Msx1 upregulates p27 expression to control cellular proliferation during valvuloseptal endocardial cushion formation in the chick embryonic heart

Transforming growth factor-β (TGFβ) is a dimeric peptide growth factor which regulates cellular differentiation and proliferation during development. Most cells secrete TGFβ as a large latent TGFβ complex containing mature TGFβ, latency associated peptide, and latent TGFβ-binding protein (LTBP)-1. The biological role of LTBP-1 in development remains unclear. Using a polyclonal antiserum specific for LTBP-1 (Ab39) and three-dimensional collagen gel culture assay of embryonic heart, we examined the tissue distribution of LTBP-1 and its functional role during the formation of endocardial cushion tissue in the mouse embryonic heart. Mature TGFβ protein was required at the onset of the endothelial-mesenchymal transformation to initiate endocardial cushion tissue formation. Double antibody staining showed that LTBP-1 colocalized with TGFβ1 as an extracellular fibrillar structure surrounding the endocardial cushion mesenchymal cells. Immunogold electronmicroscopy showed that LTBP-1 localized to 40–100 nm extracellular fibrillar structure and 5–10-nm microfibrils. The anti–LTBP-1 antiserum (Ab39) inhibited the endothelial-mesenchymal transformation in atrio-ventricular endocardial cells cocultured with associated myocardium on a three-dimensional collagen gel lattice. This inhibitory effect was reversed by administration of mature TGFβ proteins in culture. These results suggest that LTBP-1 exists as an extracellular fibrillar structure and plays a role in the storage of TGFβ as a large latent TGFβ complex.

Download Full-text

NOX2 Is Critical to Endocardial to Mesenchymal Transition and Heart Development

Oxidative Medicine and Cellular Longevity ◽

10.1155/2020/1679045 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Hoda Moazzen ◽

Yan Wu ◽

Anish Engineer ◽

Xiangru Lu ◽

Simran Aulakh ◽

...

Keyword(s):

Cell Proliferation ◽

Heart Development ◽

Ex Vivo ◽

Heart Defects ◽

Embryonic Heart ◽

Abnormal Development ◽

Endocardial Cushion ◽

Atrioventricular Canal ◽

Mesenchymal Transition ◽

Septal Defects

NADPH oxidases (NOX) are a major source of reactive oxygen species (ROS) production in the heart. ROS signaling regulates gene expression, cell proliferation, apoptosis, and migration. However, the role of NOX2 in embryonic heart development remains elusive. We hypothesized that deficiency of Nox2 disrupts endocardial to mesenchymal transition (EndMT) and results in congenital septal and valvular defects. Our data show that 34% of Nox2-/- neonatal mice had various congenital heart defects (CHDs) including atrial septal defects (ASD), ventricular septal defects (VSD), atrioventricular canal defects (AVCD), and malformation of atrioventricular and aortic valves. Notably, Nox2-/- embryonic hearts show abnormal development of the endocardial cushion as evidenced by decreased cell proliferation and an increased rate of apoptosis. Additionally, Nox2 deficiency disrupted EndMT of atrioventricular cushion explants ex vivo. Furthermore, treatment with N-acetylcysteine (NAC) to reduce ROS levels in the wild-type endocardial cushion explants decreased the number of cells undergoing EndMT. Importantly, deficiency of Nox2 was associated with reduced expression of Gata4, Tgfβ2, Bmp2, Bmp4, and Snail1, which are critical to endocardial cushion and valvoseptal development. We conclude that NOX2 is critical to EndMT, endocardial cushion cell proliferation, and normal embryonic heart development.

