Cytopathic effect of rotavirus NSP4 on rat neurons and its influence on intracellular calcium homeostasis
Objective 
To investigate the cytopathic effect of amino acid residues 86 to 175 of rotavirus nonstructural protein 4 (NSP486-175) on rat neurons and to analyze the underlying mechanism. 
 
 
Methods 
Primary cultured rat neurons were treated with NSP486-175 and the morphological changes induced in rat neurons were observed. Lactate dehydrogenase (LDH) activity in the culture supernatant of NSP486-175 treated-neurons was measured. Laser scanning confocal microscope was used to detect the concentration of intracellular Ca2+ labeled with Fluo-3 AM. 
 
 
Results 
Exogenous addition of NSP486-175 induced obvious cytopathic effect on rat neurons. The LDH activity in the culture supernatant of treated-neurons was stronger than that of the control group. The intensity and the distribution of fluorescence in neurons were altered after stimulation with NSP486-175. 
 
 
Conclusion 
NSP486-175 can induce the damage of rat neurons, which may be related to its role in increasing the concentration of intracellular Ca2+ . This study may provide certain theoretical basis for understanding extra-intestinal spread and pathogenesis of rotavirus infection. 
 
 
Key words: 
Rotavirus; NSP486-175; Cytopathic effect; Intracellular calcium ion