Publications by authors named "Agne Frismantiene"

The signaling events controlling proliferation, survival, and apoptosis during mammary epithelial acinar morphogenesis remain poorly characterized. By imaging single-cell ERK activity dynamics in MCF10A acini, we find that these fates depend on the average frequency of non-periodic ERK pulses. High pulse frequency is observed during initial acinus growth, correlating with rapid cell motility and proliferation.

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Combining single-cell measurements of ERK activity dynamics with perturbations provides insights into the MAPK network topology. We built circuits consisting of an optogenetic actuator to activate MAPK signaling and an ERK biosensor to measure single-cell ERK dynamics. This allowed us to conduct RNAi screens to investigate the role of 50 MAPK proteins in ERK dynamics.

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Cells of the stromal vascular fraction (SVF) of human adipose tissue have the capacity to generate osteogenic grafts with intrinsic vasculogenic properties. However, cultured adipose-derived stromal cells (ASCs), even after minimal monolayer expansion, lose osteogenic capacity in vivo. Communication between endothelial and stromal/mesenchymal cell lineages has been suggested to improve bone formation and vascularization by engineered tissues.

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Vascular smooth muscle cells (VSMCs) are the major cell type in blood vessels. Unlike many other mature cell types in the adult body, VSMC do not terminally differentiate but retain a remarkable plasticity. Fully differentiated medial VSMCs of mature vessels maintain quiescence and express a range of genes and proteins important for contraction/dilation, which allows them to control systemic and local pressure through the regulation of vascular tone.

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Vascular smooth muscle cells (SMCs) phenotypes span a reversible continuum from quiescent/contractile (differentiated) to proliferative/synthetic (dedifferentiated) enabling them to perform a diversity of functions that are context-dependent and important for vascular tone-diameter homeostasis, vasculogenesis, angiogenesis or vessel reparation after injury. Dysregulated phenotype modulation and failure to maintain/regain the mature differentiated and contractile phenotypic state is pivotal in the development of vascular diseases such as atherosclerosis and restenosis after angioplasty and coronary bypass grafting. Many functions of SMCs such as adhesion, migration, proliferation, contraction, differentiation and apoptosis are regulated by a broad spectrum of cell-cell and cell-matrix adhesion molecules.

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Vascular smooth muscle cell (SMC) switching between differentiated and dedifferentiated phenotypes is reversible and accompanied by morphological and functional alterations that require reconfiguration of cell-cell and cell-matrix adhesion networks. Studies attempting to explore changes in overall composition of the adhesion nexus during SMC phenotype transition are lacking. We have previously demonstrated that T-cadherin knockdown enforces SMC differentiation, whereas T-cadherin upregulation promotes SMC dedifferentiation.

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Autophagy is an evolutionary conserved intracellular catabolic process of vital importance to cell and tissue homeostasis. Autophagy is implicated in the pathogenesis of atherosclerosis but participating cells, molecular mechanisms and functional outcomes have not been fully elucidated. T-cadherin, an atypical glycosylphosphatidylinositol-anchored member of the cadherin superfamily of adhesion molecules, is upregulated on smooth muscle cells (SMCs) in atherosclerotic lesions.

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Article Synopsis
  • Stromal vascular fraction (SVF) cells from human fat tissue have the ability to create bone grafts with blood vessel-forming capabilities, but traditional adipose-derived stromal/stem cells (ASC) struggle to form bone when implanted.
  • By culturing ASC within a self-produced extracellular matrix (ECM) for 28 days without passaging (Unpass-ASC), they showed greater growth and differentiation compared to ASC that were expanded with regular passaging.
  • When tested in vivo, Unpass-ASC successfully generated bone tissue, while passaged ASC primarily produced fibrous tissue, highlighting the importance of ECM and integrin signaling in maintaining the bone-forming potential of ASC during cell culture.
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Participation of the cadherin superfamily of adhesion molecules in smooth muscle cell (SMC) phenotype modulation is poorly understood. Immunohistochemical analyses of arterial lesions indirectly suggest upregulated expression of atypical glycosylphosphatidylinositol-anchored T-cadherin on vascular SMCs as a molecular indicator of the dedifferentiated/proliferative phenotype. This study investigated the role of T-cadherin in SMC phenotypic modulation.

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Close relationships exist between presence of adiponectin (APN) within vascular tissue and expression of T-cadherin (T-cad) on vascular cells. APN and T-cad are also present in the circulation but here their relationships are unknown. This study investigates associations between circulating levels of high molecular weight APN (HMW-APN) and T-cad in a population comprising 66 women and 181 men with angiographically proven stable coronary artery disease (CAD).

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T-cadherin is an atypical glycosylphosphatidylinsoitol-anchored member of the cadherin superfamily of adhesion molecules. We found that T-cadherin overexpression in malignant (DU145) and benign (BPH-1) prostatic epithelial cell lines or silencing in the BPH-1 cell line, respectively, promoted or inhibited migration and spheroid invasion in collagen I gel and Matrigel. T-cadherin-dependent effects were associated with changes in cell phenotype: overexpression caused cell dissemination and loss of polarity evaluated by relative positioning of the Golgi/nuclei in cell groups, whereas silencing caused formation of compact polarized epithelial-like clusters.

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Expression of GPI-anchored T-cadherin (T-cad) on vascular smooth muscle cells (VSMC) is elevated in vascular disorders such as atherosclerosis and restenosis which are associated with insulin resistance. Functions for T-cad and signal transduction pathway utilization by T-cad in VSMC are unknown. The present study examines the consequences of altered T-cad expression on VSMC for constitutive and insulin-induced Akt/mTOR axis signaling and contractile competence.

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