scholarly journals Experimental membranous nephropathy redux

2005 ◽  
Vol 289 (4) ◽  
pp. F660-F671 ◽  
Author(s):  
Andrey V. Cybulsky ◽  
Richard J. Quigg ◽  
David J. Salant
Keyword(s):  
Signaling Pathways ◽  
Complement Activation ◽  
Membranous Nephropathy ◽  
Plasma Membranes ◽  
Stress Proteins ◽  
Experimental Models ◽  
Slit Diaphragm ◽  
Glomerular Epithelial Cell ◽  
Substantial Progress ◽  
Key Steps

Membranous nephropathy (MN) is a common cause of nephrotic syndrome in adults. Active and passive Heymann nephritis (HN) in rats are valuable experimental models because their features so closely resemble human MN. In HN, subepithelial immune deposits form in situ as a result of circulating antibodies. Complement activation leads to assembly of C5b-9 on glomerular epithelial cell (GEC) plasma membranes and is essential for sublethal GEC injury and the onset of proteinuria. This review revisits HN and focuses on areas of substantial progress in recent years. The response of the GEC to sublethal C5b-9 attack is not simply due to disruption of the plasma membrane but is due to the activation of specific signaling pathways. These include activation of protein kinases, phospholipases, cyclooxygenases, transcription factors, growth factors, NADPH oxidase, stress proteins, proteinases, and others. Ultimately, these signals impact on cell metabolic pathways and the structure/function of lipids and key proteins in the cytoskeleton and slit-diaphragm. Some signals affect GEC adversely. Thus C5b-9 induces partial dissolution of the actin cytoskeleton. There is a decline in nephrin expression, reduction in F-actin-bound nephrin, and loss of slit-diaphragm integrity. Other signals, such as endoplasmic reticulum stress, may limit complement-induced injury, or promote recovery. The extent of complement activation and GEC injury is dependent, in part, on complement-regulatory proteins, which act at early or late steps within the complement cascade. Identification of key steps in complement activation, the cellular signaling pathways, and the targets will facilitate therapeutic intervention in reversing GEC injury in human MN.

scholarly journals Advances in Membranous Nephropathy

2021 ◽  
Vol 10 (4) ◽  
pp. 607
Author(s):  
Pierre Ronco ◽  
Emmanuelle Plaisier ◽  
Hanna Debiec
Keyword(s):  
Membranous Nephropathy ◽  
Calcineurin Inhibitor ◽  
Sequential Therapy ◽  
Randomized Controlled ◽  
Therapeutic Algorithms ◽  
Long Time ◽  
Substantial Progress ◽  
Thrombotic Complications ◽  
Mixed Classes ◽  
End Stage

Membranous nephropathy (MN) is a rare auto-immune disease where the glomerulus is targeted by circulating auto-antibodies mostly against podocyte antigens, which results in the formation of electron-dense immune complexes, activation of complement and massive proteinuria. MN is the most common cause of nephrotic syndrome in adults leading to severe thrombotic complications and kidney failure. This review is focused on the recent therapeutic and pathophysiological advances that occurred in the last two years. For a long time, we were lacking a head-to-head comparison between cyclophosphamide considered as the gold standard therapy and other medications, notably rituximab. Substantial progress has been achieved owing to three randomized controlled trials. MENTOR (Membranous Nephropathy Trial of Rituximab) and STARMEN (Sequential Therapy with Tacrolimus and Rituximab in Primary Membranous Nephropathy) conclusively established that calcineurin inhibitor-based regimens are slower to result in an immunologic response than rituximab or cyclophosphamide, achieve fewer complete clinical remissions, and are less likely to maintainremission. Rituximab Versus Steroids and Cyclophosphamide in the Treatment of Idiopathic Membranous Nephropathy (RI-CYCLO) suggested that competition between cyclophosphamide and rituximab remains open. Given the technological leap combining laser microdissection of glomeruli and mass spectrometry of solubilized digested proteins, four “new antigens” were discovered including NELL-1 and Semaphorin 3B in so-called primary MN, and exostosins 1 and 2 and NCAM 1 in lupus MN. NELL-1 is associated with about 8% of primary MN and is characterized by segmental immune deposits and frequent association with cancer (30%). Semaphorin 3B-associated MN usually occurs in children, often below the age of two years, where it is the main antigen, representing about 16% of non-lupus MN in childhood. Exostosins 1/2 and NCAM 1 are associated with 30% and 6% of lupus MN, respectively. Exostosins 1/2 (EXT1/2) staining is associated with a low rate of end-stage kidney disease (ESKD) even in mixed classes III/IV+V. These findings already lead to revisiting the diagnostic and therapeutic algorithms toward more personalized medicine.

