Are Odorant-binding Proteins Involved in Odorant Discrimination?

Pheromone-sensitive sensilla trichodea of nine moth speciesbelonging to six families and three superfamilies of Lepidopterawere immunolabelled with an antiserum against the pheromone-bindingprotein of Antheraea polyphemus. Strong immunolabelling of thesensillum lymph was observed in all long sensilla trichodeaof A. polyphemus, A. pernyi (Saturniidae), Bombyx mori (Bombycidae)and Manduca sexta (Sphingidae). Very weak labelling was foundwith all sensilla trichodea of Dendrolimus kikuchii (Lasiocampidae)and Lymantria dispar (Lymantriidae). In three noctuid species,some long sensilla trichodea were labelled strongly, some onlyweakly and some were not labelled at all. The fraction of longsensilla trichodea that were strongly labelled was large inHelicoverpa armigera, but small in Spodoptera littoralis andAutographa gamma. The observed cross-reactivity was not correlatedwith taxonomic relatedness of the species but rather with chemicalrelatedness of the pheromones used by these species, as a highlabelling density was consistently observed in sensilla tunedto pheromones with an alcyl chain of 16 carbon atoms. The highlydivergent specificity of pheromone-receptor cells in Noctuidaeappears to be mirrored by a similar diversity of the pheromone-bindingproteins in the sensilla trichodea. These data support the notionthat pheromone-binding proteins participate in odorant discrimination.Chem. Senses 21: 719–727, 1996.     

Heterogeneity of Odorant-binding Proteins in the Antennae of Bombyx mori

Different odorant-binding proteins (OBPs) were isolated fromtotal antennal homogenates of male and female Bombyx mori. Proteinswere separated according to their isoelectric point by usingpreparative fast-flow isoelectrofocusing. Odorant-binding proteinswere identified in immunoblots by antisera raised against thepheromone-binding protein (anti-PBP) and the general odorant-bindingprotein (anti-GOBP2) of Antheraea polyphemus. Four proteinscross-reacting with anti-PBP were detected in males and twoin females, while three proteins cross-reacting with anti-GOBP2were found in males and five in females. Both anti-PBP and anti-GOBP2cross-reacting proteins had an apparent molecular weight of15–16 kDa. In parallel, the same two antisera were usedin immunocytochemical studies in order to determine the distributionof these proteins within the various subtypes of olfactory sensilla.The presence of multiple odorant-binding proteins within onemoth species as well as their complex distribution pattern supportthe suggestion that soluble OBPs might have a function in odorantdiscrimination. Chem. Senses 22: 503–515, 1997.     

Study of an Amoeboflagellate Isolated from the Nasal Mucosa of Man

ABSTRACT. This paper examines the biology, morphology, and pathogenicity for mice of an amoeboflagellate isolated from human nasal mucosa. The biological and morphological relationships of this isolate with the amoebae (Lobosea) and the true slime molds (Eumycetoza) are discussed though the taxonomic affinities of the organism have not been determined.     

Characteristics of Sodium Flux from Serosa to Mucosa in Rabbit Ileum

Sodium flux from serosa to mucosa, J_sm^Na in rabbit ileum in vitro has been studied as a function of applied electrical potential at equal sodium concentrations in the bathing solutions. The results indicate that J_sm^Na involves two pathways, a diffusional flux through a paracellular shunt pathway and a flux that is independent of applied potential and presumably involves a transcellular pathway. The latter pathway comprises approximately 25 % of J_sm^Na in Ringer's solution containing 10 mM glucose and 25 mM bicarbonate. It is stimulated significantly by theophylline unaffected by removal of glucose or addition of ouabain but is reduced to negligible values by anoxia, dinitrophenol, and replacement of all chloride and bicarbonate by isethionate. Thus this component of J_sm^Na has a number of characteristics consistent with involvement in a specific secretory process mediating an electrically neutral secretory transport of sodium plus anion from serosa to mucosa. In addition to stimulating this process, theophylline significantly reduced the permeability of the paracellular shunt pathway to sodium.     

