Biology subjects

Hawthorne, L.

Publications and source records attributed to Hawthorne, L..

6 recordsLinked to original sources

bioRxiv2026

Doxorubicin-induced Cardiotoxicity is Propagated by Paracrine Signaling through Small Extracellular Vesicles

Cardiovascular disease (CVD) is the leading cause of death in the United States and worldwide. While most of these deaths are the result of chronic heart diseases, some CVDs are induced artificially. Doxorubicin (DOX) is a chemotherapeutic that is commonly used to treat breast cancer which is one of the most common types of cancer in the United States. While DOX is an effective anti-cancer agent, over 10% of treated women show signs of acute cardiotoxicity immediately following treatment, and approximately 2% develop severe cardiotoxicity up to 10 years after the end of treatment. Despite this prevalence, the mechanism by which the onset of this cardiotoxicity occurs over time is not well understood. Here, we show that treatment of cardiac cells with DOX changes the cardiac function and the resulting paracrine signaling profile. Subsequent exposure of healthy cells to these altered paracrine agents can recapitulate the effects of direct DOX exposure in 2D and 3D in vitro models. We suggest that this is the result of an altered paracrine miRNA profile and other paracrine factors that propagate the initial disruption caused by direct DOX exposure. Plasma EV miRNA profiling of blinded patient samples revealed distinct clustering by DOX-cardiotoxicity risk, with high-risk patients exhibiting miRNA signatures similar to those from DOX-treated tissue-engineered models. Pathway analysis of the most distinguishing miRNAs linked them to cardiac homeostasis and cardiotoxicity-related mechanisms, supporting the potential of plasma EV miRNAs as noninvasive biomarkers for early risk stratification and personalized cardioprotective interventions in oncological care, and the targeting of key clusters of miRNAs to enhance both understanding of and intervention strategies for preventing the onset of DOX cardiotoxicity.

bioengineering↗

bioRxiv2025

Mitochondria Clearance Enables Macrophage-Driven Maturation of iPSC-Derived Cardiomyocyte Metabolism

Generation of functional engineered myocardial tissue remains a challenge, owing in part to lacking maturity of stem cell-derived cardiomyocytes. Current strategies to mature these cells fall short of achieving in vivo-like physiology. Macrophages, members of the innate immune system, reside in the heart and exert positive effects on cardiomyocyte function. We hypothesized that developmentally informed addition of macrophages to cardiomyocytes would improve their maturity. While some recent studies have added macrophages to stem cell-derived models of the human myocardium, these previous approaches do not replicate the early colonization of the heart. Addition of macrophages to developing cardiomyocytes 8 days after the start of differentiation significantly alters cardiomyocyte behavior. We show that macrophages drive improvements in metabolic capabilities of cardiomyocytes. Developing cardiomyocytes shed lowly polarized mitochondria, adopt a new mitochondria network architecture, and develop more active mitophagy programs after >20 days coculture with macrophages. This interaction is dependent on macrophage MerTK reception of cardiomyocyte-derived mitochondria material. These results inform our understanding of the responsibility of macrophages in the development of the myocardium, and we hope that these interactions can be leveraged to produce more physiologically relevant models of the human myocardium.

bioengineering↗

bioRxiv2025

Hybrid In Vivo Breast Cancer Model Reveals Transcriptomic Insights into Cancer Progression with Age

Aging is a key risk factor for breast cancer, yet the independent role of the extracellular matrix (ECM) in tumor progression remains understudied. Recent studies have investigated healthy mammary tissue and aging to understand their relationship; however, the independent effects of the aged ECM remain understudied. Herein, we describe a hybrid in vivo model where MCF10A ductal carcinoma (DCIS.com) cells - with or without knockdown of select targets - were seeded onto decellularized ECM from aged murine mammary glands and implanted into the mammary fat pads of young Rag1-/- mice. Knockdown of selected targets, IL1B and LOX, reduced tumor growth on aged matrices in vivo and P4HA1 knockdown enhanced tumor growth. Additionally, analysis of LOX on aged ECM highlighted LOX as a driver of tumor progression where knockdown reduced transcriptomic programs related to invasion and cellular stress. To isolate the individual ECM influence on tumor growth, MCF10A cells were seeded atop young or aged matrices where it was found that tumors grown on the aged ECM after implantation exhibited significantly greater volume and a larger tumorigenic region when compared to those from the young ECM. Furthermore, single cell RNA-sequencing revealed transcriptional enrichment of inflammatory and invasive genes within the aged matrix. Together, these results identify LOX as a driver of tumor progression and potential therapeutic target, and demonstrate that the aged ECM alone can promote breast cancer progression

bioengineering↗

bioRxiv2025

Substrate Stiffness Modulates Fibroblast Extracellular Vesicle Secretion via Mechanotransduction Pathways

