Intestinal CXCR6+ ILC3s migrate to the kidney and exacerbate renal fibrosis via IL-23 receptor signaling enhanced by PD-1 expression.

Group 3 innate lymphoid cells (ILC3s) regulate inflammation and tissue repair at mucosal sites, but whether these functions pertain to other tissues-like the kidneys-remains unclear. Here, we observed that renal fibrosis in humans was associated with increased ILC3s in the kidneys and blood. In mice, we showed that CXCR6+ ILC3s rapidly migrated from the intestinal mucosa and accumulated in the kidney via CXCL16 released from the injured tubules. Within the fibrotic kidney, ILC3s increased the expression of programmed cell death-1 (PD-1) and subsequent IL-17A production to directly activate myofibroblasts and fibrotic niche formation. ILC3 expression of PD-1 inhibited IL-23R endocytosis and consequently amplified the JAK2/STAT3/RORγt/IL-17A pathway that was essential for the pro-fibrogenic effect of ILC3s. Thus, we reveal a hitherto unrecognized migration pathway of ILC3s from the intestine to the kidney and the PD-1-dependent function of ILC3s in promoting renal fibrosis.

Proteomics-Based Identification of Potential Therapeutic Targets of Artesunate in a Lupus Nephritis MRL/lpr Mouse Model.

This study aimed to identify potential therapeutic targets of artesunate in an MRL/lpr lupus nephritis mouse model by quantitative proteomics. We detected serum autoimmune markers and proteinuria in 40 female mice that were divided into 4 groups (n = 10): normal C57BL/6 control group; untreated MRL/lpr lupus; 9 mg/kg/day prednisone positive control MRL/lpr lupus; and 15 mg/kg/day artesunate-treated MRL/lpr lupus groups. Renal pathology in the untreated MRL/lpr lupus and artesunate groups was examined by Periodic acid-Schiff (PAS) staining. Artesunate treatment in lupus mice decreased serum autoantibody levels and proteinuria while alleviating lupus nephritis pathology. Through tandem mass tag-tandem mass spectrometry (TMT-MS/MS) analyses, differentially expressed proteins were identified in the artesunate group, and subsequent functional prediction suggested associations with antigen presentation, apoptosis, and immune regulation. Data are available via ProteomeXchange with the identifier PXD046815. Parallel reaction monitoring (PRM) analysis of the top 19 selected proteins confirmed the TMT-MS/MS results. Immunohistochemistry, immunofluorescence, and Western blotting of an enriched protein from PRM analysis, cathepsin S, linked to antigen presentation, highlighted its upregulation in the untreated MRL/lpr lupus group and downregulation following artesunate treatment. This study suggests that artesunate holds potential as a therapeutic agent for lupus nephritis, with cathepsin S identified as a potential target.

Single-cell profiling reveals kidney CD163+ dendritic cell participation in human lupus nephritis.

OBJECTIVES: The current work aimed to provide a comprehensive single-cell landscape of lupus nephritis (LN) kidneys, including immune and non-immune cells, identify disease-associated cell populations and unravel their participation within the kidney microenvironment. METHODS: Single-cell RNA and T cell receptor sequencing were performed on renal biopsy tissues from 40 patients with LN and 6 healthy donors as controls. Matched peripheral blood samples from seven LN patients were also sequenced. Multiplex immunohistochemical analysis was performed on an independent cohort of 60 patients and validated using flow cytometric characterisation of human kidney tissues and in vitro assays. RESULTS: We uncovered a notable enrichment of CD163+ dendritic cells (DC3s) in LN kidneys, which exhibited a positive correlation with the severity of LN. In contrast to their counterparts in blood, DC3s in LN kidney displayed activated and highly proinflammatory phenotype. DC3s showed strong interactions with CD4+ T cells, contributing to intrarenal T cell clonal expansion, activation of CD4+ effector T cell and polarisation towards Th1/Th17. Injured proximal tubular epithelial cells (iPTECs) may orchestrate DC3 activation, adhesion and recruitment within the LN kidneys. In cultures, blood DC3s treated with iPTECs acquired distinct capabilities to polarise Th1/Th17 cells. Remarkably, the enumeration of kidney DC3s might be a potential biomarker for induction treatment response in LN patients. CONCLUSION: The intricate interplay involving DC3s, T cells and tubular epithelial cells within kidneys may substantially contribute to LN pathogenesis. The enumeration of renal DC3 holds potential as a valuable stratification feature for guiding LN patient treatment decisions in clinical practice.

