Glomerular Proliferation Research Articles

Sparsentan ameliorates glomerular hypercellularity and inflammatory-gene networks induced by IgA1-IgG immune complexes in a mouse model of IgA nephropathy.

IgA nephropathy (IgAN) is characterized by glomerular deposition of immune complexes (ICs) consisting of IgA1 with O-glycans deficient in galactose (Gd-IgA1) and Gd-IgA1-specific IgG autoantibodies. These ICs induce kidney injury, and in the absence of disease-specific therapy, up to 40% of patients with IgAN progress to kidney failure. IgA1 with its clustered O-glycans is unique to humans, which hampered development of small-animal models of IgAN. Here, we used a model wherein engineered ICs (EICs) formed from human Gd-IgA1 and recombinant human IgG autoantibody are injected into nude mice to induce glomerular injury mimicking human IgAN. In this model, we assessed the protective effects of sparsentan, a single-molecule dual endothelin angiotensin receptor antagonist (DEARA) versus vehicle on EIC-induced glomerular proliferation and dysregulation of gene expression in the kidney. Oral administration of sparsentan (60 or 120 mg/kg daily) to mice intravenously injected with EIC attenuated the EIC-induced glomerular hypercellularity. Furthermore, analysis of changes in the whole kidney transcriptome revealed that key inflammatory and proliferative biological genes and pathways that are upregulated in this EIC model of IgAN were markedly reduced by sparsentan, including complement genes, integrin components, members of the mitogen-activated protein kinase family, and Fc receptor elements. Partial overlap between mouse and human differentially expressed genes in IgAN further supported the translational aspect of the immune and inflammatory components from our transcriptional findings. In conclusion, our data indicate that in the mouse model of IgAN, sparsentan targets immune and inflammatory processes leading to protection from mesangial hypercellularity.NEW & NOTEWORTHY The mechanisms by which deposited IgA1 immune complexes cause kidney injury during early phases of IgA nephropathy are poorly understood. We used an animal model we recently developed that involves IgA1-IgG immune complex injections and determined pathways related to the induced mesangioproliferative changes. Treatment with sparsentan, a dual inhibitor of endothelin type A and angiotensin II type 1 receptors, ameliorated the induced mesangioproliferative changes and the associated alterations in the expression of inflammatory genes and networks.

Anti-DNA antibody-targeted D-peptide nanoparticles ameliorate lupus nephritis in MRL/lpr mice

Peptide ALW (ALWPPNLHAWVP) targeting anti-dsDNA antibodies has shown promising therapeutic effects in alleviating lupus nephritis, but is potentially limited by poor stability and non-kidney targeting. We recently developed a D-form modified ALW, called D-ALW, which has the capacity to widely inhibit pathogenic polyclonal anti-dsDNA antibody reactions. Further modification of D-ALW using PEG-PLGA nanoparticles to enhance good kidney-targeting ability and extend half-life. Here, we demonstrate that the D-form modified ALW maintains higher binding and inhibition efficiencies and achieves higher stability. Most importantly, D-ALW nanoparticles exhibit excellent kidney-targeting ability and prolong the half-life of the peptides in BALB/c mice. Additionally, compared to D-ALW, D-ALW nanoparticles significantly reduce the glomerular deposition of IgG and C3, improve renal histopathologies, such as glomerular proliferation and inflammatory cells infiltration, and markedly prolong lifespan in MRL/lpr lupus-prone mice. Overall, these results establish that the D-ALW nanoparticles offer synergistic benefits in both safety and efficacy, providing long-term renal preservation and treatment advantages in lupus nephritis.

SGLT2i improves kidney senescence by down-regulating the expression of LTBP2 in SAMP8 mice.

Senescent kidney can lead to the maladaptive repairment and predispose age-related kidney diseases. Here, we explore the renal anti-senescence effect of a known kind of drug, sodium-dependent glucose transporters 2 inhibitor (SGLT2i). After 4 months intragastrically administration with dapagliflozin on senescence-accelerated mouse prone 8 (SAMP8) strain mice, the physiologically effects (lowering urine protein, enhancing glomerular blood perfusion, inhibiting expression of senescence-related biomarkers) and structural changes (improving kidney atrophy, alleviating fibrosis, decreasing glomerular mesangial proliferation) indicate the potential value of delaying kidney senescence of SGLT2i. Senescent human proximal tubular epithelial (HK-2) cells induced by H2 O2 also exhibit lower senescent markers after dapagliflozin treatment. Further mechanism exploration suggests LTBP2 have the great possibility to be the target for SGLT2i to exert its renal anti-senescence role. Dapagliflozin down-regulate the LTBP2 expression in kidney tissues and HK-2 cells with senescent phenotypes. Immunofluorescence staining show SGLT2 and LTBP2 exist colocalization, and protein-docking analysis implies there is salt-bridge formation between them; these all indicate the possibility of weak-interaction between the two proteins. Apart from reducing LTBP2 expression in intracellular area induced by H2 O2 , dapagliflozin also decrease the concentration of LTBP2 in cell culture medium. Together, these results reveal dapagliflozin can delay natural kidney senescence in non-diabetes environment; the mechanism may be through regulating the role of LTBP2.

