scholarly journals P0087TRAF3 MODULATION: A NOVEL MECHANISM OF THE ANTI-INFLAMMATORY EFFECTS OF VITAMIN D RECEPTOR AGONIST PARICALCITOL IN RENAL DISEASE

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Sandra Rayego-Mateos ◽  
Jose Luis Morgado Pascual ◽  
José M Valdivielso ◽  
Ana Sanz ◽  
Enrique Bosch panadero ◽  
...  

Abstract Background and Aims Tumor necrosis factor receptor-associated factors (TRAFs) are critical signaling adaptors downstream of pro-inflammatory receptors, involved in canonical and non-canonical nuclear factor-κB (NF-κB) activation. Vitamin D receptor agonists (VDRAs) exert beneficial effects in renal disease and possess anti-inflammatory properties, but the underlying mechanism remains unknown. Our aim was to investigate TRAF3 involvement on renal disease and its potential modulation by VDRAs. Method Studies were done in isolated peripheral blood mononuclear cells (PBMCs) from end-stage renal disease (ESRD) on haemodialysis (treated or not with VDRAs) patients, healthy donors or cultured renal cells. Preclinical models of renal damage were: unilateral ureteral obstruction (UUO), acute renal damage induced by Folic acid (FA) administration and TWEAK-induced renal inflammation. The effect of VDRA (paricalcitol) was tested in vitro and in vivo. Results In PBMCs isolated from ESRD, TRAF3 protein levels were downregulated compared to healthy controls, associated to activation of non-canonical NF-κB2 (downregulation of RelB or p52/NF-κB2 protein levels) and altered pro-inflammatory cytokine profile. Interestingly, treatment of those patients with the VDRA paricalcitol restored all the described features. In vitro experiments in PBMCs and tubular epithelial cells exposed to inflammatory stimuli showed that paricalcitol prevented TRAF3 downregulation, NF-κB2 activation and proinflammatory genes upregulation. Moreover, immunoprecipitation studies showed that paricalcitol diminished TRAF3 ubiquitination in the K48-linked chains and CIAP1-TRAF3 interaction. TRAF3 overexpression by CRIPS/cas9 technology mimics VDRAs effects. In preclinical models of renal damage paricalcitol inhibited renal NF-κB2 activation, reducing p52 and RelB nuclear accumulation and transcriptional activity associated to lower renal inflammation. In TWEAK-induced renal injury in VDR knockout mice, paricalcitol prevented TRAF3 downregulation and NF-κB2-dependent gene upregulation, suggesting a VDR-independent anti-inflammatory effect of paricalcitol. Conclusion The present studies identify TRAF3 downregulation as a key feature promoting inflammation in CKD identifying non-canonical NF-κB activation as a key driver of inflammation in this context. The fact that the VDR is not required for paricalcitol actions suggests novel-signaling pathways involved in the anti-inflammatory effect of paricalcitol. This may allow the design of drugs that restore TRAF3 levels but are devoid of VDR-dependent effects on mineral bone metabolism, which may limit the use of VDRAs as anti-inflammatory agents.

2020 ◽  
Vol 31 (9) ◽  
pp. 2026-2042 ◽  
Author(s):  
Sandra Rayego-Mateos ◽  
Jose Luis Morgado-Pascual ◽  
José Manuel Valdivielso ◽  
Ana Belén Sanz ◽  
Enrique Bosch-Panadero ◽  
...  

BackgroundCKD leads to vitamin D deficiency. Treatment with vitamin D receptor agonists (VDRAs) may have nephroprotective and anti-inflammatory actions, but their mechanisms of action are poorly understood.MethodsModulation of the noncanonical NF-κB2 pathway and its component TNF receptor–associated factor 3 (TRAF3) by the VDRA paricalcitol was studied in PBMCs from patients with ESKD, cytokine-stimulated cells, and preclinical kidney injury models.ResultsIn PBMCs isolated from patients with ESKD, TRAF3 protein levels were lower than in healthy controls. This finding was associated with evidence of noncanonical NF-κB2 activation and a proinflammatory state. However, PBMCs from patients with ESKD treated with paricalcitol did not exhibit these features. Experiments in cultured cells confirmed the link between TRAF3 and NF-κB2/inflammation. Decreased TRAF3 ubiquitination in K48-linked chains and cIAP1-TRAF3 interaction mediated the mechanisms of paricalcitol action.TRAF3 overexpression by CRISPR/Cas9 technology mimicked VDRA’s effects. In a preclinical model of kidney injury, paricalcitol inhibited renal NF-κB2 activation and decreased renal inflammation. In VDR knockout mice with renal injury, paricalcitol prevented TRAF3 downregulation and NF-κB2–dependent gene upregulation, suggesting a VDR-independent anti-inflammatory effect of paricalcitol.ConclusionsThese data suggest the anti-inflammatory actions of paricalcitol depend on TRAF3 modulation and subsequent inhibition of the noncanonical NF-κB2 pathway, identifying a novel mechanism for VDRA’s effects. Circulating TRAF3 levels could be a biomarker of renal damage associated with the inflammatory state.


