Receptor Targeting Using Copolymer-Modified Gold Nanoparticles for pCMV-Luc Gene Delivery to Liver Cancer Cells In Vitro.

The formulation of novel delivery protocols for the targeted delivery of genes into hepatocytes by receptor mediation is important for the treatment of liver-specific disorders, including cancer. Non-viral delivery methods have been extensively studied for gene therapy. Gold nanoparticles (AuNPs) have gained attention in nanomedicine due to their biocompatibility. In this study, AuNPs were synthesized and coated with polymers: chitosan (CS), and polyethylene glycol (PEG). The targeting moiety, lactobionic acid (LA), was added for hepatocyte-specific delivery. Physicochemical characterization revealed that all nano-formulations were spherical and monodispersed, with hydrodynamic sizes between 70 and 250 nm. Nanocomplexes with pCMV-Luc DNA (pDNA) confirmed that the NPs could bind, compact, and protect the pDNA from nuclease degradation. Cytotoxicity studies revealed that the AuNPs were well tolerated (cell viabilities > 70%) in human hepatocellular carcinoma (HepG2), embryonic kidney (HEK293), and colorectal adenocarcinoma (Caco-2) cells, with enhanced transgene activity in all cells. The inclusion of LA in the NP formulation was notable in the HepG2 cells, which overexpress the asialoglycoprotein receptor on their cell surface. A five-fold increase in luciferase gene expression was evident for the LA-targeted AuNPs compared to the non-targeted AuNPs. These AuNPs have shown potential as safe and suitable targeted delivery vehicles for liver-directed gene therapy.

The use of human iPSC-derived alveolar organoids to explore SARS-CoV-2 variant infections and host responses.

Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) primarily targets the respiratory system. Physiologically relevant human lung models are indispensable to investigate virus-induced host response and disease pathogenesis. In this study, we generated human induced pluripotent stem cell (iPSC)-derived alveolar organoids (AOs) using an established protocol that recapitulates the sequential steps of in vivo lung development. AOs express alveolar epithelial type II cell protein markers including pro-surfactant protein C and ATP binding cassette subfamily A member 3. Compared to primary human alveolar type II cells, AOs expressed higher mRNA levels of SARS-CoV-2 entry factors, angiotensin-converting enzyme 2 (ACE2), asialoglycoprotein receptor 1 (ASGR1) and basigin (CD147). Considering the localization of ACE2 on the apical side in AOs, we used three AO models, apical-in, sheared and apical-out for SARS-CoV-2 infection. All three models of AOs were robustly infected with the SARS-CoV-2 irrespective of ACE2 accessibility. Antibody blocking experiment revealed that ASGR1 was the main receptor for SARS-CoV2 entry from the basolateral in apical-in AOs. AOs supported the replication of SARS-CoV-2 variants WA1, Alpha, Beta, Delta, and Zeta and Omicron to a variable degree with WA1 being the highest and Omicron being the least. Transcriptomic profiling of infected AOs revealed the induction of inflammatory and interferon-related pathways with NF-κB signaling being the predominant host response. In summary, iPSC-derived AOs can serve as excellent human lung models to investigate infection of SARS-CoV-2 variants and host responses from both apical and basolateral sides.

Deficiency of ASGR1 promotes liver injury by increasing GP73-mediated hepatic endoplasmic reticulum stress.

Liver injury is a core pathological process in the majority of liver diseases, yet the genetic factors predisposing individuals to its initiation and progression remain poorly understood. Here we show that asialoglycoprotein receptor 1 (ASGR1), a lectin specifically expressed in the liver, is downregulated in patients with liver fibrosis or cirrhosis and male mice with liver injury. ASGR1 deficiency exacerbates while its overexpression mitigates acetaminophen-induced acute and CCl4-induced chronic liver injuries in male mice. Mechanistically, ASGR1 binds to an endoplasmic reticulum stress mediator GP73 and facilitates its lysosomal degradation. ASGR1 depletion increases circulating GP73 levels and promotes the interaction between GP73 and BIP to activate endoplasmic reticulum stress, leading to liver injury. Neutralization of GP73 not only attenuates ASGR1 deficiency-induced liver injuries but also improves survival in mice received a lethal dose of acetaminophen. Collectively, these findings identify ASGR1 as a potential genetic determinant of susceptibility to liver injury and propose it as a therapeutic target for the treatment of liver injury.

