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1.
Environ Sci Pollut Res Int ; 31(12): 18200-18208, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37002519

RESUMO

Solar energy is one of the most feasible options to produce energy in countries where unexploited desert areas or solar radiation are abundant. An energy tower is an effective system for electrical power generation that can perform more efficiently along with solar radiation. As the primary aim of the present study, effects of different environmental parameters on total efficacy of energy tower were investigated. In this study, the efficiency of the energy tower system is investigated experimentally by an indoor fully adjustable apparatus. In this regard, a comprehensive set of influencing parameters like air velocity, humidity, and temperature and the effects of tower height on the performance of the energy tower are individually assessed. It is demonstrated that there is a direct relationship between an increase in humidity percentage of the surrounding and performance of energy tower, meaning that a 274% increase in humidification rate led to 43% elevation in airflow velocity. The kinetic energy increases in the direction of airflow from top to bottom, and as the height of the tower lengthens, the kinetic energy enhances and subsequently increases the overall efficiency of the tower. An elevation about 2.7% in airflow velocity was seen due to an increase from 180 to 250 cm in chimney height. Although the energy tower performs efficiently in the nighttime, airflow velocity increases averagely about 8% during the daytime and at the peak of the solar radiation, the airflow velocity enhances by 58% compared to nighttime.


Assuntos
Energia Solar , Umidade , Temperatura
2.
J Pharmacol Exp Ther ; 387(1): 4-14, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37164371

RESUMO

Irritable bowel syndrome (IBS) and bladder pain syndrome/interstitial cystitis (BPS/IC) are comorbid visceral pain disorders seen commonly in women with unknown etiology and limited treatment options and can involve visceral organ cross-sensitization. Calcitonin gene-related peptide (CGRP) is a mediator of nociceptive processing and may serve as a target for therapy. In three rodent models, we employed a monoclonal anti-CGRP F(ab')2 to investigate the hypothesis that visceral organ cross-sensitization is mediated by abnormal CGRP signaling. Visceral organ cross-sensitization was induced in adult female rats via transurethral infusion of protamine sulfate (PS) into the urinary bladder or infusion into the colon of trinitrobenzene sulfonic acid (TNBS). Colonic sensitivity was assessed via the visceromotor response to colorectal distension (CRD). Bladder sensitivity was assessed as the frequency of abdominal withdrawal reflexes to von Frey filaments applied to the suprapubic region. PS- or TNBS-induced changes in colonic and bladder permeability were investigated in vitro via quantification of transepithelial electrical resistance (TEER). Peripheral administration of an anti-CGRP F(ab')2 inhibited PS-induced visceral pain behaviors and colon hyperpermeability. Similarly, TNBS-induced pain behaviors and colon and bladder hyperpermeability were attenuated by anti-CGRP F(ab')2 treatment. PS into the bladder or TNBS into the colon significantly increased the visceromotor response to CRD and abdominal withdrawal reflexes to suprapubic stimulation and decreased bladder and colon TEER. These findings suggest an important role of peripheral CGRP in visceral nociception and organ cross-sensitization and support the evaluation of CGRP as a therapeutic target for visceral pain in patients with IBS and/or BPS/IC. SIGNIFICANCE STATEMENT: A monoclonal antibody against calcitonin gene-related peptide (CGRP) was found to reduce concomitant colonic and bladder hypersensitivity and hyperpermeability. The results of this study suggest that CGRP-targeting antibodies, in addition to migraine prevention, may provide a novel treatment strategy for multiorgan abdominopelvic pain following injury or inflammation.


Assuntos
Síndrome do Intestino Irritável , Dor Visceral , Ratos , Feminino , Animais , Bexiga Urinária , Peptídeo Relacionado com Gene de Calcitonina , Síndrome do Intestino Irritável/tratamento farmacológico , Dor Visceral/tratamento farmacológico , Ratos Sprague-Dawley , Colo , Analgésicos/farmacologia , Analgésicos/uso terapêutico , Modelos Animais de Doenças
3.
Life Sci ; 320: 121545, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36871932

