Yao-Lung Liu1,2, Kuan-Ho Lin2,3, Shanmugam Tamilselvi4, Wei-Kung Chen2, Chia-Yao Shen5, Ray-Jade Chen6, Cecilia Hsuan Day5, Hsi-Chin Wu2, Vijaya Padma Viswanadha7, Chih-Yang Huang4,8,9. 1. Division of Nephrology and Kidney Institute, China Medical University Hospital. 2. School of Medicine, China Medical University. 3. Department of Emergency Medicine, China Medical University Hospital. 4. Graduate Institute of Basic Medical Science, China Medical University, Taichung. 5. Department of Nursing, MeiHo University, Pingtung. 6. Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan, ROC. 7. Department of Biotechnology, Bharathiar University, Coimbatore, India. 8. Graduate Institute of Chinese Medical Science, China Medical University. 9. Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan, ROC.
Abstract
BACKGROUND/AIM: In chronic kidney disease (CKD), kidneys fail to maintain phosphorus homeostasis in serum. Elevated phosphorus levels in serum have been associated with cardiovascular diseases in CKD patients and in normal individuals. In this study, we evaluated the level of autophagy- and apoptosis-related markers under different concentrations of hyperphosphate in myocardial cells. METHODS: Modulation inflicted on the levels of various survival-, autophagy-, and apoptosis-related markers were determined by Western blotting analysis using total protein extract. FITC-annexin V staining was performed to quantify the apoptotic cells in all groups. RESULTS: Hyperphosphate treatments showed to induce autophagy-related proteins beclin-1, ATG7, and LC3 II through the pAMPK-ULK1 pathway in Western blotting analysis. Further, apoptosis-associated proteins such as Bax, Bid, cytochrome c, and c-caspase-9 were also upregulated with hyperphosphate treatment. 3-Methyladenine, an autophagy inhibitor, inhibited apoptosis significantly in FITC-annexin V staining, and the inhibition of Bax, cytochrome c, and c-caspase-3 was shown by Western blotting. CONCLUSION: The results suggest that hyperphosphate in H9c2 cardiomyoblasts would lead to cellular apoptosis via autophagy, which is mediated by the pAMPK signaling pathway. Our findings revealed the possible mechanism responsible for the heart damage under hyperphosphatemia.
BACKGROUND/AIM: In chronic kidney disease (CKD), kidneys fail to maintain phosphorus homeostasis in serum. Elevated phosphorus levels in serum have been associated with cardiovascular diseases in CKDpatients and in normal individuals. In this study, we evaluated the level of autophagy- and apoptosis-related markers under different concentrations of hyperphosphate in myocardial cells. METHODS: Modulation inflicted on the levels of various survival-, autophagy-, and apoptosis-related markers were determined by Western blotting analysis using total protein extract. FITC-annexin V staining was performed to quantify the apoptotic cells in all groups. RESULTS:Hyperphosphate treatments showed to induce autophagy-related proteins beclin-1, ATG7, and LC3 II through the pAMPK-ULK1 pathway in Western blotting analysis. Further, apoptosis-associated proteins such as Bax, Bid, cytochrome c, and c-caspase-9 were also upregulated with hyperphosphate treatment. 3-Methyladenine, an autophagy inhibitor, inhibited apoptosis significantly in FITC-annexin V staining, and the inhibition of Bax, cytochrome c, and c-caspase-3 was shown by Western blotting. CONCLUSION: The results suggest that hyperphosphate in H9c2 cardiomyoblasts would lead to cellular apoptosis via autophagy, which is mediated by the pAMPK signaling pathway. Our findings revealed the possible mechanism responsible for the heart damage under hyperphosphatemia.
Authors: Arvin Halim; Gayatri Narayanan; Takashi Hato; Lilun Ho; Douglas Wan; Andrew M Siedlecki; Eugene P Rhee; Andrew S Allegretti; Sagar U Nigwekar; Daniel Zehnder; Thomas F Hiemstra; Joseph V Bonventre; David M Charytan; Sahir Kalim; Ravi Thadhani; Tzongshi Lu; Kenneth Lim Journal: J Am Heart Assoc Date: 2022-02-18 Impact factor: 6.106