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1.
Mol Cell ; 41(6): 704-19, 2011 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-21419345

RESUMO

Studies in yeast demonstrate that signaling kinases have a surprisingly active role in the nucleus, where they tether to chromatin and modulate gene expression programs. Despite these seminal studies, the nuclear mechanism of how signaling kinases control transcription of mammalian genes is in its infancy. Here, we provide evidence for a hitherto unknown function of protein kinase C-theta (PKC-θ), which physically associates with the regulatory regions of inducible immune response genes in human T cells. Chromatin-anchored PKC-θ forms an active nuclear complex by interacting with RNA polymerase II, the histone kinase MSK-1, and the adaptor molecule 14-3-3ζ. ChIP-on-chip reveals that PKC-θ binds to promoters and transcribed regions of genes, as well as to microRNA promoters that are crucial for cytokine regulation. Our results provide a molecular explanation for the role of PKC-θ not only in normal T cell function, but also in circumstances of its ectopic expression in cancer.


Assuntos
Cromatina/metabolismo , Regulação da Expressão Gênica , Isoenzimas/metabolismo , MicroRNAs/metabolismo , Proteína Quinase C/metabolismo , Linfócitos T/fisiologia , Linhagem Celular Tumoral , Núcleo Celular/metabolismo , Humanos , Interleucina-2/genética , Isoenzimas/genética , Células Jurkat , MicroRNAs/genética , Regiões Promotoras Genéticas , Proteína Quinase C/genética , Proteína Quinase C-theta , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/metabolismo , Linfócitos T/citologia , Transcrição Gênica
2.
J Sports Sci ; 37(13): 1551-1559, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30777492

RESUMO

The aim of this study was to compare cervical spine kinematics in rugby union front row players during machine-based and "live" scrummaging. Cervical spine kinematics was measured via electromagnetic tracking of sensors attached to the head and thorax. Joint angles were extracted from each trial at two time points ("bind" prior to engagement and instant of impact) for comparison between scrummaging conditions. The effect of scrummaging condition on kinematics was evaluated using a mixed effects model and estimations were based on a Bayesian framework. With differences ranging from 38° to 50°, the results show that the cervical spine is consistently more flexed when scrummaging against opponents than against a scrum machine. In contrast, there are little differences in the excursion of lateral-flexion (range 5-8°) and axial rotation (7°) between the two conditions. The findings from this study provide clear information on motion patterns in different scrum formations, and suggest that the current design of scrum machines may not promote the same pattern of movement that occurs in live scrums. The results highlight that findings from previous studies that have investigated kinematics during machine-based scrummaging may not be generalisable to a competitive scrummaging context.


Assuntos
Vértebras Cervicais/fisiologia , Futebol Americano/fisiologia , Condicionamento Físico Humano/instrumentação , Equipamentos Esportivos , Adolescente , Adulto , Teorema de Bayes , Fenômenos Biomecânicos , Fenômenos Eletromagnéticos , Cabeça/fisiologia , Humanos , Masculino , Pescoço/fisiologia , Condicionamento Físico Humano/métodos , Postura , Amplitude de Movimento Articular , Tórax/fisiologia , Estudos de Tempo e Movimento , Adulto Jovem
3.
J Cell Sci ; 129(12): 2448-61, 2016 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-27149922

RESUMO

Memory T cells are characterized by their rapid transcriptional programs upon re-stimulation. This transcriptional memory response is facilitated by permissive chromatin, but exactly how the permissive epigenetic landscape in memory T cells integrates incoming stimulatory signals remains poorly understood. By genome-wide ChIP-sequencing ex vivo human CD4(+) T cells, here, we show that the signaling enzyme, protein kinase C theta (PKC-θ) directly relays stimulatory signals to chromatin by binding to transcriptional-memory-responsive genes to induce transcriptional activation. Flanked by permissive histone modifications, these PKC-enriched regions are significantly enriched with NF-κB motifs in ex vivo bulk and vaccinia-responsive human memory CD4(+) T cells. Within the nucleus, PKC-θ catalytic activity maintains the Ser536 phosphorylation on the p65 subunit of NF-κB (also known as RelA) and can directly influence chromatin accessibility at transcriptional memory genes by regulating H2B deposition through Ser32 phosphorylation. Furthermore, using a cytoplasm-restricted PKC-θ mutant, we highlight that chromatin-anchored PKC-θ integrates activating signals at the chromatin template to elicit transcriptional memory responses in human memory T cells.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Núcleo Celular/enzimologia , Histonas/metabolismo , Memória Imunológica/genética , Isoenzimas/metabolismo , Proteína Quinase C/metabolismo , Fator de Transcrição RelA/metabolismo , Transcrição Gênica , Sequência de Aminoácidos , Cromatina/metabolismo , Regulação da Expressão Gênica , Histonas/química , Humanos , Células Jurkat , Fosforilação , Fosfosserina/metabolismo , Proteína Quinase C-theta , Transdução de Sinais
4.
J Cell Mol Med ; 19(8): 2019-31, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26130503

