Fig. 5

Immunocytochemical analysis of the effects of FK506 on the FK506-binding protein, calcineurin, and markers of mitochondrial fusion in non-tg and gp120 tg mice. Non-tg and gp120 tg mice were treated with vehicle or FK506 for 4 weeks, and serial vibratome sections were immunostained and analyzed by digital bright-field microscopy. Representative images are shown from the frontal cortex. Calcineurin is an FK506-binding protein, and OPA1 and MFN1 are GTPases that are required for mitochondrial fusion. Black arrowheads indicate the granular staining pattern. a Representative bright-field microscopic images and b computer-aided ImageJ analysis of sections incubated with antibodies against calcineurin, which was unaffected by mouse type or treatment, while c OPA1 was significantly decreased in vehicle-treated gp120 tg mice compared to vehicle-treated non-tg mice. Treatment of gp120 mice with FK506 rescued the loss of OPA1. d Levels of MFN1 were significantly increased in FK506-treated gp120 mice compared to vehicle-treated non-tg mice. e mtHSP70 was included as a control protein and was unaffected by treatment or mouse type. Scale bar = 20 μm. *p < 0.05, by one-way ANOVA post hoc Dunnett’s; ^# p < 0.05, by one-way ANOVA post hoc Tukey-Kramer. N = 10; age = 12 months of age