A child with crescentic glomerulonephritis following SARS-CoV-2 mRNA (Pfizer-BioNTech) vaccination.

BACKGROUND: There are few reports on kidney complications after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccination, especially in the pediatric population. We report a pediatric case diagnosed with crescentic glomerulonephritis (CrGN) after the second dose of the SARS-CoV-2 mRNA vaccine. CASE-DIAGNOSIS/TREATMENT: A 16-year-old girl was admitted due to dyspnea and headache approximately 6 weeks after receiving the second SARS-CoV-2 mRNA vaccine (Pfizer-BioNTech). She had previously experienced fever, nausea, vomiting, and dyspnea after the first vaccination, which persisted for a week. On admission, her blood pressure was 155/89 mmHg with a 7 kg weight gain in a month. She had microhematuria and proteinuria. Laboratory findings were as follows: blood urea nitrogen/creatinine, 66/9.57 mg/dL; and brain natriuretic peptide, 1,167 pg/mL. Anti-neutrophil cytoplasmic antibody (ANCA), anti-glomerular basement membrane (GBM) antibody, and antinuclear antibody findings were negative. Kidney doppler sonography revealed swelling and increased echogenicity of both kidneys with increased resistive index. Cardiac magnetic resonance imaging results showed early minimal fibrosis of myocarditis. We then started hemodialysis. Kidney biopsy showed diffuse extra capillary proliferative glomerulonephritis with diffuse crescent formation. We treated the patient with methylprednisolone pulse therapy with subsequent oral steroids and mycophenolate mofetil. Although dialysis was terminated, the patient remained in the chronic kidney disease stage. CONCLUSIONS: This is the first case of ANCA-negative CrGN after SARS-CoV-2 mRNA vaccination in the pediatric population. As children are increasingly vaccinated with SARS-CoV-2 mRNA vaccines, monitoring for kidney complications is warranted.

Membranoproliferative glomerulonephritis after intravitreal vascular growth factor inhibitor injections: A case report and review of the literature.

Systemic administration of agents that inhibit vascular endothelial growth factor (VEGF) and therefore vascular proliferation is often used to treat various cancers. However, these agents are associated with a number of side effects, including proteinuria and renal injury. Intravitreal injection of anti-VEGF agents has become the cornerstone of macular disease treatment. Since these agents cross the blood-retina barrier and enter the circulation, systemic side effects have been reported. We report the novel case of a 57-year-old patient who presented with macular oedema secondary to central retinal vein occlusion, underwent three monthly loading-dose injections with the anti-VEGF agent ranibizumab, and 2 weeks after the second injection presented with biopsy-verified membranoproliferative glomerulonephritis. Twelve weeks after presenting with renal failure and 10 weeks after his last anti-VEGF injection, the patient demonstrated spontaneous recovery of his kidney function. The patient had a history that promoted renal fragility, including hypertension, liver transplantation 6 years earlier for alcohol-related cirrhosis and new-onset diabetes mellitus after transplant. Our literature review and case suggest that although adverse renal events after intravitreal anti-VEGF injections are very rare, ophthalmologists and nephrologists should be aware of this risk.

Membranoproliferative Glomerulonephritis Type I Associated with Intravenous Immunoglobulin Administration Arising in a Child with X-Linked Agammaglobulinemia: A Case Report and a Reappraisal.

In 1952, X-linked agammaglobulinemia (XLA) was discovered as a rare inherited disorder. It markedly compromises the ability of the body to combat infectious microorganisms. Membranoproliferative glomerulonephritis (MPGN) Type I is characterized by subendothelial immune complex deposits. Patients with XLA can rarely develop immune-complex-induced diseases. Here, we report a case of MPGN Type I in a 12-year-old male patient with a past and family history of XLA. The patient presented with fever, productive cough, vomiting, and lower limb edema. Clinical and radiological examinations established a diagnosis of bronchopneumonia. The laboratory findings revealed proteinuria and hematuria, and a renal biopsy was performed. The histological examination of this biopsy revealed mesangial hypercellularity and thickened basement membranes. Immunofluorescence studies showed mesangiocapillary staining for Complement 3 and Immunoglobulin (Ig) G and, to a lesser extent, for IgA, IgM, and Complement 1q. Ultrastructural studies revealed partly thick, double-contoured glomerular basement membranes, glomerular endothelial cells with swollen cell bodies, and podocytes with effaced foot processes. Small subendothelial and mesangial eosinophilic deposits were identified. The diagnosis of MPGN type I was established. The patient was started on prednisolone. To the best of our knowledge, this is a rare case of MPGN Type I in a patient with XLA. The pathogenetic mechanisms underlying the development of MPGN Type I were not apparent in our patient. However, residual humoral immunity may play a role in the development of MPGN.

