👤 Byung Ho Son

Pathological neuroinflammation is a critical factor that disrupts neuronal activity and, when sustained, ultimately contributes to neuronal death. Among the primary mediators of neuroinflammation, microglia play a central role in modulating brain immunity. However, their overactivation is closely associated with neuronal damage and structural remodeling of brain tissue, leading to the onset and progression of various neurodegenerative diseases. We investigated the neuroprotective effects of avarol, a marine-derived sesquiterpenoid, focusing on its ability to inhibit lipopolysaccharide (LPS)-induced overactivation of BV2 microglial cells and its subsequent impact on neuronal activity in HT-22 hippocampal neuronal cells. Pretreatment with avarol significantly attenuated the LPS-induced release of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), as well as oxidative stress markers such as reactive oxygen species (ROS) and nitric oxide (NO). These inhibitory effects were further substantiated by a dose-dependent reduction in nuclear translocation of nuclear factor-kappa B (NF-κB), a key transcription factor involved in the inflammatory signaling cascade. Regarding the interaction between microglia and neurons, both conditioned medium and co-culture systems demonstrated that avarol significantly attenuated alterations in neuronal plasticity-related molecules-such as nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF)-induced by activated microglia. Overall, these findings suggest that avarol exerts neuroprotective effects through the modulation of microglia-mediated neuroinflammation. Importantly, avarol's capacity to traverse the blood-brain barrier highlights its potential as an effective pharmacological agent in mitigating neuroinflammation-associated neurological disorders. Show less

Angiopoietin-like 4 (Angptl4) is a secreted glycoprotein involved in the regulation of various homeostatic and disease processes. In the intestine, prior studies have suggested protective roles for Angptl4 in inflammation using Angptl4 knockout mouse models; however, phenotypic variability-such as perinatal lethality and intestinal inflammation accompanied by lymphatic defects in only a subset of animals-has complicated the interpretation of its role in intestinal pathogenesis. In this study, the impact of Angptl4 deficiency was examined using a subset of Angptl4 knockout mice that survive postnatally without overt abnormalities. It was found that loss of Angptl4 confers protection against colitis and colitis-associated colorectal tumorigenesis. These protective effects were associated with the alternative activation of anti-inflammatory M2-like macrophages. Similarly, in a genetic model of intestinal tumorigenesis, Angptl4 deficiency resulted in reduced tumor burden and attenuated inflammation, accompanied by increased M2-like macrophages. Analysis of human colorectal cancer data sets further revealed that low ANGPTL4 expression is associated with improved survival outcomes as well as reduced expression of inflammation-related marker genes. Collectively, the findings uncover a previously unrecognized protective effect of Angptl4 deficiency against intestinal pathogenesis via anti-inflammatory mechanisms, suggesting Angptl4 as a potential therapeutic target and prognostic biomarker for colorectal cancer and inflammatory bowel disease. Show less

Alzheimer's disease (AD) involves proteostasis dysregulation causing protein misfolding, but whether these structural changes manifest as plasma conformational biomarkers remains unclear. We profiled plasma protein structures from 520 participants including individuals with AD, individuals with mild cognitive impairment (MCI) and healthy controls. Using mass spectrometry and machine learning, we systematically characterized the structural proteome changes associated with ApoE variations and neuropsychiatric symptoms to identify AD-specific signatures. We developed a diagnostic panel using peptides from C1QA, CLUS and ApoB representing AD-associated structural changes. This three-marker panel achieved 83.44% accuracy in three-way classification (healthy versus MCI versus AD). Binary classification yielded area under the receiver operating characteristic curves of 0.9343 for healthy versus MCI and 0.9325 for MCI versus AD. Longitudinal samples were classified with 86.0% accuracy. This multi-marker panel based on plasma protein structural alterations represents a promising diagnostic approach that may enhance early AD detection and provide insights for clinical trials, improving therapeutic outcomes. Show less

