scholarly journals The buds of Oscarella lobularis (Porifera): a new convenient model for sponge cell and developmental biology

2020 ◽  
Author(s):  
Rocher Caroline ◽  
Vernale Amélie ◽  
Fierro-Constaín Laura ◽  
Séjourné Nina ◽  
Chenesseau Sandrine ◽  
...  
Keyword(s):  
Cell Biology ◽  
Molecular Mechanisms ◽  
Full Description ◽  
Sponge Cell ◽  
Cell Architecture ◽  
Amphimedon Queenslandica ◽  
Summary Statement ◽  
The Comparative Study ◽  
Convenient Model

AbstractThe comparative study of the four non-bilaterian phyla (Cnidaria, Placozoa, Ctenophora, Porifera) should provide insights into the origin of bilaterian traits. Except for Cnidaria, present knowledge on the cell biology and development of these animals is so far limited. Non-bilaterian models are needed to get further into cell architecture and molecular mechanisms.Given the developmental, histological, ecological and genomic differences between the four sponge classes, we develop a new sponge model: the buds of the Oscarella lobularis (class Homoscleromorpha). This experimental model supplements the two other most famous sponge models Amphimedon queenslandica and Ephydatia muelleri, both belonging to the class Demospongiae.Budding is a natural and spontaneous asexual reproduction mean, but budding can be triggered in vitro ensuring availability of biological material all year long. We provide a full description of buds, from their formation to their development into juveniles. Their transparency enables fluorescent and live imaging, and their abundance allows for experimental replicates. Moreover, regeneration and cell reaggregation capabilities provide interesting experimental morphogenetic contexts. The numerous techniques now mastered on these buds make it a new suitable sponge model.Summary statementStudying sponge biology is needed to understand the evolution of metazoans. We developed a new model suitable for experimental biology that allows to study morphogenetic processes with modern tools.

scholarly journals Hydroxychloroquine Synergizes With The PI3K Inhibitor BKM120 to Exhibit Antitumor Efficacy Independent of Autophagy

2021 ◽  
Author(s):  
Xin Peng ◽  
Shaolu Zhang ◽  
Wenhui Jiao ◽  
Zhenxing Zhong ◽  
Yuqi Yang ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Single Agent ◽  
Antitumor Efficacy ◽  
Antitumor Effects ◽  
Autophagy Inhibitor

Abstract Background: The critical role of phosphoinositide 3-kinase (PI3K) activation in tumor cell biology has prompted massive efforts to develop PI3K inhibitors (PI3Kis) for cancer therapy. However, recent results from clinical trials have shown only a modest therapeutic efficacy of single-agent PI3Kis in solid tumors. Targeting autophagy has controversial context-dependent effects in cancer treatment. As a FDA-approved lysosomotropic agent, hydroxychloroquine (HCQ) has been well tested as an autophagy inhibitor in preclinical models. Here, we elucidated the novel mechanism of HCQ alone or in combination with PI3Ki BKM120 in the treatment of cancer.Methods: The antitumor effects of HCQ and BKM120 on three different types of tumor cells were assessed by in vitro PrestoBlue assay, colony formation assay and in vivo zebrafish and nude mouse xenograft models. The involved molecular mechanisms were investigated by MDC staining, LC3 puncta formation assay, immunofluorescent assay, flow cytometric analysis of apoptosis and ROS, qRT-PCR, Western blot, comet assay, homologous recombination (HR) assay and immunohistochemical staining. Results: HCQ significantly sensitized cancer cells to BKM120 in vitro and in vivo. Interestingly, the sensitization mediated by HCQ could not be phenocopied by treatment with other autophagy inhibitors (Spautin-1, 3-MA and bafilomycin A1) or knockdown of the essential autophagy genes Atg5/Atg7, suggesting that the sensitizing effect might be mediated independent of autophagy status. Mechanistically, HCQ induced ROS production and activated the transcription factor NRF2. In contrast, BKM120 prevented the elimination of ROS by inactivation of NRF2, leading to accumulation of DNA damage. In addition, HCQ activated ATM to enhance HR repair, a high-fidelity repair for DNA double-strand breaks (DSBs) in cells, while BKM120 inhibited HR repair by blocking the phosphorylation of ATM and the expression of BRCA1/2 and Rad51. Conclusions: Our study revealed that HCQ and BKM120 synergistically increased DSBs in tumor cells and therefore augmented apoptosis, resulting in enhanced antitumor efficacy. Our findings provide a new insight into how HCQ exhibits antitumor efficacy and synergizes with PI3Ki BKM120, and warn that one should consider the “off target” effects of HCQ when used as autophagy inhibitor in the clinical treatment of cancer.

