Melanophore β-adrenoceptors in patterning in a flatfish, Pseudopleuronectes americanus

2007 ◽  
Vol 85 (6) ◽  
pp. 695-702 ◽  
Author(s):  
D. Burton
Keyword(s):  
Salt Solution ◽  
Winter Flounder ◽  
Dark Band ◽  
Pigment Dispersion ◽  
In Vitro Experiments ◽  
Pseudopleuronectes Americanus ◽  
Adrenoceptor Agonists

In vitro experiments were performed on melanophores bourne on scale slips sampled from three major areas (general background, dark band, and white spot) of the integumentary pattern of winter flounder, Pseudopleuronectes americanus (Walbaum, 1792). The effects of the respective β1- and β2-adrenoceptor agonists dobutamine and terbutaline and antagonists atenolol and ICI 118551 on pattern-related melanosome aggregation in response to exogenously applied L-noradrenaline were determined, as well as their effects on melanosome dispersion in balanced salt solution. The results demonstrate β1-adrenoceptor mediation in flatfish melanosome dispersion, with pattern-related variation, and also provide further evidence for β2-subtype involvement. Based on mammalian physiology, two β-subtypes will facilitate melanophore responsiveness to both neural and circulatory catecholamines. The in vivo role of these β-subtypes is discussed in relation to previously described attributes of the patterning behaviour of this species, which incorporates balances between α- and β-adrenoceptors. Dark band melanophores display a β-adrenoceptor bias, in contrast with other areas of the pattern, which would be consistent with their capacity for pigment dispersion in stressed flounders and with the slow paling of these bands during background-related responses.

scholarly journals Trophectoderm-Specific Knockdown of LIN28 Decreases Expression of Genes Necessary for Cell Proliferation and Reduces Elongation of Sheep Conceptus

2020 ◽  
Vol 21 (7) ◽  
pp. 2549 ◽  
Author(s):  
Asghar Ali ◽  
Mark Stenglein ◽  
Thomas Spencer ◽  
Gerrit Bouma ◽  
Russell Anthony ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Critical Period ◽  
In Vitro Experiments ◽  
Placental Development ◽  
Expression Of Genes ◽  
Trophectoderm Cells ◽  
Successful Establishment

LIN28 inhibits let-7 miRNA maturation which prevents cell differentiation and promotes proliferation. We hypothesized that the LIN28-let-7 axis regulates proliferation-associated genes in sheep trophectoderm in vivo. Day 9-hatched sheep blastocysts were incubated with lentiviral particles to deliver shRNA targeting LIN28 specifically to trophectoderm cells. At day 16, conceptus elongation was significantly reduced in LIN28A and LIN28B knockdowns. Let-7 miRNAs were significantly increased and IGF2BP1-3, HMGA1, ARID3B, and c-MYC were decreased in trophectoderm from knockdown conceptuses. Ovine trophoblast (OTR) cells derived from day 16 trophectoderm are a useful tool for in vitro experiments. Surprisingly, LIN28 was significantly reduced and let-7 miRNAs increased after only a few passages of OTR cells, suggesting these passaged cells represent a more differentiated phenotype. To create an OTR cell line more similar to day 16 trophectoderm we overexpressed LIN28A and LIN28B, which significantly decreased let-7 miRNAs and increased IGF2BP1-3, HMGA1, ARID3B, and c-MYC compared to control. This is the first study showing the role of the LIN28-let-7 axis in trophoblast proliferation and conceptus elongation in vivo. These results suggest that reduced LIN28 during early placental development can lead to reduced trophoblast proliferation and sheep conceptus elongation at a critical period for successful establishment of pregnancy.

Renal sugar transport in the winter flounder: V. secretion of 2-deoxy-D-galactose

1978 ◽  
Vol 234 (5) ◽  
pp. F424-F431
Author(s):  
J. B. Pritchard ◽  
G. Booz ◽  
A. Kleinzeller
Keyword(s):  
Sugar Transport ◽  
Winter Flounder ◽  
Free Sugar ◽  
Renal Tubules ◽  
Pseudopleuronectes Americanus ◽  
Clearance Ratio ◽  
Renal Handling ◽  
Cell Clearance

