Detoxification of LTA by intracanal medication: analysis by macrophages proinflammatory cytokines production

Abstract The aim of this study was to evaluate in vitro the effect of calcium hydroxide [Ca(OH)2], 2% chlorhexidine gel (CHX) on macrophages (RAW 264.7) to produce pro-inflammatory cytokines and nitric oxide after pretreatment with lipoteichoic acid (LTA) of Enterococcus faecalis. Forty-eight human single-rooted teeth were instrumented with R25.08 (RECIPROC) and sterilized by gamma irradiation. LTA was inoculated in the root canal of each specimen for 96 hours. Specimens were instrumented with 40.06 and 50.05 (RECIPROC) and medicated with: I) Pyrogen-free saline solution (SS); II) 2% CHX gel; III) Ca(OH)2 + SS; or IV) Ca(OH)2 + CHX for 14 days. Three samples (S) were performed of the root canal of each specimen at: S1) immediately after instrumentation; S2) after Ethylenediaminetetraacetic acid (EDTA); S3) after intracanal medication removal. Subsequent quantification of cytokines (IL-1β, TNF-α, MIP-1α, IP-10, G-CSF and IL-6) by immunosorbent assay (ELISA) and nitric oxide by the Griess method was carried-out. Data were submitted to a normality test and then analyzed with one-way ANOVA and Tukey test with a significance level of 5% using GraphPad Prism 6. Ca(OH)2 + SS and Ca(OH)2 + CHX presented lower levels of TNF-α, TNF-α, IL-6, G-CSF and nitric oxide. Ca(OH)2 + SS was the most effective in reducing MIP-1α. CHX was effective in reducing IL-6 and G-CSF. Therefore, the combined intracanal medication of calcium hydroxide and chlorhexidine is effective in reducing the cytokines TNF-α, IL-1β, IL-6, G-CSF and nitric oxide.

Resumo O objetivo deste estudo foi avaliar in vitro o efeito do hidróxido de cálcio [Ca(OH)2], clorexidina gel a 2% (CHX) em macrófagos (RAW 264.7) na produção de citocinas pró-inflamatórias e óxido nítrico após pré-tratamento com ácido lipoteicóico (LTA) de Enterococcus faecalis. Quarenta e oito dentes humanos uniradiculares foram instrumentados com R25.08 (RECIPROC) e esterilizados por irradiação gama. LTA foi inoculado no canal radicular de cada espécime por 96 horas. Os espécimes foram instrumentados com 40.06 e 50.05 (RECIPROC) e medicados com: I) solução salina apirogênica (SS); II) CHX 2%; III) Ca(OH)2 + SS; ou IV) Ca(OH)2 + CHX durante 14 dias. Três amostras (S) foram realizadas do canal radicular de cada espécime em: S1) imediatamente após a instrumentação; S2) após ácido etilenodiaminotetracético (EDTA); S3) após a retirada da medicação intracanal. Foi realizada a quantificação subsequente de citocinas (IL-1β, TNF-α, MIP-1α, IP-10, G-CSF e IL-6) por imunoensaio (ELISA) e de óxido nítrico pelo método de Griess. Os dados foram submetidos a um teste de normalidade e então analisados com ANOVA one-way e teste de Tukey com nível de significância de 5% usando GraphPad Prism 6. Ca(OH)2 + SS e Ca(OH)2 + CHX apresentaram níveis mais baixos de TNF -α, TNF-α, IL-6, G-CSF e óxido nítrico. Ca(OH)2 + SS foi o mais eficaz na redução de MIP-1α. CHX foi eficaz na redução de IL-6 e G-CSF. Sendo assim a associação de hidróxido de cálcio e clorexidina é eficaz na redução das citocinas TNF-α, IL-1β, IL-6, G-CSF e óxido nítrico.

