Global Profiling of Lysine Acetylation and Lactylation in Kupffer Cells.

Among the various cell types that constitute the liver, Kupffer cells (KCs) are responsible for the elimination of gut-derived foreign products. Protein lysine acetylation (Kac) and lactylation (Kla) are dynamic and reversible post-translational modifications, and various global acylome studies have been conducted for liver and liver-derived cells. However, no such studies have been conducted on KCs. In this study, we identified 2198 Kac sites in 925 acetylated proteins and 289 Kla sites in 181 lactylated proteins in immortalized mouse KCs using global acylome technology. The subcellular distributions of proteins with Kac and Kla site modifications differed. Similarly, the specific sequence motifs surrounding acetylated or lactylated lysine residues also showed differences. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to better understand the differentially expressed proteins in the studies by Kac and Kla. In the newly identified Kla, we found K82 lactylation in the high-mobility group box-1 protein in the neutrophil extracellular trap formation category using KEGG enrichment analyses. Here, we report the first proteomic survey of Kac and Kla in KCs.

Benzoylpaeoniflorin Activates Anti-Inflammatory Mechanisms to Mitigate Sepsis in Cell-Culture and Mouse Sepsis Models.

Xuebijing injection (XBJI) (comprising of five herbs) is a widely used traditional Chinese medicine for sepsis treatment. However, the bioactive components of XBJI and the mechanisms responsible for its sepsis-mitigating action have not been experimentally determined. One of the main bioactive compounds in XBJI-benzoylpaeoniflorin (BPF)-inhibits the expressions of key mediators of inflammation such as nuclear factor kappa B (NF-κB), cyclooxygenase-1 (COX-1), and COX-2. However, its effects on sepsis have not been determined yet. Therefore, here, we investigated the immunomodulatory effect of BPF on severely inflamed endothelial cells, THP-1 macrophages, peritoneal macrophages, and mice. Human umbilical vein endothelial cells (HUVECs) and THP-1-macrophages were activated using lipopolysaccharide (LPS) after pretreatment with BPF. Subsequently, changes in the expression profiles of pro-inflammatory molecules including inducible nitric oxide synthase (iNOS), tumor necrosis factor (TNF)-α, and interleukin (IL)-6 were determined using quantitative real-time polymerase chain reaction (qPCR) and Western blot analysis. Furthermore, we monitored the phosphorylation of NF-kB and mitogen-activated protein kinases (MAPKs) to determine their activation levels. Using the LPS-induced mouse model of sepsis, we studied the effects of BPF on inflammatory cytokine production, pulmonary histopathology, and survival rates. Finally, we evaluated whether BPF protects against cecal ligation and puncture (CLP)-induced sepsis, as it closely mimics human sepsis. BPF pretreatment inhibited LPS-induced increase in mRNA and protein levels of iNOS, TNF-α, and IL-6 in HUVECs and THP-1-macrophages. It also suppressed LPS-mediated phosphorylation of p65, p38, JNK, and ERK. Mice with LPS-induced-sepsis who were treated with BPF had lower serum levels of IL-6, TNF-α, IL-1ß, CXCL1, and CXCL2 than the control mice treated with BPF. Histopathology revealed that BPF treatment alleviated LPS-induced lung damage. In addition, in mice given a lethal dose of LPS, BPF treatment showed a dose-dependent improvement in survival rates. BPF treatment dose-dependently inhibited the LPS-induced IL-6, TNF-α, and CXCL1 production in peritoneal macrophages. BPF treatment also dose-dependently improved the survival rates in mice with CLP-induced sepsis. These results show that BPF alleviates LPS-stimulated septic conditions and protects mice from CLP-induced sepsis. Our research marks BPF as a potential drug in the treatment of sepsis and various inflammatory diseases.

Barrier protective functions of hederacolchiside-E against HMGB1-mediated septic responses.

