Anjelica Gonzalez - Academia.edu (original) (raw)

Papers by Anjelica Gonzalez

Research paper thumbnail of Direct Comparison of B Cell Surface Receptors as Therapeutic Targets for Nanoparticle Delivery of BTK Inhibitors

Molecular Pharmaceutics

Targeting different cell surface receptors with nanoparticle (NP)-based platforms can result in d... more Targeting different cell surface receptors with nanoparticle (NP)-based platforms can result in differential particle binding properties that may impact their localization, bioavailability, and, ultimately, the therapeutic efficacy of an encapsulated payload. Conventional in vitro assays comparing the efficacy of targeted NPs often do not adequately control for these differences in particle-receptor binding, potentially confounding their therapeutic readouts and possibly even limiting their experimental value. In this work, we characterize the conditions under which NPs loaded with Bruton's Tyrosine Kinase (BTK) inhibitor differentially suppress primary B cell activation when targeting either CD19 (internalizing) or B220 (noninternalizing) surface receptors. Surface binding of fluorescently labeled CD19- and B220-targeted NPs was analyzed and quantitatively correlated with the number of bound particles at given treatment concentrations. Using this binding data, suppression of B cell activation was directly compared for differentially targeted (CD19 vs B220) NPs loaded with a BTK inhibitor at a range of particle drug loading concentrations. When NPs were loaded with lower amounts of drug, CD19-mediated internalization demonstrated increased inhibition of B cell proliferation compared with B220 NPs. However, these differences were mitigated when particles were loaded with higher concentrations of BTK inhibitor and B220-mediated "paracrine-like" delivery demonstrated superior suppression of cellular activation when cells were bound to lower overall numbers of NPs. Taken together, these results demonstrate that inhibition of B cell activation can be optimized for NPs targeting either internalizing or noninternalizing surface receptors and that particle internalization is likely not a requisite endpoint when designing particles for delivery of BTK inhibitor to B cells.

Research paper thumbnail of Endothelial cell secreted metalloproteinase‐2 enhances neural stem cell N‐cadherin expression, clustering, and migration

The FASEB Journal

Neuroblasts have a clustered phenotype critical for their unidirectional migration, which in part... more Neuroblasts have a clustered phenotype critical for their unidirectional migration, which in part is dependent on signaling from microvascular endothelial cells (EC) and pericytes (PC). Diffusible signals secreted by vascular cells have been demonstrated to increase survival, proliferation, and differentiation of subventricular zone resident neural stem cells (NSC); however, the signals that promote the necessary initiating step of NSC clustering are undefined. To investigate the role of vascular cells in promoting NSC clustering and directing migration, we created a 3‐D hydrogel that mimics the biomechanics, biochemistry, and architectural complexity of brain tissue. We demonstrate that EC, and not PC, have a crucial role in NSC clustering and migration, further verified through microfluidic chamber systems and traction force microscopy. Ablation of the extended NSC aggregate arm halts aggregate movement, suggesting that clustering is a prerequisite for migration. When cultured with EC, NSC clustering occurs and NSC coincidentally increase their expression of N‐cadherin, as compared to NSC cultured alone. NSC‐presented N‐cadherin expression was increased following exposure to EC secreted metalloproteinase‐2 (MMP2). We demonstrate that inhibition of MMP2 prevented NSC N‐cadherin surface expression and subsequent NSC clustering, even when NSC were in direct contact with EC. Furthermore, with exogenous activation of EGFR, which serves as a downstream activator of N‐cadherin cleavage, NSC form clusters. Our results suggest that EC secretion of MMP2 promotes NSC clustering through N‐cadherin expression. The insight gained about the mechanisms by which EC promote NSC migration may enhance NSC therapeutic response to sites of injury.

Research paper thumbnail of Microvascular dysfunction and kidney disease: Challenges and opportunities?

Microcirculation

Kidneys are highly vascular organs that despite their relatively small size receive 20% of the ca... more Kidneys are highly vascular organs that despite their relatively small size receive 20% of the cardiac output. The highly intricate, delicately organized structure of renal microcirculation is essential to enable renal function and glomerular filtration rate through the local modulation of renal blood flow and intraglomerular pressure. Not surprisingly, the dysregulation of blood flow within the microvessels (abnormal vasoreactivity), fibrosis driven by disordered vascular‐renal cross talk, or the loss of renal microvasculature (rarefaction) is associated with kidney disease. In addition, kidney disease can cause microcirculatory dysfunction in distant organs such as the heart and brain, mediated by mechanisms that remain to be elucidated. The objective of this review is to highlight the role of renal microvasculature in kidney disease. The overview will outline the impetus to study renal microvasculature, the bidirectional relationship between kidney disease and microvascular dysfu...

