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The mechanism by which aspirin consumption is linked to significant reductions in the incidence of multiple forms of cancer and metastatic spread to distant tissues, resulting in increased cancer patient survival is not well understood. In this study, using colon cancer as an example, we provide both in vitro (cell culture) and in vivo (chemically induced mouse model of colon cancer) evidence that this profound antineoplastic action may be associated with aspirin's ability to irreversibly inhibit COX-1-mediated platelet activation, thereby blocking platelet-cancer cell interactions, which promote cancer cell number and invasive potential. This process may be driven by platelet-induced epithelial-mesenchymal transition (EMT), as assessed using confocal microscopy, based upon changes in cell morphology, growth characteristics and fibronectin expression, and biochemical/molecular analysis by measuring changes in the expression of the EMT markers; vimentin, ß-catenin, and SNAIL. We also provide evidence that a novel, gastrointestinal-safe phosphatidylcholine (PC)-associated aspirin, PL2200 Aspirin, possesses the same or more pronounced actions versus unmodified aspirin with regard to antiplatelet effects (in vitro: reducing platelet activation as determined by measuring the release of thromboxane and VEGF in culture medium; in vivo: inhibiting platelet number/activation and extravasation into tumor tissue) and chemoprevention (in vitro: inhibiting colonic cell growth and invasive activity; in vivo: inhibiting colonic dysplasia, inflammation, and tumor mass). These results suggest that aspirin's chemopreventive effects may be due, in part, to the drug blocking the proneoplastic action of platelets, and the potential use of Aspirin-PC/PL2200 as an effective and safer chemopreventive agent for colorectal cancer and possibly other cancers. Cancer Prev Res; 10(2); 142-52. ©2016 AACR.
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Aspirina/farmacologia , Neoplasias do Colo/patologia , Ciclo-Oxigenase 1/metabolismo , Inibidores de Ciclo-Oxigenase/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Animais , Plaquetas/efeitos dos fármacos , Plaquetas/enzimologia , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Humanos , Camundongos , Camundongos Endogâmicos BALB CRESUMO
BACKGROUND: Specific factors in Parkinson's disease have become targets as to their protective and degenerative effects. We have demonstrated that cytokines and PD-CSF detrimentally affect microglia and astrocyte growth. While glial cell-derived neurotrophic factor (GDNF) has been recognized as a possible neuron-rescue agent, nitric oxide synthase (NOS) has been implicated in neurodegenerative processes. OBJECTIVE: To demonstrate that glial cell activation, cytokine production, and NOS induction, play an intimate role in the loss of dopaminergic signaling, via mechanisms that are a result of inflammation and inflammatory stimuli. METHODS: Study animals were sacrificed following endotoxin treatment and tissue sections were harvested and probed for GDNF and NOS isomers by fluorescence deconvolution microscopy. Fluorescence was mapped and quantified for each probe. RESULTS: An immune cell influx into 'vulnerable' areas of the brain was seen, and three NOS isomers, inducible (iNOS), neuronal (nNOS) and endothelial (eNOS), were synthesized in the brains, a finding which suggests that each isomer has a role in neurodegeneration. eNOS was found associated with blood vessels, while iNOS was associated with glial and matrix cells and nNOS was located with both glia and neurons. Following endotoxin treatment, serum levels of nitric oxide were higher at 6-8 hours, while tissue levels of NOS were elevated for much longer. Thus, induction of NOS occurred earlier than the induction of GDNF. CONCLUSION: Our findings suggest that the protective abilities of GDNF to combat neural destruction are not available rapidly enough, and do not remain at sufficiently high levels long enough to assert its protective effects. (250).