Kaposi sarcoma-associated herpesvirus (KSHV) induces heme oxygenase-1 expression and activity in KSHV-infected endothelial cells

Blood ◽  
2004 ◽  
Vol 103 (9) ◽  
pp. 3465-3473 ◽  
Author(s):  
Shane C. McAllister ◽  
Scott G. Hansen ◽  
Rebecca A. Ruhl ◽  
Camilo M. Raggo ◽  
Victor R. DeFilippis ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Heme Oxygenase ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Kaposi Sarcoma ◽  
Heme Oxygenase 1 ◽  
Spindle Cell Proliferation

Abstract Kaposi sarcoma (KS) is the most common AIDS-associated malignancy and is characterized by angiogenesis and the presence of spindle cells. Kaposi sarcoma-associated herpesvirus (KSHV) is consistently associated with all clinical forms of KS, and in vitro infection of dermal microvascular endothelial cells (DMVECs) with KSHV recapitulates many of the features of KS, including transformation, spindle cell proliferation, and angiogenesis. To study the molecular mechanisms of KSHV pathogenesis, we compared the protein expression profiles of KSHV-infected and uninfected DMVECs. This comparison revealed that heme oxygenase-1 (HO-1), the inducible enzyme responsible for the rate-limiting step in heme catabolism, was up-regulated in infected endothelial cells. Recent evidence suggests that the products of heme catabolism have important roles in endothelial cell biology, including apoptosis and angiogenesis. Here we show that HO-1 mRNA and protein are up-regulated in KSHV-infected cultures. Comparison of oral and cutaneous AIDS-KS tissues with normal tissues revealed that HO-1 mRNA and protein were also up-regulated in vivo. Increased HO-1 enzymatic activity in vitro enhanced proliferation of KSHV-infected DMVECs in the presence of free heme. Treatment with the HO-1 inhibitor chromium mesoporphyrin IX abolished heme-induced proliferation. These data suggest that HO-1 is a potential therapeutic target for KS that warrants further study. (Blood. 2004;103: 3465-3473)

Viruses–exploiters or dependants of the host?

Parasitology ◽  
1982 ◽  
Vol 85 (1) ◽  
pp. 189-216 ◽  
Author(s):  
Alison A. Newton
Keyword(s):  
Host Cell ◽  
Virus Replication ◽  
Cell Biology ◽  
Molecular Basis ◽  
Molecular Mechanisms ◽  
Model System ◽  
Great Emphasis ◽  
Genetic Organization ◽  
Biological Aspects ◽  
Convenient Model

Viruses are frequently referred to as the supreme parasites and yet it is now more than 20 years since any paper on this topic was published inParasitology. This deficiency probably reflects the great emphasis placed during the last two decades on those aspects of virology christened by Sir Christopher Andrewes ‘dream virology’ (Andrewes, 1973), namely the molecular and genetic properties of viruses, in contrast to the more clinical and biological aspects of ‘steam’ virology. Many modern virologists select a virus as a convenient model system with which to investigate such things as genetic organization or control of transcription, with little regard for the interaction with the host cell that supports its replication. Paradoxically, it is this very emphasis on the detailed molecular mechanisms of virus replication that has now put us in a better position to understand the relationships between these highly specialized parasites and their host systems than for any other type of parasite. Recent advances in cell biology coupled with an understanding of the molecular basis of viral replicative mechanisms mean that new insight is possible into the interactions of a virus with its host. For example, we are just beginning to appreciate why a virus should infect one individual and not another, or why it should multiply only in certain tissues at certain stages of development of a multicellular organism. Indeed, study of such tropisms may frequently tell us as much about the host cell as about the virus.

scholarly journals The hypothetical ancestral animal the Urmetazoa: Telomerase activity in sponges [Porifera]

2003 ◽  
Vol 68 (4-5) ◽  
pp. 257-268 ◽  
Author(s):  
E.G. Werner ◽  
W.E.G. Müller ◽  
I.M. Müller
Keyword(s):  
Molecular Mechanisms ◽  
Cell Lineage ◽  
Telomerase Activity ◽  
Sponge Cell ◽  
Suberites Domuncula ◽  
Dissociated Cells ◽  
Somatic Cell Lineage