The serum soluble ASGR1 concentration is elevated in patients with coronary artery disease and is associated with inflammatory markers.

BACKGROUND AND AIMS: Current research has suggested that asialoglycoprotein receptor 1 (ASGR1) is involved in cholesterol metabolism and is also related to systemic inflammation. This study aimed to assess the correlation between the serum soluble ASGR1 (sASGR1) concentration and inflammatory marker levels. Moreover, the second objective of the study was to assess the association between sASGR1 levels and the presence of coronary artery disease (CAD). METHODS: The study subjects included 160 patients who underwent coronary angiography. Ninety patients were diagnosed with CAD, while seventy age- and sex-matched non-CAD patients served as controls. We measured the serum sASGR1 levels using an ELISA kit after collecting clinical baseline characteristics. RESULTS: Patients with CAD had higher serum sASGR1 levels than non-CAD patients did (P < 0.0001). sASGR1 was independently correlated with the risk of CAD after adjusting for confounding variables (OR = 1.522, P = 0.012). The receiver operating characteristic (ROC) curve showed that sASGR1 had a larger area under the curve (AUC) than did the conventional biomarkers apolipoprotein B (APO-B) and low-density lipoprotein cholesterol (LDL-C). In addition, multivariate linear regression models revealed that sASGR1 is independently and positively correlated with high-sensitivity C-reactive protein (CRP) (ß = 0.86, P < 0.001) and WBC (ß = 0.13, P = 0.004) counts even after adjusting for lipid parameters. According to our subgroup analysis, this relationship existed only for CAD patients. CONCLUSION: Our research demonstrated the link between CAD and sASGR1 levels, suggesting that sASGR1 may be an independent risk factor for CAD. In addition, this study provides a reference for revealing the potential role of sASGR1 in the inflammation of atherosclerosis.

Research progress on asialoglycoprotein receptor-targeted radiotracers designed for hepatic nuclear medicine imaging.

Asialoglycoprotein receptor (ASGPR) specifically recognizes glycans terminated with ß-d-galactose or N-acetylgalactosamine. Its exclusive expression in mammalian hepatocytes renders it an ideal hepatic-targeted biomarker. To date, ASGPR-targeted ligands have been actively developed for drug delivery and hepatic imaging. This review provides a comprehensive summary of the progress achieved to-date in the field of developing ASGPR-targeted nuclear medicine imaging (NMI) radiotracers, highlighting the recent advancements over the last decade in terms of structure, radionuclides and labeling strategies. The biodistribution patterns, imaging characteristics, challenges and future prospective are discussed.

Asialoglycoprotein receptor 1 promotes SARS-CoV-2 infection of human normal hepatocytes.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes multi-organ damage, which includes hepatic dysfunction, as observed in over 50% of COVID-19 patients. Angiotensin I converting enzyme (peptidyl-dipeptidase A) 2 (ACE2) is the primary receptor for SARS-CoV-2 entry into host cells, and studies have shown the presence of intracellular virus particles in human hepatocytes that express ACE2, but at extremely low levels. Consequently, we asked if hepatocytes might express receptors other than ACE2 capable of promoting the entry of SARS-CoV-2 into cells. To address this question, we performed a genome-wide CRISPR-Cas9 activation library screening and found that Asialoglycoprotein receptor 1 (ASGR1) promoted SARS-CoV-2 pseudovirus infection of HeLa cells. In Huh-7 cells, simultaneous knockout of ACE2 and ASGR1 prevented SARS-CoV-2 pseudovirus infection. In the immortalized THLE-2 hepatocyte cell line and primary hepatic parenchymal cells, both of which barely expressed ACE2, SARS-CoV-2 pseudovirus could successfully establish an infection. However, after treatment with ASGR1 antibody or siRNA targeting ASGR1, the infection rate significantly dropped, suggesting that SARS-CoV-2 pseudovirus infects hepatic parenchymal cells mainly through an ASGR1-dependent mechanism. We confirmed that ASGR1 could interact with Spike protein, which depends on receptor binding domain (RBD) and N-terminal domain (NTD). Finally, we also used Immunohistochemistry and electron microscopy to verify that SARS-CoV-2 could infect primary hepatic parenchymal cells. After inhibiting ASGR1 in primary hepatic parenchymal cells by siRNA, the infection efficiency of the live virus decreased significantly. Collectively, these findings indicate that ASGR1 is a candidate receptor for SARS-CoV-2 that promotes infection of hepatic parenchymal cells.