RESUMO

AIMS: The process of Epithelial-to-mesenchymal transition (EMT) as a phenotypic invasive shift and the factors affecting it, are under extensive research. Application of supernatants of human adipose-derived mesenchymal stem cells (hADMSCs) on non-invasive cancer cells is a well known method of in vitro induction of EMT like process. While previous researches have focused on the effects of hADMSCs supernatant on the biochemical signaling pathways of the cells through expression of different proteins and genes, we investigated pro-carcinogic alterations of physico-mechanical cues in terms of changes in cell motility and aggregated formation in 3D microenvironments, and cytoskeletal actin-myosin content and fiber arrangement. MAIN METHODS: MCF-7 cancer cells were treated by the supernatant from 48 hour-starved hADMSCs, and their vimentin/E-cadherin expressions were evaluated. The invasive potential of treated and non-treated cells was measured and compared through aggregate formation and migration capability. Furthermore, alterations in cell and nucleus morphologies were studied, and F-actin and myosin-II alterations in terms of content and arrangement were investigated. KEY FINDINGS: Results indicated that application of hADMSCs supernatant enhanced vimentin expression as the biomarker of EMT, and induced pro-carcinogenic effects on non-invasive cancer cells through increased invasive potential by higher cell motility and reduced aggregate formation, rearrangement of actin structure and generation of more stress fibers, together with increased myosin II that lead to enhanced cell motility and traction force. SIGNIFICANCE: Our results indicated that in vitro induction of EMT through mesenchymal supernatant influenced biophysical features of cancer cells through cytoskeletal remodeling that emphasizes the interconnection of chemical and physical signaling pathways during cancer progress and invasion. Results give a better insight to EMT as a biological process and the synergy between biochemical and biophysical parameters that contribute to this process, and eventually assist in improving cancer treatment strategies.


Assuntos
Actinas , Neoplasias da Mama , Humanos , Feminino , Vimentina/metabolismo , Actinas/metabolismo , Linhagem Celular Tumoral , Neoplasias da Mama/metabolismo , Microfluídica , Citoesqueleto/metabolismo , Transição Epitelial-Mesenquimal , Proteínas do Citoesqueleto/metabolismo , Movimento Celular , Microambiente Tumoral
4.
Biochem Biophys Res Commun ; 622: 1-7, 2022 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-35841768

RESUMO

Cancer development comprehends changes in cell structural and physical states. Cancer cells are softer than normal cells, produce higher contractile forces, and migrate more easily. While chemotherapy, targets proteins involved in biological behaviors, it may affect cell physicomechanical state due to the interconnections among signaling pathways. Here we treated non-invasive and invasive breast cancer cell lines by targeting EGRF which modulates major biological behaviors. We quantified migration potential of cancer cells in a microfluidic device, and evaluated expression of proteins associated with physical behaviors. Results indicated significant alterations in physical behaviors, with a higher impact on invasive cells. The anti-cancer synergy between biological and physical behaviors was shown by decreasing actin, vinculin, and myosin II content and altered distribution, limiting cell invasion in 3D collagen structure, accompanied by decreasing cell viability and vimentin expression as the EMT biomarker. The center point of changes in physical behaviors was in cytoskeletal remodeling by chemical treatment, potentially through lower contractile force generation and less development of focal adhesions and stress fibers. The synergy between physical and chemical pathways can be used in enhancing anti-cancer drug efficacy.


Assuntos
Neoplasias da Mama , Actinas , Neoplasias da Mama/tratamento farmacológico , Adesão Celular , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular , Receptores ErbB/farmacologia , Feminino , Humanos , Microfluídica
5.
Subst Use Misuse ; 57(3): 472-480, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34986075

RESUMO

Background: The U.S. Food and Drug Administration (FDA) authorized the marketing of the IQOS tobacco heating system as a modified risk tobacco product (MRTP) in July 2020, permitting its 'reduced exposure' marketing. This decision is accompanied by much controversy among the global health community. We provide a preliminary analysis of Twitter conversations regarding the MRTP authorization of IQOS by identifying the authors, valence towards the policy decision, source of cited link, and focused topic. Methods: We analyzed 548 tweets mentioning MRTP posted between July 2016 (when PMI submitted the proposal) and October 2020. Results: We found a higher proportion of pro-MRTP valence (25.4%) than anti-MRTP (16.2%). Nearly half of the tweets (47.2%) expressing personal opinions presented pro-MRTP valence (vs. anti-MRTP = 23.9%). The FDA website was more frequently cited in pro-MRTP tweets (30.8% vs. anti = 4.8%), while tobacco control advocates' websites were cited only in anti-MRTP tweets (77.4% vs. pro = 0). Pro-MRTP valence appeared more frequently in tweets mentioning health (53.1% vs. anti =38.5%) and cessation (100% vs. anti = 0). Nearly 42% of tweets showed a bot score greater than .43, indicating a possibility of automation. Conclusion: Continuous efforts are needed to surveil the industry's attempts to create a climate of false consensus and circulate misinformation regarding MRTP on social media, as well as to assist non-scientific audiences' understanding of MRTP.


