Publications by authors named "Donna Stolz"

Extracellular vesicles (EVs) are an emerging class of drug carriers and are primarily reported to be internalized into recipient cells via a combination of endocytic routes such as clathrin-mediated, caveolae-mediated and macropinocytosis pathways. In this work, (1) we investigated potential effects of homotypic vs. heterotypic interactions by studying the cellular uptake of homologous EVs (EV donor cells and recipient cells of the same type) vs.

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  • TM6SF2 rs58542926 (E167K) is linked to an increased risk of metabolic liver disease, prompting the need for a human model to study the mutation's effects due to conflicting animal study results.
  • A human in vitro model was developed using gene editing on induced pluripotent stem cells, leading to observations of liver cell dysfunction, including lipid accumulation and reduced VLDL secretion associated with the mutation.
  • The model demonstrated similarities to human conditions, facilitating future research on potential clinical interventions by addressing protein misfolding and ER stress related to the TM6SF2-E167K mutation.
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  • Ischemic strokes disrupt mitochondrial function in brain endothelial cells, leading to long-term neurological issues.
  • A study found that using extracellular vesicles (EVs) from mouse brain endothelial cells (mBECs) showed better therapeutic effects in mouse models than those from human cells (hBECs).
  • mBEC-derived EVs enhanced ATP production and mitochondrial function while reducing brain damage and improving neurological outcomes in stroke-affected mice.
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  • - The study focused on KPC-Kp bloodstream infections, which are deadly, and aimed to understand how these bacteria resist a key defense mechanism in our blood, called complement.
  • - Researchers tested various KPC-Kp isolates from patients, discovering that 27% of them resisted killing by human serum; a specific gene mutation (wcaJ) linked to capsule production contributed to this resistance.
  • - This mutation resulted in less capsule presence, paradoxically increasing the bacteria's ability to bind complement proteins while also improving their survival against immune responses, potentially allowing them to thrive in the bloodstream without being overly virulent in tissues.
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Non-neovascular or dry age-related macular degeneration (AMD) is a multi-factorial disease with degeneration of the aging retinal-pigmented epithelium (RPE). Lysosomes play a crucial role in RPE health via phagocytosis and autophagy, which are regulated by transcription factor EB/E3 (TFEB/E3). Here, we find that increased AKT2 inhibits PGC-1α to downregulate SIRT5, which we identify as an AKT2 binding partner.

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A stable mitochondrial pool is crucial for healthy cell function and survival. Altered redox biology can adversely affect mitochondria through induction of a variety of cell death and survival pathways, yet the understanding of mitochondria and their dysfunction in primary human cells and in specific disease states, including asthma, is modest. Ferroptosis is traditionally considered an iron dependent, hydroperoxy-phospholipid executed process, which induces cytosolic and mitochondrial damage to drive programmed cell death.

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Vascularization plays a critical role in organ maturation and cell-type development. Drug discovery, organ mimicry, and ultimately transplantation hinge on achieving robust vascularization of in vitro engineered organs. Here, focusing on human kidney organoids, we overcame this hurdle by combining a human induced pluripotent stem cell (iPSC) line containing an inducible ETS translocation variant 2 (ETV2) (a transcription factor playing a role in endothelial cell development) that directs endothelial differentiation in vitro, with a non-transgenic iPSC line in suspension organoid culture.

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  • Vascular inflammation plays a key role in regulating the behavior of endothelial cells, which is especially significant in pulmonary arterial hypertension (PAH), showing complex connections to lysosomal activity and cholesterol metabolism.
  • Research identified that the nuclear receptor coactivator 7 (NCOA7) helps maintain lysosomal function and limits inflammation in endothelial cells; when NCOA7 is deficient, it leads to inflammation and worsened PAH symptoms.
  • A genetic variant in NCOA7 was linked to PAH severity and mortality, while a computationally designed drug that activates NCOA7 showed potential in reversing PAH symptoms in mice, highlighting a new therapeutic approach.
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is a gram-negative, intracellular pathogen which can cause serious, potentially fatal, illness in humans. Species of are found across the Northern Hemisphere and can infect a broad range of host species, including humans. Factors affecting the persistence of in the environment and its epidemiology are not well understood, however, the ability of to enter a viable but non-culturable state (VBNC) may be important.

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  • Ischemic strokes cause long-term neurological issues due to mitochondrial dysfunction in brain endothelial cells, which form the blood-brain barrier.
  • A pilot study indicated that using extracellular vesicles (EVs) from human brain endothelial cells may help post-stroke, but mouse-derived EVs (mBEC-EVs) showed better results in mice, particularly in enhancing mitochondrial function and ATP levels.
  • The study found that mBEC-EVs significantly reduced brain damage and improved neurological scores in mice after a stroke, suggesting that mBEC-EVs could be a more effective therapy in preclinical models.
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  • The TM6SF2 E167K mutation is linked to increased prevalence of Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), prompting the need for a human model to study its effects.
  • Researchers edited human-induced pluripotent stem cells (iPSC) to carry this mutation and observed changes like reduced TM6SF2 protein levels, increased lipid droplets, and altered cholesterol management in the resulting liver cells.
  • The study provides a reliable in vitro model for further research into the TM6SF2 E167K mutation, aiming to identify potential treatments and better understand its role in MASLD vulnerability.
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Implantation of the human embryo begins a critical developmental stage that comprises profound events including axis formation, gastrulation and the emergence of haematopoietic system. Our mechanistic knowledge of this window of human life remains limited due to restricted access to in vivo samples for both technical and ethical reasons. Stem cell models of human embryo have emerged to help unlock the mysteries of this stage.

