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Yokoro M, Nakayama Y, Yamagishi SI, Ando R, Sugiyama M, Ito S, Yano J, Taguchi K, Kaida Y, Saigusa D, Kimoto M, Abe T, Ueda S, Fukami K. Asymmetric Dimethylarginine Contributes to the Impaired Response to Erythropoietin in CKD-Anemia. J Am Soc Nephrol 2017; 28:2670-2680. [PMID: 28600471 DOI: 10.1681/asn.2016111184] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 04/02/2017] [Indexed: 02/05/2023] Open
Abstract
Erythropoietin-resistant anemia is associated with adverse cardiovascular events in patients with ESRD, but the underlying mechanism remains unclear. Here, we evaluated the role of the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA). In 54 patients with advanced CKD, erythrocyte but not plasma ADMA levels independently associated with low hemoglobin values, although levels of both types of ADMA were elevated compared with those in healthy volunteers. Furthermore, erythrocyte ADMA level associated with the erythropoietin resistance index in patients receiving a weekly injected dose of erythropoiesis-stimulating agents standardized for hemoglobin levels and body weight, whereas it correlated with the erythropoietin demand index (plasma erythropoietin units divided by the hemoglobin value) in patients not receiving erythropoiesis-stimulating agents. Compared with sham-operated controls, wild-type mice with 5/6 subtotal nephrectomy (Nx), a remnant kidney model with advanced CKD, had decreased hemoglobin, hematocrit, and mean corpuscular volume values but increased erythrocyte and plasma ADMA and plasma erythropoietin levels. In comparison, dimethylarginine dimethlaminohydrolase-1 transgenic (DDAH-1 Tg) mice, which efficiently metabolized ADMA, had significant improvements in all of the values except those for erythropoietin after 5/6 Nx. Additionally, wild-type Nx mice, but not DDAH-1 Tg Nx mice, had reduced splenic gene expression of erythropoietin receptor and erythroferrone, which regulates iron metabolism in response to erythropoietin. This study suggests that erythrocyte ADMA accumulation contributes to impaired response to erythropoietin in predialysis patients and advanced CKD mice via suppression of erythropoietin receptor expression.
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Affiliation(s)
- Miyuki Yokoro
- Division of Nephrology, Department of Medicine, and.,Department of Food Sciences and Nutrition, School of Human Environmental Sciences, Mukogawa Women's University, Nishinomiya, Hyogo, Japan
| | | | - Sho-Ichi Yamagishi
- Department of Pathophysiology and Therapeutics of Diabetic Vascular Complications, Kurume University School of Medicine, Kurume, Fukuoka, Japan
| | - Ryotaro Ando
- Division of Nephrology, Department of Medicine, and
| | | | - Sakuya Ito
- Division of Nephrology, Department of Medicine, and
| | - Junko Yano
- Division of Nephrology, Department of Medicine, and
| | | | - Yusuke Kaida
- Division of Nephrology, Department of Medicine, and
| | - Daisuke Saigusa
- Department of Integrative Genomics, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Miyagi, Japan
| | - Masumi Kimoto
- Department of Nutritional Science, Faculty of Health and Welfare Science, Okayama Prefectural University, Soja, Okayama, Japan
| | - Takaaki Abe
- Department of Clinical Biology and Hormonal Regulation, Tohoku University, Graduate School of Medicine, Sendai, Miyagi, Japan; and
| | - Seiji Ueda
- Division of Nephrology, Department of Internal Medicine, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Kei Fukami
- Division of Nephrology, Department of Medicine, and
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Abstract
Nitric oxide (NO) is an endogenous vasodilator molecule synthetized from L-arginine by a family of nitric oxide synthases. In differentiated human endothelial cells, it is well known that L-arginine uptake via cationic amino acid transporters (y(+)/CAT) or system y(+)L is required for the NO synthesis via endothelial nitric oxide synthase, but there are no reports in human endothelial progenitor cell (hEPC). Therefore, we isolated hEPCs from peripheral blood of healthy donors and cultured them for either 3 (hEPC-3d) or 14 days (hEPC-14d) to characterize the L-arginine transport and NO synthesis in those cells. L-arginine transport and NO synthesis were analyzed in the presence or absence of N-ethylmaleimide or L-nitroarginine methyl ester, as inhibitors of y(+)/CAT system and nitric oxide synthases, respectively. The results showed that L-arginine uptake is higher in hEPC-14d than in hEPC-3d. Kinetic parameters for L-arginine transport showed the existence of at least 2 transporter systems in hEPC: a high affinity transporter system (K(m)= 4.8 ± 1.1 μM for hEPC-3d and 6.1 ± 2.4 μM for hEPC-14d) and a medium affinity transporter system (K(m) = 85.1 ± 4.0 μM for hEPC-3d and 95.1 ± 8 μM for hEPC-14d). Accordingly, hEPC expressed mRNA and protein for CAT-1 (ie, system y(+)) and mRNA for 2 subunits of y(+)L system, yLAT1, and 4F2hc. Higher L-citruline production and NO bioavailability (4-fold), and endothelial nitric oxide synthase expression (both mRNA and protein) were observed in hEPC-14d compared with hEPC-3d. Finally, the high L-citruline formation observed in hEPC-14d was blocked by N-ethylmaleimide. In conclusion, this study allowed to identity a functional L-arginine/NO pathway in two hEPC differentiation stages, which improves the understanding of the physiology of these precursor cells.
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Yau WWY, Rujitanaroj PO, Lam L, Chew SY. Directing stem cell fate by controlled RNA interference. Biomaterials 2011; 33:2608-28. [PMID: 22209557 DOI: 10.1016/j.biomaterials.2011.12.021] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2011] [Accepted: 12/09/2011] [Indexed: 01/26/2023]
Abstract
Directing stem cell fate remains a major area of interest and also a hurdle to many, particularly in the field of regenerative medicine. Unfortunately, conventional methods of over-expressing inductive factors through the use of biochemical induction cocktails have led to sub-optimal outcomes. A potential alternative may be to adopt the opposite by selectively silencing genes or pathways that are pivotal to stem cell differentiation. Indeed, over recent years, there have been an increasing number of studies on directing stem cell fate through gene knockdown via RNA interference (RNAi). While the effectiveness of RNAi in controlling stem cell differentiation is evident from the myriad of studies, a chaotically vast collection of gene silencing targets have also been identified. Meanwhile, variations in methods of transfecting stem cells have also affected silencing efficiencies and the subsequent extent of stem cell differentiation. This review serves to unite the pioneers who have ventured into the emerging field of RNAi-enhanced stem cell differentiation by summarizing and evaluating the current approaches adopted in utilizing gene silencing to direct stem cell fate and their corresponding outcomes.
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Affiliation(s)
- Winifred Wing Yiu Yau
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 637459, Singapore
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Fan C, Xiong Y, Zhu N, Lu Y, Zhang J, Wang S, Liang Z, Shen Y, Chen M. Random small interfering RNA library screen identifies siRNAs that induce human erythroleukemia cell differentiation. Leuk Lymphoma 2011; 52:502-14. [DOI: 10.3109/10428194.2010.543712] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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