MicroRNA-802 promotes the progression of osteosarcoma through targeting p27 and activating PI3K/AKT pathway.

PURPOSE: Increasing evidences suggest dysfunctions of microRNAs (miRNAs) are playing important part in tumors. Therefore, the role of miR-802 in osteosarcoma (OS) was exploited. The object was to evaluate the effect of miR-802 and verify its influence on p27 Kip1 (p27) in OS. METHODS: RT-qPCR experiment was used to detect miR-802 and p27 expression in OS tissues and cells. We explored the function of miR-802 through Transwell assays. The phosphoinositide 3-kinase (PI3K)/AKT serine/threonine kinase pathway and epithelial-mesenchymal transition (EMT) was detected by Western blot assays. Luciferase assay was used to testify the target of miR-802. RESULTS: MiR-802 expression was elevated in OS, which was related to poor clinical outcome in OS patients. MiR-802 overexpression promoted OS migration, invasion and EMT. Further, p27 is a direct target of miR-802. P27 elevation counteracted the promotion effect of OS on EMT, migration and invasion induced by miR-802. In addition, miR-802 overexpression inactivated PI3K/AKT pathway via targeting p27 in OS. CONCLUSION: MiR-802 promoted the progress of EMT, migration and invasion in OS via targeting p27. This newly identified miR-802/p27/PI3K/AKT axis may represent potential targets for OS.

The Complete Mitochondrial Genome of the Donganyellow Chicken and Its Phylogenetic Analyses

Donganyellow chicken (Gallus gallusdomesticus, DYC) is one of the famous native breeds of Hunan province in China. It is the first time that the complete mitochondrialgenome sequence of DYC was reported. The total length of the mtDNA is16, 786bp. It contains 22transfer RNA genes, 2 ribosomal RNA genes,13 protein-coding genes and 1 D-loop region. The overall composition of the mtDNA is 30.27% for A, 23.74% for T, 32.50% for C and 13.49% for G. Phylogenetic analyses using N-J computational algorithms showed that the analyzed20Galliformes species are divided into three major clades: Phasianidae, Numidiidae and Odontophoridae. In addition, our work confirmed that DYCand Taoyuan chickenhave a closegenetic relationship with fellow tribal members Xuefeng black-boned chicken and Huang Lang chicken. This work will provide an important data set for the study in genetic mechanism of chicken in Hunan province.

The Complete Mitochondrial Genome of the Donganyellow Chicken and Its Phylogenetic Analyses

Donganyellow chicken (Gallus gallusdomesticus, DYC) is one of the famous native breeds of Hunan province in China. It is the first time that the complete mitochondrialgenome sequence of DYC was reported. The total length of the mtDNA is16, 786bp. It contains 22transfer RNA genes, 2 ribosomal RNA genes,13 protein-coding genes and 1 D-loop region. The overall composition of the mtDNA is 30.27% for A, 23.74% for T, 32.50% for C and 13.49% for G. Phylogenetic analyses using N-J computational algorithms showed that the analyzed20Galliformes species are divided into three major clades: Phasianidae, Numidiidae and Odontophoridae. In addition, our work confirmed that DYCand Taoyuan chickenhave a closegenetic relationship with fellow tribal members Xuefeng black-boned chicken and Huang Lang chicken. This work will provide an important data set for the study in genetic mechanism of chicken in Hunan province.(AU)

Analysis of serum microRNA expression in male workers with occupational noise-induced hearing loss.

Occupational noise-induced hearing loss (ONIHL) is a prevalent occupational disorder that impairs auditory function in workers exposed to prolonged noise. However, serum microRNA expression in ONIHL subjects has not yet been studied. We aimed to compare the serum microRNA expression profiles in male workers of ONIHL subjects and controls. MicroRNA microarray analysis revealed that four serum microRNAs were differentially expressed between controls (n=3) and ONIHL subjects (n=3). Among these microRNAs, three were upregulated (hsa-miR-3162-5p, hsa-miR-4484, hsa-miR-1229-5p) and one was downregulated (hsa-miR-4652-3p) in the ONIHL group (fold change >1.5 and Pbon value <0.05). Real time quantitative PCR was conducted for validation of the microRNA expression. Significantly increased serum levels of miR-1229-5p were found in ONIHL subjects compared to controls (n=10 for each group; P<0.05). A total of 659 (27.0%) genes were predicted as the target genes of miR-1229-5p. These genes were involved in various pathways, such as mitogen-activated protein kinase (MAPK) signaling pathway. Overexpression of miR-1229-5p dramatically inhibited the luciferase activity of 3' UTR segment of MAPK1 (P<0.01). Compared to the negative control, HEK293T cells expressing miR-1229-5p mimics showed a significant decline in mRNA levels of MAPK1 (P<0.05). This preliminary study indicated that serum miR-1229-5p was significantly elevated in ONIHL subjects. Increased miR-1229-5p may participate in the pathogenesis of ONIHL through repressing MAPK1 signaling.

