scholarly journals Dietary chitosan affects metabolism of arachidonic acid in weaned piglets

2017 ◽  
Vol 62 (No. 2) ◽  
pp. 58-66 ◽  
Author(s):  
J.-L. Li ◽  
Y.-Q. Xu ◽  
B.-L. Shi ◽  
D.-S. Sun ◽  
S.-M. Yan ◽  
...  

The effects of chitosan on immune function via arachidonic acid (AA) pathway in weaned piglets were investigated. A total of 180 piglets (Duroc × Yorkshire × Landrace) were randomly assigned to 5 dietary treatments and fed a basal diet supplemented with 0 (control), 100, 500, 1000, and 2000 mg chitosan/kg feed, respectively. Results showed that serum AA, prostaglandin E2 (PGE2), and leukotriene B4 (LTB4) contents in piglets were increased in a linear or quadratic dose-dependent manner with increasing chitosan on day 28 (P < 0.05). Chitosan increased serum cytosolic-phospholipase A2 (cPLA2) activity in a linear or quadratic dose-dependent manner on day 14 or 28, and improved 5-lipoxygenase (5-LOX) activity in a linear manner and cyclooxygenase-2 (COX-2) activity quadratically on day 28 (P < 0.05). Moreover, chitosan elevated gene expression of cPLA2 mRNA quadratically in the small intestine on days 14 and 28, increased the COX-2 mRNA expression in the duodenum or jejunum in a linear or quadratic manner on day 28, and improved the 5-LOX mRNA expression quadratically in the small intestine (P < 0.05). These results implied that the metabolism of AA was regulated by chitosan in a dose-dependent relationship, which may be one reason why chitosan affected immune function via AA pathway in weaned piglets.

2005 ◽  
Vol 2005 (5) ◽  
pp. 249-255 ◽  
Author(s):  
Riina Nieminen ◽  
Sari Leinonen ◽  
Aleksi Lahti ◽  
Katriina Vuolteenaho ◽  
Ulla Jalonen ◽  
...  

Inducible prostaglandin synthase (cyclooxygenase-2, COX-2) is expressed in rheumatoid and osteoarthritic cartilage and produces high amounts of proinflammatory prostanoids in the joint. In the present study we investigated the effects of the inhibitors of mitogen-activated protein kinase (MAPK) pathways Erk1/2, p38, and JNK on COX-2 expression and prostaglandin E2(PGE2) production in human chondrocytes. Proinflammatory cytokine IL-1βcaused a transient activation of Erk1/2, p38, and JNK in immortalized human T/C28a2 chondrocytes and that was followed by enhanced COX-2 expression and PGE2production. PD98059 (an inhibitor of Erk1/2 pathway) suppressed IL-1-induced COX-2 expression and PGE2production in a dose-dependent manner, and seemed to have an inhibitory effect on COX-2 activity. SB203580 (an inhibitor of p38 pathway) but not its negative control compound SB202474 inhibited COX-2 protein and mRNA expression and subsequent PGE2synthesis at micromolar drug concentrations. SP600125 (a recently developed JNK inhibitor) but not its negative control compound N1-methyl-1,9-pyrazolanthrone downregulated COX-2 expression and PGE2formation in a dose-dependent manner. SP600125 did not downregulate IL-1-induced COX-2 mRNA expression when measured 2 h after addition of IL-1βbut suppressed mRNA levels in the later time points suggesting post-transcriptional regulation. Our results suggest that activation of Erk1/2, p38, and JNK pathways belongs to the signaling cascades that mediate the upregulation of COX-2 expression and PGE2production in human chondrocytes exposed to proinflammatory cytokine IL-1β.


2002 ◽  
Vol 102 (4) ◽  
pp. 403-409 ◽  
Author(s):  
G. PRIANTE ◽  
L. BORDIN ◽  
E. MUSACCHIO ◽  
G. CLARI ◽  
B. BAGGIO

Epidemiological, clinical and experimental evidence suggests that fatty acids have a modulatory effect on bone metabolism in animals and humans. To investigate this hypothesis, we evaluated the effects of three different fatty acids, arachidonic acid (AA), eicosapentaenoic acid (EPA) and oleic acid (OA), on the expression of cytokines involved in bone remodelling. Cytokine mRNAs in the human osteoblast-like cell line MG-63 were quantified by reverse transcription-PCR. AA induced increased expression of interleukin-1α, interleukin-1β, tumour necrosis factor-α and macrophage colony-stimulating factor mRNAs in a time- and dose-dependent manner. EPA and OA had no stimulatory effects, but instead caused a significant inhibition of AA-induced cytokine mRNA expression. Cell treatment with calphostin C, an inhibitor of protein kinase C (PKC), and cellular PKC down-regulation experiments independently resulted in significant inhibition of AA-induced cytokine expression, suggesting that a PKC-dependent mechanism accounts for the effects of AA on cytokine production. In conclusion, our study demonstrates specific effects of fatty acids on cytokine gene expression in human osteoblast-like cells. The clinical relevance of our findings requires further investigation.


