scholarly journals Islet neogenesis associated protein (INGAP) protects pancreatic β cells from IL-1β and IFNγ-induced apoptosis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Eni Nano ◽  
Maria Petropavlovskaia ◽  
Lawrence Rosenberg

AbstractThe goal of this study was to determine whether recombinant Islet NeoGenesis Associated Protein (rINGAP) and its active core, a pentadecapeptide INGAP104–118 (Ingap-p), protect β cells against cytokine-induced death. INGAP has been shown to induce islet neogenesis in diabetic animals, to stimulate β-cell proliferation and differentiation, and to improve islet survival and function. Importantly, Ingap-p has shown promising results in clinical trials for diabetes (phase I/II). However, the full potential of INGAP and its mechanisms of action remain poorly understood. Using rat insulinoma cells RINm5F and INS-1 treated with interleukin-1β (IL-1β) and interferon‐gamma (IFN‐γ), we demonstrate here that both rINGAP and Ingap-p inhibit apoptosis, Caspase-3 activation, inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production, and explore the related signaling pathways. As expected, IL-1β induced nuclear factor kappa B (NF-κB), p38, and JNK signaling, whereas interferon‐gamma (IFN‐γ) activated the JAK2/STAT1 pathway and potentiated the IL-1β effects. Both rINGAP and Ingap-p decreased phosphorylation of IKKα/β, IkBα, and p65, although p65 nuclear translocation was not inhibited. rINGAP, used for further analysis, also inhibited STAT3, p38, and JNK activation. Interestingly, all inhibitory effects of rINGAP were observed for the cytokine cocktail, not IL-1β alone, and were roughly equal to reversing the potentiating effects of INFγ. Furthermore, rINGAP had no effect on IL-1β/NF-κB-induced gene expression (e.g., Ccl2, Sod2) but downregulated several IFNγ-stimulated (Irf1, Socs1, Socs3) or IFNγ-potentiated (Nos2) genes. This, however, was observed again only for the cytokine cocktail, not IFNγ alone, and rINGAP did not inhibit the IFNγ-induced JAK2/STAT1 activation. Together, these intriguing results suggest that INGAP does not target either IL-1β or IFNγ individually but rather inhibits the signaling crosstalk between the two, the exact mechanism of which remains to be investigated. In summary, our study characterizes the anti-inflammatory effects of INGAP, both protein and peptide, and suggests a new therapeutic utility for INGAP in the treatment of diabetes.

2020 ◽  
Vol 472 (10) ◽  
pp. 1469-1480
Author(s):  
Bashair M. Mussa ◽  
Ankita Srivastava ◽  
Abdul Khader Mohammed ◽  
Anthony J. M. Verberne

Abstract Dysfunction of the pancreatic β cells leads to several chronic disorders including diabetes mellitus. Several mediators and mechanisms are known to be involved in the regulation of β cell secretory function. In this study, we propose that cytokine-induced nitric oxide (NO) production interacts with cholinergic mechanisms to modulate insulin secretion from pancreatic β cells. Using a rat insulinoma cell line INS-1, we demonstrated that β cell viability decreases significantly in the presence of SNAP (NO donor) in a concentration- and time-dependent manner. Cell viability was also found to be decreased in the presence of a combined treatment of SNAP with SMN (muscarinic receptor antagonist). We then investigated the impact of these findings on insulin secretion and found a significant reduction in glucose uptake by INS-1 cells in the presence of SNAP and SMN as compared with control. Nitric oxide synthase 3 gene expression was found to be significantly reduced in response to combined treatment with SNAP and SMN suggesting an interaction between the cholinergic and nitrergic systems. The analysis of gene and protein expression further pin-pointed the involvement of M3 muscarinic receptors in the cholinergic pathway. Upon treatment with cytokines, reduced cell viability was observed in the presence of TNF-α and IFN-γ. A significant reduction in insulin secretion was also noted after treatment with TNF-α and IFN-γ and IL1-β. The findings of the present study have shown for the first time that the inhibition of the excitatory effects of cholinergic pathways on glucose-induced insulin secretion may cause β cell injury and dysfunction of insulin secretion in response to cytokine-induced NO production.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Haidy A. Saleh ◽  
Eman Ramdan ◽  
Mohey M. Elmazar ◽  
Hassan M. E. Azzazy ◽  
Anwar Abdelnaser

