Structural features of explant cells in vivo and morphogenic callus formation in vitro (Review).

Biomics ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 8-19
Author(s):  
A.E. Zinatullina
Keyword(s):  
Callus Formation ◽  
Structural Features ◽  
Integrated System ◽  
Target Cells ◽  
In Vitro Cultivation ◽  
Positive Role ◽  
Endogenous Factors ◽  
Morphogenic Callus

Morphogenic callus is an integrated system that is formed in vitro from an explant both exogenously (as a result of proliferation of surface cells of various tissues) and endogenously (in the depth of these tissues), initially consisting of homogeneous meristematic cells, which are gradually transformed into groups of heterogeneous morphogenetically competent cells. Under optimal conditions of further in vitro cultivation the potencies of such cells are realized by various pathways of morphogenesis, including the formation of full-fledged regenerated plants, which is the goal of a number of biotechnologies. The advantage of using morphogenic calli in biotechnological research, in addition to a number of undoubted methodological usability, is the similarity of morphogenetic processes in plants in vivo and in cultured calli in vitro, which should be regarded as the manifestation of the universality of morphogenesis in various plant reproduction systems. The formation of morphogenic calli from explants in in vitro conditions is determined by a complex of interrelated endogenous and exogenous factors. In general, endogenous factors are regarded as the presence in explants in vivo of target cells capable of perceiving the inducer (so-called initial callus cells), while exogenous (usually stressful) factors – as an inducer of the process of callus formation in vitro. The review article uses the example of representatives of various plant families to analyze the literature and own data on the identification and characterization of structural features of initial morphogenic callus cells in explants in vivo. The available literature provides answers to the fundamental questions: what are the initial cells of callus (having the properties of meristematicity, pluri- and totipopotency and, possibly, stemness) and how do they structurally differ from other explant cells; whether the initial cells have the competence to callus formation under in vivo conditions or whether the conditions of preliminary stress conditions in situ and/or the initial stages of in vitro culture induce the acquisition of these cells the ability to reprogramming. The positive role of the positional arrangement of initial callus cells in the explant cell and tissue system is suggested.

Immunohistochemical and in Vitro Functional Analysis of Pineal-Germinoma Infiltrating Lymphocytes: Report of a Case

Neurosurgery ◽  
1989 ◽  
Vol 25 (3) ◽  
pp. 454-458 ◽  
Author(s):  
Yutaka Sawamura ◽  
Marie-France Hamou ◽  
Maria C. Kuppner ◽  
Nicolas de Tribolet
Keyword(s):  
Functional Analysis ◽  
Tumor Infiltrating Lymphocytes ◽  
Immunohistochemical Analysis ◽  
Pineal Region ◽  
Target Cells ◽  
In Vitro Cultivation ◽  
Pineal Region Tumor ◽  
Infiltrating Lymphocytes

Abstract The present study describes the phenotypic and functional analysis of tumor-infiltrating lymphocytes isolated from a germinoma located in the pineal region. Tumor-infiltrating lymphocytes were separated from the germinoma and cultured in medium containing IL-2 (1000 U/ml). An immunohistochemical analysis of frozen sections revealed that 90% of the germinoma-infiltrating lymphocytes were CD3-positive T cells expressing CD4, CD8, and HLA Class I and Class II antigens, but were negative for CD16, CD20, CD23, CD25 and CD14 antigens. After in vitro cultivation in the presence of high concentrations of IL-2, the lymphocytes proliferated for 2 weeks, showing marked DNA synthesis. In addition, the lymphocytes could lyse NK-resistant allogeneic target cells. These results provide evidence for a potential role of germinoma-infiltrating lymphocytes in vivo, and suggest that the lymphocytes may control the growth of autochthonous tumor cells by killing those that are not restricted to the major histocompatibility complex.