Assuntos
Mídias Sociais , Produtos do Tabaco , Humanos , Marketing , Nicotiana , Uso de Tabaco , Estados Unidos , United States Food and Drug Administration
6.
Neurologist ; 27(4): 168-172, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34855658

RESUMO

BACKGROUND: Perihematomal edema (PHE) following primary intracranial hemorrhages (ICHs) affects the patient outcome. Also, serum biomarkers such as S100 calcium-binding protein B (S100B) and glial fibrillary acidic protein (GFAP) have been associated with ICHs outcome. We aimed to investigate the association between these biomarkers and PHE in ICH patients. METHODS: In this cross-sectional study, patients with primary ICH between January 2020 and August 2020 were evaluated. All participants underwent spiral brain computed tomography scans upon admission, and 48 to 72 hours later and quantification of initial hematoma volume was performed. Serum level of matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF), GFAP, and S100B on admission were measured by enzyme-linked immunosorbent assays. Acute clinical outcome was assessed by the modified-Rankin scale, National Institute of Health Stroke Scale (NIHSS), and ICH score. RESULTS: Thirty-seven ICH patients (21 patients with a favorable outcome and 16 unfavorable) were studied. Compared with survival patients, nonsurvivor patients showed a higher serum level of MMP-9, VEGF, GFAP, and S100B ( P <0.05). Scores of absolute PHE, edema expansion distance, and PHE growth rate in the nonsurvivor group were higher than the survivors ( P <0.001). The regression model revealed that MMP-9, VEGF, ICH score, and hematoma volume were associated with the PHE growth rate. S100B and ICH score were associated with edema expansion distance. CONCLUSIONS: Our data showed that the serum level of molecular biomarkers was associated with higher PHE volume and PHE scores were higher in nonsurvival patients, suggesting it may have a pathogenic role in developing PHE after ICH.


Assuntos
Edema Encefálico , Metaloproteinase 9 da Matriz , Biomarcadores , Encéfalo/patologia , Edema Encefálico/diagnóstico por imagem , Edema Encefálico/etiologia , Hemorragia Cerebral/complicações , Hemorragia Cerebral/diagnóstico por imagem , Estudos Transversais , Edema/complicações , Hematoma/complicações , Hematoma/patologia , Humanos , Hemorragias Intracranianas/complicações , Hemorragias Intracranianas/diagnóstico por imagem , Metaloproteinase 9 da Matriz/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
8.
Biochem Biophys Res Commun ; 565: 14-20, 2021 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-34087508

RESUMO

Regardless of their target and mechanism, anticancer drugs directly influence biological behavior of cancer cells by activating chemical signaling pathways. Due to the complex interaction between diverse signaling pathways, these drugs may profoundly impact the physical characteristics of cancer cells and regulate their mechanical properties. In this study, the effects of two Aromatase Inhibitor (Letrozole and Exemestane), and one mTOR Inhibitor (Everolimus) on cell mechanical properties, actin content/distribution, and nuclear areas of two invasive and non-invasive breast cancer cell line after 24 h treatment with concentrations previously reported were investigated. While metabolic activity of cell lines was highly affected by drug treatment, significant alterations in Young's modulus of cell bodies, nuclear areas, and actin content and distribution were reported with higher impact on invasive cells. It was concluded that regulation of mechanical behavior of cells by all three drugs emphasizes the cross talk between chemical and physical signaling cascades, and describes a correlation between biological and physical behaviors of cancer cells which might give an insight to a better understanding of mechanisms by which anti-cancer drugs function to enhance their performances.


Assuntos
Androstadienos/farmacologia , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Citoesqueleto/efeitos dos fármacos , Everolimo/farmacologia , Letrozol/farmacologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Sobrevivência Celular/efeitos dos fármacos , Citoesqueleto/metabolismo , Feminino , Humanos , Células Tumorais Cultivadas
9.
Pharmacol Res Perspect ; 9(1): e00709, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33540486

RESUMO

Few therapeutic options exist for treatment of IC/BPS. A novel high MW GAG biopolymer ("SuperGAG") was synthesized by controlled oligomerization of CS, purified by TFF and characterized by SEC-MALLS and 1H-NMR spectroscopy. The modified GAG biopolymer was tested in an OVX female rat model in which bladder permeability was induced by a 10-minute intravesicular treatment with dilute (1 mg/ml) protamine sulfate and measured by classical Ussing Chamber TEER measurements following treatment with SuperGAG, chondroitin sulfate, or saline. The effect on abrogating the abdominal pain response was assessed using von Frey filaments. The SuperGAG biopolymer was then investigated in a second, genetically modified mouse model (URO-MCP1) that increasingly is accepted as a model for IC/BPS. Permeability was induced with a brief exposure to a sub-noxious dose of LPS and was quantified using contrast-enhanced MRI (CE-MRI). The SuperGAG biopolymer restored impermeability to normal levels in the OVX rat model as measured by TEER in the Ussing chamber and reduced the abdominal pain response arising from induced permeability. Evaluation in the URO-MCP1 mouse model also showed restoration of bladder impermeability and showed the utility of CE-MRI imaging for evaluating the efficacy of agents to restore bladder impermeability. We conclude novel high MW SuperGAG biopolymers are effective in restoring urothelial impermeability and reducing pain produced by loss of the GAG layer on the urothelium. SuperGAG biopolymers could offer a novel and effective new therapy for IC/BPS, particularly if combined with MRI to assess the efficacy of the therapy.


