The residue of tetracycline antibiotics in soil and Brassica juncea var. gemmifera, and the diversity of soil bacterial community under different livestock manure treatments

Tetracycline antibiotics (TCs) are a broad-spectrum antibiotic, widely used in livestock and poultry breeding. Residue of tetracycline antibiotics in animal manure may cause changes in vegetable TCs content and soil microbial community. On the basis of the investigation and analysis of TCs pollution in the soil of main vegetable bases and the livestock manure of major large-scale farms in Chongqing, China, field experiment was conducted to study the residues of tetracycline antibiotics in Brassica juncea var. gemmifera and soil under different kinds and different dosages of livestock manures. Effects of tetracycline antibiotics on the structure and diversity of soil microbial community were also investigated by high-throughput sequencing. TCs content in soil was increased by applying livestock manure. The contents of tetracycline, oxytetracycline (OTC) and chlortetracycline (CTC) in the soil under pig manure treatment were 171.07-660.20 μg kg^-1, 25.38-345.78 μg kg^-1 and 170.77-707.47 μg kg^-1, respectively. The contents of TC, OTC and CTC in the soil under the treatment of chicken manure were 166.62-353.61 μg kg^-1, 122.25-251.23 μg kg^-1 and 15.12-80.91 μg kg^-1, respectively. TCs in edible parts of Brassica juncea var. gemmifera was increased after livestock manure treatment Proteobacteria, Acidobacteria, Actinobacteria, Chioroflexi and Bacteroidetes under livestock manure treatment were the dominant phyla, accounting for 85.2-92.4% of the total abundance of soil bacteria. The soil OTUs under the treatment of pig manure was higher than that under the treatment of chicken manure. Biogas residue (Livestock manure after fermentation treatment) can effectively reduce the environmental and ecological risks caused by antibiotic residues.

Tripterygium glycoside fraction n2: Alleviation of DSS-induced colitis by modulating immune homeostasis in mice

BACKGROUND

The Tripterygium glycosides (TG) is the main active extractive of Tripterygium wilfordii Hook F and is widely used in clinical practice to treat inflammatory diseases (including inflammatory bowel disease). However, due to its severe toxicity, TG is restricted to the treatment of many diseases. Therefore, it is necessary to study a new method to obtain the attenuated and synergistic extracts from TG.

PURPOSE

Tripterygium glycosides-n2 (TG-n2) was obtained from TG by a new preparation method. In this study, we aimed to investigate the difference in the chemical compositions between TG and TG-n2, further explored its toxicity and therapeutic effects on DSS-induced colitis in mice.

METHODS

The major chemical compositions of TG and TG-n2 were analyzed by ultra-performance liquid chromatography (UPLC). Subsequently, acute toxicity test was applied to evaluate the toxicity difference between TG and TG-n2. Dextran sulfate sodium (DSS)-induced acute colitis model was used to explore the therapeutic effect of TG and TG-n2 and their potential mechanisms of action.

RESULTS

We found that the chemical compositions of TG-n2 is different from TG. The main difference is the ratio of triptriolide (T11) / triptolide (T9). Acute toxicity test proved that TG-n2 was less toxic than TG. Base on this, further studies showed that TG-n2 has a similar therapeutic effect as compared to TG on attenuating the symptoms of colitis, such as diarrhea, bloody stools, body weight loss, colonic atrophy, histopathological changes, inhibiting cytokines secretion and reducing absolute lymph number. In addition, TG and TG-n2 can increase the apoptosis of T lymphocyte in vivo. Further investigated showed that TG and TG-n2 could increase the expressions of Bax and p62 on CD3-positive T cells.

CONCLUSION

This study showed that oral administration of TG-n2 is safer than TG. Moreover, the attenuated TG-n2 has the similar therapeutic effect on treating experimental colitis in mice when compared to TG. Its mechanism may be related to activating the expression of Bax in T cells and inducing T cells autophagy to regulate the survival of T lymphocytes in colitis mice, thus reducing inflammation in colon.

Gastrodin suppresses BACE1 expression under oxidative stress condition via inhibition of the PKR/eIF2α pathway in Alzheimer's disease

