Mouse Kidney Tissue Research Articles

Klotho protects chromosomal DNA from radiation-induced damage.

Klotho is an anti-aging, single-pass transmembrane protein found mainly in the kidney. Although aging is likely to be associated with DNA damage, the involvement of Klotho in protecting cells from DNA damage is still unclear. In this study, we examined DNA damage in human kidney cells and mouse kidney tissue after ionizing radiation (IR). The depletion and overexpression of Klotho in human kidney cells reduced and increased the cell survival rates after IR, respectively. The formation of γ-H2AX foci, representing DNA damage, was significantly elevated immediately after IR in cells with Klotho depletion and decreased in cells overexpressing Klotho. These results were confirmed in mouse renal tissues after IR. Quantification of DNA damage by a comet assay revealed that the Klotho knockdown significantly increased the amount of DNA damage immediately after IR, suggesting that Klotho protects chromosomal DNA from the induction of damage, rather than facilitating DNA repair. Consistent with this notion, Klotho was detected in both the nucleus and cytoplasm. In the nucleus, Klotho may serve to protect chromosomal DNA from damage, leading to its anti-aging effects.

LIM and Cysteine-Rich Domains 1 Promotes Transforming Growth Factor β1–Induced Epithelial–Mesenchymal Transition in Human Kidney 2 Cells

Renal fibrosis is the major pathologic manifestation of chronic kidney disease (CKD). LIM and cysteine-rich domains 1 (LMCD1) is upregulated in the kidney tissue from patients with CKD and the transforming growth factor β1 (TGF-β1)–treated human renal tubular epithelial cell line human kidney 2 (HK-2) (Gene Expression Omnibus: GSE66494 and GSE23338). Previously, we have demonstrated that the knockdown of LMCD1 ameliorated renal fibrosis in mice by blocking the activation of the extracellular signal-regulated kinase pathway. In this study, we sought to further investigate whether LMCD1 affects TGF-β1–induced epithelial–mesenchymal transition (EMT) of kidney tubular epithelial cells and its potential role in the TGF-β1/Smad signaling pathway. First, we confirmed that LMCD1 expression was increased in the fibrotic kidneys of patients with CKD compared with that in normal kidneys and that LMCD1 was predominantly localized in the renal tubules. LMCD1 and mesenchymal markers were upregulated in obstructed kidney tissues of mice at 21 days after unilateral ureteral obstruction surgery compared with the tissues in sham mice. Next, we demonstrated that TGF-β1 significantly increased LMCD1 expression through Smad-mediated transcription in HK-2 cells in vitro. In turn, LMCD1 acted as a transcriptional coactivator of E2F transcription factor 1 to promote the transcription of TGF-β1. Moreover, TGF-β1 increased the interaction between LMCD1 and Smad ubiquitination regulatory factor 2 (Smurf2) and accelerated Smurf2-mediated LMCD1 degradation via the ubiquitination system. The knockdown of LMCD1 inhibited TGF-β1–induced EMT in both HK-2 cells and unilateral ureteral obstruction mice. Our results indicate a positive feedback loop between TGF-β1 and LMCD1 for EMT induction in HK-2 cells and that Smurf2 acts as a negative regulator in this process by accelerating LMCD1 degradation.

Nephropathy Is Aggravated by Fatty Acids in Diabetic Kidney Disease through Tubular Epithelial Cell Necroptosis and Is Alleviated by an RIPK-1 Inhibitor

