Hornerin deposits in neuronal intranuclear inclusion disease: direct identification of proteins with compositionally biased regions in inclusions

Clinical features of neuronal intranuclear inclusion disease with seizures: a systematic literature review

Background

Infant, junior, and adult patients with neuronal intranuclear inclusion disease (NIID) present with various types of seizures. We aimed to conduct a systematic literature review on the clinical characteristics of NIID with seizures to provide novel insight for early diagnosis and treatment and to improve prognosis of these patients.

Methods

We used keywords to screen articles related to NIID and seizures, and data concerning the clinical characteristics of patients, including demographic features, disease characteristics of the seizures, treatment responses, imaging examinations, and other auxiliary examination results were extracted.

Results

The included studies comprised 21 patients with NIID with seizures. The most common clinical phenotypes were cognitive impairment (76.20%) and impaired consciousness (57.14%), and generalized onset motor seizures (46.15%) represented the most common type. Compared with infantile and juvenile cases, the use of antiepileptic drugs in adults led to significant seizure control and symptom improvement, in addition to providing a better prognosis. The number of GGC sequence repeats in the NOTCH2NLC gene in six NIID patients with seizures who underwent genetic testing ranged 72-134.

Conclusion

The most common clinical phenotypes in patients with NIID with seizures were cognitive impairment and consciousness disorders. Patients with NIID presented with various types of seizures, with the most common being generalized onset motor seizures. Adult patients had a better prognosis and were relatively stable. The early diagnosis of NIID with seizures is of great significance for treatment and to improve prognosis.

Mass Spectrometry Imaging in Alzheimer's Disease

Introduction: Amyloid-beta (Aβ) pathology is the precipitating histopathological characteristic of Alzheimer's disease (AD). Although the formation of amyloid plaques in human brains is suggested to be a key factor in initiating AD pathogenesis, it is still not fully understood the upstream events that lead to Aβ plaque formation and its metabolism inside the brains. Methods: Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) has been successfully introduced to study AD pathology in brain tissue both in AD mouse models and human samples. By using MALDI-MSI, a highly selective deposition of Aβ peptides in AD brains with a variety of cerebral amyloid angiopathy (CAA) involvement was observed. Results: MALDI-MSI visualized depositions of shorter peptides in AD brains; Aβ1-36 to Aβ1-39 were quite similarly distributed with Aβ1-40 as a vascular pattern, and deposition of Aβ1-42 and Aβ1-43 was visualized with a distinct senile plaque pattern distributed in parenchyma. Moreover, how MALDI-MSI covered in situ lipidomics of plaque pathology has been reviewed, which is of interest as aberrations in neuronal lipid biochemistry have been implicated in AD pathogenesis. Discussion: In this study, we introduce the methodological concepts and challenges of MALDI-MSI for the studies of AD pathogenesis. Diverse Aβ isoforms including various C- and N-terminal truncations in AD and CAA brain tissues will be visualized. Despite the close relationship between vascular and plaque Aβ deposition, the current strategy will define cross talk between neurodegenerative and cerebrovascular processes at the level of Aβ metabolism.

A case report of neuronal intranuclear inclusion disease with paroxysmal peripheral neuropathy-like onset lacking typical signs on diffusion-weighted imaging

Background

Neuronal intranuclear inclusion disease (NIID) is a slowly progressive neurodegenerative disease characterized by eosinophilic hyaline intranuclear inclusions and the GGC repeats in the 5'-untranslated region of NOTCH2NLC. The prevalent presence of high-intensity signal along the corticomedullary junction on diffusion-weighted imaging (DWI) helps to recognize this heterogeneous disease despite of highly variable clinical manifestations. However, patients without the typical sign on DWI are often misdiagnosed. Besides, there are no reports of NIID patients presenting with paroxysmal peripheral neuropathy-like onset to date.

Case presentation

We present a patient with NIID who suffered recurrent transient numbness in arms for 17 months. Magnetic resonance imaging (MRI) showed diffuse, bilateral white matter lesions without typical subcortical DWI signals. Electrophysiological studies revealed mixed demyelinating and axonal sensorimotor polyneuropathies involving four extremities. After excluding differential diagnosis of peripheral neuropathy through body fluid tests and a sural nerve biopsy, NIID was confirmed by a skin biopsy and the genetic analysis of NOTCH2NLC.

Conclusion

This case innovatively demonstrates that NIID could manifest as paroxysmal peripheral neuropathy-like onset, and addresses the electrophysiological characteristics of NIID in depth. We broaden the clinical spectrum of NIID and provide new insights into its differential diagnosis from the perspective of peripheral neuropathy.

Proteomic profile of nuclei containing p62-positive inclusions in a patient with neuronal intranuclear inclusion disease

Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disease characterized by eosinophilic hyaline intranuclear inclusions in the neurons, glial cells, and other somatic cells. Although CGG repeat expansions in NOTCH2NLC have been identified in most East Asian patients with NIID, the pathophysiology of NIID remains unclear. Ubiquitin- and p62-positive intranuclear inclusions are the pathological hallmark of NIID. Targeted immunostaining studies have identified several other proteins present in these inclusions. However, the global molecular changes within nuclei with these inclusions remained unclear. Herein, we analyzed the proteomic profile of nuclei with p62-positive inclusions in a NIID patient with CGG repeat expansion in NOTCH2NLC to discover candidate proteins involved in the NIID pathophysiology. We used fluorescence-activated cell sorting and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify each protein identified in the nuclei with p62-positive inclusions. The distribution of increased proteins was confirmed via immunofluorescence in autopsy brain samples from three patients with genetically confirmed NIID. Overall, 526 proteins were identified, of which 243 were consistently quantified using MS. A 1.4-fold increase was consistently observed for 20 proteins in nuclei with p62-positive inclusions compared to those without. Fifteen proteins identified with medium or high confidence in the LC-MS/MS analysis were further evaluated. Gene ontology enrichment analysis showed enrichment of several terms, including poly(A) RNA binding, nucleosomal DNA binding, and protein binding. Immunofluorescence studies confirmed that the fluorescent intensities of increased RNA-binding proteins identified by proteomic analysis, namely hnRNP A2/B1, hnRNP A3, and hnRNP C1/C2, were higher in the nuclei with p62-positive inclusions than in those without, which were not confined to the intranuclear inclusions. We identified several increased proteins in nuclei with p62-positive inclusions. Although larger studies are needed to validate our results, these proteomic data may form the basis for understanding the pathophysiology of NIID.