Research paper thumbnail of Endothelial cell secreted VEGF-C enhances NSC VEGFR3 expression and promotes NSC survival

Stem Cell Research, 2021

Although delivery of neural stem cell (NSC) as a therapeutic treatment for intracerebral hemorrha... more Although delivery of neural stem cell (NSC) as a therapeutic treatment for intracerebral hemorrhage (ICH) provides promise, NSC delivery typically has extremely low survival rates. Here, we investigate endothelial cell (EC) and pericyte (PC) interactions with NSC, where our results demonstrate that EC, and not PC, promote NSC cell proliferation and reduce cytotoxicity under glucose deprivation (GD). Additionally, NSC proliferation was increased upon treatment with EC conditioned media, inhibited with antagonism of VEGFR3. In an NSC + EC coculture we detected elevated levels of VEGF-C, not seen for NSC cultured alone. Exogenous VEGF-C induced NSC upregulation of VEGFR3, promoted proliferation, and reduced cytotoxicity. Finally, we delivered microbeads containing NSC + EC into a murine ICH cavity, where VEGF-C was increasingly present in the injury site, not seen upon delivery NSC encapsulated alone. These studies demonstrate that EC-secreted VEGF-C may promote NSC survival during injury, enhancing the potential for cell delivery therapies for stroke.

Research paper thumbnail of Fibrotic cytokine tgf-b1 increases pericyte migration in a 3-d microvascular model

Research paper thumbnail of Micr o v as cu lar Tar get s fo r An t i-Fibr o t ic Ther ap eu t ics

Fibrosis is characterized by excessive extracellular matrix deposition and is the pathologi cal o... more Fibrosis is characterized by excessive extracellular matrix deposition and is the pathologi cal outcome of repetitive tissue injury in many disorders. The accumulation of matrix disrupts the structure and function of the native tissue and can affect multiple organs including the lungs, heart, liver, and skin. Unfortunately, current therapies against the deadliest and most common fibrosis are ineffective. The pathogenesis of fibrosis is the result of aberrant wound healing, therefore, the microvasculature plays an important role, contributing through regu lation of leukocyte recruitment, inflammation, and angiogenesis. Further exacerbating the condition, microvascular endothelial cells and pericytes can transdifferentiate into matrix depositing myofibroblasts. The contribution of the microvasculature to fibrotic progression makes its cellular components and acellular products attractive therapeutic targets. In this review, we examine many of the cytokine, matrix, and cellular microva...

Research paper thumbnail of ECM hydrogel improves the delivery of PEG microsphere-encapsulated neural stem cells and endothelial cells into tissue cavities caused by stroke

Brain Research Bulletin, 2021

Intracerebral implantation of neural stem cells (NSCs) to treat stroke remains an inefficient pro... more Intracerebral implantation of neural stem cells (NSCs) to treat stroke remains an inefficient process with <5% of injected cells being retained. To improve the retention and distribution of NSCs after a stroke, we investigated the utility of NSCs' encapsulation in polyethylene glycol (PEG) microspheres. We first characterized the impact of the physical properties of different syringes and needles, as well as ejection speed, upon delivery of microspheres to the stroke injured rat brain. A 20 G needle size at a 10 µL/min flow rate achieved the most efficient microsphere ejection. Secondly, we optimized the delivery vehicles for in vivo implantation of PEG microspheres. The suspension of microspheres in extracellular matrix (ECM) hydrogel showed superior retention and distribution in a cortical stroke caused by photothrombosis, as well as in a striatal and cortical cavity ensuing middle cerebral artery occlusion (MCAo). Thirdly, NSCs or NSCs + endothelial cells (ECs) encapsulated into biodegradable microspheres were implanted into a large stroke cavity. Cells in microspheres exhibited a high viability, survived freezing and transport. Implantation of 110 cells/microsphere suspended in ECM hydrogel produced a highly efficient delivery that resulted in the widespread distribution of NSCs in the tissue cavity and damaged peri-infarct tissues. Co-delivery of ECs enhanced the in vivo survival and distribution of ∼1.1 million NSCs. The delivery of NSCs and ECs can be dramatically improved using microsphere encapsulation combined with suspension in ECM hydrogel. These biomaterial innovations are essential to advance clinical efforts to improve the treatment of stroke using intracerebral cell therapy.

