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1.
Mol Divers ; 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39102113

RESUMO

Edaravone, a pyrazalone derivative, is an antioxidant and free radical scavenger used to treat oxidative stress-related diseases. It is a proven drug to mitigate conditions prevailing to oxidative stress by inhibiting lipid peroxidation, reducing inflammation, and thereby preventing endothelial cell death. In recent years, considerable interest has been given by researchers in the derivatization of edaravone by adding varieties of substituents of versatile steric and functional properties to improve its antioxidant and pharmacological activity. This review accounts all the important methods developed for the derivatization of edaravone and the impacts of the structural modifications on the antioxidant activity of the motif.

2.
Curr Microbiol ; 81(8): 242, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38913141

RESUMO

Chikungunya virus (CHIKV) is a causative agent of a disease continuum, ranging from an acute transient chikungunya fever to chronic incapacitating viral arthralgia. The interaction between anti-CHIKV antibodies and the complement system has recently received attention. However, the contribution of complement activation in CHIKV-induced pathologies has not been fully elucidated. The present study was undertaken to delineate the possible contribution of complement activation in CHIKV-induced disease progression. In this study, using plasma specimens of chikungunya patients in the acute, chronic, and recovered phases of infection, we explicated the involvement of complement activation in CHIKV disease progression by ELISAs and Bio-Plex assays. Correlation analysis was carried out to demonstrate interrelation among C1q-binding IgG-containing circulating immune complexes (CIC-C1q), complement activation fragments (C3a, C5a, sC5b-9), and complement-modulated pro-inflammatory cytokines (IL-1ß, IL-18, IL-6, and TNF-α). We detected elevated complement activation fragments, CIC-C1q, and complement-modulated cytokines in the varied patient groups compared with the healthy controls, indicating persistent activation of the complement system. Furthermore, we observed statistically significant correlations among CIC-C1q with complement activation fragments and C3a with complement modulatory cytokines IL-1ß, IL-6, and IL-18 during the CHIKV disease progression. Taken together, the current data provide insight into the plausible association between CICs, complement activation, subsequent complement modulatory cytokine expression, and CHIKV etiopathology.


Assuntos
Complexo Antígeno-Anticorpo , Febre de Chikungunya , Vírus Chikungunya , Ativação do Complemento , Complemento C1q , Citocinas , Humanos , Complemento C1q/metabolismo , Complemento C1q/imunologia , Febre de Chikungunya/imunologia , Febre de Chikungunya/virologia , Febre de Chikungunya/sangue , Complexo Antígeno-Anticorpo/sangue , Complexo Antígeno-Anticorpo/imunologia , Vírus Chikungunya/imunologia , Masculino , Citocinas/sangue , Citocinas/metabolismo , Pessoa de Meia-Idade , Adulto , Feminino , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Idoso , Adulto Jovem
3.
Eur J Immunol ; 52(11): 1842-1858, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36074916

RESUMO

IL-17-producing Th17 cells play an important role in pathogenesis of rheumatoid arthritis (RA). Aberrant immune activation due to an imbalance between Th17 and regulatory T (Treg) cells is associated with the development of RA and other autoimmune diseases. Targeting pathogenic Th17 cells and their associated molecules is emerging as a promising strategy to treat and reverse RA. Here, we demonstrate that IL-3 inhibits the differentiation of Th17 cells and promotes the development of Treg cells in IL-2-dependent manner. In IL-2 KO mice, we observed that IL-3 has no effect on differentiation of both Th17 and Treg cells. In addition, IL-3 decreases pathogenic IL-17A+ TNF-α+ , IL-17A+ IFN-γ+ and IL-23R+ Th17 cells, secretion of GM-CSF and IFN-γ, and osteoclastogenesis when presented in the culture together with Th17 polarizing cytokines. Mechanistically, IL-3 regulates the development of Th17 cells through the inhibition of STAT3 phosphorylation. IL-3 treatment significantly decreases the pathogenic Th17 cell responses and arthritic scores in the mouse model of RA. Importantly, IL-3 inhibits the differentiation of human Th17 cells. Thus, our results suggest a novel therapeutic role of IL-3 in the regulation of Th17 cell-mediated pathophysiology of RA.