AbstractDoxorubicin (DOX) chemotherapy is associated with the release of inflammatory cytokines from macrophages. This has been suggested to be, in part, due to DOX-mediated leakage of endotoxins from gut microflora, which activate Toll-like receptor 4 (TLR4) signaling in macrophages, causing severe inflammation. However, the direct function of DOX on macrophages is still unknown. In the present study, we tested the hypothesis that DOX alone is incapable of stimulating inflammatory response in macrophages. Then, we compared the anti-inflammatory effects of curcumin (CUR), resveratrol (RES) and sulforaphane (SFN) against lipopolysaccharide/interferon-gamma (LPS/IFN-γ)-mediated inflammation in the absence or presence of DOX. For this purpose, RAW 264.7 cells were stimulated with LPS/IFN-γ (10 ng/mL/10 U/mL) in the absence or presence of DOX (0.1 µM). Our results showed that DOX alone is incapable of stimulating an inflammatory response in RAW 264.7 macrophages. Furthermore, after 24 h of incubation with LPS/IFN-γ, a significant increase in tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and inducible nitric oxide synthase (iNOS) mRNA levels was observed. Similarly, nitric oxide (NO) production and TNF-α and IL-6 protein levels were significantly upregulated. Moreover, in LPS/IFN-γ-treated macrophages, the microRNAs (miRNAs) miR-146a, miR-155, and miR-21 were significantly overexpressed. Interestingly, upon testing CUR, RES, and SFN against LPS/IFN-γ-mediated inflammation, only SFN was able to significantly reverse the LPS/IFN-γ-mediated induction of iNOS, TNF-α and IL-6 and attenuate miR-146a and miR-155 levels. In conclusion, SFN, at the transcriptional and posttranscriptional levels, exhibits potent immunomodulatory action against LPS/IFN-γ-stimulated macrophages, which may indicate SFN as a potential treatment for DOX-associated inflammation.


Author(s):  
Mohamed A. Salama ◽  
Mohamed A. Younis ◽  
Roba M. Talaat

AbstractObjectiveThe present study aimed to evaluate cytotoxic, apoptotic, and anti-inflammatory properties of bee venom (BV) as well as changes in cytokine secretion levels and nitric oxide (NO) production using three different cancer cell lines [liver (Hep-G2), breast (MCF-7), and cervical (HPV-18 infected HeLa cells)] and two normal cells (splenocytes and macrophages (MQ).MethodsCytotoxic activity of BV against tumor cell lines and normal splenocytes/MQ was tested by MTT assay. By ELISA (ELISA); Tumor necrosis factor (TNF-α), Interleukine (IL-10) and interferon (IFN-γ) were measured. Caspase three expressions was evaluated using reverse transcription-polymerase chain reaction (RT-PCR). Nitric oxide (NO) was estimated using a colorimetric assay.ResultsBV has a significant cytotoxic effect on all cell lines in a dose- and time-dependent manner; none of them was toxic for normal cells. Treating Hep-G2 cells with BV showed a reduction in IL-10, elevation in TNF-α with no change in IFN-γ level. MCF-7 cells have low IL-10 and TNF-α and high IFN-γ production level. Elevation of IL-10 and IFN-γ coincides with a reduction in TNF-α level was demonstrated in HeLa cells. The expression of Caspase three was dramatically increased with elevation in BV concentration in all tested cancer cell lines. A gradual decrease in NO production by MQ with increasing BV dose was observed.ConclusionTaken together, our results stressed on the importance of BV as a potent anti-tumor agent against various types of cancers (Liver, Breast, and Cervix). Further steps towards the use of BV for pharmacological purposes must be done.


2021 ◽  
Vol 22 (13) ◽  
pp. 6894
Author(s):  
Mei Tong He ◽  
Hye Sook Park ◽  
Young Sil Kim ◽  
Ah Young Lee ◽  
Eun Ju Cho

Recently, adipose-derived stem cells (ADSCs) are considered to be ideal for application in cell therapy or tissue regeneration, mainly due to their wide availability and easy access. In this study, we examined the anti-inflammatory effects of membrane-free stem cell extract (MFSC-Ex) derived from ADSCs against lipopolysaccharide (LPS)/interferon-gamma (IFN-γ) on RAW 264.7 macrophage cells. Exposure of RAW macrophages to LPS and IFN-γ stimuli induced high levels of nitric oxide (NO), cyclooxygenase-2 (COX-2), and prostaglandin E2 (PGE2) production. However, pretreatment with MFSC-Ex inhibited LPS/IFN-γ-induced these pro-inflammatory mediators. To clarify the molecular mechanisms underlying the anti-inflammatory property of MFSC-Ex, we analyzed nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) protein expressions by Western blotting. Our study showed that treatment of MFSC-Ex significantly down-regulated inducible nitric oxide synthase (iNOS) and COX-2 protein expressions. Furthermore, phosphorylation of extracellular signal-regulated kinase (ERK) and p38 was also blocked by treatment with MFSC-Ex, indicating that inhibitory effect of MFSC-Ex on MAPK signaling cascade may attribute to inactivation of NF-κB. From these findings, we suggest that MFSC-Ex exert anti-inflammatory activities, which suppressed LPS/IFN-γ-induced production of NO, COX-2 and PGE2 by regulation of NF-κB and MAPK signaling pathway in RAW 264.7 macrophages. In conclusion, MFSC-Ex might provide a new therapeutic opportunity to treatment of inflammatory-related diseases.


