• Archives of Pharmacal Research
• /
• v.19 no.3
• /
• pp.201-206
• /
• 1996

Nitric oxide (NO) is thought to be a second messenger involved in secretion. Upon stimulating pancreatic acinar cells with cholecystokinin-pancreozymin (CCK-PZ), NO formation has been shown to be associated with increased levels of cGMP (Seo et al., 1995). To elucidate the signaling pathway of VIP-induced enzyme secretion, we investigated the NO and cGMP synthesis steps as potential steps where two signal pathways triggered by CCK-PZ and VIP interact. The results obtained in this work provide evidence that increase in pancreatic enzyme secretion by treatment with VIP has no relationship with NOS activity and cGMP level. This conclusion was derived from the following findings that VIP treatment of rat pancreatic tissue increased amylase release as well as protein output in a dose- and time-dependent manner, whereas NOS activity and cGMP synthesis were not affected by VIP treatment as monitored by NOS activity assay and determining cGMP level, which was further confirmed by a NOS-inhibitor study. Consequently, CCK-PZ or VIP increases enzyme secretion in rat pancreatic tissue, but the two hormones are different in their mode of action. Together the results suggest that signaling pathway of VIP-induced enzyme secretion might either bypass the NO and cGMP synthesis steps or lie on a distinct pathway from CCK-PZ-induced pathway.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.21 no.3
• /
• pp.82-93
• /
• 2008

Objective: Previously, the methanol extracts of the semen of Xanthium strumsrium could involved anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated Raw 264,7 cells, We evaluated the anti-allergic effects of X. strumarium on rat basophilic leukemia (RBL-2H3) cells, Methodes : To investigate the effect of X. strumarium on the phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187-induced RBL-2H3 cells. The effects of X. strumarium on the degranulation and the pro-inflammatory cytokines secretion and expression from RBL-2H3 cells were evaluated with $\beta$-hexosaminidase assay, ELISA, and RT-PCR analysis, In addition, we examined the effects of X. strumarium on nuclear factor (NF)-${\kappa}B$ activation and $I{\kappa}B-\alpha$ degradation using Western blot analysis. Results : X. strumarium inhibited degranulation and secretions and expressions of pro-inflammatory cytokines, such as tumor necrosis factor-alpha ($TNF-\alpha$), interleukin (IL)-4 and cyclooxygenase (COX)-2, on stimulated RBL-2H3 cells, however, X. strumarium not affect cell viability. In stimulated RBL-2H3 cells, the protein expression level of nuclear factor-kappa B (NF-${\kappa}B$) was decreased in the nucleus by X. strumarium. In addition, X. strumarium suppressed the degradation of inhibitory protein $I{\kappa}B-{\alpha}$ protein in RBL-2H3 cells. Conclusion : These results suggest that X. strumarium inhibits the degranulation and secretion of pro-inflammatory cytokines through blockade of NF-${\kappa}B$ activation and I $I{\kappa}B-{\alpha}$ degradation.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.3
• /
• pp.379-384
• /
• 2010

The principal objective of this experiment was to determine the effects of dietary betaine on IGF-I, IGFBP-3 and IGFBP-1 secretion and IGF-I mRNA gene expression in the serum and liver of laying hens. A total of 72 ISA-Brown laying hens were fed with four different levels of betaine (0, 300, 600, 1,200 ppm) based on a corn-soybean meal diet containing 2,800 kcal/kg of metabolizable energy (ME) and 16% crude protein (CP) for four weeks. The results indicated significantly higher serum and liver IGF-I concentrations in the laying hens fed with 600 and 1,200 ppm betaine (p<0.05) compared to controls. IGF-I gene expression in liver showed a statistically correlated increase in 600 and 1,200 ppm betaine-fed groups as compared to the controls (p<0.05). Serum IGFBP-3 concentrations were elevated significantly in the groups fed 600 ppm of betaine. However, the secretion of IGFBP-1 in the liver of laying hens fed on 600 and 1,200 ppm of betaine was significantly lower than in the controls (p<0.05). The results of this experiment showed that dietary betaine supplementation plays a pivotal role in changes of the IGFs system in laying hens.

• YAKHAK HOEJI
• /
• v.51 no.4
• /
• pp.264-269
• /
• 2007

Alzheimer’s disease (AD) is characterized pathologically by the presence of intracellular neurofibrillary tangles and deposition of ${\beta}-amyloid $ (A ${\beta}$) peptides, which are generated by processing of amyloid precursor protein (APP). It is urgent to develop effective therapies for the treatment of AD, since our society rapidly accelerate aging. A${\beta}$ peptides have been believed to be neurotoxic and now are also considered to have effects on the mechanism of memory formation. In this study, effects of radicicol on the metabolism of APP were analyzed. Radicicol inhibited the secretion of A${\beta}$ from the Neuro2a cell line (APPswe cell) expressing APPswe. Beta-site APP cleaving enzyme (BACE) fluorescence resonance energy transfer (FRET) assay revealed that it inhibited BACE activity in a dose dependently manner. Immunoblotting study showed that it inhibited intracellular heat shock protein (HSP)90 and it increased the secretion of HSP90 from the APPswe cells. We suggest that radicicol inhibits APP metabolism and Ap generation by the means of HSP90 inhibitory mechanism and partially BACE inhibitory mechanism. This is the first report that radicicol inhibits the secretion of A${\beta}$ peptides from neuroblastoma cells.

