scholarly journals Eiger/TNFα-mediated Dilp8 and ROS production coordinate intra-organ growth inDrosophila

2019 ◽  
Author(s):  
Juan A. Sanchez ◽  
Duarte Mesquita ◽  
María C. Ingaramo ◽  
Federico Ariel ◽  
Marco Milán ◽  
...  

ABSTRACTCoordinated intra- and inter-organ growth is essential during animal development to generate individuals of proper size and shape. TheDrosophilawing has been a valuable model system to reveal the existence of a stress response mechanism mediated by Drosophila p53 (Dmp53) and involved in the coordination of tissue growth between adjacent cell populations upon targeted reduction of growth rates. Here we present evidence that a two-step molecular mechanism is being used by Dmp53 to reduce in a non-autonomous manner growth and proliferation in adjacent cell populations. First, Dmp53-mediated transcriptional induction ofDrosophilaTNFα ligand Eiger leads to cell autonomous activation of JNK. Second, two different signaling events downstream of the Eiger/JNK axis are induced in the growth depleted territory in order to independently regulate tissue size and cell number in adjacent cell populations. Whereas expression of the systemic hormone dILP8 coordinates intra-organ growth and final tissue size, induction of Reactive Oxygen Species downstream of Eiger/JNK and, as a consequence of apoptosis induction, acts non-cell-autonomously to regulate proliferation rates of adjacent epithelial cells. Our results unravel how local and systemic signals can act concertedly to coordinate growth and proliferation within an organ in order to generate well-proportioned organs and functionally integrated adults.Author SummaryCoordination of growth between the different parts of a given developing organ is an absolute requirement for the generation of functionally integrated structures during animal development. Although this question has fascinated biologists for centuries, the responsible molecular mechanisms have remained so far unknown. In this work, we have used the developing wing primordium of Drosophila to identify the molecular mechanisms and signaling molecules mediating communication between adjacent cell populations upon targeted reduction in growth rates. We first present evidence that activation of Drosophila p53 in the growth-depleted territory induces expression of the fly TNF ligand Eiger which cell autonomously activates the JNK stress signaling pathway. While JNK-dependent expression of the systemic hormone dILP8 reduces growth and final size of the adjacent territories, production of Reactive Oxygen Species downstream of JNK and the apoptotic machinery act locally to regulate proliferation rates in adjacent epithelial cells. Our data reveal how signals acting locally or systemically can regulate cell proliferation and growth independently to accomplish coordination in tissue size and cell number among different parts of an organ in order to give rise to well-proportioned adult structures.HIGHLIGHTS✓ Dmp53-dependent Eiger expression is required to coordinate intra-organ growth✓ Eiger acts through its receptor Grindelwald and JNK signaling to reduce growth and proliferation rates in a non-cell-autonomous manner✓ Eiger/JNK-dependent Dilp8 expression coordinates intra-organ growth but not proliferation✓ Eiger/JNK activation triggers ROS production✓ ROS act non-cell-autonomously to regulate proliferation of adjacent epithelial cells.

2020 ◽  
Vol 19 (2) ◽  
pp. 133-138
Author(s):  
Wenyu Chen ◽  
Hui He

Trilobatin is a natural plant-derived glycosylated flavonoid that has been shown to exhibit multiple beneficial pharmacologic activities including protection of heart against H/R-induced cardiomyocyte injury. However, the molecular mechanisms underlying protection from H/R-induced cardiomyocyte injury remain unknown. Using H9C2 cells as a model, we examined the effect of trilobatin on H/R-induced cellular injury, apoptosis, and generation of reactive oxygen species. The results showed that trilobatin protected H9C2 cells not only from cell death and apoptosis, but also counteracted H/R-induced changes in malondialdehyde, superoxide dismutase, glutathione, and glutathione peroxidase. The evaluation of the mechanism underlying the effect of trilobatin on protection from H/R-induced cellular injury suggested changes in the regulation of nuclear factor erythroid 2-related factor 2/heme oxygenase-1 pathway.


2020 ◽  
Vol 16 (1) ◽  
pp. 85-89
Author(s):  
Mahesh M. Gouda ◽  
Ashwini Prabhu ◽  
Varsha Reddy S.V. ◽  
Rafa Jahan ◽  
Yashodhar P. Bhandary

Background: Bleomycin (BLM) is known to cause DNA damage in the Alveolar Epithelial Cells (AECs). It is reported that BLM is involved in the up-regulation of inflammatory molecules such as neutrophils, macrophages, chemokines and cytokines. The complex underlying mechanism for inflammation mediated progression of lung injury is still unclear. This investigation was designed to understand the molecular mechanisms associated with p53 mediated modulation of Plasminogen Activator Inhibitor-I (PAI-I) expression and its regulation by nano-curcumin formulation. Methods: A549 cells were treated with BLM to cause the cellular damage in vitro and commercially available nano-curcumin formulation was used as an intervention. Cytotoxic effect of nano-curcumin was analyzed using Methyl Thiazolyl Tetrazolium (MTT) assay. Protein expressions were analyzed using western blot to evaluate the p53 mediated changes in PAI-I expression. Results: Nano-curcumin showed cytotoxicity up to 88.5 % at a concentration of 20 μg/ml after 48 h of treatment. BLM exposure to the cells activated the phosphorylation of p53, which in turn increased PAII expression. Nano-curcumin treatment showed a protective role against phosphorylation of p53 and PAI-I expression, which in turn regulated the fibro-proliferative phase of injury induced by bleomycin. Conclusion: Nano-curcumin could be used as an effective intervention to regulate the severity of lung injury, apoptosis of AECs and fibro-proliferation during pulmonary injury.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chu-nan Zhang ◽  
Lin-yi Zhou ◽  
Shu-jiao Qian ◽  
Ying-xin Gu ◽  
Jun-yu Shi ◽  
...  