Isolated renal tubules and renal clearance techniques were used to characterize the renal handling of 2-deoxy-D-galactose (2-d-Gal) by the winter flounder (Pseudopleuronectes americanus). In vitro, energy-dependent, pH-sensitive uptake of 2-d-Gal (2–100 micron) was seen at the antiluminal face of the cell. Clearance measurements showed net secretion of 2-d-Gal in vivo. The mean clearance of 2-d-Gal in 18 fish was 0.98 +/- 0.16 ml/h while the glomerular filtration rate (GFR) was only 0.37 +/- 0.10 ml/h. Secretion was associated with marked renal accumulation of both 2-d-Gal and phosphorylated derivatives (2-d-Gal-1-phosphate). Tissue-to-plasma ratios (T/P) averaged 19 for free sugar and 59 for total sugar. Both clearance ratio and T/P were reduced to approximately 1 by injection of galactose (2.5 mmol/kg) simultaneously with 2-d-Gal (25 mumol/kg). Phlorizin (2.5 mumol/kg) increased net 2-d-Gal secretion, whereas glucose (2.5 mmol/kg) produced no change in secretion. Both compounds depressed 2-d-Gal T/P. This result suggests the presence of readsorptive transport at the brush border, sensitive to glucose and phlorizin.

Role of Activated Platelets in the Homing, Maturation, and Differentiation of Endotheleal Progenitor Cells (EPCs) to Vascular Subendotheleal Matrix.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3938-3938
Author(s):  
Eli I. Lev ◽  
Jing-fei Dong ◽  
Marcin Bujak ◽  
Khatira Aboulfatova ◽  
Neal S. Kleiman ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Vascular Injury ◽  
Human Platelets ◽  
In Vitro Experiments ◽  
Cell Markers ◽  
Femoral Arteries ◽  
In Vivo Experiments

Abstract We and others have found that platelets play an important role in the recruitment of endothelial progenitor cells to sights of vascular injury. However, it is not clear whether the EPCs mature and differentiate to endothelial cells following recruitment to the vascular injury sites. In addition, there is limited in vivo data to support the role of EPCs in re-endothlialization following vascular injury. We conducted in vitro experiments to investigate the maturation of EPCs on platelet based-media and in vivo experiments to evaluate the recruitment of EPCs following vascular injury. In in vitro experiments human EPCs were isolated from donated buffy coats by magnetic microbeads and flow cytometry cell sorting using CD133 and VEGFR-2, respectively, as cell markers. Isolated viable EPCs (CD133+, VEGFR-2+ cells) were plated on human fibronectin or a monolayer of washed human platelets. Cell colonies were counted 7 days after plating and stained for the endothelial cell markers CD31 (PECAM-1) and CD144 (VE-cadherin). The mean number of colony-forming cells was 35±2.6 colonies/106 cells on platelets, which was significantly higher than 18±4.2 colonies/106 cells on fibronectin (n = 4, P<0.01). Apart from the difference in colony numbers, the EPC colonies grew faster on the platelet substrate, were larger, and had more spindle-shaped cells (Figure 1 - staining of EPC colonies for CD31 and CD144). In the in vivo experiments a model of transluminal injury to mouse femoral arteries was used. Femoral artery denudation was performed by 0.25-mm-diameter angioplasty guidewire. Injured femoral arteries were compared to the contra-lateral controls (uninjured), and were harvested 1.5 hours following the injury and immunostaining performed with an anti-VEGFR-2 antibody. Four experiments showed a markedly higher number of VEGFR-2+ cells in the artery that has undergone denudation. These experiments indicate that a media composed of platelets promotes the maturation and differentiation of EPCs. Furthermore, in vivo, EPCs are recruited early following vascular injury. Thus, homing, maturation, and differentiation of EPCs are mediated by platelets.

Inhibin-like activity in Sertoli cell culture media and testicular homogenates from rats of various ages

1987 ◽  
Vol 113 (1) ◽  
pp. 103-110 ◽  
Author(s):  
A. M. Ultee-van Gessel ◽  
F. H. de Jong
Keyword(s):  
Sertoli Cells ◽  
Culture Media ◽  
Reciprocal Relationship ◽  
Pituitary Cells ◽  
In Vitro Experiments ◽  
Old Rats ◽  
Lh Secretion

