Fibroblast Growth Factor 23 Levels Research Articles

Fibroblast Growth Factor 23 and Risk of New Onset Heart Failure With Preserved or Reduced Ejection Fraction: The PREVEND Study.

BackgroundThe role of fibroblast growth factor 23 (FGF23) in the development of new‐onset heart failure (HF) with reduced (HFrEF) or preserved ejection fraction (HFpEF) in the general population is unknown. Therefore, we set out to investigate associations of C‐terminal FGF23 with development of new‐onset HF and, more specifically, with HFrEF or HFpEF in a large, prospective, population‐based cohort.Methods and ResultsWe studied 6830 participants (aged 53.8±12.1 years; 49.7% men; estimated glomerular filtration rate, 93.1±15.7 mL/min per 1.73 m2) in the community‐based PREVEND (Prevention of Renal and Vascular End‐Stage Disease) study who were free of HF at baseline. Cross‐sectional multivariable linear regression analysis showed that ferritin (standardized β, −0.24; P<0.001) and estimated glomerular filtration rate (standardized β, −0.13; P<0.001) were the strongest independent correlates of FGF23. Multivariable Cox proportional hazard regression was used to study the association between baseline FGF23 and incident HF, HFrEF (ejection fraction ≤40%) or HFpEF (ejection fraction ≥50%). After median follow‐up of 7.4 [IQR 6.9–7.9] years, 227 individuals (3.3%) developed new‐onset HF, of whom 132 had HFrEF and 88 had HFpEF. A higher FGF23 level was associated with an increased risk of incident HF (fully adjusted hazard ratio, 1.29 [95% CI, 1.06–1.57]) and with an increased risk of incident HFrEF (fully adjusted hazard ratio, 1.31 [95% CI, 1.01–1.69]). The association between FGF23 and incident HFpEF lost statistical significance after multivariable adjustment (hazard ratio, 1.22 [95% CI, 0.87–1.71]).ConclusionsHigher FGF23 is independently associated with new‐onset HFrEF in analyses fully adjusted for cardiovascular risk factors and other potential confounders. The association between FGF23 and incident HFpEF lost statistical significance upon multivariable adjustment.

The direct effect of fibroblast growth factor 23 on vascular smooth muscle cell phenotype and function.

In chronic kidney disease (CKD) patients, increased levels of fibroblast growth factor 23 (FGF23) are associated with cardiovascular mortality. The relationship between FGF23 and heart hypertrophy has been documented, however, it is not known whether FGF23 has an effect on vasculature. Vascular smooth muscle cells VSMCs may exhibit different phenotypes; our hypothesis is that FGF23 favours a switch from a contractile to synthetic phenotype that may cause vascular dysfunction. Our objective was to determine whether FGF23 may directly control a change in VSMC phenotype. This study includes in vitro, in vivo and ex vivo experiments and evaluation of patients with CKD stages 2-3 studying a relationship between FGF23 and vascular dysfunction. In vitro studies show that high levels of FGF23, by acting on its specific receptor FGFR1 and Erk1/2, causes a change in the phenotype of VSMCs from contractile to synthetic. This change is mediated by a downregulation of miR-221/222, which augments the expression of MAP3K2 and PAK1. miR-221/222 transfections recovered the contractile phenotype of VSMCs. Infusion of recombinant FGF23 to rats increased vascular wall thickness, with VSMCs showing a synthetic phenotype with a reduction of miR-221 expression. Ex-vivo studies on aortic rings demonstrate also that high FGF23 increases arterial stiffening. In CKD 2-3 patients, elevation of FGF23 was associated with increased pulse wave velocity and reduced plasma levels of miR-221/222. In VSMCs, high levels of FGF23, through the downregulation of miR-221/222, causes a change to a synthetic phenotype. This change in VSMCs increases arterial stiffening and impairs vascular function, which might ultimately worsen cardiovascular disease.

