Urinary Protein Levels Research Articles

Resveratrol Improves Hyperuricemia and Ameliorates Renal Injury by Modulating the Gut Microbiota.

Resveratrol (RES) has been reported to prevent hyperuricemia (HUA); however, its effect on intestinal uric acid metabolism remains unclear. This study evaluated the impact of RES on intestinal uric acid metabolism in mice with HUA induced by a high-fat diet (HFD). Moreover, we revealed the underlying mechanism through metagenomics, fecal microbiota transplantation (FMT), and 16S ribosomal RNA analysis. We demonstrated that RES reduced the serum uric acid, creatinine, urea nitrogen, and urinary protein levels, and improved the glomerular atrophy, unclear renal tubule structure, fibrosis, and renal inflammation. The results also showed that RES increased intestinal uric acid degradation. RES significantly changed the intestinal flora composition of HFD-fed mice by enriching the beneficial bacteria that degrade uric acid, reducing harmful bacteria that promote inflammation, and improving microbial function via the upregulation of purine metabolism. The FMT results further showed that the intestinal microbiota is essential for the effect of RES on HUA, and that Lactobacillus may play a key role in this process. The present study demonstrated that RES alleviates HFD-induced HUA and renal injury by regulating the gut microbiota composition and the metabolism of uric acid.

Racial Differences in Plasma Microbial Translocation and Plasma Microbiome, Implications in Systemic Lupus Erythematosus Disease Pathogenesis.

Black groups have increased prevalence and accelerated pathogenicity of systemic lupus erythematosus (SLE) compared to other ethnic/racial groups. The microbiome and systemic microbial translocation are considered contributing factors to SLE disease pathogenesis. However, racial differences in the plasma microbiome and microbial translocation in lupus remain unknown. In the current study, we investigated plasma levels of microbial translocation (lipopolysaccharide [LPS] and zonulin) and the plasma microbiome using microbial 16S RNA sequencing of Black and White patients with SLE and Black and White healthy controls. Plasma microbial translocation was increased in Black patients versus in White patients and in patients with SLE versus healthy controls regardless of race. Compared to sex, age, and disease status, race had the strongest association with plasma microbiome differences. Black groups (Black controls and Black patients) had lower α-diversity than White groups (White controls and White patients) and more distinct β-diversity. Black and White patients demonstrated differences in plasma bacterial presence, including Staphylococcus and Burkholderia. Compared to White patients, Black patients had higher SLE Disease Activity Index (SLEDAI) scores and urinary protein levels as well as a trend for increased anti-double-stranded DNA (dsDNA) antibody levels consistent with the known increased severity of lupus in Black patients overall. Certain plasma bacteria at the genus level were identified that were associated with the SLEDAI score, urinary protein, and anti-dsDNA antibody levels. This study reveals racial differences in both quality and quantity of plasma microbial translocation and identified specific plasma microbiome differences associated with SLE disease pathogenesis. Thus, this study may provide new insights into future potential microbiome therapies on SLE pathogenesis.

Protective effect of modified Huangqi Chifeng decoction on immunoglobulin A nephropathy through toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-kappa B signaling pathway.

To examine the nephroprotective mechanism of modified Huangqi Chifeng decoction (, MHCD) in immunoglobulin A nephropathy (IgAN) rats. To establish the IgAN rat model, the bovine serum albumin, lipopolysaccharide, and carbon tetrachloride 4 method was employed. The rats were then randomly assigned to the control, model, telmisartan, and high-, medium-, and low-dose MHCD groups, and were administered the respective treatments via intragastric administration for 8 weeks. The levels of 24-h urinary protein, serum creatinine (CRE), and blood urea nitrogen (BUN) were measured in each group. Pathological alterations were detected. IgA deposition was visualized through the use of immunofluorescence staining. The ultrastructure of the kidney was observed using a transmission electron microscope. The expression levels of interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and transforming growth factor-β1 (TGF-β1) were examined by immunohistochemistry and quantitative polymerase chain reaction. Levels of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and nuclear factor-kappa B (NF-κB) P65, were examined by immunohistochemistry, Western blotting, and quantitative polymerase chain reaction. The 24-h urine protein level in each group increased significantly at week 6, and worsen from then on. But this process can be reversed by treatments of telmisartan, and high-, medium-, and low-dose of MHCD, and these treatments did not affect renal function. Telmisartan, and high-, and medium-dose of MHCD reduced IgA deposition. Renal histopathology demonstrated the protective effect of high-, medium-, and low-dose of MHCD against kidney injury. The expression levels of MCP-1, IL-6, and TGF-β1 in kidney tissues were downregulated by low, medium and high doses of MHCD treatment. Additionally, treatment of low, medium and high doses of MHCD decreased the protein and mRNA levels of TLR4, MyD88, and NF-κB. MHCD exerted nephroprotective effects on IgAN rats, and MHCD regulated the expressions of key targets in TLR4/MyD88/NF-κB signaling pathway, thereby alleviating renal inflammation by inhibiting MCP-1, IL-6 expressions, and ameliorating renal fibrosis by inhibiting TGF-β1 expression.

