No, PoS staking and lending are two very different activities. In PoS staking, the owner of the relevant cryptocurrency pledges their tokens to a validator for the purpose of validating transactions on the network or dApp associated with the token, but never forfeits the right to dispose of these assets. In turn, the owner is rewarded for contributing to the governance process.
In lending, by contrast, assets are loaned out to third parties in exchange for payment of interest, and there are different (and often greater) risks involved for the lender. Notably, the borrower may use or pledge the asset as they wish, and there is the risk that the borrower may fail to repay the loan.
Uphold does not engage in lending.