New paradigms in the study of the cholinergic system and metabolic diseases: Acetyl-and-butyrylcholinesterase.

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are enzymes that belong to the neuromuscular cholinergic system, their main function is to hydrolyze the neurotransmitter acetylcholine (ACh), through their hydrolysis these enzymes regulate the neuronal and neuromuscular cholinergic system. They have recently attracted considerable attention due to the discovery of new enzymatic and nonenzymatic functions. These discoveries have aroused the interest of numerous scientists, consolidating the relevance of this group of enzymes. Recent investigations have revealed a positive correlation between several risk factors for metabolic syndrome (MetS) and the expression of cholinesterases (ChE's), which underscore the impact of high ChE's activity on the pro-inflammatory state associated with MetS. In addition, the excessive hydrolysis of ACh and other choline esters (succinylcholine, propionylcholine, butyrylcholine, etc.) by both ChE's results in the overproduction of fatty acid precursor metabolites, which facilitate the synthesis of very low-density lipoproteins and triacylglycerols. Participation in these processes may represent the link between ChE's and metabolic disorders. However, further scientific research is required to fully elucidate the involvement of ChE's in metabolic diseases. This review aims to collect recent research studies that contribute to understanding the association between the cholinergic system and metabolic diseases.

Negative interaction of Staphylococcus aureus on Fusarium falciforme growth ocular isolates in an in vitro mixed biofilm.

The interactions between prokaryotes and eukaryotes are abundant in nature. These microorganisms also interact in the human body. Fungal-bacteria interactions are present in many diseases. In this study, we evaluated the microbial interaction of Fusarium falciforme and Staphylococcus aureus developing mixed biofilm in vitro. When both microorganisms grew up together the mixed biofilm biomass decreased than F. falciforme monobiofilm biomass. S. aureus was able to interact and form aggregates over the mycelium and conidia surface of F. falciforme. Our results suggest that S. aureus could bind to colloidal chitin. On another hand, the supernatants from S. aureus biofilm and S. aureus-F. falciforme presented an antifungal effect over F. falciforme biofilm formation. Finally we found that the pH had an inhibitory effect over fungal biofilm formation. We concluded that S. aureus can affect the F. falciforme growth negatively in mixed biofilm involving factors like pH, supernatants compounds, anchor to chitin, and bacterial viability.

Acetylcholinesterase is associated with a decrease in cell proliferation of hepatocellular carcinoma cells.

Acetylcholinesterase (AChE), the enzyme that rapidly splits acetylcholine into acetate and choline, presents non-cholinergic functions through which may participate in the control of cell proliferation and apoptosis. These two features are relevant in cancer, particularly in hepatocellular carcinoma (HCC), a very aggressive liver tumor with high incidence and poor prognosis in advanced stages. Here we explored the relation between acetylcholinesterase and HCC growth by testing the influence of AChE on proliferation of Huh-7 and HepG2 cell lines, addressed in monolayer cultures, spheroid formation and human liver tumor samples. Results showed a clear relation in AChE expression and cell cycle progression, an effect which depended on cell confluence. Inhibition of AChE activity led to an increase in cell proliferation, which was associated with downregulation of p27 and cyclins. The fact that Huh-7 and HepG2 cell lines provided similar results lent weight to the relationship of AChE expression with cell cycle progression in hepatoma cell lines at least. Human liver tumor samples exhibited a decrease in AChE activity as compared with normal tissue. The evidence presented herein provides additional support for the proposed tumor suppressor role of AChE, which makes it a potential therapeutic target in therapies against hepatocellular carcinoma.

Preliminary exploration of the expression of acetylcholinesterase in normal human T lymphocytes and leukemic Jurkat T cells.

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.

Changes in the Acetylcholinesterase Enzymatic Activity in Tumor Development and Progression.

Acetylcholinesterase is a well-known protein because of the relevance of its enzymatic activity in the hydrolysis of acetylcholine in nerve transmission. In addition to the catalytic action, it exerts non-catalytic functions; one is associated with apoptosis, in which acetylcholinesterase could significantly impact the survival and aggressiveness observed in cancer. The participation of AChE as part of the apoptosome could explain the role in tumors, since a lower AChE content would increase cell survival due to poor apoptosome assembly. Likewise, the high Ach content caused by the reduction in enzymatic activity could induce cell survival mediated by the overactivation of acetylcholine receptors (AChR) that activate anti-apoptotic pathways. On the other hand, in tumors in which high enzymatic activity has been observed, AChE could be playing a different role in the aggressiveness of cancer; in this review, we propose that AChE could have a pro-inflammatory role, since the high enzyme content would cause a decrease in ACh, which has also been shown to have anti-inflammatory properties, as discussed in this review. In this review, we analyze the changes that the enzyme could display in different tumors and consider the different levels of regulation that the acetylcholinesterase undergoes in the control of epigenetic changes in the mRNA expression and changes in the enzymatic activity and its molecular forms. We focused on explaining the relationship between acetylcholinesterase expression and its activity in the biology of various tumors. We present up-to-date knowledge regarding this fascinating enzyme that is positioned as a remarkable target for cancer treatment.

