Redox-regulated suppression of Splenic T-lymphocyte activation in a model of sympathoexcitation

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Sympathoexcitation, increased circulating norepinephrine, and elevated levels of reactive oxygen species are driving forces underlying numerous cardiovascular diseases, including hypertension. However, the effects of elevated norepinephrine and subsequent reactive oxygen species production in splenic T-lymphocytes during hypertension are not currently understood. We hypothesized that increased systemic levels of norepinephrine inhibits the activation of splenic T-lymphocytes via redox signaling. To address this hypothesis, we examined the status of T-lymphocyte activation in spleens of a mouse model of sympathoexcitation-driven hypertension (ie, norepinephrine infusion). Splenic T-lymphocytes from norepinephrine-infused mice demonstrated decreased proliferation accompanied by a reduction in interferon gamma and tumor necrosis factor-α production as compared with T-lymphocytes from saline-infused mice. Additionally, norepinephrine directly inhibited splenic T-lymphocyte proliferation and cytokine production ex vivo in a dose-dependent manner. Furthermore, norepinephrine caused an increase in G1 arrest in norepinephrine-treated T-lymphocytes, and this was accompanied by a decrease in pro-growth cyclin D3, E1, and E2 mRNA expression. Interestingly, norepinephrine caused an increase in cellular superoxide, which was shown to be partially causal to the inhibitory effects of norepinephrine, as antioxidant supplementation (ie, Tempol) to norepinephrine-infused mice moderately restored T-lymphocyte growth and proinflammatory cytokine production. Our findings indicate that suppression of splenic T-lymphocyte activation occurs in a norepinephrine-driven model of hypertension due to, at least in part, an increase in superoxide. We speculate that further understanding of how norepinephrine mediates its inhibitory effects on splenic T-lymphocytes may elucidate novel pathways for therapeutic mimicry to suppress T-lymphocyte-mediated inflammation in an array of diseases.

Original languageEnglish (US)
Pages (from-to)916-923
Number of pages8
JournalHypertension
Volume65
Issue number4
DOIs
StatePublished - Apr 20 2015

Fingerprint

Lymphocyte Activation
Oxidation-Reduction
Norepinephrine
T-Lymphocytes
Hypertension
Superoxides
Reactive Oxygen Species
Cyclin D3
Cytokines
Growth
Interferon-gamma
Cardiovascular Diseases
Spleen
Tumor Necrosis Factor-alpha
Antioxidants
Inflammation

Keywords

  • cardiovascular disease
  • hypertension
  • immunosuppression
  • inflammation
  • norepinephrine
  • reactive oxygen species
  • superoxide

ASJC Scopus subject areas

  • Internal Medicine

Cite this

Redox-regulated suppression of Splenic T-lymphocyte activation in a model of sympathoexcitation. / Case, Adam; Zimmerman, Matthew C.

In: Hypertension, Vol. 65, No. 4, 20.04.2015, p. 916-923.

Research output: Contribution to journalArticle

@article{610f9df766734d5386bc5819dbd8d1a9,
title = "Redox-regulated suppression of Splenic T-lymphocyte activation in a model of sympathoexcitation",
abstract = "Sympathoexcitation, increased circulating norepinephrine, and elevated levels of reactive oxygen species are driving forces underlying numerous cardiovascular diseases, including hypertension. However, the effects of elevated norepinephrine and subsequent reactive oxygen species production in splenic T-lymphocytes during hypertension are not currently understood. We hypothesized that increased systemic levels of norepinephrine inhibits the activation of splenic T-lymphocytes via redox signaling. To address this hypothesis, we examined the status of T-lymphocyte activation in spleens of a mouse model of sympathoexcitation-driven hypertension (ie, norepinephrine infusion). Splenic T-lymphocytes from norepinephrine-infused mice demonstrated decreased proliferation accompanied by a reduction in interferon gamma and tumor necrosis factor-α production as compared with T-lymphocytes from saline-infused mice. Additionally, norepinephrine directly inhibited splenic T-lymphocyte proliferation and cytokine production ex vivo in a dose-dependent manner. Furthermore, norepinephrine caused an increase in G1 arrest in norepinephrine-treated T-lymphocytes, and this was accompanied by a decrease in pro-growth cyclin D3, E1, and E2 mRNA expression. Interestingly, norepinephrine caused an increase in cellular superoxide, which was shown to be partially causal to the inhibitory effects of norepinephrine, as antioxidant supplementation (ie, Tempol) to norepinephrine-infused mice moderately restored T-lymphocyte growth and proinflammatory cytokine production. Our findings indicate that suppression of splenic T-lymphocyte activation occurs in a norepinephrine-driven model of hypertension due to, at least in part, an increase in superoxide. We speculate that further understanding of how norepinephrine mediates its inhibitory effects on splenic T-lymphocytes may elucidate novel pathways for therapeutic mimicry to suppress T-lymphocyte-mediated inflammation in an array of diseases.",
keywords = "cardiovascular disease, hypertension, immunosuppression, inflammation, norepinephrine, reactive oxygen species, superoxide",
author = "Adam Case and Zimmerman, {Matthew C}",
year = "2015",
month = "4",
day = "20",
doi = "10.1161/HYPERTENSIONAHA.114.05075",
language = "English (US)",
volume = "65",
pages = "916--923",
journal = "Hypertension",
issn = "0194-911X",
publisher = "Lippincott Williams and Wilkins",
number = "4",