1987 ◽  
Vol 40 (4) ◽  
pp. 405
Author(s):  
David Mann ◽  
Audrey M Bersten

The incorporation of long-chain fatty acids into phospholipids has been detected in adipocyte ghosts that were incubated with [1_14 C] stearic, [1_14 C] linoleic or [l_14C] arachidonic acid. Adrenaline and adenosine activated this incorporation within 15 s of exposure of the ghosts to the hormones and the response was dose dependent. Maximum incorporation of labelled linoleic acid occurred at 10-5 M adrenaline and 10-7 M adenosine. The a-agonist phenylephrine and the ~-agonist isoproterenol were also shown to stimulate the incorporation of fatty acid in a dose dependent manner. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were each labelled preferentially with linoleic or arachidonic acid. p-Bromophenacylbromide, quinacrine and centrophenoxine inhibited the adrenaline-stimulated incorporation of fatty acids into ghost membrane phospholipids, and p-bromophenacylbromide also reduced the activation of adenylate cyclase by adrenaline. NaF, an activator of adenylate cyclase, like adrenaline, stimulated the incorporation of linoleic acid into ghost membrane phospholipids.


2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Liang Hu ◽  
Michael A Nardi ◽  
Michael Merolla ◽  
Yajaira Suarez ◽  
Jeffrey Berger

Arachidonic acid (AA) is converted to thromboxane A2 via the cyclooxygenase pathway; however its exact mechanism of platelet activation is uncertain. Inhibition of this pathway via aspirin highlights the importance of this pathway in decreasing thrombotic events. In the present study, we investigate the effect of AA on platelet activity indicators (leukocyte- and monocyte-platelet aggregation [LPA, MPA] and reticulated platelets [RP]), as well as the expression (mRNA and protein) of platelet markers PF4 and Par-1, previously well established platelet transcripts with quantitative determinations. To this end, whole blood was incubated with AA (150mM) for 30 min at room temperature in the absence or presence of aspirin (1mM) prior to addition of antibodies for platelet activity indicators, and isolating platelets for mRNA and protein expression. LPA and MPA were significantly increased after AA stimulation in a dose dependent manner, and were inhibited by aspirin treatment. AA significantly increased PF4 and Par-1 protein level as determined by flow cytometry and western blot assays. Pretreatment with aspirin also attenuated this increase in protein levels. Surprisingly, AA stimulation significantly increased thiazole orange staining (a measure of nucleic acids), another marker of increased platelet activity. Importantly, these results suggest that AA-mediated platelet activation produced an overall increase in platelet total RNA content. To confirm these findings, we analyzed the mRNA expression of PF4 and Par-1 by quantitative real time PCR from platelets treated with AA. Interestingly, AA significantly up-regulated the platelet mRNA transcripts of PF4 and Par-1 by 40% to 60%, and pretreatment with aspirin completely attenuated this effect supporting the specificity of the AA effect on platelet RNA. Altogether, these data suggest that platelet mRNA is affected by AA stimulation, which is attenuated by pretreatment with aspirin. However, the mechanisms responsible for the increased mRNA levels and expression of PF4 and Par-1 (processing of pre-RNA to mRNA) require further investigation. Importantly, our findings provide novel insight regarding platelet activation and a better understanding of mediators in the processes of thrombosis and hemostasis.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4435 ◽  
Author(s):  
Lin Yuan ◽  
Wanli Li ◽  
Qianqian Huo ◽  
Chenhong Du ◽  
Zhixiang Wang ◽  
...  

This study investigated the effects of xylo-oligosaccharide (XOS) and flavomycin (FLA) on the performance and immune function of broiler chickens. A total of 150 ArborAcres broilers were randomly divided into three groups and fed for six weeks from one day of age in cascade cages. The diets of each test group were (1) a basal diet, (2) the basal diet supplemented with 2 mg/kg FLA, and (3) the basal diet supplemented with 2 mg/kg XOS. At 21 and 42 days, the growth performance index values and short-chain fatty acid (SCFA) concentrations in the cecum were quantified. Furthermore, immunoglobulin G (IgG) and plasma interleukin 2 (IL-2) as well as mRNA expression of LPS-Induced TNF-alpha Factor (LITAF), Toll-like receptor-5 (TLR5) and interferon gamma (IFNγ) in the jejunum were quantified. The results showed that administration of XOS or FLA to chickens significantly improved the average daily gain. Supplementation with XOS increased acetate and butyrate in the cecum, while FLA supplementation increased propionate in the cecum. An increase in plasma IgG was observed in XOS-fed 21-day-old broilers, but FLA supplementation decreased IgG in the plasma of 42-day-old broilers and increased plasma IL-2. Furthermore, FLA or XOS supplementation downregulated mRNA expression of IFNγ, LITAF and TLR5. The above data suggest that addition of XOS and FLA to the diet could improve the growth performance of broilers and reduce the expression of cytokine genes by stimulating SCFA.


