Amyloid-β peptide (Aβ) is eliminated from the brain across the blood–brain barrier (BBB) by an insulin-sensitive process. To investigate the involvement of insulin-degrading enzyme (IDE) in this process, the present study was implemented to clarify the effect of a novel IDE-specific inhibitor, Ii1, on the elimination of [¹²⁵I]Aβ(1-40) from rat brain via the brain efflux index method. The results showed that such elimination was significantly inhibited by the co-administration of Ii1. The maximum inhibitory effect of Ii1 and IC₅₀ were 69.4% and 9.96 µM, respectively. Insulin alone inhibited the elimination of [¹²⁵I]Aβ(1-40), but the inhibitory effect of co-administering insulin and Ii1 was not significantly different from that of Ii1 alone. Meanwhile, thiorphan, an inhibitor of neprilysin, showed an additive inhibitory effect with Ii1. Aβ(1-13) and Aβ(1-14), which are major fragments produced by the degradation of Aβ(1-40) by IDE, and inhibitors of receptor for advanced glycation end products (RAGE) did not significantly inhibit the [¹²⁵I]Aβ(1-40) elimination. These results suggest that IDE is involved in the insulin-sensitive process of [¹²⁵I]Aβ(1-40) elimination across the BBB, to which neprilysin and RAGE make minor contributions. These findings suggest that impairment of IDE may be involved in the onset of sporadic Alzheimer’s disease.

This study investigated the protective effects of metformin against combined high glucose (HG)- and UVA-induced cytotoxicity in fetal rat skin keratinocytes (FRSK cells), a model of diabetic photoaging. HG combined with UVA caused a synergistic loss of cell viability accompanied by marked increases in phosphorylation of AMP-activated protein kinase (p-AMPK), reactive oxygen species (ROS) generation, senescence-associated β-galactosidase (SA-β-Gal) activity, and Sirtuin 1 (SIRT1) expression. HG alone induced moderate cytotoxicity and senescence, whereas UVA alone under normal glucose conditions (NG + UVA) produced negligible ROS and minimal viability loss. Metformin improved cell viability under dual stress conditions in a dose-dependent manner, with maximal protection observed at 8 mM. In UVA-free cultures, metformin increased p-AMPK in both NG and HG, peaking at 8 mM. Under HG + UVA, p-AMPK was higher than in NG + UVA and HG alone, with no additional increase following metformin treatment. ROS accumulation occurred only under HG + UVA and was strongly suppressed by metformin, nearly to baseline at 8 mM. The HG + UVA-induced increases in SA-β-Gal activity and SIRT1 expression were reduced in parallel with ROS suppression. These findings suggest that metformin’s cytoprotective effect in this model is primarily mediated by attenuation of ROS rather than by further AMPK activation, indicating an AMPK-independent antioxidant mechanism.

“Antibody engineering” is a promising strategy for generating high-affinity antibodies required for developing sensitive immunoassays. Therein, the variable domains (V_H and V_L) of the parental antibody are genetically randomized and combined to produce diverse single-chain Fv fragment (scFv) molecules. Subsequently, high-affinity scFv mutants are selectively isolated. In the randomization process, mutations have conventionally been targeted to the complementarity-determining regions (CDRs) in the variable domains, which often interact directly with antigens. However, we previously discovered that, pinpoint insertion of only a single amino acid (leucine, asparagine, aspartic acid, proline, glutamine, arginine, or histidine) between positions 6 and 7 in the framework region 1 (FR1) of the V_H, which is unlikely to interact with antigens, enhanced the affinity of an anti-cortisol scFv (original K_a, 3.6 × 10⁸ M⁻¹) up to 17–61-fold. These findings prompted us to conduct a comprehensive study of this affinity-enhancement phenomenon involving the remaining amino acids. Thus, we generated the necessary 13 scFv mutants and compared their K_a values. Remarkably, all mutants showed enhanced affinities, similar to those of the previous 7 mutants. Among the 20 mutants, the leucine-inserted scFv showed the largest K_a (2.2 × 10¹⁰ M⁻¹) and consequently enabled a 75-fold more sensitive enzyme-linked immunosorbent assay (midpoint, 9.86 pg/assay) compared to the assay using the parental scFv (midpoint, 744 pg/assay). In silico modeling suggested that, regardless of the amino acid inserted, elongated FR1 can alter the conformation of the CDR3 in V_H to facilitate a favorable interaction with cortisol.

