Takayuki Ishige

Moesin is a possible target molecule for cytomegalovirus-related Guillain-Barré syndrome

Objective: Previous histochemical studies in the demyelinating form of Guillain-Barré syndrome (GBS), acute inflammatory demyelinating polyneuropathy (AIDP), have shown complement deposition on the surface of Schwann cells, and therefore unknown epitopes would be present on the outer surface of Schwann cells. Methods: We used a proteomic-based approach to search for the target molecules of AIDP in the extracted proteins from schwannoma cells. Sera were obtained from 40 patients with GBS, 31 controls with inflammatory disease, and 46 normal controls. Results: We found that patients with AIDP after cytomegalovirus (CMV) infection have serum autoantibodies against membrane-organizing extension spike protein (moesin), which is expressed in the Schwann cell processes at the nodes of Ranvier and is crucial for myelination. Of the 40 patients with GBS, 6 had recent CMV infection and 5 of them (83%) had high levels of serum immunoglobulin G antibodies against moesin. The anti-moesin antibodies were found in none of the control subjects with disease including 5 with CMV infection but no neuropathy, and only 2 (4%) of the 46 normal control subjects. Immunocytochemistry showed that moesin was stained at the distal tips of schwannoma cells by sera from the patients with CMV-related AIDP but not by sera from controls. Conclusion: Moesin is a possible immunologic target molecule of pathogenic autoantibodies in patients with CMV-related AIDP. Classification of evidence: This study provides Class II evidence that levels of serum anti-moesin antibodies accurately distinguishes CMV-related AIDP from non–CMV-related AIDP (sensitivity 83%, specificity 93%).

The FLS (fatty liver Shionogi) mouse reveals local expressions of lipocalin-2, CXCL1 and CXCL9 in the liver with non-alcoholic steatohepatitis.

BackgroundNonalcoholic fatty liver disease (NAFLD) encompasses a wide spectrum of diseases, ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), which carries a significant risk of progression to cirrhosis and hepatocellular carcinoma. Since NASH is a progressive but reversible condition, it is desirable to distinguish NASH from simple steatosis, and to treat NASH patients at an early stage. To establish appropriate diagnosis and therapy, the pathological mechanisms of the disease should be elucidated; however, these have not been fully clarified for both NASH and simple steatosis. This study aims to reveal the differences between simple steatosis and NASH.MethodsThis study used fatty liver Shionogi (FLS) mice as a NASH model, for comparison with dd Shionogi (DS) mice as a model of simple steatosis. Genome-wide gene expression analysis was performed using Affymetrix GeneChip Mouse Genome 430 2.0 Array, which contains 45101 probe sets for known and predicted genes. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry were used to investigate gene expression changes and protein localizations.ResultsDNA microarray analysis of the liver transcriptomes and qRT-PCR of both types of mice revealed that LCN2, CXCL1 and CXCL9 mRNAs were overexpressed in FLS mouse livers. Immunohistochemistry showed that CXCL1 protein was mainly localized to steatotic hepatocytes. CXCL9 protein-expressing hepatocytes and sinusoidal endothelium were localized in some areas of inflammatory cell infiltration. Most interestingly, hepatocytes expressing LCN2, a kind of adipokine, were localized around almost all inflammatory cell clusters. Furthermore, there was a positive correlation between the number of LCN2-positive hepatocytes in the specimen and the number of inflammatory foci.ConclusionsOverexpression and distinct localization of LCN2, CXCL1 and CXCL9 in the liver of fatty liver Shionogi mice suggest significant roles of these proteins in the pathogenesis of NASH.

Serum cytokine and chemokine profiles in patients with chronic inflammatory demyelinating polyneuropathy

To identify serum cytokine networks specific to chronic inflammatory demyelinating polyneuropathy (CIDP), serum samples of two subgroups (18 patients with typical CIDP and 12 patients with multifocal acquired demyelinating sensory and motor neuropathy [MADSAM]) were analyzed with multiplex magnetic bead-based cytokine assay. TNF-α, HGF, MIP-1β and IL-1β levels were significantly higher in total CIDP patients than in normal controls. Of these, HGF levels were elevated in typical CIDP patients, but not in MADSAM patients. Patients with high HGF levels showed good responses to steroid treatment. Different cytokine profiles among the CIDP subtypes presumably reflect differences in pathophysiology.