Expression of a Lipocalin in Human Nasal Mucosa

A 19 kDa soluble protein was purified from human nasal mucus. Its N-terminal amino-acid sequence appeared to be identical to that of a lipocalin synthesised both in lachrymal glands and in von Ebner's glands (VEG) of circumvallate papillae. In order to verify whether this protein was synthesised in the nasal cavity or was the result of tear contamination, we adopted an immunohistochemical approach. Polyclonal antibodies, raised against a primate VEG protein, were used on sections of human nasal mucosa obtained from surgery. The results clearly indicate that the protein is synthesised in sero-mucous glands underlying the respiratory ciliated epithelium. Although ligand-binding experiments with some odorant molecules have given negative results, we cannot exclude a role of odorant solubiliser and carrier for this protein.     

Nasal Mucosa Derived-Mesenchymal Stem Cells from Mice Reduce Inflammation via Modulating Immune Responses

Mesenchymal stem cells (MSCs) have arisen the attention to be a new attractive therapeutic tool treating autoimmune diseases such as allergic rhinitis (AR). AR is a chronic reversible allergic inflammation caused by the excessive activation of T-helper 2 (Th2) cells. Recently, MSCs have been proposed as a new therapy of AR as it can suppress some cytokines to control allogeneic Th2 response and functions. However, how MSCs function to reduce inflammation remains unclear. In this study, we aimed to investigate the role of ectomesenchymal stem cells (ECTO-MSCs) derived from nasal mucosa in eosinophilic inflammation and how it affects some immunoglobulins and cytokines. We used ovalbumin (OVA) as a sensitizer to induce nasal inflammation in mice by both injection and inhalation. In order to obtain deeper insights into the influences of ECTO-MSCs on nasal inflammation, the migration of ECTO-MSCs was assessed, the numbers of eosinophils and sneezing were counted, and several immunoglobulins and cytokines were measured. Here we show the ECTO-MSCs are able to migrate to inflammation site via tail vein injection. Eosinophils and sneezing were suppressed by ECTO-MSCs. Interestingly, IgE, interleukin (IL)-4, IL-5 and IL-10 secreted by Th-2 cells were down-regulated by ECTO-MSCs whereas IgG₂ and IFN-γ were up-regulated. In conclusion, we have observed that ECTO-MSCs are associated with enhanced Th-1 immune response to nasal inflammation and reduced Th-2 immune response. Given the contributions of Th-2 cells to AR, the injection of ECTO-MSCs can be a promising therapy of AR through balancing immune response.     

Characterization of Isolates of Acanthamoeba from the Nasal Mucosa and Cutaneous Lesions of Dogs

Acanthamoeba spp. are free-living amoebae that are ubiquitously distributed in the environment and can cause encephalomyelitis in animals and humans. The factors that contribute to Acanthamoeba infections include parasite biology, genetic diversity, environmental spread, and host susceptibility. The aim of the present study was to characterize isolates of Acanthamoeba from the nasal mucosa and cutaneous lesions of dogs in order to access the occurence and pathogenicity of these organisms in this animal group. We studied 13 isolates of Acanthamoeba confirmed by polymerase chain reaction. They were sequenced, the genotype was determined, and their potential of pathogenicity was evaluated.     

Role of the Lymphoreticular System in Prion Neuroinvasion from the Oral and Nasal Mucosa

