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.

N-acetyl-galactosamine modified metal-organic frameworks to inhibit the growth and pulmonary metastasis of liver cancer stem cells through targeted chemotherapy and starvation therapy.

Hepatocellular carcinoma (HCC) is a common high-mortality malignancy which still needs efficient treatments. HCC patients undergoing extrahepatic metastases are mostly with unsatisfactory prognosis. Therefore, specific attention has been paid to extrahepatic HCC metastasis. We integrated Sorafenib (Sor) and glucose oxidase (GOx) into a N-acetyl-galactosamine (GalNAc) modified zeolitic imidazolate framework (ZIF-8), designated as SG@GR-ZIF-8, for targeted bimodal therapies of chemotherapy and starvation therapy against HCC. The hepatic delivery of SG@GR-ZIF was mediated by the specific recognition of GalNAc residues with asialoglycoprotein (ASGPR) on the liver cell surface. Sor is a clinically approved anti-proliferation and anti-angiogenesis drug for advanced HCC treatment. GOx can efficiently induce cell death and disturb malignant progression by suppressing glucose supply of cancer cells, which is highly associated with metabolic rewiring in metastasis. The nano-formulation exhibit significant anti-metastatic HCC activity against C5WN1 cells, a liver cancer stem cell-like cell line with tumorigenicity and pulmonary metastasis activity. In a subcutaneous C5WN1-tumor carrying mouse model, SG@GR-ZIF exhibits potent synergistic anti-tumor activity with a tumor inhibition rate of 89% and a prolonged survival status. The growth and pulmonary metastasis of HCC in an orthotopic mouse model of HCC was remarkably suppressed in SG@GR-ZIF treated group. The therapeutic strategy targeting energy supply combined with first-line treatment holds great promise for the future treatment of metastatic HCC. STATEMENT OF SIGNIFICANCE: SG@GR-ZIF, a N-acetyl-galactosamine modified metal-organic framework carrying Sorafenib and glucose oxidase, was fabricated for treating metastatic hepatocellular carcinoma (HCC). Sorafenib is an anti-proliferation and anti-angiogenesis drug for advanced HCC treatment. Glucose oxidase blocks energy demand in HCC metastasis by depleting glucose. C5WN1 was used for therapeutic evaluations as a liver cancer stem cell-like cell line with tumorigenicity and pulmonary metastasis activity. In subcutaneous C5WN1-tumor bearing mice, SG@GR-ZIF exhibited a tumor inhibition rate of 89% and prolonged survival period. In orthotopic C5WN1-tumor carrying mice, the growth and pulmonary metastasis of hepatocarcinoma was remarkably suppressed by SG@GR-ZIF. Together, this study suggests the great potential of synergistic chemo/starvation therapy mediated by SG@GR-ZIF for treating metastatic HCC.

Inhibition of ASGR1 decreases lipid levels by promoting cholesterol excretion.

High cholesterol is a major risk factor for cardiovascular disease1. Currently, no drug lowers cholesterol through directly promoting cholesterol excretion. Human genetic studies have identified that the loss-of-function Asialoglycoprotein receptor 1 (ASGR1) variants associate with low cholesterol and a reduced risk of cardiovascular disease2. ASGR1 is exclusively expressed in liver and mediates internalization and lysosomal degradation of blood asialoglycoproteins3. The mechanism by which ASGR1 affects cholesterol metabolism is unknown. Here, we find that Asgr1 deficiency decreases lipid levels in serum and liver by stabilizing LXRα. LXRα upregulates ABCA1 and ABCG5/G8, which promotes cholesterol transport to high-density lipoprotein and excretion to bile and faeces4, respectively. ASGR1 deficiency blocks endocytosis and lysosomal degradation of glycoproteins, reduces amino-acid levels in lysosomes, and thereby inhibits mTORC1 and activates AMPK. On one hand, AMPK increases LXRα by decreasing its ubiquitin ligases BRCA1/BARD1. On the other hand, AMPK suppresses SREBP1 that controls lipogenesis. Anti-ASGR1 neutralizing antibody lowers lipid levels by increasing cholesterol excretion, and shows synergistic beneficial effects with atorvastatin or ezetimibe, two widely used hypocholesterolaemic drugs. In summary, this study demonstrates that targeting ASGR1 upregulates LXRα, ABCA1 and ABCG5/G8, inhibits SREBP1 and lipogenesis, and therefore promotes cholesterol excretion and decreases lipid levels.

