Co-exposure to lipopolysaccharide and desert dust causes exacerbation of ovalbumin-induced allergic lung inflammation in mice via TLR4/MyD88-dependent and -independent pathways.

BACKGROUND: Lipopolysaccharide (LPS) often presents in high concentrations in particulate matter (PM), few studies have reported the enhancing effects of both LPS and PM on airway inflammation in mice and the role of toll-like receptors (TLRs) in this process. Asian sand dust (ASD) is observed most frequently during the spring. This study aimed to clarify the role of TLRs in murine lung eosinophilia exacerbated by ASD and LPS. METHODS: The effects of LPS and ASD co-treatment on ovalbumin (OVA)-induced lung eosinophilia were investigated using wild-type (WT), TLR2-/-, TLR4-/-, and adaptor protein myeloid differentiation factor 88 (MyD88)-/- BALB/c mice. ASD was heated (H-ASD) to remove the toxic organic substances. WT, TLR2-/-, TLR4-/- and MyD88-/- BALB/c mice were intratracheally instilled with four different combinations of LPS, H-ASD and OVA treatment. Subsequently, the pathological changes in lungs, immune cell profiles in bronchoalveolar lavage fluid (BALF), inflammatory cytokines/chemokines levels in BALF and OVA-specific immunoglobulin (Ig) in serum were analyzed. RESULTS: In WT mice, H-ASD + LPS exacerbated OVA-induced lung eosinophilia. This combination of treatments increased the proportion of eosinophils and the levels of IL-5, IL-13, eotaxin in BALF, as well as the production of OVA-specific IgE and IgG1 in serum compared to OVA treatment alone. Although these effects were stronger in TLR2-/- mice than in TLR4-/- mice, the expression levels of IL-5, IL-13, eotaxin were somewhat increased in TLR4-/- mice treated with OVA + H-ASD + LPS. In MyD88-/- mice, this pro-inflammatory mediator-induced airway inflammation was considerably weak and the pathological changes in lungs were negligible. CONCLUSIONS: These results suggest that LPS and H-ASD activate OVA-induced Th2 response in mice, and exacerbate lung eosinophilia via TLR4/MyD88, TLR4/TRIF and other TLR4-independent pathways.

Intermittent Fasting Alleviates the Increase of Lipoprotein Lipase Expression in Brain of a Mouse Model of Alzheimer's Disease: Possibly Mediated by ß-hydroxybutyrate.

Intermittent fasting has been demonstrated to protect against Alzheimer's disease (AD), however, the mechanism is unclear. Histone acetylation and lipoprotein lipase (LPL) are involved in AD progression. Importantly, LPL has been documented to be regulated by histone deacetylases (HDACs) inhibitors (increase histone acetylation level) in adipocyte and mesenchymal stem cells, or by fasting in adipose and muscle tissues. In brain, however, whether histone acetylation or fasting regulates LPL expression is unknown. This study was designed to demonstrate intermittent fasting may protect against AD through increasing ß-hydroxybutyrate, a HDACs inhibitor, to regulate LPL. We also investigated microRNA-29a expression associating with regulation of LPL and histone acetylation. The results showed LPL mRNA expression was increased and microRNA-29a expression was decreased in the cerebral cortex of AD model mice (APP/PS1), which were alleviated by intermittent fasting. No significant differences were found in the total expression of LPL protein (brain-derived and located in capillary endothelial cells from peripheral tissues) in the cerebral cortex of APP/PS1 mice. Further study indicated that LPL located in capillary endothelial cells was decreased in the cerebral cortex of APP/PS1 mice, which was alleviated by intermittent fasting. LPL and microRNA-29a expression were separately increased and down-regulated in 2 µM Aß25-35-exposed SH-SY5Y cells, but respectively decreased and up-regulated in 10 µM Aß25-35-exposed cells, which were all reversed by ß-hydroxybutyrate. The increase of HDAC2/3 expression and the decrease of acetylated H3K9 and H4K12 levels were alleviated in APP/PS1 mice by intermittent fasting treatment, as well in 2 or 10 µM Aß25-35-exposed cells by ß-hydroxybutyrate treatment. These findings above suggested the results from APP/PS1 mice were consistent with those from cells treated with 2 µM Aß25-35. Interestingly, LPL expression was reduced (0.2-folds) and microRNA-29a expression was up-regulated (1.7-folds) in HDAC2-silenced cells, but respectively increased (1.3-folds) and down-regulated (0.8-folds) in HDAC3-silenced cells. Furthermore, LPL expression was decreased in cells treated with microRNA-29a mimic and increased with inhibitor treatment. In conclusion, intermittent fasting inhibits the increase of brain-derived LPL expression in APP/PS1 mice partly through ß-hydroxybutyrate-mediated down-regulation of microRNA-29a expression. HDAC2/3 may be implicated in the effect of ß-hydroxybutyrate on microRNA-29a expression.

