Biology subjects

Swiderski, P.

Publications and source records attributed to Swiderski, P..

4 recordsLinked to original sources

bioRxiv2025

Endothelial AGO1 Drives Vascular Inflammation and Atherosclerosis via a Non-Canonical Nuclear Mechanism

BACKGROUNDEndothelial cell (EC) dysfunction is a cause and consequence of vascular inflammation and lipid dysregulation in atherosclerosis, yet the molecular drivers linking EC dysfunction to systemic metabolic derangements remain incompletely understood. Moreover, whether inhibiting an endogenous gene in ECs can impact liver function, lipid profile, and the vascular inflammation in the context of atherosclerosis has not been demonstrated. We previously identified Argonaute 1 (AGO1), a component of the RNA-induced silencing complex, as a regulator of EC function in angiogenesis and obesity. However, the role of endothelial AGO1 in vascular inflammation and liver function in the context of hyperlipidemia and atherosclerosis is unknown. METHODSEC-conditional AGO1 knockout (EC-AGO1-KO) and wildtype mice were subjected to pro-atherosclerotic models induced by AAV9-PCSK9 coupled with a Western diet or partial carotid ligation. Metabolic and vascular phenotype and gene expression were analyzed. In human liver sinusoidal and aortic ECs, AGO1 was knocked down using antisense oligonucleotides (ASO), followed by assessment of inflammatory responses (qPCR, RNA-seq, ELISA, and monocyte adhesion assays). To identify the molecular mechanisms linking AGO1 and EC inflammation, Cut&Tag sequencing, chromatin immunoprecipitation, immunofluorescence, proximal ligation assay, and co-immunoprecipitation were performed. The therapeutic effect of AGO1 inhibition was assessed using ASO-delivered via lipid nanoparticle (LNP) for systemic distribution and monocyte membrane-coated nanoparticles (MoNP) to target the inflamed endothelium. RESULTSEC-AGO1-KO mice exhibited improved plasma lipid profiles, reduced hepatic steatosis, inflammation, and fibrosis, and decreased aortic atherosclerotic burden. AGO1 knockdown in ECs attenuated inflammatory responses. Mechanistically, AGO1 interacted with NF-{kappa}B p65 and promoted p65 nuclear translocation and the transcriptional activation of pro-inflammatory genes, including ICAM1 and THBS1. AGO1-ASO delivered through LNP or MoNP achieved the anti-inflammatory, anti-hyperlipidemic, and anti-atherosclerotic effects, recapitulating the phenotypes observed with EC-AGO1-KO. CONCLUSIONSEndothelial AGO1 promotes vascular inflammation and liver dysfunction in the context of hyperlipidemia and atherosclerosis, in part through a non-canonical nuclear action of AGO1 as an NF-{kappa}B coactivator. Inhibition of endothelial AGO1 provides the dual benefits of ameliorating lipid dysregulation and suppressing vascular inflammation. These results highlight EC-AGO1 as a possible therapeutic target for atherosclerosis and cardiometabolic diseases.

pathology↗

bioRxiv2023

Local CpG-Stat3 siRNA treatment improves antitumor effects of checkpoint inhibitors

Immune checkpoint blockade (ICB) therapy has significantly benefited patients with several types of solid tumors and some lymphomas. However, many of the treated patients do not have durable clinical response. It has been demonstrated that rescuing exhausted CD8+ T cells is required for ICB-mediated antitumor effects. We recently developed an immunostimulatory strategy based on silencing STAT3 while stimulating immune responses by CpG, ligand for Toll-like receptor 9 (TLR9). The CpG-small interfering RNA (siRNA) conjugates efficiently enter immune cells, silencing STAT3 and activating innate immunity to enhance T-cell mediated antitumor immune responses. In the present study, we demonstrate that blocking STAT3 through locally delivered CpG-Stat3 siRNA enhances the efficacies of the systemic PD-1 and CTLA4 blockade against mouse A20 B cell lymphoma. In addition, locally delivered CpG-Stat3 siRNA combined with systemic administration of PD-1 antibody significantly augmented both local and systemic antitumor effects against mouse B16 melanoma tumors, with enhanced tumor-associated T cell activation. Overall, our studies in both B cell lymphoma and melanoma mouse models demonstrate the potential of combinatory immunotherapy with CpG-Stat3 siRNA and checkpoint inhibitors as a therapeutic strategy for B cell lymphoma and melanoma.