Assuntos
Artrite Reumatoide , Diferenciação Celular , Interleucina-3 , Células Th17 , Animais , Humanos , Camundongos , Interleucina-17/metabolismo , Interleucina-2/metabolismo , Interleucina-3/metabolismo , Linfócitos T Reguladores/citologia , Células Th17/citologia
4.
Appl Opt ; 62(10): D157-D162, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37132781

RESUMO

We demonstrate that a time of flight (TOF) camera can be used to perform range selective temporal-heterodyne frequency-modulated continuous wave digital holography (TH FMCW DH). The modulated arrayed detection of a TOF camera allows efficient integration of holograms at a selected range with range resolutions significantly less than the optical system's depth of field. TH FMCW DH also allows for on-axis geometries to be achieved, where background light not at the internal modulation frequency of the camera is filtered out. Range selective TH FMCW DH imaging was achieved for both image holograms and Fresnel holograms using on-axis DH geometries. A 2.39 GHz FMCW chirp bandwidth resulted in a DH range resolution of 6.3 cm.

5.
Acta Orthop Belg ; 89(3): 539-546, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37935240

RESUMO

Intramedullary Titanium elastic nailing (TENS) is successfully used for irreducible and displaced forearm bone fractures in children. The purpose of this study was to report the potential complications and functional outcomes associated with paediatric forearm fractures treated with TENS nails. We retrospectively reviewed 65 children with displaced forearm bone fractures treated by TENS nailing with a mean follow-up of 5.84 months (4-12). Data detailing patient demographics, fracture characteristics, associated fractures, injury surgery interval, grade of the operating surgeon, methods of fixation, time to union, the timing of removal of the nail, and complications were collected and analysed. The mean age in our study was 9.13 years. 92% had fractures of both radius and ulna, 83.3% had fixation of both bones, and 16.7% had single bone fixation only. Open reduction was required in 38.5% of cases. The average time to fracture union was 10.34 weeks (6-20). The average time of implant removal was 20.12 weeks (9-32). We observed an overall complication rate of 41.5%. We noted a higher (56% vs 32.5%, p=0.059) complication rate in open reduction cases. According to the Price criteria, we had excellent to good results in over 98% of patients despite a slightly higher complication rate. Titanium elastic nailing is a safe, reliable method of internal fixation for irreducible or unstable fractures of both bones of the forearm in children. Open reduction of fracture was associated with higher complications. Despite higher overall complications, we noted excellent functional results in most cases.


Assuntos
Fixação Intramedular de Fraturas , Fraturas do Rádio , Fraturas da Ulna , Criança , Humanos , Fixação Intramedular de Fraturas/efeitos adversos , Fixação Intramedular de Fraturas/métodos , Titânio , Antebraço , Estudos Retrospectivos , Fraturas da Ulna/cirurgia , Fraturas do Rádio/cirurgia , Fraturas do Rádio/etiologia , Hospitais Gerais , Pinos Ortopédicos , Resultado do Tratamento , Consolidação da Fratura
6.
Acta Orthop Belg ; 89(1): 37-43, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37294983

RESUMO

The UK National Joint Registry(NJR) has not reported total knee replacement (TKR) survivorship based on design phi- losophy alone, unlike its international counterparts. We report outcomes of implant survivorship based on design phi- losophy using data from NJR's 2020 annual report. All TKR implants with an identifiable design philosophy from NJR data were included. Cumulative revision data for cruciate-retaining(CR), posterior stabilised(PS), mobile-bearing(MB) design philosophies was derived from merged NJR data. Cumulative revision data for individual brands of implants with the medial pivot (MP) philosophy were used to calculate overall survivorship for this design philosophy. The all-cause revision was used as the endpoint and calculated to 15 years follow-up with Kaplan-Meier curves. 1,144,384 TKRs were included. CR is the most popular design philosophy (67.4%), followed by PS(23.1%), MB (6.9%) and least commonly MP (2.6%). MP and CR implants showed the best survivorship (95.7% and 95.6% respectively) at 15 years which is statistically significant at, and beyond, 10 years. Observed survivorship was lower at all time points with the PS and MB implants (94.5% for both designs at 15 years). While all design philosophies considered in this study survive well, CR and MP designs offer statistically superior survivorship at and beyond 10 years. MP design performs better than CR beyond 13 years yet, remain the least popular design philosophy used. Publishing data based on knee arthroplasty design phi- losophy would help surgeons when making decisions on implant choice.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Humanos , Sobrevivência , Desenho de Prótese , Reoperação , Sistema de Registros , Reino Unido , Articulação do Joelho/cirurgia
7.
J Surg Res ; 279: 480-490, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35842973

