scholarly journals The m6A reader IMP2 directs autoimmune inflammation through an IL-17– and TNFα-dependent C/EBP transcription factor axis

2021 ◽  
Vol 6 (61) ◽  
pp. eabd1287
Author(s):  
Rami Bechara ◽  
Nilesh Amatya ◽  
Rachel D. Bailey ◽  
Yang Li ◽  
Felix E. Y. Aggor ◽  
...  

Excessive cytokine activity underlies many autoimmune conditions, particularly through the interleukin-17 (IL-17) and tumor necrosis factor–α (TNFα) signaling axis. Both cytokines activate nuclear factor κB, but appropriate induction of downstream effector genes requires coordinated activation of other transcription factors, notably, CCAAT/enhancer binding proteins (C/EBPs). Here, we demonstrate the unexpected involvement of a posttranscriptional “epitranscriptomic” mRNA modification [N6-methyladenosine (m6A)] in regulating C/EBPβ and C/EBPδ in response to IL-17A, as well as IL-17F and TNFα. Prompted by the observation that C/EBPβ/δ-encoding transcripts contain m6A consensus sites, we show that Cebpd and Cebpb mRNAs are subject to m6A modification. Induction of C/EBPs is enhanced by an m6A methylase “writer” and suppressed by a demethylase “eraser.” The only m6A “reader” found to be involved in this pathway was IGF2BP2 (IMP2), and IMP2 occupancy of Cebpd and Cebpb mRNA was enhanced by m6A modification. IMP2 facilitated IL-17–mediated Cebpd mRNA stabilization and promoted translation of C/EBPβ/δ in response to IL-17A, IL-17F, and TNFα. RNA sequencing revealed transcriptome-wide IL-17–induced transcripts that are IMP2 influenced, and RNA immunoprecipitation sequencing identified the subset of mRNAs that are directly occupied by IMP2, which included Cebpb and Cebpd. Lipocalin-2 (Lcn2), a hallmark of autoimmune kidney injury, was strongly dependent on IL-17, IMP2, and C/EBPβ/δ. Imp2−/− mice were resistant to autoantibody-induced glomerulonephritis (AGN), showing impaired renal expression of C/EBPs and Lcn2. Moreover, IMP2 deletion initiated only after AGN onset ameliorated disease. Thus, posttranscriptional regulation of C/EBPs through m6A/IMP2 represents a previously unidentified paradigm of cytokine-driven autoimmune inflammation.

2018 ◽  
Vol 46 (2) ◽  
pp. 153-159 ◽  
Author(s):  
Grzegorz Kade ◽  
Sławomir Literacki ◽  
Agnieszka Rzeszotarska ◽  
Stanisław Niemczyk ◽  
Arkadiusz Lubas

Introduction: The purpose of this study was to evaluate the impact of continuous veno-venous hemodialysis (CVVHD) using high cutoff (HCO) hemofilters on the removal of procalcitonin (PCT), and other inflammatory markers in the treatment of patients during septic shock with acute kidney injury (AKI). Materials and Methods: Thirty-six patients with septic shock and AKI were included in the study. Before and after the 24-h HCO-CVVHD, PCT, native C-reactive protein (CRP) and cytokines (interleukin-1β, interleukin-6, interleukin-12, interleukin-17, tumor necrosis factor-α) in serum and effluent were assessed. Results: After the HCO-CVVHD serum concentrations of PCT, CRP and selected cytokines were significantly lower. The decrease in PCT was bigger than in CRP (p = 0.007). The change in PCT concentration was significantly influenced by PCT and IL-17 clearances (R2 = 0.525; p < 0.001). Conclusion: In contrast to the native CRP, monitoring of PCT during HCO-CVVHD is less useful because it reflects the clearance of this marker and anti-inflammatory effectiveness of the method.


