Abdominal irradiation increases inflammatory cytokine expression and activates NF-κB in rat ileal muscularis layer

2003 ◽  
Vol 285 (3) ◽  
pp. G556-G565 ◽  
Author(s):  
C. Linard ◽  
A. Ropenga ◽  
M. C. Vozenin-Brotons ◽  
A. Chapel ◽  
D. Mathe

The small bowel is an important dose-limiting organ in abdominal radiotherapy because irradiation can cause acute enteritis that, in turn, leads to progressively reduced motility and finally, in a later phase, to fibrosis. Because these clinical symptoms may be caused by the early stage of an inflammatory process, we characterized the radiation-induced intestinal inflammation in rats. Abdominal γ-irradiation (10-Gy) induced a cascade of inflammatory events characterized by an early (6 h after exposure) increase in IL-1β, TNF-α, and IL-6 mRNA levels in the rat ileal muscularis layer. IL-8 [a cytokine-induced neutrophil chemoattractant (CINC)] mRNA appeared later (at 3 days). The expression of TGF-β (a profibrotic cytokine) was higher in irradiated than control tissue at day 1, whereas IL-10 (an anti-inflammatory cytokine) expression vanished completely. Despite strong IL-1ra expression, the IL-1ra/IL-1β ratio, which is an indicator of inflammatory balance, was -41% at day 1 in irradiated compared with control tissue. The nuclear transcription factors NF-κB and activator protein-1 (AP-1) govern transcription of these genes, directly or indirectly. Although expression of the subunits of NF-κB (p65, p50) and AP-1 (c- fos, c- jun) did not increase, irradiation caused a rapid and persistent translocation of p65 and p50. An imbalance between proinflammatory and anti-inflammatory mediators may contribute to perpetuating intestinal inflammation, thus making it chronic.

2011 ◽  
Vol 286 (18) ◽  
pp. 16374-16385 ◽  
Author(s):  
Claude A. Piantadosi ◽  
Crystal M. Withers ◽  
Raquel R. Bartz ◽  
Nancy Chou MacGarvey ◽  
Ping Fu ◽  
...  

The induction of heme oxygenase-1 (HO-1; Hmox1) by inflammation, for instance in sepsis, is associated both with an anti-inflammatory response and with mitochondrial biogenesis. Here, we tested the idea that HO-1, acting through the Nfe2l2 (Nrf2) transcription factor, links anti-inflammatory cytokine expression to activation of mitochondrial biogenesis. HO-1 induction after LPS stimulated anti-inflammatory IL-10 and IL-1 receptor antagonist (IL-1Ra) expression in mouse liver, human HepG2 cells, and mouse J774.1 macrophages but blunted tumor necrosis factor-α expression. This was accompanied by nuclear Nfe2l2 accumulation and led us to identify abundant Nfe2l2 and other mitochondrial biogenesis transcription factor binding sites in the promoter regions of IL10 and IL1Ra compared with pro-inflammatory genes regulated by NF-κΒ. Mechanistically, HO-1, through its CO product, enabled these transcription factors to bind the core IL10 and IL1Ra promoters, which for IL10 included Nfe2l2, nuclear respiratory factor (NRF)-2 (Gabpa), and MEF2, and for IL1Ra, included NRF-1 and MEF2. In cells, Hmox1 or Nfe2l2 RNA silencing prevented IL-10 and IL-1Ra up-regulation, and HO-1 induction failed post-LPS in Nfe2l2-silenced cells and post-sepsis in Nfe2l2−/− mice. Nfe2l2−/− mice compared with WT mice, showed more liver damage, higher mortality, and ineffective CO rescue in sepsis. Nfe2l2−/− mice in sepsis also generated higher hepatic TNF-α mRNA levels, lower NRF-1 and PGC-1α mRNA levels, and no enhancement of anti-inflammatory Il10, Socs3, or bcl-xL gene expression. These findings disclose a highly structured transcriptional network that couples mitochondrial biogenesis to counter-inflammation with major implications for immune suppression in sepsis.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2630
Author(s):  
Jiah Yeom ◽  
Seongho Ma ◽  
Jeong-Keun Kim ◽  
Young-Hee Lim