It is known that the daily feeding cycle affects the dosing time-dependent changes in the pharmacodynamics and pharmacokinetics of many drugs. Our previous study demonstrated that administration of empagliflozin (EMPA), sodium-glucose cotransporter 2 (SGLT2) inhibitor, at the beginning of daily feeding cycle (active phase) effectively prevents the development of neuropathic pain in streptozotocin (STZ)-induced diabetic mice. Although the blood glucose levels are closely related to feeding, the relationship between the daily feeding cycle and the optimal dosing time of EMPA remains unclear. In this study, we used STZ-induced diabetic mice and implemented a daily time-restricted feeding (TRF) regimen to investigate whether the dosing time-dependent preventive effect of EMPA on the diabetic neuropathy is modulated by TRF. Animals were housed under a 12-h light/dark cycle, and were assigned to either light-phase TRF (feeding during the light phase) or dark-phase TRF (feeding during the dark phase). The hypoglycemic effect of EMPA was enhanced when the drug was administrated at the beginning of both TRF conditions. A similar influence of the daily feeding cycle on the dosing time-dependent hypoglycemic effect of EMPA was also observed in its preventive effect on the development of diabetic neuropathic pain. Further analysis revealed that dosing time-dependent variations in both the hypoglycemic effect of EMPA and its preventive effect on diabetes-induced pain hypersensitivity were attributable to corresponding changes in urinary glucose excretion. Our results support the notion that the administration of EMPA at the onset of daily feeding cycle effectively suppresses the development of diabetic peripheral neuropathy.

Metabolic enzymes are occasionally downregulated in in vitro induction studies. Recently, HepaRG cells have been used for CYP induction assays instead of human hepatocytes in the early drug discovery stage; however, there is limited information on CYP downregulation by drug stimulation. In this study, we evaluated the effect of hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) inhibitors, which downregulate CYP in human hepatocytes, on CYP gene expression in HepaRG cells. Microarray analysis to determine the expression levels of pharmacokinetics-related enzymes and RT-PCR to determine the expression levels of CYP3A4, CYP2B6, CYP1A2, and their nuclear receptor mRNA were conducted in HepaRG cells treated with HIF-PH inhibitors. Treatment of HepaRG cells with HIF-PH inhibitors decreased the expression of several pharmacokinetics-related metabolic enzymes, whereas Erythropoietin (EPO) and Pyruvate Dehydrogenase Kinase1 (PDK1) genes were induced. The expression of CYP3A4 and CYP2B6 in HepaRG cells showed concentration- and time-dependent downregulation following treatment with the HIF-PH inhibitor. The downregulation of these enzymes was correlated with the decrease of PXR/RXRα and CAR/RXRα, respectively. CYP1A2 decreased transiently, but recovered with continued HIF-PH inhibitor treatment. CYP3A4 and CYP2B6 were downregulated by HIF-PH inhibitors in HepaRG cells and human hepatocytes. In contrast, CYP1A2 in HepaRG cells responded differently to HIF-PH inhibitors than in human hepatocytes. Since CYP downregulation is commonly observed with HIF-PH inhibitors, along with the induction of EPO and PDK1 genes, stabilizing HIF may be one of the factors involved in CYP downregulation.