Development of Asialoglycoprotein-Mediated Hepatocyte-Targeting Antitumor Prodrugs Triggered by Glutathione.

One antitumor ß-elemene derivative W-105 and three novel hepatocyte-targeting prodrugs (W-1-5, W-2-9, and W-3-8) were designed and synthesized. W-105 (IC50 6.107 µM) could cause cell apoptosis through upregulating the activity of caspase-3. The hepatocyte-targeting capacities of the aimed compounds followed the W-105 (parent compound) < W-1-5 (monodentate-galactose) < W-2-9 (bidentate-galactose) < W-3-8 (tridentate-galactose) order, which is attributed to the excellent affinity of the galactose ligand to ASGPR and the galactose-cluster recognition effect. Furthermore, prodrugs W-3-8 exhibited good antitumor activity and low toxic side effects. The liquid chromatography-mass spectrometry (LC-MS) assays revealed that prodrugs (W-1-5, W-2-9, and W-3-8) could release the antitumor pharmacophore in the presence of GSH (mimic the condition of the tumor cell) and maintain the low-toxic structures in the absence of GSH (mimic the condition of the normal cell). The release mechanisms of prodrugs were also proposed. Overall, these prodrugs developed in this study had potential in the treatment of liver cancer.

Intestinal lamina propria macrophages upregulate interleukin-10 mRNA in response to signals from commensal bacteria recognized by MGL1/CD301a.

Ligand-induced cellular signaling involved in interleukin 10 (IL-10) production by lamina propria macrophages (LPMs) during their interactions with commensal bacteria is not clearly understood. We previously showed, using mice lacking a C-type lectin MGL1/CD301a, that this molecule on colonic LPMs plays an important role in the induction of IL-10 upon interaction with commensal bacteria, Streptococcus sp. In the present report, we show that the physical engagement of MGL1/CD301a on LPMs with in-situ isolated Streptococcus sp. bacteria leads to IL-10 messenger RNA (mRNA) induction. Spleen tyrosine kinase (Syk), caspase recruitment domain 9 (CARD9) and extracellular signal-regulated kinase (ERK), but not NF-κB pathway, are shown to be indispensable for IL-10 mRNA induction after stimulation with heat-killed Streptococcus sp. Guanidine hydrochloride treatment of Streptococcus sp., which is known to extract bacterial cell surface glycan-rich components, abolished bacterial binding to recombinant MGL1/CD301a. The extract contained materials which bound rMGL1 in ELISA and appeared to induce IL-10 mRNA expression in LPMs in vitro. Lectin blotting showed that the extract contained glycoproteins that are considered as putative ligands for MGL1. Some human commensal Lactobacillus species also induced IL-10 mRNA expression by colonic LPMs in vitro, which depends on the presence of MGL1/CD301a and CARD9. The present results are the first to show that MGL1/CD301a acts as a signal transducer during colonic host-microbe interactions.

Subsets of CD1c+ DCs: Dendritic Cell Versus Monocyte Lineage.

Currently three bona fide dendritic cell (DC) types are distinguished in human blood. Herein we focus on type 2 DCs (DC2s) and compare the three defining markers CD1c, CD172, and CD301. When using CD1c to define DC2s, a CD14+ and a CD14- subset can be detected. The CD14+ subset shares features with monocytes, and this includes substantially higher expression levels for CD64, CD115, CD163, and S100A8/9. We review the current knowledge of these CD1c+CD14+ cells as compared to the CD1c+CD14- cells with respect to phenotype, function, transcriptomics, and ontogeny. Here, we discuss informative mutations, which suggest that two populations have different developmental requirements. In addition, we cover subsets of CD11c+CD8- DC2s in the mouse, where CLEC12A+ESAMlow cells, as compared to the CLEC12A-ESAMhigh subset, also express higher levels of monocyte-associated markers CD14, CD3, and CD115. Finally, we summarize, for both man and mouse, the data on lower antigen presentation and higher cytokine production in the monocyte-marker expressing DC2 subset, which demonstrate that the DC2 subsets are also functionally distinct.

Rosiglitazone ameliorates skeletal muscle insulin resistance by decreasing free fatty acids release from adipocytes.