A case report of pre-eclampsia-like endothelial injury in the kidney of an 85-year-old man treated with ibrutinib.

BACKGROUND: Glomerular endotheliosis is the pathognomonic glomerular lesion in pre-eclampsia that has also been described in those taking tyrosine kinase inhibitors for cancer treatment. Ibrutinib is a Bruton's tyrosine kinase inhibitor used to treat chronic lymphocytic leukemia (CLL). We report the first known case of glomerular endotheliosis on kidney biopsy in a patient on ibrutinib monotherapy. CASE PRESENTATION: The patient presented with acute on chronic kidney disease, proteinuria, low C3 and C4 and a high rheumatoid factor titer. A kidney biopsy was performed to confirm a preliminary diagnosis of membranoproliferative glomerulonephritis (MPGN), the most common glomerular disease in patients with CLL. Unexpectedly, the kidney biopsy showed pre-eclampsia-like lesions on light and electron microscopy: occlusion of glomerular peripheral capillary lumens by swollen reactive endothelial cells. Findings of glomerulonephritis were not seen, and there were no specific glomerular immune deposits by immunofluorescence or electron microscopy. CONCLUSIONS: CLL is known to cause glomerular lesions, mainly MPGN. There is increasing evidence that ibrutinib, a major treatment for CLL, can cause kidney disease, but the precise pathology is not characterized. We present a patient with CLL on ibrutinib with signs of glomerular endotheliosis. Based on the absence of CLL-induced kidney pathologies typically seen on the kidney biopsy and the non-selectivity of ibrutinib, we attributed the glomerular endotheliosis to ibrutinib. In pre-eclampsia, increased soluble fms-like tyrosine kinase 1 (sFlt1) levels induce endothelial dysfunction by decreasing vascular endothelial growth factor (VEGF). Ibrutinib has been demonstrated to have non-selective tyrosine kinase inhibition, including inhibition of VEGF receptor (VEGFR) and epidermal growth factor receptor (EGFR). VEGFR and EGFR inhibitors have recently been described in the literature to cause hypertension, proteinuria, and glomerular endotheliosis. Kidney biopsy should be performed in CLL patients on ibrutinib that present with acute kidney injury (AKI) or proteinuria to determine whether the clinical picture is attributable to the disease itself or a complication of the therapy.

Tocilizumab-induced immunocomplex glomerulonephritis: a report of two cases.

We report here two cases of membranoproliferative glomerulonephritis that developed during treatment of rheumatoid arthritis with tocilizumab. In both cases, the initial findings were proteinuria and haematuria, followed by development of bilateral lower leg oedema. One of the patients was weakly positive for anti-nuclear antibody; both had hypocomplementaemia. The patients' renal impairment gradually resolved with discontinuation of tocilizumab followed by treatment with moderate doses of oral prednisolone. Pathological examination of renal biopsies resulted in diagnoses of immunocomplex glomerulonephritis and immunofluorescence staining revealed depositions of IgG, IgA, and IgM, accompanied by C3. Tocilizumab rarely induces autoimmune disorders; therefore, the underlying mechanism is unknown. One patient with immunocomplex glomerulonephritis that may have been associated with tocilizumab therapy for rheumatoid arthritis has been reported previously; that patient and our two are similar in their clinical courses and pathological findings. We conclude that such glomerulonephritis can occur during tocilizumab treatment, but this is rare. Clinicians should be aware of the possibility of paradoxical development of autoimmune diseases during tocilizumab therapy.

