Age of heart disease presentation and dysmorphic nuclei in patients with LMNA mutations

• Published in: PloS one 2017-11, Vol.12 (11), p.e0188256-e0188256
• Main Authors: Core, Jason Q, Mehrabi, Mehrsa, Robinson, Zachery R, Ochs, Alexander R, McCarthy, Linda A, Zaragoza, Michael V, Grosberg, Anna
• Format: Article
• Language: English
• Subjects: Adult; Age Factors; Age of Onset; Aged; Artificial intelligence; Automation; Biology and Life Sciences; Biomedical engineering; Cardiovascular disease; Case-Control Studies; Cell Nucleus - genetics; Cell Nucleus - metabolism; Cell Nucleus - ultrastructure; Coronary artery disease; Defects; Engineering; Exons; Female; Fibroblasts; Fibroblasts - metabolism; Fibroblasts - ultrastructure; Gene Expression; Gene mutations; Genetic aspects; Heart; Heart diseases; Heart Diseases - diagnosis; Heart Diseases - genetics; Heart Diseases - pathology; Humans; Image Processing, Computer-Assisted; Lamin Type A - genetics; Lamin Type A - metabolism; Male; Mathematical morphology; Matlab; Mechanical properties; Medicine and Health Sciences; Microscopy; Middle Aged; Missense mutation; Morphology; Mutation; Nonsense mutation; Nuclei; Nuclei (cytology); Observer Variation; Organelle Shape; Patients; Physiological aspects; Primary Cell Culture; Progeria; Progeria - diagnosis; Progeria - genetics; Progeria - pathology; Proteins; Quantitative analysis; Research and Analysis Methods; Risk factors; Skin; Skin tests
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0188256

Nuclear shape defects are a distinguishing characteristic in laminopathies, cancers, and other pathologies. Correlating these defects to the symptoms, mechanisms, and progression of disease requires unbiased, quantitative, and high-throughput means of quantifying nuclear morphology. To accomplish this, we developed a method of automatically segmenting fluorescently stained nuclei in 2D microscopy images and then classifying them as normal or dysmorphic based on three geometric features of the nucleus using a package of Matlab codes. As a test case, cultured skin-fibroblast nuclei of individuals possessing LMNA splice-site mutation (c.357-2A>G), LMNA nonsense mutation (c.736 C>T, pQ246X) in exon 4, LMNA missense mutation (c.1003C>T, pR335W) in exon 6, Hutchinson-Gilford Progeria Syndrome, and no LMNA mutations were analyzed. For each cell type, the percentage of dysmorphic nuclei, and other morphological features such as average nuclear area and average eccentricity were obtained. Compared to blind observers, our procedure implemented in Matlab codes possessed similar accuracy to manual counting of dysmorphic nuclei while being significantly more consistent. The automatic quantification of nuclear defects revealed a correlation between in vitro results and age of patients for initial symptom onset. Our results demonstrate the method's utility in experimental studies of diseases affecting nuclear shape through automated, unbiased, and accurate identification of dysmorphic nuclei.