Dexmedetomidine alleviates diabetic neuropathic pain by inhibiting microglial activation via regulation of miR618/P2Y12 pathway

Purpose: To investigate the effect of dexmedetomidine on streptozotocin (STZ)-induced diabetic neuropathy pain (DNP) in rats and elucidate its mechanism of action.Methods: The DNP rat model was established by injecting STZ (70 mg/kg) following dexmedetomidine treatment. Next BV-2 cells were stimulated using lipopolysaccharide (LPS, 200 ng/mL) and then administered 20 μM dexmedetomidine. Blood glucose levels, body weight, and paw withdrawal threshold (PWT) were measured once a week in DNP rats. Transfection was performed, and luciferasereporter assay was used to verify microRNA (miR)-337 binding to Rap1A mRNA. Reverse transcriptionpolymerase chain reaction (RT-PCR) was used to measure the levels of miR-618 and P2Y12 while the protein levels of P2Y12 and ionized calcium-binding adaptor molecule 1 (IBA-1) were determined by western blot analysis.Results: Dexmedetomidine treatment significantly increased PWT (p < 0.01) in DNP rats and decreased miR-618 expression (p < 0.01) but increased P2Y12 expression (p < 0.01) in the spinal cord of DNP rats. Luciferase reporter assay data showed that the presumed binding site of miR-618 is located in the 3′-untranslated regions of P2Y12. MiR-618 overexpression significantly reduced P2Y12levels (p < 0.01). Dexmedetomidine upregulated P2Y12 expression (p < 0.01) but decreased IBA-1 expression (p < 0.01).Conclusion: Dexmedetomidine application attenuates DNP by inhibiting microglial activation via the regulation of miR-618/P2Y12 pathway. This finding provides a potential therapeutic strategy for DNP management. Keywords: Dexmedetomidine, Diabetic neuropathy pain, Paw withdrawal threshold, Calcium-binding adaptor molecule 1, MiR-618, P2Y1

Maternal dietary choline availability alters the balance of netrin-1 and DCC neuronal migration proteins in fetal mouse brain hippocampus

Alterations in maternal dietary choline availability during days 12–17 of pregnancy led to an increase in the level of immunoreactive netrin-1 and a decrease in the level of DCC protein in the developing fetal mouse brain hippocampus compared with controls. Changes in the expression of cell migration cues during development could account for some of the lifelong consequences of maternal dietary choline availability for cognitive and memory processes

Phosphatidylethanolamine N -methyltransferase ( PEMT ) gene expression is induced by estrogen in human and mouse primary hepatocytes

Choline is an essential nutrient for humans, though some of the requirement can be met by endogenous synthesis catalyzed by phosphatidylethanolamine N-methyltransferase (PEMT). Premenopausal women are relatively resistant to choline deficiency compared with postmenopausal women and men. Studies in animals suggest that estrogen treatment can increase PEMT activity. In this study we investigated whether the PEMT gene is regulated by estrogen. PEMT transcription was increased in a dose-dependent manner when primary mouse and human hepatocytes were treated with 17-β-estradiol for 24 h. This increased message was associated with an increase in protein expression and enzyme activity. In addition, we report a region that contains a perfect estrogen response element (ERE) ∼7.5 kb from the transcription start site corresponding to transcript variants {"type":"entrez-nucleotide","attrs":{"text":"NM_007169","term_id":"22538481","term_text":"NM_007169"}}NM_007169 and NM-008819 of the human and murine PEMT genes, respectively, three imperfect EREs in evolutionarily conserved regions and multiple imperfect EREs in nonconserved regions in the putative promoter regions. We predict that both the mouse and human PEMT genes have three unique transcription start sites, which are indicative of either multiple promoters and/or alternative splicing. This study is the first to explore the underlying mechanism of why dietary requirements for choline vary with estrogen status in humans.—Resseguie, M., Song, J., Niculescu, M. D., da Costa, K., Randall, T. A., Zeisel, S. H. Phosphatidylethanolamine N-methyltransferase (PEMT) gene expression is induced by estrogen in human and mouse primary hepatocytes

Polymorphism of the PEMT gene and susceptibility to nonalcoholic fatty liver disease (NAFLD)

Phosphatidylethanolamine N-methyltransferase (PEMT) catalyzes phosphatidylcholine synthesis. PEMT knockout mice have fatty livers, and it is possible that, in humans, nonalcoholic fatty liver disease (NAFLD) might be associated with PEMT gene polymorphisms. DNA samples from 59 humans without fatty liver and from 28 humans with NAFLD were genotyped for a single nucleotide polymorphism in exon 8 of PEMT which leads to a V175M substitution. V175M is a loss of function mutation, as determined by transiently transfecting McArdle-RH7777 cells with constructs of wildtype PEMT open reading frame or the V175M mutant. Met/Met at residue 175 (loss of function SNP) occurred in 67.9% of the NAFLD subjects and in only 40.7% of control subjects (p< 0.03). For the first time we report that a polymorphism of the human PEMT gene (V175M) is associated with diminished activity and may confer susceptibility to NAFLD

Common genetic polymorphisms affect the human requirement for the nutrient choline

