scholarly journals Sensory Stimuli Directly Acting at the Central Nervous System Regulate Gastric Ghrelin Secretion. An ex Vivo Organ Culture Study

Endocrinology ◽  
2007 ◽  
Vol 148 (8) ◽  
pp. 3998-4006 ◽  
Author(s):  
Luisa M. Seoane ◽  
Omar Al-Massadi ◽  
J. Eduardo Caminos ◽  
Sulay A. Tovar ◽  
Carlos Dieguez ◽  
...  

Ghrelin, a novel gastrointestinal hormone involved in GH regulation, has been postulated as a relevant orexigenic peptide released by splanchnic tissues. Descriptive studies have shown that plasma ghrelin levels increase in states of negative energy balance or fasting, while decreasing in obesity and after feeding. In the present study, a novel organ-culture model of gastric tissue explants obtained from rat donors has been validated for ex vivo experiments. Fasting induced gastric ghrelin release as well as ghrelin mRNA expression that were reflected in plasma. Interestingly, those changes were fully reverted by 15 min of refeeding before stomach extraction. Unexpectedly, when animals were allowed 15 min before explant extraction to see or smell, but not eat, the food (tease feeding), ghrelin secretion was suppressed just like in gastric explants from refed animals. This effect was blocked when the animals were subjected to surgical vagotomy or treated with atropine sulphate. In conclusion, gastric explants were a suitable model for testing ghrelin mechanism of secretion in vitro, and they were found to maintain memory of the previously received signals. Similar to feeding, tease feeding resulted in suppression of ghrelin discharge by explants.

2020 ◽  
Vol 21 (10) ◽  
pp. 3631 ◽  
Author(s):  
Raffaella Boggia ◽  
Federica Turrini ◽  
Alessandra Roggeri ◽  
Guendalina Olivero ◽  
Francesca Cisani ◽  
...  

The immune system and the central nervous system message each other to preserving central homeostasis. Both systems undergo changes during aging that determine central age-related defects. Ellagic acid (EA) is a natural product which is beneficial in both peripheral and central diseases, including aging. We analyzed the impact of the oral administration of a new oral ellagic acid micro-dispersion (EAm), that largely increased the EA solubility, in young and old mice. Oral EAm did not modify animal weight and behavioral skills in young and old mice, but significantly recovered changes in “ex-vivo, in vitro” parameters in old animals. Cortical noradrenaline exocytosis decreased in aged mice. EAm administration did not modify noradrenaline overflow in young animals, but recovered it in old mice. Furthermore, GFAP staining was increased in the cortex of aged mice, while IBA-1 and CD45 immunopositivities were unchanged when compared to young ones. EAm treatment significantly reduced CD45 signal in both young and old cortical lysates; it diminished GFAP immunopositivity in young mice, but failed to affect IBA-1 expression in both young and old animals. Finally, EAm treatment significantly reduced IL1beta expression in old mice. These results suggest that EAm is beneficial to aging and represents a nutraceutical ingredient for elders.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 299 ◽  
Author(s):  
Raanan Gvirtz ◽  
Navit Ogen-Shtern ◽  
Guy Cohen

Several in vitro models that mimic different aspects of local skin inflammation exist. The use of ex vivo human skin organ culture (HSOC) has been reported previously. However, comprehensive evaluation of the cytokine secretory capacity of the system and its kinetics has not been performed. Objective: the aim of the current study was to investigate the levels and secretion pattern of key cytokine from human skin tissue upon lipopolysaccharide (LPS) stimulation. HSOC maintained in an air–liquid interface was used. Epidermal and tissue viability was monitored by MTT and Lactate Dehydrogenase (LDH) activity assay, respectively. Cytokine levels were examined by ELISA and multiplex array. HSOCs were treated without or with three different LPS subtypes and the impact on IL-6 and IL-8 secretion was evaluated. The compounds enhanced the secreted levels of both cytokines. However, differences were observed in their efficacy and potency. Next, a kinetic multiplex analysis was performed on LPS-stimulated explants taken from three different donors to evaluate the cytokine secretion pattern during 0–72 h post-induction. The results revealed that the pro-inflammatory cytokines IL-6, IL-8, TNFα and IL-1β were up-regulated by LPS stimuli. IL-10, an anti-inflammatory cytokine, was also induced by LPS, but exhibited a different secretion pattern, peak time and maximal stimulation values. IL-1α and IL-15 showed donor-specific changes. Lastly, dexamethasone attenuated cytokine secretion in five independent repetitions, supporting the ability of the system to be used for drug screening. The collective results demonstrate that several cytokines can be used as valid inflammatory markers, regardless of changes in the secretion levels due to donor’s specific alterations.


Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2366
Author(s):  
Alba Miguéns-Gómez ◽  
Carme Grau-Bové ◽  
Marta Sierra-Cruz ◽  
Rosa Jorba-Martín ◽  
Aleidis Caro ◽  
...  

In this study we compare the interaction of three protein sources—insect, beef, and almond—with the gastrointestinal tract. We measured the enterohormone secretion ex vivo in human and pig intestine treated with in vitro digestions of these foods. Insect and beef were the most effective in inducing the secretion of CCK, while almond was the most effective in inducing PYY in pig duodenum. In the human colon, almond was also the most effective in inducing PYY, and GLP-1 levels were increased by insect and beef. The three digested proteins reduced ghrelin secretion in pig duodenum, while only insect reduced ghrelin secretion in human colon. We also found that food intake in rats increased in groups fed a raw insect pre-load and decreased when fed raw almond. In conclusion, the insect Alphitobius diaperinus modulates duodenal and colonic enterohormone release and increases food intake in rats. These effects differ from beef and almond.


2020 ◽  
Author(s):  
Mehdi Farokhnia ◽  
Sara L Deschaine ◽  
Adriana Gregory-Flores ◽  
Lia J Zallar ◽  
Zhi-Bing You ◽  
...  

Ghrelin is a gastric-derived peptide hormone with demonstrated impact on alcohol intake and craving, but the reverse side of this bidirectional link, i.e., the effects of alcohol on the ghrelin system, remains to be fully established. To characterize the downstream effects of alcohol on the ghrelin system, we examined the following: (1) plasma ghrelin levels across four human laboratory alcohol administration experiments with non-treatment seeking, heavy-drinking participants, (2) expression of ghrelin, ghrelin receptor, and ghrelin-O-acyltransferase (GOAT) genes (GHRL, GHSR, and MBOAT4, respectively) in human post-mortem brain tissue from individuals with alcohol use disorder (AUD) vs. controls, (3) plasma ghrelin levels in Ghsr knockout and wild-type rats following intraperitoneal (i.p.) ethanol administration, (4) effect of ethanol on ghrelin secretion from gastric mucosa cells ex vivo and GOAT enzymatic activity in vitro, and (5) plasma ghrelin levels in rats following i.p. ethanol administration vs. an iso-caloric sucrose solution. Peripheral acyl- and total ghrelin levels significantly decreased following acute ethanol administration in humans. No difference in GHRL, GHSR, and MBOAT4 mRNA expression in the brain was observed between AUD vs. control post-mortem samples. In rats, acyl-ghrelin levels significantly decreased following i.p. ethanol administration in both genotype groups (Ghsr knockout and wild-type), while des-acyl-ghrelin was not affected by ethanol. No effect of ethanol was observed ex vivo on ghrelin secretion from gastric mucosa cells or in vitro on GOAT acylation activity. Lastly, we observed different effects of i.p. ethanol and sucrose solution on acyl- and des-acyl-ghrelin in rats despite administering amounts with equivalent caloric value. Ethanol acutely decreases peripheral ghrelin concentrations in humans and rats, and our findings suggest that this effect does not occur through interaction with ghrelin-secreting gastric mucosal cells, the ghrelin receptor, or the GOAT enzyme. Moreover, this effect does not appear to be proportional to caloric load. Our findings, therefore, suggest that ethanol does not suppress circulating ghrelin through direct interaction with the ghrelin system, or in proportion to the caloric value of alcohol, and may differentially affect ghrelin acylation and ghrelin peptide secretion.


2021 ◽  
Vol 12 ◽  
Author(s):  
Paul Tetteh Asare ◽  
Anna Greppi ◽  
Alessia Pennacchia ◽  
Katharina Brenig ◽  
Annelies Geirnaert ◽  
...  

Continuous in vitro fermentation models provide a useful tool for a fast, reproducible, and direct assessment of treatment-related changes in microbiota metabolism and composition independent of the host. In this study, we used the PolyFermS model to mimic the conditions of the chicken cecum and evaluated three nutritive media for in vitro modeling of the chicken cecal microbiota ecology and metabolism. We observed that our model inoculated with immobilized cecal microbiota and fed with a modified Viande Levure medium (mVL-3) reached a high bacterial cell density of up to approximately 10.5 log cells per mL and stable microbiota composition, akin to the host, during 82 days of continuous operation. Relevant bacterial functional groups containing primary fibrolytic (Bacteroides, Bifidobacteriaceae, Ruminococcaceae), glycolytic (Enterococcus), mucolytic (Bacteroides), proteolytic (Bacteroides), and secondary acetate-utilizing butyrate-producing and propionate-producing (Lachnospiraceae) taxa were preserved in vitro. Besides, conserved metabolic and functional Kyoto Encyclopedia of Genes and Genomes pathways were observed between in vitro microbiota and cecal inoculum microbiota as predicted by functional metagenomics analysis. Furthermore, we demonstrated that the continuous inoculation provided by the inoculum reactor generated reproducible metabolic profiles in second-stage reactors comparable to the chicken cecum, allowing for the simultaneous investigation and direct comparison of different treatments with a control. In conclusion, we showed that PolyFermS is a suitable model for mimicking chicken cecal microbiota fermentation allowing ethical and ex vivo screening of environmental factors, such as dietary additives, on chicken cecal fermentation. We report here for the first time a fermentation medium (mVL-3) that closely mimics the substrate conditions in the chicken cecum and supports the growth and metabolic activity of the cecal bacterial akin to the host. Our PolyFermS chicken cecum model is a useful tool to study microbiota functionality and structure ex vivo.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Kun Wang ◽  
Qian Wang ◽  
Qinghao Li ◽  
Zhaoqiang Zhang ◽  
Jing Gao ◽  
...  

