Tumor necrosis factor-α regulates glucocorticoid synthesis in the adrenal glands of Trypanosoma cruzi acutely-infected mice. the role of TNF-R1

PLoS One. 2013 May 22;8(5):e63814. doi: 10.1371/journal.pone.0063814. Print 2013.

Abstract

Adrenal steroidogenesis is under a complex regulation involving extrinsic and intrinsic adrenal factors. TNF-α is an inflammatory cytokine produced in response to tissue injury and several other stimuli. We have previously demonstrated that TNF-R1 knockout (TNF-R1(-/-)) mice have a dysregulated synthesis of glucocorticoids (GCs) during Trypanosoma cruzi acute infection. Since TNF-α may influence GCs production, not only through the hypothalamus-pituitary axis, but also at the adrenal level, we now investigated the role of this cytokine on the adrenal GCs production. Wild type (WT) and TNF-R1(-/-) mice undergoing acute infection (Tc-WT and Tc-TNF-R1(-/-) groups), displayed adrenal hyperplasia together with increased GCs levels. Notably, systemic ACTH remained unchanged in Tc-WT and Tc-TNF-R1(-/-) compared with uninfected mice, suggesting some degree of ACTH-independence of GCs synthesis. TNF-α expression was increased within the adrenal gland from both infected mouse groups, with Tc-WT mice showing an augmented TNF-R1 expression. Tc-WT mice showed increased levels of P-p38 and P-ERK compared to uninfected WT animals, whereas Tc-TNF-R1(-/-) mice had increased p38 and JNK phosphorylation respect to Tc-WT mice. Strikingly, adrenal NF-κB and AP-1 activation during infection was blunted in Tc-TNF-R1(-/-) mice. The accumulation of mRNAs for steroidogenic acute regulatory protein and cytochrome P450 were significantly increased in both Tc-WT and Tc-TNF-R1(-/-) mice; being much more augmented in the latter group, which also had remarkably increased GCs levels. TNF-α emerges as a potent modulator of steroidogenesis in adrenocortical cells during T. cruzi infection in which MAPK pathways, NF-κB and AP-1 seem to play a role in the adrenal synthesis of pro-inflammatory cytokines and enzymes regulating GCs synthesis. These results suggest the existence of an intrinsic immune-adrenal interaction involved in the dysregulated synthesis of GCs during murine Chagas disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenal Glands / metabolism*
  • Adrenocorticotropic Hormone / metabolism
  • Animals
  • Chagas Disease / blood
  • Chagas Disease / genetics
  • Chagas Disease / metabolism*
  • Chagas Disease / parasitology*
  • Corticosterone / genetics
  • Corticosterone / metabolism
  • Cytochrome P-450 Enzyme System / genetics
  • Cytochrome P-450 Enzyme System / metabolism
  • Gene Expression / genetics
  • Glucocorticoids / biosynthesis*
  • Glucocorticoids / genetics
  • Glucocorticoids / metabolism*
  • Inflammation / genetics
  • Inflammation / metabolism
  • Inflammation / parasitology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mitogen-Activated Protein Kinases / genetics
  • Mitogen-Activated Protein Kinases / metabolism
  • NF-kappa B / genetics
  • NF-kappa B / metabolism
  • Phosphorylation / genetics
  • RNA, Messenger / genetics
  • Transcription Factor AP-1 / genetics
  • Transcription Factor AP-1 / metabolism
  • Trypanosoma cruzi
  • Tumor Necrosis Factor-alpha / blood
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism*

Substances

  • Glucocorticoids
  • NF-kappa B
  • RNA, Messenger
  • Transcription Factor AP-1
  • Tumor Necrosis Factor-alpha
  • Adrenocorticotropic Hormone
  • Cytochrome P-450 Enzyme System
  • Mitogen-Activated Protein Kinases
  • Corticosterone

Grants and funding

S.R.V., A.R.P., M.T.R. and O.A.B. are members of National Council Research (CONICET). Support for this study was provided by SCYT-UNR (1MED 372) and Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT, PICT 2008-0980), AmSud-Pasteur Network, as well as CNPq and Faperj (Brazil). The funders had no role in study design, data collection and analysis, decision to publish or preparation the manuscript.