The extracellular matrix (ECM) is recognized as a key regulator of cell behavior, with its stiffness playing a crucial role in the progression of pathological conditions such as cancer and cardiovascular diseases. While extracellular vesicles (EVs) are essential mediators of intercellular communication, the influence of matrix stiffness on EV secretion remains poorly understood. This study investigates how substrate stiffness affects EV size and composition in mouse mammary and cardiac fibroblasts, the key stromal cell types in breast cancer and cardiac microenvironments. Importantly, we uncovered stiffness-tuned EV proteomic cargo, providing new insights into how mechanical cues can reprogram the signaling functions of fibroblast-derived vesicles. Our findings show that substrate stiffness significantly alters EV characteristics, with sizes increasing below stiffnesses of 20 kPa and decreasing on stiffer substrates. Mechanotransduction pathways involving p53 and thioredoxin were identified as regulators of these alterations, with thioredoxin dominating the modulation in mammary fibroblasts and p53 in cardiac fibroblasts. These results underscore the importance of ECM stiffness in modulating EV secretion and highlight candidate pathways influenced by ECM remodeling that may warrant further investigation for therapeutic relevance.

bioengineering↗

bioRxiv2024

Investigating the impact of fibroblast proximity to a tumor on fibroblast extracellular vesicle production utilizing 3D bioprinted stromal models

Extracellular vesicles (EVs) are an important carrier of cellular communication that are secreted from the cell. Different cells will produce EVs with different cargo such as cytokines, RNAs, or microRNAs (miRNA). EVs have been proven to play an important role in breast cancer tumorigenesis, progression, and metastasis. Although the role of cancer associated fibroblasts (CAFs), and EVs originated from them have been studied extensively, there is a lack in knowledge on the contribution of normal fibroblasts surrounding the tumor and their roles with respect to their proximity to the tumor. Here we investigate how the proximity of the tumor affects the EV production of the normal fibroblasts. We created stromal models by 3D bioprinting two different fibroblasts, normal human mammary fibroblasts (hMFs) and normal tumor adjacent fibroblasts (NTAF), within a collagen gel. After one week of culture, we isolated EVs from both the effluent media and the 3D stromal model, which were then characterized using nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), ELISA, zeta potential, and cytokine array analysis of the cargo. The EVs from each group were of consistent exosome size and displayed traditional exosome markers, however the EVs from different groups also displayed different cytokine profiles of their cargo, with the NTAF media group showing an upregulation of cytokines associated with breast cancer progression. After this, we used the EVs to treat breast cancer cells to investigate the effects the EVs from different tumor proximities have on the breast cancer cell behavior. The breast cancer cells treated with the NTAF groups had increased migration. Finally, we utilized a 3D breast tumor model to investigate the effects of the EVs on a tumor spheroid. Tumor spheroids treated with either NTAF EV groups showed increased proliferation, tumor radius, and local invasion. This study is the first to investigate the effect of proximity to a breast tumor on EV production and the first to utilize 3D bioprinting of stromal models specifically to obtain EVs. Overall, our results show that EVs from normal fibroblasts closer to a tumor produce EVs that promote breast cancer progression, regardless of the secretion location of the EVs. These cells have a distinct EV secretome different from normal human mammary fibroblasts, showing that the proximity to a tumor influences the normal fibroblasts surrounding the tumor.

bioengineering↗

bioRxiv2024

Engineered Age-Mimetic Breast Cancer Models Reveal Differential Drug Responses in Young and Aged Microenvironments

Aging is one of the most significant risk factors for breast cancer. With the growing interests in the alterations of the aging breast tissue microenvironment, it has been identified that aging is related to tumorigenesis, invasion, and drug resistance. However, current pre-clinical disease models often neglect the impact of aging and sometimes result in worse clinical outcomes. In this study, we utilized aged animal-generated materials to create and validate a novel age-mimetic breast cancer model that generates an aging microenvironment for cells and alters cells towards a phenotype found in the aged environment. Furthermore, we utilized the age-mimetic models for 3D breast cancer invasion assessment and high-throughput screening of over 700 drugs in the FDA-approved drug library. We identified 36 potential effective drug targets and 34 potential drug targets with different drug responses in different age groups, demonstrating the potential of this age-mimetic breast cancer model for further in-depth breast cancer studies and drug development.

bioengineering↗