ASGR1 deficiency diverts lipids toward adipose tissue but results in liver damage during obesity.

BACKGROUND: Asialoglycoprotein receptor 1 (ASGR1), primarily expressed on hepatocytes, promotes the clearance and the degradation of glycoproteins, including lipoproteins, from the circulation. In humans, loss-of-function variants of ASGR1 are associated with a favorable metabolic profile and reduced incidence of cardiovascular diseases. The molecular mechanisms by which ASGR1 could affect the onset of metabolic syndrome and obesity are unclear. Therefore, here we investigated the contribution of ASGR1 in the development of metabolic syndrome and obesity. METHODS: ASGR1 deficient mice (ASGR1-/-) were subjected to a high-fat diet (45% Kcal from fat) for 20 weeks. The systemic metabolic profile, hepatic and visceral adipose tissue were characterized for metabolic and structural alterations, as well as for immune cells infiltration. RESULTS: ASGR1-/- mice present a hypertrophic adipose tissue with 41% increase in fat accumulation in visceral adipose tissue (VAT), alongside with alteration in lipid metabolic pathways. Intriguingly, ASGR1-/- mice exhibit a comparable response to an acute glucose and insulin challenge in circulation, coupled with notably decreased in circulating cholesterol levels. Although the liver of ASGR1-/- have similar lipid accumulation to the WT mice, they present elevated levels of liver inflammation and a decrease in mitochondrial function. CONCLUSION: ASGR1 deficiency impacts energetic homeostasis during obesity leading to improved plasma lipid levels but increased VAT lipid accumulation and liver damage.

Design, synthesis and biological evaluation of the positional isomers of the galactose conjugates able to target hepatocellular carcinoma cells via ASGPR-mediated cellular uptake and cytotoxicity.

Galactose as a recognizing motif for asialoglycoprotein receptor (ASGPR) is a widely accepted vector to deliver cytotoxic agents in the therapy of hepatocellular carcinoma (HCC), however, the individual hydroxyl group of galactose (Gal) contributed to recognizing ASGPR is obscure and remains largely unanswered in the design of glycoconjugates. Herein, we designed and synthesized five positional isomers of Gal-anthocyanin Cy5.0 conjugates and three Gal-doxorubicin (Dox) isomers, respectively. The fluorescence intensity of Gal-Cy5.0 conjugates accumulated in cancer cells hinted the optimal modification sites of positions C2 and C6. Comparing to the cytotoxicity of other conjugates, C2-Gal-Dox (11) was the most potent. Moreover, Gal-Dox conjugates significantly the toxicity of Dox. A progressively lower internalization capacity and siRNA technology implied the cellular uptake and cytotoxicity directly related to the ASGPR expression level. Accordingly, position C2 of galactose may be the best substitution site via ASGPR mediation in the design of anti-HCC glycoconjugates.

Asialoglycoprotein Receptor 2 Expression in Patients With Locally Advanced Gastric Cancer After Curative Resection.