RESUMO

Escherichia coli's heat-labile enterotoxin (Etx) and its non-toxic B subunit (EtxB) have been characterized as adjuvants capable of enhancing T cell responses to co-administered antigen. Here, we investigate the direct effect of intravenously administered EtxB on the size of the dendritic and myeloid cell populations in spleen. EtxB treatment appears to enhance the development and turnover of dendritic and myeloid cells from precursors within the spleen. EtxB treatment also gives a dendritic cell (DC) population with higher viability and lower activation status based on the reduced expression of MHC-II, CD80 and CD86. In this respect, the in vivo effect of EtxB differs from that of the highly inflammatory mediator lipopolysaccharide. In in vitro bone marrow cultures, EtxB treatment was also found to enhance the development of DC from precursors dependent on Flt3L. In terms of the in vivo effect of EtxB on CD4 and CD8 T cell responses in mice, the interaction of EtxB directly with DC was demonstrated following conditional depletion of CD11c(+) DC. In summary, all results are consistent with EtxB displaying adjuvant ability by enhancing the turnover of DC in spleen, leading to newly mature myeloid and DC in spleen, thereby increasing DC capacity to perform as antigen-presenting cells on encounter with T cells.


Assuntos
Apresentação de Antígeno/imunologia , Toxinas Bacterianas/farmacologia , Células Dendríticas/imunologia , Enterotoxinas/farmacologia , Proteínas de Escherichia coli/farmacologia , Subunidades Proteicas/farmacologia , Animais , Apresentação de Antígeno/efeitos dos fármacos , Células da Medula Óssea/citologia , Contagem de Células , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Células Dendríticas/efeitos dos fármacos , Feminino , Ativação Linfocitária/efeitos dos fármacos , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Células Mieloides/citologia , Baço/citologia
5.
J Transl Med ; 13: 173, 2015 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-26031516

RESUMO

BACKGROUND: Multiple autoimmune syndrome (MAS), an extreme phenotype of autoimmune disorders, is a very well suited trait to tackle genomic variants of these conditions. Whole exome sequencing (WES) is a widely used strategy for detection of protein coding and splicing variants associated with inherited diseases. METHODS: The DNA of eight patients affected by MAS [all of whom presenting with Sjögren's syndrome (SS)], four patients affected by SS alone and 38 unaffected individuals, were subject to WES. Filters to identify novel and rare functional (pathogenic-deleterious) homozygous and/or compound heterozygous variants in these patients and controls were applied. Bioinformatics tools such as the Human gene connectome as well as pathway and network analysis were applied to test overrepresentation of genes harbouring these variants in critical pathways and networks involved in autoimmunity. RESULTS: Eleven novel and rare functional variants were identified in cases but not in controls, harboured in: MACF1, KIAA0754, DUSP12, ICA1, CELA1, LRP1/STAT6, GRIN3B, ANKLE1, TMEM161A, and FKRP. These were subsequently subject to network analysis and their functional relatedness to genes already associated with autoimmunity was evaluated. Notably, the LRP1/STAT6 novel mutation was homozygous in one MAS affected patient and heterozygous in another. LRP1/STAT6 disclosed the strongest plausibility for autoimmunity. LRP1/STAT6 are involved in extracellular and intracellular anti-inflammatory pathways that play key roles in maintaining the homeostasis of the immune system. Further; networks, pathways, and interaction analyses showed that LRP1 is functionally related to the HLA-B and IL10 genes and it has a substantial impact within immunological pathways and/or reaction to bacterial and other foreign proteins (phagocytosis, regulation of phospholipase A2 activity, negative regulation of apoptosis and response to lipopolysaccharides). Further, ICA1 and STAT6 were also closely related to AIRE and IRF5, two very well known autoimmunity genes. CONCLUSIONS: Novel and rare exonic mutations that may account for autoimmunity were identified. Among those, the LRP1/STAT6 novel mutation has the strongest case for being categorised as potentially causative of MAS given the presence of intriguing patterns of functional interaction with other major genes shaping autoimmunity.