Dry preserved multilayered fibroblast cell sheets are a new manageable tool for regenerative medicine to promote wound healing

This study investigated the therapeutic effects of dry-preserved multi-layered fibroblast cell sheets (dry sheets) on cutaneous ulcers. Dry sheets were prepared by air-drying multi-layered fibroblast cell sheets (living sheets) to cease their life activities. Before in vivo application, we tested the release of growth factors into the medium to examine the mechanisms of dry sheets in wound healing. Vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) were released from both dry and living sheets, while high levels of fibroblast growth factor-2 (FGF-2) and high mobility group box 1 (HMGB1) protein were only from dry sheets. An in vitro fibroblast proliferation assay revealed that the dry sheet eluate significantly enhanced cell proliferation and VEGF and HGF production compared with living sheet eluate. FGF-2-neutralizing antibodies significantly blocked this proliferative response. In wounds created on diabetic mice, the dry sheet-treatment groups using autologous or allogeneic cells showed significantly accelerated wound closure compared with that in the no-treatment group. The storage stability of the dry sheet was better at refrigeration temperature than at room temperature and remained stable for at least 4 weeks. Our data indicated that allogeneic dry sheets represent a promising new tool for regenerative medicine that promotes wound healing.

A case report to assess the safety and efficacy of Burosumab, an investigational antibody to FGF23, in a single pediatric patient with Epidermal Nevus Syndrome and associated hypophosphatemic rickets

Epidermal Nevus Syndrome (ENS), also known as Cutaneous Skeletal Hypophosphatemia Syndrome or Linear Sebaceous Nevus Syndrome, is caused by a mosaic somatic mutation of RAS (Rat Sarcoma genes) which leads to abnormally elevated levels of fibroblast growth factor 23 (FGF23). FGF23 is a major regulator in phosphate homeostasis. There are multiple disorders, along with Epidermal Nevus Syndrome (ENS), that result in unusually high circulating levels of FGF23. This increase ultimately leads to renal phosphate wasting and reduced levels of 1,25-dihydroxy vitamin D. Across these disorders, the clinical symptoms are similar and often include osteomalacia (hypophosphatemic rickets in children), muscle weakness, fatigue, joint deformities, bone pain, and fractures. Burosumab (KRN23), is an IgG1 monoclonal antibody that binds to the FGF23 receptor and inhibits the activity of FGF23. This leads to an increase in serum phosphate levels. Burosumab emerged as a potential therapy in FGF23 overactivity disorders. Burosumab was successful in the treatment of X-linked hypophosphatemia (XLH) and is now FDA-approved for its treatment. Studies have indicated that Burosumab therapy in subjects with XLH consistently increases and sustains serum phosphorus levels and tubular reabsorption of phosphate without a major impact on urine calcium levels or vitamin D metabolism. We studied the effect of Burosumab treatment in a single pediatric patient with Epidermal Nevus Syndrome. Serum phosphorus rose gradually as we titrated the dose of Burosumab upwards. During treatment, a persistent elevation of parathyroid hormone levels was noted along with a persistent elevation of serum calcium. We presumed the patient had tertiary hyperparathyroidism. However, after the removal of three parathyroid glands, the pathology came back with a single enlarged parathyroid adenoma. Subsequently, his calcium and PTH, and phosphorus levels stabilized while taking only Burosumab.ClinicalTrials.gov NCT04320316.

α-Lipoic acid up-regulates gene expression but reduces protein levels of fibroblast growth factor 21 in HepG2 cells.

Fibroblast growth factor 21 (FGF21) is a metabolism-regulating hepatokine, and its expression is finely controlled by the nutrients and cellular stressors. α-Lipoic acid (ALA) regulates fuel metabolism as a nutrient, but it also arouses mitochondrial and endoplasmic reticulum (ER) stress as well as oxidative stress in hepatocytes. However, the role of cellular stress in ALA-regulated FGF21 expression has not been demonstrated as yet. The present study found that ALA up-regulated FGF21 gene expression while it reduced FGF21 protein levels in HepG2 cells, which was accompanied by mitochondrial damage that was shown by ATP reduction and ROS elevation. ALA led to mitochondrial stress and ER stress as shown by the increased expression of HSP60, ATF6 and ATF4. Inhibition of ER stress by 4-PBA significantly attenuated ALA-stimulated FGF21 gene expression while it did not influence the reduction of FGF21 protein levels. H2 O2 -induced oxidative stress reduced FGF21 protein levels in HepG2 cells, and anti-oxidation by Tempol blocked ALA-induced reduction of FGF21 proteins. In conclusion, ALA up-regulates FGF21 gene expression through the stimulation of mitochondrial and ER stress while it reduces FGF21 protein levels through the induction of oxidative stress in HepG2 cells. Further studies are needed to demonstrate the in vivo effect of ALA on hepatic FGF21 expression.

