Project description:We aimed to identify miRNA biomarkers of renal injury in kidney biopsies from patients with lupus nephritis. MiRNA profiles of 8 patients were analyzed for correlation with various clinical features including Progression, Activity, Chronicity, and Time to Kidney Failure. MicroRNAs (miRs) are promising biomarkers and are involved in pathogenesis of kidney diseases. We aimed to identify miR biomarkers of renal injury in kidney biopsies from patients with lupus nephritis and study their potential role in renal fibrosis. miR-150 was significantly increased in kidneys with high chronicity compared to low chronicity and it correlated positively with chronicity index scores and renal collagen I expression. In kidneys with high chronicity, miR-150 was found predominantly in proximal tubular cells (PTCs) and was moderately expressed in podocytes and to lesser degree in mesangial cells (MCs). We hypothesized that miR-150 increases fibrosis by downregulating a negative regulator of profibrotic proteins. Suppressor of cytokine signaling1 (SOCS1) is a predicted target of miR-150 and has shown antifibrotic role. After confirming that SOCS1 is a direct target of miR-150, we showed that transfection of a miR-150 analog downregulated SOCS1 protein and upregulated the profibrotic proteins fibronectin, collagen I, collagen III, and TGF-β1 in both primary normal human renal PTCs and MCs. A similar effect was seen when using a SOCS1 siRNA to confirm that the effect of miR-150 on profibrotic proteins is mediated through SOCS1. Stimulation with TGF-β1 induced miR-150 increase in PTCs and human podocytes but not MCs. These results suggest that miR-150 might be a useful quantitative renal biomarker of kidney injury in lupus nephritis and that miR-150, which might be partially induced by TGF-β1, plays an important role in renal fibrosis by increasing profibrotic molecules through downregulation of SOCS1.
Project description:We aimed to identify miRNA biomarkers of renal injury in kidney biopsies from patients with lupus nephritis. MiRNA profiles of 8 patients were analyzed for correlation with various clinical features including Progression, Activity, Chronicity, and Time to Kidney Failure. MicroRNAs (miRs) are promising biomarkers and are involved in pathogenesis of kidney diseases. We aimed to identify miR biomarkers of renal injury in kidney biopsies from patients with lupus nephritis and study their potential role in renal fibrosis. miR-150 was significantly increased in kidneys with high chronicity compared to low chronicity and it correlated positively with chronicity index scores and renal collagen I expression. In kidneys with high chronicity, miR-150 was found predominantly in proximal tubular cells (PTCs) and was moderately expressed in podocytes and to lesser degree in mesangial cells (MCs). We hypothesized that miR-150 increases fibrosis by downregulating a negative regulator of profibrotic proteins. Suppressor of cytokine signaling1 (SOCS1) is a predicted target of miR-150 and has shown antifibrotic role. After confirming that SOCS1 is a direct target of miR-150, we showed that transfection of a miR-150 analog downregulated SOCS1 protein and upregulated the profibrotic proteins fibronectin, collagen I, collagen III, and TGF-β1 in both primary normal human renal PTCs and MCs. A similar effect was seen when using a SOCS1 siRNA to confirm that the effect of miR-150 on profibrotic proteins is mediated through SOCS1. Stimulation with TGF-β1 induced miR-150 increase in PTCs and human podocytes but not MCs. These results suggest that miR-150 might be a useful quantitative renal biomarker of kidney injury in lupus nephritis and that miR-150, which might be partially induced by TGF-β1, plays an important role in renal fibrosis by increasing profibrotic molecules through downregulation of SOCS1. FFPE kidney specimens (n=25) including baseline and repeated needle renal biopsies were from 14 patients with LN enrolled in IRB-approved protocols at the NIDDK between 1976 and 1999. The specimens were divided in two groups based on histological chronicity index (CI). CI ≥ 4 were categorized as having high degree of chronicity of chronic kidney injury. 18 kidneys from 8 patients including high CI (n=9) and low CI (n=9) were used for miR profiling by Affymetrix microRNA microarrays.
