Abstract
Purpose:
To examine whether peritoneal macrophages have deleterious effect on retinal ganglion cell (RGC) survival and axon regeneration in retinal explant co-culture.
Methods:
Seven days after optic nerve (ON) transaction, retinas of adult Fischer rats were dissected out and cut into eight pieces, then co-cultured with inactivated peritoneal macrophages and zymosan activated macrophages. After incubation for seven days, total number and length of outgrown neurites from each retinal explant were determined under an inverted microscope. To examine RGC survival, whole retinas without cutting and pre-ON transection were co-culture with macrophages in different conditions described above. After immunostaining with anti-βIII tubulin antibody, surviving RGCs were observed and quantified under a fluorescence microscope.
Results:
After co-cultured for seven days, our results showed that both zymosan activated and inactivated peritoneal macrophages substantially decreased RGC survival and axon generation. For RGC survival, nearly 50% decrease of the surviving RGCs was shown, regardless of the activated or inactivated status of peritoneal macrophages. For axon regeneration, the average number of regenerated axons per explant was seen to be down-regulated by over 70%; and the average length of axons was decreased by about 60% compared with the control group.
Conclusions:
This study demonstrated that both activated and inactivated peritoneal macrophages have apparent deleterious effects on RGC survival and axonal regeneration when co-cultured with retinal explant.