Diosgenin protects against cationic bovine serum albumin-induced membranous glomerulonephritis by attenuating oxidative stress and renal inflammation via the NF-κB pathway

Context Membranous glomerulonephritis (MGN) is a leading cause of nephrotic syndrome in adults. Diosgenin (DG) has been reported to exert antioxidative and anti-inflammatory effects. Objective To investigate the renoprotective activity of DG in a cationic bovine serum albumin-induced rat model of MGN. Materials and methods Fourty male Sprague-Dawley rats were randomized into four groups. The MGN model was established and treated with a DG dose (10 mg/kg) and a positive control (TPCA1, 10 mg/kg), while normal control and MGN groups received distilled water by gavage for four consecutive weeks. At the end of the experiment, 24 h urinary protein, biochemical indices, oxidation and antioxidant levels, inflammatory parameters, histopathological examination, immunohistochemistry and immunoblotting were evaluated. Results DG significantly ameliorated kidney dysfunction by decreasing urinary protein (0.56-fold), serum creatinine (SCr) (0.78-fold), BUN (0.71-fold), TC (0.66-fold) and TG (0.73-fold) levels, and increasing ALB (1.44-fold). DG also reduced MDA (0.82-fold) and NO (0.83-fold) levels while increasing the activity of SOD (1.56-fold), CAT (1.25-fold), glutathione peroxidase (GPx) (1.55-fold) and GSH (1.81-fold). Furthermore, DG reduced Keap1 (0.76-fold) expression, Nrf2 nuclear translocation (0.79-fold), and induced NQO1 (1.25-fold) and HO-1 (1.46-fold) expression. Additionally, DG decreased IL-2 (0.55-fold), TNF-α (0.80-fold) and IL-6 (0.75-fold) levels, and reduced protein expression of NF-κB p65 (0.80-fold), IKKβ (0.93-fold), p-IKKβ (0.89-fold), ICAM-1 (0.88-fold), VCAM-1 (0.91-fold), MCP-1 (0.88-fold) and E-selectin (0.87-fold), and also inhibited the nuclear translocation of NF-κB p65 (0.64-fold). Discussion and conclusions The results suggest a potential therapeutic benefit of DG against MGN due to the inhibition of the NF-κB pathway, supporting the need for further clinical trials.

Clinical study on growth impairment induced by oral glucocorticoids based on FGF23/Klotho homeostasis observations

To observe the correlation between growth impairment induced by long-term oral glucocorticoids (GC) therapy and the ratio of FGF23/Klotho in children with primary nephrotic syndrome (PNS). A prospective study was conducted on 56 children with GC-sensitive PNS who had discontinued GC therapy for more than 3 months and revisited the Department of Pediatrics of the First Affiliated Hospital of Henan University of Traditional Chinese Medicine between June 2022 and December 2022. After monitoring qualitative and quantitative urine protein levels upon admission, the children with proteinuria relapse were treated with GC (GC group; n=29), while those without relapse did not receive GC treatment (non-GC group; n=27). In addition, 29 healthy children aged 3 to prepuberty were selected as the control group. Height, bone age, growth rate, and the FGF23/Klotho ratio were compared among the groups. The correlations of the FGF23/Klotho ratio with height, bone age, and growth rate were analyzed. The FGF23/Klotho ratio in the GC group was significantly higher than that in the non-GC group after 1 month of GC therapy (P<0.05), and the height and bone age growth rates within 6 months were lower than those in the non-GC group (P<0.05). Correlation analysis showed significant negative correlations between the FGF23/Klotho ratio after 1 month of treatment and the growth rates of height and bone age within 6 months in children with PNS (r=-0.356 and -0.436, respectively; P<0.05). The disturbance in FGF23/Klotho homeostasis is one of the mechanisms underlying the growth impairment caused by long-term oral GC therapy.

