In vitro imaginal disc development and moulting hormone

Development ◽  
1980 ◽  
Vol 57 (1) ◽  
pp. 107-118
Author(s):  
Christiane Guillermet ◽  
Paul Mandaron

Imaginal leg and wing discs obtained from late-third-instar Drosophila larvae were cultured in vitro in various concentrations of ecdysterone ranging from 10−10 to 10−5 M inorder to test the effect of hormone concentration on evagination and cell differentiation. At the optimal concentration of 8 × 10−8 M discs evaginated normally, secreted the pupal cuticle, underwent apolysis, differentiated imaginal structures and secreted the imaginal cuticle. At suboptimal concentrations (10−8 M and less), evagination was incomplete in a variable proportion of appendages. Morphogenetic movements were limited to the earlier ones; so that appendages did not emerge from the peripodial sac. Subsequent development, whenever it occurred, took place inside the peripodial sac. This particular type of ‘endoevagination’ was only obtained with sub-optimal hormone concentration. At supra-optimal concentrations (10−6 M and more), evagination was always complete but further differentiation was inhibited. These results show that endoevagination is strictly related to insufficient supply ofhormone and that morphogenesis and cell differentiation in imaginal discs are two independent phenomena, which respond to different levels of hormone stimulation.

Development ◽  
1988 ◽  
Vol 102 (4) ◽  
pp. 805-814 ◽  
Author(s):  
D.A. Currie ◽  
M.J. Milner ◽  
C.W. Evans

We have devised a new in vitro culture system in which cells from dissociated Drosophila leg and wing imaginal discs grow and differentiate. Primary cultures consist of epithelial and fibroblast-like cells, together with some lamellocyte-like cells. These cultures have given rise to continuously dividing leg and wing cell lines, in which epithelial, fibroblast-like, lamellocyte-like and distinct sickle-shaped cells are found. Vesicles composed of epithelial cells form in primary cultures and these differentiate imaginal cuticular structures under the influence of 20-hydroxyecdysone. Two types of cuticle-like material are formed spontaneously in established cultures. One type is present as thin, untanned sheets resembling apolysed pupal cuticle, while the other consists of thicker, tanned material similar to imaginal cuticle.


Author(s):  
M. Kraemer ◽  
J. Foucrier ◽  
J. Vassy ◽  
M.T. Chalumeau

Some authors using immunofluorescent techniques had already suggested that some hepatocytes are able to synthetize several plasma proteins. In vitro studies on normal cells or on cells issued of murine hepatomas raise the same conclusion. These works could be indications of an hepatocyte functionnal non-specialization, meanwhile the authors never give direct topographic proofs suitable with this hypothesis.The use of immunoenzymatic techniques after obtention of monospecific antisera had seemed to us useful to bring forward a better knowledge of this problem. We have studied three carrier proteins (transferrin = Tf, hemopexin = Hx, albumin = Alb) operating at different levels in iron metabolism by demonstrating and localizing the adult rat hepatocytes involved in their synthesis.Immunological, histological and ultrastructural methods have been described in a previous work.


1990 ◽  
Vol 29 (03) ◽  
pp. 120-124
Author(s):  
R. P. Baum ◽  
E. Rohrbach ◽  
G. Hör ◽  
B. Kornhuber ◽  
E. Busse

The effect of triiodothyronine (T3) on the differentiation of cultured neuroblastoma (NB) cells was studied after 9 days of treatment with a dose of 10-4 M/106 cells per day. Using phase contrast microscopy, 30-50% of NB cells showed formation of neurites as a morphological sign of cellular differentiation. The initial rise of the mitosis rate was followed by a plateau. Changes in cyclic nucleotide content, in the triphosphates and in the activity of the enzyme ornithine decarboxylase (ODC) were assessed in 2 human and 2 murine cell lines to serve as biochemical parameters of the cell differentiation induced by T3. Whereas the cAMP level increased significantly (3 to 7 fold compared with its initial value), the cGMP value dropped to 30 to 50% of that of the control group. ATP and GTP increased about 200%, the ODC showed a decrease of about 50%. The present studies show a biphasic effect of T3 on neuroblastoma cells: the initial rise of mitotic activity is followed by increased cell differentiation starting from day 4 of the treatment.