Traceable Peptidic Ligands that Target Ghrelin Receptors

2020 ◽  
Vol 21 (10) ◽  
pp. 955-964 ◽  
Author(s):  
Mengjie Liu ◽  
John Wade ◽  
Mohammed Akhter Hossain
Keyword(s):  
In Vivo Imaging ◽  
Peptide Hormone ◽  
Structural Features ◽  
Pharmacological Properties ◽  
Imaging Studies ◽  
Cognate Receptor ◽  
Ghrelin Receptors ◽  
Biochemical Research

: Ghrelin is a 28-amino acid octanoylated peptide hormone that is implicated in many physiological and pathophysiological processes. Specific visualization of ghrelin and its cognate receptor using traceable ligands is crucial in elucidating the localization, functions, and expression pattern of the peptide’s signaling pathway. Here 12 representative radio- and fluorescently-labeled peptide-based ligands are reviewed for in vitro and in vivo imaging studies. In particular, the focus is on their structural features, pharmacological properties, and applications in further biochemical research.

Polyamines and Related Nitrogen Compounds in the Chemotherapy of Neglected Diseases Caused by Kinetoplastids

2018 ◽  
Vol 18 (5) ◽  
pp. 321-368 ◽  
Author(s):  
Juan A. Bisceglia ◽  
Maria C. Mollo ◽  
Nadia Gruber ◽  
Liliana R. Orelli
Keyword(s):  
Drug Targets ◽  
Redox Homeostasis ◽  
Cost Effective ◽  
Structural Features ◽  
Mammalian Host ◽  
Neglected Diseases ◽  
Nitrogen Compounds ◽  
Chemical Structures

Neglected diseases due to the parasitic protozoa Leishmania and Trypanosoma (kinetoplastids) affect millions of people worldwide, and the lack of suitable treatments has promoted an ongoing drug discovery effort to identify novel nontoxic and cost-effective chemotherapies. Polyamines are ubiquitous small organic molecules that play key roles in kinetoplastid parasites metabolism, redox homeostasis and in the normal progression of cell cycles, which differ from those found in the mammalian host. These features make polyamines attractive in terms of antiparasitic drug development. The present work provides a comprehensive insight on the use of polyamine derivatives and related nitrogen compounds in the chemotherapy of kinetoplastid diseases. The amount of literature on this subject is considerable, and a classification considering drug targets and chemical structures were made. Polyamines, aminoalcohols and basic heterocycles designed to target the relevant parasitic enzyme trypanothione reductase are discussed in the first section, followed by compounds directed to less common targets, like parasite SOD and the aminopurine P2 transporter. Finally, the third section comprises nitrogen compounds structurally derived from antimalaric agents. References on the chemical synthesis of the selected compounds are reported together with their in vivo and/or in vitro IC50 values, and structureactivity relationships within each group are analyzed. Some favourable structural features were identified from the SAR analyses comprising protonable sites, hydrophobic groups and optimum distances between them. The importance of certain pharmacophoric groups or amino acid residues in the bioactivity of polyamine derived compounds is also discussed.

Non-Viral Vectors for Gene Delivery

2018 ◽  
Vol 9 (1) ◽  
pp. 4-11 ◽  
Author(s):  
Aparna Bansal ◽  
Himanshu
Keyword(s):  
Gene Therapy ◽  
Viral Vectors ◽  
Transfection Efficiency ◽  
Gene Transfection ◽  
Expression System ◽  
Target Cells ◽  
Specific Expression ◽  
Naked Dna

Introduction: Gene therapy has emerged out as a promising therapeutic pave for the treatment of genetic and acquired diseases. Gene transfection into target cells using naked DNA is a simple and safe approach which has been further improved by combining vectors or gene carriers. Both viral and non-viral approaches have achieved a milestone to establish this technique, but non-viral approaches have attained a significant attention because of their favourable properties like less immunotoxicity and biosafety, easy to produce with versatile surface modifications, etc. Literature is rich in evidences which revealed that undoubtedly, non–viral vectors have acquired a unique place in gene therapy but still there are number of challenges which are to be overcome to increase their effectiveness and prove them ideal gene vectors. Conclusion: To date, tissue specific expression, long lasting gene expression system, enhanced gene transfection efficiency has been achieved with improvement in delivery methods using non-viral vectors. This review mainly summarizes the various physical and chemical methods for gene transfer in vitro and in vivo.