Phenobarbital ameliorates hyperglycemia-induced angiogenesis in diabetic nephropathy-possible intervention at the HIF-1α/VEGF axis

Hyperglycemia contributes to a cascade of inflammatory responses in kidneys that result in the development of renal hypoxia and angiogenesis with subsequent chronic renal failure. As the hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) axis is a key pathway for neovascularization, the inhibition of this axis is a target for renal angiogenesis therapy. We speculate that Phenobarbital (PB) which has a potential to reduce vascularization in clinical settings might have an influence on the development of angiogenesis in diabetic kidney. The aim of the study was to explore the effects of PB on the HIF-1α and VEGF expression and angiogenesis in renal tissue of rats with hyperglycemia and diabetic nephropathy. Sixty-four male Wistar rats were devided into 4 groups: control group received a single intraperitoneal saline injection; PB group received 0.05% PB orally in drinking water; diabetic group received a single intra-peritoneal STZ (65 mg/kg) injection; PB-STZ group received 0.05% PB orally two weeks before STZ administration. At the end of the experiment period (8 weeks), the kidneys were removed and used for biochemical analyses. Serum glucose, urea and creatinine levels, IL-6 levels in kidney homogenate and changes in HIF-1α and VEGF gene expression were estimated. Hematoxylin-eosin staining was performed for histopathological exa­mination. The results obtained showed that both HIF-1α and VEGF gene expression and IL6 level in diabetic rat group were significantly elevated compared to that in control group, whereas in PB and PB-STZ groups, these indices were significantly down-regulated compared to the diabetic group. Abundant glomerular congestion and mesangial proliferation were detected in diabetic rat renal tissues. However, in PB-treated diabetic group, newly formed vessels were significantly decreased. These findings confirmed that phenobarbital, affecting the HIF-1α/VEGF signaling pathway, ameliorates angiogenesis after hyperglycemic kidney injury. Keywords: angiogenesis, HIF-1α, hyperglycemia, IL6, kidney injury, VEGF

Effects of Lifelong Aerobic Exercise on Ferroptosis-Related Gene Expressions in Kidney of Aged Mice

PURPOSE: This study sought to explore the impact of continuous aerobic exercise throughout life on the expression of ferroptosis-related genes in aging kidneys, elucidating the role of exercise in maintaining kidney health.METHODS: Male C57BL/6 mice were divided into young control, young exercise, old control, and old exercise groups, with the latter providing access to spontaneous running wheels. Aged mice were observed until 99 weeks, while young mice were followed until 22 weeks. Kidney tissue samples underwent analysis through quantitative polymerase chain reaction, iron assays, histological staining, and pathological damage scoring.RESULTS: Expression of <i>Nphs1</i> and <i>Nphs2</i> exhibited no significant changes after exercise. However, histological analysis revealed that age-related kidney damage, including glomerular mesangial proliferation, was notably offset by lifelong aerobic exercise. The expression of <i>Slc7a11</i> and <i>Gpx4</i> remained unaffected by exercise, whereas <i>Nfe2l2</i> expression decreased significantly in the young exercise groups. <i>Acsl4</i> expression exhibited no aging- or exercise-induced differences. Additionally, <i>Tfrc</i> expression was lower in the young exercise group than in the young control group but remained consistent between the old and old-exercise groups. Total iron (Fe) increased in aged mice compared to that in the young-exercise group, and the Fe<sup>2+</sup>/Total Fe ratio was lower in the old-exercise than in the old control group.CONCLUSIONS: Lifelong aerobic exercise positively impacted kidney health by enhancing antioxidant capacity and mitigating iron accumulation. These findings underscore the significance of exercise in preventing age-related deterioration in kidney function.