Effect of furosemide combined with continuous renal replacement therapy on cardiorenal function and inflammatory response in patients with chronic renal and heart failure after hemodialysis

Purpose: To determine the effect of furosemide combined with continuous renal replacement therapy (CRRT) on cardiorenal function and inflammatory response in patients with chronic renal failure (CRF) and heart failure after hemodialysis. &#x0D; Methods: 130 patients with both CRF and heart failure, who underwent hemodialysis at the Second Hospital Affiliated to Hainan Medical College, China, from October 2020 to October 2022 were recruited as study subjects. They were randomly divided into two groups, with control group administered the Continuous Renal Replacement Therapy (CRRT) while study group received furosemide in addition. The study assessed the clinical outcomes, cardiorenal function and inflammatory factors before and after treatment. Additionally, adverse reactions during treatment were documented for both groups. &#x0D; Results: Study group exhibited a significantly higher (p &lt; 0.001) total response rate compared to control group. Post-treatment, both groups displayed significant increases (p &lt; 0.05) in left ventricular ejection fraction, cardiac output and stroke volume, with study group showing significantly superior results (p &lt; 0.05). Furthermore, post-treatment, both groups experienced significant reductions (p &lt; 0.05) in serum creatinine, blood urea nitrogen, and 24-hour urinary protein levels, with study group displaying significantly lower levels (p &lt; 0.05). Additionally, the interleukin-6, interleukin-1β and tumor necrosis factor-α levels decreased significantly in both groups post-treatment, with study group exhibiting significantly lower levels (p &lt; 0.05). There was no significant difference in adverse reaction incidence between the two groups. &#x0D; Conclusion: Furosemide combined with CRRT significantly improves cardiorenal function and reduces inflammatory response in patients with CRF and heart failure after hemodialysis. Future research could optimize dosage and administration protocols, explore long-term effects and assess applicability in diverse patient populations.

Imbalance of Tfollicular helper cell subsets trigger the differentiation of pathogenic B cells in idiopathic membranous nephropathy.

This study aims to elucidate the role of T follicular helper (Tfh) cells and their subsets in idiopathic membranous nephropathy (IMN). The frequencies of Tfh cell subsets and B cell subsets in peripheral blood (PB) were detected in both IMN patients and healthy controls (HCs). The involvement of Tfh cells in the disease pathogenesis was examined by coculturing human Tfh cells with B cells. The dynamic changes of Tfh cells in PB or spleen were monitored in passive Heymann nephritis (PHN) rats. The frequencies of circulating Tfh (cTfh) cells, cTfh2 cells, and plasmablasts were enriched in the PB of patients with IMN. cTfh cells expressed higher ICOS, and lower BTLA than healthy counterparts. The frequency of ICOS + cTfh2 was associated with the severity of IMN, including 24h urine protein, IgG4 concentration and the IgG4: IgG ratio. Positive correlations were also observed between the frequency of cTfh2 cells with plasmablasts, serum IL-21 and IL-4 levels. Importantly, cTfh cells isolated from IMN patients were able to induce the differentiation of B cells to memory B cells (MBC) and plasmablasts, this process could be substantially attenuated by blocking the IL-21. Similar increases of ICOS + cTfh cells were also detected in spleen of PHN rats, concomitant with elevated urine protein levels. Collectively, our results demonstrate that the imbalance of cTfh cell subsets play a crucial pathogenic role in IMN by inducing the differentiation of B cells through IL-21, and cTfh2 cells might serve as useful markers to evaluate the progression of IMN.

METTL3 promotes trophoblast ferroptosis in preeclampsia by stabilizing the ACSL4 m6A modification

This study aims to explore the role of methyltransferase-like 3 (METTL3) modulation of ferroptosis in the pathogenesis of trophoblast-mediated preeclampsia. The expression of METTL3 and acyl-CoA synthetase long chain family member 4 (ACSL4) was measured in clinical placental tissues and trophoblasts using qPCR and Western blot techniques. The effects of METTL3 on the symptoms of preeclampsia were also validated in rat models. METTL3 and ACSL4 were upregulated in placental tissues from patients with preeclampsia and in hypoxia-induced trophoblasts. METTL3 silencing increased the migration and invasion of trophoblasts cultured under hypoxic conditions. Knockdown of METTL3 increased cell viability and suppressed ferroptosis in hypoxia-stimulated trophoblasts. Hypoxia increased the level of m6A in cells, whereas silencing METTL3 partially reversed this change. Silencing METTL3 resulted in a decrease in m6A modification of ACSL4 mRNA, which led to a reduction in ACSL4 mRNA stability. ACSL4 upregulation partially reversed the effects of METTL3 silencing on cell viability, migration, invasion, and ferroptosis in hypoxia-stimulated trophoblasts. Inhibition of METTL3 in preeclampsia rats decreased blood pressure, urine protein levels, fetal survival rate, and ACSL4-mediated ferroptosis. METTL3 elevates ferroptosis to inhibit the migration and invasion of trophoblasts and in vivo preeclampsia symptoms by catalyzing the m6A modification of ACSL4 mRNA.

