scholarly journals Distinct Differentiation Characteristics of Endothelium Determine Its Ability to Form Pseudo-Embryos in Tomato Ovules

2019 ◽  
Vol 21 (1) ◽  
pp. 12 ◽  
Author(s):  
Inna Chaban ◽  
Ekaterina Baranova ◽  
Neonila Kononenko ◽  
Marat Khaliluev ◽  
Elena Smirnova
Keyword(s):  
Functional Organization ◽  
Embryo Sac ◽  
Secretory Activity ◽  
Parthenocarpic Fruit ◽  
Gene Encoding ◽  
Solanum Lycopersicum L ◽  
Embryo Cells ◽  
Additional Cell ◽  
Chitin Binding Protein

The endothelium is an additional cell layer, differentiating from the inner epidermis of the ovule integument. In tomato (Solanum lycopersicum L.), after fertilization, the endothelium separates from integument and becomes an independent tissue developing next to the growing embryo sac. In the absence of fertilization, the endothelium may proliferate and form pseudo-embryo. However, the course of the reorganization of endothelium into pseudo-embryo in tomato ovules is poorly understood. We aimed to investigate specific features of endothelium differentiation and the role of the endothelium in the development of fertilized and unfertilized tomato ovules. The ovules of tomato plants (“YaLF” line), produced by vegetative growth plants of transgenic tomato line expressing the ac gene, encoding chitin-binding protein from Amaranthus caudatus L., were investigated using light and transmission electron microscopy. We showed that in the fertilized ovule of normally developing fruit and in the unfertilized ovule of parthenocarpic fruit, separation of the endothelium from integument occurs via programmed death of cells of the integumental parenchyma, adjacent to the endothelium. Endothelial cells in normally developing ovules change their structural and functional specialization from meristematic to secretory and back to meristematic, and proliferate until seeds fully mature. The secretory activity of the endothelium is necessary for the lysis of dying cells of the integument and provides the space for the growth of the new sporophyte. However, in ovules of parthenocarpic fruits, pseudo-embryo cells do not change their structural and functional organization and remain meristematic, no zone of lysis is formed, and pseudo-embryo cells undergo programmed cell death. Our data shows the key role of the endothelium as a protective and secretory tissue, needed for the normal development of ovules.

scholarly journals The Role of Mitochondria in Carcinogenesis

2021 ◽  
Vol 22 (10) ◽  
pp. 5100
Author(s):  
Paulina Kozakiewicz ◽  
Ludmiła Grzybowska-Szatkowska ◽  
Marzanna Ciesielka ◽  
Jolanta Rzymowska
Keyword(s):  
Prostate Cancer ◽  
Mitochondrial Dna ◽  
Nuclear Dna ◽  
Dna Polymorphisms ◽  
Gene Encoding ◽  
Dna Mutations ◽  
Nadh Ubiquinone Oxidoreductase ◽  
Gene Coi ◽  
The Impact

The mitochondria are essential for normal cell functioning. Changes in mitochondrial DNA (mtDNA) may affect the occurrence of some chronic diseases and cancer. This process is complex and not entirely understood. The assignment to a particular mitochondrial haplogroup may be a factor that either contributes to cancer development or reduces its likelihood. Mutations in mtDNA occurring via an increase in reactive oxygen species may favour the occurrence of further changes both in mitochondrial and nuclear DNA. Mitochondrial DNA mutations in postmitotic cells are not inherited, but may play a role both in initiation and progression of cancer. One of the first discovered polymorphisms associated with cancer was in the gene NADH-ubiquinone oxidoreductase chain 3 (mt-ND3) and it was typical of haplogroup N. In prostate cancer, these mutations and polymorphisms involve a gene encoding subunit I of respiratory complex IV cytochrome c oxidase subunit 1 gene (COI). At present, a growing number of studies also address the impact of mtDNA polymorphisms on prognosis in cancer patients. Some of the mitochondrial DNA polymorphisms occur in both chronic disease and cancer, for instance polymorphism G5913A characteristic of prostate cancer and hypertension.

