• Journal of Microbiology and Biotechnology
• /
• 제28권1호
• /
• pp.59-64
• /
• 2018

Listeria monocytogenes can asymptomatically inhabit the human intestine as a commensal bacterium. However, the mechanism by which L. monocytogenes is able to inhabit the intestine without pathogenic symptoms remains unclear. We compared the invasion efficiency of L. monocytogenes strains with the 268- and 385-bp-long actA gene. Clinical strains SMFM-CI-3 and SMFM-CI-6 with 268-bp actA isolated from patients with listeriosis, and strains SMFM-SI-1 and SMFM-SI-2 with the 385-bp gene isolated from carcasses, were used for inoculum preparation. The invasion efficiency of these strains was evaluated using Caco-2 cells (intestinal epithelial cell line), prepared as normal and healthy cells with tightened tight junctions and senescent cells with loose tight junctions that were loosened by adriamycin treatment. The invasion efficiency of L. monocytogenes strains with the 268-bp-long actA gene was 1.1-2.6-times lower than that of the strains with the 385-bp-long gene in normal and healthy cells. However, the invasion efficiency of both types of strains did not differ in senescent cells. Thus, L. monocytogenes strains with the 268-bp-long actA gene can inhabit the intestine asymptomatically as a commensal bacterium, but they may invade the intestinal epithelial cells and cause listeriosis in senescent cells.

• 한국축산식품학회지
• /
• 제32권4호
• /
• pp.434-440
• /
• 2012

It has been suggested that probiotics could be useful for the prevention of symptomatic relapse in patients with inflammatory bowel disease (IBD). Interleukin (IL)-8 has been well recognized as one of the pro-inflammatory cytokines that could trigger inflammation and epithelial barrier dysfunction. In this study, the anti-inflammatory effects of probiotics were investigated using a human epithelial cell line (HT-29). Probiotics from infant feces and kimchi were tested for their cytotoxicity and effects on adhesion to epithelial cells. The present results show that seven strains could form 70 % adhesion on HT-29. The probiotics used in this study did not affect HT-29 cell viability. To screen anti-inflammatory lactic acid bacteria, HT-29 cells were pretreated with live and heat-killed probiotics, and lipopolysaccharide (LPS) ($1{\mu}g/mL$) was then added to stimulate the cells. The cell culture supernatant was then used to measure IL-8 secretion by ELISA, and the cell pellet was used to determine IL-8 and toll-like receptor (TLR-4) mRNA expression levels by RT-PCR. Some probiotics (KJP421, KDK411, SRK414, E4191, KY21, and KY210) exhibited anti-inflammatory effects through the repression of IL-8 secretion from HT-29 cells. In particular, Lactobacillus salivarius E4191, originating from Egyptian infant feces, not only decreased IL-8 mRNA expression, but also decreased TLR-4 expression. These results indicate that Lactobacillus salivarius E4191 may have a protective effect in intestinal epithelial cells.

• 대한수의학회지
• /
• 제42권3호
• /
• pp.289-297
• /
• 2002

쏘가리 (Siniperca scherzeri Steindachner)의 위장관에 존재하는 내분비세포의 부위별 분포 및 출현빈도를 포유류의 peptide에 대한 7종류의 항혈청을 사용하여 면역조직화학적 방법으로 관찰하였다. 쏘가리의 위장관은 근위부에서부터 원위부까지 위, 소장 및 대상으로 3 등분 하였으며, 다양한 종류의 항혈청에 면역반응성을 나타내는 면역반응세포들이 상피세포 사이와 위샘 또는 장샘에서 관찰되었다. 상피세포 사이에서는 대부분의 면역반응세포들은 장 내강까지 신장되어 있는 긴 세포질 돌기를 함유한 방추형의 개방형 세포 (open type cell)로 관찰되었으며, 세포질 돌기 없이 원형 또는 타원형의 형태를 나타내는 폐쇄형 세포 (close type cell)들이 위 부위에서 소수 관찰되었다. 본 실험에서는 serotonin, somatostatin, pastrin, cholecystokinin (CCK)-8 및 human pancreatic polypeptide (HPP) 면역반응세포들이 관찰되었으나, insulin 및 glucagon 면역반응세포들은 관찰되지 않았다. Serotonin 및 somatostatin 면역반응세포들은 위 부위에 국한되어 각각 중등도 및 다수의 출현빈도로 관찰되었다. 또한 gastrin 면역반응세포들은 위와 소장에서 출현하였으며, 각각 소수 및 중등도의 출현빈도를 나타내었고, CCK-8 면역반응세포들은 소장에 국한되어 중등도의 출현빈도를 나타내었다. 한편 HPP 면역반응세포들은 위와 소장에서 다수 관찰되었다. 이상에서 쏘가리 위장관 내분비세포들의 부위별 분포 및 출현 빈도는 다른 경골어류에 비해 특이한 양상을 나타내는 것으로 관찰되었다.

