Potential role of 25(OH)D insufficiency in the dysfunction of glycolipid metabolism and cognitive impairment in patients with T2DM.

Purpose: To investigate the changes of plasma 25(OH)D levels in type 2 diabetes mellitus (T2DM) patients and explore its role in the dysfunction of glucose and lipid metabolism and cognition. Methods: One hundred and thirty-two T2DM patients were enrolled and the demographic and clinical data were collected. The plasma concentration of 25(OH)D was detected and the patients were divided into two groups including a Vitamin D insufficient (VDI) group and a normal VD group according to the clinical diagnostic criterial of VDI with the plasma 25(OH)D level less than 29 ng/mL. The glycolipid metabolic and routine blood biochemical indices were detected, the plasma concentrations of C-reactive protein (CRP), interleukin-6 (IL-6), soluble myeloid soluble trigger receptor 1 (sTREM1) were measured. The cognitive function was assessed using the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A). The depressive symptomatology was assessed using the Center for Epidemiological Survey Depression Scale (CES-D). Sleep quality was assessed using the Pittsburgh sleep quality index (PSQI). Results: There were 70 T2DM patients with VDI (70/132, 53.03%) in this study. The plasma concentrations of glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), postprandial blood glucose (PBG), IL-6, and sTREM1 were remarkably increased in T2DM patients with VDI as compared with that with the normal VD, accompanied with an elevated BRIEF-A scores. There was no significant difference between groups with regard to the indices of blood lipid, liver function, and scores in CES-D and PSQI. Moreover, results of Pearson correlation test showed that the plasma 25(OH)D levels were negatively correlated with HbA1c, FPG, PBG, CRP, IL-6, sTREM1, CES-D sum scores, and PSQI sum scores, but positively correlated with the plasma levels of Serum creatinine (Scr). Furthermore, result of Receiver Operating Characteristic (ROC) curve analysis showed a predictive role of VDI levels in discriminating T2DM patients with higher cognitive impairments, with the sensitivity and specificity being 62.12% and 62.12%, respectively. Conclusion: VDI is harmful for T2DM patients with a significant relation with the hyperglycosemia and cognitive dysfunction.

Cigarette smoke extract combined with LPS down-regulates the expression of MRP2 in chronic pulmonary inflammation may be related to FXR.

The transporter multidrug resistance protein 2 (MRP2) plays an important role in chronic pulmonary inflammation by transporting cigarette smoke and other related inflammatory mediators. However, it is not completely clear whether pulmonary inflammation caused by cigarette smoke extract (CSE) and lipopolysaccharide (LPS) is related to MRP2 and its signal factors. In this study, CSE combined with LPS was used to establish an inflammation model in vivo and in vitro. We found that compared with the control group, after CSE combined with LPS treatment, the expression of MRP2 in rat lung tissue in vivo and human alveolar cell line in vitro was down-regulated, while the expression of inflammatory factors was up-regulated. Through silencing and overexpression of FXR, it was found that silent FXR could down-regulate MRP2 and up-regulate the expression of inflammatory factors. On the contrary, overexpression of FXR could up-regulate MRP2 and down-regulate the expression of inflammatory factors. Our results show that CSE combined with LPS can down-regulate the expression of MRP2 under inflammatory conditions, and the down-regulation of MRP2 expression may be achieved partly through the FXR signal pathway.

The changes of MRP2 expression in three kinds of pulmonary inflammation models: the downregulation occurred in cigarette smoke extract (CSE) stimulation group and CSE plus LPS stimulation group, unchanged in LPS stimulation group.

