title: Microarray analyses of glucocorticoid and vitamin D3 target genes in differentiating cultured human podocytes.
abstract: Glomerular podocytes are highly differentiated epithelial cells that are key components of the kidney filtration units. Podocyte damage or loss is the hallmark of nephritic diseases characterized by severe proteinuria. Recent studies implicate that hormones including glucocorticoids (ligand for glucocorticoid receptor) and vitamin D3 (ligand for vitamin D receptor) protect or promote repair of podocytes from injury. In order to elucidate the mechanisms underlying hormone-mediated podocyte-protecting activity from injury, we carried out microarray gene expression studies to identify the target genes and corresponding pathways in response to these hormones during podocyte differentiation. We used immortalized human cultured podocytes (HPCs) as a model system and carried out in vitro differentiation assays followed by dexamethasone (Dex) or vitamin D3 (VD3) treatment. Upon the induction of differentiation, multiple functional categories including cell cycle, organelle dynamics, mitochondrion, apoptosis and cytoskeleton organization were among the most significantly affected. Interestingly, while Dex and VD3 are capable of protecting podocytes from injury, they only share limited target genes and affected pathways. Compared to VD3 treatment, Dex had a broader and greater impact on gene expression profiles. In-depth analyses of Dex altered genes indicate that Dex crosstalks with a broad spectrum of signaling pathways, of which inflammatory responses, cell migration, angiogenesis, NF-κB and TGFβ pathways are predominantly altered. Together, our study provides new information and identifies several new avenues for future investigation of hormone signaling in podocytes.
authors.affiliation: Department of Biochemistry, School of Medicine, Case Western Reserve University (CWRU) and the Comprehensive Cancer Center of CWRU, Cleveland, Ohio, United States of America.
authors.forename: Xiwen
authors.initials: X
authors.lastname: Cheng
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhao
authors.forename: Simran
authors.initials: S
authors.lastname: Khurana
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Bruggeman
authors.forename: Hung-Ying
authors.initials: HY
authors.lastname: Kao
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D002762:Cholecalciferol / Q000494:pharmacology*; D016000:Cluster Analysis; D020869:Gene Expression Profiling / Q000379:methods; D005786:Gene Expression Regulation / Q000187:drug effects*; D053263:Gene Regulatory Networks; D005938:Glucocorticoids / Q000494:pharmacology*; D006801:Humans; D058977:Molecular Sequence Annotation; D050199:Podocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D059467:Transcriptome
chemical_list: D005938:Glucocorticoids; D002762:Cholecalciferol