scholarly journals Combined In Vitro and In Vivo Approaches to Propose a Putative Adverse Outcome Pathway for Acute Lung Inflammation Induced by Nanoparticles: A Study on Carbon Dots

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 180
Author(s):  
Maud Weiss ◽  
Jiahui Fan ◽  
Mickaël Claudel ◽  
Luc Lebeau ◽  
Françoise Pons ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Lung Inflammation ◽  
Adverse Outcome ◽  
Cellular Responses ◽  
Target Cells ◽  
Inflammasome Activation ◽  
Adverse Outcome Pathway ◽  
Acute Lung Inflammation

With the growth of nanotechnologies, concerns raised regarding the potential adverse effects of nanoparticles (NPs), especially on the respiratory tract. Adverse outcome pathways (AOP) have become recently the subject of intensive studies in order to get a better understanding of the mechanisms of NP toxicity, and hence hopefully predict the health risks associated with NP exposure. Herein, we propose a putative AOP for the lung toxicity of NPs using emerging nanomaterials called carbon dots (CDs), and in vivo and in vitro experimental approaches. We first investigated the effect of a single administration of CDs on mouse airways. We showed that CDs induce an acute lung inflammation and identified airway macrophages as target cells of CDs. Then, we studied the cellular responses induced by CDs in an in vitro model of macrophages. We observed that CDs are internalized by these cells (molecular initial event) and induce a series of key events, including loss of lysosomal integrity and mitochondrial disruption (organelle responses), as well as oxidative stress, inflammasome activation, inflammatory cytokine upregulation and macrophage death (cellular responses). All these effects triggering lung inflammation as tissular response may lead to acute lung injury.

scholarly journals Interaction of Lactoferrin with Unsaturated Fatty Acids: In Vitro and In Vivo Study of Human Lactoferrin/Oleic Acid Complex Cytotoxicity

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1602
Author(s):  
Anna Elizarova ◽  
Alexey Sokolov ◽  
Valeria Kostevich ◽  
Ekaterina Kisseleva ◽  
Evgeny Zelenskiy ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Structural Changes ◽  
Unsaturated Fatty Acids ◽  
Structural Features ◽  
Control Group ◽  
Acid Complex ◽  
Hepatoma 22A ◽  
Constitutive Parameters

As shown recently, oleic acid (OA) in complex with lactoferrin (LF) causes the death of cancer cells, but no mechanism(s) of that toxicity have been disclosed. In this study, constitutive parameters of the antitumor effect of LF/OA complex were explored. Complex LF/OA was prepared by titrating recombinant human LF with OA. Spectral analysis was used to assess possible structural changes of LF within its complex with OA. Structural features of apo-LF did not change within the complex LF:OA = 1:8, which was toxic for hepatoma 22a cells. Cytotoxicity of the complex LF:OA = 1:8 was tested in cultured hepatoma 22a cells and in fresh erythrocytes. Its anticancer activity was tested in mice carrying hepatoma 22a. In mice injected daily with LF-8OA, the same tumor grew significantly slower. In 20% of animals, the tumors completely resolved. LF alone was less efficient, i.e., the tumor growth index was 0.14 for LF-8OA and 0.63 for LF as compared with 1.0 in the control animals. The results of testing from 48 days after the tumor inoculation showed that the survival rate among LF-8OA-treated animals was 70%, contrary to 0% rate in the control group and among the LF-treated mice. Our data allow us to regard the complex of LF and OA as a promising tool for cancer treatment.

scholarly journals Glycoprotein D-Independent Infectivity of Pseudorabies Virus Results in an Alteration of In Vivo Host Range and Correlates with Mutations in Glycoproteins B and H

2001 ◽  
Vol 75 (21) ◽  
pp. 10054-10064 ◽  
Author(s):  
Jerg Schmidt ◽  
Volker Gerdts ◽  
Jörg Beyer ◽  
Barbara G. Klupp ◽  
Thomas C. Mettenleiter
Keyword(s):  
Host Range ◽  
Pseudorabies Virus ◽  
Natural Host ◽  
Target Cells ◽  
Glycoprotein D ◽  
Wild Type ◽  
Cellular Receptors ◽  
Receptor Usage

