• The Korean Journal of Physiology and Pharmacology
• /
• v.19 no.1
• /
• pp.1-7
• /
• 2015

Our previous study has shown berberine prevents damage to the intestinal mucosal barrier during early phase of sepsis in rat through mechanisms independent of the NOD-like receptors signaling pathway. In this study, we explored the regulatory effects of berberine on Toll-like receptors during the intestinal mucosal damaging process in rats. Male Sprague-Dawlay (SD) rats were treated with berberine for 5 d before undergoing cecal ligation and puncture (CLP) to induce polymicrobial sepsis. The expression of Toll-like receptor 2 (TLR 2), TLR 4, TLR 9, the activity of nuclear factor-kappa B ($NF-{\kappa}B$), the levels of selected cytokines and chemokines, percentage of cell death in intestinal epithelial cells, and mucosal permeability were investigated at 0, 2, 6, 12 and 24 h after CLP. Results showed that the tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and interleukin-6 (IL-6) level were significantly lower in berberine-treated rats compared to the control animals. Conversely, the expression level of tight junction proteins, percentage of cell death in intestinal epithelial cells and the mucosal permeability were significantly higher in berberine-treated rats. The mRNA expression of TLR 2, TLR 4, and TLR 9 were significantly affected by berberine treatment. Our results indicate that pretreatment with berberine attenuates tissue injury and protects the intestinal mucosal barrier in early phase of sepsis and this may possibly have been mediated through the TLRs pathway.

• Journal of Pharmacopuncture
• /
• v.27 no.2
• /
• pp.59-69
• /
• 2024

This study investigates the therapeutic potential of Indigo Naturalis (IN) in treating a Inflammatory Bowel Disease (IBD). The objective is to comprehensively examine the effects and pharmacological mechanisms of IN on IBD, assessing its potential as an novel treatment for IBD. Analysis of 11 selected papers is conducted to understand the effects of IN, focusing on compounds like indirubin, isatin, indigo, and tryptanthrin. This study evaluates their impact on Disease Activity Index (DAI) score, colon length, mucosal damage, and macrophage infiltration in Dextran Sulfate Sodium (DSS)-induced colitis mice. Additionally, It investigate into the anti-inflammatory mechanisms, including Aryl hydrocarbon Receptor (AhR) pathway activation, Nuclear Factor kappa B (NF-κB)/nod-like receptor family pyrin domain containing 3 (NLRP3)/Interleukin 1 beta (IL-1β) inhibition, and modulation of Toll-like receptor 4 (TLR4)/myeloid differentiation primary response 88 (MYD88)/NF-κB and Mitogen Activated Protein Kinase (MAPK) pathways. Immunomodulatory effects on T helper 17 (Th17)/regulatory T cell (Treg cell) balance and Glycogen synthase kinase-3 beta (GSK3-β) expression are also explored. Furthermore, the study addresses the role of IN in restoring intestinal microbiota diversity, reducing pathogenic bacteria, and increasing beneficial bacteria. The findings reveal that IN, particularly indirubin and indigo, demonstrates significant improvements in DAI score, colon length, mucosal damage, and macrophage infiltration in DSS-induced colitis mice. The anti-inflammatory effects are attributed to the activation of the AhR pathway, inhibition of inflammatory pathways, and modulation of immune responses. These results exhibit the potential of IN in IBD treatment. Notably, the restoration of intestinal microbiota diversity and balance further supports its efficacy. IN emerges as a promising and effective treatment for IBD, demonstrating anti-inflammatory effects and positive outcomes in preclinical studies. However, potential side effects necessitate further investigation for safe therapeutic development. The study underscores the need for future research to explore a broader range of active ingredients in IN to enhance therapeutic efficacy and safety.

• Journal of Life Science
• /
• v.31 no.2
• /
• pp.237-247
• /
• 2021

Immune responses in the central nervous system (CNS) function as the host's defense system against pathogens and usually help with repair and regeneration. However, chronic and exaggerated neuroinflammation is detrimental and may create neuronal damage in many cases. The NOD-, LRR-, and pyrin domain―containing 3 (NLRP3) inflammasome, a kind of NOD-like receptor, is a cytosolic multiprotein complex that consists of sensors (NLRP3), adaptors (apoptosis-associated speck like protein containing a caspase recruitment domain, ASC) and effectors (caspase 1). It can detect a broad range of microbial pathogens along with foreign and host-derived danger signals, resulting in the assembly and activation of the NLRP3 inflammasome. Upon activation, NLRP3 inflammasome leads to caspase 1-dependent secretion of the pro-inflammatory cytokines IL-1β and IL-18, as well as to gasdermin D-mediated pyroptotic cell death. NLRP3 inflammasome is highly expressed in CNS-resident cell types, including microglia and astrocytes, and growing evidence suggests that NLRP3 inflammasome is a crucial player in the pathophysiology of several neuroinflammatory and psychiatric diseases, such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, stroke, traumatic brain injury, amyotrophic lateral sclerosis, and major depressive disorder. Thus, this review describes the molecular mechanisms of NLRP3 inflammasome activation and its crucial roles in the pathogenesis of neurological disorders.

