RESUMO
The canonical role of platelets as central players in cardiovascular disease by way of their fundamental role in mediating thrombosis and haemostasis is well appreciated. However, there is now a large body of experimental evidence demonstrating that platelets are also pivotal in various physiological and pathophysiological processes other than maintaining haemostasis. Foremost amongst these is the emerging data highlighting the key role of platelets in driving cancer growth, metastasis and modulating the tumour microenvironment. As such, there is significant interest in targeting platelets therapeutically for the treatment of cancer. Therefore, the purpose of this review is to provide an overview of how platelets contribute to the cancer landscape and why platelets present as valuable targets for the development of novel cancer diagnosis tools and therapeutics.
Assuntos
Neoplasias , Trombose , Humanos , Plaquetas/fisiologia , Hemostasia , Neoplasias/tratamento farmacológico , Trombose/etiologia , Microambiente TumoralRESUMO
Vaccine-induced thrombotic thrombocytopenia (VITT) is a rare, but serious, syndrome characterised by thrombocytopenia, thrombosis, a markedly raised D-dimer and the presence of anti-platelet factor-4 (PF4) antibodies following COVID-19 adenovirus vector vaccination. VITT occurs at a rate of approximately 2 per 100 000 first-dose vaccinations and appears exceedingly rare following second doses. Our current understanding of VITT pathogenesis is based on the observations that patients with VITT have antibodies that bind to PF4 and have the ability to form immune complexes that induce potent platelet activation. However, the precise mechanisms that lead to pathogenic VITT antibody development remain a source of active investigation. Thrombosis in VITT can manifest in any vascular bed and affect multiple sites simultaneously. While there is a predilection for splanchnic and cerebral venous sinus thrombosis, VITT also commonly presents with deep vein thrombosis and pulmonary embolism. Pillars of management include anticoagulation with a non-heparin anticoagulant, intravenous immunoglobulin and 'rescue' therapies, such as plasma exchange for severe cases. VITT can be associated with a high mortality rate and significant morbidity, but awareness and optimal therapy have significantly improved outcomes in Australia. A number of questions remain unanswered, including why VITT is so rare, reasons for the predilection for thrombosis in unusual sites, how long pathological antibodies persist, and the optimal duration of anticoagulation. This review will provide an overview of the presentation, diagnostic workup and management strategies for patients with VITT.
Assuntos
COVID-19 , Trombocitopenia , Trombose , Vacinas , Anticoagulantes/efeitos adversos , Vacinas contra COVID-19/efeitos adversos , Humanos , Fator Plaquetário 4/efeitos adversos , SARS-CoV-2 , Trombocitopenia/induzido quimicamente , Trombose/induzido quimicamente , Trombose/complicações , Vacinas/efeitos adversosRESUMO
Human papillomavirus (HPV) vaccines are safe and effective in preventing HPV infection and cervical precancers. Neutralizing antibodies are thought to be the primary mechanism of protection for HPV vaccines, although the exact level required for protection has not been identified. Three common serological assays used in clinical trials to measure HPV antibodies are HPV pseudovirion-based neutralization assay (PBNA), competitive or total Luminex immunoassays (cLIA or LIA) and VLP-based enzyme linked immunosorbent assays (ELISA). While PBNA is the gold-standard for measuring neutralizing antibodies (NAb), it is labor intensive. Luminex immunoassay and VLP-ELISA are rapid and high throughput, but their reagents and equipment can be difficult to source. Nevertheless, data generated from these assays generally correlate well with PBNA. Here, we described a simplified high-throughput PsV-based ELISA for HPV antibody measurement, to circumvent some of the limitations of existing assays. Using this assay, we were able to differentiate HPV-specific IgG and IgM, and found a strong correlation between HPV-specific IgG and NAb levels, as previously determined by PBNA. This assay platform is simpler and less time-consuming than PBNA. In addition, the materials can be readily produced and obtained commercially. This assay can be used as an alternative method to measure HPV antibodies.
Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Vacinas contra Papillomavirus/sangue , Adolescente , Feminino , Ensaios de Triagem em Larga Escala/métodos , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Papillomaviridae , Infecções por Papillomavirus/imunologia , Vacinas contra Papillomavirus/imunologiaRESUMO
BACKGROUND: Oxidative stress and inflammation are considered to be important pathways leading to particulate matter (PM)-associated disease. In this exploratory study, we examined the effects of metals and oxidative potential (OP) in urban PM on biomarkers of systemic inflammation, oxidative stress and neural function. METHODS: Fifty-three healthy non-smoking volunteers (mean age 28â¯years, twenty-eight females) were exposed to coarse (2.5-10⯵m, mean 213⯵g/m3), fine (0.15-2.5⯵m, 238⯵g/m3), and/or ultrafine concentrated ambient PM (<0.3⯵m, 136⯵g/m3). Exposures lasted 130â¯min, separated by ≥2â¯weeks. Metal concentrations and OP (measured by ascorbate and glutathione depletion in synthetic airway fluid) in PM were analyzed. Blood and urine samples were collected pre-exposure, and 1-h and 21-h post exposure for assessment of biomarkers. We used mixed-regression models to analyze associations adjusting for PM size and mass concentration. RESULTS: Results for metals were expressed as change (%) from daily pre-exposure biomarker levels after exposure to a metal at a level equivalent to the mean concentration. Exposure to various metals (silver, aluminum, barium, copper, iron, potassium, lithium, nickel, tin, and/or vanadium) was significantly associated with increased levels of various blood or urinary biomarkers. For example, the blood inflammatory marker vascular endothelia growth factor (VEGF) increased 5.3% (95% confidence interval: 0.3%, 10.2%) 1-h post exposure to nickel; the traumatic brain injury marker ubiquitin C-terminal hydrolase L1 (UCHL1) increased 11% (1.2%, 21%) and 14% (0.3%, 29%) 1-h and 21-h post exposure to barium, respectively; and the systemic stress marker cortisol increased 1.5% (0%, 2.9%) and 1.5% (0.5%, 2.8%) 1-h and 21-h post exposure to silver, respectively. Urinary DNA oxidation marker 8hydroxydeoxyguanosine increased 14% (6.4%, 21%) 1-h post exposure to copper; urinary neural marker vanillylmandelic acid increased 29% (3%, 54%) 1-h post exposure to aluminum; and urinary cortisol increased 88% (0.9%, 176%) 1-h post exposure to vanadium. Results for OP were expressed as change (%) from daily pre-exposure biomarker levels after exposure to ascorbate-related OP at a level equivalent to the mean concentration, or for exposure to glutathione-related OP at a level above the limit of detection. Exposure to ascorbate- or glutathione-related OP was significantly associated with increased inflammatory and neural biomarkers including interleukin-6, VEGF, UCHL1, and S100 calcium-binding protein B in blood, and malondialdehyde and 8-hydroxy-deoxy-guanosine in urine. For example, UCHL1 increased 9.4% (1.8%, 17%) in blood 21-h post exposure to ascorbate-related OP, while urinary malondialdehyde increased 19% (3.6%, 35%) and 8-hydroxy-deoxy-guanosine increased 24% (2.9%, 48%) 21-h post exposure to ascorbate- and glutathione-related OP, respectively. CONCLUSION: Our results from this exploratory study suggest that metal constituents and OP in ambient PM may influence biomarker levels associated with systemic inflammation, oxidative stress, perturbations of neural function, and systemic physiological stress.
