Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 54
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Mol Biol Rep ; 50(6): 5273-5282, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37145211

RESUMO

BACKGROUND: Commensal bacteria secrete metabolites that reach distant cancer cells through the circulation and influence cancer behavior. Deoxycholic acid (DCA), a hormone-like metabolite, is a secondary bile acid specifically synthesized by intestinal microbes. DCA may have both pro- and antineoplastic effects in cancers. METHODS AND RESULTS: The pancreatic adenocarcinoma cell lines, Capan-2 and BxPC-3, were treated with 0.7 µM DCA, which corresponds to the reference concentration of DCA in human serum. DCA influenced the expression of epithelial to mesenchymal transition (EMT)-related genes, significantly decreased the expression level of the mesenchymal markers, transcription factor 7- like 2 (TCF7L2), snail family transcriptional repressor 2 (SLUG), CLAUDIN-1, and increased the expression of the epithelial genes, zona occludens 1 (ZO-1) and E-CADHERIN, as shown by real-time PCR and Western blotting. Consequently, DCA reduced the invasion capacity of pancreatic adenocarcinoma cells in Boyden chamber experiments. DCA induced the protein expression of oxidative/nitrosative stress markers. Moreover, DCA reduced aldehyde dehydrogenase 1 (ALDH1) activity in an Aldefluor assay and ALDH1 protein level, suggesting that DCA reduced stemness in pancreatic adenocarcinoma. In Seahorse experiments, DCA induced all fractions of mitochondrial respiration and glycolytic flux. The ratio of mitochondrial oxidation and glycolysis did not change after DCA treatment, suggesting that cells became hypermetabolic. CONCLUSION: DCA induced antineoplastic effects in pancreatic adenocarcinoma cells by inhibiting EMT, reducing cancer stemness, and inducing oxidative/nitrosative stress and procarcinogenic effects such as hypermetabolic bioenergetics.


Assuntos
Adenocarcinoma , Antineoplásicos , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Transição Epitelial-Mesenquimal , Antineoplásicos/farmacologia , Ácido Desoxicólico/farmacologia , Linhagem Celular Tumoral , Neoplasias Pancreáticas
2.
Molecules ; 28(11)2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37298834

RESUMO

Although hyperpolarization-activated and cyclic nucleotide-gated 2 channels (HCN2) are expressed in multiple cell types in the gut, the role of HCN2 in intestinal motility is poorly understood. HCN2 is down-regulated in intestinal smooth muscle in a rodent model of ileus. Thus, the purpose of this study was to determine the effects of HCN inhibition on intestinal motility. HCN inhibition with ZD7288 or zatebradine significantly suppressed both spontaneous and agonist-induced contractile activity in the small intestine in a dose-dependent and tetrodotoxin-independent manner. HCN inhibition significantly suppressed intestinal tone but not contractile amplitude. The calcium sensitivity of contractile activity was significantly suppressed by HCN inhibition. Inflammatory mediators did not affect the suppression of intestinal contractile activity by HCN inhibition but increased stretch of the intestinal tissue partially attenuated the effects of HCN inhibition on agonist-induced intestinal contractile activity. HCN2 protein and mRNA levels in intestinal smooth muscle tissue were significantly down-regulated by increased mechanical stretch compared to unstretched tissue. Increased cyclical stretch down-regulated HCN2 protein and mRNA levels in primary human intestinal smooth muscle cells and macrophages. Overall, our results suggest that decreased HCN2 expression induced by mechanical signals, such as intestinal wall distension or edema development, may contribute to the development of ileus.


Assuntos
Íleus , Canais de Potássio , Humanos , Canais de Potássio/genética , Canais de Potássio/metabolismo , Canais de Cátion Regulados por Nucleotídeos Cíclicos/genética , Canais de Cátion Regulados por Nucleotídeos Cíclicos/metabolismo , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Regulação para Baixo
3.
Molecules ; 28(15)2023 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-37570868