ABSTRACT Infection of cells by herpesviruses is initiated by the interaction of viral envelope glycoproteins with cellular receptors. In the alphaherpesvirus pseudorabies virus (PrV), the causative agent of Aujeszky's disease in pigs, the essential glycoprotein D (gD) mediates secondary attachment of virions to target cells by binding to newly identified cellular receptors (R. J. Geraghty, C. Krummenacher, G. H. Cohen, R. J. Eisenberg, and P. G. Spear, Science 280:1618–1620, 1998). However, in the presence of compensatory mutations, infection can also occur in the absence of gD, as evidenced by the isolation in cell culture of an infectious gD-negative PrV mutant (PrV-gD− Pass) (J. Schmidt, B. G. Klupp, A. Karger, and T. C. Mettenleiter, J. Virol. 71:17–24, 1997). PrV-gD− Pass is replication competent with an only moderate reduction in specific infectivity but appears to bind to receptors different from those recognized by wild-type PrV (A. Karger, J. Schmidt, and T. C. Mettenleiter, J. Virol. 72:7341–7348, 1998). To analyze whether this alteration in receptor usage in vitro influences infection in vivo, the model host mouse and the natural host pig were intranasally infected with PrV-gD− Pass and were compared to animals infected by wild-type PrV. For mice, a comparable progress of disease was observed, and all animals infected with mutant virus died, although they exhibited a slight delay in the onset of symptoms and, correspondingly, a longer time to death. In contrast, whereas wild-type PrV-infected pigs showed clinical signs and histological and histopathological findings typical of PrV infection, no signs of disease were observed after infection with PrV-gD− Pass. Moreover, in these animals, virus-infected cells were not detectable by immunohistochemical staining of different organ samples and no virus could be isolated from nasal swabs. Mutations in glycoproteins B and H were found to correlate with, and probably contribute to, gD-independent infectivity. In conclusion, although PrV-gD− Pass is virulent in mice, it is apparently unable to infect the natural host, the pig. This altered host range in vivo correlates with a difference of receptor usage in vitro and demonstrates for the first time the importance of gD receptors in alphaherpesvirus infection of an animal host.

scholarly journals CELL-MEDIATED CYTOTOXICITY DURING REJECTION AND ENHANCEMENT OF ALLOGENEIC SKIN GRAFTS IN RATS

1972 ◽  
Vol 135 (6) ◽  
pp. 1301-1315 ◽  
Author(s):  
Hans-Hartmut Peter ◽  
Joseph D. Feldman
Keyword(s):  
Lymph Nodes ◽  
Thoracic Duct ◽  
Lymphoid Cells ◽  
Target Cells ◽  
Skin Grafts ◽  
Peak Activity ◽  
Adult Rats ◽  
Background Levels

Cell-mediated cytotoxicity (CMC) in spleens and lymph nodes of allografted rats was determined by release of 51Cr from labeled target cells incubated with aggressor lymphoid cells. CMC was first detected in grafted adult rats on day 5, peaked on days 7 and 8, and declined rapidly to background levels by days 9 to 11. In allografted neonates and in cyclophosphamide-treated or neonatally thymectomized adults CMC was a fraction of that observed in normal adult rats. Enhancing antibodies deferred in vivo peak activity of CMC in allografted neonates for 3–4 days, and blocked in vitro the action of aggressor lymphocytes by binding to target cells. Enhancing antibodies had no effect on the cytotoxicity of aggressor cells, but horse antibodies to rat thoracic duct cells inhibited in vitro CMC of aggressor cells.

