Metallothionein gene transfection reverses the phenotype of activated human hepatic stellate cells

Generation and Utilization of a Monoclonal Antibody against Hepatitis B Virus Core Protein for a Comprehensive Interactome Analysis

Hepatitis B virus (HBV) core antigen (HBc) is a structural protein that forms the viral nucleocapsid and is involved in various steps of the viral replication cycle, but its role in the pathogenesis of HBV infection is still elusive. In this study, we generated a mouse monoclonal antibody (mAb) against HBc and used it in antibody-based in situ biotinylation analysis in order to identify host proteins that interact with HBc. HBc antigen was produced with a wheat germ cell-free protein synthesis system and used to immunize mice. Among the established hybridoma clones, a single clone (mAb #7) was selected and further characterized for its ability in the antibody-based in situ biotinylation analysis to collect host proteins that are in the vicinity of HBc. Using mass spectrometry, we identified 215 HBc-interacting host proteins, three of which bind HBc most significantly under hypoxic conditions. Our results indicate that mAb #7 can be used to systematically identify host proteins that interact with HBc under pathophysiological conditions, and thus may be useful to explore the molecular pathways involved in HBV-induced cytopathogenesis.

A bioengineered living cell construct activates metallothionein/zinc/MMP8 and inhibits TGFβ to stimulate remodeling of fibrotic venous leg ulcers

Venous leg ulcers (VLU) represent a major clinical unmet need, impairing quality of life for millions worldwide. The bioengineered bilayered living cell construct (BLCC) is the only FDA-approved therapy demonstrating efficacy in healing chronic VLU, yet its in vivo mechanisms of action are not well understood. Previously, we reported a BLCC-mediated acute wounding response at the ulcer edge; in this study we elucidated the BLCC-specific effects on the epidermis-free ulcer bed. We conducted a randomized controlled clinical trial (ClinicalTrials.gov NCT01327937) enrolling 30 subjects with nonhealing VLUs, and performed genotyping, genomic profiling, and functional analysis on wound bed biopsies obtained at baseline and 1 week after treatment with BLCC plus compression or compression therapy (control). The VLU bed transcriptome featured processes of chronic inflammation and was strikingly enriched for fibrotic/fibrogenic pathways and gene networks. BLCC application decreased expression of profibrotic TGFß1 gene targets and increased levels of TGFß inhibitor decorin. Surprisingly, BLCC upregulated metallothioneins and fibroblast-derived MMP8 collagenase, and promoted endogenous release of MMP-activating zinc to stimulate antifibrotic remodeling, a novel mechanism of cutaneous wound healing. By activating a remodeling program in the quiescent VLU bed, BLCC application shifts nonhealing to healing phenotype. As VLU bed fibrosis correlates with poor clinical healing, findings from this study identify the chronic VLU as a fibrotic skin disease and are first to support the development and application of antifibrotic therapies as a successful treatment approach.

Mammalian Metallothionein-2A and Oxidative Stress

Mammalian metallothionein-2A (MT2A) has received considerable attention in recent years due to its crucial pathophysiological role in anti-oxidant, anti-apoptosis, detoxification and anti-inflammation. For many years, most studies evaluating the effects of MT2A have focused on reactive oxygen species (ROS), as second messengers that lead to oxidative stress injury of cells and tissues. Recent studies have highlighted that oxidative stress could activate mitogen-activated protein kinases (MAPKs), and MT2A, as a mediator of MAPKs, to regulate the pathogenesis of various diseases. However, the molecule mechanism of MT2A remains elusive. A deeper understanding of the functional, biochemical and molecular characteristics of MT2A would be identified, in order to bring new opportunities for oxidative stress therapy.