Publications by authors named "J G Letourneau"
Metabolites derived from the intestinal microbiota, including bile acids (BA), extensively modulate vertebrate physiology, including development, metabolism, immune responses and cognitive function. However, to what extent host responses balance the physiological effects of microbiota-derived metabolites remains unclear. Here, using untargeted metabolomics of mouse tissues, we identified a family of BA-methylcysteamine (BA-MCY) conjugates that are abundant in the intestine and dependent on vanin 1 (VNN1), a pantetheinase highly expressed in intestinal tissues.
View Article and Find Full Text PDFStudy Question: Is there an increased risk of reproductive or colon cancer in women with Turner syndrome and their family members?
Summary Answer: Our data suggest that there is an increased risk for sigmoid colon cancer in women with Turner syndrome and an increased prostate cancer risk in second- and third-degree male relatives.
What Is Known Already: Turner syndrome has been associated with lower risk of breast cancer, but increased risk of gonadoblastoma and colon cancer in some, but not all studies. There is also evidence for a genetic predisposition to sex chromosome aneuploidy, which may indicate a predisposition to Turner syndrome and the associated cancer risk in family members.
Autoimmune Disease is Increased in Women with Primary Ovarian Insufficiency.
J Clin Endocrinol Metab
November 2024
Article Synopsis
- - Researchers studied the link between autoimmune diseases and women with primary ovarian insufficiency (POI) using health records from Utah, finding that 25% of POI women had at least one autoimmune condition.
- - Women with POI showed significantly higher risks for several autoimmune diseases, with conditions like autoimmune hypothyroidism and vitiligo being particularly prevalent compared to the general population.
- - Interestingly, the study found no increased risk of autoimmune diseases in the family members of women with POI, suggesting environmental factors might play a role rather than genetic inheritance.
Article Synopsis
- Physical particles, specifically fecal particle size (FPS), are influenced by gut microbiomes in humans, highlighting their role as abiotic factors in microbial ecology.
- A study involving 76 individuals revealed that FPS is highly individualized and not significantly impacted by chewing efficiency or diet, contrary to initial assumptions.
- Findings indicate that gut microbiota diversity and composition, as well as factors like transit time, are critical in determining FPS, suggesting that the microbiome is essential for efficient digestion and energy extraction in the gastrointestinal tract.
Activation of the cGAS-STING pathway plays a key role in the innate immune response to cancer through Type-1 Interferon (IFN) production and T cell priming. Accumulation of cytosolic double-stranded DNA (dsDNA) within tumor cells and dying cells is recognized by the DNA sensor cyclic GMP-AMP synthase (cGAS) to create the secondary messenger cGAMP, which in turn activates STING (STimulator of INterferon Genes), resulting in the subsequent expression of IFN-related genes. This process is regulated by Three-prime Repair EXonuclease 1 (TREX1), a 3' → 5' exonuclease that degrades cytosolic dsDNA, thereby dampening activation of the cGAS-STING pathway, which in turn diminishes immunostimulatory IFN secretion.
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