ABSTRACT The influence of age on testicular inhibin in untreated, neonatally hemicastrated and prenatally irradiated rats was studied using in-vivo and in-vitro experiments. In testicular cytosols prepared from 1-, 7-, 14-, 21-, 42- and 63-day-old rats concentrations of testicular inhibin could be measured with an in-vitro bioassay method using dispersed pituitary cells. Preparations of testicular cytosols caused a dose-dependent suppression of pituitary FSH secretion, whereas no effects were found on LH secretion. Testicular content of inhibin increased gradually with age, while after 14 days of age a relatively large increase of peripheral FSH concentrations occurred in all experimental groups. Neonatal hemicastration or prenatal irradiation resulted in decreased inhibin content of the testis and increased plasma FSH levels. The production of inhibin activity by Sertoli cells obtained from 7-, 14-, 21-, 42- and 63-day-old normal rats was measured during a 24-h incubation period on the third day of culture. The inhibin production per 106 plated Sertoli cells decreased rapidly after 14 days of age and the lowest production of inhibin was found in Sertoli cells from rats of 63 days of age. After preincubation with ovine FSH significantly larger amounts of inhibin activity were detected in spent media from 21-day-old rat testes. In contrast, suppression of inhibin production was found after preculture in the presence of testosterone at most of the ages studied. These data from in-vivo and in-vitro experiments indicate that a reciprocal relationship exists between pituitary FSH secretion and inhibin production before the age of 21 days. This relationship supports the concept that inhibin is a physiologically important modulator of FSH secretion before puberty, while the role of the large amount of testicular inhibin present at the older ages remains to be determined. J. Endocr. (1987) 113, 103–110

scholarly journals Complex role of NK cells in regulation of oncolytic virus–bortezomib therapy

2018 ◽  
Vol 115 (19) ◽  
pp. 4927-4932 ◽  
Author(s):  
Yangjin Kim ◽  
Ji Young Yoo ◽  
Tae Jin Lee ◽  
Joseph Liu ◽  
Jianhua Yu ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Tumor Microenvironment ◽  
Nk Cells ◽  
Proteasome Inhibitor ◽  
Oncolytic Virus ◽  
In Vitro Experiments ◽  
Hematological Cancers

In the present work, we investigated the role of natural killer (NK) cells in combination therapy with oncolytic virus (OV) and bortezomib, a proteasome inhibitor. NK cells display rapid and potent immunity to metastatic and hematological cancers, and they overcome immunosuppressive effects of tumor microenvironment. We developed a mathematical model to address the question of how the density of NK cells affects the growth of the tumor. We found that the antitumor efficacy increases when the endogenous NKs are depleted and also when exogenous NK cells are injected into the tumor. These predictions were validated by our in vivo and in vitro experiments.

scholarly journals GORASPs link Golgi cisternae laterally to stabilize the rims and prevent vesiculation

2020 ◽  
Author(s):  
Rianne Grond ◽  
Tineke Veenendaal ◽  
Juan Duran ◽  
Ishier Raote ◽  
Sebastiaan Corstjens ◽  
...  
Keyword(s):  
Dynamic Control ◽  
Vesicle Fusion ◽  
In Vitro Experiments ◽  
Cross Sectional ◽  
Data Support

AbstractIn vitro experiments have shown GRASP65 (GORASP1) and GRASP55 (GORASP2) proteins function in stacking Golgi cisternae. However, in vivo depletion of GORASPs in metazoans have given equivocal results. We have generated a mouse lacking both GORASPs and find that Golgi cisternae remained stacked. However, the stacks are disconnected laterally from each other and the cisternal cross-sectional diameters are significantly reduced compared to their normal counterparts. These data support earlier findings on the role of GORASPs in linking stacks and we suggest that unlinking of stacks affects dynamic control of COPI budding and vesicle fusion at the rims. The net result is that cisternal cores remain stacked, but cisternal diameter is reduced by rim consumption.

Role of progesterone in embryo development in cattle

2016 ◽  
Vol 28 (2) ◽  
pp. 66 ◽  
Author(s):  
Pat Lonergan ◽  
Niamh Forde ◽  
Thomas Spencer
Keyword(s):  
Corpus Luteum ◽  
Embryo Development ◽  
Early Pregnancy ◽  
Pregnancy Rates ◽  
In Vitro Experiments ◽  
Conceptus Development

Progesterone (P4) from the corpus luteum is critical for the establishment and maintenance of pregnancy and plays a major role in regulating endometrial secretions essential for stimulating and mediating changes in conceptus growth and differentiation throughout early pregnancy in ruminants. Numerous studies have demonstrated an association between elevated systemic P4 and acceleration in conceptus elongation. A combination of in vivo and in vitro experiments found that the effects of P4 on conceptus elongation are indirect and mediated through P4-induced effects in the endometrium. Despite effects on elongation, data on the effects of post-insemination supplementation with P4 on pregnancy rates are conflicting. This review highlights the effects of P4 on conceptus development and examines strategies that have been undertaken to manipulate P4 concentrations to increase fertility.

