Usually, the journal’s copy editor will have an opinion on this. My personal guideline is to adapt the spelling as much to a regular one as possible without diminuishing the identifiability of the name.
Thus, Toys R Us stays like this (because, at least I would have to think am moment about who Toys Are Us is), and Change4Life becomes Change 4 Life ore stays as it is. However, BIG STUFF INC becomes Big Stuff Inc., and etechnicks becomes Etechnicks or possibly eTechnicks, and Ovəя!†he!†0p!!! becomes Over The Top. In particular, there should be a capital letter at the beginning of the word or at least near it and only there (unless it is a real abbrevation), so it can be easily identified as a proper name, hence this is the function of capitalisation in the English (and almost every other) orthography.
For further reading, I recommended: Editors’ enemies and ‘But FUNKY!!!web!!!DUDES.com is their trademark!’.
As for italics and quotation marks, I would not treat such names different from others. If you follow the above rules, they should be identifiable as proper names through capitalisation, which should be sufficient.¹ If the journal’s style reqires you to italicise company names or equip them with quotation marks, that’s another story.
¹ I only italicised the names in the above, because I was talking about the names, not the companies.