2017 ◽  
Vol 37 (9) ◽  
pp. 937-943 ◽  
Author(s):  
AA Fouad ◽  
WN Al-Melhim

The present study investigated the probable protective effect of vanillin (VLN) against kidney injury induced by cisplatin (CSN) and methotrexate (MTX) in rats. The rats received a single injection of either CSN (7.5 mg/kg, i.p.) or MTX (20 mg/kg, i.p.). VLN treatment (150 mg/kg/day, i.p.) was started 1 day before administration of the nephrotoxic agents and continued for 7 days. Both CSN and MTX significantly increased serum creatinine, cystatin C, and neutrophil gelatinase–associated lipocalin and kidney tissue renal malondialdehyde, inducible nitric oxide synthase, tumor necrosis factor-α, interleukin-18, nuclear factor-κB p65, cytosolic cytochrome C, and caspase-3 and significantly decreased renal total antioxidant capacity and Bcl-2/Bax ratio in rats. VLN significantly ameliorated the changes of biochemical parameters induced by CSN and MTX. VLN also significantly reduced CSN- and MTX-induced histopathological injury and the expression of Fas ligand in rat kidneys. In conclusion, VLN significantly protected against CSN- and MTX-induced kidney injury in rats by inhibiting oxidative/nitrosative stress, inflammation, and apoptosis.


2019 ◽  
Vol 19 (3) ◽  
pp. 247-258 ◽  
Author(s):  
Mahsa Hatami ◽  
Mina Abdolahi ◽  
Neda Soveyd ◽  
Mahmoud Djalali ◽  
Mansoureh Togha ◽  
...  

Objective: Neuroinflammatory disease is a general term used to denote the progressive loss of neuronal function or structure. Many neuroinflammatory diseases, including Alzheimer’s, Parkinson’s, and multiple sclerosis (MS), occur due to neuroinflammation. Neuroinflammation increases nuclear factor-κB (NF-κB) levels, cyclooxygenase-2 enzymes and inducible nitric oxide synthase, resulting in the release of inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). It could also lead to cellular deterioration and symptoms of neuroinflammatory diseases. Recent studies have suggested that curcumin (the active ingredient in turmeric) could alleviate the process of neuroinflammatory disease. Thus, the present mini-review was conducted to summarize studies regarding cellular and molecular targets of curcumin relevant to neuroinflammatory disorders. Methods: A literature search strategy was conducted for all English-language literature. Studies that assessed the various properties of curcuminoids in respect of neuroinflammatory disorders were included in this review. Results: The studies have suggested that curcuminoids have significant anti- neuroinflammatory, antioxidant and neuroprotective properties that could attenuate the development and symptom of neuroinflammatory disorders. Curcumin can alleviate neurodegeneration and neuroinflammation through multiple mechanisms, by reducing inflammatory mediators (such as TNF-α, IL-1β, nitric oxide and NF-κB gene expression), and affect mitochondrial dynamics and even epigenetic changes. Conclusion: It is a promising subject of study in the prevention and management of the neuroinflammatory disease. However, controlled, randomized clinical trials are needed to fully evaluate its clinical potential.


2000 ◽  
Vol 279 (3) ◽  
pp. H939-H945 ◽  
Author(s):  
Shareef Mustapha ◽  
Alla Kirshner ◽  
Danielle De Moissac ◽  
Lorrie A. Kirshenbaum

Nuclear factor-κB (NF-κB) is a ubiquitously expressed cellular factor regulated by the cytoplasmic factor inhibitor protein κBα (IκBα). Activation of NF-κB by cytokines, including tumor necrosis factor-α (TNF-α), requires the phosphorylation and degradation of IκBα. An anti-apoptotic role for NF-κB has recently been suggested. In the present study, we ascertained whether death-promoting signals and apoptosis mediated by TNF-α are suppressed by NF-κB in postnatal ventricular myocytes. Stimulation of myocytes with TNF-α resulted in a 12.1-fold increase ( P < 0.01) in NF-κB-dependent gene transcription and DNA binding compared with controls. This was accompanied by a corresponding increase in the NF-κB target protein A20 as determined by Western blot analysis. Vital staining revealed that TNF-α was not cytotoxic to myocytes and did not provoke apoptosis. Adenovirus-mediated delivery of a nonphosphorylatable form of IκBα to inactivate NF-κB prevented TNF-α-stimulated NF-κB-dependent gene transcription and nuclear NF-κB DNA binding. Importantly, myocytes stimulated with TNF-α and defective for NF-κB activation resulted in a 2.2-fold increase ( P < 0.001) in apoptosis. To our knowledge, the data provide the first indication that a functional NF-κB signaling pathway is crucial for suppressing death-promoting signals mediated by TNF-α in ventricular myocytes.