Skeletal muscle and white adipose tissue are important organs of glucose-lipid metabolism. However, excessive lipolysis and free fatty acids (FFA) release in adipocytes elevate plasma FFA, leading to insulin resistance in skeletal muscle. Here, we investigated effects of insulin-resistant adipocytes on skeletal muscle in vitro by simulating body environment using a transwell coculture method. Insulin-resistant 3T3-L1 adipocytes increased lipolysis and FFA release, which reduced insulin sensitivity in the cocultured C2C12 myotubes. Rosiglitazone (RSG) decreased excessive lipolysis by reducing expression of adipose triglyceride lipase (ATGL) and activity of hormone-sensitive lipase (HSL), which led to decrease of FFA release from insulin-resistant 3T3-L1 adipocytes. Meanwhile, insulin resistance in C2C12 myotubes cocultured with insulin-resistant 3T3-L1 adipocytes was ameliorated after RSG treatment. Taken together, our present study provided direct evidence to better understand insulin resistance between skeletal muscle and adipose tissue in type 2 diabetes.

Targeted delivery of mitochondria to the liver in rats.

BACKGROUND AND AIM: Mitochondrial damage is commonly involved in liver injury. We have previously shown that normal mitochondria can be coated with a carrier protein to form complexes that are specifically taken up by liver cells in culture. The aim of the current study was to determine whether mitochondrial complexes could be specifically delivered to the livers of living rats by intravenous injection. METHODS: Mitochondria were harvested from fresh mouse liver, mixed with an asialoglycoprotein-based carrier, asialoorosomucoid-polylysine (AsOR-PL), and purified to form complexes. To facilitate the release of internalized mitochondria from endosomes, an endosomolytic peptide, listeriolysin O (LLO), was coupled to AsOR to form AsOR-LLO. Mitochondria alone, mitochondrial complexes with AsOR-PL, and mitochondrial complexes plus AsOR-LLO conjugate all containing the same number of mitochondria were injected intravenously. Animals were killed, and organs were removed and analyzed by quantitative polymerase chain reaction of mouse mitochondrial DNA, electron microscopy (EM), and in situ polymerase chain reaction and hybridization followed by immunohistochemical analyses. RESULTS: Calculations revealed that approximately 27% of the total injected mitochondria was detected in the liver, while less than 2% was found in spleen, and < 1% in lungs. Immunohistochemistry showed that mouse mitochondrial DNA staining was minimal with mitochondrial complexes alone, strong periportal with mitochondrial complexes co-injected with AsOR-LLO, and absent with mitochondria alone. CONCLUSIONS: Targetable mitochondrial complexes can be delivered to rat liver, and the efficiency of that process is greatly enhanced by co-injection of a targetable endosomal release agent, AsOR-LLO.

Development of a Computational Tool for Automated Interpretation of Intact O-Glycopeptide Tandem Mass Spectra from Single Proteins.

Precise and automated analysis of site-specific O-glycosylation on single proteins is crucial for comprehensive characterization of some important glycoproteins, such as tumor biomarkers and recombinant drug proteins. Mass spectrometry has been proven to be a powerful technique for protein sequencing and N-glycosylation analysis. However, challenges remain in developing computational tools for intact O-glycopeptide analysis, which has greatly hindered the development of mass-spectrometry-based O-glycosylation analysis. Herein, an integrated strategy together with a dedicated automated computational tool termed AOGP was developed for intact O-glycopeptide analysis on single proteins. AOGP utilized de novo sequencing for O-glycans and a database search strategy for peptide backbones. The false discovery rate (FDR) of the identification results was controlled and validated by a mixed Gaussian distribution estimation method. AOGP exhibited superior performance in identifying intact O-glycopeptides of the human erythropoietin with a total of 188 O-glycopeptide spectra reported under 1% FDR. AOGP is developed in Python, is fully open-sourced, and is equipped with a user-friendly interface. Such an easy-operating and robust tool would greatly facilitate O-glycosylation analysis on single proteins in tumor biomarker and recombinant drug protein development.

Plasmonic biosensors fabricated by galvanic displacement reactions for monitoring biomolecular interactions in real time.