d,l-Sulforaphane Induces ROS-Dependent Apoptosis in Human Gliomablastoma Cells by Inactivating STAT3 Signaling Pathway.

d,l-Sulforaphane (SFN), a synthetic analogue of broccoli-derived isomer l-SFN, exerts cytotoxic effects on multiple tumor cell types through different mechanisms and is more potent than the l-isomer at inhibiting cancer growth. However, the means by which SFN impairs glioblastoma (GBM) cells remains poorly understood. In this study, we investigated the anti-cancer effect of SFN in GBM cells and determined the underlying molecular mechanisms. Cell viability assays, flow cytometry, immunofluorescence, and Western blot results revealed that SFN could induced apoptosis of GBM cells in a dose- and time-dependent manner, via up-regulation of caspase-3 and Bax, and down-regulation of Bcl-2. Mechanistically, SFN treatment led to increase the intracellular reactive oxygen species (ROS) level in GBM cells. Meanwhile, SFN also suppressed both constitutive and IL-6-induced phosphorylation of STAT3, and the activation of upstream JAK2 and Src tyrosine kinases, dose- and time-dependently. Moreover, blockage of ROS production by using the ROS inhibitor N-acetyl-l-cysteine totally reversed SFN-mediated down-regulation of JAK2/Src-STAT3 signaling activation and the subsequent effects on apoptosis by blocking the induction of apoptosis-related genes in GBM cells. Taken together, our data suggests that SFN induces apoptosis in GBM cells via ROS-dependent inactivation of STAT3 phosphorylation. These findings motivate further evaluation of SFN as a cancer chemopreventive agent in GBM treatment.

PM2.5-rich dust collected from the air in Fukuoka, Kyushu, Japan, can exacerbate murine lung eosinophilia.

PM2.5 can exacerbate asthma. Organic substances adsorbed on PM2.5-rich dust (PM2.5rd) were inactivated by heating at 360 °C. To characterize the role of organic substances, the effects of PM2.5rd and heated PM2.5-rich dust (H-PM2.5 rd) on allergic lung inflammation were investigated. BALB/c mice were intratracheally administered PM2.5rd or H-PM2.5rd with or without ovalbumin (OVA) four times at 2-week intervals. PM2.5rd, but not H-PM2.5rd, caused neutrophilic alveolitis and bronchitis. In the presence of OVA, PM2.5rd caused severe eosinophil infiltration and goblet cells proliferation in airways, along with a marked induction of the Th2 cytokines interleukin (IL)-4 and IL-13, and the eosinophil-related cytokine IL-5 in bronchoalveolar lavage fluid (BALF). OVA + H-PM2.5rd caused a weaker response. PM2.5rd showed adjuvant effects on OVA-specific immunoglobulin E (IgE) and IgG1 production, but H-PM2.5rd showed minimal effects. These findings suggested that PM2.5rd-bound substances might aggravate lung eosinophilia. To clarify the roles of TLR2, TLR4, and MyD88 on cytokine production in PM2.5rd, murine bone marrow-derived macrophages (BMDMs) from wild-type (WT), TLR2(-/-), TLR4(-/-), and MyD88(-/-) BALB/c mice were stimulated with dust. Cytokine production was low or undetectable in TLR4(-/-) cells, but occurred from TLR2(-/-) cells, and production by MyD88(-/-) cells was higher than by TLR4(-/-) cells. These results suggest that TLR4 and TLR2 ligands (LPS and ß-glucan, respectively) mainly contributed to cytokines production induced by PM2.5rd. In addition to chemical substances, PM2.5-bound microbial substances might act in inflammatory and allergic lung diseases.

Aggravation of ovalbumin-induced murine asthma by co-exposure to desert-dust and organic chemicals: an animal model study.