• Korean Circulation Journal
• /
• v.53 no.6
• /
• pp.387-403
• /
• 2023

Background and Objectives: Myocardial ischemia and reperfusion injury (MIRI) has high morbidity and mortality worldwide. We aimed to explore the role of long noncoding RNA lysyl oxidase like 1 antisense RNA 1 (LOXL1-AS1) in cardiomyocyte pyroptosis. Methods: Hypoxia/reoxygenation (H/R) injury was constructed in human cardiomyocyte (HCM). The level of LOXL1-AS1, miR-761, phosphatase and tensin homolog (PTEN) and pyroptosis-related proteins was monitored by quantitative real-time polymerase chain reaction or western blot. Flow cytometry examined the pyroptosis level. Lactate dehydrogenase (LDH), creatine kinase-MB and cardiac troponin I levels were detected by test kits. Enzyme-linked immunosorbent assay measured the release of inflammatory cytokines. Dual-luciferase assay validated the binding relationship among LOXL1-AS1, miR-761, and PTEN. Finally, ischemia/reperfusion (I/R) animal model was constructed. Hematoxylin and eosin staining assessed morphological changes of myocardial tissue. NOD-like receptor pyrin domain-containing protein 3 (NLRP3) and casepase-1 expression was determined by immunohistochemistry. Results: After H/R treatment, LOXL1-AS1 and PTEN were highly expressed but miR-761 level was suppressed. LOXL1-AS1 inhibition or miR-761 overexpression increased cell viability, blocked the release of LDH and inflammatory cytokines (interleukin [IL]-1β, IL-18), inhibited pyroptosis level, and downregulated pyroptosis-related proteins (ASC, cleaved caspase-1, gasdermin D-N, NLRP3, IL-1β, and IL-18) levels in HCMs. LOXL1-AS1 sponged miR-761 to up-regulate PTEN. Knockdown of miR-761 reversed the effect of LOXL1-AS1 down regulation on H/R induced HCM pyroptosis. LOXL1-AS1 aggravated the MIRI by regulating miR-761/PTEN axis in vivo. Conclusions: LOXL1-AS1 targeted miR-761 to regulate PTEN expression, then enhance cardiomyocyte pyroptosis, providing a new alternative target for the treatment of MIRI.

• Biomolecules & Therapeutics
• /
• v.30 no.3
• /
• pp.246-256
• /
• 2022

The present study focused on the potential mechanism of betulin (BT), a pentacyclic triterpenoid isolated from the bark of white birch (Betula pubescens), against chronic alcohol-induced lipid accumulation and metaflammation. AML-12 and RAW 264.7 cells were administered ethanol (EtOH), lipopolysaccharide (LPS) or BT. Male C57BL/6 mice were fed Lieber-DeCarli liquid diets containing 5% EtOH for 4 weeks, followed by single EtOH gavage on the last day and simultaneous treatment with BT (20 or 50 mg/kg) by oral gavage once per day. In vitro, MTT showed that 0-25 mM EtOH and 0-25 µM BT had no toxic effect on AML-12 cells. BT could regulate sterolregulatory-element-binding protein 1 (SREBP1), lipin1/2, P2X7 receptor (P2X7r) and NOD-like receptor family, pyrin domains-containing protein 3 (NLRP3) expressions again EtOH-stimulation. Oil Red O staining also indicated that BT significantly reduced lipid accumulation in EtOH-stimulated AML-12 cells. Lipin1/2 deficiency indicated that BT might mediate lipin1/2 to regulate SREBP1 and P2X7r expression and further alleviate lipid accumulation and inflammation. In vivo, BT significantly alleviated histopathological changes, reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and triglyceride (TG) levels, and regulated lipin1/2, SREBP1, peroxisome proliferator activated receptor α/γ (PPARα/γ) and PGC-1α expression compared with the EtOH group. BT reduced the secretion of inflammatory factors and blocked the P2X7r-NLRP3 signaling pathway. Collectively, BT attenuated lipid accumulation and metaflammation by regulating the lipin1/2-mediated P2X7r signaling pathway.

