Genotypic Categorization of Loeys-Dietz Syndrome Based on 24 Novel Families and Literature Data
GENES
Authors: Camerota, Letizia; Ritelli, Marco; Wischmeijer, Anita; Majore, Silvia; Cinquina, Valeria; Fortugno, Paola; Monetta, Rosanna; Gigante, Laura; Sangiuolo, Federica Carla; Novelli, Giuseppe; Colombi, Marina; Brancati, Francesco; Ruvolo, Giovanni; Bertoldo, Fabio; Donzelli, Concettina; Polisca, Patrizio; Salehi, Leila Baghernajad; Mancino, Raffaele; Di Carlo, Emiliano; Bollero, Patrizio; Cozza, Paola; Lagana, Giuseppina; Farsetti, Pasquale; De Maio, Fernando; De Luna, Vincenzo; Mancini, Federico; Chini, Loredana; Graziani, Simona; Floris, Roberto; Sperandio, Massimiliano; Infante, Angela; De Stefano, Alberto; Chiariello, Luigi; Grego, Susanna
Abstract
Loeys-Dietz syndrome (LDS) is a connective tissue disorder first described in 2005 featuring aortic/arterial aneurysms, dissections, and tortuosity associated with craniofacial, osteoarticular, musculoskeletal, and cutaneous manifestations. Heterozygous mutations in 6 genes (TGFBR1/2, TGFB2/3, SMAD2/3), encoding components of the TGF-beta pathway, cause LDS. Such genetic heterogeneity mirrors broad phenotypic variability with significant differences, especially in terms of the age of onset, penetrance, and severity of life-threatening vascular manifestations and multiorgan involvement, indicating the need to obtain genotype-to-phenotype correlations for personalized management and counseling. Herein, we report on a cohort of 34 LDS patients from 24 families all receiving a molecular diagnosis. Fifteen variants were novel, affecting the TGFBR1 (6), TGFBR2 (6), SMAD3 (2), and TGFB2 (1) genes. Clinical features were scored for each distinct gene and matched with literature data to strengthen genotype-phenotype correlations such as more severe vascular manifestations in TGFBR1/2-related LDS. Additional features included spontaneous pneumothorax in SMAD3-related LDS and cervical spine instability in TGFB2-related LDS. Our study broadens the clinical and molecular spectrum of LDS and indicates that a phenotypic continuum emerges as more patients are described, although genotype-phenotype correlations may still contribute to clinical management.
Overexpression of alpha-Synuclein Reorganises Growth Factor Profile of Human Astrocytes
MOLECULAR NEUROBIOLOGY
Authors: Sengul, Busra; Dursun, Erdinc; Verkhratsky, Alexei; Gezen-Ak, Duygu
Abstract
Misfolding and accumulation of aberrant alpha-synuclein in the brain is associated with the distinct class of neurodegenerative diseases known as alpha-synucleinopathies, which include Parkinson's disease, dementia with Lewy bodies and multiple system atrophy. Pathological changes in astrocytes contribute to all neurological disorders, and astrocytes are reported to possess alpha-synuclein inclusions in the context of alpha-synucleinopathies. Astrocytes are known to express and secrete numerous growth factors, which are fundamental for neuroprotection, synaptic connectivity and brain metabolism; changes in growth factor secretion may contribute to pathobiology of neurological disorders. Here we analysed the effect of alpha-synuclein overexpression in cultured human astrocytes on growth factor expression and release. For this purpose, the intracellular and secreted levels of 33 growth factors (GFs) and 8 growth factor receptors (GFRs) were analysed in cultured human astrocytes by chemiluminescence-based western/dot blot. Overexpression of human alpha-synuclein in cultured foetal human astrocytes significantly changes the profile of GF production and secretion. We found that human astrocytes express and secrete FGF2, FGF6, EGF, IGF1, AREG, IGFBP2, IGFBP4, VEGFD, PDGFs, KITLG, PGF, TGFB3 and NTF4. Overexpression of human alpha-synuclein significantly modified the profile of GF production and secretion, with particularly strong changes in EGF, PDGF, VEGF and their receptors as well as in IGF-related proteins. Bioinformatics analysis revealed possible interactions between alpha-synuclein and EGFR and GDNF, as well as with three GF receptors, EGFR, CSF1R and PDGFRB.