Assuntos
Predisposição Genética para Doença , Genoma Humano , Mutação/genética , Síndrome de Sjogren/genética , Adulto , Idoso , Autoimunidade/genética , Sequência de Bases , Estudos de Casos e Controles , Conectoma , Feminino , Redes Reguladoras de Genes , Humanos , Pessoa de Meia-Idade , Fenótipo
6.
Cancers (Basel) ; 14(6)2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35326747

RESUMO

Protein kinase C (PKC)-θ is a serine/threonine kinase with both cytoplasmic and nuclear functions. Nuclear chromatin-associated PKC-θ (nPKC-θ) is increasingly recognized to be pathogenic in cancer, whereas its cytoplasmic signaling is restricted to normal T-cell function. Here we show that nPKC-θ is enriched in circulating tumor cells (CTCs) in patients with triple-negative breast cancer (TNBC) brain metastases and immunotherapy-resistant metastatic melanoma and is associated with poor survival in immunotherapy-resistant disease. To target nPKC-θ, we designed a novel PKC-θ peptide inhibitor (nPKC-θi2) that selectively inhibits nPKC-θ nuclear translocation but not PKC-θ signaling in healthy T cells. Targeting nPKC-θ reduced mesenchymal cancer stem cell signatures in immunotherapy-resistant CTCs and TNBC xenografts. PKC-θ was also enriched in the nuclei of CD8+ T cells isolated from stage IV immunotherapy-resistant metastatic cancer patients. We show for the first time that nPKC-θ complexes with ZEB1, a key repressive transcription factor in epithelial-to-mesenchymal transition (EMT), in immunotherapy-resistant dysfunctional PD1+/CD8+ T cells. nPKC-θi2 inhibited the ZEB1/PKC-θ repressive complex to induce cytokine production in CD8+ T cells isolated from patients with immunotherapy-resistant disease. These data establish for the first time that nPKC-θ mediates immunotherapy resistance via its activity in CTCs and dysfunctional CD8+ T cells. Disrupting nPKC-θ but retaining its cytoplasmic function may offer a means to target metastases in combination with chemotherapy or immunotherapy.

7.
Cell Rep ; 34(6): 108684, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33567273

RESUMO

The diversity of circulating human B cells is unknown. We use single-cell RNA sequencing (RNA-seq) to examine the diversity of both antigen-specific and total B cells in healthy subjects and malaria-exposed individuals. This reveals two B cell lineages: a classical lineage of activated and resting memory B cells and an alternative lineage, which includes previously described atypical B cells. Although atypical B cells have previously been associated with disease states, the alternative lineage is common in healthy controls, as well as malaria-exposed individuals. We further track Plasmodium-specific B cells after malaria vaccination in naive volunteers. We find that alternative lineage cells are primed after the initial immunization and respond to booster doses. However, alternative lineage cells develop an atypical phenotype with repeated boosts. The data highlight that atypical cells are part of a wider alternative lineage of B cells that are a normal component of healthy immune responses.


Assuntos
Anticorpos Antiprotozoários/imunologia , Linfócitos B/imunologia , Vacinas Antimaláricas/administração & dosagem , Malária/imunologia , Plasmodium/imunologia , Vacinação , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Malária/prevenção & controle , Vacinas Antimaláricas/imunologia , Masculino , RNA-Seq
8.
BMC Geriatr ; 10: 62, 2010 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-20843367

RESUMO

BACKGROUND: Cognitive function and telomere length both decline with age. A correlation between these two measures would suggest that they may be influenced by the same underlying age-related biological process. Several studies suggest telomere length may be positively correlated with cognitive performance but the evidence is equivocal. In this report, the relationships between telomere length and cognitive performance at Wave 2 and cognitive change from Wave 1 to Wave 2 are assessed in two narrow age-range population cohorts. METHODS: We tested the hypothesis that leukocyte telomere length correlates positively with cognitive performance and cognitive decline in two community cohorts of middle-aged (n = 351, 44-49 years) and older (n = 295, 64-70 years) adults, who participated in two waves of a longitudinal study undertaken in the Canberra-Queanbeyan region of Australia. Telomere length was estimated at Wave 2. Cognitive performance was measured using the Symbol Digit Modalities Test, the immediate recall test of the California Verbal Learning Test, reaction time (simple & choice) and the Trails Test Part B. RESULTS: Cross-sectionally at Wave 2, telomere length correlated with Symbol Digit Modalities Test scores (men) and simple reaction time (women) for the older cohort only, although the latter finding was in the opposite direction to that hypothesised. Telomere length measured at Wave 2 was not associated with cognitive change from Wave 1 to Wave 2 for either cohort, except for two associations of small magnitude (immediate recall in the older cohort, choice reaction time in older women), which were also in the contrary direction to that predicted. CONCLUSIONS: These results do not give strong support to the hypothesis that leukocyte telomere length is associated with either levels of cognitive performance or age-related cognitive change.


