The extracellular vesicles from gram-positive bacteria: a review / 生物工程学报

Extracellular vesicles (EVs), also known as membrane vesicles, are vesicular bodies secreted by eukaryotic cells and bacteria. EVs can carry proteins, DNA, RNA, and various metabolites for the exchange and transmission of substances between cells. They play contents-dependent physiological functions, such as delivering nutrients, participating in immune response, and treating cancers. Currently, most studies focus on the exploration of vesicles secreted by eukaryotic cells and gram-negative bacteria, while few studies focus on gram-positive bacteria. This review summarized the production, content composition, physiological function, and engineering of EVs secreted by gram-positive bacteria, and prospected future perspectives in this area.

Ideological and political education in Microbiology Experiment: reform and exploration / 生物工程学报

Deepening the ideological and political construction of curriculum and carrying out the fundamental task of cultivating people with morality are the important requirements of education reform and talent cultivation in the new era. Microbiology Experiment is an important basic course and core practice course of Bioengineering, Pharmaceutical Engineering, Food Science and Engineering, et al. In order to give full play to the education function of Microbiology Experiment, this article deeply developed the ideological elements contained in the curriculum referring to the guidelines for the construction of ideological and political courses in institutions of higher education. And the article explored the ideological and political reform of Microbiology Experiment from three aspects: teaching content reform, teaching method innovation and improvement of teachers' ideological and political construction ability. Strive to integrate the value shaping, knowledge transference and ability training, cultivate high-quality professionals with firm ideals and beliefs.

Molecular characterization and expression pattern analysis of a novel stress-responsive gene ‘BeSNAC1’ in Bambusa emeiensis

NAC transcription factors (TFs) are master regulators of environmental stresses exerting a crucial role in plant growth and development. However, the studies on NAC TFs from Bambusa emeiensis are scarce. In this investigation, a novel gene from B. emeiensis encoding NAC protein was cloned and characterized. The gene was isolated based on the amino acid sequence data of stress-responsive SNAC1 of rice, named ‘BeSNAC1 (accession no. MG763922)’. The full-length sequence of 1681 bp was found to contain an open-reading frame of 912 bp that encode a protein of 303 amino-acid residues. The multiple protein sequence alignments unveiled that BeSNAC1 contains a typical NAC domain. Additionally, the phylogenetic analysis showed that the corresponding protein belonged to the SNAC group, as it cladded with SNAC1, HvSNAC1, TaNAC2, SbSNAC1 and ZmSNAC1 proteins. Transactivation and subcellular localization assay disclosed that BeSNAC1 is a transcriptional activator localized in the cell nucleus.Moreover, the time-dependent expression pattern of BeSNAC1 was profiled under abscisic acid (ABA), polyethylene glycol 6000 (PEG-6000), NaCl, H2O2 and Na2SO4 treatments via a quantitative real-time polymerase chain reaction. The results revealed that the expression of BeSNAC1 was significantly upregulated in all treatments, a significant difference was observed under H2O2, NaCland ABA (P 0.001) and PEG and Na2SO4 (P < 0.01) treatments, respectively. Conclusively, our findings provide evidence that ‘BeSNAC1’ is a nuclear protein that might act as part of the transcription regulation complex and is involved in the ABA signalling pathway and abiotic stress tolerance mechanisms in B. emeiensis.

MALAT1 upregulates SMYD3 by competition with miR-124 and promotes proliferation and migration of breast cancer cells / 中国药科大学学报

@#To investigate whether lncRNA MALAT1 affects the migration and proliferation of breast cancer cells through the regulation with histone methyltransferase SMYD3, the endogenous MALAT1 in the MCF-7 and MDA-MB-231 breast cancer cells were knocked down by siRNA, and then the migration and proliferation of cells were detected by wound healing migration and MTT assay. The effects of si-MALAT1 on the mRNA and protein levels of miRNA-124, SMYD3 and its downstream genes were detected by Real time PCR and Western blot. The results showed that siRNA-targeted knockdown of MALAT1 reduced the migration and proliferation of breast cancer cells, and inhibited the transcriptional expression of SMYD3 and its downstream genes, including N-cadherin, MYL9, MMP9 and CYR61, and up-regulated miR-124. Overexpression of miR-124 reduced the expression of SMYD3 in breast cancer cells, and knockdown of MALAT1 attenuated the promotion of SMYD3 protein expression by miR-124 inhibitors. In addition, SMYD3 overexpression activated MALAT1 transcription, whereas siRNA interference with SMYD3 downregulated MALAT1. These results indicate that LncRNA MALAT1 acted as a competing endogenous RNA(ceRNA)of miR-124 to regulate expression of SMYD3 in breast cancer cells, and SMYD3 can activate the transcription of MALAT1, which will affect the proliferation and migration of breast cancer cells.

