Implication of serum growth differentiation factor-15 level in patients with renal diseases

Biomarkers in Contrast-Induced Nephropathy: Advances in Early Detection, Risk Assessment, and Prevention Strategies

Contrast-induced nephropathy (CIN) represents a significant complication associated with the use of iodinated contrast media (ICM), especially in individuals with preexisting renal impairment. The pathophysiology of CIN encompasses oxidative stress, inflammation, endothelial dysfunction, and hemodynamic disturbances, resulting in acute kidney injury (AKI). Early detection is essential for effective management; however, conventional markers like serum creatinine (sCr) and estimated glomerular filtration rate (eGFR) exhibit limitations in sensitivity and timeliness. This review emphasizes the increasing significance of novel biomarkers in enhancing early detection and risk stratification of contrast-induced nephropathy (CIN). Recent advancements in artificial intelligence and computational analytics have improved the predictive capabilities of these biomarkers, enabling personalized risk assessment and precision medicine strategies. Additionally, we discuss mitigation strategies, including hydration protocols, pharmacological interventions, and procedural modifications, aimed at reducing CIN incidence. Incorporating biomarker-driven assessments into clinical decision-making can enhance patient management and outcomes. Future research must prioritize the standardization of biomarker assays, the validation of predictive models across diverse patient populations, and the exploration of novel therapeutic targets. Utilizing advancements in biomarkers and risk mitigation strategies allows clinicians to improve the safety of contrast-enhanced imaging and reduce the likelihood of renal injury.

Circulating GDF15 May Estimate Vasculitis Activity and Predict Poor Outcomes During the Disease Course of ANCA-Associated Vasculitis

Objective: This study investigated whether circulating growth differentiation factor 15 (GDF15) at diagnosis could estimate the Birmingham Vasculitis Activity Score (BVAS) and potentially predict all-cause mortality and end-stage kidney disease (ESKD) during follow-up in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Methods: This study included 79 patients selected from a cohort of Korean patients with AAV. Circulating GDF15 was measured from patients' sera collected at diagnosis and stored at -80 °C. Clinical data at diagnosis and during follow-up were reviewed. Results: The median age was 64.0 years (40.5% men, and 59.5% women). Median circulating GDF15 was measured as 995.0 pg/mL. Of the 79 patients, 6 (7.6%) died and 20 (25.3%) progressed to ESKD during the disease course. Circulating GDF15 levels were significantly correlated with BVAS (r = 0.340) at diagnosis. Patients with circulating GDF15 ≥ 3350.5 pg/mL exhibited a significantly higher risk of the highest tertile of BVAS than those without (relative risk [RR], 11.229). Similarly, patients with circulating GDF15 ≥ 2239.5 pg/mL and ≥2208.5 pg/mL showed higher risks of all-cause mortality (RR, 7.733) and progression to ESKD (RR 7.125) than those without. Patients with circulating GDF15 ≥ 2239.5 pg/mL and ≥2208.5 pg/mL also showed significantly lower patient and ESKD-free survival rates than those without. Conclusions: Circulating GDF15 at diagnosis is useful in estimating BVAS and potentially predicts all-cause mortality and ESKD progression in patients with AAV.

The role of GDF15 in attenuating noise-induced hidden hearing loss by alleviating oxidative stress

Noise-induced hidden hearing loss (HHL) is a newly uncovered form of hearing impairment that causes hidden damage to the cochlea. Patients with HHL do not have significant abnormalities in their hearing thresholds, but they experience impaired speech recognition in noisy environments. However, the mechanisms underlying HHL remain unclear. In this study, we developed single-cell transcriptome profiles of the cochlea of mice with HHL, detailing changes in individual cell types. Our study revealed a transient threshold shift, reduced auditory brainstem response wave I amplitude, and decreased number of ribbon synapses in HHL mice. Our findings suggest elevated oxidative stress and GDF15 expression in cochlear hair cells of HHL mice. Notably, the upregulation of GDF15 attenuated oxidative stress and auditory impairment in the cochlea of HHL mice. This suggests that a therapeutic strategy targeting GDF15 may be efficacious against HHL.

GDF15, an Emerging Player in Renal Physiology and Pathophysiology

These last years, the growth factor GDF15 has emerged as a key element in many different biological processes. It has been established as being produced in response to many pathological states and is now referred to as a stress-related hormone. Regarding kidney functions, GDF15 has been involved in different pathologies such as chronic kidney disease, diabetic nephropathy, renal cancer, and so on. Interestingly, recent studies also revealed a role of GDF15 in the renal homeostatic mechanisms allowing to maintain constant, as far as possible, the plasma parameters such as pH and K+ values. In this review, we recapitulate the role of GDF15 in physiological and pathological context by focusing our interest on its renal effect.

The Influence of Betulin Derivatives EB5 and ECH147 on the Expression of Selected TGFβ Superfamily Genes, TGFβ1, GDF15 and BMP2, in Renal Proximal Tubule Epithelial Cells

Betulin derivatives are proposed to serve as an alternative to the drugs already established in oncologic treatment. Drug-induced nephrotoxicity leading to acute kidney injury frequently accompanies cancer treatment, and thus there is a need to research the effects of betulin derivatives on renal cells. The objective of our study was to assess the influence of the betulin derivatives 28-propynylobetulin (EB5) and 29-diethoxyphosphoryl-28-propynylobetulin (ECH147) on the expression of TGFβ1, BMP2 and GDF15 in renal proximal tubule epithelial cells (RPTECs) cultured in vitro. The changes in mRNA expression and copy numbers were assessed using real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR) and the standard curve method, respectively. An enzyme-linked immunosorbent assay (ELISA) was used to evaluate the effect of the betulin derivatives on the protein concentration in the culture media's supernatant. The assessment of the betulin derivatives' influence on gene expression demonstrated that the mRNA level and protein concentration did not always correlate with each other. Each of the tested compounds affected the mRNA expression. The RT-qPCR analyses showed that EB5 and ECH147 induced effects similar to those of betulin or cisplatin and resulted in a decrease in the mRNA copy number of all the analyzed genes. The ELISA demonstrated that EB5 and ECH147 elevated the protein concentration of TGFβ1 and GDF15, while the level of BMP2 decreased. The concentration of the derivatives used in the treatment was crucial, but the effects did not always exhibit a simple linear dose-dependent relationship. Betulin and its derivatives, EB5 and ECH147, influenced the gene expression of TGFβ1, BMP2 and GDF15 in the renal proximal tubule epithelial cells. The observed effects raise the question of whether treatment with these compounds could promote the development of renal fibrosis.