Instructor, Pediatrics - Gastroenterology
Honors & Awards
Research Scholar Award, American Gastroenterological Association (2022)
Research Grant, National Pancreas Foundation (2019)
NIH T32 Immunology Training Grant, Stanford (2017)
Boards, Advisory Committees, Professional Organizations
Member, American Gastroenterological Association (2019 - Present)
Member, American Pancreatic Association (2017 - Present)
PhD, University of Minnesota, Twin Cities, Pharmacology Department, School of Medicine (2016)
Master of Science, Kyung Hee University, Microbiology and Immunology, Pharmacy School (2009)
Bachelor, Kyung Hee University, Oriental Medicine, Pharmacy School (2007)
Distinct serum immune profiles define the spectrum of acute and chronic pancreatitis from the multi-center PROCEED study.
Pancreatitis is a disease continuum, starting with acute pancreatitis (AP) and, in some cases, progressing to recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP). Currently, there are no approved therapies or early diagnostic or prognostic biomarkers for pancreatitis. The current study aimed to examine whether patient serum immune profiling could identify non-invasive biomarkers and provide mechanistic insight into the disease continuum of pancreatitis.Using Olink immunoassay, we assessed the protein levels of 92 immune markers in serum samples from participants enrolled in the PROCEED study of the CPDPC consortium. Samples (n=231) were obtained from subjects without the pancreatic disease (n=56) and those with chronic abdominal pain (CAP) (n=24), AP (n=38), RAP (n=56), and CP (n=57).Thirty-three immune markers differentiated the combined pancreatitis groups from controls. Immune markers related to IL-17 signaling distinguished CP from AP and RAP. Similarly, the serum level of IL-17A and CCL20 differentiated CP from CAP, suggesting the involvement of Th17 cells in CP pathogenesis. The receiver operator characteristic (ROC) curve with two immune markers (IL-17A and ST1A1) could differentiate CP from CAP (optimistic AUC=0.78). Macrophage classical activation pathway elevated along the continuum of pancreatitis, suggesting an accumulation of proinflammatory signals over disease progression. Several immune markers were associated with smoking, alcohol, and diabetes status.Immune profiling of serum samples from a large pancreatitis cohort led to identifying distinct immune markers that could serve as potential biomarkers to differentiate the varying pancreatitis disease states. In addition, the finding of IL-17 signaling in CP could provide insight into the immune mechanisms underlying disease progression.
View details for DOI 10.1053/j.gastro.2023.03.236
View details for PubMedID 37061168
A systems approach points to a therapeutic role for retinoids in asparaginase-associated pancreatitis.
Science translational medicine
2023; 15 (687): eabn2110
Among drug-induced adverse events, pancreatitis is life-threatening and results in substantial morbidity. A prototype example is the pancreatitis caused by asparaginase, a crucial drug used to treat acute lymphoblastic leukemia (ALL). Here, we used a systems approach to identify the factors affecting asparaginase-associated pancreatitis (AAP). Connectivity Map analysis of the transcriptomic data showed that asparaginase-induced gene signatures were potentially reversed by retinoids (vitamin A and its analogs). Analysis of a large electronic health record database (TriNetX) and the U.S. Federal Drug Administration Adverse Events Reporting System demonstrated a reduction in AAP risk with concomitant exposure to vitamin A. Furthermore, we performed a global metabolomic screening of plasma samples from 24 individuals with ALL who developed pancreatitis (cases) and 26 individuals with ALL who did not develop pancreatitis (controls), before and after a single exposure to asparaginase. Screening from this discovery cohort revealed that plasma carotenoids were lower in the cases than in controls. This finding was validated in a larger external cohort. A 30-day dietary recall showed that the cases received less dietary vitamin A than the controls did. In mice, asparaginase administration alone was sufficient to reduce circulating and hepatic retinol. Based on these data, we propose that circulating retinoids protect against pancreatic inflammation and that asparaginase reduces circulating retinoids. Moreover, we show that AAP is more likely to develop with reduced dietary vitamin A intake. The systems approach taken for AAP provides an impetus to examine the role of dietary vitamin A supplementation in preventing or treating AAP.
View details for DOI 10.1126/scitranslmed.abn2110
View details for PubMedID 36921036
Genetically Engineered Mouse Models Shine New Light on Decades-old Story of Trypsin in Pancreatitis.
View details for DOI 10.1053/j.gastro.2023.02.002
View details for PubMedID 36773768
Vitamin A and association with asparaginase-associated pancreatitis in children with acute lymphocytic leukemia.
