• 생명과학회지
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• 제33권12호
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• pp.1062-1073
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• 2023

우울증은 개인과 사회에 부정적인 영향을 미치는 흔한 정신질환이지만 그 원인은 아직 명확히 밝혀져 있지 않다. 스트레스는 우울증의 주요 위험인자이며, 염증을 유발하여 우울증에 대한 취약성을 증가시키는 것으로 알려져 있다. 수많은 연구는 우울증과 염증의 강한 연관성을 제안하고 있다. 우울증 환자 혈액에서는 IL-1β, IL-6, IL-12, TNF-α 및 IFN-γ와 같은 친염증성 사이토카인이 증가하였으며, IL-4, IL-10 및 TGF-β와 같은 항염증성 사이토카인이 감소하였다. 설치류에 친염증성 사이토카인을 투여하면 우울 유사 행동이 관찰되는 반면, 항염증제를 투여하면 우울 증상이 완화된다. 이러한 연구들은 우울증의 병인에 염증의 중요성을 강조하고 있다. 우울증에서 염증이 활성화되는 기전에 관한 다양한 연구들이 진행되고 있다. 최근 연구에서는 스트레스로 유발되는 무균 염증의 중요성을 밝히고 있다. 병원균의 감염이 없는 상태에서 신체 및 심리적 스트레스로 인해 염증 과정이 활성화되는 것을 무균 염증이라 한다. 스트레스는 무균 염증을 활성화하기 위해 DAMPs (damage-associated molecular patterns)로 알려진 내인성 인자의 방출을 촉진시키며, 방출된 DAMPs는 해당 수용체인 PRRs (pattern recognition receptors)에 결합함으로서 신호전달을 통해 친염증성 사이토카인 생성을 증가시킨다. 본 종설에서 무균 염증의 조절 장애에 대한 전임상 및 임상 증거를 바탕으로 우울증에서 DAMP의 역할을 검토하고자 한다.

• 생명과학회지
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• 제29권11호
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• pp.1179-1191
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• 2019

암세포는 epithelial mesenchymal transition (EMT)를 통해 tumor invasion과 metastasis가 일어나며, 또한 정상세포와 다른 oncogenic metabolic phenotypes 획득 즉, glycolytic switch 등이 암 발생과 진행에 깊이 연관되어 있음이 잘 알려져 있다. High-mobility group box 1 (HMGB1)은 chromatin-associated nuclear protein으로 알려져 있으나, dying cells 또는 immune cells로부터 방출되기도 한다. 방출된 HMGB1은 damage-associated molecular pattern (DAMP)로서 작용하여 EMT 및 invasion, metastasis를 유도함으로서 tumor progression에 기여한다고 알려졌다. 본 연구에서 HMGB1에 의해 EMT와 glycolytic switch 유도되며, 이 과정은 Snail 의존적임을 확인하였다. 또한 HMGB1/Snail cascade는 COX subunits인 COXVIIa와 COXVIIc의 발현 억제를 통해 mitochondrial repression과 cytochrome c oxidase (COX) inhibition을 유도하였다. HMGB1은 Snail를 통해 glycolytic switch의 주요 효소인 hexokinase 2 (HK2), phosphofructokinase-2/fructose-2,6-bisphosphatase 2 (PFKFB2), phosphoglycerate mutase 1 (PGAM1)의 발현을 증가시켰다. 이들 효소는 glycolytic switch에 중요하게 관여하는 것으로 알려져 있다. 이들 해당과정의 효소들을 knockdown한 결과 HMGB1에 의한 EMT를 억제함으로써 glycolysis와 HMGB1-induced EMT가 밀접하게 연관되어 있을 제시하였다. 이상의 연구 결과들은 HMGB1/Snail cascade가 EMT 및 glycolytic switch, mitochondrial repression에 중요하게 작용할 것임을 시사한다.