Author(s):  
Reza Afrisham ◽  
Sahar Sadegh-Nejadi ◽  
Reza Meshkani ◽  
Solaleh Emamgholipour ◽  
Molood Bagherieh ◽  
...  

Introduction: Obesity is a disorder with low-grade chronic inflammation that plays a key role in the hepatic inflammation and steatosis. Moreover, there are studies to support the role of exosomes in the cellular communications, the regulation of metabolic homeostasis and immunomodulatory activity. Accordingly, we aimed to evaluate the influence of plasma circulating exosomes derived from females with normal-weight and obesity on the secretion of inflammatory cytokines in human liver cells. Methods: Plasma circulating exosomes were isolated from four normal (N-Exo) and four obese (O-Exo) women. The exosomes were characterized and approved for CD63 expression (common exosomal protein marker) and morphology/size using the western blot and TEM methods, respectively. The exosomes were used for stimulation of HepG2 cells in vitro. After 24 h incubation, the protein levels of TNF-α,IL-6, and IL-1β were measured in the culture supernatant of HepG2 cells using the ELISA kit. Results: The protein levels of IL-6 and TNF-α in the cells treated with O-Exo and N-Exo reduced significantly in comparison with control group (P=0.039 and P<0.001 respectively), while significance differences were not found between normal and obese groups (P=0.808, and P=0.978 respectively). However, no significant differences were found between three groups in term of IL-1β levels (P=0.069). Based on the correlation analysis, the protein levels of IL-6 were positively correlated with TNF-α (r 0.978, P<0.001). Conclusion: These findings suggest that plasma circulating exosomes have probably anti-inflammatory properties independently from body mass index and may decrease the secretion of inflammatory cytokines in liver. However, further investigations in vitro and in vivo are needed to address the anti-inflammatory function of N-Exo and O-Exo in human liver cells and/or other cells.


Acta Tropica ◽  
2021 ◽  
Vol 218 ◽  
pp. 105886
Author(s):  
Sara Benazzouz ◽  
Manel Amri ◽  
Junhua Wang ◽  
Samia Bouaziz ◽  
Fahima Ameur ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2529
Author(s):  
Haeyeop Kim ◽  
Woo Seok Yang ◽  
Khin Myo Htwe ◽  
Mi-Nam Lee ◽  
Young-Dong Kim ◽  
...  

Dipterocarpus tuberculatus Roxb. has been used traditionally as a remedy for many diseases, especially inflammation. Therefore, we analyzed and explored the mechanism of the anti-inflammatory effect of a Dipterocarpus tuberculatus Roxb. ethanol extract (Dt-EE). Dt-EE clearly and dose-dependently inhibited the expression of pro-inflammatory cytokines such as IL-6, TNF-α, and IL-1β in lipopolysaccharide (LPS)-treated RAW264.7 cells. Also, Dt-EE suppressed the activation of the MyD88/TRIF-mediated AP-1 pathway and the AP-1 pathway related proteins JNK2, MKK4/7, and TAK1, which occurred as a result of inhibiting the kinase activity of IRAK1 and IRAK4, the most upstream factors of the AP-1 pathway. Finally, Dt-EE displayed hepatoprotective activity in a mouse model of hepatitis induced with LPS/D-galactosamine (D-GalN) through decreasing the serum levels of alanine aminotransferase and suppressing the activation of JNK and IRAK1. Therefore, our results strongly suggest that Dt-EE could be a candidate anti-inflammatory herbal medicine with IRAK1/AP-1 inhibitory and hepatoprotective properties.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rosangela Montanaro ◽  
Alessio D’Addona ◽  
Andrea Izzo ◽  
Carlo Ruosi ◽  
Vincenzo Brancaleone