scholarly journals Paving the Way for Fertilization: The Role of the Transmitting Tract

2021 ◽  
Vol 22 (5) ◽  
pp. 2603
Author(s):  
Ana Marta Pereira ◽  
Diana Moreira ◽  
Sílvia Coimbra ◽  
Simona Masiero
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Current Knowledge ◽  
Embryo Sac ◽  
Tube Growth ◽  
Signaling Cascades ◽  
Secretory Cells ◽  
Transmitting Tract ◽  
Specialized Tissue

Angiosperm reproduction relies on the precise growth of the pollen tube through different pistil tissues carrying two sperm cells into the ovules’ embryo sac, where they fuse with the egg and the central cell to accomplish double fertilization and ultimately initiate seed development. A network of intrinsic and tightly regulated communication and signaling cascades, which mediate continuous interactions between the pollen tube and the sporophytic and gametophytic female tissues, ensures the fast and meticulous growth of pollen tubes along the pistil, until it reaches the ovule embryo sac. Most of the pollen tube growth occurs in a specialized tissue—the transmitting tract—connecting the stigma, the style, and the ovary. This tissue is composed of highly secretory cells responsible for producing an extensive extracellular matrix. This multifaceted matrix is proposed to support and provide nutrition and adhesion for pollen tube growth and guidance. Insights pertaining to the mechanisms that underlie these processes remain sparse due to the difficulty of accessing and manipulating the female sporophytic tissues enclosed in the pistil. Here, we summarize the current knowledge on this key step of reproduction in flowering plants with special emphasis on the female transmitting tract tissue.

scholarly journals Controlled Transcription of Regulator Gene carS by Tet-on or by a Strong Promoter Confirms Its Role as a Repressor of Carotenoid Biosynthesis in Fusarium fujikuroi

2020 ◽  
Vol 9 (1) ◽  
pp. 71
Author(s):  
Julia Marente ◽  
Javier Avalos ◽  
M. Carmen Limón
Keyword(s):  
Wild Strain ◽  
Ring Finger ◽  
Carotenoid Biosynthesis ◽  
Negative Regulator ◽  
Fusarium Fujikuroi ◽  
Structural Genes ◽  
Gene Encoding ◽  
In The Wild ◽  
Set Up

Carotenoid biosynthesis is a frequent trait in fungi. In the ascomycete Fusarium fujikuroi, the synthesis of the carboxylic xanthophyll neurosporaxanthin (NX) is stimulated by light. However, the mutants of the carS gene, encoding a protein of the RING finger family, accumulate large NX amounts regardless of illumination, indicating the role of CarS as a negative regulator. To confirm CarS function, we used the Tet-on system to control carS expression in this fungus. The system was first set up with a reporter mluc gene, which showed a positive correlation between the inducer doxycycline and luminescence. Once the system was improved, the carS gene was expressed using Tet-on in the wild strain and in a carS mutant. In both cases, increased carS transcription provoked a downregulation of the structural genes of the pathway and albino phenotypes even under light. Similarly, when the carS gene was constitutively overexpressed under the control of a gpdA promoter, total downregulation of the NX pathway was observed. The results confirmed the role of CarS as a repressor of carotenogenesis in F. fujikuroi and revealed that its expression must be regulated in the wild strain to allow appropriate NX biosynthesis in response to illumination.

scholarly journals Quantitative assessment of CYP11B1 and CYP11B2 expression in aldosterone-producing adenomas

2002 ◽  
pp. 795-802 ◽  
Author(s):  
F Fallo ◽  
V Pezzi ◽  
L Barzon ◽  
P Mulatero ◽  
F Veglio ◽  
...  
Keyword(s):  
Real Time ◽  
Secretory Activity ◽  
Zona Glomerulosa ◽  
Zona Fasciculata ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Pathophysiological Role ◽  
Aldosterone Production