Evaluation of serum Fibroblast growth factor-23 in patients with beta-thalassemia major compared to healthy population

Background: The role of phosphate hemostasis in development of thalassemia bone disease has not been extensively studied yet. Due to the lack of sufficient human studies about the changes of serum Fibroblast growth factor-23(FGF23) in patients with beta-thalassemia major as the first step of investigating the role of FGF23 in thalassemia bone disease, the present study aimed to investigate the serum level of FGF23 in patients with thalassemia major.&#x0D; Material and Method: In this case-control study, 25 patients with beta thalassemia major and their age- and sex-matched healthy volunteers were enrolled. Serum phosphorous, calcium, parathyroid hormone (PTH), 25(OH) D, erythropoietin (EPO), serum intact FGF23 (iFGF23) and 1,25 (OH)2 D were checked and analyzed.&#x0D; Result: Patients with beta-thalassemia major had lower 1,25 (OH)2D, (p = 0.025), higher phosphate (p = 0.002), and higher PTH (P &lt;0.001) compared to the control group; however, all of them were in their normal blood range. They also had higher serum FGF23 (p = 0.007) and higher EPO (P&lt;0.001). Serum FGF23 had an independent association with serum Iron (p=0.016), 1, 25(OH)2 Vitamin D (p&lt;0.001), and hemoglobin (p=0.002).&#x0D; Conclusion: Serum FGF23 was associated with serum Iron, 1, 25(OH)2 Vitamin D, and hemoglobin in beta-thalassemia major patients. Hence, it seems that regular transfusions and chelating agents which can decrease the serum iron and increase hemoglobin level can be associated with lower iFGF23.

Activation of RAAS Signaling Contributes to Hypertension in Aged Hyp Mice.

High circulating levels of fibroblast growth factor-23 (FGF23) are associated with left ventricular hypertrophy as well as increased morbidity and mortality in patients suffering from chronic kidney disease. However, the mechanisms underlying this association are controversial. Here, we aimed to further characterize the cardiovascular sequelae of long term endogenous FGF23 hypersecretion using 14-month-old male Hyp mice as a model of FGF23 excess. Hyp mice were characterized by a ~10-fold increase in circulating intact FGF23, hypophosphatemia, increased serum aldosterone, but normal kidney function, relative to wildtype (WT) controls. Cardiovascular phenotyping did not reveal any evidence of left ventricular hypertrophy or functional impairment in 14-month-old Hyp mice. Fractional shortening, ejection fraction, molecular markers of hypertrophy (Anp, Bnp), and intracardiac markers of contractility and diastolic function were all unchanged in these animals. However, intraarterial catheterization revealed an increase in systolic, diastolic, and mean arterial pressure of ~12 mm Hg in aged Hyp mice relative to WT controls. Hypertension in Hyp mice was associated with increased peripheral vascular resistance. To test the hypothesis that a stimulation of the renin–angiotensin–aldosterone system (RAAS) contributes to hypertension in aged Hyp mice, we administered the angiotensin receptor blocker losartan (30 mg/kg twice daily) or the mineralocorticoid receptor antagonist canrenone (30 mg/kg once daily) to aged Hyp and WT mice over 5 days. Both drugs had minor effects on blood pressure in WT mice, but reduced blood pressure and peripheral vascular resistance in Hyp mice, suggesting that a stimulation of the RAAS contributes to hypertension in aged Hyp mice.

Low Klotho/Fibroblast Growth Factor 23 Ratio Is an Independent Risk Factor for Renal Progression in Chronic Kidney Disease: Finding From KNOW-CKD.

