scholarly journals Klotho/FGF23 and Wnt Signaling as Important Players in the Comorbidities Associated with Chronic Kidney Disease

Toxins ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 185 ◽  
Author(s):  
Juan Rafael Muñoz-Castañeda ◽  
Cristian Rodelo-Haad ◽  
Maria Victoria Pendon-Ruiz de Mier ◽  
Alejandro Martin-Malo ◽  
Rafael Santamaria ◽  
...  

Fibroblast Growth Factor 23 (FGF23) and Klotho play an essential role in the regulation of mineral metabolism, and both are altered as a consequence of renal failure. FGF23 increases to augment phosphaturia, which prevents phosphate accumulation at the early stages of chronic kidney disease (CKD). This effect of FGF23 requires the presence of Klotho in the renal tubules. However, Klotho expression is reduced as soon as renal function is starting to fail to generate a state of FGF23 resistance. Changes in these proteins directly affect to other mineral metabolism parameters; they may affect renal function and can produce damage in other organs such as bone, heart, or vessels. Some of the mechanisms responsible for the changes in FGF23 and Klotho levels are related to modifications in the Wnt signaling. This review examines the link between FGF23/Klotho and Wnt/β-catenin in different organs: kidney, heart, and bone. Activation of the canonical Wnt signaling produces changes in FGF23 and Klotho and vice versa; therefore, this pathway emerges as a potential therapeutic target that may help to prevent CKD-associated complications.

Author(s):  
Stuart M. Sprague ◽  
Menaka Sarav

The kidneys play a critical role in maintaining normal serum calcium and phosphorus concentrations, under the regulation of three main hormones: parathyroid hormone, calcitriol, and fibroblast growth factor 23. With the progression of chronic kidney disease (CKD), most patients develop CKD–mineral and bone disorder (CKD-MBD), which is a systemic disorder involving derangement in mineral metabolism, renal osteodystrophy, and extraskeletal calcification. Disturbances in mineral metabolism develop early in CKD and include phosphate retention, hypocalcaemia, vitamin D deficiency, and hyperparathyroidism. Renal osteodystrophy involves pathologic changes of bone morphology related to progressive CKD and is quantifiable by histomorphometry, based on bone biopsy. CKD-MBD is associated with significant morbidity, including bone loss, fractures, cardiovascular disease, immune suppression, as well as increased mortality. As the disorder begins early in the course of CKD, a proactive approach with intervention is important. Therapeutic strategies could then be employed to prevent and correct these disturbances, aiming to improve cardiovascular outcomes and survival. Current practice guidelines for CKD-MBD are based on insufficient data and high-quality studies are required before specific treatment can be advocated strongly.


2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Kenichi Akiyama ◽  
Takaaki Kimura ◽  
Kazuhiro Shiizaki

Calciprotein particles (CPPs) are a new biological marker of chronic kidney disease-mineral and bone disorder (CKD-MBD). CPPs consist of phosphate, calcium, and some proteins, with phosphate being the major contributor to the level and biological activity of CPPs. Recent studies have shown the physiological and pathological significance of CPPs, including contributions to bone and mineral metabolism, and to tissue and organ impairments such as cardiovascular damage and inflammatory responses. These actions are well known as important aspects of CKD-MBD. Fibroblast growth factor 23 (FGF23), which is secreted from the bone as the phosphaturic hormone, is markedly elevated in CKD-MBD. Many clinical studies have shown significant relationships between the level of FGF23 and outcomes such as mortality, prevalence of cardiovascular disease, bone fracture, and levels of inflammatory markers. Basic and clinical studies have suggested that CPPs contribute to synthesis and secretion of FGF23. Surgical treatments such as renal transplantation and parathyroidectomy for patients with CKD-MBD suppress excess levels of phosphate, calcium, parathyroid hormone (PTH), and FGF23, which are related to the CPP level. Therefore, suppression of CPPs might also contribute to improved clinical outcomes after these treatments.


2016 ◽  
pp. 9-14
Author(s):  
Huu Vu Quang Nguyen ◽  
Tam Vo

Fibroblast growth factor 23 (FGF23) is a key regulator of phosphorus metabolism whose effects in patients with chronic kidney disease (CKD) have only recently begun to be appreciated. Recent study of this phosphaturic hormone has revealed new path-ways of mineral regulation in both individuals with normal kidney function and in patients with CKD. While the effects of FGF23 on mineral metabolism in CKD appears to be similar to its effects in individuals with normal kidney function, elevated levels of the protein in the CKD population have also been linked to kidney disease progression, altered skeletal histology, and increased mortality rates, relationships that have not been examined in the general population.Thus, potential differences in FGF23 metabolism accompany the elevated levels found in CKD patients and, although the exact pathophysiological consequences remain mostly unknown, elevated FGF23 levels appear to contribute to major complications of CKD that plague both adults and children. Key words: FGF23, chronic kidney


2019 ◽  
Vol 23 (6) ◽  
pp. 83-91 ◽  
Author(s):  
E. O. Bogdanova ◽  
O. N. Beresneva ◽  
I. M. Zubina ◽  
G. T. Ivanova ◽  
M. M. Parastaeva ◽  
...  

