Xanthan gum-functionalised span nanoparticles for gene targeting to endothelial cells

The emigration of mature thymocytes from the thymus is critical for establishing peripheral T cell compartments. However, the pathways controlling this process and the timing of egress in relation to postselection developmental stages are poorly defined. Here, we reexamine thymocyte egress and test current and opposing models in relation to the requirement for LTβR, a regulator of thymic microenvironments and thymocyte emigration. Using cell-specific gene targeting, we show that the requirement for LTβR in thymocyte egress is distinct from its control of thymic epithelium and instead maps to expression by endothelial cells. By separating emigration into sequential phases of perivascular space (PVS) entry and transendothelial migration, we reveal a developmentally ordered program of egress where LTβR operates to rate limit access to the PVS. Collectively, we show the process of thymic emigration ensures only the most mature thymocytes leave the thymus and demonstrate a role for LTβR in the initiation of thymus emigration that segregates from its control of medulla organization.

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Positive Effects of Heme Oxygenase Upregulation on Adiposity and Vascular Dysfunction: Gene Targeting vs. Pharmacologic Therapy

International Journal of Molecular Sciences ◽

10.3390/ijms20102514 ◽

2019 ◽

Vol 20 (10) ◽

pp. 2514 ◽

Cited By ~ 15

Author(s):

Stephen J. Peterson ◽

Rochelle Rubinstein ◽

Mouzam Faroqui ◽

Adnan Raza ◽

Imene Boumaza ◽

...

Keyword(s):

Endothelial Cells ◽

Endothelial Cell ◽

Gene Targeting ◽

Heme Oxygenase ◽

Vascular Reactivity ◽

Cell Function ◽

Pharmacologic Therapy ◽

Endothelial Cell Function ◽

Direct Targeting

Objective: Heme oxygenase (HO-1) plays a critical role in adipogenesis and it is important to understand its function in obesity. Many studies have shown that upregulation of HO-1 can affect the biologic parameters in obesity-mediated diabetes, hypertension and vascular endothelial cell function. Thus, we aimed to explore the hypothesis that upregulation of HO-1, using a pharmacologic approach as well as gene targeting, would improve both adiposity and endothelial cell dysfunction by direct targeting of endothelial cells. Our second aim was to compare the short-term effect of a HO-1 inducer, cobalt-protoporphrin IX (CoPP), with the long-term effects of gene targeted therapy on vascular and adipocyte stem cells in obese mice. Method: We examined the effect of CoPP on fat pre-adipocytes and mesenchymal stem cells (MSC) in mice fed a high-fat diet (HFD). We also used a lentiviral construct that expressed heme oxygenase (HO-1) that was under the control of an endothelium specific promoter, vascular endothelium cadherin (VECAD) heme oxygenase (VECAD-HO-1). We targeted endothelial cells using vascular endothelium cadherin/green fluorescent protein fusion construct (VECAD-GFP) as the control. Conditioned media (CM) from endothelial cells (EC) was added to fat derived adipocytes. Additionally, we treated renal interlobar arteries with phenylephrine and dosed cumulative increments of acetylcholine both with and without exposure to CoPP. We did the same vascular reactivity experiments with VECAD-HO-1 lentiviral construct compared to the control. Results: CoPP improved vascular reactivity and decreased adipogenesis compared to the control. MSCs exposed to CM from EC transfected with VECAD-HO-1 showed decreased adipogenesis, smaller lipid droplet size and decreased PPAR-γ, C/EBP and increased Wnt 10b compared to the control. HO-1 upregulation had a direct effect on reducing adipogenesis. This effect was blocked by tin mesoporphrin (SnMP). EC treated with VECAD-HO-1 expressed lower levels of ICAM and VCAM compared to the control, suggesting improved EC function. This also improved ACH induced vascular reactivity. These effects were also reversed by SnMP. The effect of viral transfection was much more specific and sustained than the effects of pharmacologic therapy, CoPP. Conclusion: This study demonstrates that a pharmacological inducer of HO-1 such as CoPP improves endothelial cell function while dampening adipogenesis, but long-term HO-1 expression by direct targeting of endothelial cells by gene transfer therapy may offer a more specific and ideal solution. This was evidenced by smaller healthier adipocytes that had improved insulin sensitivity, suggesting increased adiponectin levels. HO-1 upregulation reestablished the “crosstalk” between perivascular adipose tissue and the vascular system that was lost in the chronic inflammatory state of obesity. This study demonstrates that gene targeting of EC may well be the future direction in treating obesity induced EC dysfunction, with the finding that targeting the vasculature had a direct and sustained effect on adipogenesis.

