Areca catechu-(Betel-nut)-induced whole transcriptome changes in a human monocyte cell line that may have relevance to diabetes and obesity; a pilot study

Background Betel-nut consumption is the fourth most common addictive habit globally and there is good evidence linking the habit to obesity, type 2 diabetes (T2D) and the metabolic syndrome. The aim of our pilot study was to identify gene expression relevant to obesity, T2D and the metabolic syndrome using a genome-wide transcriptomic approach in a human monocyte cell line incubated with arecoline and its nitrosated products. Results The THP1 monocyte cell line was incubated separately with arecoline and 3-methylnitrosaminopropionaldehyde (MNPA) in triplicate for 24 h and pooled cDNA indexed paired-end libraries were sequenced (Illumina NextSeq 500). After incubation with arecoline and MNPA, 15 and 39 genes respectively had significant changes in their expression (q < 0.05, log fold change 1.5). Eighteen of those genes have reported associations with T2D and obesity in humans; of these genes there was most marked evidence for CLEC10A, MAPK8IP1, NEGR1, NQ01 and INHBE genes. Conclusions Our preliminary studies have identified a large number of genes relevant to obesity, T2D and metabolic syndrome whose expression was changed significantly in human TPH1 cells following incubation with betel-nut derived arecoline or with MNPA. These findings require validation by further cell-based work and investigation amongst betel-chewing communities.

Areca catechu-(Betel-nut)-induced whole transcriptome changes associated with diabetes, obesity and metabolic syndrome in a human monocyte cell line

Betel-nut consumption is the fourth most common addictive habit globally and there is good evidence to link it with obesity, type 2 diabetes and the metabolic syndrome. We adopted a genome-wide transcriptomic approach in a human monocyte cell line incubated with arecoline and its nitrosated products to identify gene expression changes relevant to obesity, type 2 diabetes and the metabolic syndrome. The THP1 monocyte cell line was incubated separately with arecoline and 3-methylnitrosaminopropionaldehyde (MNPA) in triplicate for 24 hours and pooled cDNA indexed paired-end libraries were sequenced (Illumina NextSeq 500). After incubation with arecoline and MNPA, 15 and 39 genes respectively had significant changes in their expression (q<0.05, log fold change 1.5). Eighteen of those genes have reported associations with type 2 diabetes and obesity in humans; of these genes there was strong evidence to implicate CLEC10A, MAPK8IP1, NEGR1, NQ01 and INHBE. In summary, these pilot studies have identified a large number of genes whose expression was changed significantly in human TPH1 cells following incubation with arecoline or with 3-methylnitrosaminopropionaldehyde. These findings suggest that further investigation of these genes in betel-quid chewers with obesity and/or type 2 diabetes is warranted.

GSDMB promotes non-canonical pyroptosis by enhancing caspase-4 activity

Gasdermin B (GSDMB) has been reported to be associated with immune diseases in humans, but the detailed molecular mechanisms remain unsolved. The N-terminus of GSDMB by itself, unlike other gasdermin family proteins, does not induce cell death. Here, we show that GSDMB is highly expressed in the leukocytes of septic shock patients, which is associated with increased release of the gasdermin D (GSDMD) N-terminus. GSDMB expression and the accumulation of the N-terminal fragment of GSDMD are induced by the activation of the non-canonical pyroptosis pathway in a human monocyte cell line. The downregulation of GSDMB alleviates the cleavage of GSDMD and cell death. Consistently, the overexpression of GSDMB promotes GSDMD cleavage, accompanied by increased LDH release. We further found that GSDMB promotes caspase-4 activity, which is required for the cleavage of GSDMD in non-canonical pyroptosis, by directly binding to the CARD domain of caspase-4. Our study reveals a GSDMB-mediated novel regulatory mechanism for non-canonical pyroptosis and suggests a potential new strategy for the treatment of inflammatory diseases.

Serum of Bipolar Patients Induces Pro-inflammatory Activation of Macrophages

IntroductionEvidence has suggested that immune imbalance is involved with bipolar disorder (BD); however, its precise mechanism is poorly understood.ObjectiveThis study investigated whether biochemical changes in the serum from BD patients could modulate the phenotype of macrophages.MethodsEighteen subjects with BD and healthy individuals (n = 5) were included in this study. The human monocyte cell line U-937 was activated with PMA (phorbol 12-myristate 13-acetate) and polarization was induced with RPMI-1640 media supplemented with 10% serum from each patient for 24 h. Gene expression of selected M1 and M2 markers was assessed by qPCR.ResultsMacrophages exposed to serum of manic and depressive BD patients displayed an increase of IL-1β (6.40 ± 3.47 and 9.04 ± 5.84 versus 0.23 ± 0.11; P < 0.05) and TNF-α (2.23 ± 0.91 and 2.03 ± 0.45 versus 0.62 ± 0.24; P = 0.002 and P = 0.004, respectively) compared to remitted group. In parallel, U-937 macrophages treated with serum of patients in acute episode displayed a down-regulation of CXCL9 (0.29 ± 0.20 versus 1.86 ± 1.61; P = 0.006) and CXCL10 expression (0.36 ± 0.15 and 0.86 ± 0.24 versus 1.83 ± 0.88; P < 0.000 and P = 0.04) compared to remitters.ConclusionsOur results are consistent with previous studies showing that changes in peripheral blood markers could modulate M1/M2 polarization in BD. The evidence of macrophages as source of inflammatory cytokines might be helpful to unravel how the mononuclear phagocyte system can be involved in the etiology of BD.Disclosure of interestThe authors have not supplied their declaration of competing interest.