AbstractClodronate is a bisphosphonate agent commonly used as anti-osteoporotic drug. Throughout its use, additional anti-inflammatory and analgesic properties have been reported, although the benefits described in the literature could not solely relate to their inhibition of bone resorption. Thus, the purpose of our in vitro study is to investigate whether there are underlying mechanisms explaining the anti-inflammatory effect of clodronate and possibly involving hydrogen sulphide (H2S). Immortalised fibroblast-like synoviocyte cells (K4IM) were cultured and treated with clodronate in presence of TNF-α. Clodronate significantly modulated iNOS expression elicited by TNF-α. Inflammatory markers induced by TNF-α, including IL-1, IL-6, MCP-1 and RANTES, were also suppressed following administration of clodronate. Furthermore, the reduction in enzymatic biosynthesis of CSE-derived H2S, together with the reduction in CSE expression associated with TNF-α treatment, was reverted by clodronate, thus rescuing endogenous H2S pathway activity. Clodronate displays antinflammatory properties through the modulation of H2S pathway and cytokines levels, thus assuring the control of the inflammatory state. Although further investigation is needed to stress out how clodronate exerts its control on H2S pathway, here we showed for the first the involvement of H2S in the additive beneficial effects observed following clodronate therapy.


2006 ◽  
Vol 20 (4) ◽  
pp. 735-748 ◽  
Author(s):  
Samuel Seoane ◽  
Roman Perez-Fernandez

Abstract Pituitary transcription factor-1 (Pit-1) plays a key role in cell differentiation during organogenesis of the anterior pituitary, and as a transcriptional activator for the pituitary GH and prolactin genes. However, Pit-1 is also expressed in nonpituitary cell types and tissues. In breast tumors, Pit-1 mRNA and protein levels are increased with respect to normal breast, and in MCF-7 human breast adenocarcinoma cells, Pit-1 increases GH secretion and cell proliferation. We report here that 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] administration to MCF-7 cells induces a significant decrease in Pit-1 mRNA and protein levels. By deletion analyses, we mapped a region (located between −147 and −171 bp from the transcription start site of the Pit-1 gene) that is sufficient for the repressive response to 1,25-(OH)2D3. Gel mobility shift and chromatin immunoprecipitation assays confirmed the direct interaction between the vitamin D receptor (VDR) as homodimer (without the retinoid X receptor), and the Pit-1 promoter, supporting the view that Pit-1 is a direct transcriptional target of VDR. Our data also indicate that recruitment of histone deacetylase 1 is involved in this repressive effect. This ligand-dependent Pit-1 gene inhibition by VDR in the absence of the retinoid X receptor seems to indicate a new mechanism of transcriptional repression by 1,25-(OH)2D3.


2000 ◽  
Vol 11 (10) ◽  
pp. 1857-1864
Author(s):  
L. SHANNON HOLLIDAY ◽  
STEPHEN L. GLUCK ◽  
EDUARDO SLATOPOLSKY ◽  
ALEX J. BROWN

Abstract. 1,25-Dihydroxy-19-nor-vitamin D2 (19-norD2), a new analog of 1,25(OH)2D3, suppresses parathyroid hormone in renal failure patients and in uremic rats but has less calcemic activity than 1,25(OH)2D3. Although 19-norD2 has high affinity for the vitamin D receptor and similar pharmacokinetics to those of 1,25(OH)2D3, it has much less bone resorbing activity in vivo. The intrinsic activity of 19-norD2 on osteoclastogenesis and activation of bone resorption in mouse bone marrow cultures was examined to determine the mechanism involved. 19-norD2 and 1,25(OH)2D3 (10 nM) were equivalent in stimulating the formation and maintenance of large multinucleated, tartrate-resistant acid phosphatase-positive cells. However, the amount of bone resorbed by osteoclasts stimulated by 10 nM 19-norD2, as measured by pit-forming assays, was reduced 62% compared with 10 nM 1,25(OH)2D3-stimulated osteoclasts (P < 0.05). This difference could not be attributed to enhanced catabolism or to downregulated vitamin D receptor. The rate of degradation of 19-norD2 in cultures was approximately 20% greater than 1,25(OH)2D3, not enough to account for the different effects on bone resorption. The VDR levels were identical in cultures that were treated with 19-norD2 and 1,25(OH)2D3. In summary, 19-norD2 is less effective than 1,25(OH)2D3 in stimulating mouse marrow osteoclasts to resorb bone. The reason for this difference is not clear but seems to involve the late maturation and/or activation of osteoclasts as the number of pits produced by each tartrate-resistant acid phosphatase-positive cell is reduced under stimulation by 19-norD2 compared with 1,25(OH)2D3.


Sign in / Sign up

Export Citation Format

Share Document