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- Tajeddinn, W., et al.
(författare)
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Pharmacological Modulations of the Serotonergic System in a Cell-Model of Familial Alzheimer's Disease
- 2016
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Ingår i: Journal of Alzheimers Disease. - : IOS Press. - 1387-2877 .- 1875-8908. ; 53:1, s. 349-361
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Tidskriftsartikel (refereegranskat)abstract
- Serotonin (5-HT) plays a central role in the integrity of different brain functions. The 5-HT homeostasis is regulated by many factors, including serotonin transporter (SERT), monoamine oxidase enzyme (MAO), and several 5-HT receptors, including the 5-HT1B. There is little knowledge how the dynamics of this system is affected by the amyloid-beta (A beta) burden of Alzheimer's disease (AD) pathology. SH-SY5Y neuroblastoma cells transfected with the amyloid precursor protein (APP) gene containing the Swedish mutations causing familial AD (APPswe), were used as a model to explore the effect of A beta pathology on 5-HT1B and related molecules including the receptor adaptor protein (p11), SERT and MAOA gene expression, and MAOA activity after treatment with selective serotonin reuptake inhibitor (SSRI) (sertraline), and a 5-HT1B receptor antagonist. Sertraline led more than 70 fold increase of 5-HT1B gene expression (p < 0.001), an increased serotonin turnover in both APPswe and control cells and reduced intracellular serotonin levels by 75% in APPswe cells but not in controls (p > 0.05). Treatment with the 5-HT1B receptor antagonist increased SERT gene-expression in control cells but not in the APPswe cells. 5-HT and 5-HT1B antagonist treatment resulted in different p11 expression patterns in APPswe cells compared to controls. Although MAOA gene expression was not changed by APPswe overexpression, adding 5-HT lead to a significant increase in MAOA gene expression in APPswe but not control cells. These findings suggest that the sensitivity of the 5-HT1B receptor and related systems is affected by APPswe overexpression, with potential relevance for pharmacologic intervention in AD. This may at least partly explain the lack of effect of SSRIs in patients with AD and depression.
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| 3. |
- Canaider, S., et al.
(författare)
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Human Stem Cell Exposure to Developmental Stage Zebrafish Extracts : a Novel Strategy for Tuning Stemness and Senescence Patterning
- 2014
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Ingår i: Cell. - 2329-7042. ; 2:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: Zebrafish exhibits extraordinary ability for tissue regeneration. Despite growing investigations dissecting the molecular underpinning of such regenerative potential, little is known about the possibility to use the chemical inventory of the zebrafishembryo to modulate human stem cell dynamics.Methods: Extracts from zebrafish embryo were collected at different developmental stages, referred to as ZF1, ZF2, ZF3 (early stages), and ZF4, ZF5 (late stages). Human adipose-derived stem cells (hASCs), isolated from microfractured fat tissue obtained with a novel non-enzymatic method (Lipogems), were cultured in absence or presence of each developmental stage extract. Cell viability was assessed by MTT assay. Nuclear morphology was investigated by cell-permeable dye 4’,6-DAPI. Caspase-3 activity was assessed by ELISA. Gene transcription was monitored by real-time PCR.Results: Late developmental stage extracts decreased cell viability and elicited caspase-3 mediated apoptosis. This effect did not involve Bax or Bcl-2 transcription. Conversely, early developmental stage ZF1 did not affect cell viability or apoptosis, albeit increasing Bax/Bcl-2mRNA ratio. ZF1 enhanced transcription of the stemness/pluripotency genes Oct-4, Sox-2and c-Myc. ZF1 also induced the transcription of TERT, encoding the catalytic subunit of telomerase, as well as the gene expression of Bmi-1, a chromatin remodeler acting as a major telomerase-independent repressor of senescence. These transcriptional responses were restricted to the action of early stage factors, since they were not elicited by late developmental stage ZF5.Conclusions: Exposure to early developmental stage zebrafish embryo extracts may enhance stem cell expression of multipotency and activate both telomerase-dependent and -independent antagonists of cell senescence. These outcomes may prove rewarding during prolonged expansion in culture, as it occurs in most cell therapy protocols.
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| 6. |
- Loera-Valencia, R, et al.
(författare)
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Brain Renin-Angiotensin System as Novel and Potential Therapeutic Target for Alzheimer's Disease
- 2021
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Ingår i: International journal of molecular sciences. - : MDPI AG. - 1422-0067. ; 22:18
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Tidskriftsartikel (refereegranskat)abstract
- The activation of the brain renin-angiotensin system (RAS) plays a pivotal role in the pathophysiology of cognition. While the brain RAS has been studied before in the context of hypertension, little is known about its role and regulation in relation to neuronal function and its modulation. Adequate blood flow to the brain as well as proper clearing of metabolic byproducts become crucial in the presence of neurodegenerative disorders such as Alzheimer’s disease (AD). RAS inhibition (RASi) drugs that can cross into the central nervous system have yielded unclear results in improving cognition in AD patients. Consequently, only one RASi therapy is under consideration in clinical trials to modify AD. Moreover, the role of non-genetic factors such as hypercholesterolemia in the pathophysiology of AD remains largely uncharacterized, even when evidence exists that it can lead to alteration of the RAS and cognition in animal models. Here we revise the evidence for the function of the brain RAS in cognition and AD pathogenesis and summarize the evidence that links it to hypercholesterolemia and other risk factors. We review existent medications for RASi therapy and show research on novel drugs, including small molecules and nanodelivery strategies that can target the brain RAS with potential high specificity. We hope that further research into the brain RAS function and modulation will lead to innovative therapies that can finally improve AD neurodegeneration.
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