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Introduction: Ischemic stroke-induced mitochondrial dysfunction in brain endothelial cells () leads to breakdown of the blood-brain barrier () causing long-term neurological dysfunction. Restoration of mitochondrial function in injured BECs is a promising therapeutic strategy to alleviate stroke-induced damage. Mounting evidence demonstrate that selected subsets of cell-derived extracellular vehicles (), such as exosomes () and microvesicles (), contain functional mitochondrial components.

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Actin-binding protein Profilin1 is an important regulator of actin cytoskeletal dynamics in cells and critical for embryonic development in higher eukaryotes. The objective of the present study was to examine the consequence of loss-of-function of Pfn1 in vascular endothelial cells (ECs) in vivo. We utilized a mouse model engineered for tamoxifen-inducible biallelic inactivation of the gene selectively in EC (Pfn1).

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Cardiac arrest (CA) causes high mortality due to multi-system organ damage attributable to ischemia-reperfusion injury. Recent work in our group found that among diabetic patients who experienced cardiac arrest, those taking metformin had less evidence of cardiac and renal damage after cardiac arrest when compared to those not taking metformin. Based on these observations, we hypothesized that metformin's protective effects in the heart were mediated by AMPK signaling, and that AMPK signaling could be targeted as a therapeutic strategy following resuscitation from CA.

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Implantation of the human embryo commences a critical developmental stage that comprises profound morphogenetic alteration of embryonic and extra-embryonic tissues, axis formation, and gastrulation events. Our mechanistic knowledge of this window of human life remains limited due to restricted access to samples for both technical and ethical reasons. Additionally, human stem cell models of early post-implantation development with both embryonic and extra-embryonic tissue morphogenesis are lacking.

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  • *Researchers found that 27% of KPC-Kp isolates showed increased resistance to human serum, linked to a mutation that reduces capsule content and helps the bacteria evade immune responses.
  • *The mutation allows KPC-Kp to survive better in the bloodstream while being less virulent in tissues, highlighting a complex interaction that aids the bacteria's persistence in the host.
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  • Vascularization is super important for organs to grow and for cells to develop properly, especially in making organs like kidneys for medical use.
  • Scientists created human kidney organoids that have good blood vessel structures by mixing different types of stem cells in a special culture.
  • These organoids not only have better blood flow but also show improved development of kidney cells, making this research a big step towards using lab-grown organs in real medical treatments.
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Prader-Willi syndrome (PWS) is a multisystem disorder with neurobehavioral, metabolic, and hormonal phenotypes, caused by loss of expression of a paternally-expressed imprinted gene cluster. Prior evidence from a PWS mouse model identified abnormal pancreatic islet development with retention of aged insulin and deficient insulin secretion. To determine the collective roles of PWS genes in β-cell biology, we used genome-editing to generate isogenic, clonal INS-1 insulinoma lines having 3.

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Introduction: () is a common cause of hospital-acquired pneumonia. Although previous studies have suggested that evasion of phagocytic uptake is a virulence determinant of , few studies have examined phagocytosis sensitivity in clinical isolates.

Methods: We screened 19 clinical respiratory isolates that were previously assessed for mucoviscosity for their sensitivity to macrophage phagocytic uptake, and evaluated phagocytosis as a functional correlate of pathogenicity.

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Background: Ischemic cholangiopathy is a process of bile duct injury that might result from peribiliary vascular plexus (PBP) thrombosis and remains a dreaded complication in liver transplantation from donors after circulatory death (DCD). The aim of this study was to propose a mechanical method of clot destruction to clear microvascular thrombi in DCD livers before transplantation.

Methods: Sonothrombolysis (STL) is a process by which inertial cavitation of circulating microbubbles entering an ultrasound field create a high-energy shockwave at a microbubble-thrombus interface, causing mechanical clot destruction.

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Ischemic stroke causes brain endothelial cell (BEC) death and damages tight junction integrity of the blood-brain barrier (BBB). We harnessed the innate mitochondrial load of BEC-derived extracellular vesicles (EVs) and utilized mixtures of EV/exogenous 27 kDa heat shock protein (HSP27) as a one-two punch strategy to increase BEC survival (via EV mitochondria) and preserve their tight junction integrity (via HSP27 effects). We demonstrated that the medium-to-large (m/lEV) but not small EVs (sEV) transferred their mitochondrial load, that subsequently colocalized with the mitochondrial network of the recipient primary human BECs.

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Expansion microscopy enables nanoimaging with conventional microscopes by physically and isotropically magnifying preserved biological specimens embedded in a crosslinked water-swellable hydrogel. Current expansion microscopy protocols require prior treatment with reactive anchoring chemicals to link specific labels and biomolecule classes to the gel. We describe a strategy called Magnify, which uses a mechanically sturdy gel that retains nucleic acids, proteins and lipids without the need for a separate anchoring step.

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Introduction: Extracellular vesicles (EVs) are promising carriers for the delivery of biotherapeutic cargo such as RNA and proteins. We have previously demonstrated that the innate EV mitochondria in microvesicles (MVs), but not exosomes (EXOs) can be transferred to recipient BECs and mouse brain slice neurons. Here, we sought to determine if the innate EV mitochondrial load can be further increased increasing mitochondrial biogenesis in the donor cells.

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