• Journal of Life Science
• /
• v.22 no.5
• /
• pp.621-626
• /
• 2012

$Drosophila$ $melanogaster$ has been used as a useful model to study development and disease. In this study, we established the primary culture method of $Drosophila$ in the intestine to understand how intestinal stem cells (ISCs) mediate tissue repair during infection and disease. To obtain intestinal cells, we separated intestines from adult flies and isolated single cells by enzymatic treatment. The survival of cultured cells was measured using MTS-analysis. The maximum growth rate of the cells was observed on the 9th day after seeding. In addition, the presence of ISCs and enteroendocrine cells was confirmed by delta and prospero staining. Accordingly, we supposed that $Drosophila$ $melanogaster$ gut cells established in this study are probably useful in studies about intestinal stem cell regulation and various diseases occurring in the intestine.

• Journal of Life Science
• /
• v.22 no.12
• /
• pp.1600-1607
• /
• 2012

The matrix metalloproteinase (MMP) family plays essential roles in physiological processes such as embryonic development, angiogenesis, wound healing, and tissue homeostasis as a consequence of MMPr capacity for breaking down many types of extracellular matrix proteins. Imbalanced regulation of MMP expression can also lead to pathological conditions such as tumor progression. We recently reported that the Drosophila Mmp1 gene is highly expressed in the digestive tract and is required for the maintenance of intestinal homeostasis such as by restriction of uncontrolled intestinal stem cell proliferation. However, the regulatory mechanisms of MMP gene expression in the intestine remain unclear. In this study, we determined that the expression of Mmp1 is regulated by the homeodomain transcription factor Caudal. Experiments using the targeted expression of Caudal under the regulation of Gal4-UAS system indicated that endogenous Caudal is required for the Mmp1 gene expression in the adult Drosophila intestine and that exogenous Caudal induces Mmp1 expression. Transient transfection experiments indicated that Caudal can activate the promoter activity of Mmp1 and that several putative Caudal binding sites in the 5'-flanking region of the Mmp1 gene may be critical to the upregulation by Caudal. Our data suggest that Mmp1 is one of the target genes of Caudal in physiological normal condition and in tumorigenesis.

• Molecules and Cells
• /
• v.41 no.6
• /
• pp.603-611
• /
• 2018

Triglyceride homeostasis is a key process of normal development and is essential for the maintenance of energy metabolism. Dysregulation of this process leads to metabolic disorders such as obesity and hyperlipidemia. Here, we report a novel function of the Drosophila flightless-I (fliI) gene in lipid metabolism. Drosophila fliI mutants were resistant to starvation and showed increased levels of triglycerides in the fat body and intestine, whereas fliI overexpression decreased triglyceride levels. These flies suffered from metabolic stress indicated by increased levels of trehalose in hemolymph and enhanced phosphorylation of eukaryotic initiation factor 2 alpha ($eIF2{\alpha}$). Moreover, upregulation of triglycerides via a knockdown of fliI was reversed by a knockdown of desat1 in the fat body of flies. These results indicate that fliI suppresses the expression of desat1, thereby inhibiting the development of obesity; fliI may, thus, serve as a novel therapeutic target in obesity and metabolic diseases.

• Molecules and Cells
• /
• v.40 no.12
• /
• pp.976-985
• /
• 2017

Iron is an essential divalent ion for aerobic life. Life has evolved to maintain iron homeostasis for normal cellular and physiological functions and therefore imbalances in iron levels exert a wide range of consequences. Responses to iron dysregulation in blood development, however, remain elusive. Here, we found that iron homeostasis is critical for differentiation of Drosophila blood cells in the larval hematopoietic organ, called the lymph gland. Supplementation of an iron chelator, bathophenanthroline disulfate (BPS) results in an excessive differentiation of the crystal cell in the lymph gland. This phenotype is recapitulated by loss of Fer1HCH in the intestine, indicating that reduced levels of systemic iron enhances crystal cell differentiation. Detailed analysis of Fer1HCH-tagged-GFP revealed that Fer1HCH is also expressed in the hematopoietic systems. Lastly, blocking Fer1HCH expression in the mature blood cells showed marked increase in the blood differentiation of both crystal cells and plasmatocytes. Thus, our work suggests a relevance of systemic and local iron homeostasis in blood differentiation, prompting further investigation of molecular mechanisms underlying iron regulation and cell fate determination in the hematopoietic system.