BACKGROUND/AIM: The asialoglycoprotein receptor 2 gene (ASGR2) encodes a subunit of the asialoglycoprotein receptor, a transmembrane protein, which has recently been reported to be involved in gastric cancer (GC) progression. This study aimed to investigate the clinical significance of ASGR2 expression in GC tissues of patients with locally advanced gastric cancer (LAGC) after curative resection. PATIENTS AND METHODS: ASGR2 expression was measured in GC tissues and adjacent normal gastric mucosa in 253 patients with pStage II/III GC who underwent curative resection, by using quantitative polymerase chain reaction. We compared the expression levels in GC tissues and adjacent normal stomach mucosa, and evaluated the relationship of its expression in GC tissues with clinicopathological factors and overall survival (OS). RESULTS: ASGR2 expression was significantly associated with lymph node metastasis and venous invasion. The high ASGR2-expression group demonstrated significantly lower survival than the low expression group (5-year survival 55.5% vs. 72.6%; p=0.009). Furthermore, in multivariate analysis, high ASGR2 expression was an independent factor for poor OS (hazard ratio=2.030; 95% confidence interval=1.318-3.127; p=0.001). CONCLUSION: ASGR2 expression in GC tissues may be a useful prognostic marker in patients with LAGC after curative resection.

Serum IgA augments adhesiveness of cultured lung microvascular endothelial cells and suppresses angiogenesis.

Immunoglobulin A (IgA) is important in local immunity and is also abundant in the blood. This study aimed to evaluate the effects of serum IgA on cultured lung microvascular endothelial cells (HMVEC-Ls), which are involved in the pathogenesis of inflammatory lung diseases. Serum IgA induced adhesion molecules and inflammatory cytokine production from HMVEC-Ls, and enhanced adhesion of peripheral blood mononuclear cells to HMVEC-Ls. In contrast, migration, proliferation, and tube formation of HMVEC-Ls were significantly suppressed by serum IgA. Experiments with siRNAs and western blotting revealed that two known IgA receptors, ß1,4-galactosyltransferase 1 (b4GALT1) and asialoglycoprotein receptor 1 (ASGR1), and mitogen-activated protein kinase and nuclear factor-kappa B pathways were partly involved in serum IgA-induced cytokine production by HMVEC-Ls. Collectively, serum IgA enhanced cytokine production and adhesiveness of HMVEC-L, with b4GALT1 and ASGR1 partially being involved, and suppressed angiogenesis. Thus, serum IgA may be targeted to treat inflammatory lung diseases.

Correlation between serum soluble ASGR1 concentration and low-density lipoprotein cholesterol levels: a cross-sectional study.

BACKGROUND: Recent studies have shown that loss-of-function mutations in hepatic asialoglycoprotein receptor 1 (ASGR1) are associated with low levels of circulating cholesterol and a reduced risk of coronary artery disease (CAD). In contrast to ASGR1 on the hepatocyte membrane, serum soluble ASGR1 (sASGR1) is a secreted form that has been detected in circulation. However, the functions of serum sASGR1 are unclear. This study aims to investigate the relationship between human serum sASGR1 concentration and low-density lipoprotein cholesterol (LDL-C) levels. METHODS: In a cohort of 134 participants who underwent coronary angiography examination, basic information was recorded, and blood samples were collected for biochemical testing. The serum sASGR1 concentration was determined by ELISA kits. The relationship between sASGR1 concentration and LDL-C levels was examined using linear regression models and interaction tests. Univariate and multivariate analyses were used to identify clinical variables that affect sASGR1 levels. RESULTS: After adjusting for potential confounders such as age, sex, BMI, and statin use, the serum sASGR1 concentration was positively correlated with LDL-C levels (ß = 0.093, 95% CI: 0.04 to 0.14, P < 0.001). Subgroup analysis and interaction tests showed that the effect of serum sASGR1 concentration on LDL-C levels was significantly influenced by hypertension status (P for interaction = 0.0067). The results of a multivariate linear regression analysis incorporating age, serum TG, LDL-C, nonesterified fatty acid (NEFA), white blood cell counts (WBCC), and fibrinogen revealed that LDL-C (ß = 1.005, 95% CI: 0.35 to 1.66, P = 0.003) and WBCC (ß = 0.787, 95% CI: 0.41 to 1.16, P < 0.0001) were independent influencing factors for serum sASGR1 levels. CONCLUSIONS: The serum sASGR1 concentration was positively correlated with LDL-C levels. In addition, hypertension status significantly affected the effect of serum sASGR1 on LDL-C levels. This study provides some research ideas for clinical doctors and researchers, as well as some references for additional research on serum sASGR1.