The transporter multidrug resistance protein 2 (MRP2) can transport some tobacco carcinogens and plays an important role in the transport of mediators related to pulmonary inflammatory diseases. However, it is not fully understood whether the pulmonary inflammation caused by cigarette smoke extract (CSE) and lipopolysaccharide (LPS) is related to the regulation of MRP2. In this study, CSE and LPS were used alone and in combination as stimuli to induce pulmonary inflammation. In addition, the establishment of a pulmonary inflammation model was verified by animal experiments in vivo. We found that compared with those in the control group, the expression of MRP2 protein was downregulated and the expression of inflammatory cytokines was upregulated in pulmonary inflammation in the CSE group and the CSE combined with LPS group. However, there was almost no change in the expression of MRP2 stimulated by LPS alone. Our results show that CSE and CSE combined with LPS downregulate the expression of MRP2 under inflammatory conditions, while LPS has almost no effect on the expression of MRP2 under inflammatory conditions. The in vivo experimental results of CSE combined with LPS were consistent with the cellular results of CSE combined with LPS, which provides a model and basis for other studies of the role of MRP2 in pulmonary inflammation.

Ligustrazine Suppresses Platelet-Derived Growth Factor-BB-Induced Pulmonary Artery Smooth Muscle Cell Proliferation and Inflammation by Regulating the PI3K/AKT Signaling Pathway.

Pulmonary arterial hypertension (PAH) is a serious pulmonary vascular disease. Excessive proliferation of pulmonary artery smooth muscle cells (PASMCs) plays an important role in the course of this disease. Ligustrazine is an alkaloid monomer extracted from the rhizome of the herb Ligusticum chuanxiong. It is often used to treat cardiovascular diseases, but its effect on PAH has rarely been reported. This study aims to explore the protective effect and mechanism of ligustrazine on PAH. In the in vivo experiment, monocrotaline (MCT) was used to induce PAH in rats, and then ligustrazine (40, 80, 160 mg/kg/day) or sildenafil (25 mg/kg/day) was administered. Four weeks later, hemodynamic changes, right ventricular hypertrophy index, lung morphological characteristics, inflammatory factors, phosphoinositide 3-kinase (PI3K), and AKT expression were evaluated. In addition, primary rat PASMCs were extracted by the tissue adhesion method, a proliferation model was established with platelet-derived growth factor-BB (PDGF-BB), and the cells were treated with ligustrazine to investigate its effects on cell proliferation, inflammation, and cell cycle distribution. The results indicate that ligustrazine can markedly alleviate right ventricular systolic pressure, right ventricular hypertrophy, pulmonary vascular remodeling, and inflammation caused by MCT, and that it decreased PI3K and AKT phosphorylation expression. Moreover, ligustrazine can inhibit the proliferation and inflammation of PASMCs and arrest the progression of G0/G1 to S phase through the PI3K/AKT signaling pathway. Therefore, we conclude that ligustrazine may inhibit the proliferation and inflammation of PASMCs by regulating the activation of the PI3K/AKT signaling pathway, thereby attenuating MCT-induced PAH in rats. Collectively, these findings suggest that ligustrazine may be a promising therapeutic for PAH.

DJ-1 modulates Nrf2-mediated MRP1 expression by activating Wnt3a/ß-catenin signalling in A549 cells exposed to cigarette smoke extract and LPS.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is an inflammatory disease characterized by airway obstruction and abnormal inflammatory responses. Multidrug resistance-related protein 1 (MRP1) can reduce lung inflammation and damage by excreting various toxic exogenous substances and certain pro-inflammatory molecules. AIMS: We studied whether DJ-1 modulates nuclear factor erythroid 2-related factor 2 (Nrf2) by activating the Wnt3a/ß-catenin signalling pathway to further regulate MRP1 expression and pulmonary antioxidant defences in alveolar epithelial (A549) cells treated with smoke extract (CSE) and lipopolysaccharide (LPS). MAIN METHODS: Marker expression was studied by western blot analysis, quantitative real-time PCR and immunofluorescence staining of A549 cells. KEY FINDINGS: A549 cells exposed to CSE and LPS showed downregulation of DJ-1, Wnt3a, MRP1 and haem oxygenase-1 (HO-1) and upregulation of inflammatory factors. Additionally, Nrf2 protein levels were significantly decreased, while there was no change in Nrf2 mRNA levels. Overexpression of DJ-1 and Wnt3a activated Nrf2 signalling, increased MRP1 and HO-1 levels and decreased IL-6 protein expression, while knockdown of DJ-1 and Wnt3a had the opposite effects. Furthermore, DJ-1 overexpression and DJ-1 knockdown increased and decreased, respectively, the levels of Wnt3a and ß-catenin. Interestingly, Nrf2 and Wnt3a deficiency reduced the protective effects of Wnt3a and DJ-1, respectively, in A549 cells. However, the levels of DJ-1 and Wnt3a were not altered by Wnt3a and Nrf2 deletion, respectively. SIGNIFICANCE: In A549 cells treated with CSE and LPS, DJ-1 regulates Nrf2-mediated MRP1 expression and antioxidant defences by activating the Wnt3a/ß-catenin signalling pathway. These findings may provide potential therapeutic targets for COPD intervention.

