Braun, G. | bioRxiv Science

bioRxiv2023

MeXpose - A modular imaging pipeline for the quantitative assessment of cellular metal bioaccumulation

We introduce MeXpose, an imaging pipeline for single-cell metallomics by laser ablation inductively coupled plasma time-of-flight mass spectrometry (LA-ICP-TOFMS). MeXpose is designed for mechanistic studies on metal exposure unravelling cellular phenotypes and tissue level characteristics of metal bioaccumulation. MeXpose leverages the high-resolution capabilities of low-dispersion laser ablation setups, a standardised approach to quantitative bioimaging, and the toolbox of immunohistochemistry using metal-labelled antibodies for cellular phenotyping. MeXpose further offers the full scope of single-cell metallomics via an extended mass range accessible through ICP-TOFMS instrumentation (covering isotopes from m/z 14-256) and integration of a complete image analysis workflow. This enables studying quantitative metal accumulation in phenotypically characterized tissue at cellular resolution. Metal amounts in the sub-fg range per cell can be absolutely quantified. As a showcase, an ex vivo human skin model exposed to cobalt chloride (CoCl2) was investigated. Metal permeation was studied for the first time at single-cell resolution, showing high bioaccumulation in the epidermal layers and especially in mitotic cells, accumulating cobalt (Co) in the low fg range per cell. In this cellular phenotype, Co accumulation was correlated to DNA damage. While the amount of cobalt was significantly lower in the collagenous matrix of the dermal layer, cells in the vicinity of blood vessels and smooth muscle showed significant Co deposits as well. MeXpose provides unprecedented insights into metal bioaccumulation with the ability to explore novel relationships between metal exposure and cellular responses on a single-cell level, paving the way for advanced toxicological and therapeutic studies. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=141 SRC="FIGDIR/small/571675v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@7a9548org.highwire.dtl.DTLVardef@1deab3dorg.highwire.dtl.DTLVardef@1bc5186org.highwire.dtl.DTLVardef@8c6898_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioinformatics↗

bioRxiv2022

Topical GZ21T inhibits the growth of actinic keratoses in a UVB induced model of skin carcinogenesis

Actinic keratoses (AKs) are premalignant intraepidermal neoplasms that occur as a result of cumulative sun damage. AKs commonly relapse, and up to 16% undergo malignant transformation into cutaneous squamous cell carcinoma (cSCC). There is a need for novel therapies that reduce the quantity and surface area of AKs as well as prevent malignant transformation to cSCCs. We recently showed that GZ17-6.02, an anti-cancer agent composed of curcumin, haramine, and isovanillin, inhibited the growth of H297.T cells. The present study evaluated the efficacy of a novel topical formulation of GZ17-6.02, known as GZ21T, in a murine model of AK generated by exposing SKH1 mice to ultraviolet irradiation. Treatment of mice with topical GZ21T inhibited the growth of AKs by decreasing both lesion count (p=.028) and surface area occupied by tumor (p=.026). GZ21T also suppressed the progression of AKs to cSCC by decreasing the count (p=.047) and surface area (p=.049) of lesions more likely to represent cSCC. RNA sequencing and proteomic analyses revealed that GZ21T suppressed several pathways, including MAPK (p=.026), Pi3K-Akt (p=.028), HIF-1 (p=.030), Wnt (p=.031), insulin (p=.011), and ErbB (p=.006) signaling. GZ21T also upregulated the autophagy-promoting protein AMPK, while suppressing proteins such as PD-L1, glutaminase, pAkt1 S473, and eEF2K. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/506864v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@1254e6corg.highwire.dtl.DTLVardef@3fd190org.highwire.dtl.DTLVardef@1d75eb5org.highwire.dtl.DTLVardef@8afc97_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