Cell populations with differing proliferative, stem-like and tumorigenic states co-exist in most tumors and especially malignant gliomas. Whether metabolic variations can drive this heterogeneity by controlling dynamic changes in cell states is unknown. Metabolite profiling of human adult glioblastoma stem-like cells upon loss of their tumorigenicity revealed a switch in the catabolism of the GABA neurotransmitter toward enhanced production and secretion of its by-product GHB (4-hydroxybutyrate). This switch was driven by succinic semialdehyde dehydrogenase (SSADH) downregulation. Enhancing GHB levels via SSADH downregulation or GHB supplementation triggered cell conversion into a less aggressive phenotypic state. GHB affected adult glioblastoma cells with varying molecular profiles, along with cells from pediatric pontine gliomas. In all cell types, GHB acted by inhibiting α-ketoglutarate-dependent Ten-eleven Translocations (TET) activity, resulting in decreased levels of the 5-hydroxymethylcytosine epigenetic mark. In patients, low SSADH expression was correlated with high GHB/α-ketoglutarate ratios, and distinguished weakly proliferative/differentiated glioblastoma territories from proliferative/non-differentiated territories. Our findings support an active participation of metabolic variations in the genesis of tumor heterogeneity.
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http://dx.doi.org/10.1007/s00401-016-1659-5 | DOI Listing |
J Dairy Sci
December 2024
Ruminant Nutrition and Emissions, Agroscope, 1700 Posieux, Switzerland. Electronic address:
Exhaled breath offers an interesting matrix of low invasive sampling of potentially relevant information about the organism's metabolism in the form of volatile organic compounds (VOC). The VOC can be exhaled by the ructus (Islam et al., 2023) or passed the blood-lung barrier for expiration through the lungs.
View Article and Find Full Text PDFProtein Sci
October 2024
Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
γ-Hydroxybutyric acid (GHB) analogs are small molecules that bind competitively to a specific cavity in the oligomeric CaMKIIα hub domain. Binding affects conformation and stability of the hub domain, which may explain the neuroprotective action of some of these compounds. Here, we describe molecular details of interaction of the larger-type GHB analog 2-(6-(4-chlorophenyl)imidazo[1,2-b]pyridazine-2-yl)acetic acid (PIPA).
View Article and Find Full Text PDFJ Anal Toxicol
September 2024
Office of the Chief Medical Examiner, 1 Newhall Street, San Francisco, California, United States.
A streamlined LC-MS/MS method utilizing protein precipitation and filtration extraction was developed to consolidate analyses for drug-facilitated crime (DFC), postmortem investigations, and driving under the influence of drugs (DUID) testing. Fifty-seven target drug and metabolite analytes eluted in under 6-minutes and compromised of GHB precursors (1), hallucinogens (3), muscle relaxants (3), anticonvulsants (7), antidepressants (20), antihistamines (5), antipsychotics (11), antihypertensives and alpha-adrenergics (3), analgesics and anesthetics (3), and miscellaneous (1) in blood (quantitatively) and urine (qualitatively). Limits of detection were set to meet the more challenging sensitivity requirements for DFC, and are therefore also suitable for postmortem investigations, and other forensic casework, including DUID.
View Article and Find Full Text PDFPharmacol Biochem Behav
November 2024
Seed Health, Inc., 2100 Abbot Kinney Blvd, Unit G, Venice, CA 90291, United States of America; Swiss Institute for Allergy & Asthma Research, Herman-Burchard Strasse 9, 7265 Davos Wolfgang, Graubünden, Switzerland. Electronic address:
The gut microbiome is a vast, variable, and largely unexplored component of human biology that sits at the intersection of heritable and environmental factors, and represents a rich source of novel chemistry that is already known to be compatible with the human body. This alone would make it a promising place to search for new therapeutics, but recent work has also identified gut microbiome abnormalities in patients with a number of psychiatric disorders, including anxiety disorders-suggesting that not only treatments, but cures may lie therein. Here, we'll discuss two known "para-endogenous" anxiolytics-γ-hydroxybutyrate and the neurosteroid allopregnanolone-which have recently been discovered to be produced by the microbiome.
View Article and Find Full Text PDFCell Chem Biol
October 2024
Departments of Cancer Biology and Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA. Electronic address:
BCL-w is a BCL-2 family protein that promotes cell survival in tissue- and disease-specific contexts. The canonical anti-apoptotic functionality of BCL-w is mediated by a surface groove that traps the BCL-2 homology 3 (BH3) α-helices of pro-apoptotic members, blocking cell death. A distinct N-terminal portion of BCL-w, termed the BCL-2 homology 4 (BH4) domain, selectively protects axons from paclitaxel-induced degeneration by modulating IP3 receptors, a noncanonical BCL-2 family target.
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