DNA methylation may regulate gene expression by restricting the access of transcription factors. We have previously demonstrated that GATA-1 regulates the transcription of the CCR3 gene by dynamically interacting with both positively and negatively acting GATA elements of high affinity binding in the proximal promoter region including exon 1. Exon 1 has three CpG sites, two of which are positioned at the negatively acting GATA elements. We hypothesized that the methylation of these two CpGs sites might preclude GATA-1 binding to the negatively acting GATA elements and, as a result, increase the availability of GATA-1 to the positively acting GATA element, thereby contributing to an increase in GATA-1-mediated transcription of the gene. To this end, we determined the methylation of the three CpG sites by bisulfate pyrosequencing in peripheral blood eosinophils, cord blood (CB)-derived eosinophils, PBMCs, and cell lines that vary in CCR3 mRNA expression. Our results demonstrated that methylation of CpG sites at the negatively acting GATA elements severely reduced GATA-1 binding and augmented transcription activity in vitro. In agreement, methylation of these CpG sites positively correlated with CCR3 mRNA expression in the primary cells and cell lines examined. Interestingly, methylation patterns of these three CpG sites in CB-derived eosinophils mostly resembled those in peripheral blood eosinophils. These results suggest that methylation of CpG sites at the GATA elements in the regulatory regions fine-tunes CCR3 transcription.
Binding Sites ; Cell Line ; *CpG Islands ; DNA Methylation ; Enhancer Elements, Genetic ; Eosinophils/cytology/*metabolism ; Exons ; Fetal Blood/cytology/metabolism ; GATA1 Transcription Factor/*genetics/metabolism ; Gene Expression Regulation ; Humans ; Promoter Regions, Genetic ; RNA, Messenger/metabolism ; Receptors, CCR3/*genetics/metabolism ; Sequence Analysis, DNA ; *Transcription, Genetic

A number of acid-base or electrolyte disorders are associated with decreased or increased HCO3- reabsorption in the renal tubules. The present study was to examine the alterations of expression and distribution of Carbonic anhydrase II in the kidneys of normal and potassium-depleted rats using Western blot analysis and immuno-histochemistry. Western blot analysis demonstrated that CA II protein, ~30 kDa at molecular mass, was abundantly expressed in normal group. All potassium-depleted groups showed slightly increased CA II protein compared to normal group. In control group, immunoreactivity of CA II protein was detected in the entire collecting duct. Signal intensity was prominent in the intercalated cells and weak in the principal cells of the cortical collecting ducts. In potassium-depleted groups, the pattern of cellular labeling of CA II protein was identical to that of normal group, but the signal intensity was decreased in cortical collecting duct, markedly increased in the inner stripe of outer medullary and inner medullary collecting ducts, and unchanged in the outer stripe of outer medullary collecting duct. These results suggest that chronic hypokalemia impact the expression pattern of CA II protein depending the portion of the collecting duct.
Animals ; Blotting, Western ; Carbon ; Carbonic Anhydrase II ; Carbonic Anhydrases ; Hypokalemia ; Immunohistochemistry ; Kidney ; Rats

Homeobox genes seem to play critical roles in regulating morphogenesis, patterning, organogenesis, and differentiation. They have the conserved sequence that codes the DNA-binding domain called homeodomain. The expression and cellular localization of rPsx mRNA in rat placenta during placental development were examined by in situ hybridization histochemistry at different embryonic stages (Embryonic days 7.5~16.5). rPsx mRNA was first detected in chorionic ectoderm of placenta at E 10.5. This transcript was localized in labyrinth trophoblast and trophoblast giant cells at E 11.5. Hybridization signals were observed in labyrinth trophoblast, spongiotrophoblast, and trophoblast giant cells at E 12.5, E 13.5, and E 14.5. At E 15.5, hybridization signal was detected in labyrinth trophoblast and spongiotrophoblast but not in trophoblast giant cells. Hybridization signal was only detected in labyrinth trophoblast at E 16.5. rPsx mRNA was not detected in decidua and any tissues of the embryo from E 7.5 to E 9.5 of gestations. From these results, a new rPsx homeobox gene is first expressed at E 10.5 and detected in chorionic ectoderm, labyrinth trophblast, spongiotrophoblast and trophoblast giant cells of the placenta. This gene may play a critical role in differentiation and development of trophoblast cells.
Animals ; Chimera ; Chorion ; Conserved Sequence ; Decidua ; Ear, Inner ; Ectoderm ; Embryonic Structures ; Female ; Gene Expression ; Genes, Homeobox ; Giant Cells ; In Situ Hybridization ; Morphogenesis ; Organogenesis ; Placenta ; Placentation ; Rats ; RNA, Messenger ; Trophoblasts

