Biology subjects

Patterson, A. E.

Publications and source records attributed to Patterson, A. E..

4 recordsLinked to original sources

bioRxiv2026

Mitochondrial transfer mediates metabolic communication between beta cells and islet macrophages

Pancreatic islet macrophages support islet homeostasis and adapt their metabolic program in response to environmental cues, including beta cell released factors. Intercellular mitochondrial transfer is a biological process that modulates cellular responses. To test whether beta cells, which are strongly secretory, transfer mitochondria to islet macrophages, we generated mice with beta cell-specific expression of mitochondrial GFP (PhAMfloxIns1Cre). We demonstrate that beta cells transfer mitochondria to islet macrophages in vivo and in vitro. Diabetogenic stressors did not alter the frequency of mitochondrial transfer and macrophages containing beta cell-derived GFP exhibit increased protein synthesis rates. RNA-seq identified upregulation of activity-regulated cytoskeleton associated protein (Arc) in macrophages receiving beta cell-derived mitochondria, while disruption of actin cytoskeleton dynamics prevented mitochondrial transfer. Together, these findings identify mitochondrial transfer as a previously unrecognized mechanism of beta cell-macrophage communication that may contribute to islet homeostasis and immune regulation.

cell biology↗

bioRxiv2023

Inducing an oxidized redox-balance improves anti-tumor CD8+ T cell function

Cancer immunotherapy using antigen-specific CD8+ T cells depends on long-lasting anti-tumor function of the in vitro expanded T cells. T cell function is intricately linked to the activity of many metabolic pathways directly impacting the ability of CD8+ T cells to kill tumor cells. Metabolic conditioning in vitro better prepares CD8+ T cells for in vivo survival, tumor infiltration and tumor clearance. The mechanism underlying in vitro metabolic conditioning-induced augmented in vivo T cell function remains poorly understood. Here we show that metabolic conditioning of CD8+ effector T cells induces an oxidized cellular redox balance at least in part mediated by increased mitochondrial reactive oxygen species (ROS). This redox shift contributes to enhanced in vivo persistence and tumor clearance. In human tumour-infiltrating T cells, altering the redox balance ex-vivo reinvigorated pro-inflammatory cytokine production. Therefore, we believe that redox alterations present a targetable pathway to increase T cell-based anti-tumor immunotherapy efficacy.

immunology↗

bioRxiv2022

Deletion of carboxypeptidase E in beta cells disrupts proinsulin processing and alters beta cell identity in mice

Carboxypeptidase E (CPE) facilitates the conversion of prohormones into mature hormones and is highly expressed in multiple neuroendocrine tissues. Carriers of CPE mutations have elevated plasma proinsulin and develop severe obesity and hyperglycemia. We aimed to determine whether loss of Cpe in pancreatic beta cells disrupts proinsulin processing and accelerates development of diabetes and obesity in mice. Pancreatic beta cell-specific Cpe knockout mice ({beta}CpeKO; Cpefl/fl x Ins1Cre/+) lack mature insulin granules and have elevated proinsulin in plasma; however, glucose-and KCl-stimulated insulin secretion in {beta}CpeKO islets remained intact. High fat diet-fed {beta}CpeKO mice showed comparable weight gain and glucose tolerance compared to Wt littermates. Notably, beta-cell area was increased in chow-fed {beta}CpeKO mice and beta-cell replication was elevated in {beta}CpeKO islets. Transcriptomic analysis of {beta}CpeKO beta cells revealed elevated glycolysis and Hif1-target gene expression. Upon high glucose challenge, beta cells from {beta}CpeKO mice showed reduced mitochondrial membrane potential, increased reactive oxygen species, reduced MafA, and elevated Aldh1a3 transcript levels. Following multiple low-dose streptozotocin treatment, {beta}CpeKO mice had accelerated hyperglycemia with reduced beta-cell insulin and Glut2 expression. These findings suggest that Cpe and proper proinsulin processing are critical in maintaining beta cell function during the development of diabetes.

physiology↗

bioRxiv2020

Risk-related decision making evokes distinct brain activation patterns in reward evaluation regions in substance use naïve versus non-naïve adolescents

Identifying brain and behavioral precursors to substance use (SU) may guide interventions that delay initiation in youth at risk for SU disorders (SUD). Heightened reward-sensitivity and risk-taking may confer risk for SUD. In a longitudinal, prospective study, we characterized behavioral and neural profiles associated with reward-sensitivity and risk-taking in substance-naive adolescents, examining whether they differed as a function of SU initiation at 18- and 36-months follow-up. Adolescents (N=70; 11.1-14.0 years) completed a reward-related decision-making task (Wheel of Fortune (WOF)) while undergoing functional MRI. Measures of reward sensitivity (Behavioral Inhibition System-Behavioral Approach System; BIS-BAS), impulsive decision-making (delay discounting task), and SUD risk (Drug Use Screening Inventory, Revised (DUSI-R)) were collected at baseline. Baseline metrics were compared for youth who did (SI; n=27) and did not (SN; n=43) initiate SU at follow-up. While groups displayed similar discounting and risk taking behavior, SI youth showed more variable patterns of activation in left insular cortex during high-risk selections, and left anterior cingulate cortex in response to rewarded outcomes. SI participants scored higher on the DUSI-R and BAS subscales. Results suggest differences in brain regions critical in the development and experience of SUDs may precede SU and serve as a biomarker for SUD risk.

neuroscience↗