Optical sensors are prepared by reduction of gold ions using freshly etched hydride-terminated porous silicon, and their ability to specifically detect binding between protein A/rabbit IgG and asialofetuin/Erythrina cristagalli lectin is studied. The fabrication process is simple, fast, and reproducible, and does not require complicated lab equipment. The resulting nanostructured gold layer on silicon shows an optical response in the visible range based on the excitation of localized surface plasmon resonance. Variations in the refractive index of the surrounding medium result in a color change of the sensor which can be observed by the naked eye. By monitoring the spectral position of the localized surface plasmon resonance using reflectance spectroscopy, a bulk sensitivity of 296 nm ± 3 nm/RIU is determined. Furthermore, selectivity to target analytes is conferred to the sensor through functionalization of its surface with appropriate capture probes. For this purpose, biomolecules are deposited either by physical adsorption or by covalent coupling. Both strategies are successfully tested, i.e., the optical response of the sensor is dependent on the concentration of respective target analyte in the solution facilitating the determination of equilibrium dissociation constants for protein A/rabbit IgG as well as asialofetuin/Erythrina cristagalli lectin which are in accordance with reported values in literature. These results demonstrate the potential of the developed optical sensor for cost-efficient biosensor applications. Graphical abstract.

Glioblastomas exploit truncated O-linked glycans for local and distant immune modulation via the macrophage galactose-type lectin.

Glioblastoma is the most aggressive brain malignancy, for which immunotherapy has failed to prolong survival. Glioblastoma-associated immune infiltrates are dominated by tumor-associated macrophages and microglia (TAMs), which are key mediators of immune suppression and resistance to immunotherapy. We and others demonstrated aberrant expression of glycans in different cancer types. These tumor-associated glycans trigger inhibitory signaling in TAMs through glycan-binding receptors. We investigated the glioblastoma glycocalyx as a tumor-intrinsic immune suppressor. We detected increased expression of both tumor-associated truncated O-linked glycans and their receptor, macrophage galactose-type lectin (MGL), on CD163+ TAMs in glioblastoma patient-derived tumor tissues. In an immunocompetent orthotopic glioma mouse model overexpressing truncated O-linked glycans (MGL ligands), high-dimensional mass cytometry revealed a wide heterogeneity of infiltrating myeloid cells with increased infiltration of PD-L1+ TAMs as well as distant alterations in the bone marrow (BM). Our results demonstrate that glioblastomas exploit cell surface O-linked glycans for local and distant immune modulation.

Macrophage galactose lectin is critical for Kupffer cells to clear aged platelets.

Every day, megakaryocytes produce billions of platelets that circulate for several days and eventually are cleared by the liver. The exact removal mechanism, however, remains unclear. Loss of sialic acid residues is thought to feature in the aging and clearance of platelets. Using state-of-the-art spinning disk intravital microscopy to delineate the different compartments and cells of the mouse liver, we observed rapid accumulation of desialylated platelets predominantly on Kupffer cells, with only a few on endothelial cells and none on hepatocytes. Kupffer cell depletion prevented the removal of aged platelets from circulation. Ashwell-Morell receptor (AMR) deficiency alone had little effect on platelet uptake. Macrophage galactose lectin (MGL) together with AMR mediated clearance of desialylated or cold-stored platelets by Kupffer cells. Effective clearance is critical, as mice with an aged platelet population displayed a bleeding phenotype. Our data provide evidence that the MGL of Kupffer cells plays a significant role in the removal of desialylated platelets through a collaboration with the AMR, thereby maintaining a healthy and functional platelet compartment.

MGL1 Receptor Plays a Key Role in the Control of T. cruzi Infection by Increasing Macrophage Activation through Modulation of ERK1/2, c-Jun, NF-κB and NLRP3 Pathways.

Macrophage galactose-C type lectin (MGL)1 receptor is involved in the recognition of Trypanosoma cruzi (T. cruzi) parasites and is important for the modulation of the innate and adaptive immune responses. However, the mechanism by which MGL1 promotes resistance to T. cruzi remains unclear. Here, we show that MGL1 knockout macrophages (MGL1-/- Mφ) infected in vitro with T. cruzi were heavily parasitized and showed decreased levels of reactive oxygen species (ROS), nitric oxide (NO), IL-12 and TNF-α compared to wild-type macrophages (WT Mφ). MGL1-/- Mφ stimulated in vitro with T. cruzi antigen (TcAg) showed low expression of TLR-2, TLR-4 and MHC-II, which resulted in deficient splenic cell activation compared with similar co-cultured WT Mφ. Importantly, the activation of p-ERK1/2, p-c-Jun and p-NF-κB p65 were significantly reduced in MGL1-/- Mφ exposed to TcAg. Similarly, procaspase 1, caspase 1 and NLRP3 inflammasome also displayed a reduced expression that was associated with low IL-ß production. Our data reveal a previously unappreciated role for MGL1 in Mφ activation through the modulation of ERK1/2, c-Jun, NF-κB and NLRP3 signaling pathways, and to the development of protective innate immunity against experimental T. cruzi infection.