• The Korean Journal of Zoology
• /
• v.39 no.3
• /
• pp.266-272
• /
• 1996

Experiments were carried out to ascertain whether gonadotropin or a phorbol ester (12-O-tetradecanoyl phorbol-13-acetate, TPA) induces oocyte ovulation and stimulates prostaglandin synthesis by Rana ovarian follicles in vitro. Rana nigromaculata collected from underground in spring were utilized for the present experiment. Treatment of frog pituitary homogenate (FPH) or TPA to ovarian fragments in culture induced oocyte ovulation in a dose dependent manner and stimulated prostaglandin F2a (PGF$_2$$\alpha$ synthesis. Both treatruents were more effective in inducing the ovulation and PGF$_2$$\alpha$ secretion by the follicles obtained in May than those in April. A Protein kinase C inactivator, 1-(5-isoquinolinyl-sulfonyl)-2-methyl-piperazine (H-7), or cyclooxygenase inhibitor, indomethacin (IM) suppressed the FPH- or TPA-induced PGF$_2$$\alpha$ production, but IM failed to suppress the FPH- or TPA-induced ovulation. Time course of oocyte ovulation and PGF$_2$$\alpha$ secretion by FPH and TPA treatments were very similar to each other. FPH stimulated progesterone secretion by the follicle but TPA failed to do so. Taken together, the data presented here suggest that protein kinase C (PKC) in follicle play a role in the ovulation process of Rana nigromaculata, probably via prostaglandin synthesis.

• IMMUNE NETWORK
• /
• v.3 no.3
• /
• pp.182-187
• /
• 2003

Background: The mushroom Phellinus linteus (PL) has been shown to have the anti-tumor and immunostimulatory effects. We hypothesized that the hot water extract of PL (WEPL) exerts its significant immunostimulatory effect by inducing production of the Th1-derived cytokine interferon-${\gamma}$ (IFN-${\gamma}$) by T lymphocytes. Methods: T lymphocytes were isolated from the mice fed with 200 mg/kg of WEPL once a day for 4 weeks, and then stimulated with the mitogen concanavaline A (Con A). IFN-${\gamma}$ gene and intracellular protein expressions were analyzed by RT-PCR and flow cytometry, respectively. The production of IFN-${\gamma}$ was measured by enzyme-linked immunosorbent assay. Results: WEPL significantly enhanced the transcription of IFN-${\gamma}$ mRNA. The effect of WEPL on IFN-${\gamma}$ expression was further supported by a concomitant increase in the number of cells with intracellular IFN-${\gamma}$ protein as well as the secretion of IFN-${\gamma}$. However, WEPL did not modulate either gene expression or protein secretion of interleukin-4, a Th2-associated cytokine, by Con A-stimulated T lymphocytes. Conclusion: Our results demonstrate that one of the potentially beneficial anti-tumor and immunostimulatory effects of WEPL may be mediated through the enhancement of IFN-${\gamma}$ secretion by T lymphocytes.

• BMB Reports
• /
• v.51 no.10
• /
• pp.538-543
• /
• 2018

Pancreatic beta cell destruction and dysfunction induced by cytokines is a major cause of type 1 diabetes. Paraoxonase 1 (PON1), an arylesterase with antioxidant activity, has been shown to play an important role in preventing the development of diabetes in transgenic mice. However, no studies have examined the anti-diabetic effect of PON1 delivered to beta cells using protein transduction. In this study, we expressed the cell-permeable PON1 fused with PEP-1 protein transduction domain (PEP-1-PON1) to investigate whether transduced PEP-1-PON1 protects beta cells against cytokine-induced cytotoxicity. PEP-1-PON1 was effectively delivered to INS-1 cells and prevented cytokine-induced cell destruction in a dose-dependent manner. Transduced PEP-1-PON1 significantly reduced the levels of reactive oxygen species (ROS) and nitric oxide (NO), DNA fragmentation, and expression of inflammatory mediators, endoplasmic reticulum (ER) stress proteins, and apoptosis-related proteins in cytokine-treated cells. Moreover, transduced PEP-1-PON1 restored the decrease in basal and glucose-stimulated insulin secretion induced by cytokines. These data indicate that PEP-1-PON1 protects beta cells from cytokine-induced cytotoxicity by alleviating oxidative/nitrosative stress, ER stress, and inflammation. Thus, PEP-1-mediated PON1 transduction might be an effective method to reduce the extent of destruction and dysfunction of pancreatic beta cells in autoimmune diabetes.