Glioblastoma is a highly invasive primary malignant tumor of the central nervous system. Cannabinoid analogue WIN 55,212-2 (WIN) exhibited a novel anticancer effect against human tumors. However, the anticancer potential and underlying mechanism of WIN against human glioma remain unclear. Herein, the anticancer efficiency and mechanism of WIN in U251 human glioma cells were investigated. The results showed that WIN dose-dependently inhibited U251 cell proliferation, migration, and invasion in vitro. WIN treatment also effectively suppressed U251 tumor spheroids growth ex vivo. Further studies found that WIN induced significant apoptosis as convinced by the caspase-3 activation and release of cytochrome C. Mechanism investigation revealed that WIN triggered ROS-mediated DNA damage and caused dysfunction of VEGF-AKT/FAK signal axis. However, ROS inhibition effectively attenuated WIN-induced DNA damage and dysfunction of VEGF-AKT/FAK signal axis and eventually improved U251 cell proliferation, migration, and invasion. Taken together, our findings validated that WIN had the potential to inhibit U251 cell proliferation, migration, and invasion and induce apoptosis by triggering ROS-dependent DNA damage and dysfunction of VEGF-AKT/FAK signal axis.


2007 ◽  
Vol 30 (9) ◽  
pp. RC22-RC25 ◽  
Author(s):  
L. M. Seoane ◽  
O. Al-Massadi ◽  
F. Barreiro ◽  
C. Dieguez ◽  
F.F Casanueva

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Dhriti Chatterjee ◽  
Kaushiki Biswas ◽  
Soma Nag ◽  
S. G. Ramachandra ◽  
Jayasri Das Sarma

Microglia are the resident macrophage-like populations in the central nervous system (CNS). Microglia remain quiescent, unable to perform effector and antigen presentation (APC) functions until activated by injury or infection, and have been suggested to represent the first line of defence for the CNS. Previous studies demonstrated that microglia can be persistently infected by neurotropic mouse hepatitis virus (MHV) which causes meningoencephalitis, myelitis with subsequent axonal loss, and demyelination and serve as a virus-induced model of human neurological disease multiple sclerosis (MS). Current studies revealed that MHV infection is associated with the pronounced activation of microglia during acute inflammation, as evidenced by characteristic changes in cellular morphology and increased expression of microglia-specific proteins, Iba1 (ionized calcium-binding adaptor molecule 1), which is a macrophage/microglia-specific novel calcium-binding protein and involved in membrane ruffling and phagocytosis. During chronic inflammation (day 30 postinfection), microglia were still present within areas of demyelination. Experiments performed inex vivospinal cord slice culture andin vitroneonatal microglial culture confirmed direct microglial infection. Our results suggest that MHV can directly infect and activate microglia during acute inflammation, which in turn during chronic inflammation stage causes phagocytosis of myelin sheath leading to chronic inflammatory demyelination.


2009 ◽  
Vol 206 (8) ◽  
pp. 1653-1660 ◽  
Author(s):  
Elizabeth C. Nowak ◽  
Casey T. Weaver ◽  
Henrietta Turner ◽  
Sakhina Begum-Haque ◽  
Burkhard Becher ◽  
...  

We report that like other T cells cultured in the presence of transforming growth factor (TGF) β, Th17 cells also produce interleukin (IL) 9. Th17 cells generated in vitro with IL-6 and TGF-β as well as purified ex vivo Th17 cells both produced IL-9. To determine if IL-9 has functional consequences in Th17-mediated inflammatory disease, we evaluated the role of IL-9 in the development and progression of experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis. The data show that IL-9 neutralization and IL-9 receptor deficiency attenuates disease, and this correlates with decreases in Th17 cells and IL-6–producing macrophages in the central nervous system, as well as mast cell numbers in the regional lymph nodes. Collectively, these data implicate IL-9 as a Th17-derived cytokine that can contribute to inflammatory disease.


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