Bevacizumab-associated glomerular microangiopathy.

Bevacizumab is a humanized monoclonal IgG1 antibody, which neutralizes vascular endothelial growth factor and is used for treating multiple cancer types. As a known and frequent adverse event, this therapy can lead to renal damage including proteinuria and nephrotic syndrome. In a retrospective approach, we analyzed 17 renal biopsies from patients receiving bevacizumab treatment. We observed a distinctive histopathological pseudothrombotic pattern different from the previously reported thrombotic microangiopathy. Since this pattern includes some features similar to acute and chronic thrombotic microangiopathy, focal segmental glomerulosclerosis and cryoglobulinemic membranoproliferative glomerulonephritis, biopsies with these diagnoses were included for comparison. Clinical, laboratory, light microscopic, immunohistochemical (including a proximity ligation assay), proteomic and electron microscopic features were assessed. Nephrotic syndrome was present in 15 of the 17 bevacizumab-treated patients. All 17 displayed a patchy pattern of variably PAS-positive hyaline pseudothrombi occluding markedly dilated glomerular capillaries in their biopsies. Mass spectrometry-based proteome analysis revealed a special protein pattern demonstrating some features of thrombotic microangiopathy and some of cryoglobulinemic glomerulonephritis, including a strong accumulation of IgG in the pseudothrombi. Proximity ligation assay did not show interaction of IgG with C1q, arguing for accumulation without classic pathway complement activation. In contrast to thrombi in thrombotic microangiopathy cases, the hyaline pseudothrombi did not contain clusters of CD61-positive platelets. Electron microscopy of bevacizumab cases did not show fibrin polymers or extensive loss of podocyte foot processes. Even though cases of bevacizumab-associated microangiopathy share some features with thrombotic microangiopathy, its overall histopathological pattern is quite different from acute or chronic thrombotic microangiopathy cases. We conclude that bevacizumab therapy can lead to a unique hyaline occlusive glomerular microangiopathy, likely arising from endothelial leakage followed by subendothelial accumulation of serum proteins. It can be diagnosed by light microscopy and is an important differential diagnosis in cancer patients with nephrotic syndrome.

Filgrastim-Induced Crescentic Transformation of Recurrent IgG2λ GN.

Proliferative GN with monoclonal IgG deposits is an increasingly recognized form of GN, but its relation to hematologic malignancy remains poorly understood. Filgrastim, an analog for granulocyte colony-stimulating factor produced by recombinant DNA technology, is frequently used to stimulate bone marrow release of hematopoietic progenitor cells in preparation for stem cell transplant. We report an exceptional case of proliferative GN with monoclonal IgG2λ deposits in a young man whose disease progressed slowly to CKD, which was followed by a preemptive kidney transplant. The patient developed recurrent GN in the allograft and clinically detectable plasma cell neoplasm 9 years after the first renal manifestations. Contemporaneous with filgrastim administration for stem cell mobilization, the patient's slowly progressive GN underwent severe crescentic transformation, leading to rapidly progressive and irreversible allograft failure. This report explores the spectrum of GN with monoclonal IgG deposits and the pathophysiologic role of granulocyte colony-stimulating factor in exacerbation of preexisting GN.

Tyrosine kinases inhibition by Imatinib slows progression in chronic anti-thy1 glomerulosclerosis of the rat.

