Jiang, T.; Xu, X.; Yu, Y.; Zhu, C.; Ma, C.; Tang, Y.; Min, L.; Tan, M.; Bai, J.; Feng, Z.; Hou, J.

Aberrant alternative splicing alters multiple disease-associated splicing events, including MAPT exon 10 inclusion linked to tau pathology, and thereby impacts Alzheimers disease (AD) progression. Heterogeneous nuclear ribonucleoprotein AB (hnRNPAB) functions as a splicing regulator, yet its roles in AD remain poorly defined. Here, we identified AB332, the full-length isoform of hnRNPAB, as a novel repressor of MAPT exon 10 inclusion. AB332 binds a conserved AAUAU motif and recruits RBMX and RBMXL1 through its RRM and glycine-rich domains to assemble a complex. Beyond MAPT, AB332 modulates a network of splicing events in multiple AD-associated genes, including STAG2, ApoER2, MCL-1, PICALM, and zDHHC7. Importantly, the exon 7-skipping isoform AB285 lacks these activities. Transcriptomic analysis of post-mortem brain tissues from AD patients revealed reduced expression of hnRNPAB, while selective downregulation of AB332 was confirmed in the hippocampus of 3xTg AD mice. We performed a systematic antisense oligonucleotide-tiling screen targeting hnRNPAB exon 7 and its flanking intronic regions, identifying ASO30 that specifically upregulated AB332 expression. In 3xTg AD mice, ASO30 restored hippocampal AB332 levels, reduced pathological tau phosphorylation, and rescued cognitive deficits. These findings define a molecular mechanism by which AB332 regulates AD-associated splicing events, thereby providing a therapeutic strategy targeting hnRNPAB for AD. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=79 SRC="FIGDIR/small/736008v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): [email protected]@b72648org.highwire.dtl.DTLVardef@326851org.highwire.dtl.DTLVardef@15ea418_HPS_FORMAT_FIGEXP M_FIG C_FIG