Discovery of Natural Products Alleviating Renal Fibrosis with a Viscosity-Responsive Molecular Probe.

Renal fibrosis poses a significant threat to individuals suffering from chronic progressive kidney disease. Given the absence of effective medications for treating renal fibrosis, it becomes crucial to assess the extent of fibrosis in real time and explore the development of novel drugs with substantial therapeutic benefits. Due to the accumulation of renal tissue damage and the uncontrolled deposition of fibrotic matrix during the course of the disease, there is an increase in viscosity both intracellularly and extracellularly. Therefore, a viscosity-sensitive near-infrared fluorescence (NIRF) and photoacoustic (PA) imaging probe, BDP-KY, was developed to detect aberrant changes in viscosity during fibrosis. Furthermore, BDP-KY has been applied to screen the effective components of herbal medicine, rhubarb, resulting in the identification of potential antirenal fibrotic compounds such as emodin-8-glucoside and chrysophanol 8-O-glucoside. Ultrasound, PA, and NIRF imaging of a unilateral uretera obstruction mice model show that different concentrations of emodin-8-glucoside and chrysophanol 8-O-glucoside effectively reduce viscosity levels during the renal fibrosis process. The histological results showed a significant decrease in fibrosis factors α-smooth muscle actin and collagen deposition. Combining these findings with their pharmacokinetic characteristics, these compounds have the potential to fill the current market gap for effective antirenal fibrosis drugs. This study demonstrates the potential of BDP-KY in the evaluation of renal fibrosis, and the two identified active components from rhubarb hold great promise for the treatment of renal fibrosis.

Discovering a New Drug Against Acute Kidney Injury by Using a Tailored Photoacoustic Imaging Probe.

Acute kidney injury (AKI) has become an increasing concern for patients due to the widespread clinical use of nephrotoxic drugs. Currently, the early diagnosis of AKI is still challenging and the available therapeutic drugs cannot meet the clinical demand. Herein, this work has investigated the key redox couple involved in AKI and develops a tailored photoacoustic (PA) imaging probe (AB-DiOH) which can reversibly respond to hypochlorite (ClO-)/glutathione (GSH) with high specificity and sensitivity. This probe enables the real-time monitoring of AKI by noninvasive PA imaging, with better detection sensitivity than the blood test. Furthermore, this probe is utilized for screening nephroprotective drugs among natural products. For the first time, astragalin is discovered to be a potential new drug for the treatment of AKI. After oral administration, astragalin can be efficiently absorbed by the animal body, alleviate kidney injury, and meanwhile induce no damage to other normal tissues. The treatment mechanism of astragalin has also been revealed to be the simultaneous inhibition of oxidative stress, ferroptosis, and cuproposis. The developed PA imaging probe and the discovered drug candidate provide a promising new tool and strategy for the early diagnosis and effective treatment of AKI.

Small-Molecule Photoacoustic Imaging Probe with Aggregation-Enhanced Amplitude for Real-Time Visualization of Acute Kidney Injury.

Acute kidney injury (AKI) has become a growing issue for patients with the extensive use of all kinds of drugs in clinic. Photoacoustic (PA) imaging provides a noninvasive and real-time imaging method for studying kidney injury, but it has inherent shortages in terms of high background signal and low detection sensitivity for exogenous imaging agents. Intriguingly, J-aggregation offers to tune the optical properties of the dyes, thus providing a platform for developing new PA probes with desired performance. In this study, a small-molecule PA probe (BDP-3) was designed and synthesized. We serendipitously discovered that BDP-3 can transform into renal clearable nanoaggregates under physiological conditions. The hydrodynamic diameter of the BDP-3 increased from 0.64 ± 0.11 to 3.74 ± 0.39 nm when the content of H2O increased from 40 to 90%. In addition, it was surprising that such a transforming process can significantly enhance its PA amplitude (2.06-fold). On this basis, PA imaging with BDP-3 was applied as a new method for the noninvasive detection of AKI induced by anticancer drugs, traditional Chinese medicine, and clinical contrast agents in animal models and exhibited higher sensitivity than the conventional serum index test, demonstrating great potential for further clinical diagnostic applications.

