Brighten up run-down university, the one I went to (8)
I believe the answer is:
illumine
'brighten up' is the definition.
(I've seen this in another clue)
'run-down university the one i went to' is the wordplay.
I cannot quite understand how this works, but
'down' could be 'ill' (I've seen this in another clue) and 'ill' is found in the answer.
'university' could be 'u' (abbreviation for university) and 'u' is present in the answer.
'one' could be 'i' (Roman numeral) and 'i' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for illumine that I've seen before include "Light up (arch/lit)" , "Shed light on, literally or spiritually" .)