Mitochondrial micropeptide MOXI promotes fibrotic gene transcription by translocation to the nucleus and bridging N-acetyltransferase 14 with transcription factor c-Jun.

Progressive fibrosis is a hallmark of chronic kidney disease, but we lack effective treatments to halt this destructive process. Micropeptides (peptides of no more than 100 amino acids) encoded by small open reading frames represent a new class of eukaryotic regulators. Here, we describe that the micropeptide regulator of ß-oxidation (MOXI) regulates kidney fibrosis. MOXI expression was found to be up-regulated in human fibrotic kidney disease, and this correlated with the degree of fibrosis and loss of kidney function. MOXI was expressed in the cytoplasm and mitochondria of cultured tubular epithelial cells and translocated to the nucleus upon Transforming Growth Factor-ß1 stimulation. Deletion of Moxi protected mice against fibrosis and inflammation in the folic acid and unilateral ureteral obstruction models. As a potential molecular therapy, treatment with an antisense MOXI oligonucleotide effectively knocked-down MOXI expression and protected against kidney fibrosis in both models. Bimolecular fluorescence complementation identified the enzyme N-acetyltransferase 14 (Nat14) and transcription factor c-Jun as MOXI binding partners. The MOXI/Nat14/c-Jun complex enhances basal and Transforming Growth Factor-ß1 induced collagen I gene promoter activity. Phosphorylation at T49 is required for MOXI nuclear localization and for complex formation with Nat14 and c-Jun. Furthermore, mice with a MoxiT49A point mutation were protected in the models of kidney fibrosis. Thus, our studies demonstrate a key role for the micropeptide MOXI in kidney fibrosis and identify a new function of MOXI in forming a transcriptional complex with Nat14 and c-Jun.

Low potassium disrupt intestinal barrier and result in bacterial translocation.

BACKGROUND: Bacterial translocation was observed in critical illness and patients with chronic diseases such as liver cirrhosis and chronic kidney disease (CKD). Hypokalemia is a common complication in these diseases. Whether low potassium diet may increase intestinal permeability and result in bacterial translocation lack of evidence. The present study was aimed to investigate the potential effects of LK on intestinal permeability. METHODS: Grade 8-week-old male Bal B/C mice were randomly placed either on a normal potassium (NK) mouse chow or a low potassium (LK) diet for 28 days. Intestinal permeability and expression of tight junction proteins were compared between the two groups. RESULTS: Compared with the NK group, the mice in LK group had significantly lower serum potassium level, increased levels of plasmas endotoxin and plasma D-lactate. The bacterial translocation was higher and in occurred mainly in mesenteric lymph nodes (MLN), liver and spleen. The pathologic change of small intestine was obvious with thinner villus lamina propria, shorter crypt depth and thinner intestinal wall. Slight increases in the expression of proteins and mRNA levels of both claudin-1 and claudin-2 were observed in LK group. CONCLUSIONS: Low potassium diet could increase intestinal permeability and thereby lead to bacterial translocation, which was suspected to result from impaired intestinal epithelial barrier and biological barrier.

Biomolecular Surface Functionalization and Stabilization Method to Fabricate Quantum Dots Nanobeads for Accurate Biosensing Detection.

The surface functionalization of quantum dots (QDs) is essential for their application as a label material in a biological field. Here, a protein surface functionalization approach was introduced to combine with silica encapsulation for the sustainable and stable synthesis of QDs nanobeads for biomarker detection. The formation of QDs nanobeads was achieved by multiple mercapto groups in bovine serum albumin (BSA) macromolecules as multidentate ligands to replace hydrophobic ligands on the surface of QDs and decompression. The resulting QDs nanobeads exhibited 20 times more photoluminescence than the corresponding hydrophobic QDs and presented excellent stability under physiological conditions due to the protection of BSA and silica. The nanobeads served as a robust signal-generating reagent to construct the lateral flow immunoassay (LFIA) biosensor for the detection of glycosylated hemoglobin (HbA1c). The concentration of HbA1c was determined within 10 min with high specificity using only 60 µL of whole blood samples collected clinically. The nanobeads-based LFIA biosensor exhibited linear detection of HbA1c from 4.2% to 13.6%. The accuracy and stability of this approach in clinical utility was demonstrated by the detection of HbA1c after a long-term storage of test strips. This protein surface modification technology provides a new way for improving the biological properties of QDs in clinical diagnosis.