2013 ◽  
Vol 8 (4) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Pornanong Aramwit ◽  
Pasarapa Towiwat ◽  
Teerapol Srichana

Silk sericin was found to suppress the production of pro-inflammatory cytokines, which are related to the inflammatory reaction. The objectives of this study were to investigate the anti-inflammatory effect of sericin in vivo using the carrageenan-induced rat edema model and changes in the histology of tissues. The effects of sericin on the expression of COX-2 and iNOS were also evaluated. Sericin solutions at 0.004-0.080 mg/mL were applied topically to the top of the hind paw and carrageenan (1.0 mg) was injected subcutaneously to the plantar surface of the right hind paw. Our results indicated that sericin significantly reduced the inflammation in rats’ paw compared with the negative control (water and acetone) and its effect at 0.080 mg/mL was only slightly lower than that of 1.0% w/v indomethacin. Similar numbers of polymorphonuclear and macrophage cells were found in rats’ tissue treated with indomethacin and sericin solution, while the numbers were significantly higher in their absence. The gene expression results by RT-PCR showed that the COX-2 and iNOS genes were down-regulated in samples treated with sericin in a dose dependent manner. These data indicated that the anti-inflammatory properties of sericin may be partly attributable to the suppression of the COX-2 enzyme and nitric oxide production.


2020 ◽  
Vol 98 (2) ◽  
Author(s):  
Lanmei Yin ◽  
Jun Li ◽  
Huiru Wang ◽  
Zhenfeng Yi ◽  
Lei Wang ◽  
...  

Abstract Vitamin B6 (VB6), which is an essential functional substance for biosome, plays an irreplaceable role in animal health. However, there are few studies that focus on the correlation between VB6 and intestinal health in weaned piglets. This study was conducted to investigate the effects of VB6 on the growth performance, intestinal morphology, and inflammatory cytokines and amino acid (AA) transporters mRNA expression in weaned piglets that are fed a low crude-protein (CP, 18%) diet. Eighteen crossbred piglets with initial body weights of 7.03 ± 0.17 kg (means ± SEM), weaned at 21-d age, were randomly assigned three diets with 0, 4, and 7 mg/kg VB6 supplementation, respectively. The experimental period lasted 14 days. Our results showed that there were no significant differences in growth performance, diarrhea rate, and biochemical parameters among the three treatments. In the jejunum, dietary VB6 supplementation did not affect the morphology and positive Ki67 counts. Dietary supplementation with 4 mg/kg VB6 decreased the mRNA expression of COX-2, IL-10, and TGF-β (P < 0.05). Dietary supplementation with 7 mg/kg VB6 increased the mRNA expression of SLC7A1, SLC7A6, SLC16A14, and SLC38A5 (P < 0.05) and 4 or 7 mg/kg VB6 decreased SLC36A1 mRNA expression (P < 0.05). In the ileum, VB6 supplementation did not affect positive Ki67 counts but significantly decreased villus area (P < 0.05) and tended to decrease villus height (P = 0.093). Dietary supplementation with 4 mg/kg VB6 had significantly increased the mRNA expression of IL-1β, TNF-α, COX-2, IL-10, and TGF-β (P < 0.05). Dietary supplementation with 4 or 7 mg/kg VB6 had significantly decreased SLC6A20, SLC7A1, SLC7A6, SLC16A14, and SLC38A5 mRNA expression (P < 0.05). These findings suggest that dietary supplementation of VB6 mainly down-regulated inflammatory cytokines and up-regulated AA transporters mRNA expression in jejunum, while up-regulated (4 mg/kg) inflammatory cytokines and down-regulated AA transporters mRNA expression in ileum, which may provide a reference for the intestinal development of weaned piglets that are fed a low-CP diet.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 4706-4706
Author(s):  
Hongyan Tong ◽  
Jie Jin ◽  
Weilai Xu ◽  
Wenbin Qian ◽  
Maofang Lin

