Are Dark Matter and Dark Energy related to each other?

Not as far as we know. It would be nice if they were two sides of the same coin, because then Physicists would only have to come up with one theory that would cover both. But it doesn’t seem as though that is the case. They do different things to the Universe: dark matter slows down the expansion rate, dark energy speeds it up. The history of Universe is very much dependent on both the amount of dark matter and the amount of dark energy (oddly, so far as we can tell currently, the history doesn’t depend all that much on what dark matter and dark energy are).