| The inhalation injury is common incorporated injury in burn patient, which smoke is the most frequent vulnerant factor. The organism priming injury repair immediately to ensure normal function of lung following inhalation injury appearance, It may repair completely after injury or lead to airway fibrosis and scar formation which induces airway constr-iction. It causes dyspnea of patient and quality of life serious degression. How to encourage inhalation injury repair earlier and prevent airway fibrosis and scar formation which induces airway stenosis?This is a very formidable clinical question, at present study hot spot centralizes cell cycle control and extracellular matrix and cytokines in the course of airway mucous membrane injury repair. Airway injury repair is a complex process, integrating multiple cell types including airway epithelial cell and fibroblast, soluble mediators, and extracellular matrix (ECM) components, it may result in airway fibrosis and scar formation which induces airway stenosis. At present studyindicates that inflammation is an integral component of wound healing in the course of airway injury repair, although it can promote injury repair earlier, excessive inflammation has been linked to injury repair outcomes, specifically fibrosis and scar formation. On the other hand, diminished inflammatory reaction to injury, as in the case of fetal wound healing, is associated with a regenerative wound healing process that lacks scar formation and fibrosis. Previous studies have shown that fibroblast is fundamental source of extracellular matrix, its recruitment,aggregation and activation impacts process of normal healing and fibrosis formation of post injury tissue, a link between inflammation and fibroblast activity in the wound bed may be important responsible for the final outcome of wound healing and the degree of scarring. Thus, studying on role of inflammatory factor and airway fibroblast in the course of airway mucous membrane injury repair has been important significance to promote airway injury repair earlier and prevent airway stegnosis post injury repair.Interleukin 1βis a multifunction bioactive compound, an important early inflammatory mediator is interleukin 1β, a cytokine secreted by a variety of clls including epithelial cells,macrophages,and neutrophils.Secretion of interleukin 1βwithin the wound bed can stimulate production of secondary inflammatory mediators such as IL-6, IL-8, and prostaglandin E2. These mediators are part of a well-integrated inflammatory response that coordinates subsequent activity in the wound bed. Prostaglandin E2 is a secondary inflammatory mediator, synthesized via cyclo-oxygenase(COX) and PGE2 synthase (PGES) activities and degraded by multiple enzymes including dehydrogenases. Prostaglandin E2 (PGE2) is an important mediator involved in regulating inflammation and fibrotic responses during tissue repair, Prostaglandin E2 can inhibit fibroblast chemotaxis through adjusting fibroblast mobility and influence fibroblast role in matrix contraction and remodeling of the injury repair through blocking fibroblast proliferation and collagen synthesis. Prostaglandin E2 expresses in the early and late stage of injury repair course,it can inhibit fibrosis reaction including collagen synthesis, extracellular matrix contraction and fibroblast proliferation and stimulate epithelial cell migration and participate in the phase of injury repair. Accordingly we hypothesized that interleukin-1βand prostaglandin E2 may play an important role in the course of airway injury repair, it may provide new means which judges different stages in the course of airway injury repair and offer some theory which encourages airway mucous membrane injury repair earlier and prevent airway stegnosis post injury repair.At first, establishing the smoke inhalation injury repair model of New Zealand white rabbits and detecting interleukin-1βand prostaglandin E2 of airway secretion, pathologic changes, interleukin-1βmRNA and cyclo-oxygenase 2mRNA expression aim to decide①different stages of injury repair(injury stage, repair stage).②different time points levels changes of interleukin-1βand prostaglandin E2 were asscioated with pathologic changes in the course of smoke inhalation injury repair, it may provide detecting means which judges different stages in the course of airway injury repair.③expression changes of interleukin-1βmRNA and cyclooxygenase 2mRNA were asscioated with pathologic changes.Then, according to research results, it regarded primary airway fibro-blast as study object to observe relation of interleukin-1βand prostag-landin E2, ELISA(enzyme-linked immunosorbent assay) and western blotting method were used to analyse levels of prostaglandin E2 and expressions of cyclooxygenase 2, membrane-associated prostaglandin E synthase-1, EP2, 15-hydroxyprostaglandin dehydrogenase. From cell and molecular biology level, we study effects of interleukin-1βon the expression of prostagl- andin E2 in cultured airway fibroblast and explore role of interleukin-1βand prostaglandin E2 in inhalation injury repair. Objective:To investigate the expression changes of interleukin 1βand prostaglandin E2 in the smoke inhalation injury repair from New Zealand white rabbits and be related to pathologic changes.Methods:New Zealand white rabbits were randomly divided into normal control group, the 1 day, the 4 day, the 7 day, the 14 day, the 21 day following smoke inhalation injury,with 6 New Zealand white rabbits in each group. Airway secretions and pathologic section were assembled and stained by HE(Hematoxylin and Eosin) in order. ELISA and RT-PCR were used to analyse