Synthesis, characterization, and biological verification of asialoglycoprotein receptor-targeted lipopolysaccharide-encapsulated PLGA nanoparticles for the establishment of a liver fibrosis animal model.

Liver fibrosis is generally preceded by various liver injuries and often leads to chronic liver diseases and even cirrhosis. Therefore, a liver fibrosis animal model is the cornerstone for the development of therapeutic strategies for hepatic diseases. Although administration of hepatotoxic substances and/or bile duct ligation have been widely performed to construct the in vivo model over the last decades, they are seriously hindered by time-consuming protocols, high mortality, and instability, indicating that an effective and safe approach for the induction of liver fibrosis is still urgently needed nowadays. In this study, we have developed asialoglycoprotein receptor (ASGPR)-targeted lipopolysaccharide (LPS)-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles named ALPNPs for establishing an animal model of liver fibrosis. The ALPNPs are characterized as having a spherical nanostructure with size of 182.9 ± 8.89 nm and surface charge of -8.3 ± 1.48 mV. An anti-ASGPR antibody bound to the surface of the nanoparticles with a crosslinking efficiency of 95.03% allows ALPNPs to have hepatocyte-binding specificity. In comparison to free LPSs, the ALPNPs can induce higher aspartate aminotransferase and total bilirubin concentrations in plasma, reduce the blood flow rate in the portal system and the kidneys, and increase vascular resistance in the liver, kidneys, and collateral shunting vasculature. Based on histological and RNA-seq analyses, the ALPNPs can provide similar capability on inducing hepatic inflammation and fibrosis compared to free LPS but possess higher liver targetability than the naked drug. In addition, the ALPNPs are less toxic in organs other than the liver in comparison to free LPS, demonstrating that the ALPNPs do not elicit off-target effects in vivo. Given the aforementioned efficacies with other merits such as biocompatibility and drug release controllability provided by PLGA, we anticipate that the developed ALPNPs are highly applicable in establishing animal models of liver fibrosis in pre-clinical studies.

In silico discovery of food-derived phytochemicals against asialoglycoprotein receptor 1 for treatment of hypercholesterolemia: Pharmacophore modeling, molecular docking and molecular dynamics simulation approach.

Hypercholesterolemia is a significant risk factor for atherosclerotic cardiovascular disease (ASCVD). Successful management of cholesterol metabolism disorders can prevent these ASCVD effectively. Asialoglycoprotein receptor 1 (ASGR1) is the main subtype of sialoglycoprotein receptor, which is specifically expressed in the liver and mediates the endocytosis of blood asialoglycoprotein to lysosome degradation. Recently, ASGR1 has been reported as a new therapeutic target for the treatment of hypercholesterolemia. In this study, the main aim was to identify natural ASGR1 inhibitors from plant food chemicals library through pharmacophore and docking based virtual screening. Total 14 phytochemicals of potential ASGR1 inhibitors were identified, which presented docking affinity higher than control compound through docking based virtual screening. The docking pose showed the top three hits interacted residues were located at active pocket of ASGR1 with hydrogen bonds, hydrophobic interactions and electrostatic interactions. The top three hits (ZINC85664954, ZINC169372863, and ZINC195764535) were then subjected to 200 ns molecular dynamics simulation to evaluate the stability of docked complexes. These results showed that selected phytochemicals bound to ASGR1 with higher stability than control compound. Binding free energy of each docked complex was calculated by the Molecular Mechanics Poisson-Boltzmann Surface Area (MM/PBSA) method. The binding free energy of ZINC85664954, ZINC169372863, ZINC195764535, and control-ASGR1 docked complexes were -18.359, -13.303, -14.389, and -6.229 kcal/mol, respectively. This indicated that selected hits bound to ASGR1 with higher affinity than control compound. Network pharmacology analysis shows that these phytochemicals have obvious multiple-effects and can regulate various biochemical pathways related to hypercholesterolemia. Besides, selected phytochemicals have suitable pharmacokinetics properties, suggesting that these compounds may be potential drug candidates. This study may be contributed to rational design of novel ASGR1 inhibitors for treatment of hypercholesterolemia.

