Paracrine effects of hypoxic fibroblast-derived factors on the MPT-ROS threshold and viability of adult rat cardiac myocytes

K. Shivakumar, S. J. Sollott, M. Sangeetha, S. Sapna, B. Ziman, S. Wang, Edward Lakatta

Research output: Contribution to journalArticle

Abstract

Cardiac fibroblasts contribute to multiple aspects of myocardial function and pathophysiology. The pathogenetic relevance of cytokine production by these cells under hypoxia, however, remains unexplored. With the use of an in vitro cell culture model, this study evaluated cytokine production by hypoxic cardiac fibroblasts and examined two distinct effects of hypoxic fibroblast-conditioned medium (HFCM) on cardiac myocytes and fibroblasts. Hypoxia caused a marked increase in the production of tumor necrosis factor (TNF)-α by cardiac fibroblasts. HFCM significantly enhanced the susceptibility of cardiac myocytes to reactive oxygen species (ROS)-induced mitochondrial permeability transition (MPT), determined by high-precision confocal line-scan imaging following controlled, photoexcitation-induced ROS production within individual mitochondria. Furthermore, exposure of cardiac myocytes to HFCM for 5 h led to loss of viability, as evidenced by change in morphology and annexin staining. HFCM also decreased DNA synthesis in cardiac fibroblasts. Normoxic fibroblast-conditioned medium spiked with TNF-α at 200 pg/ml, a concentration comparable to that in HFCM, promoted loss of myocyte viability and decreased DNA synthesis in cardiac fibroblasts. These effects of HFCM are similar to the reported effects of hypoxia per se on these cell types, showing that hypoxic fibroblast-derived factors may amplify the distinct effects of hypoxia on cardiac cells. Importantly, because both hypoxia and oxidant stress prevail in a setting of ischemia and reperfusion, the effects of soluble factors from hypoxic fibroblasts on the MPT-ROS threshold and viability of myocytes may represent a novel paracrine mechanism that could exacerbate ischemia-reperfusion injury to cardiomyocytes.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume294
Issue number6
DOIs
StatePublished - Jun 2008
Externally publishedYes

Fingerprint

Cardiac Myocytes
Permeability
Reactive Oxygen Species
Fibroblasts
Conditioned Culture Medium
Muscle Cells
Tumor Necrosis Factor-alpha
Cytokines
Annexins
Cell Hypoxia
DNA
Reperfusion Injury
Oxidants
Reperfusion
Mitochondria
Ischemia
Cell Culture Techniques

Keywords

  • Apoptosis
  • Cardiac fibroblasts
  • Cardiac myocyte viability
  • Fibroblast proliferation
  • Fibroblast-conditioned medium
  • Hypoxia
  • Mitochondrial permeability transition-reactive oxygen species threshold
  • Necrosis
  • Tumor necrosis factor-α

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)
  • Cardiology and Cardiovascular Medicine

Cite this

Paracrine effects of hypoxic fibroblast-derived factors on the MPT-ROS threshold and viability of adult rat cardiac myocytes. / Shivakumar, K.; Sollott, S. J.; Sangeetha, M.; Sapna, S.; Ziman, B.; Wang, S.; Lakatta, Edward.

In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 294, No. 6, 06.2008.

Research output: Contribution to journalArticle

@article{607331d2607c4d9893c9286e1426e264,
title = "Paracrine effects of hypoxic fibroblast-derived factors on the MPT-ROS threshold and viability of adult rat cardiac myocytes",
abstract = "Cardiac fibroblasts contribute to multiple aspects of myocardial function and pathophysiology. The pathogenetic relevance of cytokine production by these cells under hypoxia, however, remains unexplored. With the use of an in vitro cell culture model, this study evaluated cytokine production by hypoxic cardiac fibroblasts and examined two distinct effects of hypoxic fibroblast-conditioned medium (HFCM) on cardiac myocytes and fibroblasts. Hypoxia caused a marked increase in the production of tumor necrosis factor (TNF)-α by cardiac fibroblasts. HFCM significantly enhanced the susceptibility of cardiac myocytes to reactive oxygen species (ROS)-induced mitochondrial permeability transition (MPT), determined by high-precision confocal line-scan imaging following controlled, photoexcitation-induced ROS production within individual mitochondria. Furthermore, exposure of cardiac myocytes to HFCM for 5 h led to loss of viability, as evidenced by change in morphology and annexin staining. HFCM also decreased DNA synthesis in cardiac fibroblasts. Normoxic fibroblast-conditioned medium spiked with TNF-α at 200 pg/ml, a concentration comparable to that in HFCM, promoted loss of myocyte viability and decreased DNA synthesis in cardiac fibroblasts. These effects of HFCM are similar to the reported effects of hypoxia per se on these cell types, showing that hypoxic fibroblast-derived factors may amplify the distinct effects of hypoxia on cardiac cells. Importantly, because both hypoxia and oxidant stress prevail in a setting of ischemia and reperfusion, the effects of soluble factors from hypoxic fibroblasts on the MPT-ROS threshold and viability of myocytes may represent a novel paracrine mechanism that could exacerbate ischemia-reperfusion injury to cardiomyocytes.",
keywords = "Apoptosis, Cardiac fibroblasts, Cardiac myocyte viability, Fibroblast proliferation, Fibroblast-conditioned medium, Hypoxia, Mitochondrial permeability transition-reactive oxygen species threshold, Necrosis, Tumor necrosis factor-α",
author = "K. Shivakumar and Sollott, {S. J.} and M. Sangeetha and S. Sapna and B. Ziman and S. Wang and Edward Lakatta",
year = "2008",
month = "6",
doi = "10.1152/ajpheart.91443.2007",
language = "English (US)",
volume = "294",
journal = "American Journal of Physiology",
issn = "0363-6135",
publisher = "American Physiological Society",
number = "6",

