毛喉鞘蕊花提取物对大鼠哮喘模型炎症介质的影响及机制研究

为探讨毛喉鞘蕊花提取物(Coleus Forskohlii extract,CFE)对哮喘的治疗作用及机制,采用卵清蛋白(ovalbumin,OVA)结合佐剂氢氧化铝建立大鼠哮喘模型,SPF级SD雄性大鼠60只,随机分为5组,即空白组、模型组、地塞米松组、CFE高剂量组(12.8g/kg)和CFE低剂量组(6.4g/kg),分别用生理盐水、地塞米松及CFE每天灌胃1次,连续14天,灌胃容积为1mL/100g。通过HE染色观察肺组织病理学形态学变化;ELISA法测定大鼠血清(serum)及肺泡灌洗液(BALF)中IFN-γ、IL-4和IL-17A含量变化;Western blot检测MAPK通路相关蛋白的表达变化。HE结果显示,与模型组相比,CFE高、低剂量组能显著减轻OVA刺激后大鼠肺组织病理性损伤,气道轮廓清晰,上皮细胞脱落明显减少;ELISA结果显示,与模型组相比,CFE高、低剂量组大鼠血清及BALF中IL-4、IL-17A的含量明显下降,IFN-γ的含量明显上升(P<0.05或P<0.01);WB结果显示,CFE高剂量组可显著降低大鼠肺组织p-ERK、p-JNK及p-p38蛋白表达(P<0.05或P<0.01)。综上,毛喉鞘蕊花提取物可有效缓解OVA诱导的大鼠哮喘气道炎症反应,其机制与调节MAPK信号传导通路有关。     

Effect of arbuscular mycorrhizal fungi and Pseudomonas fluorescens on root-rot and wilt,growth and yield of Coleus forskohlii

Root-rot and wilt caused by Fusarium chlamydosporum affects the cultivation of Coleus forskohlii, a medicinal plant grown for its roots, which contain a pharmaceutically important compound called forskolin. In this study, management of this disease under low and high inoculum levels was assessed with four arbuscular mycorrhizal (AM) fungi and a strain of Pseudomonas fluorescens. The AM fungus Glomus fasciculatum and P. fluorescens were the most effective treatments that reduced the severity of root-rot and wilt of C. forskohlii by 56–65% and 61–66%, respectively, under lower and higher levels of pathogen F. chlamydosporum. G. fasciculatum increased the dry shoot and root weight by 108–241% and 92–204%, respectively, while in plants treated with P. fluorescens, an increase of 97–223% and 97–172% in dry shoot and root weight, respectively, was observed. Although P. fluorescens was effective, it gave higher root yields only under lower inoculum level of the pathogen. G. fasciculatum performed equally well under both lower and higher inoculum levels. Increase in yields with both the biocontrol agents was accompanied by increase in P uptake (230–303%) and in K uptake (270–335%). The forskolin content of the roots was significantly increased (14–21%) by G. fasciculatum, P. fluorescens or G. mosseae under lower inoculum level of pathogen.     

Biocontrol of root-rot disease of Coleus forskohlii and Coleus amboinicus by using plant extracts as antifungal agents

Different plant extracts were screened for their potential antifungal activity against Fusarium chlamydosporum causing root rot of Coleus amboinicus and Coleus forskohlii; the aqueous and 50% ethanol extract of Annona squamosa, Azadircta indica, Eucalyptus Spp., Ocimum sanctum, Lawsonia inermis, Allium schoenoprasum, Cinnamomum verum Zingiber officinale, Piper nigrum, Calendula officinalis species were found to be effective. Both aqueous and 50% ethanol extract of the aforementioned plants showed a significant inhibition.     

The root endophyte fungus Piriformospora indica leads to early flowering,higher biomass and altered secondary metabolites of the medicinal plant,Coleus forskohlii

This study was undertaken to investigate the influence of plant probiotic fungus Piriformospora indica on the medicinal plant C. forskohlii. Interaction of the C. forskohlii with the root endophyte P. indica under field conditions, results in an overall increase in aerial biomass, chlorophyll contents and phosphorus acquisition. The fungus also promoted inflorescence development, consequently the amount of p-cymene in the inflorescence increased. Growth of the root thickness was reduced in P. indica treated plants as they became fibrous, but developed more lateral roots. Because of the smaller root biomass, the content of forskolin was decreased. The symbiotic interaction of C. forskohlii with P. indica under field conditions promoted biomass production of the aerial parts of the plant including flower development. The plant aerial parts are important source of metabolites for medicinal application. Therefore we suggest that the use of the root endophyte fungus P. indica in sustainable agriculture will enhance the medicinally important chemical production.     