Smad4 promotes diabetic nephropathy by modulating glycolysis and OXPHOS.

Diabetic nephropathy (DN) is the leading cause of end-stage kidney disease. TGF-ß1/Smad3 signalling plays a major pathological role in DN; however, the contribution of Smad4 has not been examined. Smad4 depletion in the kidney using anti-Smad4 locked nucleic acid halted progressive podocyte damage and glomerulosclerosis in mouse type 2 DN, suggesting a pathogenic role of Smad4 in podocytes. Smad4 is upregulated in human and mouse podocytes during DN. Conditional Smad4 deletion in podocytes protects mice from type 2 DN, independent of obesity. Mechanistically, hyperglycaemia induces Smad4 localization to mitochondria in podocytes, resulting in reduced glycolysis and oxidative phosphorylation and increased production of reactive oxygen species. This operates, in part, via direct binding of Smad4 to the glycolytic enzyme PKM2 and reducing the active tetrameric form of PKM2. In addition, Smad4 interacts with ATPIF1, causing a reduction in ATPIF1 degradation. In conclusion, we have discovered a mitochondrial mechanism by which Smad4 causes diabetic podocyte injury.

Upregulation of C/EBP Homologous Protein induced by ER Stress Mediates Epithelial to Myofibroblast Transformation in ADTKD-UMOD.

Autosomal dominant tubulointerstitial kidney disease due to UMOD mutations (ADTKD-UMOD) results in chronic interstitial nephritis, which gradually develops into end-stage renal disease. It is believed that the accumulation of mutant uromodulin causes the endoplasmic reticulum (ER) stress, then leads to the kidney damage. But the underlying mechanism remains unclear. To find the ADTKD-UMOD patients, UMOD gene screening was performed in 26 patients with unexplained chronic interstitial nephritis, during the past 10 years in our department, and among them three ADTKD-UMOD cases were discovered. Routine pathological staining and electron microscopy sections were reviewed again to confirm their kidney lesions. Immunostaining of UMOD and ER stress marker GRP78, as well as CHOP have all been done. The strong colocalization of UMOD with GRP78 and CHOP in ADTKD-UMOD patients but not in other chronic interstitial nephritis patients had been found. Moreover in vitro experiments, ER stress induced by tunicamycin (TM) not only significantly increased the expression of GRP78 and CHOP, but also caused the epithelial to myofibroblast transformation (EMT) of renal tubular epithelial cells, evidenced by decreased expression of E-cadherin and increased expression of vimentin, and extracellular matrix (ECM) deposition, evidenced by increased expression of fibronectin (FN). CHOP knockdown could restore the upregulation of vimentin and FN induced by TM. Thus, specific activation of CHOP in renal tubular epithelial cells induced by UMOD protein might be the key reason of renal interstitial fibrosis in ADTKD-UMOD patients.

Calcium-Modified Fe3O4 Nanoparticles Encapsulated in Humic Acid for the Efficient Removal of Heavy Metals from Wastewater.

Ca-modified Fe3O4 nanoparticles encapsulated in humic acid (HA-Ca/Fe3O4) were produced using a co-precipitation method. Furthermore, the adsorption performance of HA-Ca/Fe3O4 as well as the effect of coexisting ions and mechanisms were evaluated. A good description of the adsorption process was given using pseudo-second-order kinetic and Langmuir models. The adsorption capacities of HA-Ca/Fe3O4 for Pb2+, Cu2+, and Cd2+ were 208.33, 98.33, and 99.01 mg g-1, respectively. The 0.02-0.1 times concentrations in alkali and alkaline-earth metals promoted Pb2+ and Cd2+ adsorption; however, any concentration of alkali and alkaline-earth metals inhibited Cu2+-ion adsorption, probably owing to the differences in ionic radii between the interfering and heavy-metal ions. Pb2+, Cu2+, and Cd2+ removal using HA-Ca/Fe3O4 occurred via ion exchange, complexation of O-containing functional groups, mineral precipitation, and π-electron coordination. A method was proposed to calculate the contribution of these mechanisms to the adsorption process. In practice, HA-Ca/Fe3O4 can remove 99% Pb2+ and 91% Cu2+ and Cd2+ from real wastewater samples. Following five adsorption-desorption cycles, HA-Ca/Fe3O4 adsorption capacity did not change significantly. The aforementioned results indicated that HA-Ca/Fe3O4 presented a good potential in removing heavy metals in wastewater.