scholarly journals MicroRNA-Assisted Hormone Cell Signaling in Colorectal Cancer Resistance

Cells ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 39
Author(s):  
Crescenzo Massaro ◽  
Elham Safadeh ◽  
Giulia Sgueglia ◽  
Hendrik G. Stunnenberg ◽  
Lucia Altucci ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Drug Resistance ◽  
Signaling Pathways ◽  
Cancer Progression ◽  
Therapy Resistance ◽  
Disease Recurrence ◽  
Hormone Signaling ◽  
Cancer Resistance ◽  
Comprehensive Overview ◽  
Substantial Progress

Despite substantial progress in cancer therapy, colorectal cancer (CRC) is still the third leading cause of cancer death worldwide, mainly due to the acquisition of resistance and disease recurrence in patients. Growing evidence indicates that deregulation of hormone signaling pathways and their cross-talk with other signaling cascades inside CRC cells may have an impact on therapy resistance. MicroRNAs (miRNAs) are small conserved non-coding RNAs thatfunction as negative regulators in many gene expression processes. Key studies have identified miRNA alterations in cancer progression and drug resistance. In this review, we provide a comprehensive overview and assessment of miRNAs role in hormone signaling pathways in CRC drug resistance and their potential as future targets for overcoming resistance to treatment.

scholarly journals The Landscape of Signaling Pathways and Proteasome Inhibitors Combinations in Multiple Myeloma

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1235
Author(s):  
Tina Paradzik ◽  
Cecilia Bandini ◽  
Elisabetta Mereu ◽  
Maria Labrador ◽  
Elisa Taiana ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Signaling Pathways ◽  
Plasma Cells ◽  
Proteasome Inhibitors ◽  
Treatment Resistance ◽  
Positive Outcome ◽  
Chromatin Remodelers ◽  
Histone Modifiers ◽  
Substantial Progress ◽  
Immune Dysfunctions

Multiple myeloma is a malignancy of terminally differentiated plasma cells, characterized by an extreme genetic heterogeneity that poses great challenges for its successful treatment. Due to antibody overproduction, MM cells depend on the precise regulation of the protein degradation systems. Despite the success of PIs in MM treatment, resistance and adverse toxic effects such as peripheral neuropathy and cardiotoxicity could arise. To this end, the use of rational combinatorial treatments might allow lowering the dose of inhibitors and therefore, minimize their side-effects. Even though the suppression of different cellular pathways in combination with proteasome inhibitors have shown remarkable anti-myeloma activities in preclinical models, many of these promising combinations often failed in clinical trials. Substantial progress has been made by the simultaneous targeting of proteasome and different aspects of MM-associated immune dysfunctions. Moreover, targeting deranged metabolic hubs could represent a new avenue to identify effective therapeutic combinations with PIs. Finally, epigenetic drugs targeting either DNA methylation, histone modifiers/readers, or chromatin remodelers are showing pleiotropic anti-myeloma effects alone and in combination with PIs. We envisage that the positive outcome of patients will probably depend on the availability of more effective drug combinations and treatment of early MM stages. Therefore, the identification of sensitive targets and aberrant signaling pathways is instrumental for the development of new personalized therapies for MM patients.