Abstract The telomerase activity can be down regulated by arsenic trioxide (As2O3), which is regarded as an apoptotic induction agent, is confirmed in many kinds of tumor cells. To investigate the mechanisms of telomerase regulation and to explore the correlation of As2O3 inducing apoptosis and telomerase regulation in MUTZ-1 cells, which are established as a high-risk myelodysplasia Cell line that derived from a MDS patient (FAB subtype refractory anemia with excess of blasts), a quantitative assessment of the telomerase activity by TRAP-ELISA and detection of the expression levels of hTERT, TRF1 (TTAGGG repeat binding factor 1), TRF2 (TTAGGG repeat binding factor 2), bcl-2, bax mRNA were performed, together with the assessment of the apoptosis by means of translocation of phosphatidylserine (PS) through flow cytometry assay. The results indicated that a typical apoptotic cell group distribution of DNA content was represented in the MUTZ-1 cells after being exposed to As2O3 at the range of concentration from 1μmol/L to 8μmol/L in a dose-dependent manner (r=0.736, P<0.001) and time-dependent manner (r=0.674, p<0.05), and the telomerase activity was down-regulated in a time-dependent manner (r=−0.976,P=0.024), and the expression level of hTERT mRNA in MUTZ-1 cells was represented in a dose-dependent manner (r=−0.892,P=0.042) and time-dependent manner (r=−1.000,P=0.04), after the cells were treated by As2O3 at the dosage as above. It was showed that a significant correlation between the decreased telomerase activity and the increased percentage of apoptotic cells in the treated cells (r=0.938,P=0.018), and there was a strong relationship between the telomerase activity and the mRNA expression of hTERT gene (r=0.783,P=0.022). However, As2O3 has no obvious effect on the expression level of TRF1 mRNA and TRF2 mRNA, which were regarded as two telomere-binding proteins. Further findings indicated that the inhibition of telomerase activity in MUTZ-1 cells was accompanied with down-regulated mRNA expression of bcl-2 gene (densitometry readings: 0.255±0.017 vs 0.466±0.069, P<0.05) and decreased ration of bcl-2/bax (densitometry reading ratios: 0.890±0.083 vs 0.546±0.014, P<0.05) at the dosage of 4μmol/L for 24 hours. These observations suggest that the apoptosis induced by As2O3 on MUTZ- 1 cells might be mediated through the inhibition of telomerase activity regulated by expression of hTERT gene, which implies that may be one of the mechanisms of As2O3 inducing apoptosis in MUTZ-1 cells.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Yueh-Ling Hsieh ◽  
Shun-An Yang ◽  
Chen-Chia Yang ◽  
Li-Wei Chou

Background and Purpose. Dry needling is an effective therapy for the treatment of pain associated with myofascial trigger point (MTrP). However, the biochemical effects of dry needling that are associated with pain, inflammation, and hypoxia are unclear. This study investigated the activities ofβ-endorphin, substance P, TNF-α, COX-2, HIF-1α, iNOS, and VEGF after different dosages of dry needling at the myofascial trigger spots (MTrSs) of a skeletal muscle in rabbit. Materials and Methods. Dry needling was performed either with one dosage (1D) or five dosages (5D) into the biceps femoris with MTrSs in New Zealand rabbits. Biceps femoris, serum, and dorsal root ganglion (DRG) were sampled immediately and 5 d after dry needling forβ-endorphin, substance P, TNF-α, COX-2, HIF-1α, iNOS, and VEGF immunoassays.Results. The 1D treatment enhanced theβ-endorphin levels in the biceps femoris and serum and reduced substance P in the biceps femoris and DRG. The 5D treatment reversed these effects and was accompanied by increase of TNF-α, COX-2, HIF-1α, iNOS, and VEGF production in the biceps femoris. Moreover, the higher levels of these biochemicals were still maintained 5 d after treatment.Conclusion. Dry needling at the MTrSs modulates various biochemicals associated with pain, inflammation, and hypoxia in a dose-dependent manner.


2008 ◽  
Vol 36 (5) ◽  
pp. 1032-1038 ◽  
Author(s):  
B Kong ◽  
Y Tian ◽  
W Zhu ◽  
S Su ◽  
Y Kan

The effects of cyclooxygenase 2 (COX-2) selective inhibitors on the proliferation of ectopic endometrial stromal cells in vitro were investigated. Ectopic endometrial stromal cells were treated with either celecoxib or nimesulide for 24 and 48 h. The results showed that (i) both celecoxib and nimesulide inhibited the proliferation of ectopic endometrial stromal cells in vitro in a time- and dose-dependent manner; (ii) the expression of prostaglandin E2 was significantly inhibited by both celecoxib and nimesulide in a dose-dependent manner; (iii) the percentage of apoptotic cells was significantly higher for cells treated with celecoxib or nimesulide than for untreated cells; and (iv) the percentage of the cells in the G0/G1 phase increased after the cells were treated with either agent in a dose-dependent manner. These data suggest that celecoxib and nimesulide inhibited proliferation of ectopic endometrial stromal cells by inducing apoptosis and blocking the cell cycle at the G0/G1 phase.


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