FXYD Domain Research Articles

FXYD6 is transcriptionally activated by KLF10 to suppress the aggressiveness of gastric cancer cells.

Despite improvements in therapeutic approaches, the mortality rate of gastric cancer (GC) remains unacceptably high. Evidence suggests that FXYD domain containing ion transport regulator 6 (FXYD6) is downregulated in GC. However, its exact function and the molecular mechanism in GC are still unclear. FXYD6 expression in different cell lines was estimated using RT-qPCR. Western blotting was employed for protein expression detection. Cell counting kit-8 assay, colony formation assay, and flow cytometry were implemented to assess GC cell viability, proliferation, and apoptosis, respectively. Bioinformatics analysis as well as chromatin immunoprecipitation and luciferase reporter assays were utilized for verifying FXYD6 interaction with the transcription factor Krüppel-like factor 10 (KLF10). The results showed thatFXYD6 displayed a decreased level in GC cell lines. Impaired proliferative ability and enhanced apoptotic capacity were observed in GC cells overexpressing FXYD6. KLF10 expression is positively correlated with FXYD6 expression in GC samples. KLF10 binds to the FXYD6 promoter to enhance its transcription. FXYD6 depletion counteracted KLF10 upregulation-triggered reduction in GC cell proliferation and elevation in apoptosis. In conclusion,KLF10 activates FXYD6 transcription, thereby impeding GC cell proliferation and promoting cell apoptosis.

FXYD1 was identified as a hub gene in recurrent miscarriage and involved in decidualization via regulating Na/K-ATPase activity.

Recurrent miscarriage (RM) is a distressing and complicated adverse pregnancy outcome. It is commonly recognized that insufficient decidualization could result in RM, but the molecular mechanisms of decidual impairment are still not fully understood. Thus, this study aimed to identify novel key genes potentially involved in RM and explore their roles played in endometrial decidualization. Initially, a combinative analysis of decidual and mid-secretory endometrial transcriptomes was performed to discover hub genes involved in the etiology of RM. And the expression levels of hub genes were evaluated in both primary decidual stromal cells (DSCs) and decidual tissues. Subsequently, the immortalized human endometrial cell line, T-HESCs, was used to investigate whether FXYD1 overexpression affects decidualization by regulating Na/K-ATPase activity. FXYD domain containing ion transport regulator 1 (FXYD1) was identified as a hub gene in the pathogenesis of RM through various bioinformatic methods. Abnormally increased FXYD1 expression was observed in DSCs and decidual tissues from RM patients compared to that of the normal group. Furthermore, in vitro decidualization was obviously inhibited by the overexpression of FXYD1. Additionally, Na/K-ATPase activity was significantly elevated during decidualization, whereas overexpression of FXYD1 reduced Na/K-ATPase activity. Bufalin, a Na/K-ATPase inhibitor, showed an effectively inhibitory effect on decidualization. Collectively, FXYD1 was discovered as a hub gene associated with RM, and its expression levels in RM patients were significantly upregulated. Increased FXYD1 expression might lead to decidualization defects by reducing Na/K-ATPase activity, of which presented a novel prospective treatment target for RM.

Dipyridamole-grafted copolymer electrospun nanofiber membranes for suppression of peritendinous adhesions