Prion neuroinvasion from peripheral tissues involves agent replication in the lymphoreticular system (LRS) prior to entry into the nervous system. This study investigated the role of the LRS in prion neuroinvasion from the oral and nasal mucosa in wild-type and immunodeficient mice and in hamsters infected with the HY and DY strains of the transmissible mink encephalopathy (TME) agent. Following inoculation at neural sites, all hosts were susceptible to prion disease and had evidence of prion infection in the brain, but infection of the LRS was found only in scrapie-infected wild-type mice and HY TME-infected hamsters. In the LRS replication-deficient models, prion neuroinvasion was not observed following intraperitoneal or oral inoculation. However, immunodeficient mice, which have impaired follicular dendritic cells, were susceptible to scrapie following intratongue and intranasal inoculation despite the absence of PrP^Sc in the tongue or the nasal cavity. For DY TME, hamsters were susceptible following intratongue but not intranasal inoculation and PrP^Sc was limited to nerve fibers of the tongue. These findings indicate that neuroinvasion from the tongue and nasal cavity can be independent of LRS infection but neuroinvasion was partially dependent on the strain of the prion agent and/or the host species. The paucity of PrP^Sc deposition in the oral and nasal mucosa from LRS replication-deficient hosts following neuroinvasion from these tissues suggests an infection of nerve fibers that is below the threshold of PrP^Sc detection and/or the transport of the prion agent along cranial nerves without agent replication.In natural and experimental prion infections originating in the periphery, prion agent replication in the lymphoreticular system (LRS) precedes agent entry and spread in the peripheral nervous system. In the LRS, follicular dendritic cells (FDCs) are the major target of prion infection, and blocking or reversing FDC maturation can prevent scrapie agent replication in the LRS (25, 26, 28, 30, 32). Other migrating cell populations may also influence the progression of experimental prion disease (27, 36). From the LRS, centripetal spread of the prion agent to the spinal cord or brain occurs by spread along nerve fibers of the peripheral nervous system. In the central nervous system, prion agent replication can induce neurodegeneration and disease after an incubation period that can last from weeks to years. For example, in lambs from flocks with endemic scrapie, agent replication is initially detected in the gut-associated lymphoid tissues prior to proximal and distal spread in the LRS, infection of peripheral nerves that innervate the LRS, and subsequent spread to the spinal cord (19, 42). In addition, scrapie agent infection of the vagal nerve, which innervates many peripheral organs including the digestive tract, results in axonal transport directly to the dorsal motor nucleus of the vagus in the brain stem (29, 41). The role of scrapie infection in the LRS in the latter pathway of neuroinvasion is unknown. A similar pathway of prion neuroinvasion occurs in mule deer experimentally infected with the chronic wasting disease agent with the exception that early infection is also established in the lymph nodes of the upper gastrointestinal tract (37, 38). Recent studies indicate that a similar pathway of neuroinvasion occurs in natural and experimental bovine spongiform encephalopathy (BSE) following oral exposure except that agent replication in the LRS is greatly reduced and appears restricted to portions of the gut-associated lymphoid tissues (13, 20, 39).There are natural prion diseases in sheep and cattle that do not exhibit the typical distribution of the prion agent in the brain and LRS that are presumably acquired via oral prion exposure (5, 33). The absence of the abnormal isoform of the prion protein, PrP^Sc, in the LRS and dorsal motor nucleus of the vagus in atypical scrapie and the H type or L type of BSE raises the question as to whether these cases are due to infection by an alternate route(s) other than ingestion or whether these cases have an etiology that is distinct from that of acquired prion diseases. Direct prion infection of nerve fibers or terminals in highly innervated tissues, such as the mucosa in the head, has been suggested to represent potential sites of prion agent entry that would not require prior agent replication in the LRS (4, 12, 31). The presence of scrapie or BSE infection in the retina, sensory fibers of the tongue, and nasal mucosa of sheep, goat, and/or cattle suggests that the eye, tongue, or nasal cavity could be alternate sites of prion agent entry into hosts (8, 11, 15, 16, 40). Experimental prion inoculation at these mucosal sites can cause prion disease and in some cases rapid neuroinvasion (4, 9, 17, 18). Another explanation for this distribution of infection is that centrifugal spread of the prion agent away from the brain and along cranial nerves could serve as a pathway for prion infection and accumulation in these mucosal tissues (4, 10, 43).In this work, we investigated the role of the LRS in prion neuroinvasion from the oral and nasal cavities. In order to investigate neuroinvasion following neural and extraneural routes of inoculation in which prion replication is blocked in the LRS, we used two rodent models for prion infection. In muMT mice, which lack mature B cells, and in lymphotoxin-α (LTα) null mice, FDCs do not undergo maturation, and as a result, these mice do not develop clinical disease following intraperitoneal inoculation of the scrapie agent but are susceptible following direct inoculation into the brain (23, 30). In a second model, the HY and DY strains of the transmissible mink encephalopathy (TME) agent were used to investigate neuroinvasion in Syrian hamsters. The HY and DY TME agents can replicate in the nervous system, but the DY TME agent does not replicate in the LRS, and therefore, the DY TME agent is not pathogenic following intraperitoneal (i.p.) inoculation (2, 3). Following intratongue (i.t.) or intranasal (i.n.) inoculation, prion neuroinvasion was independent of scrapie agent replication in the LRS of immunodeficient mice, but evidence for scrapie infection of peripheral nerve fibers or olfactory neurons at these mucosa was lacking. In hamsters, i.t. inoculation of the HY or DY TME agent resulted in PrP^Sc deposition in nerve fibers and prion disease, but only the HY TME agent caused disease following i.n. inoculation. These findings suggest that neuroinvasion from the oral and nasal mucosa in LRS replication-deficient rodents can be independent of LRS infection, but the paucity of PrP^Sc at these mucosal sites of exposure in immunodeficient mice and DY TME-infected hamsters suggests that neuroinvasion is due to either a low-level prion infection of the nervous system at the site of inoculation or transport of the prion agent in axons in the absence of agent replication at the site of prion entry. These findings indicate that these mucosal tissues may not exhibit early evidence of infection and therefore will prove difficult to identify as a portal for agent entry.     