TMIC-23. UNRAVELLING THE HETEROGENEITY OF GLIOBLASTOMA'S VASCULAR LANDSCAPE

Abstract BACKGROUND Glioblastoma tumours are highly vascular and angiogenic. However, they are also heterogeneous, comprising many different macro- and microenvironments. Reflecting this, tumour-associated blood vessels are variable in their distribution, structure, and function. Despite the significance of vasculature in the development and progression of glioblastoma, its complexity remains poorly defined. Therefore, characterising vascular diversity across the glioblastoma landscape is a crucial step in the development of targeted therapies. METHODS 40 glioblastoma and 5 epilepsy cases were immunohistochemically labelled with a vascular antibody panel (PDGFRβ, ColIV, αSMA, UEA-1 and GFAP) to identify and subtype vessels. Single-vessel image analysis was performed to analyse vascular coverage and to classify vascular subtypes based on marker co-expression. Labelling with haemoglobin, ZO-1, and claudin-5 allowed for the evaluation of vascular leakage and blood-brain barrier integrity. Tissue segmentation was performed to analyse vascular coverage, vascular subtypes, and vascular integrity across the tumour macro-environment. RESULTS No significant difference in gross vascular coverage was found between tumour and epilepsy tissue. However, vascular coverage within glioblastoma varied significantly depending on the tumour macro-environment. Whilst vascular coverage in the tumour periphery was comparable to epilepsy tissue, increased vessel density was observed in the intermediate tumour zone, followed by decreased vessel density towards the tumour core. Reflecting this variation, multiple vessel subtypes, including previously described glomerular microvascular proliferation, mother vessels, vascular malformations and hyperplastic vessels, were identified. These tumour vessels display highly irregular shapes, sizes, and cellular compositions. Finally, glioblastoma tissue displayed a significant increase in haemoglobin leakage and a decrease in vascular integrity compared to epilepsy tissue. CONCLUSION Characterising this vascular landscape provides valuable insights for treatment strategies related to hypoxia and angiogenesis, two key factors driving tumour growth. Indeed, targeting specific vessel subtypes to address compromised vascular function and aberrant vascularisation may improve outcomes for glioblastoma patients.

Clinical value of the renal pathologic scoring system in complement-mediated thrombotic microangiopathy

Objectives This study was initiated to establish a renal thrombotic microangiopathy (TMA) scoring system based on clinical needs and investigate its predictive value for patients’ long-term outcomes. Methods Kidney biopsy-proven Complement-mediated TMA (C-TMA) patients from January 2000 to December 2017 in Peking University First Hospital were retrospectively studied. Both acute and chronic TMA-related lesions, including 15 pathologic indices, were semiquantitatively scored. The interobserver and intraobserver reproducibility and correlation between the pathologic indices and clinical parameters were analyzed. Furthermore, the patients were divided into 2 groups by dialysis use at baseline, and the association of these pathologic indices with their prognostic outcomes was assessed between the two groups. Results Ninety-two patients with renal biopsy-proven C-TMA were enrolled. All fifteen included pathology indices showed good or moderate interobserver and intraobserver reproducibility and correlated well with several clinical parameters. Several clinicopathological indices were worse in the dialysis group than in the nondialysis group, such as serum creatinine, hemoglobin, platelet count, and estimated glomerular filtration rate. Moreover, morphologic features in the dialysis group presented with more severe vascular lesions. Interstitial fibrosis and chronic tubulointerstitial lesions were related to a trend of high risk of continuous dialysis in the dialysis group. Based on univariate and multivariable Cox regression analysis, more severe glomerular lesions, including glomerular mesangiolysis, glomerular basement membrane double contours and glomerular mesangial proliferation, were identified as risk factors predicting worse prognosis. Conclusions Our renal C-TMA semiquantitative scoring system is reliable with good reproducibility and prognostic value in clinical practice, which needs further validation.

Inflammatory mediator responses of Vaccinium corymbosum extracts on the streptokinase induced acute glomerulonephritis in rats

Blueberry (Vaccinium corymbosum) has many health benefits including anti-inflammatory and antioxidant activities. Glomerulonephritis is a commonly found kidney disease in companion animals that is characterized by glomerular proliferation and inflammation likes characteristics. The present study was carried out to evaluate the potential of blueberry against inflammatory response in the kidney of acute glomerulonephritis (AGN) in animal models. For this, twenty male Wistar rats were randomized into five groups i.e. A - E (n=4). Among these Group A has four healthy individuals administrated with aqua dest (negative control), group B individuals have streptokinase (6000IU/rat) induced acute glomerulonephritis rats treated with aqua dest (positive control) while group C-E has streptokinase (6000IU/rat) induced acute glomerulonephritis rats treated with different concentrations of blueberry extract (500, 1000, and 1500 mg/kg body weight) for 14 days, respectively. After 14 days, kidney samples were harvested for histology and immunohistochemistry examinations. One-way ANOVA followed by the Tukey test was used for statistical analysis (P< 0.05). The blueberry extract treated AGN rats showed a significantly decreased in IL-1beta expression and inflammatory cell numbers compared to negative and positive control rats and 1500 mg/kg of the blueberry extract was found as the optimal dose. Results of the study can be concluded that blueberry extract has a strong anti-inflammatory effect that could depress the inflammatory responses in acute glomerulonephritis rat animal models.

Axl Expression in Renal Mesangial Cells Is Regulated by Sp1, Ap1, MZF1, and Ep300, and the IL-6/miR-34a Pathway.

