RÉSUMÉ
The classic enzymatic function of acetylcholinesterase (AChE) is the hydrolysis of acetylcholine (ACh) in the neuronal synapse. However, AChE is also present in nonneuronal cells such as lymphocytes. Various studies have proposed the participation of AChE in the development of cancer. The ACHE gene produces three mRNAs (T, H and R). AChE-T encodes amphiphilic monomers, dimers, tetramers (G1 A, G2 A and G4 A) and hydrophilic tetramers (G4 H). AChE-H encodes amphiphilic monomers and dimers (G1 A and G2 A). AChE-R encodes a hydrophilic monomer (G1 H). The present study considered the differences in the mRNA expression (T, H and R) and protein levels of AChE, as well as the molecular forms of AChE, the glycosylation pattern and the enzymatic activity of AChE present in normal T lymphocytes and leukemic Jurkat E6-1 cells. The results revealed that AChE enzymatic activity was higher in normal T lymphocytes than in Jurkat cells. Normal T cells expressed AChE-H transcripts, whereas Jurkat cells expressed AChE-H and AChE-T. The molecular forms identified in normal T cells were G2 A (5.2 S) and G1 A (3.5 S), whereas those in Jurkat cells were G2 A (5.2 S), G1 A (3.5 S) and G4 H (10.6S). AChE in Jurkat cells showed altered posttranslational maturation since a decrease in the incorporation of galactose and sialic acid into its structure was observed. In conclusion, the content and composition of AChE were altered in Jurkat cells compared with those in normal T lymphocytes. The present study opened new avenues for exploring the development of novel therapeutic strategies against T-cell leukemia and for identifying potential molecular targets for the early detection of this type of cancer.
RÉSUMÉ
Nervous and immune systems maintain a bidirectional communication, expressing receptors for neurotransmitters and cytokines. Despite being well established in mammals, this has been poorly described in lower vertebrates as fishes. Experimental evidence shows that the neurotransmitter acetylcholine (ACh) regulates the immune response. In this research, we evaluated mRNA levels of muscarinic acetylcholine receptor (mAChR) in spleen mononuclear cells of Nile tilapia (Oreochromis niloticus) and compared the expression levels of immune cells with the brain. The mAChR subtypes (M2-M5A) were detected in both tissues, but mAChRs mRNA levels were higher in immune cells. This data have a potential use in biomedical and comparative immunology fields.
Sujet(s)
Encéphale/immunologie , Cichlides/immunologie , Agranulocytes/immunologie , Récepteur muscarinique/biosynthèse , Animaux , Encéphale/métabolisme , Cichlides/métabolisme , Protéines de poisson/biosynthèse , Protéines de poisson/immunologie , Agranulocytes/métabolismeRÉSUMÉ
The expression of elements of the cholinergic system has been demonstrated in non-neuronal cells, such as immune cells, where acetylcholine modulates innate and adaptive responses. However, the study of the non-neuronal cholinergic system has focused on lymphocyte cholinergic mechanisms, with less attention to its role of innate cells. Considering this background, the aims of this review are 1) to review information regarding the cholinergic components of innate immune system cells; 2) to discuss the effect of cholinergic stimuli on cell functions; 3) and to describe the importance of cholinergic stimuli on host immunocompetence, in order to set the base for the design of intervention strategies in the biomedical field.
Sujet(s)
Acétylcholine/immunologie , Immunité innée/immunologie , Leucocytes/immunologie , Animaux , HumainsRÉSUMÉ
BACKGROUND: Acetylcholine (ACh) is known to be a key neurotransmitter in the central and peripheral nervous systems, which is also produced in a variety of non-neuronal tissues and cell. The existence of ACh in maxilla in vivo and potential regulation role for osteogenesis need further study. RESULTS: Components of the cholinergic system (ACh, esterase, choline acetyltransferase, high-affinity choline uptake, n- and mAChRs) were determined in maxilla of rat in vivo, by means of Real-Time PCR and immunohistochemistry. Results showed RNA for CarAT, carnitine/acylcarnitine translocase member 20 (Slc25a20), VAChT, OCTN2, OCT1, OCT3, organic cation transporter member 4 (Slc22a4), AChE, BChE, nAChR subunits α1, α2, α3, α5, α7, α10, ß1, ß2, ß4, γ and mAChR subunits M1, M2, M3, M4, M5 were detected in rat's maxilla. RNA of VAChT, AChE, nAChR subunits α2, ß1, ß4 and mAChR subunits M4 had abundant expression (2(-ΔCt) > 0.03). Immunohistochemical staining was conducted for ACh, VAChT, nAChRα7 and AChE. ACh was expressed in mesenchymal cells, chondroblast, bone and cartilage matrix and bone marrow cells, The VAChT expression was very extensively while ACh receptor α7 was strongly expressed in newly formed bone matrix of endochondral and bone marrow ossification, AchE was found only in mesenchymal stem cells, cartilage and bone marrow cells. CONCLUSIONS: ACh might exert its effect on the endochondral and bone marrow ossification, and bone matrix mineralization in maxilla.