scholarly journals MicroRNA Analysis of Human Stroke Brain Tissue Resected during Decompressive Craniectomy/Stroke-Ectomy Surgery

Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1860
Author(s):  
Andrew P. Carlson ◽  
William McKay ◽  
Jeremy S. Edwards ◽  
Radha Swaminathan ◽  
Karen S. SantaCruz ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Brain Tissue ◽  
Stroke Patient ◽  
Mirna Expression ◽  
Strong Association ◽  
Bioinformatic Analysis ◽  
Experimental Models ◽  
Aberrant Expression ◽  
Tissue Samples ◽  
Human Stroke

Background: Signaling pathways mediated by microRNAs (miRNAs) have been identified as one of the mechanisms that regulate stroke progression and recovery. Recent investigations using stroke patient blood and cerebrospinal fluid (CSF) demonstrated disease-specific alterations in miRNA expression. In this study, for the first time, we investigated miRNA expression signatures in freshly removed human stroke brain tissue. Methods: Human brain samples were obtained during craniectomy and brain tissue resection in severe stroke patients with life-threatening brain swelling. The tissue samples were subjected to histopathological and immunofluorescence microscopy evaluation, next generation miRNA sequencing (NGS), and bioinformatic analysis. Results: miRNA NGS analysis detected 34 miRNAs with significantly aberrant expression in stroke tissue, as compared to non-stroke samples. Of these miRNAs, 19 were previously identified in stroke patient blood and CSF, while dysregulation of 15 miRNAs was newly detected in this study. miRNA direct target gene analysis and bioinformatics approach demonstrated a strong association of the identified miRNAs with stroke-related biological processes and signaling pathways. Conclusions: Dysregulated miRNAs detected in our study could be regarded as potential candidates for biomarkers and/or targets for therapeutic intervention. The results described herein further our understanding of the molecular basis of stroke and provide valuable information for the future functional studies in the experimental models of stroke.

Nephrotoxic antiserum identifies a beta 1-integrin on rat glomerular epithelial cells

1992 ◽  
Vol 262 (6) ◽  
pp. F1083-F1091 ◽  
Author(s):  
Y. M. O'Meara ◽  
Y. Natori ◽  
A. W. Minto ◽  
D. J. Goldstein ◽  
E. C. Manning ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Direct Interaction ◽  
Surface Antigens ◽  
Surface Proteins ◽  
Glomerular Injury ◽  
Fibronectin Receptor ◽  
Glomerular Epithelial Cell ◽  
Beta 1 Integrin ◽  
Cell Matrix Interactions

A postulated mechanism of immune glomerular injury is a direct interaction between antibody and glomerular epithelial cell (GEC) surface antigens. To explore this hypothesis, we examined the interaction of the noncomplement-fixing gamma 2-subclass of sheep anti-rat nephrotoxic serum (NTS), which causes immediate complement- and neutrophil-independent proteinuria in vivo, with rat GECs in culture. Reactivity of NTS with GEC surface antigens was determined by positive immunofluorescence of GEC plasma membranes and by the ability of NTS-coated tissue culture wells to provide an adhesive substrate for GECs. NTS immunoprecipitated two proteins (135 and 118 kDa) from surface-labeled GECs. Proteins of similar molecular mass were precipitated by a polyclonal rabbit antibody that identifies the beta 1-integrin chain of the mouse fibronectin receptor (anti-FnR). In addition, NTS identified similarly sized bands on Western blot analysis of cell membranes from isolated rat glomeruli. Similar reactivity was eluted from the glomeruli of proteinuric rats injected with NTS. NTS significantly inhibited GEC adhesion to laminin, types I and IV collagen, and fibronectin and prevented GEC spreading on types I and IV collagen. Anti-FnR similarly inhibited GEC adhesion. Cell viability was not affected. These results show that NTS recognizes a pair of GEC surface proteins that have the characteristics of an alpha- and beta 1-integrin and, at low concentrations, disrupt cell-matrix interactions.

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