Axl receptor tyrosine kinase expression in the kidney contributes to a variety of inflammatory renal disease by promoting glomerular proliferation. Axl expression in the kidney is negligible in healthy individuals but upregulated under inflammatory conditions. Little is known about Axl transcriptional regulation. We analyzed the 4.4 kb mouse Axl promoter region and found that many transcription factor (TF)-binding sites and regulatory elements are located within a 600 bp fragment proximal to the translation start site. Among four TFs (Sp1, Ap1, MZF1, and Ep300) identified, Sp1 was the most potent TF that promotes Axl expression. Luciferase assays confirmed the siRNA results and revealed additional mechanisms that regulate Axl expression, including sequences encoding a 5′-UTR mini-intron and potential G-quadruplex forming regions. Deletion of the Axl 5′-UTR mini-intron resulted in a 3.2-fold increases in luciferase activity over the full-length UTR (4.4 kb Axl construct). The addition of TMPyP4, a G-quadruplex stabilizer, resulted in a significantly decreased luciferase activity. Further analysis of the mouse Axl 3′-UTR revealed a miRNA-34a binding site, which inversely regulates Axl expression. The inhibitory role of miRNA-34a in Axl expression was demonstrated in mesangial cells using miRNA-34a mimicry and in primary kidney cells with IL-6 stimulated STAT3 activation. Taken together, Axl expression in mouse kidney is synergistically regulated by multiple factors, including TFs and secondary structures, such as mini-intron and G-quadruplex. A unique IL6/STAT3/miRNA-34a pathway was revealed to be critical in inflammatory renal Axl expression.

MO616: The Genetic Background Predicts The Kind of Renal Damage and Fibrosis Progression in Diabetic Patients

Abstract BACKGROUND AND AIMS Diabetic Nephropathy (DN) is the major causes of end-stage renal failure. DN diagnosis is based on typical histological features (Kimmelstiel–Wilson lesions, glomerular basal membrane thickening and proliferation of mesangial matrix). Not all diabetic patients with kidney disease develop true DN: kidney impairment can be due to a nondiabetic renal disease (NDRD) in the presence or absence of real DN. Thus, there is the need for noninvasive biomarkers, related to specific pathogenic processes, to discriminate DN and NDRD, and/or to predict DN onset. In the case of DN, there is extensive evidence in literature of genetic contribution to disease susceptibility and lots of efforts aim at the identification of specific loci. The research group demonstrated that a characteristic feature of DN is an increase in Lys63-ubiquitinated proteins at tubular level that leads to epithelial-to-mesenchymal transition (EMT) and finally to the progression of the tubular-interstitial fibrosis and the renal damage in DN patients (Pontrelli P et al. FASEB J 2017). Ube2V1 is the unique E2 enzyme known for producing Lys63-linked ubiquitin chains. Moreover, two miRNAs (miR27b-3p e miR1228-3p), which interact specifically with Ube2V1 transcript, predict the type of renal damage in diabetic patients and are related with kidney fibrosis (Conserva F et al. Sci Rep 2019). The goal of this project was to identify single nucleotide polymorphisms (SNPs) able to predict the different kind of renal damage and the progression of kidney disease in diabetic patients. METHOD We selected by UCSC genome, 10 HapMap SNPs of patients within coding and regulatory sequences both of miR27b-3p and miR1228-3p and Ube2V1 gene in order to evaluate their diagnostic and prognostic potential. The patients enrolled in this study were diabetic patients with a biopsy-proven DN diagnosis (DN), diabetic patients with a biopsy-proven diagnosis of other nephropathy than DN (NDRD), diabetic patients without clinical signs of impaired renal function (T2D), diabetic patients with a biopsy-proven coexistence of both conditions (ND + NDRD), non-diabetic patients with glomerulonephritis (CKD), non-diabetic patients without renal damage (CTRL). The DNA of 201 subjects (patients and controls) was isolated from blood samples, and 10 HapMap SNPs (rs3802456, rs4744422, rs10761364, rs7853195 in the control region of miR27b-3p; rs2306692, rs4759277, rs4759044, rs17547610, rs4759275 in the control region of miR1228-3p; rs761214 in the UBE2v1 gene) for each patient were analyzed using TaqMan real-time PCR. Glomerular and tubulointerstitial fibrosis in kidney biopsies was quantified on Sirius Red staining using the Aperio Imagescope software. RESULTS The analyzed SNPs showed a different genotype frequency among all the patients’ classes. Interestingly, SNPs rs4759275, rs4759277, rs4744422 and rs3802456 showed a statistically significant difference in genotype frequency comparing DN patients with CEU Population (Northern and Western European Ancestry in Utah) (P < 0.04, 0.05, 0.002, 0.001, respectively) and a control cohort enclosing CTRL and T2D (P < 0.02, 0.05, 0.001 and 0.04, respectively). SNPs rs761214, rs10761364 and rs2306692 genotypes frequency was statistically different among DN patients and the control cohort (P < 0.001). The genotype frequencies of the SNPs rs10761364 (P < 0.01) and rs7853195 (P < 0.04) resulted significantly related to tubular fibrosis in DN patients, while the SNPs rs4744422 (P < 0.03) and rs761214 (P < 0.02) to the glomerular one. In order to evaluate the diagnostic power of the identified SNPs, we used a logistic regression model, and we observed that the SNP rs10761364, adjusted for age, sex, eGFR and glycaemic index, discriminate DN from NDRD {P < 0.05; OR = 1.002–1.008; [95% confidence interval (CI)]}. CONCLUSION Our data demonstrated that the allelic forms of the analyzed SNPs are related to the different kind of renal damage in diabetic patients. Their prognostic and diagnostic potential could represent the starting point to create a new noninvasive diagnosis system based on clinical and genotyping data.