RESUMO

Breast cancer patients are characterized by the oncobiotic transformation of multiple microbiome communities, including the gut microbiome. Oncobiotic transformation of the gut microbiome impairs the production of antineoplastic bacterial metabolites. The goal of this study was to identify bacterial metabolites with antineoplastic properties. We constructed a 30-member bacterial metabolite library and screened the library compounds for effects on cell proliferation and epithelial-mesenchymal transition. The metabolites were applied to 4T1 murine breast cancer cells in concentrations corresponding to the reference serum concentrations. However, yric acid, glycolic acid, d-mannitol, 2,3-butanediol, and trans-ferulic acid exerted cytostatic effects, and 3-hydroxyphenylacetic acid, 4-hydroxybenzoic acid, and vanillic acid exerted hyperproliferative effects. Furthermore, 3-hydroxyphenylacetic acid, 4-hydroxybenzoic acid, 2,3-butanediol, and hydrocinnamic acid inhibited epithelial-to-mesenchymal (EMT) transition. We identified redox sets among the metabolites (d-mannitol-d-mannose, 1-butanol-butyric acid, ethylene glycol-glycolic acid-oxalic acid), wherein only one partner within the set (d-mannitol, butyric acid, glycolic acid) possessed bioactivity in our system, suggesting that changes to the local redox potential may affect the bacterial secretome. Of the nine bioactive metabolites, 2,3-butanediol was the only compound with both cytostatic and anti-EMT properties.


Assuntos
Antineoplásicos , Neoplasias da Mama , Citostáticos , Humanos , Animais , Camundongos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Transição Epitelial-Mesenquimal , Citostáticos/farmacologia , Ácido Butírico/farmacologia , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Proliferação de Células
4.
Cancer Metastasis Rev ; 40(4): 1223-1249, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34967927

RESUMO

Breast cancer, the most frequent cancer in women, is characterized by pathological changes to the microbiome of breast tissue, the tumor, the gut, and the urinary tract. Changes to the microbiome are determined by the stage, grade, origin (NST/lobular), and receptor status of the tumor. This year is the 50th anniversary of when Hill and colleagues first showed that changes to the gut microbiome can support breast cancer growth, namely that the oncobiome can reactivate excreted estrogens. The currently available human and murine data suggest that oncobiosis is not a cause of breast cancer, but can support its growth. Furthermore, preexisting dysbiosis and the predisposition to cancer are transplantable. The breast's and breast cancer's inherent microbiome and the gut microbiome promote breast cancer growth by reactivating estrogens, rearranging cancer cell metabolism, bringing about a more inflammatory microenvironment, and reducing the number of tumor-infiltrating lymphocytes. Furthermore, the gut microbiome can produce cytostatic metabolites, the production of which decreases or blunts breast cancer. The role of oncobiosis in the urinary tract is largely uncharted. Oncobiosis in breast cancer supports invasion, metastasis, and recurrence by supporting cellular movement, epithelial-to-mesenchymal transition, cancer stem cell function, and diapedesis. Finally, the oncobiome can modify the pharmacokinetics of chemotherapeutic drugs. The microbiome provides novel leverage on breast cancer that should be exploited for better management of the disease.


Assuntos
Neoplasias da Mama , Microbiota , Animais , Bactérias/metabolismo , Neoplasias da Mama/patologia , Disbiose/microbiologia , Estrogênios/metabolismo , Feminino , Humanos , Camundongos , Microambiente Tumoral
5.
Int J Mol Sci ; 24(1)2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36613619

RESUMO

Normal gastrointestinal function relies on sensing and transducing mechanical signals into changes in intracellular signaling pathways. Both specialized mechanosensing cells, such as certain enterochromaffin cells and enteric neurons, and non-specialized cells, such as smooth muscle cells, interstitial cells of Cajal, and resident macrophages, participate in physiological and pathological responses to mechanical signals in the gastrointestinal tract. We review the role of mechanosensors in the different cell types of the gastrointestinal tract. Then, we provide several examples of the role of mechanotransduction in normal physiology. These examples highlight the fact that, although these responses to mechanical signals have been known for decades, the mechanosensors involved in these responses to mechanical signals are largely unknown. Finally, we discuss several diseases involving the overstimulation or dysregulation of mechanotransductive pathways. Understanding these pathways and identifying the mechanosensors involved in these diseases may facilitate the identification of new drug targets to effectively treat these diseases.


Assuntos
Células Intersticiais de Cajal , Mecanotransdução Celular , Mecanotransdução Celular/fisiologia , Trato Gastrointestinal , Transdução de Sinais , Intestino Delgado
6.
Int J Mol Sci ; 23(13)2022 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-35805922

RESUMO

Feeding intolerance and the development of ileus is a common complication affecting critically ill, surgical, and trauma patients, resulting in prolonged intensive care unit and hospital stays, increased infectious complications, a higher rate of hospital readmission, and higher medical care costs. Medical treatment for ileus is ineffective and many of the available prokinetic drugs have serious side effects that limit their use. Despite the large number of patients affected and the consequences of ileus, little progress has been made in identifying new drug targets for the treatment of ileus. Inflammatory mediators play a critical role in the development of ileus, but surprisingly little is known about the direct effects of inflammatory mediators on cells of the gastrointestinal tract, and many of the studies are conflicting. Understanding the effects of inflammatory cytokines/chemokines on the development of ileus will facilitate the early identification of patients who will develop ileus and the identification of new drug targets to treat ileus. Thus, herein, we review the published literature concerning the effects of inflammatory mediators on gastrointestinal motility.