LIPPINCOTT WILLIAMS & WILKINS. 2022
View details for Web of Science ID 000863680300025
Single-cell sequencing unveils distinct immune microenvironments with CCR6-CCL20 crosstalk in human chronic pancreatitis.
OBJECTIVE: Chronic pancreatitis (CP) is a potentially fatal disease of the exocrine pancreas, with no specific or effective approved therapies. Due to difficulty in accessing pancreas tissues, little is known about local immune responses or pathogenesis in human CP. We sought to characterise pancreatic immune responses using tissues derived from patients with different aetiologies of CP and non-CP organ donors in order to identify key signalling molecules associated with human CP.DESIGN: We performed single-cell level cellular indexing of transcriptomes and epitopes by sequencing and T-cell receptor (TCR) sequencing of pancreatic immune cells isolated from organ donors, hereditary and idiopathic patients with CP who underwent total pancreatectomy. We validated gene expression data by performing flow cytometry and functional assays in a second patient with CP cohort.RESULTS: Deep single-cell sequencing revealed distinct immune characteristics and significantly enriched CCR6+ CD4+ T cells in hereditary compared with idiopathic CP. In hereditary CP, a reduction in T-cell clonality was observed due to the increased CD4+ T (Th) cells that replaced tissue-resident CD8+ T cells. Shared TCR clonotype analysis among T-cell lineages also unveiled unique interactions between CCR6+ Th and Th1 subsets, and TCR clustering analysis showed unique common antigen binding motifs in hereditary CP. In addition, we observed a significant upregulation of the CCR6 ligand (CCL20) expression among monocytes in hereditary CP as compared with those in idiopathic CP. The functional significance of CCR6 expression in CD4+ T cells was confirmed by flow cytometry and chemotaxis assay.CONCLUSION: Single-cell sequencing with pancreatic immune cells in human CP highlights pancreas-specific immune crosstalk through the CCR6-CCL20 axis, a signalling pathway that might be leveraged as a potential future target in human hereditary CP.
View details for DOI 10.1136/gutjnl-2021-324546
View details for PubMedID 34702715
Single-cell Sequencing Unveils Distinct Immune Microenvironment in Human Chronic Pancreatitis
LIPPINCOTT WILLIAMS & WILKINS. 2021: 1073
View details for Web of Science ID 000706786400147
Antitumor effects of iPSC-based cancer vaccine in pancreatic cancer.
Stem cell reports
Induced pluripotent stem cells (iPSCs) and cancer cells share cellular similarities and transcriptomic profiles. Here, we show that an iPSC-based cancer vaccine, comprised of autologous iPSCs and CpG, stimulated cytotoxic antitumor CD8+ Tcell effector and memory responses, induced cancer-specific humoral immune responses, reduced immunosuppressive CD4+ T regulatory cells, and prevented tumor formation in 75% of pancreatic ductal adenocarcinoma (PDAC) mice. We demonstrate that shared gene expression profiles of "iPSC-cancer signature genes" and others are overexpressed in mouse and human iPSC lines, PDAC cells, and multiple human solid tumor types compared with normal tissues. These results support further studies of iPSC vaccination in PDAC in preclinical and clinical models and in other cancer types that have low mutational burdens.
View details for DOI 10.1016/j.stemcr.2021.04.004
View details for PubMedID 33961792
Distinct immune characteristics distinguish hereditary and idiopathic chronic pancreatitis.
The Journal of clinical investigation
Chronic pancreatitis (CP) is considered an irreversible fibroinflammatory pancreatic disease. Despite numerous animal model studies, questions remain about local immune characteristics in human CP. We profiled pancreatic immune cell characteristics in control organ donors and CP patients that included hereditary and idiopathic CP undergoing total pancreatectomy with islet auto-transplantation. Flow cytometric analysis revealed a significant increase in the frequency of CD68+ macrophages in idiopathic CP. In contrast, hereditary CP showed a significant increase in CD3+ T cell frequency, which prompted us to investigate the T cell receptor beta (TCRbeta) repertoire in CP and controls. TCRbeta-sequencing revealed a significant increase in TCRbeta repertoire diversity and reduced clonality in both CP groups versus controls. Interestingly, we observed differences in Vbeta-Jbeta gene family usage between hereditary and idiopathic CP and a positive correlation of TCRbeta rearrangements with disease severity scores. Immunophenotyping analyses in hereditary and idiopathic CP pancreata indicate differences in innate and adaptive immune responses, which highlights differences in immunopathogenic mechanism of disease among subtypes of CP. TCR repertoire analysis further suggests a role for specific T cell responses in hereditary versus idiopathic CP pathogenesis providing new insights into immune responses associated with human CP.