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This study examined inflammatory cell and cytokine production in brain tissue from a lipopolysaccharide (LPS)-treated rat model that mimics many of the neuropathologic changes associated with neurodegenerative diseases We also monitored the appearance of a glial cell line-derived neurotrophic factor (GDNF) and circulating nitric oxide (NO) levels, as well as an immune system-associated cells in a selected area of the brain, the olfactory lobe. The studies were based on the hypothesis that LPS treatment stimulates temporal changes within the brain and that these responses include immune cell recruitment, increased tissue levels of immune modulating cytokines and NO, as well as greater glial cell activation resulting in increased production of GDNF. As previously reported by other investigators, our animal model of systemic LPS treatment leads to an increase in the concentrations of circulating cytokines, including TNF-α, IL-Iß, and IL-6, with a maximum response 6 h post LPS administration. Concomitant with cytokine elevations, circulating NO levels were elevated for several hours post LPS administration. The brain content of the GDNF was also elevated over a similar time frame. Lymphocytes, neutrophils, macrophages, plasma cells, and cytokines were all seen in various areas of LPS-treated brains, often around blood vessels associated with the meninges, with these localizations possibly indicating involvement of both the blood-brain and blood-cerebral spinal fluid barriers in these inflammatory episodes. Our results suggest an involvement of both the peripheral and the central nervous system immune components in response to inflammation and inflammatory episodes. This leads us to propose that inflammation initiates an immune response by activating both microglia and astrocytes and that the presence of continuing and increasing proinflammatory mechanisms results in a situation, where cellular protective mechanisms are overcome and the more susceptible cells enter into cell death pathways, initiating a train of events that is a major part of neurodegeneration.
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Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Inflamação/imunologia , Leucócitos/imunologia , Doenças Neurodegenerativas/imunologia , Bulbo Olfatório/metabolismo , Animais , Barreira Hematoencefálica/imunologia , Movimento Celular/imunologia , Células Cultivadas , Citocinas/metabolismo , Modelos Animais de Doenças , Fator Neurotrófico Derivado de Linhagem de Célula Glial/genética , Humanos , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos/imunologia , Masculino , Óxido Nítrico/metabolismo , Bulbo Olfatório/imunologia , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVE: To determine alterations in quantities and distributions of natural antimicrobials following ischemia-reperfusion injury. We hypothesized that these compounds would be upregulated in areas of small intestine where changes in permeability and cellular disruption were likely and where protective mechanisms would be initiated. METHODS: Rats with ischemia-reperfusion underwent superior mesenteric artery clamping and reperfusion. Shams were subjected to laparotomy but no clamping. Ileum and jejunum were harvested and sectioned, and subjected to fluorescence deconvolution microscopy for determinations of content and localization of rat beta defensins, 1, 2, 3; rat neutrophil protein-1; and cathelicidin LL-37. Modeling was performed to determine cellular location of antimicrobials. RESULTS: Ischemia-reperfusion increased neutrophil defensin alpha (RNP-1) in jejunum; rat beta defensin 1 was increased 2-fold in ileal mucosa and slightly reduced in jejunal mucosa; rat beta defensin 2 was reduced by ischemia-reperfusion in ileum, but slightly increased in jejunum; rat beta defensin 3 was concentrated in the muscularis externa and myenteric plexus of the jejunum; ischemia-reperfusion did not alter cathelicidin LL-37 content in the small intestine, although a greater concentration was seen in jejunum compared with ileum. CONCLUSION: Ischemia-reperfusion injury caused changes in antimicrobial content in defined areas, and these different regulations might reflect the specific roles of jejunum versus ileum.
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Purpose. To provide an ovine model of ventricular remodeling and reverse remodeling by creating congestive heart failure (CHF) and then treating it by implanting a left ventricular assist device (LVAD). Methods. We induced volume-overload heart failure in 2 sheep; 20 weeks later, we implanted an LVAD and assessed recovery 11 weeks thereafter. We examined changes in histologic and hemodynamic data and levels of cellular markers of CHF. Results. After CHF induction, we found increases in LV end-diastolic pressure, LV systolic and diastolic dimensions, wall thickness, left atrial diameter, and atrial natriuretic protein (ANP) and endothelin-1 (ET-1) levels; ß-adrenergic receptor (BAR) and dystrophin expression decreased markedly. Biopsies confirmed LV remodeling. After LVAD support, LV systolic and diastolic dimensions, wall thickness, and mass, and ANP and ET-1 levels decreased. Histopathologic and hemodynamic markers improved, and BAR and dystrophin expression normalized. Conclusions. We describe a successful sheep model for ventricular and reverse remodeling.