BACKGROUND: The organic chemicals present in Asian sand dust (ASD) might contribute to the aggravation of lung eosinophila. Therefore, the aggravating effects of the Tar fraction from ASD on ovalbumin (OVA)-induced lung eosinophilia were investigated. METHODS: The Tar fraction was extracted from ASD collected from the atmosphere in Fukuoka, Japan. ASD collected from the Gobi desert was heated at 360°C to inactivate toxic organic substances (H-ASD). ICR mice were instilled intratracheally with 12 different test samples prepared with Tar (1 µg and 5 µg), H-ASD, and OVA in a normal saline solution containing 0.02% Tween 80. The lung pathology, cytological profiles in the bronchoalveolar lavage fluid (BALF), inflammatory cytokines/chemokines in BALF and OVA-specific immunoglobulin in serum were investigated. RESULTS: Several kinds of polycyclic aromatic hydrocarbons (PAHs) were detected in the Tar sample. H-ASD + Tar 5 µg induced slight neutrophilic lung inflammation. In the presence of OVA, Tar 5 µg increased the level of eosinophils slightly and induced trace levels of Th2 cytokines IL-5 and IL-13 in BALF. Also mild to moderate goblet cell proliferation and mild infiltration of eosinophils in the submucosa of airway were observed. These pathological changes caused by H-ASD + OVA were relatively small. However, in the presence of OVA and H-ASD, Tar, at as low a level as 1 µg, induced severe eosinophil infiltration and proliferation of goblet cells in the airways and significantly increased Th2 cytokines IL-5 and IL-13 in BALF. The mixture showed an adjuvant effect on OVA-specific IgG1 production. CONCLUSIONS: These results indicate that H-ASD with even low levels of Tar exacerbates OVA-induced lung eosinophilia via increases of Th2-mediated cytokines. These results suggest that ASD-bound PAHs might contribute to the aggravation of lung eosinophila.

Enhancement of OVA-induced murine lung eosinophilia by co-exposure to contamination levels of LPS in Asian sand dust and heated dust.

BACKGROUND: A previous study has shown that the aggravation of Asian sand dust (ASD) on ovalbumin (OVA)-induced lung eosinphilia was more severe in lipopolysaccharide (LPS)-rich ASD than in SiO2-rich ASD. Therefore, the effects of different LPS contamination levels in ASD on the aggravation of OVA-induced lung eosinophilia were investigated in the present study. METHODS: Before beginning the in vivo experiment, we investigated whether the ultra-pure LPS would act only on TLR4 or not using bone marrow-derived macrophages (BMDMs) of wild-type, TLR2-/-, TLR4-/- and MyD88-/- BALB/c mice. ASD collected from the desert was heated to remove toxic organic substances (H-ASD). BALB/c mice were instilled intratracheally with 12 different testing samples prepared with LPS (1 ng and 10 ng), H-ASD, and OVA in a normal saline solution. The lung pathology, cytological profiles in the bronchoalveolar lavage fluid (BALF), the levels of inflammatory cytokines/chemokines in BALF and OVA-specific immunoglobulin in serum were investigated. RESULTS: The LPS exhibited no response to the production of TNF-α and IL-6 in BMDMs from TLR4-/-, but did from TLR2-/-. H-ASD aggravated the LPS-induced neutrophilic lung inflammation. In the presence of OVA, LPS increased the level of eosinophils slightly and induced trace levels of Th2 cytokines IL-5 and IL-13 at the levels of 1 ng and 10 ng. In the presence of OVA and H-ASD, LPS induced severe eosinophil infiltration and proliferation of goblet cells in the airways as well as remarkable increases in Th2 cytokines IL-5 and IL-13 in BALF. The mixture containing LPS (1 ng) showed adjuvant activity on OVA-specific IgE and IgG1 production. CONCLUSIONS: The results suggest that H-ASD with naturally-occurring levels of LPS enhances OVA-induced lung eosinophilia via increases in Th2-mediated cytokines and antigen-specific immunoglobulin. These results indicate that LPS is a strong candidate for being a major aggravating substance in ASD.

Mild maternal iron deficiency anemia induces DPOAE suppression and cochlear hair cell apoptosis by caspase activation in young guinea pigs.