View details for DOI 10.1172/JCI134066
View details for PubMedID 32053120
Prevalence, risk factors and clinical outcomes of COVID-19 in patients with a history of pancreatitis in Northern California.
View details for DOI 10.1136/gutjnl-2020-321772
View details for PubMedID 32493828
RIP140 in Osteoclast Precursors Regulates Bone Homeostasis, Growth and Osteoclast Activity.
WILEY. 2017: S36
View details for Web of Science ID 000418869200107
Immunology of pancreatitis and environmental factors
CURRENT OPINION IN GASTROENTEROLOGY
2017; 33 (5): 383–89
This report reviews recent aspects of pancreatitis immunology and environmental factors that link to development and progression of disease.Limited human and animal model studies have recently attempted to understand immune mechanisms that lead to the pathogenesis of acute and chronic pancreatitis. Based on these studies innate immune responses emerge as critical elements in disease pathogenesis and severity of inflammation. The immune basis for environmental factors such as smoking, which are highly associated with disease progression highlight novel cross talk mechanisms between immune and nonimmune pancreatic cells such as the pancreatic stellate cells.Better understanding of immune responses and signaling pathways are emerging as important contributors in pancreatitis development and progression. Such mechanisms are likely to offer future targetable therapies that can either halt or reverse disease progression.
View details for PubMedID 28682796
RIP140 in monocytes/macrophages regulates osteoclast differentiation and bone homeostasis
2017; 2 (7): e90517
Osteolytic bone diseases, such as osteoporosis, are characterized by diminished bone quality and increased fracture risk. The therapeutic challenge remains to maintain bone homeostasis with a balance between osteoclast-mediated resorption and osteoblast-mediated formation. Osteoclasts are formed by the fusion of monocyte/macrophage-derived precursors. Here we report, to our knowledge for the first time, that receptor-interacting protein 140 (RIP140) expression in osteoclast precursors and its protein regulation are crucial for osteoclast differentiation, activity, and coupled bone formation. In mice, monocyte/macrophage-specific knockdown of RIP140 (mϕRIP140KD) resulted in a cancellous osteopenic phenotype with significantly increased bone resorption and reduced bone formation. Osteoclast precursors isolated from mϕRIP140KD mice had significantly increased differentiation potential. Furthermore, conditioned media from mϕRIP140KD primary osteoclast cultures significantly suppressed osteoblast differentiation. This suppressive activity was effectively and rapidly terminated by specific Syk-stimulated RIP140 protein degradation. Mechanistic analysis revealed that RIP140 functions primarily by inhibiting osteoclast differentiation through forming a transcription-suppressor complex with testicular receptor 4 (TR4) to repress osteoclastogenic genes. These data reveal that monocyte/macrophage RIP140/TR4 complexes may serve as a critical transcription regulatory complex maintaining homeostasis of osteoclast differentiation, activity, and coupling with osteoblast formation. Accordingly, we propose a potentially novel therapeutic strategy, specifically targeting osteoclast precursor RIP140 protein in osteolytic bone diseases.
View details for DOI 10.1172/jci.insight.90517
View details for Web of Science ID 000399393700007
View details for PubMedID 28405613
View details for PubMedCentralID PMC5374065
Synergistic activation of Arg1 gene by retinoic acid and IL-4 involves chromatin remodeling for transcription initiation and elongation coupling
NUCLEIC ACIDS RESEARCH
2016; 44 (16): 7568–79
All-trans Retinoic acid (RA) and its derivatives are potent therapeutics for immunological functions including wound repair. However, the molecular mechanism of RA modulation in innate immunity is poorly understood, especially in macrophages. We found that topical application of RA significantly improves wound healing and that RA and IL-4 synergistically activate Arg1, a critical gene for tissue repair, in M2 polarized macrophages. This involves feed forward regulation of Raldh2, a rate-limiting enzyme for RA biosynthesis, and requires Med25 to coordinate RAR, STAT6 and chromatin remodeler, Brg1 to remodel the +1 nucleosome of Arg1 for transcription initiation. By recruiting elongation factor TFIIS, Med25 also facilitates transcriptional initiation-elongation coupling. This study uncovers synergistic activation of Arg1 by RA and IL-4 in M2 macrophages that involves feed forward regulation of RA synthesis and dual functions of Med25 in nucleosome remodeling and transcription initiation-elongation coupling that underlies robust modulatory activity of RA in innate immunity.