Unilateral olfactory functional deprivation model in the left peripheral nostrils by electric cautery injury:olfactory bulb neurogenesis and transformation / 中国组织工程研究

BACKGROUND:Olfactory bulb neurogenesis, transformation and maturation have been considered the hot topic. Olfactory bulb experience and nervous activity can influence olfactory bulb neurogenesis. However, no study reports that olfactory bulb functions can affect olfactory bulb neurogenesis in guinea pigs. OBJECTIVE:To investigate the effect of unilateral olfactory functional deprivation on doublecortin, calbindin and parvalbumin expression in olfactory bulb of juvenile guinea pigs. METHODS:Total y 24 guinea pigs were randomly divided into two groups, which were kil ed after establishing olfactory functional deprivation model through electric cautery injury at the left peripheral nostrils. At 3 and 6 weeks after modeling, the specimens were harvested. The expression change of doublecortin, calbindin and parvalbumin in two sides’ olfactory bulb of juvenile guinea pigs was detected by immunohistochemistry. RESULTS AND CONCLUSION:The number of doublecortin, calbindin and parvalbumin positive cells in olfactory bulb at the un-deprived side was significantly higher than that at the deprived side at 3 and 6 weeks (P<0.05). This finding indicates that olfactory neural activities can affect neurogenesis and transformation in guinea pigs.

Role of LRRN3 in the cerebellum postnatal development in rats / 中南大学学报(医学版)

OBJECTIVE@#To explore the effect and possible mechanism of LRRN3 in the cerebellum postnatal development in rats.@*METHODS@#New born rats were randomly divided into an experimental group and a control group, and each group included 3 sub-groups of different time points. Behavioral experiment, hematoxylin-eosin (HE) staining and immunohistochemistry were used to evaluate the effects of anti-LRRN3 injection on the cerebellum development in new born rats.@*RESULTS@#Compared with the control, the balance ability in the experiment group was weak, and there was significant difference in the static balance between the 2 groups (P<0.05). HE staining showed that molecular layer (ML) grew thicker from the 7th day to the 21st day after birth,and the structure changed dynamically. Vesicular glutamate transporter 1(VGluT1) expression was positive in the cerebellum of all groups, and the positive ML grew thicker from the 7th day to the 21st day after birth. Compared with the control, there was no obvious difference between the 2 groups on the 7th day after birth (P<0.05), while on the 14th day and the 21st day, there was significant difference (P<0.01).@*CONCLUSION@#LRRN3 plays an important role in cerebellum postnatal development. Anti-LRRN3 antibody injection may down-regulate the expression of VGluT1, reduce the synapse formation in the molecular layer,decrease the thickness of ML and inhibit the growth of cerebellum cortex and the functional neural circuit formation.

Study on proton magnetic resonance spectroscopy in the basal ganglia of elderly people / 中华老年医学杂志

Objective To assess metabolic alterations in the human basal ganglia area during maturation and aging by using 2D chemical shift imaging (2D CSI) of proton magnetic resonance spectroscopy (1H-MRS). Methods Seventy healthy subjects were examined by 2D CSI. 2D CSI imaging acquisition was performed in the bilateral caudate, lentiform and thalamus. 1H-MRS was processed to determine the metabolite ratios, including NAA/Cho, NAA/Cr, Cho/Cr. Seventy healthy subjects were divided into 3 groups:20 to 39 years of age group, 40 to 59 years of age group and 60 to 87 years of age group. The three groups of healthy participants were compared. Results There was a significant decrease with aging in the NAA/Cho ratio in the bilateral lcntiform, thalamus and left caudate, and a significant decrease with aging in NAA/Cr ratio in the bilateral thalamus,right lentiform and left caudate (P<0.05), whereas the Cho/Cr ratio was significantly increased in the bilateral lentiform with aging(P<0.05). Conclusions The results of 1H-MRS show significant changes in the level of metabolites during the process of aging. This technique may play an important role in clinical studies and applications for various conditions of metabolic disorders of the human brain.

