I wouldn't fold. Re-raising may end up commiting you with a hand you don't want to be commited with. Short handed, I definitely call to see a flop and go from there. You should still be in good enough shape unless something crazy happens here. He could have you dominated, but there's a much better chance he's raising with a lesser Ace or some other hand you beat if you flop a pair.

reraise to 8000...as long as your image isnt terrible...

If villian has AJ beat he'll probably push and you'll be able to get away from it. If he does flat call that means he has a low-med PP. As long as the flop doesnt come 345 or something push any flop.

But he wont wanna mess with the other big stack so he'll fold almost every time.