Molecular cloning, functional verification, and evolution of TmPm3, the powdery mildew resistance gene of Triticum monococcum L.

Powdery mildew (Pm) is one of the most harmful diseases in wheat. Three Pm-resistance genes, Pm3, Pm21, and Pm8, have been cloned but most Pm3/Pm8 alleles have lost their resistance to Pm in hexaploid wheat. In this study, a new Pm3 homolog gene (TmPm3) was isolated from Triticum monococcum L. using a homology-based cloning strategy, being the first report of a functional Pm3 homolog gene from a diploid wheat species. The transient expression of TmPm3 in leaf epidermal cells showed that over-expressed TmPm3 could significantly inhibit the penetration of Blumeria graminis f. sp tritici conidia spores and the formation of haustoria. Sequence analysis of Pm3 alleles shed new light on the evolution of Pm3 genes, providing a better understanding of the molecular basis of disease resistance. This study also suggested that homology-based cloning of resistance genes is a feasible method for the isolation of functional resistance genes from wheat germplasm.

Modification research on in wall of capillary copper tube with Norland optical adhesive 68 in a double stereo PCR microfluidic chip.

In this study, a Norland optical adhesive 68 (NOA68) film, approximately 2.2 µm thick, was manufactured using ultraviolet solidified NOA68 in apparatus manufacturing film on the inwall of a capillary copper pipe, developed in our laboratory. The roughness of the inwall of capillary copper pipe was improved from Ra = 0.766 to 0.204 µm and the contact angle was improved from approximately 96° to 55°, increasing hydrophilicity. Polymerase chain reaction experiments indicated that the ratio of work pressure in the microfluidic chip before modification to that after modification was 2.71/1, indicating that the extension efficiency increased. Our results provide a basis for the construction of a microform chip based on function integration.

Cloning and expression of the sucrose transporter gene PsSUT1 from tree peony leaf.

This study reports the cloning of a sucrose transporter gene, PsSUT1, from the leaf of tree peony (Paeonia suffruticosa Lind. cv 'Huhong'). Expression patterns were examined in different organs and at different developmental stages. The full-length cDNA of PsSUT1 consisted of a 2001-bp sequence containing a 1557-bp open reading frame, encoding 519 amino acids with a conserved domain typical of the glycoside-pentoside-hexuronide superfamily. The amino acid sequence of PsSUT1 in tree peony shared high homology with that of other plants. At different developmental stages, PsSUT1 was expressed in roots, stems, leaves, and petals. Its expression level in stems was 10.9-fold higher than in petals at the flowering stage. Expression of PsSUT1 at the flowering stage was highest during flower development. The significant differences in PsSUT1 expression observed among developmental stages and organs were closely related to changes in sucrose content during flower opening. These results form the basis for further research on the molecular mechanisms of carbohydrate metabolism and transport during flower development in tree peony.

Inhibition of human chronic myelogenous leukemia K562 cell growth following combination treatment with resveratrol and imatinib mesylate.

To investigate the effect of treatment with resveratrol combined with imatinib mesylate on human chronic myelogenous leukemia K562 cell growth inhibition and apoptosis, in vitro cultured human chronic myelogenous leukemia K562 cells were incubated with different concentrations of resveratrol and imatinib mesylate when the cells were in the logarithmic phase. Next, the cell growth inhibition was evaluated using the MTT assay and cellular morphology observation. Apoptosis was determined using Annexin V fluorescein isothiocyanate/propidium iodide double staining. The results demonstrated that treatment with resveratrol (concentration-dependent) and imatinib mesylate showed significantly greater inhibition of K562 cell growth and a higher apoptosis rate of K562 cells than imatinib mesylate medication alone and the control group (P < 0.01). The imatinib mesylate medication alone group showed significant inhibition of K562 cell growth and apoptosis rate of K562 cells compared to the control group (P < 0.01). Our findings indicate that imatinib mesylate and resveratrol are potent drug treatments for human chronic myelogenous leukemia, offering a promising means of inhibiting cell growth and apoptosis.

