RESUMO
The advent of super-resolution microscopy allowed for new insights into cellular and physiological processes of normal and diseased cells. In this study, we report for the first time on the super-resolved DNA structure of buccal cells from patients with Alzheimer's disease (AD) versus age- and gender-matched healthy, non-caregiver controls. In this super-resolution study cohort of 74 participants, buccal cells were collected and their spatial DNA organization in the nucleus examined by 3D Structured Illumination Microscopy (3D-SIM). Quantitation of the super-resolution DNA structure revealed that the nuclear super-resolution DNA structure of individuals with AD significantly differs from that of their controls (p < 0.05) with an overall increase in the measured DNA-free/poor spaces. This represents a significant increase in the interchromatin compartment. We also find that the DNA structure of AD significantly differs in mild, moderate, and severe disease with respect to the DNA-containing and DNA-free/poor spaces. We conclude that whole genome remodeling is a feature of buccal cells in AD.
Assuntos
Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Núcleo Celular/ultraestrutura , Cromatina/genética , Cromatina/ultraestrutura , DNA/genética , DNA/ultraestrutura , Mucosa Bucal/ultraestrutura , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Núcleo Celular/química , Cromatina/isolamento & purificação , Montagem e Desmontagem da Cromatina , DNA/isolamento & purificação , Feminino , Humanos , Imageamento Tridimensional , Masculino , Microscopia/métodos , Pessoa de Meia-Idade , Mucosa Bucal/química , Conformação de Ácido Nucleico , Índice de Gravidade de DoençaRESUMO
This study validates and expands on our previous work that assessed three-dimensional (3D) nuclear telomere profiling in buccal cells of Alzheimer's disease (AD) patients and non-AD controls (Mathur et al., J Alzheimers Dis 39, 35-48, 2014). While the previous study used age- and gender-matched caregiver controls, the current study consented a new cohort of 44 age- and gender-matched healthy non-caregiver controls and 44 AD study participants. 3D telomeric profiles of buccal cells of AD patients and their non-AD controls were examined with participant information blinded to the analysis. In agreement with our previous study, we demonstrate that 3D telomeric profiles allow for the distinction between AD and non-AD individuals. This validation cohort provides an indication that the total number of 3D telomeric signals and their telomere lengths may be a suitable biomarker to differentiate between AD and non-AD and between mild, moderate, and severe AD. Further studies with larger sample sizes are required to move this technology further toward the clinic.