Qi-dan-dihuang decoction ameliorates renal fibrosis in diabetic rats via p38MAPK/AKT/mTOR signaling pathway.

Qi-dan-dihuang decoction (QDD) has been used to treat diabetic kidney disease (DKD), but the underlying mechanisms are poorly understood. This study reveals the mechanism by which QDD ameliorates DKD. The compounds in QDD were identified by high-performance liquid chromatography and quadrupole-time-of-flight tandem mass spectrometry (HPLC-Q-TOF-MS). Key targets and signaling pathways were screened through bioinformatics. Nondiabetic Lepr db/m mice were used as control group, while Lepr db/db mice were divided into model group, dapagliflozin group, 1% QDD-low (QDD-L), and 2% QDD-high (QDD-H) group. After 12 weeks of administration, 24 h urinary protein, serum creatinine, and blood urea nitrogen levels were detected. Kidney tissues damage and fibrosis were evaluated by pathological staining. In addition, 30 mmol/L glucose-treated HK-2 and NRK-52E cells to induce DKD model. Cell activity and migration capacity as well as protein expression levels were evaluated. A total of 46 key target genes were identified. Functional enrichment analyses showed that key target genes were significantly enriched in the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and mitogen-activated protein kinase (MAPK) signaling pathways. In addition, in vivo and in vitro experiments confirmed that QDD ameliorated renal fibrosis in diabetic mice by resolving inflammation and inhibiting the epithelial-mesenchymal transition (EMT) via the p38MAPK and AKT-mammalian target of rapamycin (mTOR) pathways. QDD inhibits EMT and the inflammatory response through the p38MAPK and AKT/mTOR signaling pathways, thereby playing a protective role in renal fibrosis in DKD.

Rituximab may affect T lymphocyte subsets balance in primary membranous nephropathy

BackgroundThe aim of this study was to investigate the effects and significance of rituximab (RTX) on the levels of T lymphocyte subsets in patients diagnosed with primary membranous nephropathy (PMN).MethodsA total of 58 PMN patients and 25 healthy donors were chosen as the subjects. Among the PMN patients, 40 individuals received RTX treatment and completed at least 6 months of follow-up. All subjects underwent flow cytometry analysis to determine the peripheral blood lymphocyte subsets. The changes in anti-PLA2R antibody titers and 24-hour urinary protein levels were evaluated by ELISA and Biuret method before and after treatment.Results(1) The PMN group exhibited a significantly greater percentage of peripheral blood CD3−CD19+ B cells than the healthy group, which is consistent with the findings of previous reports. Additionally, compared with those in the peripheral blood of healthy individuals, the numbers of CD4+ central memory T cells, CD4+ effector memory T cells, CD4+/CD8+, and CD4+CD25+ T cells in the PMN peripheral blood were markedly greater. However, the number of peripheral blood Treg cells was reduced in the PMN group. (2) After 6 months of RTX treatment, PMN patients exhibited significant decreases in anti-PLA2R antibody titers, 24-hour urinary protein levels, and peripheral blood CD3−CD19+ B cells. Importantly, RTX administration decreased CD4+CD25+ T cells and CD4+/CD8+ in the peripheral blood of PMN patients and improved Treg cell levels. (3) RTX treatment induced alterations in the CD4+ T lymphocyte subsets in PMN patients, which did not correlate with B lymphocyte counts or anti-PLA2R antibody titers.ConclusionsRTX treatment might have a beneficial impact on cellular immunity by effectively restoring the balance of CD4+ T lymphocyte subsets in PMN patients, which is beyond its effects on B cells and antibody production.Trial registrationThe research was registered at the First Affiliated Hospital of Soochow University. Registration Number: MR-32-23-016211. Registration Date: May 31, 2023.

Urinary protein and coagulation-fibrinolysis indicators in preeclampsia: Expression and significance.

