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1.
Int J Mol Sci ; 20(10)2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-31108898

RESUMO

BACKGROUND: Studies on the regulation of gastric and pancreatic secretion began more than 100 years ago. Secretin was the first hormone postulated to exist, initiating the field of endocrinology. Gastrin produced in the antral mucosa was the second postulated hormone, and together with histamine and acetylcholine, represent the three major gastric acid secretagogues known since 1920. For a long time, the mast cell was the only recognized histamine-producing cell in the oxyntic mucosa and, in the mid-1980s, the ECL cell was recognized as the cell producing histamine, taking part in the regulation of gastric acid secretion. METHODS: This review is based upon literature research and personal knowledge. RESULTS: The ECL cell carries the gastrin receptor, and gastrin regulates its function (histamine release) as well as proliferation. Long-term hypergastrinemia results in gastric neoplasia of variable malignancies, implying that gastric hypoacidity resulting in increased gastrin release will induce gastric neoplasia, including gastric cancer. CONCLUSIONS: The trophic effect of gastrin on the ECL cell has implications to the treatment with inhibitors of acid secretion.


Assuntos
Celulas Tipo Enterocromafim/metabolismo , Mucosa Gástrica/metabolismo , Gastrinas/metabolismo , Acetilcolina/metabolismo , Animais , Celulas Tipo Enterocromafim/patologia , Mucosa Gástrica/patologia , Histamina/metabolismo , Humanos , Receptor de Colecistocinina B/metabolismo
2.
Esophagus ; 16(2): 201-206, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30600486

RESUMO

BACKGROUND: To evaluate the efficacy of on-demand therapy using 20-mg vonoprazan for non-erosive reflux disease. METHODS: On-demand therapy by taking one 20-mg tablet of vonoprazan only when reflux symptoms occurred was performed for 8 weeks by 30 patients (11 men, mean age: 67.8) with non-erosive reflux disease who responded well to maintenance therapy using proton pump inhibitor and answered "very satisfied" or "satisfied" to an overall satisfaction survey (5-grade scale). The degree of overall satisfaction with the treatment, score of symptoms, and fasting gastrin levels before breakfast was examined before and after on-demand therapy. The number of vonoprazan tablets taken and the frequency (regular, temporary, rare) of its administration were also investigated. RESULTS: All patients completed 8-week on-demand therapy with 20-mg vonoprazan. Comparisons of patient satisfaction levels before and after therapy revealed no significant differences in the number of patients who were very satisfied and satisfied with the therapy. Furthermore, there were no significant differences in score of symptoms or gastrin levels before and after therapy. During 8-week on-demand therapy, patients took 11 tablets (median) (7.0-18.0 tablets: 25-75 percentiles), and 30.0% of patients (n = 9) took vonoprazan on a regular basis (at least 2 tablets a week). CONCLUSION: On-demand therapy with 20-mg vonoprazan exerted equivalent effects to continuous PPI maintenance therapy for patients with non-erosive reflux disease.


Assuntos
Refluxo Gastroesofágico/tratamento farmacológico , Inibidores da Bomba de Prótons/administração & dosagem , Pirróis/administração & dosagem , Sulfonamidas/administração & dosagem , Idoso , Esquema de Medicação , Feminino , Gastrinas/metabolismo , Refluxo Gastroesofágico/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Estudos Prospectivos , Resultado do Tratamento
3.
Pancreas ; 48(1): 131-134, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30531243

RESUMO

Our group observed the first case of synchronous gastric neuroendocrine tumor (NET) and duodenal gastrinoma with autoimmune chronic atrophic gastritis (CAG), in the absence of Helicobacter pylori infection. Demographic, clinical, endoscopic, and pathologic data were abstracted from the electronic medical record at Mount Sinai Hospital from 2013 to 2015. The patient's anonymity was carefully protected, and informed consent was obtained for publication of protected health information. A 53-year-old woman with hypertension presented to Mount Sinai Hospital in June 2013 for a second opinion for management of gastric and duodenal NETs. After evaluation by gastroenterology and surgery, repeat upper endoscopy with ultrasound and fine-needle aspiration revealed multiple diminutive type I gastric NETs and 2 duodenal NETs, against a background of autoimmune CAG, with biopsy pathology negative for H. pylori. She subsequently underwent a transduodenal resection of the duodenal NETs, confirming low-grade, gastrin-positive, stage T2 duodenal NET. On routine follow-up over the next 2 years, clinical, radiographic, and endoscopic surveillance revealed no recurrent or metastatic gastric or duodenal disease. This first report of synchronous duodenal gastrinoma and gastric NET in the setting of autoimmune CAG can broaden our understanding of gastric NET pathophysiology.


Assuntos
Doenças Autoimunes/diagnóstico , Neoplasias Duodenais/diagnóstico , Gastrinoma/diagnóstico , Gastrite Atrófica/diagnóstico , Tumores Neuroendócrinos/diagnóstico , Neoplasias Gástricas/diagnóstico , Doenças Autoimunes/complicações , Doença Crônica , Neoplasias Duodenais/complicações , Feminino , Gastrinoma/complicações , Gastrinas/metabolismo , Gastrite Atrófica/complicações , Humanos , Hipertensão/etiologia , Pessoa de Meia-Idade , Tumores Neuroendócrinos/complicações , Neoplasias Gástricas/complicações
4.
Obes Surg ; 29(2): 593-600, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30353248