Assuntos
Poluentes Atmosféricos , Inflamação/induzido quimicamente , Exposição por Inalação/efeitos adversos , Metais , Oxidantes , Material Particulado/efeitos adversos , Adulto , Poluentes Atmosféricos/sangue , Poluentes Atmosféricos/urina , Biomarcadores/sangue , Biomarcadores/urina , Feminino , Humanos , Masculino , Metais/sangue , Metais/urina , Pessoa de Meia-Idade , Fenômenos Fisiológicos do Sistema Nervoso/efeitos dos fármacos , Ontário , Oxidantes/sangue , Oxidantes/urina , Estresse Oxidativo , Adulto JovemRESUMO
BACKGROUNDS: Influenza can spread rapidly in long-term care facilities (LTCFs), and residents are usually at higher risk for influenza infections. OBJECTIVE: Our study aimed to evaluate the effectiveness of antiviral interventions on outbreak control. METHODS: Taiwan Centers for Disease Control used a syndromic surveillance system to monitor outbreaks in LTCFs. Local public health authorities verified those outbreaks and logged reports to the Epidemic Investigation Report Files Management System (EIRFMS). We conducted a retrospective cohort study by reviewing EIRFMS reports of influenza outbreaks in LTCFs during 2008-2014. An influenza outbreak was defined as 3 or more cases of influenza-like illness occurring within a 48-hours period with ≥1 case of real-time RT-PCR-confirmed influenza in the same LTCF. Antiviral interventions included providing antiviral treatment for patients and antiviral prophylaxis for contacts during outbreaks. RESULTS: Of 102 influenza outbreaks, median days from onset of the first patient to outbreak notification was 4 (range 0-22). Median attack rate was 24% (range 2.2%-100%). Median influenza vaccination coverage among residents was 81% (range 0%-100%); 43% occurred during the summer months. Even though antiviral treatment was provided in 87% of the outbreaks, antiviral prophylaxis was implemented in only 40%. Starting antiviral treatment within 2 days of outbreak onset was associated with keeping attack rates at <25% (OR 0.29, 95% CI: 0.12-0.71). CONCLUSIONS: Early initiation of antiviral treatment may reduce the magnitude of influenza outbreaks. Clinicians should identify patients with influenza and start antiviral use early to prevent large outbreaks in LTCFs.
Assuntos
Antivirais/uso terapêutico , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/epidemiologia , Surtos de Doenças , Controle de Infecções/métodos , Influenza Humana/tratamento farmacológico , Influenza Humana/epidemiologia , Quimioprevenção/métodos , Transmissão de Doença Infecciosa/prevenção & controle , Instalações de Saúde , Humanos , Assistência de Longa Duração , Orthomyxoviridae/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taiwan/epidemiologiaRESUMO
Loss of the microvascular (MV) network results in tissue ischemia, loss of tissue function, and is a hallmark of chronic diseases. The incorporation of a functional vascular network with that of the host remains a challenge to utilizing engineered tissues in clinically relevant therapies. We showed that vascular-bed-specific endothelial cells (ECs) exhibit differing angiogenic capacities, with kidney microvascular endothelial cells (MVECs) being the most deficient, and sought to explore the underlying mechanism. Constitutive activation of the phosphatase PTEN in kidney MVECs resulted in impaired PI3K/AKT activity in response to vascular endothelial growth factor (VEGF). Suppression of PTEN in vivo resulted in microvascular regeneration, but was insufficient to improve tissue function. Promoter analysis of the differentially regulated genes in KMVECs suggests that the transcription factor FOXO1 is highly active and RNAseq analysis revealed that hyperactive FOXO1 inhibits VEGF-Notch-dependent tip-cell formation by direct and indirect inhibition of DLL4 expression in response to VEGF. Inhibition of FOXO1 enhanced angiogenesis in human bio-engineered capillaries, and resulted in microvascular regeneration and improved function in mouse models of injury-repair.