Expression and Bioactivity Assay of a Novel Clamworm Antimicrobial Peptide Perinerin in Pichia pastoris / 中国生物工程杂志

A novel antimicrobial peptide, named as perinerin (GenBank accession No. P84117), was isolated and characterized from Asian marine clamworms, Perinereis aibuhitensis Grube. Perinerin showes powerful and broad activity against both grampositive and gramnegtive bacteria in vitro, especially on Pseudemonas aeruginosa. To obtain large amounts of active perinerin and characterize its main physiochemical features, The perinerin weve expressed in Pichia pastoris. Intact perinerin gene amplified by the modified gene SOEing method(Gene splicing by overlap extension)was cloned into expression vector pPICZ?A and obtained recombinant vector pPICZ?APEN, then pPICZ?APEN was expressed in the Pichia pastoris GS115. The expressed sample was analyzed by TricineSDSPAGE. The results showed that Pichia pastoris was a suitable system producing the secreted form of perinerin. Bioactivity assay showed that the recombinant perinerin had marked antimicrobial effects.

Relation of integrin ?5?1 expression in human vein grafts to restenosis / 第三军医大学学报

Objective To detect the expression of integrin ?5?1 in restenosed human vein grafts.Methods The expression of integrin ?5?1 and ?-smooth muscle actin(?-SMA) in 30 resected restenosed human vein grafts(from Kerfuff clinical hospital of Germany) was detected by confocal immunofluorescence with specific antibodies against ?5?1 and ?-SMA.Images were processed with Silicon Graphics Octane.Results In normal veins,integrin ?5?1 expression was very weak in media smooth muscle cells and in endothelium,and ?-SMA expression was present in media smooth muscle cells.In the restenosed vein grafts,integrin ?5?1 was strongly stained in the media smooth muscle cells and intimal endothelial cells,and moderately in the intimal smooth muscle cells,?-SMA was present in media smooth muscle cells and in the intimal smooth muscle cells.Conclusion Our research reveals that integrin ?5?1 is significantly upregulated in the media smooth muscle cells and intimal endothelial cells in the restenosed human vein grafts,suggesting the participation of integrin ?5?1 in the restenosis formation of human vein grafts.

ACTIVATION OF NEUROGLIA CELLS AND EXPRESSION OF iNOS IN THE BRAINS OF app/ps1 DOUBLE TRANSGENIC MOUSE / 解剖学报

Objective To examine the expression of inducible nitric oxide synthase(iNOS) and activation of neuroglia cells in the brain of app/ps1 double transgenic mouse(app/ps1 dtg). Methods The brain sections from 6 app/ps1 dtg and 3 wild type female mice aged at 10 to 12 month were subjected to immunohistochemistry and Congo red histological staining,and observed under microscope. Results The widespread neuritic plaques were observed in the hippocampus and cerebral cortex of app/ps1 dtg mice.These plaques were surrounded by activated microglia cells and astrocytes,and the activated astrocytes expressed iNOS.Conclusion The findings in the present study indicate that app/ps1 dtg mice could mimic the main pathological changes similar to those in Alzheimer disease(AD),suggesting neuroglia activation and expression of iNOS play an important role in app/ps1 dtg mice and AD.