Assuntos
Gastroenteropatias , Íleus , Estado Terminal , Gastroenteropatias/complicações , Motilidade Gastrointestinal , Humanos , Íleus/etiologia , Recém-Nascido , Mediadores da Inflamação/farmacologia , Complicações Pós-Operatórias/etiologia
7.
Mol Med ; 27(1): 33, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33794773

RESUMO

Ovarian cancer is characterized by dysbiosis, referred to as oncobiosis in neoplastic diseases. In ovarian cancer, oncobiosis was identified in numerous compartments, including the tumor tissue itself, the upper and lower female genital tract, serum, peritoneum, and the intestines. Colonization was linked to Gram-negative bacteria with high inflammatory potential. Local inflammation probably participates in the initiation and continuation of carcinogenesis. Furthermore, local bacterial colonies in the peritoneum may facilitate metastasis formation in ovarian cancer. Vaginal infections (e.g. Neisseria gonorrhoeae or Chlamydia trachomatis) increase the risk of developing ovarian cancer. Bacterial metabolites, produced by the healthy eubiome or the oncobiome, may exert autocrine, paracrine, and hormone-like effects, as was evidenced in breast cancer or pancreas adenocarcinoma. We discuss the possible involvement of lipopolysaccharides, lysophosphatides and tryptophan metabolites, as well as, short-chain fatty acids, secondary bile acids and polyamines in the carcinogenesis of ovarian cancer. We discuss the applicability of nutrients, antibiotics, and probiotics to harness the microbiome and support ovarian cancer therapy. The oncobiome and the most likely bacterial metabolites play vital roles in mediating the effectiveness of chemotherapy. Finally, we discuss the potential of oncobiotic changes as biomarkers for the diagnosis of ovarian cancer and microbial metabolites as possible adjuvant agents in therapy.


Assuntos
Disbiose , Microbiota , Neoplasias Ovarianas/microbiologia , Animais , Bactérias/metabolismo , Feminino , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/etiologia , Transdução de Sinais
8.
Int J Mol Sci ; 22(21)2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34768998

RESUMO

Mechanical cues are crucial for survival, adaptation, and normal homeostasis in virtually every cell type. The transduction of mechanical messages into intracellular biochemical messages is termed mechanotransduction. While significant advances in biochemical signaling have been made in the last few decades, the role of mechanotransduction in physiological and pathological processes has been largely overlooked until recently. In this review, the role of interactions between the cytoskeleton and cell-cell/cell-matrix adhesions in transducing mechanical signals is discussed. In addition, mechanosensors that reside in the cell membrane and the transduction of mechanical signals to the nucleus are discussed. Finally, we describe two examples in which mechanotransduction plays a significant role in normal physiology and disease development. The first example is the role of mechanotransduction in the proliferation and metastasis of cancerous cells. In this system, the role of mechanotransduction in cellular processes, including proliferation, differentiation, and motility, is described. In the second example, the role of mechanotransduction in a mechanically active organ, the gastrointestinal tract, is described. In the gut, mechanotransduction contributes to normal physiology and the development of motility disorders.


Assuntos
Membrana Celular/fisiologia , Citoesqueleto/fisiologia , Mecanotransdução Celular/fisiologia , Animais , Núcleo Celular/fisiologia , Adesões Focais/fisiologia , Humanos
9.
Am J Physiol Regul Integr Comp Physiol ; 318(4): R722-R729, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32023079

RESUMO

The role of the hepatic transudation barrier in determining ascites volume and protein content in chronic liver disease is poorly understood. Therefore, the purpose of the present study was to characterize how chronic sinusoidal hypertension impacts hepatic transudation barrier properties and the transudation rate. The suprahepatic inferior vena cava was surgically constricted, and animals were exposed to either short-term (SVH; 2-3 wk) or long-term venous hypertension (LVH; 5-6 wk). Compared with SVH, LVH resulted in lower peritoneal fluid pressure, ascites volume, and ascites protein concentration. The transudation barrier protein reflection coefficient was significantly higher, and the transudation barrier hydraulic conductivity, transudation rate, and transudate-to-lymph protein concentration ratio were significantly lower in LVH animals compared with SVH animals. The sensitivity of transudation rates to acute changes in interstitial fluid pressures was also significantly lower in LVH animals compared with SVH animals. In contrast, there was no detectable difference in hepatic lymph flow rate or sensitivity of lymph flow to acute changes in interstitial fluid pressures between SVH and LVH animals. Taken together, these data suggest that decreased hepatic transudation barrier permeability to fluid and protein and increased reflection coefficient led to a decrease in the hepatic contribution to ascites volume. The present work, to the best of our knowledge, is the first to quantify an anti-ascites adaptation of the hepatic transudation barrier in response to chronic hepatic sinusoidal hypertension.