Introduction: Diabetic kidney disease (DKD), one of the leading causes of end-stage renal disease, has complex pathogenic mechanisms and few effective clinical therapies. DKD progression is accompanied by the loss of renal resident cells, followed by chronic inflammation and extracellular matrix deposition. Necroptosis is a newly discovered form of regulated cell death and is a major form of intrinsic cell loss in certain diabetic complications such as cardiomyopathy, intestinal disease, and retinal neuropathy; however, its significance in DKD is largely unknown. Methods: In this study, the expression of necroptosis marker phosphorylated MLKL (p-MLKL) in renal biopsy tissues of patients with DKD was detected using immunofluorescence and semiquantified using immunohistochemistry. The effects of different disease-causing factors on necroptosis activation in human HK-2 cells were evaluated using immunofluorescence and Western blotting. db/db diabetic mice were fed a high-fat diet to establish an animal model of DKD with significant renal tubule damage. Mice were treated with the RIPK1 inhibitor RIPA-56 to evaluate its renal protective effects. mRNA transcriptome sequencing was used to explore the changes in signaling pathways after RIPA-56 treatment. Oil red O staining and electron macroscopy were used to observe lipid droplet accumulation in renal biopsy tissues and mouse kidney tissues. Results: Immunostaining of phosphorylated RIPK1/RIPK3/MLKL verified the occurrence of necroptosis in renal tubular epithelial cells of patients with DKD. The level of the necroptosis marker p-MLKL correlated positively with the severity of renal functional, pathological damages, and lipid droplet accumulation in patients with DKD. High glucose and fatty acids were the main factors causing necroptosis in human renal tubular HK-2 cells. Renal function deterioration and renal pathological injury were accelerated, and the necroptosis pathway was activated in db/db mice fed a high-fat diet. Application of RIPA-56 effectively reduced the degree of renal injury, inhibited the necroptosis pathway activation, and reduced necroinflammation and lipid droplet accumulation in the renal tissues of db/db mice fed a high-fat diet. Conclusion: The present study revealed the role of necroptosis in the progression of DKD and might provide a new therapeutic target for the treatment of DKD.

Isolation of Mitochondria from Mouse Tissues for Functional Analysis.

Methods for isolating mitochondria from different rodent tissues have been established for decades. Although the general principles for crude mitochondrial preparations are largely shared across tissues - tissue disruption followed by differential centrifugation - critical differences exist for isolation from different tissues to optimize mitochondrial yield and function. This protocol offers a unified resource for preparations of isolated mitochondria from mouse liver, kidney, heart, brain, skeletal muscle, and brown and white adipose tissue suitable for functional analysis.

Spatial Transcriptomics in Kidney Tissue.

Unlike bulk and single-cell/single-nuclei RNA sequencing methods, spatial transcriptome sequencing (ST-seq) resolves transcriptome expression within the spatial context of intact tissue. This is achieved by integrating histology with RNA sequencing. These methodologies are completed sequentially on the same tissue section placed on a glass slide with printed oligo-dT spots, termed ST-spots. Transcriptomes within the tissue section are captured by the underlying ST-spots and receive a spatial barcode in the process. The sequenced ST-spot transcriptomes are subsequently aligned with the hematoxylin and eosin (H&E) image, giving morphological context to the gene expression signatures within intact tissue. We have successfully employed ST-seq to characterize mouse and human kidney tissue. Here, we describe in detail the application of Visium Spatial Tissue Optimization (TO) and Visium Spatial Gene Expression (GEx) protocols for ST-seq in fresh frozen kidney tissue.

Enhancing metabolite coverage in MALDI-MSI using laser post-ionisation (MALDI-2).

Matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI) of metabolites can reveal how metabolism is altered throughout heterogeneous tissues. Here negative ion mode MALDI-MSI has been coupled with laser post-ionisation (MALDI-2) and applied to the MSI of low molecular weight (LMW) metabolites (<m/z 600) to investigate the benefits MALDI-2 offers for spatial metabolomics in terms of metabolite coverage and sensitivity. When applied to mouse kidney tissue MALDI-2 provided almost double the number of on-tissue specific mass features compared to conventional MALDI. MALDI-2 also resulted in not only the increased detection sensitivity for multiple metabolite species but also permitted the imaging of LMW metabolites (e.g. uridine) that were not detected using conventional MALDI-MSI. When compared against ∼140 publically available kidney datasets submitted through the METASPACE analysis platform using the same N-(1-naphthyl) ethylenediamine dihydrochloride (NEDC) matrix, MALDI-2 provided 34 unique metabolite m/z features that were not consistently annotated previously. To further evaluate the usefulness of this MALDI-2 approach to metabolite imaging, MALDI-2 was applied to the imaging of mouse liver tissue containing a metastasised breast cancer at a pixel size of 20 μm. Using a co-localisation analysis, MALDI-2 detected six tumour-specific metabolites that were not detected using conventional MALDI, as well as providing an up to 20-fold increase in signal intensities for many others (e.g., glutamate). This work provides one of the first reports of MALDI-2 applied to metabolite imaging and demonstrates the dramatic improvements in sensitivity and metabolite coverage it provides.