Abstract 129: Embryonic Stem Cell Derived Exosomes Revive Endogenous Repair Mechanisms In Failing Heart

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Mohsin Khan ◽  
Suresh K Verma ◽  
Alexander R Mackie ◽  
Erin Vaughan ◽  
Srikanth Garikipati ◽  
...  
Keyword(s):  
Stem Cells ◽  
Therapeutic Potential ◽  
Embryonic Stem ◽  
Cardiac Regeneration ◽  
Great Promise ◽  
Target Cells ◽  
Free System ◽  
Teratoma Formation

Rationale: Embryonic stem cells (ESCs) hold great promise for cardiac regeneration but are susceptible to ethical concerns, lack of autologous donors and teratoma formation. Recently, it has been observed that beneficial effects of stem cells are mediated by exosomes secreted out under various physiological conditions. ESCs have the ability to produce exosomes however their effect in the context of the heart is unknown. Objective: Determine the effect of ESC derived exosomes for cardiac repair and modulation of CPCs functions in the heart following myocardial infarction. Methods and Results: Exosomes were isolated from murine ESCs (mES Ex) or embryonic fibroblasts (MEFs) by ultracentrifugation and verified by Flotillin-1 immunoblot analysis. Induction of pluripotent markers, survival and in vitro tube formation was enhanced in target cells receiving ESC exosomes indicating therapeutic potential of mES Ex. mES Ex administration resulted in enhanced neovascularization, cardiomyocyte survival and reduced fibrosis post infarction consistent with resurgence of cardiac proliferative response. Importantly, mES Ex mediated considerable enhancement of cardiac progenitor cell (CPC) survival, proliferation and cardiac commitment concurrent with increased c-kit+ CPCs in vivo 4 weeks after mES Ex transfer. miRNA Array analysis of ESC and MEF exosomes revealed significantly high expression of miR290-295 cluster in the ESC exosomes compared to MEF exosomes. The underlying beneficial effect of mES Ex was tied to delivery of ESC miR-294 to the heart and in particular CPCs thereby promoting CPC survival and proliferation as analyzed by FACS based cell death analysis and CyQuant assay respectively. Interestingly, enhanced G1/S transition was observed in CPCs treated with miR-294 in conjunction with significant reduction of G1 phase. Conclusion: In conclusion, mES Ex provide a novel cell free system for cardiac regeneration with the ability to modulate both cardiomyocyte and CPC based repair programs in the heart thereby avoiding the risk of teratoma formation associated with ESCs.

scholarly journals Repression and Derepression of Minus-Strand Synthesis in a Plus-Strand RNA Virus Replicon

2004 ◽  
Vol 78 (14) ◽  
pp. 7619-7633 ◽  
Author(s):  
Guohua Zhang ◽  
Jiuchun Zhang ◽  
Anne E. Simon
Keyword(s):  
Solution Structure ◽  
Rna Virus ◽  
Structural Features ◽  
General Mechanism ◽  
Minus Strand ◽  
Turnip Crinkle Virus ◽  
Structural Elements ◽  
Transcription In Vitro

ABSTRACT Plus-strand viral RNAs contain sequences and structural elements that allow cognate RNA-dependent RNA polymerases (RdRp) to correctly initiate and transcribe asymmetric levels of plus and minus strands during RNA replication. cis-acting sequences involved in minus-strand synthesis, including promoters, enhancers, and, recently, transcriptional repressors (J. Pogany, M. R. Fabian, K. A. White, and P. D. Nagy, EMBO J. 22:5602-5611, 2003), have been identified for many viruses. A second example of a transcriptional repressor has been discovered in satC, a replicon associated with turnip crinkle virus. satC hairpin 5 (H5), located proximal to the core hairpin promoter, contains a large symmetrical internal loop (LSL) with sequence complementary to 3′-terminal bases. Deletion of satC 3′-terminal bases or alteration of the putative interacting bases enhanced transcription in vitro, while compensatory exchanges between the LSL and 3′ end restored near-normal transcription. Solution structure analysis indicated that substantial alteration of the satC H5 region occurs when the three 3′-terminal cytidylates are deleted. These results indicate that H5 functions to suppress synthesis of minus strands by sequestering the 3′ terminus from the RdRp. Alteration of a second sequence strongly repressed transcription in vitro and accumulation in vivo, suggesting that this sequence may function as a derepressor to free the 3′ end from interaction with H5. Hairpins with similar sequence and/or structural features that contain sequence complementary to 3′-terminal bases, as well as sequences that could function as derepressors, are located in similar regions in other carmoviruses, suggesting a general mechanism for controlling minus-strand synthesis in the genus.

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