The role of high mobility group box 1 (HMGB1) has been recognized as important, and suppression of HMGB1 release and restoration of vascular barrier integrity are regarded as potentially promising therapeutic strategies against sepsis. Hederacolchiside-E (HCE), namely 3-O-{α-L-rhamnopyranosyl (1→2)-[ß-D-glucopyranosyl(1→4)]-α-L-arabinopyranosyl}-28-O-[α-L-rhamnopyranosyl (1→4)-ß-D-glucopyranosyl(1→6)-ß-D-glucopyranosyl ester, is a bidesmosidic oleanane saponin first isolated in 1970 from the leaves of Hedera colchica. We tested our hypothesis that HCE inhibits HMGB1-induced vascular hyperpermeability and thereby increases the survival of septic mouse model from suppression of HMGB1 release upon lipopolysaccharide (LPS)-stimulation. In LPS-activated human endothelial cells and a sepsis mouse model by cecal ligation and puncture (CLP), antiseptic activity of HCE was investigated from suppression of vascular permeability, pro-inflammatory proteins, and tissue injury markers. Post-treatment of HCE significantly suppressed HMGB1 release both in LPS-activated human endothelial cells and the CLP-induced sepsis mouse model. HCE inhibited hyperpermeability and alleviated HMGB1-mediated vascular disruptions, and reduced sepsis-related mortality and tissue injury in mice. Our results suggest that reduction of HMGB1 release and septic mortality by HCE may be useful for the drug candidate of sepsis, indicating a possibility of successful repositioning of HCE.

Characterization of complement C3 as a marker of alpha-amanitin toxicity by comparative secretome profiling.

In the human body, proteins secreted into peripheral blood vessels are known as the secretome, and they represent the physiological or pathological status of cells. The unique response of cells to toxin exposure can be confirmed via secretome analysis, which can be used to discover toxic mechanisms or exposure markers. Alpha-amanitin (α-AMA) is the most widely studied amatoxin and inhibits transcription and protein synthesis by directly interacting with RNA polymerase II. However, secretory proteins released during hepatic failure caused by α-AMA have not been fully characterized. In this study, we analyzed the secretome of α-AMA-treated Huh-7 cells and mice using a comparative proteomics technique. Overall, 1440 and 208 proteins were quantified in cell media and mouse serum, respectively. Based on the bioinformatics results for the commonly downregulated proteins in cell media and mouse serum, we identified complement component 3 (C3) as a marker for α-AMA-induced hepatotoxicity. Through western blot in cell secretome and C3 ELISA assays in mouse serum, we validated α-AMA-induced downregulation of C3. In conclusion, using comparative proteomics and molecular biology techniques, we found that α-AMA-induced hepatotoxicity reduced C3 levels in the secretome. We expect that this study will aid in identifying new toxic mechanisms, therapeutic targets, and exposure markers of α-AMA-induced hepatotoxicity. Supplementary Information: The online version contains supplementary material available at 10.1007/s43188-022-00163-z.

Novel Time-dependent Multi-omics Integration in Sepsis-associated Liver Dysfunction.

The recently developed technologies that allow the analysis of each single omics have provided an unbiased insight into ongoing disease processes. However, it remains challenging to specify the study design for the subsequent integration strategies that can associate sepsis pathophysiology and clinical outcomes. Here, we conducted a time-dependent multi-omics integration (TDMI) in a sepsis-associated liver dysfunction (SALD) model. We successfully deduced the relation of the toll-like receptor 4 (TLR4) pathway with SALD. Although TLR4 is a critical factor in sepsis progression, it is not specified in single-omics results but only in the TDMI analysis. This result indicates that the TDMI-based approach is more advantageous than single-omics analysis in terms of exploring the underlying pathophysiological mechanism of this disease. Furthermore, this approach can be an ideal paradigm for insightful biological interpretations of multi-omics datasets that will potentially reveal novel insights into basic biology, health, and diseases, thus allowing the identification of promising candidates for therapeutic strategies.

Using Comparative Proteomics to Identify Protein Signatures in Clear Cell Renal Cell Carcinoma.

BACKGROUND/AIM: Renal cell carcinoma (RCC) is one of the most commonly diagnosed cancers in the world. Approximately 25-30% of patients identified with initial kidney cancer will have metastasized tumors, thus 5-year survival rates for these patients are poor. Therefore, biomarker research is required to identify and predict molecular signatures in RCC. MATERIALS AND METHODS: To address this, we used a mass spectrometry (MS)-based proteomics approach to identify proteins related to clear cell RCC (ccRCC) tissues from patients with T1G2, T1G3, T3G2, T3G3, and metastatic RCC (mRCC) stages. RESULTS: We identified and quantified 2,608 and 2,463 proteins, respectively, in ccRCC tissue and identified 1,449 differentially expressed proteins (DEPs). Bioinformatics analysis revealed that serpin family A member 3 (SERPINA3) qualified as biomarker for ccRCC progression. Using indirect enzyme-linked immunosorbent assay (ELISA), immunoblotting, and immunohistochemistry assays it was found that SERPINA3 expression levels in ccRCC tissues were much higher in stages before metastasis. CONCLUSION: Comparative proteomics analysis of ccRCC tissues provided new evidence of SERPINA3 association with ccRCC progression.