• The Korean Journal of Physiology and Pharmacology
• /
• v.4 no.2
• /
• pp.129-135
• /
• 2000

Previously, we have reported that ${\rho}-chlorophenylalanine$ (PCPA), a serotonin depletor, profoundly increased pancreatic fluid and bicarbonate secretion but remarkably inhibited pancreatic amylase secretion in anesthetized rats. The present study was performed to verify the detailed effects of PCPA on pancreatic amylase synthesis that is directly related to amylase exocrine secretion. PCPA significantly decreased pancreatic RNA and protein contents as well as the amylase activity. However, pancreatic DNA content, trypsin and chymotrypsin activities were not influenced by the treatment of PCPA. The rate of pancreatic amylase synthesis, which was assessed by the amount of incorporated $[^{35}S]-methionine$ into amylase for 1 h, was also significantly decreased by 44% in PCPA-treated rats. In order to determine whether the PCPA-induced decrease of amylase synthesis resulted from change in the level of amylase mRNA, Northern blot analysis was performed. The mRNA expression level of amylase was also decreased by 48% in the PCPA-treated rats, indicating that the inhibitory effect of PCPA on the synthesis of pancreatic amylase was mainly regulated at a step prior to translation. It was also revealed in SDS-polyacrylamide gel electrophoresis that the qualitative change of amylase was induced by PCPA. The 54 KDa amylase band seems to be degraded into small molecular weight protein bands in PCPA-treated rats, suggesting that the PCPA- induced decrease of amylase may be partly attributed to the degradation of synthesized amylase.

• Journal of Nutrition and Health
• /
• v.55 no.2
• /
• pp.240-249
• /
• 2022

Purpose: Glabridin (GD) is a bio-available isoflavane isolated from the root extract of licorice (Glycyrrhiza glabra L.). It exhibits a variety of pharmacological activities such as anti-inflammatory and anti-oxidant activities. However, extracellular vesicles (EVs) secretion and the anti-cancer mechanism of action remains largely unknown. The present study investigates the anticancer effects of GD by determining the inhibition of EVs secretion in the human breast cancer cell line, MDA-MB-231. Methods: Cell viability, reactive oxygen species (ROS) production, migration, invasion rate, and vascular endothelial growth factor (VEGF) concentration were assessed in MDA-MB-231 cells treated with increasing concentrations of GD (0.1, 1, 5, 10, 20 µM). Subsequently, EV secretion and exosomal DEL-1 protein expression were evaluated to determine the anticancer effects of GD. Results: The results showed that GD significantly inhibited the cell proliferation of MDA-MB-231 cells in a dose- or time-dependent manner. Also, ROS production and apoptosis marker protein cleaved caspase-3 were significantly increased in GD-treated MDA-MB-231, compared to control. Furthermore, GD exposure resulted in significantly decreased not only migration and invasion rates but also the VEGF concentration, thereby contributing to a reduction in angiogenesis. Interestingly, the concentration and number of EVs as well as EV marker proteins, such as CD63 and TSG101, were decreased in GD-treated MDA-MB-231 cells. Markedly, extracellular matrix protein DEL-1 as angiogenesis factor was decreased in EVs from GD-treated MDA-MB-231 cells. Conclusion: This study identifies that the anti-cancer molecular mechanism of GD is exerted via inhibition of angiogenesis and EVs secretion, indicating the potential of GD as a chemotherapeutic agent for breast cancer.

• The Korean Journal of Food And Nutrition
• /
• v.6 no.3
• /
• pp.219-230
• /
• 1993

This research aims to study the changes In gastrointestinal function attributed to aging In human. The thresholds for recognition and detection of flavors became elevated and salivary gland acinar cells decreased in the old age. But most esophageal function remained relatively Intact. Although gastric emptying time has been slowed with aging, the total intestinal transit time did not differ. Atropic gastritis due to H. pylori in old man decreased secretion of acid and Intrinsic factor and absorbability of calcium and iron. Pancreatic secretion is droned in older persons. Prevalence of gallstones rised with age. Liver size and portal blood flow decreased significantly with age. Mucosal surface area has been reported to be slightly diminished in the aging man. Glucose transporters decreased and Insulin tolerance Increased. Absorption of aromatic amino acid is diminished with age. Dietary protein In that aging human increased fecal nitrogen excretion. Vitamin A tolerance increased. Vitamin D receptor concentration decreased and resistance to 1,25-(OH)2D3 action increased. Permeability of aging small Intestine Increased. Zinc balance dirt not differ Copper absorption appeared not to be significantly affected by age. Neurotensin secretion decreased thus slowed colonic peristaltic movements and Intestinal mucosal growth.