Iron deficiency (ID) anemia (IDA) alters auditory neural normal development in the mammalian cochlea. Previous results suggest that mild maternal IDA during pregnancy and lactation altered the hearing and nervous system development of the young offspring, but the mechanisms underlying the association are incompletely understood. The objective of this study was to evaluate the role of apoptosis in the development of sensory hair cells following mild maternal IDA during pregnancy and lactation. We established a maternal anemia model in female guinea pigs by using a mild iron deficient diet. The offspring were weaned on postnatal day (PND) 9 and then was given the iron sufficient diet. Maternal blood samples were collected on gestational day (GD) 21, GD 42, GD 63 and PND 9, serum level of iron (SI) or hemoglobin (Hb) was measured. Blood samples of pups were collected on PND 9 for SI measurement. On PND 24, pups were examined the distortion product otoacoustic emission (DPOAE) task, and then the cochleae were harvested for assessment of apoptosis by immunohistochemistry of cysteine-aspartic acid proteases 3/9 (caspase-3/9) and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay, and by double immunofluorescence for the colocalization of TUNEL and caspase-3. Blood samples of pups were collected on PND 24 for SI and Hb measurements. Here we show that mild maternal IDA during pregnancy and lactation resulted in hearing impairment, decreased hair cell number, caspase-3/9 activation and increased apoptotic cell number of young guinea pigs. These results indicate a key role for apoptosis in inhibition of hair cell development, caused by mild maternal IDA during pregnancy and lactation.

[Effects of resveratrol on morphology and oxidative stress of brain tissues in aging mice].

OBJECTIVE: To investigate the protective effects of resveratrol on brain tissues in aging mice induced by D-galactose. METHODS: 54 Kunming male mice aged 16 weeks were randomly divided into control group, aging group, intervention group. The control group was prepared by subcutaneous injection of normal saline and the other two groups were prepared by subcutaneous injection of D-galactose(200 mg/kg BW). The intervention group was fed with resveratrol (22.5 mg/kg BW)by oral gavage and the other two groups were fed with solution of 0.5% sodium carboxymethyl cellulose. All animals were sacrificed 16 weeks later, morphology of brain was observed, calculate the organ coefficients, and GSH-Px, SOD, CAT, MAO activity and MDA content were detected in the mice brain. RESULTS: Compared with the control group, the aging group lost normal morphological structure of nerve cells and the number of nerve cells was significantly decreased (P < 0.05), the organ coefficients were significantly decreased (P < 0.05), and GSH-Px, SOD, CAT activities were significantly decreased (P < 0.05), MAO activity and MDA content were significantly increased in brain of the aging group (P < 0.05). Compared with the aging group, the intervention group brain maintain normal morphological structure of nerve cells and the number of nerve cells was significantly increased (P < 0.05), the organ coefficients were significantly increased (P < 0.05), and GSH-Px, SOD, CAT activities were significantly increased (P < 0.05), MAO activity and MDA content were significantly decreased in brain of the intervention group (P < 0.05). CONCLUSION: Resveratrol can maintain normal morphological structure of nerve cells of aging mice, decrease oxidative stress responses, and has protective effects on brain tissues in aging mice induced by D-galactose.

[Effects of resveratrol on lipid metabolism in C57BL/6J mice].

OBJECTIVE: To investigate the effects of resveratrol on serum and liver lipids in C57BL/6J mice. METHODS: 30 male C57BL/6J mice were randomly assigned to the following three groups: control group given a normal diet, high-fat diet group and resveratrol group (22.5 mg/kg BW) were given high fat diet. the resveratrol were dissolved in 0.5% sodium carboxymethyl cellulose and were given to the Resveratrol group by intragastric administration. The levels of serum total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), the levels of TG and TC in liver, and the pathological changes of liver were measured after the treatment lasted for 8 weeks. RESULTS: The serum TC, LDL-C, HDL-C levels of high-fat diet and resveratrol groups were higher than those of control group (P < 0.05), and the serum TC and LDL-C levels of high-fat diet were also higher than those of resveratrol group (P < 0. 05). But the serum TG levels of high-fat diet and resveratrol groups were lower than those of control group (P < 0.05). The TC content of liver in high-fat diet group were higher than those of control and resveratrol groups (P < 0.05). CONCLUSION: The TC content in C57BL/6J mice can be decreased by resveratrol (22.5 mg/kg BW).

Adipogenic differentiation is not influenced by lentivirus-mediated shRNA targeting the SOCS3 gene in adipose-derived stromal cells.