BackgroundWe aimed to evaluate soluble Klotho and circulating fibroblast growth factor 23 (FGF23) ratio as a risk factor for renal progression, cardiovascular (CV) events, and mortality in chronic kidney disease (CKD).MethodsWe analyzed 2,099 subjects from a CKD cohort whose soluble Klotho and C-terminal FGF23 levels were measured at enrollment. The Klotho to FGF23 ratio was calculated as Klotho values divided by FGF23 values + 1 (hereinafter called the Klotho/FGF23 ratio). Participants were categorized into quartiles according to Klotho/FGF23 ratio. The primary outcome was renal events, defined as the doubling of serum creatinine, 50% reduction of estimated glomerular filtration rate from the baseline values, or development of end-stage kidney disease. The secondary outcomes consisted of CV events and death. Changes in CV parameters at the time of enrollment and during follow-up according to the Klotho/FGF23 ratio were also examined.ResultsDuring the follow-up period of 64.0 ± 28.2 months, 735 (35.1%) and 273 (13.0%) subjects developed renal events and composite outcomes of CV events and death, respectively. After adjustment, the first (HR: 1.36; 95% CI: 1.08–1.72, P = 0.010) and second (HR: 1.45; 95% CI: 1.15–1.83, P = 0.002) quartiles with regard to the Klotho/FGF23 ratio showed elevated risk of renal events as compared to the fourth quartile group. There was no significant association between Klotho/FGF23 ratio and the composite outcome of CV events and death. The prevalence of left ventricular hypertrophy and vascular calcification was higher in the low Klotho/FGF23 ratio quartiles at baseline and at the fourth-year follow-up.ConclusionsLow Klotho/FGF23 ratio was significantly associated with increased renal events in the cohort of Korean predialysis CKD patients.

Impact of etelcalcetide on fibroblast growth factor-23 and calciprotein particles in patients with secondary hyperparathyroidism undergoing haemodialysis.

Recently, we demonstrated the efficacy of etelcalcetide in the control of secondary hyperparathyroidism (SHPT). This post hoc analysis aimed to evaluate changes in fibroblast growth factor-23 (FGF23) and calciprotein particles (CPPs) after treatment with calcimimetics. The DUET trial was a 12-week multicenter, open-label, parallel-group, randomized (1:1:1) study with patients treated with etelcalcetide plus active vitamin D (E + D group; n= 41), etelcalcetide plus oral calcium (E + Ca group; n= 41), or control (C group; n= 42) under maintenance haemodialysis. Serum levels of FGF23 and CPPs were measured at baseline, and 6 and 12 weeks after the start. In the linear mixed model, serum levels of FGF23 in etelcalcetide users were significantly lower than those in non-users at week 6 (p< .001) and week 12 (p< .001). When compared the difference between the E + Ca group and the E + D group, serum levels of FGF23 in the E + Ca group were significantly lower than those in the E + D group at week 12 (p= .017). There were no significant differences in the serum levels of CPPs between etelcalcetide users and non-users at week 6 and week 12, while CPPs in the E + Ca group were significantly lower than those in the E + D group (p< .001) at week 12. Etelcalcetide may be useful through suppression of FGF23 levels among haemodialysis patients with SHPT. When correcting hypocalcaemia, loading oral calcium preparations could be more advantageous than active vitamin D for the suppression of both FGF23 and CPPs.

Lipocalin-2: a novel link between the injured kidney and the bone.

Fibroblast growth factor 23 (FGF23) excess is associated with left ventricular hypertrophy (LVH) and early mortality in patients with chronic kidney disease (CKD) and in animal models. Elevated Lipocalin-2 (LCN2), produced by the injured kidneys, contributes to CKD progression and might aggravate cardiovascular outcomes. The current review aims to highlight the role of LCN2 in CKD, particularly its interactions with FGF23. Inflammation, disordered iron homeostasis and altered metabolic activity are common complications of CKD, and are associated with elevated levels of kidney-produced LCN2 and bone-secreted FGF23. A recent study shows that elevated LCN2 increases FGF23 production, and contributes to cardiac injury in patients and animals with CKD, whereas LCN2 reduction in mice with CKD reduces FGF23, improves cardiovascular outcomes and prolongs lifespan. In this manuscript, we discuss the potential pathophysiological functions of LCN2 as a major kidney-bone crosstalk molecule, linking the progressive decline in kidney function to excessive bone FGF23 production. We also review associations of LCN2 with kidney, cardiovascular and bone and mineral alterations. We conclude that the presented data support the design of novel therapeutic approaches to improve outcomes in CKD.

Cholecalciferol supplementation effectively improved tertiary hyperparathyroidism, FGF23 resistance and lowered coronary calcification score: a prospective study.

