The multifunctional enzyme S-adenosylhomocysteine/methylthioadenosine nucleosidase is a key metabolic enzyme in the virulence of Salmonella enterica var Typhimurium

Key physiological differences between bacterial and mammalian metabolism provide opportunities for the development of novel antimicrobials. We examined the role of the multifunctional enzyme S-adenosylhomocysteine/Methylthioadenosine (SAH/MTA) nucleosidase (Pfs) in the virulence of S. enterica var Typhimurium (S. Typhimurium) in mice, using a defined Pfs deletion mutant (i.e. Δpfs). Pfs was essential for growth of S. Typhimurium in M9 minimal medium, in tissue cultured cells, and in mice. Studies to resolve which of the three known functions of Pfs were key to murine virulence suggested that downstream production of autoinducer-2, spermidine and methylthioribose were non-essential for Salmonella virulence in a highly sensitive murine model. Mass spectrometry revealed the accumulation of SAH in S. Typhimurium Δpfs and complementation of the Pfs mutant with the specific SAH hydrolase from Legionella pneumophila reduced SAH levels, fully restored growth ex vivo and the virulence of S. Typhimurium Δpfs for mice. The data suggest that Pfs may be a legitimate target for antimicrobial development, and that the key role of Pfs in bacterial virulence may be in reducing the toxic accumulation of SAH which, in turn, suppresses an undefined methyltransferase.

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Generation of Prostacyclin (PGI2) Activity by Lewis Lung Carcinoma (3LL) Cells

10.1055/s-0039-1687338 ◽

1979 ◽

Author(s):

A. Poggi ◽

A. Dall’Olio ◽

G. Balconi ◽

F. Delaini ◽

G. de Gaetano ◽

...

Keyword(s):

Inhibitory Activity ◽

Cultured Cells ◽

Ex Vivo ◽

Primary Tumour ◽

Primary Cultures ◽

Human Platelet Aggregation ◽

Rat Platelets ◽

Muscular Tissues

The role of prostaglandins in tumour growth is still a natter of discussion. We have inve stigatcd the capacity of tissues and cultured cells from a murine metastasizing tumour (3LL) to generate PGI2 activity. Intact fragments and homogenatcs from 51.1. tissues, collected at different intervals after i.m. implantation of 2 χ 105 cells into a hind leg of CS7B1/6J mice, were incubated in Tris buffer at pH 7.4 for 5-15 min or at pH 9.2 for. 45 min. The supernatant showed strong inhibitory activity against ADP-induced human platelet aggregation with many characteristics in common with PGI2. It was progressively released into the medium, was labile at acidic pH, was inhibited by indomethacin both in vitro and ex vivo, was potentiated by theophylline and, unlike PGD2, it inhibited aggregation of rat platelets. Muscular tissues from the contralateral leg had very low inhibitory activity in comparison. Metastatic lungs showed 10-20 times the activity of the primary tumour tissue, similar(however, to the inhibitory activity of normal lungs. Isolated metastatic tissue had lover activity than surrounding lung tissue, but still higher than the primary tumour. 3LL cells harvested from primary cultures of the tumour showed strong PGI2 actiyity. These data suggest that in 3LL tissues PGI2 activity may derive not only from their vascular net but also from the cancer cells themselvcs. [Supported by a grant from Italian CNR).

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Supportive Role of TNF-Family Death Receptors in Hematopoietic Cell Engraftment.