Glomerulonephritis with non-Randall-type, non-cryoglobulinaemic monoclonal immunoglobulin G deposits (PGNMID and ITG).

ABSTRACTBackgroundGlomerulonephritis (GN) with non-Randall-type, non-cryoglobulinaemic monoclonal immunoglobulin G deposits encompasses rare diseases [proliferative GN with non-organized deposits (PGNMID) and immunotactoid GN] that cannot be distinguished without ultrastructural analysis by electron microscopy (EM).MethodsHere, we report and analyse the prognosis of 41 EM-proven (PGNMID for 39/41) and 22 non-EM-proven/DNAJB9-negative cases, diagnosed between 2001 and 2019 in 12 French nephrology centres.ResultsMedian (interquartile range) serum creatinine (SCr) at presentation was 150 (92–256) µmol/L. The predominant histological pattern was membranoproliferative GN (79%), with IgG3 (74%) kappa (78%) deposits the most frequently observed. Disease presentation and patient management were similar between EM-proven and non-EM-proven cases. A serum monoclonal spike was detected for 21 patients and 10 had an underlying haematological malignancy. First-line therapy was mixed between clone-targeted therapy (n = 33), corticosteroids (n = 9) and RAAS inhibitors (n = 19). After 6 months, nine patients achieved complete and 23 partial renal recovery. In univariate analysis, renal recovery was associated with baseline SCr (odds ratio 0.70, P = 0.07). After a median follow-up of 52 (35–74) months, 38% of patients had progressed to end-stage kidney disease independently associated with baseline SCr [hazard ratio (HR) 1.41, P = 0.003] and glomerular crescentic proliferation (HR 4.38, P = 0.004).ConclusionsOur results confirm that non-cryoglobulinaemic and non-Randall GN with monoclonal IgG deposits are rarely associated with haematological malignancy. The prognosis is uncertain but may be improved by early introduction of a specific therapy.

Thrombotic microangiopathy with transiently positive direct Coombs test in an adult with poststreptococcal acute glomerulonephritis: a case report

BackgroundTo date, a few case reports have described the association between poststreptococcal acute glomerulonephritis (PSAGN) and hemolytic anemia/thrombocytopenia, both with or without a pathology similar to that of thrombotic microangiopathy (TMA). However, the detailed mechanism leading to the complication of TMA in PSAGN patients remains to be clarified. In contrast, infection with neuraminidase-producing Streptococcus pneumoniae is a well-known cause of TMA, and it has been reported that transient positivity of the direct Coombs test is observed in up to 90% of such patients.Case presentationA 44-year-old man was hospitalized for acute nephritic syndrome 3 weeks after developing pharyngitis. PSAGN was suspected owing to a low complement C3, increased antistreptolysin-O and serum creatinine (5.46 mg/dL), and hematuria/proteinuria. The throat antigen test for group A Streptococcus was positive. He developed hemolytic anemia with thrombocytopenia from hospital day 9. TMA was suspected owing to minimal coagulation abnormalities. ADAMTS-13 activity was normal, whereas the direct Coombs test was transiently positive. Renal biopsy demonstrated glomerular endocapillary proliferation without crescents, but with severe tubulitis and peritubular capillaritis on light microscopy. Immunofluorescence demonstrated C3 deposition along the glomerular capillary walls, and many subepithelial humps were observed on electron microscopy. The deposition of nephritis-associated plasmin receptor (NAPlr), a nephritogenic protein of Streptococcus pyogenes, was observed only in glomeruli. Thus, the histological diagnosis was typical PSAGN, but with atypical severe tubulointerstitial lesions. A positive direct Coombs test is often observed in pneumococcal TMA patients, which is attributed to the exposure of Thomsen–Friedenreich (T) antigen by neuraminidase. As Streptococcus pyogenes is one of the neuraminidase-producing bacteria other than Streptococcus pneumoniae, T-antigen exposure was analyzed in the renal tissue of this patient using labelled peanut lectin as a probe, which has strong and specific binding affinity for T-antigen. Exposure of T-antigen was found on tubular epithelial cells and small vessels in the tubulointerstitial area, but not in the glomeruli of this patient.ConclusionThese findings suggest that 2 pathogenic proteins of Streptococcus pyogenes, i.e., NAPlr and neuraminidase, induced glomerular lesions of PSAGN and tubulointerstitial inflammation with TMA, respectively, resulting in severe acute kidney injury in this patient.