Project description:BackgroundExostosin 1/2 (EXT1/2) and neural cell adhesion molecule 1 (NCAM1) associated membranous lupus nephritis (MLN) may represent distinct disease phenotypes with prognostic significance.MethodsWe searched our archives for patients with systemic lupus erythematous (SLE) and at least two kidney biopsies demonstrating MLN. Each biopsy was stained for EXT1 and NCAM1 and scored as positive or negative. Histopathologic and clinical data were reviewed.ResultsWe identified 31 patients with a clinical diagnosis of SLE and at least two kidney biopsies with MLN. A total of 28 patients (90%) showed concordant staining for EXT1 and NCAM1 in both biopsies; 8 patients (26%) were EXT1 positive and NCAM1 negative, 18 patients (58%) were EXT1 negative and NCAM1 negative and 2 patients (7%) were EXT1 negative and NCAM1 positive. A total of three patients (10%) had discordant EXT1 staining between their first and last biopsies; two patients (7%) were EXT1 positive in their first biopsy and EXT1 negative in the last biopsy and one patient (3%) was EXT1 negative in his first biopsy and EXT1 positive in the last biopsy. Compared with the EXT1-negative cohort at the time of the first biopsy, the EXT1-positive cohort had a higher average estimated glomerular filtration rate (eGFR; 141 versus 108 mL/min/1.73 m2; P = 0.04), lower average percent global glomerulosclerosis (0.5 versus 12%; P = 0.05), lower average interstitial fibrosis and tubular atrophy (2.5 versus 11.7%; P = 0.06) and lower average total National Institutes of Health (NH) chronicity scores (0.75 versus 2.33; P = 0.05). On long-term follow-up, the rate of change in eGFR did not significantly differ between the two groups (P = 0.24). One EXT1-positive patient (12.5%) developed stage 4 chronic kidney disease (CKD) or end-stage kidney disease (ESKD) compared with four patients (20%) in the EXT-negative group and two of the three EXT1-discordant patients (P = 0.38).ConclusionsWe performed the largest retrospective repeat-biopsy study to evaluate EXT1 and NCAM1 autoantigens in MLN. Our data demonstrate that EXT1 positivity is associated with better kidney function at the time of diagnosis and raises the possibility that EXT1 status may change throughout the disease course of MLN.
Project description:Lupus nephritis (LN) occurs in up to 60% of SLE patients, and is a leading cause of disability and death. Current treatment of LN consists of a combination of high dose corticosteroids that non-specifically decrease inflammation and cytotoxic medications that reduce auto-antibody production. That combination of therapy is associated with significant side effects while remission rates remain inadequate. Since the introduction of biologics into the pharmacological armamentarium, there has been hope for less toxic and more effective therapies for LN. Unfortunately, after multiple clinical trials, no biologic has improved efficacy over standard of care therapies for LN. This is likely, in part, due to disease heterogeneity. The utilization of biomarkers in LN may provide a way to stratify patients and guide therapeutic options. In this review, we summarize traditional and novel LN biomarkers and discuss how they may be used to diagnose, stratify, and guide therapy in patients with LN, bringing precision medicine to the forefront of LN therapy.
Project description:Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus (SLE). LN often leads to kidney failure, affecting the quality of a patient's life. There are several classical biomarkers that assist nephrologists' daily practice. For more than 50 years, anti-double stranded DNA antibodies and complement components C3 and C4 have been used for LN disease activity evaluation. The major obstacle in the usage of conventional biomarkers is that none of them have both high specificity and high sensitivity. Moreover, an invasive kidney biopsy is still the gold standard for renal involvement detection in SLE patients. Therefore, new non-invasive biomarkers are needed for the early and accurate establishment of LN. Among the promising candidates are long non-coding RNAs (lncRNAs). Their dysregulation appears to have predictive and diagnostic potential. Furthermore, these biomarkers like other conventional biomarkers give insight into the pathogenesis of LN. This review aims to summarize the available information on lncRNAs in SLE patients and to present their future opportunities to add to the conventional biomarkers in the diagnosis and monitoring of LN.
Project description:ObjectivesThis study aimed to determine the prevalence and localization of complement factor C4d in renal biopsies from patients with lupus nephritis (LN), as well as its associations with the disease's clinico-pathological features. The correlation between arteriolar C4d deposition and renal microvascular lesions (RVLs) was further analyzed.MethodsA total of 325 biopsy-proven LN patients were enrolled, and their clinico-pathological data were collected. C4d staining of renal biopsies was performed by immunohistochemistry. The associations between C4d deposition and the clinico-pathological features were further analyzed.ResultsC4d deposition was present in most (98.8%) renal specimens in our cohort. These deposits were localized in the glomeruli (98.2%), tubular basement membrane (TBM) (43.7%), arterioles (31.4%), and peritubular capillary (33.8%). Patients with TBM C4d staining had higher disease activity (measured with the Systemic Lupus Erythematous Disease Activity Index) and higher National Institutes of Health pathological activity and chronicity indices (all P < 0.01). Patients with arteriolar C4d deposition were more likely to develop RVLs (91.2%) compared to those with no arteriolar C4d deposition (78.0%; P = 0.004), especially with two or more types of RVLs (P < 0.001). During the mean follow-up of 55.8 months, arteriolar C4d was related to worse renal outcomes [hazard ration (HR): 2.074, 95% confidence interval (CI) 1.056-4.075, P = 0.034]. Multivariate Cox hazard analysis showed that co-deposition of arteriolar C4d and C3c was an independent risk factor (HR: 3.681, 95% CI 1.519-8.921, P = 0.004) for predicting renal outcomes.ConclusionsC4d deposition was common in renal tissues from LN patients. TBM C4d deposition was related to the disease activity, and arteriolar C4d deposition was associated with RVLs and worse renal outcomes.
