Project description:We studied differences in epithelial thickness by histology and gene expression by Affymetrix gene arrays and PCR in the skin/fat of 10 obese (BMI 35-50) and 10 normal weight (BMI 18.5-26.9) postmenopausal women paired by age and race
Project description:Obesity is accompanied by dysfunction of many organs, but effects on the skin have received little attention. We studied differences in epithelial thickness by histology and gene expression by Affymetrix gene arrays and PCR in the skin of 10 obese (BMI 35-50) and 10 normal weight (BMI 18.5-26.9) postmenopausal women paired by age and ethnicity. Epidermal thickness did not differ with obesity but the expression of genes encoding proteins associated with skin blood supply and wound healing were altered. In the obese, many gene expression pathways were broadly downregulated and subdermal fat showed pronounced inflammation. There were no changes in skin microbiota or metabolites. African American subjects differed from European Americans with a trend to increased epidermal thickening. In obese African Americans, compared to obese European Americans, we observed altered gene expression that may explain known differences in water content and stress response. African Americans showed markedly lower expression of the gene encoding the cystic fibrosis transmembrane regulator characteristic of the disease cystic fibrosis. The results from this preliminary study may explain the functional changes found in the skin of obese subjects and African Americans.
Project description:Epithelial cells provide an initial line of defense against damage and pathogens in barrier tissues such as the skin; however this balance is disrupted in obesity and metabolic disease. Skin gamma delta T cells recognize epithelial damage and release cytokines and growth factors that facilitate wound repair. To determine the impact of obesity and metabolic disease on skin gamma delta T cells, we isolated skin gamma delta T cells from 10-week old C57BLKS/J lean db/+ and obese db/db animals for further study. Due to a deficiency in the leptin receptor (db), homozygous db/db animals do not process satiety signals, continually eat and develop severe obesity and metabolic disease. Skin gamma delta T cells isolated from these animals were compared for changes in mRNA expression using microarray. We have determined that obesity and metabolic disease negatively impacts homeostasis and functionality of skin gamma delta T cells, rendering host defense mechanisms vulnerable to injury and infection. The goal of this experiment was to compare skin gamma delta T cells in a control mouse to skin gamma delta T cells isolated from an obese mouse to see what homeostatic changes occur in obesity and metabolic disease. gamma delta T cells were isolated from two 10-week old lean db/+ control and two 10-week old obese db/db animals for comparison. We wanted to determine which growth factors and signaling pathways were altered in skin gamma delta T cells residing in the obese environment.
Project description:Epithelial cells provide an initial line of defense against damage and pathogens in barrier tissues such as the skin; however this balance is disrupted in obesity and metabolic disease. Skin gamma delta T cells recognize epithelial damage and release cytokines and growth factors that facilitate wound repair. To determine the impact of obesity and metabolic disease on skin gamma delta T cells, we isolated skin gamma delta T cells from 10-week old C57BLKS/J lean db/+ and obese db/db animals for further study. Due to a deficiency in the leptin receptor (db), homozygous db/db animals do not process satiety signals, continually eat and develop severe obesity and metabolic disease. Skin gamma delta T cells isolated from these animals were compared for changes in mRNA expression using microarray. We have determined that obesity and metabolic disease negatively impacts homeostasis and functionality of skin gamma delta T cells, rendering host defense mechanisms vulnerable to injury and infection.
Project description:The green algal Botryococcus braunii (Chlorophyte) is known for accumulating high levels of hydrocarbons that are a useful alternative to fossil fuels. B. braunii is categorized into three groups based on types of their accumulated hydrocarbons: alkadiene/triene in race A, botryococcenes in race B, and lycopadiene in race L. Transcriptomic studies in race A and race B have discovered tremendous information related to the genes encoding proteins involved in hydrocarbon biosynthesis. However, transcriptome of race L has not been reported. In this study, we report a transcriptome of race L B. braunii AC768 through the de novo assembly using Hiseq platform. Our analyses indicate that photosynthesis and protein biosynthesis are the most abundantly transcribed in actively growing race L B. braunii. We show that the transcriptome of race L shares similar amounts (~20%) of mutual best-hits with that of race A or race B. Sequence homologous analyses indicate that enzymes involved in squalene and phytoene biosynthesis are well separated into geranyl-diphosphate synthase, farnesyl-diphosphate synthase, geranylgeranyl-diphosphate synthase, phytoene synthase, and squalene synthase. Both B. braunii specific enzymes botryococcene synthase SSL3 and lycopaoctaene synthase LOS are found to form distinctive subgroups in the group of squalene synthase. One of the ESTs in AC768 transcriptome that falls into the subgroup with LOS and shares >88% identity with that of LOS. Together, our results show that SSL and LOS are unique to race B and race L B. braunii subspecies, respectively. We propose that phytoene synthase in race L shares higher homolog to squalene synthase than phytoene synthase in other algae.