Endodontic biofilms: contemporary and future treatment options

Apical periodontitis is a biofilm-mediated infection. The biofilm protects bacteria from host defenses and increase their resistance to intracanal disinfecting protocols. Understanding the virulence of these endodontic microbiota within biofilm is essential for the development of novel therapeutic procedures for intracanal disinfection. Both the disruption of biofilms and the killing of their bacteria are necessary to effectively treat apical periodontitis. Accordingly, a review of endodontic biofilm types, antimicrobial resistance mechanisms, and current and future therapeutic procedures for endodontic biofilm is provided.

Study of regulatory effect of Astragalus injection on inflammatory response of sepsis / 中国中西医结合急救杂志

Objective To observe the effect of Astragalus injection on the expressions of inflammatory cytokines in human primary macrophages stimulated by lipoteichoic acid (LTA) and lipopolysaccharide (LPS),and investigate its effects on inflammatory reactions of Gram-positive (G+) and Gram-negative (G-) bacteria sepsis and its mechanisms.Methods Percoll density gradient centrifugation was used to isolate the human peripheral blood mononuclear cells,then they were purified by immune Anti-Biotin Microbeads with magnetic character and under the induction of recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF),the cells were cultivated for 12 days in vitro,eventually the human monocyte-derived macrophage was formed.The cultured human macrophages were inoculated in 96-well plates (each group 3 wells) and 6-well plates (each group 3 wells).The cells were divided into control group (200 μL DMEM added in each well),LTA 1 mg/L group,LPS 0.1 mg/L group and low astragalus injection (0.1 mg/L) and high astragalus injection (0.2 mg/L) dose groups.After the incubator plates were put in an incubator for 24 hours,the protein content of IL-8 and IL-10 in supernatant were detected by enzymelinked immunosorbent assay (ELISA),and the mRNA expression levels of IL-8 and IL-10 were detected by real time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-qPCR).Results LTA and LPS all can obviously up-regulate the expression levels of pro-inflammatory factor IL-8 and anti-inflammatory factor IL-10 of macrophage.The expressions of IL-8 and IL-10 protein and mRNA in LTA group and LPS group were significantly higher than those in control group after cuhure for 8 hours and 24 hours,the degrees of increment were more significantly at 24 hours [LTA stimute group:IL-8 protein (ng/L,× 103):41.57± 1.90 vs.1.58 ±0.24,IL-8 mRNA (A value):21.49±8.05 vs.1.00±0.16;IL-10 protein (ng/L):5.90±3.02 vs.2.91 ± 1.54,IL-10 mRNA (A value):1.35±0.34 vs.0.95±0.14;LPS stimute group:IL-8 protein (ng/L,× 103):345.00±22.80 vs.5.60±0.31,IL-8 mRNA (A value):29.84 ± 8.93 vs.1.00 ± 0.16,IL-10 protein (ng/L):122.37 ± 39.26 vs.44.79 ± 3.67,IL-10 mRNA (A value):7.38 ± 1.58 vs.1.35 ± 0.34,all P ＜ 0.05].The Astragalus injection could regulate LTA and LPS to stimulate the macrophage to decrease the expression levels of pro-inflammatory factor IL-8 protein and mRNA and increase the expression levels of anti-inflammatory factor IL-10 protein and mRNA in the macrophage;the changes of regulatory effect in the 24 hour-culture of Astragalus injection high dose group was the most significant [LTA stimute group:IL-8 protein (ng/L,×103):22.63±1.91 vs.41.57±1.90,IL-8 mRNA (A value):12.10±1.93 vs.21.49±8.05,IL-10 protein (ng/L):14.03±2.22 vs.5.90±3.02,IL-10 mRNA (A value):10.37±6.08 vs.1.35±0.34;LPS stimute group:IL-8 protein (ng/L,× 103):167.75 ± 19.90 vs.345.01 ±22.80,IL-8 mRNA (A value):15.61 ± 3.63 vs.29.84±8.93;IL-10 protein (ng/L):243.22±14.41 vs.122.37±39.26,IL-10 mRNA (A value):16.14±4.10 vs.7.38± 1.58,all P ＜ 0.05].Conclusions In the process of inflammatory response,the pro-inflammatory and anti-inflammatory factors co-exist simultaneously.Astragalus injection can inhibit the expression levels of pro-inflammatory factor gene and protein in the inflammatory response of G+ and G-bacteria sepsis and in the mean time,it can promote the expression levels of anti-inflammatory factor gene and protein,thus the immune mechanism of sepsis is affected,achieving the balance between pro-inflammation and anti-inflammation.

