DNA methylation status of SHATI/NAT8L promoter in the blood of cigarette smokers

AIMS

Cigarette smoking is a preventable risk factor for various diseases such as cancer, ischemic stroke, cardiac stroke, and chronic obstructive pulmonary disease. Smoking cessation is of great importance not only for individual smokers but also for social health. Regarding current cessation therapies, the effectiveness of nicotine replacement is limited, and the cost of varenicline medication is considerable. Thus, a method for screening smokers who are responsive to cessation therapy based on the therapeutic effectiveness is required. Peripheral biomarkers reflecting smoking dependence status are necessary to establish a method for achieving effective cessation therapy.

METHODS

Methylation status of smokers' blood DNA was evaluated focusing on SHATI/NAT8L, an addiction-related gene. Eight CpG sites in SHATI/NAT8L were quantified by pyrosequencing.

RESULTS

There was no difference in the methylation status of this gene between smokers (n = 129) and non-smokers (n = 129) at all CpG sites. No correlations between the methylation status of SHATI/NAT8L and indicators of smoking dependence were found.

CONCLUSIONS

Although the present study found no significance in the DNA methylation of SHATI/NAT8L among smokers, the exploration of predictable peripheral biomarkers for the effectiveness of smoking cessation therapy is required.

Sphingolipid abnormalities in encephalomyeloradiculoneuropathy (EMRN) are associated with an anti-neutral glycolipid antibody

Accumulating evidence suggests that various sphingolipids and glycosphingolipids can act as mediators for inflammation or signaling molecules in the nervous system. In this article, we explore the molecular basis of a new neuroinflammatory disorder called encephalomyeloradiculoneuropathy (EMRN), which affects the brain, spinal cord, and peripheral nerves; in particular, we discuss whether glycolipid and sphingolipid dysmetabolism is present in patients with this disorder. This review will focus on the pathognomonic significance of sphingolipid and glycolipid dysmetabolism for the development of EMRN and the possible involvement of inflammation in the nervous system.

Multicenter propensity score-matched analysis comparing short versus long cap-assisted colonoscopy for acute hematochezia

Background and Aim

While short and long attachment caps are available for colonoscopy, it is unclear which type is more appropriate for stigmata of recent hemorrhage (SRH) identification in acute hematochezia. This study aimed to compare the performance of short versus long caps in acute hematochezia diagnoses and outcomes.

Methods

We selected 6460 patients who underwent colonoscopy with attachment caps from 10 342 acute hematochezia cases in the CODE BLUE-J study. We performed propensity score matching (PSM) to balance baseline characteristics between short and long cap users. Then, the proportion of definitive or presumptive bleeding etiologies found on the initial colonoscopy and SRH identification rates were compared. We also evaluated rates of blood transfusions, interventional radiology, or surgery, as well as the rate of rebleeding and mortality within 30 days after the initial colonoscopy.

Results

A total of 3098 patients with acute hematochezia (1549 short cap and 1549 long cap users) were selected for PSM. The rate of colonic diverticular bleeding (CDB) diagnosis was significantly higher in long cap users (P = 0.006). While the two groups had similar rates of the other bleeding etiologies, the frequency of unknown etiologies was significantly lower in long cap users (P < 0.001). The rate of SRH with active bleeding was significantly higher in long cap users (P < 0.001). Other clinical outcomes did not differ significantly.

Conclusion

Compared to that with short caps, long cap-assisted colonoscopy is superior for the diagnosis of acute hematochezia, especially CDB, and the identification of active bleeding.

