The Potential Biotherapeutic Targets of Contrast-Induced Acute Kidney Injury

Innovative approaches beyond periprocedural hydration for preventing contrast-induced acute kidney injury

Contrast-induced acute kidney injury (CI-AKI) is a major concern in clinical practice, particularly among high-risk patients with preexisting renal and cardiovascular conditions. Although periprocedural hydration has long been the primary approach for CI-AKI prevention, recent advancements have led to the development of novel approaches such as RenalGuard and contrast removal systems. This editorial explores these emerging approaches and highlights their potential for enhancing CI-AKI prevention. By incorporating the latest evidence into clinical practice, health-care professionals can more effectively maintain renal function and improve outcomes for patients undergoing contrast-enhanced procedures.

Unveiling the Mysteries of Contrast-Induced Acute Kidney Injury: New Horizons in Pathogenesis and Prevention

The utilization of contrast media (CM) in clinical diagnostic imaging and interventional procedures has escalated, leading to a gradual increase in the incidence of contrast-induced acute kidney injury (CI-AKI). Presently, the scarcity of effective pharmacological treatments for CI-AKI poses significant challenges to clinical management. Firstly, we explore the pathogenesis of CI-AKI in this review. Beyond renal medullary ischemia and hypoxia, oxidative stress, cellular apoptosis, and inflammation, emerging mechanisms such as ferroptosis, release of neutrophil extracellular traps (NETs), and nitrosative stress, which offer promising avenues for the management of CI-AKI, are identified. Secondly, a comprehensive strategy for the early prevention of CI-AKI is introduced. Investigating the risk factors associated with CI-AKI is essential for the timely identification of high-risk groups. Additionally, exploring early sensitive biomarkers is crucial for early diagnosis. A synergistic approach that combines these sensitive biomarkers, CI-AKI risk factors, and disease risk prediction models enhances both the accuracy and efficiency of early diagnostic processes. Finally, we explore recent pharmacological and non-pharmacological interventions for the management of Cl-AKI. Beyond the traditional focus on the antioxidant N-acetylcysteine (NAC), we look at active compounds from traditional Chinese medicine, including tetramethylpyrazine (TMP), salvianolic acid B (Sal B), as well as emerging preventive medications like N-acetylcysteine amide (NACA), alprostadil, and others, which all showed potential benefits in animal and clinical studies for CI-AKI prevention. Furthermore, innovative strategies such as calorie restriction (CR), enhanced external counterpulsation (EECP), and mesenchymal stem cell therapy are highlighted as providing fresh insights into Cl-AKI prevention and management.

Layer-by-Layer Assembly of Renal-Targeted Polymeric Nanoparticles for Robust Arginase-2 Knockdown and Contrast-Induced Acute Kidney Injury Prevention

The mitochondrial enzyme arginase-2 (Arg-2) is implicated in the pathophysiology of contrast-induced acute kidney injury (CI-AKI). Therefore, Arg-2 represents a candid target for CI-AKI prevention. Here, layer-by-layer (LbL) assembled renal-targeting polymeric nanoparticles are developed to efficiently deliver small interfering RNA (siRNA), knockdown Arg-2 expression in renal tubules, and prevention of CI-AKI is evaluated. First, near-infrared dye-loaded poly(lactic-co-glycolic acid) (PLGA) anionic cores are electrostatically coated with cationic chitosan (CS) to facilitate the adsorption and stabilization of Arg-2 siRNA. Next, nanoparticles are coated with anionic hyaluronan (HA) to provide protection against siRNA leakage and shielding against early clearance. Sequential electrostatic layering of CS and HA improves loading capacity of Arg-2 siRNA and yields LbL-assembled nanoparticles. Renal targeting and accumulation is enhanced by modifying the outermost layer of HA with a kidney targeting peptide (HA-KTP). The resultant kidney-targeting and siRNA loaded nanoparticles (PLGA/CS/HA-KTP siRNA) exhibit proprietary accumulation in kidneys and proximal tubular cells at 24 h post-tail vein injection. In iohexol-induced in vitro and in vivo CI-AKI models, PLGA/CS/HA-KTP siRNA delivery alleviates oxidative and nitrification stress, and rescues mitochondrial dysfunction while reducing apoptosis, thereby demonstrating a robust and satisfactory therapeutic effect. Thus, PLGA/CS/HA-KTP siRNA nanoparticles offer a promising candidate therapy to protect against CI-AKI.