RESUMO

BACKGROUND: Sleeve gastrectomy with ileal transposition has been shown to be superior to sleeve gastrectomy alone for promoting weight loss in rat and porcine models. The absence of a mouse model for this procedure has impeded efforts to understand the molecular physiology underlying its efficacy. This study demonstrates the long-term survivability of sleeve gastrectomy with ileal transposition in mice. MATERIALS AND METHODS: In this study of technical feasibility, a sleeve gastrectomy with ileal transposition (SGIT), sleeve gastrectomy (SG), or sham surgery (SH) was performed on 7- to 8-week-old C57Bl/6J mice (n = 8 for each). To evaluate long-term survivability, mice were placed on an obesogenic diet and weighed weekly for 10 weeks. The intestinal identity of the transposed segment was assessed with gene expression analysis of duodenal-, jejunal-, and ileal-specific hormones using quantitative polymerase chain reaction. RESULTS: Overall, SGIT better prevented weight gain than the SG or sham procedures (10-week post-operative weight: SH 45.3 ± 1.0 g, SG 41.25 ± 1.6 g, SGIT 35.4 ± 0.8 g). Gene expression pattern analysis of three markers of intestinal identity (gastrin, cholecystokinin, and peptide YY) suggests that the ileal identity of the transposed segment is maintained 10 weeks after transposition. CONCLUSIONS: We demonstrate for the first time a reproducible mouse model of sleeve gastrectomy with ileal transposition. Future studies utilizing this model will expand our understanding of the molecular pathways through which the hindgut regulates satiety.


Assuntos
Gastrectomia/métodos , Íleo/cirurgia , Animais , Biomarcadores , Glicemia/análise , Colecistocinina/genética , Colecistocinina/metabolismo , Modelos Animais de Doenças , Estudos de Viabilidade , Gastrinas/genética , Gastrinas/metabolismo , Expressão Gênica , Camundongos Endogâmicos C57BL , Peptídeo YY/genética , Peptídeo YY/metabolismo , RNA/metabolismo , Distribuição Aleatória , Perda de Peso
5.
J Nucl Med ; 60(3): 393-399, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30002107

RESUMO

Patients with metastatic medullary thyroid cancer (MTC) have limited systemic treatment options. The use of radiolabeled gastrin analogs targeting the cholecystokinin-2 receptor (CCK2R) is an attractive approach. However, their therapeutic efficacy is presumably decreased by their enzymatic degradation in vivo. We aimed to investigate whether the chemically stabilized analog 177Lu-DOTA-PP-F11N (177Lu-DOTA-(dGlu)6-Ala-Tyr-Gly-Trp-Nle-Asp-Phe-NH2) performs better than reference analogs with varying in vivo stability, namely 177Lu-DOTA-MG11 (177Lu-DOTA-dGlu-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH2) and 177Lu-DOTA-PP-F11 (177Lu-DOTA-(dGlu)6-Ala-Tyr-Gly-Trp-Met-Asp-Phe-NH2), and whether the use of protease inhibitors further improves CCKR2 targeting. First human data on 177Lu-DOTA-PP-F11N are also reported. Methods: In vitro stability of all analogs was assessed against a panel of extra- and intracellular endoproteases, whereas their in vitro evaluation was performed using the human MTC MZ-CRC-1 and the transfected A431-CCK2R(+) cell lines. Biodistribution without and with the protease inhibitors phosphoramidon and thiorphan was assessed 4 h after injection in MZ-CRC-1 and A431-CCK2R(+) dual xenografts. Autoradiography of 177Lu-DOTA-PP-F11N (without and with phosphoramidon) and NanoSPECT/CT were performed. SPECT/CT images of 177Lu-DOTA-PP-F11N in a metastatic MTC patient were also acquired. Results: natLu-DOTA-PP-F11N is less of a substrate for neprilysins than the other analogs, whereas intracellular cysteine proteases, such as cathepsin-L, might be involved in the degradation of gastrin analogs. The uptake of all radiotracers was higher in MZ-CRC-1 tumors than in A431-CCK2R(+), apparently because of the higher number of binding sites on MZ-CRC-1 cells. 177Lu-DOTA-PP-F11N had the same biodistribution as 177Lu-DOTA-PP-F11; however, uptake in the MZ-CRC-1 tumors was almost double (20.7 ± 1.71 vs. 11.2 ± 2.94 %IA [percentage injected activity]/g, P = 0.0002). Coadministration of phosphoramidon or thiorphan increases 177Lu-DOTA-MG11 uptake significantly in the CCK2R(+) tumors and stomach. Less profound was the effect on 177Lu-DOTA-PP-F11, whereas no influence or even reduction was observed for 177Lu-DOTA-PP-F11N (20.7 ± 1.71 vs. 15.6 ± 3.80 [with phosphoramidon] %IA/g, P < 0.05 in MZ-CRC-1 tumors). The first clinical data show high 177Lu-DOTA-PP-F11N accumulation in tumors, stomach, kidneys, and colon. Conclusion: The performance of 177Lu-DOTA-PP-F11N without protease inhibitors is as good as the performance of 177Lu-DOTA-MG11 in the presence of inhibitors. The human application of single compounds without unessential additives is preferable. Preliminary clinical data spotlight the stomach as a potential dose-limiting organ besides the kidneys.