• BMB Reports
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• 제51권10호
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• pp.508-513
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• 2018

Fibronectin fragments found in the synovial fluid of patients with osteoarthritis (OA) induce the catabolic responses in cartilage. Nuclear high-mobility group protein Box 1 (HMGB1), a damage-associated molecular pattern, is responsible for the regulation of signaling pathways related to cell death and survival in response to various stimuli. In this study, we investigated whether changes induced by 29-kDa amino-terminal fibronectin fragment (29-kDa FN-f) in HMGB1 expression influences the pathogenesis of OA via an HMGB1-modulated autophagy signaling pathway. Human articular chondrocytes were enzymatically isolated from articular cartilage. The level of mRNA was measured by quantitative real-time PCR. The expression of proteins was examined by western blot analysis, immnunofluorescence assay, and enzyme-linked immunosorbent assay. Interaction of proteins was evaluated by immunoprecipitation. The HMGB1 level was significantly lower in human OA cartilage than in normal cartilage. Although 29-kDa FN-f significantly reduced the HMGB1 expression at the mRNA and protein levels 6 h after treatment, the cytoplasmic level of HMGB1 was increased in chondrocytes treated with 29-kDa FN-f, which significantly inhibited the interaction of HMGB1 with Beclin-1, increased the interaction of Bcl-2 with Beclin-1, and decreased the levels of Beclin-1 and phosphorylated Bcl-2. In addition, the level of microtubule-associated protein 1 light chain 3-II, an autophagy marker, was down-regulated in chondrocytes treated with 29-kDa FN-f, whereas the effect was antagonized by mTOR knockdown. Furthermore, prolonged treatment with 29-kDa FN-f significantly increased the release of HMGB1 into the culture medium. These results demonstrated that 29-kDa FN-f inhibits chondrocyte autophagy by modulating the HMGB1 signaling pathway.

• Journal of Microbiology and Biotechnology
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• 제25권10호
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• pp.1680-1686
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• 2015

Inhibition of 4-nitroquinoline-1-oxide (4-NQO) genotoxicity by a probiotic strain of Lactobacillus rhamnosus (IMC501) was assessed by the prokaryotic short-term bioassay SOSChromotest, using Escherichia coli PQ37 as the target organism. Results showed the ability of strain IMC501 to rapidly and markedly counteract, in vitro, the DNA damage originated by the considered genotoxin. The inhibition was associated with a spectroscopic hypsochromic shift of the original 4-NQO profile and progressive absorbance increase of a new peak. IR-Raman and GC-MS analyses confirmed the disappearance of 4-NQO after contact with the microorganism, showing also the absence of any genotoxic molecule potentially available for metabolic activation (i.e., 4-hydroxyaminoquinoline-1-oxide and 4-nitrosoquinoline-1-oxide). Furthermore, we have shown the presence of the phenyl-quinoline and its isomers as major non-genotoxic conversion products, which led to the hypothesis of a possible pattern of molecular transformation. These findings increase knowledge on lactobacilli physiology and contribute to the further consideration of antigenotoxicity as a nonconventional functional property of particular probiotic strains.

• IMMUNE NETWORK
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• 제21권5호
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• pp.36.1-36.16
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• 2021

Peroxiredoxins (Prxs) are ubiquitously expressed peroxidases that reduce hydrogen peroxide or alkyl peroxide production in cells. Prxs are released from cells in response to various stress conditions, and they function as damage-associated molecular pattern molecules. However, the secretory mechanism of Prxs and their roles have not been elucidated. Thus, we aimed to determine whether inflammasome activation is a secretory mechanism of Prxs and subsequently identify the effect of the secreted Prxs on activation of the classical complement pathway. Using J774A.1, a murine macrophage cell line, we demonstrated that NLRP3 inflammasome activation induces Prx1, Prx2, Prx5, and Prx6 secretion in a caspase-1 dependent manner. Using HEK293T cells with a transfection system, we revealed that the release of Prx1 and Prx2 relies on gasdermin-D (GSDMD)-mediated secretion. Next, we confirmed the binding of both Prx1 and Prx2 to C1q; however, only Prx2 could induce the C1q-mediated classical complement pathway activation. Collectively, our results suggest that inflammasome activation is a secretory mechanism of Prxs and that GSDMD is a mediator of their secretion. Moreover, secreted Prx1 and Prx2 bind with C1q, but only Prx2 mediates the classical complement pathway activation.