RESUMO

INTRODUCTION: Outcomes in patients with isolated traumatic brain injury (iTBI) have not been evaluated comprehensively in low-income and middle-income countries. We aimed to study the in-hospital iTBI mortality and its associated risk factors in a prospective multicenter Indian trauma registry. METHODS: Patients with iTBI (head and neck Abbreviated Injury Score ≥2 and other region Abbreviated Injury Score ≤2) were included. Study variables comprised age, gender, mechanism of injury, systolic blood pressure (SBP) at arrival, Glasgow Coma Scale (GCS) score - classified as mild (13-15), moderate (9-12), and severe (3-8), transfer status, and time to presentation at any participating hospital. A multivariable logistic regression was performed to assess the impact of these factors on 24-h and 30-d mortality following iTBI. RESULTS: Among 5042 included patients, 24-h and 30-d in-hospital mortalities were 5.9% and 22.4%. On a regression analysis, 30-d mortality was associated with age ≥45 y (odds ratio [OR] = 2.1 [1.6-2.7]), railway injury mechanisms (OR = 2.1 [1.3-3.5]), SBP <90 mmHg (OR = 2.6 [1.6-4.1]), and moderate (OR = 3.8 [3.0-5.0]) to severe (OR = 21.1 [16.8-26.7]) iTBI based on GCS scores. 24-h mortality showed similar trends. Patients transferred to the participating hospitals from other centers had higher odds of 30-d mortality (OR = 1.4 [1.2-1.8]) compared to those arriving directly. Those who received neurosurgical intervention had lower odds of 24-h mortality (0.3 [0.2-0.4]). CONCLUSIONS: Age ≥45 y, GCS score ≤12, and SBP <90 mmHg at arrival increased the risk of in-hospital mortality from iTBI.


Assuntos
Lesões Encefálicas Traumáticas , Escala de Coma de Glasgow , Mortalidade Hospitalar , Humanos , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Risco
8.
J Immunol ; 204(4): 819-831, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31900339

RESUMO

IL-3, a cytokine secreted by activated T lymphocytes, is known to regulate the proliferation, survival, and differentiation of hematopoietic cells. However, the role of IL-3 in regulation of T cell functions is not fully delineated. Previously, we have reported that IL-3 plays an important role in development of regulatory T cells in mice. In this study, we investigated the regulation of IL-3R expression on human Th cells and also examined the role of IL-3 in effector functions of these cells. We found that human peripheral blood Th cells in resting state do not show surface expression of IL-3R; however, its expression was observed at transcript and intracellular protein levels. The functional IL-3R expression on the surface was seen only after antigenic stimulation. When naive Th cells were activated in the presence of various cytokines, we found that IL-4 significantly increases the surface expression of IL-3R and also increases the number of IL-3R+ Th cells. Interestingly, IL-3R+ cells exhibit a Th2 cell-like phenotype and show high GATA-3 expression. Moreover, Th2 cells in presence of IL-3 show increased expression of type 2 effector cytokines, such as IL-4, IL-5, and IL-13. Furthermore, IL-3R expressing and IL-3-secreting Th cells were high in house dust mite-allergic patients. Thus, to our knowledge, we provide the first evidence that the expression of IL-3R on activated human Th cells is modulated by IL-4, and IL-3 regulates the effector functions of Th2 cells. Our results suggest that IL-3 may play an important role in regulating allergic immune responses.


