Novel Variants in the CLCN1, RYR2, and DCTN1 Found in Elderly Japanese Dementia Patients: A Case Series

Dementia has an enormous impact on medical and financial resources in aging societies like Japan. Diagnosis of dementia can be made by physical and mental examinations, imaging tests, and findings of high abnormal proteins in cerebrospinal fluids. In addition, genetic tests can be performed in neurodegenerative diseases such as Alzheimer's disease (AD), frontotemporal dementia (FTD), and Parkinson's disease (PD). In this case series, we presented three cases of dementia with unknown causes who carry novel variants in the genes associated with neurodegenerative diseases. Three patients (Patients 1, 2, and 6) were found by screening 18 dementia patients using a gene panel including 63 genes. The age of onset for Patient 1 was 74 years old, and his father had PD and mother had AD. The age of onset for Patient 2 was 75 years old, and her mother had AD. The age of onset for Patient 6 was 83 years old, and her father, two sisters, and daughter had dementia. The Mini-Mental State Examination produced results of 20, 15, and 22, respectively. The suspected diagnosis by neurological examinations and imaging studies for Patients 1 and 2 was AD, and for Patient 6 was FTD. Patient 1 was treated with donepezil; Patient 2 was treated with donepezil and memantine; and Patient 6 was treated with donepezil, galantamine, and rivastigmine. The three rare variants identified were: CLCN1, encoding a chloride channel, c.2848G>A:p.Glu950Lys (Patient 1); RYR2, encoding a calcium releasing ryanodine receptor, c.13175A>G:p.Lys4392Arg (Patient 2); and DCTN1, encoding a subunit of dynactin, c. 3209G>A:p.Arg1070Gln (Patient 6). The detected variants were interpreted according to the American College of Medical Genetics (ACMG) guidelines. The minor allele frequency for each variant was 0.025%, 0.023%, and 0.0004% in East Asians, respectively. The DCTN1 variant found in Patient 6 might be associated with FTD. Although none of them were previously reported in dementia patients, all variants were classified as variants of unknown significance (VUS). Our report suggests that results of genetic tests in elderly patients with dementia need to be carefully interpreted. Further data accumulation of genotype-phenotype relationships and development of appropriate functional models are warranted

Immunohistochemical Detection of Propionibacterium acnes in Granulomas for Differentiating Sarcoidosis from Other Granulomatous Diseases Utilizing an Automated System with a Commercially Available PAB Antibody

Propionibacterium acnes is implicated in the pathogenesis of sarcoidosis. We investigated the usefulness of immunohistochemistry (IHC) with a commercially available P. acnes-specific monoclonal antibody (PAB antibody) for differentiating sarcoidosis from other granulomatous diseases. Formalin-fixed paraffin-embedded tissue samples from 94 sarcoidosis patients and 30 control patients with other granulomatous diseases were examined by the original manual IHC method. We also compared the detection frequency of P. acnes in sarcoid granulomas between manual and automated IHC methods. P. acnes was detected in sarcoid granulomas of samples obtained by transbronchial lung biopsy (64%), video-associated thoracic surgery (67%), endobronchial-ultrasound-guided transbronchial-needle aspiration (32%), lymph node biopsy (80%), and skin biopsy (80%) from sarcoidosis patients, but not in any non-sarcoid granulomas of the samples obtained from control patients. P. acnes outside granulomas, however, was frequently detected in both groups. The detection status of P. acnes in granulomas did not correlate with the clinical characteristics of sarcoidosis patients. The automated Leica system exhibited the best detection sensitivity (72%) and almost an identical localization for P. acnes in sarcoid granulomas compared with the manual method. IHC with a PAB antibody is useful for differentiating sarcoidosis from other granulomatous diseases by detecting P. acnes in granulomas. An automated method by the Leica system can be used in pathology laboratories for differential diagnosis of granulomas by IHC with the PAB antibody

Proteomic Biomarkers for Acute Interstitial Lung Disease in Gefitinib-Treated Japanese Lung Cancer Patients