CD301 mediates fusion in IL-4-driven multinucleated giant cell formation.

Multinucleated giant cells (MGCs) are prominent in foreign body granulomas, infectious and inflammatory processes, and auto-immune, neoplastic and genetic disorders, but the molecular determinants that specify the formation and function of these cells are not defined. Here, using tandem mass tag-mass spectrometry, we identified a differentially upregulated protein, C-type lectin domain family 10 member (herein denoted CD301, also known as CLEC10A), that was strongly upregulated in mouse RAW264.7 macrophages and primary murine macrophages undergoing interleukin (IL-4)-induced MGC formation. CD301+ MGCs were identified in biopsy specimens of human inflammatory lesions. Function-inhibiting CD301 antibodies or CRISPR/Cas9 deletion of the two mouse CD301 genes (Mgl1 and Mgl2) inhibited IL-4-induced binding of N-acetylgalactosamine-coated beads by 4-fold and reduced MGC formation by 2.3-fold (P<0.05). IL-4-driven fusion and MGC formation were restored by re-expression of CD301 in the knockout cells. We conclude that in monocytes, IL-4 increases CD301 expression, which mediates intercellular adhesion and fusion processes that are required for the formation of MGCs.This article has an associated First Person interview with the first author of the paper.

Study on glycoprotein terahertz time-domain spectroscopy based on composite multiscale entropy feature extraction method.

Tumor genesis is accompanied by glycosylation of related proteins. Glycoprotein is usually regarded as a tumor marker since glycoproteins are consumed remarkably more by the cancer cells than the normal ones. In this paper, the terahertz time-domain attenuated total reflection (ATR) technique is applied to inspect the glycoprotein solution from a concentration gradient of 0.2 mg/ml to 50 mg/ml. A significant nonlinear relationship between the absorption coefficient and the concentrations has been discovered. The influence of the dynamical hydration shell around glycoprotein molecules on the absorption coefficient is discussed and the phenomenon is explained by the concepts of THz excess and THz defect. In order to identify glycoproteins, features are obtained by composite multiscale entropy (CMSE) method and clustered by the K-means algorithm. The results indicate that features extracted by the CMSE method are better than the Principal Component Analysis (PCA) method in both specificity and sensitivity of recognition. Meanwhile, the absorption coefficient and dielectric loss angle tangent are more suitable for qualitative identification. Research shows that the CMSE method has important directive significance for analyzing glycoprotein terahertz spectroscopy. And it has the potential for glycoprotein related tumor markers identification using terahertz technology in medical applications.

Activated microglia desialylate their surface, stimulating complement receptor 3-mediated phagocytosis of neurons.

The glycoproteins and glycolipids of the cell surface have sugar chains that normally terminate in a sialic acid residue, but inflammatory activation of myeloid cells can cause sialidase enzymes to remove these residues, resulting in desialylation and altered activity of surface receptors, such as the phagocytic complement receptor 3 (CR3). We found that activation of microglia with lipopolysaccharide (LPS), fibrillar amyloid beta (Aß), Tau or phorbol myristate acetate resulted in increased surface sialidase activity and desialylation of the microglial surface. Desialylation of microglia by adding sialidase, stimulated microglial phagocytosis of beads, but this was prevented by siRNA knockdown of CD11b or a blocking antibody to CD11b (a component of CR3). Desialylation of microglia by a sialyl-transferase inhibitor (3FAx-peracetyl-Neu5Ac) also stimulated microglial phagocytosis of beads. Desialylation of primary glial-neuronal co-cultures by adding sialidase or the sialyl-transferase inhibitor resulted in neuronal loss that was prevented by inhibiting phagocytosis with cytochalasin D or the blocking antibody to CD11b. Adding desialylated microglia to glial-neuronal cultures, in the absence of neuronal desialylation, also caused neuronal loss prevented by CD11b blocking antibody. Adding LPS or Aß to primary glial-neuronal co-cultures caused neuronal loss, and this was prevented by inhibiting endogenous sialidase activity with N-acetyl-2,3-dehydro-2-deoxyneuraminic acid or blockage of CD11b. Thus, activated microglia release a sialidase activity that desialylates the cell surface, stimulating CR3-mediated phagocytosis of neurons, making extracellular sialidase and CR3 potential treatment targets to prevent inflammatory loss of neurons.