Intestinal epithelial cells (IECs) play a crucial role in forming a protective barrier and regulating the absorption of substances passing through the small intestine. Disrupting the epithelial barrier function can result in intestinal diseases such as inflammatory bowel disease. Glyceraldehyde (GA)-derived advanced glycation end-products (AGEs) (toxic AGEs, TAGE) are AGEs formed by the nonenzymatic Maillard reaction. Although AGEs have been implicated in intestinal barrier breakdown, the associated mechanism remains underexplored. In this study, the effects of accumulated TAGE in IECs were investigated by focusing on tight junctions using Caco-2 cells—a human colorectal epithelial adenocarcinoma cell line. While GA treatment induced the formation of intracellular TAGE in Caco-2 cells, resulting in cell death, the generated intracellular TAGE triggered increased paracellular permeability. In addition, immunofluorescence staining showed that GA treatment decreased the fluorescence intensities of ZO-1 and claudin-7, which are tight junction proteins attached to the plasma membrane. Furthermore, an evaluation of the mechanism behind intestinal barrier breakdown revealed excessive reactive oxygen species (ROS) production and increased expression of reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase subunit genes, a mechanism of ROS production, in the GA-treated group compared with the control group. Furthermore, GA treatment induced necrosis and caused cytotoxicity in this condition. Overall, these results suggest that TAGE induction can disrupt tight junctions in IECs via cell injury as a pathway.

Chronic kidney disease (CKD) is a serious chemotherapy-associated clinical condition. CKD complicates the pharmacokinetics of anticancer drugs, requiring personalized dosing strategies to minimize toxicity. S-1 and oxaliplatin (the SOX regimen) are widely used for gastrointestinal cancer treatment. However, the specific association between systemic drug exposure and renal biomarker levels in CKD remains unclear. This study evaluated the pharmacokinetics of S-1 and oxaliplatin in 2 CKD model rats (5/6 nephrectomy and adenine-induced) and examined their relationships with renal biomarkers. S-1 (2 mg/kg as tegafur) and oxaliplatin (5 mg/kg) were administered separately, and plasma levels of tegafur, 5-fluorouracil (5-FU), 5-chloro-2,4-dihydropyridine, oxaliplatin, and platinum were measured by LC-tandem MS. Systemic exposure to S-1 and oxaliplatin was higher in the CKD model rats than in the normal group, with 5-FU levels being particularly higher in the adenine-induced model than in the 5/6 nephrectomy model. The area under the curve values of 5-FU and platinum were strongly correlated with plasma creatinine (P_Cr) levels (r = 0.79 and 0.88, respectively). Population pharmacokinetic analysis identified P_Cr as a significant covariate of 5-FU clearance. A nomogram constructed using P_Cr-based simulations demonstrated the feasibility of individualized S-1 dosing. Overall, our findings suggest that P_Cr is a practical biomarker to guide S-1 dose optimization and highlight the importance of pharmacokinetics-based strategies for patients with cancer and CKD.

He-Wei-Decoction (HWD), a traditional Chinese medicine formula, emphasizes “strengthening the spleen and supplementing qi (Jianpi Yiqi),” and “resolving stasis and detoxifying (Huayu Jiedu).” This formula has been utilized in the treatment of chronic atrophic gastritis (CAG), however, its precise mechanisms of action remain to be elucidated. This study integrates network pharmacology with molecular dockings to identify the underlying mechanisms of HWD in the treatment of CAG. Then, immunohistochemistry assay analyzed the gastric mucosal lesions before and after treatment with HWD in CAG patients. The efficacy and mechanism of key active compounds in the treatment of CAG were validated using a 1-methyl-3-nitro-1-nitrosoguanidine (MNNG)-induced GES-1 cell in vitro model. A total of 165 active compounds from HWD were identified, along with 169 targets associated with CAG. Gene oncology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and Component-Target-Pathway network analysis revealed that the Toll-like receptor (TLRs) signaling pathway may play a role in HWD’s regulation of inflammation in gastric mucosa. Molecular docking identified that luteolin, quercetin, and hederagenin potentially interact with key target proteins TLR4 and nuclear factor-kappaB (NF-κB). Experimental results validated that HWD significantly improved atrophic mucosa and inhibited the expression of TLR4, NF-κB, and cyclooxygenase 2 (COX2) proteins. The active compounds, luteolin, quercetin, and hederagenin, inhibit cell viability, migration and invasion, and reduce the expression of TLR4, NF-κB, and COX2. In summary, luteolin, quercetin, and hederagenin, the primary active components of HWD, can ameliorate the CAG by regulating the TLR4/NF-κB signaling pathway.