BACKGROUND: The presence and pathophysiological role of CYP11B1 (11beta-hydroxylase) gene in the zona glomerulosa of human adrenal cortex is still controversial. METHODS: In order to specifically quantify CYP11B1, CYP11B2 (aldosterone synthase) and CYP17(17alpha-hydroxylase) mRNA levels, we developed a real-time RT-PCR assay and examined the expression in a series of adrenal tIssues, including six normal adrenals from patients adrenalectomized for renal cancer and twelve aldosterone-producing adenomas (APA) from patients with primary aldosteronism. RESULTS: CYP11B1 mRNA levels were clearly detected in normal adrenals, which comprised both zona glomerulosa and fasciculata/reticularis cells, but were also measured at a lower range (P<0.05) in APA. The levels of CYP11B2 mRNA were lower (P<0.005) in normal adrenals than in APA. CYP17 mRNAlevels were similar in normal adrenals and in APA. In patients with APA, CYP11B2 and CYP11B1 mRNA levels were not correlated either with basal aldosterone or with the change from basal aldosterone in response to posture or to dexamethasone. No correlation between CYP11B1 mRNA or CYP11B2 mRNA and the percentage of zona fasciculata-like cells was observed in APA. CONCLUSIONS: Real-time RT-PCR can be reliably used to quantify CYP11B1 and CYP11B2 mRNA levels in adrenal tIssues. Expression of CYP11B1 in hyperfunctioning zona glomerulosa suggests an additional formation of corticosterone via 11beta-hydroxylase, providing further substrate for aldosterone biosynthesis. CYP11B1 and CYP11B2 mRNA levels in APA are not related to the in vivo secretory activity of glomerulosa cells, where post-transcriptional factors might ultimately regulate aldosterone production.

scholarly journals Regulatory Role of the MisR/S Two-Component System in Hemoglobin Utilization in Neisseria meningitidis

2009 ◽  
Vol 78 (3) ◽  
pp. 1109-1122 ◽  
Author(s):  
Shuming Zhao ◽  
Grisselle E. Montanez ◽  
Pradeep Kumar ◽  
Soma Sannigrahi ◽  
Yih-Ling Tzeng
Keyword(s):  
Posttranscriptional Regulation ◽  
Regulatory Mechanisms ◽  
Two Component System ◽  
Gene Encoding ◽  
Positive Role ◽  
Upstream Gene ◽  
Component System ◽  
Two Component ◽  
Major Surface

ABSTRACT Outer membrane iron receptors are some of the major surface entities that are critical for meningococcal pathogenesis. The gene encoding the meningococcal hemoglobin receptor, HmbR, is both independently transcribed and transcriptionally linked to the upstream gene hemO, which encodes a heme oxygenase. The MisR/S two-component system was previously determined to regulate hmbR transcription, and its hemO and hmbR regulatory mechanisms were characterized further here. The expression of hemO and hmbR was downregulated in misR/S mutants under both iron-replete and iron-restricted conditions, and the downregulation could be reversed by complementation. No significant changes in expression of other iron receptors were detected, suggesting that the MisR/S system specifically regulates hmbR. When hemoglobin was the sole iron source, growth defects were detected in the mutants. Primer extension analysis identified a promoter upstream of the hemO-associated Correia element (CE) and another promoter at the proximal end of CE, and processed transcripts previously identified for other cotranscribed CEs were also detected, suggesting that there may be posttranscriptional regulation. MisR directly interacts with sequences upstream of the CE and upstream of the hmbR Fur binding site and thus independently regulates hemO and hmbR. Analysis of transcriptional reporters of hemO and hmbR further demonstrated the positive role of the MisR/S system and showed that the transcription of hmbR initiated from hemO was significantly reduced. A comparison of the effects of the misS mutation under iron-replete and iron-depleted conditions suggested that activation by the MisR/S system and iron-mediated repression by Fur act independently. Thus, the expression of hemO and hmbR is coordinately controlled by multiple independent regulatory mechanisms, including the MisR/S two-component system.