• BMB Reports
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• 제52권6호
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• pp.373-378
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• 2019

The nucleotide-binding and oligomerization domain (NOD) is an innate pattern recognition receptor that recognizes pathogen- and damage-associated molecular patterns. The 29-kDa amino-terminal fibronectin fragment (29-kDa FN-f) is a matrix degradation product found in the synovial fluids of patients with osteoarthritis (OA). We investigated whether NOD2 was involved in 29-kDa FN-f-induced pro-catabolic gene expression in human chondrocytes. The expression of mRNA and protein was measured using quantitative real-time polymerase chain reaction (qrt-PCR) and Western blot analysis. Small interfering RNAs were used for knockdown of NOD2 and toll-like receptor 2 (TLR-2). An immunoprecipitation assay was performed to examine protein interactions. The NOD2 levels in human OA cartilage were much higher than in normal cartilage. NOD1 and NOD2 expression, as well as pro-inflammatory cytokines, including interleukin-1beta (IL-$1{\beta}$) and tumor necrosis factor-alpha (TNF-${\alpha}$), were upregulated by 29-kDa FN-f in human chondrocytes. NOD2 silencing showed that NOD2 was involved in the 29-kDa FN-f-induced expression of TLR-2. Expressions of IL-6, IL-8, matrix metalloproteinase (MMP)-1, -3, and -13 were also suppressed by TLR-2 knockdown. Furthermore, NOD2 and TLR-2 knockdown data demonstrated that both NOD2 and TLR-2 modulated the expressions of their adaptors, receptorinteracting protein 2 (RIP2) and myeloid differentiation 88, in 29-kDa FN-f-treated chondrocytes. 29-kDa FN-f enhanced the interaction of NOD2, RIP2 and transforming growth factor beta-activated kinase 1 (TAK1), an indispensable signaling intermediate in the TLR-2 signaling pathway, and activated nuclear factor-${\kappa}B$ (NF-${\kappa}B$), subsequently leading to increased expressions of pro-inflammatory cytokines and cartilage-degrading enzymes. These results demonstrate that 29-kDa FN-f modulated pro-catabolic responses via cross-regulation of NOD2 and TLR-2 signaling pathways.

• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4517-4525
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• 2016

Background: Sperm DNA damage is underlying aetiology of poor implantation and pregnancy rates but also affects health of offspring and may also result in denovo mutations in germ line and post fertilization. This may result in complex diseases, polygenic disorders and childhood cancers. Childhood cancer like retinoblastoma (RB) is more prevalent in developing countries and the incidence of RB has increased more than three fold in India in the last decade. Recent studies have documented increased incidence of cancers in children born to fathers who consume alcohol in excess and tobacco or who were conceived by assisted conception. The aetiology of childhood cancer and increased disease burden in these children is lin ked to oxidative stress (OS) and oxidative DNA damage( ODD) in sperm of their fathers. Though several antioxidants are in use to combat oxidative stress, the effect of majority of these formulations on DNA is not known. Yoga and meditation cause significant decline in OS and ODD and aid in regulating OS levels such that reactive oxygen speues meditated signal transduction, gene expression and several other physiological functions are not disrupted. Thus, this study aimed to analyze sperm ODD as a possible etiological factor in childhood cancer and role of simple life style interventions like yoga and meditation in significantly decreasing seminal oxidative stress and oxidative DNA damage and thereby decreasing incidence of childhood cancers. Materials and Methods: A total of 131 fathers of children with RB (non-familial sporadic heritable) and 50 controls (fathers of healthy children) were recruited at a tertiary center in India. Sperm parameters as per WHO 2010 guidelines and reactive oxygen species (ROS), DNA fragmentation index (DFI), 8-hydroxy-2'-deoxy guanosine (8-OHdG) and telomere length were estimated at day 0, and after 3 and 6 months of intervention. We also examined the compliance with yoga and meditation practice and smoking status at each follow-up. Results: The seminal mean ROS levels (p<0.05), sperm DFI (p<0.001), 8-OHdG (p<0.01) levels were significantly higher in fathers of children with RB, as compared to controls and the relative mean telomere length in the sperm was shorter. Levels of ROS were significantly reduced in tobacco users (p<0.05) as well as in alcoholics (p<0.05) after intervention. DFI reduced significantly (p<0.05) after 6 months of yoga and meditation practice in all groups. The levels of oxidative DNA damage marker 8-OHdG were reduced significantly after 3 months (p<0.05) and 6 months (p<0.05) of practice. Conclusions: Our results suggest that OS and ODD DNA may contribute to the development of childhood cancer. This may be due to accumulation of oxidized mutagenic base 8OHdG, and elevated MDA levels which results in MDA dimers which are also mutagenic, aberrant methylation pattern, altered gene expression which affect cell proliferation and survival through activation of transcription factors. Increased mt DNA mutations and aberrant repair of mt and nuclear DNA due to highly truncatred DNA repair mechanisms all contribute to sperm genome hypermutability and persistant oxidative DNA damage. Oxidative stress is also associated with genome wide hypomethylation, telomere shortening and mitochondrial dysfunction leading to genome hypermutability and instability. To the best of our knowledge, this is the first study to report decline in OS and ODD and improvement in sperm DNA integrity following adoption of meditation and yoga based life style modification.This may reduce disease burden in next generation and reduce incidence of childhood cancers.