Combined Secretomics and Transcriptomics Revealed Cancer-Derived GDF15 is Involved in Diffuse-Type Gastric Cancer Progression and Fibroblast Activation

Gastric cancer is classified into two subtypes, diffuse and intestinal. The diffuse-type gastric cancer (DGC) has poorer prognosis, and the molecular pathology is not yet fully understood. The purpose of this study was to identify functional secreted molecules involved in DGC progression. We integrated the secretomics of six gastric cancer cell lines and gene expression analysis of gastric cancer tissues with publicly available microarray data. Hierarchical clustering revealed characteristic gene expression differences between diffuse- and intestinal-types. GDF15 was selected as a functional secreted molecule owing to high expression only in fetal tissues. Protein expression of GDF15 was higher in DGC cell lines and tissues. Serum levels of GDF15 were significant higher in DGC patients as compared with healthy individuals and chronic gastritis patients, and positively correlated with wall invasion and lymph node metastasis. In addition, the stimulation of GDF15 on NIH3T3 fibroblast enhanced proliferation and up-regulated expression of extracellular matrix genes, which were similar to TGF-β stimulation. These results indicate that GDF15 contributes to fibroblast activation. In conclusion, this study revealed that GDF15 may be a novel functional secreted molecule for DGC progression, possibly having important roles for cancer progression via the affecting fibroblast function, as well as TGF-β.

Application of proteomic technologies to discover and identify biomarkers for periodontal diseases in gingival crevicular fluid: A review

Periodontal disease is a bacterial infection that destroys the gingiva and surrounding tissues of the oral cavity. In recent years, studies have shown a definite association between periodontal disease and other inflammatory conditions of the body. High‐throughput analysis of proteins has become possible with the development of MS technology. This breakthrough in proteome technology enables comparative studies of comprehensive protein expression and identification of protein. In case of periodontal disease, proteome analysis using 2DE, as well as gel‐free methods, has been reported. As a fluid lying in close proximity to periodontal tissue, the gingival crevicular fluid (GCF) is the principal target in the search for biomarkers of periodontal disease, because its protein composition may reflect the disease pathophysiology. Biochemical marker analysis of GCF is effective for objective diagnosis in the early and advanced stages of periodontal disease. Increasing numbers of recent reports have provided evidence that the proteomic approach is a promising tool for the discovery and identification of biochemical markers of periodontal disease. This search is of continuing interest in the field of experimental and clinical periodontal disease research. In this article, we summarize recent comprehensive proteomic studies aimed at discovering and identifying biomarkers of periodontal disease in GCF.

Pentanucleotide repeat-primed PCR for genetic diagnosis of spinocerebellar ataxia type 31

Spinocerebellar ataxia type 31 (SCA31) is defined by the presence of an insertion mutation containing a TGGAA repeat within the intron of the brain-expressed, associated with NEDD4 (BEAN) gene. Detecting this mutation is conventionally done by southern blotting or DNA sequencing, but these methods are technically demanding and not easily implemented in clinical diagnosis. Here, we adapted repeat-primed PCR (RP-PCR) to develop a clinical genetic test for SCA31 using only the PCR process to detect the TGGAA repeat within the insertion mutation. Pentanucleotide RP-PCR and subsequent DNA fragment analysis demonstrated characteristic ladder peaks with a 5-bp periodicity, originating from the TGGAA repeat, in 100% of samples (n=14) from SCA31 patients in whom the presence of the TGGAA repeat had been verified by DNA sequencing. No peaks were observed in a normal control and two non-SCA31 patients, in whom the TGGAA repeat was absent. This method is valuable for genetic diagnosis of SCA31 in clinical practice.

High-throughput screening of extended RAS mutations based on high-resolution melting analysis for prediction of anti-EGFR treatment efficacy in colorectal carcinoma.

OBJECTIVES Recent studies have demonstrated that, in advanced colorectal carcinoma (CRC) patients, extended RAS (in KRAS exons 2-4 and NRAS exons 2-4) and BRAF mutations are negative predictors for anti-EGFR treatment efficacy and negative prognostic factor, respectively. Thus, high-throughput and cost-effective methods for identification of the mutation status are required. DESIGN AND METHODS We developed a PCR-high-resolution melting (HRM)-based method for screening extended RAS and BRAF mutations, and relative frequency of mutations in formalin-fixed paraffin-embedded samples of CRC was analyzed. RESULTS Among 93 CRC samples, 29 harbored mutations in KRAS exon 2, and 9 harbored mutations in BRAF exon 15. Analysis of 55 KRAS exon 2 and BRAF exon 15 wild-type CRC samples identified the following mutations: 1/55 in exon 3 and 2/55 in exon 4 of KRAS; 1/55 in exon 2, 3/55 in exon 3, and 0/55 in exon 4 of NRAS. CONCLUSIONS Our PCR-HRM method will enable rapid determination of the extended RAS and BRAF mutation status prior to anti-EGFR treatment in the clinical setting.