Assuntos
Adaptação Fisiológica , Constrição Patológica/cirurgia , Hipertensão/etiologia , Fígado/fisiopatologia , Animais , Ascite/fisiopatologia , Cães , Exsudatos e Transudatos , Masculino
10.
Microcirculation ; 25(2)2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29047195

RESUMO

OBJECTIVE: Fluid and protein continuously transude from the surface of the liver. Despite a common understanding that transudation plays a critical role in hepatic interstitial and peritoneal fluid balance, transudation from the entire liver has not been studied. Therefore, the goal of the present work was to provide the first direct measurement of the hepatic transudation rate and transudation barrier properties. METHODS: Transudation rates were determined by collecting transudate from the entire liver. Hydraulic conductivity, and fluid transudation and protein reflection coefficients of the transudation barrier (formed by the subscapular interstitial matrix, capsule, and peritoneum) were determined from changes in fluid and protein transudation rates in response to hepatic venous pressure elevation. RESULTS: Following hepatic venous pressure elevation from 6.1 ± 0.9 to 11.1 ± 0.6 mm Hg, transudation rate increased from 0.13 ± 0.03 to 0.37 ± 0.03 mL/min·100 g. Transudation barrier hydraulic conductivity, fluid transudation and protein reflection coefficients (3.9 × 10-4  ± 5.7 × 10-5  mL/min·mm Hg·cm2 , 0.36 ± 0.04 mL/min·mm Hg, and 0.09 ± 0.03, respectively) were comparable to those reported for hepatic sinusoids. CONCLUSIONS: Taken together, these findings suggest that the hepatic transudation barrier is highly permeable at elevated sinusoidal pressures. These fundamental studies provide a better understanding of the hepatic transudation barrier properties and transudation under conditions that are physiologically and clinically relevant to ascites formation.


Assuntos
Exsudatos e Transudatos/metabolismo , Fígado/metabolismo , Pressão Venosa/fisiologia , Animais , Ascite , Permeabilidade Capilar/fisiologia , Humanos , Cinética
11.
J Neuroinflammation ; 15(1): 84, 2018 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-29548333

RESUMO

BACKGROUND: Traumatic brain injury (TBI) is a major cause of death and disability. TBI results in a prolonged secondary central neuro-inflammatory response. Previously, we have demonstrated that multiple doses (2 and 24 h after TBI) of multipotent adult progenitor cells (MAPC) delivered intravenously preserve the blood-brain barrier (BBB), improve spatial learning, and decrease activated microglia/macrophages in the dentate gyrus of the hippocampus. In order to determine if there is an optimum treatment window to preserve the BBB, improve cognitive behavior, and attenuate the activated microglia/macrophages, we administered MAPC at various clinically relevant intervals. METHODS: We administered two injections intravenously of MAPC treatment at hours 2 and 24 (2/24), 6 and 24 (6/24), 12 and 36 (12/36), or 36 and 72 (36/72) post cortical contusion injury (CCI) at a concentration of 10 million/kg. For BBB experiments, animals that received MAPC at 2/24, 6/24, and 12/36 were euthanized 72 h post injury. The 36/72 treated group was harvested at 96 h post injury. RESULTS: Administration of MAPC resulted in a significant decrease in BBB permeability when administered at 2/24 h after TBI only. For behavior experiments, animals were harvested post behavior paradigm. There was a significant improvement in spatial learning (120 days post injury) when compared to cortical contusion injury (CCI) in groups when MAPC was administered at or before 24 h. In addition, there was a significant decrease in activated microglia/macrophages in the dentate gyrus of hippocampus of the treated group (2/24) only when compared to CCI. CONCLUSIONS: Intravenous injections of MAPC at or before 24 h after CCI resulted in improvement of the BBB, improved cognitive behavior, and attenuated activated microglia/macrophages in the dentate gyrus.