Diffusion Coefficients of Endogenous Cytosolic Proteins from Rabbit Skinned Muscle Fibers

Efflux time courses of endogenous cytosolic proteins were obtained from rabbit psoas muscle fibers skinned in oil and transferred to physiological salt solution. Proteins were separated by gel electrophoresis and compared to load-matched standards for quantitative analysis. A radial diffusion model incorporating the dissociation and dissipation of supramolecular complexes accounts for an initial lag and subsequent efflux of glycolytic and glycogenolytic enzymes. The model includes terms representing protein crowding, myofilament lattice hindrance, and binding to the cytomatrix. Optimization algorithms returned estimates of the apparent diffusion coefficients, D(r,t), that were very low at the onset of diffusion (∼10⁻¹⁰ cm² s⁻¹) but increased with time as cytosolic protein density, which was initially high, decreased. D(r,t) at later times ranged from 2.11 × 10⁻⁷ cm² s⁻¹ (parvalbumin) to 0.20 × 10⁻⁷ cm² s⁻¹ (phosphofructose kinase), values that are 3.6- to 12.3-fold lower than those predicted in bulk water. The low initial values are consistent with the presence of complexes in situ; the higher later values are consistent with molecular sieving and transient binding of dissociated proteins. Channeling of metabolic intermediates via enzyme complexes may enhance production of adenosine triphosphate at rates beyond that possible with randomly and/or sparsely distributed enzymes, thereby matching supply with demand.     

Diffusion Coefficients of Endogenous Cytosolic Proteins from Rabbit Skinned Muscle Fibers

Efflux time courses of endogenous cytosolic proteins were obtained from rabbit psoas muscle fibers skinned in oil and transferred to physiological salt solution. Proteins were separated by gel electrophoresis and compared to load-matched standards for quantitative analysis. A radial diffusion model incorporating the dissociation and dissipation of supramolecular complexes accounts for an initial lag and subsequent efflux of glycolytic and glycogenolytic enzymes. The model includes terms representing protein crowding, myofilament lattice hindrance, and binding to the cytomatrix. Optimization algorithms returned estimates of the apparent diffusion coefficients, D(r,t), that were very low at the onset of diffusion (∼10⁻¹⁰ cm² s⁻¹) but increased with time as cytosolic protein density, which was initially high, decreased. D(r,t) at later times ranged from 2.11 × 10⁻⁷ cm² s⁻¹ (parvalbumin) to 0.20 × 10⁻⁷ cm² s⁻¹ (phosphofructose kinase), values that are 3.6- to 12.3-fold lower than those predicted in bulk water. The low initial values are consistent with the presence of complexes in situ; the higher later values are consistent with molecular sieving and transient binding of dissociated proteins. Channeling of metabolic intermediates via enzyme complexes may enhance production of adenosine triphosphate at rates beyond that possible with randomly and/or sparsely distributed enzymes, thereby matching supply with demand.     

