Analytical and clinical validation of rapid chemiluminescence enzyme immunoassay for urinary thioredoxin, an oxidative stress-dependent early biomarker of acute kidney injury

Liquid Biopsy at the Frontier of Kidney Diseases: Application of Exosomes in Diagnostics and Therapeutics

In the era of precision medicine, liquid biopsy techniques, especially the use of urine analysis, represent a paradigm shift in the identification of biomarkers, with considerable implications for clinical practice in the field of nephrology. In kidney diseases, the use of this non-invasive tool to identify specific and sensitive biomarkers other than plasma creatinine and the glomerular filtration rate is becoming crucial for the diagnosis and assessment of a patient's condition. In recent years, studies have drawn attention to the importance of exosomes for diagnostic and therapeutic purposes in kidney diseases. Exosomes are nano-sized extracellular vesicles with a lipid bilayer structure, composed of a variety of biologically active substances. In the context of kidney diseases, studies have demonstrated that exosomes are valuable carriers of information and are delivery vectors, rendering them appealing candidates as biomarkers and drug delivery vehicles with beneficial therapeutic outcomes for kidney diseases. This review summarizes the applications of exosomes in kidney diseases, emphasizing the current biomarkers of renal diseases identified from urinary exosomes and the therapeutic applications of exosomes with reference to drug delivery and immunomodulation. Finally, we discuss the challenges encountered when using exosomes for therapeutic purposes and how these may affect its clinical applications.

Urinary Thioredoxin as a Biomarker of Renal Redox Dysregulation and a Companion Diagnostic to Identify Responders to Redox-Modulating Therapeutics

Significance: The development and progression of renal diseases, including acute kidney injury (AKI) and chronic kidney disease (CKD), are the result of heterogeneous pathophysiology that reflects a range of environmental factors and, in a lesser extent, genetic mutations. The pathophysiology specific to most kidney diseases is not currently identified; therefore, these diseases are diagnosed based on non-pathological factors. For that reason, pathophysiology-based companion diagnostics for selection of pathophysiology-targeted treatments have not been available, which impedes personalized medicine in kidney disease. Recent Advances: Pathophysiology-targeted therapeutic agents are now being developed for the treatment of redox dysregulation. Redox modulation therapeutics, including bardoxolone methyl, suppresses the onset and progression of AKI and CKD. On the other hand, pathophysiology-targeted diagnostics for renal redox dysregulation are also being developed. Urinary thioredoxin (TXN) is a biomarker that can be used to diagnose tubular redox dysregulation. AKI causes oxidation and urinary excretion of TXN, which depletes TXN from the tubules, resulting in tubular redox dysregulation. Urinary TXN is selectively elevated at the onset of AKI and correlates with the progression of CKD in diabetic nephropathy. Critical Issues: Diagnostic methods should provide information about molecular mechanisms that aid in the selection of appropriate therapies to improve the prognosis of kidney disease. Future Directions: A specific diagnostic method enabling detection of redox dysregulation based on pathological molecular mechanisms is much needed and could provide the first step toward personalized medicine in kidney disease. Urinary TXN is a candidate for a companion diagnostic method to identify responders to redox-modulating therapeutics. Antioxid. Redox Signal. 36, 1051-1065.

When AIE meets enzymes

Applications of AIEgens in biosensing, disease diagnosis, and drug release.