Assuntos
Diferenciação Celular/imunologia , Interleucina-3/imunologia , Interleucina-4/imunologia , Receptores de Interleucina-3/imunologia , Células Th2/imunologia , Humanos , Hipersensibilidade/imunologia , Interleucina-3/metabolismo , Interleucina-4/metabolismo , Ativação Linfocitária/imunologia , Receptores de Interleucina-3/metabolismo
9.
Appl Opt ; 61(5): B255-B261, 2022 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-35201147

RESUMO

The integration of chirped frequency modulated continuous wave (FMCW) lidar techniques into digital holography enables range selective holographic imaging well beyond the depth of field of the system. The technique uses FMCW transmit and reference beams. By frequency shifting the reference beam to compensate for the typical FMCW beat frequency associated with a particular range, temporally stable holograms are formed for objects at the selected range. The holograms associated with objects at all other ranges oscillate and integrate towards zero. Experimental demonstrations of the technique are presented, showing enhanced imaging of objects at different ranges and cancellation of obscuring objects. The technique is expandable to range-Doppler selective digital holographic imaging.

10.
J Pharmacol Exp Ther ; 378(2): 77-86, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34006586

RESUMO

The central role of ß-catenin in the Wnt pathway makes it an attractive therapeutic target for cancers driven by aberrant Wnt signaling. We recently developed a small-molecule inhibitor, BC-2059, that promotes apoptosis by disrupting the ß-catenin/transducin ß-like 1 (TBL1) complex through an unknown mechanism of action. In this study, we show that BC-2059 directly interacts with high affinity for TBL1 when in complex with ß-catenin. We identified two amino acids in a hydrophobic pocket of TBL1 that are required for binding with ß-catenin, and computational modeling predicted that BC-2059 interacts at the same hydrophobic pocket. Although this pocket in TBL1 is involved in binding with NCoR/SMRT complex members G Protein Pathway Suppressor 2 (GSP2) and SMRT and p65 NFκB subunit, BC-2059 failed to disrupt the interaction of TBL1 with either NCoR/SMRT or NFκB. Together, our results show that BC-2059 selectively targets TBL1/ß-catenin protein complex, suggesting BC-2059 as a therapeutic for tumors with deregulated Wnt signaling pathway. SIGNIFICANCE STATEMENT: This study reports the mechanism of action of a novel Wnt pathway inhibitor, characterizing the selective disruption of the transducin ß-like 1/ß-catenin protein complex. As Wnt signaling is dysregulated across cancer types, this study suggests BC-2059 has the potential to benefit patients with tumors reliant on this pathway.


Assuntos
Transducina , beta Catenina , Comunicação Celular , Humanos , Fator de Transcrição RelA
11.
Parasite Immunol ; 43(7): e12837, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33811350

RESUMO

AIM: An immunoproteomic approach was followed to identify immunoreactive antigens of fish ectoparasite, Argulus siamensis with rohu (Labeo rohita) immune sera for screening of potential vaccine candidates. MATERIALS AND RESULTS: The whole adult Argulus antigen was run in 2D electrophoresis with IEF in 7 cm IPG strips of pH 4-7 and SDS-PAGE with 12% acrylamide concentration. Two parallel gels were run; one was stained with silver stain, and the other was Western blotted to nitrocellulose paper (NCP) and reacted with rohu anti-A siamensis sera. Fourteen protein spots corresponding to the spots developed in NCP were picked from the silver-stained gel and subjected to mass spectrometry in MALDI-TOF/TOF. The MS/MS spectra were analysed in MASCOT software with taxonomy 'other metazoa' and the proteins identified based on similarity with the proteins from heterologous species. The gene ontology analysis revealed a majority of proteins being involved in binding activity in 'molecular function' and belonging to metabolic processes in 'biologic process' categories. The possibility of these proteins as vaccine candidates against A siamensis is discussed in the paper. CONCLUSION: Three of the identified proteins namely, bromodomain-containing protein, anaphase-promoting complex subunit 5 and elongation factor-2 could possibly serve as vaccine candidates against argulosis in carps.