During the prostate cancer (PCa) development and its progression into hormone independency, androgen receptor (AR) signals play a central role by triggering the regulation of target genes, including prostate-specific antigen. However, the regulation of these AR-mediated target genes is not fully understood. We have previously demonstrated a unique role of HOXB13 homeodomain protein as an AR repressor. Expression of HOXB13 was highly restricted to the prostate and its suppression dramatically increased hormone-activated AR transactivation, suggesting that prostate-specific HOXB13 was a highly potent transcriptional regulator. In this report, we demonstrated the action mechanism of HOXB13 as an AR repressor. HOXB13 suppressed androgen-stimulated AR activity by interacting with AR. HOXB13 did neither bind to AR responsive elements nor disturb nuclear translocation of AR in response to androgen. In PCa specimen, we also observed mutual expression pattern of HOXB13 and AR. These results suggest that HOXB13 not only serve as a DNA-bound transcription factor but play an important role as an AR-interacting repressor to modulate hormone-activated androgen receptor signals. Further extensive studies will uncover a novel mechanism for regulating AR-signaling pathway to lead to expose new role of HOXB13 as a non-DNA-binding transcriptional repressor.
Passive Cutaneous Anaphylaxis ; Prostate ; Prostate-Specific Antigen ; Prostatic Neoplasms ; Receptors, Androgen ; Staphylococcal Protein A ; Transcription Factors ; Transcriptional Activation

There has been a general agreement that potassium depletion causes metabolic alkalosis and substantial morphological changes in kidney structure, and is associated with renal functional abnormalities, including a decrease in urinary concentrating ability. The present study was to examine the alterations of expression and distribution of AQP-1, 2, 3 and 4 mRNAs and proteins in the kidneys of normal and K-depleted rats using RT-PCR, Western blot analysis, and immunohistochemistry. Predicted size of AQP-1, 2, 3, and 4 mRNAs was 119, 822, 539, and 642 bp, respectively. AQP-1 mRNA expression was gradually decreased in K-depleted rats, particularly LK 2W. AQP-2, 3 mRNAs were markedly decreased in K-depleted rats. AQP-4 mRNA expression was markedly increased in K-depleted rats, particularly LK 2W. Western blot analysis demonstrated that AQP-1 protein expression was only decreased in LK 3D and others were comparable with normal rat. AQP-2, 3 proteins expression was markedly decreased in K-depleted rats, compared with normal rat. But, AQP-4 protein expression was markedly increased in K-depleted rats, particularly LK 3W. In immunohistochemistry, AQP-1 was detected in the apical membranes of proximal tubules and thin limb of Henle loop. In potassium-depleted kidney, the pattern of cellular labeling and signal intensity of AQP-1 protein is identical to that of normal rat. AQP-2 was detected in apical region and cytoplasm of the principal cells of entire collecting duct. In potassium-depleted kidney, the pattern of cellular labeling of AQP-2 protein is identical to that of normal rat, but signal intensity is markedly decreased. AQP-3 was detected in the bosolateral plasma membrane of principal cells of entire collecting duct. In potassium-depleted kidney, the pattern of cellular labeling of AQP-3 protein is identical to that of normal rat, but signal intensity is markedly decreased. AQP-4 was detected in the bosolateral plasma membrane of principal cells of entire collecting duct. In potassium-depleted kidney, the pattern of cellular labeling of AQP-4 protein is identical to that of normal rat, but signal intensity is markedly increased in outer and inner medullary collecting ducts. In summary, these results demonstrate that chronic hypokalemia shows the different expression pattern of AQP-1, 2, 3, and 4 mRNAs and proteins. These results suggest that a decrease in urinary concentrating ability is a major factor in the decreased AQP-2, 3 expression, and that is partly compensated by increased expression of AQP-4.
Alkalosis ; Animals ; Aquaporins ; Blotting, Western ; Cell Membrane ; Cytoplasm ; Extremities ; Hypokalemia ; Immunohistochemistry ; Kidney ; Loop of Henle ; Membranes ; Potassium ; Proteins ; Rats ; RNA, Messenger