2020 ◽  
Vol 16 (3) ◽  
pp. 392-402
Author(s):  
Christiaan W. van der Westhuyzen ◽  
Richard K. Haynes ◽  
Jenny-Lee Panayides ◽  
Ian Wiid ◽  
Christopher J. Parkinson

Background: With few exceptions, existing tuberculosis drugs were developed many years ago and resistance profiles have emerged. This has created a need for new drugs with discrete modes of action. There is evidence that tuberculosis (like other bacteria) is susceptible to oxidative pressure and this has yet to be properly utilised as a therapeutic approach in a manner similar to that which has proven highly successful in malaria therapy. Objective: To develop an alternative approach to the incorporation of bacterial siderophores that results in the creation of antitubercular peroxidic leads for subsequent development as novel agents against tuberculosis. Methods: Eight novel peroxides were prepared and the antitubercular activity (H37Rv) was compared to existing artemisinin derivatives in vitro. The potential for toxicity was evaluated against the L6 rat skeletal myoblast and HeLa cervical cancer lines in vitro. Results: The addition of a pyrimidinyl residue to an artemisinin or, preferably, a tetraoxane peroxidic structure results in antitubercular activity in vitro. The same effect is not observed in the absence of the pyrimidine or with other heteroaromatic substituents. Conclusion: The incorporation of a pyrimidinyl residue adjacent to the peroxidic function in an organic peroxide results in anti-tubercular activity in an otherwise inactive peroxidic compound. This will be a useful approach for creating oxidative drugs to target tuberculosis.


2020 ◽  
Vol 209 (4-6) ◽  
pp. 177-188
Author(s):  
Katerina Cizkova ◽  
Katerina Koubova ◽  
Tereza Foltynkova ◽  
Jana Jiravova ◽  
Zdenek Tauber

There is growing evidence that soluble epoxide hydrolase (sEH) may play a role in cell differentiation. sEH metabolizes biologically highly active and generally cytoprotective epoxyeicosatrienoic acids (EETs), generated from arachidonic acid metabolism by CYP epoxygenases (CYP2C and CYP2J subfamilies), to less active corresponding diols. We investigated the effect of sEH inhibitor (TPPU) on the expression of villin, CYP2C8, CYP2C9, CYP2J2, and sEH in undifferentiated and in vitro differentiated HT-29 and Caco2 cell lines. The administration of 10 μM TPPU on differentiated HT-29 and Caco2 cells resulted in a significant decrease in expression of villin, a marker for intestinal cell differentiation. It was accompanied by a disruption of the brush border when microvilli appeared sparse and short in atomic force microscope scans of HT-29 cells. Although inhibition of sEH in differentiated HT-29 and Caco2 cells led to an increase in sEH expression in both cell lines, this treatment had an opposite effect on CYP2J2 expression in HT-29 and Caco2 cells. In addition, tissue samples of colorectal carcinoma and adjacent normal tissues from 45 patients were immunostained for sEH and villin. We detected a significant decrease in the expression of both proteins in colorectal carcinoma in comparison to adjacent normal tissue, and the decrease in both sEH and villin expression revealed a moderate positive association. Taken together, our results showed that sEH is an important player in intestinal cell differentiation.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Di Hua ◽  
Jie Yang ◽  
Qinghai Meng ◽  
Yuanyuan Ling ◽  
Qin Wei ◽  
...  