Research paper thumbnail of Integrins and extracellular matrix proteins modulate adipocyte thermogenic capacity

Scientific Reports, 2021

Obesity and the metabolic disease epidemic has led to an increase in morbidity and mortality. A r... more Obesity and the metabolic disease epidemic has led to an increase in morbidity and mortality. A rise in adipose thermogenic capacity via activation of brown or beige fat is a potential treatment for metabolic diseases. However, an understanding of how local factors control adipocyte fate is limited. Mice with a null mutation in the laminin α4 (LAMA4) gene (KO) exhibit resistance to obesity and enhanced expression of thermogenic fat markers in white adipose tissue (WAT). In this study, changes in WAT extracellular matrix composition in the absence of LAMA4 were evaluated using liquid chromatography/tandem mass spectrometry. KO-mice showed lower levels of collagen 1A1 and 3A1, and integrins α7 (ITA7) and β1 (ITB1). ITA7-ITB1 and collagen 1A1-3A1 protein levels were lower in brown adipose tissue compared to WAT in wild-type mice. Immunohistochemical staining confirmed lower levels and different spatial distribution of ITA7 in KO-WAT. In culture studies, ITA7 and LAMA4 levels decreased ...

Research paper thumbnail of An endothelial microRNA-1–regulated network controls eosinophil trafficking in asthma and chronic rhinosinusitis

Journal of Allergy and Clinical Immunology, 2020

Research paper thumbnail of Minimally Invasive Delivery of Microbeads with Encapsulated, Viable and Quiescent Neural Stem Cells to the Adult Subventricular Zone

Scientific Reports, 2019

Stem cell therapies demonstrate promising results as treatment for neurological disease and injur... more Stem cell therapies demonstrate promising results as treatment for neurological disease and injury, owing to their innate ability to enhance endogenous neural tissue repair and promote functional recovery. However, delivery of undifferentiated and viable neuronal stem cells requires an engineered delivery system that promotes integration of transplanted cells into the inflamed and cytotoxic region of damaged tissue. Within the brain, endothelial cells (EC) of the subventricular zone play a critical role in neural stem cell (NSC) maintenance, quiescence and survival. Therefore, here, we describe the use of polyethylene glycol microbeads for the coincident delivery of EC and NSC as a means of enhancing appropriate NSC quiescence and survival during transplantation into the mouse brain. We demonstrate that EC and NSC co-encapsulation maintained NSC quiescence, enhanced NSC viability, and facilitated NSC extravasation in vitro, as compared to NSC encapsulated alone. In addition, co-enca...

Research paper thumbnail of Stroke Repair via Biomimicry of the Subventricular Zone

Frontiers in Materials, 2018

Research paper thumbnail of Engineered Biomimetic Neural Stem Cell Niche

Current Stem Cell Reports, 2019

Research paper thumbnail of Physical and biochemical interactions drive fibrocytes accumulation in the scleroderma lung matrix

ILD/DPLD of known origin, 2018

Research paper thumbnail of Endothelial cell-secreted MIF reduces pericyte contractility and enhances neutrophil extravasation

FASEB journal : official publication of the Federation of American Societies for Experimental Biology, Jan 25, 2018

Dysregulated neutrophil extravasation contributes to the pathogenesis of many inflammatory disord... more Dysregulated neutrophil extravasation contributes to the pathogenesis of many inflammatory disorders. Pericytes (PCs) have been implicated in the regulation of neutrophil transmigration, and previous work demonstrates that endothelial cell (EC)-derived signals reduce PC barrier function; however, the signaling mechanisms are unknown. Here, we demonstrate a novel role for EC-derived macrophage migration inhibitory factor (MIF) in inhibiting PC contractility and facilitating neutrophil transmigration. With the use of micro-ELISAs, RNA sequencing, quantitative PCR, and flow cytometry, we found that ECs secrete MIF, and PCs upregulate CD74 in response to TNF-α. We demonstrate that EC-derived MIF decreases PC contractility on 2-dimensional silicone substrates via reduction of phosphorylated myosin light chain. With the use of an in vitro microvascular model of the human EC-PC barrier, we demonstrate that MIF decreases the PC barrier to human neutrophil transmigration by increasing interc...

Research paper thumbnail of Biomimetic, ultrathin and elastic hydrogels regulate human neutrophil extravasation across endothelial-pericyte bilayers

PloS one, 2017

The vascular basement membrane-a thin, elastic layer of extracellular matrix separating and encas... more The vascular basement membrane-a thin, elastic layer of extracellular matrix separating and encasing vascular cells-provides biological and mechanical cues to endothelial cells, pericytes, and migrating leukocytes. In contrast, experimental scaffolds typically used to replicate basement membranes are stiff and bio-inert. Here, we present thin, porated polyethylene glycol hydrogels to replicate human vascular basement membranes. Like commercial transwells, our hydrogels are approximately 10μm thick, but like basement membranes, the hydrogels presented here are elastic (E: 50-80kPa) and contain a dense network of small pores. Moreover, the inclusion of bioactive domains introduces receptor-mediated biochemical signaling. We compare elastic hydrogels to common culture substrates (E: >2GPa) for human endothelial cell and pericyte monolayers and bilayers to replicate postcapillary venules in vitro. Our data demonstrate that substrate elasticity facilitates differences in vascular phen...