Biapenem reduces sepsis mortality via barrier protective pathways against HMGB1-mediated septic responses.

BACKGROUND: As a late mediator of sepsis, the role of high mobility group box 1 (HMGB1) has been recognized as important, and suppression of HMGB1 release and restoration of vascular barrier integrity are regarded as potentially promising therapeutic strategies for sepsis. For repositioning of previously FDA-approved drugs to develop new therapies for human diseases, screening of chemical compound libraries, biological active, is an efficient method. Our study illustrates an example of drug repositioning of Biapenem (BIPM), a carbapenem antibiotic, for the modulation of HMGB1-induced septic responses. METHODS: We tested our hypothesis that BIPM inhibits HMGB1-induced vascular hyperpermeability and thereby increases the survival of septic mouse model from suppression of HMGB1 release upon lipopolysaccharide (LPS)-stimulation. In LPS-activated human umbilical vein endothelial cells (HUVECs) and a cecal ligation and puncture (CLP)-induced sepsis mouse model, antiseptic activity of BIPM was investigated from suppression of vascular permeability, pro-inflammatory proteins, and markers for tissue injury. RESULTS: BIPM significantly suppressed release of HMGB1 both in LPS-activated HUVECs (upto 60%) and the CLP-induced sepsis mouse model (upto 54%). BIPM inhibited hyperpermeability (upto 59%) and reduced HMGB1-mediated vascular disruptions (upto 62%), mortality (upto 50%), and also tissue injury including lung, liver, and kidney in mice. CONCLUSION: Reduction of HMGB1 release and septic mortality by BIPM (in vitro, from 5 to 15 µM for 6 h; in vivo, from 0.37 to 1.1 mg/kg, 24 h) indicate a possibility of successful repositioning of BIPM for the treatment of sepsis.

Sulforaphane Alleviates Particulate Matter-Induced Oxidative Stress in Human Retinal Pigment Epithelial Cells.

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly, and oxidative damage to retinal pigment epithelial (RPE) cells plays a major role in the pathogenesis of AMD. Exposure to high levels of atmospheric particulate matter (PM) with an aerodynamic diameter of <2.5 µm (PM2.5) causes respiratory injury, primarily due to oxidative stress. Recently, a large community-based cohort study in the UK reported a positive correlation between PM2.5 exposure and AMD. Sulforaphane (SFN), a natural isothiocyanate found in cruciferous vegetables, has known antioxidant effects. However, the protective effects of SNF in the eye, especially in the context of AMD, have not been evaluated. In the present study, we evaluated the effect of SFN against PM2.5-induced toxicity in human RPE cells (ARPE-19) and elucidated the molecular mechanism of action. Exposure to PM2.5 decreased cell viability in ARPE-19 cells in a time- and dose-dependent manner, potentially due to elevated intracellular reactive oxygen species (ROS). SFN treatment increased ARPE-19 cell viability and decreased PM2.5-induced oxidative stress in a dose-dependent manner. PM2.5-induced downregulation of serum- and glucocorticoid-inducible kinase 1 (SGK1), a cell survival factor, was recovered by SFN. PM2.5 treatment decreased the enzymatic activities of the antioxidant enzymes including superoxide dismutase and catalase, which were restored by SFN treatment. Taken together, these findings suggest that SFN effectively alleviates PM2.5-induced oxidative damage in human ARPE-19 cells via its antioxidant effects, and that SFN can potentially be used as a therapeutic agent for AMD, particularly in cases related to PM2.5 exposure.

The Decursin Analog, CYJ-27, Suppresses Inflammation Via the Downregulation of NF-κB and STAT-1.