Multivalent Targeting of the Asialoglycoprotein Receptor by Virus-Like Particles.

The asialoglycoprotein receptor (ASGPR) is expressed in high density on hepatocytes. Multivalent variants of galactosyl carbohydrates bind ASGPR with high affinity, enabling hepatic delivery of ligand-bound cargo. Virus-like particle (VLP) conjugates of a relatively high-affinity ligand were efficiently endocytosed by ASGPR-expressing cells in a manner strongly dependent on the nature and density of ligand display, with the best formulation using a nanomolar-, but not a picomolar-level, binder. Optimized particles were taken up by HepG2 cells with greater efficiency than competing small molecules or the natural multigalactosylated ligand, asialoorosomucoid. Upon systemic injection in mice, these VLPs were rapidly cleared to the liver and were found in association with sinusoidal endothelial cells, Kupffer cells, hepatocytes, dendritic cells, and other immune cells. Both ASGPR-targeted and nontargeted particles were distributed similarly to endothelial and Kupffer cells, but targeted particles were distributed to a greater number and fraction of hepatocytes. Thus, selective cellular trafficking in the liver is difficult to achieve: even with the most potent ASGPR targeting available, barrier cells take up much of the injected particles and hepatocytes are accessed only approximately twice as efficiently in the best case.

Impact of Asialoglycoprotein Receptor and Mannose Receptor Deficiency on Murine Plasma N-glycome Profiles.

The asialoglycoprotein receptor (ASGPR) and the mannose receptor C-type 1 (MRC1) are well known for their selective recognition and clearance of circulating glycoproteins. Terminal galactose and N-Acetylgalactosamine are recognized by ASGPR, while terminal mannose, fucose, and N-Acetylglucosamine are recognized by MRC1. The effects of ASGPR and MRC1 deficiency on the N-glycosylation of individual circulating proteins have been studied. However, the impact on the homeostasis of the major plasma glycoproteins is debated and their glycosylation has not been mapped with high molecular resolution in this context. Therefore, we evaluated the total plasma N-glycome and plasma proteome of ASGR1 and MRC1 deficient mice. ASGPR deficiency resulted in an increase in O-acetylation of sialic acids accompanied by higher levels of apolipoprotein D, haptoglobin, and vitronectin. MRC1 deficiency decreased fucosylation without affecting the abundance of the major circulating glycoproteins. Our findings confirm that concentrations and N-glycosylation of the major plasma proteins are tightly controlled and further suggest that glycan-binding receptors have redundancy, allowing compensation for the loss of one major clearance receptor.

Genetically mimicked effects of ASGR1 inhibitors on all-cause mortality and health outcomes: a drug-target Mendelian randomization study and a phenome-wide association study.