Transcription Factor Sox9 Exacerbates Kidney Injury through Inhibition of MicroRNA-96-5p and Activation of the Trib3/IL-6 Axis

Introduction: Our study investigated the possible mechanisms of the role of the transcription factor Sox9 in the development and progression of kidney injury through regulation of the miR-96-5p/Trib3/IL-6 axis. Methods: Bioinformatics analysis was performed to identify differentially expressed genes in kidney injury and normal tissues. An in vivo animal model of kidney injury and an in vitro cellular model of kidney injury were constructed using LPS induction in 8-week-old female C57BL/6 mice and human normal renal tubular epithelial cells HK-2 for studying the possible roles of Sox9, miR-96-5p, Trib3, and IL-6 in kidney injury. Results: Sox9 was highly expressed in both mouse and cellular models of kidney injury. Sox9 was significantly enriched in the promoter region of miR-96-5p and repressed miR-96-5p expression. Trib3 was highly expressed in both mouse and cellular models of kidney injury and promoted inflammatory responses and kidney injury. In addition, Trib3 promoted IL-6 expression, which was highly expressed in kidney injury, and promoted the inflammatory response and extent of injury in kidney tissue. In vivo and in vitro experiments confirmed that the knockdown of Sox9 improved the inflammatory response and fibrosis of mouse kidney tissues and HK-2 cells, while the ameliorative effect of silencing Sox9 was inhibited by overexpression of IL-6. Conclusion: Collectively, Sox9 up-regulates miR-96-5p-mediated Trib3 and activates the IL-6 signaling pathway to exacerbate the inflammatory response, ultimately promoting the development and progression of kidney injury.

Role of Cisplatin in Inducing Acute Kidney Injury and Pyroptosis in Mice via the Exosome miR-122/ELAVL1 Regulatory Axis

Although cisplatin is an effective chemotherapy drug for the treatment of various cancers, its clinical use is limited due to its side effects, especially nephrotoxicity. Unfortunately, acute kidney injury (AKI) caused by cisplatin remains one of the main challenges in effective cancer treatment. Evidence increasingly suggests that renal inflammation and pyroptotic inflammatory cell death of renal tubular epithelial cells (RTECs) mainly determine the progression and outcome of cisplatin-induced AKI. However, it is not clear how cisplatin regulates the pyroptosis of RTECs cells in AKI. The current study aimed to determine the regulation mechanism of AKI induced by cisplatin. We used cisplatin to induce AKI in vivo. We performed H&amp;E staining of mouse kidney tissue sections and evaluated serological indicators of kidney injury (including blood urea nitrogen (BUN), serum creatinine, and tumor necrosis factor-alpha (TNF-α)). We used immunohistochemistry and western blot to detect the important substrate protein gasdermin D (GSDMD) and key target caspase-1 of pyroptosis, respectively. Cisplatin induced mouse AKI and RTECs pyroptosis. HK2 cell-derived exosomes treated with cisplatin influenced pyroptosis of the surrounding HK2 cells. Cisplatin-treated HK2 cells exosome-derived miR-122 regulated pyroptosis in the surrounding cells. Exosome-derived miR-122 affected cisplatin-induced AKI and HK2 cells pyroptosis by regulating the expression of embryonic lethal abnormal vision (ELAVL1). These results suggest that exosome miR-122 inhibited pyroptosis and AKI by targeting ELAVL1 under cisplatin treatment, and this offers a potential target for the treatment of AKI.