Interstitial lung disease (ILD) events have been reported in Japanese non-small-cell lung cancer (NSCLC) patients receiving EGFR tyrosine kinase inhibitors. We investigated proteomic biomarkers for mechanistic insights and improved prediction of ILD. Blood plasma was collected from 43 gefitinib-treated NSCLC patients developing acute ILD (confirmed by blinded diagnostic review) and 123 randomly selected controls in a nested case-control study within a pharmacoepidemiological cohort study in Japan. We generated ∼7 million tandem mass spectrometry (MS/MS) measurements with extensive quality control and validation, producing one of the largest proteomic lung cancer datasets to date, incorporating rigorous study design, phenotype definition, and evaluation of sample processing. After alignment, scaling, and measurement batch adjustment, we identified 41 peptide peaks representing 29 proteins best predicting ILD. Multivariate peptide, protein, and pathway modeling achieved ILD prediction comparable to previously identified clinical variables; combining the two provided some improvement. The acute phase response pathway was strongly represented (17 of 29 proteins, p = 1.0×10−25), suggesting a key role with potential utility as a marker for increased risk of acute ILD events. Validation by Western blotting showed correlation for identified proteins, confirming that robust results can be generated from an MS/MS platform implementing strict quality control

Progenitor properties of symmetrically dividing Drosophila neuroblasts during embryonic and larval development

AbstractAsymmetric cell division generates two daughter cells of differential gene expression and/or cell shape. Drosophila neuroblasts undergo typical asymmetric divisions with regard to both features; this is achieved by asymmetric segregation of cell fate determinants (such as Prospero) and also by asymmetric spindle formation. The loss of genes involved in these individual asymmetric processes has revealed the roles of each asymmetric feature in neurogenesis, yet little is known about the fate of the neuroblast progeny when asymmetric processes are blocked and the cells divide symmetrically. We genetically created such neuroblasts, and found that in embryos, they were initially mitotic and then gradually differentiated into neurons, frequently forming a clone of cells homogeneous in temporal identity. By contrast, larval neuroblasts with the same genotype continued to proliferate without differentiation. Our results indicate that asymmetric divisions govern lineage length and progeny fate, consequently generating neural diversity, while the progeny fate of symmetrically dividing neuroblasts depends on developmental stages, presumably reflecting differential activities of Prospero in the nucleus

Protein Kinase C-gamma and Calcium/Calmodulin-Dependent Protein Kinase II-alpha Are Persistently Translocated to Cell Membranes of the Rat Brain During and After Middle Cerebral Artery Occlusion.

The levels of protein kinase C-γ (PKC-γ) and the calcium/calmodulin-dependent kinase II-α (CaMKII-α) were measured in crude synaptosomal (P2), particulate (P3), and cytosolic (S3) fractions of the neocortex of rats exposed to 1-hour and 2-hour middle cerebral artery occlusion (MCAO) and 2-hour MCAO followed by 2-hour reperfusion. During MCAO, PKC levels increased in P2 and P3 in the most severe ischemic areas concomitantly with a decrease in S3. In the penumbra, PKCγ decreased in S3 without any significant increases in P2 and P3. Total PKC-γ also decreased in the penumbra but not in the ischemic core, suggesting that the protein is degraded by an energy-dependent mechanism, possibly by the 26S proteasome. The CaMKII-α levels increased in P2 but not P3 during ischemia and reperfusion in all ischemic regions, particularly in the ischemic core. Concomitantly, the levels in S3 decreased by 20% to 40% in the penumbra and by approximately 80% in the ischemic core. There were no changes in the total levels of CaMKII-α during MCAO. The authors conclude that during and after ischemia, PKC and CaMKII-α are translocated to the cell membranes, particularly synaptic membranes, where they may modulate cellular function, such as neurotransmission, and also affect cell survival. Drugs preventing PKC and/or CaMKII-α translocation may prove beneficial against ischemic cell death