Yakirevich, E. | Search bioRxiv

bioRxiv2024

The IQGAP1-Claudin Cell Junction Axis in Cisplatin-induced Kidney Damage

Kidney damage resulting from nephrotoxicity is a major side effect of chemotherapy. Cisplatin is an effective antineoplastic agent broadly used in oncology where it interferes with DNA replication in dividing cells, however, its mechanism in kidney damage remains unclear. We tested the hypothesis that cisplatin displaces cell-contact proteins such as IQGAP1-claudin complex in the kidney tubules, causing epithelial cell dissociation and kidney damage. Employing a multifaceted approach, using mutant analyses and optimal cisplatin dose, this hypothesis was tested in cell culture and iqgap1-/- mouse models. Cisplatin inhibited cell proliferation and migration in an IQGAP1-dependent manner, displaced IQGAP1 from cell junctions and altered the expression level of key junctional markers, including claudins 2/4/8 and nephrin. Similar effects were observed in animal models where cisplatin treatment and loss of IQGAP1 had additive effects. These functional outcomes are accounted for by suppression of Akt1/PKB survival and ERK1/2 proliferation signals and activation of JNK-GSK3{beta} stress and inflammatory signal, widely implicated in kidney injury. These findings present IQGAP1-claudin axis as biomarkers and therapeutic targets in kidney damage and pave the way for formulating new analogs that eliminate cisplatin adverse side effects while preserving its antineoplastic efficacy.

cell biology↗

bioRxiv2020

Validation and Performance Comparison of Three SARS-CoV-2 Antibody Assays

Serology testing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is increasingly being used during the current pandemic of Coronavirus Disease 2019 (COVID-19). The clinical and epidemiologic utilities of antibody-based SARS-CoV-2 testing are under debate. Characterizing these assays helps to understand the disease and provides scientific basis for deciding how to best use these assays. The study assessed one chemiluminescent assay (Abbott COVID-2 IgG) and two lateral flow assays (STANDARD Q [SQ] IgM/IgG Duo and Wondfo Total Antibody Test). Validation included 113 blood samples from 71 PCR-confirmed COVID-19 patients and 1182 samples from negative controls with potential interferences/cross-reactions, including 1063 pre-pandemic samples. IgM antibodies against SARS-CoV-2 were detected as early as post-symptom onset days 3-4. IgG antibodies were first detected post-onset days 5-6 by SQ assays. The detection rates increased gradually, and SQ IgG, Abbott IgG and Wondfo Total detected antibodies from all the PCR-confirmed patients 14 days after symptom onset. Overall agreements between SQ IgM/IgG and Wondfo Total was 88.5% and between SQ IgG and Abbott IgG was 94.6% (Kappa = 0.75, 0.89). No cross-reaction with other endemic coronavirus infections were identified. Viral hepatitis and autoimmune samples were the main cross-reactions observed. However, the interferences/cross-reactions were low. The specificities were 100% for SQ IgG and Wondfo Total and 99.62% for Abbott IgG and 98.87% for SQ IgM. These findings demonstrate high sensitivity and specificity of appropriately validated antibody-based SARS-CoV-2 assays with implications for clinical use and epidemiological seroprevalence studies.View Full Text

pathology↗