BACKGROUND: Chronic progressive mesangioproliferative nephropathy represents a major cause of end-stage renal disease worldwide. Until now, effective approaches to stop or even slow its progression are limited. We tested the effects of an inhibitor of PDGF receptor, abl and c-kit tyrosine kinases, Imatinib, in a chronic progressive model of mesangioproliferative glomerulosclerosis. METHODS: Anti-thy1 glomerulosclerosis was induced by injection of anti-thy1 antibody into uninephrectomized Wistar rats. One week after disease induction, according to the degree of proteinuria, animals were stratified and assigned to chronic glomerulosclerosis (cGS) and cGS plus Imatinib (10 mg/kg body weight/day). In week 20, renoprotective actions of Imatinib were analyzed by a set of functional, histological and molecular biological parameters. RESULTS: Untreated cGS rats showed elevation of systolic blood pressure and marked progression in proteinuria, renal fibrosis, cell infiltration, cell proliferation and function lost. Administration of Imatinib went along significantly with lower systolic blood pressure (-10 mmHg) and proteinuria (-33%). Imatinib administration was paralled by significant reductions in tubulointerstitial accumulation of matrix proteins (-44%), collagen I deposition (-86%), expression of TGF-beta1 (-30%), production of fibronectin (-23%), myofibroblast differentiation (-87%), macrophage infiltration (-36%) and cell proliferation (-45%), respectively. In comparison with untreated cGS animals, Imatinib therapy lowered also blood creatinine (-41%) and blood urea concentrations (-36%) and improved creatinine clearance (+25%). Glomerular fibrotic changes were lowered moderately by Imatinib. CONCLUSIONS: Therapy with Imatinib limits the progressive course of chronic anti-thy1 glomerulosclerosis towards tubulointerstitial fibrosis and renal insufficiency. This was paralleled by direct and indirect sign of TGF-ß1 and PDGF inhibition. The findings suggest that the pharmacological principal of inhibition of tyrosine kinases with drugs such as Imatinib might serve as approach for limiting progression of human mesangioproliferative glomerulosclerosis.

Aldosterone mediates glomerular inflammation in experimental mesangial proliferative glomerulonephritis.

BACKGROUND: The renoprotection of the mineralocorticoid receptor antagonist (MRA) is considered to be mainly via its antifibrotic activity, and the possibility that it may also have antiinflammatory effects has not been studied. We tested the hypothesis that MRA might influence the inflammatory changes that accompany experimental glomerular injury. METHODS: Administration of vehicle (control) or a selective MRA, eplerenone (50 mg/kg x 2 times/day) was started 7 days (-7d) before induction of anti-Thy-1.1 glomerulonephritis. Kidney samples were evaluated serially over a 12-day period for the presence of cell proliferation, macrophage infiltration, mesangial cell phenotypic activation and expression of the chemokine monocyte chemoattractant protein-1 (MCP-1). RESULTS: MRA did not prevent the mesangiolysis associated with anti-Thy-1 antibody. However, MRA significantly inhibited MCP-1 expression, glomerular macrophage infiltration and mesangial phenotypic activation (alpha-smooth muscle actin expression). CONCLUSION: MRA alters glomerular inflammation and mesangial cell activation in experimental glomerular injury. MRA may be a novel way to treat acute glomerular diseases.

Sublytic C5b-9 complexes induce apoptosis of glomerular mesangial cells in rats with Thy-1 nephritis through role of interferon regulatory factor-1-dependent caspase 8 activation.

The apoptosis of glomerular mesangial cells (GMC) in rat Thy-1 nephritis (Thy-1N), a model of human mesangioproliferative glomerulonephritis, is accompanied by sublytic C5b-9 deposition, but the mechanism of sublytic C5b-9-mediated GMC apoptosis has not been elucidated. In the present study, the gene expression profiles both in the GMC stimulated by sublytic C5b-9 and the rat renal tissue of Thy-1N were detected using microarrays. Among the co-up-regulated genes, the up-regulation of interferon regulatory factor-1 (IRF-1) was further confirmed. Increased caspase 8 and caspase 3 expression and caspase 8 promoter activity in the GMC were also identified. Meanwhile, overexpression or knockdown of IRF-1 not only enhanced or inhibited GMC apoptosis and caspase 8 and 3 induction but also increased or decreased caspase 8 promoter activity, respectively. The element of IRF-1 binding to the caspase 8 promoter was first revealed. Furthermore, silencing IRF-1 or repressing the activation of caspases 8 and 3 significantly reduced GMC apoptosis, including other pathologic changes of Thy-1N. These novel findings indicate that GMC apoptosis of Thy-1N is associated with the IRF-1-activated caspase 8 pathway.

