Reactive Astrogliosis in an Experimental Model of Fibromyalgia: Effect of Dexmedetomidine

2018 ◽  
Vol 205 (2) ◽  
pp. 105-119
Author(s):  
Rasha B. Abd-ellatief ◽  
Heba K. Mohamed ◽  
Hassan I. Kotb

To our knowledge, this is the first study which investigates the induction of neuroinflammation in rats using an acidic-saline model of fibromyalgia. It is well known that the hippocampus has a fundamental role in pain perception, and astrocytes play a crucial role in pain signaling. Our aim is to evaluate the ability of dexmedetomidine to attenuate the inflammatory responses induced in astrocytes. In a group of healthy rats, induction of chronic muscle pain by intramuscular injection of 100 µL of acidic saline on days 0 and 5 resulted in peripheral sensitization (measured using the von Frey test) and significant (p < 0.05) increases in IL-1β (160.2 ± 1.1 to 335.2 ± 1.8), IL-6 (100.1 ± 1.4 to 202.4 ± 1.1), and TNF-α (60.0 ± 0.7 to 115.5 ± 1). Light and electron microscopy revealed degenerative changes in the hippocampus and reactive astrogliosis. Immunohistochemistry showed increased expression of glial fibrillary acid protein and inducible nitric oxide synthase. Surprisingly, treatment with a single dose of an α2-adrenergic agonist, dexmedetomidine (5 µg/kg i.p.), attenuated these changes. This trial suggests that dexmedetomidine possibly directly acts on astrocytes, and a peripheral action is also suggested.

Foods ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 582 ◽  
Author(s):  
Yuan ◽  
Zhang ◽  
Shen ◽  
Jia ◽  
Xie

Phytosterols, found in many commonly consumed foods, exhibit a broad range of physiological activities including anti-inflammatory effects. In this study, the anti-inflammatory effects of ergosterol, β-sitosterol, stigmasterol, campesterol, and ergosterol acetate were investigated in lipopolysaccharide (LPS)-induced RAW264.7 macrophages. Results showed that all phytosterol compounds alleviated the inflammatory reaction in LPS-induced macrophage models; cell phagocytosis, nitric oxide (NO) production, release of tumor necrosis factor-α (TNF-α), and expression and activity of pro-inflammatory mediator cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and phosphorylated extracellular signal-regulated protein kinase (p-ERK) were all inhibited. The anti-inflammatory activity of β-sitosterol was higher than stigmasterol and campesterol, which suggests that phytosterols without a double bond on C-22 and with ethyl on C-24 were more effective. However, inconsistent results were observed upon comparison of ergosterol and ergosterol acetate (hydroxy or ester group on C-3), which suggest that additional research is still needed to ascertain the contribution of structure to their anti-inflammatory effects.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Shasha Yang ◽  
Jing Wu ◽  
Qinxiu Zhang ◽  
Xinrong Li ◽  
Daien Liu ◽  
...  

Allergic rhinitis (AR) is a major concern in personal and public health, which negatively affects emotions and behavior, leading to cognitive deficits, memory decline, poor school performance, anxiety, and depression. Several cellular and molecular mediators are released in the inflammatory process of AR and activate common neuroimmune mechanisms, involving emotionally relevant circuits and the induction of anxiety. Responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis to allergic processes have been reported, which may also include responsiveness of the hippocampus, cortex, and other brain regions. Here, we have used an optimized rat model of AR to explore whether the disease has a relationship with inflammatory responses in the hippocampus. AR was established in adult rats by ovalbumin sensitization, and the expression of various inflammatory substances in the hippocampus was measured by specific assays. Comparison between experimental and various control groups of animals revealed an association of AR with significant upregulation of substance P, microglia surface antigen (CD11b), glial fibrillary acid protein (GFAP), tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) in the hippocampus. Thus, we hypothesize that the AR challenge may activate these inflammatory mediators in the hippocampus, which in turn contribute to the abnormal behavior and neurological deficits associated with AR.


2014 ◽  
Vol 42 (04) ◽  
pp. 869-889 ◽  
Author(s):  
Shing-Hwa Liu ◽  
Tien-Hui Lu ◽  
Chin-Chuan Su ◽  
Ing-Shiow Lay ◽  
Hui-Yi Lin ◽  
...  