Activation of NOD1 and NOD2 in the development of liver injury and cancer

Hepatocytes and liver-resident antigen-presenting cells are exposed to microbe-associated molecular patterns (MAMPs) and microbial metabolites, which reach the liver from the gut via the portal vein. MAMPs induce innate immune responses via the activation of pattern recognition receptors (PRRs), such as toll-like receptors (TLRs), nucleotide-binding oligomerization domain 1 (NOD1), and NOD2. Such proinflammatory cytokine responses mediated by PRRs likely contribute to the development of chronic liver diseases and hepatocellular carcinoma (HCC), as shown by the fact that activation of TLRs and subsequent production of IL-6 and TNF-α is required for the generation of chronic fibroinflammatory responses and hepatocarcinogenesis. Similar to TLRs, NOD1 and NOD2 recognize MAMPs derived from the intestinal bacteria. The association between the activation of NOD1/NOD2 and chronic liver diseases is poorly understood. Given that NOD1 and NOD2 can regulate proinflammatory cytokine responses mediated by TLRs both positively and negatively, it is likely that sensing of MAMPs by NOD1 and NOD2 affects the development of chronic liver diseases, including HCC. Indeed, recent studies have highlighted the importance of NOD1 and NOD2 activation in chronic liver disorders. Here, we summarize the roles of NOD1 and NOD2 in hepatocarcinogenesis and liver injury.

Tas2R signaling enhances mouse neutrophil migration via a ROCK-dependent pathway

Type-2 bitter taste receptors (Tas2Rs) are a large family of G protein-coupled receptors that are expressed in the oral cavity and serve to detect substances with bitter tastes in foods and medicines. Recent evidence suggests that Tas2Rs are also expressed extraorally, including in immune cells. However, the role of Tas2Rs in immune cells remains controversial. Here, we demonstrate that Tas2R126, Tas2R135, and Tas2R143 are expressed in mouse neutrophils, but not in other immune cells such as macrophages or T and B lymphocytes. Treatment of bone marrow-derived neutrophils from wild-type mice with the Tas2R126/143 agonists arbutin and d-salicin led to enhanced C-X-C motif chemokine ligand 2 (CXCL2)-stimulated migration in vitro, but this response was not observed in neutrophils from Tas2r126/135/143-deficient mice. Enhancement of CXCL2-stimulated migration by Tas2R agonists was accompanied by increased phosphorylation of myosin light chain 2 (MLC2) and was blocked by pretreatment of neutrophils with inhibitors of Rho-associated coiled-coil-containing protein kinase (ROCK), but not by inhibitors of the small GTPase RhoA. Taken together, these results demonstrate that mouse neutrophils express functional Tas2R126/143 and suggest a role for Tas2R126/143–ROCK–MLC2-dependent signaling in the regulation of neutrophil migration.

Neutrophil extracellular traps-mediated Beclin-1 suppression aggravates atherosclerosis by inhibiting macrophage autophagy

A growing body of evidence suggests that neutrophil extracellular traps (NETs) critically contribute to the development of atherosclerosis. However, the detailed mechanism of how NETs promote atherogenesis remains unknown. In this study, we explored the role of NETs for promoting atherosclerosis by modulating the activity of autophagy in macrophages. NETs were effectively induced by a nicotine administration to the HL-60 cell-derived neutrophil-like cells. Treatment with NETs markedly suppressed both autophagosome formation and autophagosome–lysosome fusion in 7-ketocholesterol-treated macrophages, which are accompanied by the enhancement of inflammasome activity. NETs upregulate epidermal growth factor receptor (EGFR) activity, which enhances Beclin-1 phosphorylation of the tyrosine residues of Beclin-1 by EGFR, inhibits the PI3 kinase activity of the Beclin1–Vps34 complex, and suppresses autophagosome formation in macrophages. Furthermore, NET-induced activation of EGFR allows Rubicon to increase its expression, thereby suppressing autophagosome-lysosome fusion. In vivo experiments revealed that the suppression of NET formation by ablating peptidyl arginine deiminase-4 in neutrophil leukocytes resulted in the attenuation of atherosclerotic plaques in a nicotine-administered HFD-fed ApoE−/−mice. Taken together, these results suggest that NET-mediated EGFR–Beclin-1 signaling in the macrophages promotes atherogenesis by autophagy inhibition-mediated inflammasome activation.

Retention and impairment of neurocognitive functions in mild cognitive impairment and Alzheimer's disease with a comprehensive neuropsychological test

AIM

MATRICS Consensus Cognitive Battery was developed by the National Institute of Mental Health to establish acceptance criteria for measuring cognitive changes in schizophrenia and can be used to assess cognitive functions in other psychiatric disorders. We used a Japanese version of MATRICS Consensus Cognitive Battery to explore the changes in multiple cognitive functions in patients with mild cognitive impairment and mild Alzheimer's disease.