Assuntos
Proteína Forkhead Box O1/metabolismo , Rim/irrigação sanguínea , Rim/fisiopatologia , Microvasos/fisiopatologia , Neovascularização Fisiológica , Adulto , Animais , Células Cultivadas , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Humanos , Rim/lesões , Rim/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microvasos/metabolismo , Microvasos/fisiologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
Amyotrophic lateral sclerosis (ALS) is a lethal degenerating disease, characterized by progressive muscular atrophy without any effective treatment. Here, we demonstrated the efficacy of abrograting autophagy in motor neurons (MN) by treatment with n-butylidenephthalide (n-BP) in ALS transgenic mice (SOD1(G93A)). Pre-symptomatic oral administration of 250 mg/kg/bid n-BP significantly prolonged the survival period (203.9 ± 18.3 days), improved motor function, and attenuated MN loss compared to vehicle control (126.4 ± 7.2 days). This prolonged survival of ALS mice is much more robust than that reported with riluzole (140 days), which is an approved clinical therapy for ALS. The therapeutic mechanism targeted by n-BP involved the autophagic pathway as evidenced by decreased LC3-II expression (a biomarker of autophagy), enhanced mTOR levels, and attenuated autophagic activity, altogether increasing MN survival in a dose-dependent manner. This result was also confirmed by double transgenic mice (SOD1(G93A):LC3-GFP) which showed that oral administration of n-BP reduced GFP density and decreased caspase-3 expression. In addition, electron microscopy revealed that n-BP administration not only decreased autophagosome number but also reduced morphological dysfunction of mitochondria. In summary, these results indicate that down-regulation of autophagy activation via n-BP may pose as a therapeutic regimen for ALS and relevant neurodegenerative diseases.
Assuntos
Esclerose Lateral Amiotrófica/tratamento farmacológico , Esclerose Lateral Amiotrófica/patologia , Autofagia/fisiologia , Regulação para Baixo/fisiologia , Neurônios Motores/fisiologia , Anidridos Ftálicos/farmacologia , Esclerose Lateral Amiotrófica/genética , Animais , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios Motores/efeitos dos fármacos , Anidridos Ftálicos/uso terapêutico , Distribuição Aleatória , Superóxido Dismutase-1/genética , Taxa de Sobrevida/tendênciasRESUMO
The lack of a rapid and quantitative autophagy assay has substantially hindered the development and implementation of autophagy-targeting therapies for a variety of human diseases. To address this critical issue, we developed a novel autophagy assay using the newly developed Cyto-ID fluorescence dye. We first verified that the Cyto-ID dye specifically labels autophagic compartments with minimal staining of lysosomes and endosomes. We then developed a new Cyto-ID fluorescence spectrophotometric assay that makes it possible to estimate autophagy flux based on measurements of the Cyto-ID-stained autophagic compartments. By comparing to traditional autophagy approaches, we found that this assay yielded a more sensitive, yet less variable, quantification of the stained autophagic compartments and the estimate of autophagy flux. Furthermore, we tested the potential application of this autophagy assay in high throughput research by integrating it into an RNA interference (RNAi) screen and a small molecule screen. The RNAi screen revealed WNK2 and MAP3K6 as autophagy-modulating genes, both of which inhibited the MTOR pathway. Similarly, the small molecule screen identified sanguinarine and actinomycin D as potent autophagy inducers in leukemic cells. Moreover, we successfully detected autophagy responses to kinase inhibitors and chloroquine in normal or leukemic mice using this assay. Collectively, this new Cyto-ID fluorescence spectrophotometric assay provides a rapid, reliable quantification of autophagic compartments and estimation of autophagy flux with potential applications in developing autophagy-related therapies and as a test to monitor autophagy responses in patients being treated with autophagy-modulating drugs.
