Biology subjects

Zorlutuna, P.

Publications and source records attributed to Zorlutuna, P..

At least 19 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

3D Bioprinted Fat-Myocardium Model Unravels the Role of Adipocyte Hypertrophy in Atrial Dysfunction

Cardiovascular diseases (CVD) are the leading cause of mortality in individuals with obesity. Epicardial adipose tissue (EAT) dysfunction serves as a link between obesity and CVD, promoting inflammatory and metabolic alterations that increase CVD risk. While EAT normally supports cardiac health, obesity-induced adipocyte hypertrophy triggers excessive fatty acid and cytokine release, driving myocardial lipotoxicity and inflammation that impair electrophysiology and metabolism, leading to beating irregularities, insulin resistance, and heart failure. The lack of sufficient EAT in small animal models and the impracticality of using large mammals hinder insights into the effects of EAT hypertrophy on the myocardium. To address this gap, a human-derived 3D bioprinted coculture of obese adipocytes and cardiomyocytes (CMs) is developed using patient-derived adipocytes and human induced pluripotent stem cell (hiPSC)-derived atrial CMs (a-iCMs). This platform enables the investigation of both cell-cell and paracrine interactions between hypertrophic adipocytes and a-iCMs, allowing assessment of electrophysiological, structural, and proteomic changes to uncover mechanisms linking EAT hypertrophy to obesity-related atrial dysfunction. Screening of metformin, a cardioprotective drug, reveals improvement in electrophysiological function in hypertrophic adipocyte-a-iCM cultures. 3D bioprinted fat-myocardium model provides a high-throughput platform to study obesity-induced atrial dysfunction and facilitate discovery of therapies for the obese heart.

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↗

bioRxiv2025

Instant fluorescence lifetime imaging microscopy reveals mechano-metabolic reprogramming of stromal cells in breast cancer peritumoral microenvironments

The breast peritumor microenvironment (pTME) is increasingly recognized as a mediator of breast cancer progression and treatment resistance. However, if and how growth-induced tumor compressive forces (i.e., solid stresses) influence the breast pTME remains unclear. Here we show using instant fluorescence lifetime imaging microscopy (FLIM)--a frequency-domain FLIM system capable of simultaneous image acquisition and instantaneous data processing--that breast tumor-mimicking in vitro compression promotes metabolic changes in stromal cells found in the breast pTME. Namely, compression shifts NIH3T3 fibroblasts and differentiated 3T3-L1 (d3T3-L1) adipocytes toward a more glycolytic state, while it promotes increased oxidative phosphorylation in 3T3-L1 undifferentiated adipocytes. The gold-standard Seahorse extracellular flux assay fails to capture these changes, underscoring the superior sensitivity of instant FLIM in detecting metabolic shifts. We validate these phenotypic findings at the transcriptomic level via RNA sequencing, confirming that compressed fibroblasts downregulate oxidative phosphorylation and upregulate glycolysis compared to uncompressed controls. We further demonstrate that compression induces mitochondrial dysregulation in undifferentiated adipocytes, driven in part by upregulated mitophagy and disrupted fusion dynamics. Finally, we confirm that these stromal cell types recapitulate these distinct metabolic states in human breast cancer patient samples, consistent with our in vitro findings. By elucidating mechano-metabolic interactions occurring at the tumor-host interface, these results will inform the development of innovative mechano-metabolic reprogramming treatment strategies to improve breast cancer patient survival.

biochemistry↗

bioRxiv2024

Small Extracellular Vesicles Isolated from Cardiac Tissue Matrix or Plasma Display Distinct Aging-Related Changes in Cargo Contributing to Chronic Cardiovascular Disease