We previously reported that CD8⁺ T cell activation via drug-induced altered self-presentation increases the tumor immunogenicity and cancer immunotherapy efficacy. Although the anti-human immunodeficiency virus drug abacavir (ABC) increases the tumor immunogenicity and induces CD8⁺ T cell anti-tumor immune responses in mice inoculated with tumor cells ectopically expressing the human leukocyte antigen (HLA)-B*57:01, whether such anti-tumor immunity is also triggered in hosts with high HLA-B*57:01 expression levels remain unclear. To verify this, we investigated the anti-tumor effects of ABC on HLA-B*57:01-expressing tumor and normal host cells using HLA-B*57:01 transgenic (B*57:01-Tg) mice in this study. ABC suppressed the HLA-B*57:01-expressing B16F10 tumor growth and increased the CD8⁺ T cell tumor infiltration in B*57:01-Tg mice. ABC also activated the tumor-infiltrating CD8⁺ T cells to secrete interferon-γ but did not promote their proliferation in the tumors of B*57:01-Tg mice. Moreover, ABC did not increase the effector CD8⁺ T cell proportions in the tumor-draining lymph nodes of B*57:01-Tg mice. Overall, CD8⁺ T cells preferentially recognized the ABC-induced altered self-antigen-presenting HLA-B*57:01-expressing tumor cells, but not host cells, to elicit anti-tumor immunity.

Resistance to thyroid hormone-β (RTHβ) is caused by mutations in thyroid hormone receptors (TRs), with palpitations, tachycardia, and/or goiter being the most frequently reported clinical features. In recent years, several synthetic thyromimetics have been developed to target mutations associated with RTHβ. Resmetirom, which was granted an accelerated approval by the U.S. Food and Drug Administration, is a TRβ-agonist for the first line therapy for metabolic dysfunction-associated steatohepatitis. This study aimed to evaluate the potential mechanisms of action of resmetirom on RTHβ through co-factors and association with clinical manifestations. We selected cases from 13 clinical records based on recently reported domestic cases in Japan. Based on these clinical reports, we conducted screenings using clinical symptoms, laboratory findings, and mutation data. We attempted to unveil the interaction between 26 RTHβ mutants and resmetirom focusing on recruitment of co-factors. Among the 26 probands, dominant-negative effects (DNE) were identified in 12 mutant TRs (48.5 ± 11.8%). Resmetirom was involved in the recruitment of the co-activators, steroid receptor coactivator-1 and glucocorticoid receptor-interacting protein-1, as well as the co-repressors (CoRs), nuclear-CoR and silencing mediator of retinoic acid and TR. Co-factor recruitment by resmetirom was detected in all mutants. In eight patients with DNE, an association between transcriptional activity and clinical symptoms was observed, which were the reasons for clinical investigation. Notably, in the helix-12 mutant-P453, mild induction of DNE was associated with the recruitment of CoRs, suggesting that resmetirom may be effective in alleviating subjective symptoms in mutants with attenuated DNE located in helix-12.

Glioblastoma (GBM) is a highly aggressive and lethal brain tumor with very poor prognosis despite recent progress in multimodal treatments. Within glioma tissue, various niche cells such as macrophages and neutrophils form a unique glioma immune microenvironment (GIME) by interacting with heterogenous cancer cells, and this has been implicated in disease progression and responsiveness to immunomodulatory therapies. This study explores novel potential prognostic markers associated with the GIME using integrated bioinformatics analyses, including single-cell RNA-sequencing (scRNA-seq), and spatial transcriptome (ST) datasets of clinical GBM specimens. We first identified 42 genes as being associated with poor prognosis in GBM from 5 different cohorts, GBM vs. nontumor tissue, grade IV vs. grade II gliomas, isocitrate dehydrogenase (IDH)-wild-type vs. IDH-mutant variants, mesenchymal vs. proneural and classical subtypes, and hazard ratio for overall survival. Among these, 32 genes were positively correlated with ESTIMATEScore, infiltration of various immune cell types, expression of known immune-related genes, and representative immune-associated biological signals. On scRNA-seq analysis, 7 genes were relatively concentrated in tumor-associated macrophages rather than in malignant cells. ST analysis revealed that Collagen beta(1-O)galactosyltransferase 1 (COLGALT1), Integrin subunit beta 2 (ITGB2), and Myosin light chain 12A (MYL12A) were distributed in the interface between the tumor and the peritumoral area, overlapping with the expression of representative immune-related genes. These findings support the potential of COLGALT1, ITGB2 and MYL12A as biomarkers for predicting the prognosis and immune responses of GBM, which can help in the development of potential immunotherapeutic strategies for GBM.