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BACKGROUND: Excessive and abnormal accumulation of alpha-synuclein (α-synuclein) is a factor contributing to pathogenic cell death in Parkinson's disease. The purpose of this study, based on earlier observations of Parkinson's disease cerebrospinal fluid (PD-CSF) initiated cell death, was to determine the effects of CSF from PD patients on the functionally different microglia and astrocyte glial cell lines. Microglia cells from human glioblastoma and astrocytes from fetal brain tissue were cultured, grown to confluence, treated with fixed concentrations of PD-CSF, non-PD disease control CSF, or control no-CSF medium, then photographed and fluorescently probed for α-synuclein content by deconvolution fluorescence microscopy. Outcome measures included manually counted cell growth patterns from day 1-8; α-synuclein density and distribution by antibody tagged 3D model stacked deconvoluted fluorescent imaging. RESULTS: After PD-CSF treatment, microglia growth was reduced extensively, and a non-confluent pattern with morphological changes developed, that was not evident in disease control CSF and no-CSF treated cultures. Astrocyte growth rates were similarly reduced by exposure to PD-CSF, but morphological changes were not consistently noted. PD-CSF treated microglia showed a significant increase in α-synuclein content by day 4 compared to other treatments (p ≤ 0.02). In microglia only, α-synuclein aggregated and redistributed to peri-nuclear locations. CONCLUSIONS: Cultured microglia and astrocytes are differentially affected by PD-CSF exposure compared to non-PD-CSF controls. PD-CSF dramatically impacts microglia cell growth, morphology, and α-synuclein deposition compared to astrocytes, supporting the hypothesis of cell specific susceptibility to PD-CSF toxicity.
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Astrócitos/patologia , Proteínas do Líquido Cefalorraquidiano/efeitos adversos , Microglia/patologia , Doença de Parkinson/líquido cefalorraquidiano , Astrócitos/fisiologia , Morte Celular/fisiologia , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Proliferação de Células , Forma Celular/fisiologia , Células Cultivadas , Humanos , Corpos de Lewy/metabolismo , Microglia/fisiologia , Doença de Parkinson/imunologia , Doença de Parkinson/metabolismo , alfa-Sinucleína/fisiologiaRESUMO
CONTEXT: Hawthorn is an herb indicated for treating cardiac illness. Because a patient taking digoxin may also take hawthorn, we investigated potential interference of hawthorn in serum digoxin measurements using immunoassays as well as pharmacodynamic interaction between hawthorn and digoxin. Hawthorn contains alkaloids that are structurally similar to digoxin and may interfere with serum digoxin measurement using immunoassays. In addition, hawthorn has cardioactive properties similar to digoxin. OBJECTIVE: To study potential pharmacodynamic interaction between hawthorn and digoxin. DESIGN: The effects of hawthorn extract on serum digoxin measurements using Digoxin III (Abbott Laboratories, Abbott Park, Illinois) and the Tina-Quant digoxin assay (Roche Diagnostics, Indianapolis, Indiana) were investigated using 2 different brands of extract. To study the pharmacodynamic interaction between hawthorn and digoxin, we used an isolated adult rat cardiomyocyte system, measuring calcium transients by real-time fluorescence spectrophotometry. RESULTS: Hawthorn interfered only with the Digoxin III immunoassay but had no effect on the Tina-Quant assay. Both hawthorn extracts increased intracellular calcium levels, but the lack of additive response with digoxin suggests both may bind to the same site of Na, K adenosine triphosphatase. CONCLUSION: Because of interference of hawthorn with a digoxin immunoassay and pharmacodynamic interaction with digoxin, a patient receiving digoxin should avoid hawthorn.