• Parasites, Hosts and Diseases
• /
• 제33권4호
• /
• pp.357-364
• /
• 1995

이질아메바에 의한 장염 환자의 조직 또는 이질아메바를 실험적으로 감염시킨 동물의 조직 검사에서 호중구의 침윤이 특징적으로 관찰된다. 그러나 이와같은 호중구의 침윤을 설명할 수 있는 기전에 대한 연구는 매우 미흡하다. 따라서 본 연구자들은 아메바 감염 초기에 인체 대장상피 세포에서 interleukin-8(IL-8)이 유도되어 호중구 침윤과 같은 염증반응이 유발될 것이라는 가설을 설정하였다. 이를 위하여 인체 대장상피세포주인 HT-29에 이질아메바 영양형을 실험적으로 노출시킨 뒤 발현되는 IL-S mRNA를 역전사 중합효소법(reverse transcriptional polymerase chain reaction, RT-PCR)으로 검사함과 퐁시에 발현된 IL-8 mRNA를 인공적으로 합성시킨 표준 RNA와 RT-PCR법을 이용하여 정량하였다. 실험 결과 이질아메바 영양형에 노출된 30분 후 부터 IL-8 mRAN가 발현되기 시작하였다 그리고 그 발현 분자수는 노출 시간의 증가에 따라 계속 증가하여 3시간 대에는 $3.1{\;}{\times}{\;}10^7{\;}molecules/\mu\textrm{g}$ total RNA를 나타내었다. 동시에 IL-8 mRNA의 발현은 노출시킨 이질아메바 영양형의 수에 비례하였다. 즉 HT-29/아메바 영양형의 비율이 10:1인 경우 IL-8 mRNA의 발현 분자수는 $1.2{\;}{\times}{\;}10^7{\;}molecules/\mu\textrm{g}$ total RNA로 나타났다. 이와같은 IL-8 mRNA의 발현은 IL-8 단백질 분비로 이어짐을 ELISA 검사로 확인할 수 있었다. 한편 이질아메바 파쇄액(Iysate)도 대장상피세포군인 Caco-2에서 IL-8 mRNA발현을 유도하였다. 결론적으로 본 실험은 이질아메바 감염 초기에 대장상피세포로 부터 IL-8이 발현되며, 이에 의하여 염증반응이 촉발될 가능성이 있음을 시사해 준다.

• 약학회지
• /
• 제52권5호
• /
• pp.402-406
• /
• 2008

Previously, we have shown that 1-furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) has an anti-inflammatory activity in a rat paw-edema model. In the present study, we investigated an inhibitory effect of FPP-3 on the tumor necrosis factor (TNF)-${\apha}$-induced inflammatory cytokine response in HT-29 human colon epithelial cells. Treatment with FPP-3 significantly prevented the TNF-${\apha}$-induced attachment of leukocytes to HT-29 colon epithelial cells, which is one of the pathologic hallmarks in colon inflammation. The effect of FPP-3 was markedly superior than that of 5-aminosalicylic acid (5-ASA), a commonly used drug for the treatment of inflammatory bowel disease (IBD). The pretreatment with FPP-3 inhibited TNF-${\apha}$- induced monocyte chemoattractant protein (MCP)-1, interleukin (IL)-8 mRNA expressions. In addition, FPP-3 significantly suppressed TNF-${\apha}$-induced nuclear factor (NF)-${\kappa}B$ transcription activity. These results demonstrate that FPP-3 modulates intestinal inflammation via suppressing the NF-${\kappa}B$ dependent expressions of MCP-1 and IL-8, and suggest that FPP-3 may be a valuable agent for the treatment of IBD.