Research paper thumbnail of IL-17 Promotes Neutrophil-Mediated Immunity by Activating Microvascular Pericytes and Not Endothelium

The Journal of Immunology, 2016

A classical hallmark of acute inflammation is neutrophil infiltration of tissues, a multistep pro... more A classical hallmark of acute inflammation is neutrophil infiltration of tissues, a multistep process that involves sequential cell–cell interactions of circulating leukocytes with IL-1– or TNF-activated microvascular endothelial cells (ECs) and pericytes (PCs) that form the wall of the postcapillary venules. The initial infiltrating cells accumulate perivascularly in close proximity to PCs. IL-17, a proinflammatory cytokine that acts on target cells via a heterodimeric receptor formed by IL-17RA and IL-17RC subunits, also promotes neutrophilic inflammation but its effects on vascular cells are less clear. We report that both cultured human ECs and PCs strongly express IL-17RC and, although neither cell type expresses much IL-17RA, PCs express significantly more than ECs. IL-17, alone or synergistically with TNF, significantly alters inflammatory gene expression in cultured human PCs but not ECs. RNA sequencing analysis identifies many IL-17–induced transcripts in PCs encoding prote...

Research paper thumbnail of Extracellular matrix biomimicry for the creation of investigational and therapeutic devices

WIREs Nanomedicine and Nanobiotechnology, 2015

The extracellular matrix (ECM) is a web of fibrous proteins that serves as a scaffold for tissues... more The extracellular matrix (ECM) is a web of fibrous proteins that serves as a scaffold for tissues and organs, and is important for maintaining homeostasis and facilitating cellular adhesion. Integrin transmembrane receptors are the primary adhesion molecules that anchor cells to the ECM, thus integrating cells with their microenvironments. Integrins play a critical role in facilitating cell–matrix interactions and promoting signal transduction, both from the cell to the ECM and vice versa, ultimately mediating cell behavior. For this reason, many advanced biomaterials employ biomimicry by replicating the form and function of fibrous ECM proteins. The ECM also acts as a reservoir for small molecules and growth factors, wherein fibrous proteins directly bind and present these bioactive moieties that facilitate cell activity. Therefore biomimicry can be enhanced by incorporating small molecules into ECM‐like substrates. Biomimetic ECM materials have served as invaluable research tools ...

Research paper thumbnail of The effects of extracellular matrix proteins on neutrophil-endothelial interaction--a roadway to multiple therapeutic opportunities

The Yale journal of biology and medicine, 2012

Polymorphoneuclear leukocytes or neutrophils, a major component of white blood cells, contribute ... more Polymorphoneuclear leukocytes or neutrophils, a major component of white blood cells, contribute to the innate immune response in humans. Upon sensing changes in the microenvironment, neutrophils adhere to the vascular wall, migrate through the endothelial cell (EC)-pericyte bilayer, and subsequently through the extracellular matrix to reach the site of inflammation. These cells are capable of destroying microbes, cell debris, and foreign proteins by oxidative and non-oxidative processes. While primarily mediators of tissue homeostasis, there are an increasing number of studies indicating that neutrophil recruitment and transmigration can also lead to host-tissue injury and subsequently inflammation-related diseases. Neutrophil-induced tissue injury is highly regulated by the microenvironment of the infiltrated tissue, which includes cytokines, chemokines, and the provisional extracellular matrix, remodeled through increased vascular permeability and other cellular infiltrates. Thus...

Research paper thumbnail of Human Microvascular Pericyte Basement Membrane Remodeling Regulates Neutrophil Recruitment

Microcirculation, 2015

ObjectiveNeutrophil extravasation at post‐capillary venules, consisting of EC, PC, and the shared... more ObjectiveNeutrophil extravasation at post‐capillary venules, consisting of EC, PC, and the shared ECM, increases following fibrotic remodeling in the lung, liver, and skin. The role of fibrotic pericyte‐derived ECM in regulating EC activation and neutrophil recruitment remains unexplored.MethodsTo elucidate the role of human pericyte‐derived ECM in EC activation, we characterized PC‐derived ECM following transforming growth factor‐β1, IL‐1β, CCL2, or bleomycin activation, and examined surface adhesion molecule expression and neutrophil recruitment by EC cultured on PC‐ECM.ResultsPro‐inflammatory activation of PC‐induced deposition of compositionally distinct ECM compared with non‐activated control. Bleomycin activation induced fibronectin‐rich and collagen‐poor ECM remodeling by PC, facilitating increased neutrophil transendothelial migration when compared with non‐activated pericyte ECM (49.9 ± 3.4% versus 29.7 ± 1.4%). Increases in fibronectin compared to collagen I, are largely r...