• IMMUNE NETWORK
• /
• v.24 no.2
• /
• pp.3.1-3.23
• /
• 2024

Cigarette smoke extract (CSE)-treated mouse airway epithelial cells (MAECs)-derived exosomes accelerate the progression of chronic obstructive pulmonary disease (COPD) by upregulating triggering receptor expressed on myeloid cells 1 (TREM-1); however, the specific mechanism remains unclear. We aimed to explore the potential mechanisms of CSE-treated MAECs-derived exosomes on M1 macrophage polarization and pyroptosis in COPD. In vitro, exosomes were extracted from CSE-treated MAECs, followed by co-culture with macrophages. In vivo, mice exposed to cigarette smoke (CS) to induce COPD, followed by injection or/and intranasal instillation with oe-TREM-1 lentivirus. Lung function and pathological changes were evaluated. CD68⁺ cell number and the levels of iNOS, TNF-α, IL-1β (M1 macrophage marker), and pyroptosis-related proteins (NOD-like receptor family pyrin domain containing 3, apoptosis-associated speck-like protein containing a caspase-1 recruitment domain, caspase-1, cleaved-caspase-1, gasdermin D [GSDMD], and GSDMD-N) were examined. The expression of maternally expressed gene 3 (MEG3), spleen focus forming virus proviral integration oncogene (SPI1), methyltransferase 3 (METTL3), and TREM-1 was detected and the binding relationships among them were verified. MEG3 increased N6-methyladenosine methylation of TREM-1 by recruiting SPI1 to activate METTL3. Overexpression of TREM-1 or METTL3 negated the alleviative effects of MEG3 inhibition on M1 polarization and pyroptosis. In mice exposed to CS, EXO^-CSE further aggravated lung injury, M1 polarization, and pyroptosis, which were reversed by MEG3 inhibition. TREM-1 overexpression negated the palliative effects of MEG3 inhibition on COPD mouse lung injury. Collectively, CSE-treated MAECs-derived exosomal long non-coding RNA MEG3 may expedite M1 macrophage polarization and pyroptosis in COPD via the SPI1/METTL3/TREM-1 axis.

• IMMUNE NETWORK
• /
• v.13 no.5
• /
• pp.194-198
• /
• 2013

Recent papers have shown that the initial event in the pathogenesis of autoimmune type 1 diabetes (T1D) comprises sensing of molecular patterns released from apoptotic ${\beta}$-cells by innate immune receptors such as toll-like receptor (TLR). We have reported that apoptotic ${\beta}$-cells undergoing secondary necrosis called 'late apoptotic' ${\beta}$-cells stimulate dendritic cells (DCs) and induce diabetogenic T cell priming through TLR2. The role of other innate immune receptors such as TLR7 or TLR9 in the initiation of T1D has also been suggested. We hypothesized that TLR2 blockade could inhibit T1D at the initial step of T1D. Indeed, when a TLR2 agonist, $Pam3CSK_4$ was administered chronically, the development of T1D in nonobese diabetic (NOD) mice was inhibited. Diabetogenic T cell priming by DCs was attenuated by chronic treatment with $Pam3CSK_4$, indicating DC tolerance. For the treatment of established T1D, immune tolerance alone is not enough because ${\beta}$-cell mass is critically reduced. We employed TLR2 tolerance in conjunction with islet transplantation, which led to reversal of newly established T1D. Dipeptidyl peptidase 4 (DPP4) inhibitors are a new class of anti-diabetic agents that have beneficial effects on ${\beta}$-cells. We investigated whether a combination of DPP4 inhibition and TLR2 tolerization could reverse newly established T1D without islet transplantation. We could achieve normoglycemia by TLR2 tolerization in combination with DPP4 inhibition but not by TLR2 tolerization or DPP4 inhibition alone. ${\beta}$-cell mass was significantly increased by combined treatment with TLR2 tolerization and DPP4 inhibition. These results suggest the possibility that a novel strategy of TLR tolerization will be available for the inhibition or treatment of established T1D when combined with measures increasing critically reduced ${\beta}$-cell mass of T1D patients such as DPP4 inhibition or stem cell technology.