Assuntos
Gastrinas/química , Gastrinas/metabolismo , Compostos Heterocíclicos com 1 Anel/química , Lutécio , Inibidores de Proteases/farmacologia , Radioisótopos , Receptor de Colecistocinina B/metabolismo , Sequência de Aminoácidos , Animais , Transporte Biológico/efeitos dos fármacos , Linhagem Celular Tumoral , Estabilidade de Medicamentos , Feminino , Gastrinas/farmacocinética , Humanos , Camundongos , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único , Distribuição Tecidual/efeitos dos fármacos
6.
Surg Today ; 49(1): 38-48, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30159780

RESUMO

PURPOSE: Functional outcomes were prospectively compared between two types of reconstruction [double tract (L-DT; n = 15) and jejunal interposition (L-JIP; n = 15)] following laparoscopic half-proximal gastrectomy (LPG), including laparoscopic total gastrectomy (L-TG; n = 30) as a control group, at 1 year after surgery. METHODS: Clinical investigations were performed in each patient, and functional evaluations, involving the swallowing of an alimentary liquid containing acetaminophen (AAP), followed by measurements of the concentrations of AAP and hormones in the sitting (n = 5) and in the supine positions (n = 5), were carried out in each group. RESULTS: The post-/preoperative body weight ratios were significantly higher in the L-DT and L-JIP groups than in the L-TG group. The AAP levels were significantly lower in the LPG group than in the LTG group. The AAP, insulin, and gastrin levels in the L-JIP group were markedly increased in the sitting position compared with the supine position, while those in the L-DT and L-TG groups were stable in both positions. CONCLUSIONS: L-JIP and L-DT are procedures that maintain gradual intestinal absorption and help improve the quality of life. Intestinal absorption and hormonal secretion were relatively unaffected by the posture of the meal intake after L-DT, so L-DT might be the procedure providing the most stable results.


Assuntos
Gastrectomia/métodos , Jejuno/cirurgia , Laparoscopia/métodos , Procedimentos Cirúrgicos Reconstrutivos/métodos , Neoplasias Gástricas/cirurgia , Estômago/cirurgia , Acetaminofen/metabolismo , Idoso , Peso Corporal , Feminino , Gastrinas/metabolismo , Humanos , Insulina/metabolismo , Absorção Intestinal , Masculino , Pessoa de Meia-Idade , Período Perioperatório , Postura/fisiologia , Estudos Prospectivos , Qualidade de Vida , Neoplasias Gástricas/metabolismo , Fatores de Tempo
7.
J Clin Endocrinol Metab ; 104(4): 1336-1344, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30566620

RESUMO

PURPOSE: Peptide receptor radionuclide therapy (PRRT) with the radiolabeled somatostatin analogue [Lutetium-177-DOTA0-Tyr3]octreotate (177Lu-DOTATATE) is widely applied for inoperable metastatic small intestinal and nonfunctioning pancreatic neuroendocrine tumors (pNETs). The aim of this study is to describe the safety and efficacy of the treatment of functioning pNETs. METHODS: Patients were treated with up to four cycles of 177Lu-DOTATATE with an intended dose of 7.4 Gbq per cycle. Radiological (Response Evaluation Criteria in Solid Tumors 1.1), symptomatic, and biochemical response were analyzed retrospectively for all patients with a functioning pNET (insulinoma, gastrinoma, VIPoma, and glucagonoma) treated with 177Lu-DOTATATE. Quality of life (QOL) was assessed with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core Module questionnaire. RESULTS: Thirty-four patients with a metastatic functioning pNET (European Neuroendocrine Tumor Society grade 1 or 2) were included: 14 insulinomas, 5 VIPomas, 7 gastrinomas, and 8 glucagonomas. Subacute hematological toxicity, grade 3 or 4 occurred in 4 patients (12%) and a hormonal crisis in 3 patients (9%). PRRT resulted in partial or complete response in 59% of patients and the disease control rate was 78% in patients with baseline progression. 71% of patients with uncontrolled symptoms had a reduction of symptoms and a more than 80% decrease of circulating hormone levels was measured during follow-up. After PRRT, median progression-free survival was 18.1 months (interquartile range: 3.3 to 35.7) with a concurrent increase in QOL. CONCLUSION: Treatment with 177Lu-DOTATATE is a safe and effective therapy resulting in radiological, symptomatic and biochemical response in a high percentage of patients with metastatic functioning pNETs. Hormonal crises occur relatively frequent and preventive therapy should be considered before and/or during PRRT.


Assuntos
Complexos de Coordenação/administração & dosagem , Lutécio/administração & dosagem , Tumores Neuroendócrinos/radioterapia , Octreotida/análogos & derivados , Neoplasias Pancreáticas/radioterapia , Radioisótopos/administração & dosagem , Adulto , Idoso , Complexos de Coordenação/efeitos adversos , Feminino , Gastrinas/sangue , Gastrinas/metabolismo , Glucagon/sangue , Glucagon/metabolismo , Humanos , Insulina/sangue , Insulina/metabolismo , Lutécio/efeitos adversos , Masculino , Pessoa de Meia-Idade , Tumores Neuroendócrinos/sangue , Tumores Neuroendócrinos/patologia , Octreotida/administração & dosagem , Octreotida/efeitos adversos , Pâncreas/metabolismo , Pâncreas/patologia , Pâncreas/efeitos da radiação , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/patologia , Qualidade de Vida , Doses de Radiação , Radioisótopos/efeitos adversos , Critérios de Avaliação de Resposta em Tumores Sólidos , Estudos Retrospectivos , Peptídeo Intestinal Vasoativo/sangue , Peptídeo Intestinal Vasoativo/metabolismo
8.
Pak J Pharm Sci ; 31(6 (Supplementary): 2585-2589, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30587465