Molecular mechanism of osteoclast differentiation induced by staphylococcal lipoteichoic acid / 实用医学杂志

Objective To investigate the molecular mechanism of osteoclast differentiation induced by staphylococcal lipoteichoic acid (LTA-sa). Methods Raw264.7 cells were treated with LTA-sa in a concentration of 200 ng/mL for 0, 5, 10, 20, 40, 60 min and 0, 1, 2, 3 days respectively, and the proteins in signaling pathways associated with osteoclast differentiation were measured with western blot. In addition, Raw264.7 cells were treated with different concentrations of LTA-sa (100, 200 and 400 ng/mL) and PBS for 0, 1, 2, 3 days, the expression of TNF-α, IL-1α and IL-6 was detected with Enzyme linked immunosorbent assay (ELISA). Results (1)Western blot showed that, under stimulation of LTA-sa, IκB-α decreased at 5 min and 10 min, while the phosphorylation of nuclear factor κB increased at 10 min . In addition , NFATc1 increased in 2 and 3 days gradually. The above results were statistically analyzed, and the difference was significant in statistics (P < 0.001). (2)ELISA showed that the expression of IL-6 increased in 2 and 3 days along with the increasing concentration and prolonging stimulation time of LTA-sa. Data were statistically analyzed, the difference was significant in statistics (P < 0.001). Conclusion LTA-sa promotes osteoclast differentiation through the NF-κB signaling pathway and the secretion of IL-6.

Effect of bifidobacterial lipoteichoic acid on cellular immunity of mice with systemic Candida albicans infection / 重庆医学

Objective To observe the effect of bifidobacterial lipoteichoic acid (BLTA) on cellular immunity of mice with systemic Candida albicans infection .Methods Systemic C .albicans infection model in immunocompromised mice were established by injecting standard strain of C .albicans via caudal vein .The effects of BLTA on thymus index ,spleen index ,splenic lymphocytes proliferation and NK cells cytotoxicity were observed as well as serum levels of cytokines .Results After systemic C .albicans infec‐tion in immunocompromised mice ,thymus index ,spleen index and splenic lymphocytes proliferation activity were decreased (P>0 .05) ,NK cells cytotoxicity was decreased significantly (P0 .05) ,IL‐10 levels were increased significantly(P<0 .05) .After treated by BLTA ,thymus index ,spleen index ,splenic lymphocytes proliferation and NK cells cytotoxicity were increased significantly (P<0 .01) ,IL‐2 and INF‐γ levels were increased significantly (P<0 .05) ,IL‐4 levels showed little change ,IL‐10 levels were decreased significantly (P<0 .01) .Conclusion BLTA can improve immune status of immunocompromised mice ,which can restore and enhance the compromised cellular immunity of mice with sys‐temic C .albicans infection .