Single application of low-dose mycophenolate mofetil-OX7-immunoliposomes ameliorates experimental mesangial proliferative glomerulonephritis.

IgA nephropathy, one of the most frequent forms of glomerulonephritis, characterized by mesangial hypercellularity and glomerular extracellular matrix (ECM) expansion, often leads to end-stage renal disease over a prolonged period. We investigated whether antiproliferative treatment in a single low dose specifically targeted to the glomerular mesangium by immunoliposomes (ILs) results in an amelioration of mesangial proliferative glomerulonephritis in rats (anti-Thy1.1 nephritis). Mycophenolate mofetil (MMF) containing ILs was generated that targets the Thy1.1 antigen (OX-7) in rat mesangial cells. Treatment benefit of a single intravenous dose of these ILs given 2 days after disease induction was investigated by stereology, immunohistochemistry, and functional analyses (creatinine, albuminuria) until day +9 and was compared among untreated and free MMF-treated rats using six male Wistar rats per group. MMF-loaded OX7-IL prevented creatinine increase and albuminuria. Stereological analyses of MMF OX7-IL-treated animals yielded 30% reduction of mesangial cells on day +9 and a 40% reduction of glomerular ECM volume on day +5, compared with all of the other nephritic animals. Furthermore, at days +5 and +9 we observed decreased ECM content and decreased glomerular volume (day +5) in the MMF-OX7-IL-treated group compared with the nephritic group treated with free MMF. In conclusion, MMF-OX7-IL-based directed drug delivery represents a novel approach for treating mesangial cell-mediated forms of glomerulonephritis.

Membranoproliferative glomerulonephritis possibly associated with over-vaccination in a cocker spaniel.

Membranoproliferative glomerulonephritis was observed in a seven-month-old male cocker spaniel dog. The clinical, microbiological, biochemical, radiographic and ultrasonographic examinations ruled out neoplasia, congenital disease and infectious disease. The anamnesis revealed that the owner had vaccinated the dog seven times, one vaccination per month, without veterinarian supervision. In both kidneys, severe thickening of the glomerular capillary walls was observed. Electron microscope examination revealed a large number of electron-dense deposits that were primarily in the glomerular subendothelial spaces and the basal membrane, which is compatible with antigen-antibody complexes. The immunohistochemical examination revealed that the antigen present in the glomeruli corresponded with the antigen present in the vaccine. We report a type III hypersensitivity nephropathy in a young dog, which was possibly caused by over-vaccination.

Trophoblast glycoprotein: possible candidate mediating podocyte injuries in glomerulonephritis.

BACKGROUND: trophoblast glycoprotein (Tpbg), a 72-kDa transmembrane glycoprotein, is known to regulate the phenotypes of epithelial cells by modifying actin organization and cell motility. Recently, a microarray study showed that Tpbg is upregulated in Thy1 glomerulonephritis (Thy1 GN). We hypothesized that Tpbg regulates cytoskeletal rearrangement and modulates phenotypic alteration in podocytes under pathological conditions. METHODS: we examined Tpbg expression in Thy1 GN and Tpbg function in mouse podocytes. RESULTS: we demonstrated that Tpbg is upregulated in the injured podocytes of Thy1 GN. In vitro, immunofluorescence studies revealed that Tpbg colocalized with the focal adhesion protein, vinculin, in parallel with stress fiber formation. This colocalization was observed even when actin filaments were depolymerized with cytochalasin D. Tpbg localization at focal adhesions was induced by dominant-active RhoA and suppressed by the ROCK1 inhibitor Y-26732. In addition, transforming growth factor-ß increased Tpbg expression at focal adhesions concurrently with rearrangement of stress fibers. Stress fiber formation was suppressed in differentiated podocytes transfected with full-length Tpbg. Furthermore, knockdown of Tpbg using small interfering RNA decreased podocyte motility. CONCLUSION: our findings suggest a novel role of Tpbg in the phenotypic alteration of injured podocytes, and we accordingly propose a new mechanism of glomerular injury in glomerulonephritis.

Endothelin signaling via guanine exchange factor C3G in renal glomerular mesangial cells.