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Crataegus/química , Digoxina/sangue , Digoxina/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Compostos de Anilina , Animais , Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Células Cultivadas , Contraindicações , Interações Medicamentosas , Imunoensaio , Masculino , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Ratos , XantenosRESUMO
Cartilage oligomeric matrix protein (COMP) is a pentameric extracellular protein expressed in cartilage and other musculoskeletal tissues. Mutations in the COMP gene cause pseudoachondroplasia (PSACH), a severe dwarfing condition that has a growth plate chondrocyte pathology. PSACH is characterized by intracellular retention of COMP and other extracellular matrix (ECM) proteins, which form an ordered matrix within large rough endoplasmic reticulum cisternae. This accumulation is cytotoxic and causes premature chondrocyte cell death, thereby depleting chondrocytes needed for normal long bone growth. Research to define the underlying molecular mechanisms of PSACH has been hampered by the lack of a suitable model system. In this study, we achieved robust expression of human mutant (MT) or wild-type (WT) COMP in mice by using a tetracycline-inducible promoter. Normal growth plate distribution of ECM proteins was observed in 1-month-old WT-COMP and C57BL\6 control mice. In contrast, the structure of the MT-COMP growth plate recapitulated the findings of human PSACH growth plate morphology, including (1) retention of ECM proteins, (2) intracellular matrix formation in the rER cisternae, and (3) increased chondrocyte apoptosis. Therefore, we have generated the first mouse model to show extensive intracellular retention of ECM proteins recapitulating the human PSACH disease process at the cellular level.
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Proteínas da Matriz Extracelular/metabolismo , Glicoproteínas/metabolismo , Osteocondrodisplasias/patologia , Animais , Apoptose , Proteína de Matriz Oligomérica de Cartilagem , Condrócitos/metabolismo , Condrócitos/patologia , Colágeno Tipo IX/metabolismo , Modelos Animais de Doenças , Retículo Endoplasmático/metabolismo , Proteínas da Matriz Extracelular/química , Glicoproteínas/química , Lâmina de Crescimento/anormalidades , Lâmina de Crescimento/patologia , Humanos , Proteínas Matrilinas , Camundongos , Camundongos Transgênicos , Mutação/genética , Fenótipo , Estrutura Quaternária de ProteínaRESUMO
Neonatal and adult cardiomyocytes were isolated from rat hearts. Some of the adult myocytes were cultured to allow for cell dedifferentiation, a phenomenon thought to mimic cell changes that occur in stressed myocardium, with myocytes regressing to a fetal pattern of metabolism and stellate neonatal shape.Using fluorescence deconvolution microscopy, cells were probed with fluorescent markers and scanned for a number of proteins associated with ion control, calcium movements and cardiac function. Image analysis of deconvoluted image stacks and sequential real-time image recordings of calcium transients of cells were made.All three myocyte groups were predominantly comprised of binucleate cells. Clustering of proteins to a single nucleus was a common observation, suggesting that one nucleus is active in protein synthesis pathways, while the other nucleus assumes a 'dormant' or different role and that cardiomyocytes might be mitotically active even in late development, or specific protein syntheses could be targeted and regulated for reintroduction into the cell cycle.Such possibilities would extend cardiac disease associated stem cell research and therapy options, while producing valuable insights into developmental and death pathways of binucleate cardiomyocytes (word count 183).
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Human derived glioblastoma cells were cultured and treated with cytokines interleukin-6 (IL6), tumor necrosis factor alpha (TNF) and interferon-gamma (IFN) and imaged by fluorescence deconvolution microscopy to localize alpha-synuclein, tau and ubiquitin. Exposures were for short (2 h) and prolonged times (up to 96 h), with doses at both low (10 ng/ml), and high (100 ng/ml) concentrations. Further experiments used additive doses up to 200 ng/ml (2 x 100 ng), mimicking a super-infection state. Single, low doses of the cytokines initiated changes in levels of intracellular proteins, but these changes, be they increases or decreases, were not sustained, so we added higher doses of cytokine to the culture medium or fresh aliquots of cytokines over time. Finally, we treated cells with high, single doses of cytokine (200 ng/ml), to try to sustain perturbations of the proteins with cytokines. IFN caused a disruption and reduction of peripheral synuclein, TNF treatment resulted in increased levels of ubiquitin and IL6 disrupted and appeared to fragment tau. Of note, each of the proteins was found in a specific locale, tau being perinuclear, ubiquitin residing in the cytoplasm, and alpha-synuclein occupying the tips of cellular processes, exhibiting the characteristics of an adhesion protein/molecule [Word count=198].