Affinities of Nutty and Green-smelling Pyrazines and Thiazoles to Odorant-binding Proteins, in Relation with their Lipophilicity

Thirty-two green- and/or nutty-smelling compounds, most of thempyrazine and thiazole derivatives, were tested in ligand bindingassays with purified 19 kDa bovine and 22 kDa porcine olfactivebinding proteins (OBPs). Unlike the nutty ones, all the greenodorants were found to be good ligands for both proteins. Lipophilicityappears as an interesting discriminating physicochemical parameter,predictive of the affinity for OBPs and of the related odourprofile. Chem. Senses 20: 601–608, 1995.     

High Expression of Antiviral Proteins in Mucosa from Individuals Exhibiting Resistance to Human Immunodeficiency Virus

Background

Several soluble factors have been reported to have the capacity of inhibiting HIV replication at different steps of the virus life cycle, without eliminating infected cells and through enhancement of specific cellular mechanisms. Yet, it is unclear if these antiviral factors play a role in the protection from HIV infection or in the control of viral replication. Here we evaluated two cohorts: i) one of 58 HIV-exposed seronegative individuals (HESNs) who were compared with 59 healthy controls (HCs), and ii) another of 13 HIV-controllers who were compared with 20 HIV-progressors. Peripheral blood, oral and genital mucosa and gut-associated lymphoid tissue (GALT) samples were obtained to analyze the mRNA expression of ELAFIN, APOBEC3G, SAMHD1, TRIM5α, RNase 7 and SerpinA1 using real-time PCR.

Results

HESNs exhibited higher expression of all antiviral factors in peripheral blood mononuclear cells (PBMCs), oral or genital mucosa when compared with HCs. Furthermore, HIV-controllers exhibited higher levels of SerpinA1 in GALT.

Conclusions

These findings suggest that the activity of these factors is compartmentalized and that these proteins have a predominant role depending on the tissue to avoid the infection, reduce the viral load and modulate the susceptibility to HIV infection.     

Postmortem Changes in Regulatory Proteins of Rabbit Muscle

The procedures for complete extraction of regulatory proteins, particularly troponin and tropomyosin from the myofibrils of fresh and stored muscles were developed and the effect of postmortem storage of muscle on the properties of the regulatory proteins was studied. The ATPase enhancing ability and the sedimentation behavior of α-actinin from post-rigor muscle did not differ from those of α-actinin from pre-rigor muscle. The amounts of both troponin and tropomyosin decreased during the storage of muscle. Troponin decreased more rapidly than tropomyosin. These results were interpreted to support our hypothesis that the structural alteration of myofibril, which is mainly due to the change in the troponin-tropomyosin complex of thin filaments, proceeds during the postmortem storage of muscle.     

An Ex Vivo Porcine Nasal Mucosa Explants Model to Study MRSA Colonization

Staphylococcus aureus is an opportunistic pathogen able to colonize the upper respiratory tract and skin surfaces in mammals. Methicillin-resistant S. aureus ST398 is prevalent in pigs in Europe and North America. However, the mechanism of successful pig colonization by MRSA ST398 is poorly understood. To study MRSA colonization in pigs, an ex vivo model consisting of porcine nasal mucosa explants cultured at an air-liquid interface was evaluated. In cultured mucosa explants from the surfaces of the ventral turbinates and septum of the pig nose no changes in cell morphology and viability were observed up to 72 h. MRSA colonization on the explants was evaluated followed for three MRSA ST398 isolates for 180 minutes. The explants were incubated with 3×10⁸ CFU/ml in PBS for 2 h to allow bacteria to adhere to the explants surface. Next the explants were washed and in the first 30 minutes post adhering time, a decline in the number of CFU was observed for all MRSA. Subsequently, the isolates showed either: bacterial growth, no growth, or a further reduction in bacterial numbers. The MRSA were either localized as clusters between the cilia or as single bacteria on the cilia surface. No morphological changes in the epithelium layer were observed during the incubation with MRSA. We conclude that porcine nasal mucosa explants are a valuable ex vivo model to unravel the interaction of MRSA with nasal tissue.     