This study investigates the expression and significance of urinary protein and coagulation-fibrinolysis indicators in preeclampsia, categorized into mild preeclampsia (109 cases) and severe preeclampsia (97 cases) based on disease severity. Additionally, 110 patients with gestational hypertension (gestational hypertension group) were included for comparative analysis. General information, laboratory indicators, urinary protein, and coagulation-fibrinolysis indicator levels were collected for each group. Significant differences were observed in blood pressure among groups (P<.05), while uric acid, serum creatinine, aspartate transaminase, alanine transaminase, and triglycerides showed no significant differences (P>.05). Total cholesterol, triglycerides, and low-density Lipoprotein levels in severe preeclampsia were higher than those in mild preeclampsia and gestational hypertension groups, whereas high-density lipoprotein, albumin, and platelet levels were lower in severe preeclampsia. No significant differences were observed in prothrombin time or D-dimer levels among groups (P>.05). Urinary protein, urinary protein quantification, activated partial thromboplastin time, thrombin time, and fibrinogen were identified as influencing factors for adverse maternal and infant outcomes in severe preeclampsia patients. The study concludes that urinary protein and coagulation-fibrinolysis indicators are elevated in preeclampsia, particularly in severe preeclampsia cases, suggesting their potential use as diagnostic influencing factors for severe preeclampsia.

Identification of novel pathogenic variants of CUBN in patients with isolated proteinuria.

Although proteinuria is long recognized as an independent risk factor for progressive chronic kidney diseases, not all forms of proteinuria are detrimental to kidney function, one of which is isolated proteinuria caused by cubilin (CUBN)-specific mutations. CUBN encodes an endocytic receptor, initially found to be responsible for the Imerslund-Gräsbeck syndrome (IGS; OMIM #261100) characterized by a combined phenotype of megaloblastic anemia and proteinuria. After analyzing their clinical and pathological characterizations, next-generation sequencing for renal disease genes or whole-exome sequencing (WES) was performed on four patients with non-progressive isolated proteinuria. CUBN biallelic pathogenic variants were identified and further analyzed by cDNA-PCR sequencing, immunohistochemistry, minigene assay, and multiple in silico prediction tools, including 3D protein modeling. Here, we present four patients with isolated proteinuria caused by CUBN C-terminal biallelic pathogenic variants, all of which showed no typical IGS symptoms, such as anemia and vitamin B12 deficiency. Their urine protein levels fluctuated between +~++ and estimated glomerular filtration rate (eGFR) were normal or slightly higher. Mild mesangial hypercellularity was found in three children's renal biopsies. A homozygous splice-site variant of CUBN (c.6821+3 (IVS44) A>G) was proven to result in the exon 44 skipping and premature translation termination by cDNA sequencing and immunohistochemistry. Compound heterozygous mutations were identified among the other three children, including another novel splice-site variant (c.10764+1 (IVS66) G>A) causing the retention of first 4 nucleotides in intron 66 by minigene assay, two unreported missense mutations (c.4907G>A (p.R1636Q); c. 9095 A>G (p.Y3032C)), and two reported missense mutations in China (c.8938G>A (p.D2980N); c. 9287T>C (p.L3096P)), locating behind the vitamin B12-binding domain, affecting CUB11, CUB16, CUB22, CUB23, and CUB27 domains, respectively. These results demonstrate that above CUBN mutations may cause non-progressive and isolated proteinuria, expanding the variant spectrum of CUBN and benefiting our understanding of proteinuria and renal function.

Assessing the effects of tempol on renal fibrosis, inflammation, and oxidative stress in a high-salt diet combined with 5/6 nephrectomy rat model: utilizing oxidized albumin as a biomarker

