• International Journal of Stem Cells
• /
• 제17권1호
• /
• pp.51-58
• /
• 2024

With the activity of intestinal stem cells and continuous turnover, the gut epithelium is one of the most dynamic tissues in animals. Due to its simple yet conserved tissue structure and enteric cell composition as well as advanced genetic and histologic techniques, Drosophila serves as a valuable model system for investigating the regulation of intestinal stem cells. The Drosophila gut epithelium is in constant contact with indigenous microbiota and encounters externally introduced "non-self" substances, including foodborne pathogens. Therefore, in addition to its role in digestion and nutrient absorption, another essential function of the gut epithelium is to control the expansion of microbes while maintaining its structural integrity, necessitating a tissue turnover process involving intestinal stem cell activity. As a result, the microbiome and pathogens serve as important factors in regulating intestinal tissue turnover. In this manuscript, I discuss crucial discoveries revealing the interaction between gut microbes and the host's innate immune system, closely associated with the regulation of intestinal stem cell proliferation and differentiation, ultimately contributing to epithelial homeostasis.

• Molecules and Cells
• /
• 제46권10호
• /
• pp.637-653
• /
• 2023

The physiology of most organisms, including Drosophila, is heavily influenced by their interactions with certain types of commensal bacteria. Acetobacter and Lactobacillus, two of the most representative Drosophila commensal bacteria, have stimulatory effects on host larval development and growth. However, how these effects are related to host immune activity remains largely unknown. Here, we show that the Drosophila development-promoting effects of commensal bacteria are suppressed by host immune activity. Mono-association of germ-free Drosophila larvae with Acetobacter pomorum stimulated larval development, which was accelerated when host immune deficiency (IMD) pathway genes were mutated. This phenomenon was not observed in the case of mono-association with Lactobacillus plantarum. Moreover, the mutation of Toll pathway, which constitutes the other branch of the Drosophila immune pathway, did not accelerate A. pomorum-stimulated larval development. The mechanism of action of the IMD pathway-dependent effects of A. pomorum did not appear to involve previously known host mechanisms and bacterial metabolites such as gut peptidase expression, acetic acid, and thiamine, but appeared to involve larval serum proteins. These findings may shed light on the interaction between the beneficial effects of commensal bacteria and host immune activity.

• Animal cells and systems
• /
• 제5권1호
• /
• pp.59-64
• /
• 2001

To understand the late gut development and differentiation, identification and characterization of target genes of homeotic genes involved in gut development are required. We have previously reported that homeodomain proteins can regulate expression of the cell proliferation-related genes. We investigated here the expression of the Drosophila proliferating cell nuclear antigen(PCNA) and E2F(dE2F) genes in larval and adult guts using transgenic flies bearing lacz reporter genes. Both PCNA and dE2F genes were expressed strongly in whole regions of the larval and adult guts including the esophagus, proventriculus, midgut and hindgut, showing higher expression in foregut and hindgut imaginal rings of larva. Nitric Oxide(NO) has been known to be involved in cell proliferation and tumor growth and also to have an antiproliferative activity. Therefore, we also investigated effects of NO on the expression of PCNA and dE2F genes in gut through analyses of lacz reporter expression level in the SNP (NO donor)-treated larval guts. Expressions of both PCNA and dE2F were greatly declined by SNP. The inhibitory effect of NO was shown in whole regions of the gut, especially in hindgut, while the internal region of proventriculus, esophagus, foregut imaginal ring and hindgut imaginal ring was resistant. Our results suggest that this inhibitory effect may be related with the antiproliferative activity of NO.

• 생명과학회지
• /
• 제22권5호
• /
• pp.621-626
• /
• 2012

초파리는 발생과 질병연구를 위한 모델 곤충으로 널리 이용되어 왔다. 본 연구에서도 초파리를 모델곤충으로 한 장질환 연구의 일환으로 다양한 병원균 감염 및 장질환 유발시 어떻게 장줄기세포가 작용하는지를 이해하기 위해 초파리 장세포의 일차배양 방법을 확립하였다. 초파리 성충으로부터 장을 해부하고 다양한 효소를 처리하여 장세포를 분리한 후 배양하였다. 배양세포의 생존여부는 현미경 검경 및 MTS assay에 의해 확인한 결과 배양 후 9일째 최대 증식되었고 14일까지 생존함을 확인할 수 있었다. 또한 장줄기세포 및 장내분비세포의 존재도 immunostaining에 의해 확인하였다. 따라서 본 연구에서 구축된 초파리 일차배양 장세포는 다양한 유전자에 의한 장줄기 세포 조절연구뿐만 아니라 장에서 발생하는 다양한 질병을 연구하는 도구로 매우 유용할 것으로 추측된다.

• 한국생명과학회:학술대회논문집
• /
• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
• /
• pp.68.1-68.1
• /
• 2007

See Full Text

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 2000년도 한국생물과학협회 학술발표대회
• /
• pp.241.2-241
• /
• 2000

No Abstract, See Full Text

• 한국생명과학회:학술대회논문집
• /
• 한국생명과학회 2006년도 제47회 학술심포지움 및 추계국제학술대회
• /
• pp.72.2-72.2
• /
• 2006