Squamous cell carcinomas (SCCs) are a common form of non-melanoma skin cancer, posing a significant health burden due to their invasive nature and metastatic potential. SCCs in the head and neck region are associated with increased morbidity and mortality, making it crucial to understand SCC tumor evolution to improve prevention and treatment strategies. The Lowry Lab identified hair follicle stem cells (HFSCs) as the cell of origin for SCCs, highlighting their metabolic flexibility. While SCCs primarily rely on the Warburg effect and lactate production via anaerobic glycolysis, deletion of lactate dehydrogenase (LDHA) in HFSCs does not prevent tumor progression. Instead, SCCs activate glutaminolysis, metabolizing glutamine via glutaminase (GLS) to support the TCA cycle. This study investigates whether dual inhibition of glycolysis and glutaminolysis can suppress SCC initiation and progression. Using K15CrePR mice, GLS and LDHA were deleted in HFSCs (GLSKO/LDHAKO), followed by DMBA/TPA-induced carcinogenesis. Notably, while single knockouts formed SCCs through compensatory mechanisms, dual knockouts abrogated tumor development. To pharmacologically recapitulate these findings, small-molecule inhibitors of GLS (CB839), LDHA (GSK), glutamine transporters (V-9302), and lactate transporters (AZD0095) were evaluated. Preliminary results from combined GLS and LDHA inhibition demonstrated delayed SCC formation and progression. This work offers insight into SCC tumorigenesis and supports combinatorial therapies for cancer treatment.

Quiescence, a reversible exit from the cell cycle, is required for proper formation of organs and tissues. This state can be reached through serum starvation (SS). Autophagy, a pathway in which cells sequester and degrade cellular material, is used in response to SS to support quiescent cells. However, as not all quiescent cells are SS, we sought to understand how autophagy is regulated in cells that become quiescent in response to signals beyond SS. Contact inhibition (CI) is quiescence under a nutrient-rich but limited space environment. Imaging and immunoblotting revealed that SS and CI primary human dermal fibroblasts (HDFs) accumulate autophagy proteins (LC3), autophagosomes, and autolysosomes as well as gain larger lysosomes. Upon re-entry into the cell cycle, autophagosome levels are strongly reduced, lysosomes shrink, and LC3 levels decrease. We discovered that the increase in LC3+ puncta and lipidated LC3 formed in CI likely reflects activation of a noncanonical autophagy pathway in which extracellular material is degraded, as LC3-II levels were reversed in CI mouse embryonic fibroblasts (MEFs) unable to perform LC3-associated endocytosis. Our findings show that CI MEFs endocytose extracellular material and degrade in lysosomes. CI MEFs unable to perform LC3-associated endocytosis also exhibit reduced viability. The findings suggest a model in which quiescent, CI MEFs activate noncanonical autophagy to engulf extracellular material that is stored in lysosomes until it is required for the cells’ bioenergetic needs.

In a previous study, we found a potentially protective effect of the novel pharmacological TREK-1 K+ channel agonist ML335 in mice against viral pneumonia, but whether this compound could also protect against bacterial pneumonia is unknown. Therefore, we designed a mouse model of live Pseudomonas aeruginosa (PA)-induced bacterial pneumonia by dividing mice into 3 experimental groups: (1) untreated/non-infected, (2) PAinfection (20 × 106 CFU/mouse), and PAinfection + ML335 (100μM, once daily). Both PA and ML335 were delivered intratracheally. Endpoint analysis in bronchoalveolar lavage fluid (BALF) at 48 hrs included quantification of the total cell count to determine the extent of immune cell infiltration (Diff-Quick stain), Reactive Oxygen Species production by BALF cells (DCFDA method) to evaluate oxidative stress, immunoglobulin M levels (ELISA) to assess alveolar-capillary barrier dysfunction, and cytokine concentrations (ELISA) to assess the molecular inflammatory response. Treatment with ML335 improved all these inflammatory endpoints. Mechanistically, fluorometric electric membrane potential (Em) measurements (FLIPR assays) from BALF cells revealed Em depolarization after PA infection, which could be counteracted by ML335 treatment.. Combined with our previous findings in viral pneumonia models, these results with PA lay the groundwork for exploring TREK-1 channel activation as a novel anti-inflammatory approach against a variety of infectious pulmonary insults.

Studies have explored the effects of electronic cigarette (EC) use on heart rate (HR) and heart rate variability (HRV), though noise can also confound these measures. When performing mouse exposures to understand EC usage, we noticed a click-noise. Synchronization Theory states external stimuli can induce physiological responses, so we applied this framework to assess whether noise could influence HR. We aimed to measure the sound intensity [dB] of the click-noise and compared it across exposure conditions. Floxed mice in the C57BL/6 background were implanted with telemetry devices recording electrocardiographic parameters, body temperature, and activity. Mice were exposed to EC (bluPLUS+, Tobacco, 2.4% nicotine), filtered air, and PBS (secondary control), with each event followed by a post-exposure period. The exposure protocol was repeated once a day, per week for 3 weeks. Noise intensity was measured using the SoundChek Device placed inside and outside the chamber. This device measured baseline noise, exposure noise (in each condition), and post-exposure noise. Bradycardic effects were observed in EC-exposed mice compared to Air. A significant difference in sound intensity was found between air and post-air (p <0.0001), PBS and Post-PBS (p <0.0001). There was no significant difference between exposure conditions. This data shows that noise remained constant between EC, PBS, and air exposure periods, so differences in HR effects induced by the various exposure conditions were not due to differences in the level of noise

1 in 4 Americans have MASLD. While it is reversible, it could have chronic implications. An important risk factor is the Western diet, lacking in the key nutrient choline. It is important to understand how choline deficiency affects cellular metabolism and epigenetics. This study seeks to understand how choline availability influences the competition for SAM in vLDL production or DNA/chromatin methylation. Infusing heavy-labeled methionine showed that SAM and 5-MTA levels increased in mice fed the CD diet compared to the control. Histological analyses indicated pathological differences in deficient mice, likely due to affected vLDL levels and decreased efficiency in fat export.