Integration of transcriptomic and genomic data suggests candidate mechanisms for APOE4-mediated pathogenic action in Alzheimer's disease
SCIENTIFIC REPORTS
Authors: Caberlotto, Laura; Marchetti, Luca; Lauria, Mario; Scotti, Marco; Parolo, Silvia
Abstract
Among the genetic factors known to increase the risk of late onset Alzheimer's diseases (AD), the presence of the apolipoproteine e4 (APOE4) allele has been recognized as the one with the strongest effect. However, despite decades of research, the pathogenic role of APOE4 in Alzheimer's disease has not been clearly elucidated yet. In order to investigate the pathogenic action of APOE4, we applied a systems biology approach to the analysis of transcriptomic and genomic data of APOE44 vs. APOE33 allele carriers affected by Alzheimer's disease. Network analysis combined with a novel technique for biomarker computation allowed the identification of an alteration in aging-associated processes such as inflammation, oxidative stress and metabolic pathways, indicating that APOE4 possibly accelerates pathological processes physiologically induced by aging. Subsequent integration with genomic data indicates that the Notch pathway could be the nodal molecular mechanism altered in APOE44 allele carriers with Alzheimer's disease. Interestingly, PSEN1 and APP, genes whose mutation are known to be linked to early onset Alzheimer's disease, are closely linked to this pathway. In conclusion, APOE4 role on inflammation and oxidation through the Notch signaling pathway could be crucial in elucidating the risk factors of Alzheimer's disease.
Novel Mutations in PSENEN Gene in Two Chinese Acne Inversa Families Manifested as Familial Multiple Comedones and Dowling-Degos Disease
CHINESE MEDICAL JOURNAL
Authors: Zhou, Cheng; Wen, Guang-Dong; Soe, Lwin Myint; Xu, Hong-Jun; Du, Juan; Zhang, Jian-Zhong
Abstract
Background: Acne inversa (AI), also called hidradenitis suppurativa, is a chronic, inflammatory, recurrent skin disease of the hair follicle. Familial AI shows autosomal-dominant inheritance caused by mutations in the gamma-secretase genes. This study was aimed to identify the specific mutations in the gamma-secretase genes in two Chinese families with AI. Methods: In this study, two Chinese families with AI were investigated. All the affected individuals in the two families mainly manifested with multiple comedones, pitted scars, and a few inflammatory nodules on their face, neck, trunk, axilla, buttocks, upper arms, and thighs. Reticulate pigmentation in the flexures areas resembled Dowling-Degos disease clinically and pathologically. In addition, one of the affected individuals developed anal canal squamous cell carcinoma. Molecular mutation analysis of gamma-secretase genes including PSENEN, PSEN1, and NCSTN was performed by polymerase chain reaction and direct DNA sequencing. Results: Two novel mutations of PSENEN gene were identified, including a heterozygous missense mutation c. 194T>G (p.L65R) and a splice site mutation c. 167-2A>G. Conclusions: The identification of the two mutations could expand the spectrum of mutations in the gamma-secretase genes underlying AI and provide valuable information for further study of genotype-phenotype correlations.