View details for DOI 10.1093/nar/gkw392
View details for Web of Science ID 000384687000010
View details for PubMedID 27166374
View details for PubMedCentralID PMC5027474
Receptor-Interacting Protein 140 Orchestrates the Dynamics of Macrophage M1/M2 Polarization
JOURNAL OF INNATE IMMUNITY
2016; 8 (1): 97–107
Macrophage classical (M1) versus alternative (M2) polarization is critical for the homeostatic control of innate immunity. Uncontrolled macrophage polarization is frequently implicated in diseases. This study reports a new functional role for receptor-interacting protein 140 (RIP140) in regulating this phenotypic switch. RIP140 is required for M1 activation, and its degradation is critical to LPS-induced endotoxin tolerance (ET). Here, we found that failure to establish RIP140 degradation-mediated ET prevents M2 polarization, and reducing RIP140 level facilitates an M1/M2 switch, resulting in more efficient wound healing in animal models generated with either transgenic or bone marrow transplant procedures. The M2-suppressive effect is elicited by a new function of RIP140 that, in macrophages exposed to M2 cues, is exported to cytosol, forming complexes with CAPNS1 (calpain regulatory subunit) to activate calpain 1/2, that activates PTP1B phosphatase. The activated PTP1B then reduces STAT6 phosphorylation, thereby suppressing the efficiency of M2 polarization. It is concluded that RIP140 plays dual roles in regulating the M1-M2 phenotype switch: the first, in the nucleus, is an M1 enhancer and the second, in the cytosol, is an M2 suppressor. Modulating the level and/or subcellular distribution of RIP140 can be a new therapeutic strategy for diseases where inflammatory/anti-inflammatory responses are critical.
View details for DOI 10.1159/000433539
View details for Web of Science ID 000368969000010
View details for PubMedID 26228026
View details for PubMedCentralID PMC5105833
Reducing RIP140 Expression in Macrophage Alters ATM Infiltration, Facilitates White Adipose Tissue Browning, and Prevents High-Fat Diet-Induced Insulin Resistance
2014; 63 (12): 4021–31
Adipose tissue macrophage (ATM) recruitment and activation play a critical role in obesity-induced inflammation and insulin resistance (IR). The mechanism regulating ATM activation and infiltration remains unclear. In this study, we found receptor interacting protein 140 (RIP140) can regulate the dynamics of ATM that contribute to adipose tissue remodeling. A high-fat diet (HFD) elevates RIP140 expression in macrophages. We generated mice with RIP140 knockdown in macrophages using transgenic and bone marrow transplantation procedures to blunt HFD-induced elevation in RIP140. We detected significant white adipose tissue (WAT) browning and improved systemic insulin sensitivity in these mice, particularly under an HFD feeding. These mice have decreased circulating monocyte population and altered ATM profile in WAT (a dramatic reduction in inflammatory classically activated macrophages [M1] and expansion in alternatively activated macrophages [M2]), which could improve HFD-induced IR. These studies suggest that reducing RIP140 expression in monocytes/macrophages can be a new therapeutic strategy in treating HFD-induced and inflammation-related diseases.
View details for DOI 10.2337/db14-0619
View details for Web of Science ID 000345335500014
View details for PubMedID 24969109
View details for PubMedCentralID PMC4238008
Linker Histone H1.2 cooperates with Cul4A and PAF1 to drive H4K31 ubiquitylation-mediated transactivation.
2013; 5 (6): 1690-703
Increasing evidence suggests that linker histone H1 can influence distinct cellular processes by acting as a gene-specific regulator. However, the mechanistic basis underlying such H1 specificity and whether H1 acts in concert with other chromatin-altering activities remain unclear. Here, we show that one of the H1 subtypes, H1.2, stably interacts with Cul4A E3 ubiquitin ligase and PAF1 elongation complexes and that such interaction potentiates target gene transcription via induction of H4K31 ubiquitylation, H3K4me3, and H3K79me2. H1.2, Cul4A, and PAF1 are functionally cooperative because their individual knockdown results in the loss of the corresponding histone marks and the deficiency of target gene transcription. H1.2 interacts with the serine 2-phosphorylated form of RNAPII, and we argue that it recruits the Cul4A and PAF1 complexes to target genes by bridging the interaction between the Cul4A and PAF1 complexes. These data define an expanded role for H1 in regulating gene transcription and illustrate its dependence on the elongation competence of RNAPII.
View details for DOI 10.1016/j.celrep.2013.11.038
View details for PubMedID 24360965
View details for PubMedCentralID PMC3901356
Selective requirement of H2B N-Terminal tail for p14ARF-induced chromatin silencing.
