Glomerular podocytes are highly differentiated cells that are key components of the kidney filtration units. The podocyte cytoskeleton builds the basis for the dynamic podocyte cytoarchitecture and plays a central role for proper podocyte function. Recent studies implicate that immunosuppressive agents including the mTOR-inhibitor everolimus have a protective role directly on the stability of the podocyte cytoskeleton. To elucidate mechanisms underlying mTOR-inhibitor mediated cytoskeletal rearrangements, we carried out microarray gene expression studies to identify target genes and corresponding pathways in response to everolimus. We analyzed the effect of everolimus in a puromycin aminonucleoside experimental in vitro model of podocyte injury. Upon treatment with puromycin aminonucleoside, microarray analysis revealed gene clusters involving cytoskeletal-associated pathways, adhesion, migration and extracellular matrix composition to be affected. Everolimus is capable of protecting podocytes from injury, both on the transcriptome and protein level. Rescued genes included TUBB2B and DCDC2, both involved in microtubule structure formation in neuronal cells but not identified in podocytes so far. Confirming gene expression data, Western-blot analysis in cultured podocytes showed an increase of TUBB2B and DCDC2 protein after everolimus treatment, and immunohistochemistry in healthy control kidneys confirmed a podocyte-specific expression. Microtubule-inhibitor experiments led to a maldistribution of TUBB2B and DCDC2 as well as an aberrant reorganization of the actin cytoskeleton. Tubb2bbrdp/brdp mice showed a delay in glomerular podocyte and capillary development. Taken together, our study suggests that off-target, non-immune mediated effects of the mTOR-inhibitor everolimus on the podocyte cytoskeleton might involve regulation of microtubules, revealing a potential novel role of TUBB2B and DCDC2 in glomerular podocyte development
Everolimus Stabilizes Podocyte Microtubules via Enhancing TUBB2B and DCDC2 Expression.
Specimen part, Treatment
View SamplesComparison of Mpl-/- mouse LSK cells, either treated with control (GFP) or Mpl lentivirus. Lineage negative bone marrow cells were isolated and transduced and transplanted into Mpl-/- recipient mice. After transplantation and follow up mice were sacrificed and LSK (lineage negative, Sca-1 positive, cKit positive) cells were isolated by FACS. RNA was isolated using RNeasy Micro Kit (Qiagen GmbH, Hilden, Germany) and RNA was amplified for microarray hybridization using the Nugen Ovation system (Nugen Technologies, AC Bemmel, Netherlands). The resulting material was hybridized to Affymetrix Mouse 430 2.0 arrays. RMA normalization and summarization was performed in R 2.10 using Bioconductor packages. The aim was to show the normalization of Mpl associated gene expression.
Lentiviral gene transfer regenerates hematopoietic stem cells in a mouse model for Mpl-deficient aplastic anemia.
Specimen part
View SamplesIn this study we investigated the changes in mRNA expression upon treatment of SH-SY5Y cells to 10M cisplatin for 72h.
Calcium-regulatory proteins as modulators of chemotherapy in human neuroblastoma.
Specimen part, Cell line, Treatment
View SamplesMultiple myeloma (MM) is a clonal plasma cell disorder frequently accompanied by hematopoietic impairment. Genomic profiling of distinct HSPC subsets revealed a consistent deregulation of signaling cascades, including TGF beta signaling, p38MAPK signaling and pathways involved in cytoskeletal organization, migration, adhesion and cell cycle regulation in MM patients.
Multiple myeloma-related deregulation of bone marrow-derived CD34(+) hematopoietic stem and progenitor cells.
Specimen part, Disease, Disease stage
View Samples