Involvement of the inhibition of mitochondrial apoptotic, p53, NF-κB pathways and the activation of Nrf2/HO-1 pathway in the protective effects of curcumin against copper sulfate-induced nephrotoxicity in mice

Chronic copper exposure could cause potential nephrotoxicity and effective therapy strategies are limited. This study investigated the protective effects of curcumin on copper sulfate (CuSO4)-induced renal damage in a mouse model and the underlying molecular mechanisms. Mice were administrated orally with CuSO4 (100 mg/kg per day) in combination with or without curcumin (50, 100 or 200 mg/kg per day, orally) for 28 days. Results showed that curcumin supplementation significantly reduce the Cu accumulation in the kidney tissues of mice and improved CuSO4-induced renal dysfunction. Furthermore, curcumin supplantation also significantly ameliorated Cu exposure-induced oxidative stress and tubular necrosis in the kidneys of mice. Moreover, compared to the CuSO4 alone group, curcumin supplementation at 200 mg/kg per day significantly decreased CuSO4-induced the expression of p53, Bax, IL-1β, IL-6, and TNF-α proteins, levels of NF-κB mRNA, levels of caspases-9 and − 3 activities, and cell apoptosis, and significantly increased the levels of Nrf2 and HO-1 mRNAs in the kidney tissues. In conclusion, for the first time, our results reveal that curcumin could trigger the inhibition of oxidative stress, mitochondrial apoptotic, p53, and NF-κB pathways and the activation of Nrf2/HO-1 pathway to ameliorate Cu overload-induced nephrotoxicity in a mouse model. Our study highlights that curcumin supplementation may be a promising treatment strategy for treating copper overload-caused nephrotoxicity.

Hiring of the Anti-Quorum Sensing Activities of Hypoglycemic Agent Linagliptin to Alleviate the Pseudomonas aeruginosa Pathogenesis.

Bacteria communicate with each other using quorum sensing (QS) which works in an inducer/receptor manner. QS plays the main role in orchestrating diverse bacterial virulence factors. Pseudomonas aeruginosa is one of the most clinically important bacterial pathogens that can cause infection in almost all body tissues. Besides its efficient capability to develop resistance to different antibiotics, P. aeruginosa acquires a huge arsenal of virulence factors that are controlled mainly by QS. Challenging QS with FDA-approved drugs and natural products was proposed as a promising approach to mitigate bacterial virulence enabling the host immunity to complete the eradication of bacterial infection. The present study aims to evaluate the dipeptidase inhibitor-4 inhibitor hypoglycemic linagliptin anti-QS and anti-virulence activities against P. aeruginosa in vitro, in vivo, and in silico. The current results revealed the significant ability to diminish the production of protease and pyocyanin, motility, and biofilm formation in P. aeruginosa. Furthermore, the histopathological examination of liver and kidney tissues of mice injected with linagliptin-treated bacteria showed an obvious reduction of pathogenesis. Linagliptin downregulation to QS-encoding genes, besides the virtual ability to interact with QS receptors, indicates its anti-QS activities. In conclusion, linagliptin is a promising anti-virulence and anti-QS candidate that can be used solely or in combination with traditional antimicrobial agents in the treatment of P. aeruginosa aggressive infections.

Shen-Qi-Jiang-Tang granule ameliorates diabetic nephropathy via modulating tumor necrosis factor signaling pathway