RESUMO

Neuroendocrine tumors (NET) are the rare tumors which often impose graveyard threat. These tumors are characterized by the over expression of various G-protein coupled receptors including cholecystokinin (CCK) receptors-1 and 2 (A or B). Minigastrin peptides are being investigated for theranostic purposes of CCK-2 receptor positive NET. The minigastrin analogue (APHO70) was modified by engineering enzyme susceptible tetrapeptide sequence into APHO70 peptide to reduce the random degradation by lysosome enzymes which pave the way to random trafficking in patient's body and dipeptide addition at c-terminus. All the four modified minigastrin peptides (MG-CL1-4) were investigated for lysosome cathepsin B (catB) enzyme susceptibility and fate into AR42J cancer cell line. The indium-111 labeled MG-CL1-4 peptides were also studied for target (tumor) and non-target saccumulation by using tumor induced mice. The RP-HPLC analysis result showed nonspecific cleavage of standard 111In-APH070 and 111In-MGCL1 while specific cleavage was noted in case of 111In-MGCL (2-4). The effect of specific and non-specific cleavage on biodistribution in tumor induced nude mice model indicates the promising accumulation of 111In-MGCL2, 111In-MGCL3, and 111In-MGCL4 radiotracers while 111In-MGCL1 showed less accumulation. 111In-MGCL2 and 111In-MGCL3 showed highest target-to-kidney ratio (T/K) i.e. 1.71 and 1.72, respectively whereas standard compound showed T/K 1.13. In conclusion, the two indium-111 labeled analogues i.e. 111In-MGCL2 and 111In-MGCL3 showed promising sensitivity for tumor andcould be tested for further investigation to reach pre-clinical studies.


Assuntos
Catepsina B/metabolismo , Gastrinas/metabolismo , Radioisótopos de Índio/metabolismo , Tumores Neuroendócrinos/metabolismo , Fragmentos de Peptídeos/metabolismo , Compostos Radiofarmacêuticos/metabolismo , Animais , Linhagem Celular Tumoral , Feminino , Camundongos , Camundongos Nus , Tumores Neuroendócrinos/diagnóstico por imagem
9.
Exp Mol Med ; 50(12): 156, 2018 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-30510283

RESUMO

DNA methylation is a regulatory mechanism in epigenetics that is frequently altered during human carcinogenesis. To detect critical methylation events associated with gastric cancer (GC), we compared three DNA methylomes from gastric mucosa (GM), intestinal metaplasia (IM), and gastric tumor (GT) cells that were microscopically dissected from an intestinal-type early gastric cancer (EGC) using methylated DNA binding domain sequencing (MBD-seq) and reduced representation bisulfite sequencing (RRBS) analysis. In this study, we focused on differentially methylated promoters (DMPs) that could be directly associated with gene expression. We detected 2,761 and 677 DMPs between the GT and GM by MBD-seq and RRBS, respectively, and for a total of 3,035 DMPs. Then, 514 (17%) of all DMPs were detected in the IM genome, which is a precancer of GC, supporting that some DMPs might represent an early event in gastric carcinogenesis. A pathway analysis of all DMPs demonstrated that 59 G protein-coupled receptor (GPCR) genes linked to the hypermethylated DMPs were significantly enriched in a neuroactive ligand-receptor interaction pathway. Furthermore, among the 59 GPCRs, six GI hormone receptor genes (NPY1R, PPYR1, PTGDR, PTGER2, PTGER3, and SSTR2) that play an inhibitory role in the secretion of gastrin or gastric acid were selected and validated as potential biomarkers for the diagnosis or prognosis of GC patients in two cohorts. These data suggest that the loss of function of gastrointestinal (GI) hormone receptors by promoter methylation may lead to gastric carcinogenesis because gastrin and gastric acid have been known to play a role in cell differentiation and carcinogenesis in the GI tract.


Assuntos
Mucosa Gástrica/fisiologia , Regiões Promotoras Genéticas/genética , Receptores dos Hormônios Gastrointestinais/genética , Neoplasias Gástricas/genética , Carcinogênese , Diferenciação Celular , Linhagem Celular Tumoral , Metilação de DNA , Ácido Gástrico/metabolismo , Gastrinas/metabolismo , Humanos , Metaplasia , Neurotransmissores/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Receptores dos Hormônios Gastrointestinais/metabolismo , Transdução de Sinais , Neoplasias Gástricas/diagnóstico , Sulfitos , Sequenciamento Completo do Genoma
10.
Physiol Behav ; 194: 466-473, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-29964068

RESUMO

Gastric vagal afferents play an important role in the peripheral control of food intake. Apelin, a central appetite regulating hormone, is also abundantly released from the stomach. Whether apelin modulates gastric vagal afferent signalling is unknown. We aimed to determine whether apelin modulates gastric vagal afferent signalling under different states of nutrition. Female C57BL/6 mice were fed either a standard laboratory diet (SLD) or a high fat diet (HFD) for 12 weeks. An in vitro gastric vagal afferent preparation was used to determine the effect of apelin on gastric vagal afferent mechanosensitivity in SLD mice, fed ad libitum or fasted overnight, and HFD mice. To determine the signalling pathway of apelin via gastric vagal afferents, we determined the expression of apelin receptor (APJ receptor) in the gastric mucosa, the whole nodose ganglion and in gastric vagal afferent neurons innervating the stomach using retrograde tracing and real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The location of apelin and APJ receptor within the gastric mucosa was determined by immunohistochemistry. Expression of apelin and APJ receptor mRNA in gastric mucosa was determined using qRT-PCR. Apelin inhibited the response of gastric mucosal vagal afferents to mucosal stroking in fasted SLD mice, but not in mice fed ad libitum a SLD or HFD. Apelin inhibited the response of gastric tension sensitive afferents to circular stretch in SLD mice fed ad libitum or fasted, an effect not observed in HFD mice. APJ receptor mRNA was detected in the gastric mucosa and whole nodose ganglion, but not specifically in gastric vagal afferents neurons. In the gastric mucosa, APJ receptor immunoreactive cells were co-localised or closely associated with apelin containing cells and co-localised with serotonin, gastrin, histamine and gastric intrinsic factor containing cells. In conclusion, apelin modulates gastric vagal afferent signalling in a nutritional status dependent manner. Further, apelin modulates gastric vagal afferents through an indirect pathway, possibly through the release of hormones/peptides from the gastric mucosa.


