title: Essential roles of Cdc42 and MAPK in cadmium-induced apoptosis in Litopenaeus vannamei.
abstract: Cadmium, one of the most toxic heavy metals in aquatic environments, has severe effects on marine invertebrates and fishes. The MAPK signaling pathway plays a vital role in stress responses of animals. The mitogen-activated protein kinase (MAPK) signaling pathway plays a vital role in animals' stress responses, including mediation of apoptosis induced by the Rho GTPase Cdc42. However, there is limited knowledge about its function in shrimps, although disorders exacerbated by environmental stresses (including heavy metal pollution) have caused serious mortality in commercially cultured shrimps. Thus, we probed roles of Cdc42 in Litopenaeus vannamei shrimps (LvCdc42) during cadmium exposure by inhibiting its expression using dsRNA-mediated RNA interference. The treatment successfully reduced expression levels of MAPKs (including p38, JNK, and ERK). Cadmium exposure induced significant increases in expression levels of LvCdc42 and MAPKs, accompanied by reductions in total hemocyte counts (THC) and increases in apoptotic hemocyte ratios and ROS production. However, all of these responses were much weaker in LvCdc42-suppressed shrimps, in which mortality rates were higher than in controls. Our results suggest that the MAPK pathway plays a vital role in shrimps' responses to Cd(2+). They also indicate that LvCdc42 in shrimps participates in its regulation, and thus plays key roles in ROS production, regulation of apoptosis and associated stress responses.
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors: Ting
authors: T
authors: Peng
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China. Electronic address: weina63@aliyun.com.
authors: Wei-Na
authors: WN
authors: Wang
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors: Mei-Mei
authors: MM
authors: Gu
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors: Chen-Ying
authors: CY
authors: Xie
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors: Yu-Chao
authors: YC
authors: Xiao
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors: Yuan
authors: Y
authors: Liu
authors: Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, Guangdong Provincial Key Laboratory for Healthy and Safe Aquaculture, College of Life Science, South China Normal University, Guangzhou 510631, PR China.
authors: Lei
authors: L
authors: Wang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002104:Cadmium / Q000633:toxicity*; D033364:Decapoda / Q000187:drug effects* / Q000378:metabolism; D006434:Hemocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D020764:cdc42 GTP-Binding Protein / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D012330:RNA, Double-Stranded; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D002104:Cadmium; D020928:Mitogen-Activated Protein Kinases; D020764:cdc42 GTP-Binding Protein
keywords: Apoptosis; Cdc42; Litopenaeus vannamei; MAPKs; ROS production; THC; dsRNA interfering technique