THE EXPRESSION OF TrkA AND ChAT IN THE BASAL NUCLEUS OF MEYNERT IN RATS OF DIFFERENT AGE / 神经解剖学杂志

The distribution of TrkA and the postnatal development(PD) of TrkA and ChAT-immunoreactive(-IR) neurons andthe relation between them in the basal nucleus of Meynert of rats were studied with immunohistochemical method. The number,mean profile areas and grey degree of TrkA-IR and ChAT-IR neurons were examined with image analyser. The data revealed thatTrkA-IR neurons were localized in the basal forebrain of rats. TrkA immunostaining was present at PDI, but ChAT was not.ChAT immunostaining was present at PD5. Most densely stained TrkA and ChAT neuronal bodies and fibers were present atPD20, the mean grey degrees of TrkA-IR and ChAT-IR neuronal profiles reached its peak. Both TrkA and ChAT neurons beganto cline at PD30 and maintained a relatively higher level in the adult. However, during aging both TrkA and ChAT-IR neuronsatrophy and became smaller than that in the adult. The number of TrkA-IR and ChAT-IR neurons were decreased by 41.38% and 51.61%; the mean profile areas decreased by 15.7% and 12.8%; and the mean grey degrees by 29.9% and 9.9%, respec-tively. The mean profile areas of TrkA-IR and ChAT-IR neurons from PD5 to aged rats were positively correlated. The resultsindicated that the expression of TrkA was earlier than ChAT. The expression of TrkA and ChAT followed a very similar tempo-ral pattern in the basal nucleus of Meynert from PD5 to aged rats, suggesting that TrkA might participate the regulation ofChAT-IR neuronal development, differentiation, maturation, and ageing. The down-regulation of TrkA and ChAT of aged ratsis associated with neuronal atrophy and loss and may contribute to the pronounced vulnerability of these neurons to degenerationin aging animals and Alzheimer's disease.

THE EXPRESSION OF TrkA AND ChAT IN NEURONS OF THE HORIZONTAL LIMB OF DIAGONAL BAND OF DIFFERENTLY AGED RATS──AN IMMUNOHISTOCHEMICAL STUDY / 解剖学报

Objective To investigate the postnatal developmental rule of TrkA and ChAT\|immunoreactive(ChAT\|ir) neurons and the relationship between TrkA and ChAT\|ir neurons in the horizontal limb of diagonal band(HDB) of rats. Methods Immunohistochemistry technique combined with image analyser were used. Results TrkA and ChAT\|ir neurons localized in the neurons of basal forebrain of rats. TrkA immunostaining was present at postnatal day 1(PD1), but ChAT immunostaining was present at PD5 Most densely stained TrkA and ChAT neuronal bodies and fibers were present at PD20, while the mean grey degrees of TrkA and ChAT\|ir neurons reached to the peak. Both TrkA and ChAT began to decline at PD30 and maintain a relatively higher level in the adult. However, during aging both TrkA and ChAT\|ir neurons atrophied and became smaller than that of adult. The number of TrkA and ChAT\|ir neurons decreased 39 8% and 33 3%;the mean areas 15 7% and 12 8%; the mean grey degree values were 29 9% and 9 9%, respectively. The mean areas, grey degrees and numbers of TrkA and ChAT\|ir neurons from PD5 to aged rats had positive correlation. Conclusion The results indicate that the expression of TrkA was earlier than ChAT. The expression of TrkA and ChAT followed a very similar temporal pattern in HDB from PD5 to aged rats, suggesting that TrkA may participate in the regulation of ChAT\|ir neuronal development, differentiation, maturation and aging. The down\|regulation of TrkA and ChAT of aged rats is associated with neuronal atrophy and loss and may contribute to the pronounced vulnerability of these neurons to degeneration in aging animals and Alzheimer disease.\;

HISTOCHEMICAL INVESTIGATION OF THE CYTOCHROME OXIDASE OF RAT RETINAL GANGLION CELLS BY ACUTE EXPERIMENTAL ELEVATION OF INTRAOCULAR PRESSURE / 解剖学报

The changes of cytochrome oxidase activity of retinal ganglion cell (RGC) caused by the artificial high intraocular pressure (HIOP) was presented in this paper. Normal saline was injected into the anterior chamber of the right eye of 36 rats. that resulted in an intraocular pressure up to 60 mmHg for 3 hours. The experimental rats were divided into 0-, 3- and 7-day groups according to their survival time. Both retinae of each rat were whole mounted on the same slide, the left one being used as control. Thirty-six pairs of retina were treated with the modified cytochrome oxidase (CCO) histochemical technique under similar conditions. The high CCO activity of RGC were counted. The extinction of the cytoplasm of RGC, which indicates the degree of CCO activity, was measured with microphotometer. As compared with the normal eyes, the high CCO activity RGC of experimental eyes were reduced significantly. It was found that the high CCO activity of RGC in the temporal side of retina has been reduced much more than that of the nasal side. However, the high CCO activity of RGC in 3- and 7-day groups were more than that of 0-day group, the extinction of CCO activity of RGC in 7-day group was lower than that of the 3-day group. These facts showed that the CCO activity might restore in various degrees followed by a longer survival time. This experiment emphasized the fact that the HIOP led to metabolic changes of RGC, which may be of value to the study of glaucoma.