Assuntos
Lesões Encefálicas Traumáticas/cirurgia , Terapia Baseada em Transplante de Células e Tecidos/métodos , Células-Tronco Multipotentes/fisiologia , Animais , Barreira Hematoencefálica/fisiopatologia , Proteínas de Ligação ao Cálcio/metabolismo , Permeabilidade Capilar/fisiologia , Citocinas/metabolismo , Modelos Animais de Doenças , Proteínas do Domínio Duplacortina , Injeções Intraventriculares , Masculino , Aprendizagem em Labirinto , Proteínas dos Microfilamentos/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Células-Tronco Multipotentes/transplante , Neuropeptídeos/metabolismo , Ratos , Tempo de Reação , Fatores de Tempo
12.
FASEB J ; 31(10): 4216-4225, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28821637

RESUMO

Every institution that is involved in research with animals is expected to have in place policies and procedures for the management of allegations of noncompliance with the Animal Welfare Act and the U.S. Public Health Service Policy on the Humane Care and Use of Laboratory Animals. We present here a model set of recommendations for institutional animal care and use committees and institutional officials to ensure appropriate consideration of allegations of noncompliance with federal Animal Welfare Act regulations that carry a significant risk or specific threat to animal welfare. This guidance has 3 overarching aims: 1) protecting the welfare of research animals; 2) according fair treatment and due process to an individual accused of noncompliance; and 3) ensuring compliance with federal regulations. Through this guidance, the present work seeks to advance the cause of scientific integrity, animal welfare, and the public trust while recognizing and supporting the critical importance of animal research for the betterment of the health of both humans and animals.-Hansen, B. C., Gografe, S., Pritt, S., Jen, K.-L. C., McWhirter, C. A., Barman, S. M., Comuzzie, A., Greene, M., McNulty, J. A., Michele, D. E., Moaddab, N., Nelson, R. J., Norris, K., Uray, K. D., Banks, R., Westlund, K. N., Yates, B. J., Silverman, J., Hansen, K. D., Redman, B. Ensuring due process in the IACUC and animal welfare setting: considerations in developing noncompliance policies and procedures for institutional animal care and use committees and institutional officials.


Assuntos
Comitês de Cuidado Animal , Experimentação Animal , Bem-Estar do Animal , Animais de Laboratório , Direitos Civis , Experimentação Animal/normas , Bem-Estar do Animal/legislação & jurisprudência , Animais , DNA/metabolismo , Humanos
13.
Am J Physiol Gastrointest Liver Physiol ; 308(9): G785-93, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25721304

RESUMO

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used to treat a number of conditions, and proton pump inhibitors (PPIs) are often used to prevent NSAID-induced gastric mucosal damage; however, the effects of NSAIDs on intestinal motility are poorly understood. The purpose of the present study is to determine the effects of a prototypical NSAID, indomethacin, either alone or in conjunction with the PPI omeprazole, on intestinal motility. Rats were randomly divided into four groups treated with vehicle, omeprazole, indomethacin, or a combination of indomethacin and omeprazole. Intestinal motility and transit were measured along with inflammatory mediators in the intestinal smooth muscle, markers of mucosal damage, and bacterial counts in the intestinal wall. Indomethacin, but not omeprazole, caused mucosal injury indicated by lower gut bleeding; however, both omeprazole and indomethacin suppressed contractile activity and frequency in the distal part of the small intestine. Cotreatment with omeprazole did not reduce indomethacin-induced intestinal bleeding. Furthermore, although indomethacin caused increased inflammation as indicated by increased edema development and inflammatory mediators, cotreatment with omeprazole did not reduce inflammation in the intestinal smooth muscle or prevent the increased bacterial count in the intestinal wall induced by indomethacin. We conclude that both NSAID and PPI treatment suppressed contractile activity in the distal regions of the small intestine. The suppression of intestinal contractility was associated with increased inflammation in both cases; however, indomethacin and omeprazole appear to affect intestinal motility by different mechanisms.


Assuntos
Anti-Inflamatórios não Esteroides/toxicidade , Motilidade Gastrointestinal/efeitos dos fármacos , Íleo/efeitos dos fármacos , Indometacina/toxicidade , Jejuno/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Omeprazol/toxicidade , Inibidores da Bomba de Prótons/toxicidade , Animais , Biomarcadores/metabolismo , Enterite/induzido quimicamente , Enterite/metabolismo , Enterite/fisiopatologia , Hemorragia Gastrointestinal/induzido quimicamente , Hemorragia Gastrointestinal/patologia , Hemorragia Gastrointestinal/fisiopatologia , Íleo/metabolismo , Íleo/microbiologia , Íleo/patologia , Íleo/fisiopatologia , Mediadores da Inflamação/metabolismo , Jejuno/metabolismo , Jejuno/microbiologia , Jejuno/patologia , Jejuno/fisiopatologia , Masculino , Músculo Liso/metabolismo , Músculo Liso/fisiopatologia , Ratos Sprague-Dawley
14.
J Biol Chem ; 288(2): 1200-13, 2013 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-23161543