CYJ-27, a synthetic analog of decursin, prevents the generation of proinflammatory cytokines and oxidative stress. In this study, the effects of CYJ-27 on the regulation of inducible nitric oxide synthase (iNOS), heme oxygenase (HO)-1, and cyclooxygenase (COX-)2 were characterized in lipopolysaccharide (LPS)-treated human umbilical vein endothelial cells (HUVECs). In addition, the effects of CYJ-27 on the production of iNOS and representative proinflammatory cytokines, such as tumor necrosis factor (TNF)-α and interleukin (IL)-1ß, were tested in the lung tissues of LPS-treated mice. CYJ-27 promoted the expression of HO-1, suppressed NF-κB-luciferase activity, and reduced COX-2/PGE2 and iNOS/NO, resulting in a diminution in phosphorylated-STAT-1. Furthermore, CYJ-27 promoted the nuclear translocation of Nrf2, enhanced the combination of Nrf2 to antioxidant response elements, and diminished IL-1ß production in LPS-activated HUVECs. CYJ-27-downregulated iNOS/NO expression was rescued after the RNAi suppression of HO-1. In LPS-treated mice, CYJ-27 significantly diminished iNOS production in the lung tissues and TNF-α expression in the bronchoalveolar lavage fluid. These findings indicate that CYJ-27 exerts anti-inflammatory activities by regulating iNOS through downregulation of both NF-κB activation and phosphorylated-STAT-1. Hence, it can act as a template for the development of novel substances to treat inflammatory diseases.

Fisetin Suppresses Pulmonary Inflammatory Responses Through Heme Oxygenase-1 Mediated Downregulation of Inducible Nitric Oxide Synthase.

The effects of a mixture of fisetin on cytokine-mediated pulmonary damages have not been studied, despite its known antiviral, neuroprotective, and anti-inflammatory activities. Using lipopolysaccharide (LPS)-activated human pulmonary artery endothelial cells (HPAECs), we determined the effects of fisetin on the induction of heme oxygenase-1 (HO-1), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). In the lung tissue of LPS-treated mice, fisetin was also evaluated for its effect on the regulation of iNOS and tumor necrosis factor (TNF)-α. In LPS-activated HPAECs, fisetin increased nuclear factor erythrocyte 2-related factor 2-antioxidant response element (Nrf2-ARE) reporter activity through the nuclear translocation of Nrf2, and the expression of HO-1, and decreased IL-1ß and iNOS/NO production. In particular, the suppression of iNOS/NO expression by the administration of fisetin was dependent on HO-1. Current findings indicate that the anti-inflammatory activity of fisetin was due to its HO-1 dependent downregulation of p-STAT-1 and nuclear factor kappa B (NF-κB) and the resultant inhibition of iNOS, and also suggest TNF-α as a potential target for HO-1. We propose that administration of fisetin may be a novel approach, ideal for the treatment of inflammatory pulmonary disease.

Inhibitory functions of cardamonin against particulate matter-induced lung injury through TLR2,4-mTOR-autophagy pathways.

Particulate matter with an aerodynamic diameter equal to or less than 2.5 µm (PM2.5) is a form of air pollutant that causes significant lung damage when inhaled. Cardamonin, a flavone found in Alpinia katsumadai Heyata seeds, has been reported to have anti-inflammatory and anticoagulative activity. The aim of this study was to determine the protective effects of cardamonin on PM2.5-induced lung injury. Mice were treated with cardamonin via tail-vein injection 30 min after the intratracheal instillation of PM2.5. The results showed that cardamonin markedly reduced the pathological lung injury, lung wet/dry weight ratio, and hyperpermeability caused by PM2.5. Cardamonin also significantly inhibited PM2.5-induced myeloperoxidase (MPO) activity in lung tissue, decreased the levels of PM2.5-induced inflammatory cytokines and effectively attenuated PM2.5-induced increases in the number of lymphocytes in the bronchoalveolar lavage fluid (BALF). And, cardamonin increased the phosphorylation of mammalian target of rapamycin (mTOR) and dramatically suppressed the PM2.5-stimulated expression of toll-like receptor 2 and 4 (TLR 2,4), MyD88, and the autophagy-related proteins LC3 II and Beclin 1. In conclusion, these findings indicate that cardamonin has a critical anti-inflammatory effect due to its ability to regulate both the TLR2,4-MyD88 and mTOR-autophagy pathways and may thus be a potential therapeutic agent against PM2.5-induced lung injury.