Ammonia stress under high environmental ammonia induces Hsp70 and Hsp90 in the mud eel, Monopterus cuchia

作者：Hangzo Hnunlalliani; Banerjee Bodhisattwa; Saha Shrabani; Saha Nirmalendu^*

来源：Fish Physiology and Biochemistry, 2017, 43(1): 77-88.

DOI：10.1007/s10695-016-0269-4

• Hyper-ammonia stress
• Ammonia toxicity
• Oxidative stress
• Heat shock protein 70
• Heat shock protein 90
• Monopterus cuchia

The obligatory air-breathing mud eel (Monopterus cuchia) is frequently being challenged with high environmental ammonia (HEA) exposure in its natural habitats. The present study investigated the possible induction of heat shock protein 70 and 90 (hsp70, hsc70, hsp90 alpha and hsp90 beta) genes and more expression of Hsp70 and Hsp90 proteins under ammonia stress in different tissues of the mud eel after exposure to HEA (50 mM NH4Cl) for 14 days. HEA resulted in significant accumulation of toxic ammonia in different body tissues and plasma, which was accompanied with the stimulation of oxidative stress in the mud eel as evidenced by more accumulation of malondialdehyde (MDA) and hydrogen peroxide (H2O2) during exposure to HEA. Further, hyper-ammonia stress led to significant increase in the levels of mRNA transcripts for inducible hsp70 and hsp90 alpha genes and also their translated proteins in different tissues probably as a consequence of induction of hsp70 and hsp90 alpha genes in the mud eel. However, hyper-ammonia stress was neither associated with any significant alterations in the levels of mRNA transcripts for constitutive hsc70 and hsp90 beta genes nor their translated proteins in any of the tissues studied. More abundance of Hsp70 and Hsp90 alpha proteins might be one of the strategies adopted by the mud eel to defend itself from the ammonia-induced cellular damages under ammonia stress. Further, this is the first report of ammonia-induced induction of hsp70 and hsp90 alpha genes under hyper-ammonia stress in any freshwater air-breathing teleost.

• 出版日期2017-2