Assuntos
Biopolímeros/uso terapêutico , Cistite Intersticial/tratamento farmacológico , Glicosaminoglicanos/uso terapêutico , Animais , Cistite Intersticial/diagnóstico por imagem , Cistite Intersticial/metabolismo , Feminino , Imageamento por Ressonância Magnética , Camundongos Transgênicos , Ovariectomia , Permeabilidade/efeitos dos fármacos , Protaminas , Ratos Sprague-Dawley , Bexiga Urinária/diagnóstico por imagem , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/metabolismo
10.
Front Neurosci ; 14: 590871, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33192275

RESUMO

Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic urological condition characterised by urinary urgency, frequency and pelvic pain, that significantly impacts the quality of life for ∼5% of women. Bladder sensation is coordinated by primary afferent sensory neurons that innervate the bladder wall, translating bladder stretch into signals that travel to the brain via the spinal cord. Whilst the pathophysiology of IC/BPS remains unknown, an increase in the permeability of the bladder urothelium has been proposed as an initiating cause. Here we experimentally increased bladder permeability and tracked bladder afferent sensitivity for up to 28 days. We found that one day after increasing bladder epithelial permeability with in vivo bladder infusion of protamine sulfate, mechanosensitive bladder afferents exhibited significant hypersensitivity to bladder filling. This mechanical hypersensitivity was characterised by significantly increased peak afferent firing rates and a decrease in the activation threshold of individual afferents. Bladder afferent hypersensitivity occurred in the absence of inflammation and changes in bladder muscle compliance, indicating a direct sensitisation of peripheral afferent endings. Bladder afferent mechanosensitive responses to distension returned to control levels by day 7 post-protamine sulfate treatment and remained at control levels at 28-days post-treatment. Here we demonstrate, contrary to the prevailing hypothesis, that increased bladder permeability alone does not induce chronic bladder afferent sensitisation. Whilst experimentally induced changes in bladder permeability are able to induce transient bladder afferent hypersensitivity in the absence of inflammation, highly regulated homeostatic mechanisms exist to rapidly repair the urothelial barrier and normalise bladder afferent mechanosensitivity. Together, these data suggest that additional pathophysiology is required to induce chronic bladder dysfunction.

11.
PLoS One ; 15(10): e0239282, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33095778

RESUMO

OBJECTIVES: To determine if the URO-MCP-1 mouse model for bladder IC/BPS is associated with in vivo bladder hyper-permeability, as measured by contrast-enhanced MRI (CE-MRI), and assess whether molecular-targeted MRI (mt-MRI) can visualize in vivo claudin-2 expression as a result of bladder hyper-permeability. Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic, painful condition of the bladder that affects primarily women. It is known that permeability plays a substantial role in IC/BPS. Claudins are tight junction membrane proteins that are expressed in epithelia and endothelia and form paracellular barriers and pores that determine tight junction permeability. Claudin-2 is a molecular marker that is associated with increased hyperpermeability in the urothelium. MATERIALS AND METHODS: CE-MRI was used to measure bladder hyper-permeability in the URO-MCP-1 mice. A claudin-2-specific mt-MRI probe was used to assess in vivo levels of claudin-2. The mt-MRI probe consists of an antibody against claudin-2 conjugated to albumin that had Gd-DTPA (gadolinium diethylenetriamine pentaacetate) and biotin attached. Verification of the presence of the mt-MRI probe was done by targeting the biotin moiety for the probe with streptavidin-horse radish peroxidase (SA-HRP). Trans-epithelial electrical resistance (TEER) was also used to assess bladder permeability. RESULTS: The URO-MCP-1 mouse model for IC/BPS was found to have a significant increase in bladder permeability, following liposaccharide (LPS) exposure, compared to saline-treated controls. mt-MRI- and histologically-detectable levels of the claudin-2 probe were found to increase with LPS -induced bladder urothelial hyper-permeability in the URO-MCP-1 IC mouse model. Levels of protein expression for claudin-2 were confirmed with immunohistochemistry and immunofluorescence imaging. Claudin-2 was also found to highly co-localize with zonula occlidens-1 (ZO-1), a tight junction protein. CONCLUSION: The combination of CE-MRI and TEER approaches were able to demonstrate hyper-permeability, a known feature associated with some IC/BPS patients, in the LPS-exposed URO-MCP-1 mouse model. This MRI approach could be clinically translated to establish which IC/BPS patients have bladder hyper-permeability and help determine therapeutic options. In addition, the in vivo molecular-targeted imaging approach can provide invaluable information to enhance our understanding associated with bladder urothelium hyper-permeability in IC/BPS patients, and perhaps be used to assist in developing further therapeutic strategies.