Role of Mononuclear Macrophages in the Regulation of Haemopoiesis: In vitro Experiments and Observations in vivo

2015 ◽  
pp. 44-53
Author(s):  
E. Wunder ◽  
B. Thing-Mortensen ◽  
H. Sovalat ◽  
Ph. Henon ◽  
P. Charbord
Keyword(s):  
In Vitro Experiments

Renal sugar transport in the winter flounder. VI. Reabsorption of D-mannose

1982 ◽  
Vol 242 (4) ◽  
pp. F415-F422 ◽  
Author(s):  
J. B. Pritchard ◽  
G. W. Booz ◽  
A. Kleinzeller
Keyword(s):  
Plasma Concentrations ◽  
Sugar Transport ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Paralichthys Lethostigma ◽  
Southern Flounder ◽  
Cotransport System ◽  
Stimulation Experiments

The transport of D-mannose (Man) in flounder kidney was studied using renal clearance techniques in vivo and brush border membrane (BBM) vesicles in vitro. At plasma concentrations of 50-100 microM Man, the winter flounder (Pseudopleuronectes americanus) reabsorbed up to 70% of the filtered sugar. Man phosphates, but not free Man, accumulated in renal cells. Reabsorption of Man was reduced by phlorizin, D-glucose, methyl-alpha-D-glucoside, methyl-alpha-D-mannoside, and 2-deoxy-D-glucose. In BBM vesicles a Na+-dependent, phlorizin-sensitive overshoot in Man uptake (10 microM) was seen. Na+-dependent Man uptake was saturable, with an apparent Km of 127 microM. The transport properties for Man were identical in BBM vesicles from the winter flounder and southern flounder (Paralichthys lethostigma). The transport specificity was determined by cis-inhibition and trans-stimulation experiments with BBM. Glucose, galactose, 1,5-anhydro-D-mannitol (i.e., 1-deoxymannose), 2-deoxy-2-fluoro-D-glucose, and methyl-alpha-mannoside were shown to share the carrier-mediating mannose transport. 2-Deoxyglucose, methyl-alpha-2-deoxy-D-glucoside, and both the isomers (alpha and beta) of methyl-D-glucoside did not. In contrast, alpha-methyl-D-glucoside inhibited D-glucose transport both in vivo and in BBM vesicles. It is concluded that Man reabsorption in the flounder occurs via a Na+-cotransport system that also handles glucose but that differs from the glucose/methyl-alpha-D-glucoside reabsorptive pathway in that 1) an oxygen on C-1 is not required, and 2) an axial configuration for -OH on C-2 (C1 conformation) is readily accommodated.

scholarly journals The function of GORASPs in Golgi apparatus organization in vivo

2020 ◽  
Vol 219 (9) ◽  
Author(s):  
Rianne Grond ◽  
Tineke Veenendaal ◽  
Juan M. Duran ◽  
Ishier Raote ◽  
Johan H. van Es ◽  
...  
Keyword(s):  
Golgi Apparatus ◽  
Dynamic Control ◽  
Vesicle Fusion ◽  
In Vitro Experiments ◽  
Cross Sectional ◽  
Data Support

In vitro experiments have shown that GRASP65 (GORASP1) and GRASP55 (GORASP2) proteins function in stacking Golgi cisternae. However, in vivo depletion of GORASPs in metazoans has given equivocal results. We have generated a mouse lacking both GORASPs and find that Golgi cisternae remained stacked. However, the stacks are disconnected laterally from each other, and the cisternal cross-sectional diameters are significantly reduced compared with their normal counterparts. These data support earlier findings on the role of GORASPs in linking stacks, and we suggest that unlinking of stacks likely affects dynamic control of COPI budding and vesicle fusion at the rims. The net result is that cisternal cores remain stacked, but cisternal diameter is reduced by rim consumption.

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