Sponges (Porifera) represent the lowest metazoan phylum, characterized by a pronounced plasticity in the determination of cell lineages, and they are the closest related taxon to the hypothetical ancestral animal, the Urmetazoa, from which the metazoan lineages diverged. In a first approach to elucidate the molecular mechanisms controlling the switch from the cell lineage with a putative indefinite growth capacity to senescent, somatic cells, the activity of the telomerase as an indicator for immortality has been determined. The studies were performed with the marine demosponges Suberites domuncula and Geodia cydonium, in vivo with tissue but also in vitro using the primmorph system. Primmorphs are formed from dissociated cells which have retained their proliferation potency. It was found that the activity of telomerase in tissue of both sponges is high. Based on this and additional findings it is assumed that the separation of the senescent sponge cell lineage from the immortal germ-/somatic cell lineage is triggered by the loss of contact to cell adhesion factors. First evidence is included which suggests that the final progress of the senescent telomerase- negative cells to cell death is caused by apoptosis.

scholarly journals Hydroxychloroquine synergizes with the PI3K inhibitor BKM120 to exhibit antitumor efficacy independent of autophagy

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Xin Peng ◽  
Shaolu Zhang ◽  
Wenhui Jiao ◽  
Zhenxing Zhong ◽  
Yuqi Yang ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Single Agent ◽  
Antitumor Efficacy ◽  
Antitumor Effects ◽  
Autophagy Inhibitor

Abstract Background The critical role of phosphoinositide 3-kinase (PI3K) activation in tumor cell biology has prompted massive efforts to develop PI3K inhibitors (PI3Kis) for cancer therapy. However, recent results from clinical trials have shown only a modest therapeutic efficacy of single-agent PI3Kis in solid tumors. Targeting autophagy has controversial context-dependent effects in cancer treatment. As a FDA-approved lysosomotropic agent, hydroxychloroquine (HCQ) has been well tested as an autophagy inhibitor in preclinical models. Here, we elucidated the novel mechanism of HCQ alone or in combination with PI3Ki BKM120 in the treatment of cancer. Methods The antitumor effects of HCQ and BKM120 on three different types of tumor cells were assessed by in vitro PrestoBlue assay, colony formation assay and in vivo zebrafish and nude mouse xenograft models. The involved molecular mechanisms were investigated by MDC staining, LC3 puncta formation assay, immunofluorescent assay, flow cytometric analysis of apoptosis and ROS, qRT-PCR, Western blot, comet assay, homologous recombination (HR) assay and immunohistochemical staining. Results HCQ significantly sensitized cancer cells to BKM120 in vitro and in vivo. Interestingly, the sensitization mediated by HCQ could not be phenocopied by treatment with other autophagy inhibitors (Spautin-1, 3-MA and bafilomycin A1) or knockdown of the essential autophagy genes Atg5/Atg7, suggesting that the sensitizing effect might be mediated independent of autophagy status. Mechanistically, HCQ induced ROS production and activated the transcription factor NRF2. In contrast, BKM120 prevented the elimination of ROS by inactivation of NRF2, leading to accumulation of DNA damage. In addition, HCQ activated ATM to enhance HR repair, a high-fidelity repair for DNA double-strand breaks (DSBs) in cells, while BKM120 inhibited HR repair by blocking the phosphorylation of ATM and the expression of BRCA1/2 and Rad51. Conclusions Our study revealed that HCQ and BKM120 synergistically increased DSBs in tumor cells and therefore augmented apoptosis, resulting in enhanced antitumor efficacy. Our findings provide a new insight into how HCQ exhibits antitumor efficacy and synergizes with PI3Ki BKM120, and warn that one should consider the “off target” effects of HCQ when used as autophagy inhibitor in the clinical treatment of cancer.

scholarly journals Modeling human trophoblast, the placental epithelium at the maternal fetal interface

Reproduction ◽  
2020 ◽  
Vol 160 (1) ◽  
pp. R1-R11 ◽  
Author(s):  
Mariko Horii ◽  
Ojeni Touma ◽  
Tony Bui ◽  
Mana M Parast
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Culture Conditions ◽  
Model Systems ◽  
Placental Development ◽  
Human Organ ◽  
Human Trophoblast