Anti-neuro-inflammatory effects of Nardostachys chinensis in lipopolysaccharide-and lipoteichoic acid-stimulated microglial cells / 中国天然药物

Excessive microglial cell activation is related to the progression of chronic neuro-inflammatory disorders. Heme oxygenase-1 (HO-1) expression mediated by the NFE2-related factor (Nrf-2) pathway is a key regulator of neuro-inflammation. Nardostachys chinensis is used as an anti-malarial, anti-nociceptive, and neurotrophic treatment in traditional Asian medicines. In the present study, we examined the effects of an ethyl acetate extract of N. chinensis (EN) on the anti-neuro-inflammatory effects mediated by HO-1 up-regulation in Salmonella lipopolysaccharide (LPS)- or Staphylococcus aureus lipoteichoic acid (LTA)-stimulated BV2 microglial cells. Our results indicated that EN suppressed pro-inflammatory cytokine production and induced HO-1 transcription and translation through Nrf-2/antioxidant response element (ARE) signaling. EN markedly inhibited LPS- and LTA-induced activation of nuclear factor-kappa B (NF-κB) as well as phosphorylation of mitogen-activated protein kinases (MAPKs) and signal transducer and activator of transcription (STAT). Furthermore, EN protected hippocampal HT22 cells from indirect neuronal toxicity mediated by LPS- and LTA-treated microglial cells. These results suggested that EN impairs LPS- and LTA-induced neuro-inflammatory responses in microglial cells and confers protection against indirect neuronal damage to HT22 cells. In conclusion, our findings indicate that EN could be used as a natural anti-neuro-inflammatory and neuroprotective agent.

Screening and identification of peptide mimics to lipoteichoic acid by phage displayed random peptide library / 中国免疫学杂志

Objective:To screen epitope mimics to lipoteichoic acid from a random 12-mer phage display peptide library and i-dentify the specificity of the mimotopes of LTA.Methods:The monoclonal antibody against LTA was used as a target to screen the 12-mer phage display peptide library and the specificity of phage clones were identified by sandwich ELISA.The amino acid sequences of positive phage clones were deduced from DNA sequencing.The specificity of synthetic peptide were identified by sandwich ELISA.Results:4 clones were obtained after 3 rounds of screening.Amino acid sequence analysis revealed four different types of mimotope sequence.A linear peptide (GHxDFRQxxQPS),named L2,which derived from positive sequence was synthesized.ELISA result indicates that L2 can bind to anti-LTA mAb specifically in a dose-dependent manner.Conclusion:The mimotopes of LTA were obtained by using the phage display technology.

Mechanism of Action of Antimicrobial Peptides Against Bacterial Membrane

Resistance to antibiotics is becoming a very serious problem, with so-called superbugs exhibiting resistance to nearly all conventional antibiotic drugs. Consequently, these organisms often cause severe illness and even death. Alternatives to conventional antibiotics are antimicrobial peptides (AMPs). These widely expressed short peptides, which have been isolated from insects, plants, marine organisms and mammals, including humans, show strong antimicrobial activity against both Gram-negative and Gram-positive bacteria. Most AMPs act by disrupting the bacterial membrane through "Barrel-stave", "Toroidal pore", "carpet" mechanism. In addition, AMPs may prevent septic shock through strongly binding lipopolysaccharides and lipoteichoic acid located on the bacterial membrane. The action mechanisms of AMP to minimize the likelihood developing resistance to the peptides would be particular advantage. For these reasons, we anticipate that AMPs will replace conventional antibiotic drugs in a variety of contexts.

Efecto del ácido lipoteicoico sobre la expresión de genes en cardiomiocitos de ratón (H9c2) / Effect of lipoteichoic acid on gene expression in mice (H9c2) cardiomyocite