Cloning and expression of an APETALA1-like gene from Nelumbo nucifera.

The objective of this study was to clone the full-length cDNA of the APETALA1 (AP1) gene from lotus and analyze its sequence and expression pattern. The full-length cDNA sequence of the NnAP1 gene was amplified from the petals of Nelumbo nucifera 'Hongxia' using RT-PCR and rapid amplification of cDNA ends. Bioinformatic methods were used to analyze the sequence characteristics of the gene. Quantitative real-time PCR methods were used to investigate the expression pattern of NnAP1 in various organs and during different developmental stages. The cloned full-length NnAP1 cDNA (GenBank accession No. KF361315) was 902 bp, containing a 795-bp open reading frame encoding 264 amino acids with a relative molecular mass of 30,288.4 and an isoelectric point of 9.13. NnAP1 had a MADS-box domain and a K-box domain, which is typical of the SQUA/AP1 gene family. A protein sequence identity search showed that NnAP1 was 75-96% similar to other plant AP1s. Phylogenetic tree analysis indicated that NnAP1 was very closely related to AP1 of Glycine max, suggesting that they shared the same protein ancestor. Quantitative real-time PCR analysis showed that NnAP1 was expressed in various organs during different developmental stages; it had the highest expression in blooming flowers and had trace expression in the young vegetative and flower senescence stages. Our analysis suggests that NnAP1 plays an important role in controlling floral meristem identity and floral organ formation.

Interleukin-10 polymorphisms and nasopharyngeal carcinoma risk: a meta-analysis.

It has been reported that interleukin-10 (IL-10) promoter genes (1082 A/G, 819 T/C, 592 A/C) are associated with nasopharyngeal carcinoma (NPC). However, the results remain controversial and ambiguous. To resolve inconsistencies in published data, we performed a meta-analysis to ascertain the association between IL-10 polymorphisms and NPC risk. Two case-control studies and two cohort studies were quantitatively analyzed to evaluate IL-10 promoter gene polymorphisms and NPC risk. Odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated for each genetic model and allelic comparison. A random-effect model or a fixed-effect model was used to calculate the overall combined risk estimates. Overall, the variant genotypes (AA and AG) of the IL-10-1082 A/G polymorphism were associated with elevated risk of NPC compared with the GG homozygote (AG vs GG: OR = 1.77; 95%CI = 1.39-2.26; AG + GG vs AA: OR = 1.78; 95%CI = 1.42-2.22); no significant associations were observed in allelic contrast and the recessive model. Strong positive association was seen in the cohort studies but not in the case-control studies. No statistically significant association was detected between IL-10-819 T/C and IL-10-592 A/C polymorphisms and NPC. Additionally, publication bias was not found. Based on the current evidence, this meta-analysis suggests that IL-1082 A/G polymorphism may increase the risk of NPC, but IL-10-819 T/C and IL-10-592 A/C polymorphisms do not. Further multicenter studies that are better controlled are required to confirm these findings.

Roles of GILZ in protein metabolism of L6 muscle cells exposed to serum from septic rats.

Sepsis is a complex inflammatory response to infection, associating with dramatic metabolic disorders. Although the mechanisms of immune response during sepsis have been largely clarified, current studies rarely pay attention to the disordered protein metabolism in sepsis. In this study, L6 rat skeletal muscle cells treated with serum from septic rats were used as an in vitro model for sepsis-like condition in skeletal muscle. We found that the expression of glucocorticoid-induced leucine zipper (GILZ) positively correlates with glucocorticoid receptor and negatively correlates with myosin heavy chain expression in L6 muscle cells upon septic serum induction. Moreover, we propose that GILZ may associate with cytokines such as TNF-α, IL-1ß as well as IL-10 to cooperatively modulate the glucocorticoid/glucocorticoid receptor-mediated regulation of protein metabolism during sepsis. So the present study provides a new approach and theoretical basis for further studies on the regulation of protein metabolism of skeletal muscle during sepsis.

Inhibitory effect of survivin-targeting small interfering RNA on gastric cancer cells.