Inflammation is a serious health issue worldwide that induces many diseases, such as inflammatory bowel disease (IBD), sepsis, acute pancreatitis and lung injury. Thus, there is a great deal of interest in new methods of limiting inflammation. In this study, we investigated the leaves of Nelumbo nucifera Gaertn, an aquatic perennial plant cultivated in eastern Asia and India, in anti-inflammatory pharmacological effects in the murine macrophage cell line RAW264.7. Results showed that lipopolysaccharide (LPS) increased the protein expression of inducible nitric oxide synthase (iNOS) and COX-2, as well as the mRNA expression and level of IL-6 and TNF-α, while NNE significantly reduced these effects of LPS. LPS also induced phospho-JNK protein expression. The JNK-specific inhibitor SP600125 decreased the proteins expression of phospho-JNK, iNOS, COX-2, and the mRNAs expression and levels of IL-6 and TNF-α. Further, NNE reduced the protein expression of phospho-JNK. LPS was also found to promote the translocation of NF-κB from the cytosol to the nucleus and to decrease the expression of cytosolic IκB. NNE and SP600125 treatment recovered the LPS-induced expression of NF-κB and IκB. While phospho-ERK and phospho-p38 induced by LPS, could not be reversed by NNE. To further investigate the major components of NNE in anti-inflammatory effects, we determined the quercetin and catechin in inflammatory signals. Results showed that quercetin and catechin significantly decreased the proteins expression of iNOS, COX-2 and phospho-JNK. Besides, the mRNAs and levels of IL-6 and TNF-α also decreased by quercetin and catechin treatment in LPS-induced RAW264.7 cells. These results showed that NNE and its major components quercetin and catechin exhibit anti-inflammatory activities by inhibiting the JNK- and NF-κB-regulated pathways and could therefore be an useful anti-inflammatory agent.


Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3197 ◽  
Author(s):  
Irene Cuadrado ◽  
Ángel Amesty ◽  
Juan Cedrón ◽  
Juan Oberti ◽  
Ana Estévez-Braun ◽  
...  

A series of nine derivatives (2–10) were prepared from the diterpene solidagenone (1) and their structures were elucidated by means of spectroscopic studies. Their ability to inhibit inflammatory responses elicited in peritoneal macrophages by TLR ligands was investigated. Compounds 5 and 6 showed significant anti-inflammatory effects, as they inhibited the protein expression of nitric oxide synthase (NOS-2), cyclooxygenase-2 (COX-2), and cytokine production (TNF-α, IL-6, and IL-12) induced by the ligand of TLR4, lipopolysaccharide (LPS), acting at the transcriptional level. Some structure–activity relationships were outlined. Compound 5 was selected as a representative compound and molecular mechanisms involved in its biological activity were investigated. Inhibition of NF-κB and p38 signaling seems to be involved in the mechanism of action of compound 5. In addition, this compound also inhibited inflammatory responses mediated by ligands of TLR2 and TLR3 receptors. To rationalize the obtained results, molecular docking and molecular dynamic studies were carried out on TLR4. All these data indicate that solidagenone derivative 5 might be used for the design of new anti-inflammatory agents.


2013 ◽  
Vol 305 (7) ◽  
pp. F1031-F1041 ◽  
Author(s):  
Curtis Whiting ◽  
Alexander Castillo ◽  
Mohammed Z. Haque ◽  
Dewan S. A. Majid

In the present study, we examine the hypothesis that the nitric oxide (NO) produced by endothelial NO synthase (eNOS) plays a protective role in the development of ANG II-induced hypertension and renal injury by minimizing oxidative stress and the inflammation induced by TNF-α. Systolic blood pressure (SBP) and renal injury responses to chronic infusions of ANG II (via implanted minipumps) were evaluated for 2 wk in wild-type (WT) and in eNOS knockout mice (KO) cotreated with or without a superoxide (O2−) scavenger, tempol (400 mg/l in the drinking water), or a TNF-α receptor blocker, etanercept (5 mg/kg/day ip). In study 1, when ANG II was given at a dose of 25 ng/min, it increased mean SBP in WT mice (Δ36 ± 3 mmHg; n = 7), and this effect was attenuated in mice pretreated with tempol (Δ24 ± 3 mmHg; n = 6). In KO mice ( n = 9), this dose of ANG II resulted in severe renal injury associated with high mortality. To avoid this high mortality in KO, study 2 was conducted with a lower dose of ANG II (10 ng/min) that increased SBP slightly in WT (Δ17 ± 7 mmHg; n = 6) but exaggeratedly in KO (Δ48 ± 12 mmHg, n = 6) associated with severe renal injury. Cotreatment with either tempol ( n = 6) or etanercept ( n = 6) ameliorated the hypertensive, as well as the renal injury responses in KO compared with WT. These data demonstrate a protective role for eNOS activity in preventing renal inflammatory injury and hypertension induced by chronic increases in ANG II.