Blood ◽

10.1182/blood.v110.11.4048.4048 ◽

2007 ◽

Vol 110 (11) ◽

pp. 4048-4048

Author(s):

Michal Pearl-Yafe ◽

Nadir Askenasy ◽

Jerry Stein ◽

Isaac Yaniv

Keyword(s):

Cultured Cells ◽

Ex Vivo ◽

Death Receptors ◽

Hematopoietic Cell ◽

Cell Engraftment ◽

Tnf Superfamily ◽

Supportive Role ◽

Receptor Cross Talk ◽

Regulatory Functions

Abstract The activity of death receptors of the tumor necrosis factor (TNF) superfamily as negative regulators of distal differentiation in the immuno-hematopoietic system is well characterized. The role of these receptors, classically associated with transduction of apoptotic signals, is unknown. A series of studies have attributed these receptors also negative regulatory functions in ex vivo expanded hematopoietic progenitors, showing variable supporting and suppressive interactions with growth factors. We observed robust upregulation of Fas, TNF-R1, TNF-R2 and TRAIL-R2 in bone marrow homed donor cells, reaching levels of 60–75% expression after 6 days. All putative SCA-1+c-kit+lin− progenitors ubiquitously expressed all four receptors. These receptor-positive cells were largely resistant to apoptotic signals delivered by the corresponding soluble and membranous ligands. Furthermore, there was no evidence of receptor cross-talk in sensitization of the cells to apoptotic death. The engraftment potential of cells was markedly diminished by ex vivo incubation, without any relationship to the viability of the putative progenitors. Taken together these data suggest a supportive role of the “death receptors” in hematopoietic cell engraftment and dissociate the deficient engraftment of cultured cells from apoptosis of progenitors.

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Role of Immunohistochemistry in the Evaluation of Needle Core Biopsies in Adult Renal Cortical Tumors: An Ex Vivo Study

Yearbook of Pathology and Laboratory Medicine ◽

10.1016/j.ypat.2011.10.001 ◽

2012 ◽

Vol 2012 ◽

pp. 161-163

Author(s):

M.L. Smith

Keyword(s):

Ex Vivo ◽

Ex Vivo Study

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The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000116 ◽

2012 ◽

Vol 82 (3) ◽

pp. 228-232 ◽

Cited By ~ 7

Author(s):

Mauro Serafini ◽

Giuseppa Morabito

Keyword(s):

Antioxidant Capacity ◽

Dietary Intervention ◽

Ex Vivo ◽

The Body ◽

Dietary Polyphenols ◽

Enzymatic Antioxidant ◽

Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

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Highly sensitive adolescent benefits in positive school transitions: Evidence for vantage sensitivity in Japanese high-schoolers

10.31234/osf.io/kmxqs ◽

2020 ◽

Author(s):

Shuhei Iimura

Keyword(s):

High School ◽

Statistical Power ◽

Environmental Influences ◽

Differential Susceptibility ◽

School Transition ◽

Well Being ◽

Crossover Point ◽

Japanese Adolescents ◽

Highly Sensitive

Some researchers indicate that the transition to high school deflects adolescent developmental trajectories. Others assert it provides a new possibility for the promotion of adolescents’ socioemotional well-being. One critical view missing in such claims is that individual variabilities interact with environmental influences. We employed the framework of Differential Susceptibility Theory, which postulates that individual susceptibilities moderate external influences for better and for worse. In order to clarify the mechanism of adolescents’ differential adjustments, this paper investigated the role of sensory-processing sensitivity using the Japanese version of Highly Sensitive Child Scale for Adolescence (J-HSCS), and tested whether the diathesis-stress model or the differential susceptibility model best describes students’ socioemotional adjustment across their high school transition. The current paper used the two-wave data collected from Japanese adolescents aged from 14 to 15 years (n = 412, 50% girls). In Study 1, we investigated the replicability of psychometric properties of J-HSCS. The results supported previous findings, indicating its validity for the bifactor model. In Study 2, we utilized confirmatory competitive model testing, which maximizes statistical power by parameterizing the crossover point to allow a direct comparison of alternative models. The results indicated that neither the diathesis-stress nor the differential susceptibility models fitted the data. Rather, a strong vantage sensitivity model was revealed, suggesting that highly susceptible adolescents disproportionately benefitted from a positive school transition over their counterparts. This finding signified the role of adolescents’ sensitivity to environmental influences and the importance of considering its moderation under person x environment interactions.

