Zebrafish tbx-c functions during formation of midline structures

Development ◽  
1999 ◽  
Vol 126 (12) ◽  
pp. 2703-2713 ◽  
Author(s):  
T. Dheen ◽  
I. Sleptsova-Friedrich ◽  
Y. Xu ◽  
M. Clark ◽  
H. Lehrach ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Dominant Negative ◽  
Tail Bud ◽  
T Box ◽  
Developmental Role ◽  
Vitro Analysis ◽  
Lateral Mesoderm ◽  
In Vitro Analysis

Several genes containing the conserved T-box region in invertebrates and vertebrates have been reported recently. Here, we describe three novel members of the T-box gene family in zebrafish. One of these genes, tbx-c, is studied in detail. It is expressed in the axial mesoderm, notably, in the notochordal precursor cells immediately before formation of the notochord and in the chordoneural hinge of the tail bud, after the notochord is formed. In addition, its expression is detected in the ventral forebrain, sensory neurons, fin buds and excretory system. The expression pattern of tbx-c differs from that of the other two related genes, tbx-a and tbx-b. The developmental role of tbx-c has been analysed by overexpression of the full-length tbx-c mRNA and a truncated form of tbx-c mRNA, which encodes the dominant-negative Tbx-c. Overexpression of tbx-c causes expansion of the midline mesoderm and formation of ectopic midline structures at the expense of lateral mesodermal cells. In dominant-negative experiments, the midline mesoderm is reduced with the expansion of lateral mesoderm to the midline. These results suggest that tbx-c plays a role in formation of the midline mesoderm, particularly, the notochord. Moreover, modulation of tbx-c activity alters the development of primary motor neurons. Results of in vitro analysis in zebrafish animal caps suggest that tbx-c acts downstream of early mesodermal inducers (activin and ntl) and reveal an autoregulatory feedback loop between ntl and tbx-c. These data and analysis of midline (ntl−/− and flh−/−) and lateral mesoderm (spt−/−) mutants suggest that tbx-c may function during formation of the notochord.

Role of the 807 C/T Polymorphism of the α2 Gene in Platelet GP Ia Collagen Receptor Expression and Function

1999 ◽  
Vol 81 (06) ◽  
pp. 951-956 ◽  
Author(s):  
J. Corral ◽  
R. González-Conejero ◽  
J. Rivera ◽  
F. Ortuño ◽  
P. Aparicio ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Cell Types ◽  
Receptor Expression ◽  
Case Control Studies ◽  
Platelet Surface ◽  
Vitro Analysis ◽  
And Function ◽  
In Vitro Analysis

SummaryThe variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by “in vitro” analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.

In vitro analysis of the role of DCC in mucus-secreting intestinal differentiation

1999 ◽  
Vol 81 (5) ◽  
pp. 799-807 ◽  
Author(s):  
Myriam Fabre ◽  
Merc� Martin, ◽  
Fausto Ulloa ◽  
Francisco X. Real
Keyword(s):  
Intestinal Differentiation ◽  
Vitro Analysis ◽  
In Vitro Analysis

scholarly journals The role of microRNA-3085 in chondrocyte function

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Linh Le ◽  
Lingzi Niu ◽  
Matthew J. Barter ◽  
David A. Young ◽  
Tamas Dalmay ◽  
...  
Keyword(s):  
Feedback Inhibition ◽  
Interleukin 1 ◽  
Early Time ◽  
Null Cell ◽  
Time Points ◽  
Vitro Analysis ◽  
In Vitro Analysis ◽  
Cultured Chondrocytes

AbstractMicroRNAs have been shown to play a role in cartilage development, homeostasis and breakdown during osteoarthritis. We previously identified miR-3085 in humans as a chondrocyte-selective microRNA, however it could not be detected by Northern blot. The aim of the current study was to prove that miR-3085 is a microRNA and to investigate the function of miR-3085 in signaling pathways relevant to cartilage homeostasis and osteoarthritis. Here, we confirm that miR-3085 is a microRNA and not another class of small RNA using (1) a pre-miR hairpin maturation assay, (2) expression levels in a Dicer null cell line, and (3) Ago2 pulldown. MicroRNA-3085-3p is expressed more highly in micromass than monolayer cultured chondrocytes. Transfection of miR-3085-3p into chondrocytes decreases expression of COL2A1 and ACAN, both of which are validated as direct targets of miR-3085-3p. Interleukin-1 induces the expression of miR-3085-3p, at least in part via NFκB. In a feed-forward mechanism, miR-3085-3p then potentiates NFκB signaling. However, at early time points after transfection, its action appears to be inhibitory. MyD88 has been shown to be a direct target of miR-3085-3p and may be responsible for the early inhibition of NFκB signaling. However, at later time points, MyD88 knockdown remains inhibitory and so other functions of miR-3085-3p are clearly dominant. TGFβ1 also induces the expression of miR-3085-3p, but in this instance, it exerts a feedback inhibition on signaling with SMAD3 and SMAD4 shown to be direct targets. This in vitro analysis shows that miR-3085-3p functions in chondrocytes to induce IL-1-signaling, reduce TGFβ1 signaling, and inhibit expression of matrix genes. These data suggest that miR-3085-3p has a role in chondrocyte function and could contribute to the process of osteoarthritis.

in vivo and in vitro analysis of the functional role of Epstein-Barr virus-induced gene 3 (EBI3) for regulation of Th2 mediated immune responses

2003 ◽  
Vol 124 (4) ◽  
pp. A335
Author(s):  
Stefan J. Wirtz ◽  
Christoph Becker ◽  
Edward E.S. Nieuwenhuis ◽  
Mark Birkenbach ◽  
Richard S. Blumberg ◽  
...  
Keyword(s):  
Immune Responses ◽  
Functional Role ◽  
Epstein Barr Virus ◽  
Barr Virus ◽  
Epstein Barr ◽  
Vitro Analysis ◽  
In Vitro Analysis

scholarly journals The Chemokine CCL2 Is Required for Control of Murine Gastric Salmonella enterica Infection

2005 ◽  
Vol 73 (10) ◽  
pp. 6514-6522 ◽  
Author(s):  
R. William DePaolo ◽  
Rashida Lathan ◽  
Barrett J. Rollins ◽  
William J. Karpus
Keyword(s):  
Typhoid Fever ◽  
Salmonella Enterica ◽  
Critical Factor ◽  
Wild Type ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Vitro Analysis ◽  
In Vitro Analysis

ABSTRACT Salmonella enterica is a gram-negative intracellular pathogen that can cause a variety of diseases ranging from gastroenteritis to typhoid fever. The Typhimurium serotype causes gastroenteritis in humans; however, infection of mice results in an enteric fever that resembles human typhoid fever and has been used as a model for typhoid fever. The present study examined the role of the chemokine CCL2 in the control of Salmonella infection. Upon infection with salmonellae, mucosal expression of CCL2 is rapidly up-regulated, followed by systemic expression in the spleen. CCL2−/− mice became moribund earlier and had a higher rate of mortality compared to wild-type C57BL/6 mice. Moreover, CCL2−/− mice had significantly higher levels of bacteria in the liver compared to wild-type controls. Mucosal and serum interleukin-6 and tumor necrosis factor alpha levels were elevated in CCL2−/− mice compared to wild-type mice. In vitro analysis demonstrated that CCL2−/− macrophages infected with salmonellae resulted in dysregulated cytokine production compared to macrophages derived from wild-type mice. These data are the first to directly demonstrate CCL2 as a critical factor for immune responses and survival following S. enterica infection.

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