Adropin is a 43-amino acid peptide that is highly conserved among mammals. First identified in the mouse liver in 2008, adropin is broadly expressed throughout the body and has been implicated in various pathological conditions, including obesity, altered food intake, insulin resistance, glucose intolerance, and other disorders related to energy metabolism. However, its precise physiological role remains unclear. In this study, we developed a specific competitive enzyme-linked immunosorbent assay (ELISA) for adropin using an in-house generated anti-adropin polyclonal antibody. We then examined plasma adropin levels in mice under different energy metabolic conditions: fed a normal diet, subjected to short-term fasting, and fed a long-term high-fat diet. In addition, we assessed hepatic and hypothalamic expression of Enho mRNA, which encodes adropin. We observed a wide range of plasma adropin levels, spanning from those in normal healthy mice on a high-fat diet to preclinical and obese diabetic mice. Both plasma adropin concentrations and hepatic Enho mRNA expression increased in response to feeding and high-fat diet intake. Multiple regression analysis revealed a significant negative correlation between plasma adropin and plasma glucagon concentrations. These findings suggest that adropin secretion is modulated by the peripheral hormone glucagon and may contribute to the maintenance of energy metabolic homeostasis. In conclusion, the ELISA developed in this study provides a useful and reliable tool for investigating the mechanisms underlying energy metabolism.

Parthanatos is a noncanonical form of regulated cell death mediated by the overactivation of poly(ADP-ribose) polymerase-1, yet its regulatory mechanisms are not fully understood. To fully elucidate its regulatory mechanisms, it is necessary to establish useful research tools to investigate parthanatos. We have previously identified the human fibrosarcoma HT1080 cells as highly sensitive cells to parthanatos, and cefotaxime, a 3rd-generation cephem antibiotic, as the parthanatos inducer. In this study, we comprehensively characterized the ability of various cephem antibiotics, including cephalothin (also called cefalotin) (CET), cefoxitin, ceftriaxone, cefoperazone, ceftezole, and cefalexin, to induce parthanatos. Among them, CET exhibited the lowest LD₅₀. Therefore, our results show that CET works as the more potent and useful parthanatos inducer.

Allergic contact dermatitis (ACD) is a common skin disorder caused by contact with allergens. ACD treatment is based on patient education to avoid contact with allergens. However, sometimes patients may not be able to avoid the allergen because of its close proximity to their living environment. Thus, a novel therapeutic strategy that does not involve the avoidance of allergens is required. We previously reported that methionine, an essential amino acid, significantly suppressed ACD development caused by the repeated application of 1-fluoro-2,4-dinitrobenzene (DNFB). However, the magnitude of this suppressive effect of methionine depended on the mouse strain used to establish ACD, and the mechanism of this difference was still unclear in past studies. In this study, we investigated the mechanism underlying these strain differences and found that a lack of selenium-binding protein 1 (SBP1) enhanced the ACD-suppressive effect of methionine. The lack of SBP1 does not affect ACD progression; however, it reduces the hepatic beta-homocysteine methyltransferase (Bhmt) expression suppression by ACD. In support of this hypothesis, the lack of SBP1 reduced the suppression of hepatic dimethylglycine (DMG) production by ACD. These results suggest that the lack of SBP1 enhances the suppressive effects of methionine on ACD by suppressing DMG production.