La mayoría de las enfermedades de la pulpa dental y de los tejidos perirradiculares guardan relación con microorganismos. Los peptidoglucanos y el ácido lipoteicoico son dos de los principales componentes de las bacterias Gram positivas que tienen actividades relacionadas con el desarrollo de sepsis. Tras la invasión microbiana de estos tejidos, el huésped responde con defensas tanto inflamatorias inespecíficas como inmunológicas específicas. El tratamiento endodóncico quirúrgico y no quirúrgico son en esencia, procedimientos de desbridamiento destinados a destruir y eliminar el ecosistema microbiano, asociado con el proceso patológico. Es importante que los clínicos comprendan la íntima relación entre presencia de microorganismos y enfermedad endodóncica, con el fin de diseñar un tratamiento racional y efectivo; sobre todo en aquellos individuos susceptibles a Endocarditis Infecciosa. En el presente estudio se investigó la expresión de TNFα, IL-1 y COX-2 por efecto del ácido lipoteicoico (ALT) de Streptococcus sanguinis caracterizando las señales intracelulares involucradas en cardiomiocitos H9c2. La línea celular fue tratada con ALT a diferentes concentraciones durante 30 minutos. Comparadas con los controles, las respuestas al tratamiento con ALT fueron dependientes de la dosis y mediante un análisis de One Step RT-PCR (Invitrogen) se evaluó dicha expresión; la cual se asemeja a la respuesta fisiológica del organismo durante un episodio de Endocarditis infecciosa y a la agudización durante un procedimiento endodóncico.

Most dental pulp diseases and diseases of tissues surrounding the root are somehow related to micro-organisms. Peptidoglycans and lipoteichoic acid are two of the main Gram-positive bacteria components with activities related to sepsis development. When tissues sustain microbial invasion the host responds with both unspecific inflammatory defenses and specific immunological reactions. Surgical and non surgical endodontic treatments are essentially debridement procedures intended to destroy and eliminate the microbial eco-system associated to the pathological process. It is essential for clinicians to understand the intimate relationship existing between micro-organisms and endodontic disease, so as to be able to tailor a rational and effective treatment especially in subjects susceptible to infective endocarditis processes. In the present study research was conducted on TNFα, IL-1 COX-2 expression through the effect of lipoteichoic acid (LTA) of Streptococcus sanguinis by characterizing intra-cellular signals involved in H9c'' cardiomyocytes. The cell line was treated with LTA at different concentrations during 30 minutes. When compared to control group, responses to LTA treatment were dependent on dosage. That expression was assessed by means of a One Step RT-PCR (Invitrogen) analysis. It was noted that the aforementioned expression resembled the organisms's physiological response during an infective endocarditis episode and to exacerbation observed during an endodontic procedure.

Influence of moxifloxacin on lipoteichoic acid induced apoptosis and expression of inflammatory cytokines in human alveolar macrophage / 中华微生物学和免疫学杂志

Objective To investigate the lipoteichoic acid(LTA) induced apoptosis and the expression of inflammatory cytokines in human alveolar macrophage (AM) and the anti-apoptotic and anti-inflamatory effect of moxifloxacin (MXF).Methods Obtained human AM from bronchoalveolar lavage and used MTT assay to observe the effects of LTA and MXF on cell activity,optical microscope to investigate the change of the cell morphology,flow cytometry to assess cell apoptosis,RT-PCR to detect the mRNA levels of TLR2,IL-1 β,IL-8 and TNF-α,ELISA for the production of IL-8 to exam RT-PCR.Results LTA showed cytotoxicity on AM in a dose-dependent manner ( P＜0.05 ) ; MXF inhibited the effect of LTA without cytotoxicicy ( P＜0.05 ).LTA promoted apoptosis ( P＜0.05 ) and the mRNA expressions of TRL2,IL-1 β,IL-8 and TNF-α significantly in AM (P＜0.05),the peaks and peak time ofthe above factors were (3.56±0.03) at 12 h,(46.63±7.06) at 6 h,(28.07±1.24) at 12 h and (2.34 ±0.50) at 3 h respectively and increased the release of IL-8 protein level at 24 h (P＜0.05).MXF inhibited the cell apoptosis and the above mRNA expression at 12h ( P＜0.05 ),and inhibited the IL-8 protein level at 24 h( P＜0.05 ).Conclusion LTA showed cytotoxicity on AM,induced AM apoptosis and increased the expression of TLR2,IL-I β,IL-8 and TNF-α of AM ; MXF could protect AM through inhibiting of the above effects and may play a key role beside bactericidal effect in gram-positive bacteria pneumonia.