The guanine nucleotide exchange factor C3G is one of the mediators of endothelin-1 (ET-1) intracellular signaling cascades and is vital for kidney development and homeostasis. The aim of the current study was to analyze the specificity of ET-1-induced signaling via C3G in rat glomerular mesangial cells (GMC) and to investigate the biological significance of C3G during mesangioproliferative glomerulonephritis. In GMC, C3G expression was increased (1) in vivo after induction of the anti-Thy1 model of glomerulonephritis and (2) in cell culture experiments after fetal bovine serum incubation. To examine the consequences of C3G up-regulation, adenovirus-mediated gene transfer of C3G into cultured glomerular cells was done, and the GTP loading of the small G proteins Rap1 and R-Ras was analyzed. Overexpression of C3G in mesangial cells resulted in enhanced activation of Rap1, but failed to affect the GTP-bound status of R-Ras in ET-1-stimulated cells. C3G overexpression led to significant changes in GMC spreading and migration patterns in response to ET-1 stimulation and increased stress fiber formation, which was mimicked by Rap1A overexpression. Together, these findings suggest (1) the existence of regulatory mechanisms resulting in disease-related up-regulation of C3G in GMC and (2) that an increase in the C3G protein level may contribute to the resolution stage of mesangioproliferative glomerulonephritis by reducing GMC sensitivity to ET-1, modulating cellular motility, and actin dynamics.

Effect of the absence of interleukin-12 on mesangial proliferative glomerulonephritis induced by habu snake venom.

BACKGROUND: Interleukin-12 (IL12) participates in the pathophysiology of various experimental types of progressive glomerulonephritis, but its role in acute mesangial glomerulonephritis (AMG) induced by habu snake venom (HSV) has not been determined. This study aims to evaluate the effect of the absence of IL12 on AMG induced by HSV. METHODS: AMG was induced in IL12 knockout (IL12-/-) and C57Bl/6 (IL12+/+) mice by a single i.v. administration of HSV. Vehicle was used in control animals. Mice were studied after 3, 7, and 14 days (D3, D7, and D14). RESULTS: After treatment with HSV, IL12+/+ and -/- mice developed focal glomerular lesions, but groups of both lineages showed no statistical difference concerning albuminuria, serum creatinine, histopathology, number of cells by glomerular tuft, and glomerular tuft area. Compared to IL12+/+ mice, IL12-/- mice showed lower scores of glomerular desmin expression on D7 [1.55 (1.32; 1.65) vs. 1.12 (1.07; 1.22); p < 0.01] and D14 [1.60 (1.55; 1.75) vs. 1.20 (1.15; 1.20); p < 0.001], respectively, and lower scores of glomerular alpha-SMA expression on D14 [0.30 (0.21; 0.38) vs. 0.16 (0.26; 0.36); p < 0.001], respectively. CONCLUSION: The absence of IL12 reduced the activity of mesangial cells, but did not modify the course of HSV-induced AMG in mice.

Lipopolysaccharide-triggered acute aggravation of mesangioproliferative glomerulonephritis through activation of coagulation in a high IgA strain of ddY mice.

BACKGROUND: The high IgA (HIGA) strain of ddY mice represents an inbred model of IgA nephropathy that shows mesangioproliferative glomerulonephritis with mesangial IgA deposition. In this study, aggravation of glomerulonephritis in HIGA mice through lipopolysaccharide (LPS)-triggered activation of coagulation was investigated. METHODS: Twelve-week-old HIGA and BALB/c mice were intraperitoneally injected with LPS twice at an interval of 3 days, and kidney specimens were collected 7 days after the second LPS injection. In an intervention experiment, the factor Xa inhibitor danaparoid was injected intraperitoneally every day for 7 days after the first LPS injection. RESULTS: LPS injection induced macrophage infiltration and cellular proliferation in the mesangium together with fibrin deposition and monocyte chemoattractant protein 1 mRNA expression, as well as antigen deposition of tissue factor, factor V, factor X, and protease-activated receptor 2. These phenomena were obvious in HIGA mice when compared to BALB/c mice. Interestingly, toll-like receptor 4 was intensely expressed in HIGA mice before LPS injection and subsequently decreased. Danaparoid treatment significantly ameliorated proteinuria, cellular proliferation, and fibrin deposition. CONCLUSIONS: The present data suggest that tissue factor and factor V induction by LPS may in part accelerate mesangioproliferative glomerulonephritis through activation of factor X and downstream proinflammatory and procoagulant mechanisms.

