Role of Sex Hormones And Their Receptors On Gastric Nrf2 And Neuronal Nitric Oxide Synthase Function In An Experimental Hyperglycemia Model

Nitrite Production ◽

Oxide Synthase ◽

Abstract Background: Gastroparesis, a condition of abnormal gastric emptying, is most commonly observed in diabetic women. To date, the role of ovarian hormones and/or gastric hormone receptors on regulating nitrergic-mediated gastric motility remains inconclusive. Aim: The purpose of this study is to investigate whether sex hormones/their receptors can attenuate altered Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), neuronal Nitric Oxide Synthase (nNOS) expression and nitrergic relaxation in gastric neuromuscular tissues exposed to in-vitro hyperglycemia (HG). Methods: Gastric neuromuscular sections from adult female C57BL/6J mice were incubated in normoglycemic (NG, 5mM) or hyperglycemic (30 mM or 50 mM) conditions in the presence or absence of selective estrogen receptor (ER) agonists (ERα /PPT or ERβ: DPN); or non-selective sex hormone receptor antagonists (ER/ICI 182,780, or progesterone receptor (PR)/ RU486) for 48 hours. mRNA, protein expression and nitrergic relaxation of circular gastric neuromuscular strips were assessed. Results: Our findings in HG, compared to NG, demonstrate a significant reduction in ER, Nrf2, and nNOS expression in gastric specimens. In addition, in-vitro treatment with sex hormones and/or their agonists significantly (*p<0.05) restored Nrf2/nNOSα expression and total nitrite production. Conversely, ER, but not PR, antagonist significantly reduced Nrf2/nNOSα expression and nitrergic relaxation. Conclusions: Our data suggest that ER’s can regulate nitrergic function by improving Nrf2/nNOS expression in experimental hyperglycemia.

Role of sex hormones and their receptors on gastric Nrf2 and neuronal nitric oxide synthase function in an experimental hyperglycemia model

BMC Gastroenterology ◽

10.1186/s12876-020-01453-2 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Jeremy Sprouse ◽

Chethan Sampath ◽

Pandu R. Gangula

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Sex Hormones ◽

Hormone Receptors ◽

Nitrite Production ◽

Oxide Synthase ◽

Abstract Background Gastroparesis, a condition of abnormal gastric emptying, is most commonly observed in diabetic women. To date, the role of ovarian hormones and/or gastric hormone receptors on regulating nitrergic-mediated gastric motility remains inconclusive. Aim The purpose of this study is to investigate whether sex hormones/their receptors can attenuate altered Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), neuronal Nitric Oxide Synthase (nNOS) expression and nitrergic relaxation in gastric neuromuscular tissues exposed to in-vitro hyperglycemia (HG). Methods Gastric neuromuscular sections from adult female C57BL/6 J mice were incubated in normoglycemic (NG, 5 mM) or hyperglycemic (30 mM or 50 mM) conditions in the presence or absence of selective estrogen receptor (ER) agonists (ERα /PPT or ERβ: DPN); or non-selective sex hormone receptor antagonists (ER/ICI 182,780, or progesterone receptor (PR)/ RU486) for 48 h. mRNA, protein expression and nitrergic relaxation of circular gastric neuromuscular strips were assessed. Results Our findings in HG, compared to NG, demonstrate a significant reduction in ER, Nrf2, and nNOS expression in gastric specimens. In addition, in-vitro treatment with sex hormones and/or their agonists significantly (*p < 0.05) restored Nrf2/nNOSα expression and total nitrite production. Conversely, ER, but not PR, antagonist significantly reduced Nrf2/nNOSα expression and nitrergic relaxation. Conclusions Our data suggest that ER’s can regulate nitrergic function by improving Nrf2/nNOS expression in experimental hyperglycemia.

Role of Sex Hormones And Their Receptors On Gastric Nrf2 And Neuronal Nitric Oxide Synthase Function In An Experimental Hyperglycemia Model

10.21203/rs.2.14913/v1 ◽

2019 ◽

Author(s):