A pair of inverted repeated sequences of the gene survivin was designed for stable double-stranded RNA establishment. After stable transfection, the biological behaviors of gastric cancer cells were observed. The interference rates of survivin-targeting siRNA (siRNA-survivin) in BGC823, MKN45, SGC7901, and cisplatin-resistant SGC7901 groups were 55.363 ± 3.974, 71.433 ± 3.774, 69.433 ± 7.336, and 76.767 ± 3.541%, respectively, compared with those in the control group. After siRNA-survivin interference, survivin protein expression noticeably decreased, apoptotic rates markedly increased, and cell proliferation was inhibited to varying degrees. Mitochondrial cytochrome C protein expression decreased and the levels of cytoplasmic cytochrome C and caspase-3 increased, which showed significant differences compared with values before transfection. pRNA-shSU eukaryotic expression vectors were constructed. After plasmid transfection, green fluorescent protein expression increased and survivin protein expression noticeably increased in BGC823 and SGC7901. siRNA-survivin promotes GC cell apoptosis and inhibits cell proliferation by downregulating survivin mRNA and protein expression. The underlying mechanisms are correlated with a decrease in mitochondrial cytochrome C and cytoplasmic cytochrome C and caspase-3.

Influence of hepatic ischemia-reperfusion on postoperative spatial cognitive function in mice.

The aim of this study was to investigate the effects of partial hepatic ischemia/reperfusion (I/R) on postoperative cognitive function in mice. One hundred Kunming mice were randomized into control group (N = 20), sham group (N = 20) and I/R group (N = 60), which was equally divided into 3 subgroups according to the ischemia time (20, 30 and 40 min). Half of the mice in each group underwent a passive avoidance test on the 4th day, and the other underwent the test on the 18th day, which lasted for 6 days before euthanasia for analysis of brain pathology and immunohistochemistry for ChAT. The passive avoidance test showed that there was no significance in the incubation period and number of errors between the control and sham group, but there was a longer incubation period and more errors in the I/R group than control group; at G2, there was no significance between all groups. Hematoxylin-eosin staining of the hippocampus showed that at G1, there was no obvious change in hippocampal neurons in structure and arrangement except for IR/40 min; at G2, there was no significance between all groups. Immunohistochemistry of hippocampus for ChAT showed the following: at G1, there was no significance in average optical density of CA3 area between control and sham group, but optical density was significantly lower in I/R groups with I/R 40 min showing the lowest; at G2, there was no significance between all groups. Pentobarbital has no effect on cognitive function, but hepatic partial ischemia and reperfusion injury does and could become worse over time.

Effects of simulated weightlessness on cellular morphology and biological characteristics of cell lines SGC-7901 and HFE-145.

We investigated the effects of simulated weightlessness on cellular morphology, proliferation, cell cycle, and apoptosis of the human gastric carcinoma cell line SGC-7901 and the human gastric normal cell line HFE-145. A rotating clinostat was used to simulate weightlessness. The Image-Pro4.5 image analysis system was used for morphometric analysis. Proliferating cell nuclear antigen expression was examined by immunohistochemical staining. Changes in the cell cycle were examined using a cytometer. Apoptosis was measured using the terminal dUTP nick-end labeling (TUNEL) method. When subjected to simulated weightlessness, the cellular morphology of SGC-7901 cells was changed at 12, 24, 48, and 72 h, cell conversion from the G1 to S phase was blocked, proliferation was inhibited at 48 and 72 h, and the apoptosis index was increased at 72 h. The same changes were observed for HFE-145 cells at 12 h when subjected to simulated weightlessness, but no significant changes were found afterward compared with controls. SGC-7901 cells change their cellular morphology and biological characteristics during clinostat-simulated weightlessness at 72 h, but HFE-145 cells only change at 12 h and adapt to simulated weightlessness after that point.