Higher Eosinophils Predict Death-Censored Technique Failure in Peritoneal Dialysis Patients.

INTRODUCTION: Eosinophilia (eosinophil fraction of leukocytes >5%), an indicative parameter for bioincompatibility in various circumstances, is well established in hemodialysis. However, change in eosinophil count (EOC) and its association with death-censored technique failure among peritoneal dialysis (PD) patients remain unclear. METHODS: We compared eosinophils before and after PD initiation among 1,432 eligible continuous ambulatory PD patients regularly followed up in our PD center during 2007-2018. Risk factors of early-stage eosinophilia were examined by the logistic regression test. The relationship of early-stage eosinophilia and EOC with death-censored technique failure was examined using the Cox proportional hazards model for overall patients and for men and women separately. RESULTS: After PD initiation, the EOC and percentage of patients with eosinophilia were significantly increased compared with baseline. Being male (odds ratio [OR]: 2.26; 95% confidence interval [CI]: 1.55-3.31; p < 0.001) and higher EOC at baseline (100 cells/µL increase, OR: 1.62; 95% CI: 1.45-1.82; p < 0.001) were risk factors of early-stage eosinophilia after PD initiation. During follow-up, 204 death-censored technique failures were recorded. In fully adjusted models, each with 100 cells/µL increase in EOC, the adjusted hazard ratios (HRs) of technique failure were 1.11 (95% CI: 1.03-1.20; p = 0.009) in the whole cohort, 1.29 (95% CI: 1.10-1.51; p = 0.002) in women, and 1.07 (95% CI: 0.97-1.17; p = 0.196) in men. Eosinophilia was significantly associated with the risk of technique failure for women (HR: 2.24; 95% CI: 1.07-4.70; p = 0.033), which was especially significant for women aged <55 years (HR: 7.61; 95% CI: 1.88-30.90; p = 0.005). CONCLUSION: EOC was increased significantly after PD initiation, and increased numbers of eosinophils were associated with higher death-censored technique failure in PD patients, especially women.

The protective role of Nrf2 against aristolochic acid-induced renal tubular epithelial cell injury.

Aristolochic acid nephropathy is a rapidly progressive tubulointerstitial disease induced by aristolochic acid (AA) and effective treatment is lacking. Nuclear factor erythroid 2-related factor 2 (Nrf2) has been proven to be protective in acute kidney injury and chronic kidney disease progression. But its role in AA-induced renal tubular epithelial cell injury has not been determined. This study aimed to investigate the role of Nrf2 in AA-induced renal tubular epithelial cell injury in vitro. NRK-52E cells were incubated with 5-50 µM AA to evaluate cell viability, reactive oxygen species (ROS) production, cell apoptosis/necrosis, and Nrf2 signaling pathway protein levels. We found that AA reduced cell viability and induced cell apoptosis in a time-dependent manner, accompanied by increased production of intracellular ROS. Meanwhile, the expression of Nrf2 signaling pathway proteins was significantly decreased. Downregulation of Nrf2 by Nrf2 siRNA decreased its downstream antioxidant proteins HO-1 and NQO1 and resulted in increased AA-induced ROS production and cell death. On the contrary, overexpression of Nrf2 increased HO-1 and NQO1 expression and resulted in decreased cell death. In conclusion, Nrf2 plays an important role in AA-induced injury. Enhanced Nrf2 signaling pathway could ameliorate AA-induced renal tubular epithelial cell injury, while downregulation of Nrf2 signaling exacerbated the injury.

Association of Lean Body Mass Index and Peritoneal Protein Clearance in Peritoneal Dialysis Patients.