Nucleic acids research
2011; 39 (21): 9167-80
The N-terminal tail of histone H2B is believed to be involved in gene silencing, but how it exerts its function remains elusive. Here, we report the biochemical characterization of p14ARF tumor suppressor as a transcriptional repressor that selectively recognizes the unacetylated H2B tails on nucleosomes. The p14ARF-H2B tail interaction is functional, as the antagonistic effect of p14ARF on chromatin transcription is lost upon deletion or acetylation of H2B tails. Gene expression profiling and chromatin immunoprecipitation studies emphasize the significance of H2B deacetylation and p14ARF recruitment in establishing a repressive environment over the cell cycle regulatory genes. Moreover, HDAC1-mediated H2B deacetylation, especially at K20, constitutes an essential step in tethering p14ARF near target promoters. Our results thus reveal a hitherto unknown role of p14ARF in the regulation of chromatin transcription, as well as molecular mechanisms governing the repressive action of p14ARF.
View details for DOI 10.1093/nar/gkr642
View details for PubMedID 21846774
View details for PubMedCentralID PMC3241654
Inhibitory effects of steroidal timosaponins isolated from the rhizomes of Anemarrhena asphodeloides against passive cutaneous anaphylaxis reaction and pruritus
IMMUNOPHARMACOLOGY AND IMMUNOTOXICOLOGY
2010; 32 (3): 357–63
To investigate the antiallergic effect of the rhizome of Anemarrhena asphodeloides (AA, family Liliaceae), which was found to inhibit the mouse passive cutaneous anaphylaxis (PCA) reaction induced by the antigen-immunoglobulin E (IgE) complex in preliminary experiments, main steroidal saponins, timosaponins AIII, BIII, and D, were isolated and their inhibitory effects against PCA reaction and scratching behaviors investigated in mice. Oral administration of three main steroidal sapogenins blocked the PCA reaction and scratching behaviors, timosaponin AIII was the most potent. However, intraperitoneal administration of timosaponin AIII showed weak inhibition. To understand its metabolism and antiallergic mechanism, timosaponin AIII was anaerobically incubated with human intestinal microflora to afford a main metabolite, sarsasapogenin. Intraperitoneal administration of sarsasapogenin inhibited allergic reaction more potently than timosaponin AIII. In addition, sarsasapogenin more potently inhibited degranulation and IL-4 protein expression of RBL-2H3 cells induced by IgE-antigen complex than timosaponin AIII. On the basis of these findings, antiallergic effect of AA may be due to those of its steroidal constituents, and that of timosaponin AIII may be activated by using intestinal microflora.
View details for DOI 10.3109/08923970903383889
View details for Web of Science ID 000281917300001
View details for PubMedID 20095799
Anti-scratching Behavioral Effects of N-Stearoyl-phytosphingosine and 4-Hydroxysphinganine in Mice
2010; 45 (7): 613–18
N-Stearoyl-phytosphingosine (SPS) and 4-hydroxysphinganine (phytosphingosine, PS), which are sphingolipids frequently found in mammalian skin, plants, and yeast, have been used as ingredients in cosmetics. In mice, treatment with SPS and PS inhibited histamine-induced scratching behavior and vascular permeability. These agents inhibited the expression of the allergic cytokines, IL-4 and TNF-alpha, and the activation of the transcription factors, NF-kappaB and c-jun, in histamine-stimulated skin tissues. These agents also showed potent anti-histamine effects in the Magnus test using guinea pig ileum. Based on these results, SPS and PS may improve scratching behavioral reactions in skin by regulating the action of histamine and the activation of the transcription factors NF-kappaB and c-jun.
View details for DOI 10.1007/s11745-010-3441-0
View details for Web of Science ID 000279695400005
View details for PubMedID 20585891
Timosaponin AIII, a saponin isolated from Anemarrhena asphodeloides, ameliorates learning and memory deficits in mice (vol 93, pg 121, 2009)
PHARMACOLOGY BIOCHEMISTRY AND BEHAVIOR
2010; 94 (3): 496
View details for DOI 10.1016/j.pbb.2009.07.011
View details for Web of Science ID 000274226500024
Mangiferin Inhibits Passive Cutaneous Anaphylaxis Reaction and Pruritus in Mice
2009; 75 (13): 1415–17
The antiallergic effect of mangiferin isolated from the rhizome of Anemarrhena asphodeloides Bunge (family Liliaceae) was measured in vitro and in vivo. Orally and intraperitoneally administered mangiferin potently inhibited passive cutaneous anaphylaxis (PCA) reaction induced by IgE-antigen complex as well as pruritus induced by compound 48/80 in mice. Mangiferin also inhibited the expression of the proinflammatory cytokine TNF-alpha and the IgE-switching cytokine IL-4 as well as transcription factor NF-kappaB activation in RBL-2H3 cells stimulated by IgE-antigen complex. These findings suggest that mangiferin may improve PCA reaction and pruritus.