RESUMO

Supraphysiological mechanical stretching in smooth muscle results in decreased contractile activity. However, the mechanism is unclear. Previous studies indicated that intestinal motility dysfunction after edema development is associated with increased smooth muscle stress and decreased myosin light chain (MLC) phosphorylation in vivo, providing an ideal model for studying mechanical stress-mediated decrease in smooth muscle contraction. Primary human intestinal smooth muscle cells (hISMCs) were subjected to either control cyclical stretch (CCS) or edema (increasing) cyclical stretch (ECS), mimicking the biophysical forces in non-edematous and edematous intestinal smooth muscle in vivo. ECS induced significant decreases in phosphorylation of MLC and MLC phosphatase targeting subunit (MYPT1) and a significant increase in p21-activated kinase (PAK) activity compared with CCS. PAK regulated MLC phosphorylation in an activity-dependent biphasic manner. PAK activation increased MLC and MYPT1 phosphorylation in CCS but decreased MLC and MYPT1 phosphorylation in hISMCs subjected to ECS. PAK inhibition had the opposite results. siRNA studies showed that PAK1 plays a critical role in regulating MLC phosphorylation in hISMCs. PAK1 enhanced MLC phosphorylation via phosphorylating MYPT1 on Thr-696, whereas PAK1 inhibited MLC phosphorylation via decreasing MYPT1 on both Thr-696 and Thr-853. Importantly, in vivo data indicated that PAK activity increased in edematous tissue, and inhibition of PAK in edematous intestine improved intestinal motility. We conclude that PAK1 positively regulates MLC phosphorylation in intestinal smooth muscle through increasing inhibitory phosphorylation of MYPT1 under physiologic conditions, whereas PAK1 negatively regulates MLC phosphorylation via inhibiting MYPT1 phosphorylation when PAK activity is increased under pathologic conditions.


Assuntos
Motilidade Gastrointestinal , Intestinos/fisiologia , Músculo Liso/fisiologia , Cadeias Leves de Miosina/metabolismo , Quinases Ativadas por p21/metabolismo , Animais , Células Cultivadas , Humanos , Masculino , Contração Muscular , Fosforilação , Ratos , Ratos Sprague-Dawley
15.
Am J Physiol Gastrointest Liver Physiol ; 306(5): G445-53, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24407593

RESUMO

Intestinal intussusception (ISS) commonly causes intestinal obstruction in children. One mechanism that has been proposed to cause ISS is inflammation-induced alteration of intestinal motility. We investigated whether innate inflammatory factors or altered motility is required for induction of ISS by LPS. We compared rates of ISS among BALB/c and C57BL/6 mice, mice lacking lymphocytes or depleted of phagocytes, or mice with defects in the Toll-like receptor 4 (TLR4) signaling pathway following administration of LPS or the Ca(2+) analog MnCl2. At 6 or 2 h after administration of LPS or MnCl2, respectively, mice underwent image analysis to assess intestinal contraction rate or laparotomy to identify ISS. LPS-induced ISS (LPS-ISS) was observed in BALB/c mice, but not in C57BL/6 mice or any BALB/c mice with disruptions of TLR4 signaling. LPS-induced serum TNF-α, IL-6, and nitric oxide (NO) and intestinal NO levels were similar in BALB/c and C57BL/6 mice. The rate of LPS-ISS was significantly reduced in phagocyte-depleted, but not lymphocyte-deficient, mice. Intestinal contraction rates were reduced in LPS-ISS-susceptible BALB/c mice, but not in LPS-ISS-resistant C57BL/6 or TLR4 mutant mice, suggesting a role for reduced intestinal contraction rate in LPS-ISS susceptibility. This was tested with MnCl2, a Ca(2+) antagonist that reduced intestinal contraction rates and induced ISS, irrespective of mouse strain. Therefore, LPS-ISS is initiated by innate immune signaling that requires TLR4 and phagocytes but may be independent of TNF-α, IL-6, and NO levels. Furthermore, alteration of intestinal motility, specifically, reduced intestinal contraction rate, is a key factor in the development of ISS.