METHODS

We administered the Japanese version of MATRICS Consensus Cognitive Battery to 11 patients with mild cognitive impairment (MCI), 11 patients with Alzheimer's disease, and 27 healthy controls. All Japanese versions of MATRICS Consensus Cognitive Battery domain scores were converted to t-scores using sample means and standard deviations and were compared for significant performance differences among healthy control, MCI, and mild Alzheimer's disease groups.

RESULTS

Compared with healthy controls, patients with MCI and mild Alzheimer's disease demonstrated the same degree of impairment to processing speed, verbal learning, and visual learning. Reasoning and problem-solving showed significant impairments only in mild Alzheimer's disease. Verbal and visual abilities in working memory showed different performances in the MCI and mild Alzheimer's disease groups, with the Alzheimer's disease group demonstrating significantly more deficits in these domains. No significant difference was found among the groups in attention/vigilance and social cognition.

CONCLUSIONS

The Japanese version of MATRICS Consensus Cognitive Battery can be used to elucidate the characteristics of cognitive dysfunction of normal aging, MCI, and mild dementia in clinical practice.

Higher Serum Soluble TREM2 as a Potential Indicative Biomarker for Cognitive Impairment in Inadequately Controlled Type 2 Diabetes Without Obesity: The DOR-KyotoJ-1

OBJECTIVE

Type 2 diabetes is a risk factor for dementia. We investigated whether serum levels of soluble triggering receptor expressed on myeloid cell 2 (sTREM2), a soluble form of the cell surface receptor TREM2, were predictive of cognitive impairment in type 2 diabetes without obesity.

METHODS

A total of 166 Japanese patients with type 2 diabetes without obesity were followed-up for 2 years. We measured clinical parameters, assessed cognitive function using the mini-mental state examination (MMSE), quantified and divided serum sTREM2 levels into quartiles, and examined the longitudinal associations.

RESULTS

During the follow-up, HbA_1c levels were elevated in 98 patients and decreased in 68 patients. In the HbA_1c-elevated group, higher sTREM2 levels at baseline showed a significant association with a greater tendency for reduction in MMSE scores (P for trend = 0.015), whereas they were not significantly associated with other examined parameters. In the HbA_1c-decreased group, there was no significant association between sTREM2 levels at baseline and changes in MMSE scores, but higher sTREM2 levels at baseline were significantly associated with a greater tendency for reduction in waist circumference (P for trend = 0.027), homeostasis model assessment of insulin resistance (P for trend = 0.039), and sTREM2 levels (P for trend = 0.023).

CONCLUSIONS

Glycemic control is suggested to be important in preventing cognitive impairment in patients with type 2 diabetes without obesity. Higher serum sTREM2 levels would be a predictive marker for cognitive impairment in inadequately controlled type 2 diabetes without obesity.

S100A8 may govern hyper-inflammation in severe COVID-19

The coronavirus disease 2019 (COVID-19) pandemic threatens human species with mortality rate of roughly 2%. We can hardly predict the time of herd immunity against and end of COVID-19 with or without success of vaccine. One way to overcome the situation is to define what delineates disease severity and serves as a molecular target. The most successful analogy is found in BCR-ABL in chronic myeloid leukemia, which is the golden biomarker, and simultaneously, the most effective molecular target. We hypothesize that S100 calcium-binding protein A8 (S100A8) is one such molecule. The underlying evidence includes accumulating clinical information that S100A8 is upregulated in severe forms of COVID-19, pathological similarities of the affected lungs between COVID-19 and S100A8-induced acute respiratory distress syndrome (ARDS) model, homeostatic inflammation theory in which S100A8 is an endogenous ligand for endotoxin sensor Toll-like receptor 4/Myeloid differentiation protein-2 (TLR4/MD-2) and mediates hyper-inflammation even after elimination of endotoxin-producing extrinsic pathogens, analogous findings between COVID-19-associated ARDS and pre-metastatic lungs such as S100A8 upregulation, pulmonary recruitment of myeloid cells, increased vascular permeability, and activation coagulation cascade. A successful treatment in an animal COVID-19 model is given with a reagent capable of abrogating interaction between S100A8/S100A9 and TLR4. In this paper, we try to verify our hypothesis that S100A8 governs COVID-19-associated ARDS.