View details for DOI 10.1055/s-0029-1185773
View details for Web of Science ID 000271577000008
View details for PubMedID 19533581
Timosaponin AIII, a saponin isolated from Anemarrhena asphodeloides, ameliorates learning and memory deficits in mice
PHARMACOLOGY BIOCHEMISTRY AND BEHAVIOR
2009; 93 (2): 121–27
Anemarrhena asphodeloides Bunge (AA, family Liliaceae), which primarily contains xantones, such as mangiferin, and steroidal saponins, such as timosaponin AIII and sarsasapogenin, has been used as an anti-pyretic, anti-inflammatory, anti-diabetic, anti-platelet aggregation, and anti-depressant agent in traditional Chinese medicine. In the present study, the memory-enhancing effects of these saponins were investigated in scopolamine-treated mice. Among saponins, timosaponin AIII (TA3) significantly reversed the scopolamine-induced deficits in a passive avoidance test and in the Morris water maze test. TA3 also increased hippocampal acetylcholine levels in scopolamine-treated mice and dose-dependently inhibited acetylcholinesterase (AChE) activity (IC(50) value, 35.4 microM). When TA3 (50 mg/kg) was orally administered to mice and its blood concentration was measured by liquid chromatography and tandem mass spectrometry, the C(max) of TA3 occurred 4-6 h after TA3 treatment. The memory-enhancing effect of TA3 was greater when it was administered 5 h before the acquisition trial than 1 h before. Scopolamine treatment in mice increased brain levels of TNF-alpha and IL-1beta expression. However, treatment with TA3 and scopolamine inhibited the increase of TNF-alpha and IL-1beta expression. These results suggest that scopolamine may cause learning and memory deficits that are further complicated by inflammation. TA3 also inhibited the activation of NF-kappaB signaling in BV-2 microglia and in SK-N-SH neuroblastoma cells induced with TNF-alpha or scopolamine. Nevertheless, TA3 may ameliorate memory deficits, mainly by inhibiting AChE.
View details for DOI 10.1016/j.pbb.2009.04.021
View details for Web of Science ID 000267728900005
View details for PubMedID 19426756
Glycosaminoglycan Degradation-inhibitory Lactic Acid Bacteria Ameliorate 2,4,6-Trinitrobenzenesulfonic Acid-Induced Colitis in Mice
JOURNAL OF MICROBIOLOGY AND BIOTECHNOLOGY
2009; 19 (6): 616–21
To evaluate the effects of lactic acid bacteria (LAB) in inflammatory bowel diseases (IBD), we measured the inhibitory effect of several LAB isolated from intestinal microflora and commercial probiotics against the glycosaminoglycan (GAG) degradation by intestinal bacteria. Bifidobacterium longum HY8004 and Lactobacillus plantarum AK8-4 exhibited the most potent inhibition. These LAB inhibited colon shortening and myeloperoxidase production in 2,4,6- trinitrobenzenesulfonic acid (TNBS)-induced experimental colitic mice. These LAB also blocked the expression of the proinflammatory cytokines, IL-1beta and TNF-alpha, as well as of COX-2, in the colon. LAB also blocked activation of the transcription factor, NF-kappaB, and expression of TLR-4 induced by TNBS. In addition, LAB reduced the TNBS-induced bacterial degradation activities of chondroitin sulfate and hyaluronic acid. These findings suggest that GAG degradation-inhibitory LAB may improve colitis by inhibiting inflammatory cytokine expression via TLR-4-linked NF-kB activation and by inhibiting intestinal bacterial GAG degradation.
View details for DOI 10.4014/jmb.0808.479
View details for Web of Science ID 000267498800013
View details for PubMedID 19597321
Mangiferin Ameliorates Scopolamine-Induced Learning Deficits in Mice
BIOLOGICAL & PHARMACEUTICAL BULLETIN
2009; 32 (2): 242–46
The aim of this study was to evaluate the effects of Anemarrhena asphodeloides BUNGE (AA) on cholinergic memory deficits in mice. This agent has previously been used as an antipyretic, anti-inflammatory, anti-diabetic, and antidepressant in traditional Chinese medicine. Mangiferin was isolated from AA and showed a dose-dependent inhibition of acetylcholinesterase (AChE) activity (IC(50) value, 62.8 microM). Cholinergic dysfunction was induced in mice by administering scopolamine, and the animals were then tested using the passive avoidance test as well as the Morris water maze test. Mangiferin (20 mg/kg, p.o.) significantly reversed scopolamine-induced deficits in the passive avoidance test, and also improved escape latencies in training trials and increased swimming times in the Morris water maze test (p<0.05). Mangiferin also reduced acetylcholine and tumor necrosis factor (TNF)-alpha levels induced by scopolamine in mice brain (p<0.05) and inhibited nuclear factor (NF)-kappaB activation in scopolamine or TNF-alpha-stimulated BV-2 microglial cells. These results suggest that mangiferin can improve long-term cholinergic memory deficits by AChE inhibition or cholinergic receptor stimulation and inhibition of NF-kappaB activation.