IntroductionTertiary hyperparathyroidism (THPT) and vitamin D deficiency are commonly seen in kidney transplant recipients, which may result in persistently elevated fibroblast growth factor 23 (FGF23) level after transplantation and decreased graft survival. The aim of this study is to evaluate the effect of vitamin D supplementation on THPT, FGF23-alpha Klotho (KLA) axis and cardiovascular complications after transplantation.Materials and methodsTwo hundred nine kidney transplant recipients were included and further divided into treated and untreated groups depending on whether they received vitamin D supplementation. We tracked the state of THPT, bone metabolism and FGF23–KLA axis within 12 months posttransplant and explored the predictors and risk factors for intact FGF23 levels, KLA levels, THPT and cardiovascular complications in recipients.ResultsVitamin D supplementation significantly improved FGF23 resistance, THPT and high bone turnover status, preserved better graft function and prevented coronary calcification in the treated group compared to the untreated group at month 12. The absence of vitamin D supplementation was an independent risk factor for THPT and a predictor for intact FGF23 and KLA levels at month 12. Age and vitamin D deficiency were independent risk factors for coronary calcification in recipients at month 12.ConclusionVitamin D supplementation effectively improved THPT, FGF23 resistance and bone metabolism, preserved graft function and prevented coronary calcification after transplantation.

Short-Term Effects of Cholecalciferol Supplementation on cFGF23 Levels in Children with Chronic Kidney Disease and Vitamin D Insufficiency.

Data on the effect of vitamin D supplementation on fibroblast growth factor 23 (FGF23), in chronic kidney disease (CKD) are scarce. In a prospective interventional study, the effect of vitamin D supplementation on cFGF23 (C-terminal FGF23) levels in children with CKD stages 2-4 was examined. Forty-one children with CKD and vitamin D insufficiency were administered 600,000 units of cholecalciferol over 3 d; 88% of patients achieved sufficiency at 8 wk. Significant increase in serum cFGF23 and phosphate levels was observed in CKD stage 2 after supplementation, but not in CKD stages 3 and 4. There was no correlation of the change in cFGF23 level with baseline or change in bone health parameters (calcium, phosphate, parathormone or alkaline phosphatase) or with change in flow-mediated dilatation (FMD) of the brachial artery. It is concluded that cholecalciferol supplementation increases serum calcium and reduces PTH, but does not adversely affect FGF23 levels in CKD.

Priming with a Combination of FGF2 and HGF Restores the Impaired Osteogenic Differentiation of Adipose-Derived Stem Cells.

Classical aging-associated diseases include osteoporosis, diabetes, hypertension, and arthritis. Osteoporosis causes the bone to become brittle, increasing fracture risk. Among the various treatments for fractures, stem cell transplantation is currently in the spotlight. Poor paracrine/differentiation capacity, owing to donor age or clinical history, limits efficacy. Lower levels of fibroblast growth factor 2 (FGF2) and hepatocyte growth factor (HGF) are involved in cell repopulation, angiogenesis, and bone formation in the elderly ADSCs (ADSC-E) than in the young ADSCs (ADSC-Y). Here, we study the effect of FGF2/HGF priming on the osteogenic potential of ADSC-E, determined by calcium deposition in vitro and ectopic bone formation in vivo. Age-induced FGF2/HGF deficiency was confirmed in ADSCs, and their supplementation enhanced the osteogenic differentiation ability of ADSC-E. Priming with FGF2/HGF caused an early shift of expression of osteogenic markers, including Runt-related transcription factor 2 (Runx-2), osterix, and alkaline phosphatase (ALP) during osteogenic differentiation. FGF2/HGF priming also created an environment favorable to osteogenesis by facilitating the secretion of bone morphogenetic protein 2 (BMP-2) and vascular endothelial growth factor (VEGF). Bone tissue of ADSC-E origin was observed in mice transplanted with FGF/HGF-primed ADSC-E. Collectively, FGF2/HGF priming could enhance the bone-forming capacity in ADSC-E. Therefore, growth factor-mediated cellular priming can enhance ADSC differentiation in bone diseases and thus contributes to the increased efficacy in vivo.

Circular RNA hsa_circ_0043688 serves as a competing endogenous RNA for microRNA-145-5p to promote the progression of Keloids via Fibroblast growth factor-2.