Assuntos
Claudina-2/metabolismo , Cistite Intersticial/patologia , Imageamento por Ressonância Magnética/métodos , Sondas Moleculares/química , Bexiga Urinária/fisiopatologia , Animais , Anticorpos/química , Anticorpos/imunologia , Claudina-2/imunologia , Cistite Intersticial/metabolismo , Modelos Animais de Doenças , Gadolínio DTPA/química , Imuno-Histoquímica , Lipopolissacarídeos/toxicidade , Camundongos , Permeabilidade/efeitos dos fármacos , Albumina Sérica/química
12.
Int Rev Cell Mol Biol ; 355: 205-243, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32859371

RESUMO

Cancer, as a major cause of mortality, is highly related to alterations in the structure and behavior of cells of cancerous tissues. The invasive nature of cancer cells is correlated with their increased traction force, high deformability and altered cell adhesion. These changes are directly attributed to the remodeling of cell cytoskeleton mostly in actin structure. While microtubules and intermediate filaments are mostly involved in mechanical properties of cytoskeleton, actin fibers actively contribute to not only mechanical properties, but also other aspects. Hence study of actin mechanics assists in a deeper understanding of cancer related events. Here, with a biomechanical perspective, we describe the cytoskeleton changes in cancer onset and progress in fiber and protein levels, with focus on actin structure in terms of content and arrangement. Cytoskeleton remodeling and particularly alterations in the content and arrangement of actin structure, highly influence cell mechanical properties, force generation and adhesion potentials.


Assuntos
Citoesqueleto de Actina/metabolismo , Neoplasias/metabolismo , Fenômenos Biomecânicos , Adesão Celular , Humanos , Neoplasias/etiologia , Neoplasias/fisiopatologia
13.
Neurogastroenterol Motil ; 31(4): e13479, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30311722

RESUMO

BACKGROUND: The expression of RET in the developing enteric nervous system (ENS) suggests that RET may contribute to adult intestinal function. ENS cholinergic nerves play a critical role in the control of colonic function through the release of acetylcholine (ACh). In the current study, we hypothesized that a RET-mediated mechanism may regulate colonic ion transport and motility through modulation of cholinergic nerves. METHODS: The effect of RET inhibition on active ion transport was assessed electrophysiologically in rat colonic tissue mounted in Ussing chambers via measurements of short circuit current (Isc) upon electrical field stimulation (EFS) or pharmacologically with cholinergic agonists utilizing a gastrointestinal (GI)-restricted RET inhibitor. We assessed the effect of the RET inhibitor on propulsive motility via quantification of fecal pellet output (FPO) induced by the acetylcholinesterase inhibitor neostigmine. KEY RESULTS: We found that enteric ganglia co-expressed RET and choline acetyltransferase (ChAT) transcripts. In vitro, the RET kinase inhibitor GSK3179106 attenuated the mean increase in Isc induced by either EFS or carbachol but not bethanechol. In vivo, GSK3179106 significantly reduced the prokinetic effect of neostigmine. CONCLUSION AND INFERENCES: Our findings provide evidence that RET-mediated mechanisms regulate colonic function by maintaining cholinergic neuronal function and enabling ACh-evoked chloride secretion and motility. We suggest that modulating the cholinergic control of the colon via a RET inhibitor may represent a novel target for the treatment of intestinal disorders associated with increased secretion and accelerated GI transit such as irritable bowel syndrome with diarrhea (IBS-D).


Assuntos
Neurônios Colinérgicos/efeitos dos fármacos , Colo/efeitos dos fármacos , Motilidade Gastrointestinal/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Transporte de Íons/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-ret/antagonistas & inibidores , Animais , Colina O-Acetiltransferase/metabolismo , Agonistas Colinérgicos/farmacologia , Neurônios Colinérgicos/metabolismo , Colo/metabolismo , Defecação/efeitos dos fármacos , Sistema Nervoso Entérico/efeitos dos fármacos , Sistema Nervoso Entérico/metabolismo , Trânsito Gastrointestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Masculino , Proteínas Proto-Oncogênicas c-ret/metabolismo , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos
14.
J Pharmacol Exp Ther ; 368(2): 299-307, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30413627