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Glioblastoma/metabolismo , Interferon gama/farmacologia , Interleucina-6/farmacologia , Doença de Parkinson/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Ubiquitina/metabolismo , alfa-Sinucleína/metabolismo , Proteínas tau/metabolismo , Células Cultivadas , Humanos , Imageamento Tridimensional , Microscopia de Fluorescência , Ubiquitina/efeitos dos fármacos , alfa-Sinucleína/efeitos dos fármacos , Proteínas tau/efeitos dos fármacosRESUMO
OBJECTIVE: The aim of this study was to visualize and localize the sheep antimicrobials, beta-defensins 1, 2, and 3, (SBD-1, SBD-2, SBD-3), sheep neutrophil defensin alpha (SNP-1), and the cathelicidin LL-37 in sheep small intestine after burn injury, our hypothesis being that these compounds would be upregulated in an effort to overcome a compromised endothelial lining. Response to burn injury includes the release of proinflammatory cytokines and systemic immune suppression that, if untreated, can progress to multiple organ failure and death, so protective mechanisms have to be initiated and implemented. METHODS: Tissue sections were probed with antibodies to the antimicrobials and then visualized with fluorescently labeled secondary antibodies and subjected to fluorescence deconvolution microscopy and image reconstruction. RESULTS: In both the sham and burn samples, all the aforementioned antimicrobials were seen in each of the layers of small intestine, the highest concentration being localized to the epithelium. SBD-2, SBD-3, and SNP-1 were upregulated in both enterocytes and Paneth cells, while SNP-1 and LL-37 showed increases in both the inner circular and outer longitudinal muscle layers of the muscularis externa following burn injury. Each of the defensins, except SBD-1, was also seen in between the muscle layers of the externa and while burn caused slight increases of SBD-2, SBD-3, and SNP-1 in this location, LL-37 content was significantly decreased. CONCLUSION: That while each of these human antimicrobials is present in multiple layers of sheep small intestine, SBD-2, SBD-3, SNP-1, and LL-37 are upregulated in the specific layers of the small intestine.
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We studied the potential cardiac effects of two alcohol extracts of commercially available hawthorn using rat cardiomyocytes and measuring calcium transients by real-time fluorescence spectrophotometry. One preparation was a blend of hawthorn flowers, leaves, and berries (extract #1), and the other (extract #2) was from a "berries-only" preparation. Fluorescent images and calcium transients were acquired concurrently. Addition of extract #1 resulted in the initiation of robust calcium transients and eventual calcium overload, while addition of extract #2 caused increased calcium sparking, initiation of calcium transients, and an increased beating rate but no calcium overload. To identify the mechanisms of increased calcium influx, adult rat cardiomyocytes were challenged with 10 microM ouabain, a Na(+),K(+)-ATPase inhibitor, and the calcium channel blocker nifedipine. The findings revealed that equal volumes of the two readily available hawthorn preparations demonstrated markedly different effects on isolated adult rat cardiomyocytes, suggesting important implications for patients who are using these preparations to supplement or even replace their prescribed cardiac medications as to which preparation(s) to use, and potential dire consequences, particularly in cardiac patients. Our study indicates that the mechanism of cardiac activity of hawthorn is via the Na(+),K(+)-ATPase and intracellular calcium concentrations are influenced.
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Cálcio/metabolismo , Crataegus , Miócitos Cardíacos/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/farmacologia , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Cardiotônicos/farmacologia , Insuficiência Cardíaca/tratamento farmacológico , Interações Ervas-Drogas , Hipertensão/tratamento farmacológico , Masculino , Miócitos Cardíacos/metabolismo , Nifedipino/farmacologia , Extratos Vegetais/uso terapêutico , Estruturas Vegetais , Ratos , Ratos Sprague-Dawley , ATPase Trocadora de Sódio-Potássio/metabolismoRESUMO
BACKGROUND: We hypothesized that not all subtypes of alpha- and beta-adrenoreceptors undergo similar upregulation and redistribution in human myocardium after mechanical unloading with an assist device. METHODS: We obtained core biopsy samples of the left ventricle in 19 patients before and after removal of a Jarvik or Thoratec left ventricular assist device (LVAD) to study the effect of mechanical unloading on the distribution of alpha- and beta-adrenoreceptors. Fresh, embedded tissue sections were incubated with receptor blockers and antibodies before the fluorescent labeling of receptors. Images were obtained by fluorescence deconvolution microscopy, and composite tissue renditions were made from the stacked images. Multiple adrenoreceptor subtypes were studied. RESULTS: We saw a reversal of myocyte hypertrophy in all patients, but the upregulation of receptors was not seen in all post-LVAD tissue samples. Furthermore, we noted receptor relocalization from an initial punctate/clumped pattern to a normal homogeneous distribution in many patients. Significant differences were seen in the distribution of beta(2)- and alpha(1)-receptors and in alpha(1A) subtypes. CONCLUSIONS: In this study we show not only the expected reversal of myocyte hypertrophy and the increase in adrenoreceptors after ventricular unloading, but also the relocalization of specific receptor subtypes.