Ethnopharmacological relevanceShen-Qi-Jiang-Tang granule (SQJTG), a classic traditional Chinese medicine (TCM) prescription, has been widely used in clinical for diabetes, especially type Ⅱ diabetes. Previous anti-diabetic studies stumbled across that SQJTG has a potential kidney protective effect on diabetic nephropathy (DN). However, the protective mechanism of SQJTG on DN still needs to be explored. Aim of the studyThe purpose of the present study was to explore the therapeutic effect of SQJTG on DN through both bioinformatics analysis and in vivo experiments. Methods and materialsThe TCMIP database was used for screening potential compounds and targets of SQJTG, and the GeneCards, OMIM, DrugBank, and TTD databases were used for collecting DN-related genes. Then protein-protein interaction analysis for the common targets of SQJTG and DN was performed by the STRING database. Meanwhile, KEGG and GO were carried out using the Metascape and DAVID databases. In vivo experiments, to testify the potential kidney protective effects of SQJTG, STZ-induced DN mice with different dosages of SQJTG treatment were collected and the renal tissues were detected by H&E, PAS, Masson and TUNEL staining. Immunohistochemistry and immunoblotting were used to assess the proteins’ expressions. Flow cytometry and ELISA assay were used to detect the levels of pro-inflammatory cytokines. ResultsAmong the 338 compounds ascertained by SQJTG, there were 789 related targets as well. Moreover, 1,221 DN-related targets were predicted and 20 core targets were screened by the PPI analyses. According to GO and KEGG pathway analysis, SQJTG may affect DN via the TNF pathway. For the in vivo experiments, renal histomorphological examinations demonstrated that SQJTG treatment significantly ameliorated STZ-induced kidney damage and had a dosage dependence. Meanwhile, mice with DN were found to have dramatic increases in IL-1, TNF-α, IL-6, and IL-12, but markedly decreased after administration of SQJTG. In addition, the protein levels of TNF signaling molecules, like p-P65, p-JNK, and p-p38, showed significantly elevated in kidney tissues of DN mice and attenuated after SQJTG treatment. ConclusionsSQJTG exerts a kidney protective effect in DN mice via modulating TNF signaling pathways, and it has promising applications for the treatment of DN.

In-silico and in-vitro evaluation of docetaxel and berberine as potential p53 modulating apoptotic inducers in oral squamous cell carcinoma

Objective: To investigate the interaction of p53 with docetaxel and berberine and their anticancer activities against oral squamous cell carcinoma. Methods: The interaction between p53 with docetaxel and berberine was investigated and their mechanisms of action against oral squamous cell carcinoma were studied. Toxicity studies were performed to determine any toxic impact of the drugs on the vital organs of tested animals. Results: In silico results revealed the molecular interaction of docetaxel and berberine with p53 and the molecules were found to be potential p53 inducers. Docetaxel and berberine inhibited the proliferation of cancer cells in a concentration-dependent manner. Flow cytometry analysis revealed that docetaxel and berberine at IC50 concentrations upregulated the expression of p53 in oral squamous cell carcinoma cells, thus triggering apoptotic cell death. In addition, no toxicity was observed in the liver and kidney tissues of mice after docetaxel and berberine treatment. Conclusions: Docetaxel and berberine significantly suppressed the proliferation of oral cancer cells by activating p53 expression and causing apoptotic cell death. Both compounds can be potential agents for the treatment of oral cancer, with little to no toxicity at the tissue level.

PPARG agonist pioglitazone influences diurnal kidney medulla mRNA expression of core clock, inflammation-, and metabolism-related genes disrupted by reverse feeding in mice.

This study examined the influence of PPARG activation by pioglitazone (PG) on the mRNA of core clock, inflammation- and metabolism-related genes in the mouse kidney medulla as well as urinary sodium/potassium excretion rhythms disrupted by reverse feeding. Mice were assigned to daytime feeding and nighttime feeding groups. PG 20 mg/kg was administered at 7am or 7pm. On day 8 of the feeding intervention, mice were killed at noon and midnight. Kidney medulla expression of Arntl, Clock, Nr1d1, Cry1, Cry2, Per1, Per2, Nfe2l2, Pparg, and Scnn1g was determined by qRT PCR. We measured urinary K+ , Na+ , urine volume, food, and H2 O intake. The reverse feeding uncoupled the peripheral clock gene rhythm in mouse kidney tissues. It was accompanied by a decreased expression of Nfe2l2 and Pparg as well as an increased expression of Rela and Scnn1g. These changes in gene expressions concurred with an increase in urinary Na+ , K+ , water excretion, microcirculation disorders, and cell loss, especially in distal tubules. PG induced the restoration of diurnal core clock gene expression as well as Nfe2l2, Pparg, Scnn1g mRNA, and decreased Rela expressions, stimulating Na+ reabsorption and inhibiting K+ excretion. PG intake at 7pm was more effective than at 7am.

Novel targets in renal fibrosis based on bioinformatic analysis.