Autophagy induces eosinophil extracellular traps formation and allergic airway inflammation in a murine asthma model

Studies have shown autophagy participation in the immunopathology of inflammatory diseases. However, autophagy role in asthma and in eosinophil extracellular traps (EETs) release is poorly understood. Here, we attempted to investigate the autophagy involvement in EETs release and in lung inflammation in an experimental asthma model. Mice were sensitized with ovalbumin (OVA), followed by OVA challenge. Before the challenge with OVA, mice were treated with an autophagy inhibitor, 3-methyladenine (3-MA). We showed that 3-MA treatment decreases the number of eosinophils, eosinophil peroxidase (EPO) activity, goblet cells hyperplasia, proinflammatory cytokines, and nuclear factor kappa B (NFκB) p65 immunocontent in the lung. Moreover, 3-MA was able to improve oxidative stress, mitochondrial energy metabolism, and Na⁺, K⁺-ATPase activity. We demonstrated that treatment with autophagy inhibitor 3-MA reduced EETs formation in the airway. On the basis of our results, 3-MA treatment can be an interesting alternative for reducing lung inflammation, oxidative stress, mitochondrial damage, and EETs formation in asthma.     

颗粒蛋白前体通过抑制IL-6表达减轻哮喘气道炎症

目的: 探究颗粒蛋白前体(PGRN)在过敏性哮喘中的作用及机制。方法: 分别在野生鼠和IL-6 缺陷鼠中设置对照组和哮喘模型组,每组8只。模型组中,在第0日和第7日致敏小鼠(腹腔注射OVA 100 μg),从第14日起连续激发8 d(5％OVA雾化吸入,30 min/d,每日1次),末次激发24 h后取标本;对照组用PBS代替OVA做相同处理。采集支气管肺泡灌洗液(BALF)进行白细胞计数和分类计数;HE染色观察肺组织病理情况;Q-PCR及ELISA检测小鼠肺匀浆、血清和BALF中细胞因子水平。用IL-13刺激A549或BEAS-2B细胞建立体外哮喘炎症模型,每组3个复孔,共4组:PBS处理组、IL-13处理组、IL-13与重组人PGRN蛋白(rhPGRN)共同处理组及p38磷酸化抑制剂(SB203508)处理组。0 min~48 h后收集细胞及上清,用Q-PCR及ELISA检测PGRN和IL-6的表达;Western blot检测p38的磷酸化。结果: 与对照组相比,哮喘组小鼠肺匀浆和BALF中PGRN均显著降低(P＜ 0.01),血清PGRN有降低的趋势,然而哮喘小鼠BALF中IL-6显著升高(P＜0.05)。与野生鼠哮喘组相比,IL-6缺陷鼠哮喘组BALF中白细胞总数降低(P＜0.05),中性粒细胞数降低(P＜0.05),PGRN显著升高(P＜0.05),肺部病理损伤也减轻。体外实验中,IL-13处理组与PBS处理组相比,PGRN显著降低(P＜0.05),IL-6显著增高(P＜ 0.05),p38的磷酸化增加;p38抑制剂处理组比未处理组中IL-6水平降低(P＜0.05)。IL-13与rhPGRN共同处理组的IL-6显著低于IL-13处理组(P＜0.05),p38的磷酸化降低(P＜0.05)。结论: PGRN通过抑制p38磷酸化降低IL-6水平从而减轻哮喘小鼠气道炎症。     