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Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/terapia , Miocárdio/patologia , Receptores Adrenérgicos alfa , Receptores Adrenérgicos beta , Adulto , Biópsia por Agulha , Feminino , Transplante de Coração , Coração Auxiliar , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The purpose of this study was to determine the effects of specific proinflammatory cytokines interleukin-6 (Il-6), interleukin-1beta (Il-1beta), interferon-gamma (IFN), and tumor necrosis factor-alpha (TNFalpha), on content and distribution of alpha-synuclein (alpha-synuclein), tau and ubiquitin in human derived cultured glial cells. Exposure paradigms mimicked acute (2 h), intermediate (18 h) and prolonged time frames (96 h); consisting of single or repeated low doses (10 ng/ml) or high doses (50 ng/ml), consistent with either mild or serious systemic infectious/inflammatory responses. Images of intracellular protein content and distribution were reconstructed from emission patterns generated by fluorescence deconvolution microscopy. Minor alterations were seen in protein content with IFN; Il-1beta decreased alpha-synuclein and tau at 18 and 96 h; TNFalpha inversely reduced alpha-synuclein and increased ubiquitin content. Combinations of Il-1beta and IFN produced a robust increase of alpha-synuclein and tau at 2 h. Consecutive low doses of Il-6 produced only minor increases in alpha-synuclein and ubiquitin after 4 h, whereas a single high dose resulted in major increases for all three proteins over the first 18 h. Protein localization patterns were distinctly different and were altered dependent upon cytokine treatment. A high dose exposure (2 x 50 ng/ml) with Il-6 and IFN demonstrated that protein increases and dispersals could be sustained and that the normal perinuclear tau and peripheral alpha-synuclein patterns were disrupted. These results support the postulate that specific cytokines affect temporal protein changes with concomitant pattern disruptions, possibly reflecting a mechanism of cell dysfunction in Parkinson's degeneration.
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Citocinas/metabolismo , Neuroglia/metabolismo , Doença de Parkinson/metabolismo , Ubiquitina/metabolismo , alfa-Sinucleína/metabolismo , Proteínas tau/metabolismo , Células Cultivadas , Humanos , Microscopia de Fluorescência , Neuroglia/químicaRESUMO
Due to up-regulation of the parathyroid gland calcium-sensing receptor (CaR), burned children have hypocalcemic hypoparathyroidism, and decreased myocardial contractility. Our aim was to localize the CaR in the heart and measure receptor density changes due to burns. Heart and aorta samples from sheep subjected to 40% burn or sham conditions were probed for CaR via fluorescence microscopy. CaR was localized to endocardial endothelium, myocardial microvasculature, and fibroblasts and vessels of the aortic adventitia. CaR was not found in cardiomyocytes or smooth muscle cells. No differences in density of CaR or beta-adrenergic receptors were noted. No differences in CaR distribution were seen in the myocardium or aorta, in contrast to the parathyroid where burn injury up-regulates CaR. We suggest that CaR has a local, tissue-specific role, and functions in vascular calcium sensing for intravascular calcium deposition or regulation of other calcium channels after trauma or burn.