Assessment of Cytogenetic Damage and Cholinesterases' Activity in Workers Occupationally Exposed to Pesticides in Zamora-Jacona, Michoacan, Mexico.

Pesticides have been considered as potential chemical mutagens; however, little is known about toxic and genotoxic effects during pesticide application in Zamora-Jacona, Michoacan State in Mexico. This study sought to determine DNA damage and cholinesterase activities inhibitions in 54 agricultural workers exposed to complex mixtures of pesticides vs. control group (26 individuals) using Comet assay in peripheral whole blood, micronucleus (MN) test in oral mucosa cells, Cytokinesis-blocked MN assay in lymphocytes (L-CBMNcyt) and measuring AChE and BChE activities in whole blood and plasma samples, respectively. Exposed subjects demonstrated significantly elevated levels of primary (Comet assay: tail intensity, tail length, tail moment, Olive tail moment) and permanent DNA damage (MN assay: in blood/buccal cells; frequencies of nuclear buds, binucleated cells, cells with condensed chromatin, karyorrhexis, pyknosis, and karyolysis). However, inhibition of cholinesterase activities (AChE and BChE) was not observed in the workers. Confounding factors including sex, age, BMI, working exposure period, protection level, smoking habit (cigarettes per day units), alcohol consumption (weekly), medication, were considered in the analysis. These combined techniques demonstrated usefulness in the health hazards risks pesticide exposure assessment and suggested the need for periodic monitoring together with the education and the training of occupational workers for the safe application of potentially harmful pesticides.

Phytochemical Profile, Toxicity, and Pharmacological Potential of Peels from Four Species of Tropical Fruits.

Tropical fruit peels are generally discarded as waste, yet they contain bioactive substances that could have various uses; in addition, their pharmacological potential remains unexplored. This study aims to characterize the phytochemical profile, toxicity, and pharmacological potential of methanol extracts obtained from the peels of the following tropical fruit species: Annona squamosa L. (purple sugar apple), Annona reticulata L. (custard apple), Chrysophyllum cainito L. (green star apple), and Melicoccus bijugatus Jacq. (mamoncillo). Methanol peel extracts were obtained by maceration. All extracts contained flavonoids, anthraquinones, and triterpenoids as determined by colorimetric methods. A. squamosa and C. cainito exhibited the highest content of total phenols as assayed by the Folin-Ciocalteu method. M. bijugatus showed the highest content of total sugars (fructose, glucose, and sucrose) as determined by high-performance liquid chromatography. A. squamosa and C. cainito presented the highest antioxidant capacities (according to 2,2'-diphenyl-1-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid, and cupric reducing antioxidant capacity assays), displayed moderate toxicity against HCT-116 cells, and increased the vinblastine susceptibility of MCF-7/Vin+. A. squamosa and M. bijugatus extracts demonstrated modulation of acetylcholinesterase activity, whereas those of A. reticulata showed anti-inflammatory activity by inhibiting protein denaturation. These results confirm that tropical fruit peels can be valuable sources of bioactive compounds, and our findings provide new information about their pharmacologic potential so that they can be used as raw material for the development of new drugs aimed at treating a variety of ailments.

Fibroblasts: The Unknown Sentinels Eliciting Immune Responses Against Microorganisms.

Fibroblasts are present in all tissues but predominantly in connective tissues. Some of their functions include contractility, locomotion, collagen and elastin fiber production, and the regulation and degradation of the extracellular matrix. Also, fibroblasts act as sentinels to produce inflammatory mediators in response to several microorganisms. There is evidence that fibroblasts can synthesize toll-like receptors (TLRs), antimicrobial peptides, proinflammatory cytokines, chemokines, and growth factors, which are important molecules involved in innate immune response against microorganisms. Fibroblasts can express TLRs (TLR-1 to TLR-10) to sense microbial components or microorganisms. They can synthesize antimicrobial peptides, such as LL-37, defensins hBD-1, and hBD-2, molecules that perform antimicrobial activity. Also, they can produce proinflammatory cytokines, such as TNFα, INFγ, IL-6, IL-12p70, and IL-10; other chemokines, such as CCL1, CCL2, CCL5, CXCL1, CXCL8, CXCL10, and CX3CL1; and the growth factors granulocyte/macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) to induce and recruit inflammatory cells. According to their immunological attributes, we can conclude that fibroblasts are sentinel cells that recognize pathogens, induce the recruitment of inflammatory cells via cytokines and growth factors, and release antimicrobial peptides, complying with the characteristics of real sentinels.