Total polyamine assay kit

DMEM/F-12, penicillin/streptomycin, amphotericin, and fetal bovine serum (FBS) were from Thermo (Massachusetts, USA); collagenase XI, dispase II, IL-1β, and diacetyl dichlorofluorescein (DCFH-DA) kit were purchased from Sigma (Ohio, United States); Masson's and Safranin O Stain Kit was from Solarbio (Shanghai, China); anti-collagen II (ab34712), anti-PAOX (ab230441), anti-p16 (ab51243), anti-β-actin (ab6276), anti-8-hydroxy-2′-deoxyguanosine (ab48508), anti-gamma H2A.X (ab81299), IgG H&L Alexa Fluor 488 (ab150113), Hydrogen Peroxide Assay Kit (ab138874, ab102500), and Total Polyamine Assay Kit (ab239728) were from Abcam (Cambridge, USA); Trizol reagent and reverse transcriptase kit were from Vazyme (Nanjing, China). SYBR Green Master Mix was from Applied Biosystems (Waltham, USA); Vectastain Elite ABC reagent was obtained from KeyGen (Nanjing, China); spermidine and N-acetylcysteine (NAC) were from Selleck (Shanghai, China); Lipofectamine 2000 transfection reagent (89900) and Protein Extraction Kit (78510) were from Thermo Fisher Scientific (Waltham, USA); ethylenediaminetetraacetic acid (EDTA), paraformaldehyde, and enhanced chemiluminescence (ECL) were from Beyotime (Shanghai, China).

Creatinine levels were measured with a colorimetric Creatinine Assay Kit (Cat. # ab65340, Abcam Inc., Toronto, ON, Canada). The optical density was measured at 570 nm on a spectrophotometer. Total polyamine levels were measured with a fluorometric Total Polyamine Assay Kit (Cat. # ab239728, Abcam Inc., Toronto, ON, Canada). The fluorescence of the final product was measured with a fluorescence spectrophotometer (Fluoroskan Ascent, Thermo-Fisher Scientific) at 535/587 nm excitation/emission wavelengths.