Download Full-text

Cell death and differentiation in the development of the endocardial cushion of the embryonic heart

Microscopy Research and Technique ◽

10.1002/jemt.10159 ◽

2002 ◽

Vol 58 (5) ◽

pp. 395-403 ◽

Cited By ~ 28

Author(s):

Eltyeb Abdelwahid ◽

Lauri J. Pelliniemi ◽

Eero Jokinen

Keyword(s):

Cell Death ◽

Embryonic Heart ◽

Endocardial Cushion

Download Full-text

Correlation Between Cellular Functions and Morphological Changes of Human Trophoblast in Vitro

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100116620 ◽

1975 ◽

Vol 33 ◽

pp. 600-601

Author(s):

John C. Garancis ◽

Robert O. Hussa ◽

Michael T. Story ◽

Donald Yorde ◽

Roland A. Pattillo

Keyword(s):

Electron Microscopy ◽

Cellular Proliferation ◽

Morphological Changes ◽

Culture Fluid ◽

Cellular Functions ◽

Human Trophoblast ◽

Transmission Electron ◽

Marked Activity ◽

Malignant Trophoblast

Human malignant trophoblast cells in continuous culture were incubated for 3 days in medium containing 1 mM N6-O2'-dibutyryl cyclic adenosine 3':5'-monophosphate (dibutyryl cyclic AMP) and 1 mM theophylline. The culture fluid was replenished daily. Stimulated cultures secreted many times more chorionic gonadotropin and estrogens than did control cultures in the absence of increased cellular proliferation. Scanning electron microscopy revealed remarkable surface changes of stimulated cells. Control cells (not stimulated) were smooth or provided with varying numbers of microvilli (Fig. 1). The latter, usually, were short and thin. The surface features of stimulated cells were considerably different. There was marked increase of microvilli which appeared elongated and thick. Many cells were covered with confluent polypoid projections (Fig. 2). Transmission electron microscopy demonstrated marked activity of cytoplasmic organelles. Mitochondria were increased in number and size; some giant forms with numerous cristae were observed.

Download Full-text

Vascular adaptations to hypoxia: molecular and cellular mechanisms regulating vascular tone

Essays in Biochemistry ◽

10.1042/bse0430105 ◽

2007 ◽

Vol 43 ◽

pp. 105-120 ◽

Cited By ~ 8

Author(s):

Michael L. Paffett ◽

Benjimen R. Walker

Keyword(s):

Vascular Tone ◽

Cellular Proliferation ◽

Hypoxic Pulmonary Vasoconstriction ◽

Hypoxia Inducible Factor ◽

Systemic Circulation ◽

Cellular Mechanisms ◽

Hypoxia Inducible Factor 1 ◽

Pulmonary Vasoconstriction ◽

Adaptive Mechanisms ◽

Adaptive Processes

Several molecular and cellular adaptive mechanisms to hypoxia exist within the vasculature. Many of these processes involve oxygen sensing which is transduced into mediators of vasoconstriction in the pulmonary circulation and vasodilation in the systemic circulation. A variety of oxygen-responsive pathways, such as HIF (hypoxia-inducible factor)-1 and HOs (haem oxygenases), contribute to the overall adaptive process during hypoxia and are currently an area of intense research. Generation of ROS (reactive oxygen species) may also differentially regulate vascular tone in these circulations. Potential candidates underlying the divergent responses between the systemic and pulmonary circulations may include Nox (NADPH oxidase)-derived ROS and mitochondrial-derived ROS. In addition to alterations in ROS production governing vascular tone in the hypoxic setting, other vascular adaptations are likely to be involved. HPV (hypoxic pulmonary vasoconstriction) and CH (chronic hypoxia)-induced alterations in cellular proliferation, ionic conductances and changes in the contractile apparatus sensitivity to calcium, all occur as adaptive processes within the vasculature.