2001 ◽  
Vol 280 (6) ◽  
pp. G1197-G1208 ◽  
Author(s):  
Eva Vaquero ◽  
Ilya Gukovsky ◽  
Vjekoslav Zaninovic ◽  
Anna S. Gukovskaya ◽  
Stephen J. Pandol

Transcription factor nuclear factor-κB (NF-κB) is activated in cerulein pancreatitis and mediates cytokine expression. The role of transcription factor activation in other models of pancreatitis has not been established. Here we report upregulation of NF-κB and inflammatory molecules, and their correlation with local pancreatic injury, in a model of severe pancreatitis. Rats received intraductal infusion of taurocholate or saline, and the pancreatic head and tail were analyzed separately. NF-κB and activator protein-1 (AP-1) activation were assessed by gel shift assay, and mRNA expression of interleukin-6, tumor necrosis factor-α, KC, monocyte chemoattractant protein-1, and inducible nitric oxide synthase was assessed by semiquantitative RT-PCR. Morphological damage and trypsin activation were much greater in the pancreatic head than tail, in parallel with a stronger activation of NF-κB and cytokine mRNA. Saline infusion mildly affected these parameters. AP-1 was strongly activated in both pancreatic segments after either taurocholate or saline infusion. NF-κB inhibition with N-acetylcysteine ameliorated the local inflammatory response. Correlation between localized NF-κB activation, cytokine upregulation, and tissue damage suggests a key role for NF-κB in the development of the inflammatory response of acute pancreatitis.


2019 ◽  
Vol 9 (1) ◽  
pp. 42-48
Author(s):  
Ali Ayaash ◽  
Dipesh Maan ◽  
Anastasios Kapetanos ◽  
Mark Bunker ◽  
Mary Chester Wasko ◽  
...  

Crescentic glomerulonephritis (GN) without immune reactants or deposits (referred to as pauci-immune) is typically characterized by the presence of anti-neutrophilic cytoplasmic antibodies (ANCA). While ANCA-negative patients might be expected to have a more benign course, they often have poor renal outcomes, especially without treatment with steroids and immune-modulating therapy. Pauci-immune crescentic GN can also co-exist with other autoimmune conditions, including rheumatoid arthritis (RA). Here, we describe an ANCA-negative patient with RA who developed dialysis-requiring acute kidney injury (AKI) with findings consistent with focal pauci-immune crescentic GN (i.e., no IgG or immune complex on kidney biopsy). Coexistent conditions included Klebsiella sepsis attributed to pneumonia, rhabdomyolysis, leukocytoclastic immune-mediated skin vasculitis, and positive ANA. He had spontaneous improvement in renal function without immunosuppressive therapy. This crescentic GN was not associated with poor renal outcome as AKI resolved with supportive care and treatment of his infection. The AKI was likely multifactorial with co-existing acute tubular necrosis in the setting of Kebsiella sepsis and rhabdomyolysis, and the crescentic GN was felt more likely to be related to the infection rather than having a primary role. This case highlights the importance of viewing crescentic GN in the context of the clinical picture, as it may not always lead to the need of aggressive immune suppression and is not a universally poor prognostic kidney finding. However, these cases do warrant close follow-up as our patient had recurrent RA disease manifestations over the next 2 years that eventually led to his death from severe pulmonary hypertension.


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