Impaired glymphatic function is considered an important characteristic of cognitive decline, but the role of tau pathology as a mediator remains unclear. This study investigated whether tau burden mediates the association between diffusion tensor image analysis along the perivascular space (DTI-ALPS) and cognitive impairment or brain atrophy. Also, we explored whether DTI-ALPS index predicts longitudinal cognitive deterioration over time. We included 144 individuals with mild cognitive impairment (MCI), Alzheimer's disease dementia (ADD), and other dementia, or normal cognition. All participants underwent 3.0-Tesla MRI, DTI-ALPS index was significantly lower in cognitively impaired individuals compared to cognitively normal (CN) participants. Lower DTI-ALPS index was associated with higher tau burden and worse cognitive function. Tau burden was also inversely associated with cognition. Mediation analysis indicated that tau burden accounted for approximately 21-27% of the association between DTI-ALPS and cognition. Longitudinal analysis showed baseline lower DTI-ALPS index also predicted faster longitudinal cognitive decline. Our findings suggest that the DTI-ALPS index is an indirect marker of glymphatic dysfunction associated with tau accumulation and cognitive decline. Tau pathology may partially link compromised glymphatic clearance to cognitive impairment. Show less

Many older adults with chronic obstructive pulmonary disease (COPD) are inactive and moderate-to-vigorous physical activity (MVPA) can be too strenuous for long-term maintenance. We examined effects of an intervention to increase light physical activity (LPA). Primary outcomes were physical activity (PA) and sedentary behavior (SB). Active for Life with COPD (Active-Life) is a self-efficacy-based intervention designed to increase LPA. Chair Exercises with Health Education (Chair-HE) served as an active control. PA and SB were measured with ActivPAL and ActiGraph accelerometers. We randomized 159 people with COPD to 10 weeks of Active-Life or Chair-HE. 128 people completed the intervention; 105 completed 1-year follow-up. The sample was 45% female, mean (SD) age was 69.6 (8.2), FEV Active-Life produced significant, sustained increases in PA for 12 months. Further work is needed to reduce SB and establish longer-term PA effects. Show less

IRE1α is an endoplasmic reticulum (ER) transmembrane protein with cytoplasmic kinase and endoribonuclease (RNase) domains. Under ER stress, IRE1α can splice Xbp1 mRNA enabling translation of this unfolded protein response transcription factor or mediate sequence-specific degradation of mRNAs through regulated IRE1α-dependent decay (RIDD). Somatic mutations in IRE1α occur in many different human cancers including non-melanoma skin cancer (NMSC). To understand their role in skin cancer pathogenesis, we generated immortalized primary mouse keratinocytes with inducible expression of multiple engineered and cancer-associated mutations, including those present in NMSC. All NMSC mutations tested were activating mutations with elevated autophosphorylation and enhanced RIDD activity relative to the degree of change seen in Xbp1 splicing. Pathway analysis of RNA-Seq data and in vitro studies showed that RNase-impaired mutations enhanced cell migration due to increased levels of active RhoA and the RIDD target Angptl4. In contrast, activating mutations caused elevated Rac1 activation, enrichment of genes involved in DNA repair, increased phospho-ATR levels and improved survival in response to UVB irradiation, a crucial etiological factor for sun-exposure-induced skin cancers. Together, these results suggest divergent roles of IRE1α mutations that mediate crucial tumor-promoting events in keratinocytes. Show less

Atherosclerotic cardiovascular disease (ASCVD) is a leading cause of death. Systemic autoimmune and inflammatory diseases are associated with increased ASCVD risk, severity, and mortality. The inflammatory cytokine interleukin 9 (IL-9) has been linked to murine atherogenesis, raising fundamental questions about the populations in which and the mechanisms by which IL-9 drives ASCVD. Circulating T helper subsets and coronary computed tomography angiography data were analysed in patients with psoriasis. Murine models of psoriatic atherogenesis (imiquimod-ApoE Here, we found that expansion of IL-9-producing T helper cells (Th9) was significantly associated with high-risk radiographic ASCVD in patients with the autoimmune disease psoriasis. Th9 cells were poised to migrate to coronary vessels and were identified in human atherosclerotic plaque from individuals with psoriasis. In vivo, murine inflammatory atherogenesis was prevented by IL-9 blockade and by IL-9 receptor (IL-9R) deletion in endothelial cells. In human arterial endothelial cells, IL-9R/STAT3 signalling promoted endothelial dysfunction via diverse mechanisms including adhesion, activation, angiogenesis, and release of leukocyte chemoattractants. These findings suggest the Th9 Show less