BACKGROUND/AIMS: The relationship between peritoneal protein clearance (PPCl) and nutritional status in peritoneal dialysis (PD) population have not been clarified. This study aims to investigate the relationship between PPCl and nutritional status in PD population. METHODS: Prevalent PD patients were enrolled in the cross-sectional survey in a single center from April to November 2013. The total amount of protein loss in the dialysate was calculated. PPCl reflects the individual differences of peritoneal protein loss, and is calculated by the formula, that PPCl (ml/day)=24-h dialysate protein loss / (albumin/0.4783). Nutritional status measured by lean body mass index (LBMI) was assessed by multi-frequency bioelectrical impedance analysis (BIA). RESULTS: Totally 351 PD patients (55% male, 17.1% with diabetes, mean age 47.7±14.3 years) were included. The median PPC l was 58 ml/day. Patients were divided into four groups for comparison according to the PPC quartiles. Compared with lower PPCl quartiles, patients with higher PPCl had higher body mass index (BMI) (P< 0.001), body surface area (BSA) (P < 0 .001), LBMI (P<0.001), 4-hour D/P creatinine ratio (P< 0.001), and lower residual renal CCl (P<0.001). Compared with conventional body index (BMI and BSA) in ROC analysis, LBMI (area under curve: 0.71, 95% confidence interval [CI]: 0.66-0.77) had better performance in predicting higher PPCl. After adjustment in logistic regression models, each 1 kg/m2 increase of LBMI (odd ratio[OR] =1.37; 95% CI: 1.17-1.60), each 0.1 increase of 4-hour D/P creatinine ratio (OR =1.47; 95% CI: 1.11-1.93), and every 1 L/week/1.73m2 decrease of residual renal CCl (OR =0.98; 95% CI: 0.96-0.99) were independently associated with higher PPCl (> 58 ml/day). CONCLUSION: Higher LBMI was independently associated with higher , indicating that better nutritional status dominates peritoneal protein metabolism in PD patients.

Roles of Inflammasomes in Inflammatory Kidney Diseases.

The immune system has a central role in eliminating detrimental factors, by frequently launching inflammatory responses towards pathogen infection and inner danger signal outbreak. Acute and chronic inflammatory responses are critical determinants for consequences of kidney diseases, in which inflammasomes were inevitably involved. Inflammasomes are closely linked to many kidney diseases such as acute kidney injury and chronic kidney diseases. Inflammasomes are macromolecules consisting of multiple proteins, and their formation initiates the cleavage of procaspase-1, resulting in the activation of gasdermin D as well as the maturation and release of interleukin-1ß and IL-18, leading to pyroptosis. Here, we discuss the mechanism in which inflammasomes occur, as well as their roles in inflammatory kidney diseases, in order to shed light for discovering new therapeutical targets for the prevention and treatment of inflammatory kidney diseases and consequent end-stage renal disease.

Heat Shock Protein 72 Antagonizes STAT3 Signaling to Inhibit Fibroblast Accumulation in Renal Fibrogenesis.

Heat shock protein 72 (HSP72) has been shown to attenuate unilateral ureteral obstruction-induced kidney fibrosis. It remains unknown whether HSP72 has direct effects on fibroblast proliferation in the renal fibrotic evolution. Herein, we first confirmed that increased HSP72 expression occurred in fibrotic human kidneys. Using three different animal models of kidney fibrosis, pharmacological down-regulation or genetic deletion of endogenous HSP72 expression exacerbated STAT3 phosphorylation, fibroblast proliferation, and tubulointerstitial fibrosis. In contrast, treatment with geranylgeranyl acetone, a specific inducer of HSP72, reduced phosphorylated STAT3 and protected animals from kidney fibrosis. In cultured renal interstitial fibroblasts, overexpression of HSP72 blocked transforming growth factor (TGF)-ß1-induced cell activation and proliferation, as evidenced by inhibiting expression of α-smooth muscle actin, fibronectin, and collagen I/III, as well as by reducing cell numbers and DNA synthesis. Mechanical studies showed that overexpressed HSP72 attenuated TGF-ß-induced phosphorylation and nuclear translocation of STAT3 and its downstream protein expression. However, siRNA knockdown of HSP72 increased TGF-ß-induced STAT3 activity and fibroblast proliferation. Ectopic expression of a constitutively active STAT3 conferred resistance to HSP72 inhibition of fibroblast proliferation. Thus, HSP72 blocks fibroblast activation and proliferation in renal fibrosis via targeting the STAT3 pathway and may serve as a novel therapeutic agent for chronic kidney disease regardless of the etiology.

Increased Abundance of Plasmacytoid Dendritic Cells and Interferon-Alpha Induces Plasma Cell Differentiation in Patients of IgA Nephropathy.