Colitis causes destruction of the intestinal mucus layer and increases intestinal inflammation. The use of antioxidants and anti-inflammatory agents derived from natural sources has been recently highlighted as a new approach for the treatment of colitis. Oxyresveratrol (OXY) is an antioxidant known to have various beneficial effects on human health, such as anti-inflammatory, antibacterial activity, and antiviral activity. The aim of this study was to investigate the therapeutic effect of OXY in rats with dextran sulfate sodium (DSS)-induced acute colitis. OXY ameliorated DSS-induced colitis and repaired damaged intestinal mucosa. OXY downregulated the expression of pro-inflammatory cytokine genes (TNF-α, IL-6, and IL-1β) and chemokine gene MCP-1, while promoting the production of anti-inflammatory cytokine IL-10. OXY treatment also suppressed inflammation via inhibiting cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression in the colon, as well as the activity of myeloperoxidase (MPO). OXY exhibited anti-apoptotic effects, shifting the Bax/Bcl-2 balance. In conclusion, OXY might improve DSS-induced colitis by restoring the intestinal mucus layer and reducing inflammation within the intestine.


RSC Advances ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 7321-7327
Author(s):  
Shihui Chang ◽  
Liping Wang ◽  
Ting Zhang ◽  
Yan Nie ◽  
Ruijie Liu ◽  
...  

POP-1 performed excellent anti-inflammatory potency by attenuating the pro-inflammatory cytokine expression (TNF-α, NO, IL-1β); inhibiting iNOS and COX-2 expressions and regulating the MAPK, PI3K/Akt and NF-κB signaling pathways.


SLEEP ◽  
2020 ◽  
Vol 43 (11) ◽  
Author(s):  
Shannon Hall ◽  
Samüel Deurveilher ◽  
George S Robertson ◽  
Kazue Semba

Abstract Chronic sleep restriction (CSR) negatively impacts brain functions. Whether microglia, the brain’s resident immune cells, play any role is unknown. We studied microglia responses to CSR using a rat model featuring slowly rotating wheels (3 h on/1 h off), which was previously shown to induce both homeostatic and adaptive responses in sleep and attention. Adult male rats were sleep restricted for 27 or 99 h. Control rats were housed in locked wheels. After 27 and/or 99 h of CSR, the number of cells immunoreactive for the microglia marker ionized calcium-binding adaptor molecule-1 (Iba1) and the density of Iba1 immunoreactivity were increased in 4/10 brain regions involved in sleep/wake regulation and cognition, including the prelimbic cortex, central amygdala, perifornical lateral hypothalamic area, and dorsal raphe nucleus. CSR neither induced mitosis in microglia (assessed with bromodeoxyuridine) nor impaired blood–brain barrier permeability (assessed with Evans Blue). Microglia appeared ramified in all treatment groups and, when examined quantitatively in the prelimbic cortex, their morphology was not affected by CSR. After 27 h, but not 99 h, of CSR, mRNA levels of the anti-inflammatory cytokine interleukin-10 were increased in the frontal cortex. Pro-inflammatory cytokine mRNA levels (tumor necrosis factor-α, interleukin-1β, and interleukin-6) were unchanged. Furthermore, cortical microglia were not immunoreactive for several pro- and anti-inflammatory markers tested, but were immunoreactive for the purinergic P2Y12 receptor. These results suggest that microglia respond to CSR while remaining in a physiological state and may contribute to the previously reported homeostatic and adaptive responses to CSR.


2014 ◽  
Vol 41 (2) ◽  
pp. 172-182 ◽  
Author(s):  
Sebastián Reyes-Cerpa ◽  
Felipe Reyes-López ◽  
Daniela Toro-Ascuy ◽  
Ruth Montero ◽  
Kevin Maisey ◽  
...  

2012 ◽  
Vol 32 (2) ◽  
pp. 291-300 ◽  
Author(s):  
Sebastián Reyes-Cerpa ◽  
Felipe E. Reyes-López ◽  
Daniela Toro-Ascuy ◽  
Jorge Ibañez ◽  
Kevin Maisey ◽  
...  

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