View details for DOI 10.1248/bpb.32.242
View details for Web of Science ID 000262838800015
View details for PubMedID 19182383
Lactobacillus suntoryeus inhibits pro-inflammatory cytokine expression and TLR-4-linked NF-kappa B activation in experimental colitis
INTERNATIONAL JOURNAL OF COLORECTAL DISEASE
2009; 24 (2): 231–37
Lactic acid bacteria (LAB) can improve disturbances of indigenous microflora as well as inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease. We examined the anticolitic effect of Lactobacillus suntoryeus HY7801, which inhibited toll-like receptor (TLR)-4-linked NF-kappaB activation in human embryonic kidney (HEK) cells, in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitic mice.We measured the ability of commercial and intestinal LAB to inhibit lipopolysaccharide (LPS)-stimulated, TLR-4-linked NF-kappaB activation in HEK cells, as well as to inhibit colitis outcomes in TNBS-induced colitic mice. We also measured levels of the inflammatory markers, interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, and IL-6, and their transcription factor, NF-kappaB, in intestinal mucosa by enzyme-linked immunosorbent assay and immunoblotting.LAB inhibited TLR-4-linked NF-kappaB activation, and L. suntoryeus HY7801 was the most potent inhibitor. Intrarectal treatment of TNBS in mice caused colon shortening and also increased colonic expression of IL-1beta, IL-6, and TNF-alpha expression. However, oral administration of Lactobacillus HY7801 (100 mg/kg) inhibited colon shortening (p < 0.001) and myeloperoxidase activity in TNBS-induced colitic mice (p < 0.0002) and also decreased colonic expression of IL - 1beta (p < 0.003), IL-6 (p < 0.0001), and TNF-alpha (p < 0.0001). Lactobacillus HY7801 inhibited the NF-kappaB activation and TLR-4 expression induced by TNBS, as well as the expression of cyclooxygenase 2. Lactobacillus HY7801 also reduced the activity of intestinal bacterial glycosaminoglycan degradation and beta-glucuronidase induced by TNBS.L. suntoryeus HY7801 can improve colitis via the inhibition of TLR-4-linked NF-kappaB activation.
View details for DOI 10.1007/s00384-008-0618-6
View details for Web of Science ID 000262412400015
View details for PubMedID 19050899
Antiallergic effect of the root of Paeonia lactiflora and its constituents paeoniflorin and paeonol
ARCHIVES OF PHARMACAL RESEARCH
2008; 31 (4): 445–50
The root of Paeonia lactiflora PALL (PL, Family Paeoniaceae) has been used frequently as an antipyretic and anti-inflammatory agent in traditional medicines of Korea, China and Japan. To evaluate antiallergic effect of PL, we isolated its main constituents, paeoniflorin and paeonol, and evaluated in vivo their inhibitory effects against passive cutaenous anaphylaxis (PCA) reaction induced by IgE-antigen complex and scratching behaviors induced by compound 48/80. PL, paeoniflorin and paeonol potently inhibited PCA reaction and scratching behaviors in mice. Paeoniflorin exhibited the most potent inhibition against scratching behaviors and the acetic acid-induced writhing syndrome in mice. Paeonol most potently inhibited PCA reaction and mast cells degranulation. These findings suggest that PL can improve IgE-induced anaphylaxis and scratching behaviors, and may be due to the effect of its constituents, paeoniflorin and paeonol.
View details for DOI 10.1007/s12272-001-1177-6
View details for Web of Science ID 000255033000006
View details for PubMedID 18449501
Antiasthmic effect of fermented Artemisia princeps in asthmic mice induced by ovalbumin
JOURNAL OF MICROBIOLOGY AND BIOTECHNOLOGY
2007; 17 (9): 1554–57
Artemisia princeps Pampanini (AP) was fermented with Bifidobacterium infantis K-525 and its antiasthmic effect investigated. AP and fermented AP (FAP) reduced the IgE level in the blood of ovalbumin-induced asthmic mice. Moreover, FAP reduced the IgE, proinflammatory cytokine IL-6, and IL-4 levels in the trachea, as well as in the lung of the experimental asthmic mice, whereas AP only reduced the IgE and IL-6 levels in the lungs. Nonetheless, AP and FAP both inhibited the mRNA expression of IL-6 and TNF-alpha in IgE-induced RBL-2H3 cells. The in vivo antiasthmic effect of FAP was more potent than that of AP. Therefore, these findings suggest that the enhanced antiasthmic effect of AP after bifidus fermentation was possibly due to the regulation of the proinflammatory cytokine biosynthesis of IL-6 and TNF-alpha.