Assuntos
Arguloida , Carpas , Cyprinidae , Doenças dos Peixes , Animais , Doenças dos Peixes/prevenção & controle , Espectrometria de Massas em Tandem
12.
Appl Opt ; 60(22): 6526-6537, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34612890

RESUMO

An off-axis digital holographic imaging polarimeter was developed to estimate the Jones matrices of an object. The Jones vector image of the electric field returned from the object is determined from a single holographic recording using the interference between the dual, nearly orthogonal, reference beams. The technique compensates for phase variations in the optical beam paths between the recorded holograms and relaxes the need to generate orthogonal illumination polarization states. A minimization algorithm was developed to compute an estimation of the Jones matrix image of an object based on a set of measured Jones vector images. A proof-of-concept demonstration was performed to compute an estimated Jones matrix image of a polarimetrically complex object using digital holograms recorded with 6 different illumination polarizations.

13.
Nucleic Acids Res ; 47(4): 1637-1652, 2019 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-30649466

RESUMO

The DNA binding domain (DBD) of the tumor suppressor p53 is the site of several oncogenic mutations. A subset of these mutations lowers the unfolding temperature of the DBD. Unfolding leads to the exposure of a hydrophobic ß-strand and nucleates aggregation which results in pathologies through loss of function and dominant negative/gain of function effects. Inspired by the hypothesis that structural changes that are associated with events initiating unfolding in DBD are likely to present opportunities for inhibition, we investigate the dynamics of the wild type (WT) and some aggregating mutants through extensive all atom explicit solvent MD simulations. Simulations reveal differential conformational sampling between the WT and the mutants of a turn region (S6-S7) that is contiguous to a known aggregation-prone region (APR). The conformational properties of the S6-S7 turn appear to be modulated by a network of interacting residues. We speculate that changes that take place in this network as a result of the mutational stress result in the events that destabilize the DBD and initiate unfolding. These perturbations also result in the emergence of a novel pocket that appears to have druggable characteristics. FDA approved drugs are computationally screened against this pocket.


Assuntos
Proteínas de Ligação a DNA/química , Proteínas Mutantes/química , Bibliotecas de Moléculas Pequenas/química , Proteína Supressora de Tumor p53/química , Proteínas de Ligação a DNA/genética , Avaliação Pré-Clínica de Medicamentos/métodos , Humanos , Interações Hidrofóbicas e Hidrofílicas/efeitos dos fármacos , Modelos Moleculares , Simulação de Dinâmica Molecular , Proteínas Mutantes/genética , Mutação/genética , Conformação Proteica/efeitos dos fármacos , Domínios Proteicos/efeitos dos fármacos , Domínios Proteicos/genética , Desdobramento de Proteína/efeitos dos fármacos , Proteína Supressora de Tumor p53/genética
14.
J Dairy Sci ; 104(1): 1175-1182, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33162086