BackgroundOxidative stress has been implicated in the pathogenesis of chronic kidney disease (CKD), prompting the exploration of antioxidants as a potential therapeutic avenue for mitigating disease progression. This study aims to investigate the beneficial impact of Tempol on the progression of CKD in a rat model utilizing oxidized albumin as a biomarker.MethodsAfter four weeks of treatment, metabolic parameters, including body weight, left ventricle residual weight, kidney weight, urine volume, and water and food intake, were measured. Systolic blood pressure, urinary protein, oxidized albumin level, serum creatinine (Scr), blood urea nitrogen (BUN), 8-OHdG, TGF-β1, and micro-albumin were also assessed. Renal fibrosis was evaluated through histological and biochemical assays. P65-NF-κB was quantified using an immunofluorescence test, while Smad3, P65-NF-κB, and Collagen I were measured using western blot. TNF-α, IL-6, MCP-1, TGF-β1, Smad3, and P65-NF-κB were analyzed by RT-qPCR.ResultsRats in the high-salt diet group exhibited impaired renal function, characterized by elevated levels of blood urea nitrogen, serum creatinine, 8-OHdG, urine albumin, and tubulointerstitial damage, along with reduced body weight. However, these effects were significantly ameliorated by Tempol administration. In the high-salt diet group, blood pressure, urinary protein, and oxidized albumin levels were notably higher compared to the normal diet group, but Tempol administration in the treatment group reversed these effects. Rats in the high-salt diet group also displayed increased levels of proinflammatory factors (TNF-α, IL-6, MCP1) and profibrotic factors (NF-κB activation, Collagen I), elevated expression of NADPH oxidation-related subunits (P65), and activation of the TGF-β1/Smad3 signaling pathway. Tempol treatment inhibited NF-κB-mediated inflammation and TGF-β1/Smad3-induced renal fibrosis signaling pathway activation.ConclusionThese findings suggest that Tempol may hold therapeutic potential for preventing and treating rats undergoing 5/6 nephrectomy. Further research is warranted to elucidate the mechanisms underlying Tempol’s protective effects and its potential clinical applications. Besides, there is a discernible positive relationship between oxidized albumin and other biomarkers, such as 8-OHG, urinary protein levels, mALB, Scr, BUN, and TGF-β1 in a High-salt diet combined with 5/6 nephrectomy rat model. These findings suggest the potential utility of oxidized albumin as a sensitive indicator for oxidative stress assessment.

Urinary liver-type fatty acid-binding protein levels may be associated with the occurrence of acute kidney injury induced by trauma.

Acute kidney injury (AKI), with a fatality rate of 8.6%, is one of the most common types of multiorgan failure in the intensive care unit (ICU). Thus, AKI should be diagnosed early, and early interventions should be implemented. Urinary liver-type fatty acid-binding protein (L-FABP) could aid in the diagnosis of AKI. In this prospective, single-center, observational study, we included 100 patients with trauma. Urinary L-FABP levels were measured using a semi-quantitative rapid assay kit 6 and 12 h after injury. Negative, weakly positive, and strongly positive urinary L-FABP levels were examined using two protocols. Using protocol 1, measurements were performed at 6 h after injury negative levels were considered "negative," and weakly positive and strongly positive levels were considered "positive." Using protocol 2, strongly positive levels at 6 h after injury were considered "positive," and negative or weakly positive levels at 6 h after injury were considered "positive" if they were weakly positive or positive at 12 h after injury. Fifteen patients were diagnosed with AKI. Using protocol 1, the odds ratio (OR) was 20.55 (p = 0.001) after adjustment for the injury severity score (ISS), contrast media use, and shock index. When the L-FABP levels at 6 and 12 h were similarly adjusted for those three factors, the OR was 18.24 (p < 0.001). The difference in ORs for protocols 1 and 2 was 1.619 (p = 0.04). Associations between urinary L-FABP and AKI can be examined more precisely by performing measurements at 6 and 12 h after injury than only one time at 6 h.

Iron-induced kidney cell damage: insights into molecular mechanisms and potential diagnostic significance of urinary FTL.

Background: Iron overload can lead to organ and cell injuries. Although the mechanisms of iron-induced cell damage have been extensively studied using various cells, little is known about these processes in kidney cells. Methods: In this study, we first examined the correlation between serum iron levels and kidney function. Subsequently, we investigated the molecular impact of excess iron on kidney cell lines, HEK293T and HK-2. The presence of the upregulated protein was further validated in urine. Results: The results revealed that excess iron caused significant cell death accompanied by morphological changes. Transcriptomic analysis revealed an up-regulation of the ferroptosis pathway during iron treatment. This was confirmed by up-regulation of ferroptosis markers, ferritin light chain (FTL), and prostaglandin-endoperoxide synthase 2 (PTGS2), and down-regulation of acyl-CoA synthetase long-chain family member 4 (ACSL4) and glutathione peroxidase 4 (GPX4) using real-time PCR and Western blotting. In addition, excess iron treatment enhanced protein and lipid oxidation. Supportively, an inverse correlation between urinary FTL protein level and kidney function was observed. Conclusion: These findings suggest that excess iron disrupts cellular homeostasis and affects key proteins involved in kidney cell death. Our study demonstrated that high iron levels caused kidney cell damage. Additionally, urinary FTL might be a useful biomarker to detect kidney damage caused by iron toxicity. Our study also provided insights into the molecular mechanisms of iron-induced kidney injury, discussing several potential targets for future interventions.

