How did agre use simple osmosis experiment to prove the function of aquaporin?

Agre verified his hypothesis in anexperiment where he associated cells which includes the protein with cells that did not have it. When the cells were placed inside a water solution, those that had the protein inside their membranes absorbed water by osmosis and increased up. Those that lacked the protein were unaffected. He also conducted trials with artificial cells called liposomes, which are a type of soap bubble surrounded  by water on its extremities and also inside. He figured out that the liposomes became permeable to water if the protein was planted inside their membranes.