Seven compounds, comprising three anthraquinones and four stilbenoids, were isolated from the roots of Rheum palmatum L. These compounds include chrysophanol (1), aloe-emodin (2), aloe-emodin 8-O-β-D-glucopyranoside (3), desoxyrhapontigenin (4), rhapontigenin (5), desoxyrhaponticin (6), and piceatannol 3'-O-β-D-glucopyranoside (7). Among these, compound 5 showed potent β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitory activity with an IC Show less

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening conditions marked by extensive epidermal necrolysis and skin sloughing. The study aimed to assess the serum levels of specific proinflammatory interleukins (IL-18, -21, 22, -23, -27, and -31) and their relationship with the severity of SJS/TEN within the Vietnamese population. This descriptive cross-sectional study was conducted from 2018 to 2020. Serum levels of IL-18, -21, -22, -23, -27, and -31 were measured using the fluorescence covalent microbead immunosorbent assay. The study included 61 patients (29 males and 32 females; 21 with SJS and 40 with TEN), with a median age of 51 years (interquartile range: 37-58), and 20 healthy controls. The median lesional area covered 45% of the body surface area (interquartile range: 8-70%). The most frequently identified medications were traditional medicine (19 patients; 31.15%), allopurinol (9 patients; 14.75%), and carbamazepine (8 patients; 13.11%). In the TEN group, the serum level of IL-18 was significantly elevated compared to the healthy control group. A correlation was found between serum levels of IL-18 and IL-27 and the lesional area in SJS/TEN patients, as well as between serum levels of IL-18 and IL-31 and the lesional area in TEN patients. Serum levels of IL-18 were increased in TEN group. Additionally, serum concentrations of IL-18, IL-27, and IL-31 were associated with disease severity as indicated by the lesional area. These interleukins may play an important role in the pathogenesis of SJS/TEN. Show less

Overt immune activation by viral infections can lead to cytokine storm syndromes, such as hemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS). We aimed to compare the immune response to different viral pathogens to understand the connection between infections and cytokine storm syndromes. We recruited children who sought care at the emergency department with fever for ≥3 days. We performed immune profiling using Olink proximity extension assay and flow cytometry. We compared the findings with cases of HLH, MAS, Kawasaki disease (KD), and multisystem inflammatory syndrome in children (MIS-C). We enrolled 352 febrile patients and studied 110 cases of confirmed common viral infections. We found that Epstein-Barr virus (EBV) uniquely triggered high levels of multiple cytokines (IL-18, IL-27, TNF, FLT3 ligand, and lymphotoxin alpha) and IFN-γ-induced chemokines (CXCL9/10/11 and CCL19). These patterns are similar to the hyperinflammatory response associated with HLH/MAS but are less consistent with the findings in KD and MIS-C. Flow cytometry analysis revealed that CD38 This work broadens our understanding of common viral infections in children and provides an immunologic basis for the link between EBV infection and HLH/MAS. Show less