2001 ◽  
Vol 86 (11) ◽  
pp. 1257-1263 ◽  
Author(s):  
Attilio Bondanza ◽  
Angelo Manfredi ◽  
Valérie Zimmermann ◽  
Matteo Iannacone ◽  
Angela Tincani ◽  
...  

SummaryScavenger phagocytes are mostly responsible for the in vivo clearance of activated or senescent platelets. In contrast to other particulate substrates, the phagocytosis of platelets does not incite pro-inflammatory responses in vivo. This study assessed the contribution of macrophages and dendritic cells (DCs) to the clearance of activated platelets. Furthermore, we verified whether antibodies against the β2 Glycoprotein I (β2GPI), which bind to activated platelets, influence the phenomenon. DCs did not per se internalise activated platelets. In contrast, macrophages efficiently phagocytosed platelets. In agreement with the uneventful nature of the clearance of platelets in vivo, phagocytosing macrophages did not release IL-1β, TNF-α or IL-10. β2GPI bound to activated platelets and was required for their recognition by anti-ββ2GPI antibodies. DCs internalised platelets opsonised by anti-ββ2GPI antibodies. The phagocytosis of opsonised platelets determined the release of TNF-α and IL-1β by DCs and macrophages. Phagocytosing macrophages, but not DCs, secreted the antiinflammatory cytokine IL-1β0. We conclude that anti-ββ2GPI antibodies cause inflammation during platelet clearance and shuttle platelet antigens to antigen presenting DCs.


Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3573
Author(s):  
Lian-Chun Li ◽  
Zheng-Hong Pan ◽  
De-Sheng Ning ◽  
Yu-Xia Fu

Simonsinol is a natural sesqui-neolignan firstly isolated from the bark of Illicium simonsii. In this study, the anti-inflammatory activity of simonsinol was investigated with a lipopolysaccharide (LPS)-stimulated murine macrophages RAW264.7 cells model. The results demonstrated that simonsinol could antagonize the effect of LPS on morphological changes of RAW264.7 cells, and decrease the production of nitric oxide (NO), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6) in LPS-stimulated RAW264.7 cells, as determined by Griess assay and enzyme-linked immunosorbent assay (ELISA). Furthermore, simonsinol could downregulate transcription of inducible nitric oxide synthase (iNOS), TNF-α, and IL-6 as measured by reverse transcription polymerase chain reaction (RT-PCR), and inhibit phosphorylation of the alpha inhibitor of NF-κB (IκBα) as assayed by Western blot. In conclusion, these data demonstrate that simonsinol could inhibit inflammation response in LPS-stimulated RAW264.7 cells through the inactivation of the nuclear transcription factor kappa-B (NF-κB) signaling pathway.


Nutrients ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2794 ◽  
Author(s):  
Cao ◽  
Chen ◽  
Ren ◽  
Zhang ◽  
Tan ◽  
...  

Punicalagin, a hydrolysable tannin of pomegranate juice, exhibits multiple biological effects, including inhibiting production of pro-inflammatory cytokines in macrophages. Autophagy, an intracellular self-digestion process, has been recently shown to regulate inflammatory responses. In this study, we investigated the anti-inflammatory potential of punicalagin in lipopolysaccharide (LPS) induced RAW264.7 macrophages and uncovered the underlying mechanisms. Punicalagin significantly attenuated, in a concentration-dependent manner, LPS-induced release of NO and decreased pro-inflammatory cytokines TNF-α and IL-6 release at the highest concentration. We found that punicalagin inhibited NF-κB and MAPK activation in LPS-induced RAW264.7 macrophages. Western blot analysis revealed that punicalagin pre-treatment enhanced LC3II, p62 expression, and decreased Beclin1 expression in LPS-induced macrophages. MDC assays were used to determine the autophagic process and the results worked in concert with Western blot analysis. In addition, our observations indicated that LPS-induced releases of NO, TNF-α, and IL-6 were attenuated by treatment with autophagy inhibitor chloroquine, suggesting that autophagy inhibition participated in anti-inflammatory effect. We also found that punicalagin downregulated FoxO3a expression, resulting in autophagy inhibition. Overall these results suggested that punicalagin played an important role in the attenuation of LPS-induced inflammatory responses in RAW264.7 macrophages and that the mechanisms involved downregulation of the FoxO3a/autophagy signaling pathway.


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