Abstract Objectives This study aims to evaluate the ability of tantalum-coated titanium to improve human gingival fibroblasts’ adhesion, viability, proliferation, migration performance, and the potential molecular mechanisms. Materials and methods Titanium plates were divided into two groups: (1) no coating (Ti, control), (2) Tantalum-coated titanium (Ta-coated Ti). All samples were characterized by scanning electronic microscopy, surface roughness, and hydrophilicity. Fibroblasts’ performance were analyzed by attached cell number at 1 h, 4 h, and 24 h, morphology at 1 h and 4 h, viability at 1 day, 3 days, 5 days, and 7 days, recovery after wounding at 6 h, 12 h, and 24 h. RT-PCR, western blot were applied to detect attachment-related genes’ expression and protein synthesis at 4 h and 24 h. Student’s t test was used for statistical analysis. Results Tantalum-coated titanium demonstrates a layer of homogeneously distributed nano-grains with mean diameter of 25.98 (± 14.75) nm. It was found that after tantalum deposition, human gingival fibroblasts (HGFs) adhesion, viability, proliferation, and migration were promoted in comparison to the control group. An upregulated level of Integrin β1 and FAK signaling was also detected, which might be the underlying mechanism. Conclusion In the present study, adhesion, viability, proliferation, migration of human gingival fibroblasts are promoted on tantalum-coated titanium, upregulated integrin β1 and FAK might contribute to its superior performance, indicating tantalum coating can be applied in transmucosal part of dental implant. Clinical significance Tantalum deposition on titanium surfaces can promote human gingival fibroblast adhesion, accordingly forming a well-organized soft tissue sealing and may contribute to a successful osseointegration.


Biomolecules ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 476 ◽  
Author(s):  
Chia-Jung Li ◽  
Pei-Yi Chu ◽  
Giou-Teng Yiang ◽  
Meng-Yu Wu

The transforming growth factor-β (TGF-β) signaling pathway plays multiple regulatory roles in the tumorigenesis and development of cancer. TGF-β can inhibit the growth and proliferation of epithelial cells and induce apoptosis, thereby playing a role in inhibiting breast cancer. Therefore, the loss of response in epithelial cells that leads to the inhibition of cell proliferation due to TGF-β is a landmark event in tumorigenesis. As tumors progress, TGF-β can promote tumor cell invasion, metastasis, and drug resistance. At present, the above-mentioned role of TGF-β is related to the interaction of multiple signaling pathways in the cell, which can attenuate or abolish the inhibition of proliferation and apoptosis-promoting effects of TGF-β and enhance its promotion of tumor progression. This article focuses on the molecular mechanisms through which TGF-β interacts with multiple intracellular signaling pathways in tumor progression and the effects of these interactions on tumorigenesis.


Parasitology ◽  
1985 ◽  
Vol 90 (2) ◽  
pp. 241-254 ◽  
Author(s):  
Stephanie M. Millott ◽  
F. E. G. Cox

Swiss mice with chronicTrypanosoma bruceiinfections become refractory to subsequent infection withBabesia microtiandB. rodhaini. Infection withB. microti7 days afterT. bruceiresulted in an obvious inhibition of the babesia parasitaemias and this inhibition became more profound as the time interval between the infections increased, until at 17–20 days the parasitaemias were totally abolished. Even after intravenous injection of large numbers of parasites parasitaemias were inhibited. Similar inhibition was obtained in BALB/c mice but not in C57BL/6 mice. Mice with establishedT. bruceiinfections also showed reduced susceptibility toB. rodhaini. In mice similarly infected withT. bruceiand the malaria parasitesPlasmodium chabaudi chabaudiandP. c. adamithe pre-patent periods were noticeably prolonged but the subsequent parasitaemias were unaffected. Infections withP. yoeliiwere unaffected.Trypanosoma bruceiinfections were not affected by the intracellular parasites. Among the mechanisms investigated to explain these findings were changes in red blood cell populations, cross-reacting antigens, the release of toxic factors and the generation of activated oxygen species. None of these could account for the inhibition observed.


2014 ◽  
Vol 307 (6) ◽  
pp. L449-L459 ◽  
Author(s):  
Seong Chul Kim ◽  
Thomas Kellett ◽  
Shaohua Wang ◽  
Miyuki Nishi ◽  
Nagaraja Nagre ◽  
...  

The molecular mechanisms for lung cell repair are largely unknown. Previous studies identified tripartite motif protein 72 (TRIM72) from striated muscle and linked its function to tissue repair. In this study, we characterized TRIM72 expression in lung tissues and investigated the role of TRIM72 in repair of alveolar epithelial cells. In vivo injury of lung cells was introduced by high tidal volume ventilation, and repair-defective cells were labeled with postinjury administration of propidium iodide. Primary alveolar epithelial cells were isolated and membrane wounding and repair were labeled separately. Our results show that absence of TRIM72 increases susceptibility to deformation-induced lung injury whereas TRIM72 overexpression is protective. In vitro cell wounding assay revealed that TRIM72 protects alveolar epithelial cells through promoting repair rather than increasing resistance to injury. The repair function of TRIM72 in lung cells is further linked to caveolin 1. These data suggest an essential role for TRIM72 in repair of alveolar epithelial cells under plasma membrane stress failure.


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