The DR1‑CSE/H2S system inhibits renal fibrosis by downregulating the ERK1/2 signaling pathway in diabetic mice.

Glomerular mesangial cell (MC) proliferation and extracellular matrix deposition are the main pathological changes in diabetic nephropathy. Hydrogen sulfide (H2S) inhibits the proliferation of MCs. Dopamine 1 receptors (DR1) are expressed in MCs and serve important physiological roles. However, it is unclear whether DR1 activation inhibits MC proliferation by increasing endogenous H2S. The present study found that the production of H2S and the expression of DR1 and cystathionine-γ-lyase (CSE) were decreased in the renal tissues of diabetic mice and high glucose (HG)-induced MCs. SKF38393 (a DR1 agonist) increased the production of H2S and the expression of DR1 and CSE and NaHS (an exogenous H2S donor) only increased H2S production and CSE expression but not DR1 expression. HG increased the thickness of the glomerular basement membrane, cell viability and proliferation, the expression of cyclin D1, PCNA, collagen 1 and α-smooth muscle actin and the activity of phosphorylated ERK1/2 and decreased the expression of P21 and MMP9. SKF38393 and NaHS reversed the effects of HG. PPG (a CSE inhibitor) abolished the beneficial effects of SKF38393. The beneficial effects of SKF38393 were similar to those of PD98059 (an ERK1/2 inhibitor). Taken together, the findings suggested that the DR1-CSE/H2S pathway activation attenuated diabetic MC proliferation and extracellular matrix deposition by downregulating the ERK1/2 signaling pathway.

Soluble CD89 is a critical factor for mesangial proliferation in childhood IgA nephropathy

Childhood IgA nephropathy (IgAN) includes a wide spectrum of clinical presentations, from isolated hematuria to acute nephritis with rapid loss of kidney function. In adults, IgAN is an autoimmune disease and its pathogenesis involves galactose deficient (Gd) IgA1, IgG anti-Gd-IgA1 autoantibodies and the soluble IgA Fc receptor (CD89). However, implication of such factors, notably soluble CD89, in childhood IgAN pathogenesis remains unclear. Here, we studied these biomarkers in a cohort of 67 patients with childhood IgAN and 42 pediatric controls. While Gd-IgA1 was only moderately increased in patient plasma, levels of circulating IgA complexes (soluble CD89-IgA and IgG-IgA) and free soluble CD89 were markedly increased in childhood IgAN. Soluble CD89-IgA1 complexes and free soluble CD89 correlated with proteinuria, as well as histological markers of disease activity: mesangial, endocapillary hypercellularity and cellular crescents. Soluble CD89 was found in patient's urine but not in urine from pediatric controls. Mesangial deposits of soluble CD89 were detected in biopsies from patients with childhood IgAN. Serum chromatographic fractions containing covalently linked soluble CD89-IgA1 complexes or free soluble CD89 from patients induced mesangial cell proliferation invitro in a soluble CD89-dependent manner. Recombinant soluble CD89 induced mesangial cell proliferation invitro which was inhibited by free soluble recombinant CD71 (also a mesangial IgA receptor) or mTOR blockers. Interestingly, injection of recombinant soluble CD89 induced marked glomerular proliferation and proteinuria in mice expressing human IgA1. Thus, free and IgA1-complexed soluble CD89 are key players in mesangial proliferation. Hence, our findings suggest that soluble CD89 plays an essential role in childhood IgAN pathogenesis making it a potential biomarker and therapeutic target.

IgA Vasculitis with Nephritis in Adults: Histological and Clinical Assessment.

Patients with IgA vasculitis (IgAV), an immune complex-mediated disease, may exhibit kidney involvement—IgAV with nephritis (IgAVN). The kidney-biopsy histopathologic features of IgAVN are similar to those of IgA nephropathy, but little is known about histopathologic disease severity based on the interval between purpura onset and diagnostic kidney biopsy. We assessed kidney histopathology and clinical and laboratory data in a cohort of adult patients with IgAVN (n = 110). The cases were grouped based on the interval between the onset of purpura and kidney biopsy: Group 1 (G1, <1 month, n = 14), Group 2 (G2, 1–6 months, n = 58), and Group 3 (G3, >6 months, n = 38). Glomerular leukocytes were more common in G1 than in the other groups (p = 0.0008). The proportion of neutrophils among peripheral-blood leukocytes was the highest in the patients biopsied within a month after onset of purpura (G1: 71 ± 8%). In the patients with an interval >6 months, the neutrophil proportion was lower, 60%. Moreover, the glomerular mesangial proliferation score correlated with the serum total IgA concentration (p = 0.0056). In conclusion, IgAVN patients biopsied <1 month from purpura onset showed an elevated percentage of blood neutrophils and glomerular leukocytes, consistent with an acute-onset inflammatory reaction. In all IgAVN patients, the mesangial proliferation score correlated with the serum IgA level.