Research paper thumbnail of αVβ3 Integrin Regulation of Respiratory Burst in Fibrinogen Adherent Human Neutrophils

Cellular and Molecular Bioengineering, 2014

Research paper thumbnail of Direct Comparison of B Cell Surface Receptors as Therapeutic Targets for Nanoparticle Delivery of BTK Inhibitors

Molecular Pharmaceutics

Targeting different cell surface receptors with nanoparticle (NP)-based platforms can result in d... more Targeting different cell surface receptors with nanoparticle (NP)-based platforms can result in differential particle binding properties that may impact their localization, bioavailability, and, ultimately, the therapeutic efficacy of an encapsulated payload. Conventional in vitro assays comparing the efficacy of targeted NPs often do not adequately control for these differences in particle-receptor binding, potentially confounding their therapeutic readouts and possibly even limiting their experimental value. In this work, we characterize the conditions under which NPs loaded with Bruton's Tyrosine Kinase (BTK) inhibitor differentially suppress primary B cell activation when targeting either CD19 (internalizing) or B220 (noninternalizing) surface receptors. Surface binding of fluorescently labeled CD19- and B220-targeted NPs was analyzed and quantitatively correlated with the number of bound particles at given treatment concentrations. Using this binding data, suppression of B cell activation was directly compared for differentially targeted (CD19 vs B220) NPs loaded with a BTK inhibitor at a range of particle drug loading concentrations. When NPs were loaded with lower amounts of drug, CD19-mediated internalization demonstrated increased inhibition of B cell proliferation compared with B220 NPs. However, these differences were mitigated when particles were loaded with higher concentrations of BTK inhibitor and B220-mediated "paracrine-like" delivery demonstrated superior suppression of cellular activation when cells were bound to lower overall numbers of NPs. Taken together, these results demonstrate that inhibition of B cell activation can be optimized for NPs targeting either internalizing or noninternalizing surface receptors and that particle internalization is likely not a requisite endpoint when designing particles for delivery of BTK inhibitor to B cells.

Research paper thumbnail of Endothelial cell secreted metalloproteinase‐2 enhances neural stem cell N‐cadherin expression, clustering, and migration

The FASEB Journal

Neuroblasts have a clustered phenotype critical for their unidirectional migration, which in part... more Neuroblasts have a clustered phenotype critical for their unidirectional migration, which in part is dependent on signaling from microvascular endothelial cells (EC) and pericytes (PC). Diffusible signals secreted by vascular cells have been demonstrated to increase survival, proliferation, and differentiation of subventricular zone resident neural stem cells (NSC); however, the signals that promote the necessary initiating step of NSC clustering are undefined. To investigate the role of vascular cells in promoting NSC clustering and directing migration, we created a 3‐D hydrogel that mimics the biomechanics, biochemistry, and architectural complexity of brain tissue. We demonstrate that EC, and not PC, have a crucial role in NSC clustering and migration, further verified through microfluidic chamber systems and traction force microscopy. Ablation of the extended NSC aggregate arm halts aggregate movement, suggesting that clustering is a prerequisite for migration. When cultured with EC, NSC clustering occurs and NSC coincidentally increase their expression of N‐cadherin, as compared to NSC cultured alone. NSC‐presented N‐cadherin expression was increased following exposure to EC secreted metalloproteinase‐2 (MMP2). We demonstrate that inhibition of MMP2 prevented NSC N‐cadherin surface expression and subsequent NSC clustering, even when NSC were in direct contact with EC. Furthermore, with exogenous activation of EGFR, which serves as a downstream activator of N‐cadherin cleavage, NSC form clusters. Our results suggest that EC secretion of MMP2 promotes NSC clustering through N‐cadherin expression. The insight gained about the mechanisms by which EC promote NSC migration may enhance NSC therapeutic response to sites of injury.

Research paper thumbnail of Microvascular dysfunction and kidney disease: Challenges and opportunities?

Microcirculation

Kidneys are highly vascular organs that despite their relatively small size receive 20% of the ca... more Kidneys are highly vascular organs that despite their relatively small size receive 20% of the cardiac output. The highly intricate, delicately organized structure of renal microcirculation is essential to enable renal function and glomerular filtration rate through the local modulation of renal blood flow and intraglomerular pressure. Not surprisingly, the dysregulation of blood flow within the microvessels (abnormal vasoreactivity), fibrosis driven by disordered vascular‐renal cross talk, or the loss of renal microvasculature (rarefaction) is associated with kidney disease. In addition, kidney disease can cause microcirculatory dysfunction in distant organs such as the heart and brain, mediated by mechanisms that remain to be elucidated. The objective of this review is to highlight the role of renal microvasculature in kidney disease. The overview will outline the impetus to study renal microvasculature, the bidirectional relationship between kidney disease and microvascular dysfu...

