Zymosan足底炎性疼痛大鼠模型的建立及其脊髓背角COX-2表达水平变化

目的评价该模型大鼠的疼痛行为学特点和炎性水肿程度,并对该模型大鼠脊髓背角COX-2表达水平进行分析。方法 SD大鼠48只,随机分为3组,即对照组(n=8)、假手术组(n=16)及zymosan组(n=24)。按Meller方法制作zymosan足底炎性疼痛模型,假手术组在左侧后足皮下注射同等容积的PBS。采用电子VonFrey压力测痛仪、热板和电子数显卡尺分别于制模后0.5h、1h、2h、4h、8h、24h和48h测定各组大鼠左侧后足机械刺激缩足阈值、热敏缩足反射阈值和左足最大厚度。各组大鼠在指定时间点处死后取制模侧腰段脊髓背角,采用Western blot方法测定脊髓背角中COX-2表达水平。结果与对照组和假手术组比较,zymosan组大鼠制模侧后足机械刺激缩足阈值和热敏缩足反射阈值显著降低(P<0.05,P<0.01),最大厚度显著增加(P<0.01),提示zymosan组大鼠出现机械痛敏、热痛敏和炎性水肿。Zymosan组大鼠制模侧脊髓背角COX-2表达水平显著增加,与对照组和假手术组比较有显著性差异(P<0.05)。结论 Zymosan足底炎性疼痛大鼠模型可以产生持续的、可信的痛觉过敏,与人体损伤后情况基本一致,并诱导脊髓背角COX-2表达水平增加,是研究组织损伤诱发炎性疼痛机制的较佳选择。

Dimethyl sulfoxide inhibits zymosan-induced intestinal inflammation and barrier dysfunction

AIM: To investigate whether dimethyl sulfoxide(DMSO) inhibits gut inflammation and barrier dysfunction following zymosan-induced systemic inflammatoryresponse syndrome and multiple organ dysfunction syndrome.METHODS: Sprague-Dawley rats were randomly divided into four groups: sham with administration of normal saline(SS group); sham with administration of DMSO(SD group); zymosan with administration of normal saline(ZS group); and zymosan with administration of DMSO(ZD group). Each group contained three subgroups according to 4 h,8 h,and 24 h after surgery. At 4 h,8 h,and 24 h after intraperitoneal injection of zymosan(750 mg/kg),the levels of intestinal inflammatory cytokines [tumor necrosis factor-alpha(TNF-α) and interleukin(IL)-10] and oxides(myeloperoxidase,malonaldehyde,and superoxide dismutase) were examined. The levels of diamine oxidase(DAO) in plasma and intestinal mucosal blood flow(IMBF) were determined. Intestinal injury was also evaluated using an intestinal histological score and apoptosis of intestinal epithelial cells was determined by deoxynucleotidyl transferase d UTP nick end labeling(TUNEL) assay. The intestinal epithelial tight junction protein,ZO-1,was observed by immunofluorescence.RESULTS: DMSO decreased TNF-α and increased IL-10 levels in the intestine compared with the ZS group at the corresponding time points. The activity of intestinal myeloperoxidase in the ZS group was higher than that in the ZD group 24 h after zymosan administration(P < 0.05). DMSO decreased the content of malondialdehyde(MDA) and increased the activity of superoxide dehydrogenase(SOD) 24 h after zymosan administration. The IMBF was lowest at 24 h and was 49.34% and 58.26% in the ZS group and ZD group,respectively(P < 0.05). DMSO alleviated injury in intestinal villi,and the gut injury score was significantly lower than the ZS group(3.6 ± 0.2 vs 4.2 ± 0.3,P < 0.05). DMSO decreased the level of DAO in plasma compared with the ZS group(65.1 ± 4.7 U/L vs 81.1 ± 5.0 U/L,P < 0.05). DMSO significantly preserved ZO-1 protein expression and localization 24 h after zymosan administration. The TUNEL analysis indicated that the number of apoptotic intestinal cells in the ZS group was much higher than the ZD group(P < 0.05).CONCLUSION: DMSO inhibited intestinal cytokines and protected against zymosan-induced gut barrier dysfunction.

