Nanoprotein Interaction Atlas Reveals the Transport Pathway of Gold Nanoparticles across Epithelium and Its Association with Wnt/β-Catenin Signaling

A tremendous
number of proteins participate in the delivery and
transport process of nanomedicines. Nanoprotein interactions not only
mediate drug delivery but also determine drug safety. In the field
of biomedical sciences, the epithelial barrier is a huge challenge
for gastrointestinal, intratracheal, intranasal, vaginal, and intrauterine
delivery of nanomedicines. However, the molecular mechanisms by which
nanomedicines cross tissue or cell barriers are not well understood.
Here, we explored the nanoprotein interactions during the transcytosis
of nanoparticles across the epithelial barrier by focusing on the
transport pathway and mechanisms. Due to the limitations of traditional
methods in resolving nanoprotein interactions, we developed a backward
analysis strategy. By simultaneously analyzing the protein corona
on the particle surface and the cellular response after transcytosis,
we integrated the information on both directly and indirectly interacting
proteins, establishing a holistic nanoprotein interaction atlas. It
revealed the dominant role of the EV/ER/Golgi/SV pathway in the transcytosis
of nanoparticles. More importantly, based on the established atlas,
we discovered the association of Wnt/β-catenin signaling with
nanoparticle transportation. The endocytosis for entering cells and
exocytosis/transcytosis for leaving cells were differently regulated
by the Wnt pathway. Notably, this regulatory effect was dependent
on the particle size. Bigger nanoparticles departed from cells through
the exocytosis pathway faster because of the specific bridging effect
on the Wnt-Frizzled interaction and the feedback loop construction
based on the exosomes. This mechanism gives an interpretation at the
molecular level to the transcytosis dilemma of larger nanoparticles.
Moreover, the size-dependent Wnt/β-catenin signaling pathway
provides a promising regulatory and screening platform for the transportation
of different nanomedicines through the epithelial barrier.