Lipoprotein lipase (LPL) is critical for clearance of circulating triglycerides and for tissue fatty acid supply. LPL is primarily synthesized and secreted by adipocytes into the interstitium and must traffic from there to the abluminal/basolateral side of capillary endothelial cells. There, LPL binds glycosylphosphatidylinositol-anchored protein 1, GPIHBP1, which stabilizes the protein and facilitates its movement across the endothelial cells to the luminal side where it functions in hydrolysis of lipoprotein triglycerides. Importance of LPL traffic is supported by findings that rare mutations in GPIHBP1 cause hypertriglyceridemia. However our understanding of how LPL is secreted by adipocytes and traffics to endothelial cells is incomplete. Here we examined the possibility that secretion and traffic of adipocyte LPL might involve generation of small extracellular vesicles (sEVs/exosomes) which often mediate cell-cell communication. Proteomic analysis of sEVs secreted by adipocytes showed them enriched in LPL. To study LPL secretion and transfer we generated human derived pre-adipocytes (HPA) that stably express tagged LPL (FLAG and His epitopes). LPL pulldown and sEV isolation from HPA conditioned media documented that greater than 70% of secreted LPL is present in sEVs. The mechanism for LPL secretion in sEVs was found to involve the ESCRT-independent neutral sphingomyelinase 2 (nSMase2) pathway, as treatment with the nSMase2 inhibitor GW4869 reduced secretion by 80%. The above observations were reproduced using highly sensitive nanoparticle flow cytometry. The sEV associated LPL has lipolytic activity and it is released by heparin addition indicating it is on the sEV surface. In addition, using human derived microvascular endothelial cells with stable lentiviral expression of GPIHBP1 we show that LPL positive sEVs transfer LPL to these cells, but not to control cells without GPIHBP1. Our findings suggest that sEV formation by nSMase2 controls adipocyte LPL secretion and traffic, that sEVs protect LPL activity and facilitate LPL transfer to GPIHBP1 on endothelial cells. Show less

Most deleterious variants are recessive and segregate at relatively low frequency. Therefore, high sample sizes are required to identify these variants. In this study we report a large-scale sequence based genome-wide association study (GWAS) in pigs, with a total of 120,000 Large White and 80,000 Synthetic breed animals imputed to sequence using a reference population of approximately 1,100 whole genome sequenced pigs. We imputed over 20 million variants with high accuracies (R2>0.9) even for low frequency variants (1-5% minor allele frequency). This sequence-based analysis revealed a total of 14 additive and 9 non-additive significant quantitative trait loci (QTLs) for growth rate and backfat thickness. With the non-additive (recessive) model, we identified a deleterious missense SNP in the CDHR2 gene reducing growth rate and backfat in homozygous Large White animals. For the Synthetic breed, we revealed a QTL on chromosome 15 with a frameshift variant in the OBSL1 gene. This QTL has a major impact on both growth rate and backfat, resembling human 3M-syndrome 2 which is related to the same gene. With the additive model, we confirmed known QTLs on chromosomes 1 and 5 for both breeds, including variants in the MC4R and CCND2 genes. On chromosome 1, we disentangled a complex QTL region with multiple variants affecting both traits, harboring 4 independent QTLs in the span of 5 Mb. Together we present a large scale sequence-based association study that provides a key resource to scan for novel variants at high resolution for breeding and to further reduce the frequency of deleterious alleles at an early stage in the breeding program. Show less

Genome-wide association studies (GWAS) of metabolic syndrome (MetS) have predominantly focused on non-Asian populations, with limited representation from East Asian cohorts. Moreover, previous GWAS analyses have primarily emphasized the significance of top single nucleotide polymorphisms (SNPs), poorly explaining other SNP signals in linkage disequilibrium. This study aimed to reveal the interaction between rs651821 and rs2266788, the principal variants of apolipoprotein A5 (APOA5), within the most significant loci identified through GWAS on MetS. GWAS on MetS and its components was conducted using the data from the Korean Genome and Epidemiology Study (KoGES) city cohort comprising 58,600 individuals with available biochemical, demographic, lifestyle factors, and the most significant APOA5 locus was analyzed further in depth. According to GWAS of MetS and its diagnostic components, a significant association between the APOA5 SNPs rs651821/rs2266788 and MetS/triglycerides/high-density lipoprotein phenotypes was revealed. However, a conditional analysis employing rs651821 unveiled a reversal in the odds ratio for rs2266788. Therefore, rs651821 and rs2266788 emerged as independent and opposing signals in the extended GWAS analysis, i.e., the multilayered effects. Further gene-environment interaction analyses regarding lifestyle factors such as smoking, alcohol consumption, and physical activity underscored these multilayered effects. This study unveils the intricate interplay between rs651821 and rs2266788 derived from MetS GWAS. Removing the influence of lead SNP reveals an independent protective signal associated with rs2266788, suggesting a multilayered effect between these SNPs. These findings underline the need for novel perspectives in future MetS GWAS. Show less