Sodium selenite attenuates inflammatory response and oxidative stress injury by regulating the Nrf2/ARE pathway in contrast-induced acute kidney injury in rats

BACKGROUND

Contrast-induced acute kidney injury (CI-AKI) is an acute renal complication that occurs after intravascular contrast agent administration. Sodium selenite (SS) is an inorganic source of Se and has potent antioxidant properties. This study intends to examine its anti-inflammatory and antioxidant effects in CI-AKI.

METHODS

A rat CI-AKI model was established with the pretreatment of SS (0.35 mg/kg). Hematoxylin-eosin staining was employed for histopathological analysis of rat kidney specimens. Biochemical analysis was conducted for renal function detection. Tissue levels of oxidative stress-related markers were estimated. Reverse transcription-quantitative polymerase chain reaction revealed the mRNA levels of proinflammatory cytokines. Western blotting showed the Nrf2 signaling-related protein expression in the rat kidney.

RESULTS

SS administration alleviated the renal pathological changes and reduced the serum levels of serum creatinine, blood urea nitrogen, neutrophil gelatinase-associated lipocalin, cystatin C, and urinary level of kidney injury molecule-1 in CI-AKI rats. SS attenuated oxidative stress and inflammatory response in CI-AKI rat kidney tissues. SS activated the Nrf2 signaling transduction in the renal tissues of rats with CI-AKI.

CONCLUSION

SS ameliorates CI-AKI in rats by reducing oxidative stress and inflammation via the Nrf2 signaling.

High-mobility group box 1 and its related receptors: potential therapeutic targets for contrast-induced acute kidney injury

Percutaneous coronary intervention (PCI) is a crucial diagnostic and therapeutic approach for coronary heart disease. Contrast agents' exposure during PCI is associated with a risk of contrast-induced acute kidney injury (CI-AKI). CI-AKI is characterized by a sudden decline in renal function occurring as a result of exposure to intravascular contrast agents, which is associated with an increased risk of poor prognosis. The pathophysiological mechanisms underlying CI-AKI involve renal medullary hypoxia, direct cytotoxic effects, endoplasmic reticulum stress, inflammation, oxidative stress, and apoptosis. To date, there is no effective therapy for CI-AKI. High-mobility group box 1 (HMGB1), as a damage-associated molecular pattern molecule, is released extracellularly by damaged cells or activated immune cells and binds to related receptors, including toll-like receptors and receptor for advanced glycation end product. In renal injury, HMGB1 is expressed in renal tubular epithelial cells, macrophages, endothelial cells, and glomerular cells, involved in the pathogenesis of various kidney diseases by activating its receptors. Therefore, this review provides a theoretical basis for HMGB1 as a therapeutic intervention target for CI-AKI.

Blood-urea-nitrogen-to-serum-albumin ratio in predicting the value of patients with contrast-induced nephropathy for coronary heart disease

BACKGROUND

The blood-urea-nitrogen (BUN)-to-serum-albumin (ALB) ratio (BAR) has been identified as a novel indicator of both inflammatory and nutritional status, exhibiting a correlation with adverse cardiovascular outcomes. This study aims to investigate the potential predictive value of BAR levels at admission for the development of CIN in patients undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI).

METHODS

Retrospective data were collected from patients who were admitted and underwent CAG or PCI between January 2018 and December 2022 at the Cardiac Medical Center of Union Hospital of Fujian Medical University, and the patients were divided into CIN and non-CIN groups. The BAR was computed by dividing the BUN count by the ALB count. Using multiple variable logistic regression, risk variables associated with the development of CIN were found.

