title: Inhibition of Brain Mitogen-Activated Protein Kinase Signaling Reduces Central Endoplasmic Reticulum Stress and Inflammation and Sympathetic Nerve Activity in Heart Failure Rats.
abstract: Mitogen-activated protein kinase (MAPK) signaling and endoplasmic reticulum (ER) stress in the brain have been implicated in the pathophysiology of hypertension. This study determined whether ER stress occurs in subfornical organ and hypothalamic paraventricular nucleus in heart failure (HF) and how MAPK signaling interacts with ER stress and other inflammatory mediators. HF rats had significantly higher levels of the ER stress biomarkers (glucose-regulated protein 78, activating transcription factor 6, activating transcription factor 4, X-box binding protein 1, P58(IPK), and C/EBP homologous protein) in subfornical organ and paraventricular nucleus, which were attenuated by a 4-week intracerebroventricular infusion of inhibitors selective for p44/42 MAPK (PD98059), p38 MAPK (SB203580), or c-Jun N-terminal kinase (SP600125). HF rats also had higher mRNA levels of tumor necrosis factor-α, interleukin-1β, cyclooxygenase-2, and nuclear factor-κB p65, and a lower mRNA level of IκB-α, in subfornical organ and paraventricular nucleus, compared with SHAM rats, and these indicators of increased inflammation were attenuated in the HF rats treated with the MAPK inhibitors. Plasma norepinephrine level was higher in HF rats than in SHAM rats but was reduced in the HF rats treated with PD98059 and SB203580. A 4-week intracerebroventricular infusion of PD98059 also improved some hemodynamic and anatomic indicators of left ventricular function in HF rats. These data demonstrate that ER stress increases in the subfornical organ and paraventricular nucleus of rats with ischemia-induced HF and that inhibition of brain MAPK signaling reduces brain ER stress and inflammation and decreases sympathetic excitation in HF. An interaction between MAPK signaling and ER stress in cardiovascular regions of the brain may contribute to the development of HF.
authors.affiliation: From the Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City (S.-G.W., Y.Y., R.M.W., R.B.F.); and Research Service, Veterans Affairs Medical Center, Iowa City, IA (R.B.F.).
authors.forename: Shun-Guang
authors.initials: SG
authors.lastname: Wei
authors.affiliation: From the Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City (S.-G.W., Y.Y., R.M.W., R.B.F.); and Research Service, Veterans Affairs Medical Center, Iowa City, IA (R.B.F.).
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.affiliation: From the Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City (S.-G.W., Y.Y., R.M.W., R.B.F.); and Research Service, Veterans Affairs Medical Center, Iowa City, IA (R.B.F.).
authors.forename: Robert M
authors.initials: RM
authors.lastname: Weiss
authors.affiliation: From the Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City (S.-G.W., Y.Y., R.M.W., R.B.F.); and Research Service, Veterans Affairs Medical Center, Iowa City, IA (R.B.F.). robert-felder@uiowa.edu.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Felder
mesh_terms: D000818:Animals; D015153:Blotting, Western; D004195:Disease Models, Animal; D059865:Endoplasmic Reticulum Stress / Q000235:genetics*; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation; D006333:Heart Failure / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D006439:Hemodynamics / Q000502:physiology; D007249:Inflammation / Q000235:genetics* / Q000378:metabolism; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics* / Q000378:metabolism; D012313:RNA / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D013564:Sympathetic Nervous System / Q000378:metabolism / Q000503:physiopathology*
chemical_list: D012313:RNA; D020928:Mitogen-Activated Protein Kinases
keywords: brain; endoplasmic reticulum stress; heart failure; hypothalamic paraventricular nucleus; subfornical organ; sympathetic nerve activity