Determination of acetylcholine in human blood

Watanabe, Minoru; Kimura, Atsushi; Akasaka, Kazuaki; Hayashi, Shiro

doi:10.1016/0885-4505(86)90147-7

Cited by 37 publications

(14 citation statements)

References 5 publications

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“…In this sense, for the first time we are reporting a direct response of the ameba to a neurotransmitter, throughout the binding of ACh to E. histolytica trophozoites membrane. This interaction does not affect the parasites viability but stimulates parasite proliferation at physiological ACh intestinal concentrations ( Watanabe et al., 1986 ; Beckmann and Lips, 2013 ); a similar effect has been described in other organisms ( Amaroli, 2017 ). We observed that ACh treatment activated E. histolytica trophozoites and significantly upregulated the expression of virulence factors, including the Gal/GalNAc lectin heavy subunit, amebapore C , and ehcp-a2 and ehcp-a5 cysteine proteases.…”

Section: Discussionsupporting

confidence: 67%

Acetylcholine Upregulates Entamoeba histolytica Virulence Factors, Enhancing Parasite Pathogenicity in Experimental Liver Amebiasis

Medina-Rosales

Muñoz‐Ortega

García-Hernández

et al. 2021

Front. Cell. Infect. Microbiol.

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Entamoeba histolytica is an invasive enteric protozoan, whose infections are associated to high morbidity and mortality rates. However, only less than 10% of infected patients develop invasive amebiasis. The ability of E. histolytica to adapt to the intestinal microenvironment could be determinant in triggering pathogenic behavior. Indeed, during chronic inflammation, the vagus nerve limits the immune response through the anti-inflammatory reflex, which includes acetylcholine (ACh) as one of the predominant neurotransmitters at the infection site. Consequently, the response of E. histolytica trophozoites to ACh could be implicated in the establishment of invasive disease. The aim of this study was to evaluate the effect of ACh on E. histolytica virulence. Methods include binding detection of ACh to plasma membrane, quantification of the relative expression of virulence factors by RT-PCR and western blot, evaluation of the effect of ACh in different cellular processes related to E. histolytica pathogenesis, and assessment of the capability of E. histolytica to migrate and form hepatic abscesses in hamsters. Results demonstrated that E. histolytica trophozoites bind ACh on their membrane and show a clear increase of the expression of virulence factors, that were upregulated upon stimulation with the neurotransmitter. ACh treatment increased the expression of L220, Gal/GalNAc lectin heavy subunit (170 kDa), amebapore C, cysteine proteinase 2 (ehcp-a2), and cysteine proteinase 5 (ehcp-a5). Moreover, erythrophagocytosis, cytotoxicity, and actin cytoskeleton remodeling were augmented after ACh treatment. Likewise, by assessing the formation of amebic liver abscess, we found that stimulated trophozoites to develop greater hamster hepatic lesions with multiple granulomas. In conclusion, ACh enhanced parasite pathogenicity by upregulating diverse virulence factors, thereby contributing to disease severity, and could be linked to the establishment of invasive amebiasis.

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Section: Discussionsupporting

confidence: 67%

Acetylcholine Upregulates Entamoeba histolytica Virulence Factors, Enhancing Parasite Pathogenicity in Experimental Liver Amebiasis

Medina-Rosales

Muñoz‐Ortega

García-Hernández

et al. 2021

Front. Cell. Infect. Microbiol.

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“…In neurons, ACh is prepared from choline using choline acetyltransferase (ChAT) and acetylcoenzyme A [1,2,3]. The level of ACh in human blood is ~0.52 µM in males and ~0.47 µM in females [4]. ACh also has a therapeutic utility as an intraocular irrigating fluid [5].…”

Section: Introductionmentioning

confidence: 99%

Novel Carbon/PEDOT/PSS-Based Screen-Printed Biosensors for Acetylcholine Neurotransmitter and Acetylcholinesterase Detection in Human Serum