BackgroundKeloids are benign fibroproliferative skin tumors. Circular RNA (circRNA) hsa_circ_0043688 has been exhibited to the freakishly expressed in keloid tissues. Here, we aimed to investigate the regulatory network of hsa_circ_0043688 in the pathological process of keloid.MethodsHsa_circ_0043688, microRNA‐145‐5p (miR‐145‐5p), and Fibroblast growth factor‐2 (FGF2) level were detected using RT‐qPCR. Cell viability, proliferation, apoptosis, invasion, and migration were investigated using Cell Counting Kit‐8 (CCK‐8), 5‐ethynyl‐2′‐deoxyuridine (EdU), flow cytometry, transwell, and wound healing assays, respectively. Western blot analysis of protein levels of FGF2, CyclinD1, Collagen I, and Collagen III. After the prediction of Circinteractome and Starbase, their interaction was verified based on a dual‐luciferase reporter and RIP assays.ResultsIncreased hsa_circ_0043688 and FGF2, and decreased miR‐145‐5p in keloids samples and fibroblasts were found. Also, hsa_circ_0043688 absence hindered proliferation, invasion, migration, and boost apoptosis of keloid fibroblasts. In mechanism, hsa_circ_0043688 modulated FGF2 content via sponging miR‐145‐5p.ConclusionHsa_circ_0043688 knockdown inhibited cell growth and metastasis of keloid fibroblasts via miR‐145‐5p/FGF2, providing a new mechanism to understand the keloid progression.

Anemia is associated with increased risk of non-vertebral osteoporotic fractures in elderly men: the MrOS Sweden cohort

SummaryThis study includes 1005 men from the Gothenburg part of the Osteoporotic Fracture in Men Study (MrOS). Included are 66 men with anemia (hemoglobin < 130 g/L). The follow-up time was up to 16 years, and the main results are that anemia is associated with all fractures and non-vertebral osteoporotic fractures.IntroductionAnemia and osteoporotic fractures are conditions that are associated with increased morbidity and mortality. Clinical studies have suggested that anemia can be used as a predictor of future osteoporotic fractures.MethodMen from the Osteoporotic Fractures in Men Study (MrOS) Sweden, Gothenburg, with available hemoglobin (Hb) values (n = 1005, median age 75.3 years (SD 3.2)), were included in the current analyses. Of these, 66 suffered from anemia, defined as Hb < 130 g/L. Median follow-up time for fracture was 10.1 years and the longest follow-up time was 16.1 years.ResultsMen with anemia had, at baseline, experienced more falls and had a higher prevalence of diabetes, cancer, prostate cancer, hypertension, and stroke. Anemia was not statistically significantly associated with bone mineral density (BMD). Men with anemia had higher serum levels of fibroblast growth factor 23 (iFGF23) (p < 0.001) and phosphate (p = 0.001) and lower serum levels of testosterone (p < 0.001) and estradiol (p < 0.001). Moreover, men with anemia had an increased risk of any fracture (hazard ratio (HR) 1.97, 95% CI 1.28–3.02) and non-vertebral osteoporotic fracture (HR 2.15, 95% CI 1.18–3.93), after adjustment for age and total hip BMD, in 10 years. The risk for any fracture was increased in 10 and 16 years independently of falls, comorbidities, inflammation, and sex hormones. The age-adjusted risk of hip fracture was increased in men with anemia (HR 2.32, 95% CI 1.06–5.12), in 10 years, although this was no longer statistically significant after further adjustment for total hip BMD.ConclusionsAnemia is associated with an increased risk for any fracture and non-vertebral osteoporotic fracture in elderly men with a long follow-up time. The cause is probably multifactorial and our results support that anemia can be used as a predictor for future fracture.