Influences of PON1 on airway inflammation and remodeling in bronchial asthma

This study aims to explore the influences of Paraoxonase‐1 (PON1) involved in airway inflammation and remodeling in asthma. Mice were divided into control, asthma, asthma + PON1 and asthma + NC groups, and asthma models were established via aerosol inhalation of ovalbumin (OVA). HE, Masson, and PAS stains were used to observe airway inflammation and remodeling, Giemsa staining to assess inflammatory cells in bronchoalveolar lavage fluid (BALF), qRT‐PCR and Western blot to detect PON1 expression, lipid peroxidation and glutathione assays to quantify malondialdehyde (MDA) activity and glutathione peroxidase (GSH) levels, ELISA to determine inflammatory cytokines and immunoglobulin, and colorimetry to detect PON1 activities. Additionally, mice lung macrophages and fibroblasts were transfected with PON1 plasmid in vitro; ELISA and qRT‐PCR were performed to understand the effects of PON1 on inflammatory cytokines secreted by lung macrophages, MTT assay for lung fibroblasts proliferation and qRT‐PCR and Western blot for the expressions of PON1, COL1A1, and fibronectin. After overexpression of PON1, the asthma mice had decreased inflammatory cell infiltration, fibrosis degree, and airway wall thickness; inflammatory cells and inflammatory cytokines in BALF were also reduced, expressions of OVA‐IgE and IgG1, and MDA activity were decreased, but the expressions of OVA‐IgG2a and INF‐γ and GSH levels were increased. Besides, PON1 significantly inhibited microphage expression of LPS‐induced inflammatory cytokines, lung fibroblast proliferation, and COL1A1 and fibronectin expression. Thus, PON1 could relieve airway inflammation and airway remodeling in asthmatic mice and inhibit the secretion of LPS‐induced macrophage inflammatory cytokines and the proliferation of lung fibroblasts.     

Resolvin E1 dampens airway inflammation and hyperresponsiveness in a murine model of asthma

Resolvin E1 (RvE1; 5S, 12R, 18R-trihydroxyeicosapentaenoic acid) is an anti-inflammatory lipid mediator derived from the omega-3 fatty acid eicosapentaenoic acid (EPA). It has been recently shown that RvE1 is involved in the resolution of inflammation. However, it is not known whether RvE1 is involved in the resolution of asthmatic inflammation. To investigate the anti-inflammatory effect of RvE1 in asthma, a murine model of asthma was studied. After RvE1 was administered to mice intraperitoneally, there were decreases in: airway eosinophil and lymphocyte recruitment, specific Th2 cytokine, IL-13, ovalbumin-specific IgE, and airway hyperresponsiveness (AHR) to inhaled methacholine. Moreover, RvE1-treated mice had significantly lower mucus scores compared to vehicle-treated mice based on the number of goblet cells stained with periodic acid-schiff (PAS). These findings provide evidence that RvE1 is a pivotal counterregulatory signal in allergic inflammation and offer novel multi-pronged therapeutic approaches for human asthma.     

Decoction of heat-clearing,detoxifying and blood stasis removing relieves acute soft tissue injury via modulating miR-26b-5p/COX2 axis to inhibit inflammation

Traditional Chinese medicine (TCM), such as Huanglian-Jie-Du-Tang, a heat-clearing and detoxifying decoction is beneficial for alleviation of inflammation-related diseases. The objective of the present study is to uncover the effect and mechanism of heat-clearing, detoxifying and blood stasis removing decoction (HDBD) on the treatment of acute soft tissue injury (STI) which is characterized with excessive inflammatory cascade at the onset. Male Sprague–Dawley (SD) rats with hammer beating served as the in vivo models of acute STI. Hematoxylin–Eosin (HE) staining was used for histopathology assessment. The levels of inflammatory factors, including prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), interleukin (IL)-1t and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA). Human dermal microvascular endothelium cell line HMEC-1 and rat vascular endothelium cell line RAOEC were used to explore the mechanism in vitro. Luciferase gene reporter assay was applied to determine the relationship between miR-26b-5p and Cyclo-oxygenase 2 (COX2). The results showed that HDBD intervention significantly reduced the temperature difference between the healthy side and affected side of rats with hammer beating, together with the decreased levels of COX2, PGE2, TNF-α, IL-6 and IL-1β, and the increased level of miR-26b-5p. In mechanism, miR-26b-5p targeted COX2 and decreased its expression, leading to significant decreases in the levels of PGE2, TNF-α and IL-6 in RAOEC and HMEC-1 cells. In addition, miR-26b-5p inhibition impaired the effects of HDBD on the suppression of PGE2, TNF-α, IL-6 and IL-1β in vitro. In conclusion, the present study revealed that HDBD relieved acute STI via modulating miR-26b-5p/COX2 axis to inhibit inflammation.     