• 대한의생명과학회지
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• 제21권2호
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• pp.122-125
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• 2015

House dust mite (HDM) as a major allergen and damage-associated molecular pattern (DAMP) such as S100A8 and S100A9 trigger the pathogenesis and severity of allergic disease such as asthma. Regulation of neutrophil apoptosis is an important immune response and its dysregulation is involved in pathogenesis of allergic diseases. In this study, we examined the effects of HDM, S100A8 and S100A9 on spontaneous apoptosis of normal neutrophils. We considered the importance of the difference between in vitro and in vivo results and developed a new in vitro system consisting of a combination of immune cells and T helper (Th) cytokines. Extract of Dermatophagoides pteronyssinus (DP), S100A8, and S100A9 inhibited neutrophil apoptosis in culture of neutrophils alone without other leukocytes. DP and S100A8 more strongly suppressed neutrophil apoptosis in combinations of neutrophils, eosinophils, lymphocytes or monocytes than in a culture of neutrophils alone. Anti-apoptotic effect of S100A9 in the mixture of immune cells was similar to that in neutrophils. DP, S100A8, and S100A9 blocked neutrophil apoptosis, regardless of pretreatment with a T helper (Th) 1 cytokine (IFN-$\gamma$), Th2 cytokines (IL-4 and IL-10), a Th9 cytokine (IL-9), a Th17 cytokine (IL-17), a Treg-producing cytokine (TGF-$\beta$). These findings may enable elucidation of allergy pathogenesis due to HDM and DAMP.

• Fisheries and Aquatic Sciences
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• 제19권4호
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• pp.18.1-18.10
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• 2016

In this study, to clarify the function of $PoPLC-{\beta}1$, in response to stress challenge, we examined the $PoPLC-{\beta}1$ expression pattern in response to external stress (pathogen-associated molecular pathogen challenge and environmental challenge including temperature and salinity). $PoPLC-{\beta}1$ expression analysis of tissue from olive flounder showed that the messenger RNA (mRNA) was predominantly expressed in the brain, heart, eye, liver, spleen, and stomach. We also tested the mRNA expression of the $PoPLC-{\beta}1$ in the spleen and kidney of olive flounder by RT-PCR and real-time PCR following stimulation with lipopolysaccharide (LPS), concanavalin A (ConA), or polyinosinic:polycytidylic acid (PolyI:C) and compared with the inflammatory cytokines IL-1b and IL-6 in the stimulated flounder tissues. Each of the spleen and kidney and mRNA transcripts of $PoPLC-{\beta}1$ were increased 30- and 10-fold than normal tissue at 1-6 h post injection (HPI) with PolyI:C when the expression of $PoPLC-{\beta}1$ transcript was similar to LPS and ConA. We also tested the expression of $PoPLC-{\beta}1$ in response to temperature and salinity stress. The expression of $PoPLC-{\beta}1$ also was affected by temperature and salinity stress. Our results provide clear evidence that the olive flounder $PLC-{\beta}1$ signal pathways may play a critical role in immune function at the cellular level and in inflammation reactions. In addition, $PLC-{\beta}1$ appears to act as an oxidative-stress suppressor to prevent cell damage in fish.