Research paper thumbnail of Endothelial cell secreted VEGF-C enhances NSC VEGFR3 expression and promotes NSC survival

Stem Cell Research, 2021

Although delivery of neural stem cell (NSC) as a therapeutic treatment for intracerebral hemorrha... more Although delivery of neural stem cell (NSC) as a therapeutic treatment for intracerebral hemorrhage (ICH) provides promise, NSC delivery typically has extremely low survival rates. Here, we investigate endothelial cell (EC) and pericyte (PC) interactions with NSC, where our results demonstrate that EC, and not PC, promote NSC cell proliferation and reduce cytotoxicity under glucose deprivation (GD). Additionally, NSC proliferation was increased upon treatment with EC conditioned media, inhibited with antagonism of VEGFR3. In an NSC + EC coculture we detected elevated levels of VEGF-C, not seen for NSC cultured alone. Exogenous VEGF-C induced NSC upregulation of VEGFR3, promoted proliferation, and reduced cytotoxicity. Finally, we delivered microbeads containing NSC + EC into a murine ICH cavity, where VEGF-C was increasingly present in the injury site, not seen upon delivery NSC encapsulated alone. These studies demonstrate that EC-secreted VEGF-C may promote NSC survival during injury, enhancing the potential for cell delivery therapies for stroke.

Research paper thumbnail of Fibrotic cytokine tgf-b1 increases pericyte migration in a 3-d microvascular model

Research paper thumbnail of Micr o v as cu lar Tar get s fo r An t i-Fibr o t ic Ther ap eu t ics

Fibrosis is characterized by excessive extracellular matrix deposition and is the pathologi cal o... more Fibrosis is characterized by excessive extracellular matrix deposition and is the pathologi cal outcome of repetitive tissue injury in many disorders. The accumulation of matrix disrupts the structure and function of the native tissue and can affect multiple organs including the lungs, heart, liver, and skin. Unfortunately, current therapies against the deadliest and most common fibrosis are ineffective. The pathogenesis of fibrosis is the result of aberrant wound healing, therefore, the microvasculature plays an important role, contributing through regu lation of leukocyte recruitment, inflammation, and angiogenesis. Further exacerbating the condition, microvascular endothelial cells and pericytes can transdifferentiate into matrix depositing myofibroblasts. The contribution of the microvasculature to fibrotic progression makes its cellular components and acellular products attractive therapeutic targets. In this review, we examine many of the cytokine, matrix, and cellular microva...

Research paper thumbnail of ECM hydrogel improves the delivery of PEG microsphere-encapsulated neural stem cells and endothelial cells into tissue cavities caused by stroke

Brain Research Bulletin, 2021

Intracerebral implantation of neural stem cells (NSCs) to treat stroke remains an inefficient pro... more Intracerebral implantation of neural stem cells (NSCs) to treat stroke remains an inefficient process with <5% of injected cells being retained. To improve the retention and distribution of NSCs after a stroke, we investigated the utility of NSCs' encapsulation in polyethylene glycol (PEG) microspheres. We first characterized the impact of the physical properties of different syringes and needles, as well as ejection speed, upon delivery of microspheres to the stroke injured rat brain. A 20 G needle size at a 10 µL/min flow rate achieved the most efficient microsphere ejection. Secondly, we optimized the delivery vehicles for in vivo implantation of PEG microspheres. The suspension of microspheres in extracellular matrix (ECM) hydrogel showed superior retention and distribution in a cortical stroke caused by photothrombosis, as well as in a striatal and cortical cavity ensuing middle cerebral artery occlusion (MCAo). Thirdly, NSCs or NSCs + endothelial cells (ECs) encapsulated into biodegradable microspheres were implanted into a large stroke cavity. Cells in microspheres exhibited a high viability, survived freezing and transport. Implantation of 110 cells/microsphere suspended in ECM hydrogel produced a highly efficient delivery that resulted in the widespread distribution of NSCs in the tissue cavity and damaged peri-infarct tissues. Co-delivery of ECs enhanced the in vivo survival and distribution of ∼1.1 million NSCs. The delivery of NSCs and ECs can be dramatically improved using microsphere encapsulation combined with suspension in ECM hydrogel. These biomaterial innovations are essential to advance clinical efforts to improve the treatment of stroke using intracerebral cell therapy.

Research paper thumbnail of Integrins and extracellular matrix proteins modulate adipocyte thermogenic capacity

Scientific Reports, 2021

Obesity and the metabolic disease epidemic has led to an increase in morbidity and mortality. A r... more Obesity and the metabolic disease epidemic has led to an increase in morbidity and mortality. A rise in adipose thermogenic capacity via activation of brown or beige fat is a potential treatment for metabolic diseases. However, an understanding of how local factors control adipocyte fate is limited. Mice with a null mutation in the laminin α4 (LAMA4) gene (KO) exhibit resistance to obesity and enhanced expression of thermogenic fat markers in white adipose tissue (WAT). In this study, changes in WAT extracellular matrix composition in the absence of LAMA4 were evaluated using liquid chromatography/tandem mass spectrometry. KO-mice showed lower levels of collagen 1A1 and 3A1, and integrins α7 (ITA7) and β1 (ITB1). ITA7-ITB1 and collagen 1A1-3A1 protein levels were lower in brown adipose tissue compared to WAT in wild-type mice. Immunohistochemical staining confirmed lower levels and different spatial distribution of ITA7 in KO-WAT. In culture studies, ITA7 and LAMA4 levels decreased ...