Angiogenic regulatory influence of extracellular matrix deposited by resting state asthmatic and non-asthmatic airway smooth muscle cells is similar

The extracellular matrix (ECM) is the tissue microenvironment that regulates the characteristics of stromal and systemic cells to control processes such as inflammation and angiogenesis. Despite ongoing anti-inflammatory treatment, low levels of inflammation exist in the airways in asthma, which alters ECM deposition by airway smooth muscle (ASM) cells. The altered ECM causes aberrant behaviour of cells, such as endothelial cells, in the airway tissue. We therefore sought to characterize the composition and angiogenic potential of the ECM deposited by asthmatic and non-asthmatic ASM. After 72 hours under non-stimulated conditions, the ECM deposited by primary human asthmatic ASM cells was equal in total protein, collagen I, III and fibronectin content to that from non-asthmatic ASM cells. Further, the matrices of non-asthmatic and asthmatic ASM cells were equivalent in regulating the growth, activity, attachment and migration of primary human umbilical vein endothelial cells (HUVECs). Under basal conditions, asthmatic and non-asthmatic ASM cells intrinsically deposit an ECM of equivalent composition and angiogenic potential. Previous findings indicate that dysregulation of the airway ECM is driven even by low levels of inflammatory provocation. This study suggests the need for more effective anti-inflammatory therapies in asthma to maintain the airway ECM and regulate ECM-mediated aberrant angiogenesis.     

Liraglutide ameliorated peripheral neuropathy in diabetic rats: Involvement of oxidative stress,inflammation and extracellular matrix remodeling

Diabetic peripheral neuropathy is one of the most common microvascular complications that occurs with both type 1 and type 2 diabetes mellitus. It has a significant negative impact on patients’ quality of life; as it starts with loss of limbs’ sensation and may lead to lower limb amputation. This study aimed at investigating the effect of liraglutide on peripheral neuropathy in diabetic rats. Experimental diabetes was induced by single intraperitoneal injections of nicotinamide (50 mg/kg) and streptozotocin (52.5 mg/kg). Rats were allocated into five groups. Two groups were given saline or liraglutide (0.8 mg/kg, s.c.). Three diabetic groups were either untreated or treated with liraglutide (0.8 mg/kg, s.c.) or pregabalin (10 mg/kg, i.p.). After 2 weeks of treatment, behavioral, biochemical, histopathological, and immunohistochemical investigations were performed. Treatment with liraglutide‐restored animals’ body weight, normalized blood glucose, decreased glycated hemoglobin, and increased insulin levels. In parallel, it normalized motor coordination and the latency withdrawal time of both tail flick and hind paw cold allodynia tests and reversed histopathological alterations. Treatment with liraglutide also normalized malondialdehyde, matrix metalloproteinase‐2 and ‐9 contents in sciatic nerve. Likewise, it decreased sciatic nerve nitric oxide and interleukin‐6 contents, DNA fragmentation and expression of cyclooxygenase‐2. Meanwhile, it increased superoxide dismutase and interleukin‐10 contents in sciatic nerve. These findings indicate the neuroprotective effect of liraglutide against diabetic peripheral neuropathy probably via modulating oxidative stress, inflammation, and extracellular matrix remodeling.

     