}

TY - JOUR

T1 - Redox-regulated suppression of Splenic T-lymphocyte activation in a model of sympathoexcitation

AU - Case, Adam

AU - Zimmerman, Matthew C

PY - 2015/4/20

Y1 - 2015/4/20

N2 - Sympathoexcitation, increased circulating norepinephrine, and elevated levels of reactive oxygen species are driving forces underlying numerous cardiovascular diseases, including hypertension. However, the effects of elevated norepinephrine and subsequent reactive oxygen species production in splenic T-lymphocytes during hypertension are not currently understood. We hypothesized that increased systemic levels of norepinephrine inhibits the activation of splenic T-lymphocytes via redox signaling. To address this hypothesis, we examined the status of T-lymphocyte activation in spleens of a mouse model of sympathoexcitation-driven hypertension (ie, norepinephrine infusion). Splenic T-lymphocytes from norepinephrine-infused mice demonstrated decreased proliferation accompanied by a reduction in interferon gamma and tumor necrosis factor-α production as compared with T-lymphocytes from saline-infused mice. Additionally, norepinephrine directly inhibited splenic T-lymphocyte proliferation and cytokine production ex vivo in a dose-dependent manner. Furthermore, norepinephrine caused an increase in G1 arrest in norepinephrine-treated T-lymphocytes, and this was accompanied by a decrease in pro-growth cyclin D3, E1, and E2 mRNA expression. Interestingly, norepinephrine caused an increase in cellular superoxide, which was shown to be partially causal to the inhibitory effects of norepinephrine, as antioxidant supplementation (ie, Tempol) to norepinephrine-infused mice moderately restored T-lymphocyte growth and proinflammatory cytokine production. Our findings indicate that suppression of splenic T-lymphocyte activation occurs in a norepinephrine-driven model of hypertension due to, at least in part, an increase in superoxide. We speculate that further understanding of how norepinephrine mediates its inhibitory effects on splenic T-lymphocytes may elucidate novel pathways for therapeutic mimicry to suppress T-lymphocyte-mediated inflammation in an array of diseases.

AB - Sympathoexcitation, increased circulating norepinephrine, and elevated levels of reactive oxygen species are driving forces underlying numerous cardiovascular diseases, including hypertension. However, the effects of elevated norepinephrine and subsequent reactive oxygen species production in splenic T-lymphocytes during hypertension are not currently understood. We hypothesized that increased systemic levels of norepinephrine inhibits the activation of splenic T-lymphocytes via redox signaling. To address this hypothesis, we examined the status of T-lymphocyte activation in spleens of a mouse model of sympathoexcitation-driven hypertension (ie, norepinephrine infusion). Splenic T-lymphocytes from norepinephrine-infused mice demonstrated decreased proliferation accompanied by a reduction in interferon gamma and tumor necrosis factor-α production as compared with T-lymphocytes from saline-infused mice. Additionally, norepinephrine directly inhibited splenic T-lymphocyte proliferation and cytokine production ex vivo in a dose-dependent manner. Furthermore, norepinephrine caused an increase in G1 arrest in norepinephrine-treated T-lymphocytes, and this was accompanied by a decrease in pro-growth cyclin D3, E1, and E2 mRNA expression. Interestingly, norepinephrine caused an increase in cellular superoxide, which was shown to be partially causal to the inhibitory effects of norepinephrine, as antioxidant supplementation (ie, Tempol) to norepinephrine-infused mice moderately restored T-lymphocyte growth and proinflammatory cytokine production. Our findings indicate that suppression of splenic T-lymphocyte activation occurs in a norepinephrine-driven model of hypertension due to, at least in part, an increase in superoxide. We speculate that further understanding of how norepinephrine mediates its inhibitory effects on splenic T-lymphocytes may elucidate novel pathways for therapeutic mimicry to suppress T-lymphocyte-mediated inflammation in an array of diseases.

KW - cardiovascular disease

KW - hypertension

KW - immunosuppression

KW - inflammation

KW - norepinephrine

KW - reactive oxygen species

KW - superoxide

UR - http://www.scopus.com/inward/record.url?scp=84937544479&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84937544479&partnerID=8YFLogxK

U2 - 10.1161/HYPERTENSIONAHA.114.05075

DO - 10.1161/HYPERTENSIONAHA.114.05075

M3 - Article

C2 - 25691620

AN - SCOPUS:84937544479

VL - 65

SP - 916

EP - 923

JO - Hypertension

JF - Hypertension

SN - 0194-911X

IS - 4

ER -