RESULTS

A total of 156 patients developed CIN (7.78%). The development of CIN was predicted by a BAR ratio > 4.340 with a sensitivity of 84.0% and a specificity of 70.2%, according to receiver operating characteristic (ROC) analysis. BAR, female gender, diuretic use, and statin medication use were found to be independent predictors of CIN using multifactorial analysis.

CONCLUSIONS

When patients are receiving CAG/PCI, BAR is a simple-to-use marker that can be used independently to predict the presence of CIN.

NMR-based metabolomic analysis of plasma from elderly patients with CVD before and after using contrast media

Contrast-induced acute kidney injury (CI-AKI) is a growingly common kidney problem caused by medical procedures involving contrast media (CM), especially in older patients with existing health issues. It is crucial to pinpoint potential biomarkers for the early detection of CI-AKI. Previously, we observed that iodixanol affects glucose, choline, and glutathione metabolism in endothelial cells under laboratory conditions. In this study, we used 1H NMR-based metabolomics to examine the metabolic changes in the blood plasma of elderly patients with cardiovascular disease (CVD) before and after receiving iodixanol. We identified altered metabolites in plasma 24 and 48 h after iodixanol injection compared to levels before injection. Notably, metabolites such as glucose, unsaturated fatty acids (UFA), low-density lipoprotein (LDL)/very low-density lipoprotein (VLDL), pyruvate, choline, and glycine showed potential as biomarkers at 24 h post-injection compared to levels before injection. Similarly, glucose, pyruvate, lactate, choline, and glycine in plasma could serve as potential biomarkers at 48 h post-injection. Iodixanol notably affected pathways related to glycolysis, fatty acid breakdown, and amino acid metabolism according to our metabolic pathway analysis. The altered levels of specific metabolites in plasma could be indicative of CM-induced kidney injury. Overall, this research aids in understanding the physiological mechanisms involved and in identifying early biomarkers and prevention strategies for CI-AKI.

P16INK4a deletion alleviates contrast-induced acute kidney injury by ameliorating renal cell apoptosis and suppressing inflammation and oxidative stress

Contrast-induced acute kidney injury (CI-AKI) is the third leading cause of hospital-acquired acute kidney injury. Cellular senescence is associated with CI-AKI. P16INK4a (p16) is a cell cycle regulator and link to aging and senescence. We found that the expression of p16 was elevated in CI-AKI renal tissues, however its role in CI-AKI remains insufficiently understood. In this study, we used p16 knockout (p16KO) mice and wild-type (WT) littermates to establish CI-AKI mice model to elucidate the impact of p16 on CI-AKI. The results showed that serum creatinine (SCr), blood urea nitrogen (BUN), and serum neutrophil gelatinase-associated lipocalin (NGAL) levels were markedly reduced in p16KO CI-AKI mice. Both immunohistochemistry and western blot analyses confirmed that p16 knockout alleviated renal cell apoptosis. Furthermore, interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) were attenuated by downregulating NLRP3 and NF-κB inflammasomes. Additionally, ROS levels were diminished via activating Nrf2/Keap-1 pathway in p16KO CI-AKI mice. Collectively, our findings suggest that p16 deletion exerts protective effects against apoptosis, inflammation, and oxidative stress in CI-AKI mice model, p16 deletion might be a potential therapeutic strategy for ameliorating CI-AKI.

Prevention of contrast-associated acute kidney injury in an era of increasingly complex interventional procedures

Radiological and interventional cardiology procedures are in continuous expansion, leading to an important increase in the incidence of contrast-associated acute kidney injury (CA-AKI). Although numerous methods of CA-AKI prevention have been studied, at present, there is no consensus on the definition of this entity or on its prevention. In this paper, we aim to provide a critical analysis of the existing data on the epidemiology, pathophysiology, and clinical significance of CA-AKI. Existing and emergent approaches for CA-AKI prevention are also discussed, with a focus on parenteral fluid administration and on the most recent clinical and experimental data. We also emphasize a number of questions that remain to be answered, and we identify hotspots for future research.