The involvement of polyamine uptake and synthesis pathways in the proliferation of neonatal astrocytes

Malpica-Nieves, Christian J.; Rivera-Aponte, David E.; Tejeda-Bayron, Flavia A; Mayor, Angel M.; Phanstiel, Otto; Veh, Rüdiger W.; Eaton, Misty J.; Skatchkov, Serguei N.

doi:10.1007/s00726-020-02881-w

Cited by 20 publications

(39 citation statements)

References 73 publications

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“…Primary cultures of astrocytes were prepared from the neocortex of 1-3-day-old C57 mice, as previously described [33]. Briefly, brains were removed after decapitation, and the meninges were stripped to avoid fibroblast contamination.…”

Section: Preparation Of Primary Cortical Astrocyte Culturesmentioning

confidence: 99%

“…After 4 weeks in culture, cortical astrocytes were harvested, pelleted, and resuspended in homogenization buffer as previously described [33]. Briefly, Western blotting was performed using anti-Connexin-43 antibody produced in rabbit (1:2000; #C6219, Sigma Aldrich, St. Louis, MO, USA) and 15 µg/mL of protein from each sample.…”

Section: Sds-page and Western Blotting Analysismentioning

confidence: 99%

“…The trimer44NMe is a novel polyamine transport inhibitor (PTI) [33,44,45] that was developed and synthesized in the laboratory of Dr. Otto Phanstiel at the University of Central Florida in Orlando, FL. The PTI has been used in combination with difluoromethylornithine (DFMO) to deplete PAs in cancer cells [44].…”

Section: Polyamine Transport Inhibitor (Pti)mentioning

confidence: 99%

“…The release of PAs was observed in the brain [30] and nerves [31]. Ultimately, PAs are taken up by glia, where they can be the source of release to modulate both the glial and neuronal channels [32,33]. Since glia outnumber neurons [34] and PAs increase longevity [35,36], glial cells are the focus of the current research.…”

Section: Introductionmentioning

confidence: 98%

“…To study the potential pathways for PA uptake in astrocytes expressing HIV-Tat protein, we incubated cultured astrocytes with SPM tagged with biotin (biotinylated SPM, b-SPM (see Section 2 below)) and visualized b-SPM uptake using fluorescent rhodamine-avidin (biotin-avidin binding) with confocal microscopy. Cx43 HCs were knocked down using siRNA, whereas potential PA uptake via transporters was blocked using a novel polyamine transport inhibitor (PTI) that we have characterized in astrocytes [33]. To mimic HAND conditions, we exposed cultured astrocytes for 72 h prior to experimentation to HIV-1 IIIB Tat Recombinant Protein.…”

Section: Introductionmentioning

confidence: 99%

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Uptake of Biotinylated Spermine in Astrocytes: Effect of Cx43 siRNA, HIV-Tat Protein and Polyamine Transport Inhibitor on Polyamine Uptake

et al. 2021

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Polyamines (PAs) are polycationic biomolecules containing multiple amino groups. Patients with HIV-associated neurocognitive disorder (HAND) have high concentrations of the polyamine N-acetylated spermine in their brain and cerebral spinal fluid (CSF) and have increased PA release from astrocytes. These effects are due to the exposure to HIV-Tat. In healthy adult brain, PAs are accumulated but not synthesized in astrocytes, suggesting that PAs must enter astrocytes to be N-acetylated and released. Therefore, we tested if Cx43 hemichannels (Cx43-HCs) are pathways for PA flux in control and HIV-Tat-treated astrocytes. We used biotinylated spermine (b-SPM) to examine polyamine uptake. We found that control astrocytes and those treated with siRNA-Cx43 took up b-SPM, similarly suggesting that PA uptake is via a transporter/channel other than Cx43-HCs. Surprisingly, astrocytes pretreated with both HIV-Tat and siRNA-Cx43 showed increased accumulation of b-SPM. Using a novel polyamine transport inhibitor (PTI), trimer 44NMe, we blocked b-SPM uptake, showing that PA uptake is via a PTI-sensitive transport mechanism such as organic cation transporter. Our data suggest that Cx43 HCs are not a major pathway for b-SPM uptake in the condition of normal extracellular calcium concentration but may be involved in the release of PAs to the extracellular space during viral infection.

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Section: Preparation Of Primary Cortical Astrocyte Culturesmentioning

confidence: 99%

Section: Sds-page and Western Blotting Analysismentioning

confidence: 99%

Section: Polyamine Transport Inhibitor (Pti)mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

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Uptake of Biotinylated Spermine in Astrocytes: Effect of Cx43 siRNA, HIV-Tat Protein and Polyamine Transport Inhibitor on Polyamine Uptake

et al. 2021

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Acute hypoxia elevates arginase 2 and induces polyamine stress response in zebrafish via evolutionarily conserved mechanism

Banerjee

Khrystoforova

Polis

et al. 2021

Cell. Mol. Life Sci.

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Living organisms repeatedly encounter stressful events and apply various strategies to survive. Polyamines are omnipresent bioactive molecules with multiple functions. Their transient synthesis, inducible by numerous stressful stimuli, is termed the polyamine stress response. Animals developed evolutionarily conserved strategies to cope with stresses. The urea cycle is an ancient attribute that deals with ammonia excess in terrestrial species. Remarkably, most fish retain the urea cycle genes fully expressed during the early stages of development and silenced in adult animals. Environmental challenges instigate urea synthesis in fish despite substantial energetic costs, which poses the question of the urea cycle's evolutionary significance. Arginase plays a critical role in oxidative stress-dependent reactions being the final urea cycle enzyme. Its unique subcellular localization, high inducibility, and several regulation levels provide a supreme ability to control the polyamine synthesis rate. Notably, oxidative stress instigates the arginase-1 activity in mammals. Arginase is also dysregulated in aging organisms' brain and muscle tissues, indicating its role in the pathogenesis of age-associated diseases. We designed a study to investigate the levels of the urea cycle and polyamine synthesis-related enzymes in a fish model of acute hypoxia. We evidence synchronized elevation of arginase-2 and ornithine decarboxylase following oxidative stress in adult fish and aging animals signifying the specific function of arginase-2 in fish. Moreover, we demonstrate oxidative stress-associated polyamine synthesis' induction and urea cycle' arrest in adult fish. The subcellular arginase localization found in the fish seems to correspond to its possible evolutionary roles.

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Effects of Chronic Arginase Inhibition with Norvaline on Tau Pathology and Brain Glucose Metabolism in Alzheimer's Disease Mice

et al. 2022

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The involvement of polyamine uptake and synthesis pathways in the proliferation of neonatal astrocytes

Cited by 20 publications

References 73 publications

Uptake of Biotinylated Spermine in Astrocytes: Effect of Cx43 siRNA, HIV-Tat Protein and Polyamine Transport Inhibitor on Polyamine Uptake

Uptake of Biotinylated Spermine in Astrocytes: Effect of Cx43 siRNA, HIV-Tat Protein and Polyamine Transport Inhibitor on Polyamine Uptake

Acute hypoxia elevates arginase 2 and induces polyamine stress response in zebrafish via evolutionarily conserved mechanism

Effects of Chronic Arginase Inhibition with Norvaline on Tau Pathology and Brain Glucose Metabolism in Alzheimer's Disease Mice

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