et al. 2019

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New reliable and robust potentiometric ion-selective electrodes were fabricated using poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) as the solid contact between the sensing membrane and electrical substrate for an acetylcholine (ACh) bioassay. A film of PEDOT/PSS was deposited on a solid carbon screen-printed platform made from ceramic substrate. The selective materials used in the ion-selective electrode (ISE) sensor membrane were acetylcholinium tetraphenylborate (ACh/TPB/PEDOT/PSS-ISE) (sensor I) and triacetyl-β-cyclodextrin (β-CD/PEDOT/PSS-ISE) (sensor II). The sensors revealed clear enhanced Nernstian response with a cationic slope 56.4 ± 0.6 and 55.3 ± 1.1 mV/decade toward (ACh+) ions over the dynamic linear range 1.0 × 10−6–1 × 10−3 and 2.0 × 10−6–1.0 × 10−3 M at pH 5 with limits of detection 2.0 × 10−7 and 3.2 × 10−7 M for sensors I and II, respectively. The selectivity behavior of both sensors was also tested and the sensors showed a significant high selectivity toward ACh+ over different common organic and inorganic cations. The stability of the potential response for the solid-contact (SC)/ISEs was evaluated using a chronopotentiometric method and compared with that of electrodes prepared without adding the solid-contact material (PEDOT/PSS). Enhanced accuracy, excellent repeatability, good reproducibility, potential stability, and high selectivity and sensitivity were introduced by these cost-effective sensors. The sensors were also used to measure the activity of acetylcholinesterase (AChE). A linear plot between the initial rate of the hydrolysis of ACh+ substrate and enzyme activity held 5.0 × 10−3–5.2 IU∙L−1 of AChE enzyme. Application to acetylcholine determination in human serum was done and the results were compared with the standard colorimetric method.

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“…Our observations show that human T cell-release of ACh to the extracellular space is sufficient to promote arterial relaxation through muscarinic ACh receptor activation. The cell density and resulting ACh concentration in these experiments are in a physiological range relevant to human blood 8,22,23 , suggesting that ACh released by activated human T cells could be a source for blood ACh and sufficient to promote local vascular relaxation in vivo. Should further studies corroborate that human ChAT + CD4 + T cells indeed promote vasodilation, it would be conceivable to use these insights for therapeutic purposes in patients that require local vasodilation to improve regional circulation and tissue entry of immune cells.…”

Section: Resultsmentioning

confidence: 85%

Identification and Characterization of Human Activation-Induced ChAT⁺CD4⁺T Cells

Tarnawski

Kort

et al. 2021

Preprint

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Vasodilation is a cornerstone of inflammation physiology. By regulating vasodilation and tissue entry of T cells, CD4+ T lymphocytes expressing choline acetyltransferase (ChAT), a key enzyme for biosynthesis of the vasorelaxant acetylcholine (ACh), critically link immunity with vascular biology in mice. However, the characterization of primary human ChAT+ T cells remained elusive. Here, we identified human ChAT+ T cells and report that ChAT mRNA was induced by activation. Functional studies demonstrated that T cell-derived ACh increased muscarinic ACh-receptor dependent NO-synthase activity and vasorelaxation. Further, single-cell RNA-sequencing revealed ChAT+CD4+ T cells in blood from patients with severe circulatory failure and a high relative frequency of ChAT+CD4+ T cells correlated with better 30-day survival in this cohort. Our findings provide the first insights into ChAT biology in primary human T cells, linking ChAT+ T cells with vasorelaxation as well as survival in a cohort of critically ill patients.

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Determination of acetylcholine in human blood

Cited by 37 publications

References 5 publications

Acetylcholine Upregulates Entamoeba histolytica Virulence Factors, Enhancing Parasite Pathogenicity in Experimental Liver Amebiasis

Acetylcholine Upregulates Entamoeba histolytica Virulence Factors, Enhancing Parasite Pathogenicity in Experimental Liver Amebiasis

Novel Carbon/PEDOT/PSS-Based Screen-Printed Biosensors for Acetylcholine Neurotransmitter and Acetylcholinesterase Detection in Human Serum

Identification and Characterization of Human Activation-Induced ChAT⁺CD4⁺T Cells

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Determination of acetylcholine in human blood

Cited by 37 publications

References 5 publications

Acetylcholine Upregulates Entamoeba histolytica Virulence Factors, Enhancing Parasite Pathogenicity in Experimental Liver Amebiasis

Acetylcholine Upregulates Entamoeba histolytica Virulence Factors, Enhancing Parasite Pathogenicity in Experimental Liver Amebiasis

Novel Carbon/PEDOT/PSS-Based Screen-Printed Biosensors for Acetylcholine Neurotransmitter and Acetylcholinesterase Detection in Human Serum

Identification and Characterization of Human Activation-Induced ChAT+CD4+T Cells

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Identification and Characterization of Human Activation-Induced ChAT⁺CD4⁺T Cells