Platelet Glycoprotein Receptor IIIa Polymorphism PlA1/PlA2 and Coronary Risk: a Meta-Analysis

2001 ◽  
Vol 85 (04) ◽  
pp. 626-633 ◽  
Author(s):  
Augusto Di Castelnuovo ◽  
Giovanni de Gaetano ◽  
Maria Benedetta Donati ◽  
Licia Iacoviello
Keyword(s):  
Odds Ratio ◽  
Meta Analysis ◽  
Platelet Glycoprotein ◽  
Published Data ◽  
Coronary Risk ◽  
Gene Encoding ◽  
Glycoprotein Iiia ◽  
Artery Disease ◽  
Revascularization Procedures

SummaryMembrane glycoprotein IIb/IIIa plays a major role in platelet function. The gene encoding the glycoprotein IIIa shows a common polymorphism PlA1/PlA2 that was variably associated with vascular disease. To clarify the role of PlA1/PlA2 polymorphism in coronary risk, a meta-analysis of published data was conducted. Studies were identified both by MEDLINE searches, and hand searching of journals and abstract books.A total of 34 studies for coronary artery disease (CAD), and 6 for restenosis after revascularization were identified, for a total of 9,095 cases and 12,508 controls. In CAD, the overall odds ratio for carriers of the PlA2 allele was 1.10 (95% CI: 1.03 to 1.18), and it was 1.21 (95% CI: 1.05 to 1.38) in subjects younger than 60. Overall odds ratio was 1.31 (95% CI: 1.10 to 1.56) after revascularization procedures.The association of PlA2 status with overall cardiovascular disease in the general population is significant but weak; higher risk has been identified in less heterogeneous subgroups as in the younger cohorts and in the restenosis subset with stents.

Impact of some environmental chemical carcinogens on the incidence of hormone-dependent tumors and possible mechanisms of its realization (literary review)

2021 ◽  
Vol 99 (2) ◽  
pp. 44-55
Author(s):  
I.O. Chernychenko ◽  
◽  
N.V. Balenko ◽  
O.M. Lytvychenko ◽  
V.F. Babii ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Functional Organization ◽  
Endocrine System ◽  
Epidemiological Data ◽  
Environmental Carcinogens ◽  
Chemical Carcinogens ◽  
Environmental Chemical ◽  
Polycyclic Aromatic ◽  
Pollution Emissions

Objective: We determined the possible effects of priority chemical environmental carcinogens on the incidence of hormone-dependent tumors and the mechanisms of their effect on the basis of the analysis of literature data and our own research. Results: The performed analysis demonstrates the scanity of the research devoted to the study of chemical carcinogens which are concerned only with the class of polycyclic aromatic hydrocarbons (PAH), benzo(a)pyrene (BP), atmospheric pollution, emissions from vehicles, the cadmium heavy metal and products of smoking containing these substances. The connection with PAH (BP) and the development of breast, ovarian cancer, cadmium with the development of breast, endometrial, ovarian cancer in women and prostate cancer in men was established. Epidemiological data, combined with experimental ones, suggest a possible contribution of carcinogens into the increase of the incidence of hormone-dependent tumors. At the same time, mechanisms of action of PAH and cadmium on the development of hormone-dependent tumors are unclear. The accumulated experimental and epidemiological data allow us to conclude that the oncological danger of these carcinogens lies in the combination of genotoxic and hormone-mimetic properties; the main mechanisms, involved in the realization of the effect of BP and cadmium, are associated with changes and disorders at different levels of the structural and functional organization of the organism, including the endocrine system, which can lead to the development of tumors. The urgency of the problem of the incidence of hormone-dependent tumors and the potential role of the studied chemical carcinogens as pollutants of the environment of human functions indicate the need to take these circumstances into account when developing and implementing preventive measures.

scholarly journals cAMP-dependent recruitment of acidic organelles for Ca2+ signaling in the salivary gland