Aging is a major risk factor for cardiovascular disease, the leading cause of death worldwide, and numerous other diseases, but the mechanisms of these aging-related effects remain elusive. Recent evidence suggests that chronic changes in the microenvironment and local paracrine signaling are major drivers of these effects, but the precise effect of aging on these factors remains understudied. Here, for the first time, we directly compare extracellular vesicles obtained from young and aged patients to identify therapeutic or disease-associated agents, and directly compare vesicles isolated from heart tissue matrix (TEVs) or plasma (PEVs). While young TEVs and PEVs showed notable overlap of miRNA cargo, aged EVs differed substantially, indicating differential aging-related changes between TEVs and PEVs. TEVs overall were uniquely enriched in miRNAs which directly or indirectly demonstrate cardioprotective effects, with 45 potential therapeutic agents identified in our analysis. Both populations also showed increased predisposition to disease with aging, though through different mechanisms. Changes in PEV cargo were largely correlated with chronic systemic inflammation, while those in TEVs were more related to cardiac homeostasis and local inflammation. From this, 17 protein targets were identified which were unique to TEVs and highly correlated with aging and the onset of cardiovascular disease. Further analysis via machine learning techniques implicated several new miRNA and protein targets, independently suggesting several of the targets identified by non-machine learning analysis, which correlated with aging-related changes in TEVs. With further study, this biomarker set may serve as a powerful, potential indicator of cardiac health and age which can be measured from PEVs. Additionally, several proposed "young-enriched" therapeutic agents were validated and, when tested, could successfully prevent cell death and cardiac fibrosis in disease-like conditions.

bioinformatics↗

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↗

bioRxiv2023

Adult Human Heart ECM Improves Human iPSC-CM Function via Mitochondrial and Metabolic Maturation

Myocardial infarction can lead to the loss of billions of cardiomyocytes, and while cell-based therapies are a promising option, the immature nature of in vitro-generated human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iCMs) is a significant roadblock to their development. Through the years, various approaches have emerged to improve iCM maturation, yet none could fully recapitulate the complexity of cardiac development and were not enough to achieve full cardiac maturity in vitro. Cardiac differentiation occurs at the early stages of development in a highly dynamic environment. Although significantly improved over the past two decades, small molecule-based iPSC differentiation protocols dont go beyond producing high purity fetal iCMs. Recently adult extracellular matrix (ECM) was shown to retain tissue memory and has shown some success in driving tissue-specific differentiation in unspecified cells in various organ systems. Therefore, here, we first characterized the adult human heart left ventricle components. We then investigated the effect of adult human heart-derived ECM on iPSC cardiac differentiation and subsequent maturation. By preconditioning iPSCs with ECM, we tested whether creating a cardiac environment around iPSCs would drive them toward cardiac fate before small molecule mediated differentiation. Ultimately, we investigated ECM components that might be responsible for the observed effects. We identified critical glycoproteins and proteoglycans involved in early cardiac development in the adult heart ECM. Namely, adult ECM had extracellular galactin-1, fibronectin, fibrillins, and basement-membrane-specific heparan-sulfate proteoglycan (HSPG), which have been implicated in normal heart development and associated with various embryonic developmental processes. Relatedly, we showed that preconditioning iPSCs with adult ECM resulted in enhanced cardiac differentiation, yielding iCMs with higher functional maturity. Further investigation revealed that a more developed mitochondrial network and coverage as well as enhanced metabolic maturity and a shift towards a more energetic profile allowed the observed functional enhancement in ECM pretreated iCMs. These findings demonstrate the potential of using cardiac ECM for promoting iCM maturation and suggest a promising strategy for improving the development of iCM-based therapies and in vitro cardiac disease modeling and drug screening studies. Upon manipulating ECM, such as heat denaturation and sonication to eliminate protein components and release ECM bound vesicle contents, respectively, we concluded that the beneficial effects that we observed are not solely due to the ECM proteins, and might be related to the decorative units attached to them.