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Proapoptotic BH3-Only Bcl-2 Family Member Bik/Blk/Nbk Is Expressed in Hemopoietic and Endothelial Cells but Is Redundant for Their Programmed Death

Molecular and Cellular Biology ◽

10.1128/mcb.24.4.1570-1581.2004 ◽

2004 ◽

Vol 24 (4) ◽

pp. 1570-1581 ◽

Cited By ~ 81

Author(s):

Leigh Coultas ◽

Philippe Bouillet ◽

Edouard G. Stanley ◽

Thomas C. Brodnicki ◽

Jerry M. Adams ◽

...

Keyword(s):

Endothelial Cells ◽

Cell Death ◽

Kidney Disease ◽

Programmed Cell Death ◽

Gene Targeting ◽

Physiological Function ◽

Polycystic Kidney ◽

Programmed Death ◽

Induced Apoptosis

ABSTRACT The BH3-only members of the Bcl-2 protein family are essential for initiation of programmed cell death and stress-induced apoptosis. We have determined the expression pattern in mice of the BH3-only protein Bik, also called Blk or Nbk, and examined its physiological function by gene targeting. We found that Bik is expressed widely in the hematopoietic compartment and in endothelial cells of the venous but not arterial lineages. Nevertheless, its loss did not increase the numbers of such cells in mice or protect hematopoietic cells in vitro from apoptosis induced by cytokine withdrawal or diverse other cytotoxic stimuli. Moreover, whereas loss of the BH3-only protein Bim rescued mice lacking the prosurvival protein Bcl-2 from fatal polycystic kidney disease and lymphopenia, loss of Bik did not. These results indicate that any function of Bik in programmed cell death and stress-induced apoptosis must overlap that of other BH3-only proteins.

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VEGF is required for growth and survival in neonatal mice

Development ◽

10.1242/dev.126.6.1149 ◽

1999 ◽

Vol 126 (6) ◽

pp. 1149-1159 ◽

Cited By ~ 12

Author(s):

H.P. Gerber ◽

K.J. Hillan ◽

A.M. Ryan ◽

J. Kowalski ◽

G.A. Keller ◽

...

Keyword(s):

Endothelial Cells ◽

Gene Targeting ◽

Chimeric Protein ◽

Cell Types ◽

Postnatal Life ◽

Vegf Receptor ◽

Newborn Mice ◽

Growth And Survival ◽

Liver Endothelial Cells ◽

Inducible Gene

We employed two independent approaches to inactivate the angiogenic protein VEGF in newborn mice: inducible, Cre-loxP- mediated gene targeting, or administration of mFlt(1–3)-IgG, a soluble VEGF receptor chimeric protein. Partial inhibition of VEGF achieved by inducible gene targeting resulted in increased mortality, stunted body growth and impaired organ development, most notably of the liver. Administration of mFlt(1–3)-IgG, which achieves a higher degree of VEGF inhibition, resulted in nearly complete growth arrest and lethality. Ultrastructural analysis documented alterations in endothelial and other cell types. Histological and biochemical changes consistent with liver and renal failure were observed. Endothelial cells isolated from the liver of mFlt(1–3)-IgG-treated neonates demonstrated an increased apoptotic index, indicating that VEGF is required not only for proliferation but also for survival of endothelial cells. However, such treatment resulted in less significant alterations as the animal matured, and the dependence on VEGF was eventually lost some time after the fourth postnatal week. Administration of mFlt(1–3)-IgG to juvenile mice failed to induce apoptosis in liver endothelial cells. Thus, VEGF is essential for growth and survival in early postnatal life. However, in the fully developed animal, VEGF is likely to be involved primarily in active angiogenesis processes such as corpus luteum development.

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Endotoxin Alteration of the Mucopolysaccharide Blood Vessel Coating in Rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050755 ◽

1974 ◽

Vol 32 ◽

pp. 148-149

Author(s):

D. E. Philpott ◽

A. Takahashi

Keyword(s):

Skeletal Muscle ◽

Endothelial Cells ◽

Salivary Gland ◽

Carotid Artery ◽

Basement Membrane ◽

Coronary Vessels ◽

Ruthenium Red ◽

E Coli ◽

Old Rats ◽

The Brain

Two month, eight month and two year old rats were treated with 10 or 20 mg/kg of E. Coli endotoxin I. P. The eight month old rats proved most resistant to the endotoxin. During fixation the aorta, carotid artery, basil arartery of the brain, coronary vessels of the heart, inner surfaces of the heart chambers, heart and skeletal muscle, lung, liver, kidney, spleen, brain, retina, trachae, intestine, salivary gland, adrenal gland and gingiva were treated with ruthenium red or alcian blue to preserve the mucopolysaccharide (MPS) coating. Five, 8 and 24 hrs of endotoxin treatment produced increasingly marked capillary damage, disappearance of the MPS coating, edema, destruction of endothelial cells and damage to the basement membrane in the liver, kidney and lung.