变应性鼻炎模型小鼠鼻黏膜的形态学观察

目的:建立小鼠变应性鼻炎模型,观察小鼠鼻腔黏膜组织的重塑情况。方法:20只BALB/c小鼠被随机分为致敏组和对照组,使用卵清蛋白(OVA)诱导建立小鼠变应性鼻炎模型。通过HE染色观察小鼠鼻黏膜的大体重塑情况,吉姆萨染色观察嗜酸性粒细胞,阿辛蓝-过碘酸-希夫染色观察杯状细胞;酶联免疫吸附(ELISA)法检测小鼠血清中白细胞介素-4(IL-4)的水平。结果:小鼠变应性鼻炎模型的生物学行为评分为6.5±1.3,提示造模成功。与对照组相比,致敏组鼻腔黏膜出现上皮细胞脱落、坏死,杯状细胞增生,鳞状上皮化生,固有层和黏膜下层腺体增生、血管扩张,组织水肿,固有层内可见特征性的嗜酸性粒细胞浸润,造模后鼻腔黏膜结构存在重塑。致敏组小鼠鼻黏膜嗜酸性粒细胞计数及杯状细胞计数分别为(26.4±5.72)和(24.14±3.12),而对照组分别是(8.31±2.42)和(9.41±1.22),两组比较均具有统计学差异(P0.05);致敏组血清中白细胞介素4(IL-4)水平为(18.9±3.1)pg/ml,对照组为(8.3±1.4)pg/ml,致敏组显著高于对照组,差异有统计学意义(P0.05)。结论:通过卵清蛋白诱导建立的小鼠变应性鼻炎模型鼻腔黏膜存在组织重塑。     

Effect of Lipopolysaccharide on Glucocorticoid Receptor Function in Control Nasal Mucosa Fibroblasts and in Fibroblasts from Patients with Chronic Rhinosinusitis with Nasal Polyps and Asthma

BackgroundChronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic inflammatory disease of the upper airways frequently associated with asthma. Bacterial infection is a feature of CRSwNP that can aggravate the disease and the response to glucocorticoid treatment.ObjectiveWe examined whether the bacterial product lipopolysaccharide (LPS) reduces glucocorticoid receptor (GR) function in control nasal mucosa (NM) fibroblasts and in nasal polyp (NP) fibroblasts from patients with CRSwNP and asthma.MethodsNP (n = 12) and NM fibroblasts (n = 10) were in vitro pre-incubated with LPS (24 hours) prior to the addition of dexamethasone. Cytokine/chemokine secretion was measured by ELISA and Cytometric Bead Array. GRα, GRβ, mitogen-activated protein-kinase phosphatase-1 (MKP-1) and glucocorticoid-induced leucine zipper (GILZ) expression was measured by RT-PCR and immunoblotting, GRα nuclear translocation by immunocytochemistry, and GRβ localization by immunoblotting. The role of MKP-1 and GILZ on dexamethasone-mediated cytokine inhibition was analyzed by small interfering RNA silencing.ResultsPre-incubation of nasal fibroblasts with LPS enhanced the secretion of IL-6, CXCL8, RANTES, and GM-CSF induced by FBS. FBS-induced CXCL8 secretion was higher in NP than in NM fibroblasts. LPS effects on IL-6 and CXCL8 were mediated via activation of p38α/β MAPK and IKK/NF-κB pathways. Additionally, LPS pre-incubation: 1) reduced dexamethasone’s capacity to inhibit FBS-induced IL-6, CXCL8 and RANTES, 2) reduced dexamethasone-induced GRα nuclear translocation (only in NM fibroblasts), 3) did not alter GRα/GRβ expression, 4) decreased GILZ expression, and 5) did not affect dexamethasone’s capacity to induce MKP-1 and GILZ expression. MKP-1 knockdown reduced dexamethasone’s capacity to suppress FBS-induced CXCL8 release.ConclusionThe bacterial product LPS negatively affects GR function in control NM and NP fibroblasts by interfering with the capacity of the activated receptor to inhibit the production of pro-inflammatory mediators. This study contributes to the understanding of how bacterial infection of the upper airways may limit the efficacy of glucocorticoid treatment.     