• BMB Reports
• /
• v.52 no.10
• /
• pp.613-618
• /
• 2019

Microglial cells are known as the main immune cells in the central nervous system, both regulating its immune response and maintaining its homeostasis. Furthermore, the antioxidant ${\alpha}-lipoic$ acid (LA) is a recognized therapeutic drug for diabetes because it can easily invade the blood-brain barrier. This study investigated the effect of ${\alpha}-LA$ on the inflammatory response in lipopolysaccharide (LPS)-treated BV-2 microglial cells. Our results revealed that ${\alpha}-LA$ significantly attenuated several inflammatory responses in BV-2 microglial cells, including pro-inflammatory cytokines, such as tumor necrosis $factor-{\alpha}$ and interleukin (IL)-6, and other cytotoxic molecules, such as nitric oxide and reactive oxygen species. In addition, ${\alpha}-LA$ inhibited the LPS-induced phosphorylation of ERK and p38 and its pharmacological properties were facilitated via the inhibition of the nuclear factor kappa B signaling pathway. Moreover, ${\alpha}-LA$ suppressed the activation of NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasomes, multiprotein complexes consisting of NLRP3 and caspase-1, which are involved in the innate immune response. Finally, ${\alpha}-LA$ decreased the genes accountable for the M1 phenotype, $IL-1{\beta}$ and ICAM1, whereas it increased the genes responsible for the M2 phenotype, MRC1 and ARG1. These findings suggest that ${\alpha}-LA$ alleviates the neuroinflammatory response by regulating microglial polarization.

• BMB Reports
• /
• v.52 no.5
• /
• pp.336-341
• /
• 2019

The cGAS-STING pathway plays an important role in pathogen-induced activation of the innate immune response. The 29-kDa amino-terminal fibronectin fragment (29-kDa FN-f) found predominantly in the synovial fluid of osteoarthritis (OA) patients increases the expression of catabolic factors via the toll-like receptor-2 (TLR-2) signaling pathway. In this study, we investigated whether 29-kDa FN-f induces inflammatory responses via the cyclic GMP-AMP synthase (cGAS)/stimulator of interferon gene (STING) pathway in human primary chondrocytes. The levels of cGAS and STING were elevated in OA cartilage compared with normal cartilage. Long-term treatment of chondrocytes with 29-kDa FN-f activated the cGAS/STING pathway together with the increased level of gamma-H2AX, a marker of DNA breaks. In addition, the expression of pro-inflammatory cytokines, including granulocyte-macrophage colony-stimulating factor (GM-CSF/CSF-2), granulocyte colony-stimulating factor (G-CSF/CSF-3), and type I interferon ($IFN-{\alpha}$), was increased more than 100-fold in 29-kDa FN-f-treated chondrocytes. However, knockdown of cGAS and STING suppressed 29-kDa FN-f-induced expression of GM-CSF, G-CSF, and $IFN-{\alpha}$ together with the decreased activation of TANK-binding kinase 1 (TBK1), interferon regulatory factor 3 (IRF3), and inhibitor protein ${\kappa}B{\alpha}$ ($I{\kappa}B{\alpha}$). Furthermore, NOD2 or TLR-2 knockdown suppressed the expression of GM-CSF, G-CSF, and $IFN-{\alpha}$ as well as decreased the activation of the cGAS/STING pathway in 29-kDa FN-f-treated chondrocytes. These data demonstrate that the cGAS/STING/TBK1/IRF3 pathway plays a critical role in 29-kDa FN-f-induced expression of pro-inflammatory cytokines.

• Korean Journal of Clinical Laboratory Science
• /
• v.54 no.3
• /
• pp.201-208
• /
• 2022

Neuroinflammation is defined as a neurological inflammation within the brain and the spinal cord. In neuroinflammation, microglia are the tissue-resident macrophages of the central nervous system, which act as the first line of defense against harmful pathogens. Dexmedetomidine (Dex) has an anti-inflammatory effect in many neurological conditions. Additionally, the microRNA-30a-5p (miR-30a-5p) mimic has been proven to be effective in macrophages in inflammatory conditions. This study aimed to investigate the synergistic anti-inflammatory effects of both miR-30a-5p and Dex in lipopolysaccharide (LPS)-induced BV2 cells. This study showed that miR-30a-5p and Dex decreased nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) translocation in LPS-induced BV2 cells. MiR-30a-5p and Dex alleviated tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), LPS-induced phosphorylation c-Jun N-terminal kinases (JNK), extracellular signal-regulated kinase (ERK) and p38. Also, the expression of the NOD-like receptor pyrin domain containing 3 inflammasome (NLRP3), cleaved caspase-1, and ASC was inhibited. Furthermore, LPS-stimulated nitric oxide (NO) production, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) expression were attenuated by Dex and miR-30a-5p. Our results indicate that a combination of Dex and miR-30a-5p, attenuates NF-κB activation, the mitogen-activated protein kinase (MAPK) signaling pathway, and inflammatory mediators involved in LPS-induced inflammation and inhibits the activation of the NLRP3 inflammasome in LPS-activated BV2 cells.