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Complex Vesicles, Microtubules, and Cytoplasmic Filaments in the Endothelial Cells of Normal Dog Aorta

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100603 ◽

1968 ◽

Vol 26 ◽

pp. 172-173

Author(s):

C. N. Sun ◽

J. J. Ghidoni

Keyword(s):

Electron Microscopy ◽

Endothelial Cells ◽

Cross Sections ◽

Functional Significance ◽

Tubular Structures ◽

Aldehyde Fixation ◽

Cytoplasmic Filaments

Endothelial cells in longitudinal and cross sections of aortas from 3 randomly selected “normal” mongrel dogs were studied by electron microscopy. Segments of aorta were distended with cold cacodylate buffered 5% glutaraldehyde for 10 minutes prior to being cut into small, well oriented tissue blocks. After an additional 1-1/2 hour period in glutaraldehyde, the tissue blocks were well rinsed in buffer and post-fixed in OsO4. After dehydration they were embedded in a mixture of Maraglas, D.E.R. 732, and DDSA.Aldehyde fixation preserves the filamentous and tubular structures (300 Å and less) for adequate demonstration and study. The functional significance of filaments and microtubules has been recently discussed by Buckley and Porter; the precise roles of these cytoplasmic components remains problematic. Endothelial cells in canine aortas contained an abundance of both types of structures.

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Ultrastructural Alterations in Sinusoidal Endothelial Fenestrae as a Result of Hypoxia

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100090828 ◽

1976 ◽

Vol 34 ◽

pp. 168-169

Author(s):

Waykin Nopanitaya ◽

Raeford E. Brown ◽

Joe W. Grisham ◽

Johnny L. Carson

Keyword(s):

Endothelial Cells ◽

Experimental Model ◽

Hepatic Lobule ◽

Ultrastructural Alterations ◽

Large Type ◽

Sinusoidal Endothelial Fenestrae ◽

General Size ◽

Sem Studies

Mammalian endothelial cells lining hepatic sinusoids have been found to be widely fenestrated. Previous SEM studies (1,2) have noted two general size catagories of fenestrations; large fenestrae were distributed randomly while the small type occurred in groups. These investigations also reported that large fenestrae were more numerous and larger in the endothelial cells at the afferent ends of sinusoids or around the portal areas, whereas small fenestrae were more numerous around the centrilobular portion of the hepatic lobule. It has been further suggested that under some physiologic conditions small fenestrae could fuse and subsequently become the large type, but this is, as yet, unproven.We have used a reproducible experimental model of hypoxia to study the ultrastructural alterations in sinusoidal endothelial fenestrations in order to investigate the origin of occurrence of large fenestrae.

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Ultrastructural studies on the interaction of haemophilus influenzae with human endothelial cells in vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010016073x ◽

1990 ◽

Vol 48 (3) ◽

pp. 636-637

Author(s):

D.J.P. Ferguson ◽

M. Virji ◽

H. Kayhty ◽

E.R. Moxon

Keyword(s):

Endothelial Cells ◽

Haemophilus Influenzae ◽

Intercellular Junctions ◽

Blood Stream ◽

Ultrastructural Studies ◽

Endothelial Barriers ◽

Serotype B ◽

Meningitis In Children ◽

Respiratory Epithelial

Haemophilus influenzae is a human pathogen which causes meningitis in children. Systemic H. influenzae infection is largely confined to encapsulated serotype b organisms and is a major cause of meningitis in the U.K. and elsewhere. However, the pathogenesis of the disease is still poorly understood. Studies in the infant rat model, in which intranasal challenge results in bacteraemia, have shown that H. influenzae enters submucosal tissues and disseminates to the blood stream within minutes. The rapidity of these events suggests that H. influenzae penetrates both respiratory epithelial and endothelial barriers with great efficiency. It is not known whether the bacteria penetrate via the intercellular junctions, are translocated within the cells or carried across the cellular barrier in 'trojan horse' fashion within phagocytes. In the present studies, we have challenged cultured human umbilical cord_vein endothelial cells (HUVECs) with both capsulated (b+) and capsule-deficient (b-) isogenic variants of one strain of H. influenzae in order to investigate the interaction between the bacteria and HUVEC and the effect of the capsule.

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