Assuntos
Apelina/fisiologia , Mecanotransdução Celular/fisiologia , Nervo Vago/fisiologia , Animais , Apelina/metabolismo , Receptores de Apelina/biossíntese , Dieta Hiperlipídica , Feminino , Polipeptídeo Inibidor Gástrico/metabolismo , Mucosa Gástrica/metabolismo , Gastrinas/metabolismo , Histamina/metabolismo , Camundongos , Neurônios Aferentes/metabolismo , Gânglio Nodoso/metabolismo , Serotonina/metabolismo , Nervo Vago/metabolismo
11.
J Exp Clin Cancer Res ; 37(1): 115, 2018 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-29866191

RESUMO

BACKGROUND: To test the hypothesis that activated extracellular signal-regulated kinase (ERK) regulates P65-miR23a/27a/24 axis in gastric cancer (GC) and the ERK-P65-miR23a/27a/24 axis plays an important role in the development of GC, and to evaluate the role of gastrin in GC progression and ERK-P65-miR23a/27a/24 axis. METHODS: The component levels of the ERK-P65-miR23a/27a/24 axis in four fresh GC tissues, 101 paraffin-embedded GC tissues and four GC cell lines were determined by Western blotting, immunohistochemistry (IHC) or qRT-PCR. The effects of gastrin on GC were first evaluated by measuring gastrin serum levels in 30 healthy and 70 GC patients and performing a correlation analysis between gastrin levels and survival time in 27 GC patients after eight years of follow-up, then evaluated on GC cell lines, GC cell xenograft models, and patient-derived xenografts (PDX) mouse models. The roles of ERK-P65-miR23a/27a/24 axis in GC progression and in the effects of gastrin on GC were examined. RESULTS: ERK- P65-miR23a/27a/24 axis was proved to be present in GC cells. The levels of components of ERK-P65-miR23a/27a/24 axis were decreased in GC tissue samples and PGC cells. The decreased levels of components of ERK-P65-miR23a/27a/24 axis were associated with poor prognosis of GC, and ERK-P65-miR23a/27a/24 axis played a suppressive role in GC progression. Low blood gastrin was correlated with poor prognosis of the GC patients and decreased expression of p-ERK and p-P65 in GC tissues. Gastrin inhibited proliferation of poorly-differentiated GC (PGC) cells through activating the ERK-P65-miR23a/27a/24 axis. Gastrin inhibited GC growth and enhanced the suppression of GC by cisplatin in mice or PGC cell culture models through activating the ERK-P65-miR23a/27a/24 axis or its components. CONCLUSIONS: ERK-P65-miR23a/27a/24 axis is down-regulated, leading to excess GC growth and poor prognosis of GC. Low gastrin promoted excess GC growth and contributed to the poor prognosis of the GC patients by down-regulating ERK-P65-miR23a/27a/24 axis. Gastrin inhibits gastric cancer growth through activating the ERK-P65-miR23a/27a/24 axis.


Assuntos
MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Gastrinas/metabolismo , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Fator de Transcrição RelA/metabolismo , Animais , Linhagem Celular Tumoral , Cisplatino/farmacologia , Modelos Animais de Doenças , Progressão da Doença , Feminino , Expressão Gênica , Genes Reporter , Xenoenxertos , Humanos , Camundongos , Interferência de RNA , Transdução de Sinais , Neoplasias Gástricas/patologia
12.
Eur J Pharmacol ; 833: 357-363, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-29920282

RESUMO

The gastrointestinal hormone cholecystokinin (CCK) regulates digestive processes and satiety in addition to centrally mediated effects on nociception and anxiety. CCK signals through two seven-trans-membrane receptors named the CCK-1 receptor and the CCK-2 receptor. The expression pattern and biological effects mediated by the CCK-1 and CCK-2 receptors are highly divergent. The pig is a widely used preclinical animal model in medical research, but up until recently, the porcine CCK-2 receptor was described as a pseudogene in the publicly available genomic sequence databases. Thus, it was challenging to interpret data from this animal model in studies of CCK biology and pharmacology. Here we describe an in silico prediction of the porcine CCK-2 receptor and the subsequent cloning, expression, and in vitro pharmacological characterization. We find a high degree of sequence homology with the human orthologue as well as CCK-2 receptors of other major species used in pre-clinical research. We also show that the endogenous ligands CCK-8 and Gastrin-17 bind and activate the porcine CCK-2 receptor with similar affinities and potencies as seen for the human CCK-2 receptor. We conclude that the pig has a functional CCK-2 receptor which is highly comparable to the human orthologue and therefore the pig qualifies as a valid preclinical model for the study of human CCK biology and pharmacology.


