Autophagy, a cellular degradation process, is crucial for maintaining cellular homeostasis and responding to various forms of stress. LC3-associated phagocytosis (LAP) is a non-canonical autophagy pathway in which the autophagy-associated protein LC3 is recruited to a single-membrane phagosome, mediating the engulfment and degradation of extracellular material. LAP is distinct from classical autophagy but shares key molecular machinery. Dendritic cells (DCs) residing in the TME are professional antigen-presenting cells that play a crucial role in anti-tumor immunity. Our study examines how LAP-deficient DCs respond to tumor stimuli. We used a mouse model carrying a point mutation (E230) in the Atg16l1 gene, which disrupts LAP specifically while preserving canonical autophagy. We differentiated DCs in vitro from bone marrow isolated from LAP+ or LAP- mice and from B16-F10 mouse melanoma cell lysates, and measured proinflammatory cytokine expression using RT-qPCR. Our results demonstrate that LAP- DCs express higher levels of proinflammatory cytokines than their LAP+ counterparts. To examine the effects of LAP deficiency in vivo, B16-F10 melanoma cells were injected into LAP- and LAP+ mice. Consistent with our in vitro findings, LAP- mice developed significantly smaller tumors. Together, these results suggest that LAP contributes to immunosuppression in the TME. This study highlights that LAP may be a potential target for novel immunotherapies that enhance DC activity to improve antitumor immune responses.

ZFP36L1 is a member of the ZFP36 family of RNA-binding proteins which post-transcriptionally regulate gene targets by binding to AU-rich elements (AREs) in the 3'UTR of mRNA. ZFP36 proteins have been identified as regulators of hepatic metabolic homeostasis, and ZFP36L1 was previously shown to target the low-density lipoprotein receptor (LDLR), a critical mediator of cholesterol metabolism, in vitro. We demonstrate that loss of hepatic ZFP36L1 in mice leads to upregulation of LDLR and reduction of plasma cholesterol. Given that LDLR plays a central role in clearance of circulating LDL, disruption of which can lead to atherosclerosis, we investigated whether hepatic ZFP36L1 contributes to atherogenesis. We demonstrate that loss of hepatic ZFP36L1 in a mouse model of atherosclerosis confers protection against atheromatous plaque formation, mediated through upregulation of LDLR in the absence of ZFP36L1. This implicates ZFP36L1 as an important mediator of LDLR, cholesterol homeostasis, and ultimately atherosclerosis. To elucidate the molecular mechanism underlying post-transcriptional regulation of LDLR by ZFP36L1, we cloned the Ldlr 3’UTR downstream of a luciferase construct and show that ZFP36L1 regulates Ldlr mRNA stability at canonical ARE binding sites. We generated antisense oligonucleotides (ASOs) against the AREs in the Ldlr 3’UTR to determine whether ZFP36L1 demonstrates preferential binding to a specific site. These findings reveal ZFP36L1 as an important regulator of LDLR within the context of atherosclerosis.

Bacterial pneumonia affects over one million patients annually in the United States and is commonly treated with supplemental oxygen (hyperoxia; HO), which can paradoxically worsen lung injury. Our lab has identified TREK-1 (K2P2.1), a two-pore domain potassium channel, as a new pharmacological target against hyperoxia- and influenza-induced lung injury. Here, we tested whether TREK-1 activation is protective in a clinically more relevant “two-hit” model combining Pseudomonas aeruginosa (PA) infection with HO exposure (PA+HO). As expected, mice infected with PA and exposed to HO developed moderate-severe lung injury, as evidenced by increased bronchoalveolar lavage fluid inflammatory cell infiltration, barrier dysfunction, ROS generation, and cytokine release. Intratracheal treatment of mice with novel TREK-1 activating compounds (ML335, BL1249) attenuated these effects. Mechanistically, PA+HO treatment of primary human alveolar epithelial cells resulted in TREK-1 downregulation, cell membrane depolarization, increased intracellular Ca²⁺ levels, and ROS and cytokine production. secretion. Pharmacological TREK-1 activation with ML335 and BL1249 restored the cell membrane potential, limited Ca²⁺ influx via voltage-gated Ca²⁺ channels and downstream ROS and IL-6 production in HAEC.  Therefore, pharmacological activation of residual TREK-1 K+ channels may represent a new therapeutic strategy against both viral and bacterial pneumonia, likely via cell membrane repolarization during acute inflammation.

Axon caliber (cross-sectional diameter) is critical to neuronal function because it directly influences the speed at which neurons send messages. Establishing a standard understanding of the determinants of axon caliber fluctuation will enable a deeper comprehension of related disease phenotypes associated with abnormal axon caliber, such as Giant Axonal Neuropathy. However, the current channels to measure axon caliber in vivo, and thus assess axon caliber variation, are limited. The preferred technique of in vivo axon caliber measurement, Peak-to-Peak (PTP), is highly accurate, but requires Super-Resolution (SR) imaging and is limited to larger axons. The inferior technique, Full Width at Half Maximum (FWHM), lacks precision, but can be applied to a greater variety of image qualities. By taking both types of measurements on the same developing neurons, we have drawn an experimental and mathematical comparison between these two caliber assessment techniques to determine a conversion factor that, when applied to FWHM measurements, prioritizes both precision and reduction of methodical constraints. As neurodegenerative disorder diagnoses continue to rise, research funding in the United States falls, meaning that resource optimization is the only path forward. Developing an accessible and robust technique for axon caliber measurement will enable greater research efforts for a lower cost.

Prostate cancer (PCa) exhibits significant biological and clinical heterogeneity across different racial and ethnic populations, yet Asian patients remain underrepresented in genomic studies. This project aims to characterize gene expression (GE) profiles in prostate tumors from Asian patients and compare them with reference datasets from White patients to better understand potential molecular differences. This ongoing study will aim to analyze the severity of PCa amongst 45 Asian samples, which will be subdivided according to ethnicity. Ethnicities studied include Chinese, Korean, Japanese, Taiwanese, Filipino, Indian, Armenian, Iranian, and Emirati. The samples are extracted from the UCLA SPORE fresh frozen tissue bank. Each case undergoes pathological evaluation, such as tumor content, cellularity, Gleason score assignment, presence of intraductal carcinoma (IDC), cribriform architecture, and tumor-infiltrating lymphocyte (TIL) annotation. To supplement pathological annotations, tumor DNA and RNA will be extracted from these samples. Downstream analyses will include differential gene expression and pathway enrichment, comparing Asian PCa profiles with those from White patients in TCGA’s reference database. By identifying unique features within Asian PCa, this study’s findings will contribute to understanding cancer disparities and minimizing the knowledge gap of how PCa affects Asian minorities.