Assuntos
Autofagia , Corantes Fluorescentes/química , Espectrometria de Fluorescência/métodos , Animais , Sobrevivência Celular , Cloroquina/química , Dactinomicina/química , Endossomos/química , Regulação Leucêmica da Expressão Gênica , Células HEK293 , Células HeLa , Humanos , Mesilato de Imatinib/química , Células K562 , Leucemia/metabolismo , Lisossomos/química , MAP Quinase Quinase Quinases/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos SCID , Microscopia de Fluorescência , Transplante de Neoplasias , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNARESUMO
The utility of human induced pluripotent stem cells (hiPSCs) to create tissue-engineered vascular grafts was evaluated in this study. hiPSC lines were first induced into a mesenchymal lineage via a neural crest intermediate using a serum-free, chemically defined differentiation scheme. Derived cells exhibited commonly known mesenchymal markers (CD90, CD105, and CD73 and negative marker CD45) and were shown to differentiate into several mesenchymal lineages (osteogenic, chondrogenic, and adipogenic). Functional vascular grafts were then engineered by culturing hiPSC-derived mesenchymal progenitor cells in a pulsatile bioreactor system over 8 weeks to induce smooth muscle cell differentiation and collagenous matrix generation. Histological analyses confirmed layers of calponin-positive smooth muscle cells in a collagen-rich matrix. Mechanical tests revealed that grafts had an average burst pressure of 700 mmHg, which is approximately half that of native veins. Additionally, studies revealed that karyotypically normal mesenchymal stem cell clones led to generation of grafts with predicted features of engineered vascular grafts, whereas derived clones having chromosomal abnormalities generated calcified vessel constructs, possibly because of cell apoptosis during culture. Overall, these results provide significant insight into the utility of hiPS cells for vascular graft generation. They pave the way for creating personalized, patient-specific vascular grafts for surgical applications, as well as for creating experimental models of vascular development and disease.
Assuntos
Prótese Vascular , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Engenharia Tecidual/métodos , Antígenos de Diferenciação/biossíntese , Linhagem Celular , Matriz Extracelular/metabolismo , HumanosRESUMO
Taiwanin A (α,ß-bis(piperonylidene)-γ-butyrolactone) is extracted from Taiwania cryptomerioides. Taiwanin A is extracted from tree bark and exhibits antitumor activity in breast, liver, and lung cancer cell lines. The objective of this study was to demonstrate the cytotoxicity of Taiwanin A against tumor cells by increasing the expression of non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1). NAG-1 has been reported to exhibit antitumor and proapoptotic activities, suggesting potential use in cancer therapy. Inhibiting NAG-1 mRNA expression in A549 reduced the cytotoxicity caused by Taiwanin A. Furthermore, the c-Jun-N-terminal kinase/Ste20-related protein proline/alanine-rich kinase (JNK/SPAK) pathway played a key role in the influence of NAG-1 on cell viability, whereas the addition of the JNK pathway inhibitor SP600125 resulted in an inhibitory effect on NAG-1 and recovery of Taiwanin-A-treated cells. A xenograft tumor model demonstrated that Taiwanin A dose-dependently significantly decreases tumor-mediated growth in nude mice by increasing the NAG-1 expression accompanying tumor apoptosis. These data supported the hypothesis that Taiwanin A inhibits lung carcinoma growth by increasing NAG-1 expression through the JNK pathway both in vivo and in vitro. This result can contribute to a compound design for increasing cytotoxicity activity in the future.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Furanos/farmacologia , Fator 15 de Diferenciação de Crescimento/metabolismo , Lignanas/farmacologia , Neoplasias Pulmonares/metabolismo , Animais , Antracenos/farmacologia , Apoptose , Linhagem Celular Tumoral , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Serina-Treonina Quinases/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Tissue-engineered small-diameter vascular grafts have been developed as a promising alternative to native veins or arteries for replacement therapy. However, there is still a crucial need to improve the current approaches to render the tissue-engineered blood vessels more favorable for clinical applications. A completely biological blood vessel (3-mm inner diameter) was constructed by culturing a 50:50 mixture of bovine smooth muscle cells (SMCs) with neonatal human dermal fibroblasts in fibrin gels. After 30 days of culture under pulsatile stretching, the engineered blood vessels demonstrated an average burst pressure of 913.3±150.1 mmHg (n=6), a suture retention (53.3±15.4 g) that is suitable for implantation, and a compliance (3.1%±2.5% per 100 mmHg) that is comparable to native vessels. These engineered grafts contained circumferentially aligned collagen fibers, microfibrils and elastic fibers, and differentiated SMCs, mimicking a native artery. These promising mechanical and biochemical properties were achieved in a very short culture time of 30 days, suggesting the potential of co-culturing SMCs with fibroblasts in fibrin gels to generate functional small-diameter vascular grafts for vascular reconstruction surgery.
