2022, Vol. 26 ›› Issue (24): 3897-3902

Autophagy-related gene Rubicon deficiency inhibits cellular senescence in the heart

He Fan, Lai Shuaiwei, Zhang Shasha, Dong Fan, Amber Naz, Haniya Mazhar, He Lin, Zhu Hongxin   

Abstract: BACKGROUND: Cardiac aging is the major risk factor for heart diseases. Cellular senescence is the key mechanism of cardiac aging, which plays an important role in age-related heart disease. Our previous work has shown that deletion of autophagy-related gene Uvrag promotes cellular senescence in the heart. Rubicon is an inhibitory interacting partner of Uvrag. However, the function of Rubicon in cellular senescence in the heart remains unknown.
OBJECTIVE: To determine the effect of Rubicon gene on cellular senescence in the heart.
METHODS: Wild type and Rubicon-deficient mice at 15 months of age were utilized. Uvrag-deficient mice were applied as observation objects. Uvrag-deficient mice of the same age were used as positive controls. Fluorescence quantitative PCR was used to detect changes in mRNA expression of senescence-related secreted phenotype-related factors in mouse heart tissue. Hematoxylin-eosin staining, Sirius red staining, and senescence-associated β-galactosidase staining were performed to observe myocardial histology. Western blot assay was conducted to measure the expression of p53 and p16 protein in the mouse heart. The protocols were approved by the Animal Experiment Ethics Committee of Shanghai Jiao Tong University.   
RESULTS AND CONCLUSION: (1) Hematoxylin-eosin staining and Sirius red staining demonstrated that Rubicon deficiency ameliorated myocardial cell remodeling and cardiac fibrosis during aging. (2) Senescence-associated β-galactosidase staining displayed that Rubicon-deficient mice had significantly fewer senescence-associated β-galactosidase-positive cells in hearts from Rubicon-deficient mice than in control mice (P < 0.05). (3) Fluorescence quantitative PCR results suggested that expression of interleukin 1β, interleukin 6, transforming growth factor β, type III collagen α1 chain, and tissue inhibitor of matrix metalloproteinase 1 mRNA in hearts was significantly decreased in Rubicon-deficient mice than that in control mice (P < 0.05). (4) Western blot assay results showed that p53 protein abundance, a key protein regulating cellular senescence, was significantly lower in hearts from Rubicon-deficient mice than in control mice (P < 0.05). (5) It is indicated that Rubicon deficiency obviously inhibits cellular senescence in the heart and delays cardiac aging. Rubicon is a potential target for the treatment of cardiac aging and age-related heart disease.
Key words: Rubicon, cellular senescence, cardiac aging, senescence-associated secretory phenotype, p53, mice