Assuntos
Envelhecimento/fisiologia , Cognição/fisiologia , Leucócitos/fisiologia , Vigilância da População , Desempenho Psicomotor/fisiologia , Telômero/fisiologia , Adulto , Fatores Etários , Idoso , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/fisiopatologia , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Vigilância da População/métodos
9.
Front Immunol ; 11: 1228, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612611

RESUMO

Lysine specific demethylase 1 (LSD1) is a key epigenetic eraser enzyme implicated in cancer metastases and recurrence. Nuclear LSD1 phosphorylated at serine 111 (nLSD1p) has been shown to be critical for the development of breast cancer stem cells. Here we show that circulating tumor cells isolated from immunotherapy-resistant metastatic melanoma patients express higher levels of nLSD1p compared to responders, which is associated with co-expression of stem-like, mesenchymal genes. Targeting nLSD1p with selective nLSD1 inhibitors better inhibits the stem-like mesenchymal signature than traditional FAD-specific LSD1 catalytic inhibitors such as GSK2879552. We also demonstrate that nLSD1p is enriched in PD-1+CD8+ T cells from resistant melanoma patients and 4T1 immunotherapy-resistant mice. Targeting the LSD1p nuclear axis induces IFN-γ/TNF-α-expressing CD8+ T cell infiltration into the tumors of 4T1 immunotherapy-resistant mice, which is further augmented by combined immunotherapy. Underpinning these observations, nLSD1p is regulated by the key T cell exhaustion transcription factor EOMES in dysfunctional CD8+ T cells. EOMES co-exists with nLSD1p in PD-1+CD8+ T cells in resistant patients, and nLSD1p regulates EOMES nuclear dynamics via demethylation/acetylation switching of critical EOMES residues. Using novel antibodies to target these post-translational modifications, we show that EOMES demethylation/acetylation is reciprocally expressed in resistant and responder patients. Overall, we show for the first time that dual inhibition of metastatic cancer cells and re-invigoration of the immune system requires LSD1 inhibitors that target the nLSD1p axis.


Assuntos
Reprogramação Celular/efeitos dos fármacos , Reprogramação Celular/genética , Histona Desmetilases/genética , Neoplasias/etiologia , Proteínas com Domínio T/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Animais , Biomarcadores , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linhagem Celular Tumoral , Núcleo Celular/genética , Núcleo Celular/metabolismo , Feminino , Citometria de Fluxo , Imunofluorescência , Expressão Gênica , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Histona Desmetilases/metabolismo , Humanos , Imunoterapia , Camundongos , Neoplasias/metabolismo , Neoplasias/patologia , Neoplasias/terapia , Proteínas com Domínio T/genética , Linfócitos T/imunologia , Resultado do Tratamento
10.
J Sports Med Phys Fitness ; 58(10): 1474-1481, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28558447

RESUMO

BACKGROUND: Neck pain and injury are common in rugby union. Physical characteristics predisposing players to neck injury are largely unknown. This study aimed to determine physical characteristics associated with neck pain and injury in rugby union players. METHODS: Semi-professional rugby union players (N.=142) underwent pre-season measurements including cervical active range of motion (AROM), strength, sensorimotor proprioception (joint position error), and anthropometry. A structured interview established previous neck injury history, current symptoms, playing position, competition level, age, and years playing rugby. Team physiotherapists and player telephone interviews identified players sustaining a neck injury during the competitive season (defined as any reported neck pain or neck injury). T-tests or Mann-Whitney U tests determined differences between neck injured and non-injured players. Logistic regression determined factors associated with neck injury history and incidence. RESULTS: Sixty-five (46%) players reported a previous neck injury; 11 (8%) sustained a neck injury during the competitive season. Player age (OR 1.14, 95% CI 1.03-1.25, P=0.009) was associated with neck injury history. Pre-season lateral flexion AROM was less in players sustaining a neck injury or reporting neck pain during the season (median left 23.6°, IQR 21.8-26.2°; right 27.9°, 23.6-32.5°) than in other players (left 34.8°, 28.8-41.0°, P<0.01; right 39.1°, 28.9-48.1°, P=0.03). Lateral flexion AROM was associated with increased risk of neck pain or injury (OR 0.82, 95%CI 0.71-0.94, P=0.005). CONCLUSIONS: Decreased cervical lateral flexion AROM may contribute to neck injury risk in rugby union players. However, few physical characteristics predicted neck injury incidence, suggesting additional factors should be explored to determine injury risk.