Although stem cells are a promising avenue for harnessing the potential of adipose tissue, conventional two-dimensional (2D) culture methods have limitations. This study explored the use of three-dimensional (3D) cultures to preserve the regenerative potential of adipose-derived stem cells (ADSCs) and investigated their cellular properties. Flow cytometric analysis revealed significant variations in surface marker expressions between the two culture conditions. While 2D cultures showed robust surface marker expressions, 3D cultures exhibited reduced levels of CD44, CD90.2, and CD105. Adipogenic differentiation in 3D organotypic ADSCs faced challenges, with decreased organoid size and limited activation of adipogenesis-related genes. Key adipocyte markers, such as lipoprotein lipase (LPL) and adipoQ, were undetectable in 3D-cultured ADSCs, unlike positive controls in 2D-cultured mesenchymal stem cells (MSCs). Surprisingly, 3D-cultured ADSCs underwent mesenchymal-epithelial transition (MET), evidenced by increased E-cadherin and EpCAM expression and decreased mesenchymal markers. This study highlights successful ADSC organoid formation, notable MSC phenotype changes in 3D culture, adipogenic differentiation challenges, and a distinctive shift toward an epithelial-like state. These findings offer insights into the potential applications of 3D-cultured ADSCs in regenerative medicine, emphasizing the need for further exploration of underlying molecular mechanisms. Show less

Skeletal muscle differentiation is an essential process in embryonic development as well as regeneration and repair throughout the lifespan. It is well-known that dietary fat intake impacts biological and physiological function in skeletal muscle, however, understanding of the contribution of nutritional factors in skeletal muscle differentiation is limited. Therefore, the objective of the current study was to evaluate the effects of free fatty acids (FFAs) on skeletal muscle differentiation in vitro. We used C2C12 murine myoblasts and treated them with various FFAs, which revealed a unique response of angiopoietin-like protein-4 (ANGPTL4) with linoleic acid (LA) treatment that was associated with reduced differentiation. LA significantly inhibited myotube formation and lowered the protein expression of myogenic regulatory factors, including MyoD and MyoG and increased Pax7 during cell differentiation. Next, recombinant ANGPTL4 protein or siRNA knockdown of ANGPTL4 was employed to examine its role in skeletal muscle differentiation, and we confirmed that ANGPTL4 knockdown at day two and six of differentiation restored myotube formation in the presence of LA. RNA-sequencing analysis revealed that ANGPTL4-mediated inhibition of skeletal muscle differentiation at day two as well as LA at day two or -6 led to a reduction in Wnt/β-catenin signaling pathways. We confirmed that LA reduced Wnt11 and Axin2 while increasing expression of the Wnt inhibitor, Dkk2. ANGPTL4 knockdown increased β-catenin protein in the nucleus in response to LA and increased Axin2 and Wnt11 expression. Taken together, these results demonstrate that LA induced ANGPTL4 inhibits C2C12 differentiation by suppressing Wnt/β-catenin signaling. Show less