2004 ◽  
Vol 286 (3) ◽  
pp. E329-E336 ◽  
Author(s):  
Sarah M. Weber ◽  
Anna L. Scarim ◽  
John A. Corbett

Peroxisome proliferator-activated receptor (PPAR)γ agonists, such as 15-deoxy-Δ12,14-prostaglandin J2 (PGJ2) and troglitazone, have been shown to elicit anti-inflammatory effects in pancreatic β-cells that include inhibition of cytokine-stimulated inducible nitric oxide synthase (iNOS) gene expression and production of nitric oxide. In addition, these ligands impair IL-1-induced NF-κB and MAPK as well as IFN-γ-stimulated signal transducer and activator of transcription (STAT)1 activation in β-cells. The purpose of this study was to determine if PPARγ activation participates in the anti-inflammatory actions of PGJ2 in β-cells. Pretreatment of RINm5F cells for 6 h with PGJ2 results in inhibition of IL-1-stimulated IκB degradation and IFN-γ-stimulated STAT1 phosphorylation. Overexpression of a dominant-negative (dn) PPARγ mutant or treatment with the PPARγ antagonist GW-9662 does not modulate the inhibitory actions of PGJ2 on cytokine signaling in RINm5F cells. Although these agents fail to attenuate the inhibitory actions of PGJ2 on cytokine signaling, they do inhibit PGJ2-stimulated PPARγ response element reporter activity. Consistent with the inability to attenuate the inhibitory actions of PGJ2 on cytokine signaling, neither dnPPARγ nor GW-9662 prevents the inhibitory actions of PGJ2 on IL-1-stimulated iNOS gene expression or nitric oxide production by RINm5F cells. These findings support a PPARγ-independent mechanism by which PPARγ ligands impair cytokine signaling and iNOS expression by islets.


2018 ◽  
Vol 19 (12) ◽  
pp. 3746 ◽  
Author(s):  
Ye Jeong ◽  
Mi-Young Lee

Populus deltoides, known as eastern cottonwood, has been commonly used as a medicinal plant. The aim of the present study was to investigate the mechanism underlying the anti-inflammatory activity of P. deltoides leaf extract (PLE). PLE effectively inhibited the expression of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, but not that of cyclooxygenase-2 (COX-2) and prostaglandin E2. Proinflammatory tumor necrosis factor alpha (TNF-α) levels were also reduced by the extract. PLE inhibited the phosphorylation of nuclear factor-kappa B (NF-κB) and inhibitor of Kappa Bα (IκBα), and blunted LPS-triggered enhanced nuclear translocation of NF-κB p65. In mitogen-activated protein kinase (MAPK) signaling, PLE effectively decreased the phosphorylation of p38 and c-Jun N-terminal protein kinase (JNK), but not of extracellular signal-regulated kinase 1/2 (ERK1/2). Taken together, these results suggest that anti-inflammatory activity of P. deltoides leaf extract might be driven by iNOS and NO inhibition mediated by modulation of the NF-κB and p38/JNK signaling pathways.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Min Hwangbo ◽  
Ji Yun Jung ◽  
Sung Hwan Ki ◽  
Sang Mi Park ◽  
Kyung Hwan Jegal ◽  
...  