Post-traumatic tendon adhesions significantly affect patient prognosis and quality of life, primarily stemming from the absence of effective preventive and curative measures in clinical practice. Current treatment modalities, including surgical excision and non-steroidal anti-inflammatory drugs, frequently exhibit limited efficacy or result in severe side effects. Consequently, the use of anti-adhesive barriers for drug delivery and implantation at the injury site to address peritendinous adhesion (PA) has attracted considerable attention. Electrospun nanofiber membranes (ENMs) have been extensively employed as drug-delivery platforms. In this study, we fabricated a polylactic acid (PLA)–dipyridamole (DP)-graft copolymer ENM called PLC-DP. This membrane exhibits enzyme-sensitive features, allowing more controlled and sustained drug release compared with conventional drug-loaded ENMs. In experiments, PLC-DP implantation reduced tissue adhesion by 47 % relative to the control group while not adversely affecting tendon healing. Mechanistically, PLC-DP effectively activates the FXYD domain containing ion-transport regulator 2 (FXYD2) protein, thereby downregulating the fibroblast-transforming growth factor beta (TGF-β)/Smad3 signaling pathway. PLC-DP leverages the anti-adhesive properties of DP and the enzyme-sensitive characteristics of graft copolymers, providing a promising approach for the future clinical treatment and prevention of PA. Statement of significancePeritendinous adhesions (PA) are a common and disabling condition that seriously affects the prognosis and quality of life of post-trauma patients. Current treatments often have limited efficacy or severe side effects, leaving a serious gap in clinical practice. We developed a significant biomaterial, poly(lactic acid)-dipyridamole graft copolymer electrospun nanofibrous membrane (PLC-DP), specifically for PA inhibition. In addition, this study uniquely combines dipyridamole, an anti-adhesive agent, and enzyme-sensitive copolymers in electrospun nanofibrous membrane. Unlike conventional drug-loaded electrospun nanofibrous membranes, PLC-DPs have enzyme-sensitive drug properties that allow for sustained drug release on demand. Our experiments showed that implantation of PLC-DP was effective in reducing tissue adhesions by 47 % without affecting tendon healing. We elucidated the mechanism behind this phenomenon, suggesting that PCD activates FXYD2 to inhibit TGF-β-induced expression of Col III, which is a key factor in PA development.

Microglial SIX2 suppresses lipopolysaccharide (LPS)-induced neuroinflammation by up-regulating FXYD2 expression

Parkinson’s disease (PD) is a severe neurodegenerative disease associated with the loss of dopaminergic (DA) neurons in the substantia nigra (SN). Although its pathogenesis remains unclear, microglia-mediated neuroinflammation significantly contributes to the development of PD. Here we showed that the sine oculis homeobox (SIX) homologue family transcription factors SIX2 exerted significant effects on neuroinflammation. The SIX2 protein, which is silenced during development, was reactivated in lipopolysaccharide (LPS)-treated microglia. The reactivated SIX2 in microglia mitigated the LPS induced inflammatory effects, and then reduced the toxic effect of conditioned media (CM) of microglia on co-cultured MES23.5 DA cells. Using the LPS-stimulated Cx3cr1-CreERT2 mouse model, we also demonstrated that the highly-expressed SIX2 in microglia obviously attenuated neuroinflammation and protected the DA neurons in SN. Further RNA-Seq analysis on the inflammatory activated microglia revealed that the SIX2 exerted these effects via up-regulating the FXYD domain containing ion transport regulator 2 (FXYD2). Taken together, our study demonstrated that SIX2 was an endogenous anti-inflammatory factor in microglia, and it exerted anti-neuroinflammatory effects by regulating the expression of FXYD2, which provides new ideas for anti-neuroinflammation in PD.

Fxyd5 activates the NF‑κB pathway and is involved in chondrocytes inflammation and extracellular matrix degradation.

It is known that increased inflammation and extracellular matrix (ECM) degradation in chondrocytes can promote the development of osteoarthritis (OA). The FXYD domain containing ion transport regulator 5 (Fxyd5) has been found to promote chronic inflammatory responses. The present study aimed to investigate the role of Fxyd5 in OA. Murine ATDC5 chondrocytes were transfected with short hairpin RNAs specifically targeting Fxyd5 to silence its expression. Subsequently, cells were induced with lipopolysaccharide (LPS). The protein expression levels of Fxyd5, MMPs and proteins related to ECM, apoptosis and NF-κB signaling were detected using western blot analysis. In addition, cell viability was assessed using a Cell Counting Kit-8 assay, while the secretion of the proinflammatory factors and those of the oxidative stress-related markers were measured using the corresponding kits. Finally, cells were treated with the NF-κB activator, betulinic acid (BA) and the above experiments were repeated. The results demonstrated that Fxyd5 was significantly upregulated in ATDC5 cells treated with LPS. Additionally, Fxyd5 knockdown increased cell viability, enhanced the protein expression of Bcl-2, Aggrecan and collagen II, while reduced the expression of Bax, cleaved caspase-3/caspase-3, MMP3 and MMP13 in LPS-induced ATDC5 cells. The production of IL-1β, IL-6 and IL-18 as well as reactive oxygen species and malondialdehyde, and the reduction of superoxide dismutase caused by LPS in ATDC5 cells, were also reversed by Fxyd5 silencing. Fxyd5 silencing inhibited the phosphorylation of p65 and IκBα induced by LPS. Finally, BA reversed the protective effect of Fxyd5 silencing on LPS induced chondrocytes injury. In conclusion, Fxyd5 could enhance chondrocyte inflammation and ECM degradation via activating the NF-κB signaling.

FXYD domain containing ion transport regulator 5 (FXYD5) silencing promotes cell viability and alleviates inflammatory response in cerulein-induced AR42J cells by blocking JAK2/STAT3 signaling pathway

ABSTRACT Acute pancreatitis (AP), which causes severe morbidity and mortality, is a heavy burden for people clinically and financially. This study was designed to explore the mechanism of AP and try to find effective therapies against AP. The expression of FXYD5 was interfered by performing transfection. RT-qPCR and Western blot were utilized to measure FXYD5 expression. In addition, the viability, apoptosis and inflammatory response were evaluated using CCK-8, TUNEL and ELISA, respectively. Moreover, Western blot was employed to measure the expressions of apoptosis-, inflammation- and signaling pathway-related proteins. FXYD5 was found to be overexpressed in AP patients and AP cell model. The results showed that in cerulein-induced AR42J cells, cell viability was remarkably increased, and apoptosis was inhibited compared to the normal FXYD5-expressing group because FXYD5 was downregulated. Similarly, in such cells, interference with FXYD5 significantly suppressed the inflammatory response. In addition, Western blot analysis revealed that JAK2/STAT3 signaling was also strongly inhibited by FXYD5 interference. However, the effect of FXYD5 downregulation was reversed upon simultaneous activation of JAK2/STAT3 signaling. In conclusion, downregulation of FXYD5 could promote cell viability and alleviate inflammatory response in cerulein-induced AP via blocking JAK2/STAT3 signaling pathway.

FXYD1 Is Protective Against Vascular Dysfunction.

[Figure: see text].

The Long Noncoding RNA RP11-728F11.4 Promotes Atherosclerosis.

Noncoding RNAs are emerging as important players in gene regulation and cardiovascular diseases. Their roles in the pathogenesis of atherosclerosis are not fully understood. The purpose of this study was to determine the role played by a previously uncharacterized long noncoding RNA, RP11-728F11.4, in the development of atherosclerosis and the mechanisms by which it acts. Approach and Results: Expression microarray analysis revealed that atherosclerotic plaques had increased expression of RP11-728F11.4 as well as the cognate gene FXYD6 (FXYD domain containing ion transport regulator 6), which encodes a modulator of Na+/K+-ATPase. In vitro experiments showed that RP11-728F11.4 interacted with the RNA-binding protein EWSR1 (Ewings sarcoma RNA binding protein-1) and upregulated FXYD6 expression. Lentivirus-induced overexpression of RP11-728F11.4 in cultured monocytes-derived macrophages resulted in higher Na+/K+-ATPase activity, intracellular cholesterol accumulation, and increased proinflammatory cytokine production. The effects of RP11-728F11.4 were enhanced by siRNA-mediated knockdown of EWSR1 and reduced by downregulation of FXYD domain containing ion transport regulator 6. In vivo experiments in apoE knockout mice fed a Western diet demonstrated that RP11-728F11.4 increased proinflammatory cytokine production and augmented atherosclerotic lesions. RP11-728F11.4 promotes atherosclerosis, with an influence on cholesterol homeostasis and proinflammatory molecule production, thus representing a potential therapeutic target. Graphic Abstract: A graphic abstract is available for this article.

FXYD Domain Containing Ion Transport Regulator 3 (FXYD3) is Over-Expressed in Germinal Centre Derived Aggressive Lymphomas and Plasma Cell Myeloma

The FXYD domain containing ion transport regulator 3 (FXYD3) belongs to the FXYD protein family, originally identified by Sweadner and Rael [1] basing on sequence similarity, and accounting in mammal for at least seven members.

Transcriptional Analysis of Endothelial Cell Alternation Induced by Atrial Natriuretic Polypeptide in Human Umbilical Vein Endothelial Cells.

The aim of this study was to explore how atrial natriuretic polypeptide (ANP) affects the properties and function of endothelial cells. Gene expression data GSE56976 generated at 0, 1, and 6 hours after ANP incubation in human umbilical vein endothelial cells (HUVEC) was used. Microarray data were preprocessed for differentially expressed genes (DEGs) in each time-dependent group. Next, gene ontology (GO), pathway analysis, and transcriptional regulation were performed. Co-expression clustering analysis of DEGs and functional enrichment analysis of co-expression modules were processed. RT-PCR analysis was performed to validate gene expression. DEGs were obtained and their counts were increased from 0 hours to 6 hours. No overlapping DEGs were obtained among the 3 groups. The DEGs of ANP_6hours, including TGFB2 (transforming growth factor, beta 2), LTF (lactotransferrin/lactoferrin), and ETV7 (Ets variant 7) were mainly related with cell apoptosis and immune responses. The DEGs in the network of ANP_0hour were mainly associated with epithelial ion transport processes. In addition, 3 co-expressed modules were detected. CSF2 (colony stimulating factor 2) and PF4 (platelet factor 4) of the blue module were related with cytolysis, while FXYD1 (FXYD domain containing ion transport regulator 1) and TGFB2 of the yellow module were mainly enriched in ion transport and the ovulation cycle. The expression of TGFB2 obtained by microarray analysis was consistent with that of RT-PCR. Ion transport could be affected promptly after ANP treatment, and subsequently, the cytolysis of vein endothelial cells may be promoted and endothelial permeability would be enhanced, followed by activated immune responses.

The effect of a preparation of minerals, vitamins and trace elements on the cardiac gene expression pattern in male diabetic rats

BackgroundDiabetic patients have an increased risk of developing cardiovascular diseases, which are the leading cause of death in developed countries. Although multivitamin products are widely used as dietary supplements, the effects of these products have not been investigated in the diabetic heart yet. Therefore, here we investigated if a preparation of different minerals, vitamins, and trace elements (MVT) affects the cardiac gene expression pattern in experimental diabetes.MethodsTwo-day old male Wistar rats were injected with streptozotocin (i.p. 100 mg/kg) or citrate buffer to induce diabetes. From weeks 4 to 12, rats were fed with a vehicle or a MVT preparation. Fasting blood glucose measurement and oral glucose tolerance test were performed at week 12, and then total RNA was isolated from the myocardium and assayed by rat oligonucleotide microarray for 41012 oligonucleotides.ResultsSignificantly elevated fasting blood glucose concentration and impaired glucose tolerance were markedly improved by MVT-treatment in diabetic rats at week 12. Genes with significantly altered expression due to diabetes include functional clusters related to cardiac hypertrophy (e.g. caspase recruitment domain family, member 9; cytochrome P450, family 26, subfamily B, polypeptide; FXYD domain containing ion transport regulator 3), stress response (e.g. metallothionein 1a; metallothionein 2a; interleukin-6 receptor; heme oxygenase (decycling) 1; and glutathione S-transferase, theta 3), and hormones associated with insulin resistance (e.g. resistin; FK506 binding protein 5; galanin/GMAP prepropeptide). Moreover the expression of some other genes with no definite cardiac function was also changed such as e.g. similar to apolipoprotein L2; brain expressed X-linked 1; prostaglandin b2 synthase (brain). MVT-treatment in diabetic rats showed opposite gene expression changes in the cases of 19 genes associated with diabetic cardiomyopathy. In healthy hearts, MVT-treatment resulted in cardiac gene expression changes mostly related to immune response (e.g. complement factor B; complement component 4a; interferon regulatory factor 7; hepcidin).ConclusionsMVT-treatment improved diagnostic markers of diabetes. This is the first demonstration that MVT-treatment significantly alters cardiac gene expression profile in both control and diabetic rats. Our results and further studies exploring the mechanistic role of individual genes may contribute to the prevention or diagnosis of cardiac complications in diabetes.Electronic supplementary materialThe online version of this article (doi:10.1186/s12933-015-0248-6) contains supplementary material, which is available to authorized users.

FXYD6: a novel therapeutic target toward hepatocellular carcinoma

FXYD6, FXYD domain containing ion transport regulator 6, has been reported to affect the activity of Na+/K+-ATPase and be associated with mental diseases. Here, we demonstrate that FXYD6 is up-regulated in hepatocellular carcinoma (HCC) and enhances the migration and proliferation of HCC cells. Up-regulation of FXYD6 not only positively correlates with the increase of Na+/K+-ATPase but also coordinates with the activation of its downstream Src-ERK signaling pathway. More importantly, blocking FXYD6 by its functional antibody significantly inhibits the growth potential of the xenografted HCC tumors in mice, indicating that FXYD6 represents a potential therapeutic target toward HCC. Altogether, our results establish a critical role of FXYD6 in HCC progression and suggest that the therapy targeting FXYD6 can benefit the clinical treatment toward HCC patients.Electronic supplementary materialThe online version of this article (doi:10.1007/s13238-014-0045-0) contains supplementary material, which is available to authorized users.

FXYD3 (FXYD domain containing ion transport regulator 3)

Review on FXYD3 (FXYD domain containing ion transport regulator 3), with data on DNA, on the protein encoded, and where the gene is implicated.

Reduced expression of FXYD domain containing ion transport regulator 5 in association with hypertension

Experimental evidence indicates that hypertension is a multifactorial disorder and that the products of several genes may contribute to its development. The aim of this study was to investigate the expression of hypertension-related genes in spontaneous hypertensive rats (SHRs). A microarray screening for hypertension-related genes was conducted in SHRs and Wistar-Kyoto (WKY) rats using total-RNA extracted from second-order mesenteric arteries and kidneys. The FXYD5 mRNA expression in vascular smooth muscle cells (VSMCs) was silenced by RNA interference (RNAi). Meanwhile, the FXYD5 mRNA overexpression in renal tubular epithelial cells (RTECs) was induced by the recombinant plasmid pcDNA3.1(+)-FXYD5. The expression of FXYD5 mRNA was found to be 14.8-fold lower in SHR rats compared to that in WKY rats (P<0.01). The levels of FXYD5 mRNA expression were the highest in kidneys of SHR 13-week-old rats when the blood pressure reached the highest levels. The down-regulated FXYD5 mRNA expression inhibited the migration of smooth muscle cells (P<0.01) and cell membrane Na⁺-K⁺-ATPase activity (P<0.01). Up-regulated FXYD5 mRNA expression enhanced the renal tubular epithelial cell membrane Na⁺-K⁺-ATPase activity (P<0.05) and cell proliferation (P<0.05). FXYD5 is related to the migration of smooth muscle cells and cell membrane Na⁺-K⁺-ATPase activity in rodents. The results of the present study suggest that FXYD5 may have profound impact on the regulation of blood pressure, and that this gene may be a potential target for anti-hypertensive therapy.

FXYD5 (FXYD domain containing ion transport regulator 5)

Review on FXYD5 (FXYD domain containing ion transport regulator 5), with data on DNA, on the protein encoded, and where the gene is implicated.

Reduced expression of FXYD domain containing ion transport regulator 5 (FXYD5) in association with hypertension

BackgroundTo investigate the expression of hypertension-related genes in spontaneous hypertension.MethodsA microarray screening for hypertension-related genes was conducted in rats with spontaneous hypertension (SHR) and rats with normotensive Wistar-Kyoto (WKY) using...

Reduced expression of FXYD domain containing ion transport regulator 5 (FXYD5) in association with hypertension

Reduced expression of FXYD domain containing ion transport regulator 5 (FXYD5) in association with hypertension

Pancreatic islet and progenitor cell surface markers with cell sorting potential

The aim of the study was to identify surface bio-markers and corresponding antibody tools that can be used for the imaging and immunoisolation of the pancreatic beta cell and its progenitors. This may prove essential to obtain therapeutic grade human beta cells via stem cell differentiation. Using bioinformatics-driven data mining, we generated a gene list encoding putative plasma membrane proteins specifically expressed at distinct stages of the developing pancreas and islet beta cells. In situ hybridisation and immunohistochemistry were used to further prioritise and identify candidates. In the developing pancreas seizure related 6 homologue like (SEZ6L2), low density lipoprotein receptor-related protein 11 (LRP11), dispatched homologue 2 (Drosophila) (DISP2) and solute carrier family 30 (zinc transporter), member 8 (SLC30A8) were found to be expressed in early islet cells, whereas discoidin domain receptor tyrosine kinase 1 (DDR1) and delta/notch-like EGF repeat containing (DNER) were expressed in early pancreatic progenitors. The expression pattern of DDR1 overlaps with the early pancreatic and duodenal homeobox 1 (PDX1)⁺/NK6 homeobox 1 (NKX6-1)⁺ multipotent progenitor cells from embryonic day 11, whereas DNER expression in part overlaps with neurogenin 3 (NEUROG3)⁺ cells. In the adult pancreas SEZ6L2, LRP11, DISP2 and SLC30A8, but also FXYD domain containing ion transport regulator 2 (FXYD2), tetraspanin 7 (TSPAN7) and transmembrane protein 27 (TMEM27), retain an islet-specific expression, whereas DDR1 is undetectable. In contrast, DNER is expressed at low levels in peripheral mouse and human islet cells. Re-expression of DDR1 and upregulation of DNER is observed in duct-ligated pancreas. Antibodies to DNER and DISP2 have been successfully used in cell sorting. Extracellular epitopes of SEZ6L2, LRP11, DISP2, DDR1 and DNER have been identified as useful tags by applying specific antibodies to visualise pancreatic cell types at specific stages of development. Furthermore, antibodies recognising DISP2 and DNER are suitable for FACS-mediated cell purification.

A genomic-based approach identifies FXYD domain containing ion transport regulator 2 (FXYD2)γa as a pancreatic beta cell-specific biomarker

Non-invasive imaging of the pancreatic beta cell mass (BCM) requires the identification of novel and specific beta cell biomarkers. We have developed a systems biology approach to the identification of promising beta cell markers. We followed a functional genomics strategy based on massive parallel signal sequencing (MPSS) and microarray data obtained in human islets, purified primary rat beta cells, non-beta cells and INS-1E cells to identify promising beta cell markers. Candidate biomarkers were validated and screened using established human and macaque (Macacus cynomolgus) tissue microarrays. After a series of filtering steps, 12 beta cell-specific membrane proteins were identified. For four of the proteins we selected or produced antibodies targeting specifically the human proteins and their splice variants; all four candidates were confirmed as islet-specific in human pancreas. Two splice variants of FXYD domain containing ion transport regulator 2 (FXYD2), a regulating subunit of the Na(+)-K(+)-ATPase, were identified as preferentially present in human pancreatic islets. The presence of FXYD2gammaa was restricted to pancreatic islets and selectively detected in pancreatic beta cells. Analysis of human fetal pancreas samples showed the presence of FXYD2gammaa at an early stage (15 weeks). Histological examination of pancreatic sections from individuals with type 1 diabetes or sections from pancreases of streptozotocin-treated Macacus cynomolgus monkeys indicated a close correlation between loss of FXYD2gammaa and loss of insulin-positive cells. We propose human FXYD2gammaa as a novel beta cell-specific biomarker.

Effect of D3 receptor on α-adrenergic receptor mediated proliferation of vascular smooth muscle cells

results with quantitative real time RT-PCR and Northern Blot. Blood pressure was measured to determine the time of development of hypertension. Results: Among the 10,000 genes examined, we found that expression of the human gene homolog FXYD domain containing ion transport regulator 5 (FXYD5)was downregulated in thekidneys and second-order mesenteric arteries of SHR. FXYD5 expression was 14.8fold lower in SHR than in WKY rats (P<0.01). Northern blot results indicated that expression of FXYD5 occurred in a timeand tissuedependent manner. FXYD5 expression did not differ between SHR and WKY rats at 4 and 8 weeks of age, but FXYD5 mRNA levels were significantly lower in SHR by 13 weeks of age (P<0.01). Peak FXYD5 expression was seen at 8 weeks in SHR and at 13 weeks in WKY rats. Conclusion: The FXYD5gene,which is involved in the induction ofNa, KATPase activity, was significantly suppressed in SHR. This downregulation may have a profound effect on blood pressure regulation. Thus, FXYD5 may serve as a potential target for antihypertensive therapy.