Download Full-text

Gut-enriched kruppel-like factor (GKLF) inhibits cellular proliferation by blocking the G1/S boundary of the cell cycle

Gastroenterology ◽

10.1016/s0016-5085(01)80506-0 ◽

2001 ◽

Vol 120 (5) ◽

pp. A103-A103

Author(s):

X CHEN ◽

D JOHNS ◽

D GEIMAN ◽

E MARBAN ◽

V YANG

Keyword(s):

Cell Cycle ◽

Cellular Proliferation

Download Full-text

An in vitro model for investigation of vitamin A effects on wound healing

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000692 ◽

2021 ◽

pp. 1-6

Author(s):

Hoda Keshmiri Neghab ◽

Mohammad Hasan Soheilifar ◽

Gholamreza Esmaeeli Djavid

Keyword(s):

Wound Healing ◽

Endothelial Cell ◽

Vitamin A ◽

In Vitro Model ◽

Cellular Proliferation ◽

Endothelial Cell Migration ◽

Normal Fibroblast ◽

Anti Inflammatory ◽

Vitro Model

Abstract. Wound healing consists of a series of highly orderly overlapping processes characterized by hemostasis, inflammation, proliferation, and remodeling. Prolongation or interruption in each phase can lead to delayed wound healing or a non-healing chronic wound. Vitamin A is a crucial nutrient that is most beneficial for the health of the skin. The present study was undertaken to determine the effect of vitamin A on regeneration, angiogenesis, and inflammation characteristics in an in vitro model system during wound healing. For this purpose, mouse skin normal fibroblast (L929), human umbilical vein endothelial cell (HUVEC), and monocyte/macrophage-like cell line (RAW 264.7) were considered to evaluate proliferation, angiogenesis, and anti-inﬂammatory responses, respectively. Vitamin A (0.1–5 μM) increased cellular proliferation of L929 and HUVEC (p < 0.05). Similarly, it stimulated angiogenesis by promoting endothelial cell migration up to approximately 4 fold and interestingly tube formation up to 8.5 fold (p < 0.01). Furthermore, vitamin A treatment was shown to decrease the level of nitric oxide production in a dose-dependent effect (p < 0.05), exhibiting the anti-inflammatory property of vitamin A in accelerating wound healing. These results may reveal the therapeutic potential of vitamin A in diabetic wound healing by stimulating regeneration, angiogenesis, and anti-inﬂammation responses.

Download Full-text

T Lymphocyte Proliferative Responses Induced by Recombinant Factor VIII in Hemophilia A Patients with Inhibitors

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650515 ◽

1996 ◽

Vol 76 (01) ◽

pp. 017-022 ◽

Cited By ~ 27

Author(s):

Sylvia T Singer ◽

Joseph E Addiego ◽

Donald C Reason ◽

Alexander H Lucas

Keyword(s):

T Lymphocytes ◽

Factor Viii ◽

Cellular Proliferation ◽

Mononuclear Cells ◽

Hemophilia A ◽

Normal Subjects ◽

Normal Male ◽

Cell Fractionation ◽

Severe Hemophilia ◽

Human Factor Viii

SummaryIn this study we sought to determine whether factor VUI-reactive T lymphocytes were present in hemophilia A patients with inhibitor antibodies. Peripheral blood mononuclear cells (MNC) were obtained from 12 severe hemophilia A patients having high titer inhibitors, 4 severe hemophilia A patients without inhibitors and 5 normal male subjects. B cell-depleted MNC were cultured in serum-free medium in the absence or presence of 2 µg of recombinant human factor VIII (rFVIII) per ml, and cellular proliferation was assessed after 5 days of culture by measuring 3H-thymidine incorporation. rFVIII induced marked cellular proliferation in cultures of 4 of 12 inhibitor-positive hemophilia patients: fold increase over background (stimulation index, SI) of 7.8 to 23.3. The remaining 8 inhibitor-positive patients, the 4 hemophilia patients without inhibitors and the 5 normal subjects, all had lower proliferative responses to rFVIII, SI range = 1.6 to 6.0. As a group, the inhibitor-positive subjects had significantly higher proliferative responses to rFVIII than did the inhibitor-negative and normal subjects (p < 0.05 by t-test). Cell fractionation experiments showed that T lymphocytes were the rFVIII-responsive cell type, and that monocytes were required for T cell proliferation. Thus, rFVIII-reactive T lymphocytes are present in the peripheral circulation of some inhibitor-positive hemophilia A patients. These T cells may recognize FVIII in an antigen-specific manner and play a central role in the regulation of inhibitor antibody production

Download Full-text