immunology↗

bioRxiv2023

Oligo-PROTAC strategy for cell-selective and targeted degradation of activated STAT3

Decoy-oligodeoxynucleotides (D-ODNs) can target undruggable transcription factors, such as STAT3. However, challenges in D-ODN delivery and potency hampered their translation. To overcome these limitations, we conjugated STAT3-specific D-ODN to thalidomide (Tha), a known ligand to cereblon (CRBN, a component of E3 ubiquitin ligase) to generate a proteolysis-targeting chimera (STAT3DPROTAC). STAT3DPROTAC downregulated STAT3, but not STAT1 or STAT5, in target cells. Computational modeling of the STAT3DPROTAC ternary complex predicted two surface lysines on STAT3, K601 and K626 as potential ubiquitination sites for the PROTAC bound E3 ligase. Accordingly, K601/K626 point mutations in STAT3, as well as proteasome inhibitors, and CRBN deletion alleviated STAT3DPROTAC effect. Next, we conjugated STAT3DPROTAC to a CpG ligand targeting Toll-like receptor 9 (TLR9) to generate myeloid/B-cell-selective C-STAT3DPROTAC conjugate. Naked C-STAT3DPROTAC was spontaneously internalized by TLR9+ myeloid cells, B cells as well as human Ly18 and mouse A20 lymphoma cells, but not by T cells. C-STAT3DPROTAC decreased STAT3 levels to 50% at 250 nM and over 85% at 2 {micro}M dosing in myeloid cells. We also observed significantly improved downregulation of STAT3 target genes involved in lymphoma cell proliferation and/or survival (BCL2L1, CCND2, MYC). Finally, we assessed the antitumor efficacy of C-STAT3DPROTAC compared to C-STAT3D or scrambled control (C-SCR) against human lymphoma xenotransplants. Local C-STAT3DPROTAC administration triggered lymphoma regression while control treatments had limited effects. Our results underscore feasibility of using PROTAC strategy for cell-selective, decoy oligonucleotide-based targeting of STAT3 and potentially other tumorigenic transcription factors for cancer therapy.

cancer biology↗

bioRxiv2017

AptaBlocks: Accelerating the Design of RNA-based Drug Delivery Systems

Synthetic RNA molecules are increasingly used to alter cellular functions. These successful applications indicate that RNA-based therapeutics might be able to target currently undruggable genes. However, to achieve this promise, an effective method for delivering therapeutic RNAs into specific cells is required. Recently, RNA aptamers emerged as promising delivery agents due to their ability of binding specific cell receptors. Crucially, these aptamers can frequently be internalized into the cells expressing these receptors on their surfaces. This property is leveraged in aptamer based drug delivery systems by combining such receptor-specific aptamers with a therapeutic \"cargo\" such that the aptamer facilitates the internalization of the cargo into the cell. The advancement of this technology however is contingent on an efficient method to produce stable molecular complexes that include specific aptamers and cargoes. A recently proposed experimental procedure for obtaining such complexes relies on conjugating the aptamer and the cargo with complementary RNA strands so that when such modified molecules are incubated together, the complementary RNA strands hybridize to form a double-stranded \"sticky bridge\" connecting the aptamer with its cargo. However, designing appropriate sticky bridge sequences guaranteeing the formation and stability of the complex while simultaneously not interfering with the aptamer or the cargo as well as not causing spurious aggregation of the molecules during incubation has proven highly challenging. To fill this gap, we developed AptaBlocks, a computational method to design sticky bridges to connect RNA-based molecules (blocks). AptaBlocks relies on a biophysically inspired theoretical model capturing the complex objectives of the design and yet is simple enough to allow for efficient parameter estimation. Given this model, the sticky bridge sequence is optimized using a Monte Carlo algorithm based on heat-bath transitions. The effectiveness of the algorithm has been verified computationally and experimentally. AptaBlocks can be used in variety of experimental settings and its preliminary version has already been leveraged to design an aptamer based delivery system for a cytotoxic drug targeting Pancreatic ductal adenocarcinoma cells. It is thus expected that AptaBlocks will play a substantial role in accelerating RNA-based drug delivery design.\n\nAptaBlocks is available at https://github.com/wyjhxq/AptaBlocks.

bioinformatics↗