Assuntos
Cloretos/toxicidade , Motilidade Gastrointestinal/efeitos dos fármacos , Imunidade Inata/fisiologia , Intussuscepção/induzido quimicamente , Lipopolissacarídeos/toxicidade , Proteínas de Fase Aguda/genética , Proteínas de Fase Aguda/metabolismo , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Feminino , Regulação da Expressão Gênica/imunologia , Imunidade Inata/efeitos dos fármacos , Intussuscepção/imunologia , Intussuscepção/metabolismo , Receptores de Lipopolissacarídeos/genética , Receptores de Lipopolissacarídeos/metabolismo , Masculino , Compostos de Manganês , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos SCID , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo
16.
Cell Death Discov ; 10(1): 248, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38782891

RESUMO

Lithocholic acid (LCA) is a secondary bile acid. LCA enters the circulation after bacterial synthesis in the gastrointestinal tract, reaches distantly located cancer cells, and influences their behavior. LCA was considered carcinogenic, but recent studies demonstrated that LCA has antitumor effects. We assessed the possible role of LCA in pancreatic adenocarcinoma. At the serum reference concentration, LCA induced a multi-pronged antineoplastic program in pancreatic adenocarcinoma cells. LCA inhibited cancer cell proliferation and induced mesenchymal-to-epithelial (MET) transition that reduced cell invasion capacity. LCA induced oxidative/nitrosative stress by decreasing the expression of nuclear factor, erythroid 2-like 2 (NRF2) and inducing inducible nitric oxide synthase (iNOS). The oxidative/nitrosative stress increased protein nitration and lipid peroxidation. Suppression of oxidative stress by glutathione (GSH) or pegylated catalase (pegCAT) blunted LCA-induced MET. Antioxidant genes were overexpressed in pancreatic adenocarcinoma and decreased antioxidant levels correlated with better survival of pancreatic adenocarcinoma patients. Furthermore, LCA treatment decreased the proportions of cancer stem cells. Finally, LCA induced total and ATP-linked mitochondrial oxidation and fatty acid oxidation. LCA exerted effects through the farnesoid X receptor (FXR), vitamin D receptor (VDR), and constitutive androstane receptor (CAR). LCA did not interfere with cytostatic agents used in the chemotherapy of pancreatic adenocarcinoma. Taken together, LCA is a non-toxic compound and has antineoplastic effects in pancreatic adenocarcinoma.

17.
Geroscience ; 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38196068

RESUMO

Ascites plays a key role in supporting the metastatic potential of ovarian cancer cells. Shear stress and carry-over of cancer cells by ascites flow support carcinogenesis and metastasis formation. In addition, soluble factors may participate in the procarcinogenic effects of ascites in ovarian cancer. This study aimed to determine the biological effects of cell-free ascites on carcinogenesis in ovarian cancer cells. Cell-free ascites from ovarian cancer patients (ASC) non-selectively induced cell proliferation in multiple models of ovarian cancer and untransformed primary human dermal fibroblasts. Furthermore, ASC induced a Warburg-type rearrangement of cellular metabolism in A2780 ovarian cancer cells characterized by increases in cellular oxygen consumption and glycolytic flux; increases in glycolytic flux were dominant. ASC induced mitochondrial uncoupling and fundamentally reduced fatty acid oxidation. Ascites-elicited effects were uniform among ascites specimens. ASC-elicited transcriptomic changes in A2780 ovarian cancer cells included induction of the TGFß-ERK/MEK pathway, which plays a key role in inducing cell proliferation and oncometabolism. ASC-induced gene expression changes, as well as the overexpression of members of the TGFß signaling system, were associated with poor survival in ovarian cancer patients. We provided evidence that the activation of the autocrine/paracrine of TGFß signaling system may be present in bladder urothelial carcinoma and stomach adenocarcinoma. Database analysis suggests that the TGFß system may feed forward bladder urothelial carcinoma and stomach adenocarcinoma. Soluble components of ASC support the progression of ovarian cancer. These results suggest that reducing ascites production may play an essential role in the treatment of ovarian cancer by inhibiting the progression and reducing the severity of the disease.

18.
Sci Rep ; 13(1): 16142, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37752232

RESUMO

Traumatic brain injury (TBI) results in activated microglia. Activated microglia can be measured in vivo by using positron emission topography (PET) ligand peripheral benzodiazepine receptor standardized uptake values (PBR28suv). Cell based therapies have utilized autologous bone marrow mononuclear cells (BMMNCs) to attenuate activated microglia after TBI. This study aims to utilize in vivo PBR28suv to assess the efficacy of BMMNCs therapy after TBI. Seventy-two hours after CCI injury, BMMNCs were harvested from the tibia and injected via tail-vein at 74 h after injury at a concentration of 2 million cells per kilogram of body weight. There were three groups of rats: Sham, CCI-alone and CCI-BMMNCs (AUTO). One hundred twenty days after injury, rodents were imaged with PBR28 and their cognitive behavior assessed utilizing the Morris Water Maze. Subsequent ex vivo analysis included brain volume and immunohistochemistry. BMMNCs therapy attenuated PBR28suv in comparison to CCI alone and it improved spatial learning as measured by the Morris Water Maze. Ex vivo analysis demonstrated preservation of brain volume, a decrease in amoeboid-shaped microglia in the dentate gyrus and an increase in the ratio of ramified to amoeboid microglia in the thalamus. PBR28suv is a viable option to measure efficacy of BMMNCs therapy after TBI.


