G protein coupled receptor (GPCR) signaling in osteoblasts (OBs) is an important regulator of bone formation. We previously described a mouse model expressing Rs1, an engineered constitutively active Gs-coupled GPCR, under the control of the 2.3 kb-Col I promoter. These mice showed a dramatic age-dependent increase in trabecular bone which were accompanied by an increase in OB lineage cells, especially immature OBs, indicated by an expansion of cells expressing Osterix and Runx2 in the whole femur. In this study, we further evaluated how Gs signaling in OBs affects intramembranous bone formation by examining calvariae of one-and nine-week-old Col1(2.3)/Rs1 mice. Rs1 calvariae displayed a dramatic increase in total volume and trabecular bone volume with partial loss of cortical structure. By immunohistochemistry, Osterix was detected in cells throughout the inter-trabecular space in Rs1 expressing mice while Osteocalcin was expressed predominantly in cells along bone surfaces. These findings resembled that previously seen in Rs1 femoral bones, suggesting the role of paracrine mediators secreted from OBs driven by 2.3 kb-Col I promoter could influence early OB commitment, differentiation, and/or proliferation. However, it is still unclear how G protein signaling in mature OBs leads to the observed alterations in bone mass. In this study, we investigated the cellular basis of the skeletal changes by assessing the effect of Rs1 expression in vivo on the transcriptome of mature OBs. We identified the complete set of Gs-GPCRs and other GPCRs that are expressed on OBs which may contribute to the observed skeletal phenotype. Candidate paracrine mediators of the effect of Gs signaling in OBs were determined. Genes affected by Rs1 signaling include those encoding proteins important for cell differentiation, cytokines and growth factors, angiogenesis, coagulation, and energy metabolism. Our results identify novel candidate mediators of the anabolic response to the skeleton to Gs signaling in mature OBs.
Assessing the osteoblast transcriptome in a model of enhanced bone formation due to constitutive Gs-G protein signaling in osteoblasts.
Specimen part
View SamplesPurpose: To investigate the effects of T cell-derived cytokines on gene and protein expression of chemokines in a human RPE cell line (ARPE-19).
Chemokine expression in retinal pigment epithelial ARPE-19 cells in response to coculture with activated T cells.
Specimen part, Cell line
View SamplesPurpose: The complement system is closely linked to the pathogenesis of age-related macular degeneration (AMD). Several complement genes are expressed in retinal pigment epithelium (RPE), and complement proteins accumulate in drusen. Further, a common variant of complement factor H (CFH) confers increased risk of developing AMD. Because the mechanisms by which changes in the function of CFH influence development of AMD are unclear, we examined ocular complement expression as a consequence of age in control and CFH null mutant mice.
Complement factor H deficiency results in decreased neuroretinal expression of Cd59a in aged mice.
Specimen part
View SamplesPurpose: Uveal melanoma (UM) is the most common primary intraocular tumor in adults and the presence of infiltrating leucocytes is associated with a poor prognosis. Little is known how infiltrating leucocytes influence the tumor cells. The purpose of this study was to investigate the effect of activated T cells on the expression of chemotactic cytokines in UM cells. Furthermore, we examined the ability of stimulated UM cells to attract monocytes.
Inflammation-induced chemokine expression in uveal melanoma cell lines stimulates monocyte chemotaxis.
Specimen part, Cell line
View SamplesIn this study we examined the effect of T cell-derived cytokines on retinal pigment epithelial (RPE) cells with respect to expression of complement components. We used an in vitro co-culture system in which CD3/CD28-activated human T cells were separated from the human RPE cell line (ARPE-19) by a membrane. Differential gene expression in the RPE cells of complement factor genes was identified using gene arrays, and selected gene transcripts were validated by q-RT-PCR. Protein expression was determined by ELISA and immunoblotting. Co-culture with activated T cells increased RPE mRNA and/or protein expression of complement components C3, factors B, H, H-like 1, CD46, CD55, CD59, and clusterin, in a dose-dependent manner. Soluble factors derived from activated T cells are capable of increasing expression of complement components in RPE cells. This is important for the further understanding of inflammatory ocular diseases such as uveitis and age-related macular degeneration.
Retinal pigment epithelial cells upregulate expression of complement factors after co-culture with activated T cells.
Disease, Disease stage
View SamplesPurpose
Chemokine Expression in Murine RPE/Choroid in Response to Systemic Viral Infection and Elevated Levels of Circulating Interferon-γ.
No sample metadata fields
View SamplesWe analyzed mRNAs in transiliacal bone biopsies from 7 patients with primary hyperparathyroidism using Affymetrix HG-U133A Gene Chips Similar analyses of the global transcriptional activity were repeated in a second bone biopsy from the same patient taken one year after surgery and reversal of disease parameters.
Abnormal muscle and hematopoietic gene expression may be important for clinical morbidity in primary hyperparathyroidism.
Sex, Age, Specimen part, Disease, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Metabolic pathway profiling of mitochondrial respiratory chain mutants in C. elegans.
No sample metadata fields
View SamplesUtilizing C. elegans as a model of mitochondrial dysfunction provides insight into cellular adaptations which occur as a consequence of genetic alterations causative of human disease. We characterized genome-wide expression profiles of hypomorhpic C. elegans mutants in nuclear-encoded subunits of respiratory chain complexes I, II and III.
Metabolic pathway profiling of mitochondrial respiratory chain mutants in C. elegans.
No sample metadata fields
View SamplesUtilizing C. elegans as a model of mitochondrial dysfunction provides insight into cellular adaptations which occur as a consequence of genetic alterations causative of human disease. We characterized genome-wide expression profiles of hypomorphic C. ele
Metabolic pathway profiling of mitochondrial respiratory chain mutants in C. elegans.
No sample metadata fields
View Samples