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Role of MRI evaluation in acute secondary inability to walk in children

Egyptian Journal of Radiology and Nuclear Medicine ◽

10.1186/s43055-021-00417-0 ◽

2021 ◽

Vol 52 (1) ◽

Author(s):

K. H. Sedeek ◽

K. Aboualfotouh ◽

S. M. Hassanein ◽

N. M. Osman ◽

M. H. Shalaby

Keyword(s):

Transverse Myelitis ◽

High Sensitivity ◽

Acute Disseminated Encephalomyelitis ◽

Limb Weakness ◽

Non Invasive ◽

Highly Sensitive ◽

Common Causes ◽

Bilateral Lower Limb ◽

Severity Of The Disease

Abstract Background Acute bilateral lower limb weakness is a common problem in children which necessitates a rapid method for diagnosis. MRI is a non-invasive imaging technique that produces high-quality images of the internal structure of the brain and spinal cord. Results MRI was very helpful in reaching rapid and prompt diagnosis in children with acute inability to walk. Acute disseminated encephalomyelitis (ADEM), Guillain–Barré syndrome (GBS), and acute transverse myelitis (ATM) were the most common causes in our study. MRI proved to be of high sensitivity in detecting the lesions and reaching the diagnosis in ADEM and GBS; however, there was no significant relation between the lesions’ size, enhancement pattern, and severity of the disease or prognosis, yet in ATM the site of the lesion and number of cord segment affection were significantly related to the severity of the disease and prognosis. Conclusion MRI is a quick tool to reach the diagnosis of children with acute secondary inability to walk, and to eliminate other differential diagnosis which is essential for proper treatment and rapid full recovery. It is highly sensitive in detecting the lesions, their site and size.

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Evaluating Targeted Therapies in Ovarian Cancer Metabolism: Novel Role for PCSK9 and Second Generation mTOR Inhibitors

Cancers ◽

10.3390/cancers13153727 ◽

2021 ◽

Vol 13 (15) ◽

pp. 3727

Author(s):

Dafne Jacome Sanz ◽

Juuli Raivola ◽

Hanna Karvonen ◽

Mariliina Arjama ◽

Harlan Barker ◽

...

Keyword(s):

Ovarian Cancer ◽

Lipid Metabolism ◽

Cell Survival ◽

Drug Testing ◽

Cancer Metabolism ◽

Ex Vivo ◽

Specific Inhibitor ◽

Low Grade ◽

Serous Ovarian Cancer

Background: Dysregulated lipid metabolism is emerging as a hallmark in several malignancies, including ovarian cancer (OC). Specifically, metastatic OC is highly dependent on lipid-rich omentum. We aimed to investigate the therapeutic value of targeting lipid metabolism in OC. For this purpose, we studied the role of PCSK9, a cholesterol-regulating enzyme, in OC cell survival and its downstream signaling. We also investigated the cytotoxic efficacy of a small library of metabolic (n = 11) and mTOR (n = 10) inhibitors using OC cell lines (n = 8) and ex vivo patient-derived cell cultures (PDCs, n = 5) to identify clinically suitable drug vulnerabilities. Targeting PCSK9 expression with siRNA or PCSK9 specific inhibitor (PF-06446846) impaired OC cell survival. In addition, overexpression of PCSK9 induced robust AKT phosphorylation along with increased expression of ERK1/2 and MEK1/2, suggesting a pro-survival role of PCSK9 in OC cells. Moreover, our drug testing revealed marked differences in cytotoxic responses to drugs targeting metabolic pathways of high-grade serous ovarian cancer (HGSOC) and low-grade serous ovarian cancer (LGSOC) PDCs. Our results show that targeting PCSK9 expression could impair OC cell survival, which warrants further investigation to address the dependency of this cancer on lipogenesis and omental metastasis. Moreover, the differences in metabolic gene expression and drug responses of OC PDCs indicate the existence of a metabolic heterogeneity within OC subtypes, which should be further explored for therapeutic improvements.