BACKGROUND. The molecular mechanisms of the initial stages of inorganic phosphate (Pi) metabolic disorders in chronic kidney disease (CKD) remain poorly understood.THE AIM. To test the hypothesis about changes in canonical Wnt signaling pathway inhibitors biosynthesis and a concomitant decrease in bone turnover as one of early mechanisms of Pi imbalance in CKD.MATERIAL AND METHODS. Creatinine (Cr), inorganic phosphate (Pi), serum parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), osteoprotegerin (OPG), sclerostin (SOST) and Dickkopf-1 (DKK), renal SOST and DKK mRNA expression, albuminuria (Alb), proteinuria (uTP) levels, fractional (FEPi) and daily (uPi24) Pi excretion were analyzed in SHR rats (N = 52) with 3/4 nephrectomy (NE) or sham operation (SO) and observation periods of 2, 4, and 6 months.RESULTS. Experimental model was comparable with 1-2 stages of CKD. In groups NE4 and NE6, the concentration of sPi and renal Pi excretion (FEPi and uPi24) were significantly higher vs corresponding controls SO4 (p = 0.006, p <0.010) and SO6 (p = 0.002, p = 0.028). Serum concentrations of FGF23 and PTH in NE and SO animals did not change significantly. In NE4 and NE6 groups, serum SOST and DKK concentrations were significantly higher vs controls (p <0.049, p <0.043), while the kidney expression SOST and DKK mRNA in NE rats did not change significantly or decreased (p = 0.002, p <0.011). The serum concentration of OPG was higher in the NE6 vs SO6 control (p = 0.028).CONCLUSION. The initial stages of experimental CKD are characterized by an increase in serum concentrations of Dikkopf-1, sclerostin and osteoprotegerin. The obtained data suggest the possible role of canonical Wnt signaling inhibition and reduction of bone turnover in the pathogenesis of Pi metabolic disorders in early stages of CKD.


2020 ◽  
Vol 9 (8) ◽  
pp. 2640
Author(s):  
Bernhard Bielesz ◽  
Thomas Reiter ◽  
Fabian Peter Hammerle ◽  
Wolfgang Winnicki ◽  
Marija Bojic ◽  
...  

Anemia in chronic kidney disease (CKD) is an almost universal complication of this condition. Fibroblast growth factor 23 (FGF23), a key-player in mineral metabolism, is reportedly associated with anemia and hemoglobin levels in non-dialysis CKD patients. Here, we sought to further characterize this association while taking into account the biologically active, intact fraction of FGF23, iron metabolism, and erythropoietin (EPO). Hemoglobin, EPO, iron, and mineral metabolism parameters, including both intact and c-terminal-FGF23 (iFGF23 and cFGF23, respectively) were measured cross-sectionally in 225 non-dialysis CKD patients (stage 1–5, median eGFR: 30 mL/min./1.73m2) not on erythropoiesis stimulating agents or intravenous iron therapy. Statistical analysis was performed by multiple linear regression. After adjustment for eGFR and other important confounders, only cFGF23 but not iFGF23 was significantly associated with hemoglobin levels and this association was largely accounted for by iron metabolism parameters. cFGF23 but not iFGF23 was also associated with mean corpuscular hemoglobin (MCH) and mean corpuscular volume (MCV), again in dependence on iron metabolism parameters. Similarly, EPO concentrations were associated with cFGF23 but not iFGF23, but their contribution to the association of cFGF23 with hemoglobin levels was marginal. In pre-dialysis CKD patients, the observed association of FGF23 with hemoglobin seems to be restricted to cFGF23 and largely explained by the iron status.


2018 ◽  
Vol 2018 ◽  
pp. 1-4 ◽  
Author(s):  
Hodaka Yamada ◽  
Makoto Kuro-o ◽  
Shunsuke Funazaki ◽  
San-e Ishikawa ◽  
Masafumi Kakei ◽  
...  

Renal function decline is associated with progressive type 2 diabetes mellitus, which causes mineral and bone disorders. In the present study, we defined the ratio of urinary phosphate excretion (mg/day) to serum fibroblast growth factor 23 as the nephron index. We examined changes in the nephron index in type 2 diabetes patients with early stage chronic kidney disease (stages 1–3), enrolling 15 patients and retrospectively analysing the follow-up data. After follow-up at 5.4 years, we observed no significant changes in the estimated glomerular filtration rate; the nephron index, however, was significantly reduced between the baseline and the follow-up. We propose that the nephron index may be potentially useful as a biomarker for monitoring the decline of renal function in the early stages of diabetic chronic kidney disease patients.


2018 ◽  
Vol 19 (8) ◽  
pp. 2352 ◽  
Author(s):  
Yoshiko Iwasaki ◽  
Hideyuki Yamato ◽  
Masafumi Fukagawa

Transforming growth factor (TGF)-β signaling is not only important in skeletal development, but also essential in bone remodeling in adult bone. The bone remodeling process involves integrated cell activities induced by multiple stimuli to balance bone resorption and bone formation. TGF-β plays a role in bone remodeling by coordinating cell activities to maintain bone homeostasis. However, mineral metabolism disturbance in chronic kidney disease (CKD) results in abnormal bone remodeling, which leads to ectopic calcification in CKD. High circulating levels of humoral factors such as parathyroid hormone, fibroblast growth factor 23, and Wnt inhibitors modulate bone remodeling in CKD. Several reports have revealed that TGF-β is involved in the production and functions of these factors in bone. TGF-β may act as a factor that mediates abnormal bone remodeling in CKD.


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