High mobility group box 1 and homocysteine as preprocedural predictors for contrast-induced acute kidney injury after percutaneous coronary artery intervention

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.

Impact of folic acid supplementation on ischemia‒reperfusion-induced kidney injury in rats: folic acid prophylactic role revisited

Folic acid (FA), with its anti-inflammatory and antioxidant properties, may offer protection against ischemia-reperfusion (IR) injury. This study investigated whether FA safeguards rat kidneys from IR by targeting high mobility group box-1 (HMGB1), a key inflammatory mediator. Fifty adult male Wistar rats were randomly allocated into four groups: control, IR, IR + FA pretreatment, and FA alone. Compared to controls, IR significantly impaired renal function and elevated levels of malondialdehyde, HMGB1, NF-κB, and caspase 3. FA pretreatment effectively reversed these detrimental changes, protecting renal function and minimizing tissue damage. The FA-alone group showed no significant differences compared to the control group, indicating no adverse effects of FA treatment. Mechanistically, FA inhibited HMGB1 expression and its downstream activation of NF-κB and caspase 3, thereby quelling inflammation and cell death. FA shields rat kidneys from IR-induced injury by suppressing HMGB1-mediated inflammation and apoptosis, suggesting a potential therapeutic avenue for IR-associated kidney damage.

Role of uranium toxicity and uranium-induced oxidative stress in advancing kidney injury and endothelial inflammation in rats

OBJECTIVE

Uranium exposure may cause serious pathological injury to the body, which is attributed to oxidative stress and inflammation. However, the pathogenesis of uranium toxicity has not been clarified. Here, we evaluated the level of oxidative stress to determine the relationship between uranium exposure, nephrotoxic oxidative stress, and endothelial inflammation.

METHODS

Forty male Sprague-Dawley rats were divided into three experimental groups (U-24h, U-48h, and U-72h) and one control group. The three experimental groups were intraperitoneally injected with 2.0 mg/kg uranyl acetate, and tissue and serum samples were collected after 24, 48, and 72 h, respectively, whereas the control group was intraperitoneally injected with 1.0 ml/kg normal saline and samples were collected after 24 h. Then, we observed changes in the uranium levels and oxidative stress parameters, including the total oxidative state (TOS), total antioxidant state (TAS), and oxidative stress index (OSI) in kidney tissue and serum. We also detected the markers of kidney injury, namely urea (Ure), creatine (Cre), cystatin C (CysC), and neutrophil gelatinase-associated lipocalin (NGAL). The endothelial inflammatory markers, namely C-reactive protein (CRP), lipoprotein phospholipase A2 (Lp-PLA2), and homocysteine (Hcy), were also quantified. Finally, we analyzed the relationship among these parameters.

RESULTS

TOS (z = 3.949; P < 0.001), OSI (z = 5.576; P < 0.001), Ure (z = 3.559; P < 0.001), Cre (z = 3.476; P < 0.001), CysC (z = 4.052; P < 0.001), NGAL (z = 3.661; P < 0.001), and CRP (z = 5.286; P < 0.001) gradually increased after uranium exposure, whereas TAS (z = -3.823; P < 0.001), tissue U (z = -2.736; P = 0.001), Hcy (z = -2.794; P = 0.005), and Lp-PLA2 (z = -4.515; P < 0.001) gradually decreased. The serum U level showed a V-shape change (z = -1.655; P = 0.094). The uranium levels in the kidney tissue and serum were positively correlated with TOS (r = 0.440 and 0.424; P = 0.005 and 0.007) and OSI (r = 0.389 and 0.449; P = 0.013 and 0.004); however, serum U levels were negatively correlated with TAS (r = -0.349; P = 0.027). Partial correlation analysis revealed that NGAL was closely correlated to tissue U (rpartial = 0.455; P = 0.003), CysC was closely correlated to serum U (rpartial = 0.501; P = 0.001), and Lp-PLA2 was closely correlated to TOS (rpartial = 0.391; P = 0.014), TAS (rpartial = 0.569; P < 0.001), and OSI (rpartial = -0.494; P = 0.001). Pearson correlation analysis indicated that the Hcy levels were negatively correlated with tissue U (r = -0.344; P = 0.030) and positively correlated with TAS (r = 0.396; P = 0.011).