Effect of Lipoteichoic Acid on Phagocytosis of Peritoneal Macrophages and NO Production in vitro / 华中科技大学学报(医学版)

Objective To explore the effects of lipoteichoic acid(LTA)on phagocytosis of peritoneal maerophages and NO production in vitro.Methods The peritoneal macrophages that were isolated sterilely from Kunming mice were divided into two groups:co-culture with RPMI 1640,and pretreatment with dexamethasone(DEX).Then,the LTA isolated from BFA with different final concentrations(5,10,20 and 40 ug/ml) was added.After the peritoneal macrophages were cultured for 4 and 24 h,the effects of LTA on cytophagocytesis and NO production in vitro were determined respectively by using neutral red and NO assay kit.Results LTA with final concentrations of 5,10,20 and 40/μg/mL significantly promoted the phagocytosis of peritoneal macrophages and production of NO(P<0.05).It also effectively antagonized the inhibitory response of DEX against peritoneal macrophages(P<0.05).The higher concentration of LTA,the stronger effect.Conclusion Not only can LTA stimulate and activate the peritoneal macrophages significantly,but also antagonize the inhibition from DEX in vitro.

Effect of nano-sized-Fe3O4-lipoteichoic acid from Bifidobacterium on cytokine expression in human gastric cancer in nude mice / 中华微生物学和免疫学杂志

Objective To investigate the effect of lipoteichoic acid from Bifidobacterium loaded with magnetic particle nano-sized-Fe3O4(nano-sized-Fe3O4-BLTA)on several cytokines in vivo expression in beterologous graft model for human gastric cancer in nude mice.and to analyze the inhibition mechanism of nano-sized-Fe3 O4-BLTA on BGC-823 human gastric carcinoma transplanted tumor.Methods Forty male nude mice(BALB/e.nu/nu)were used for in vivo transplant tumor model.the experimental animals were randomly divided into five groups to administrated by several dosages of Hano-sized-Fe3 O4-BLTA,and were executed after 12 d.The tumors were collected and photographed.and the tumor tissues were used for differ-ent assays for measuring tumor inhibition.The peritoneal fluid was extracted to isolate the macrophages for cytokines assays.Using irmnunohistochemical staining for vascular endothelial growth factor(VEGF)and CD3 l in tumor to investigate the tumor inhibition rate.Double antibody sandwich ELISA was used to detect the level of cytokine change.Results The mice treated with low dosage(10 μg/d)of nano-sized-Fe3O4-BLTA.the growth inhibifion rate of tumor was 49%,and the levels of VEGF(0.0224±0.0763)and CD31 (57.000 4±6.790)were lower than other treated groups(P<0.01).The high dosage(100μg/d)and me-dium dosage(50μg/d)of nano-sized-Fe3 O4-BLTA groups were significant difference(P<0.01)on the content of cytokines excreted by macrophages.The level of TNF-α(39.4040 ±-1.5590)induced by the low dosage group was higher relatively(P<0.01).Conclusion Nano-sized-Fe3O4-BLTA exerts an inhibiting effect on the growth of human gastric cancer in nude mice.Using nano-sited-Fe3 O4-BLTA,LTA can get more permeability and improve the therapy effect.which will be a new drug on the stomach cancer targeted therapy.

Expression of Toll-like Receptor 4 on Human Keratinocytes by Lipoteichoic Acid / 대한피부과학회지