RESUMO

The objective of this study was to compare the transcription of gene markers for gastrointestinal (GI) epithelial cells, including fatty acid binding protein 2 (FABP2) and cytokeratin 8 (KRT8), and tight junction complex genes (TJP1, CLDN1, CLDN4) in fecal RNA against several GI tract tissue sections in dairy calves. Eight healthy Jersey calves were euthanized at 5 wk of age, and postmortem samples were collected from rumen, duodenum, jejunum, ileum, large intestine, cecum, and feces for total RNA isolation. Tissues and fecal samples were immediately frozen in liquid nitrogen until RNA isolation. A real-time quantitative PCR analysis was performed using a single standard curve composited of equal amounts of all samples, including cDNA from fecal and GI tract tissues. The mRNA expression of the tight junctions TJP1, CLDN1, and CLDN4 was greater in fecal RNA compared with lower GI tract tissues (i.e., duodenum, jejunum, ileum, large intestine, and cecum). Similar to fecal RNA, rumen tissue had greater expression of tight junctions CLDN1 and CLDN4 than lower GI tract tissues. Similarly, rumen tissue had greater expression of TPJ1 than all lower GI tract tissues except duodenum. The expression of TJP1 and CLDN4 was greater in fecal RNA than in rumen tissue; in contrast, CLDN1 mRNA expression was greater in rumen tissue than in the fecal RNA. The expression of FABP2 was greater in duodenum in comparison to all tissue except ileum. The mRNA expression of FABP2 in fecal samples was similar to jejunum and ileum. The expression of KRT8 in fecal samples was similar to duodenum, large intestine, and cecum. The fecal RNA had a greater expression of KRT8 in comparison to jejunum and ileum. The rumen tissue had the lowest mRNA expression of KRT8. The expression levels of FABP2, KRT8, and tight junction genes observed in fecal transcripts suggest that a considerable amount of RNA derived from GI tract epithelial cells can be detected in fecal RNA, which is in agreement with previous data in neonatal dairy calves and other biological models including humans, rodents, and primates. The greater expression of tight junctions in fecal RNA in comparison to sections of the low GI remains to be understood, and due to the importance of tight junctions in GI physiology, further clarification of this effect is warranted. The similarities in mRNA expression of FABP2 and KRT8 between fecal RNA and intestinal sections add up to the accumulating evidence that fecal RNA can be used to investigate molecular alterations in the GI tract of neonatal dairy calves. Further research in this area should include high-throughput transcriptomic analysis via RNA-seq to uncover novel molecular markers for specific sections of the GI tract of neonates.


Assuntos
Antígenos de Diferenciação/metabolismo , Biomarcadores/metabolismo , Bovinos/metabolismo , Trato Gastrointestinal/metabolismo , Mucosa Intestinal/metabolismo , RNA/metabolismo , Animais , Bovinos/anatomia & histologia , Ceco/metabolismo , Células Epiteliais/metabolismo , Fezes , Trato Gastrointestinal/citologia , Íleo/metabolismo , Mucosa Intestinal/citologia , Intestino Grosso , Jejuno/metabolismo , Masculino , Reação em Cadeia da Polimerase em Tempo Real , Rúmen/metabolismo , Junções Íntimas , Transcriptoma
15.
J Biol Chem ; 294(41): 14879-14895, 2019 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-31413110

RESUMO

F-box protein 31 (FBXO31) is a reported putative tumor suppressor, and its inactivation due to loss of heterozygosity is associated with cancers of different origins. An emerging body of literature has documented FBXO31's role in preserving genome integrity following DNA damage and in the cell cycle. However, knowledge regarding the role of FBXO31 during normal cell-cycle progression is restricted to its functions during the G2/M phase. Interestingly, FBXO31 levels remain high even during the early G1 phase, a crucial stage for preparing the cells for DNA replication. Therefore, we sought to investigate the functions of FBXO31 during the G1 phase of the cell cycle. Here, using flow cytometric, biochemical, and immunofluorescence techniques, we show that FBXO31 is essential for maintaining optimum expression of the cell-cycle protein cyclin A for efficient cell-cycle progression. Stable FBXO31 knockdown led to atypical accumulation of cyclin A during the G1 phase, driving premature DNA replication and compromised loading of the minichromosome maintenance complex, resulting in replication from fewer origins and DNA double-strand breaks. Because of these inherent defects in replication, FBXO31-knockdown cells were hypersensitive to replication stress-inducing agents and displayed pronounced genomic instability. Upon entering mitosis, the cells defective in DNA replication exhibited a delay in the prometaphase-to-metaphase transition and anaphase defects such as lagging and bridging chromosomes. In conclusion, our findings establish that FBXO31 plays a pivotal role in preserving genomic integrity by maintaining low cyclin A levels during the G1 phase for faithful genome duplication and segregation.