Renal-clearable and biodegradable black phosphorus quantum dots for photoacoustic imaging of kidney dysfunction.

The kidney is a vital organ and susceptible to various diseases. Photoacoustic (PA) imaging provides a powerful technique for studying kidney dysfunction, for which many smart photoacoustic imaging agents have been developed. But the complete clearance of the introduced contrast agents after imaging remains to be challenging, leading to long-term toxicity concerns. In this study, we synthesized black phosphorous quantum dots (BPQDs) with ultra-small size (1.74 ± 0.23 nm after surface modification) and strong PA signal for imaging kidney dysfunction. Importantly, the renal-clearance property and biodegradability of the developed BPQDs help circumvent the long-term toxicity issue for in vivo studies. Based on these BPQDs, both acute kidney injury and chronic kidney disease were successfully detected in the living mice by PA imaging, with higher detection sensitivity than the clinical serum indices examination method. This BPQDs-based PA imaging method should have a promising potential for the early diagnosis of kidney dysfunction in clinic.

Near-Infrared Photoacoustic Probe for Reversible Imaging of the ClO-/GSH Redox Cycle In Vivo.

Homeostasis of the cellular redox status plays an indispensable role in diverse physiological and pathological processes. Hypochlorite anion (ClO-) and glutathione (GSH) represent an important redox couple to reflect the redox status in living cells. The current cellular redox probes that detect either ClO- or GSH alone are not accurate enough to monitor the real redox status. In this work, a reversible photoacoustic (PA) probe, DiOH-BDP, has been synthesized and applied for PA imaging to monitor the ClO-/GSH couple redox state in an acute liver injury (ALI) model. The near-infrared PA probe DiOH-BDP features significant changes in absorption between 648 and 795 nm during the selective oxidation by ClO- and the reductive recovery of GSH, which exhibits excellent selectivity and sensitivity toward ClO- and GSH with the limits of detection of 77.7 nM and 7.2 µM, respectively. Additionally, using PA770 as a detection signal allows for the in situ monitoring of the ClO-/GSH couple, which realizes mapping of the localized redox status of the ALI by the virtue of a PA imaging system. Therefore, the probe provides a potentially technical tool to understand redox imbalance-related pathological formation processes.

Point-of-care testing of MicroRNA based on personal glucose meter and dual signal amplification to evaluate drug-induced kidney injury.

The upregulation or downregulation of microRNA-21 (miRNA-21) is closely related with drug-induced kidney injury (DIKI). As a potential and significant biomarker, the point-of-care testing (POCT) of miRNA-21 is worthy of attention and can provide essential information for clinical diagnosis. Hence, we design a portable and sensitive POCT assay for miRNA-21 using personal glucose meters (PGM). The whole operational system is constructed on streptavidin-coated magnetic beads (MBs) modified with substrate strands linked invertase and DNAzyme molecules each silenced by a locking strand. In the presence of miRNA-21, the locking strand can hybridize to miRNA-21, which originates the activation of the DNAzyme. The DNAzyme cleaves the substrate strands and induces the release of invertase from the surface of MBs. The separated invertase hydrolyzes sucrose to glucose which can be measured by PGM. The dual enzyme mediated catalyzation by DNAzyme and invertase therefore triggers the signal amplification. We establish a linear relationship between PGM and different concentration of miRNA-21 in the range of 100 fM to 1 pM. The limit of detection is 68.08 fM, which is comparable with some of the previous reports. The biosensor also exhibits excellent sequence selectivity, well-presented reproducibility and stability. Notably, by detecting miRNA-21 in urine, this method has been successfully used to predict DIKI and evaluate the protection effect of drugs on DIKI. Therefore, a dependable and low-cost POCT strategy for the detection of miRNA-21 is established, which is promising to supply valuable information for drug screening and evaluation of DIKI.