CONCLUSION

The uranium-induced oxidative injury may be mainly reflected in enhanced endothelial inflammation, and the direct chemical toxicity of uranium plays an important role in the process of kidney injury, especially in renal tubular injury. In addition, CysC may be a sensitive marker reflecting the nephrotoxicity of uranium; however, Hcy is not suitable for evaluating short-term endothelial inflammation involving oxidative stress.

Association between serum homocysteine and postoperative acute kidney injury in patients undergoing cardiac surgery

Background: To explore the relationship between homocysteine (Hcy) and cardiac surgery-associated acute kidney injury (AKI). Methods: A total of 944 patients who underwent cardiac surgery were enrolled. The association between Hcy levels and the risk of cardiac surgery-associated AKI was evaluated. Results: A total of 135 patients were diagnosed with AKI and the prevalence of AKI was 14.30%. The AKI group had significantly higher levels of Hcy compared with the non-AKI group (16.90 vs 13.56 umol/l; p < 0.001). The incidence rates of AKI increased from 7.2% to 26.72% across increasing Hcy quartiles (p < 0.001). Compared with the first Hcy quartile group, the odds ratio of cardiac surgery-associated AKI was 4.43 (95% CI: 2.27-8.66) in the highest Hcy group. Conclusion: Elevated Hcy level is an independent risk factor for cardiac surgery-associated AKI.

Determination of HMGB1 in hepatitis B virus-related acute-on-chronic liver failure patients with acute kidney injury: Early prediction and prognostic implications

Background: Acute kidney injury (AKI) is a frequent complication in patients with hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) and is associated with high rates of mortality. We aimed to estimate serum high mobility group protein 1 (HMGB1) levels in hepatitis B virus-related acute-on-chronic liver failure patients and analyze their clinical value in the development and outcomes of Acute kidney injury. Methods: A total of 251 consecutive patients with hepatitis B virus-related acute-on-chronic liver failure were enrolled in this retrospective study. Using the International Club of Ascites staging criteria of Acute kidney injury, 153 patients developed Acute kidney injury. The clinical data of patients were collected and serum levels of high mobility group protein 1 were measured by ELISA. All patients were followed up until death or for a minimum of 3 months. Early prediction and prognostic implications of high mobility group protein 1 in Hepatitis B Virus-Related Acute-on-Chronic Liver Failure Patients with Acute Kidney Injury were investigated in different cohorts, including a propensity score-matched ACLF cohort. Results: Among all individuals with hepatitis B virus-related acute-on-chronic liver failure, the incidence of Acute kidney injury was 61.0% (153/251). The patients who developed stage 2/3 Acute kidney injury showed the highest high mobility group protein 1 levels, followed by those who developed stage 1 Acute kidney injury, and those without Acute kidney injury showed the lowest high mobility group protein 1 levels. Moreover, high mobility group protein 1 levels were significantly higher in non-survivors than in survivors among hepatitis B virus-related acute-on-chronic liver failure patients with Acute kidney injury. Furthermore, analysis of the area under the receiver operating characteristic curve (AUROC) indicated that serum high mobility group protein 1 levels (pre-matching: AUC = 0.740; post-matching: AUC = 0.661) may be a potential predictive factor for Acute kidney injury development and that high mobility group protein 1 (AUC = 0.727) might be a reliable biomarker for prognosis in patients with Acute kidney injury. Conclusion: In patients with hepatitis B virus-related acute-on-chronic liver failure, Acute kidney injury is universal. Acute kidney injury and its stages negatively influence the 90-day transplant-free mortality rate. Serum high mobility group protein 1 levels can serve as a positive predictor of Acute kidney injury development, and high mobility group protein 1 might also be a prognostic biomarker for Acute kidney injury among hepatitis B virus-related acute-on-chronic liver failure patients.