RESUMO

Abdominal pain represents a significant complaint in patients with irritable bowel syndrome (IBS). While the etiology of IBS is incompletely understood, prior exposure to gastrointestinal inflammation or psychologic stress is frequently associated with the development of symptoms. Inflammation or stress-induced expression of growth factors or cytokines may contribute to the pathophysiology of IBS. Here, we aimed to investigate the therapeutic potential of inhibiting the receptor of glial cell line-derived neurotrophic factor, rearranged during transfection (RET), in experimental models of inflammation and stress-induced visceral hypersensitivity resembling IBS sequelae. In RET-cyan fluorescent protein [(CFP) RetCFP/+] mice, thoracic and lumbosacral dorsal root ganglia were shown to express RET, which colocalized with calcitonin gene-related peptide. To understand the role of RET in visceral nociception, we employed GSK3179106 as a potent, selective, and gut-restricted RET kinase inhibitor. Colonic hyperalgesia, quantified as exaggerated visceromotor response to graded pressures (0-60 mm Hg) of isobaric colorectal distension (CRD), was produced in multiple rat models induced 1) by colonic irritation, 2) following acute colonic inflammation, 3) by adulthood stress, and 4) by early life stress. In all the rat models, RET inhibition with GSK3179106 attenuated the number of abdominal contractions induced by CRD. Our findings identify a role for RET in visceral nociception. Inhibition of RET kinase with a potent, selective, and gut-restricted small molecule may represent a novel therapeutic strategy for the treatment of IBS through the attenuation of post-inflammatory and stress-induced visceral hypersensitivity.


Assuntos
Colo/enzimologia , Modelos Animais de Doenças , Síndrome do Intestino Irritável/enzimologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-ret/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-ret/metabolismo , Células A549 , Animais , Linhagem Celular Tumoral , Colo/efeitos dos fármacos , Feminino , Humanos , Síndrome do Intestino Irritável/tratamento farmacológico , Masculino , Camundongos , Camundongos Transgênicos , Gravidez , Inibidores de Proteínas Quinases/farmacologia , Ratos , Ratos Long-Evans , Ratos Sprague-Dawley
15.
J Pharmacol Exp Ther ; 368(1): 116-124, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30377215

RESUMO

The gastrointestinal (GI) prokinetic effects of ghrelin occur through direct peripheral effects on ghrelin receptors within the enteric nervous system and via the ghrelin receptor on the vagus nerve, which activate a centrally mediated mechanism. However, the relative contribution of peripheral versus central effects to the overall prokinetic effect of ghrelin agonists requires further investigation. Here, we investigated the central versus peripheral prokinetic effect of ghrelin by using two novel ghrelin agonists: HM01 (N'-[(1S)-1-(2,3-dichloro-4-methoxyphenyl)ethyl]-N-methyl-N-[1,3,3-trimethyl-(4R)-piperidyl]-urea HCL) with high brain penetration compared with HM02 (N'-[(1S)-1-(2,3-dichloro-4-methoxyphenyl)ethyl]-N-hydroxy-N-(1-methyl-4-piperidinyl)-urea), a more peripherally acting ghrelin agonist. The pharmacokinetic profiles of both ghrelin agonists were evaluated after intravenous and oral administration in rats. The efficacy of HM01 and HM02 was assessed in a rat model of postoperative ileus (POI) induced by abdominal surgery and in a rodent defecation assay. Pharmacokinetic results in our models confirmed that HM01, but not HM02, was a brain-penetrant ghrelin agonist. Administration of either HM01 or HM02 reversed the delayed upper and lower gastrointestinal transit induced by abdominal surgery to levels resembling the non-POI controls. In the defecation test, HM01, but not HM02, significantly increased the weight of fecal pellets. Our findings suggest that, in a rodent model of POI, synthetic ghrelin agonists stimulate GI transit through a peripheral site of action. However, in the defecation assay, our data suggest that a ghrelin-mediated mechanism is located at a central site. Taken together, a ghrelin agonist with both central and peripheral prokinetic activity may show therapeutic potential to treat delayed GI transit disorders.


Assuntos
Materiais Biomiméticos/administração & dosagem , Trânsito Gastrointestinal/fisiologia , Grelina/administração & dosagem , Grelina/agonistas , Piperidinas/administração & dosagem , Administração Intravenosa , Administração Oral , Animais , Relação Dose-Resposta a Droga , Motilidade Gastrointestinal/efeitos dos fármacos , Motilidade Gastrointestinal/fisiologia , Trânsito Gastrointestinal/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley
16.
J Pharmacol Exp Ther ; 366(2): 274-281, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29784661

