Caromile, L. A. | Search bioRxiv

bioRxiv2023

Single nucleotide polymorphisms and Zn transport by nuclear ZIP11 shape cancer phenotypes in HeLa cells

Zinc (Zn) is an essential micronutrient that regulates critical biological processes such as enzymatic function, gene expression, and cell signaling and provides structural stability to proteins. Under physiological conditions, Zn is a divalent cation (Zn2+) in an inactive redox state. Maintaining Zn homeostasis is essential for normal cell development and function, and any dysregulation in supply and transport can lead to pathophysiological conditions. Zn transporters, such as ZIP11, are critical regulators in Zn homeostasis. In mammals, ZIP11 belongs to the GufA subfamily of ZIP transporters and is primarily found in the nucleus and the Golgi apparatus. Our laboratory recently reported an essential role of ZIP11 in maintaining nuclear Zn levels in the cervical cancer cell line HeLa that supports various hallmark phenotypes of cancer. Genomic analysis of publicly available cervical and ovarian cancer patient datasets identified several single-nucleotide polymorphisms (SNPs) in the ZIP11 coding region that correlated with disease severity. We hypothesized that these SNPs might have potentially deleterious consequences as they are in coding regions that could affect ZIP11 function by increasing substrate accessibility, potentially enhancing the carcinogenic phenotype of HeLa cells. In addition, we identified a classic Zn-metal binding site (MBS) composed of three relevant residues which may be required for transmembrane Zn-transport, maintenance of metal homeostasis, and the carcinogenic properties of HeLa cells. To address these questions, we utilized our well-established model of stably knock down (KD) ZIP11 in HeLa cells and overexpressed ZIP11 encoding single mutations corresponding to the SNPs and the MBS. Overexpression of ZIP11 encoding SNPs restored the Zn levels and the proliferation, migration, and invasive defects of ZIP11 KD cells. On the other hand, cells expressing ZIP11 with single MBS mutations exhibited a phenotype similar to KD cells, suggesting that Zn transport by this transporter is necessary for establishing and maintaining carcinogenic properties. The work highlights the functional relevance of nuclear Zn transport by ZIP11 to maintain homeostasis and support carcinogenic properties in ovarian cancer cells.

cell biology↗

bioRxiv2018

The Innate Immune Response to Ischemic Injury: a Multiscale Modeling Perspective

BackgroundCell death as a result of ischemic injury triggers powerful mechanisms regulated by germline-encoded Pattern Recognition Receptors (PRRs) with shared specificity that recognize invading pathogens and endogenous ligands released from dying cells, and as such are essential to human health. Alternatively, dysregulation of these mechanisms contributes to extreme inflammation, deleterious tissue damage and impaired healing in various diseases. The Toll-like receptors (TLRs) are a prototypical family of PRRs that may be powerful anti-inflammatory targets if agents can be designed that antagonize their harmful effects while preserving host defense functions. This requires an understanding of the complex interactions and consequences of targeting the TLR-mediated pathways as well as technologies to analyze and interpret these, which will then allow the simulation of perturbations targeting specific pathway components, predict potential outcomes and identify safe and effective therapeutic targets.\n\nResultsWe constructed a multiscale mathematical model that spans the tissue and intracellular scales, and captures the consequences of targeting various regulatory components of injury-induced TLR4 signal transduction on potential pro-inflammatory or pro-healing outcomes. We applied known interactions to simulate how inactivation of specific regulatory nodes affects dynamics in the context of injury and to predict phenotypes of potential therapeutic interventions. We propose rules to link model behavior to qualitative estimates of pro-inflammatory signal activation, macrophage infiltration, production of reactive oxygen species and resolution. We tested the validity of the model by assessing its ability to reproduce published data not used in its construction.\n\nConclusionsThese studies will enable us to form a conceptual framework focusing on TLR4-mediated ischemic repair to assess potential molecular targets that can be utilized therapeutically to improve efficacy and safety in treating ischemic/inflammatory injury.

systems biology↗