2016 ◽  
Vol 311 (5) ◽  
pp. C697-C709 ◽  
Author(s):  
John F. Imbery ◽  
Sumit Bhattacharya ◽  
Sura Khuder ◽  
Amanda Weiss ◽  
Priyodarshan Goswamee ◽  
...  
Keyword(s):  
Secretory Activity ◽  
Neural Activation ◽  
Potential Therapeutic Target ◽  
Parotid Acinar Cells ◽  
Saliva Secretion ◽  
Intracellular Ca ◽  
Low Levels ◽  
Protein Components ◽  
Acidic Organelles

Autonomic neural activation of intracellular Ca2+ release in parotid acinar cells induces the secretion of the fluid and protein components of primary saliva critical for maintaining overall oral homeostasis. In the current study, we profiled the role of acidic organelles in shaping the Ca2+ signals of parotid acini using a variety of imaging and pharmacological approaches. Results demonstrate that zymogen granules predominate as an apically polarized population of acidic organelles that contributes to the initial Ca2+ release. Moreover, we provide evidence that indicates a role for the intracellular messenger NAADP in the release of Ca2+ from acidic organelles following elevation of cAMP. Our data are consistent with the “trigger” hypothesis where localized release of Ca2+ sensitizes canonical intracellular Ca2+ channels to enhance signals from the endoplasmic reticulum. Release from acidic stores may be important for initiating saliva secretion at low levels of stimulation and a potential therapeutic target to augment secretory activity in hypofunctioning salivary glands.

The IGF-I Receptor in Mitogenesis and Transformation of Mouse Embryo Cells: Role of Receptor Number

1997 ◽  
Vol 230 (2) ◽  
pp. 284-292 ◽  
Author(s):  
Michele Rubini ◽  
Atsushi Hongo ◽  
Consuelo D'Ambrosio ◽  
Renato Baserga
Keyword(s):  
Mouse Embryo ◽  
Igf I ◽  
Embryo Cells ◽  
Receptor Number

scholarly journals Expression of Mycobacterium smegmatisPyrazinamidase in Mycobacterium tuberculosis Confers Hypersensitivity to Pyrazinamide and Related Amides

2000 ◽  
Vol 182 (19) ◽  
pp. 5479-5485 ◽  
Author(s):  
Helena I. M. Boshoff ◽  
Valerie Mizrahi
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mycobacterium Smegmatis ◽  
Intracellular Localization ◽  
Wild Type ◽  
Gene Encoding ◽  
Allelic Exchange ◽  
Mutant Strains ◽  
Established Role ◽  
Amidase Gene

ABSTRACT A pyrazinamidase (PZase)-deficient pncA mutant ofMycobacterium tuberculosis, constructed by allelic exchange, was used to investigate the effects of heterologous amidase gene expression on the susceptibility of this organism to pyrazinamide (PZA) and related amides. The mutant was highly resistant to PZA (MIC, >2,000 μg/ml), in accordance with the well-established role ofpncA in the PZA susceptibility of M. tuberculosis (A. Scorpio and Y. Zhang, Nat. Med. 2:662–667, 1996). Integration of the pzaA gene encoding the major PZase/nicotinamidase from Mycobacterium smegmatis (H. I. M. Boshoff and V. Mizrahi, J. Bacteriol. 180:5809–5814, 1998) or the M. tuberculosis pncA gene into the pncAmutant complemented its PZase/nicotinamidase defect. In bothpzaA- and pncA-complemented mutant strains, the PZase activity was detected exclusively in the cytoplasm, suggesting an intracellular localization for PzaA and PncA. ThepzaA-complemented strain was hypersensitive to PZA (MIC, ≤10 μg/ml) and nicotinamide (MIC, ≥20 μg/ml) and was also sensitive to benzamide (MIC, 20 μg/ml), unlike the wild-type andpncA-complemented mutant strains, which were highly resistant to this amide (MIC, >500 μg/ml). This finding was consistent with the observation that benzamide is hydrolyzed by PzaA but not by PncA. Overexpression of PzaA also conferred sensitivity to PZA, nicotinamide, and benzamide on M. smegmatis (MIC, 150 μg/ml in all cases) and rendered Escherichia colihypersensitive for growth at low pH.

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