The Kelch-like ECH-associated protein 1 (Keap1)/nuclear factor (erythroid-derived 2)-like 2 (Nrf2) system plays an important role in defense against oxidative stress, and its involvement has been implicated in body weight reduction under obese conditions. While the effect on white adipose tissue (WAT) has been intensely studied, focusing on the anti-inflammatory and anti-oxidative stress effects exerted by Nrf2 activation, the involvement of skeletal muscle has not been investigated. We assessed the body weight changes induced by Nrf2 activation by comparing its effect on WAT with those on skeletal muscle. We evaluated TBE-31, a potent Nrf2 activator, in a high-fat diet (HFD)-induced obesity model. Notably, TBE-31 significantly suppressed HFD-induced body weight gain compared with vehicle treatment. While treatment with TBE-31 induced a significant WAT weight decrease compared with vehicle, skeletal muscle weight was not affected. In addition, body weight changes were significantly correlated with WAT but not with skeletal muscle. Lipid deposition was remarkably improved in the adipose tissue, but muscle histology was not affected. A gene expression analysis revealed that Ucp-1 was upregulated and Il-6 downregulated by TBE-31 treatment in an Nrf2-dependent manner. Taken together, these findings suggest that pharmacological activation of Nrf2 suppressed HFD-induced body weight gain by affecting WAT.

Allergy immunotherapy (AIT) plays a pivotal role in the treatment of type I allergic conditions such as allergic rhinitis and rhinoconjunctivitis. However, AIT faces persistent issues, notably the risk of anaphylaxis and the need for long-term treatment. To address these issues, various strategies have been explored, including the use of adjuvants, allergen delivery systems, and allergen modifications. This study used a prophylactic mouse model of allergic sensitization to explore the potential for improving the efficacy and safety of Japanese cedar pollen (JCP) subcutaneous immunotherapy (SCIT). In this model, JCP extract was combined with an adjuvant (K3 CpG oligodeoxynucleotide [CpG-ODN]) and/or a delivery system (dilauroyl phosphatidylcholine/deoxycholic acid [DLPC/DA] micelles) for subcutaneous immunization of naïve mice. Compared to immunization with JCP alone, the combination of JCP with K3 CpG-ODN and DLPC/DA micelles resulted in a general reduction of the JCP-induced T-helper 2 (Th2) immune response, including reduced airway inflammation and allergen-specific plasma immunoglobulin E. In addition, Th1 markers were either largely unaffected (interferon-γ) or markedly increased (allergen-specific plasma IgG2a). These immunological changes coincided with reduced sneezing frequency in response to allergen exposure. For most parameters, a synergistic effect was observed when both K3 CpG-ODN and DLPC/DA micelles were combined with JCP at the time of immunization. In conclusion, the data presented here indicate that the combination of JCP, K3 CpG-ODN, and DLPC/DA micelles is a promising candidate for the development of a more effective SCIT treatment for Japanese cedar pollinosis, which may include a shorter treatment regimen and reduced risk of anaphylactic reactions.

Caco-2 cells, derived from colorectal cancer cells, are generally used to evaluate drug absorption in the gastrointestinal tract. However, differences between Caco-2 and normal intestinal cells have been observed. Cells cultured directly from crypts are maintained in their biological state. Therefore, we developed a rapid and easy method of monolayer culture of epithelial cells isolated from the jejunum of mice. We analyzed the usefulness of the jejunal epithelial cell monolayer culture system as a research tool and evaluated changes in the transport activity and mRNA expression of transporters. We focused on P-glycoprotein (P-gp) and peptide transporter 1 (Pept1) as representative transporters expressed in the small intestine. A P-gp inhibitor significantly enhanced the accumulation of Rhodamine 123 (Rho123), a substrate of P-gp, indicating that the transport activity of P-gp could be evaluated. Uptake of glycylsarcosine, a Pept1 substrate, significantly decreased in the presence of the Pept1 inhibitor, indicating that the transport activity of Pept1 could be evaluated. Rho123 accumulation significantly decreased in the group treated with calcitriol, an inducer of P-gp and Cyp3a11, suggesting that changes in P-gp expression could be evaluated. Furthermore, we examined whether mRNA expression levels of transporters and drug-metabolizing enzyme were altered. In the calcitriol-supplemented group, P-gp and Cyp3a11 mRNA levels significantly increased. However, no significant differences were observed in Pept1 mRNA levels. Overall, the jejunal epithelial cell monolayer culture system developed from intestinal tissues is a useful research tool for assessing the transport activities and expression variabilities of transporters.

