TLR4 signaling is involved in the protective effect of propofol in BV2 microglia against OGD/reoxygenation

Propofol exhibits neuroprotective effects against hypoxic–ischemic brain injury, but the underlying mechanisms are still not clear. Toll-like receptor 4 (TLR4) plays a considerable role in the induction of innate immune and inflammatory responses. The purposes of this study are to investigate the effect of propofol on the oxygen and glucose deprivation (OGD)/reoxygenation (OGD/R) BV2 microglia and to explore the role of TLR4/myeloid differentiation protein 88 (MyD88)/nuclear factor-kappa B (NF-κB) pathway in the neuroprotective effects of propofol. BV2 microglia were placed into an airtight chamber and in glucose-free medium for OGD/reoxygenation. Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay. TLR4 and its downstream signaling molecules, MyD88 and NF-κB expressions were detected by Western blotting. Level of tumor necrosis factor alpha (TNF-α) in culture medium was determined with enzyme-linked immunosorbent assay. BV2 microglia apoptosis was determined by flow cytometry. We found that pretreatment with propofol significantly alleviated the hypoxic injury in BV2 microglia. Propofol inhibited upregulation of TLR4, MyD88, and NF-κB expressions in BV2 microglia exposed to OGD/reoxygenation. Propofol pretreatment also significantly reduced the production of TNF-α and apoptosis in OGD/reoxygenation BV2 microglia. The results indicated that TLR4 and its downstream MyD88-dependent signaling pathway contributed to neuroprotection of propofol to microglia exposed to OGD/reoxygenation.     

Lactobacillus paracasei subsp. paracasei LC01 positively modulates intestinal microflora in healthy young adults

Lactobacillus paracasei subsp. paracasei LC01 (LC01) can tolerate intestinal stresses and has antioxidant activity. To evaluate the effect of the bacterium on human intestinal microflora, a randomized, double-blind, placebo-controlled human trial was carried out. Fifty-two healthy adult volunteers were randomized equally to two groups. One group consumed 12% (wt/vol) skimmed milk supplemented with 10¹⁰ CFU of LC01 each day for the 4-week treatment period, and then consumed placebo in the next treatment period, separated by a 2-week washout. The other group followed the reverse order. Group-specific real-time PCR and biochemical analyses was used to determine the intestinal bacterial composition of fecal samples collected at the end of every period, and the concentration of short-chain fatty acids and ammonia. A significant inhibition in fecal Escherichia coli and increase in Lactobacillus, Bifidobacterium, and Roseburia intestinalis were observed after consumption of LC01. Acetic acid and butyric acid were significantly higher in the probiotic stage and fecal ammonia was significantly lower. The results indicated a modulation effect of LC01 on the intestinal microflora of young adults, suggesting a beneficial effect on bowel health. LC01 may have potential value as a probiotic.     

Gender-dependent expression of pancreatic proteins in streptozotocin-induced diabetic rats

To elucidate gender-dependent protein regulation and molecular abnormalities in streptozotocin (STZ)-induced diabetes, we compared differentially expressed pancreatic proteins between male and female diabetic rats and their healthy controls using a 2-DE-based proteomic approach. In animal experiments, we found that females exposed to STZ displayed greater susceptibility towards diabetes development due to lower insulin secretion and severe β-cell damage. It was also accompanied with more impaired regulation of sex hormones, lower glucose tolerance, and higher blood glucose levels compared to male diabetic rats. Among 748 detected protein spots ranging in mass from 6 to 240 kDa between pH 3 and 10, a total of 42 proteins showed significant sexually-dimorphic regulation patterns between male and female diabetic rats. Proteomic data revealed that male and female rats displayed prominent gender-dimorphic differential regulation of pancreatic proteins involved in glycolysis, the citric acid cycle, amino acid synthesis, lipid metabolism, insulin biosynthesis, β-cell regeneration, cell signaling, as well as antioxidative and cellular stress defense. In conclusion, the current proteomic study revealed that severely impaired protein regulation in the pancreas, at least in part, is responsible for increased susceptibility of female rats to STZ-induced diabetes.     