The expression of β-site APP-cleaving enzyme 1 (BACE1) is increased in the brain of late-onset sporadic Alzheimer's disease (AD) and oxidative stress may be the potential cause of this event. The phenolic glucoside gastrodin (Gas), a main component of a Chinese herbal medicine Gastrodia elata Blume, has been demonstrated to display antioxidant activity and suppresses BACE1 expression. However, the mechanisms by which Gas suppresses BACE1 expression are not clear. Morris water maze test was performed to assess the effect of Gas treatment on memory impairments in Tg2576 mice. The level of oxidative stress in the brain of Tg2576 mice was determined by measuring the superoxide dismutase (SOD) activity, catalase (CAT) activity, and the levels of malondialdehyde (MDA) and ROS. In vivo and in vitro, we detected the expression levels of BACE1, pPKRThr446, PKR, pPERKThr981, PERK, peIF2αSer51, and eIF2α using western blot analysis. We found that Gas improved learning and memory abilities of Tg2576 transgenic mice and attenuated intracellular oxidative stress in hippocampi of Tg2576 mice. We discovered that the expression levels of BACE1, activated PKR (pPKRThr446) and activated eIF2α (peIF2αSer51) were elevated in the brains of Tg2576 mice and hydrogen peroxide (H2O2)-stimulated SH-SY5Y cells. Moreover, peptide PKR inhibitor (PRI) and Gas down-regulated BACE1 expression in Tg2576 mice and H2O2-stimulated SH-SY5Y cells by inhibiting activation of PKR and eIF2α. Gas alleviates memory deficits in mice and suppresses BACE1 expression by inhibiting the protein kinase/Eukaryotic initiation factor-2α (PKR/eIF2α) pathway. The research suggested that Gas may develop as an drug candidate in neurodegenerative diseases.

Distribution of LIM domain kinase 1 in the olfactory bulb, cerebral cortex, hippocampus, and cerebellum of the App/PS+/- mice

LIM domain kinase 1 (LIMK1), an actin-binding kinase, can phosphorylate and inactivate its substrates, and can regulate long-term memory and synaptic plasticity. Both β-amyloid precursor protein (App) and presenilin (PS) are functional degeneration factors during early neuronal development, and are considered as potential factors that contribute to the development of Alzheimer's disease (AD). However, hardly any information is available about the distribution and expression of LIMK1. Thus, using the App and PS deficient mice, the role of LIMK1 was demonstrated in the absence of App and PS. Our results showed that LIMK1 was present in the nerve fiber layer and external plexiform layer of the olfactory bulb, as well as in the mitral cells and Purkinje cells of the cerebellum in App and PS deficient mice. Additionally, LIMK1 was concentrated in the granule cell layer of the olfactory bulb and cerebellum and LIMK1 positive cells were located in the CA1 region of the hippocampus. Our study indicates that there is a connection between LIMK1 and AD in the mouse model of AD. This might explain neurological problems such as cerebellar ataxia, impaired long-term memory, and impaired synaptic plasticity observed in AD.

Molecular cloning, characterization, and bioactivity analysis of interleukin 18 in giant panda (Ailuropoda melanoleuca)

Interleukin 18 (IL-18), as a member of IL-1 superfamily, is an important pleiotropic cytokine that modulates Th1 immune responses. In this report, we cloned and identified a homolog of IL-18 in giant panda (Ailuropoda melanoleuca) (designated as AmIL-18) from peripheral blood mononuclear cells stimulated with lipopolysaccharide. The open readin g frame of AmIL-18 cDNA is 579 bp encoding a deduced protein of 192 amino acids. AmIL-18 gDNA fragments contained 5 exons and 4 introns. The amino acid sequence of AmIL-18 shared 23.9 to 87.0% identity with other species. To evaluate the effects of AmIL-18 on the immune response, we expressed the recombinant AmIL-18 in Escherichia coli BL21 (DE3). The fusion protein PET-AmIL-18 was purified by nickel affinity column chromatography and verified by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot analysis. The biological function of purified PET-AmIL-18 was determined on mouse splenocytes by quantitative real-time polymerase chain reaction. INF-γ and other cytokines were increased when stimulated by PET-AmIL-18, particularly when combined with recombinant human interleukin 12, while a Th2-type cytokine, interleukin-4, was strikingly suppressed. These results will provide information for the potential use of recombinant proteins to manipulate the immune response in giant pandas and facilitate the study to protect this treasured species.

Neuronal apoptosis in the developing cerebellum

The following study analysed apoptosis in proliferative cells and migrating neurons of the developing cerebellum. The external granular layer, Purkinje cell layer and internal granular layer in the developing mouse cerebellar cortex were analysed by active caspase-3 immunohistochemistry, Hoechst 33258 staining and Western blot analysis. Immunocytochemistry results indicated that the peak of apoptosis appeared at postnatal days P8, P5 and P9 in the external granular layer, Purkinje cell layer and internal granular layer, respectively. Subsequently, in each region, the rate of apoptosis decreased with increasing age. In contrast, Western blot results demonstrated the highest expression of activated caspase-3 in the cerebellum at P5, followed by a subsequent decline and disappearance of expression by P14. Activated caspase-8 was expressed maximally at P10, and subsequently disappeared by P30. The results of this study suggest that the key period of neuronal apoptosis in the cerebellar cortex is between P0 and P14, indicating that this developmental period could be susceptible to treatment for congenital neurodegenerative diseases.