The roles of pDC and IFN-α have not been well defined in IgA nephropathy (IgAN). In this study, we investigated the abundance of pDCs and IFN-α in IgAN patients and the response of peripheral blood mononuclear cells (PBMCs) after stimulation of the pDC-preferred TLR9 ligand CpG2216. The effects of IFN-α on plasma cell differentiation and leukocyte migration were also investigated. Here, we found that the percentages of pDCs were increased in PBMCs of IgAN patients, than in those of healthy controls. Plasma levels of IFN-α proteins and abundance of plasma cells were higher in IgAN patients than in healthy donors. Plasma IFN-α levels were positively associated with proteinuria, renal IgM deposition, and renal tubular atrophy/interstitial fibrosis grade in IgAN patients. Ex vivo activation of TLR9 on pDCs resulted in increased IFN-α production and enhanced plasma cell differentiation in IgAN patients as compared with healthy donors. IFN-α treatment led to increased plasma cell differentiation in vitro. IFN-α also significantly promoted expression of chemokines IP-10 and MCP-1 in human mesangial cells, which subsequently facilitated the transendothelial migration of human CD4+ and CD14+ cells. In conclusion, pDC and its secreted cytokine IFN-α may play important roles in pathological changes of IgA nephropathy.

Possible role of mitochondrial injury in Caulis Aristolochia manshuriensis-induced chronic aristolochic acid nephropathy.

CONTEXT: The proximal tubular epithelial cells (PTECs) are the primary target of aristolochic acids and especially vulnerable to mitochondrial injury from insults of toxic xenobiotics. OBJECTIVES: This study aimed to investigate the possible role of mitochondrial injury in Caulis Aristolochia manshuriensis (CAM)-induced aristolochic acid nephropathy (AAN). MATERIALS AND METHODS: Male Sprague-Dawley rats were gavaged with CAM extract every other week for 1, 4, 8 and 12 weeks, respectively. RESULTS: The rats in the model group showed chronic AAN as evidenced by worsening kidney function evaluated by blood urea nitrogen, creatinine and proteinuria levels, and severe tubulointerstitial injury marked by massive tubular atrophy and interstitial fibrosis in kidney tissues. Moreover, overt apoptosis and impaired regeneration of PTECs were observed in AAN rats. Furthermore, the study revealed that mitochondria in PTECs were fragmented into small, punctuate suborganelles in AAN rats. Two mitochondrial respiratory chain proteins, mitochondrial DNA (mtDNA)-encoded cytochrome c oxidase subunit І (COX-І) and nuclear DNA-encoded nicotinamide adenine dinucleotide dehydrogenase (ubiquinone)-1ß subcomplex 8 (NDUFß8), were both down-regulated after one week of CAM treatment. However, with AAN progression, NDUFß8 level restored, while COX-І level maintained low. Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), master regulator of mitochondrial biogenesis, was significantly down-regulated at week 4 and week 8, but significantly up-regulated at week 12. In addition, mtDNA copy number reduced markedly along with AAN progression. DISCUSSION AND CONCLUSION: A rat model of chronic AAN was successfully reproduced by gavage with CAM extract. Dynamic changes of mitochondrial injury induced by CAM might contribute to the AAN progression.

Role of MAPK signal pathways in differentiation process of M2 macrophages induced by high-ambient glucose and TGF-ß1.

Macrophage can be alternatively activated by TGF-ß1, whether high-ambient glucose can enhance the sensitivity of TGF-ß1 and the intracellular mechanisms involved in this process are not fully understood. We examined whether the mitogen-activated protein kinase is involved in the activation of macrophage induced by TGF-ß1 and high-ambient glucose. The expression of arginase-1, CD206 and TGF-ß1 was accessed by Western blot and immunofluorescence in RAW 264.7 cells stimulated with TGF-ß1 and high-ambient glucose. The activation of MAPK pathways in the process was investigated by Western blot. The role of MAPK was assessed using biochemical inhibitors. The protein of arginase-1, CD206 and TGF-ß1 was significantly overexpressed in RAW264.7 cells stimulated by TGF-ß1 and high-ambient glucose. ERK and JNK phosphorylation occurred in 30 min and p38MAPK phosphorylation occurred in 30 min and 24 h after the stimulation. And the expression of arginase-1 and TGF-ß1 was partially blocked by the pretreated ERK biochemical inhibitor (U0126) instead of the JNK inhibitor (SP600125) and p38MAPK inhibitor (SB203580). In conclusion, high-ambient glucose can enhance the sensitivity of TGF-ß1 in RAW264.7 cells, which resulted in overexpression of TGF-ß1 and arginase-1 in macrophages. ERK plays a role in this process.

Aristolochic acid induces acute kidney injury through ferroptosis.