MicroRNAs-1614-3p gene seed region polymorphisms and association analysis with chicken production traits

In the present study, a total of 860 chickens from a Gushi–Anka F₂ resource population were used to evaluate the genetic effect of the gga-miR-1614-3p gene. A novel, silent, single nucleotide polymorphism (SNP, +5 C>T) was detected in the gga-miR-1614-3p gene seed region through AvaII polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) and PCR products sequencing methods. Associations between the SNP and chicken growth, meat quality and carcass traits were performed by association analysis. The results showed that the SNP was significantly associated with breast muscle shear force and leg muscle water loss rate, wing weight, liver weight and heart weight (p?<?0.05), and highly significantly associated with the weight of the abdominal fat (p?<?0.01). The secondary structure of gga-miR-1614 and the free energy were altered due to the variation predicted by the M-fold program.     

Evaluation of in vitro free radical scavenging potential of Streptomyces sp. AM-S1 culture filtrate

The present study was carried out to determine the free radical scavenging potential of culture filtrate of Streptomyces sp. AM-S1. Antioxidant activity of culture filtrate, lyophilized culture filtrate and ethyl acetate extract of Streptomyces sp. AM-S1 was determined by various in vitro assays such as ferric reducing power assay, phosphomolybdenum reduction, DPPH and ABTS radical scavenging activities. The results revealed that the culture filtrate of Streptomyces sp. AM-S1 effectively scavenged DPPH (IC₅₀ 90.2 μl/ml) and ABTS (IC₅₀ 13.2 μl/ml) radicals in a concentration dependent manner. In all the assays, ethyl acetate extract registered higher antioxidant activity when compared with the lyophilized culture filtrate (LCF). In addition, ethyl acetate extract (1123.4 μmole Fe(II)/mg extract) exhibited higher ferric reducing activity than the standard BHA (814.4 μmole Fe(II)/mg extract). Further works are needed on the isolation and identification of antioxidant molecules from the ethyl acetate extract of Streptomyces sp. AM-S1 culture filtrate.     

Free radical scavenging activity from different extracts of leaves of Bauhinia vahlii Wight & Arn.

The objectives of this study were to determine phenolic content and antioxidant activities of chloroform, acetone, methanol and hot water extracts of Bauhinia vahlii leaves. The hot water extract afforded the highest yield (6.3%) while the lowest yield was obtained from the chloroform extract (2.1%). The methanol extract contains higher levels of total phenolics (48.7 ± 0.7 g GAE/100 g extract), tannins (21.7 ± 0.7 g GAE/100 g extract) and flavonoids (10.3 ± 0.2 RE/100 g extract). The extracts were subjected to assess their antioxidant potential using various in vitro systems such as DPPH, ABTS⁺, FRAP, OH, β-carotene linoleic acid bleaching system, phosphomolybdenum reduction and Fe²⁺ chelation. It is concluded that the methanolic extract of B. vahlii leaves have strong antioxidant potential. Further study is necessary for isolation and characterization of the active antioxidants, which may serve as a potential source of natural antioxidants.     

Lipopolysaccharide neutralization by a novel peptide derived from phosvitin

Lipopolysaccharide (LPS), also known as endotoxin, is the primary trigger of sepsis, which is associated with high mortality in patients. No therapeutic agents are currently efficacious enough to protect patients from sepsis characterized by LPS-mediated tissue damage and organ failure. Previously, a phosvitin-derived peptide, Pt5, which consists of the C-terminal 55 residues of zebrafish phosvitin, has been shown to function as an antibacterial agent. In this study, we have generated six mutants by site-directed mutagenesis based on the sequence of Pt5, and found that one of the six mutants, Pt5e, showed the strongest bactericidal activities against Escherichia coli and Staphylococcus aureus. We then demonstrated that Pt5e was able to bind to LPS and lipoteichoic acid (LTA). More importantly, we showed that Pt5e significantly inhibited LPS-induced tumor-necrosis factor (TNF)-α and interleukin (IL)-1β release from murine RAW264.7 cells and considerably reduced serum TNF-α and IL-1β levels in mice. Additionally, Pt5e protected the liver from damage by LPS, and remarkably promoted the survival rate of the endotoxemia mice. Furthermore, Pt5e displayed no cytotoxicity to murine RAW264.7 macrophages and no hemolytic activity toward human red blood cells. These data together indicate that Pt5e is an endotoxin-neutralizing agent with a therapeutic potential in clinical treatment of LPS-induced sepsis.     

