Is it possible for an ace to be considered low in a straight in Texas Hold'em?

No, in Texas Hold'em, an ace cannot be considered low in a straight. In a straight, the ace can only be used as the highest card in the sequence (A-K-Q-J-10) and cannot "wrap around" to be used as a low card (A-2-3-4-5). This is a standard rule in most Poker variants, including Texas Hold'em.