Appropriate human trophoblast lineage specification and differentiation is crucial for the establishment of normal placentation and maintenance of pregnancy. However, due to the lack of proper modeling systems, the molecular mechanisms of these processes are still largely unknown. Much of the early studies in this area have been based on animal models and tumor-derived trophoblast cell lines, both of which are suboptimal for modeling this unique human organ. Recent advances in regenerative and stem cell biology methods have led to development of novel in vitro model systems for studying human trophoblast. These include derivation of human embryonic and induced pluripotent stem cells and establishment of methods for the differentiation of these cells into trophoblast, as well as the more recent derivation of human trophoblast stem cells. In addition, advances in culture conditions, from traditional two-dimensional monolayer culture to 3D culturing systems, have led to development of trophoblast organoid and placenta-on-a-chip model, enabling us to study human trophoblast function in context of more physiologically accurate environment. In this review, we will discuss these various model systems, with a focus on human trophoblast, and their ability to help elucidate the key mechanisms underlying placental development and function. This review focuses on model systems of human trophoblast differentiation, including advantages and limitations of stem cell-based culture, trophoblast organoid, and organ-on-a-chip methods and their applications in understanding placental development and disease.

scholarly journals Microinjection to deliver protein, mRNA, and DNA into zygotes of the cnidarian endosymbiosis model Aiptasia sp.

2017 ◽  
Author(s):  
Victor A. S. Jones ◽  
Madeline Bucher ◽  
Elizabeth A. Hambleton ◽  
Annika Guse
Keyword(s):  
Transgene Expression ◽  
Molecular Mechanisms ◽  
Model System ◽  
Proof Of Concept ◽  
Coral Larvae ◽  
Functional Studies ◽  
Algal Symbiosis ◽  
Summary Statement ◽  
Exogenous Genes

AbstractReef-building corals depend on an intracellular symbiosis with photosynthetic dinoflagellates for their survival in nutrient-poor oceans. Symbionts are phagocytosed by coral larvae from the environment and transfer essential nutrients to their hosts. Aiptasia, a small tropical marine sea anemone, is emerging as a tractable model system for coral symbiosis; however, to date functional tools and genetic transformation are lacking. Here we have established an efficient workflow to collect Aiptasia eggs for in vitro fertilization and microinjection as the basis for experimental manipulations in the developing embryo and larvae. We demonstrate that protein, mRNA, and DNA can successfully be injected into live Aiptasia zygotes to label actin with recombinant Lifeact-eGFP protein; to label nuclei and cell membranes with NLS-eGFP and farnesylated mCherry translated from injected mRNA; and to transiently drive transgene expression from an Aiptasia-specific promoter, respectively, in embryos and larvae. These proof-of-concept approaches pave the way for future functional studies of development and symbiosis establishment in Aiptasia, a powerful model to unravel the molecular mechanisms underlying intracellular coral-algal symbiosis.Summary StatementToolkit extension: development of microinjection for cellular labelling, expression of exogenous genes and live imaging in Aiptasia, an emerging model for intracellular coral-algal symbiosis.

scholarly journals Identification of CDCA8, DSN1 and BIRC5 in Regulating Cell Cycle and Apoptosis in Osteosarcoma Using Bioinformatics and Cell Biology

2020 ◽  
Vol 19 ◽  
pp. 153303382096560
Author(s):  
Qinwen Li ◽  
Jie Liang ◽  
Bo Chen
Keyword(s):  
Cell Cycle ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
Osteosarcoma Cells ◽  
Apoptosis Pathway ◽  
Protein Protein Interaction ◽  
Limma Package ◽  
Key Genes ◽  
Cycle Regulation

