Changes in Ataxin-10 Expression after Sciatic Nerve Crush in Adult Rats

Clinical and molecular characterization of an emerging chromosome 22q13.31 microdeletion syndrome

Microdeletion of chromosome 22q13.31 is a very rare condition. Fourteen patients have been annotated in public databases but, to date, a clinical comparison has not been done and, consequently, a specific phenotype has not been delineated yet. We describe a patient showing neurodevelopmental disorders, dysmorphic features, and multiple congenital anomalies in which SNP array analysis revealed an interstitial 3.15 Mb de novo microdeletion in the 22q13.31 region encompassing 21 RefSeq genes and seven non-coding microRNAs. To perform an accurate phenotype characterization, clinical features observed in previously reported cases of 22q13.31 microdeletions were reviewed and compared to those observed in our patient. To the best of our knowledge, this is the first time that a comparison between patients carrying overlapping 22q13.31 deletions has been done. This comparison allowed us to identify a distinct spectrum of clinical manifestations suggesting that patients with a de novo interstitial microdeletion involving 22q13.31 have an emerging syndrome characterized by developmental delay/intellectual disability, speech delay/language disorders, behavioral problems, hypotonia, urogenital, and hands/feet anomalies. The microdeletion identified in our patient is the smallest reported so far and, for this reason, useful to perform a detailed genotype-phenotype correlation. In particular, we propose the CELSR1, ATXN10, FBLN1, and UPK3A as candidate genes in the onset of the main clinical features of this contiguous gene syndrome. Thus, the patient reported here broadens our knowledge of the phenotypic consequences of 22q13.31 microdeletions facilitating genotype-phenotype correlations. Additional cases are needed to corroborate our hypothesis and confirm genotype-phenotype correlations of this emerging syndrome.

Reveal the molecular signatures of hepatocellular carcinoma with different sizes by iTRAQ based quantitative proteomics

Tumor size of hepatocellular carcinoma (HCC) is a key parameter for predicting prognosis of HCC patients. The biological behaviors of HCC, such as tumor growth, recurrence and metastasis are significantly associated with tumor size. However, the underlying molecular mechanisms remain unclear. Here, we applied iTRAQ-based proteomic strategy to analyze the proteome differences among small, media, large and huge primary HCC tissues. In brief,88 proteins in small HCC, 69 proteins in media HCC, 118 proteins in large HCC and 215 proteins in huge HCC, were identified by comparing the proteome of cancerous tissues with its corresponding non-cancerous tissues. Further analysis of dysregulated proteins involved in signaling revealed that alteration of ERK1/2 and AKT signaling played important roles in the tumorigenesis or tumor growth in all subtypes. Interestingly, alteration of specific signaling was discovered in small and huge HCC, which might reflect specific molecular mechanisms of tumor growth. Furthermore, the dysregulation degree of a group of proteins has been confirmed to be significantly correlated with the tumor size; these proteins might be potential targets for studying tumor growth of HCC. Overall, we have revealed the molecular signatures of HCC with different tumor sizes, and provided fundamental information for further in-depth study.

BIOLOGICAL SIGNIFICANCE

In this study, we compared the protein expression profiles among different HCC subtypes, including small HCC, media HCC, large HCC and huge HCC for the first time. The results clearly proved that different molecular alterations and specific signaling pathways were indeed involved in different HCC subtypes, which might explain the different malignancy biological behaviors. In addition, the dysregulation degree of a group of proteins has been confirmed to be significantly correlated with the tumor size. We believe that these findings would help us better understand the underlying molecular mechanisms of the tumorigenesis and development of HCC.

Aurora B-dependent phosphorylation of Ataxin-10 promotes the interaction between Ataxin-10 and Plk1 in cytokinesis

Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant neurologic disorder caused by ATTCT expansion in the ATXN10 gene. Previous investigations have identified that depletion of Ataxin-10, the gene product, leads to cellular apoptosis and cytokinesis failure. Herein we identify the mitotic kinase Aurora B as an Ataxin-10 interacting partner. Aurora B interacts with and phosphorylates Ataxin-10 at S12, as evidenced by in vitro kinase and mass spectrometry analysis. Both endogenous and S12-phosphorylated Ataxin-10 localizes to the midbody during cytokinesis, and cytokinetic defects induced by inhibition of ATXN10 expression is not rescued by the S12A mutant. Inhibition of Aurora B or expression of the S12A mutant renders reduced interaction between Ataxin-10 and polo-like kinase 1 (Plk1), a kinase previously identified to regulate Ataxin-10 in cytokinesis. Taken together, we propose a model that Aurora B phosphorylates Ataxin-10 at S12 to promote the interaction between Ataxin-10 and Plk1 in cytokinesis. These findings identify an Aurora B-dependent mechanism that implicates Ataxin-10 in cytokinesis.

Proteomics analyses for the global proteins in the brain tissues of different human prion diseases

Proteomics changes of brain tissues have been described in different neurodegenerative diseases including Alzheimer's disease and Parkinson's disease. However, the brain proteomics of human prion disease remains less understood. In the study, the proteomics patterns of cortex and cerebellum of brain tissues of sporadic Creutzfeldt-Jakob disease, fatal familial insomnia, and G114V genetic CJD were analyzed with isobaric tags for relative and absolute quantitation combined with multidimensional liquid chromatography and MS analysis, with the brains from three normal individuals as controls. Global protein profiling, significant pathway, and functional categories were analyzed. In total, 2287 proteins were identified with quantitative information both in cortex and cerebellum regions. Cerebellum tissues appeared to contain more up- and down-regulated proteins (727 proteins) than cortex regions (312 proteins) of Creutzfeldt-Jakob disease, fatal familial insomnia, and G114V genetic CJD. Viral myocarditis, Parkinson's disease, Alzheimer's disease, lysosome, oxidative phosphorylation, protein export, and drug metabolism-cytochrome P450 were the most commonly affected pathways of the three kinds of diseases. Almost coincident biological functions were identified in the brain tissues of the three diseases. In all, data here demonstrate that the brain tissues of Creutzfeldt-Jakob disease, fatal familial insomnia, and G114V genetic CJD have obvious proteomics changes at their terminal stages, which show the similarities not only among human prion diseases but also with other neurodegeneration diseases. This is the first study to provide a reference proteome map for human prion diseases and will be helpful for future studies focused on potential biomarkers for the diagnosis and therapy of human prion diseases.