Assuntos
Colecistocinina/fisiologia , Modelos Animais , Receptor de Colecistocinina B/metabolismo , Suínos , Animais , Células COS , Colecistocinina/agonistas , Biologia Computacional , Simulação por Computador , Feminino , Gastrinas/metabolismo , Estrutura Secundária de Proteína , Receptor de Colecistocinina B/agonistas , Receptor de Colecistocinina B/genética , Receptor de Colecistocinina B/isolamento & purificação , Homologia de Sequência de Aminoácidos , Sincalida/metabolismo
13.
Theranostics ; 8(11): 2896-2908, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29896292

RESUMO

Minigastrin (MG) analogs show high affinity to the cholecystokinin-2 receptor (CCK2R) and have therefore been intensively studied to find a suitable analog for imaging and treatment of CCK2R-expressing tumors. The clinical translation of the radioligands developed thus far has been hampered by high kidney uptake or low enzymatic stability. In this study, we aimed to develop new MG analogs with improved targeting properties stabilized against degradation through site-specific amino acid modifications. Method: Based on the lead structure of a truncated MG analog, four new MG derivatives with substitutions in the C-terminal part of the peptide (Trp-Met-Asp-Phe-NH2) were synthesized and derivatized with DOTA at the N-terminus for radiolabeling with trivalent radiometals. The in vitro properties of the new analogs were characterized by analyzing the lipophilicity, the protein binding, and the stability of the Indium-111 (111In)-labeled analogs in different media. Two different cell lines, AR42J cells physiologically expressing the rat CCK2R and A431 cells transfected with human CCK2R (A431-CCK2R), were used to study the receptor affinity and cell uptake. For the two most promising MG analogs, metabolic studies in normal BALB/c mice were carried out as well as biodistribution and imaging studies in tumor xenografted athymic BALB/c nude mice. Results: Two out of four synthesized peptide analogs (DOTA-MGS1 and DOTA-MGS4) showed retained receptor affinity and cell uptake when radiolabeled with 111In. These two peptide analogs, however, showed a different stability against enzymatic degradation in vitro and in vivo. When injected to normal BALB/c mice, for 111In-DOTA-MGS1 at 10 min post injection (p.i.) no intact radiopeptide was found in the blood, whereas for 111In-DOTA-MGS4 more than 75% was still intact. 111In-DOTA-MGS4 showed a clear increase in injected activity per gram tissue (IA/g) for A431-CCK2R xenografts (10.40±2.21% IA/g 4 h p.i.) when compared to 111In-DOTA-MGS1 (1.23±0.15% IA/g 4 h p.i.). The tumor uptake of 111In-DOTA-MGS4 was also combined with a low uptake in stomach and kidney leading to high-contrast NanoSPECT/CT images. Conclusion: Of the four new MG analogs developed, the best results in terms of enzymatic stability and increased tumor targeting were obtained with 111In-DOTA-MGS4 showing two substitutions with N-methylated amino acids. 111In-DOTA-MGS4 was also superior to other MG analogs reported thus far and seems therefore an extremely promising targeting molecule for theranostic use with alternative radiometals.


Assuntos
Gastrinas/química , Neoplasias/diagnóstico por imagem , Peptídeos/química , Receptor de Colecistocinina B/metabolismo , Substituição de Aminoácidos , Animais , Linhagem Celular Tumoral , Feminino , Gastrinas/metabolismo , Gastrinas/farmacocinética , Humanos , Radioisótopos de Índio , Marcação por Isótopo , Masculino , Taxa de Depuração Metabólica , Camundongos , Camundongos Endogâmicos BALB C , Imagem Molecular , Neoplasias/metabolismo , Peptídeos/metabolismo , Peptídeos/farmacocinética , Ligação Proteica , Estabilidade Proteica , Ratos , Distribuição Tecidual
14.
Artif Cells Nanomed Biotechnol ; 46(sup2): 1082-1090, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29886758

RESUMO

Glycine-extended gastrin 17 (G17-Gly), a dominant processing intermediate of gastrin gene, has been implicated in the development or maintenance of colorectal cancers (CRCs). Hence, neutralizing G17-Gly activity by antibody entities can provide a potential therapeutic strategy in the patients with CRCs. To this end, we isolated fully human antibody fragments from a phage antibody library through biopanning against different epitopes of G17-Gly in order to obtain the highest possible antibody diversity. ELISA screening and sequence analysis identified 2 scFvs and 4 VL antibody fragments. Kinetic analysis of the antibody fragments by SPR revealed KD values to be in the nanomolar range (87.9-334 nM). The selected anti-G17-Gly antibody fragments were analyzed for growth inhibition and apoptotic assays in a CRC cell line, HCT-116, which is well-characterized for expressing gastrin intermediate species but not amidated gastrin. The antibody fragments exhibited significant inhibition of HCT-116 cells proliferation ranging from 36.5 to 73% of controls. Further, Annexin V/PI staining indicated that apoptosis rates of scFv H8 and VL G8 treated cells were 45.8 and 63%, respectively. Based on these results, we for the first time, demonstrated the isolation of anti-G17-Gly human scFv and VL antibodies with potential therapeutic applications in G17-Gly-responsive tumors.


Assuntos
Neoplasias Colorretais/patologia , Gastrinas/imunologia , Biblioteca de Peptídeos , Anticorpos de Cadeia Única/imunologia , Proliferação de Células/efeitos dos fármacos , Gastrinas/metabolismo , Células HCT116 , Humanos
15.
Gen Comp Endocrinol ; 267: 1-8, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29782837

RESUMO

In rodents and humans, aromatic amino acids increase gut hormone secretion and H+-K+-ATPase activity by modulating calcium-sensing receptor (CaSR). However, the role of CaSR and its related signaling molecules in amino acid-induced gut hormone secretion in swine has not been investigated. Here, we examined whether a CaSR-dependent pathway modulated gastrin and somatostatin (SS) secretion and H+-K+-ATPase activity in pigs. Perfusion of pig stomach tissues in the presence of extracellular 80 mM l-phenylalanine (Phe) or 20 mM l-tryptophan (Trp) and a CaSR agonist cinacalcet triggered gastrin and SS secretion and H+-K+-ATPase activity (P < 0.05) and increased CaSR expression (P < 0.05). This effect of Phe and Trp was dependent on Ca2+ (P < 0.05) and was abolished after treatment with NPS 2143, an inhibitor of CaSR, and 2-aminoethyl diphenyl borinate, an inhibitor of CaSR downstream signaling molecule inositol 1,4,5-triphosphate receptor (IP3R). These findings indicate that Phe and Trp induce Ca2+-dependent gastrin and SS secretion and H+-K+-ATPase activity through CaSR and its downstream signaling molecule IP3R.