Assuntos
Traumatismos em Atletas/fisiopatologia , Futebol Americano/lesões , Cervicalgia/fisiopatologia , Amplitude de Movimento Articular , Adulto , Fatores Etários , Antropometria , Humanos , Incidência , Modelos Logísticos , Masculino , Propriocepção , Estudos Prospectivos , Adulto Jovem
11.
Br J Sports Med ; 41(9): 582-7; discussion 587, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17504786

RESUMO

BACKGROUND: Ground hardness is considered one of the possible risk factors associated with rugby injuries. OBJECTIVES: To examine the contribution of ground hardness, rainfall and evapotranspiration to the incidence of injury, and to investigate seasonal injury bias throughout one full season of rugby union. METHODS: A prospective epidemiological study of rugby injuries was performed on 271 players from rugby union teams involved in the premier grade rugby competition in Dunedin, New Zealand. Ground hardness was measured before each match over 20 rounds with an industrial penetrometer, and local weather information was collected through the National Institute of Weather and Atmospheric Research and the Otago Regional Council. Poisson mixed models were used to describe injury incidence as a function of ground hardness throughout the season. RESULTS: The overall injury incidence during the season was 52 injuries per 1000 match player-hours (95% CI 42 to 65). Although injury incidence decreased gradually by round with a rate ratio of 0.98 (95% CI 0.96 to 0.99) (p = 0.036), and the hardness of match grounds decreased significantly over the season (0.16 MPa/round, 95% CI 0.12 to 0.21, p<0.001), a non-significant association was demonstrated between injury incidence and ground hardness. Injury incidence was not associated with a combination of ground hardness, rainfall and evapotranspiration on the day of the match or cumulative rainfall and evapotranspiration before each match. CONCLUSIONS: Seasonal change in ground hardness and an early-season bias of injuries was demonstrated. Although the contribution of ground hardness to injury incidence was not statistically significant, match round and injury incidence were highly correlated, confirming a seasonal bias, which may confound the relationship of injury to ground condition.


Assuntos
Futebol Americano/lesões , Tempo (Meteorologia) , Traumatismos em Atletas/epidemiologia , Traumatismos em Atletas/etiologia , Futebol Americano/estatística & dados numéricos , Humanos , Incidência , Escala de Gravidade do Ferimento , Estudos Prospectivos , Fatores de Risco
12.
Cutis ; 80(1): 72-4, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17725068

RESUMO

Grover disease, or transient acantholytic dermatosis, chiefly affects the upper part of the trunk in men older than 40 years. Lesions may last for weeks, months, or years, and often are accompanied by intense pruritus. Some patients respond to topical steroid treatment but many do not. This article reports major or total resolution of Grover disease in 6 of 9 patients following topical application of a triple antibiotic ointment. It also proposes using a case registry as a way of further investigating the efficacy of this treatment so that dermatologists may participate.


Assuntos
Acantólise/tratamento farmacológico , Antibacterianos/administração & dosagem , Administração Tópica , Idoso , Idoso de 80 Anos ou mais , Combinação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pomadas/administração & dosagem
13.
Appl Ergon ; 38(3): 299-306, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-16842737

RESUMO

Sheep shearers are known to work in sustained flexed postures and have a high prevalence of low back pain (LBP). As sustained posture and spinal movement asymmetry under substantial loads are known risk factors for back injury our aim was to describe the 3D spinal movement of shearers while working. We hypothesised that thoraco-lumbar and lumbo-sacral movement would be tri-axial, asymmetric, and task specific. Sufficient retro-reflective markers were placed on the trunk of 12 shearers to define thoraco-lumbar and lumbo-sacral 3D motion during three tasks. Thoraco-lumbar movement consistently involved flexion, left lateral flexion, and right rotation. Lumbo-sacral movement consistently involved right lateral flexion in flexion with minimal rotation. Shearers therefore work in sustained spinal flexion where concurrent, asymmetric spinal movements into both lateral flexion and rotation occur. These asymmetric movements combined with repetitive loading may be risk factors leading to the high incidence of LBP in this occupational group.