The mobilization and catabolism of lipid energy is a central function of adipocytes that is under the control of the β-adrenergic signaling pathway, and defects in β-adrenergic signaling in adipocytes have been linked to obesity and obesity-related metabolic diseases. Receptor expression-enhancing proteins (REEPs) are endoplasmic reticulum (ER) proteins that play critical roles in subcellular targeting of receptor signaling complexes. Examination of gene expression profiles indicates that, among REEPs expressed in adipocytes, REEP6 expression is uniquely upregulated by sympathetic nervous system activation, suggesting involvement in regulating adrenergic signal transduction. The aim of this study was to assess the contribution of REEP6 to the thermogenic activation of adipocytes and characterize the metabolic consequences of REEP6 deficiency in vivo. Expression levels of Reep6 in adipose tissue were examined by using public transcriptomic data and validated by Western blot and qPCR analyses. Adipocyte-specific regulatory roles of REEP6 were investigated in vitro in C3H10T1/2 adipocytes and in primary adipocytes obtained from REEP6 KO mice. Effects of in vivo REEP6 deficiency on energy expenditure were measured by indirect calorimetry. Mitochondrial content in adipose tissue was accessed by immunoblot, mitochondrial DNA analysis, and confocal and electron microscopy. Effects of REEP6 KO on obesity-induced metabolic dysfunction were tested in a high-fat diet-induced obesity mouse model by glucose tolerance test, Western blot, and histological analyses. REEP6 expression is highly enriched in murine adipocytes and is sharply upregulated upon adipocyte differentiation and by cold exposure. Inactivation of REEP6 in mice increased adiposity, and reduced energy expenditure and cold tolerance. REEP6 KO severely reduced protein kinase A-mediated signaling in BAT and greatly reduced mitochondrial mass. The effect of REEP6 inactivation on diminished β-adrenergic signaling was reproduced in cultured adipocytes, indicating that this effect is cell-autonomous. REEP6 KO also suppressed expression of adenylate cyclase 3 (Adcy3) in brown adipose tissue and knockdown of REEP6 in adipocytes reduced targeting of ADCY3 to the plasma membrane. Lastly, REEP6 KO exacerbated high-fat diet-induced insulin resistance and inflammation in adipose tissue. This study indicates that REEP6 plays an important role in β-adrenergic signal transduction in adipocytes involving the expression and trafficking of Adcy3. Genetic inactivation of REEP6 reduces energy expenditure, increases adiposity, and the susceptibility to obesity-related metabolic dysfunction. Show less

Postnatal skeletal muscle differentiation from quiescent satellite cells is a highly regulated process, although our understanding of the contribution of nutritional factors in myogenesis is limited. Free fatty acids (FFAs) are known to cause detrimental effects to differentiated skeletal muscle cells by increasing oxidative stress which leads to muscle wasting and insulin resistance in skeletal muscle. In addition, FFAs are thought to act as inhibitors of skeletal muscle differentiation. However, the precise molecular mechanisms underlying the effects of FFAs on skeletal muscle differentiation remains to be elucidated. There is a clear relationship between dietary FFAs and their ability to suppress myogenesis and we propose the hypothesis that the FFA-mediated increase in angiopoietin-like protein 4 (ANGPTL4) may play a role in the inhibition of differentiation. This review discusses the role of FFAs in skeletal muscle differentiation to-date and proposes potential mechanisms of FFA-induced ANGPTL4 mediated inhibition of skeletal muscle differentiation. Show less

We aimed to determine the similarities and differences in the roles of genic and regulatory copy number variations (CNVs) in bipolar disorder (BD), schizophrenia (SCZ), and autism spectrum disorder (ASD). Based on high-resolution CNV data from 8708 Japanese samples, we performed to our knowledge the largest cross-disorder analysis of genic and regulatory CNVs in BD, SCZ, and ASD. In genic CNVs, we found an increased burden of smaller (<100 kb) exonic deletions in BD, which contrasted with the highest burden of larger (>500 kb) exonic CNVs in SCZ/ASD. Pathogenic CNVs linked to neurodevelopmental disorders were significantly associated with the risk for each disorder, but BD and SCZ/ASD differed in terms of the effect size (smaller in BD) and subtype distribution of CNVs linked to neurodevelopmental disorders. We identified 3 synaptic genes (DLG2, PCDH15, and ASTN2) as risk factors for BD. Whereas gene set analysis showed that BD-associated pathways were restricted to chromatin biology, SCZ and ASD involved more extensive and similar pathways. Nevertheless, a correlation analysis of gene set results indicated weak but significant pathway similarities between BD and SCZ or ASD (r = 0.25-0.31). In SCZ and ASD, but not BD, CNVs were significantly enriched in enhancers and promoters in brain tissue. BD and SCZ/ASD differ in terms of CNV burden, characteristics of CNVs linked to neurodevelopmental disorders, and regulatory CNVs. On the other hand, they have shared molecular mechanisms, including chromatin biology. The BD risk genes identified here could provide insight into the pathogenesis of BD. Show less