Since antiquity, medical herbs have been prescribed for both treatment and preventative purposes. Herbal formulas are used to reduce toxicity as well as increase efficacy in traditional Korean medicine.U-bang-haequi tang(UBT) is a herbal prescription containingArctii fructusandForsythia suspensaas its main components and has treated many human diseases in traditional Korean medicine. This research investigated the effects of UBT against an acute phase of inflammation. For this, we measured induction of nitric oxide (NO) and related proteins in macrophage cell line stimulated by lipopolysaccharide (LPS). Further, paw swelling was measured in carrageenan-treated rats. Carrageenan significantly induced activation of inflammatory cells and increases in paw volume, whereas oral administration of 0.3 or 1 g/kg/day of UBT inhibited the acute inflammatory response. In RAW264.7 cells, UBT inhibited mRNA and protein expression levels of iNOS. UBT treatment also blocked elevation of NO production, nuclear translocation of NF-κB, phosphorylation of Iκ-Bαinduced by LPS. Moreover, UBT treatment significantly blocked the phosphorylation of p38 and c-Jun NH2-terminal kinases by LPS. In conclusion, UBT prevented both acute inflammation in rats as well as LPS-induced NO and iNOS gene expression through inhibition of NF-κB in RAW264.7 cells.


Gut ◽  
1999 ◽  
Vol 44 (5) ◽  
pp. 659-665 ◽  
Author(s):  
A M Chavez ◽  
M J Morin ◽  
N Unno ◽  
M P Fink ◽  
R A Hodin

BACKGROUNDImpairment of intestinal barrier function occurs under a variety of inflammatory conditions and is mediated at least in part by interferon γ (IFN-γ) induced nitric oxide (NO) production. Previous in vivo studies have shown that systemic lipopolysaccharide treatment caused an induction of the rat inducible nitric oxide synthase (iNOS) mRNA primarily in villus cells, rather than in undifferentiated crypt cells.AIMSTo examine iNOS induction by IFN-γ in vitro as a function of enterocyte differentiation.METHODSPreconfluent and postconfluent Caco-2 cells were treated with IFN-γ in the presence or absence of various inhibitors. Northern analyses were performed to assess the magnitude of iNOS mRNA induction. IFN-γ receptor mRNA and protein levels were determined.RESULTSiNOS mRNA induction by IFN-γ occurred at two hours and was not blocked by cycloheximide, indicating that it is an immediate early response. iNOS induction and nitrite/nitrate increases were inhibited by dexamethasone and pyrrolidine dithiocarbamate, supporting an important role for the NF-κB transcription factor in this process. The stimulated iNOS induction was seen almost exclusively under conditions of cellular differentiation—that is, in postconfluent Caco-2 cells. This increased IFN-γ responsiveness seen in postconfluent Caco-2 cells correlated with an increased expression of IFN-γ receptor, whereas T84 and HT-29 cells did not show any significant alterations in either iNOS induction or IFN-γ receptor levels as a function of postconfluent growth.CONCLUSIONSWith regard to iNOS mRNA induction, IFN-γ responsiveness is acquired during Caco-2 cell differentiation, perhaps related to an increase in the numbers of IFN-γ receptors.


2018 ◽  
Vol 46 (06) ◽  
pp. 1281-1296 ◽  
Author(s):  
Sang Yun Han ◽  
Young-Su Yi ◽  
Seong-Gu Jeong ◽  
Yo Han Hong ◽  
Kang Jun Choi ◽  
...  

Lilium bulbs have long been used as Chinese traditional medicines to alleviate the symptoms of various human inflammatory diseases. However, mechanisms of Lilium bulb-mediated anti-inflammatory activity and the bioactive components in Lilium bulbs remain unknown. In the present study, the anti-inflammatory activity of Lilium bulbs and the underlying mechanism of action were investigated in macrophages using Lilium bulb ethanol extracts (Lb-EE). In a dose-dependent manner, Lb-EE inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and bone marrow-derived macrophages (BMDMs) without causing significant cytotoxicity. Lb-EE also down-regulated mRNA expression of inflammatory genes in LPS-stimulated RAW264.7 cells, which included inducuble nitric oxide synthase (iNOS), cyclooxygenase-2 (COX2), and tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text]). Furthermore, Lb-EE markedly restored LPS-induced morphological changes in RAW264.7 cells to a normal morphology. HPLC analysis identified quercetin, luteolin, and kaempferol as bioactive components contained in Lb-EE. Mechanistic studies in LPS-stimulated RAW264.7 cells revealed that Lb-EE suppressed MyD88- and TRIF-induced NF-[Formula: see text]B transcriptional activation and the nuclear translocation of NF-[Formula: see text]B transcription factors. Moreover, Lb-EE inhibited IKK[Formula: see text]/[Formula: see text]-induced activation of the NF-[Formula: see text]B signaling pathway and IKK inhibition significantly reduced NO production in LPS-stimulated RAW264.7 cells. Taken together, these results suggest that Lb-EE plays an anti-inflammatory role by targeting IKK[Formula: see text]/[Formula: see text]-mediated activation of the NF-[Formula: see text]B signaling pathway during macrophage-mediated inflammatory responses.


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