Man say brought up in Helsinki (4)
I believe the answer is:
isle
'man say' is the definition.
(Isle of Man is an example)
'up in helsinki' is the wordplay.
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'in' indicates the answer is hidden within the clue.
'elsi' is hidden within 'helsinki'.
'elsi' written backwards gives 'ISLE'.
'brought' is the link.
(Other definitions for isle that I've seen before include "Of Man or Youth, for example" , "Land encircled by water" , "eg Hoy, Yell or Sark" , "One surrounded by water" , "This could be key" .)