Mechanistic computational modeling of sFLT1 secretion dynamics.

Constitutively secreted by endothelial cells, soluble FLT1 (sFLT1 or sVEGFR1) binds and sequesters extracellular vascular endothelial growth factors (VEGF), thereby reducing VEGF binding to VEGF receptor tyrosine kinases and their downstream signaling. In doing so, sFLT1 plays an important role in vascular development and in the patterning of new blood vessels in angiogenesis. Here, we develop multiple mechanistic models of sFLT1 secretion and identify a minimal mechanistic model that recapitulates key qualitative and quantitative features of temporal experimental datasets of sFLT1 secretion from multiple studies.

Impact of ligand binding on VEGFR1, VEGFR2, and NRP1 localization in human endothelial cells.

The vascular endothelial growth factor receptors (VEGFRs) bind to cognate ligands to facilitate signaling pathways critical for angiogenesis, the growth of new capillaries from existing vasculature. Intracellular trafficking regulates the availability of receptors on the cell surface to bind ligands, which regulate activation, and the movement of activated receptors between the surface and intracellular pools, where they can initiate different signaling pathways. Using experimental data and computational modeling, we recently demonstrated and quantified the differential trafficking of three VEGF receptors, VEGFR1, VEGFR2, and coreceptor Neuropilin-1 (NRP1).

Mechanistic computational modeling of sFLT1 secretion dynamics.

Constitutively secreted by endothelial cells, soluble FLT1 (sFLT1 or sVEGFR1) binds and sequesters extracellular vascular endothelial growth factors (VEGF), thereby reducing VEGF binding to VEGF receptor tyrosine kinases and their downstream signaling. In doing so, sFLT1 plays an important role in vascular development and in the patterning of new blood vessels in angiogenesis. Here, we develop multiple mechanistic models of sFLT1 secretion and identify a minimal mechanistic model that recapitulates key qualitative and quantitative features of temporal experimental datasets of sFLT1 secretion from multiple studies.

Trafficking dynamics of VEGFR1, VEGFR2, and NRP1 in human endothelial cells.

The vascular endothelial growth factor (VEGF) family of cytokines are key drivers of blood vessel growth and remodeling. These ligands act via multiple VEGF receptors (VEGFR) and co-receptors such as Neuropilin (NRP) expressed on endothelial cells. These membrane-associated receptors are not solely expressed on the cell surface, they move between the surface and intracellular locations, where they can function differently.

A defined clathrin-mediated trafficking pathway regulates sFLT1/VEGFR1 secretion from endothelial cells.

FLT1/VEGFR1 negatively regulates VEGF-A signaling and is required for proper vessel morphogenesis during vascular development and vessel homeostasis. Although a soluble isoform, sFLT1, is often mis-regulated in disease and aging, how sFLT1 is trafficked and secreted from endothelial cells is not well understood. Here we define requirements for constitutive sFLT1 trafficking and secretion in endothelial cells from the Golgi to the plasma membrane, and we show that sFLT1 secretion requires clathrin at or near the Golgi.

Intermediate filament dysregulation in astrocytes in the human disease model of mutation in giant axonal neuropathy (GAN).

Giant Axonal Neuropathy (GAN) is a pediatric neurodegenerative disease caused by mutations. encodes gigaxonin, which regulates intermediate filament (IF) turnover. Previous neuropathological studies and examination of postmortem brain tissue in the current study revealed involvement of astrocytes in GAN.

Intermediate filament dysregulation and astrocytopathy in the human disease model of mutation in giant axonal neuropathy (GAN).

Giant Axonal Neuropathy (GAN) is a pediatric neurodegenerative disease caused by mutations. encodes gigaxonin, a regulator of intermediate filament (IF) protein turnover. Previous neuropathological studies and our own examination of postmortem GAN brain tissue in the current study revealed astrocyte involvement in GAN.

Nuclear SUN1 stabilizes endothelial cell junctions via microtubules to regulate blood vessel formation.

Endothelial cells line all blood vessels, where they coordinate blood vessel formation and the blood-tissue barrier via regulation of cell-cell junctions. The nucleus also regulates endothelial cell behaviors, but it is unclear how the nucleus contributes to endothelial cell activities at the cell periphery. Here, we show that the nuclear-localized nker of the ucleoskeleton and ytoskeleton (LINC) complex protein SUN1 regulates vascular sprouting and endothelial cell-cell junction morphology and function.

A defined clathrin-mediated trafficking pathway regulates sFLT1/VEGFR1 secretion from endothelial cells.

FLT1/VEGFR1 negatively regulates VEGF-A signaling and is required for proper vessel morphogenesis during vascular development and vessel homeostasis. Although a soluble isoform, sFLT1, is often mis-regulated in disease and aging, how sFLT1 is trafficked and secreted from endothelial cells is not well understood. Here we define requirements for constitutive sFLT1 trafficking and secretion in endothelial cells from the Golgi to the plasma membrane, and we show that sFLT1 secretion requires clathrin at or near the Golgi.

Trapping of Lipopolysaccharide to Promote Immunotherapy against Colorectal Cancer and Attenuate Liver Metastasis.

The development and progression of colorectal cancer (CRC) is closely related to gut microbiome. Here, the impact of lipopolysaccharide (LPS), one of the most prevalent products in the gut microbiome, on CRC immunotherapy is investigated. It is found that LPS is abundant in orthotopic CRC tissue and is associated with low responses to anti-PD-L1 mAb therapy, and clearance of Gram-negative bacteria from the gut using polymyxin B (PmB) or blockade of Toll-like receptor 4 using TAK-242 will both relieve the immunosuppressive microenvironment and boost T-cell infiltration into the CRC tumor.

Quantitation of cell-associated carbon nanotubes: selective binding and accumulation of carboxylated carbon nanotubes by macrophages.

To understand the influence of carboxylation on the interaction of carbon nanotubes with cells, the amount of pristine multi-walled carbon nanotubes (P-MWNTs) or carboxylated multi-walled carbon nanotubes (C-MWNTs) coated with Pluronic F-108 that were accumulated by macrophages was measured by quantifying CNTs extracted from cells. Mouse RAW 264.7 macrophages and differentiated human THP-1 (dTHP-1) macrophages accumulated 80-100 times more C-MWNTs than P-MWNTs during a 24-h exposure at 37 °C.

Overcoming multiple gastrointestinal barriers by bilayer modified hollow mesoporous silica nanocarriers.

Unlabelled: Oral administration of nanocarriers remains a significant challenge in the pharmaceutical sciences. The nanocarriers must efficiently overcome multiple gastrointestinal barriers including the harsh gastrointestinal environment, the mucosal layer, and the epithelium. Neutral hydrophilic surfaces are reportedly necessary for mucus permeation, but hydrophobic and cationic surfaces are important for efficient epithelial absorption.

Intercalation-mediated nucleic acid nanoparticles for siRNA delivery.

Tremendous effort has been made to improve stability and delivery efficacy of small RNA therapeutics. However, nearly all current nano-encapsulation carriers utilize the critical balance between only two interacting parameters: RNA-binding electrostatic interactions and nanoparticle-stabilizing hydrophobic interactions. We report the development of intercalation-meditated nucleic acid (IMNA) nanoparticles, which utilize intercalation as a third interaction to enhance small RNA delivery.