Background: Renal fibrosis is a widely used pathological indicator of progressive chronic kidney disease (CKD), and renal fibrosis mediates most progressive renal diseases as a final pathway. Nevertheless, the key genes related to the host response are still unclear. In this study, the potential gene network, signaling pathways, and key genes under unilateral ureteral obstruction (UUO) model in mouse kidneys were investigated by integrating two transcriptional data profiles. Methods: The mice were exposed to UUO surgery in two independent experiments. After 7days, two datasets were sequenced from mice kidney tissues, respectively, and the transcriptome data were analyzed to identify the differentially expressed genes (DEGs). Then, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were executed. A Protein-Protein Interaction (PPI) network was constructed based on an online database STRING. Additionally, hub genes were identified and shown, and their expression levels were investigated in a public dataset and confirmed by quantitative real time-PCR (qRT-PCR) in vivo. Results: A total of 537 DEGs were shared by the two datasets. GO and the KEGG analysis showed that DEGs were typically enriched in seven pathways. Specifically, five hub genes (Bmp1, CD74, Fcer1g, Icam1, H2-Eb1) were identified by performing the 12 scoring methods in cytoHubba, and the receiver operating characteristic (ROC) curve indicated that the hub genes could be served as biomarkers. Conclusion: A gene network reflecting the transcriptome signature in CKD was established. The five hub genes identified in this study are potentially useful for the treatment and/or diagnosis CKD as biomarkers.

Renoprotective anti-CD45RB antibody induces B cell production in systemic lupus erythematosus based on single-cell RNA-seq analysis

ObjectiveSystemic lupus erythematosus (SLE) is a multisystem autoimmune disease that commonly affects the kidney. Single-cell RNA sequencing (scRNA-seq) technology is a powerful tool for characterizing individual cells and elucidating biological mechanisms at the cellular level. The purpose of this study was to identify the mechanism underlying kidney injury in SLE using scRNA-seq technology.Methods: scRNA-seq data of peripheral blood mononuclear cells (PBMCs) in SLE were retrieved from the GEO database, followed by batch effect elimination, dimensionality reduction, cluster analysis, cell annotation and enrichment analysis. A model of SLE was developed in NZB/WF1 mice. Effects of anti-CD45RB antibody on the SLE-induced kidney injury were evaluated, and we measured the distribution of regulatory T cells and B cells in mouse spleen and kidney tissues, levels of kidney function-related indexes, deposition of IgG and C3 in the glomeruli, and the levels of inflammatory cytokines. ResultsCD45RB was a specific marker gene of B cell clusters and had influence on the B cells. anti-CD45RB antibody treatment induced regulatory B cells and consequently arrested the kidney injury caused by SLE. In addition, depletion of regulatory T cells was found to partially undermine the alleviatory effect of anti-CD45RB antibody on SLE-induced kidney injury. ConclusionCollectively, our data suggest that anti-CD45RB antibody can prevent the SLE-induced kidney injury, pointing to anti-CD45RB antibody as a potential therapeutic strategy in kidney injury-related disease.

Combination of tolvaptan and valsartan improves cardiac and renal functions in doxorubicin-induced heart failure in mice.

Heart failure (HF) is often complicated by renal dysfunction. Tolvaptan and valsartan are two well-known agents for the treatment of HF. However, the role of tolvaptan/valsartan combination on HF with renal dysfunction remains unclear. To establish a mice model with HF with renal dysfunction, mice were intraperitoneally injected with doxorubicin (Dox). Echocardiogram was applied to assess the left ventricular function. Additionally, serum aldosterone (ALD) and angiotensin II (Ang II) level in mice were determined by ELISA. Meanwhile, western blot assay was used to evaluate the expressions of B cell lymphoma-2 (Bcl-2), Bcl-2 associated X (Bax) and cleaved caspase 3 in the heart and kidney tissues of mice. In this study, we found that compared to tolvaptan or valsartan alone treatment group, tolvaptan/valsartan combination obviously improved the left ventricular ejection fraction (LVEF) and the left ventricular fractional shortening (LVFS), and reduced serum ALD and Ang II level in Dox-treated mice. Additionally, tolvaptan/valsartan combination significantly prevented the inflammation and fibrosis of heart and kidney tissues in Dox-treated mice. Meanwhile, tolvaptan/valsartan combination notably inhibited the myocardial and renal cell apoptosis in Dox-treated mice via upregulation of Bcl-2 and downregulation of Bax and cleaved caspase 3, compared to the single drug treatment. Collectively, tolvaptan/valsartan combination could improve cardiac and renal functions, as well as prevent the fibrosis, inflammation and apoptosis of heart and kidney tissues in Dox-treated mice. Taken together, combining tolvaptan with valsartan might be a promising approach to achieve enhanced therapeutic effect for treatment of HF with renal dysfunction.