This study presents distribution of carbonic anhydrase (CA) isozymes IV and IX, membrane associated forms, and CA I and II, cytoplasmic forms, in rat parotid and submandibular glands using Western blot analysis and immunohistochemical staining. Western blot analysis demonstrated that CAs I, II and IX were found to be abundantly expressed, but CA IV was weakly expressed in parotid gland. Submandibular gland expressed abundant CAs I and II, weak CA IX, and undetectable level of CA IV. In hematoxylin-eosin staining, parotid gland was entirely composed of serous acini and their ducts while submandibular gland was mixed population of serous and mucous lobules. Most of lobules (submandibular gland proper type) contained mostly serous acini and their ducts with granular convoluted duct. Some lobules (sublingual gland type) contained mostly mucous acini with serous demilune and their ducts without granular convoluted duct. In parotid gland, CAs IV and IX were immunolocalized in duct cells and not in serous acinar cells. Immunoreactivity for CAs I and II was also detectable in duct cells. Serous acinar cells were positive for CA II, and negative for CA I. In submandibular gland, CAs IV and IX were immunolocalized in duct cells but not in acinar cells of both types of lobules. Immunoreactivity for CAs I and II was also detectable in duct cells of both types of lobules. Cells of serous acini and serous demilune were positive for CA II, and negative for CA I. Mucous cells were negative for both CAs I and II. These results demonstrate the distribution of CA isoenzymes in parotid and submandibular glands of the rat, and suggest CAs IV and IX as well as CAs I and II are related to electrolytes metabolism of saliva in duct cells.
Acinar Cells ; Animals ; Blotting, Western ; Carbon ; Carbonic Anhydrases ; Cytoplasm ; Electrolytes ; Immunohistochemistry ; Isoenzymes ; Membranes ; Parotid Gland ; Rats ; Saliva ; Salivary Glands ; Submandibular Gland

There are several carbonic anhydrase (CA) isozymes, which differ in their kinetic properties, tissue distribution, and subcellular localization. In this study, the distribution of CA isozymes I, II, IV, and IX was investigated in the rat exorbital lacrimal gland using Western blotting analysis and immunohistochemical staining. In the Western blotting analysis of the rat lacrimal gland, CA II and CA IX were expressed abundantly and CA IV was expressed weakly. Hematoxylin-eosin staining of the exorbital lacrimal gland showed a multilobular tubuloacinar gland composed of acinar and ductal cells. Immunohistochemical reaction revealed no CAI staining in acinar cells and positive staining in intercalated and small duct cells. CA II reactivity was detected in the supranuclear cytoplasm of acinar cells and appeared to vary between acini. The intercalated and collecting duct cells showed weak or no immunoreactivity for CA II. CA IV was detected in the intercalated and collecting duct cells but not at the acinar cells. CA IX was detected in the intercalated and collecting duct cells, and in only a few acinar cells. These results demonstrate the differential distribution of CA isoenzymes in the exorbital lacrimal gland of the rat and suggest that CA II is related mainly to the electrolyte metabolism of tears in the acinar cells and that CAs I, IV, and IX are related to the electrolyte metabolism of tears in the duct cells.
Acinar Cells ; Animals ; Blotting, Western ; Carbon ; Carbonic Anhydrases ; Cytoplasm ; Immunohistochemistry ; Isoenzymes ; Lacrimal Apparatus ; Rats ; Tissue Distribution

Potassium balance in chronic hypokalemia is regulated by ion channels, ion transporters, and various related genes. We isolated general transcription factor IIA (GTF IIA) gene using a DNA chip microassay, a useful method in cloning genes. Northern analysis and in situ hybridization (ISH) were carried out to analyze the expression and localization of GTF IIA mRNA in rat in relation to the amount of potassium in the diet. Isoform-specific 32P-labeled cDNA (Northern analysis) or digoxigenin-labeled cRNA (ISH) probes were used. Northern analysis demonstrated that GTF IIA mRNA was expressed abundantly in testis; modestly in heart, kidney, lung, adrenal gland, liver, and spleen; and weakly in brain, distal colon, duodenum, salivary gland, and stomach. In potassium-restricted animals, GTF IIA expression was decreased in the kidney, adrenal gland, and spleen, but expression was restored to normal levels in L3w. The expression level in the lung was decreased in L3d and L2w, and increased in L1w and L3w. ISH showed that mRNA for the GTF IIA gene was detected in the distal convoluted tubule, S3 segment of the proximal tubule, and cortical collecting duct in the normal group. In potassium-restricted groups, the hybridization signal was detected in the distal convoluted tubule, S3 segment of the proximal tubule, and entire collecting tubule. The signal intensity of the outer and inner medullary collecting ducts was higher in the potassium-restricted group than in the normal group but was decreased in the distal convoluted tubule and S3 segment of the proximal tubule. In the normal group, mRNA of the GTF IIA gene was detected in the zona glomerulosa cells of the adrenal gland, lymphocytes of the marginal zone, germinal center of the spleen, and bronchial epithelium and lymphocytes of the lung. mRNA for the GTF IIA gene was also detected in the cells of the basal portion of the intestinal glands of the distal colon and stomach, and in spermatogonia and spermatocytes of the seminiferous tubule. These results suggest that expression of GTF IIA differs between various tissues and that increased expression of the GTF IIA gene in the outer and inner medullary collecting ducts of the hypokalemic kidney might regulate the ion transporter genes in these segments.
Adrenal Glands ; Animals ; Brain ; Chimera ; Clone Cells ; Cloning, Organism ; Colon ; Diet ; DNA, Complementary ; Duodenum ; Epithelium ; Germinal Center ; Heart ; Hypokalemia ; In Situ Hybridization ; Intestinal Mucosa ; Ion Channels ; Ion Transport ; Kidney ; Liver ; Lung ; Lymphocytes ; Oligonucleotide Array Sequence Analysis ; Potassium ; Prothrombin ; Rats ; RNA, Complementary ; RNA, Messenger ; Salivary Glands ; Seminiferous Tubules ; Spermatocytes ; Spermatogonia ; Spleen ; Stomach ; Transcription Factors ; Zona Glomerulosa