Research paper thumbnail of An endothelial microRNA-1–regulated network controls eosinophil trafficking in asthma and chronic rhinosinusitis

Journal of Allergy and Clinical Immunology, 2020

Research paper thumbnail of Minimally Invasive Delivery of Microbeads with Encapsulated, Viable and Quiescent Neural Stem Cells to the Adult Subventricular Zone

Scientific Reports, 2019

Stem cell therapies demonstrate promising results as treatment for neurological disease and injur... more Stem cell therapies demonstrate promising results as treatment for neurological disease and injury, owing to their innate ability to enhance endogenous neural tissue repair and promote functional recovery. However, delivery of undifferentiated and viable neuronal stem cells requires an engineered delivery system that promotes integration of transplanted cells into the inflamed and cytotoxic region of damaged tissue. Within the brain, endothelial cells (EC) of the subventricular zone play a critical role in neural stem cell (NSC) maintenance, quiescence and survival. Therefore, here, we describe the use of polyethylene glycol microbeads for the coincident delivery of EC and NSC as a means of enhancing appropriate NSC quiescence and survival during transplantation into the mouse brain. We demonstrate that EC and NSC co-encapsulation maintained NSC quiescence, enhanced NSC viability, and facilitated NSC extravasation in vitro, as compared to NSC encapsulated alone. In addition, co-enca...

Research paper thumbnail of Stroke Repair via Biomimicry of the Subventricular Zone

Frontiers in Materials, 2018

Research paper thumbnail of Engineered Biomimetic Neural Stem Cell Niche

Current Stem Cell Reports, 2019

Research paper thumbnail of Physical and biochemical interactions drive fibrocytes accumulation in the scleroderma lung matrix

ILD/DPLD of known origin, 2018

Research paper thumbnail of Endothelial cell-secreted MIF reduces pericyte contractility and enhances neutrophil extravasation

FASEB journal : official publication of the Federation of American Societies for Experimental Biology, Jan 25, 2018

Dysregulated neutrophil extravasation contributes to the pathogenesis of many inflammatory disord... more Dysregulated neutrophil extravasation contributes to the pathogenesis of many inflammatory disorders. Pericytes (PCs) have been implicated in the regulation of neutrophil transmigration, and previous work demonstrates that endothelial cell (EC)-derived signals reduce PC barrier function; however, the signaling mechanisms are unknown. Here, we demonstrate a novel role for EC-derived macrophage migration inhibitory factor (MIF) in inhibiting PC contractility and facilitating neutrophil transmigration. With the use of micro-ELISAs, RNA sequencing, quantitative PCR, and flow cytometry, we found that ECs secrete MIF, and PCs upregulate CD74 in response to TNF-α. We demonstrate that EC-derived MIF decreases PC contractility on 2-dimensional silicone substrates via reduction of phosphorylated myosin light chain. With the use of an in vitro microvascular model of the human EC-PC barrier, we demonstrate that MIF decreases the PC barrier to human neutrophil transmigration by increasing interc...

Research paper thumbnail of Biomimetic, ultrathin and elastic hydrogels regulate human neutrophil extravasation across endothelial-pericyte bilayers

PloS one, 2017

The vascular basement membrane-a thin, elastic layer of extracellular matrix separating and encas... more The vascular basement membrane-a thin, elastic layer of extracellular matrix separating and encasing vascular cells-provides biological and mechanical cues to endothelial cells, pericytes, and migrating leukocytes. In contrast, experimental scaffolds typically used to replicate basement membranes are stiff and bio-inert. Here, we present thin, porated polyethylene glycol hydrogels to replicate human vascular basement membranes. Like commercial transwells, our hydrogels are approximately 10μm thick, but like basement membranes, the hydrogels presented here are elastic (E: 50-80kPa) and contain a dense network of small pores. Moreover, the inclusion of bioactive domains introduces receptor-mediated biochemical signaling. We compare elastic hydrogels to common culture substrates (E: >2GPa) for human endothelial cell and pericyte monolayers and bilayers to replicate postcapillary venules in vitro. Our data demonstrate that substrate elasticity facilitates differences in vascular phen...