Locked nucleic acid probe enhances Sanger sequencing sensitivity and improves diagnostic accuracy of high-resolution melting-based KRAS mutational analysis.

BACKGROUND Sanger sequencing is the gold standard for mutational analysis and widely used after high resolution melting (HRM) screening. However, the sensitivity of this method may be insufficient for identifying low frequency mutations. Therefore, for accurate diagnosis, enhanced sensitivity is warranted. METHODS We designed a wild-type blocking cycle sequencing method using locked nucleic acid (LNA) probe (LNA-Sanger sequencing) for codons 12 and 13 of KRAS exon 2. We analyzed the sensitivities of HRM, conventional Sanger sequencing, and LNA-Sanger sequencing of formalin-fixed paraffin-embedded (FFPE) reference standard samples with low frequency (5%) mutations in codons 12 and 13. RESULTS Use of LNA probe significantly improved the sensitivity of Sanger sequencing (p=0.0003). Sensitivities of KRAS mutation tests were as follows: HRM, 5%; conventional Sanger sequencing, 10%; and LNA-Sanger sequencing, 5%. FFPE samples with 5% mutation were accurately diagnosed by LNA-Sanger sequencing, whereas it was difficult to identify the mutations by conventional Sanger sequencing. CONCLUSIONS LNA-Sanger sequencing is a facile technique for the enrichment of mutant alleles and useful for the accurate diagnosis of HRM-positive cases with low frequency mutations.

High-Resolution Melting Analyses for Gene Scanning of APC, MLH1, MSH2, and MSH6 Associated with Hereditary Colorectal Cancer

BACKGROUND Hereditary colorectal cancer accounts for approximately 4-5% of all colorectal cancers. The causative genes for familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer are large, making comprehensive analyses difficult. Therefore, high-throughput and practical methods are required to make an early diagnosis of hereditary colorectal cancers and identify high-risk individuals. For this purpose, we developed a novel gene scanning method by high-resolution melting (HRM) analysis. METHODS High-resolution melting (HRM) analysis is a promising prescreening method for nucleic acid sequence variants because of its high sensitivity and high-throughput capability. We evaluated HRM for screening APC, MLH1, MSH2, and MSH6 genes for point mutations, small deletions, and insertions. Simultaneously, we evaluated quantitative polymerase chain reaction-HRM (qPCR-HRM) for screening the MSH2 gene for large rearrangements. RESULTS All 28 point mutations and 1 large rearrangement were successfully detected by qPCR-HRM analysis. CONCLUSIONS A fast and reliable mutation detection strategy with HRM and qPCR-HRM was used to diagnose hereditary colorectal cancers. Because this method is simple and economical, it may be useful in diagnostic laboratories.

Rapid Discrimination between Methicillin-Sensitive and Methicillin-Resistant Staphylococcus aureus Using MALDI-TOF Mass Spectrometry

　Methicillin-resistant Staphylococcus aureus (MRSA) is one of the major pathogens responsible for nosocomial infections. The presence of MRSA in a hospital is detrimental to patients and to hospital management. Thus, rapid identification of MRSA is needed. Here, we report on a prospective method to rapidly discriminate of MSSA from MRSA using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and support vector machine (SVM) analysis in 160 clinical isolates of S. aureus. The predictive model was tested using 100 S. aureus isolates (50 MSSA and 50 MRSA). The identification rates were 90.0% for MSSA and 87.5% for MRSA in a 10-fold cross-validation SVM. In blind test sets, 60 S. aureus isolates (30 MSSA and 30 MRSA) were correctly classified, with identification rates of 93.3% for MSSA and 86.7% for MRSA. The method proposed in this study using the predictive model enables detection of one colony in 5 minutes, and thus is useful at clinical sites at which rapid discrimination of MRSA from MSSA is required.