Genome-wide association study for circulating FGF21 in patients with alcohol use disorder: Molecular links between the SNHG16 locus and catecholamine metabolism

ObjectiveAlcohol consumption can increase circulating levels of fibroblast growth factor 21 (FGF21). The effects of FGF21 in the central nervous system are associated with the regulation of catecholamines, neurotransmitters that play a crucial role in reward pathways. This study aims to identify genetic variants associated with FGF21 levels and evaluate their functional role in alcohol use disorder (AUD). MethodsWe performed a genome-wide association study (GWAS) using DNA samples from 442 AUD subjects recruited from the Mayo Clinic Center for the Individualized Treatment of Alcoholism Study. Plasma FGF21 levels were measured using Olink proximity extension immunoassays. Alcohol consumption at time of entry into the study was measured using the self-reported timeline followback method. Functional genomic studies were performed using HepG2 cells and induced pluripotent stem cell (iPSC)-derived brain organoids. ResultsPlasma FGF21 levels were positively correlated with recent alcohol consumption and gamma-glutamyl transferase levels, a commonly used marker for heavy alcohol use. One variant, rs9914222, located 5’ of SNHG16 on chromosome 17 was associated with plasma FGF21 levels (p = 4.60E-09). This variant was also associated with AUD risk (β: −3.23; p:0.0004). The rs9914222 SNP is an eQTL for SNHG16 in several brain regions, i.e., the variant genotype was associated with decreased expression of SNHG16. The variant genotype for the rs9914222 SNP was also associated with higher plasma FGF21 levels. Knockdown of SNHG16 in HepG2 cells resulted in increased FGF21 concentrations and decreased expression and enzyme activity for COMT, an enzyme that plays a key role in catecholamine metabolism. Finally, we demonstrated that ethanol significantly induced FGF21, dopamine, norepinephrine, and epinephrine concentrations in iPSC-derived brain organoids. ConclusionsGWAS for FGF21 revealed a SNHG16 genetic variant associated with FGF21 levels which are associated with recent alcohol consumption. Our data suggest that SNHG16 can regulate FGF21 concentrations and decrease COMT expression and enzyme activity which, in turn, have implications for the regulation of catecholamines.(The ClinicalTrials.gov Identifier: NCT00662571)

LncRNA DHFRL1‑4 knockdown attenuates cerebral ischemia/reperfusion injury by upregulating the levels of angiogenesis‑related genes.

The present study aimed to investigate the effects of long non-coding (lncRNA) dihydrofolate reductase-like 1 (DHFRL1-4) on cerebral ischemia/reperfusion (I/R)-induced injury. For this purpose, mice injected with lentivirus with small interfering RNA targeting DHFRL1-4 or negative control siRNA were used to construct models of cerebral I/R injury. Following the establishment of the model, the infarct size, neurological deficit score, apoptosis and the expression levels of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), Wnt family member 3a (Wnt3a), glycogen synthase kinase-3β (GSK-3β) and phosphorylated GSK-3β were assessed. The expression of DHFRL1-4 was significantly upregulated in the I/R model. In the control and sham groups, the boundaries between the cortex and gray matter were clear, and no edema or necrosis were observed. The nerve cells were arranged orderly and evenly, and the cell membranes were intact with visible nucleus and nucleolus. In the model group however, the nerve fibers were slightly necrotic and swollen, and the number of nerve cells was reduced. In the mice injected with si-DHFRL1-4 lentivirus, the brain tissues exhibited less liquefaction and degeneration, as well as less edema. Compared with the control and sham groups, the model group had a significantly larger infarct area, a higher apoptotic rate, higher bFGF, VEGF, Wnt3a and GSK-3β expression levels and a greater neurological deficit score. However, the mice injected with si-DHFRL1-4 lentivirus exhibited a significantly reduced infarct area, a lower apoptotic rate, lower Wnt3a and GSK-3β expression levels, a lower neurological deficit score, and significantly upregulated bFGF and VEGF levels.

Genetic and clinical profile of patients with hypophosphatemic rickets

Nutritional vitamin D deficiency is the most frequent cause of rickets followed by genetic causes, that include entities like classic hypophosphatemic rickets (FGF23 related), Dent disease, Fanconi syndrome, renal tubular acidosis, and vitamin D dependent rickets. Hypophosphatemia is a feature in all these forms. The diagnosis relies on a combination of clinical, biochemical and radiological features, but genetic testing is required to confirm the diagnosis. We screened 66 patients with hypophosphatemic rickets referred to this center between May 2015 and July 2019 using whole exome sequencing (WES) in addition to the measurement of their intact serum fibroblast growth factor 23 (FGF23) levels. WES revealed 36 pathogenic and 28 likely pathogenic variants in 16 different genes (PHEX, FGF23, DMP1, ENPP1, CLCN5, CTNS, SLC2A2, GATM, SLC34A1, EHHADH, SLC4A1, ATP6V1B1, ATP6V0A4, CYP27B1, VDR and FGFR1) in 63 patients which helped differentiate between the various forms of hypophosphatemic rickets. Intact serum FGF23 levels were significantly higher in patients with variations in PHEX, FGF23, DMP1 or ENPP1 genes. The major genetic causes of rickets were classic hypophosphatemic rickets with elevated FGF23 levels, distal renal tubular acidosis, and vitamin D dependent rickets. Based on the present results, we propose a customized gene panel for targeted exome sequencing, which will be useful for confirming the diagnosis in most patients with hypophosphatemic rickets.

