» Articles » PMID: 39165274

Short-term Therapy with R568 Ameliorated Secondary Hyperparathyroidism but Does Not Prevent Aortic Valve Calcification in Uremic Rats

Overview
Journal Front Nephrol
Specialty Nephrology
Date 2024 Aug 21
PMID 39165274
Authors
Affiliations
Soon will be listed here.
Abstract

Introduction: Renal failure associated aortic valve calcification (AVC) is the result of hyperphosphatemia and hyperparathyroidism. Calcimimetics is an effective tool for management of secondary hyperparathyroidism. Our goal was to evaluate the effect of the medical intervention with calcimimetic R568 on the AVC process.

Methods And Results: The experimental design consisted of administering a uremia-inducing phosphate-enriched diet to rats for six weeks. Rats received a daily R568 injection at different times. Biochemical analysis demonstrated increased urea (34.72 ± 3.57 . 5.18 ± 0.15 mmol/L, <0.05) and creatinine (293.93 ± 79.6 . 12.82 ± 1.56 µmol/L, <0.05). R568 treatment markedly reduced parathyroid hormone (PTH) levels in both treated groups (192.63 ± 26.85, 301.23 ± 101.79 . 3570 ± 986.63 pg/mL, <0.05), with no impact on serum calcium and phosphate. von Kossa staining showed increase in AVC in uremic rats compared to control (1409 ± 159.5 . 27.33 ± 25.83, <0.05). AVC was not affected by R568 in both groups (3343 ± 2462, 1593 ± 792 . 1409 ± 159.5, NS). Similarly, the inflammatory marker CD68 was elevated in uremic rats (15592 ± 3792 . 181.8 ± 15.29, <0.01), and was not influenced by R568 treatment (8453 ± 818.5, 9318 ± 2232 . 15592 ± 3792, NS). Runt-related transcription factor 2 (Runx2), the regulator of osteoblast differentiation, was upregulated in uremic rats (23186 ± 9226 . 3184 ± 2495), that accompanied by elevated levels of Osteopontin (158395 ± 45911 . 237.7 ± 81.5, <0.05) and Osteocalcin (22203 ± 8525 . 489.7 ± 200.6, <0.05). R568 had no impact on osteoblastic markers (Runx2: 21743 ± 3193, 23004 ± 10871 . 23186 ± 9226, NS; osteopontin: 57680 ± 19522, 137116 ± 60103 . 158395 ± 45911, NS; osteocalcin: 10496 ± 5429, 8522 ± 5031 . 22203 ± 8525, NS).

Conclusion: In an adenine-induced uremic rat model, we showed that short-term R568 therapy had no effect on AVC. Treatment with R568 decreased PTH levels but had no effect on high phosphate levels. Regression of AVC necessitates not only a decrease in PTH levels, but also a decline in phosphate levels. To achieve improved outcomes, it is advisable to consider administering a combination of R568 with other medications, such as calcium supplements or phosphate binders. Additional studies are required for further evaluation of the potential treatment of chronic kidney disease (CKD)-associated AVC.

References
1.
Di Lullo L, Gorini A, Bellasi A, Morrone L, Rivera R, Russo L . Fibroblast growth factor 23 and parathyroid hormone predict extent of aortic valve calcifications in patients with mild to moderate chronic kidney disease. Clin Kidney J. 2015; 8(6):732-6. PMC: 4655786. DOI: 10.1093/ckj/sfv073. View

2.
Kume T, Kawamoto T, Akasaka T, Watanabe N, Toyota E, Neishi Y . Rate of progression of valvular aortic stenosis in patients undergoing dialysis. J Am Soc Echocardiogr. 2006; 19(7):914-8. DOI: 10.1016/j.echo.2006.01.026. View

3.
Block G, Zaun D, Smits G, Persky M, Brillhart S, Nieman K . Cinacalcet hydrochloride treatment significantly improves all-cause and cardiovascular survival in a large cohort of hemodialysis patients. Kidney Int. 2010; 78(6):578-89. DOI: 10.1038/ki.2010.167. View

4.
Ivanovski O, Nikolov I, Joki N, Caudrillier A, Phan O, Mentaverri R . The calcimimetic R-568 retards uremia-enhanced vascular calcification and atherosclerosis in apolipoprotein E deficient (apoE-/-) mice. Atherosclerosis. 2009; 205(1):55-62. DOI: 10.1016/j.atherosclerosis.2008.10.043. View

5.
Levi R, Ben-Dov I, Lavi-Moshayoff V, Dinur M, Martin D, Naveh-Many T . Increased parathyroid hormone gene expression in secondary hyperparathyroidism of experimental uremia is reversed by calcimimetics: correlation with posttranslational modification of the trans acting factor AUF1. J Am Soc Nephrol. 2005; 17(1):107-12. DOI: 10.1681/ASN.2005070679. View