KHSRP loss increases neuronal growth and synaptic transmission and alters memory consolidation through RNA stabilization

Abstract

The KH-type splicing regulatory protein (KHSRP) is an RNA-binding protein linked to decay of mRNAs with AU-rich elements. KHSRP was previously shown to destabilize Gap43 mRNA and decrease neurite growth in cultured embryonic neurons. Here, we have tested functions of KHSRP in vivo. We find upregulation of 1460 mRNAs in neocortex of adult Khsrp−/− mice, of which 527 bind to KHSRP with high specificity. These KHSRP targets are involved in pathways for neuronal morphology, axon guidance, neurotransmission and long-term memory. Khsrp−/− mice show increased axon growth and dendritic spine density in vivo. Neuronal cultures from Khsrp−/− mice show increased axon and dendrite growth and elevated KHSRP-target mRNAs, including subcellularly localized mRNAs. Furthermore, neuron-specific knockout of Khsrp confirms these are from neuron-intrinsic roles of KHSRP. Consistent with this, neurons in the hippocampus and infralimbic cortex of Khsrp−/− mice show elevations in frequency of miniature excitatory postsynaptic currents. The Khsrp−/− mice have deficits in trace conditioning and attention set-shifting tasks compared Khsrp+/+ mice, indicating impaired prefrontal- and hippocampal-dependent memory consolidation with loss of KHSRP. Overall, these results indicate that deletion of KHSRP impairs neuronal development resulting in alterations in neuronal morphology and function by changing post-transcriptional control of neuronal gene expression.

The predicted RNA-binding protein regulome of axonal mRNAs

“…5 F), including ELAVL1, which reduces neuronal cytoplasmic mRNA; CUGBP Elav-like family member 4 (CELF4); and KHSRP ( Supplemental Fig. S5I ; Engel et al 2022 ; Olguin et al 2022 ; Patel et al 2022 ). KHSRP and CELF4 regulate mRNA abundance in axons and dendrites ( Snee et al 2002 ), whereas pumilio RNA binding family member 2 (PUM2) shapes the transcriptome in developing axons by retaining mRNAs in the cell body ( Martínez et al 2019 ).…”

“…The ratio between the genes’ abundance in the axons and in the cell body is often used to quantify mRNA axonal localization ( Martínez et al 2019 ; Olguin et al 2022 ); however, this metric correlates with the mRNA abundance in the cell body and the transcript length ( Supplemental Fig. 3C,D ).…”

Adipose-Derived Stem Cells Spontaneously Express Neural Markers When Grown in a PEG-Based 3D Matrix

“…KHRSP has been shown to be highly expressed in the brain tissue. It plays an important role in neuronal development by regulating axonal branching and elongation, while its deficits were linked to impaired neuronal development [109,110].…”

Can RNA Affect Memory Modulation? Implications for PTSD Understanding and Treatment

“…Recently published research on synaptic molecular mechanisms of memory consolidation revealed new insights into the role of KH-type splicing regulatory protein (KHSRP) [ 31 ]. Specifically, the loss of KHSRP was found to increase neuronal growth and synaptic transmission while also altering memory consolidation through RNA stabilization [ 31 ].…”