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Moonlighting in Bacillus subtilis: The Small Proteins SR1P and SR7P Regulate the Moonlighting Activity of Glyceraldehyde 3-Phosphate Dehydrogenase A (GapA) and Enolase in RNA Degradation

Microorganisms ◽

10.3390/microorganisms9051046 ◽

2021 ◽

Vol 9 (5) ◽

pp. 1046

Author(s):

Inam Ul Haq ◽

Sabine Brantl

Keyword(s):

Bacillus Subtilis ◽

Antisense Rna ◽

Rna Binding ◽

Rna Degradation ◽

Metabolic Enzyme ◽

Dual Function ◽

Small Proteins ◽

Moonlighting Proteins ◽

Rnase Y

Moonlighting proteins are proteins with more than one function. During the past 25 years, they have been found to be rather widespread in bacteria. In Bacillus subtilis, moonlighting has been disclosed to occur via DNA, protein or RNA binding or protein phosphorylation. In addition, two metabolic enzymes, enolase and phosphofructokinase, were localized in the degradosome-like network (DLN) where they were thought to be scaffolding components. The DLN comprises the major endoribonuclease RNase Y, 3′-5′ exoribonuclease PnpA, endo/5′-3′ exoribonucleases J1/J2 and helicase CshA. We have ascertained that the metabolic enzyme GapA is an additional component of the DLN. In addition, we identified two small proteins that bind scaffolding components of the degradosome: SR1P encoded by the dual-function sRNA SR1 binds GapA, promotes the GapA-RNase J1 interaction and increases the RNase J1 activity. SR7P encoded by the dual-function antisense RNA SR7 binds to enolase thereby enhancing the enzymatic activity of enolase bound RNase Y. We discuss the role of small proteins in modulating the activity of two moonlighting proteins.

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Antagonism of Adherent Invasive E. coli LF82 With Human α-defensin 5 in the Follicle-associated Epithelium of Patients With Ileal Crohn’s Disease

Inflammatory Bowel Diseases ◽

10.1093/ibd/izaa315 ◽

2020 ◽

Author(s):

Lina Y Alkaissi ◽

Martin E Winberg ◽

Stéphanie DS Heil ◽

Staffan Haapaniemi ◽

Pär Myrelid ◽

...

Keyword(s):

Crohn’S Disease ◽

Crohn's Disease ◽

Ex Vivo ◽

Ussing Chambers ◽

E Coli ◽

Follicle Associated Epithelium ◽

Vitro Model ◽

Set Up

Abstract Background The first visible signs of Crohn’s disease (CD) are microscopic erosions over the follicle-associated epithelium (FAE). The aim of the study was to investigate the effects of human α-defensin 5 (HD5) on adherent-invasive Escherichia coli LF82 translocation and HD5 secretion after LF82 exposure in an in vitro model of human FAE and in human FAE ex vivo. Methods An in vitro FAE-model was set up by the coculture of Raji B cells and Caco-2-cl1 cells. Ileal FAE from patients with CD and controls were mounted in Ussing chambers. The effect of HD5 on LF82 translocation was studied by LF82 exposure to the cells or tissues with or without incubation with HD5. The HD5 secretion was measured in human FAE exposed to LF82 or Salmonella typhimurium. The HD5 levels were evaluated by immunofluorescence, immunoblotting, and ELISA. Results There was an increased LF82 translocation across the FAE-model compared with Caco-2-cl1 (P < 0.05). Incubation of cell/tissues with HD5 before LF82 exposure reduced bacterial passage in both models. Human FAE showed increased LF82 translocation in CD compared with controls and attenuated passage after incubation with sublethal HD5 in both CD and controls (P < 0.05). LF82 exposure resulted in a lower HD5 secretion in CD FAE compared with controls (P < 0.05), whereas Salmonella exposure caused equal secretion on CD and controls. There were significantly lower HD5 levels in CD tissues compared with controls. Conclusions Sublethal HD5 reduces the ability of LF82 to translocate through FAE. The HD5 is secreted less in CD in response to LF82, despite a normal response to Salmonella. This further implicates the integrated role of antimicrobial factors and barrier function in CD pathogenesis.

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