bioengineering↗

bioRxiv2023

Aged Breast Matrix Bound Vesicles Promote Breast Cancer Invasiveness

Aging is one of the inherent risk factors for breast cancer. Although the influence of age-related cellular alterations on breast cancer development has been extensively explored, little is known about the alterations in the aging breast tissue microenvironment, specifically the extracellular matrix (ECM). Here, for the first time in literature, we have identified tissue resident matrix bound vesicles (MBVs) within the healthy mouse breast ECM, investigated and compared their characteristics in young and aged healthy breast tissues, and studied the effects of these MBVs on normal (KTB21) and cancerous (MDA-MB-231) human mammary epithelial cells with respect to the tissue age that they are extracted from. Using vesicle labeling technology, we were able to visualize cellular uptake of the MBVs directly from the native decellularized tissue sections, showing that these MBVs have regulatory roles in the tissue microenvironment. We mimicked the ECM by embedding the MBVs in collagen gels, and showed that MBVs could be taken up by the cells. The miRNA and cytokine profiling showed that MBVs shifted towards a more tumorigenic and invasive phenotype with age, as evidenced by the more pronounced presence of cancer-associated cytokines, and higher expression levels of oncomiRs miR-10b, miR-30e, and miR-210 in MBVs isolated from aged mice. When treated with MBVs or these upregulated factors, KTB21 and MDA-MB-231 cells showed significantly higher motility and invasion compared to untreated controls. Treatment of cells with a cocktail of miRNAs (miR-10b, miR-30e, and miR-210) or with the agonist of adiponectin (AdipoRon), which both were enriched in the aged MBVs, recapitulated the effect of aged MBVs on cells. This study shows for the first time that the MBVs have a regulatory role in the tissue microenvironment and that the MBV contents change towards cancer-promoting upon aging. Studying the effects of MBVs and their cargos on cellular behavior could lead to a better understanding of the critical roles of MBVs played in breast cancer progression and metastasis.

bioengineering↗

bioRxiv2023

In Need of Age-Appropriate Cardiac Models: Impact of Cell Age on Extracellular Matrix Therapy Outcomes

Aging is the main risk factor for cardiovascular disease (CVD). As the worlds population ages rapidly and CVD rates rise, there is a growing need for physiologically relevant models of aging hearts to better understand cardiac aging. Translational research relies heavily on young animal models, however, these models correspond to early ages in human life, therefore cannot fully capture the pathophysiology of age-related CVD. Here, we chronologically aged human induced pluripotent stem cell-derived cardiomyocytes (iCMs) and compared in vitro iCM aging to native human cardiac tissue aging. We showed that 14-month-old advanced aged iCMs had an aging profile similar to the aged human heart and recapitulated age-related disease hallmarks. We then used aged iCMs to study the effect of cell age on the young extracellular matrix (ECM) therapy, an emerging approach for myocardial infarction (MI) treatment and prevention. Young ECM decreased oxidative stress, improved survival, and post-MI beating in aged iCMs. In the absence of stress, young ECM improved beating and reversed aging-associated expressions in 3-month-old iCMs while causing the opposite effect on 14-month-old iCMs. The same young ECM treatment surprisingly increased SASP and impaired beating in advanced aged iCMs. Overall, we showed that young ECM therapy had a positive effect on post-MI recovery, however, cell age was determinant in the treatment outcomes without any stress conditions. Therefore, "one-size-fits-all" approaches to ECM treatments fail, and cardiac tissue engineered models with age-matched human iCMs are valuable in translational basic research for determining the appropriate treatment, particularly for the elderly.

bioengineering↗

bioRxiv2022

Maternal obesity driven changes in collagen linearity of breast extracellular matrix induces invasive mammary epithelial cell phenotype

