How do Catholics interpret those words?
I never heard of any difference between Catholic and Protestant interpretations of this. Nothing posted here so far would suggest otherwise to me.
From the Catholic Catechism:
Jesus did not experience reprobation as if he himself had sinned.But in the redeeming love that always united him to the Father, he assumed us in the state of our waywardness of sin, to the point that he could say in our name from the cross: “My God, my God, why have you forsaken me?” Having thus established him in solidarity with us sinners, God “did not spare his own Son but gave him up for us all”, so that we might be “reconciled to God by the death of his Son”.
http://www.vatican.va/archive/ENG0015/__P1O.HTM