Project description:Beta-hydroxybutyrate (BHB) is a ketone body synthesized during fasting or strenuous exercise. Our previous study demonstrated that a cyclic ketogenic diet (KD), which induces BHB levels similar to fasting every other week, reduces midlife mortality and improves memory in aging mice. BHB actively regulates gene expression and inflammatory activation through non-energetic signaling pathways. Neither of these activities has been well-characterized in the brain and they may represent mechanisms by which BHB affects brain function during aging. First, we analyzed hepatic gene expression in an aging KD-treated mouse cohort using bulk RNA-seq. In addition to the downregulation of TOR pathway activity, cyclic KD reduces inflammatory gene expression in the liver. We observed via flow cytometry that KD also modulates age-related systemic T cell functions. Next, we investigated whether BHB affects brain cells transcriptionallyin vitro. Gene expression analysis in primary human brain cells (microglia, astrocytes, neurons) using RNA-seq shows that BHB causes a mild level of inflammation in all three cell types. However, BHB inhibits the more pronounced LPS-induced inflammatory gene activation in microglia. Furthermore, we confirmed that BHB similarly reduces LPS-induced inflammation in primary mouse microglia and bone marrow-derived macrophages (BMDMs). BHB is recognized as an inhibitor of histone deacetylase (HDAC), an inhibitor of NLRP3 inflammasome, and an agonist of the GPCR Hcar2. Nevertheless, in microglia, BHB's anti-inflammatory effects are independent of these known mechanisms. Finally, we examined the brain gene expression of 12-month-old male mice fed with one-week and one-year cyclic KD. While a one-week KD increases inflammatory signaling, a one-year cyclic KD reduces neuroinflammation induced by aging. In summary, our findings demonstrate that BHB mitigates the microglial response to inflammatory stimuli, like LPS, possibly leading to decreased chronic inflammation in the brain after long-term KD treatment in aging mice.
Project description:Studies of human fetal lung in explant culture and in isolated epithelial cells have demonstrated that both glucocorticoids and cyclic AMP promote differentiated alveolar type II cell phenotype as assessed by ultrastructural morphology and surfactant production. This project profiles changes in gene expression associated with hormone induced differentiation. Undifferentiated human fetal lung (13-20 wk) epithelial cells were cultured in serum-free medium (control) or with dexamethasone/8-Bromo cyclic AMP/isobutylmethylxanthine (DCI) to promote type II cell differentiation. RNA from five sets of experiments (10 samples) was evaluated using the U133A Affymetrix GeneChip set. Keywords: Hormone treatment
Project description:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:The goal of this study was to select the optimal myometrial cells for our high-throughput drug discovery assay, as well as determine the similarity or differences of myometrial cells to vascular smooth muscle cells (VSMCs)-the most common off-target of current myometrial therapeutics. RNA-seq was used to: 1) identify which myometrial cells retained the most similar transcriptome profile to native tissue, and 2) compare the uterine myometrial transcriptome to VSMCs in hopes of identifying a uterine-selective transcriptome that was “druggable” for tocolytic or uterotonic use. Four sources of myometrial cells were examined: 1) term pregnant human primary myometrial cells isolated from tissue biopsies obtained at the time of caesarean sections, 2) term pregnant mouse primary myometrial cells, 3) commercially-available immortalized pregnant human myometrial (PHM1) cells and 4) human telomerase immortalized myometrial (hTERT-HM) cells. Correlation analysis of aligned reads identified that the transcriptome of primary human myometrial and hTERT-HM cells showed 85% and 80% correlation, respectively, to human myometrial tissue and that the transcriptome of hTERT-HM and PHM1 cells is 90% or more correlative to human primary myometrial cells. The expression levels (fold-change) of contraction-associciated transcripts (OXTR, PTGFR, PTGS2 and GJA1) strongly correlated (r=0.93) between RNA sequencing and qRT-PCR analysis. Analysis of aligned reads among myometrial cells revealed the number of differentially expressed transcripts (fold-change≥2.0, adjusted p-value≤0.01) relative to primary human myometrial cells: hTERT-HM (946 upregulated and 2,351 downregulated), PHM1 (1,575 upregulated and 2,415 downregulated) and primary mouse myometrial cells (3,435 upregulated and 2,966 downregulated). Correlation analysis showed that the human primary myometrial cell transcriptome is over 90% similar to the transcriptome of VSMCs examined. A number of genes associated with smooth muscle contractile machinery (TPM1, TPM2, CNN1, CALD1, ACTA2 and PLN)were significantly (p≤0.01) upregulated (≥2-fold) in human primary myometrial compared to vascular SMCs. We identified 498 transcripts were identified as upregulated in human primary myometrial cells compared to all three VSMCs examined. Of these, the drug-gene interaction database identified 142 genes as druggable
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.