title: Raman spectroscopy-based approach to detect aging-related oxidative damage in the mouse oocyte.
abstract: OBJECTIVE
  Detection of chemical modifications induced by aging-related oxidative damage in mouse metaphase II (MII) oocytes by Raman microspectroscopy.
  
  
  METHODS
  CD-1 mice at the age of 4-8 weeks (young mice) and 48-52 weeks (old mice), were superovulated and oocytes at metaphase II stage were recovered from oviducts. MII oocytes from young animals were divided into three groups: A) young oocytes, processed immediately after collection; B) in vitro aged oocytes, cultured in vitro for 10 h before processing; C) oxidative-stressed oocytes, exposed to 10 mM hydrogen peroxide for 2 min before processing. Oocytes from reproductively old mice were referred to as old oocytes (D). All the oocytes were analyzed by confocal Raman microspectroscopy. The spectra were statistically analyzed using Principal Component Analysis (PCA).
  
  
  RESULTS
  PCA evidenced that spectra from young oocytes (A) were clearly distinguishable from those obtained from in vitro-aged, oxidative-damaged and old oocytes (B, C, D) and presented significant differences in the bands attributable to lipid components (C = C stretching, 1,659 cm⁻¹; CH2 bending, 1,450 cm⁻¹; CH3 deformation,1,345 cm⁻¹; OH bending, C-N stretching, 1,211 cm⁻¹) and protein components (amide I band,1,659 cm⁻¹; CH2 bending modes and CH3 deformation, 1,450 cm⁻¹; C-N and C-C stretching vibrations, 1,132 cm⁻¹; phenylalanine's vibration, 1,035 cm⁻¹)
  
  
  CONCLUSIONS
  Raman spectroscopy is a valuable non-invasive tool for the identification of biochemical markers of oxidative damage and could represent a highly informative method of investigation to evaluate the oocyte quality.
authors.affiliation: Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100, Sardegna, Italy. luis@uniss.it
authors.forename: Luisa
authors.initials: L
authors.lastname: Bogliolo
authors.forename: Ombretta
authors.initials: O
authors.lastname: Murrone
authors.forename: Giovanna
authors.initials: G
authors.lastname: Di Emidio
authors.forename: Massimo
authors.initials: M
authors.lastname: Piccinini
authors.forename: Federica
authors.initials: F
authors.lastname: Ariu
authors.forename: Sergio
authors.initials: S
authors.lastname: Ledda
authors.forename: Carla
authors.initials: C
authors.lastname: Tatone
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D016922:Cellular Senescence; D005260:Female; D006861:Hydrogen Peroxide / Q000737:chemistry; D008677:Metaphase; D051379:Mice; D009865:Oocytes / Q000737:chemistry*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D015415:Biomarkers; D006861:Hydrogen Peroxide