Celastrol enhances AAV1-mediated gene expression in mice adipose tissues

Abstract

The transduction of adeno-associated virus (AAV) in adipose tissues was not well characterized and appeared to be insufficient as compared with other targeted tissues in gene therapy. We have found that celastrol, a chemical from a traditional Chinese herb known to inhibit the proteasome activity, was able to enhance the transgene expression mediated by AAV1 in 3T3-L1 preadipocytes both before and after induced differentiation. A synergism of celastrol and nonionic surfactant pluronic F68 cotreatment on AAV1 transduction was observed in the experiments with rat primary preadipocyte cultures and in adipose tissues in vivo. By fluorescent microscopy using Alexa Fluor 647-labeled AAV and quantitative PCR assays, we found that celastrol treatments increased the nuclear distribution of AAV genomic DNAs, but not the total amount of viral cellular uptake in preadipocytes, which was different from the effect of pluronic F68 treatment to significantly promote the AAV internalization. Our data suggested that bioactive monomeric compounds extracted from herbal medicines might be used to facilitate AAV-mediated gene transfer applications.

Mechanistic Insights into the Enhancement of Adeno-Associated Virus Transduction by Proteasome Inhibitors

“…Instead, it is more likely that the buildup of ubiquitinated capsid or a misfolded protein response led to increased favorability in late transduction steps. This agrees with previous results demonstrating increased nuclear localization of virus following PI treatment (6,11,17,23,26,27) and specifically increased nucleolar localization (8). Furthermore, we previously reported that treatment with arsenic trioxide leads to increased transduction through stabilization of perinuclear rAAV capsids and that this effect was distinguishable from PI effects (10).…”

“…Proteasome inhibitors (PIs) were first described to enhance recombinant AAV (rAAV) polarized airway cell transduction (6), and since then PIs, including N-acetyl-L-leucinyl-L-leucinyl-norleucinal (LLnL) (6,(14)(15)(16)(17)(18)(19), MG132 (5,6,8,11,14,17,(20)(21)(22)(23)(24), bortezomib (11,25), and celastrol (26), have been observed to enhance transduction in many cell types both in vitro and in vivo. Nevertheless, questions remain regarding the mechanism of this enhancement.…”

Multiple Recombinant Adeno-Associated Viral Vector Serotypes Display PersistentIn VivoGene Expression in Vector-Transduced Rat Stifle Joints

“…In this study, recovery of the vector approximated 100% in the presence of surfactant and ranged from 24% to 51% without the use of surfactant. When used in vivo, surfactant treatment significantly increased b-gal expression in mouse adipose tissue (Zhang et al, 2011). In vitro, we found no difference in gene expression when cells were transduced in the presence of surfactant compared with saline.…”

SelectiveIn VivoTargeting of Human Liver Tumors by Optimized AAV3 Vectors in a Murine Xenograft Model

“…In our subsequent studies, we observed that rAAV3 vectors utilize the human hepatocyte growth factor receptor (hHGFR, also named c-Met) as a cellular coreceptor (Ling et al, 2010), which offered the potential opportunity to utilize rAAV3-based vectors for targeting human liver cancers, since hHGFR is overexpressed in most HCC cells (You et al, 2011). Furthermore, we (Ling et al, 2014a;Wang et al, 2014) and others (Zhang et al, 2010;Mitchell et al, 2013) have recently proposed the idea of using leading compounds isolated from traditional Chinese medicine (TCM) to enhance the efficacy of rAAV vector-based gene therapy. It is worth noticing that most natural drugs are multifunctional (Ling et al, 2014b) and therefore have the potential to play an additive, even synergistic, effect on rAAV vector-based cancer gene therapy.…”