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Biology subjects

Finney, C.

Publications and source records attributed to Finney, C..

3 recordsLinked to original sources

The Lipid Hydrolase ABHD6 is a Therapeutic Target in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)-Related Hepatocellular Carcinoma

Primary liver cancer accounts for approximately 700,000 deaths worldwide annually ranking third in cancer-related mortality, with hepatocellular carcinoma (HCC) comprising the majority of these tumors. Metabolic dysfunction-associated steatotic liver disease (MASLD) is currently a leading cause of HCC in the United States. We previously identified the lipid hydrolase alpha/beta hydrolase domain 6 (ABHD6) as a key mediator of the development of metabolic syndrome and intimately involved in cell signaling, making it a prime target for investigation in MASLD-related HCC. ABHD6 displays higher expression within HCC tumor cores when compared to adjacent non-tumor liver tissue in human subjects. Using an in vivo antisense oligonucleotide (ASO)-driven knockdown approach, we have shown the inhibition of ABHD6 prevents the development and progression of HCC in an obesity/MASLD-driven mouse model. Additionally, a xenograft model using the human Huh7 cell line displayed reduced tumor engraftment and growth with ABHD6 genetic deletion and small molecule inhibition. ABHD6 knockout cells demonstrated increased levels of bis(monoacylglycerol)phosphates (BMPs), lipids relevant to high fat diet-induced lysosomal dysfunction, and knockout cells also demonstrated altered autophagy and lysosomal activity using in vitro model of saturated fatty acid-induced lipotoxicity. These studies reveal novel lipid signaling mechanisms by which MASLD progresses towards HCC and provide support for ABHD6 as a therapeutic target in HCC. SignificanceWe have identified that alpha/beta hydrolase domain 6 (ABHD6) plays a role in lysosomal membrane lipid remodeling pathways that are relevant in obesity/MASLD-driven HCC. Inhibitors targeting ABHD6 reorganize lysosomal lipid homeostasis to improve outcomes in HCC.

cancer biology↗

HMGB1 acts as an agent of host defense at the gut mucosal barrier

Mucosal barriers provide the first line of defense between internal body surfaces and microbial threats from the outside world.1 In the colon, the barrier consists of two layers of mucus and a single layer of tightly interconnected epithelial cells supported by connective tissue and immune cells.2 Microbes colonize the loose, outer layer of colonic mucus, but are essentially excluded from the tight, epithelial-associated layer by host defenses.3 The amount and composition of the mucus is calibrated based on microbial signals and loss of even a single component of this mixture can destabilize microbial biogeography and increase the risk of disease.4-7 However, the specific components of mucus, their molecular microbial targets, and how they work to contain the gut microbiota are still largely unknown. Here we show that high mobility group box 1 (HMGB1), the prototypical damage-associated molecular pattern molecule (DAMP), acts as an agent of host mucosal defense in the colon. HMGB1 in colonic mucus targets an evolutionarily conserved amino acid sequence found in bacterial adhesins, including the well-characterized Enterobacteriaceae adhesin FimH. HMGB1 aggregates bacteria and blocks adhesin-carbohydrate interactions, inhibiting invasion through colonic mucus and adhesion to host cells. Exposure to HMGB1 also suppresses bacterial expression of FimH. In ulcerative colitis, HMGB1 mucosal defense is compromised, leading to tissue-adherent bacteria expressing FimH. Our results demonstrate a new, physiologic role for extracellular HMGB1 that refines its functions as a DAMP to include direct, virulence limiting effects on bacteria. The amino acid sequence targeted by HMGB1 appears to be broadly utilized by bacterial adhesins, critical for virulence, and differentially expressed by bacteria in commensal versus pathogenic states. These characteristics suggest that this amino acid sequence is a novel microbial virulence determinant and could be used to develop new approaches to diagnosis and treatment of bacterial disease that precisely identify and target virulent microbes.

microbiology↗

Gut Microbe-Targeted Choline Trimethylamine Lyase Inhibition Improves Obesity Via Rewiring of Host Circadian Rhythms

Obesity has repeatedly been linked to reorganization of the gut microbiome, yet to this point obesity therapeutics have been targeted exclusively toward the human host. Here we show that gut microbe-targeted inhibition of the trimethylamine N-oxide (TMAO) pathway protects mice against the metabolic disturbances associated with diet-induced obesity (DIO) or leptin deficiency (ob/ob). Small molecule inhibition of the gut microbial enzyme choline TMA-lyase (CutC) does not reduce food intake, but is instead associated with beneficial remodeling of the gut microbiome, improvement in glucose tolerance, and enhanced energy expenditure. We also show that CutC inhibition is associated with reorganization of host circadian control of both phosphatidylcholine and energy metabolism. This study underscores the relationship between microbe and host metabolism, and provides evidence that gut microbe-derived trimethylamine (TMA) is a key regulator of the host circadian clock. This work also demonstrates that gut microbe-targeted enzyme inhibitors have untapped potential as anti-obesity therapeutics.

physiology↗