Inhibition of zymosan-induced cytokine and chemokine expression in human corneal fibroblasts by triptolide

AIM：To investigate the effects of triptolide on proinflammatory cytokine and chemokine expression induced by the fungal component zymosan in cultured human corneal fibroblasts（HCFs）.·METHODS：HCFs were cultured in the absence or presence of zymosan or triptolide.The release of interleukin（IL）-6,IL-8,and monocyte chemoattractant protein-1（MCP-1）into culture supernatants was measured with enzyme-linked immunosorbent assays.The cellular abundance of the m RNAs for these proteins was determined by reverse transcription and real-time polymerase chain reaction analysis.The phosphorylation of mitogen-activated protein kinases（MAPKs）and the endogenous nuclear factor-κB（NF-κB）inhibitor IκB-αwas examined by immunoblot analysis.The release of lactate dehydrogenase（LDH）activity from HCFs was measured with a colorimetric assay.·R ESULTS：Triptolide inhibited the zymosan-induced release of IL-6,IL-8,and MCP-1 from HCFs in a concentration-and time-dependent manner.It also inhibited the zymosan-induced up-regulation of IL-6,IL-8,and MCP-1 m RNA abundance in these cells.Furthermore,triptolide attenuated zymosan-induced phosphorylation of the MAPKs extracellular signalregulated kinase（ERK）,c-Jun NH2-terminal kinase（JNK）,and p38 as well as the phosphorylation and degradation of IκB-α.Triptolide did not exhibit cytotoxicity for HCFs.·C ONCLUSION：Triptolide inhibited proinflammatory cytokine and chemokine production by HCFs exposed tozymosan,with this action likely being mediated by suppression of MAPK and NF-κB signaling pathways.This compound might thus be expected to limit the infiltration of inflammatory cells into the cornea associated with fungal infection.

Effect of zymosan on the expression and function of the gap-junction protein connexin 43 in human corneal fibroblasts

AIM:To study the effect of zymosan,a ligand found on the surface of fungi,on gap junctional intercellular communication(GJIC)in cultured human corneal fibroblasts(HCFs).METHODS:Zymosan was added to the medium of cultured HCFs with or without the administration of mitogenactivated protein kinase(MAPK)inhibitors or the inhibitor kappa B kinase 2(IKK2)inhibitor IV.The protein and m RNA levels of connexin 43(Cx43)in HCFs were measured by Western blot,immunofluorescence,and quantitative reverse transcription-polymerase chain reaction(q RT-PCR)analyses.The GJIC activity was tested using a dye-coupling assay.RESULTS:The reduction of Cx43 protein and m RNA levels as well as a significant decrease in GJIC activity were observed in cultured HCFs when zymosan was added into the culture medium.Compared with controls(no zymosan),the protein level of Cx43 was reduced by 45%and 54%in the presence of zymosan at 200 and 600μg/m L,respectively(P<0.05);and it was reduced by 45%,48%,and 75%in the presence of zymosan(600μg/m L)for 24,36,and 48 h,respectively(P<0.05).The m RNA expression of Cx43 was reduced by 98%in the presence of zymosan(P<0.05).The effects of zymosan on Cx43 expression and GJIC activity were attenuated by the administration of PD98059[an extracellular signal-regulated kinase(ERK)signaling inhibitor](P<0.05),c-Jun NH2-terminal kinase(JNK)inhibitor II(P<0.05),and IKK2 inhibitor IV(P<0.05).CONCLUSION:Zymosan inhibits the activity of GJIC in cultured HCFs.This effect is likely regulated via the nuclear factor-κB(NF-κB),MAPK/ERK,and JNK signaling pathways.The inhibitory effects of zymosan on Cx43 expression and GJIC activity in HCFs may induce damage of corneal stroma during corneal fungal infection.

Animal model of non-bacterial multiple organ dysfunction syndrome in the elderly

Objective To establish a model of multiple organ dysfunction syndrome in the elderly (MODSE) by intraperitoneal injection of different doses of zymosan, and to compare the multiple organ dysfunction syndrome (MODS) in adult and in the elderly rats. Methods Adult and senile rats, injected with different doses of zymosan intraperitoneally were examined for the changes in the function and morphology of the vital organs, including heart, liver, brain, lungs, and kidneys using blood gas and biochemistry analysis and histopathological examination methods. Results Compared with the normal controls of the adult and the elderly rats, the blood gas and blood biochemistry changed in different degrees in the different dosed zymosan groups. Pathological changes were also found in the vital organs including lungs, heart, liver, brain, kidneys, erc in the experimental groups. Under the same concentrations of zymosan, the reductions in respiratory, cardiac and renal functions in the senile groups were much more severe than those in the corresponding adult group. In the similar degree of model duplication, the senile rats had the tendency to die later than the adult rats. Conclusions Zymosan can be used in both elderly and adult rats to induce MODS model, and the best dosage for MODSE was 0.Sg/kg injected peritoneally. The model would hopefully be used in the study of mechanisms and the therapeutics on MODSE.