Jeremy Sprouse ◽

Chethan Sampath ◽

PANDU GANGULA

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Sex Hormones ◽

Hormone Receptors ◽

Nitrite Production ◽

Oxide Synthase ◽

Abstract Background: Gastroparesis, a condition of abnormal gastric emptying, is most commonly observed in diabetic women. To date, the role of ovarian hormones and/or gastric hormone receptors on regulating nitrergic-mediated gastric motility remains inconclusive. Aim: The purpose of this study is to investigate whether sex hormones/their receptors can attenuate altered Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), neuronal Nitric Oxide Synthase (nNOS) expression and nitrergic relaxation in gastric neuromuscular tissues exposed to in-vitro hyperglycemia (HG). Methods: Gastric neuromuscular sections from adult female C57BL/6J mice were incubated in normoglycemic (NG, 5mM) or hyperglycemic (30 mM or 50 mM) conditions in the presence or absence of selective estrogen receptor (ER) agonists (ERα /PPT or ERβ: DPN); or non-selective sex hormone receptor antagonists (ER/ICI 182,780, or progesterone receptor (PR)/ RU486) for 48 hours. mRNA, protein expression and nitrergic relaxation of circular gastric neuromuscular strips were assessed. Results: Our findings in HG, compared to NG, demonstrate a significant reduction in ER, Nrf2, and nNOS expression in gastric specimens. In addition, in-vitro treatment with sex hormones and/or their agonists significantly (*p<0.05) restored Nrf2/nNOSα expression and total nitrite production. Conversely, ER, but not PR, antagonist significantly reduced Nrf2/nNOSα expression and nitrergic relaxation. Conclusions: Our data suggest that ER’s can regulate nitrergic function by improving Nrf2/nNOS expression in experimental hyperglycemia. Keywords: Gastroparesis; Sex Hormones; Estrogen Receptors; Drug Therapy; nNOS, Nrf2, Nitrergic Relaxation

Role of Sex Hormones and Their Receptors on Gastric Nrf2 and Neuronal Nitric Oxide Function in an Experimental Hyperglycemia Model

10.21203/rs.2.14913/v2 ◽

2020 ◽

Author(s):

Jeremy Sprouse ◽

Chethan Sampath ◽

PANDU GANGULA

Keyword(s):

Nitric Oxide ◽

Sex Hormones ◽

Hormone Receptors ◽

Nuclear Factor ◽

Nitrite Production ◽

Oxide Synthase ◽

Nnos Expression ◽

In Vitro Treatment

Abstract Background: Gastroparesis, a condition of abnormal gastric emptying, is most commonly observed in diabetic women. To date, the role of ovarian hormones and/or gastric hormone receptors on regulating nitrergic-mediated gastric motility remains inconclusive. Aim: The purpose of this study is to investigate whether sex hormones/their receptors can attenuate altered Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), neuronal Nitric Oxide Synthase (nNOS) expression and nitrergic relaxation in gastric neuromuscular tissues exposed to in-vitro hyperglycemia (HG). Methods: Gastric neuromuscular sections from adult female C57BL/6J mice were incubated in normoglycemic (NG, 5mM) or hyperglycemic (30 mM or 50 mM) conditions in the presence or absence of selective estrogen receptor (ER) agonists (ERα /PPT or ERβ: DPN); or non-selective sex hormone receptor antagonists (ER/ICI 182,780, or progesterone receptor (PR)/ RU486) for 48 hours. mRNA, protein expression and nitrergic relaxation of circular gastric neuromuscular strips were assessed. Results: Our findings in HG, compared to NG, demonstrate a significant reduction in ER, Nrf2, and nNOS expression in gastric specimens. In addition, in-vitro treatment with sex hormones and/or their agonists significantly (*p<0.05) restored Nrf2/nNOSα expression and total nitrite production. Conversely, ER, but not PR, antagonist significantly reduced Nrf2/nNOSα expression and nitrergic relaxation. Conclusions: Our data suggest that ER’s can regulate nitrergic function by improving Nrf2/nNOS expression in experimental hyperglycemia.

Role of neuronal nitric oxide synthase in gastric hypermotility induced by intracisternal TRH analog, RX 77368, in anesthetized rats

Gastroenterology ◽

10.1016/s0016-5085(01)82651-2 ◽

2001 ◽

Vol 120 (5) ◽

pp. A533-A534

Author(s):

K KANAMOTO ◽

K KAWAKUBO ◽

D ADELSON ◽

Y TACHE

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Anesthetized Rats ◽

Nitric oxide inhibits neuronal nitric oxide synthase by interacting with the heme prosthetic group. Role of tetrahydrobiopterin in modulating the inhibitory action of nitric oxide.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)31854-9 ◽

1994 ◽

Vol 269 (34) ◽

pp. 21644-21649 ◽

Cited By ~ 2

Author(s):

J.M. Griscavage ◽

J.M. Fukuto ◽

Y. Komori ◽

L.J. Ignarro

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Inhibitory Action ◽

Prosthetic Group ◽

Heme Prosthetic Group ◽

The antinociceptive effect of 1-(2-trifluoromethylphenyl) imidazole (TRIM), a potent inhibitor of neuronal nitric oxide synthase in vitro, in the mouse