Is podocytopathy another image of renal affection in p-SLE?

BackgroundLupus podocytopathy (LP) is a renal affection described in systemic lupus erythematosus (SLE) patients with nephrotic range proteinuria, characterized by diffuse foot process effacement without immune deposits and glomerular proliferation. This study describes LP, its pathological features and outcomes of pediatric (p-SLE) patients in comparison to the usual lupus nephritis (LN) cases.MethodologyA retrospective cohort study conducted on a 10-year registration (2010–2019) of 140 p-SLE patients at the Pediatric Department, Tanta University. Histopathological analysis with light microscopy (LM) and immunofluorescence (IF) of all renal biopsies were evaluated according to the International Society of Nephrology Renal Pathology Society (ISN/RPS) grading system. In addition, some biopsies were examined with electron microscopy (EM).ResultsEighty-six p-SLE cases (61.4%) had renal involvement; seventy-nine biopsies (91.86%) of them met the classification criteria of LN as defined by ISN/RPS system. Five biopsies were normal (MCD) and two showed focal segmental sclerosis (FSGN) that did not meet any known classification of LN. Hence, they were reevaluated using EM that revealed diffuse effaced podocytes without glomerular sub-epithelial, endocapillary or basement membrane immune deposits, and were classified as having lupus podocytopathy, representing (8.14%) of all LN biopsies. Those seven cases showed good response to steroids with a complete remission duration of 3.40 ± 1.95 weeks. However, some case had 1–3 relapses during the duration of follow up.ConclusionsLP is a spectrum of p-SLE, not an association as it is related to disease activity and its initial presentation.

Epithelioid glioblastoma with BRAF V600E mutation: a clinicopathological and molecular study

Objective: To investigate the clinicopathological and molecular characteristics of the epithelioid glioblastoma (eGBM) with BRAF V600E mutation. Methods: Sixteen cases of eGBM with BRAF V600E mutation diagnosed at the West China Hospital of Sichuan University, China from 2012 to 2019 were collected. Their clinicopathological and molecular characteristics were analyzed. Results: The range of patients' age was from 7 to 61 years (median 31.5 years). There were 4 males and 12 females, with a male to female ratio of 1∶3. Eleven cases were newly diagnosed eGBM and five cases had a previous history of astrocytomas. Most of the tumors were located in the cerebral hemisphere, often in the frontal lobe, with an average diameter of 4.6 cm (2.0-8.0 cm). The tumors were composed of relatively uniform, closely packed epithelioid cells, some showing discohesion, with distinct cell membrane, eosinophilic cytoplasm, eccentric nuclei, distinct nucleoli and mitotic activity. Palisaded/coagulative necrosis was seen in all cases. Glomerular microvascular proliferation was seen in most of the cases, while mono-or multi-nucleated tumor giant cells were seen in some cases. Focal sarcomatoid area was seen in 2 cases, and focal pleomorphic xanthoastrocytoma (PXA)-like area was seen in 3 cases. Immunohistochemistry showed variable positivity for GFAP, Olig2 and p53. The median Ki-67 index was 30% (10%-50%). Only one case lost ATRX protein expression. Sanger sequencing identified the BRAF V600E mutation in all sixteen patients. Five cases also had mutations in the TERT gene promoter. No IDH1 (R132) or IDH2 (R172) mutation was detected. Surgical resection of the tumors was performed for all patients, and 3 patients also received adjuvant radiotherapy and chemotherapy. Follow-up data were available for 15 patients, with a follow-up time of 1-89 months (median 10 months). Among the 15 patients, 7 patients died of disease and another 5 patients had recurrences. The overall survival time of the patients under 35 years of age was significantly longer than that of the patients aged 35 years or older (P=0.014), but their progression-free survival was not statistically different (P=0.232). Conclusions: eGBM with BRAF V600E mutation is more commonly detected in young women than other the populations (i.e. elderly or male). The epithelioid morphology should include rhabdoid meningioma, anaplastic PXA, atypical teratoid/rhabdoid tumor, metastatic tumors, and melanoma in its differential diagnosis. PXA-like area is observed in some eGBM cases, suggesting a relationship of these two types of tumor. eGBM is a high-grade malignant tumor and most of the cases show recurrences or deaths in a short-period time. The younger patients have a relatively better prognosis than the older ones.