BACKGROUND: We have recently shown that lipopolysaccharide (LPS), a major biologically active component of Gram-negative bacteria, mediate the activation of human keratinocytes by CD14 and Toll-like receptor (TLR 4). However, the mechanism of activation of keratinocytes by Gram-positive bacterial toxins remains unclear. OBJECTIVE: We investigated the mechanism of activation of human keratinocytes by lipoteichoic acid (LTA), a main stimulatory component of Gram-positive bacteria. METHODS: The effects of LTA on CD14, TLR2 and TLR4 mRNA expression were measured by quantitative RT-PCR in cultured human keratinocytes. To determine whether the effects of LTA on CD14, TLR2 and TLR4 expressions of the human keratinocytes were biologically functional, NF-kappaB nuclear translocation and IL-1alpha secretion were measured by immunofluorescence staining and ELISA, respectively. Furthermore, to determine whether these effects by LTA were specific for CD14, TLR2 and TLR4, some cells were pretreated with anti-CD14, anti-TLR2, or anti-TLR2 monoclonal antibodies prior to the addition of LTA. RESULTS: TLR4 mRNA expression on keratinocytes was augmented by exposure to LTA. LTA binding to keratinocytes resulted in NF-kappaB nuclear translocation and secretion of interleukin-1alpha. These responses by LTA were effectively abrogated by preincubating cells with anti-TLR4 monoclonal antibody, but not with anti-CD14 or anti- TLR2 monoclonal antibodies. CONCLUSION: These results indicate that, similar to LPS, LTA induces activation of human keratinocytes mainly through TLR4, however, in contrast to LPS signaling, LTA-induced keratinocyte activation is CD14-independent.

Endogenous nitric oxide mediates lipoteichoic acid induced preconditioning on reoxygenation injury of cultured human coronary artery endothelial cells / 药学学报

Aim To explore the effects of lipoteichoic acid (LTA) induced delayed preconditioning (PC) on hypoxia-reoxygenation (H/R) injury of cultured human coronary artery endothelial cells (HCAECs), and to investigate the potential role of endogenous nitric oxide (NO) participated in the protective mechanism. Methods HCAECs were incubated for 2 h in a hypoxic atmosphere and reoxygenated for 4 h in a normoxic atmosphere. The delayed PC was induced by pretreatment with LTA assessed by the percentage of cellular injury with Trypan blue exclusion and by the amount of lactate dehydrogenase (LDH) in culture media. The NO level of the culture media was measured detect the expression of eNOS mRNA by RT-PCR method after cells were recovered from different points.Results LTA pretreatment significantly decreased the percentage of the killed cell and the concentration of LDH in media. Also, LTA pretreatment obviously raised the concentrations of NO in culture media. The protective effects of LTA were abrogated by pretreatment with N-monomethyl-L-arginine (L-NMMA).Moreover, the expression of eNOS mRNA was significantly upregulated after HCAECs exposure to LTA for 4 h following 2 h or 4 h recovery. Conclusion LTA could induce the delayed protection against H/R induced endothelial injury and dysfunction of cultured HCAECs. NO produced by eNOS acts initially as a trigger and subsequently as a mediator of delayed PC.

Expression of Human beta Defensin-2 in HaCaT Cell by Lipoteichoic Acid and Peptidoglycan / 대한피부과학회지

BACKGROUND: Defensin, a major family of antimicrobial peptides, is small cationic, cysteine rich peptides with wide range of antimicrobial activity against Gram negative and Gram positive bacteria, fungi, yeast, and virus. Expression of human defensin-2 is upregulated by bacteria, virus, fungus and pro-inflammatory cytokines. However, this peptide was found to be only bacteriostatic, but not bactericidal, against the Gram positive bacteria. OBJECTIVE: To evaluate human defensin-2 (hBD-2) expression after exposure of human skin keratinocytes to the cell wall component of Gram positive bacteria such as lipoteichoic acid (LTA) and peptidoglycan(PEN), and to compare quantitatively the amount of expression with that after their exposure to the cell wall component of Gram negative bacteria. METHODS: Expression of hBD-2 was measured by reverse transcription polymerase chain reaction (RT-PCR), Western blotting, and immunohistochemistry(IHC). RESULTS: 1. In RT-PCR results, the amount of hBD-2 expression after exposure to LPS was larger than those of PEN and LTA at 6 and 12 hours (p=0.02). At 24 hours, hBD-2 expression showed a peak in PEN stimulated group (p=0.09). 2. In Western blot analysis, hBD-2 expressions, when treated with PEN and LTA, were stronger than that treated with LPS at 6 and 12 hours. 3. In IHC, hBD-2 was stained much stronger in LPS stimulated group than PEN or LTA stimulated groups at 12 hours. CONCLUSION: Our study demonstrated that exposure of human skin keratinocytes to the cell wall components of Gram positive bacteria such as LTA and PEN triggered production of hBD-2 in addition to the cell wall component of Gram negative bacteria such as LPS, however, the amounts of expression were relatively stronger in LPS treated group.