Changes in cardiac aldosterone and its synthase in rats with chronic heart failure: an intervention study of long-term treatment with recombinant human brain natriuretic peptide

The physiological mechanisms involved in isoproterenol (ISO)-induced chronic heart failure (CHF) are not fully understood. In this study, we investigated local changes in cardiac aldosterone and its synthase in rats with ISO-induced CHF, and evaluated the effects of treatment with recombinant human brain natriuretic peptide (rhBNP). Sprague-Dawley rats were divided into 4 different groups. Fifty rats received subcutaneous ISO injections to induce CHF and the control group (n=10) received equal volumes of saline. After establishing the rat model, 9 CHF rats received no further treatment, rats in the low-dose group (n=8) received 22.5 μg/kg rhBNP and those in the high-dose group (n=8) received 45 μg/kg rhBNP daily for 1 month. Cardiac function was assessed by echocardiographic and hemodynamic analysis. Collagen volume fraction (CVF) was determined. Plasma and myocardial aldosterone concentrations were determined using radioimmunoassay. Myocardial aldosterone synthase (CYP11B2) was detected by quantitative real-time PCR. Cardiac function was significantly lower in the CHF group than in the control group (P<0.01), whereas CVF, plasma and myocardial aldosterone, and CYP11B2 transcription were significantly higher than in the control group (P<0.05). Low and high doses of rhBNP significantly improved hemodynamics (P<0.01) and cardiac function (P<0.05) and reduced CVF, plasma and myocardial aldosterone, and CYP11B2 transcription (P<0.05). There were no significant differences between the rhBNP dose groups (P>0.05). Elevated cardiac aldosterone and upregulation of aldosterone synthase expression were detected in rats with ISO-induced CHF. Administration of rhBNP improved hemodynamics and ventricular remodeling and reduced myocardial fibrosis, possibly by downregulating CYP11B2 transcription and reducing myocardial aldosterone synthesis.

Changes in cardiac aldosterone and its synthase in rats with chronic heart failure: an intervention study of long-term treatment with recombinant human brain natriuretic peptide.

The physiological mechanisms involved in isoproterenol (ISO)-induced chronic heart failure (CHF) are not fully understood. In this study, we investigated local changes in cardiac aldosterone and its synthase in rats with ISO-induced CHF, and evaluated the effects of treatment with recombinant human brain natriuretic peptide (rhBNP). Sprague-Dawley rats were divided into 4 different groups. Fifty rats received subcutaneous ISO injections to induce CHF and the control group (n=10) received equal volumes of saline. After establishing the rat model, 9 CHF rats received no further treatment, rats in the low-dose group (n=8) received 22.5 µg/kg rhBNP and those in the high-dose group (n=8) received 45 µg/kg rhBNP daily for 1 month. Cardiac function was assessed by echocardiographic and hemodynamic analysis. Collagen volume fraction (CVF) was determined. Plasma and myocardial aldosterone concentrations were determined using radioimmunoassay. Myocardial aldosterone synthase (CYP11B2) was detected by quantitative real-time PCR. Cardiac function was significantly lower in the CHF group than in the control group (P<0.01), whereas CVF, plasma and myocardial aldosterone, and CYP11B2 transcription were significantly higher than in the control group (P<0.05). Low and high doses of rhBNP significantly improved hemodynamics (P<0.01) and cardiac function (P<0.05) and reduced CVF, plasma and myocardial aldosterone, and CYP11B2 transcription (P<0.05). There were no significant differences between the rhBNP dose groups (P>0.05). Elevated cardiac aldosterone and upregulation of aldosterone synthase expression were detected in rats with ISO-induced CHF. Administration of rhBNP improved hemodynamics and ventricular remodeling and reduced myocardial fibrosis, possibly by downregulating CYP11B2 transcription and reducing myocardial aldosterone synthesis.

Homing of chloromethylbenzoyl ammonia-labeled bone marrow mesenchymal stem cells in an immune-mediated bone marrow failure mouse model in vivo.

Aplastic anemia is an abnormal immune reaction disease in which T lymphocytes destroy hematopoietic stem and progenitor cells because of immune hyperactivity. Bone marrow mesenchymal stem cells (BMSCs) have hematopoietic supporting and immune regulation functions. This study investigated BMSCs homing in mice transplantation models after bone marrow failure. BALB/c mice were randomly divided into three groups: normal control, bone marrow failure model, and BMSC transplantation group. Chloromethyl benzamido-labeled BMSCs of BALB/c mice were transplanted through tail vein injection in mouse models with bone marrow failure. Flow cytometry and histological fluorescence microscopy were used to observe the dynamic distribution of labeled cells in different tissues. Average survival time, peripheral blood, and bone marrow morphological features were observed in mice from each group. Twenty-four hours after tail vein infusion of BMSCs, positively labeled cells were observed in the bone marrows of recipient mice, and the number of positive cells increased significantly at 72 h (P < 0.05). In dead or dying mice, white blood cells, hemoglobin, platelets, and bone marrow mononuclear cells were all significantly higher in the BMSC transplantation group than in the BMSCs of the model group (P < 0.01). Mean survival time was significantly shorter in the bone marrow failure model group than in the transplantation group (P < 0.05). These results confirmed that the major of BMSCs injected via tail vein could migrate to injured bone marrow tissues within 24-72 h in a mouse model of bone marrow failure. Furthermore, BMSCs can promote hematopoietic recovery, reduce the degree of bone marrow failure, and significantly prolong survival time.

Inactivation of putative PKS genes can double geldanamycin yield in Streptomyces hygroscopicus 17997.

The putative polyketide biosynthesis (PKS) genes cos10 and pg10 were inactivated by insertion of a kanamycin-resistance gene into the genome of the geldanamycin-producing strain, Streptomyces hygroscopicus 17997. The resultant inactivation were confirmed by PCR analysis. The abilities of the PKS gene inactivation strains to produce geldanamycin were compared with the natural geldanamycin- producing strain, S. hygroscopicus 17997. The cos10-inactivated strain exhibited an unchanged ability to produce geldanamycin, but the pg10- inactivated strain can produce twice the yield of the natural strain when grown under the same conditions. We propose that there is a sub-PKS pathway in the geldanamycin-producing strain, S. hygroscopicus 17997.

Fast preparation of a polyclonal antibody against chicken protocadherin 1.

Protocadherins constitute a large family belonging to the cadherin superfamily; they function in various tissues of a wide variety of multicellular organisms. However, their functions and expression modes are still unknown in many of these species and tissues. We developed a fast and low-cost method to produce polyclonal antibody against chicken protocadherin 1 (Pcdh1) that could be used in assays for immunological assessment of protein expression levels of chicken Pcdh1. Primers were designed with DNAStar, using the nuclear sequence of pcdh1 as a template; the pcdh101 fragment was amplified, identified by sequencing and cloned into expression vectors pGEX-2TK and pET-32a, separately, resulting in 2 recombinant plasmids, pGEX-2TK-pcdh101 and pET-32a-pcdh101. These were confirmed by double-enzyme digestion and sequencing. The recombinant expression vectors were transformed and expressed in Escherichia coli BL21. The recombinant oligopeptides glutathione-S-transferase (GST)-Pcdh101 and (His)6-Pcdh101 fused with the carrier protein GST and (His)6 separately, and were purified. Rats were immunized by injecting the emulsified GST-Pcdh101 antigen subcutaneously into their hind footpads, followed by a booster injection after 2 weeks. One week after the booster, the sera were collected and examined for antibody titer by indirect ELISA. The optimal dilution of this antiserum was 1:300. The specificity of the antiserum was confirmed by Western blotting. This antiserum had good specificity and could be used to detect chicken Pcdh1 in Western blot analysis. This method allows production of specific rat polyclonal antisera for Western blots in less than 1 month at a relatively low cost.

Regulation of WNK4 gene transcription in the kidneys.

With-no-lysine (K) kinase-4 (WNK4) is a newly cloned kinase-encoding gene that plays a crucial role in the maintenance of electrolyte homeostasis. Mutations of WNK4 can cause pseudohypoaldosteronism type α, an autosomal dominant disease characterized by hyperkalemia, metabolic acidosis and hypertension. We explored the expression and regulatory mechanism of WNK4 in the human kidneys, which is a key regulator of blood pressure. Expression of WNK4 was determined by RT-PCR. Transcription initiation site and regulatory elements in the promoter region of WNK4 were systematically analyzed with a combined set of experimental and bioinformatic methods. Using 5'-RACE, we have determined the transcription initiation site. We identified a number of putative cis-acting elements by analysis of the promoter region with the TRANSFAC-TESS software; these were subsequently confirmed with an electrophoresis mobility shift assay. As confirmed by a CAT-ELISA reporter assay, the promoter region of WNK4 has a high level of transcriptional activity. Several hormones, in particular dexamethasone, can suppress the level of WNK4 mRNA. These results have shed light on the regulatory mechanism of WNK4 expression in kidneys, as well as the influence of various hormones on expression levels. This should prove useful for studies on the roles of WNK4 in the pathogenesis of hypertension.