Joint Damage Accelerating Properties of Neutrophils

Neutrophils are innate immune cells involved in the initial inflammatory response and in the pathogenesis of rheumatoid arthritis (RA), an inflammatory joint disease. They produce cytokines, chemokines, proinflammatory mediators and secrete enzymes causing a direct destruction of cartilage and bone. Herein we investigated the ability of neutrophils to express the receptor activator of nuclear factor kappa-B ligand (RANKL) and to interfere with maturation of late pre-osteoclasts. The distribution of bone marrow (BM) Ly6G+ cells expressing RANKL was evaluated after BM cell dye labelling and transfer into zymosan-injected SCID recipient mice. Specific tartrate-resistant acid phosphatase (TRAP) staining was used to determine the number of multinucleated mature osteoclasts in the co-cultures of purified blood neutrophils with preosteoclasts. Ly6 G+ BM cells migrated extensively in synovial fluid and spleen of recipient zymosan-injected SCID mice. Labelled neutrophils have higher RANKL expression in synovial fluid unlike in spleen indicating that they obtained specific phenotype during their migration to the synovial fluid. Blood neutrophils increased the number of multinucleated mature osteoclasts in vitro. This effect was elicited by the pretreatment of neutrophils with interleukin (IL)-17. In summary, our study showed neutrophils’s properties to accelerate joint damage via RANKL and interactions with osteoclasts.

腹膜透析并发腹膜炎的实验研究

采用ｚｙｍｏｓａｎ和大肠杆菌注入新西兰兔腹腔，观察腹膜对白细胞、蛋白质、肌酐、葡萄糖的转运和水的超滤。结果显示，Ｚｙｍｏｓａｎ和大肠杆菌组透析液内白细胞数和蛋白质浓度增加，而小分子溶质肌酐、葡萄糖与对照组比较无差异；水超滤量在４．２５％葡萄糖透析液＋Ｚｙｍｏｓａｎ组高于对照组，而在０．９％ＮａＣｌ＋Ｚｙｍｏｓａｎ组，２．５％葡萄糖透析液＋Ｚｙｍｏｓａｎ组及２．５％葡萄糖透析液＋Ｅ－ｃｏｌｉ组与对照组比较均无差异。提示腹膜炎时大分子和小分子溶质的转运途径不同；不同渗透压的腹透液对水的转运机制可能不同。

MODULATION OF RAT KUPFFER CELLS ON HIGH DENSITY LIPOPROTEIN RECEPTORS ON HEPATOCYTES

The present study found that conditioned media from Kupffer cells preincubated with acetylated LDL or acetylated LDL and zymosan increased the number of HDL receptors on hepatocytes, using the method of conditioned media transfer. This indicated that the transferable factors produced by Kupffer cells modulate HDL receptors on hepatocytes.

Engagement of TLR and Dectin-1/Syk Signaling Is Required for Activation of Notch Targets in Dendritic Cells

Pattern-recognition receptors,such as toll-like receptors(TLRs),detect a wide range of microbial products and initiate innate immune responses leading to the production of inflammatory mediators.In addition,TLR signaling also activates expression of Notch target genes that play crucial roles in suppression of TLR-triggered inflammatory responses.However,whether TLR signaling pathways engaged by other classes of pattern-recognition receptors induce expression of Notch target genes remains unclear.Here we demonstrate that zymosan,a stimulus for TLR2 and dectin-1,strongly induces expression of multiple Notch target genes in both human and murine dendritic cells.Mechanistically,induction of Notch targets by zymosan is both TLR2-and Syk-dependent through activation of mitogen-activated protein kinases and the transcription factor c-Fos.Hence,our data reveals a novel mechanism that efficient induction of Notch target genes requires engagement of TLR and dectin-1/Syk signaling pathways.