Non-Lethal Heat Shock of the Asian Green Mussel, Perna viridis, Promotes Hsp70 Synthesis, Induces Thermotolerance and Protects Against Vibrio Infection

Abstract

Mild heat stress promotes thermotolerance and protection against several different stresses in aquatic animals, consequences correlated with the accumulation of heat shock protein 70 (Hsp70). The purpose of this study was to determine if non-lethal heat shock (NLHS) of the Asian green mussel, Perna viridis, an aquatic species of commercial value, promoted the production of Hsp70 and enhanced its resistance to stresses. Initially, the LT50 and LHT for P. viridis were determined to be 42°C and 44°C, respectively, with no heat shock induced death of mussels at 40°C or less. Immunoprobing of western blots revealed augmentation of constitutive (PvHsp70-1) and inducible (PvHsp70-2) Hsp70 in tissue from adductor muscle, foot, gill and mantel of P. viridis exposed to 38°C for 30 min followed by 6 h recovery, NLHS conditions for this organism. Characterization by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that PvHsp70-1 and PvHsp70-2 respectively corresponded most closely to Hsp70 from P. viridis and Mytilus galloprovincialis. Priming of adult mussels with NLHS promoted thermotolerance and increased resistance to V. alginolyticus. The induction of Hsp70 in parallel with enhanced thermotolerance and improved protection against V. alginolyticus, suggests Hsp70 functions in P. viridis as a molecular chaperone and as a stimulator of the immune system.

Sequence and expression analysis of HSP70 family genes in Artemia franciscana

“…monodon and P . viridis (green mussels) 2,26–28 . However, only the expression of one gene, HSP70, has been routinely verified in such studies.…”

“…HSPs play essential roles in organisms, particularly in terms of protection against a variety of stressors. Heat stress can disturb cellular homeostasis in all organisms, potentially resulting in death 2 . However, to mitigate such stress, metabolic profiles often undergo changes so that metabolic homeostasis can be re-established rapidly and effectively; for example, in order to repair cellular damage.…”

Phloroglucinol Treatment Induces Transgenerational Epigenetic Inherited Resistance Against Vibrio Infections and Thermal Stress in a Brine Shrimp (Artemia franciscana) Model

“…Exposure to non-lethal heat shock (NLHS) of shrimp Penaeus vannamei (21), green mussel Perna viridis (22), and brine shrimp A. franciscana (23) induced the expression of heat shock proteins (Hsp70 and Hsp90) and subsequently activated the innate immune system (e.g., proPO system in Penaeus vannamei ), resulting in enhanced disease resistance against Vibrio infections ( V. parahaemolyticus, V. alginolyticus , and V. campbellii ). NLHS has been successfully used in parthenogenetic brine shrimp for inducing transgenerational inherited resistance against vibriosis (17).…”

Heat hardening enhances mitochondrial potential for respiration and oxidative defence capacity in the mantle of thermally stressed Mytilus galloprovincialis

“…Overall, the acquired thermal stress resistance or as it is sometimes called "acquired stress memory", is a phenomenon in which cells exposed to a mild dose of one stress can subsequently survive an otherwise lethal dose of the same or a second stress. There are several reports on the beneficial effects of this adaptive response on the thermal tolerance of several mollusc species, including the Asian green mussel Perna viridis (Linnaeus, 1758) 67 , blue mussel M. edulis 68 and New Zealand green-lipped mussel Perna canaliculus (Gmelin, 1791) 40 . Moreover, warm preconditioning seems to protect against acute heat-induced respiratory dysfunction and delays bleaching in a symbiotic sea anemone 69 .…”