The adipose-derived stromal cells (ADSCs) are capable of adipogenic differentiation by which they can be used as the seed of adipocytes and as the model to study the mechanism of differentiation. Suppressor of cytokine signaling 3 (SOCS3), a negative regulator of leptin signaling, perhaps involves in cell survival and differentiation. However, to date, rare studies are performed on ADSCs differentiation and SOCS3 regulation. In this study, a lentiviral vector expressing a shRNA targeting SOCS3 gene (Lv-shSOCS3) is developed and tested. To observe the effect of Lv-shSOCS3 on ADSCs differentiation, we infected ADSCs with Lv-shSOCS3 or Lv-shSOCS3-NC (non-silenced control lentivirus) and examined adipocyte differentiation using morphology and the expression of key gene for adipogenic differentiation using real-time PCR. The results show that Lv-shSOCS3 can significantly suppress the expression of SOCS3 mRNA and protein in ADSCs. There are no distinguishable differences on adipogenic differentiation and the expression of peroxisome proliferators-activated receptor gamma (PPARgamma) mRNA for ADSCs between infection with Lv-shSOCS3 and Lv-shSOCS3-NC. We conclude that SOCS3 knock-down does not influence the growth and adipogenic differentiation feature of ADSCs. Our study provides a new molecular basis for understanding the differentiation mechanism of ADSCs and lays the foundation for further study of the biological functions of SOCS3.

Inhibition of SOCS-3 in adipocytes of rats with diet-induced obesity increases leptin-mediated fatty acid oxidation.

Rats with diet-induced obesity (DIO) usually experience hyperleptinemia. Thus, leptin produced by adipocytes does not deplete adipocyte fat, which implying a leptin resistance in adipocytes during overnutrition. Here, we induced hyperleptinemia in rats by feeding them a diet consisting of 45% fat. In epididymal adipose tissues, the mRNA and protein levels of a putative leptin resistant factor, suppressor of cytokine signaling 3 (SOCS-3), were increased. The mRNA levels of SOCS-3 in adipocytes differentiated from adipose-derived stromal cells (ADSCs) were higher in DIO rats than in rats on a 10% fat diet. Using SOCS-3 short hairpin RNA lentivirus interference, we found decreased expression of acetyl-CoA carboxylase mRNA (a marker of de novo lipogenesis) and increased expression of acetyl-CoA oxidase mRNA (a marker of fat oxidation) in SOCS-3-knockdown adipocytes after incubation with 50 nM leptin for 6 h. We conclude that the SOCS-3 knockdown may have increased the leptin-mediated in situ fatty acid oxidation in the DIO adipocytes, and therefore, SOCS-3 might be an excellent target for therapeutic intervention for obesity.

[Study on PPARgamma and aP2 mRNA expression of adipose tissues in obesity and obesity resistant rats].

OBJECTIVE: To observe the difference of serum triglyceride, total cholesterol levels and expression of PPARgamma and aP2 mRNA of adipose tissues between obesity and obesity resistant rats induced by high-fat diet. METHODS: Thirty-one healthy male Wistar rats were randomly divided into two groups. Seven of them were fed with standard diet as control group and 24 rats were fed with high-fat diet as high-fat group. At the end of the 8th week, according to the body weight increment, five rats were selected as obesity group, and five rats were selected as obesity resistant group from high-fat feeding rats. Serum triglyceride, total cholesterol, and the expressions of PPARgamma and aP2 mRNA of epididymal adipose tissues were detected. RESULTS: Serum triglyceride of obesity group were higher than those of control (P < 0.05). Total cholesterol levels of obesity group were higher than those of control and obesity resistant group (P < 0.05, P < 0.01). The expressions of PPARgamma and aP2 mRNA of obesity group were also much higher than those of control and obesity resistant group. CONCLUSION: The expressions of PPARgamma and aP2 mRNA of obesity and obesity resistant rats induced by high-fat diet existed difference.

Effects of in utero meso-2,3-dimercaptosuccinic acid with calcium and ascorbic acid on lead-induced fetal development.

To examine the effects of meso-2,3-dimercaptosuccinic acid (DMSA) on developmental toxicity resulting from exposure to lead in utero, female albino mice were exposed to lead by drinking water contaminated with lead acetate for 4 weeks. After the cessation of lead exposure, female mice were supplemented by gavage with saline solution, DMSA, or DMSA and calcium as well as ascorbic acid from the fourth day of gestation until parturition, respectively. Lead levels (blood, liver, and bone) were measured at birth. Pups were then tested about neural development including surface righting reflex, cliff avoidance and air righting reflex. The markers of physical maturation, such as body weight, pinna unfolding, incisor eruption, and eye opening were also recorded. DMSA treatment decreased blood lead levels of pregnant mice, however, increased lead levels in both liver and bone of fetus, and delayed the early physical and neural development of offspring. Calcium and ascorbic acid reduced the transfer of lead to fetus. In conclusion, DMSA treatment during pregnancy enhances lead-induced fetal developmental toxicity.