Journal of Jilin University(Medicine Edition) ›› 2025, Vol. 51 ›› Issue (1): 26-33.doi: 10.13481/j.1671-587X.20250104

• Research in basic medicine • Previous Articles     Next Articles

Ameliorative effect of ACE2/Ang(1-7)/Mas axis on high-turover bone disease in uremic rats

Yang XUE,Yingxin RUAN,Tiekun YAN,Junya JIA(),Shan LIN()   

  1. Department of Nephrology,First Affiliated Hospital,Tianjin Medical University,Tianjin 300054,China
  • Received:2023-10-31 Accepted:2024-03-19 Online:2025-01-28 Published:2025-03-06
  • Contact: Junya JIA,Shan LIN E-mail:youshalei@126.com;linshan1012@163.com

Abstract:

Objective To discuss the effect of angiotensin (1-7) [Ang(1-7)] on high-turnover bone disease in the uremic rats, and to clarify its possible mechanism. Methods Thirty SD rats were randomly divided into sham operation group(n=6) and experimental group(n=24). The rats in experimental group underwent 5/6 nephrectomy(Platt method) + high-phosphorus(P) diet[1.2% P, 1.0% calcium(Ca)] to establish the model of uremic high-turnover bone disease. The successfully modeled rats were then randomly divided into model group, Ang(1-7) group, angiotensin-converting enzyme 2(ACE2) activator dimethylacetamide amidoxime(DIZE) group, and Mas receptor antagonist group (A779 group), with 6 rats in each group. The levels of Ca, P, blood creatinine (Scr), blood urea nitrogen (BUN), and 24 h urinary protein (UP) in serum of the rats in various groups were detected by automatic biochemical analyzer at 12 and 18 weeks after operation; immunofluorescence staining was used to detect the levels of intact parathyroid hormone (iPTH) in the rats in various groups; ELISA method was used to detect the levels of osteocalcin(OC), type Ⅰ collagen N-terminal peptide (NTX), and tartrate-resistant acid phosphatase (TRAP)-5b in serum of the rats in various groups; high-resolution micro-CT scan was used to detect the bone density (BMD), tissue mineral density (TMD), trabecular thickness (Tb.Th), and trabecular separation (Tb.Sp) in femur tissue of the rats in various groups; Von Kossa staining and Giemsa staining were used to observe the pathomorphology of cortical bone and trabecular bone of the rats in various groups, and the trabecular bone volume (TBV) was calculated; fluorescence microscope was used to detect the mineral apposition rates (MAR) of the rats in vanious groups, and the osteoblast index (OBI) and osteoclast index (OCI) of the rats in various groups were calculated. Results At 12 and 18 weeks after operation, compared with sham operation group, the weights of the rats in model group, Ang(1-7) group, DIZE group, and A779 group were decreased (P<0.05). At 12 and 18 weeks after operation, compared with sham operation group, the levels of 24 h UP, Scr, and BUN in serum of the rats in model group, Ang(1-7) group, DIZE group, and A779 group were increased (P<0.05); at 18 weeks after operation, compared with model group, the levels of 24 h UP and Scr in serum of the rats in Ang(1-7) group and DIZZ group were decreased (P<0.05), and the levels of 24 h UP, Scr and BUN in serum of the rats in A779 group were increased (P<0.05). The successful establishment of the uremic high-turnover bone disease model was confirmed. At 12 and 18 weeks after operation, compared with sham operation group, the serum iPTH, P, OC, NTX, and TRAP-5b levels of the rats in model group, Ang(1-7) group, DIZE group, and A779 group were all significantly increased (P<0.05); at 18 weeks after operation, compared with model group, the serum NTX and TRAP-5b levels of the rats in Ang(1-7) group and DIZE group were decreased(P<0.05), while the serum iPTH, P, NTX and TRAP-5b levels in A779 group were increased(P<0.05). The high-resolution micro-CT scan results showed that compared with sham operation group, the values of femur BMD and TMD of the rats in model group, Ang(1-7) group, DIZE group, and A779 group were all significantly decreased (P<0.05); compared with model group, the values of femur BMD and TMD of the rats in Ang(1-7) group and DIZE group were increased (P<0.05), while the values of BMD and TMD of the rats in A779 group were decreased (P<0.05). Compared with sham operation group, the femur Tb.Th of the rats in model group was decreased (P<0.05), and the Tb.Sp was increased (P<0.05); the femur Tb.Th of the rats in Ang(1-7) group and DIZE group were increased (P<0.05), and the Tb.Sp was decreased (P<0.05). Compared with model group, the femur Tb.Th of the rats in A779 group was decreased (P<0.05), and the Tb.Sp was increased (P<0.05). The bone pathological examination results showed that compared with sham operation group, the femur TBV of the rats in model group, Ang(1-7) group, DIZZ group and A779 group were decreased (P<0.05), and MAR, OBI and OCI were increased (P<0.05); compared with model group, the OBI and OCI of the rats in Ang(1-7) group and DIZE group were decreased (P<0.05), and TBV was increased (P<0.05), while the OBI and OCI of the rats in A779 group were increased (P<0.05), and TBV was decreased (P<0.05). Conclusion The ACE2/Ang(1-7)/Mas axis improves high-turnover bone disease in the uremic rats.

Key words: Uremia, High-turnover bone disease, Osteoblasts, Osteoclasts, Angiotensin-converting enzyme 2, Angiotensin (1-7)

CLC Number: 

  • R563.13