An integrated transcriptomics and network pharmacology approach to exploring the mechanism of adriamycin-induced kidney injury.

BACKGROUND AND AIMS: Adriamycin nephropathy model (AN), a rodent model of nephrotic syndrome disease that was caused by the nephrotoxicity of adriamycin, has been widely used for pharmacodynamic evaluation of traditional Chinese medicine (TCM) in the treatment of kidney injury. Although some studies have clearly shown the pathological process of AN, the mechanism of kidney injury have not been systematically investigated. METHODS: The reliability of AN was evaluated by weight, urinary protein quantitation, serum biochemical and histopathological examination. Transcriptomic sequencing combined with network pharmacology were used to elucidate the molecular mechanism of AN, and cell experiment combined with real-time quantitative PCR (RT-qPCR) and was used to validate the accuracy of transcriptomic sequencing result and KEGG pathways. RESULTS: Network analysis result showed that Mapk10 and Ptgs2 played important roles in the development of adriamycin-induced kidney injury. KEGG pathway analysis showed that the mechanism of kidney injury may be related to the regulation of biosynthesis of unsaturated fatty acids, complement and coagulation cascades, PPAR signaling pathway and PI3K-AKT signaling pathway. CONCLUSION: These results provide a new insight into the deep research on the mechanism of kidney injury, and provide an experimental basis for finding drug targets for the treatment of AN.

Exploration the active compounds of Astragali Radix in treatment of adriamycin nephropathy by network pharmacology combined with transcriptomic approach.

PURPOSE: This paper aimed to study the active compounds of Astragali Radix (AR) in the treatment of adriamycin nephropathy (AN) by a combination of network pharmacology and transcriptomics. METHODS: The chemical compounds of AR were screened out by text mining and database searching. Pharm Mapper was used to predict the targets of these chemical compounds. Potential targets of AN were screened by integrating the data from network pharmacology with known transcriptomics analysis results of kidney tissue. Compound-active target-potential target interactions networks were constructed so as to illustrate the relationship between compounds and targets, and obtain the chemical compounds directly related to potential targets of AN. The formula of compound contribution index (CI) based on algorithm was used to screen the active compounds of AR in the treatment of AN. In addition, we established an adriamycin-induced cell damage model with MPC5 cell, and used MTT assay, trypan blue dyeing and western blot analyses to validate the pharmacodynamic effect of the active compounds. RESULTS: 27 chemical compounds and 376 targets in AR were obtained by network pharmacology. Through Compound-active target-potential target interactions networks analysis, 22 compounds and 9 active targets as well as 130 potential targets were linked through 282 edges. The CI of every chemical compounds was further calculated by formula, the first four chemical compounds, including astragaloside IV, formononetin, quercetin and calycosin, whose cumulative contribution rate reached 87.28%, were considered to be active compounds. The results of MTT and trypan blue staining indicate that four active compounds had the significant protective effect on adriamycin-induced cell damage with MPC5 cell. Western blot result showed that four active compounds could significantly increase the expression of podocin protein in MPC5 cell. CONCLUSION: The active compounds of AR in the treatment of AN were successfully identified by using a network pharmacology and transcriptomics approach. This approach is expected to be beneficial to the study of the pharmacodynamic material basis of traditional Chinese medicine (TCM) in treating specific diseases.

Elucidating the time-dependent changes in the urinary metabolome under doxorubicin-induced nephrotoxicity.

Doxorubicin has been indicated to be cardiotoxic and nephrotoxic, and thus it is often used as a model drug. Possible molecular mechanisms of this toxicity have been proposed, however, the systematic investigation of time-related metabolic trajectories specific to renal toxicity has rarely been reported. The present study was designed to assess time-dependent changes in doxorubicin-induced nephropathy through urinary metabolomics and to reveal the molecular mechanism based on key pathways. Urinary metabolomics revealed that the 14th day was the critical time point for model construction. Pathway analysis results showed that 5 pathways with impact (>0.1), FDR (<0.1) and p value (<0.05) were important. Furthermore, three pathways, including butanoate metabolism, alanine, aspartate and glutamate metabolism and arginine and proline metabolism, were focused on and validated by partial least squares regression analysis (PLS-RA) and molecular docking techniques. Our findings also showed that robust metabolomics combined with PLS-RA and molecular docking techniques is promising for elucidating time-dependent changes due to doxorubicin toxicity and for clarifying mechanisms, and the results provide a research foundation for the construction of a nephropathy model.