Histopathological Changes in the Kidney of Albino Rat due to Chromium and the Ameliorative Role of α-Tocopherol

Introduction: Potassium dichromate, a chromium {Cr(VI)} compound is the most toxic form of Cr(VI) which causes nephrotoxicity associated with oxidative stress in animals and humans. The study of toxicity and biological effects associated with chromium has generated a lot of interest due to its wider distribution in the environment and its use. Aim: To study the potassium dichromate-induced nephrotoxicity and ameliorative role of vitamin E in albino rats. Materials and Methods: The present experimental study was conducted in the Department of Anatomy, Subharti Medical College, Meerut, Uttar Pradesh, India. Study population consisted of 36 albino rats which were randomly divided into four equal groups (n=9, each). Group I served as control while groups II and III were administered Potassium dichromate (K2Cr2O7) dissolved in sterile distilled water 10 mg/kg body weight single dose orally for 1, 14 and 42 days, 3 rats in each sub-groups. In addition to Cr(VI), group III also received α-tocopherol 125 mg/kg body weight daily orally. Group IV rats were maintained as α-tocopherol control and they received α-tocopherol as above daily for 42 days. At the end of 1, 14 and 42 days, all the rats were sacrificed for the estimation of the histopathological changes in kidney. The Z-proportion test was used for evaluation of data. Results: Thirt-six albino rats of both sex, age about 60 days weighing approximately 140±10 gm were studied. Prominent pathological changes like glomerular mesangial proliferation and obliteration of bowman’s space were observed in the kidney of group II rats. Co-treatment with α-tocopherol in group III significantly reversed the Cr(VI) induced changes with a p-value=0.009 and 0.007 for glomerular mesangial proliferation and obliteration of bowman’s space respectively. Conclusion: The α-tocopherol exhibited protective effect against Cr(VI) induced damage to the kidney.

Histopathological changes of kidney tissue during aging

Kidney aging is a normal physiological process associates with various molecular, morphologic and functional changes in the kidney tissues. This work was designed to study microscopically the structural changes in the kidney tissue of aged rats compared to young rats. Male Sprague–Dawley rats were used 10 young rats (4 months) and 10 aged rats (24 months). Rats were transcardially perfused with 4% paraformaldehyde. The kidneys were post fixed for 24 hours in 4 % PFA then proceeded for normal histopathology and light microscopic examination. Kidney tissue of aged rats showed serious morphological changes such as; segmental glomerulosclerosis, pericapsular fibrosis, tubulointerstitial fibrosis, perivascular fibrosis, inflammatory cell infiltration, tubular dilatation, intra-tubular cast formation and tubular atrophy. These changes were compared to the normal histological appearance of glomeruli, tubules, interstitium, blood vessels of young rat kidneys. In addition, the kidney tissue of the aged rats showed compensatory glomerular hypertrophy, tubular hyperplasia and endothelial proliferation. Renal aging involves several degenerative changes in kidney structure and these alterations interfere with the physiologic functions and end with chronic renal failure.

Tetrandrine may treat membranous glomerulopathy via P13K/Akt signaling pathway regulation: therapeutic mechanism validation using Heymann nephritis rat model

ABSTRACT Membranous glomerulopathy (MGN) is an autoimmune kidney disease that is the primary cause of nephrotic syndrome (NS) in adults. Tetrandrine, a bisbenzylisoquinoline alkaloid, is known to have numerous pharmacological effects. In this study, network pharmacology analysis and experimental validation were conducted to analyze the mechanisms by which tetrandrine functions as a therapeutic intervention for MGN. A systematic network pharmacology method was applied to identify potential targets and determine the therapeutic mechanism of tetrandrine in MGN treatment. A Heymann nephritis (HN) rat model was developed to assess the therapeutic effects of tetrandrine on NS and validate the predicted molecular mechanisms. We obtained 86 potential targets of tetrandrine for the treatment of NS. In vivo experiments showed that tetrandrine could reduce the 24-h urine protein content, decrease glomerular basement membrane proliferation, and significantly decrease thylakoid stroma and cell proliferation in the HN rat kidney tissue. Moreover, tetrandrine suppressed kidney cell apoptosis and upregulated the expression of nephrin and podocin in HN model rats. qRT-PCR results revealed that tetrandrine inhibited IL-1β, TNFα, and MCP-1 levels in HN model rats. Western blot results indicated that tetrandrine can protect against MGN via the PI3K/Akt signaling pathway. Thus, by using a combination of network and experimental pharmacology methods, we demonstrate that tetrandrine can treat MGN via the PI3K/Akt signaling pathway and provide novel insights into the mechanisms underlying tetrandrine-mediated management of MGN.