BACKGROUND: Asialoglycoprotein receptor 1 (ASGR1) is emerging as a potential drug target to reduce low-density lipoprotein (LDL)-cholesterol and coronary artery disease (CAD) risk. Here, we investigated genetically mimicked ASGR1 inhibitors on all-cause mortality and any possible adverse effects. METHODS: We conducted a drug-target Mendelian randomization study to assess genetically mimicked effects of ASGR1 inhibitors on all-cause mortality and 25 a priori outcomes relevant to lipid traits, CAD, and possible adverse effects, i.e. liver function, cholelithiasis, adiposity and type 2 diabetes. We also performed a phenome-wide association study of 1951 health-related phenotypes to identify any novel effects. Associations found were compared with those for currently used lipid modifiers, assessed using colocalization, and replicated where possible. RESULTS: Genetically mimicked ASGR1 inhibitors were associated with a longer lifespan (3.31 years per standard deviation reduction in LDL-cholesterol, 95% confidence interval 1.01 to 5.62). Genetically mimicked ASGR1 inhibitors were inversely associated with apolipoprotein B (apoB), triglycerides (TG) and CAD risk. Genetically mimicked ASGR1 inhibitors were positively associated with alkaline phosphatase, gamma glutamyltransferase, erythrocyte traits, insulin-like growth factor 1 (IGF-1) and C-reactive protein (CRP), but were inversely associated with albumin and calcium. Genetically mimicked ASGR1 inhibitors were not associated with cholelithiasis, adiposity or type 2 diabetes. Associations with apoB and TG were stronger for ASGR1 inhibitors compared with currently used lipid modifiers, and most non-lipid effects were specific to ASGR1 inhibitors. The probabilities for colocalization were > 0.80 for most of these associations, but were 0.42 for lifespan and 0.30 for CAD. These associations were replicated using alternative genetic instruments and other publicly available genetic summary statistics. CONCLUSIONS: Genetically mimicked ASGR1 inhibitors reduced all-cause mortality. Beyond lipid-lowering, genetically mimicked ASGR1 inhibitors increased liver enzymes, erythrocyte traits, IGF-1 and CRP, but decreased albumin and calcium.

Identifying Liver Metastasis-Related Genes Through a Coexpression Network to Construct a 5-Gene Model for Predicting Pancreatic Ductal Adenocarcinoma Patient Prognosis.

OBJECTIVES: This study aimed to develop a liver metastasis-related gene prognostic index (LMPI) for pancreatic ductal adenocarcinoma prognosis and therapy. METHODS: The Cancer Genome Atlas data set was used to identify liver metastasis-related hub genes via weighted gene coexpression network analysis. The core genes were identified to construct an LMPI by using the Cox regression method. An immune cell abundance identifier was applied to determine the immune cell abundance. RESULTS: A total of 78 hub liver metastasis-related genes in the black module were significantly enriched in complement and coagulation cascades, fat digestion and absorption, and the PPAR signaling pathway. Then, an LMPI was constructed on the basis of the 5 prognostic genes (MOGAT3, ASGR1, TRPM8, SGSM1, and LOC101927851). Patients with higher LMPI scores had poor overall survival, more co-occurring or mutually exclusive pairs of driver gene mutations, and less benefit from immunotherapy than patients with lower LMPI scores. In addition, a high correlation was also found between LMPI scores and immune infiltration, such as CD4 naive, CD8 T, cytotoxic T, T helper 2, follicular helper T, and natural killer cells. CONCLUSIONS: The core genes of the LMPI developed may be independent factors for predicting prognosis, immune characteristics, and immunotherapy efficacy in pancreatic ductal adenocarcinoma.

Synthetic Site-Specific Antibody-Ligand Conjugates Promote Asialoglycoprotein Receptor-Mediated Degradation of Extracellular Human PCSK9.

Targeted degradation using cell-specific lysosome targeting receptors is emerging as a new therapeutic strategy for the elimination of disease-associated proteins. The liver-specific human asialoglycoprotein receptor (ASGPR) is a particularly attractive lysosome targeting receptor leveraged for targeted protein degradation (TPD). However, the efficiency of different glycan ligands for ASGPR-mediated lysosomal delivery remains to be further characterized. In this study, we applied a chemoenzymatic Fc glycan remodeling method to construct an array of site-specific antibody-ligand conjugates carrying natural bi- and tri-antennary N-glycans as well as synthetic tri-GalNAc ligands. Alirocumab, an anti-PCSK9 (proprotein convertase subtilisin/kexin type 9) antibody, and cetuximab (an anti-EGFR antibody) were chosen to demonstrate the ASGPR-mediated degradation of extracellular and membrane-associated proteins, respectively. It was found that the nature of the glycan ligands and the length of the spacer in the conjugates are critical for the receptor binding and the receptor-mediated degradation of PCSK9, which blocks low-density lipoprotein receptor (LDLR) function and adversely affects clearance of low-density lipoprotein cholesterol. Interestingly, the antibody-tri-GalNAc conjugates showed a clear hook effect for its binding to ASGPR, while antibody conjugates carrying the natural N-glycans did not. Both the antibody-tri-antennary N-glycan conjugate and the antibody-tri-GalNAc conjugate could significantly decrease extracellular PCSK9, as shown in the cell-based assays. However, the tri-GalNAc conjugate showed a clear hook effect in the receptor-mediated degradation of PCSK9, while the antibody conjugate carrying the natural N-glycans did not. The cetuximab-tri-GalNAc conjugates also showed a similar hook effect on degradation of the membrane-associated protein, epidermal growth factor receptor (EGFR). These results suggest that the two types of ligands may involve a distinct mode of interactions in the receptor binding and target-degradation processes. Interestingly, the alirocumab-tri-GalNAc conjugate was also found to upregulate LDLR levels in comparison with the antibody alone. This study showcases the potential of the targeted degradation strategy against PCSK9 for reducing low-density lipoprotein cholesterol, a risk factor for heart disease and stroke.