Metabolomics coupled with integrative pharmacology reveal the protective effect of FangjiHuangqi Decoction against adriamycin-induced rat nephropathy model.

With the development of the society, the number of people who got the nephrotic syndrome (NS) is going up roughly. Therefore, finding a better way to treat NS is becoming a major global public health issue. As we all know, traditional Chinese medicine (TCM), especially Fangji Huangqi Decoction (FHD), has a long history and has good curative effects on NS. However, the mechanism of FHD treating NS has not been clearly elucidated. To address this problem, a feasible system was developed by metabolomics and integrative pharmacology approach. To study the mechanisms of Chinese medical formula FHD treating NS based on metabolomics and integrative pharmacology. In this study, a NMR based metabolomics approach coupled with biochemical assay and Western Blot had been employed to study the protective effect of FHD against adriamycin-induced nephropathy using rat model. And we proposed a integrative pharmacology-based method, which combined chemical ingredients database building, target identification and network analysis. These were aimed to decipher the mechanisms of action for the FHD in NS treatment. Multivariate analysis revealed that 13 of 16 perturbed metabolites could be reversed by FHD, and the MetaboAnalyst analysis revealed that the anti-nephrotic syndrome effect of FHD was probably related with regulation of alanine, aspartate and glutamate metabolism, citrate cycle, pyruvate metabolism, cysteine and methionine metabolism and glyoxylate and dicarboxylate metabolism. The integrative pharmacology analysis revealed 93 potential targets for FHD, and suggested that the protective effect of FHD on the nephrotic syndrome was probably related with the regulation of immune, and energy metabolic and fatty acid metabolic. In addition, both the metabolomics and the integrative pharmacology are focus together on the alanine, aspartate and glutamate metabolism pathway. These metabolites changes and the core targets changes, as well as the metabolite-target pathway network provide insights into the mechanisms of FHD treating nephrotic syndrome, and further studies are needed to validate the bioactive compounds responsible for the anti-nephrotic syndrome effect of FHD.

Metabolomics coupled with system pharmacology reveal the protective effect of total flavonoids of Astragali Radix against adriamycin-induced rat nephropathy model.

Astragali Radix (AR) has been used in the traditional Chinese medicine (TCM) in the treatment of various renal diseases for many years. In this study, a NMR based metabolomic approach coupled with biochemical assay and histopathological inspection had been employed to study the protective effect of total flavonoids (TFA) in AR against adriamycin-induced nephropathy using rats model. Multivariate analysis revealed that 11 of perturbed metabolites could be reversed by TFA, and the MetaboAnalyst analysis revealed that the anti-nephrotic syndrome effect of TFA was probably related with regulation of alanine, aspartate and glutamate metabolism, citrate cycle, pyruvate metabolism, cysteine and methionine metabolism and glyoxylate and dicarboxylate metabolism. The regulatory effects on the gene expression (ACE, nephrin, podocin) suggested that the anti-nephrotic syndrome effect of TFA was also related with the protection of renal filtration function and regulation of blood pressure. The system pharmacology analysis revealed 43 potential targets for TFA, and suggested that the protective effect of TFA on the nephrotic syndrome was probably related with the regulation of immune and renin-angiotensin system. These metabolic changes and the associated pathways, as well as the compound-target-disease network provide insights into the mechanisms of TFA for the treatment of nephrotic syndrome, and further studies are needed to validate the bioactive compounds responsible for the anti-nephrotic syndrome effect of TFA.