The tyramide signal amplification (TSA) technique, based on the ability of HRP to catalyze the deposition of tyramide onto the surrounding proteins, has been proved to detect scarce tissue antigens. In this study we applied this technique to a biochip platform and an immunocytochemistry at the electron microscopic level. First, in the optical fluorescence sensing, the signal was amplified by Dako Envision(TM) (goat anti-mouse immunoglobulins IgG conjugated to peroxidase labelled-dextran polymer) and tyramide-Cy3, which was then compared to the non-amplified control using goat antimouse IgG-Cy3 conjugate instead. The result showed that the tyramide method produced a more sensitive signal than the control method. Secondly, in the pre-embedding immunocytochemistry, we investigated to see whether it is possible to label proteins within a organelle in the cell using the TSA method. The signal was amplified by a primary antibody, a biotinylated secondary antibody, streptavidin-HRP, biotinyl-tyramide, and streptavidinnanogold followed by silver enhancement and gold toning. Then, this protocol was compared to the non-amplified or simple protocol that does not include the steps of streptavidin-HRP and biotinyl-tyramide. With the TSA protocol, the labeling for a membrane bound antigen (gp100) that is known to be exclusively localized to melanosomes in melanocyte, was tested in a melanoma cell line (G361) and found to be highly sensitive and more enhanced than with the simple protocol. Moreover, the gold particles were well localized to the subcellular structures or melanosomes both in the TSA and simple protocols, which indicates that resolution of the signals remains high. Control experiment with omission of the primary antibody demonstrated that background levels or nonspecific bindings are negligible. This result showed that the TSA method can be successfully applied to label the intra-organelle protein that is known to be labeled only in the specific fixation condition with the optimal permeability.
Cell Line ; Fluorescence ; Goats ; Immunoglobulin G ; Immunoglobulins ; Immunohistochemistry ; Melanocytes ; Melanoma ; Melanosomes ; Membranes ; Microscopy, Immunoelectron* ; Organelles* ; Permeability ; Peroxidase ; Protein Array Analysis ; Silver

Carbonic anhydrase catalizes the reversible hydration of carbonic dioxide and participate in various biological processes. There are several isozymes and differ in their kinetic properties, tissue distribution and subcellular localization. The expression of carbonic anhydrase isozymes in digestive tract vary according to animal species and region of the tract. The distribution of carbonic anhydrase (CA) isozymes I, II, IV and IX was investigated in various portions of the rat small intestine using Western blotting analysis and immunohistochemical staining. Western blotting analysis of rat small intestine revealed that CAI was found to be abundantly expressed throughout the small intestine. Expression of CAII in duodenum was much higher than that in jejunum and ileum. Expression of CAIV and IX was found to be weak throughout the small intestine. Immunohistochemical reaction revealed no staining of CAI in all parts of small intestine except blood vessels. CAII was detected at the supranuclear cytoplasm of surface epithelium, but not in intestinal gland. Staining intensity was most strong in the proximal duodenum. CAIV was detected at the apical surface of epithelial cells of villi, and showed most strong staining intensity in the terminal ileum. CAIX was detected at the surfcae epithelium, cells of intestinal gland and Brunner's gland, and the positive reaction was confined to the supranuclear cytoplasm. CAIX differed from CAII in tissue distribution, but subcellular localization of CAIX and II were the same. These results indicate that the surface epithelium of small intestine express CAII, IV and IX, intestinal gland and Brunner's gland express CAIX, and suggest that CAIX may somewhat contribute the control of acid-base balance in the small intestine.
Acid-Base Equilibrium ; Animals ; Biological Processes ; Blood Vessels ; Blotting, Western ; Carbon* ; Carbonic Anhydrases* ; Cytoplasm ; Duodenum ; Epithelial Cells ; Epithelium ; Gastrointestinal Tract ; Ileum ; Immunohistochemistry ; Intestinal Mucosa ; Intestine, Small* ; Isoenzymes* ; Jejunum ; Rats* ; Tissue Distribution