Aristolochic acid (AA)-induced acute kidney injury (AKI) presents with progressive decline in renal function and rapid progression to end-stage renal disease. Among the multiple mechanisms identified in AKI, ferroptosis has been shown to be involved in various forms of AKI. But few studies have elucidated the role of ferroptosis in AA-induced AKI. In this study, we investigated the role of ferroptosis in AA-induced acute renal tubular injury in vivo and in vitro. Mice with acute aristolochic acid nephropathy showed increased malondialdehyde levels, aggravated lipid peroxidation, decreased superoxide dismutase activity, and glutathione depletion. The expression of glutathione peroxidase 4 was decreased and the expression of acyl-CoA synthetase long-chain family member 4 was increased. Inhibition of ferroptosis by ferrostatin-1 significantly improved the renal function, reduced histopathological lesions, partially alleviated lipid peroxidation, and restored the antioxidant capacity. In vitro studies also revealed that AA significantly reduced cell viability, induced reactive oxygen species production, increased intracellular iron level and decreased ferroptosis-related protein expression. Inhibition of ferroptosis significantly increased cell viability and attenuated AA-induced renal tubular epithelial cell injury. It is suggested that ferroptosis plays an important role in AA-induced acute tubular injury. And inhibition of ferroptosis may exert renoprotective effects possibly by preventing lipid peroxidation, restoring the antioxidant activity or regulating iron metabolism.

Tailored three-color quantum dots nanobeads for multiplexed detection with tunable detection range and multilevel sensitivity of signal-amplified immunosensor.

The excellent optical properties of quantum dots (QDs) make them as an ideal fluorescent probe for multiplexed detection, however, the interference between different emission spectra, the dependence of excitation wavelengths, and the sharp decrease of quantum yield (QY) during surface modification are issues that cannot be ignored. Herein, a dual protection scheme of polymer and silica was proposed to prepare high-quality three-color QDs nanobeads using QDs with different ligands. In comparison with single-core QDs, the fluorescence signal of the prepared QD nanobeads (QBs) is increased by more than 1,000 times and has better stability. Considering the excitation efficiency of QDs, we tailor three-color QBs as fluorescent probes based on fluorescence-linked immunosorbent assays (tQBs-FLISA) to detect multiple inflammatory biomarkers simultaneously with tunable detection ranges. This resulted in highly sensitive detection of three inflammatory biomarkers in comparison to the single-core QD-FLISA, the sensitivities of C-reactive protein (CRP), serum amyloid A (SAA), and procalcitonin (PCT) were increased by 16-fold, 19-fold, and 5-fold, respectively, to 0.48 ng/mL, 0.42 ng/mL, and 10 pg/mL. Furthermore, the tQBs-FLISA showed good accuracy without interference from common serum factors. In this strategy, a three-color QBs suitable for multilevel sensitivity and tunable detection range was tailored using the versatile polymer and silica dual protection method, building high-performance immunosensor for in vitro diagnostics (IVD).

Tailored different sizes of quantum dot nanobeads for sensitive and quantitative detection based on the competition fluorescence-linked immunosorbent assay platform.

Highly stable and multicolor photoluminescent (PL) quantum dots (QDs) have attracted widespread attention as ideal probe materials in the field of in vitro diagnostics (IVD), especially the fluorescence-linked immunosorbent assay (FLISA), due to their advantages of high-throughput, high stability, and high sensitivity. However, the size of QDs as fluorescent probes have significant effects on antigen-antibody performance. Therefore, it is critical to design suitable QDs for obtain excellent quantitative detection-based biosensors. In this paper, we prepared different sizes of aqueous QDs (30 nm, 116 nm, 219 nm, and 320 nm) as fluorescent probes to optimize the competitive FLISA platform. The SARS-CoV-2 neutralizing antibody (NTAB) assay was used as an example, and it was found that the size of the QDs has a significant impact on the antigen-antibody binding efficiency and detection sensitivity in competitive FLISA platform. The results showed that these QD nanobeads (QBs, ∼219 nm) could be used as a labeled probe for competitive FLISA, with half-maximal inhibitory concentration (IC50) of 1.34 ng/mL and limit of detection (LOD) of 0.21 pg/mL for NTAB detection. More importantly, the results showed good specificity and accuracy, and the QB219 probe was able to efficiently bind NTAB without interference from other substances in the serum. Given the above advantages, the nanoprobe material (∼200 nm) offers considerable potential as a competitive FLISA platform in the field of IVD.