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Aorta/metabolismo , Queimaduras/metabolismo , Miocárdio/metabolismo , Receptores de Detecção de Cálcio/metabolismo , Animais , OvinosRESUMO
OBJECTIVE: Human defensins and cathelicidins are a family of cationic antimicrobial peptides (AMPs), which play multiple roles in both innate and adaptive immune systems. They have direct antimicrobial activity against several microorganisms including burn pathogens. The majority of components of innate and adaptive immunity either express naturally occurring defensins or are otherwise chemoattracted or functionally affected by them. They also enhance adaptive immunity and wound healing and alter antibody production. All mechanisms to explain multiple functions of AMPs are not clearly understood. Prior studies to localize defensins in normal and burned skin using deconvolution fluorescence scanning microscopy indicate localization of defensins in the nucleus, perinuclear regions, and cytoplasm. The objective of this study is to further confirm the identification of HBD-1 in the nucleus by deconvolution microscopic studies involving image reconstruction and wire frame modeling. RESULTS: Our study demonstrated the presence of intranuclear HBD-1 in keratinocytes throughout the stratum spinosum by costaining with the nuclear probe DAPI. In addition, HBD-1 sequence does show some homology with known cationic nuclear localization signal sequences. CONCLUSION: To our knowledge, this is the first report to localize HBD-1 in the nuclear region, suggesting a role for this peptide in gene expression and providing new data that may help determine mechanisms of defensin functions.
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Oleanders are common, hardy shrubs that grow throughout the southern United States. They contain cardiotonic steroids formed from cardenolides and bufadienolides, making the plant poisonous to both animals and humans. Aliquots of both commercially available oleander and fresh oleander extracts were prepared. Fresh, rod-like, calcium-tolerant adult rat cardiomyocytes and cultured neonatal cardiomyocytes were isolated and treated with 0-4 ng/ml of both preparations, challenged with verapamil and ouabain, and real-time spectrophotometric calcium transients and images were acquired. A number of effects were observed with the adult cells: (1) intracellular calcium levels were increased in a concentration-dependent manner: (2) reduced calcium transient heights and eventual cessation of beating resulted; and (3) increased sparking intensity led to subsequent beating and eventual calcium overload. In the spontaneously beating cultured neonatal myocytes increased intramyocytic calcium levels were also seen, with retention of this calcium rise leading to overload and, as in the adult myocytes, cessation of beating. These observations demonstrate that oleander extract is markedly potent with respect to the elevation of calcium concentrations in cardiomyocytes, and that the inability of the cardiomyocytes to release the accumulated calcium possibly indicates a role for oleandrin in inhibition of ryanodine receptor calcium release channels, calcium uptake via Na+,K+-ATPase inhibition [EC 3.6.1.3], and/or dysfunction of sarcolemmal calcium release channels.
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Envelhecimento/fisiologia , Cálcio/metabolismo , Cardenolídeos/toxicidade , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Animais , Animais Recém-Nascidos , Bloqueadores dos Canais de Cálcio/farmacologia , Células Cultivadas , Masculino , Nerium/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-Dawley , Verapamil/farmacologiaRESUMO
Mutations in cartilage oligomeric matrix protein (COMP) cause two skeletal dysplasias, pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED/EDM1). Because COMP exists as a homopentamer, only one mutant COMP subunit may result in an abnormal complex that is accumulated in expanded rough endoplasmic reticulum (rER) cisternae, a hallmark of PSACH. Type IX collagen and matrilin-3 (MATN3), also accumulate in the rER cisternae of PSACH chondrocytes, but it is unknown how mutant COMP interacts with these proteins. The studies herein focus on defining the organization of these intracellularly retained proteins using fluorescence deconvolution microscopy. A unique matrix organization was identified in which type II procollagen formed a central core surrounded by a protein network of mutant COMP, type IX collagen, and MATN3. This pattern of matrix organization was found in multiple cisternae from single chondrocytes and in chondrocytes with different COMP mutations, indicating a common pattern of interaction. This suggests that stalling of mutant COMP and an interaction between mutant COMP and type II procollagen are initiating events in the assembly of matrix in the rER, possibly explaining why the material is not readily cleared from the rER. Altogether, these data suggest that mutant COMP initiates and perhaps catalyzes premature intracellular matrix assembly.