Paediatric orbital conjunctival epithelial cyst with positive asialotransferrin.

Conjunctival orbital cysts are rare; they are typically either conjunctival dermoid or conjunctival epithelial cysts - congenital or acquired (inclusion). We describe the case of a 15-month-old girl presenting with strabismus and proptosis who had a retrobulbar intraconal cystic lesion displacing the optic nerve, with an adjacent middle cranial fossa anomaly. Aspiration of the orbital cyst tested positive for asialotransferrin, raising the suspicion of a direct communication with cerebrospinal fluid (CSF). Subsequent fine cut CT scanning disproved any connection with the intracranial space, and the cyst was excised complete and intact. Histopathology showed a conjunctival epithelial cyst. To our knowledge, this is the first case report in the literature of an asialotransferrin positive pediatric orbital conjunctival epithelial cyst. It is of clinical relevance as it explores the possibility of either a false positive asialotransferrin or potentially a prior developmental communication with the subarachnoid space. These two diagnostic possibilities are discussed.

Clec10a regulates mite-induced dermatitis.

House dust mite (HDM) is a major allergen that causes allergic diseases such as atopic dermatitis. However, the regulatory mechanisms of HDM-induced immune responses are incompletely understood. NC/Nga mice are an inbred strain that is more susceptible to HDM and develops more severe dermatitis than other strains. Using whole-exome sequencing, we found that NC/Nga mice carry a stop-gain mutation in Clec10a, which encodes a C-type lectin receptor, Clec10a (MGL1/CD301a). The repair of this gene mutation using the CRISPR-Cas9 system ameliorated HDM-induced dermatitis, indicating that the Clec10a mutation is responsible for hypersensitivity to HDM in NC/Nga mice. Similarly, Clec10a -/- mice on the C57BL/6J background showed exacerbated HDM-induced dermatitis. Clec10a expressed on skin macrophages inhibits HDM-induced Toll-like receptor 4 (TLR4)-mediated inflammatory cytokine production through the inhibitory immunoreceptor tyrosine activating motif in its cytoplasmic portion. We identified asialoglycoprotein receptor 1 (Asgr1) as a functional homolog of mouse Clec10a in humans. Moreover, we found that a mucin-like molecule in HDM is a ligand for mouse Clec10a and human Asgr1. Skin application of the ligand ameliorated a TLR4 ligand-induced dermatitis in mice. Our findings suggest that Clec10a in mice and Asgr1 in humans play an important role in skin homeostasis against inflammation associated with HDM-induced dermatitis.

Diagnostic Performance of Serum Asialo-α1-acid Glycoprotein for Advanced Liver Fibrosis or Cirrhosis in Patients with Chronic Hepatitis B or Nonalcoholic Fatty Liver Disease.

BACKGROUND/AIMS: The utility of asialo-α1-acid glycoprotein (AsAGP) for assessing the fibrotic burden is unknown. This study examined the diagnostic performance of the AsAGP level for advanced liver fibrosis or cirrhosis in patients with chronic hepatitis B (CHB) or nonalcoholic fatty liver disease (NAFLD). METHODS: From July to December 2018, 48 patients with CHB and 75 with NAFLD were recruited prospectively. Transient elastography was used as the reference standard for liver fibrosis, and the cutoff liver stiffness values were defined as 10.0 kilopascal (kPa) for ≥F3 and 12.0 kPa for F4 in CHB patients, and 9.0 kPa for ≥F3 and 11.8 kPa for F4 in NAFLD patients. RESULTS: To predict stage ≥F3 and F4 fibrosis, the areas under the receiver operating characteristic curves of the AsAGP level in patients with CHB were 0.788 (95% CI 0.647-0.930; p=0.005) and 0.825 (95% CI 0.674-0.976; p=0.004), respectively. The cutoff AsAGP levels in patients with CHB that maximized the sum of the sensitivity and specificity values were 1.31 (sensitivity 100.0%, specificity 52.6%) and 1.55 (sensitivity 75.0%, specificity 80.0%), respectively. In contrast, the AsAGP level was similar regardless of the fibrosis stage in patients with NAFLD (all p>0.05 between the stages). CONCLUSIONS: The AsAGP level showed acceptable diagnostic accuracy in predicting advanced liver fibrosis and cirrhosis in patients with CHB but not in those with NAFLD. Further studies will be needed to validate the diagnostic performance of the AsAGP level in patients with NALFD.