interleukin 1βand prostaglandin E2 and cyclooxygenase 2 expression. The smoke inhalation injury repair model was established. The pathologic changes of smoke inhalation on trachea and lung tissues of New Zealand white rabbits were observed by light microscope.Result:①The pathologic changes showed that the 1 day, the 4 day, the 7 day groups following smoke inhalation injury were mainly inflammat-ory reaction(injury stage), the 14 day, the 21 day groups were mainly repair(repair stage). It showed that the smoke inhalation injury repair model was established succeedly;②The results of ELISA showed that interleukin 1βconcentrations were upregulated in the 1 day group following smoke inhalation injury. Interleukin 1βconcentrations were the lowest at day 21, interleukin 1βconcentrations in the 7 day group(253.3±96.2)and 14 day group (96.2± 67.8) did have significant difference (P<0.01);Prostaglandin E2 concentra tions were upregulated in the 1 day following smoke inhalation injury. Prostaglandin E2 concentrations peaked at day 21; Prostaglandin E2 concentrations in the 14 day group (85521±24015) and 7 day group(32486±19811)did have significant difference(P<0.01);③The results of RT-PCR showed that interleukin 1βmRNA expressions were upregulated in the 1 day group following smoke inhalation injury. Interleukin 1βmRNA expressions in the 1 and 4 day group of injury stage were significant higher than those in the 14 and 21 day group of repair stage, interleukin 1βmRNA expressions in the 4 day group (1.75±0.31) and 14 day group (0.75±0.33) did have significant difference (P<0.01); Cyclooxygenase 2 mRNA exessprions were upregulated in the 1 day following smoke inhalation injury, cyclooxygenase 2 mRNA expression peaked at day 21. Cyclooxygenase 2 mRNA expressions in the 14 and 21day group of repair stage were significant higher than those in the 1 and 4 day group of injury stage, cyclooxygenase 2 mRNA expressions in the 14 day group (1.86±0.31) and 1 day group (1.03±0.26) did have significant difference (P<0.01).Conclusions:Establishing the smoke inhalation injury repair model and studying the dynamic changes of interleukin 1βand prostaglandin E2 in the smoke inhalation injury repair shows that interleukin 1βexpression is upregulated in smoke inhalation injury stage, prostaglandin E2 expression steps up at repair stage of smoke inhalation injury repair process,It indicates that interleukin 1βand prostaglandin E2 may be related to pathological changes and judge different stage (injury stage,repair stage) clinically in the smoke inhalation injury repair process. Objective:To explore the role of IL-1βin inhalation injury repair by studying the effects of interleukin 1βon the expression of prostaglan din E2 in cultured airway fibroblasts of mouse.Methods:The cultured male Kunming species mouse airway fibroblasts in vivo were randomly divided into control group and treated group. The supernatant and cells were collected at different time points after tre-ated with IL-1βand different concentrations of IL-1β.The expressions of PGE2, COX-2,mPGES1,EP2 and 15-PGDH protein in supernatant and cells were measured by ELISA and western blot, respectively.Result:①Different time points after treated with lng/ml IL-1β, PGE2 levels in the cultured airway fibroblast supernatant at 8h(148±28.3pg/ml,16h(267.6±45.4pg/ml),24h(210.5±38.6pg/ml) and 48h(198.7±36.5pg/ml) were significantly higher than that in control group (P<0.01) , and PGE2 levels peaked at 16h;COX-2 expressions in the cultured airway fibroblastat 8h(0.478±0.029),16h(0.672±0.047),24h(0.617±0.036), and 48h(0.593±0.034) were significantly higher than that in control group (P<0.01), and COX-2 expressions peaked at 16h;mPGESl expressions in the cultured airway fibroblast at 8h(0.300±0.018),16h(0.549±0.034),24h( 0.497±0.030) and 48h(0.443±0.026) were significantly higher than that in control group (P<0.01), and mPGES1 expressions peaked at 16h;EP2 and 15-PGDH expressions of the cultured airway fibroblast at 8h,16h,24h,48h in treated group were no significant higher than that in control group (P>0.05). ②Airway fibroblast treated with different concentration IL-1β, PGE2 levels in the cultured airway fibroblast supernatant in 0.1ng/ml IL-1βgroup (142.9±2.3pg/ml), 1ng/ml IL-1βgroup (267.6±45.4pg/ml) and 10ng/ml IL-1βgroup (587.3±106.9pg/ml) were significantly higher than in control group(58.5±16.0pg/ml) (P<0.01), and there was significant difference between 3 groups(P<0.01);The expressions of COX-2 in the cultured airway fibroblast in 0.1ng/ml IL-1βgroup (0.525±0.031),1ng/ml IL-1βgroup(0.672±0.047) and 10ng/ml IL-1βgroup (1.012±0.064) were signifycantly higher than in control group(0.309±0.019) (P<0.01), and There was significant difference between 3 groups (P<0.01); The expressions of mPGESl in the cultured airway fibroblast in 0.1ng/ml IL-1βgroup(0.380±0.021), 1ng/ml IL-1βgroup (0.549±0.034), and 10ng /ml IL-1βgroup (0.879±0.045) were significantly higher than in control group(0.199±0.012) (P<0.01), and there was significant difference between 3 groups(P<0.01);EP2 and 15-PGDH expressions of the cultured airway fibroblast in 0.1ng/ml IL-1βgroup, lng/ml IL-1βgroup and 10ng/ml IL-1βgroup were no significant higher than that in control group (P>0.05).Conclusion:IL-1βmay upregulate PGE2, COX-2 and mPGES1 expressions of airway fibroblast, but it does not affect expressions of EP2 and 15-PGDH, this indicates that IL-1βinfluences PGE2 synthesis through COX-2 and mPGES1 expression and participates in airway inhalation injury course. Airway fibroblasts may be a main source cell of inflammatory mediators in injury repair. |
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