sinais , Estreptozocina , Fatores de Tempo
16.
Cell Mol Immunol ; 13(5): 578-83, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27593482

RESUMO

Type I interferons such as interferon-beta (IFN-ß) play essential roles in the host innate immune response to herpes simplex virus type I (HSV-1) infection. The transcription of type I interferon genes is controlled by nuclear factor-κB (NF-κB) and interferon regulatory factor (IRF) family members including IRF3. NF-κB activation depends on the phosphorylation of inhibitor of κB (IκB), which triggers its ubiqitination and degradation. It has been reported that neddylation inhibition by a pharmacological agent MLN4924 potently suppresses lipopolysaccharide (LPS)-induced proinflammatory cytokine production with the accumulation of phosphorylated IκBα. However, the role of neddylation in type I interferon expression remains unknown. Here, we report that neddylation inhibition with MLN4924 or upon UBA3 deficiency led to accumulation of phosphorylated IκBα, impaired IκBα degradation, and impaired NF-κB nuclear translocation in the early phase of HSV-1 infection even though phosphorylation and nuclear translocation of IRF3 were not affected. The blockade of NF-κB nuclear translocation by neddylation inhibition becomes less efficient at the later time points of HSV-1 infection. Consequently, HSV-1-induced early phase IFN-ß production significantly decreased upon MLN4924 treatment and UBA3 deficiency. NF-κB inhibitor JSH-23 mimicked the effects of neddylation inhibition in the early phase of HSV-1 infection. Moreover, the effects of neddylation inhibition on HSV-1-induced early phase IFN-ß production diminished in the presence of NF-κB inhibitor JSH-23. Thus, neddylation contributes to HSV-1-induced early phase IFN-ß production through, at least partially, promoting NF-κB activation.


Assuntos
Cisteína Endopeptidases/metabolismo , Herpesvirus Humano 1/fisiologia , Interferon beta/biossíntese , Animais , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Ciclopentanos/farmacologia , Herpes Simples/metabolismo , Humanos , Fator Regulador 3 de Interferon/metabolismo , Interferon beta/metabolismo , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Fenilenodiaminas/farmacologia , Pirimidinas/farmacologia , Ubiquitinas/metabolismo
17.
Sci Rep ; 5: 13536, 2015 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-26329479

RESUMO

The Shockley-Queisser limit describes the maximum solar energy conversion efficiency achievable for a particular material and is the standard by which new photovoltaic technologies are compared. This limit is based on the principle of detailed balance, which equates the photon flux into a device to the particle flux (photons or electrons) out of that device. Nanostructured solar cells represent a novel class of photovoltaic devices, and questions have been raised about whether or not they can exceed the Shockley-Queisser limit. Here we show that single-junction nanostructured solar cells have a theoretical maximum efficiency of ∼42% under AM 1.5 solar illumination. While this exceeds the efficiency of a non-concentrating planar device, it does not exceed the Shockley-Queisser limit for a planar device with optical concentration. We consider the effect of diffuse illumination and find that with optical concentration from the nanostructures of only × 1,000, an efficiency of 35.5% is achievable even with 25% diffuse illumination. We conclude that nanostructured solar cells offer an important route towards higher efficiency photovoltaic devices through a built-in optical concentration.

18.
J Atheroscler Thromb ; 22(10): 1080-90, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26004931

RESUMO

AIM: To investigate the thrombolytic and antiplatelet effects of a novel plasminogen activator from the venom of the Gloydius brevicaudus viper (GBV-PA) in vitro and in vivo. METHODS: Thrombolytic experiments were performed in rabbit models of ear vein thrombosis and carotid artery thrombosis and in dog model of acute cerebral infarction. Inhibition of thrombus formation was evaluated in rat inferior vena cava thrombosis model and ferric chloride-induced arterial thrombosis. In vitro, we assayed the antithrombotic effect of GBV-PA on rabbit blood clots, euglobulin lysis time (ELT) of rabbit plasma, and ADP-induced platelet aggregation. RESULTS: GBV-PA intravenous administration significantly reduced vascular recanalization times of rabbit ear veins thrombosis and thrombus weight of rabbit carotid artery thrombosis. The arterial recanalization rates were dose- and time-dependently improved after the administration of GBV-PA in canine acute cerebral infarction model. Thrombus length and weight were significantly reduced by GBV-PA both in rat inferior vena cava and ferric chloride-induced arterial thrombosis models. Thrombus formation in the blood of rabbits that were administered of GBV-PA was also inhibited. GBV-PA radically reduced plasma ELT of the rabbit's blood clots. ADP-induced platelet aggregation was inhibited by GBV-PA in a dose-dependent manner with a half-maximal inhibitory concentration of 19.9 µg/mL. CONCLUSION: This study demonstrates that GBV-PA is a thrombolytic and antiplatelet agent. It has significant antithrombotic effects on various in vitro and in vivo experimental models of thrombosis. The mechanisms that underline its antithrombotic effects were related to GBV-PA's capabilities of increasing fibrinolytic activity and inhibition of platelet aggregation.


Assuntos
Ativadores de Plasminogênio/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Terapia Trombolítica/métodos , Trombose/tratamento farmacológico , Venenos de Víboras/química , Animais , Modelos Animais de Doenças , Cães , Camundongos , Ativadores de Plasminogênio/química , Agregação Plaquetária/efeitos dos fármacos , Coelhos , Ratos , Ratos Sprague-Dawley , Trombose/sangue , Resultado do Tratamento
19.
Nat Commun ; 5: 4224, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24981857

RESUMO

Various band structure engineering methods have been studied to improve the performance of graphitic transparent conductors; however, none has demonstrated an increase of optical transmittance in the visible range. Here we measure in situ optical transmittance spectra and electrical transport properties of ultrathin graphite (3-60 graphene layers) simultaneously during electrochemical lithiation/delithiation. On intercalation, we observe an increase of both optical transmittance (up to twofold) and electrical conductivity (up to two orders of magnitude), strikingly different from other materials. Transmission as high as 91.7% with a sheet resistance of 3.0 Ω per square is achieved for 19-layer LiC6, which corresponds to a figure of merit σ(dc)/σ(opt) = 1,400, significantly higher than any other continuous transparent electrodes. The unconventional modification of ultrathin graphite optoelectronic properties is explained by the suppression of interband optical transitions and a small intraband Drude conductivity near the interband edge. Our techniques enable investigation of other aspects of intercalation in nanostructures.

20.
Opt Express ; 22 Suppl 2: A259-67, 2014 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-24922234

RESUMO

We propose a polymer photovoltaic device with a new scattering mechanism based on photon absorption and re-emission in a quantum dot layer. A matrix of aluminum nanorods with optimized radius and period are used to modify the coupling of light emitted from the quantum dots into the polymer layer. Our analysis shows that this architecture is capable of increasing the absorption of an ordinary polymer photovoltaic device by 28%.

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