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Acondroplasia/patologia , Condrócitos/ultraestrutura , Colágeno Tipo XI/ultraestrutura , Retículo Endoplasmático Rugoso/ultraestrutura , Acondroplasia/metabolismo , Animais , Cartilagem/metabolismo , Cartilagem/patologia , Proteína de Matriz Oligomérica de Cartilagem , Linhagem Celular , Condrócitos/metabolismo , Colágeno Tipo XI/metabolismo , Retículo Endoplasmático Rugoso/metabolismo , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Glicoproteínas/genética , Glicoproteínas/metabolismo , Humanos , Proteínas Matrilinas , Microscopia de Fluorescência , MutaçãoRESUMO
Ginsengs are widely used to improve cardiac health and circulation. Loosely termed as ginsengs, Asian (Panax), Siberian and Ashwagandha (Indian Ginseng) Indian ginsengs are prepared from different plants. We tested the popular belief of cardiotonic effects of ginsengs using both neonatal and adult rat cardiomyocytes, comparing extracts from the three ginsengs. Addition of 10% v/v of extract (100 microl of extract/ml of culture medium) of each of the ginsengs resulted in a rapid (<10 s) cessation of beating in neonatal cardiomyocytes due to calcium overload, while sequential dilutions revealed that treatment with a low dose (0.01% v/v, 0.1 microl/ml of the medium) resulted in constant, regular beats (transients), and a slight elevation of diastolic calcium without overload. Addition of extracts to sparking, calcium-tolerant adult cardiomyocytes resulted in initiation of calcium transients, and adult cells were able to tolerate exposure to high concentrations of extract. Cardiotonic effects in adult cells (cardiotoxicity in neonatal cells) were most profound with Asian ginseng (2.6 times that of Siberian ginseng, 1.6 times that of Indian ginseng) probably due to the active ingredients (ginsenosides in Asian, eleutherosides in Siberian and withanolides in Indian) being structurally different. We conclude that fully developed cardiomyocytes are able to accommodate higher doses of ginseng than neonatal cells, and that the effects of ginseng on newly formed, developing myocytes, could be extremely deleterious to the fetus. However, for adults, ginseng might well be a 'tonic' in its ability to increase beating and intramyocytic calcium levels.
Assuntos
Cardiotônicos/toxicidade , Cardiopatias/induzido quimicamente , Miócitos Cardíacos/efeitos dos fármacos , Panax/química , Extratos Vegetais/toxicidade , Animais , Animais Recém-Nascidos , Cálcio/metabolismo , Microscopia de Fluorescência , Miócitos Cardíacos/metabolismo , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVE: The objective of this study was to observe the effects of cell culture on cellular polarity in cardiomyocytes as influenced by cytoskeletal proteins. METHODS: Cardiomyocytes from adult and neonatal rats were isolated and grown on 2 different extracellular matrices--laminin and a complex, fibroblast-derived extracellular matrix, cardiogel. The location of a number of proteins was visualized by means of fluorescence deconvolution microscopy, using specific fluorescent probes for alpha-adrenergic receptors, beta-adrenergic receptors, the sarcolemmal L-type calcium channel, and the sodium + potassium adenosine triphosphatase pump protein. Intracellular migration of these proteins during the first 4 days of culture was followed and microscopic stacked images were reconstructed. A fluorescein isothiocyanate-labeled probe for actin was used to ensure that cardiomyocytes were being examined, based on protein patterns. RESULTS: We examined 2 types of myocyte: freshly isolated neonates and cultured adult cardiomyocytes that undergo dedifferentiation. Initial, perinuclear clumping (endoplasmic reticulum/Golgi-associated) of the probes with an ensuing spread to the cytoplasm and periphery, accompanied by a better organization and more rapid response to biochemical stimuli, was seen on the complex matrix. CONCLUSIONS: A complex matrix overcomes cell polarity at a faster rate than myocytes cultured on a simple matrix, although both culture matrices were able to support cell growth and differentiation, and single-layer cultures are a good method by which structural and biochemical data can be obtained. The use of a native, complex matrix is preferable to employing a simple, single protein, although temporal aspects of cell growth must be considered regarding the particular aspect of the cell structure development/biochemical pathways that the researcher intends focusing on.