Obesity-associated extracellular mtDNA activates central TGFβ pathway to cause blood pressure increase.

Abstract

Hypothalamic inflammation was recently found to mediate obesity-related hypertension, but the responsible upstream mediators remain unexplored. In this study, we show that dietary obesity is associated with extracellular release of mitochondrial DNA (mtDNA) into the cerebrospinal fluid and that central delivery of mtDNA mimics transforming growth factor-β (TGFβ) excess to activate downstream signaling pathways. Physiological study reveals that central administration of mtDNA or TGFβ is sufficient to cause hypertension in mice. Knockout of the TGFβ receptor in proopiomelanocortin neurons counteracts the hypertensive effect of not only TGFβ but also mtDNA excess, while the hypertensive action of central mtDNA can be blocked pharmacologically by a TGFβ receptor antagonist or genetically by TGFβ receptor knockout. Finally, we confirm that obesity-induced hypertension can be reversed through central treatment with TGFβ receptor antagonist. In conclusion, circulating mtDNA in the brain employs neural TGFβ pathway to mediate a central inflammatory mechanism of obesity-related hypertension.

• Authors: Albert Alé, Yalin Zhang, Cheng Han, Dongsheng Cai
• Journal: American journal of physiology. Endocrinology and metabolism (Am J Physiol Endocrinol Metab) Vol. 312 Issue 3 Pg. E161-E174 (03 01 2017) ISSN: 1522-1555 [Electronic] United States
• PMID: 27894066 (Publication Type: Journal Article)
• Copyright: Copyright © 2017 the American Physiological Society.

Chemical References

• 4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide
• Benzamides
• DNA, Mitochondrial
• Dioxoles
• Receptors, Transforming Growth Factor beta
• Transforming Growth Factor beta
• Transforming Growth Factor beta1
• Pro-Opiomelanocortin
• Protein Serine-Threonine Kinases
• Receptor, Transforming Growth Factor-beta Type II

Topics

• Animals
• Benzamides (pharmacology)
• Blood Pressure (immunology)
• Blotting, Western
• DNA, Mitochondrial (cerebrospinal fluid, immunology, metabolism, pharmacology)
• Diet, High-Fat
• Dioxoles (pharmacology)
• Hypertension (etiology, immunology)
• Hypothalamus (immunology, metabolism)
• Male
• Mice
• Mice, Knockout
• Neurons (immunology, metabolism)
• Obesity (complications, immunology)
• Pro-Opiomelanocortin (metabolism)
• Protein Serine-Threonine Kinases (antagonists & inhibitors, genetics, immunology)
• Receptor, Transforming Growth Factor-beta Type II
• Receptors, Transforming Growth Factor beta (antagonists & inhibitors, genetics, immunology)
• Third Ventricle
• Transforming Growth Factor beta (immunology)
• Transforming Growth Factor beta1 (pharmacology)