Assuntos
Fenômenos Biomecânicos , Dor Lombar/prevenção & controle , Região Lombossacral/fisiologia , Músculo Esquelético/fisiologia , Exposição Ocupacional , Amplitude de Movimento Articular , Adulto , Animais , Fenômenos Biomecânicos/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Movimento (Física) , Nova Zelândia , Carneiro Doméstico ,
14.
Transplantation ; 79(12): 1674-82, 2005 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-15973168

RESUMO

BACKGROUND: Identification of the antigens that stimulate transplant rejection can help develop graft-specific antirejection strategies. The xenoantigens recognized during rejection of porcine cellular xenografts have not been clearly defined, but it has been assumed that major histocompatibility complex (MHC) xenoantigens are involved. METHODS: The role of porcine endogenous retrovirus (PERV) as a source of xenoantigens was examined. The authors used morphometry to compare the kinetics of swine leukocyte antigen (SLA) pig thyroid xenograft rejection in control mice and mice immunized with PERV PK15 cells (porcine kidney epithelial cells), PERV SLA pig peripheral blood lymphocytes (PBL), PERV virions purified from PK15 cells, and PERV or PERV A pseudotypes produced from infected human 293 cells. The tempo of rejection for cellular xenografts of PERV A pseudotype-producing human 293 cells, uninfected human 293 cells, and PK15 cells in PERV-preimmunized and control mice was also compared. RESULTS: Mice immunized with PK15 cells rejected pig thyroid xenografts significantly faster at day 5 than control mice and mice immunized with pig PBL. This correlated with the amount of PERV RNA and virions produced, but not with the amount of SLA class I MHC expressed by PK15 cells. Immunization of mice with PERV virions purified from porcine PK15 cells and with PERV virions or PERV A pseudotypes produced by human 293 cells also induced accelerated xenograft rejection by 5 days. Accelerated rejection induced by virus pretreatment was CD4 T-cell dependent and restricted to PERV-expressing cellular xenografts of porcine or nonporcine origin. CONCLUSIONS: PERV acts as a significant source of xenoantigens that target porcine cellular xenografts for rejection.


Assuntos
Antígenos Heterófilos/imunologia , Antígenos Virais/imunologia , Retrovirus Endógenos/genética , Retrovirus Endógenos/isolamento & purificação , Rejeição de Enxerto/virologia , Glândula Tireoide/transplante , Transplante Heterólogo/patologia , Animais , Sequência de Bases , Linhagem Celular , Primers do DNA , Rejeição de Enxerto/patologia , Humanos , Complexo Principal de Histocompatibilidade , Masculino , Camundongos , Camundongos Endogâmicos CBA , Camundongos SCID , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Suínos , Porco Miniatura , Vírion/genética , Vírion/isolamento & purificação
15.
Biochem J ; 381(Pt 3): 753-60, 2004 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-15107017

RESUMO

The septins are a family of GTPase enzymes required for cytokinesis and play a role in exocytosis. Among the ten vertebrate septins, Sept5 (CDCrel-1) and Sept3 (G-septin) are primarily concentrated in the brain, wherein Sept3 is a substrate for PKG-I (cGMP-dependent protein kinase-I) in nerve terminals. There are two motifs for potential PKG-I phosphorylation in Sept3, Thr-55 and Ser-91, but phosphoamino acid analysis revealed that the primary site is a serine. Derivatization of phosphoserine to S-propylcysteine followed by N-terminal sequence analysis revealed Ser-91 as a major phosphorylation site. Tandem MS revealed a single phosphorylation site at Ser-91. Substitution of Ser-91 with Ala in a synthetic peptide abolished phosphorylation. Mutation of Ser-91 to Ala in recombinant Sept3 also abolished PKG phosphorylation, confirming that Ser-91 is the major site in vitro. Antibodies raised against a peptide containing phospho-Ser-91 detected phospho-Sept3 only in the cytosol of nerve terminals, whereas Sept3 was located in a peripheral membrane extract. Therefore Sept3 is phosphorylated on Ser-91 in nerve terminals and its phosphorylation may contribute to the regulation of its subcellular localization in neurons.