Assuntos
Prótese Vascular , Vasos Sanguíneos/crescimento & desenvolvimento , Fibrina/química , Fibroblastos/fisiologia , Miócitos de Músculo Liso/fisiologia , Engenharia Tecidual/instrumentação , Alicerces Teciduais , Animais , Vasos Sanguíneos/citologia , Bovinos , Células Cultivadas , Técnicas de Cocultura , Fibroblastos/citologia , Humanos , Miócitos de Músculo Liso/citologia , Desenho de Prótese , Engenharia Tecidual/métodosRESUMO
Recent advances in three-dimensional (3D) tissue engineering have concomitantly generated a need for new methods to visualize and assess the tissue. In particular, methods for imaging intact volumes of whole tissue, rather than a single plane, are required. Herein, we describe the use of multiphoton microscopy, combined with optical clearing, to noninvasively probe decellularized lung extracellular matrix scaffolds and decellularized, tissue-engineered blood vessels. We also evaluate recellularized lung tissue scaffolds. In addition to nondestructive imaging of tissue volumes greater than 4 mm(3), the lung tissue can be visualized using three distinct signals, combined or singly, that allow for simple separation of cells and different components of the extracellular matrix. Because the 3D volumes are not reconstructions, they do not require registration algorithms to generate digital volumes, and maintenance of isotropic resolution is not required when acquiring stacks of images. Once a virtual volume of tissue is generated, structures that have innate 3D features, such as the lumens of vessels and airways, are easily animated and explored in all dimensions. In blood vessels, individual collagen fibers can be visualized at the micron scale and their alignment assessed at various depths through the tissue, potentially providing some nondestructive measure of vessel integrity and mechanics. Finally, both the lungs and vessels assayed here were optically cleared, imaged, and visualized in a matter of hours, such that the added benefits of these techniques can be achieved with little more hassle or processing time than that associated with traditional histological methods.
Assuntos
Matriz Extracelular/química , Pulmão/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Animais , Linhagem Celular Tumoral , Humanos , Microscopia de Fluorescência por Excitação Multifotônica/métodos , RatosRESUMO
OBJECTIVES: On May 23, 2009, a school was closed for one week plus mass chemoprophylaxis to contain the pandemic after a kindergartener tested positive for pandemic influenza A/H1N1. We evaluated the impact of school closure on the students, families, and the school. METHODS: Households were surveyed using a questionnaire to obtain information on adherence to, socio-economic impact by and inconveniences of school closure. The school principal was interviewed to assess the impact on the staff. Compliance and adverse events of chemoprophylaxis were assessed. RESULTS: Of the 232 (14%) households surveyed, 29 (13%) went to public places or gatherings at least once during the closure. Sixty-one (27%) of 229 respondents reported workplace absenteeism, and 42 (18%) of 231 respondents had wage loss. In total, 194 working days lost and 6433 US dollars wage lost were noted. The school put in 6573 h of manpower during the period. For chemoprophylaxis, 6 (6%) kindergartners missed at least one dose; and 6 (6%) reported adverse events, but none sought medical care. Overall, 169 (73%) families were at least moderately supportive of school closure. CONCLUSIONS: With assistance from the school, short-term school closure was supported by the majority of families despite economic inconvenience to the households.