Introduction: Osteosarcoma is the most common primary tumor of bone, although some molecular markers have been identified, the detailed molecular mechanisms underlying osteosarcoma are currently not fully understood. In the present study, we attempted to identify the potential key genes and pathways in osteosarcoma using bioinformatics analysis. Methods: GSE14359 was downloaded from the GEO database, and analyzed using Limma package. Gene Ontology and pathway enrichment analyses of the DEGs were performed in the DAVID database, followed by the construction of a protein–protein interaction (PPI) network with software Cytoscape, subnetwork modules were subsequently identified and analyzed, and further validation in human osteosarcoma tissues and osteosarcoma cells line was performed. Results: 964 Differentially expressed genes (DEGs) identified, of which 222 were up-regulated and 742 were down-regulated. Among them, 10 genes (including BIRC5, MAD2L1, Bub1, DSN1, SPC24, CDCA8, STAG2, CENPA, MLF1IP and Mis12) were identified as hub genes and they were mainly enriched in pathways, including mRNA surveillance, RNA transport and PI3K-Akt signaling pathways. Further validation indicated 6 gene (DSN1, BIRC5, CDCA8, MLF1IP, MAD2L1 and SPC24) is highly expressed in osteosarcoma tissues. Among them, CDCA8, DSN1 and BIRC5 significantly promoted the proliferation of osteosarcoma cells in vitro. In terms of mechanism, DSN1 and CDCA8 were mainly involved in cell cycle regulation, while BIRC5 was mainly involved in the regulation of apoptosis pathway. Conclusions: We identified some key genes and pathways in osteosarcoma, which might be used as molecular targets or diagnostic biomarker for the diagnosis and therapy of osteosarcoma.

scholarly journals CD4+ T Cells from CD4C/HIVNef Transgenic Mice Show Enhanced Activation In Vivo with Impaired Proliferation In Vitro but Are Dispensable for the Development of a Severe AIDS-Like Organ Disease

2004 ◽  
Vol 78 (10) ◽  
pp. 5244-5257 ◽  
Author(s):  
Xiaoduan Weng ◽  
Elena Priceputu ◽  
Pavel Chrobak ◽  
Johanne Poudrier ◽  
Denis G. Kay ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Biology ◽  
Molecular Mechanisms ◽  
T Cell Biology ◽  
Immunodeficiency Virus ◽  
Proliferation In Vitro

ABSTRACT The cellular and molecular mechanisms of dysfunction and depletion of CD4+ T lymphocytes over the course of human immunodeficiency virus type 1 (HIV-1) infection are still incompletely understood, but chronic immune activation is thought to play an important role in disease progression. We studied CD4+ T-cell biology in CD4C/HIV transgenic (Tg) mice, in which Nef expression is sufficient to induce a severe AIDS-like disease including a preferential decrease of CD4+ T cells. We show here that Nef-expressing Tg CD4+ T cells exhibit an activated/memory-like phenotype which appears to be independent of antigenic stimulation, as documented in experiments involving breeding with AD10 TcR Tg mice. In addition, in vivo bromodeoxyuridine incorporation showed that a larger proportion of Tg than non-Tg CD4+ T cells entered the S phase. However, in vitro, Tg CD4+ T cells were found to have a very limited capacity to divide in response to stimulation with anti-CD3 and anti-CD28 or in allogeneic mixed leukocyte reactions. Interestingly, despite these observations, the deletion of Tg CD4+ T cells had little impact on the development of other AIDS-like organ phenotypes. Thus, the Nef-induced chronic activation of CD4+ T cells may exhaust the T-cell pool and may contribute to the thymic atrophy and the low number of CD4+ T cells observed in these Tg mice.

Correlative microscopy in distrubuted (client/server) computing environments: tools for catalyzing the rapid dissemination of information about the cell biology of the human prostate

1995 ◽  
Vol 53 ◽  
pp. 682-683
Author(s):  
A. Hakam ◽  
J.T. Gau ◽  
M.L. Grove ◽  
B.A. Evans ◽  
M. Shuman ◽  
...  
Keyword(s):  
United States ◽  
Cell Biology ◽  
Tissue Bank ◽  
The United States ◽  
Prostate Adenocarcinoma ◽  
Correlative Microscopy ◽  
Client Server ◽  
Critical Elements ◽  
Transplant Organ

Prostate adenocarcinoma is the most common malignant tumor of men in the United States and is the third leading cause of death in men. Despite attempts at early detection, there will be 244,000 new cases and 44,000 deaths from the disease in the United States in 1995. Therapeutic progress against this disease is hindered by an incomplete understanding of prostate epithelial cell biology, the availability of human tissues for in vitro experimentation, slow dissemination of information between prostate cancer research teams and the increasing pressure to “ stretch” research dollars at the same time staff reductions are occurring.To meet these challenges, we have used the correlative microscopy (CM) and client/server (C/S) computing to increase productivity while decreasing costs. Critical elements of our program are as follows:1) Establishing the Western Pennsylvania Genitourinary (GU) Tissue Bank which includes >100 prostates from patients with prostate adenocarcinoma as well as >20 normal prostates from transplant organ donors.

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