• Molecules and Cells
• /
• v.26 no.6
• /
• pp.554-557
• /
• 2008

Double-stranded RNA (dsRNA) induces gene silencing in a sequence-specific manner by a process known as RNA interference (RNAi). The RNA-induced silencing complex (RISC) is a multi-subunit ribonucleoprotein complex that plays a key role in RNAi. VIG (Vasa intronic gene) has been identified as a component of Drosophila RISC; however, the role VIG plays in regulating RNAi is poorly understood. Here, we examined the spatial and temporal expression patterns of VIG-1, the C. elegans ortholog of Drosophila VIG, using a vig-1::gfp fusion construct. This construct contains the 908-bp region immediately upstream of vig-1 gene translation initiation site. Analysis by confocal microscopy demonstrated GFP-VIG-1 expression in a number of tissues including the pharynx, body wall muscle, hypodermis, intestine, reproductive system, and nervous system at the larval and adult stages. Furthermore, western blot analysis showed that VIG-1 is present in each developmental stage examined. To investigate regulatory sequences for vig-1 gene expression, we generated constructs containing deletions in the upstream region. It was determined that the GFP expression pattern of a deletion construct (${\Delta}-908$ to -597) was generally similar to that of the non-deletion construct. In contrast, removal of a larger segment (${\Delta}-908$ to -191) resulted in the loss of GFP expression in most cell types. Collectively, these results indicate that the 406-bp upstream region (-596 to -191) contains essential regulatory sequences required for VIG-1 expression.

• Journal of Life Science
• /
• v.21 no.2
• /
• pp.194-201
• /
• 2011

Caudal-related homeodomain proteins play critical roles in intestine development and maintenance from Drosophila to humans. The loss or reduction of CDX1 and CDX2 are known to be associated with colon cancers. It has been well known that colorectal carcinogenesis is associated with serious oxidative stress and that catalase is decreased in colon carcinomas. However, the underlying molecular mechanisms remain elusive. Here, we report that Caudal-related homeodomain proteins positively regulate catalase expression in both Drosophila and humans. We found that Drosophila caudal heterozygotes have a decreased catalase expression and increased ROS generation in the hindgut, and that the overexpression of Caudal increases catalase promoter activity and catalase mRNA levels. We also found that CDX1 and CDX2 up-regulate catalase promoter activity and protein levels in HCT116 cells - human colorectal carcinoma cell lines. The level of catalase protein in several colorectal carcinoma cell lines was associated with CDX1 expression. These results suggest that CDX1 and CDX2 may be involved in intestinal homeostasis and tumorigenesis via regulation of catalase expression.

• Korean Journal of Veterinary Research
• /
• v.55 no.3
• /
• pp.181-184
• /
• 2015

Ciliary rootlet coiled coil protein (CROCC), the structural component that originates from the basal body at the proximal end of the ciliary rootlet, plays a crucial role in maintaining the cellular integrity of ciliated cells. In the current study, we cloned Xenopus CROCC and performed the expression analysis. The amino acid sequence of Xenopus laevis was related to those of Drosophila, cow, goat, horse, chicken, mouse and human. Reverse transcription polymerase chain reaction analysis revealed that CROCC mRNA encoding a coiled coil protein was present maternally, as well as throughout early development. In situ hybridization indicated that CROCC mRNA occurred in the animal pole of embryo during gastrulation and subsequently in the presumptive neuroectoderm at the end of gastrulation. At tailbud stages, CROCC mRNA expression was localized in the anterior roof plate of the developing brain, pharyngeal epithelium connected to gills, esophagus, olfactory placode, intestine and nephrostomes of the pronephric kidney. Our study suggests that CROCC may be responsible for control of the development of various ciliated organs.