Humans eating diets deficient in the essential nutrient choline can develop organ dysfunction. We hypothesized that common single nucleotide polymorphisms (SNPs) in genes involved in choline metabolism influence the dietary requirement of this nutrient. Fifty-seven humans were fed a low choline diet until they developed organ dysfunction or for up to 42 days. We tested DNA SNPs for allelic association with susceptibility to developing organ dysfunction associated with choline deficiency. We identified an SNP in the promoter region of the phosphatidylethanolamine N-methyltransferase gene (PEMT; −744 G→C; rs12325817) for which 18 of 23 carriers of the C allele (78%) developed organ dysfunction when fed a low choline diet (odds ratio 25, P=0.002). The first of two SNPs in the coding region of the choline dehydrogenase gene (CHDH; +318 A→C; rs9001) had a protective effect on susceptibility to choline deficiency, while a second CHDH variant (+432 G→T; rs12676) was associated with increased susceptibility to choline deficiency. A SNP in the PEMT coding region (+5465 G→A; rs7946) and a betaine:homocysteine methyl-transferase (BHMT) SNP (+742 G→A; rs3733890) were not associated with susceptibility to choline deficiency. Identification of common polymorphisms that affect dietary requirements for choline could enable us to identify individuals for whom we need to assure adequate dietary choline intake.—da Costa, K.-A., Kozyreva, O. G., Song, J., Galanko, J. A., Fischer, L. M., Zeisel, S. H. Common genetic polymorphisms affect the human requirement for the nutrient choline

Association between plasma trimethylamine N -oxide and neoatherosclerosis in patients with very late stent thrombosis

Abstract(#br)Background(#br)Trimethylamine N -oxide (TMAO) has been shown to promote the development of atherosclerosis. However, the relationship between plasma TMAO and neoatherosclerosis, an important underlying mechanism of very late stent thrombosis (VLST), is unknown.(#br)Methods(#br)This post hoc study investigated the association between TMAO and neoatherosclerosis in two independent cohorts. These included a control group of 50 healthy volunteers and a study cohort of 50 patients with VLST who presented with ST-segment elevation myocardial infarction and underwent optical coherence tomography examination. Of the 50 patients with VLST, 23 had neoatherosclerosis and 27 did not have neoatherosclerosis. Patients with neoatherosclerosis were further divided into two subgroups, including 14 patients with plaque rupture and 9 without plaque rupture.(#br)Results(#br)The plasma TMAO levels, detected using mass spectrometry, were significantly higher in patients with VLST than in healthy individuals (median [interquartile range]: 2.50 [1.67-3.84] vs. 1.32 [0.86-2.44] μM; P < 0.001). Among the VLST patients, the plasma TMAO levels were significantly higher in patients with neoatherosclerosis than in those without neoatherosclerosis (3.69 [2.46-5.29] vs. 1.96 [1.39-2.80] μM; P<0.001). In addition, in patients with neoatherosclerosis, patients with plaque rupture had significantly higher plasma TMAO concentrations than those without plaque rupture (4.51 [3.41-5.85] vs. 2.46 [2.05-3.55] μM; P=0.005). Multivariate analysis indicated that TMAO was an independent predictor of neoatherosclerosis (odds ratio 3.41; 95% confidence interval: 1.59-7.30; P=0.002). Moreover, the area under the receiver operating characteristic curve for TMAO, differentiated by neoatherosclerosis, was 0.85.(#br)Conclusions(#br)Plasma TMAO was significantly correlated with neoatherosclerosis and plaque rupture in patients with VLST

Cognitive impairment in diffuse axonal injury patients with favorable outcome

Background and purposeTraumatic brain injury (TBI), especially the severe TBI are often followed by persistent cognitive sequalae, including decision-making difficulties, reduced neural processing speed and memory deficits. Diffuse axonal injury (DAI) is classified as one of the severe types of TBI. Part of DAI patients are marginalized from social life due to cognitive impairment, even if they are rated as favorable outcome. The purpose of this study was to elucidate the specific type and severity of cognitive impairment in DAI patients with favorable outcome.MethodsThe neurocognition of 46 DAI patients with favorable outcome was evaluated by the Chinese version of the Montreal Cognitive Assessment Basic (MoCA-BC), and the differences in the domains of cognitive impairment caused by different grades of DAI were analyzed after data conversion of scores of nine cognitive domains of MoCA-BC by Pearson correlation analysis.ResultsAmong the 46 DAI patients with favorable outcome, eight had normal cognitive function (MoCA-BC ≥ 26), and 38 had cognitive impairment (MoCA-BC &lt; 26). The MoCA-BC scores were positively correlated with pupillary light reflex (r = 0.361, p = 0.014), admission Glasgow Coma Scale (GCS) (r = 0.402, p = 0.006), and years of education (r = 0.581, p &lt; 0.001). Return of consciousness (r = −0.753, p &lt; 0.001), Marshall CT (r = −0.328, p = 0.026), age (r = −0.654, p &lt; 0.001), and DAI grade (r = −0.403, p = 0.006) were found to be negatively correlated with the MoCA-BC scores. In patients with DAI grade 1, the actually deducted scores (Ads) of memory (r = 0.838, p &lt; 0.001), abstraction (r = 0.843, p &lt; 0.001), and calculation (r = 0.782, p &lt; 0.001) were most related to the Ads of MoCA-BC. The Ads of nine cognitive domains and MoCA-BC were all proved to be correlated, among patients with DAI grade 2. However, In the DAI grade 3 patients, the highest correlation with the Ads of MoCA-BC were the Ads of memory (r = 0.904, p &lt; 0.001), calculation (r = 0.799, p = 0.006), orientation (r = 0.801, p = 0.005), and executive function (r = 0.869, p = 0.001).ConclusionDAI patients with favorable outcome may still be plagued by cognitive impairment, and different grades of DAI cause different domains of cognitive impairment