Slug is a transcription factor belonging to the slug/snail superfamily. The protein is involved in embryonic development and epithelial-mesenchymal transition of tumors. Slug is also under temporal regulation during cell cycle. Here, we examined relationship between pSlug Show less

The plasma proteome of 51 non-metastatic breast cancer patients receiving neoadjuvant chemotherapy (NCT) was prospectively analyzed by high-resolution mass spectrometry coupled with nano-flow liquid chromatography using blood drawn at the time of diagnosis. Plasma proteins were identified as potential biomarkers, and their correlation with clinicopathological variables and survival outcomes was analyzed. Of 51 patients, 20 (39.2%) were HR+/HER2-, five (9.8%) were HR+/HER2+, five (9.8%) were HER2+, and 21 (41.2%) were triple-negative subtype. During a median follow-up of 52.0 months, there were 15 relapses (29.4%) and eight deaths (15.7%). Four potential biomarkers were identified among differentially expressed proteins: APOC3 had higher plasma concentrations in the pathological complete response (pCR) group, whereas MBL2, ENG, and P4HB were higher in the non-pCR group. Proteins statistically significantly associated with survival and capable of differentiating low- and high-risk groups were MBL2 and P4HB for disease-free survival, P4HB for overall survival, and MBL2 for distant metastasis-free survival (DMFS). In the multivariate analysis, only MBL2 was a consistent risk factor for DMFS (HR: 9.65, 95% CI 2.10-44.31). The results demonstrate that the proteomes from non-invasive sampling correlate with pCR and survival in breast cancer patients receiving NCT. Further investigation may clarify the role of these proteins in predicting prognosis and thus their therapeutic potential for the prevention of recurrence. Show less

Pancreatitis is the inflammation of the pancreas. However, little is known about the genes associated with pancreatitis severity. Our microarray analysis of pancreatic tissues from mild and severe acute pancreatitis mice models identified angiopoietin-like 4 (ANGPTL4) as one of the most significantly upregulated genes. Clinically, ANGPTL4 expression was also increased in the serum and pancreatic tissues of pancreatitis patients. The deficiency in ANGPTL4 in mice, either by gene deletion or neutralizing antibody, mitigated pancreatitis-associated pathological outcomes. Conversely, exogenous ANGPTL4 exacerbated pancreatic injury with elevated cytokine levels and apoptotic cell death. High ANGPTL4 enhanced macrophage activation and infiltration into the pancreas, which increased complement component 5a (C5a) level through PI3K/AKT signaling. The activation of the C5a receptor led to hypercytokinemia that accelerated acinar cell damage and furthered pancreatitis. Indeed, C5a neutralizing antibody decreased inflammatory response in LPS-activated macrophages and alleviated pancreatitis severity. In agreement, there was a significant positive correlation between C5a and ANGPTL4 levels in pancreatitis patients. Taken together, our study suggests that targeting ANGPTL4 is a potential strategy for the treatment of pancreatitis. Show less