• Journal of Microbiology and Biotechnology
• /
• 제19권5호
• /
• pp.511-519
• /
• 2009

A chimeric gene encoding enhanced green fluorescent protein (EGFP) and a S-layer protein from Lactobacillus brevis KCTC3102, and/or two copies of the Fe-binding Z-domain, a synthetic analog of the B-domain of protein A, was constructed and expressed in Escherichia coli BL21(DE3). The S-layer fusion proteins produced in a 500-1 fermentor were likely to be stable in the range of pH 5 to 8 and $0^{\circ}C$ to $40^{\circ}C$. Their adhesive property enabled an easy and rapid immobilization of enzymes or antibodies on solid materials such as plastics, glass, sol-gel films, and intestinal epithelial cells. Owing to their affinity towards intestinal cells and immunoglobulin G, the S-layer fusion proteins enabled the adhesion of antibodies to human epithelial cells. In addition, feeding a mixture of the S-layer fusion proteins and antibodies against neonatal calf diarrhea (coronavirus, rotavirus, Escherichia coli, and Salmonella typhimurium) to Hanwoo calves resulted in 100% prevention of neonatal calf diarrhea syndrome (p<0.01), whereas feeding antibodies only resulted in 56% prevention.

• Journal of Microbiology and Biotechnology
• /
• 제31권4호
• /
• pp.592-600
• /
• 2021

Probiotics can be processed into a powder, tablet, or capsule form for easy intake. They are exposed to frequent stresses not only during complex processing steps, but also in the human body after intake. For this reason, various coating agents that promote probiotic bacterial stability in the intestinal environment have been developed. Silk fibroin (SF) is a material used in a variety of fields from drug delivery systems to enzyme immobilization and has potential as a coating agent for probiotics. In this study, we investigated this potential by coating probiotic strains with 0.1% or 1% water-soluble calcium (WSC), 1% SF, and 10% trehalose. Under simulated gastrointestinal conditions, cell viability, cell surface hydrophobicity, and cell adhesion to intestinal epithelial cells were then measured. The survival ratio after freeze-drying was highest upon addition of 0.1% WSC. The probiotic bacteria coated with SF showed improved survival by more than 10.0% under simulated gastric conditions and 4.8% under simulated intestinal conditions. Moreover, the cell adhesion to intestinal epithelial cells was elevated by 1.0-36.0%. Our results indicate that SF has positive effects on enhancing the survival and adhesion capacity of bacterial strains under environmental stresses, thus demonstrating its potential as a suitable coating agent to stabilize probiotics throughout processing, packaging, storage and consumption.

• 한국영양학회:학술대회논문집
• /
• 한국영양학회 1995년도 추계학술대회 초록
• /
• pp.11-34
• /
• 1995

Growth hormone (GH) plays a key role in regulating postnatal growth and can stimulate growth of animals by acting directly on specific receptors on the plasma membrane of tissues or indirectly through stimulating insulin-like growth factor (IGF)-I synthesis and secretion by the liver and other tissues. IGF-I and IGF-Ⅱ are polypeptides with structural similarity with proinsulin that stimulate cell proliferation by endocrine, paracrine and autocrine mechanisms. The initial event in the metabolic action of IGFs on target cells appears to be their binding to specific receptors on the plasma membrane. Current evidence indicates that the mitogenic actions of both IGFs are mediated primarily by binding to the type I IGF receptors, and that IGF action is also mediated by interactions with IGF-binding proteins (IGFBPs). Six distinct IGFBPs have been identified that are characterized by cell-specific interaction, transcriptional and post-translational regulation by many different effectors, and the ability to either potentiate or inhibit IGF actions. Nutritional deficiencies can have their devastating consequence during growth. Although IGF-I is the major mediator of GH's action on somatic growth, nutritional status of an organism is a critical regulator of IGF-I and IGFBPs. Various nutrient deficiencies result in decreased serum IGF-I levels and altered IGFBP levels, but the blood levels of GH are generally unchanged or elevated in malnutrition. Effects of protein, energy, vitamin C and D, and zinc on serum IGF and IGFBP levels and tissue mRNA levels were reviewed in the text. Multiple factors are involved in the regulation of intestinal epithelial cell growth and differentiation. Among these factors the nutritional status of individuals is the most important. The intestinal epithelium is an important site for mitogenic action of the IGFs in vivo, with exogenous IGF-I stimulating mucosal hyperplasia. Therefore, the IGF system appears to provide and important mechanism linking nutrition and the proliferation of intestinal epithelial cells. In order to study the detailed mechanisms by which intestinal mucosa is regulated, we have utilized IEC-6 cells, an intestinal epithelial cell line and Caco-2 cells, a human colon adenocarcinoma cell line. Like intestinal crypt cells analyzed in vivo or freshly isolated intestinal epithelial cells, IEC-6 cells and Caco-2 cells possess abundant quatities of both type Ⅰ and type Ⅱ IGF receptors. Exogenous IGFs stimulate, whereas addition of IGFBP-2 inhibits IEC-6 cell proliferation. To investigate whether endogenously secreted IGFBP-2 inhibit proliferation, IEC-6 cells were transfected with a full-length rat IGFBP-2 cDNA anti-sense expression construct. IEC-6 cells transfected with anti-sense IGFBP-2 protein in medium. These cells grew at a rate faster than the control cells indicating that endogenous IGFBP-2 inhibits proliferation of IEC-6 cells, probably by sequestering IGFs. IEC-6 cells express many characteristics of enterocyte, but do not undergo differentiation. On the other hand, Caco-2 cells undergo a spontaneous enterocyte differentiation. On the other hand, Caco-2 cells undergo a spontaneous enterocyte differentiation after reaching confluency. We have demonstrated that Caco-2 cells produce IGF-Ⅱ, IGFBP-2, IGFBP-3, and an as yet unidentified 31,000 Mr IGFBP, and that both mRNA and peptide secretion of IGFBP-2 and IGFBP-3 increased, but IGFBP-4 mRNA and protein secretion decreased after the cells reached confluency. These changes occurred in parallel to and were coincident with differentiation of the cells, as measured by expression of sucrase-isomaltase. In addition, Caco-2 cell clones forced to overexpress IGFBP-4 by transfection with a rat IGFBP-4 cDNA construct exhibited a significantly slower growth rate under serum-free conditions and had increased expression of sucrase-isomaltase compared with vector control cells. These results indicate that IGFBP-4 inhibits proliferation and stimulates differentiation of Caco-2 cells, probably by inhibiting the mitogenic actions of IGFs.