Age-dependent differences and similarities in the plasma proteomic signature of postoperative delirium.

Delirium is an acute confusional state and a common postoperative morbidity. Prevalent in older adults, delirium occurs at other ages but it is unclear whether the pathophysiology and biomarkers for the condition are independent of age. We quantified expression of 273 plasma proteins involved in inflammation and cardiovascular or neurologic conditions in 34 middle-aged and 42 older patients before and one day after elective spine surgery. Delirium was identified by the 3D-CAM and comprehensive chart review. Protein expression was measure by Proximity Extension Assay and results were analyzed by logistic regression, gene set enrichment, and protein-protein interactions. Twenty-two patients developed delirium postoperatively (14 older; 8 middle-aged) and 89 proteins in pre- or 1-day postoperative plasma were associated with delirium. A few proteins (IL-8, LTBR, TNF-R2 postoperatively; IL-8, IL-6, LIF, ASGR1 by pre- to postoperative change) and 12 networks were common to delirium in both age groups. However, there were marked differences in the delirium proteome by age; older patients had many more delirium-associated proteins and pathways than middle-aged subjects even though both had the same clinical syndrome. Therefore, there are age-dependent similarities and differences in the plasma proteomic signature of postoperative delirium, which may signify age differences in pathogenesis of the syndrome.

Exploring Receptor Binding Affinities and Hepatic Cell Association of N-Acetyl-d-Galactosamine-Modified ß-Cyclodextrin-Based Polyrotaxanes for Liver-Targeted Therapies.

Acid-degradable polyrotaxanes (PRXs) containing threading ß-cyclodextrins (ß-CDs) are promising candidates for therapeutic applications of ß-CDs in metabolic diseases with cholesterol overload or imbalance. To improve cellular uptake specificity and efficiency of PRXs in hepatocytes, N-acetyl-d-galactosamine (GalNAc)-modified PRXs were developed to facilitate asialoglycoprotein receptor (ASGR)-mediated endocytosis. Binding affinity studies revealed that the dissociation constant (KD) values between recombinant ASGR and GalNAc-PRXs decreased with an increase in the number of modified GalNAc units. Additionally, the KD values for GalNAc-PRXs were smaller than those for GalNAc-modified ß-CD and amylose, suggesting that the PRX backbone structure improves the binding affinity with ASGR. However, the intracellular uptake levels of GalNAc-PRXs in HepG2 cells increased with a decrease in the number of modified GalNAc units, which was opposite to the trend observed in the binding affinity study. We found that GalNAc-PRXs had a large number of GalNAc units localized in recycling endosomes, resulting in the low intracellular uptake. The cholesterol-reducing abilities of GalNAc-PRXs were assessed using cholesterol-overloaded HepG2 cells. GalNAc-PRXs with a small number of GalNAc units were demonstrated to show superior cholesterol-reducing effects compared to previously designed acid-degradable PRX and clinically tested ß-CD derivatives. Thus, we conclude that GalNAc modification is a promising molecular design for the therapeutic application of ß-CD-threaded PRXs in various metabolic diseases with cholesterol overload or imbalance in the liver.