In-center Nocturnal Hemodialysis Reduced the Circulating FGF23, Left Ventricular Hypertrophy, and All-Cause Mortality: A Retrospective Cohort Study.

Fibroblast growth factor 23(FGF23) is the most important biomarker and pathogenic factor in Chronic Kidney Disease–Mineral and Bone Disorder (CKD–MBD). In the moderate and severe stages of chronic renal failure, abnormally elevated circulating FGF23 can lead to some complications, including myocardial hypertrophy, which is positively correlated with all-cause mortality. However, the circulating FGF23 level of different hemodialysis modalities, the underlying essential regulatory factors, and potential clinical benefits remain to be elucidated. In this retrospective cohort study, 90 in-center nocturnal hemodialysis (INHD) and 90 matched conventional hemodialysis (CHD) patients were enrolled. The complete blood count, intact FGF23(iFGF23), calcium, phosphorus, PTH, and other biochemical and echocardiographic parameters of INHD and CHD patients were collected and analyzed at 1-year follow-up. The all-cause mortality was recorded during the 7-year follow-up. Furthermore, the regulatory factors of iFGF23 and its association with echocardiographic parameters and mortality were investigated by multivariate regression. The levels of iFGF23 and serum phosphate in patients undergoing INHD were significantly lower than those in patients undergoing CHD. The left ventricular volume index (LVMI) in patients with INHD was significantly attenuated and positively correlated with the drop of serum iFGF23. The INHD group had reduced all-cause mortality compared to the CHD group. Multivariate analysis showed that iFGF23 was positively correlated with serum calcium, serum phosphorus, and calcium-phosphate product. The calcium-phosphate product is an independent determining factor of serum iFGF23. Compared with the CHD group, the INHD group presented with a significantly reduced circulating iFGF23 level, which was closely associated with attenuation of left ventricular hypertrophy, but INHD reduced all-cause mortality in an FGF23 independent manner.

High phosphate-induced progressive proximal tubular injury is associated with the activation of Stat3/Kim-1 signaling pathway and macrophage recruitment.

Dietary phosphate intake in the Western population greatly exceeds the recommended dietary allowance and is linked to enhanced cardiovascular and all-cause mortality. It is unclear whether a chronic high phosphate diet (HPD) causes kidney injury in healthy individuals. Here, we show that feeding a 2% HPD in C57BL/6N mice for one up to six months resulted in hyperphosphatemia, hyperphosphaturia, increased plasma levels of fibroblast growth factor (FGF) 23, and parathyroid hormone (PTH) compared to mice on a 0.8% phosphate diet. Kidney injury was already noted after two months of HPD characterized by loss of proximal tubular (PT) cell polarity, flattened epithelia, disruption of brush border membranes, vacuolization, increased PT cell proliferation, marked interstitial mononuclear infiltration, and progressive accumulation of collagen fibers. HPD increased Stat3 activation and Kim-1 expression in PT epithelial cells and enhanced renal synthesis of chemokines recruiting monocytes and macrophages as well as macrophage related factors. Enhanced recruitment of F4/80+ macrophages around injured PT lesions was timely associated with increased Kim-1 synthesis, tubular MCP-1 expression, and degree of PT injury score. Likewise, tubulointerstitial fibrosis was associated with activation of Stat3/Kim-1 signaling pathway. The stimulation of human proximal tubular cells with high phosphate activated Stat3 signaling and induced HAVCR1 and CCL2 expression. We conclude that high phosphate results in progressive proximal tubular injury, indicating that high dietary phosphate intake may affect kidney health and therefore represents an underestimated health problem for the general population.