Vascular endothelial cells (VECs) and lymphatic endothelial cells (LECs) regulate the homeostasis of fluids, nutrients, and immune cells in the blood and lymphatic systems, respectively. These specialized functions depend on distinct cell-surface proteins and tightly regulated endocytic pathways, but the molecular determinants underlying the cell-type-specific endocytic profiles of these cells remain unclear. We sought to quantitatively characterize and compare the endocytic cell-surface proteomes of human umbilical vein endothelial cells (HUVECs) and human dermal LECs (HDLECs) using cell-surface biotinylation and internalization assays combined with sequential window acquisition of all theoretical fragment ion spectra-MS–based quantitative proteomics. HUVECs and HDLECs had a similar number of cell-surface and internalized proteins, with substantial overlap, but also included sets unique to each cell type. We identified 32 HUVEC- and HDLEC-enriched endocytic cell-surface proteins, respectively; these proteins were present in both enriched cell-surface and internalized fractions, representing cell-type-selective endocytic proteins. Functional enrichment analysis showed that HUVEC-enriched proteins were associated with angiogenesis, nutrient uptake, and metabolism, whereas HDLEC-enriched proteins were linked to immune regulation, extracellular matrix organization, and lymphangiogenesis. In conclusion, our present study demonstrates that VECs and LECs possess distinct endocytic cell-surface protein profiles that define their specialized functions and represent promising targets for endothelial-selective drug delivery and imaging.

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are clinically used to control hyperglycemia and body weight in patients with type 2 diabetes mellitus and obesity. Despite their efficacy, GLP-1 RAs frequently induce nausea and vomiting as adverse effects, which are prominent factors for non-adherence to GLP-1 RAs. Therefore, new prophylaxes and treatments for GLP-1 RA-induced nausea are urgently needed. Here, we explored the U. S. Food and Drug Administration (FDA) Adverse Event Reporting System database to determine the effective drug combinations mitigating GLP-1 RA-induced nausea and vomiting in real-world settings. We further investigated the effects of the identified drugs on GLP-1 RA-induced pica behavior, a behavioral index of nausea in mice. Analysis of the FDA Adverse Event Reporting System revealed that therapeutics, including gabapentin and acetaminophen, significantly lowered the occurrence of nausea-related events in GLP-1 RA-treated patients. In mice, we confirmed that exenatide, a GLP-1 RA, significantly increased the pica behavior in a dose-dependent manner, without affecting the food intake. Finally, we found that co-treatment with gabapentin significantly decreased the pica behavior induced by exenatide. These results demonstrate the therapeutic efficacy of gabapentin against nausea and vomiting in patients administered GLP-1 RAs.

In this study, we investigated guanidinylated chitosan (GCS), a chemically modified derivative of unmodified low-molecular-weight chitosan (CS), as a multifunctional excipient to enhance the solubility and absorption of poorly water-soluble drugs. Flurbiprofen (FP) was selected as a model drug to compare the performance of kneaded dispersions GCS-based (FP-GCS) and CS-based (FP-CS). Both GCS and CS increased the solubility of FP in a concentration-dependent manner, with no significant differences between them. However, dissolution testing showed that FP-GCS kneaded dispersion significantly enhanced the dissolution rate of FP alone in water and simulated gastric fluid (pH 1.2), but not under simulated intestinal conditions (pH 6.8). In vivo pharmacokinetic studies in rats demonstrated that FP-GCS kneaded dispersion achieved the highest plasma concentration of FP, suggesting enhanced gastrointestinal permeability. Moreover, FP-GCS kneaded dispersion markedly reduced gastric ulceration in a rat ulcer model. These results indicate that GCS is an effective oral drug delivery excipient capable of improving both the bioavailability and gastrointestinal safety of FP.