Cortisol response to waterborne 4-nonylphenol exposure leads to increased brain POMC and HSP70 mRNA expressions and reduced total antioxidant capacity in juvenile sole (Solea solea).
4-Nonylphenol (4-NP) is a breakdown product of alkylphenolpolyethoxylates and can be found in almost all environmental water matrices. 4-NP can act as environmental stressor on fish, typically causing modulation of hypothalamic-pituitary-interrenal axis (HPI). To examine the effects of the xenoestrogen 4-NP or 17β-estradiol (E2) on induction of stress response mechanisms by evaluating the levels of proopiomelanocortin (POMC) mRNA, heat shock protein 70 (HSP70) mRNA and plasma cortisol, we exposed juvenile sole (Solea solea), under static condition for 7 day, to either 10(-6) or 10(-8) M 4-NP, or 10(-8) M E2. In addition, plasma cortisol titers were correlated to the total antioxidant capacity (TAC), one of the oxidative stress parameters. 4-NP treatments resulted in high levels of POMC mRNA, HSP70 mRNA and plasma cortisol. On the contrary, E2 basically down-regulated POMC expression. Moreover, elevated cortisol levels in fish exposed to the highest dose of 4-NP were accompanied by low TAC. These results suggest that 4-NP modulates the sole HPI axis inducing a cortisol-mediated stress response. Specifically, we suggest that 4-NP affects brain POMC mRNA levels via non-estrogen receptor (ER)-mediated mechanism further supporting the ability of 4-NP to target multiple receptor systems.
Centro Universitario di Ricerca per lo Sviluppo e la Gestione delle Risorse dell'Ambiente Marino e Costiero (UNICRAM), Università degli Studi di Camerino, Lungomare A. Scipioni 6, I-63074 San Benedetto del Tronto (AP), Italy. francesco.palermo@unicam.it
Francesco Alessandro
FA
Palermo
Paolo
P
Cocci
Massimo
M
Nabissi
Alberta
A
Polzonetti-Magni
Gilberto
G
Mosconi
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001786:Blood Glucose; D001921:Brain / Q000187:drug effects / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure / Q000009:adverse effects; D004958:Estradiol / Q000009:adverse effects; D005412:Flatfishes / Q000378:metabolism*; D005786:Gene Expression Regulation; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006854:Hydrocortisone / Q000097:blood* / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism; D018384:Oxidative Stress; D010636:Phenols / Q000009:adverse effects*; D011333:Pro-Opiomelanocortin / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000009:adverse effects
D000975:Antioxidants; D001786:Blood Glucose; D018840:HSP70 Heat-Shock Proteins; D010636:Phenols; D012333:RNA, Messenger; D014874:Water Pollutants, Chemical; D004958:Estradiol; D011333:Pro-Opiomelanocortin; C041594:4-nonylphenol; D006854:Hydrocortisone