Assuntos
Ciclina A/metabolismo , Replicação do DNA/genética , Proteínas F-Box/metabolismo , Genoma Humano/genética , Proteínas Supressoras de Tumor/metabolismo , Ciclo Celular/genética , Cromatina/genética , Proteínas F-Box/genética , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Cinética , Células MCF-7 , Proteínas Supressoras de Tumor/deficiência , Proteínas Supressoras de Tumor/genética , Ubiquitinação/genética
16.
J Immunol ; 200(2): 595-606, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29203513

RESUMO

Bone remodeling comprises balanced activities between osteoclasts and osteoblasts, which is regulated by various factors, including hormones and cytokines. We previously reported that IL-3 inhibits osteoclast differentiation and pathological bone loss. IL-3 also enhances osteoblast differentiation and bone formation from mesenchymal stem cells. However, the role of IL-3 in regulation of osteoblast-osteoclast interactions and underlying mechanisms is not yet delineated. In this study, we investigated the role of IL-3 on the regulation of osteoblast-specific molecules, receptor activator of NF-κB ligand (RANKL), and osteoprotegerin (OPG) that modulate bone homeostasis. We found that IL-3 increases RANKL expression at both the transcriptional and translational levels, and it showed no effect on OPG expression in calvarial osteoblasts. The increased RANKL expression by IL-3 induces mononuclear osteoclasts; however, it does not induce multinuclear osteoclasts. Interestingly, IL-3 decreases soluble RANKL by reducing ectodomain shedding of membrane RANKL through downregulation of metalloproteases mainly a disintegrin and metalloproteinase (ADAM)10, ADAM17, ADAM19, and MMP3. Moreover, IL-3 increases membrane RANKL by activating the JAK2/STAT5 pathway. Furthermore, IL-3 enhances RANKL expression in mesenchymal stem cells of wild-type mice but not in STAT5a knockout mice. Interestingly, IL-3 restores RANKL expression in adult mice by enhancing bone-specific RANKL and decreasing serum RANKL. Furthermore, IL-3 increases the serum OPG level in adult mice. Thus, our results reveal, to our knowledge for the first time, that IL-3 differentially regulates two functional forms of RANKL through metalloproteases and the JAK2/STAT5 pathway, and it helps in restoring the decreased RANKL/OPG ratio in adult mice. Notably, our studies indicate the novel role of IL-3 in regulating bone homeostasis in important skeletal disorders.


Assuntos
Interleucina-3/metabolismo , Janus Quinase 2/metabolismo , Metaloproteinases da Matriz/metabolismo , Osteoblastos/metabolismo , Ligante RANK/metabolismo , Receptor Ativador de Fator Nuclear kappa-B/metabolismo , Fator de Transcrição STAT5/metabolismo , Animais , Células Cultivadas , Técnicas de Cocultura , Expressão Gênica , Interleucina-3/farmacologia , Camundongos , Camundongos Transgênicos , Osteoblastos/efeitos dos fármacos , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Ligante RANK/sangue , Ligante RANK/genética , Receptor Ativador de Fator Nuclear kappa-B/genética , Transdução de Sinais/efeitos dos fármacos
17.
Biochim Biophys Acta Mol Cell Res ; 1865(5): 794-802, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29458077

RESUMO

Caveolin-1 (Cav1) is an integral plasma membrane protein and a complex regulator of signal transduction. The Signal Transducer and Activator of Transcription-3 (Stat3) is activated by a number of receptor and non-receptor tyrosine kinases and is positively implicated in cancer. Despite extensive efforts, the relationship between Cav1 and Stat3 has been a matter of controversy. We previously demonstrated that engagement of E- or N-cadherin or cadherin-11 cell to cell adhesion molecules, as occurs with confluence of cultured cells, triggers a dramatic increase in the levels of tyr705 phosphorylated i.e. activated Stat3, by a mechanism requiring the cRac1 small GTPase. Since confluence was not taken into account in previous studies, we revisited the question of the relationship between Cav1 and Stat3-ptyr705 in non-transformed mouse fibroblasts and in human lung carcinoma cells, by examining their effect at different cell densities. Our results unequivocally demonstrate that Cav1 downregulates cadherin-11, by a mechanism which requires the Cav1 scaffolding domain. This cadherin-11 downregulation, in turn, leads to a reduction in cRac1 and Stat3 activity levels. Furthermore, in a feedback loop possibly through p53 upregulation, Stat3 downregulation increases Cav1 levels. Our data reveal the presence of a potent, negative regulatory loop between Cav1 and cadherin-11/Stat3, leading to Stat3 inhibition and apoptosis.