Assuntos
Gastrinas/metabolismo , ATPase Trocadora de Hidrogênio-Potássio/metabolismo , Fenilalanina/metabolismo , Receptores de Detecção de Cálcio/metabolismo , Somatostatina/metabolismo , Triptofano/metabolismo , Animais , Estimulantes do Sistema Nervoso Central , Humanos , Suínos
16.
Acta Paediatr ; 107(6): 967-974, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29385274

RESUMO

AIM: This study investigated the effect of time post-ingestion on gastric digestion and gastric hormones after feeding preterm infants unfortified and fortified human milk. METHODS: Human milk and infant gastric samples were collected from 14 preterm (23-32 weeks birth gestational age) mother-infant pairs within 7-98 days postnatal age. Gastric samples were collected one, two and three hours after beginning of feeding. Samples were analysed for pH, proteolysis, general protease activity and the concentrations of pepsin, gastrin and gastrin-releasing peptide (GRP). One-way ANOVA with repeated measures followed by Tukey's multiple comparisons test was used. RESULTS: Gastric pH was significantly decreased after each hour in the preterm infant stomach from one to three hours postprandial. Proteolysis increased significantly from human milk to gastric contents at one, two and three hours postprandial (by 62, 131% and 181%, p < 0.05). General protease activity increased significantly by 58% from human milk to the gastric contents at two hours postprandial. GRP was present in human milk, whereas gastrin was produced in the infant stomach. CONCLUSION: Although preterm infants may digest human milk proteins to a lesser extent than term infants, we demonstrated that the preterm infant stomach actively degrades milk proteins with increasing breakdown over digestion time.


Assuntos
Digestão , Mucosa Gástrica/metabolismo , Recém-Nascido Prematuro/metabolismo , Proteínas do Leite/metabolismo , Feminino , Peptídeo Liberador de Gastrina/metabolismo , Gastrinas/metabolismo , Conteúdo Gastrointestinal/química , Humanos , Concentração de Íons de Hidrogênio , Recém-Nascido , Masculino , Pepsina A/metabolismo , Proteólise
17.
Pancreas ; 47(2): 190-199, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29329158

RESUMO

OBJECTIVES: Modulation of cholecystokinin (CCK) receptors has been shown to influence pancreatic endocrine function. METHODS: We assessed the impact of the CCKA and CCKB receptor modulators, (pGlu-Gln)-CCK-8 and gastrin-17, respectively, on ß-cell secretory function, proliferation and apoptosis and glucose tolerance, and investigating alterations of CCK and gastrin islet expression in diabetes. RESULTS: Initially, the presence of CCK and gastrin, and expression of their receptors were evidenced in ß-cell lines and mouse islets. (pGlu-Gln)-CCK-8 and gastrin-17 stimulated insulin secretion from BRIN-BD11 and 1.1B4 ß-cells, associated with no effect on membrane potential or [Ca]i. Only (pGlu-Gln)-CCK-8 possessed insulin secretory actions in isolated islets. In agreement, (pGlu-Gln)-CCK-8 improved glucose disposal and glucose-induced insulin release in mice. In addition, (pGlu-Gln)-CCK-8 evoked clear satiety effects. Interestingly, islet colocalization of CCK with glucagon was elevated in streptozotocin- and hydrocortisone-induced diabetic mice, whereas gastrin coexpression in α cells was reduced. In contrast, gastrin colocalization within ß-cells was higher in diabetic mice, while CCK coexpression with insulin was decreased in insulin-deficient mice. (pGlu-Gln)-CCK-8 and gastrin-17 also augmented human and rodent ß-cell proliferation and offered protection against streptozotocin-induced ß-cell cytotoxicity. CONCLUSIONS: We highlight the direct involvement of CCKA and CCKB receptors in pancreatic ß-cell function and survival.


Assuntos
Gastrinas/farmacologia , Células Secretoras de Insulina/efeitos dos fármacos , Insulina/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Animais , Glicemia/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Colecistocinina/genética , Colecistocinina/metabolismo , Colecistocinina/farmacologia , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/metabolismo , Gastrinas/genética , Gastrinas/metabolismo , Glucose/farmacologia , Humanos , Secreção de Insulina , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/farmacologia , Peptídeos/genética , Peptídeos/metabolismo , Peptídeos/farmacologia
18.
Gen Comp Endocrinol ; 255: 64-70, 2018 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-29061367

RESUMO

The related peptide hormones cholecystokinin (CCK) and gastrin are conserved throughout vertebrate clades and implicated in energy homeostasis. CCK is generally accepted as a satiety hormone in poultry, but the role of gastrin remains poorly studied. Functional dissection of these ligands is required to characterise the molecular control of growth & satiety in the domestic chicken, for which there is an increasingly pressing mandate. There are limited descriptions of physiological distributions for the two genes in birds, and these are mostly reliant on immunohistochemistry which can prove problematic due to the shared structure of the targets. Therefore, we have defined the tissue distributions of CCK and gastrin in the chicken, focussing on the gastrointestinal tract, by using transcript-dependent techniques to improve reliability by increasing specificity. Though considerably more highly expressed in the brain, gastrointestinal CCK transcripts were dispersed throughout the small intestine and particularly around the proximal ileum. Gastrin expression was strictly limited to the gastric antrum region of the intestinal tract, albeit very highly expressed. We demonstrate that CCK mRNA expression does not respond as expected for a short-term satiety hormone, and that the short-term response of gastrin expression is paradoxical compared to its role in mammals. These results partially corroborate previous peptide distribution studies and initiate exploration of the nutrient-responsive roles of these hormones in avian energy balance.


