Biology subjects

Hardy, P.

Publications and source records attributed to Hardy, P..

4 recordsLinked to original sources

bioRxiv2026

Fucoidan-Coated Layer-by-layer Lipid Nanoparticles for the Generation of CAR-Macrophages

Modulation of immune cells as therapeutic tools has gained significant clinical relevance in the treatment of cancer. Among them, macrophages represent a promising immunotherapeutic platform not only because they can internalize tumor material, but also because they profoundly shape the tumor microenvironment through cytokine production, antigen presentation, metabolic regulation, and modulation of other immune and stromal populations. Lipid Nanoparticles (LNPs) have enabled RNA therapies to the bedside and are thus considered the gold standard for gene delivery. However, optimizing LNPs for RNA delivery to macrophages remains an active area of investigation. Here, we propose the surface modification of unPEGylated LNPs using the Layer-by-Layer (LbL) approach for enhanced RNA delivery to macrophages. Specifically, we show that fucoidan, a sulfated polysaccharide, when at the outermost layer in the LbL process provides two physicochemical advantages to unPEGylated LNPs: (1) stability in PBS and (2) resistance to lyophilization in the presence of cryoprotectant. Additionally, fucoidan improves macrophage targeting and RNA transfection efficiency compared to previously synthesized hyaluronan-decorated LbL LNPs. Fucoidan LbL LNPs (Fuc-LNPs) preferentially accumulated in CD11b+ macrophages when co-cultured with U87 glioblastoma cells, which was not observed for control PEGylated LNPs. Furthermore, Fuc-LNPs induced a higher transfection of mRNA in primary human macrophages when compared to PEGylated control LNPs. Using the model mRNA encoding CAR@CD19, Fuc-LNPs generated CAR macrophages which mediated CD19 cell ablation in vitro. Altogether, these findings highlight the potential of the LbL strategy to modulate the targeting properties of LNPs, improving RNA delivery to human macrophages and encouraging further studies using LbL LNPs for the generation of CAR-Macrophages in the context of solid tumors.

bioengineering↗

bioRxiv2024

Endoplasmic reticulum stress delays choroid development in the HCAR1 knock-out mouse

The sub-retina, composed of the choroid and the retinal pigment epithelium (RPE), bears a critical role in proper vision. In addition to phagocytosis of photoreceptor debris, the RPE shuttles oxygen and nutrients to the neuroretina. For their own energy production, RPE cells mainly rely on lactate, a major by-product of glycolysis. Lactate in turn is believed to convey most of its biological effects via the HCAR1 receptor. Here, we show that the lactate-specific receptor, HCAR1, is exclusively expressed in the RPE cells and that Hcar1-/- mice exhibit a substantially thinner choroid vasculature during development. Notably, the angiogenic properties of lactate on the choroid are impacted by the absence of Hcar1. Hcar1-deficient mice exhibit elevated endoplasmic reticulum (ER) stress along with eIF2 phosphorylation, a significant decrease in the global protein translation rate, and a lower proliferation rate of choroidal vasculature. Strikingly, inhibition of the Integrated Stress Response using an inhibitor of eIF2 phosphorylation (ISRIB) restores protein translation and rescues choroidal thinning. These results provide evidence that lactate signalling via HCAR1 is important for choroidal development/angiogenesis and highlight the importance of this receptor in establishing mature vision.

cell biology↗

bioRxiv2022

Nuclear Location Bias of HCAR1 Drives Cancer Malignancy through Numerous Routes

The involvement of G-Protein-Coupled Receptors (GPCR) location bias in diverse cellular functions and their misregulation in pathology is an underexplored territory. HCAR1, a GPCR for lactate is linked to cancer progression, mainly due to Warburg effect, but its mechanism of action remains elusive. Here, we show HCAR1 has a nuclear localization, capable of signaling intranuclearly to induce nuclear-ERK and AKT phosphorylation concomitant with higher cancer cell proliferation and survival. We determine its nuclear interactome, proving its involvement in protein-translation and DNA-damage repair. Nuclear HCAR1 (N-HCAR1) directly interacts with chromatin/DNA promoting expression of genes involved in cellular migration. Notably, we show N-HCAR1 particularly regulates a broader transcriptomic signature than its PM counterpart, emphasizing on the facts that functional output of N-HCAR1 is larger than PM localized HCAR1. Our study presents several unprecedented processes by which a GPCR through location-biased activity regulate various cellular functions and how cancer cells exploit these.

cell biology↗

bioRxiv2020

Induction of Muscle Regenerative Multipotent Stem Cells from Human Adipocytes by PDGF-AB and 5-Azacytidine.

Terminally differentiated murine osteocytes and adipocytes can be reprogrammed using platelet-derived growth factor-AB and 5-Azacytidine into multipotent stem cells with stromal cell characteristics. To generate a product that is amenable for therapeutic application, we have modified and optimised culture conditions to reprogram human adipocytes into induced multipotent stem cells (iMS) and expand them in vitro. The basal transcriptomes of adipocyte-derived iMS cells and matched adipose-tissue-derived mesenchymal stem cells were remarkably similar. However, there were distinct changes in histone modifications and CpG methylation at cis-regulatory regions consistent with an epigenetic landscape that was primed for tissue development and differentiation. In a non-specific tissue injury xenograft model, iMS cells contributed directly to new muscle, bone, cartilage and blood vessels with no evidence of teratogenic potential. In a cardiotoxin muscle injury model, iMS cells contributed specifically to satellite cells and myofibres without ectopic tissue formation. Taken together, human adipocyte derived iMS cells regenerate tissues in a context dependent manner without ectopic or neoplastic growth.

cell biology↗