Project description:BackgroundThe subclinical pathophysiology of proliferative lupus nephritis (PLN) has not been fully elucidated. Myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) is associated with PLN, but prediagnostic levels have not been reported.MethodsWe performed a retrospective case-control Department of Defense Serum Repository (DoDSR) study comparing MPO-ANCA levels in longitudinal prediagnostic serum samples for 23 biopsy confirmed proliferative lupus nephritis (PLN) patients to DoDSR identified age, sex, race, and age of serum matched healthy and SLE without LN disease controls. We also compared the temporal relationship of MPO-ANCA to anti-double stranded DNA antibodies (dsDNAab).ResultsA greater proportion of PLN patients had prediagnostic MPO-ANCA levels above ≥3 U/mL and ≥6 U/mL compared to SLE without LN (91% versus 43%, p < 0.001; 57% versus 5%, p < 0.001, resp.). In subgroup analysis, the MPO-ANCA threshold of ≥3 U/mL was significant at <1 year (88% versus 39%, p = 0.007) and 1-4 years (87% versus 38%, p = 0.009) prior to diagnosis. Statistically significant subclinical MPO-ANCA levels (≥3 U/mL) occurred prior to statistically significant dsDNAab ≥ 3 IU/ml (89% versus 11%, p = 0.003).ConclusionsSubclinical MPO-ANCA levels could distinguish future PLN from SLE without LN. MPO-ANCA manifests prior to clinical disease and subclinical dsDNAab to suggest that it may contribute directly to PLN pathogenicity.
Project description:ObjectiveDisruption in the delicate symphony of genes, microRNA (miRNA), or protein expression can result in the dysregulation of the immune system, leading to the devastating consequences such as lupus nephritis (LN). The capacity of exosomes to transport miRNAs between cells and modify the phenotype of recipient cells implies their involvement in persistent kidney inflammation. This study unveils identifying two previously undiscovered exosomal miRNAs in the serum of LN patients, offering potential solutions to the current challenges in LN diagnosis and management.MethodsInitially, we used a reagent-based kit to isolate serum exosomes from patients with Systemic lupus erythematosus (SLE) and used Trizol method for total RNA extraction. Subsequently, we employed small RNA sequencing to screen for differential expression profiles of exosomal small RNAs. The RT-qPCR method was used to individually validate samples in both the screening and validation cohorts, enabling the identification of candidate small RNAs; specific to LN. We assessed the diagnostic potency using receiver operating characteristic (ROC) curve, and explored the biological roles of miRNAs using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses.ResultsCompared to SLE patients without LN, SLE patients accompanied by LN exhibited significantly spiked levels of exosomal hsa-miR-4796-5p and hsa-miR-7974. The duo of miRNAs, hsa-miR-4796-5p and hsa-miR-7974, exhibited promising potential as biomarkers for diagnosing LN, with an AUC exceeding 0.8. Correlation analysis revealed a strong positive association between these miRNAs and proteinuria, as well as the SLE Disease Activity Index (SLEDAI) score. Moreover, the levels of two miRNAs in LN patients were significantly elevated in comparison to other autoimmune nephritis conditions, such as immunoglobulin A nephropathy (IgAN) and diabetic nephropathy (DN). Furthermore, the bioinformatics analysis indicated that this miRNAs duo can play a pivotal role in the regulation of immune processes by modulating signal pathways, such as the mTOR and PI3K-Akt signaling pathway.ConclusionThis study provides a new ground that serum exosomal miRNAs can effectively identify and predict LN in SLE patients.
Project description:AbstractLupus nephritis (LN), a severe manifestation of systemic lupus erythematosus, poses a substantial risk of progression to end-stage renal disease, with increased mortality. Conventional therapy for LN relies on broad-spectrum immunosuppressants such as glucocorticoids, mycophenolate mofetil, and calcineurin inhibitors. Although therapeutic regimens have evolved over the years, they have inherent limitations, including non-specific targeting, substantial adverse effects, high relapse rates, and prolonged maintenance and remission courses. These drawbacks underscore the need for targeted therapeutic strategies for LN. Recent advancements in our understanding of LN pathogenesis have led to the identification of novel therapeutic targets and the emergence of biological agents and small-molecule inhibitors with improved specificity and reduced toxicity. This review provides an overview of the current evidence on targeted therapies for LN, elucidates the biological mechanisms of responses and failure, highlights the challenges ahead, and outlines strategies for subsequent clinical trials and integrated immunomodulatory approaches.