Risk factors and renal outcomes of AKI in children with secondary steroid-resistant nephrotic syndrome

Background Acute kidney injury (AKI) is increasingly prevalent in children with nephrotic syndrome (NS). It is associated with adverse outcomes in NS, especially steroid-resistant nephrotic syndrome (SRNS). The incidence, risk factors and outcomes of AKI in secondary SRNS remain undefined. The main objectives of this study were to determine the risk factors and prognosis of AKI in hospitalized children with secondary SRNS. Material and methods This retrospective study was conducted from January 2014 to December 2019, involving 172 hospitalizations with secondary SRNS admitted to the First Affiliated Hospital of Sun Yat-sen University. AKI was defined and classified in accordance with the 2012 Kidney Disease Improving Global Outcomes (KDIGO) guidelines. Results AKI was found in 67 (39.0%) of 172 hospitalizations with secondary SRNS. Average age of onset in our group is 4.4 (3.1, 6.7) years with AKI and 3.7 (1.8, 5.6) years without AKI. Urea nitrogen level is 5.9 (4.1, 10.0) mmol/L with AKI and 5.1 (3.7, 7.0) mmol/L. Uric acid level is 446.0 (340.0, 567.0) umol/L with AKI and 401.0 (303.0, 496.0) umol/L. 24-h urinary protein level is 4.14 (2.9, 6.5) g with AKI and 2.5 (1.3, 5.3) without AKI. Multivariate logistic regression revealed that infection (OR = 5.287; 95% confidence interval, 2.349 to 11.899; p < 0.001), age at onset (OR = 1.180; 95% confidence interval, 1.032 to 1.349; p = 0.015) and uric acid level (OR = 1.003; 95% confidence interval, 1.000 to 1.006; p = 0.031) were significantly associated with the development of AKI in children with secondary SRNS. Among 72 children with secondary SRNS, six went to end-stage kidney disease (ESKD). Children in the AKI group were more likely to progress to ESKD compared with children in the non-AKI group (p = 0.017) with a median follow‐up of 48.5months. Conclusion AKI occurred in 39.0% of total hospitalizations associated with secondary SRNS. Risk factors including infection, age of onset, and uric acid level are associated with AKI in children with secondary SRNS. Furthermore, AKI was identified as a risk factor for the progression of secondary SRNS to ESKD.

Uncovering lupus nephritis-specific genes and the potential of TNFRSF17-targeted immunotherapy: a high-throughput sequencing study.

Lupus nephritis (LN) is a severe manifestation of systemic lupus erythematosus (SLE). This study aimed to identify LN specific-genes and potential therapeutic targets. We performed high-throughput transcriptome sequencing on peripheral blood mononuclear cells (PBMCs) from LN patients. Healthy individuals and SLE patients without LN were used as controls. To validate the sequencing results, qRT-PCR was performed for 5 upregulated and 5 downregulated genes. Furthermore, the effect of the TNFRSF17-targeting drug IBI379 on patient plasma cells and B cells was evaluated by flow cytometry. Our analysis identified 1493 and 205 differential genes in the LN group compared to the control and SLE without LN groups respectively, with 70 genes common to both sets, marking them as LN-specific. These LN-specific genes were significantly enriched in the 'regulation of biological quality' GO term and the cell cycle pathway. Notably, several genes including TNFRSF17 were significantly overexpressed in the kidneys of both LN patients and NZB/W mice. TNFRSF17 levels correlated positively with urinary protein levels, and negatively with complement C3 and C4 levels in LN patients. The TNFRSF17-targeting drug IBI379 effectively induced apoptosis in patient plasma cells without significantly affecting B cells. Our findings suggest that TNFRSF17 could serve as a potential therapeutic target for LN. Moreover, IBI379 is presented as a promising treatment option for LN.

Comparative Levels of Urinary Biomarkers of Renal Injury and Inflammation Among Patients With Diabetic Nephropathy With or Without Hyperuricemia.