Project description:Obesity and insulin resistance are associated with oxidative stress, which may be implicated in their progression. The kinase JNK1 emerged as a promising drug target for the treatment of obesity and type-2 diabetes. However, JNK1 is a key mediator of the oxidative stress response, promoting either cell dead or survival depending on magnitude and context of its activation. Furthermore, JNK inactivation shortens lifespan in drosophila and c. elegans. To learn on the safety and efficacy of long-term JNK inhibition in vertebrates, we investigated mice lacking JNK1 (JNK1-/-) exposed over a long period to an obesogenic high-fat diet (HFD). JNK1-/- mice chronically fed an HFD developed more skin oxidative damage because of reduced catalase expression, but also showed sustained protection from obesity, adipose tissue inflammation, steatosis, and insulin resistance, paralleled by decreased oxidative damage in fat and liver. We conclude that JNK1 is a relatively safe drug target for obesity-related diseases. RNA was collected from liver, skin and epididymal fat tissues from JNK1 KO mice and WT mice fed in high fat diet. Each condition was run in quadruplicate
Project description:To help elucidate the metabolic changes in the skin that contribute to the obesity resistance and skin pathology in mice lacking Scd1, we performed microarray analysis of skin gene expression in male skin Scd1 knockout (SKO) and Scd1 flox/flox control (Lox) mice fed a standard rodent diet. We identified an extraordinary number of differentially expressed genes that support the previously documented histological observations of sebocyte atrophy, inflammation and epidermal hyperplasia in SKO mice. Additionally, transcript levels were reduced in skin of SKO mice for genes involved in fatty acid synthesis, elongation and desaturation, which may be attributed to decreased abundance of key transcription factors including SREBP1c, ChREBP and LXR?. Conversely, genes involved in cholesterol synthesis were increased, suggesting an imbalance between skin fatty acid and cholesterol synthesis. Unexpectedly, we observed a robust elevation in skin retinol, retinoic acid and retinoic acid-induced genes in SKO mice. These results highlight the importance of monounsaturated fatty acid synthesis for maintaining retinol homeostasis and point to disturbed retinol metabolism as a novel contributor to the Scd1 deficiency-induced skin pathology. We analyzed dorsal skin gene expression in non-fasted 8-9 week old male skin Scd1 knockout (SKO) mice (n=3) and Scd1flox/flox (Lox) control mice (n=3)on a C57BL/6J background using Affymetrix 430 2.0 microarrays.
Project description:To help elucidate the metabolic changes in the skin that contribute to the obesity resistance and skin pathology in mice lacking Scd1, we performed microarray analysis of skin gene expression in male skin Scd1 knockout (SKO) and Scd1 flox/flox control (Lox) mice fed a standard rodent diet. We identified an extraordinary number of differentially expressed genes that support the previously documented histological observations of sebocyte atrophy, inflammation and epidermal hyperplasia in SKO mice. Additionally, transcript levels were reduced in skin of SKO mice for genes involved in fatty acid synthesis, elongation and desaturation, which may be attributed to decreased abundance of key transcription factors including SREBP1c, ChREBP and LXRα. Conversely, genes involved in cholesterol synthesis were increased, suggesting an imbalance between skin fatty acid and cholesterol synthesis. Unexpectedly, we observed a robust elevation in skin retinol, retinoic acid and retinoic acid-induced genes in SKO mice. These results highlight the importance of monounsaturated fatty acid synthesis for maintaining retinol homeostasis and point to disturbed retinol metabolism as a novel contributor to the Scd1 deficiency-induced skin pathology.