Publications by authors named "Fu-Fei Hsu"

The COVID-19 pandemic continues to threaten human health worldwide as new variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerge. Currently, the predominant circulating strains around the world are Omicron variants, which can evade many therapeutic antibodies. Thus, the development of new broadly neutralizing antibodies remains an urgent need.

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Background: The variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) harbor diverse spike (S) protein sequences, which can greatly influence the efficacies of therapeutics. Therefore, it would be of great value to develop neutralizing monoclonal antibodies (mAbs) that can broadly recognize multiple variants.

Methods: Using an mRNA-LNP immunization strategy, we generated several mAbs that specifically target the conserved S2 subunit of SARS-CoV-2 (B-S2-mAbs).

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Throughout the COVID-19 pandemic, many prophylactic and therapeutic drugs have been evaluated and introduced. Among these treatments, monoclonal antibodies (mAbs) that bind to and neutralize SARS-CoV-2 virus have been applied as complementary and alternative treatments to vaccines. Although different methodologies have been utilized to produce mAbs, traditional hybridoma fusion technology is still commonly used for this purpose due to its unmatched performance record.

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The novel coronavirus disease (COVID-19) pandemic remains a global public health crisis, presenting a broad range of challenges. To help address some of the main problems, the scientific community has designed vaccines, diagnostic tools and therapeutics for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The rapid pace of technology development, especially with regard to vaccines, represents a stunning and historic scientific achievement.

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Background: With the continuous emergence of new SARS-CoV-2 variants that feature increased transmission and immune escape, there is an urgent demand for a better vaccine design that will provide broader neutralizing efficacy.

Methods: We report an mRNA-based vaccine using an engineered "hybrid" receptor binding domain (RBD) that contains all 16 point-mutations shown in the currently prevailing Omicron and Delta variants.

Results: A booster dose of hybrid vaccine in mice previously immunized with wild-type RBD vaccine induced high titers of broadly neutralizing antibodies against all tested SARS-CoV-2 variants of concern (VOCs).

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Objective: Stromal barriers, such as the abundant desmoplastic stroma that is characteristic of pancreatic ductal adenocarcinoma (PDAC), can block the delivery and decrease the tumour-penetrating ability of therapeutics such as tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), which can selectively induce cancer cell apoptosis. This study aimed to develop a TRAIL-based nanotherapy that not only eliminated the extracellular matrix barrier to increase TRAIL delivery into tumours but also blocked antiapoptotic mechanisms to overcome TRAIL resistance in PDAC.

Design: Nitric oxide (NO) plays a role in preventing tissue desmoplasia and could thus be delivered to disrupt the stromal barrier and improve TRAIL delivery in PDAC.

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Background: The accumulation of lipid-laden macrophages, foam cells, within sub-endothelial intima is a key feature of early atherosclerosis. Siglec-E, a mouse orthologue of human Siglec-9, is a sialic acid binding lectin predominantly expressed on the surface of myeloid cells to transduce inhibitory signal via recruitment of SH2-domain containing protein tyrosine phosphatase SHP-1/2 upon binding to its sialoglycan ligands. Whether Siglec-E expression on macrophages impacts foam cell formation and atherosclerosis remains to be established.

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Objective: Abdominal aortic aneurysm (AAA) is a vascular degenerative disease causing sudden rupture of aorta and significant mortality in elders. Nevertheless, no prognostic and therapeutic target is available for disease management. Gal-1 (galectin-1) is a β-galactoside-binding lectin constitutively expressed in vasculature with roles in maintaining vascular homeostasis.

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While immunotherapy holds great promise for combating cancer, the limited efficacy due to an immunosuppressive tumor microenvironment and systemic toxicity hinder the broader application of cancer immunotherapy. Here, we report a combinatorial immunotherapy approach that uses a highly efficient and tumor-selective gene carrier to improve anticancer efficacy and circumvent the systemic toxicity. In this study, we engineered tumor-targeted lipid-dendrimer-calcium-phosphate (TT-LDCP) nanoparticles (NPs) with thymine-functionalized dendrimers that exhibit not only enhanced gene delivery capacity but also immune adjuvant properties by activating the stimulator of interferon genes (STING)-cGAS pathway.