British Journal of Pharmacology ◽

10.1111/j.1476-5381.1995.tb15078.x ◽

1995 ◽

Vol 116 (5) ◽

pp. 2349-2350 ◽

Cited By ~ 85

Author(s):

Rachel L.C. Handy ◽

P. Wallace ◽

Z.A. Gaffen ◽

K.J. Whitehead ◽

P.K. Moore

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Potent Inhibitor ◽

Antinociceptive Effect ◽

Anteroventral third ventricle (AV3V) lesion affects hypothalamic neuronal nitric oxide synthase (nNOS) expression following water deprivation

Brain Research Bulletin ◽

10.1016/j.brainresbull.2011.07.020 ◽

2011 ◽

Vol 86 (3-4) ◽

pp. 239-245 ◽

Cited By ~ 7

Author(s):

Fábio Alves Aguila ◽

Gabriela Ravanelli Oliveira-Pelegrin ◽

Song Tieng Yao ◽

David Murphy ◽

Maria José Alves Rocha

Keyword(s):

Nitric Oxide ◽

Nitric Oxide Synthase ◽

Water Deprivation ◽

Third Ventricle ◽

Oxide Synthase ◽

Abstract 085: CHIP: E3 Ubiquitin Ligase Mediates Proteasomal Degradation of Neuronal Nitric Oxide Synthase in the Paraventricular Nucleus of Rats with Heart Failure

Hypertension ◽

10.1161/hyp.70.suppl_1.085 ◽

2017 ◽

Vol 70 (suppl_1) ◽

Author(s):

Neeru M Sharma ◽

Kenichi Katsurada ◽

Xuefei Liu ◽

Kaushik P Patel

Keyword(s):

Nitric Oxide ◽

Heart Failure ◽

Nitric Oxide Synthase ◽

Paraventricular Nucleus ◽

Ubiquitin Ligase ◽

Protein A ◽

Proteasomal Degradation ◽

The exaggerated sympathetic drive is a characteristic of heart failure (HF) due to reduced neuronal nitric oxide synthase (nNOS) within the paraventricular nucleus (PVN). Previously we have shown that there were increased accumulation of nNOS-ubiquitin (nNOS-Ub) conjugates in the PVN of rats with HF (1.0±0.05 Sham vs. 1.29±0.06 HF) due to the increased levels of PIN (a protein inhibitor of nNOS, known to dissociate nNOS dimers into monomers) (0.76±0.10 Sham vs. 1.12±0.09 HF) and decreased levels of tetrahydrobiopterin (BH4): a cofactor required for stabilization of nNOS dimers (0.62±0.02 Sham vs. 0.44±0.03 HF). We also showed that there is blunted nitric oxide-mediated inhibition of sympathetic tone via the PVN in HF. Here we examined whether CHIP(C-terminus of Hsp70 -interacting protein), a chaperone-dependent E3 ubiquitin-protein isopeptide ligase known to ubiquitylate Hsp90-chaperoned proteins could act as an ubiquitin ligase for nNOS in the PVN. Immunofluorescence studies revealed colocalization of nNOS and CHIP in the PVN indicating their possible interaction. CHIP expression was increased by 50% in the PVN of rats with HF(0.96±0.08 Sham vs.1.44±0.10* HF). It is shown that Hsp90 protects nNOS from ubiquitination while Hsp70 promotes the ubiquitination and degradation. We observed significant upregulation of Hsp70 (0.49±0.03 Sham vs. 0.65±0.02* HF) with a trend toward the decrease in Hsp90 expression (0.90±0.07 Sham vs. 0.71±0.06 HF). The opposing effects of the two chaperones could account for the increased CHIP-mediated ubiquitination and degradation of dysfunctional nNOS monomers in the PVN of rats with HF. Furthermore, neuronal NG108-15 cell line transfected with the pCMV3-CHIP-GFP spark (CHIP overexpression plasmid) showed approximately 74% increase in CHIP with concomitant 49% decrease in nNOS expression. In vitro ubiquitination assay in NG108 cells transfected with pCMV-(HA-Ub) 8 and pCMV3-CHIP-GFP spark plasmid reveal increased HA-Ub-nNOS conjugates (1.13 ± 0.09 Scramble vs. 1.65 ± 0.12* CHIP plasmid). Taken together, our results identify CHIP as an E3 ligase for ubiquitination of dysfunctional nNOS and CHIP expression is augmented during HF leading to increased proteasomal degradation of nNOS in the PVN.