Abstract 13265: Soluble Klotho Captures FGF23 to Mitigate Aortic Valve Inflammocalcification Associated With Chronic Kidney Disease

Calcific aortic valve disease (CAVD) is prevalent in the elderly people, particularly those with chronic kidney disease (CKD). Klotho (KL), an anti-aging protein, is expressed mainly in the kidney and the cardiovascular system as soluble and membrane forms. CKD patients have reduced levels of KL and increased levels of fibroblast growth factor 23 (FGF23), a pro-inflammatory mediator that may interact with soluble KL. We have reported that KL reduces the osteogenic response to high phosphate levels, a condition seen in CKD, in human aortic valve interstitial cells (AVICs). This study tested the hypothesis that soluble KL captures FGF23 to prevent aortic valve inflammocalcification induced by CKD. Methods and Results: We developed a novel CKD-CAVD model in old C57 mice (20 months) on AIN-76A diet and treated with adenine and calcitriol. Histology and immunostaining revealed tubular damage and monocyte/macrophage accumulation in kidney tissue of CKD mice. Aortic valve lesions, thickening and calcification, were evident in CKD mice. Serum FGF23 levels were increased while serum KL levels decreased. In addition, KL expression in the aortic valve was reduced. Recombinant FGF23 (0.04 mg/ml) elevated the inflammosteogenic activity in human AVICs. Treatment with recombinant KL (0.5 μg/ml) markedly decreased FGF23-induced inflammosteogenic activation in AVICs. Systemic analysis revealed that FGF23 upregulates YAP/SMAD3 signaling, and inhibition of YAP and SMAD3 reduced the effect of FGF23 on the inflammosteogenic activity in AVICs. In addition, recombinant KL suppressed the activation of this signaling mechanism in AVICs, and treatment of CKD mice with recombinant KL attenuated aortic valve lesions. However, denaturation of KL protein resulted in a loss of its effect on FGF23-induced AVIC inflammosteogenic activation. Further, incubation of FGF23 with recombinant KL not only resulted in the formation of complexes of these two proteins, but also markedly decreased the pro-inflammosteogenic effect of FGF23 in AVICs. Conclusion: This study demonstrates that CKD induces KL insufficiency and FGF23 accumulation that promote aortic valve lesions. Recombinant KL is capable of binding to FGF23 to suppress its pro-inflammosteogenic effect in the aortic valve.

Can the mouse model successfully predict mixed metal(loid)s bioavailability in humans from contaminated soils?

Mouse models have been employed by many scientific research groups worldwide to predict the bioavailability of metal (loid)s and other chemicals in humans. Their suitability for predicting mixed metal (loid) bioavailability has been questioned and debated for decades by many research teams. In this study soils contaminated by lead (Pb) and arsenic (As), either in the field or by spiking in the laboratory, were used in bioavailability and bioaccessibility tests. The spiked soils were aged for more than a year prior to testing to achieve steady state and eliminate soil ageing effects, as reported in previous research. The bioavailability of, firstly, Pb in the presence of As and secondly, As in the presence of Pb was determined using mice. Furthermore, bioaccessibility was determined using a range of in vitro methods: relative bioaccessibility leaching procedure (RBALP), the Unified Bioaccessibility Research Group Europe (BARGE) method (UBM) gastric and intestinal phases, and the National Institute for Public Health and the Environment (RIVM) gastric and intestinal phases. The correlations between Pb and As bioavailability and their in vitro bioaccessibility when they were present in mixtures were analysed.The results indicated that the bioavailability of Pb in mice kidney tissues significantly correlated with bioaccessibility of Pb in RBALP (p < 0.01), UBM gastric (p < 0.01) and intestinal phases (p < 0.01) and RIVM gastric phases when Pb is present in metal (loid) mixtures. Results of the current study reveal that the RBALP, and UBM gastric and intestinal phase were by far the best methods for predicting the RB of Pb when it is present in metal (loid) mixtures. Consequently, the mouse model can successfully explain the in vivo in vitro correlation (IVIVC) of Pb when it is present in metal (loid) mixtures. However, we did find that a mouse model may not be the best one to explain the IVIVC of As when it is present in metal (loid) mixtures.

