Enolase is regulated by Liver X Receptors

Mycoplasma pneumoniae MPN606 induces inflammation by activating MAPK and NF-κB signaling pathways

Mycoplasma pneumoniae (M. pneumoniae) is one of the major pathogens causing community-acquired pneumonia (CAP), and its pathogenic mechanism is not fully understood. Inflammatory response is the most basic and common pathological phenomenon of CAP, but the specific mechanism needs further investigation. In this study, the inflammatory action of M. pneumoniae MPN606 protein was confirmed and its molecular mechanism was tentatively investigated. Compared with the control group treated with PBS, stimulation of RAW264.7 cells with rMPN606 can promote the release of NO, increase the expression level of TNF-α and IL⁃6 cytokines, and up-regulate the mRNA transcription levels of iNOS, IL-6 and TNF-α in RAW264.7 cells. In addition, rMPN606 also significantly induced the expression of iNOS protein in RAW264.7 cells, resulting in increased phosphorylation levels of p65, p38 and ERK proteins. The results of cellular immunofluorescence showed that NF-κB was transferred from cytoplasm to nucleus of RAW264.7 cells after stimulation with rMPN606, and nuclear translocation of NF-κB was significantly enhanced. These results indicate that Mycoplasma pneumoniae MPN606 induces M1-type activation of macrophages and secretes pro-inflammatory factors by activating NF-κB and MAPK pathways.

Anti α-enolase antibody is a novel autoimmune biomarker for unexplained recurrent miscarriages

Background

We recently demonstrated the increased abundance of anti-trophoblast antibodies (ATAB) in sera of patients with unexplained recurrent miscarriages (uRM). Further, the ATAB-positive sera bound to JEG-3 human choriocarcinoma cells in vitro, resulting in decreased productions of β-human chorionic gonadotropin (β-hCG) and progesterone in these cells. However, the specific antigenic epitopes of ATAB have remained unknown. Therefore, it was the aim of this study to determine specific targets of ATAB in uRM patients.

Methods

Potential targets of ATAB were analyzed by 2-dimensional difference gel electrophoresis (2D-DIGE) and mass spectrometry, and thereby identifying α-Enolase (ENO1). ATAB targeting of ENO1 was further confirmed in a competitive binding assay. Levels of anti-ENO1 antibodies as well as β-hCG and progesterone were quantified with enzyme-linked immunosorbent assay (ELISA). Additionally, expression of ENO1 was analyzed in first trimester placentas by immunohistochemistry and immunofluorescence analysis.

Findings

We here identified ENO1 as a prominent target of ATAB. Serum levels of anti-ENO1 antibodies were increased in ATAB-positive compared to ATAB-negative patients. Further, increased expression of ENO1 and its co-expression with β-arrestin was found in the extra villous trophoblasts of uRM patients in first trimester placentas. In vitro, anti-ENO1 antibodies decreased the secretion of β-hCG and progesterone in JEG-3 and primary human villous trophoblast cells.

Interpretation

Serum anti-ENO1 antibodies might be an autoimmune biomarker for uRM. Targeting the formation of anti-ENO1 antibodies or inhibition of ENO1 expression could potentially represent therapeutic strategies for these patients.

Fund

All authors declare no conflict of interest. Yao Ye was supported by the China Scholarship Council. Hellen Ishikawa-Ankerhold and Christian Schulz were supported by the SFB914, projects Z01 and A10. None of the rest authors has any conflict of interest to declare.

Association between serum neuron-specific enolase, age, overweight, and structural MRI patterns in 901 subjects

Serum neuron-specific enolase (sNSE) is considered a marker for neuronal damage, related to gray matter structures. Previous studies indicated its potential as marker for structural and functional damage in conditions with adverse effects to the brain like obesity and dementia. In the present study, we investigated the putative association between sNSE levels, body mass index (BMI), total gray matter volume (GMV), and magnetic resonance imaging-based indices of aging as well as Alzheimer's disease (AD)-like patterns.

SUBJECTS/METHODS

sNSE was determined in 901 subjects (499 women, 22-81 years, BMI 18-48 kg/m²), participating in a population-based study (SHIP-TREND). We report age-specific patterns of sNSE levels between males and females. Females showed augmenting, males decreasing sNSE levels associated with age (males: p = 0.1052, females: p = 0.0363). sNSE levels and BMI were non-linearly associated, showing a parabolic association and decreasing sNSE levels at BMI values >25 (p = 0.0056). In contrast to our hypotheses, sNSE levels were not associated with total GMV, aging, or AD-like patterns. Pathomechanisms discussed are: sex-specific hormonal differences, neuronal damage/differentiation, or impaired cerebral glucose metabolism. We assume a sex-dependence of age-related effects to the brain. Further, we propose in accordance to previous studies an actual neuronal damage in the early stages of obesity. However, with progression of overweight, we assume more profound effects of excess body fat to the brain.