Assuntos
Caderinas/genética , Caveolina 1/genética , Fator de Transcrição STAT3/genética , Proteínas rac1 de Ligação ao GTP/genética , Células A549 , Animais , Apoptose/genética , Fibroblastos/metabolismo , Regulação da Expressão Gênica/genética , Humanos , Camundongos , Fosforilação , Transdução de Sinais , Proteína Supressora de Tumor p53/genética
18.
Biochemistry ; 58(32): 3422-3433, 2019 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-31287951

RESUMO

The PDZ domain is one of the most widespread protein interaction domains found in nature. Due to their integral role in numerous biological functions, their ability to act as scaffolds for signal amplification, and the occurrence of mutations linked to human diseases, PDZ domains are attractive therapeutic targets. On the basis of the differential binding affinities of selected C-terminal peptides of the human proteome for one such PDZ domain (PSMD9) and by exploring structure-activity relationships, we design and convert a low-affinity tetrapeptide (∼439 µM) to a tight binding sequence (∼5 µM). The peptide inhibits PSMD9-hnRNPA1 interactions that are critical in basal and stimulus-induced NF-κB signaling and a potential therapeutic target in cancers, including chemotherapy or radiation-induced therapy resistance. Extensive application of computer modeling, including ligand mapping and all-atom molecular dynamics simulations, helps us to rationalize the structural basis for the huge differences in binding affinity and inform us about the residue-wise contributions to the binding energy. Our findings are in accord with the classical preference of the (PSMD9) PDZ domain for C-terminal sequences that contain hydrophobic residues at the P0 (C-terminal) position. In addition, for the first time, we identify a hitherto unknown occupancy for cysteine at the P-2 position that drives high-affinity interaction in a PDZ domain.


Assuntos
Domínios PDZ , Complexo de Endopeptidases do Proteassoma/química , Complexo de Endopeptidases do Proteassoma/metabolismo , Sequência de Aminoácidos , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica
19.
Opt Lett ; 44(2): 371-374, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30644902

RESUMO

An alternative to phase-matched angled beam spatial-spectral holographic grating geometries for separating stimulated photon echoes (SPEs) from the probing pulse is proposed and demonstrated. By use of a Mach-Zehnder geometry with inhomogeneously broadened medium in both paths, the SPE can be interferometrically isolated from the generating probe pulse. This interferometric-based technique is well suited to waveguide geometries, which have benefits for future quantum and classical optical signal processing applications such as quantum memories, correlation, and efficient cryogenic microwave-to-optical conversion. Experimental demonstrations showing interferometric-based isolation in Tm3+-doped LiNbO3 at 3.2 K are performed and analyzed.

20.
J Chem Inf Model ; 59(7): 3316-3329, 2019 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-31140800

RESUMO

Solute-solvent interactions are critical for biomolecular stability and recognition. Explicit solvent molecular dynamics (MD) simulations are routinely used to probe such interactions. However, detailed analyses and interpretation of the hydration patterns seen in MD simulations can be both complex and time-consuming. A variety of approaches/tools to compute and interrogate hydration properties in structural ensembles of proteins, nucleic acids, or in general any molecule are available and are complemented here with a new and free software package ("JAL"). Central to "JAL" is an intuitive atom centric approach of computing hydration properties. In addition to the standard metrics commonly used to understand hydration, "JAL" introduces two nonstandard utilities: a program to rapidly compute buried waters in an MD trajectory and a new method to compute multiwater bridges around a solute. We demonstrate the utility of the package by probing the hydration characteristics of the tumor suppressor protein p53 and the translation initiation factor eif4E. "JAL" is hosted online and can be accessed for free at http://mspc.bii.a-star.edu.sg/minhn/jal.html .


Assuntos
Proteína Supressora de Tumor p53/química , Água/química , Modelos Moleculares , Simulação de Dinâmica Molecular , Conformação Proteica , Solventes
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