Myricetin-Loaded Nanomicelles Protect against Cisplatin-Induced Acute Kidney Injury by Inhibiting the DNA Damage-cGAS-STING Signaling Pathway.

Acute kidney injury (AKI) is the most common side effect of the anti-cancer drug cisplatin, and currently, no effective preventive measures are available in clinical practice. Oxidative stress and DNA damage mechanisms may be involved in cisplatin-induced AKI. In this study, we prepared Kolliphor HS15-based myricetin-loaded (HS15-Myr) nanomicelles and explored the mechanism of protection against cisplatin-induced AKI. In vitro results showed that the HS15-Myr nanomicelles enhanced the antioxidant activity of myricetin (Myr) and inhibited cisplatin-induced proliferation inhibition of HK-2 cells. Moreover, the HS15-Myr nanomicelles inhibited cisplatin-induced reactive oxygen species accumulation, mitochondrial membrane potential reduction, and DNA damage, which might be related to the inhibition of the cyclic GMP-AMP synthase (cGAS)─stimulating interferon gene (STING) signaling pathway. In vivo results in mice showed that the significant reductions in body weight and renal indices and the increased blood urea nitrogen and serum creatinine levels induced by cisplatin could be significantly reversed by pretreating with the HS15-Myr nanomicelles. Furthermore, nanomicelle pretreatment significantly altered the activities of antioxidant enzymes (e.g., GSH, MDA, and SOD) induced by cisplatin. In addition, cisplatin-induced inflammatory responses in mouse kidney tissue were found to be inhibited by pretreatment with HS15-Myr nanomicelles, such as IL-1β and TNF-α expression. The nanomicelles also significantly inhibited cisplatin-induced activation of the DNA damage-cGAS-STING pathway in kidney tissues. Together, our findings suggest that Myr-loaded nanomicelles are potential nephroprotective drugs.

Neferine mitigates cisplatin-induced acute kidney injury in mice by regulating autophagy and apoptosis.

The nephrotoxicity caused by cisplatin severely limits the application and affects related platinum-based therapeutics. Neferine is a dibenzylisoquinoline alkaloid extracted from a Chinese medicinal herb (Nelumbo nucifera Gaertn), which can decrease cisplatin-induced apoptosis of NRK-52E cells by activating autophagy in vitro in our previous study. In this article, we aimed to further investigate the protective effect of neferine, against to the cispltain-induced kidney damage in mice. Six groups were designed in our study. Renal index, mice serum creatinine and blood urea nitrogen levels were detected after the mice were killed. HE staining was used to observe the pathological changes of each group. The apoptosis of mouse kidney tissue was detected by TUNEL. Immunofluorescence and Western blot were used to detect the expression of cleaved-caspase3 and LC3. The transmission electron microscope was used to reveal the changes of apoptosis and autophagy of renal tubular epithelial cells in different groups. In our findings, the pathological changes of acute kidney injury were easily observed in cisplatin-treated mice while those in the neferine-pretreated groups were significantly alleviated. The apoptosis induced by cisplatin in mice increased evidently compared with the control group, which was decreased in the mice with neferine pretreatment. What' more, we found that autophagy increased obviously in mice pretreated by neferine contrast to the cisplatin-treated mice. In our study, neferine can effectively alleviate cisplatin-induced renal injury in mice, as well act as an autophagy-regulator in kidney protection.