The novel NF-kappaB activation inhibitor dehydroxymethyl-epoxyquinomicin suppresses anti-Thy1.1-induced glomerulonephritis in rats.

BACKGROUND: NF-kappaB participates in the transcriptional regulation of numerous genes, and many studies have confirmed the activation of NF-kappaB in inflammatory renal diseases. Therefore, NF-kappaB is a promising target for the treatment of these diseases. We tested the effects of dehydroxymethyl-epoxyquinomicin (DHMEQ), a novel NF-kappaB activation inhibitor, on anti-thy1.1 antibody-induced glomerulonephritis (Thy1.1 GN). METHODS: Thy1.1 GN was induced in Sprague-Dawley rats (6/group) by intravenous injection of anti-thy 1.1 antibody. The effects of DHMEQ (8 mg/kg/day) on the glomerular disease were evaluated using periodic acid-Schiff and Masson trichrome stains, immunohistochemistry for proliferating cell nuclear antigen, fibronectin and CD45 (leukocyte common antigen) and TUNEL staining. NF-kappaB activation was analyzed by a fluorescent electrophoretic mobility shift assay. RESULTS: On day 7, DHMEQ treatment resulted in marked inhibition of NF-kappaB, decreased proteinuria (223.2 +/- 42.3 vs. 434.8 +/- 16.5 mg/kg/day, p < 0.05), preserved creatinine clearance (1.93 +/- 0.38 vs. 1.07 +/- 0.29 l/day, p < 0.01), decreased glomerular cell proliferation (15.8 +/- 1.2 vs. 31.2 +/- 0.8 nuclei/glomerular cross-section) and mesangial matrix deposition, and an increase in glomerular and tubular apoptosis without inducing any obvious adverse effects. CONCLUSION: DHMEQ inhibited NF-kappaB and thereby suppressed the inflammatory renal responses in rats with Thy1.1 GN.

Preconditioning with endoplasmic reticulum stress ameliorates mesangioproliferative glomerulonephritis.

Accumulating evidence suggests a pathophysiologic role of endoplasmic reticulum (ER) stress in kidney disease. This study investigated the potential of therapeutic approaches targeting ER stress in the anti-Thy1 model of mesangioproliferative glomerulonephritis in rats. Immunohistochemistry and Western blotting showed a time-dependent increase in the expression of the ER stress-inducible chaperones glucose-regulated protein 78 (GRP78) and oxygen-related protein 150 in isolated glomeruli, especially in the glomerular epithelial cells and mesangial cells, after induction of anti-Thy1 nephritis. For evaluation of whether preconditioning with ER stress ameliorates the severity of disease, rats were pretreated with a subnephritogenic dose of the ER stress inducer tunicamycin or thapsigargin for 4 d before disease was induced. Although preconditioning with ER stress had no effect on the degree of disease induction, it strongly ameliorated the manifestations of disease, evidenced by marked reductions in microaneurysm formation, mesangial proliferation, and adhesion of Bowman's capsule to the glomerular tuft. This improvement in histologic damage was associated with reduced proteinuria (39.4 +/- 10.5 versus 126.1 +/- 18.1 mg/d; P < 0.01) and with attenuated increases in glucose-regulated protein 78 and oxygen-related protein 150 expression. Of note, pretreatment with tunicamycin or thapsigargin decreased the excessive ER stress-induced intracellular signaling observed in anti-Thy1 nephritis. In conclusion, preconditioning with ER stress ameliorates the severity of disease in rats with anti-Thy1 nephritis. These findings suggest the possibility of therapeutic approaches targeting ER stress in mesangioproliferative glomerulonephritis.