Cigarette smoke extract combined with lipopolysaccharide reduces OCTN1/2 expression in human alveolar epithelial cells in vitro and rat lung in vivo under inflammatory conditions.

Organic cation transporter 1/2 (OCTN1/2) play important roles in the transport of drugs related to pulmonary inflammatory diseases. Nevertheless, the involvement of inflammation induced by cigarette smoke extract (CSE) combined with lipopolysaccharide (LPS) in the regulation of OCTN1/2 is not fully understood. In this study, CSE combined with LPS was used to establish inflammation models in vitro and in vivo. Our study found that the expression of OCTN1/2 was downregulated in rat lung in vivo and in a human alveolar cell line in vitro after treatment with CSE and LPS compared with the control group, while the expression of inflammatory factors was upregulated. After treatment with ipratropium bromide (IB) or dexamethasone (DEX), the expression of OCTN1/2 was upregulated compared with that in the CSE-LPS model group, while the expression of inflammatory factors was significantly downregulated. After administration of the NF-κB inhibitor PDTC on the basis of the inflammatory status, the expression of OCTN1/2 was upregulated in the treated group compared with the CSE-LPS model group, while the expression of phospho-p65, phospho-IκBα and inflammatory factors was significantly downregulated. We further added the NF-κB agonist HSP70 and found a result that the exact opposite of that observed with PDTC. Our findings show that CSE combined with LPS can downregulate the expression of OCTN1/2 under inflammatory conditions, and that the downregulation of OCTN1/2 expression may partially occur via the NF-κB signaling pathway.

LPS-induced inflammation delays the transportation of ASP+ due to down-regulation of OCTN1/2 in alveolar epithelial cells.

Organic cation transporters (OCTNs) can significantly affect drug disposition in alveolar epithelial cells (A549), but this process is not well understood. We investigated the expression and function of OCTN1/2 in A549 cells under different inflammatory status to examine pulmonary drug distribution. This experiment used lipopolysaccharide (LPS)-treated A549 cells to mimic inflammation in alveolar epithelial cells, and the expression of OCTN1/2, interleukin-6 (IL6), IL18, IL1ß and tumour necrosis factor-alpha (TNF-α) was investigated by western blot and quantitative real-time PCR (qRT-PCR). The fluorescent compound 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide (ASP+) was chosen as a probe to study the activity of OCTN1/2. OCTN1/2 down-regulation induced by LPS was more pronounced than that in normal control (NC) groups. Experiments further detected the release of inflammatory factors that revealed a negative correlation between OCTN1/2 expression and inflammation secretion in human alveolar epithelial cells exposed to different concentrations of LPS. The Michaelis constant (Km) and apparent permeability coefficient (Papp) of ASP+ were also decreased significantly. Our results thus show that LPS-induced inflammation could inhibit the expression and activity of OCTN1/2 in vitro and reduce the distribution of inhaled medicine in pulmonary diseases.