Bellini, M. | Search bioRxiv

bioRxiv2019

Overexpression of Mig-6 in Cartilage Induces An Osteoarthritis-Like Phenotype In Mice.

BackgroundOsteoarthritis (OA) is the most common form of arthritis and characterized by degeneration of articular cartilage. Mitogen-inducible gene 6 (Mig-6) has been identified as a negative regulator of the Epidermal Growth Factor Receptor (EGFR). Cartilage-specific Mig-6 knockout (KO) mice display increased EGFR signaling, an anabolic buildup of articular cartilage and formation of chondro-osseous nodules. Since our understanding of the EGFR/Mig-6 network in cartilage remains incomplete, we characterized mice with cartilage-specific overexpression of Mig-6 in this study.\n\nMethodsUtilizing knee joints from cartilage-specific Mig-6 overexpressing (Mig-6over/over) mice (at multiple time points), we evaluated the articular cartilage using histology, immunohistochemical staining and semi-quantitative OARSI scoring at multiple ages. MicroCT analysis was employed to examine skeletal morphometry, body composition, and bone mineral density.\n\nResultsOur data show that cartilage-specific Mig-6 overexpression did not cause any major developmental abnormalities in articular cartilage, although Mig-6over/over mice have slightly shorter long bones compared to the control group. Moreover, there was no significant difference in bone mineral density and body composition in any of the groups. However, our results indicate that Mig-6over/over male mice show accelerated cartilage degeneration at 12 and 18 months of age. Immunohistochemistry for SOX9 demonstrated that the number of positively stained cells in Mig-6over/over mice decreased relative to controls. Immunostaining for MMP13 staining is increased in areas of cartilage degeneration in Mig-6over/over mice. Moreover, staining for phospho-EGFR (Tyr-1173) and lubricin (PRG4) was decreased in the articular cartilage of Mig-6over/over mice.\n\nConclusionOverexpression of Mig-6 in articular cartilage causes no major developmental phenotype; however these mice develop earlier OA during aging. These data demonstrate that Mig-6/EGFR pathways is critical for joint homeostasis and might present a promising therapeutic target for OA.

physiology↗

bioRxiv2019

Characterization of Intellectual disability and Autism comorbidity through gene panel sequencing

Intellectual disability (ID) and autism spectrum disorder (ASD) are clinically and genetically heterogeneous diseases. Recent whole exome sequencing studies indicated that genes associated with different neurological diseases are shared across disorders and converge on common functional pathways. Using the Ion Torrent platform, we developed a low-cost next generation sequencing (NGS) gene panel that has been transferred into clinical practice, replacing single disease gene analyses for the early diagnosis of individuals with ID/ASD. The gene panel was designed using an innovative in silico approach based on disease networks and mining data from public resources to score disease-gene associations. We analyzed 150 unrelated individuals with ID and/or ASD and a confident diagnosis has been reached in 26 cases (17%). Likely pathogenic mutations have been identified in another 15 patients, reaching a total diagnostic yield of 27%. Our data also support the pathogenic role of genes recently proposed to be involved in ASD. Although many of the identified variants need further investigation to be considered disease-causing, our results indicate the efficiency of the targeted gene panel on the identification of novel and rare variants in patients with ID and ASD.

genetics↗