Moody’s Investors Service on Friday downgraded Pennsylvania State University’s long-term credit rating, anticipating that lawsuits stemming from the Sandusky sex-abuse scandal could have “substantial” consequences for the university’s finances. The ratings agency lowered Penn State’s $893-million in debt to Aa2, the third-highest of its 10 categories, from Aa1. The move also “reflects governance and institutional-culture challenges facing the university,” the agency said, noting that it could take the university a long time to embrace the recommendations outlined in Louis J. Freeh’s damning report that implicated top Penn State administrators in the scandal. Penn State’s new rating has a stable outlook, the agency said, because the university is likely to continue enjoying favorable student demand, donor support, and a strong research operation. In a written statement, the university said it took the downgrade seriously, though officials were not surprised by the move.