Assuntos
Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Terminações Pré-Sinápticas/enzimologia , Serina/metabolismo , Animais , Sítios de Ligação , Encéfalo , Proteína Quinase Dependente de GMP Cíclico Tipo I , GTP Fosfo-Hidrolases/química , Proteínas do Tecido Nervoso/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Fosforilação , Fosfosserina/química , Ratos , Septinas
16.
FEBS Lett ; 512(1-3): 38-42, 2002 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-11852048

RESUMO

We report the first Fourier transform infrared analysis of prion protein (PrP) repeats and the first study of PrP repeats of marsupial origin. Large changes in the secondary structure and an increase in hydrogen bonding within the peptide groups were evident from a red shift of the amide I band by >7 cm(-1) and an approximately five-fold reduction in amide hydrogen-deuterium exchange for peptide interacting with Cu(2+) ions. Changes in the tertiary structure upon copper binding were also evident from the appearance of a new band at 1564 cm(-1), which arises from the ring vibration of histidine. The copper-induced conformational change is pH dependent, and occurs at pH >7.


Assuntos
Gambás/fisiologia , Príons/química , Animais , Cobre/farmacologia , Príons/metabolismo , Estrutura Secundária de Proteína/efeitos dos fármacos , Estrutura Terciária de Proteína/efeitos dos fármacos , Sequências Repetitivas de Aminoácidos , Espectroscopia de Infravermelho com Transformada de Fourier
17.
Clin Biomech (Bristol, Avon) ; 19(1): 85-90, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14659935

RESUMO

OBJECTIVE: To determine the suitability of a magnetic tracking device to measure pelvic bone range of motion based on palpated and digitized pelvic landmarks. DESIGN: A repeated measures study was conducted in two experiments to determine the reliability and validity of innominate bone range of motion measured with a magnetic tracking device in healthy subjects through passive hip abduction and external rotation. BACKGROUND: Because of the anatomical position of the pelvic joints, kinematic analysis of joint motion is difficult. Accurate and precise measurements typically require highly invasive techniques involving implantation of titanium markers and exposing the subject to multiple radiographs. There is a need for a practical and accurate measurement method that will allow researchers and clinicians to accurately and reliably evaluate motion in the pelvis. METHODS: Innominate bone angles were measured for two static hip postures from the 3D spatial coordinates of the pelvic landmarks. By palpating and subsequently digitizing pelvic landmarks using an electro-magnetic tracking device the 3D coordinates were obtained. Palpated results were validated using CT scans and a metallic bead attached to the palpated landmarks. RESULTS: The mean range of innominate bone motion was between 3 degrees and 4 degrees (transverse plane) for each side with large variability across the subjects in the range of motion. Despite this variability, the measurements were found to be reliable and valid.


Assuntos
Ossos Pélvicos/fisiologia , Articulação Sacroilíaca/fisiologia , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Palpação , Amplitude de Movimento Articular , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador
18.
J Sci Med Sport ; 17(2): 150-4, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23684371

RESUMO

OBJECTIVES: The association between tibial morphology and tibial stress fractures or tibial stress syndrome was examined in triathletes with an unusually high incidence of these injuries. DESIGN: A cross-sectional study design examined associations between tibial geometry from MRI images and training and injury data between male and female triathletes and between stress fracture (SF) and non-stress fracture (NSF) groups. METHODS: Fifteen athletes (7 females, 8 males) aged 17-23 years who were currently able to train and race were recruited from the New Zealand Triathlete Elite Development Squad. Geometric measurements were taken at 5 zones along the tibia using MRI and compared between symptomatic and asymptomatic tibiae subjects. RESULTS: SF tibiae displayed either oedema within the cancellous bone and/or stress fracture on MRI. When collapsed across levels, symptomatic tibiae had thicker medial cortices (F1,140=9.285, p=0.003), thicker lateral cortices (F1,140=10.129, p=0.002) and thinner anterior cortices (F1,140=14.517, p=0.000) than NSF tibiae. Only medial cortex thickness in SF tibia was significantly different (F4,140=3.358, p=0.012) at different levels. Follow-up analysis showed that athletes showing oedema within the cancellous bone and/or stress fracture on MRI had, within 2 years of analysis, subsequently taken time off training and racing due a tibial stress fracture. CONCLUSIONS: The thinner anterior cortex in SF tibiae is associated with a stress reaction in these triathletes.