Ferroptosis is an iron-dependent regulated necrosis mediated by lipid peroxidation. Cancer cells survive under metabolic stress conditions by altering lipid metabolism, which may alter their sensitivity to ferroptosis. However, the association between lipid metabolism and ferroptosis is not completely understood. In this study, we found that the expression of elongation of very long-chain fatty acid protein 5 (ELOVL5) and fatty acid desaturase 1 (FADS1) is up-regulated in mesenchymal-type gastric cancer cells (GCs), leading to ferroptosis sensitization. In contrast, these enzymes are silenced by DNA methylation in intestinal-type GCs, rendering cells resistant to ferroptosis. Lipid profiling and isotope tracing analyses revealed that intestinal-type GCs are unable to generate arachidonic acid (AA) and adrenic acid (AdA) from linoleic acid. AA supplementation of intestinal-type GCs restores their sensitivity to ferroptosis. Based on these data, the polyunsaturated fatty acid (PUFA) biosynthesis pathway plays an essential role in ferroptosis; thus, this pathway potentially represents a marker for predicting the efficacy of ferroptosis-mediated cancer therapy. Show less

Influenza viruses exploit host factors to successfully replicate in infected cells. Using small interfering RNA (siRNA) technology, we identified six human genes required for influenza A virus (IAV) replication. Here we focused on the role of acid phosphatase 2 (ACP2), as its knockdown showed the greatest inhibition of IAV replication. In IAV-infected cells, depletion of ACP2 resulted in a significant reduction in the expression of viral proteins and mRNA, and led to the attenuation of virus multi-cycle growth. ACP2 knockdown also decreased replication of seasonal influenza A and B viruses and avian IAVs of the H7 subtype. Interestingly, ACP2 depletion had no effect on the replication of Ebola or hepatitis C virus. Because ACP2 is known to be a lysosomal acid phosphatase, we assessed the role of ACP2 in influenza virus entry. While neither binding of the viral particle to the cell surface nor endosomal acidification was affected in ACP2-depleted cells, fusion of the endosomal and viral membranes was impaired. As a result, downstream steps in viral entry were blocked, including nucleocapsid uncoating and nuclear import of viral ribonucleoproteins. Our results established ACP2 as a necessary host factor for regulating the fusion step of influenza virus entry. Show less

Ultraviolet radiation resistance-associated gene product (UVRAG) was originally identified as a protein involved in cellular responses to UV irradiation. Subsequent studies have demonstrated that UVRAG plays as an important role in autophagy, a lysosome-dependent catabolic program, as a part of a pro-autophagy PIK3C3/VPS34 lipid kinase complex. Several recent studies have shown that UVRAG is also involved in autophagy-independent cellular functions, such as DNA repair/stability and vesicular trafficking/fusion. Here, we examined the UVRAG protein interactome to obtain information about its functional network. To this end, we screened UVRAG-interacting proteins using a tandem affinity purification method coupled with MALDI-TOF/MS analysis. Our results demonstrate that UVRAG interacts with various proteins involved in a wide spectrum of cellular functions, including genome stability, protein translational elongation, protein localization (trafficking), vacuole organization, transmembrane transport as well as autophagy. Notably, the interactome list of high-confidence UVRAG-interacting proteins is enriched for proteins involved in the regulation of genome stability. Our systematic UVRAG interactome analysis should provide important clues for understanding a variety of UVRAG functions. Show less

Genome-wide association studies have been used extensively to identify genetic variants linked to metabolic syndrome (MetS), but most of them have been conducted in non-Asian populations. This study aimed to evaluate the association between MetS and previously studied single nucleotide polymorphisms (SNPs), and their interaction with health-related behavior in Korean men. Seventeen SNPs were genotyped and their association with MetS and its components was tested in 1193 men who enrolled in the study at Seoul National University Hospital. We found that rs662799 near APOA5 and rs769450 in APOE had significant association with MetS and its components. The SNP rs662799 was associated with increased risk of MetS, elevated triglyceride (TG) and low levels of high-density lipoprotein, while rs769450 was associated with a decreased risk of TG. The SNPs showed interactions between alcohol drinking and physical activity, and TG levels in Korean men. We have identified the genetic association and environmental interaction for MetS in Korean men. These results suggest that a strategy of prevention and treatment should be tailored to personal genotype and the population. Show less