RESUMO

Bladder pain syndrome (BPS) is poorly understood; however, there is a female predominance and comorbidity with irritable bowel syndrome (IBS). Here we test the hypothesis that linaclotide, a guanylate cyclase-C (GC-C) agonist approved for the treatment of IBS with constipation (IBS-C), may represent a novel therapeutic for BPS acting through a mechanism involving an inhibition of visceral organ cross-sensitization. We showed previously that infusion of dilute protamine sulfate (PS) into the bladder increased sensitivity and permeability in the bladder and colon. PS was infused into the bladder of female rats; sensitivity was assessed via application of von Frey filaments applied to the suprapubic area and the frequency of withdrawal responses was recorded. Colonic sensitivity was measured via visceromotor behavioral response to graded pressures of colorectal distension (CRD). Permeability was measured in vitro via transepithelial electrical resistance (TEER) and conductance (G). Linaclotide (3 µg/kg, p.o.) or vehicle was administered daily for 7 days prior to experiments. Rats treated with PS bladder infusion exhibited visceral hyperalgesia, as shown by a significantly higher response frequency to individual von Frey filaments and increased behavioral responses to CRD. Linaclotide attenuated bladder and colonic hyperalgesia to control levels. PS infusion into the bladder increased bladder and colon permeability measured as a decrease in TEER and increased G. Linaclotide significantly inhibited PS-induced colonic hyperpermeability while having no effect on bladder hyperpermeability. Our findings suggest a novel treatment paradigm for GC-C agonism in IBS-C and BPS mediated through a mechanism involving visceral organ crosstalk.


Assuntos
Colo/efeitos dos fármacos , Colo/metabolismo , Guanilato Ciclase/metabolismo , Peptídeos/farmacologia , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/metabolismo , Animais , Ativação Enzimática/efeitos dos fármacos , Feminino , Permeabilidade/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Medula Espinal/citologia , Medula Espinal/efeitos dos fármacos
17.
Urology ; 116: 230.e1-230.e7, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29545038

RESUMO

OBJECTIVE: To test in an animal model the hypothesis that recombinant human proteoglycan 4 (rhPRG4; lubricin), a highly O-glycosylated mucin-like glycoprotein, may be a novel surface-active therapeutic for treating bladder permeability with comorbid bowel permeability. Previously we showed that inducing bladder permeability in rats with dilute protamine sulfate (PS) produced colonic permeability and visceral hypersensitivity, suggesting increased bladder permeability could represent an etiologic factor in both interstitial cystitis-bladder pain syndrome and irritable bowel syndrome. METHODS: We used an animal model of catheterized ovariectomized female rats instilled intravesically with 1 mg/mL PS for 10 minutes that after 24 hours were treated with 1.2 mg/mL lubricin or with vehicle alone. After 24 hours the bladder and colon were removed and permeability assessed electrophysiologically with the Ussing chamber to measure the transepithelial electrical resistance. A second set of rats was treated identically, except permeability was assessed on day 3 and on day 5 using contrast-enhanced magnetic resonance imaging with gadolinium diethylenetriamine penta-acetic acid instilled into the bladder. RESULTS: Intravesical lubricin reversed bladder permeability induced by PS and prevented the concomitant increase in permeability induced in the bowel (organ crosstalk). The protective effect was confirmed with magnetic resonance imaging, and because individual rats could be followed over time, the impermeability of the bladder restored by rhPRG4 remained for 5 days. CONCLUSION: These data indicate that instillation of rhPRG4 into a permeable bladder can restore its normally impermeable state, and that the effect lasts for 5 days and also prevents bowel symptoms often comorbid with interstitial cystitis-bladder pain syndrome.


Assuntos
Colo/metabolismo , Cistite Intersticial/tratamento farmacológico , Síndrome do Intestino Irritável/tratamento farmacológico , Proteoglicanas/uso terapêutico , Bexiga Urinária/metabolismo , Administração Intravesical , Animais , Colo/diagnóstico por imagem , Colo/efeitos dos fármacos , Colo/patologia , Cistite Intersticial/etiologia , Cistite Intersticial/patologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Feminino , Humanos , Síndrome do Intestino Irritável/etiologia , Síndrome do Intestino Irritável/patologia , Imageamento por Ressonância Magnética , Permeabilidade/efeitos dos fármacos , Proteoglicanas/farmacologia , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia , Proteínas Recombinantes/uso terapêutico , Bexiga Urinária/diagnóstico por imagem , Bexiga Urinária/efeitos dos fármacos , Bexiga Urinária/patologia
18.
Biol Sex Differ ; 7: 8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26823967