Obesity has been linked with numerous health issues as well as an increased risk of breast cancer. Although effects of direct obesity in patient outcomes is widely studied, effects of exposure to obesity-related systemic influences in utero has been overlooked. In this study, we investigated the effect of multigenerational obesity on epithelial cell migration and invasion using decellularized breast tissues explanted from normal female mouse pups from a diet induced multigenerational obesity mouse model. We first studied the effect of multigenerational diet on the mechanical properties, adipocyte size, and collagen structure of these mouse breast tissues, and then, examined the migration and invasion behavior of normal (KTB-21) and cancerous (MDA-MB-231) human mammary epithelial cells on the decellularized matrices from each diet group. Breast tissues of mice whose dams had been fed with high-fat diet exhibited larger adipocytes and thicker and curvier collagen fibers, but only slightly elevated elastic modulus and inflammatory cytokine levels. MDA-MB-231 cancer cell motility and invasion were significantly greater on the decellularized matrices from mice whose dams were fed with high-fat diet. A similar trend was observed with normal KTB-21 cells. Our results showed that the collagen curvature was the dominating factor on this enhanced motility and stretching the matrices to equalize the collagen fiber linearity of the matrices ameliorated the observed increase in cell migration and invasion in the mice that were exposed to a high-fat diet. Previous studies indicated an increase in serum leptin concentration for those children born to an obese mother. We generated extracellular matrices using primary fibroblasts exposed to various concentrations of leptin. This produced curvier ECM and increased breast cancer cell motility for cells seeded on the decellularized ECM generated with increasing leptin concentration. Our study shows that exposure to obesity in utero is influential in determining the extracellular matrix structure, and that the resultant changes in collagen curvature is a critical factor in regulating the migration and invasion of breast cancer cells.

bioengineering↗

bioRxiv2022

Age and Sex-Dependent Differences in Human Cardiac Matrix-Bound Exosomes Modulate Fibrosis through Synergistic miRNA Effects

Aging is a risk factor for cardiovascular disease, the leading cause of death worldwide. Cardiac fibrosis is a harmful result of repeated myocardial infarction that increases risk of morbidity and future injury. Interestingly, rates of cardiac fibrosis are different between young and aged individuals, as well as men and women. Here, for the first time, we identify and isolate matrix-bound extracellular vesicles from the left ventricles (LVs) of young or aged men and women. These LV vesicles (LVVs) show differences in morphology and content between these four cohorts. LVVs effects on fibrosis were also investigated in vitro, and it was shown that aged male LVVs were pro-fibrotic, while other LVVs were anti-fibrotic. miRNAs identified from these LVVs could partially recapitulate these effects together, but not individually, and confer other benefits. These data suggest that synergistic effects of matrix-resident exosomal miRNAs may influence the differential clinical response to MI.

bioengineering↗

bioRxiv2021

Tunable human myocardium derived decellularized extracellular matrix for 3D bioprinting and cardiac tissue engineering

The generation of 3D tissue constructs with multiple cell types and matching mechanical properties remains a challenge in cardiac tissue engineering. Recently, 3D bioprinting has become a powerful tool to achieve these goals. Decellularized extracellular matrix (dECM) is a common scaffold material due to providing a native biochemical environment. Unfortunately, dECMs low mechanical stability prevents usage for bioprinting applications alone. In this study, we developed bioinks composed of decellularized human heart ECM (dhECM) with either gelatin methacryloyl (GelMA) or GelMA- methacrylated hyaluronic acid (MeHA) hydrogels dual crosslinked with UV light and microbial Transglutaminase (mTGase). We characterized the bioinks mechanical, rheological, swelling, printability and biocompatibility properties. Composite GelMA-MeHA-dhECM (GME) hydrogels demonstrated improved mechanical properties by an order of magnitude, compared to GelMA-dhECM (GE) hydrogels. All hydrogels were extrudable and compatible with human induced pluripotent stem cells derived cardiomyocytes (iCMs) and human cardiac fibroblasts (hCFs). Tissue-like beating of the printed constructs with striated sarcomeric alpha-actinin and Connexin 43 expression was observed. The order of magnitude difference between the elastic modulus of these hydrogel composites offers applications in in vitro modelling of the myocardial infarct boundary. Here, as a proof of concept, we created an infarct boundary region with control over mechanical properties along with cellular and macromolecular content through printing iCMs with GE bioink and hCFs with GME bioink.

