ABSTRACT: Hydrocortisone and Triiodothyronine Regulate Hyaluronate Synthesis in a Tissue–Engineered Human Dermal Equivalent through Independent Pathways
Project description:Hydrocortisone (HC) and triiodothyronine (T3) have both been shown to be capable of independently inhibiting hyaluronate (HA, hyaluronic acid) synthesis in a self-assembled human dermal equivalent (human dermal matrix). We sought to investigate the action of these two hormones in concert on extracellular matrix formation and HA inhibition in a tissue engineered human dermal matrix.
Project description:Hydrocortisone (HC) and triiodothyronine (T3) have both been shown to be capable of independently inhibiting hyaluronate (HA, hyaluronic acid) synthesis in a self-assembled human dermal equivalent (human dermal matrix). We sought to investigate the action of these two hormones in concert on extracellular matrix formation and HA inhibition in a tissue engineered human dermal matrix. RNA preparations were sent to CFG Microarray Core (E). Three replicate samples from each condition were used in the study. The RNA was amplified, labeled, and hybridized to the GLYCOv4 microarrays.
Project description:Keloids are benign tumors of the dermis that form during a protracted wound healing process. Susceptibility to keloid formation occurs predominantly in people of African and Asian descent. The key alteration(s) responsible for keloid formation has not been identified and there is no satisfactory treatment for this disorder. The altered regulatory mechanism is limited to dermal wound healing, although several diseases characterized by an exaggerated response to injury are prevalent in individuals of African ancestry. We have observed a complex pattern of phenotypic differences in keloid fibroblasts grown in standard culture medium or induced by hydrocortisone. In this study Affymetrix-based microarray was performed on RNA obtained from fibroblasts cultured from normal scars and keloids grown in the absence and presence of hydrocortisone. We observed differential regulation of approximately 500 genes of the 38,000 represented on the Affymetrix chip. Of particular interest was increased expression of several IGF-binding and IGF-binding related proteins and decreased expression of a subset of Wnt pathway inhibitors and multiple IL-1-inducible genes. Increased expression of CTGF and IGFBP-3 was observed in keloid fibroblasts only in the presence of hydrocortisone. These findings support a role for multiple fibrosis-related pathways in the pathogenesis of keloids Keywords: cell-type comparison, drug treatment comparison Cell cultures were initiated from human biopsy material from normal dermal scars and keloids of adult males and females. Experimental cultures were derived from the first passage of cells thawed from liquid nitrogen. Cultures of fibroblasts from samples were grown with or without 1.5 micromolar hydrocortisone. RNA from each cell strain was isolated from three independent cell cultures and pooled, then run on an Affymetrix Human Genome U133 Plus 2.0 GeneChip.
Project description:We have prepared tissue engineered self assembled dermal equivalents with high similarity to the human dermis (skin). We have manipulated the culture conditions to prepare dermal equivalents with varying amounts of hyaluronic acid and potentially other glycosaminoglycans (GAGs). We are interested in using array technology to determine which genes responsible for carbohydrate and GAG (and if available protein/glycoprotein) synthesis are being either up-or down-regulated in these constructs as compared to a Normal base construct.
Project description:Keloids are benign tumors of the dermis that form during a protracted wound healing process. Susceptibility to keloid formation occurs predominantly in people of African and Asian descent. The key alteration(s) responsible for keloid formation has not been identified and there is no satisfactory treatment for this disorder. The altered regulatory mechanism is limited to dermal wound healing, although several diseases characterized by an exaggerated response to injury are prevalent in individuals of African ancestry. We have observed a complex pattern of phenotypic differences in keloid fibroblasts grown in standard culture medium or induced by hydrocortisone. In this study Affymetrix-based microarray was performed on RNA obtained from fibroblasts cultured from normal scars and keloids grown in the absence and presence of hydrocortisone. We observed differential regulation of approximately 500 genes of the 38,000 represented on the Affymetrix chip. Of particular interest was increased expression of several IGF-binding and IGF-binding related proteins and decreased expression of a subset of Wnt pathway inhibitors and multiple IL-1-inducible genes. Increased expression of CTGF and IGFBP-3 was observed in keloid fibroblasts only in the presence of hydrocortisone. These findings support a role for multiple fibrosis-related pathways in the pathogenesis of keloids Keywords: cell-type comparison, drug treatment comparison
Project description:Rationale: Despite shortening vasopressor use in shock, hydrocortisone administration remains controversial, with potential harm on the immune system. Few studies assessed hydrocortisone impact on the transcriptional response in shock, and we are lacking data in burns. Objectives: To assess the hydrocortisone-induced transcriptional modulation in severe burn shock, particularly on the immune response. Methods: We collected whole blood samples (n= 117) during a randomized controlled trial assessing the efficacy of hydrocortisone administration on burn shock. Using whole genome microarrays, we first compared burn patients from the placebo group (n=15) to healthy volunteers (n=13) to describe the transcriptional modulation induced by burn shock over the first week. Then we compared burn patients randomized for either hydrocortisone administration (n=15) or placebo (n=15) to assess hydrocortisone-induced modulation. Measurements and Main Results: Study groups were similar in terms of severity and major outcomes, but shock duration (significantly reduced in the hydrocortisone group). Many genes (n=2250) were differentially expressed between burn patients and healthy volunteers, with 85% of them exhibiting a profound and persistent modulation over seven days. Interestingly, we showed that hydrocortisone enhanced the shock-associated repression of adaptive, but also innate immunity. Conclusions: We found that the initial host response to burn shock encompasses a wide and persistent modulation of gene expression, with profound modulation of pathways associated with metabolism and immunity. Importantly, hydrocortisone administration may worsen the immunosuppression associated with severe injury. These data should be taken into account in the risk ratio of hydrocortisone administration in patients with inflammatory shock.
Project description:Mitochondria have an independent genome (mtDNA) and protein synthesis machinery that coordinately activate for mitochondrial generation. Here, we report that Krebs cycle intermediate, fumarate, connects metabolism to mitobiogenesis through binding to malic enzyme 2 (ME2). Proteomic profiling of ME2-interacting protein reveals that ME2 binds to mitoribosome proteins to regulate mitoribosome assembly and mtDNA-encoded protein production. ME2 also interacts with and modulates deoxyuridine 5-triphosphate nucleotidohydrolase activity to regulate thymidine generation and mtDNA abundance
Project description:Primary dermal fibroblasts from patients with dSSc and healthy controls were treated with TGF beta for up to 24h and the genome-wide patterns of gene expression measured on DNA microarrays. 894 genes were identified as TGF beta-responsive in 4 independent cultures of dermal fibroblasts (2 healthy control and 2 dSSc patients). The 894 genes in the TGF beta-responsive signature are associated with induction of growth factor signaling, collagen synthesis and extracellular matrix deposition.
Project description:Dermal papilla cells isolated from the human hair follicle are capable of inducing hair growth in recipient epithelia. However, demonstrating disparity from rodent dermal papilla, human cells lose this inductive competance immediately upon growth in culture under normal growth conditions. We grew dermal papilla cells in hanging drop cultures that are morphologically akin to intact dermal papilla, and found that by enhancing the environment for aggregation, we could restore the inductive capacity of human dermal papilla cells in culture. The underlying genes that regulate the inductive potential of dermal papilla cells is not well understood, and we sought to use global profiling to identify key genes and pathways related to inductive competance within dermal papilla cells. We used Affymetrix microarrays to profile human dermal papilla cells in both hair inducing, and non-hair inducing states.