Antioxidant defense and stress protein induction following heat stress in the Mediterranean snailXeropicta derbentina[Pulmonata, Hygromiidae]

Abstract

The Mediterranean snail Xeropicta derbentina (Pulmonata, Hygromiidae), being highly abundant in Southern France, has the need for efficient physiological adaptations to desiccation and overheating posed by dry and hot environmental conditions. As a consequence of heat, oxidative stress manifests in these organisms, which, in turn, leads to the formation of reactive oxygen species (ROS). In this study, we focused on adaptations at the biochemical level by investigation of antioxidant defences and heat shock protein 70 (Hsp70) induction, both essential mechanisms of the heat stress response. We exposed snails to elevated temperature (25, 38, 40, 43 and 45°C) in the laboratory and measured the activity of the antioxidant enzymes catalase (CAT) and glutathione peroxidase (GPx), determined the Hsp70 level and quantified lipid peroxidation. In general, we found a high constitutive level of CAT activity in all treatments, which may be interpreted as a permanent protection against ROS, i.e. hydrogen peroxide. CAT and GPx showed temperature-dependent activity: CAT activity was significantly increased in response to high temperatures (43 and 45°C), whereas GPx exhibited a significantly increased activity at 40°C, probably in response to high levels of lipid peroxides that occurred in the 38°C treatment. Hsp70 showed a maximum induction at 40°C, followed by a decrease at higher temperatures. Our results reveal that X. derbentina possesses a set of efficient mechanisms to cope with the damaging effects of heat. Furthermore, we demonstrated that, besides the well-documented Hsp70 stress response, antioxidant defence plays a crucial role in the snails' competence to survive extreme temperatures.

Response of the Chinese Soft-Shelled Turtle to Acute Heat Stress: Insights From the Systematic Antioxidant Defense

“…Acute heat stress usually links with intensely elevated metabolic rate in ectotherms, leading to greater oxygen consumption as well as increased ROS production. Enhanced antioxidant defenses induced by acute heat stress have been documented in several ectotherm groups, including snails, fish, and insects (Lushchak and Bagnyukova, 2006; Yang et al, 2010; Troschinski et al, 2014). In the present study, P. sinensis showed a relatively conservative antioxidant response to acute and intense heat stress at 33°C followed by 24 h recovery, which suggests a well-balanced performance to an extreme environmental stress.…”

Experimental simulation of environmental warming selects against pigmented morphs of land snails

“…Oxidative stress: Lipid peroxidation was quantified according to the method of Troschinski et al. (2014), which is a modification of the original method (“FOX assay”) of Hermes‐Lima et al. (1995).…”

Snails in the sun: Strategies of terrestrial gastropods to cope with hot and dry conditions

“…In Helix pomatia , glutathione reductase activity and lipid peroxidation remain constant during estivation and the glutathione level even increased in estivating individuals, although estivation resulted in downregulation of catalase and glutathione peroxidase (Nowakowska, Świderska‐Kołacz, Rogalska, & Caputa, ). In Xeropicta derbentina that were exposed to different temperatures for 8 hr, Troschinski, Dieterich, Krais, Triebskorn, and Köhler () and Dieterich et al () recorded the highest lipid peroxidation level at 38°C followed by a second peak at 45–48°C which they proposed to reflect a two‐phase antioxidant defense system. Troschinski, Dieterich, et al () found a high constitutive catalase level supplemented by a particularly high glutathione peroxidase level at 40°C which explained the rather low lipid peroxidation rate at around this temperature.…”

“…In Xeropicta derbentina that were exposed to different temperatures for 8 hr, Troschinski, Dieterich, Krais, Triebskorn, and Köhler () and Dieterich et al () recorded the highest lipid peroxidation level at 38°C followed by a second peak at 45–48°C which they proposed to reflect a two‐phase antioxidant defense system. Troschinski, Dieterich, et al () found a high constitutive catalase level supplemented by a particularly high glutathione peroxidase level at 40°C which explained the rather low lipid peroxidation rate at around this temperature. The catalase level peaked at 43–45°C but decreased at higher temperatures, allowing high lipid peroxidase levels to occur at temperatures of 45°C and higher.…”