Resolvin D1 inhibits TGF-β1-induced epithelial mesenchymal transition of A549 lung cancer cells via lipoxin A4 receptor/formyl peptide receptor 2 and GPR32

Epithelial-mesenchymal-transition (EMT) is a key event for tumor cells to initiate metastasis which lead to switching of E-cadherin to N-cadherin. Resolvins are known to promote the resolution of inflammation and phagocytosis of macrophages. However, the role of resolvins in EMT of cancer is not known. Therefore, we examined the effects of resolvins on transforming growth factor, beta 1 (TGF-β1)-induced EMT. Expression of E-cadherin and N-cadherin in A549 lung cancer cells was evaluated by Western blot and confocal microscopy. Involvement of lipoxin A4 receptor/formyl peptide receptor 2 (ALX/FPR2) was examined by gene silencing. TGF-β1 induced expression of N-cadherin in A549 lung cancer cells, and resolvin D1 and D2 inhibited the expression of N-cadherin at low concentrations (1–100 nM). Resolvin D1 and D2 also suppressed the expression of zinc finger E-box binding homeobox 1 (ZEB1). The effects of resolvin D1 and D2 were confirmed in other lung cancer cell lines such as H838, H1299, and H1703. Resolvin D1 and D2 did not affect the proliferation of A549 lung cancer cells. Resolvin D1 and D2 also suppressed the TGF-β1-induced morphological change. Resolvin D1 and D2 also inhibited the TGF-β1-induced migration and invasion of A549 cells. Resolvin D1 is known to act via ALX/FPR2 and GPR32. Thus, we examined the involvement of ALX/FPR2 and GPR32 in the suppressive effects of resolvin D1 on TGF-β1-induced EMT of A549 cells. Gene silencing of ALX/FPR2 and GPR32 blocked the action of resolvin D1. Overexpression of ALX/FPR2 or GPR32 increased the effects of resolvin D1. These results suggest that resolvin D1 inhibited TGF-β1-induced EMT via ALX/FPR2 and GPR32 by reducing the expression of ZEB1.     

Inhibition of hydrogen sulfide synthesis provides protection for severe acute pancreatitis rats via apoptosis pathway

We aimed to investigate the relationship between the synthesis of hydrogen sulfide (H₂S) and the pancreatic acinar cell apoptosis in severe acute pancreatitis (SAP) rats, as well as analyse the potential apoptotic pathway involved in this process. Sixty rats had been equally divided into four groups: sham, SAP, SAP + sodium hydrosulfide (NaHS) and SAP + DL-propargylglycine (PAG). 24 h after SAP induction, all surviving animals of each group were sacrificed to collect blood and tissue samples for the following measurements: the level of serum H₂S as well as the levels of tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), H₂S synthesizing activity, CSE mRNA and protein expression, maleic dialdehyde (MDA) and myeloperoxidase (MPO) activity, the expression of Bax, Bcl-2, caspase-3, -8 and -9, the release of cytochrome c and the activation of nuclear factor-kappa B (NF-κB), ERK1/2, JNK1/2 and p38 in pancreas. Furthermore, in situ detection of cell apoptosis was examined and the severity of pancreatic damage was analyzed by pathological grading and scoring. Results Significant differences in every index except IL-10 had been found between the SAP, NaHS and PAG groups (P < 0.05). Treatment with PAG obviously induced the pancreatic acinar cell apoptosis as well as improved all the pathological changes and inflammatory parameters. In contrast, administration of NaHS significantly attenuated apoptosis in the pancreas and aggravated the severity of pancreatic damage. Moreover, the expressions of caspase-3, -8, -9 and the release of cytochrome c were all increased in the apoptotic cells, and the activity of NF-κB as well as the phosphorylation of ERK1/2, JNK1/2 and p38 decreased accompanying with the reduction of the serum H₂S level. H₂S plays a pivotal role in the regulation of pancreatic acinar cell apoptosis in SAP rats. The present results showed that inhibition of H₂S synthesis provided protection for SAP rats via inducing acinar cell apoptosis. This process acted through both extrinsic and intrinsic apoptotic pathways, and may be regulated by reducing the activity of NF-κB.