View details for Web of Science ID 000249875200020
View details for PubMedID 18062237
Inhibitory effect of schizandrin on passive cutaneous anaphylaxis reaction and scratching behaviors in mice
BIOLOGICAL & PHARMACEUTICAL BULLETIN
2007; 30 (6): 1153–56
To evaluate the antiallergic effect of the fruit of Schizandra chinensis Baill (Family Magnoliaceae), which inhibited the mouse passive cutaneous anaphylaxis (PCA) reaction in a preliminary experiment, its main constituent, schizandrin, was isolated and its antiallergic effect investigated. Schizandrin inhibited the PCA reaction induced by the IgE-antigen complex, the scratching behaviors induced by compound 48/80 and the serum IgE production induced by ovalbumin. Schizandrin also inhibited the in vitro degranulation of compound 48/80-induced rat peritoneal mast cells and IgE-induced RBL 2H3 cells. Schizandrin reduced the protein expressions of TNF-alpha and IL-4 in IgE-induced RBL 2H3 cells. These findings suggest that schizandrin can improve IgE-induced anaphylaxis and scratching behaviors.
View details for DOI 10.1248/bpb.30.1153
View details for Web of Science ID 000247495000024
View details for PubMedID 17541172
In vitro and in vivo antiallergic effects of Glycyrrhiza glabra and its components
2007; 73 (3): 257–61
Licorice (Glycyrrhiza glabra L., Leguminosae) is frequently used in traditional medicine to treat inflammatory and allergic diseases. In this study, the main components (glycyrrhizin, 18beta-glycyrrhetinic acid, isoliquiritin, and liquiritigenin) were isolated from licorice, and their anti-allergic effects, such as antiscratching behavior and IgE production-inhibitory activity, were evaluated both in vitro and in vivo. Liquiritigenin and 18beta-glycyrrhetinic acid most potently inhibited the degranulation of RBL-2H3 cells induced by IgE with the antigen (DNP-HSA) and rat peritoneal mast cells induced by compound 48/80. Liquiritigenin and 18beta-glycyrrhetinic acid potently inhibited the passive cutaneous anaphylactic reaction as well as the scratching behavior in mice induced by compound 48/80. These components inhibited the production of IgE in ovalbumin-induced asthma mice but liquiritigenin had little effect. This suggests that the antiallergic effects of licorice are mainly due to glycyrrhizin, 18beta-glycyrrhetinic acid, and liquiritigenin, which can relieve IgE-induced allergic diseases such as dermatitis and asthma.
View details for DOI 10.1055/s-2007-967126
View details for Web of Science ID 000245588700010
View details for PubMedID 17327992
Effect of fermented lactic acid bacteria on antiallergic effect of Artemisia princeps Pampanini
JOURNAL OF MICROBIOLOGY AND BIOTECHNOLOGY
2006; 16 (9): 1464–67
View details for Web of Science ID 000240892200021
Lactic acid bacteria increase antiallergic effect of Artemisia princeps Pampanini SS-1
ARCHIVES OF PHARMACAL RESEARCH
2006; 29 (9): 752–56
Artemisia princeps Pampanini, which is called Ssajuarissuk in Korean (SS-1), was fermented with lactic acid bacteria (LAB) and their passive cutaneous anaphylaxis reaction-inhibitory activity was investigated. Of these fermented agents, SS-1 extract fermented with Bifidobacterium infantis K-525 (F-SS-1) most effectively inhibited the release of P-hexosamindase from RBL-2H3 cells induced IgE. In IgE-induced RBL-2H3 cells, F-SS-1 inhibited proinflammatory cytokines IL-6 and TNF-alpha mRNA expression. Oral administration of SS-1 and F-SS-1 to mice inhibited passive cutaneous anaphylaxis (PCA) reaction induced by IgE and scratching behaviors induced by compound 48/80. The inhibitory activity of F-SS-1 against scratching behaviors was more effective than that of SS-1. These findings suggest that the fermentation of SS-1 with LAB can increase its antiallergic activity.
View details for DOI 10.1007/BF02974075
View details for Web of Science ID 000240882200006
View details for PubMedID 17024848