I could give a long detailed answer but the short answer is, no .LRN doesn't support it today.
With a lot of work .LRN could be programmed to support MySQL. It's even possible that someone has done this work already, though I haven't heard any specific news on that front.
As a follow-on, personally I'm pessimistic about supporting more database systems than the Oracle and Postgres systems we support now. Keeping the vendor-specific database code in sync and bugfree on just these two adds quite a lot of overhead. More database systems will mean even more overhead.