}

TY - JOUR

T1 - Paracrine effects of hypoxic fibroblast-derived factors on the MPT-ROS threshold and viability of adult rat cardiac myocytes

AU - Shivakumar, K.

AU - Sollott, S. J.

AU - Sangeetha, M.

AU - Sapna, S.

AU - Ziman, B.

AU - Wang, S.

AU - Lakatta, Edward

PY - 2008/6

Y1 - 2008/6

N2 - Cardiac fibroblasts contribute to multiple aspects of myocardial function and pathophysiology. The pathogenetic relevance of cytokine production by these cells under hypoxia, however, remains unexplored. With the use of an in vitro cell culture model, this study evaluated cytokine production by hypoxic cardiac fibroblasts and examined two distinct effects of hypoxic fibroblast-conditioned medium (HFCM) on cardiac myocytes and fibroblasts. Hypoxia caused a marked increase in the production of tumor necrosis factor (TNF)-α by cardiac fibroblasts. HFCM significantly enhanced the susceptibility of cardiac myocytes to reactive oxygen species (ROS)-induced mitochondrial permeability transition (MPT), determined by high-precision confocal line-scan imaging following controlled, photoexcitation-induced ROS production within individual mitochondria. Furthermore, exposure of cardiac myocytes to HFCM for 5 h led to loss of viability, as evidenced by change in morphology and annexin staining. HFCM also decreased DNA synthesis in cardiac fibroblasts. Normoxic fibroblast-conditioned medium spiked with TNF-α at 200 pg/ml, a concentration comparable to that in HFCM, promoted loss of myocyte viability and decreased DNA synthesis in cardiac fibroblasts. These effects of HFCM are similar to the reported effects of hypoxia per se on these cell types, showing that hypoxic fibroblast-derived factors may amplify the distinct effects of hypoxia on cardiac cells. Importantly, because both hypoxia and oxidant stress prevail in a setting of ischemia and reperfusion, the effects of soluble factors from hypoxic fibroblasts on the MPT-ROS threshold and viability of myocytes may represent a novel paracrine mechanism that could exacerbate ischemia-reperfusion injury to cardiomyocytes.

AB - Cardiac fibroblasts contribute to multiple aspects of myocardial function and pathophysiology. The pathogenetic relevance of cytokine production by these cells under hypoxia, however, remains unexplored. With the use of an in vitro cell culture model, this study evaluated cytokine production by hypoxic cardiac fibroblasts and examined two distinct effects of hypoxic fibroblast-conditioned medium (HFCM) on cardiac myocytes and fibroblasts. Hypoxia caused a marked increase in the production of tumor necrosis factor (TNF)-α by cardiac fibroblasts. HFCM significantly enhanced the susceptibility of cardiac myocytes to reactive oxygen species (ROS)-induced mitochondrial permeability transition (MPT), determined by high-precision confocal line-scan imaging following controlled, photoexcitation-induced ROS production within individual mitochondria. Furthermore, exposure of cardiac myocytes to HFCM for 5 h led to loss of viability, as evidenced by change in morphology and annexin staining. HFCM also decreased DNA synthesis in cardiac fibroblasts. Normoxic fibroblast-conditioned medium spiked with TNF-α at 200 pg/ml, a concentration comparable to that in HFCM, promoted loss of myocyte viability and decreased DNA synthesis in cardiac fibroblasts. These effects of HFCM are similar to the reported effects of hypoxia per se on these cell types, showing that hypoxic fibroblast-derived factors may amplify the distinct effects of hypoxia on cardiac cells. Importantly, because both hypoxia and oxidant stress prevail in a setting of ischemia and reperfusion, the effects of soluble factors from hypoxic fibroblasts on the MPT-ROS threshold and viability of myocytes may represent a novel paracrine mechanism that could exacerbate ischemia-reperfusion injury to cardiomyocytes.

KW - Apoptosis

KW - Cardiac fibroblasts

KW - Cardiac myocyte viability

KW - Fibroblast proliferation

KW - Fibroblast-conditioned medium

KW - Hypoxia

KW - Mitochondrial permeability transition-reactive oxygen species threshold

KW - Necrosis

KW - Tumor necrosis factor-α

UR - http://www.scopus.com/inward/record.url?scp=49249137984&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=49249137984&partnerID=8YFLogxK

U2 - 10.1152/ajpheart.91443.2007

DO - 10.1152/ajpheart.91443.2007

M3 - Article

C2 - 18408121

AN - SCOPUS:49249137984

VL - 294

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6135

IS - 6

ER -