• 생명과학회지
• /
• 제19권7호
• /
• pp.949-955
• /
• 2009

점막 상피는 외부 인자를 감지하는 최전선의 인식부위로서 외부스트레스 자극을 하부의 반응 신호로 전달하는 주요 세포이다. 리보솜독성 반응을 유발하는 데옥시니발레놀 (DON) 및 그 관련 곰팡이 독소는 푸자륨 곰팡이 오염에 의한 식중독성 소화기 염증성 질환과의 연관성이 알려 져 있다. 본 연구의 목적은 DON이 상피세포 감지 신호 전달 분자로서 PKR과 EGR-1이 관련 되고 이들이 상피세포에서의 염증성 사이토가인 인터루킨 8의 생성에 관련 된다는 가정 하에서 연구를 수행 하였다. PKR 발현의 세포내 작용 억제는 DON에 의해 유도되는 인터루킨 8의 생성을 감소시켰다. 또한 DON에 의한 IL-8 전사 활성화는 PKR 억제에 의하여 장관 상피세포에서 감소하였다. PKR 저해제의 처리는 EGR-1 promoter 활성, mRNA, 단백질 유도 등을 감소를 유발하였으며 MAP kinase (ERK1/2, p38, JNK)는 변화가 적거나 오히려 PKR 저해제의 전처리에 의하여 항진 되었다. 결론적으로 DON에 의해 자극된 감지신호인 EGR-1은 자체적으로 또는 PKR 신호를 경유하여 인터루킨8의 생산을 항진하는데 주요한 기능을 하였다. 이를 통하여 향후 리보솜 독성 반응과 관련된 소화기 염증유발의 주요한 기전을 제공하고 있다.

• Food Science and Biotechnology
• /
• 제18권3호
• /
• pp.749-754
• /
• 2009

The polysaccharide (BB-pol) extracted from Bifidobacterium bifidum BGN4 showed growth inhibitory effects on several colon cancer cell lines such as HT-29 and HCT-116. To increase the yield of polysaccharide, B. bifidum BGN4 was cultured in various culture media with different compositions. When B. bifidum BGN4 was cultured in modified MRS broth containing phytic acid, the cells showed increased branch formation and enlarged morphology. The content of total carbohydrate and the ability of adhesion to intestinal epithelial cells were also increased by phytic acid. The polysaccharide obtained from the cells grown in the presence of phytic acid inhibited the proliferation of cancer cell lines such as HT-29 and MCF-7 cells but not normal colon cell line, FHC. Taken together, Bifidobacterium grown in the presence of phytic acid may confer enhanced beneficial function for the host.