IGSF3 mutation identified in patient with severe COPD alters cell function and motility
JCI INSIGHT
Authors: Schweitzer, Kelly S.; Jinawath, Natini; Yonescu, Raluca; Ni, Kevin; Rush, Natalia; Charoensawan, Varodom; Bronova, Irina; Berdyshev, Evgeny; Leach, Sonia M.; Gillenwater, Lucas A.; Bowler, Russel P.; Pearse, David B.; Griffin, Constance A.; Petrache, Irina
Abstract
Cigarette smoking (CS) and genetic susceptibility determine the risk for development, progression, and severity of chronic obstructive pulmonary diseases (COPD). We posited that an incidental balanced reciprocal chromosomal translocation was linked to a patient's risk of severe COPD. We determined that 46,XX,t(1;4)(p13.1;q34.3) caused a breakpoint in the immunoglobul in superfamily member 3 (IGSF3) gene, with markedly decreased expression. Examination of COPDGene cohort identified 14 IGSF3 SNPs, of which rs1414272 and rs12066192 were directly and rs6703791 inversely associated with COPD severity, including COPD exacerbations. We confirmed that IGSF3 is a tetraspanin-interacting protein that colocalized with CD9 and integrin 81 in tetraspanin-enriched domains. IGSF3-deficient patient-derived lymphoblastoids exhibited multiple alterations in gene expression, especially in the unfolded protein response and ceramide pathways. IGSF3-deficient lymphoblastoids had high ceramide and sphingosine-1 phosphate but low glycosphingolipids and ganglioside levels, and they were less apoptotic and more adherent, with marked changes in multiple TNFRSF molecules. Similarly, IGSF3 knockdown increased ceramide in lung structural cells, rendering them more adherent, with impaired wound repair and weakened barrier function. These findings suggest that, by maintaining sphingolipid and membrane receptor homeostasis, IGSF3 is required for cell mobility-mediated lung injury repair. IGSF3 deficiency may increase susceptibility to CS-induced lung injury in COPD.
The immunoglobulin superfamily member 3 (IGSF3) promotes hepatocellular carcinoma progression through activation of the NF-kappa B pathway
ANNALS OF TRANSLATIONAL MEDICINE
Authors: Sheng, Ping; Zhu, Huirong; Zhang, Wenxiu; Xu, Yanan; Peng, Wenxue; Sun, Jing; Gu, Mingqi; Jiang, Hongchi
Abstract
Background: Patients with hepatocellular carcinoma (HCC) suffer from a high fatality rate, likely due to increased incidence of tumor relapse and metastasis. Understanding the molecular mechanisms that contribute to HCC development and progression is vital for the discovery of new treatment targets. This study aims to explore the expression profiles and functions of immunoglobulin superfamily member 3 (IGSF3) in HCC. Methods: We evaluated IGSF3 levels in HCC and normal tissues using bioinformatics, western blot, quantitative real-time PCR (qRT-PCR), and immunohistochemistry. We also conducted proliferation assays, colony formation assays, flow cytometry, cell migration assay, cell invasion assay, qRT-PCR, and western blotting in HCC cell lines. Immunofluorescence and western blotting further used to study the IGSF3 pathway. A mouse xenograft model was utilized to examine the influence of IGSF3 on HCC growth in vivo. Results: IGSF3 levels were higher in HCC tissues and cell lines. Silencing of IGSF3 via lentiviral vector system (LV) inhibited migration, invasion, and growth of HCC cell lines in vitro as well as tumor growth in vivo. Overexpression of IGSF3 promoted result in vitro. Importantly, we found that IGSF3 activates the NF-kappa B pathway to promote tumorigenic features in HCC cell lines. Conclusions: We found that IGSF3 can be used as a novel biomarker for HCC detection. Moreover, IGSF3 elicits HCC progression by activating the NF-.B pathway. As such, our data provides potential options for therapeutic targets in patients with HCC.