HnRNP K mislocalisation in neurons of the dentate nucleus is a novel neuropathological feature of neurodegenerative disease and ageing. (9th February 2022)

• Record Type: Journal Article
• Authors: Sidhu, Rahul; Gatt, Ariana; Fratta, Pietro; Lashley, Tammaryn; Bampton, Alexander
• Is Part Of: Neuropathology & applied neurobiology. Volume 48:Number 4(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-02-09
• Subjects: Alzheimer's disease -- dentate nucleus -- frontotemporal dementia -- hnRNP K; Nervous system -- Diseases -- Pathology -- Periodicals; Nervous system -- Diseases -- Periodicals; 616.8
• DOI: 10.1111/nan.12793
• Languages: English
• ISSNs: 0305-1846

Abstract

Abstract: Nuclear depletion and cytoplasmic mislocalisation of the RNA‐binding protein heterogeneous ribonucleoprotein K (hnRNP K) within pyramidal neurons of the frontal cortex have been shown to be a common neuropathological feature in frontotemporal lobar degeneration (FTLD) and elderly control brain. Here, we describe a second neuronal subtype vulnerable to mislocalisation within the dentate nucleus of the cerebellum. In contrast to neurons within the cerebellar cortex that typically exhibited normal, nuclear staining, many neurons of the dentate nucleus exhibited striking mislocalisation of hnRNP K to the cytoplasm within neurodegenerative disease brain. Mislocalisation frequency in this region was found to be significantly higher in both FTLD‐TDP A and Alzheimer's disease (AD) brain than in age‐matched controls. However, within control (but not disease) subjects, mislocalisation frequency was significantly associated with age‐at‐death with more elderly controls typically exhibiting greater levels of the pathology. This study provides further evidence for hnRNP K mislocalisation being a more anatomically diverse pathology than previously thought and suggests that potential dysfunction of the protein may be more broadly relevant to the fields of neurodegeneration and ageing. Abstract : HnRNP K mislocalisation from the nucleus to the cytoplasm is a commonly observed neuropathological feature in neurons of the dentate nucleus in frontotemporal lobar degeneration (FTLD) and Alzheimer's disease (AD) brain. In keeping with previous findings within pyramidal neurons of the cortex, hnRNP K mislocalisation correlates with age in neurologically normal controls. Hence, hnRNP K mislocalisation and dysfunction is a more neuroanatomically widespread phenomenon than first appreciated and is potentially mechanistically relevant to the wider field of dementia.