Assuntos
Galinhas/genética , Colecistocinina/genética , Gastrinas/genética , Trato Gastrointestinal/metabolismo , Regulação da Expressão Gênica , Estado Nutricional , Animais , Sequência de Bases , Colecistocinina/metabolismo , Feminino , Gastrinas/metabolismo , Perfilação da Expressão Gênica , Íleo/metabolismo , Masculino , Estado Nutricional/genética , Antro Pilórico/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reprodutibilidade dos Testes
19.
Cell Tissue Res ; 371(2): 251-260, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29264643

RESUMO

G cells in the antrum region of the murine stomach produce gastrin, the central hormone for controlling gastric activities. Secretion of gastrin is induced mainly by protein breakdown products but also by distensions of the stomach wall. Although G cells respond to protein fragments via distinct chemosensory receptor types, the mechanism underlying G cell activation upon distention is entirely ambiguous. Mechanosensitive ion channels are considered as potential candidates for such a task. Therefore, we explore the possibility of whether Piezo1, a polymodal sensor for diverse mechanical forces, is expressed in antral G cells. The experimental analyses revealed that the vast majority of G cells indeed expressed Piezo1. Within flask-like G cells at the base of the antral invaginations, the Piezo1 protein was primarily located at the basolateral portion, which is thought to be the release site for the exocytic secretion of gastrin. In the spindle-like G cells, which are oriented parallel to the invaginations, Piezo1 protein was restricted to the cell body where the hormone was also located, whereas the long processes appeared to be devoid of Piezo1 protein. Our results suggest that mechanosensitive channels such as Piezo1, located in close proximity to hormone-release sites, enable G cells to respond directly to antrum distensions with gastrin secretion.


Assuntos
Células Secretoras de Gastrina/metabolismo , Canais Iônicos/metabolismo , Estômago/citologia , Animais , Gastrinas/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Canais Iônicos/genética , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Ribossômicas/metabolismo
20.
Gastroenterology ; 153(6): 1555-1567.e15, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28859856

RESUMO

BACKGROUND & AIMS: The multiple endocrine neoplasia, type 1 (MEN1) locus encodes the nuclear protein and tumor suppressor menin. MEN1 mutations frequently cause neuroendocrine tumors such as gastrinomas, characterized by their predominant duodenal location and local metastasis at time of diagnosis. Diffuse gastrin cell hyperplasia precedes the appearance of MEN1 gastrinomas, which develop within submucosal Brunner's glands. We investigated how menin regulates expression of the gastrin gene and induces generation of submucosal gastrin-expressing cell hyperplasia. METHODS: Primary enteric glial cultures were generated from the VillinCre:Men1FL/FL:Sst-/- mice or C57BL/6 mice (controls), with or without inhibition of gastric acid by omeprazole. Primary enteric glial cells from C57BL/6 mice were incubated with gastrin and separated into nuclear and cytoplasmic fractions. Cells were incubated with forskolin and H89 to activate or inhibit protein kinase A (a family of enzymes whose activity depends on cellular levels of cyclic AMP). Gastrin was measured in blood, tissue, and cell cultures using an ELISA. Immunoprecipitation with menin or ubiquitin was used to demonstrate post-translational modification of menin. Primary glial cells were incubated with leptomycin b and MG132 to block nuclear export and proteasome activity, respectively. We obtained human duodenal, lymph node, and pancreatic gastrinoma samples, collected from patients who underwent surgery from 1996 through 2007 in the United States or the United Kingdom. RESULTS: Enteric glial cells that stained positive for glial fibrillary acidic protein (GFAP+) expressed gastrin de novo through a mechanism that required PKA. Gastrin-induced nuclear export of menin via cholecystokinin B receptor (CCKBR)-mediated activation of PKA. Once exported from the nucleus, menin was ubiquitinated and degraded by the proteasome. GFAP and other markers of enteric glial cells (eg, p75 and S100B), colocalized with gastrin in human duodenal gastrinomas. CONCLUSIONS: MEN1-associated gastrinomas, which develop in the submucosa, might arise from enteric glial cells through hormone-dependent PKA signaling. This pathway disrupts nuclear menin function, leading to hypergastrinemia and associated sequelae.


Assuntos
Duodeno/metabolismo , Gastrinas/metabolismo , Neuroglia/enzimologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Neoplasias Duodenais/enzimologia , Neoplasias Duodenais/genética , Neoplasias Duodenais/patologia , Duodeno/efeitos dos fármacos , Duodeno/patologia , Gastrinoma/enzimologia , Gastrinoma/genética , Gastrinoma/patologia , Gastrinas/genética , Regulação da Expressão Gênica , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Hiperplasia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neuroglia/efeitos dos fármacos , Inibidores de Proteassoma/farmacologia , Proteólise , Proteínas Proto-Oncogênicas/genética , Inibidores da Bomba de Prótons/farmacologia , Receptor de Colecistocinina B/metabolismo , Receptores de Somatostatina/genética , Receptores de Somatostatina/metabolismo , Fatores de Tempo , Ubiquitinação
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