Assuntos
Lesões Encefálicas Traumáticas , Microglia , Animais , Ratos , Medula Óssea , Elétrons , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Lesões Encefálicas Traumáticas/terapia , Tomografia por Emissão de Pósitrons
19.
Am J Physiol Gastrointest Liver Physiol ; 302(2): G207-17, 2012 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22038824

RESUMO

Sirtuin 1 (SIRT1), a NAD(+)-dependent histone deacetylase, is involved in a wide array of cellular processes including glucose homeostasis, energy metabolism, proliferation and apoptosis, and immune response. However, it is unknown whether SIRT1 plays any physiological role in the regulation of intestinal homeostasis and motility. Thus the aim was to define SIRT1 expression and function in the gastrointestinal (GI) tract under physiological conditions. Forty 12-14-wk-old SIRT1 knockout (KO) and wild-type (WT) mice were fasted 21 h and/or refed 3 h. Fasted mice were injected intraperitoneally with bromodeoxyuridine (120 mg/kg body wt) 2 h before euthanasia. SIRT1 protein was localized to gastric and intestinal epithelial nuclei and was responsive to the nutritional status. SIRT1 was required for intestinal epithelial homeostasis. The SIRT1 KO mice showed enhanced crypt proliferation and suppressed villous apoptosis, resulting in increased intestinal villous height. In the SIRT1 KO intestine, the abundance of Forkhead box protein O1 and p53 protein decreased, whereas the subcellular localization of ß-catenin protein accumulated mainly in the crypts. The SIRT1 KO mice showed accelerated gastric emptying rate with increased abundance of ghrelin mRNA and protein in the stomach. Moreover, the SIRT1 KO mouse intestine showed enhanced ex vivo spontaneous contraction. We concluded that, SIRT1 plays a critical role in the control of intestinal homeostasis (by promoting apoptosis and inhibiting proliferation) and gastrointestinal motility (by reducing gastric emptying and intestinal contractile activity), implicating a novel role for SIRT1.


Assuntos
Jejum/metabolismo , Esvaziamento Gástrico/genética , Mucosa Gástrica/metabolismo , Mucosa Intestinal/metabolismo , Sirtuína 1/metabolismo , Animais , Apoptose/fisiologia , Proliferação de Células , Ingestão de Alimentos/fisiologia , Grelina/genética , Grelina/metabolismo , Camundongos , Camundongos Knockout , Contração Muscular/fisiologia , Sirtuína 1/genética , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , beta Catenina/genética , beta Catenina/metabolismo
20.
Microcirculation ; 19(8): 714-22, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22708850

RESUMO

OBJECTIVE: Although the causal relationship between acute myocardial edema and cardiac dysfunction has been established, resolution of myocardial edema and subsequent recovery of cardiac function have not been established. The time to resolve myocardial edema and the degree that cardiac function is depressed after edema resolves are not known. We therefore characterized temporal changes in cardiac function as acute myocardial edema formed and resolved. METHODS: Acute myocardial edema was induced in the canine model by elevating coronary sinus pressure for three hours. Myocardial water content and cardiac function were determined before and during coronary sinus pressure elevation, and after coronary sinus pressure restoration. RESULTS: Although no change in systolic properties was detected, accumulation of water in myocardial interstitium was associated with increased diastolic stiffness. When coronary sinus pressure was relieved, myocardial edema resolved within 180 minutes. Diastolic stiffness, however, remained significantly elevated compared with baseline values, and cardiac function remained compromised. CONCLUSIONS: The present work suggests that the cardiac dysfunction caused by the formation of myocardial edema may persist after myocardial edema resolves. With the advent of new imaging techniques to quantify myocardial edema, this insight provides a new avenue for research to detect and treat a significant cause of cardiac dysfunction.


Assuntos
Pressão Sanguínea , Seio Coronário/metabolismo , Miocárdio/metabolismo , Disfunção Ventricular Esquerda/metabolismo , Água/metabolismo , Animais , Distinções e Prêmios , Seio Coronário/patologia , Cães , Edema , Miocárdio/patologia , Fatores de Tempo , Disfunção Ventricular Esquerda/patologia , Disfunção Ventricular Esquerda/fisiopatologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA