scholarly journals CircRNA expression profile and functional analysis in testicular tissue of patients with non-obstructive azoospermia

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Pan Ge ◽  
Jian Zhang ◽  
Liang Zhou ◽  
Mo-qi Lv ◽  
Yi-xin Li ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Expression Profile ◽  
Function Analysis ◽  
Expression Patterns ◽  
Testicular Tissue ◽  
Differentially Expressed ◽  
Circular Rnas ◽  
Transferase Activity ◽  
Obstructive Azoospermia ◽  
Qrt Pcr

Abstract Background Non-obstructive azoospermia (NOA) is a multifactorial disorder whose molecular basis remains largely unknown. Circular RNAs (CircRNAs), a novel class of endogenous RNAs, have been recognized to play important roles in many biological processes. However, little is known about the expression patterns and functions of circRNAs in human testes involved in NOA. Methods In this study, the testicular circRNA expression profile were explored in NOA patients and the controls by high-throughput circRNA microarray. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to confirm the microarray data. Bioinformatics analyses including the circRNA/miRNA/mRNA interaction network, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were used to predict the functions of differentially expressed circRNAs. Results A total of 368 differentially down-regulated and 526 up-regulated circRNAs were detected in NOA patients. These findings have been verified by qRT-PCR on 6 selected circRNAs. Among these differentially expressed circRNAs, the hsa_circRNA_0023313 was obviously up-regulated in testicular tissue of NOA patients. The most likely potential target miRNA for hsa_circRNA_0023313 include hsa-miR-520d-3p, hsa-miR-373-3p, hsa-miR-372-3p, hsa-miR-302c-3p and hsa-miR-130b-5p. Function analysis indicated that hsa_circRNA_0023313 was ubiquitin-protein transferase activity and chromatin binding. KEGG analysis revealed that the top five pathways related to hsa_circRNA_0023313 were endocytosis, meiosis, FoxO signaling pathway, ubiquitin mediated proteolysis and AMPK signaling pathway. Conclusions This is the first report that the testicular circRNA expression profile is altered in NOA patients indicating circRNAs might play important roles in regulating spermatogenesis and be potential biomarkers for the diagnosis and treatment of NOA.

scholarly journals Microarray based circRNA expression profiles in uremic plasma and PBMCs due to chronic glomerulonephritis

2017 ◽  
Vol 69 (3) ◽  
pp. 523-534 ◽  
Author(s):  
Xi Wang ◽  
Yong Dai ◽  
Wanfan Zhang ◽  
S SunDonglin ◽  
Xinzhou Zhang
Keyword(s):  
Expression Profile ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Differentially Expressed ◽  
Circular Rnas ◽  
Chronic Glomerulonephritis ◽  
Qrt Pcr ◽  
Uremic Patients

Circular RNAs (circRNAs) have been identified in many diseases and shown to play important roles in pathological processes. The expression patterns of circRNA in uremia remains unknown. The aim of this study was to screen circRNA in plasma and peripheral blood mononuclear cells (PBMCs)in healthy controls and patients with uremia due to chronic glomerulonephritis, and to provide evidence for further exploration of the pathogenesis, diagnosis and treatment of uremic patients. Twenty individuals were included in this study, of which 10 were healthy and 10 were patients with uremia caused by chronic glomerulonephritis without systemic lupus erythematosus(SLE). Peripheral blood was collected from each individual in the two groups and the PBMCs were separated. The circRNAs expression profile was examined using a human circRNA microarray. The expression of differently expressed circRNAs was further validated by qRT-PCR. Seven hundred ten circRNAs were differentially expressed in the plasma in the two groups, accounting for 27.58% of the total circRNA(710/2578). Three hundred eighty-five up regulated circRNAs accounted for 14.93% and 325 down regulated circRNAs accounted for 12.60% of the total circRNAs. Additionally, 968 circRNAs were differentially expressed in PBMCs in the two groups, accounting for 29.24% of all circRNAs (968/3310).Six hundred seventy upregulated circRNAs accounted for 20.24% and 298 down regulated circRNAs accounted for 9.00% of the total circRNAs. The results of qRT-PCR validation were consistent with the microarray gene expression results. The expression profile of circRNAs was altered in the plasma and PBMCs of patients with uremia, which suggests that the changed circRNAs may be potential diagnostic biomarkers that play an important role in the pathogenesis of uremic patients. We speculate that hsa_circ_0053958, hsa_circ_0103281 may be associated with the pathogenesis of uremia and may be potential biological molecular markers for the diagnosis and prognosis of uremia.

scholarly journals Microarray Expression Profile of Circular RNAs in Plasma from Primary Biliary Cholangitis Patients

2017 ◽  
Vol 44 (4) ◽  
pp. 1271-1281 ◽  
Author(s):  
Jiajia Zheng ◽  
Zhenrong Li ◽  
Tiancheng Wang ◽  
Yang Zhao ◽  
Yongfeng Wang
Keyword(s):  
Expression Profile ◽  
Expression Profiles ◽  
Characteristic Curve ◽  
Group Versus ◽  
Target Prediction ◽  
Differentially Expressed ◽  
Circular Rnas ◽  
Primary Biliary Cholangitis ◽  
Healthy Controls ◽  
Qrt Pcr

Background/Aims: Circular RNAs (circRNAs) play a crucial role in the occurrence of several diseases, including autoimmune diseases. However, their role in primary biliary cholangitis (PBC) remains unclear. Here, we aimed to determine the circRNA expression profile in plasma from PBC patients and further explore the value of circRNA in diagnosing PBC. Methods: CircRNA microarrays were used to determine circRNA expression profiles in plasma samples from 6 PBC patients and 6 healthy controls. Statistical analyses identified differentially expressed circRNAs, and these circRNAs were verified by qRT-PCR in 29 PBC patients and 30 healthy controls. MicroRNA (miRNA) target prediction software identified putative miRNA response elements (MREs), which were used to construct a map of circRNA-miRNA interactions for the differentially expressed circRNAs. Results: Our results indicated that there were 18 up-regulated and 4 down-regulated circular RNAs in the plasma from PBC patients compared with that from healthy individuals. Among the differentially expressed circRNAs, hsa_circ_402458 (P=0.0033), hsa_circ_087631 and hsa_circ_406329 (P=0.0185) were up-regulated, and hsa_circ_407176 (P=0.0066) and hsa_circ_082319 were down-regulated in the PBC group versus the healthy group as demonstrated by qRT-PCR. In particular, hsa_circ_402458 was significantly higher in PBC patients not receiving UDCA treatment than in PBC patients receiving UDCA treatment (P=0.0338). The area under the receiver operating characteristic curve for hsa_circ_402458 for diagnosing PBC was 0.710 (P=0.005). For hsa_circ_402458, two putative miRNA targets, hsa-miR-522-3p and hsa-miR-943, were predicted. Conclusions: circRNA dysregulation may play a role in PBC pathogenesis, and hsa_circ_402458 shows promise as a candidate biomarker for PBC.

scholarly journals Identification of Circular RNAs Regulating Islet β-Cell Autophagy in Type 2 Diabetes Mellitus

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Chao Bai ◽  
Wenwen Yang ◽  
Yao Lu ◽  
Wei Wei ◽  
Zongbao Li ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Signaling Pathway ◽  
Expression Profile ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Differentially Expressed ◽  
Qrt Pcr

This study is to identify the circular RNA (circRNA) expression profile that is functionally related to pancreatic islet β-cell autophagy and their potential regulation mechanisms in type 2 diabetes mellitus (T2DM). T2DM rat model was constructed by administration of high-fat and high-sugar diet. β-cells were isolated from islets by flow cytometry. CircRNA expression profile in β-cells was detected by circRNA microarrays, and the differentially expressed circRNAs were identified and validated by qRT-PCR. MicroRNA (miRNA) target prediction software and multiple bioinformatic approaches were used to construct a map of circRNA-miRNA interactions for the differentially expressed circRNAs. A total of 825 differentially expressed circular transcripts were identified in T2DM rats compared with control rats, among which 388 were upregulated and 437 were downregulated. Ten circRNAs were identified to have significant differences by qRT-PCR. GO analysis enriched terms such as organelle membrane and protein binding and the top enriched pathways for the circRNAs included MAPK signaling pathway. The differentially expressed circRNAs might involve in MAPK signaling pathway, apoptosis, and Ras signaling pathway. We speculate that these circRNAs, especially rno_circRNA_008565, can regulate the autophagy of islet β-cells via interactions with miRNA. Dysregulation of several circRNAs may play a role in T2DM development, and rno_circRNA_008565 may be a potential regulator of β-cell autophagy.

scholarly journals Key circular RNAs identified in male osteoporosis patients by whole transcriptome sequencing

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11420
Author(s):  
Haijin Zhang ◽  
Xue Song ◽  
Zongyan Teng ◽  
Sujun Cheng ◽  
Weigang Yu ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Expression Profile ◽  
Systemic Disease ◽  
Enrichment Analysis ◽  
Differentially Expressed ◽  
Male Osteoporosis ◽  
Circular Rnas ◽  
Healthy Controls ◽  
Regulation Of Cell Cycle ◽  
Whole Transcriptome

Background Osteoporosis (OP) is a systemic disease with bone loss and microstructural deterioration. Numerous noncoding RNAs (ncRNAs) have been proved to participate in various diseases, especially circular RNAs (circRNAs). However, the expression profile and mechanisms underlying circRNAs in male osteoporosis have not yet been explored. Methods The whole transcriptome expression profile and differences in mRNAs, circRNAs, and microRNAs (miRNAs) were investigated in peripheral blood samples of patients with osteoporosis and healthy controls consisting of males ≥ 60-years-old. Results A total of 398 circRNAs, 51 miRNAs, and 642 mRNAs were significantly and differentially expressed in osteoporosis compared to healthy controls. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the host genes of significantly differentially expressed circRNAs were mainly enriched in the regulation of cell cycle process: biological process (BP), organelle part cellular components (CC), protein binding molecular function (MF), Toll-like receptor signaling pathway, tumor necrosis factor (TNF) signaling pathway, and thyroid hormone signaling pathway. circRNA-miRNA-mRNA regulatory network was constructed using the differentially expressed RNAs. Moreover, key circRNAs (hsa_circ_0042409) in osteoporosis were discovered and validated by qPCR. Conclusions The key cicrRNAs plays a major role in the pathogenesis of osteoporosis and could be used as potential biomarkers or targets in the diagnosis and treatment of osteoporosis.

scholarly journals Microarray Expression Profile and Functional Analysis of Circular RNAs in Osteosarcoma

2017 ◽  
Vol 43 (3) ◽  
pp. 969-985 ◽  
Author(s):  
Weihai Liu ◽  
Jiajun Zhang ◽  
Changye Zou ◽  
Xianbiao Xie ◽  
Yongqian Wang ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Expression Profile ◽  
Differentially Expressed ◽  
Circular Rnas ◽  
Global Changes ◽  
Osteosarcoma Cell ◽  
Comprehensive Understanding ◽  
Potential Target

Background/Aims: Osteosarcoma (OS) is the most common primary malignant bone tumor in children and adolescents. However, the molecular mechanisms regulating osteosarcoma tumorigenesis and progression are still poorly understood. Circular RNAs (circRNAs) have been identified as microRNA sponges and are involved in many important biological processes. This study aims to investigate the global changes in the expression pattern of circRNAs in osteosarcoma and provide a comprehensive understanding of differentially expressed circRNAs. Methods: Microarray based circRNA expression was determined in osteosarcoma cell lines and compared with hFOB1.19, which was used as the normal control. We confirmed the microarray data by real time-qPCR in both osteosarcoma cell lines and tissues. The circRNA/microRNA/mRNA interaction network was predicted using bioinformatics. Gene Ontology analysis and 4 annotation tools for pathway analysis (KEGG, Biocarta, PANTHER and Reactome) were used to predict the functions of differentially expressed circRNAs. Results: We revealed a number of differentially expressed circRNAs and 12 of them were confirmed, which suggests a potential role of circRNAs in OS. Among these differentially expressed circRNAs, hsa_circRNA_103801 was up-regulated in both osteosarcoma cell lines and tissues, while hsa_circRNA_104980 was down-regulated. The most likely potential target miRNAs for hsa_circRNA_103801 include hsa-miR-370-3p, hsa-miR-338-3p and hsa-miR-877-3p, while the most potential target miRNAs of hsa_circRNA_104980 consist of hsa-miR-1298-3p and hsa-miR-660-3p. Functional analysis found that hsa_circRNA_103801 was involved in pathways in cancer, such as the HIF-1, VEGF and angiogenesis pathway, the Rap1 signaling pathway and the PI3K-Akt signaling pathway, while hsa_circRNA_104980 was related to some pathways such as the tight junction pathway. Conclusions: This study has identified the comprehensive expression profile of circRNAs in osteosarcoma for the first time. And the ceRNA network prediction and bioinformatics functional analysis could provide a comprehensive understanding of hsa_circRNA_103801 and hsa_circRNA_104980, which may be involved in the initiation and progression of osteosarcoma. The present study indicates that circRNAs may play important roles in osteosarcoma and thus serve as biomarkers of osteosarcoma diagnosis and treatment.

Analysis Of Gene Expression Profile In SUDHL6 Cells Of siRNA-Mediated BCL11A Downregulation

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3780-3780
Author(s):  
Hong Wu ◽  
He Dongmei ◽  
Ding Li ◽  
Yangqiu Li
Keyword(s):  
Gene Expression ◽  
B Cell ◽  
Signaling Pathway ◽  
Gene Expression Profile ◽  
Differentially Expressed Genes ◽  
Expression Profile ◽  
B Cell Lymphoma ◽  
Negative Control ◽  
Differentially Expressed ◽  
Qrt Pcr

Abstract Background The B-cell chronic lymphocytic leukemia (CLL)/lymphoma 11A gene (BCL11A) was associated with hematopoietic malignancies. However, the precise function of this transcription factor in B-cell malignancies still remain poorly characterized. Previous work from our laboratory has shown that BCL11A gene by small interfering RNA (siRNA) resulted in the growth inhibition and apoptosis of the B cell lymphoma cell line (i.e., SUDHL6 and EB1). The aim of this study was to further elucidate the molecular mechanism of this process by analyzing the gene expression profile in SUDHL6 cells after BCL11A knockdown. Methods FBCL11A siRNA was transfected into SUDHL6 cells to knock down BCL11A expression. Cells were collected, and RNA isolated for transcriptional profiling using the Affymetrix HG-U133 Plus 2.0 array. The global gene expression profile of the BCL11A siRNA-treated SUDHL6 cells was identified and analyzed. Twenty-one differentially expressed genes were further validated and analyzed from the BCL11A siRNA-treated SUDHL6 cells by real-time quantitative reverse transcript-polymerase chain reaction (qRT-PCR). Results FThere were 659 genes differentially expressed between the BCL11A siRNA- and negative control-transfected cells. These included 294 upregulated genes and 365 downregulated genes. The differentially expression genes are involved in various signaling pathways including metabolic pathways, focal adhesion, the MAPK signaling pathway, the cell cycle, the JAK-STAT signaling pathway, the TGF-beta signaling pathway, the WNT signaling pathway, apoptosis, and BCR signaling. qRT-PCR validation of the selected differentially expressed genes demonstrated agreement with the microarray analysis. There was a significant difference in the relative expression level of most of the selected genes differentially expressed between the BCL11A siRNA- and negative control siRNA-treated cells (P<0.05). After the transfection of BCL11A siRNA, among the apoptosis-related genes in the BCL-2 family, BCL2L11 was upregulated 7.24-fold, and BCL-2 was downregulated 3.23-fold. Conclusions Our results indicate that BCL11A is involved in gene networks with cancer related functions. BCL11A may play a role in gene expression events related to apoptosis. Disclosures: Li: This work was supported by Grants from National Natural Science Foundation of China (30871091 and 91129720), the Collaborated grant for HK-Macao-TW of Ministry of Science and Technology (2012DFH30060), the Guangdong Science & Technology Project (2012B0506: Research Funding.

scholarly journals miRNA Expression Characterizes Histological Subtypes and Metastasis in Penile Squamous Cell Carcinoma

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1480
Author(s):  
Hiresh Ayoubian ◽  
Joana Heinzelmann ◽  
Sebastian Hölters ◽  
Oybek Khalmurzaev ◽  
Alexey Pryalukhin ◽  
...  
Keyword(s):  
Microarray Data ◽  
Expression Patterns ◽  
Hpv Infection ◽  
Differentially Expressed ◽  
Histological Subtypes ◽  
Specific Expression ◽  
Tissue Samples ◽  
Qrt Pcr ◽  
Differentially Expressed Mirnas ◽  
The Impact

Although microRNAs are described as promising biomarkers in many tumor types, little is known about their role in PSCC. Thus, we attempted to identify miRNAs involved in tumor development and metastasis in distinct histological subtypes considering the impact of HPV infection. In a first step, microarray analyses were performed on RNA from formalin-fixed, paraffin-embedded tumor (22), and normal (8) tissue samples. Microarray data were validated for selected miRNAs by qRT-PCR on an enlarged cohort, including 27 tumor and 18 normal tissues. We found 876 significantly differentially expressed miRNAs (p ≤ 0.01) between HPV-positive and HPV-negative tumor samples by microarray analysis. Although no significant differences were detected between normal and tumor tissue in the whole cohort, specific expression patterns occurred in distinct histological subtypes, such as HPV-negative usual PSCC (95 differentially expressed miRNAs, p ≤ 0.05) and HPV-positive basaloid/warty subtypes (247 differentially expressed miRNAs, p ≤ 0.05). Selected miRNAs were confirmed by qRT-PCR. Furthermore, microarray data revealed 118 miRNAs (p ≤ 0.01) that were significantly differentially expressed in metastatic versus non-metastatic usual PSCC. The lower expression levels for miR-137 and miR-328-3p in metastatic usual PSCC were validated by qRT-PCR. The results of this study confirmed that specific miRNAs could serve as potential diagnostic and prognostic markers in single PSCC subtypes and are associated with HPV-dependent pathways.

scholarly journals The role of ferroptosis in breast cancer patients: a comprehensive analysis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Zeng-Hong Wu ◽  
Yun Tang ◽  
Hong Yu ◽  
Hua-Dong Li
Keyword(s):  
Breast Cancer ◽  
T Cell ◽  
Signaling Pathway ◽  
Differentially Expressed Genes ◽  
Function Analysis ◽  
Cancer Prognosis ◽  
Differentially Expressed ◽  
Immune Checkpoints ◽  
Cell Functions

AbstractBreast cancer (BC) affects the breast tissue and is the second most common cause of mortalities among women. Ferroptosis is an iron-dependent cell death mode that is characterized by intracellular accumulation of reactive oxygen species (ROS). We constructed a prognostic multigene signature based on ferroptosis-associated differentially expressed genes (DEGs). Moreover, we comprehensively analyzed the role of ferroptosis-associated miRNAs, lncRNAs, and immune responses. A total of 259 ferroptosis-related genes were extracted. KEGG function analysis of these genes revealed that they were mainly enriched in the HIF-1 signaling pathway, NOD-like receptor signaling pathway, central carbon metabolism in cancer, and PPAR signaling pathway. Fifteen differentially expressed genes (ALOX15, ALOX15B, ANO6, BRD4, CISD1, DRD5, FLT3, G6PD, IFNG, NGB, NOS2, PROM2, SLC1A4, SLC38A1, and TP63) were selected as independent prognostic factors for BC patients. Moreover, T cell functions, including the CCR score, immune checkpoint, cytolytic activity, HLA, inflammation promotion, para-inflammation, T cell co-stimulation, T cell co-inhibition, and type II INF responses were significantly different between the low-risk and high-risk groups of the TCGA cohort. Immune checkpoints between the two groups revealed that the expressions of PDCD-1 (PD-1), CTLA4, LAG3, TNFSF4/14, TNFRSF4/8/9/14/18/25, and IDO1/2 among others were significantly different. A total of 1185 ferroptosis-related lncRNAs and 219 ferroptosis-related miRNAs were also included in this study. From the online database, we identified novel ferroptosis-related biomarkers for breast cancer prognosis. The findings of this study provide new insights into the development of new reliable and accurate cancer treatment options.

scholarly journals Microarray Profiling of TGF-β1-Induced Long Non-Coding RNA Expression Patterns in Human Lung Bronchial Epithelial BEAS-2B Cells

2018 ◽  
Vol 50 (6) ◽  
pp. 2071-2085 ◽  
Author(s):  
Wentao Hu ◽  
Weiwei Pei ◽  
Lin Zhu ◽  
Jing Nie ◽  
Hailong Pei ◽  
...  
Keyword(s):  
Human Lung ◽  
Expression Patterns ◽  
Differentially Expressed ◽  
Bronchial Epithelial ◽  
Qrt Pcr ◽  
Microarray Profiling ◽  
Underlying Mechanisms ◽  
Pathway Analyses ◽  
Trans Regulation ◽  
Tgf Β1

Background/Aims: TGF-β1 mediated radiation-induced bystander effects (RIBE) have been linked with malignant transformation and tumorigenesis. However, the underlying mechanisms are not fully understood. Methods: To reveal new molecules of regulatory functions in this process, lncRNA microarray was performed to profile both lncRNA and mRNA expression patterns in human lung bronchial epithelial BEAS-2B cells treated with TGF-β1 at a concentration measured in the medium conditioned by directly irradiated BEAS-2B cells. The potential functions of the differentially expressed lncRNAs were predicted by GO and KEGG pathway analyses of their co-expressed mRNAs. Cis- and trans-regulation of the lncRNAs were analyzed and the interaction networks were constructed using Cytoscape. qRT-PCR was conducted to validate the results of microarray profiling. CCK-8 assay was employed for functional validation of 3 identified lncRNAs. Results: 224 lncRNAs were found to be dysregulated, among which 6 lncRNAs were chosen for expression validation by qRT-PCR assay. Pathway analyses showed that differentially expressed lncRNAs are highly correlated with cell proliferation, transformation, migration, etc. Trans-regulation analyses showed that the differentially expressed lncRNAs most likely participate in the pathways regulated by four transcriptional factors, FOS, STAT3, RAD21 and E2F1, which have been identified to be involved in the modulation of oncogenic transformation, cell cycle progression, genomic instability, etc. lnc-THEMIS-2 and lnc-ITGB6-4, predicted to be regulated by STAT3 and E2F1 respectively, were found to rescue the decrease of cell viability induced by TGF-β1 treatment. Conclusion: Our findings suggest that the differentially expressed lncRNAs induced by TGF-β1 play crucial roles in the oncogenic transformation and tumorigenesis, which provide a better understanding of the underlying mechanisms related to tumorigensis induced by LD/LDR radiations.

Regional variations in ABC transporter expression along the mouse intestinal tract

2004 ◽  
Vol 17 (1) ◽  
pp. 11-20 ◽  
Author(s):  
David M. Mutch ◽  
Pascale Anderle ◽  
Muriel Fiaux ◽  
Robert Mansourian ◽  
Karine Vidal ◽  
...  
Keyword(s):  
Gene Expression ◽  
Abc Transporter ◽  
Expression Profile ◽  
Abc Transporters ◽  
Intestinal Tract ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Assessment Model ◽  
Differentially Expressed ◽  
Distal Intestine

The ATP-binding cassette (ABC) family of proteins comprise a group of membrane transporters involved in the transport of a wide variety of compounds, such as xenobiotics, vitamins, lipids, amino acids, and carbohydrates. Determining their regional expression patterns along the intestinal tract will further characterize their transport functions in the gut. The mRNA expression levels of murine ABC transporters in the duodenum, jejunum, ileum, and colon were examined using the Affymetrix MuU74v2 GeneChip set. Eight ABC transporters (Abcb2, Abcb3, Abcb9, Abcc3, Abcc6, Abcd1, Abcg5, and Abcg8) displayed significant differential gene expression along the intestinal tract, as determined by two statistical models (a global error assessment model and a classic ANOVA, both with a P < 0.01). Concordance with semiquantitative real-time PCR was high. Analyzing the promoters of the differentially expressed ABC transporters did not identify common transcriptional motifs between family members or with other genes; however, the expression profile for Abcb9 was highly correlated with fibulin-1, and both genes share a common complex promoter model involving the NFκB, zinc binding protein factor (ZBPF), GC-box factors SP1/GC (SP1F), and early growth response factor (EGRF) transcription binding motifs. The cellular location of another of the differentially expressed ABC transporters, Abcc3, was examined by immunohistochemistry. Staining revealed that the protein is consistently expressed in the basolateral compartment of enterocytes along the anterior-posterior axis of the intestine. Furthermore, the intensity of the staining pattern is concordant with the expression profile. This agrees with previous findings in which the mRNA, protein, and transport function of Abcc3 were increased in the rat distal intestine. These data reveal regional differences in gene expression profiles along the intestinal tract and demonstrate that a complete understanding of intestinal ABC transporter function can only be achieved by examining the physiologically distinct regions of the gut.

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