A Fibrin Matrix Promotes the Differentiation of EMSCs Isolated from Nasal Respiratory Mucosa to Myelinating Phenotypical Schwann-Like Cells

Because Schwann cells perform the triple tasks of myelination, axon guidance and neurotrophin synthesis, they are candidates for cell transplantation that might cure some types of nervous-system degenerative diseases or injuries. However, Schwann cells are difficult to obtain. As another option, ectomesenchymal stem cells (EMSCs) can be easily harvested from the nasal respiratory mucosa. Whether fibrin, an important transplantation vehicle, can improve the differentiation of EMSCs into Schwann-like cells (SLCs) deserves further research. EMSCs were isolated from rat nasal respiratory mucosa and were purified using anti-CD133 magnetic cell sorting. The purified cells strongly expressed HNK-1, nestin, p75^NTR, S-100, and vimentin. Using nuclear staining, the MTT assay and Western blotting analysis of the expression of cell-cycle markers, the proliferation rate of EMSCs on a fibrin matrix was found to be significantly higher than that of cells grown on a plastic surface but insignificantly lower than that of cells grown on fibronectin. Additionally, the EMSCs grown on the fibrin matrix expressed myelination-related molecules, including myelin basic protein (MBP), 2′,3′-cyclic nucleotide 3′-phosphodiesterase (CNPase) and galactocerebrosides (GalCer), more strongly than did those grown on fibronectin or a plastic surface. Furthermore, the EMSCs grown on the fibrin matrix synthesized more neurotrophins compared with those grown on fibronectin or a plastic surface. The expression level of integrin in EMSCs grown on fibrin was similar to that of cells grown on fibronectin but was higher than that of cells grown on a plastic surface. These results demonstrated that fibrin not only promoted EMSC proliferation but also the differentiation of EMSCs into the SLCs. Our findings suggested that fibrin has great promise as a cell transplantation vehicle for the treatment of some types of nervous system diseases or injuries.     

三种花生幼胚蛋白质提取方法比较研究

植物组织(或细胞)的蛋白质提取效率与效果直接影响蛋白质双向凝胶电泳等实验的结果。为探索建立适用于花生幼胚蛋白质(双向凝胶电泳用)提取的最佳条件,尝试了磷酸缓冲液直接提取法、改良的荔枝胚胎蛋白提取法和Trizol(附加)提取法等3种提取方法,根据蛋白提取得率、试剂成本、双向电泳图谱的质量(蛋白质斑点的丰度、分布特点)进行初步评价。结果表明,磷酸缓冲液直接提取法简单但总体效果较差,改良的荔枝胚胎蛋白提取法综合评价最好,与双向凝胶电泳条件更兼容。     

三种李斯特菌菌体蛋白提取方法的比较

通过对3种李斯特菌菌体蛋白提取方法主要是破壁方式的比较,找到一种可高效提取李斯特菌菌体蛋白的方法,为该菌的深入研究提供可靠技术。以绵羊李斯特菌新鲜液体培养物为材料,收集菌沉淀,分别选用3种破壁方式破除细胞壁,三氯乙酸(trichloroacetic acid,TCA)-丙酮沉淀法沉淀破壁液中的菌体蛋白,采用聚丙烯酰氨凝胶电泳(sodium dodecyl sulfate polyacrylamide gel electrophoresis,SDS-PAGE)和Western-blot分析所得菌体蛋白。溶菌酶-超声破壁-TCA-丙酮沉淀法提取得到的李斯特菌菌体蛋白SDS-PAGE条带清晰丰富,Western-blot条带特异。溶菌酶-超声破壁-TCA-丙酮沉淀法可有效提取李斯特菌菌体蛋白,满足常用蛋白分析技术的要求,是一种提取李斯特菌菌体蛋白的可靠方法。