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Abnormal tumour vasculature has a significant impact on tumour progression and response to therapy. Nitric oxide (NO) regulates angiogenesis and maintains vascular homeostasis and, thus, can be delivered to normalize tumour vasculature. However, a NO-delivery system with a prolonged half-life and a sustained release mechanism is currently lacking.

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Signal peptide peptidase (SPP) is an endoplasmic reticulum (ER)-resident aspartyl protease mediating intramembrane cleavage of type II transmembrane proteins. Increasing evidence has supported the role of SPP in ER-associated protein degradation. In the present study, we show that SPP expression is highly induced in human lung and breast cancers and correlated with disease outcome.

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Background: Heme oxygenase (HO) catalyzes NADPH-dependent degradation of heme to liberate iron, carbon monoxide and biliverdin. The interaction between HO and cytochrome P450 reductase (CPR), an electron donor, is essential for HO activity. HO-1 is a stress-inducible isoform whereas HO-2 is constitutively expressed.

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Unlabelled: The anticancer efficacy of TNF-related apoptosis-inducing ligand (TRAIL)-based therapy is limited because of systemic toxicity, poor bioavailability, and development of TRAIL resistance. We developed a tumor-targeted LCPP (lipid/calcium/phosphate/protamine) nanoparticle (NP) to deliver TRAIL plasmid DNA (pDNA) into hepatocellular carcinoma (HCC) cells in a mouse model of HCC. TRAIL pDNA was encapsulated in a pH stimuli-responsive calcium phosphate (CaP) core, and protamine was added to facilitate nuclear delivery of pDNA.

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Sorafenib is a RAF inhibitor approved for several cancers, including hepatocellular carcinoma (HCC). Inhibition of RAF kinases can induce a dose-dependent "paradoxical" upregulation of the downstream mitogen-activated protein kinase (MAPK) pathway in cancer cells. It is unknown whether "paradoxical" ERK activation occurs after sorafenib therapy in HCC, and if so, if it impacts the therapeutic efficacy.

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The progression of liver fibrosis, an intrinsic response to chronic liver injury, is associated with hepatic hypoxia, angiogenesis, abnormal inflammation, and significant matrix deposition, leading to the development of cirrhosis and hepatocellular carcinoma (HCC). Due to the complex pathogenesis of liver fibrosis, antifibrotic drug development has faced the challenge of efficiently and specifically targeting multiple pathogenic mechanisms. Therefore, CXCR4-targeted nanoparticles (NPs) were formulated to deliver siRNAs against vascular endothelial growth factor (VEGF) into fibrotic livers to block angiogenesis during the progression of liver fibrosis.

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Proper regulation of cell cycle progression is pivotal for maintaining genome stability. In a search for DNA damage-inducible, CHK1-modulated genes, we have identified BTG3 (B-cell translocation gene 3) as a direct p53 target. The p53 transcription factor binds to a consensus sequence located in intron 2 of the gene both in vitro and in vivo, and depletion of p53 by small interfering RNA (siRNA) abolishes DNA damage-induced expression of the gene.

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The Archaeal protein RadA, a RecA/Rad51 homolog, is able to promote pairing and exchange of DNA strands with homologous sequences. Here, we have expressed, purified, and crystallized the catalytically active RadA protein from Sulfolobus solfataricus (Sso). Preliminary X-ray analysis indicated that Sso RadA protein likely forms helical filament in protein crystals.

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Object: Paraspinal muscle injury is a common but neglected complication of posterior spinal surgery. Evidence suggests that surgical retraction places mechanical and oxidative stress on the paraspinal muscles and that inflammation is a major postoperative pathological finding in the muscles. The roles of cyclooxygenase (COX)-2 and nuclear factor (NF)-kappaB in the inflammatory processes after retraction remain to be clarified.

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