The association between hyperuricemia and development of progressive chronic kidney disease has received increasing attention in recent years. Recent preclinical studies have shown that non-crystalline uric acid can induce renal-specific arteriolopathy, leading to renal injury and tubulointerstitial inflammation. We conducted a open-label cross-sectional study of 25 patients with chronic kidney disease stage III (estimated glomerular filtration rate [eGFR], 7.0 mg/dL) levels of serum uric acid. To determine the correlation between hyperuricemia on urinary protein levels and renal disease progression, we retrospectively compared urine protein and eGFR data between the 2 groups. Eleven patients with normal uric acid levels and 14 with hyperuricemia were enrolled. Urinary levels of both kidney injury molecule-1 (KIM-1) and monocyte chemoattractant protein-1 (MCP-1) were significantly higher in patients with hyperuricemia. Among the normouricemic White and African American (AA) subgroups, there was no difference in KIM-1 or MCP-1 levels, whereas KIM-1 levels were significantly higher among hyperuricemic AA patients with hyperuricemia. Urinary protein was significantly higher between Whites and AA patients with serum uric acid level >7.0 mg/dL as well as patients with urinary KIM-1 levels >1000 pg/mg Cr. A trend toward a more rapid decline in eGFR was noted among hyperuricemic AAs; however, this trend was not statistically significant. Patients with type 2 diabetic nephropathy and persistently elevated serum uric acid levels express higher levels of both KIM-1 and MCP-1 reflective of on-going renal injury and inflammation.

Prevalence and immunopathologic characteristics of seropositive and seronegative hepatitis B virus-associated membranous nephropathy: a retrospective study of 420 biopsy-proven cases

Background This retrospective study aims to investigate the prevalence and immunopathologic characteristics of seropositive and seronegative hepatitis B virus-associated membranous nephropathy (HBV-MN). Methods Clinicopathologic and serologic records of 420 patients with histologically confirmed HBV-MN between January 2014 and July 2021 were examined to determine the prevalence of seropositive and seronegative HBV-MN. Serum anti-PLA2R antibody testing was conducted on 280 patients with HBV-associated membranous nephropathy (HBV-MN) from August 2018 to July 2021. Immunopathologic characteristics of HBV-MN patients and anti-PLA2R antibody positivity were analyzed. Results Among 420 pathologically confirmed HBV-MN patients, 230 (54.8%) were seropositive for HBV. The seropositive group exhibited higher blood creatinine values and incidence of liver function abnormalities than the seronegative group (p < .05). Serum anti-PLA2R antibody testing on 280 HBV-MN patients revealed a total positive rate of 44.6%, with the seronegative group showing a significantly higher rate (62.6%) compared to the seropositive group (32.1%) (p < .01). The anti-PLA2R antibody-positive group displayed higher levels of urine protein (p < .05), serum cholesterol (p < .01), and IgG4 subtypes (p < .05) compared to the negative group. Additionally, the positive group had significantly lower levels of serum albumin and IgG than the negative group (p < .01). Conclusions This comprehensive study reveals a significantly higher prevalence of seronegative HBV-MN than previously thought. The blood creatinine values and incidence of liver function abnormalities was higher in the serology-positive group than in the serology-negative group. Notably, the seronegative group displayed a higher positive rate of anti-PLA2R antibodies compared to the seropositive group, indicating distinctive clinical and immunopathologic features.

Slope of the estimated glomerular filtration rate and its associated factors among individuals with chronic kidney disease in the general Japanese population

BackgroundTo suppress the incidence of end-stage kidney disease, we need to identify chronic kidney disease (CKD) patients with a high risk of rapid decline in the estimated glomerular filtration rate (eGFR). However, the current status of eGFR slope and its associated factors in the Japanese population have not been fully elucidated.MethodsAmong examinees aged 40–70 years in the 2014 Specific Health Checkup conducted by the National Health Insurance in Kobe, Japan (n = 61,985), we prospectively observed 7291 examinees with CKD stage G3 from 2014 to 2018.ResultsUntil 2018, 4221 examinees continued to undergo annual SHCs for a total of five checkups per subject and had available records of all necessary data. The median eGFR change was −0.22 ml/min/1.73 m2/year. Only 9.2% of those subjects showed rapid eGFR decline (faster than −2.0 ml/min/1.73 m2/year). Logistic regression analysis identified diabetes, smoking habits, high urinary protein levels, older age, high systolic blood pressure, and low serum low-density lipoprotein cholesterol levels as independent predictors for rapid eGFR decline. Hemoglobin A1c levels did not contribute to the eGFR slope in CKD stage-G3 subjects with diabetes and proteinuria.ConclusionMost Japanese CKD stage-G3 subjects had a very slow decline in eGFR. A small proportion of CKD individuals who have a predictive factor of rapid eGFR decline should receive considerable attention from a nephrologist.