Abstract Background Rheumatoid arthritis (RA) is a chronic autoimmune disease. Soufeng sanjie formula (SF), which is composed of scolopendra (dried body of Scolopendra subspinipes mutilans L. Koch), scorpion (dried body of Buthus martensii Karsch), astragali radix (dried root of Astragalus membranaceus (Fisch.) Bge), and black soybean seed coats (seed coats of Glycine max (L.) Merr), is a traditional Chinese prescription for treating RA. However, the mechanism of SF in treating RA remains unclear. This study was aim to investigate the anti-arthritic effects of SF in a collagen-induced arthritis (CIA) mouse model and explore the mechanism by which SF alleviates arthritis in CIA mice. Methods For in vivo studies, female DBA/1J mice were used to establish the CIA model, and either SF (183 or 550 mg/kg/day) or methotrexate (MTX, 920 mg/kg, twice/week) was orally administered to the mice from the day of arthritis onset. After administration for 30 days, degree of ankle joint destruction and serum levels of IgG and inflammatory cytokines were determined. The balance of Th17/Treg cells in the spleen and lymph nodes was analyzed using flow cytometry. Moreover, the expression levels of retinoic acid receptor-related orphan nuclear receptor (ROR) γt and phosphorylated STAT3 (pSTAT3, Tyr705) in the spleen were detected by immunohistochemistry. Furthermore, the effect of SF on Th17 cells differentiation in vitro was investigated in CD4+ T cells under Th17 polarization conditions. Results SF decreased the arthritis score, ameliorated paw swelling, and reduced cartilage loss in the joint of CIA mice. In addition, SF decreased the levels of bovine collagen-specific IgG in sera of CIA mice. SF decreased the levels of inflammatory cytokines (TNF-α, IL-6, and IL-17A) and increased the level of IL-10 both in the sera and the joint of CIA mice. Moreover, SF treatment rebalanced the Th17/Treg ratio in the spleen and lymph nodes of CIA mice. SF also reduced the expression levels of ROR γt and pSTAT3 (Tyr705) in the spleen of CIA mice. In vitro, SF treatment reduced Th17 cell generation and IL-17A production and inhibited the expression of RORγt, IRF4, IL-17A, and pSTAT3 (Tyr705) under Th17 polarization conditions. Conclusions Our results suggest that SF exhibits anti-arthritic effects and restores Th17/Treg homeostasis in CIA mice by inhibiting Th17 cell differentiation.


2019 ◽  
Vol 116 (1) ◽  
pp. 226-236 ◽  
Author(s):  
Dan Qu ◽  
Li Wang ◽  
Mingyu Huo ◽  
Wencong Song ◽  
Chi-Wai Lau ◽  
...  

Abstract Aims Disturbed blood flow at arterial branches and curvatures modulates endothelial function and predisposes the region to endothelial inflammation and subsequent development of atherosclerotic lesions. Activation of the endothelial Toll-like receptors (TLRs), in particular TLR4, contributes to vascular inflammation. Therefore, we investigate whether TLR4 can sense disturbed flow (DF) to mediate the subsequent endothelial inflammation. Methods and results En face staining of endothelium revealed that TLR4 expression, activation, and its downstream inflammatory markers were elevated in mouse aortic arch compared with thoracic aorta, which were absent in Tlr4mut mice. Similar results were observed in the partial carotid ligation model where TLR4 signalling was activated in response to ligation-induced flow disturbance in mouse carotid arteries, and such effect was attenuated in Tlr4mut mice. DF in vitro increased TLR4 expression and activation in human endothelial cells (ECs) and promoted monocyte-EC adhesion, which were inhibited in TLR4-knockdown ECs. Among endogenous TLR4 ligands examined as candidate mediators of DF-induced TLR4 activation, fibronectin containing the extra domain A (FN-EDA) expressed by ECs was increased by DF and was revealed to directly interact with and activate TLR4. Conclusion Our findings demonstrate the indispensable role of TLR4 in DF-induced endothelial inflammation and pinpoint FN-EDA as the endogenous TLR4 activator in this scenario. This novel mechanism of vascular inflammation under DF condition may serve as a critical initiating step in atherogenesis.


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