Assuntos
Edema/diagnóstico , Fraturas de Estresse/patologia , Tíbia/lesões , Tíbia/patologia , Adolescente , Ciclismo/fisiologia , Estudos de Casos e Controles , Estudos Transversais , Transtornos Traumáticos Cumulativos/etiologia , Transtornos Traumáticos Cumulativos/patologia , Feminino , Fraturas de Estresse/etiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Corrida/fisiologia , Natação/fisiologia , Tíbia/anatomia & histologia , Tíbia/fisiopatologia , Adulto Jovem
19.
Mol Cell Biol ; 34(16): 2961-80, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24891615

RESUMO

Epithelial to mesenchymal transition (EMT) is activated during cancer invasion and metastasis, enriches for cancer stem cells (CSCs), and contributes to therapeutic resistance and disease recurrence. Signal transduction kinases play a pivotal role as chromatin-anchored proteins in eukaryotes. Here we report for the first time that protein kinase C-theta (PKC-θ) promotes EMT by acting as a critical chromatin-anchored switch for inducible genes via transforming growth factor ß (TGF-ß) and the key inflammatory regulatory protein NF-κB. Chromatinized PKC-θ exists as an active transcription complex and is required to establish a permissive chromatin state at signature EMT genes. Genome-wide analysis identifies a unique cohort of inducible PKC-θ-sensitive genes that are directly tethered to PKC-θ in the mesenchymal state. Collectively, we show that cross talk between signaling kinases and chromatin is critical for eliciting inducible transcriptional programs that drive mesenchymal differentiation and CSC formation, providing novel mechanisms to target using epigenetic therapy in breast cancer.


Assuntos
Neoplasias da Mama/patologia , Transição Epitelial-Mesenquimal/genética , Isoenzimas/genética , Proteína Quinase C/genética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Antígeno CD24/biossíntese , Antígeno CD24/genética , Diferenciação Celular/genética , Cromatina/genética , Montagem e Desmontagem da Cromatina/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Receptores de Hialuronatos/biossíntese , Receptores de Hialuronatos/genética , Células MCF-7 , Subunidade p50 de NF-kappa B/biossíntese , Subunidade p50 de NF-kappa B/genética , Invasividade Neoplásica , Metástase Neoplásica , Células-Tronco Neoplásicas/patologia , Proteína Quinase C-theta , Interferência de RNA , RNA Mensageiro/biossíntese , RNA Interferente Pequeno , Receptores de Ativador de Plasminogênio Tipo Uroquinase/genética , Transdução de Sinais/genética , Esferoides Celulares/patologia , Fator de Transcrição RelA/biossíntese , Fator de Transcrição RelA/genética , Fator de Crescimento Transformador beta/genética
20.
Front Immunol ; 3: 260, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22969762

RESUMO

We recently provided the first description of a nuclear mechanism used by Protein Kinase C-theta (PKC-θ) to mediate T cell gene expression. In this mode, PKC-θ tethers to chromatin to form an active nuclear complex by interacting with proteins including RNA polymerase II, the histone kinase MSK-1, the demethylase LSD1, and the adaptor molecule 14-3-3ζ at regulatory regions of inducible immune response genes. Moreover, our genome-wide analysis identified many novel PKC-θ target genes and microRNAs implicated in T cell development, differentiation, apoptosis, and proliferation. We have expanded our ChIP-on-chip analysis and have now identified a transcription factor motif containing NF-κB binding sites that may facilitate recruitment of PKC-θ to chromatin at coding genes. Furthermore, NF-κB association with chromatin appears to be a prerequisite for the assembly of the PKC-θ active complex. In contrast, a distinct NF-κB-containing module appears to operate at PKC-θ targeted microRNA genes, and here NF-κB negatively regulates microRNA gene transcription. Our efforts are also focusing on distinguishing between the nuclear and cytoplasmic functions of PKCs to ascertain how these kinases may synergize their roles as both cytoplasmic signaling proteins and their functions on the chromatin template, together enabling rapid induction of eukaryotic genes. We have identified an alternative sequence within PKC-θ that appears to be important for nuclear translocation of this kinase. Understanding the molecular mechanisms used by signal transduction kinases to elicit specific and distinct transcriptional programs in T cells will enable scientists to refine current therapeutic strategies for autoimmune diseases and cancer.

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