RESUMO

BACKGROUND: Painful bladder syndrome/interstitial cystitis (PBS/IC) is a chronic disorder that is commonly seen in women who report a history of adversity in early life. Here, we test the hypothesis that early life stress (ELS) induces sexually dimorphic abnormalities in urinary bladder smooth muscle function in adulthood. METHODS: Male and female rat pups were conditioned on postnatal (PN) days 8-12 with either a "predictable or "unpredictable" odor-shock, or odor only control treatment. In adulthood, urinary bladder function was assessed in vivo via urine spot analysis and in vitro via contractile responses to electrical field stimulation (EFS) and membrane depolarization with potassium chloride (KCl). RESULTS: In adulthood, we found that female rats exposed to unpredictable ELS showed a significant (p < 0.05) increase in urine voiding volume compared to predictable ELS or controls. We also found that detrusor muscle contractile responses to EFS were significantly (p < 0.001) decreased following unpredictable ELS in adult female rats compared to the predictable ELS or controls. In male rats exposed to ELS, there was no difference in voiding volume or EFS-induced contractility between groups. In adulthood, the myogenic smooth muscle response to KCl was not significantly different between groups. Histological analysis from adult female and male rats revealed no differences in the appearance of the urinary bladder in rats exposed to ELS. CONCLUSIONS: In summary, our findings provide evidence to support abnormalities in the nerve-mediated contractile responses of the detrusor smooth muscle in adult female rats following ELS. We speculate that these sexually dimorphic alterations in urinary bladder function may account, at least in part, for the female predominance of PBS/IC.

19.
J Urol ; 194(3): 804-11, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25776913

RESUMO

PURPOSE: The pathophysiology of painful bladder syndrome is poorly understood. However, there is evidence of female predominance and comorbidity with irritable bowel syndrome. Our hypothesis is that cross-sensitization between bladder and colon is due to altered permeability in 1 organ, which affects the other organ. MATERIALS AND METHODS: Experiments were performed in anesthetized, ovariectomized female rats. In separate groups protamine sulfate was infused in the bladder or trinitrobenzene sulfonic acid was infused in the colon. Untreated rats served as controls. Bladder and colonic tissue were harvested from all rats 1, 3 and 5 days after treatment. Permeability was assessed in vitro in Ussing chambers by measuring transepithelial electrical resistance and macromolecular flux of fluorescein isothiocyanate-dextran. RESULTS: Exposing the bladder to protamine sulfate induced a significant decrease in bladder transepithelial electrical resistance and an increase in the translocation of fluorescein isothiocyanate across the tissue compared to controls at 1 and 3 days (p <0.05). Colonic tissue from rats with enhanced bladder permeability showed a significant decrease in transepithelial electrical resistance and increase in fluorescein isothiocyanate compared to untreated controls at all time points (p <0.05). Conversely when colonic permeability was increased with trinitrobenzene sulfonic acid, we observed an increase in bladder permeability in the absence of any changes to the bladder urothelium. CONCLUSIONS: Changes in epithelial permeability may represent a novel mechanism for visceral organ crosstalk. It may explain the overlapping symptomology of painful bladder syndrome and irritable bowel syndrome.


Assuntos
Colo/metabolismo , Colo/fisiopatologia , Cistite Intersticial/metabolismo , Cistite Intersticial/fisiopatologia , Síndrome do Intestino Irritável/metabolismo , Síndrome do Intestino Irritável/fisiopatologia , Bexiga Urinária/metabolismo , Bexiga Urinária/fisiopatologia , Animais , Modelos Animais de Doenças , Feminino , Permeabilidade , Ratos , Ratos Sprague-Dawley
20.
Avicenna J Med Biotechnol ; 5(3): 158-67, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23919119

RESUMO

BACKGROUND: Radiation therapy is an effective method used for treatment of many types of cancers. However, this method can cause unwanted side effects such as bone marrow suppression. In this study, the effect of oral administration of biogenic selenium nanoparticles (SeNPs) on total and differentiated white cells profile of BALB/c mice exposed to X-ray radiation was investigated and compared with non-irradiated mice. METHODS: Sixty female BALB/c mice between six to eight weeks olds were divided into 4 test and control groups in two categories of normal and irradiated mice. In normal mice SeNPs administration was started from the day 0 and followed for a month. Irradiated mice were divided into three groups and were exposed to doses of 2, 4 and 8 Gy. After 72 hr of irradiation, the SeNPs treatment was started and continued for a month. Total and differentiated blood cells counts of both irradiated and non-irradiated groups were monitored during 30 days and the obtained results were compared. Also, the deposition of Se in different tissues and blood serum of normal mice was determined in normal mice after 30 days period of supplementation. RESULTS: In normal mice an increase in the count of neutrophils was observed after 30 days of supplementation. In irradiated mice, SeNPs supplementation led to increase in both lymphocytes and neutrophils counts especially in mice exposed to 2 and 4 Gys radiation. CONCLUSION: Radiotherapy is categorized as an invasive method which can cause tissue damage and suppress the host immune defense. A restore of lymphocytes which was observed after SeNPs supplementation in irradiated mice can be highly interesting and provide cellular immunity against malignant diseases or other bacterial or fungal infections after radiotherapy.

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