The human immunodeficiency virus type 1 (HIV-1) coat glycoprotein gp120 binds to its (co)receptors and orchestrates cell entry by the direct fusion of viral and target cell membranes. Here, we modulated membrane fluidity of human neuroblastoma CHP100 cells by modulating their cholesterol content, and investigated the ability of gp120 to induce cell death in comparison with the untreated cells. We show that in normal CHP100 cells gp120 induces necrosis by: (i) increased cyclooxygenase and 5-lipoxygenase activity, and metabolites generated thereof (prostaglandin E 2 and leukotriene B 4 , respectively); (ii) increased membrane lipoperoxidation; and (iii) increased mitochondrial uncoupling. These events were triggered by a rapid increase in intracellular calcium, and in cholesterol-depleted cells engaged CXCR4 chemokine receptors. The intracellular calcium chelator EGTA-AM protected CHP100 cells almost completely against the toxic effects of gp120. However, gp120-induced necrosis and related biochemical changes were negligible in cholesterolenriched, and significantly enhanced in cholesterol-depleted, CHP100 cells exposed to the viral glycoprotein under the same experimental conditions. Taken together, these results suggest that membrane fluidity may control the neurotoxic effects of HIV-1 glycoprotein gp120. Keywords: cholesterol, cyclooxygenase, HIV-1 gp120, lipoxygenase, membrane fluidity, necrosis. The human immunodeficiency virus type-1 (HIV-1) envelope glycoprotein gp120 binds to its primary receptors CD4 and galactosylceramide (Delezay et al. 1997) and orchestrates cell entry by the direct fusion of the viral and target cell membranes (Chan and Kim 1998;Santos et al. 1998). In the past few years several coreceptors of HIV-1 have been described. In particular, the CXCR4 (LESTR/fusin) receptor allows fusion and entry of T-tropic strains of HIV-1, whereas the CCR5 is the major coreceptor used by M-tropic HIV-1 strains that infect macrophages and CD4 + T- Abbreviations used: 5-HPETE, 5-hydroperoxyeicosatetraenoic acid; ADC, acquired immunodeficiency syndrome dementia complex; AIDS, acquired immunodeficiency syndrome; CCCP, carbonyl cyanide m-chlorophenylhydrazone; EGTA-AM, ethyleneglycol-bis(b-aminoethyl)-N,N,N¢,N¢-tetra-acetoxymethyl ester; FACS, fluorescence-activated cell sorting; FBS, fetal bovine serum; Fluo-3 AM, 1-[2-amino-5-(2,7-dichloro-6-hydroxy-3-oxy-9-xanthenyl)-phenoxy]-2-[2-amino-5-methyl phenoxy]ethane-N,N,N¢,N¢,-tetra-acetoxymethyl ester; HIV-1, human immunodeficiency virus type-1; JC-1, 5,5¢,6,6¢-tetrachloro-1,1¢,3,3¢-tetraethyl benzimidazolcarbocyanine iodide; LTB 4 , leukotriene B 4 ; PGE 2 , prostaglandin E 2 ; PBS, phosphate buffered saline.
Recurrence of colorectal cancer (CRC) following a potentially curative resection is a challenging clinical problem. Matrix metalloproteinase-7 (MMP-7) is over-expressed by CRC cells and supposed to play a major role in CRC cell diffusion and metastasis. MMP-7 RNA expression was assessed by real-time PCR using specific primers in peritoneal washing fluid obtained during surgical procedure. After surgery, patients underwent a regular follow up for assessing recurrence. transcripts for MMP-7 were detected in 31/57 samples (54%). Patients were followed-up (range 20–48 months) for recurrence prevention. Recurrence was diagnosed in 6 out of 55 patients (11%) and two patients eventually died because of this. Notably, all the six patients who had relapsed were positive for MMP-7. Sensitivity and specificity of the test were 100% and 49% respectively. Data from patients have also been corroborated by computational approaches. Public available coloncarcinoma datasets have been employed to confirm MMP7 clinical impact on the disease. Interestingly, MMP-7 expression appeared correlated to Tgfb-1, and correlation of the two factors represented a poor prognostic factor. This study proposes positivity of MMP-7 in peritoneal cavity as a novel biomarker for predicting disease recurrence in patients with CRC.
Type-1 cannabinoid receptor (CB1), one of the main targets of endocannabinoids, plays a key role in several pathophysiological conditions that affect both central nervous system and peripheral tissues. Today, its biochemical identification and pharmacological characterization, as well as the screening of thousands of novel ligands that might be useful for developing CB1-based therapies, are the subject of intense research. Among available techniques that allow the analysis of CB1 binding activity, radioligand-based assays represent one of the best, fast, and reliable methods.Here, we describe radioligand binding methods standardized in our laboratory to assess CB1 binding in both tissues and cultured cells. We also report a high-throughput radioligand binding assay that allows to evaluate efficacy and potency of different compounds, which might represent the basis for the development of new drugs that target CB1 receptor-dependent human diseases.
In the past decades, extensive usage of omic technologies applied to nutrition has led to the concept of personalised dietary recommendations. It is now widely accepted that gene–diet interaction is a complex, bidirectional mechanism: food components can modulate the flow of genetic information by regulating genes at transcriptional, translational and post‐translational levels, whereas the individual's genotype determines specific responses to nutrient intake. Genetic variants (that represent the focus of nutrigenetic studies) influence the metabolism of almost all macro‐ and micronutrients, thus differentially impacting on human health. Although still a young field of research, nutrigenetics appears to be a promising tool for monitoring susceptibility to chronic pathologies, as well as for designing personalised nutrition in order to prevent (or eventually treat) the most common Western diet‐associated diseases. Key Concepts Several lines of evidence indicate that diet is a key determinant of health status and that many chronic degenerative diseases (including obesity, diabetes, cardiovascular disease, cancer, neurodegenerative diseases) could be prevented by adopting a correct lifestyle. Nutrigenetic studies indicate that there is a different susceptibility to development of these diseases in relation to food intake, due to specific genetic variants. Nutrigenomic studies indicate that macronutrients, micronutrients and bioactive compounds can modulate gene expression, thus affecting physical and mental health. Gene–diet interaction is a complex network; and data interpretation is not easy, as foods contain many components usually acting in combination and dietary patterns are quite variable. It is not easy to translate scientific evidence into nutritional advice, because the organism is complex and different environmental and genetic factors have to be taken into account, especially considering the wide interindividual variability in metabolic responses. Although holding strong promise, personalised nutrition is far from being applicable, as much accurate research is needed before application to dietetic practice.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.