Lipoteichoic acid of Bifidobacterium down-regulates VEGF expressions and inhibits the metastasis of colon carcinoma / 第三军医大学学报

Objective To study the effect of lipoteichoic acid(LTA) of Bifidobacterium on the expression of vascular endothelial growth factor(VEGF) and invasion and metastasis of colon carcinoma cell lines.Methods The effects of LTA on adhesion,invasion and metastasis of human colon carcinoma lines LoVo and HT-29 in vitro were examined by MTT colorimetric and transwell chamber.The mRNA and protein expressions of VEGF in the two colon carcinoma cells treated with LTA were detected by RT-PCR and Western blot.Results The adhesion ability decreased in LoVo cells and HT-29 cells after the treatment of LTA(20,50,80 ?g/ml) for 30,60,90,120 min(P

Effects of lipoteichoic acid-induced delayed preconditioning on cardioplegic arrest/reperfusion injury in donor rat heart / 中国病理生理杂志

AIM: To study the potential effects of lipoteichoic acid (LTA)-induced delayed preconditioning (PC) on cardioplegic arrest/reperfusion injury in donor rat heart. METHODS: The rats were pretreated with LTA (1 mg/kg, ip) 24 h before the experiment, and the isolated hearts were subjected to arrested by cardioplegic solution and stored in Eurocollin's solution for 4 h by the Langendorff method, and to evaluate the changes of cardiac function at the reperfusion for 30 min and 60 min, to measure the amounts of MB isoenzyme of creatine kinase (CK-MB), lactate dehydrogenase (LDH) and total nitric oxide (NO) oxidation products in the coronary effluent, and to detect myocardial apoptosis on tissue samples of left ventricle at the end of reperfusion by TUNEL staining. RESULTS: Pretreated with LTA significantly improved the recovery of cardiac function with a significant increase in coronary flow (CF), left ventricular developed pressure (LVDP), maximal rate of left ventricular developed pressure (+dp/dt_ max), and minimal rate of left ventricular decline pressure (-dp/dt_ max) at 30 min and 60 min of reperfusion (all P

Study on delaying immunosenescent by lipoteichoic acid of bifidobacterium / 中国免疫学杂志

Objective:To explore molecule mechanism about anti-aging of bifidobacterium by investigating the effect of lipoteichoic acid (LTA) of bifidobacterium on thymus of aging mice induced by D-galactose.Methods:Male Kunming mice were divided into different groups at random. These mice were induced aging by subcutaneous injection of D-galactose on the back of mice and LTA was simultaneously administered to them daily for 40 days. Body weight, thymus index ,thymus morphology, thymus c-fos, p16 production and peripheral blood IL-2 concentration were tested by HE staining, immunochemistry method, ELISA and other methods. Results:There were significant differences for body weight ,thymus index, thymus morphology,thymus p16, c-fos production and peripheral blood IL-2 concentration between the young control group and the aging model group. Whereas, LTA can improve thymus morphology ,increase body weight ,thymus index and c-fos production, meamwhile, decrease thymus p16 and peripheral blood IL-2 concentration of aging model mice. Conclusion:The results showed that LTA can remarkably delay thymus aging, and it may be a molecular mechanism of bifidobacterium delaying immunosenescent.