Research paper thumbnail of IL-17 Promotes Neutrophil-Mediated Immunity by Activating Microvascular Pericytes and Not Endothelium

The Journal of Immunology, 2016

A classical hallmark of acute inflammation is neutrophil infiltration of tissues, a multistep pro... more A classical hallmark of acute inflammation is neutrophil infiltration of tissues, a multistep process that involves sequential cell–cell interactions of circulating leukocytes with IL-1– or TNF-activated microvascular endothelial cells (ECs) and pericytes (PCs) that form the wall of the postcapillary venules. The initial infiltrating cells accumulate perivascularly in close proximity to PCs. IL-17, a proinflammatory cytokine that acts on target cells via a heterodimeric receptor formed by IL-17RA and IL-17RC subunits, also promotes neutrophilic inflammation but its effects on vascular cells are less clear. We report that both cultured human ECs and PCs strongly express IL-17RC and, although neither cell type expresses much IL-17RA, PCs express significantly more than ECs. IL-17, alone or synergistically with TNF, significantly alters inflammatory gene expression in cultured human PCs but not ECs. RNA sequencing analysis identifies many IL-17–induced transcripts in PCs encoding prote...

Research paper thumbnail of Extracellular matrix biomimicry for the creation of investigational and therapeutic devices

WIREs Nanomedicine and Nanobiotechnology, 2015

The extracellular matrix (ECM) is a web of fibrous proteins that serves as a scaffold for tissues... more The extracellular matrix (ECM) is a web of fibrous proteins that serves as a scaffold for tissues and organs, and is important for maintaining homeostasis and facilitating cellular adhesion. Integrin transmembrane receptors are the primary adhesion molecules that anchor cells to the ECM, thus integrating cells with their microenvironments. Integrins play a critical role in facilitating cell–matrix interactions and promoting signal transduction, both from the cell to the ECM and vice versa, ultimately mediating cell behavior. For this reason, many advanced biomaterials employ biomimicry by replicating the form and function of fibrous ECM proteins. The ECM also acts as a reservoir for small molecules and growth factors, wherein fibrous proteins directly bind and present these bioactive moieties that facilitate cell activity. Therefore biomimicry can be enhanced by incorporating small molecules into ECM‐like substrates. Biomimetic ECM materials have served as invaluable research tools ...

Research paper thumbnail of The effects of extracellular matrix proteins on neutrophil-endothelial interaction--a roadway to multiple therapeutic opportunities

The Yale journal of biology and medicine, 2012

Polymorphoneuclear leukocytes or neutrophils, a major component of white blood cells, contribute ... more Polymorphoneuclear leukocytes or neutrophils, a major component of white blood cells, contribute to the innate immune response in humans. Upon sensing changes in the microenvironment, neutrophils adhere to the vascular wall, migrate through the endothelial cell (EC)-pericyte bilayer, and subsequently through the extracellular matrix to reach the site of inflammation. These cells are capable of destroying microbes, cell debris, and foreign proteins by oxidative and non-oxidative processes. While primarily mediators of tissue homeostasis, there are an increasing number of studies indicating that neutrophil recruitment and transmigration can also lead to host-tissue injury and subsequently inflammation-related diseases. Neutrophil-induced tissue injury is highly regulated by the microenvironment of the infiltrated tissue, which includes cytokines, chemokines, and the provisional extracellular matrix, remodeled through increased vascular permeability and other cellular infiltrates. Thus...

Research paper thumbnail of Human Microvascular Pericyte Basement Membrane Remodeling Regulates Neutrophil Recruitment

Microcirculation, 2015

ObjectiveNeutrophil extravasation at post‐capillary venules, consisting of EC, PC, and the shared... more ObjectiveNeutrophil extravasation at post‐capillary venules, consisting of EC, PC, and the shared ECM, increases following fibrotic remodeling in the lung, liver, and skin. The role of fibrotic pericyte‐derived ECM in regulating EC activation and neutrophil recruitment remains unexplored.MethodsTo elucidate the role of human pericyte‐derived ECM in EC activation, we characterized PC‐derived ECM following transforming growth factor‐β1, IL‐1β, CCL2, or bleomycin activation, and examined surface adhesion molecule expression and neutrophil recruitment by EC cultured on PC‐ECM.ResultsPro‐inflammatory activation of PC‐induced deposition of compositionally distinct ECM compared with non‐activated control. Bleomycin activation induced fibronectin‐rich and collagen‐poor ECM remodeling by PC, facilitating increased neutrophil transendothelial migration when compared with non‐activated pericyte ECM (49.9 ± 3.4% versus 29.7 ± 1.4%). Increases in fibronectin compared to collagen I, are largely r...

Research paper thumbnail of αVβ3 Integrin Regulation of Respiratory Burst in Fibrinogen Adherent Human Neutrophils

Cellular and Molecular Bioengineering, 2014