bioengineering↗

bioRxiv2020

Aged Breast Extracellular Matrix Drives Mammary Epithelial Cells to an Invasive and Cancer-Like Phenotype

Age is a major risk factor for cancer. While the importance of age related genetic alterations in cells on cancer progression is well documented, the effect of aging extracellular matrix (ECM) has been overlooked. Here, we show for the first time that the aging breast ECM is sufficient to drive normal mammary epithelial cells (KTB21) to a more invasive and cancer-like phenotype, while promoting motility and invasiveness in MDA-MB-231 cells. E-cadherin membrane localization was lost in KTB21 cells cultured on the decellularized breast matrix from aged mice. Cell motility, cell invasion, and inflammatory cytokine and cancer-related protein production were increased significantly on the aged matrix, and many genes related to invasion were upregulated. Strikingly, we showed using single cell RNA sequencing that the aged matrix led to enrichment of a subpopulation of KTB21 cells that highly expressed epithelial-mesenchymal transition (EMT) and invasion-related genes. Lysyl oxidase (LOX) knockdown reverted the aged matrix-induced changes to the young levels; LOX siRNA treatment prevented the loss of E-cadherin membrane localization, and reduced cell motility, cell invasion, and cytokine and cancer-related protein production. Finally, we showed that the biophysical, mechanical and biochemical properties of the breast ECM were altered dramatically upon aging. Analyzing these factors and studying the differential response of the epithelial cells to young and aged ECMs could lead to identification of new targets for cancer treatment and could pave the way for the discovery of new therapeutic options.

cancer biology↗

bioRxiv2020

Effect of Cellular and ECM Aging on Human iPSC-derived Cardiomyocyte Performance, Maturity and Senescence

Cardiovascular diseases are the leading cause of death worldwide and their occurrence is highly associated with age. However, lack of knowledge in cardiac tissue aging is a major roadblock in devising novel therapies. Here, we studied the effects of cell and cardiac extracellular matrix (ECM) aging on the induced pluripotent stem cell (iPSC)-derived cardiomyocyte cell state, function, as well as response to myocardial infarction (MI)-mimicking stress conditions in vitro. Within 3-weeks, young ECM promoted proliferation and drug responsiveness in young cells, and induced cell cycle re-entry, and protection against stress in the aged cells. Adult ECM improved cardiac function, while aged ECM accelerated the aging phenotype, and impaired cardiac function and stress defense machinery of the cells. In summary, we have gained a comprehensive understanding of cardiac aging and highlighted the importance of cell-ECM interactions. This study is the first to investigate the individual effects of cellular and environmental aging and identify the biochemical changes that occur upon cardiac aging.

bioengineering↗

bioRxiv2020

Tissue failure propagation as mediated by circulatory flow

Aging is driven by subcellular processes that are relatively well-understood. However the qualitative mechanisms and quantitative dynamics of how these micro-level failures cascade to a macro-level catastrophe in a tissue or organs remain largely unexplored. Here we experimentally and theoretically study how cell failure propagates in a synthetic tissue in the presence of advective flow. We argue that cells secrete cooperative factors, thereby forming a network of interdependence governed by diffusion and flow, which fails with a propagating front parallel to advective circulation. SIGNIFICANCEMortality rates typically increase for complex organisms as they age. This leads us to suggest that aging depends on interactions between cells. As cells become damaged, the effect propagates to other cells, eventually leading to a systemic catastrophe. Yet it is unclear how this failure dynamically propagates. Here we present experiments with synthetic tissues and analogous analytical models to investigate the dynamics of failure propagation. Our main contribution is a detailed investigation of failure propagation when interactions are mediated by advective flow. We find analytical expressions for when a pronounced propagation occurs, its velocity, and acceleration in terms of system parameters.

biophysics↗