染料木黄酮对哮喘豚鼠肺部炎症和气道重塑的预防作用

目的：研究蛋白酪氨酸激酶（PTK）抑制剂染料木黄酮对哮喘豚鼠肺部炎症和气道重塑的作用。方法：成年雄性豚鼠30只,随机分成3组（n=10）：对照组（C组）、哮喘组（A组）和染料木黄酮干预组（B组）,以腹腔内注射联合雾化吸入卵蛋白复制哮喘模型。测支气管肺泡灌洗液（BALF）中细胞总数及其分类数,测细支气管炎症细胞浸润及支气管重塑指标,免疫纽化方法测磷酸化酪氨（p-tyrosine）在肺组织中的表达。结果：A组BALF中细胞总数、嗜酸性粒细胞分类与C组比较明显增加,B组与A组比较明显降低,差异有统计学意义（P〈0．01）;A组细支气管嗜酸性粒细胞（E）数和淋巴细胞（L）数较C组明显增多,B组与A组比较明显降低,差异有统计学意义（P〈0．01）;B组细支气管重塑较A组明显减轻（P〈0．01）,与C组比较,差异无统计学意义（P〈0．05）;免疫组化显示p-tyrosine在支气管平滑肌、支气管上皮、血管滑平滑肌及炎性细胞均有表达,尤其以支气管和血管平滑肌及炎性细胞明显,A组比C组表达明显增高,差异有统计学意义（P〈0．01）,而B组与C组比较,无明显差别（P〉0．05）。结论：PTK对哮喘豚鼠肺部炎症和支气管重塑具有促进作用：PTK抑制剂染料木黄酮对哮喘豚鼠肺炎症和支气管重塑具有预防和抑制作用。     

Endometrial inflammation and abnormal expression of extracellular matrix proteins induced by Mycoplasma bovis in dairy cows

Mycoplasma bovis infection can cause endometrial inflammation leading to infertility and involuntary culling in dairy cows. Because extracellular matrix (ECM) proteins affect the adherence of mycoplasma to eukaryotic cell surface, they may play a role in the pathogenesis of the bacteria. The objective of the present study was to evaluate the endometrial inflammatory response and ECM protein expression induced by M bovis. Endometrial concentrations of inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and mRNA and protein expression of collagen IV (CL-IV), fibronectin (FN), and laminin (LN) were evaluated 10, 20, and 30 days after M bovis intrauterine infusion in breed cows 18 days postpartum. The presence of the bacteria in the uterus was detected by nested polymerase chain reaction and denaturing gradient gel electrophoresis. Endometrial TNF-α, IL-1β, and IL-6 concentrations in the treatment group were greater (P < 0.05) than in the positive and negative control groups 20 and 30 days after infusion. Endometrial CL-IV, FN, and LN mRNA and protein expression increased (P < 0.01) 20 days after infusion in all groups. However, the increase was more pronounced in the treatment group and reactive expressions were greater (P < 0.05) than in the positive and negative control groups 10, 20, and 30 days after infusion. In conclusion, M bovis triggered endometrial inflammatory response and increased CL-IV, FN, and LN mRNA and protein expression. The abnormal expression of ECM these proteins may promote the pathogenic effects of M bovis that lead to endometrial tissue damage and infertility.     

Tumstatin regulates the angiogenic and inflammatory potential of airway smooth muscle extracellular matrix

The extracellular matrix (ECM) creates the microenvironment of the tissue; an altered ECM in the asthmatic airway may be central in airway inflammation and remodelling. Tumstatin is a collagen IV‐derived matrikine reduced in the asthmatic airway wall that reverses airway inflammation and remodelling in small and large animal models of asthma. This study hypothesized that the mechanisms underlying the broad asthma‐resolving effects of tumstatin were due to autocrine remodelling of the ECM. Neutrophils and endothelial cells were seeded on decellularized ECM of non‐asthmatic (NA) or asthmatic (A) airway smooth muscle (ASM) cells previously exposed to tumstatin in the presence or absence of a broad matrix metalloproteinase inhibitor, Marimastat. Gene expression in NA and A ASM induced by tumstatin was assessed using RT‐PCR arrays. The presence of tumstatin during ECM deposition affected neutrophil and endothelial cell properties on both NA and A ASM‐derived matrices and this was only partly due to MMP activity. Gene expression patterns in response to tumstatin in NA and A ASM cells were different. Tumstatin may foster an anti‐inflammatory and anti‐angiogenic microenvironment by modifying ASM‐derived ECM. Further work is required to examine whether restoring tumstatin levels in the asthmatic airway represents a potential novel therapeutic approach.     

Iron-load exacerbates the severity of atherosclerosis via inducing inflammation and enhancing the glycolysis in macrophages

Atherosclerosis is still the major cause of morbidity and mortality all over the world. Recently, it has been reported increased levels of tissue iron increase the risk of atherosclerosis. However, the detailed mechanism of iron-induced atherosclerosis progression is barely known. Here, we used apoE-deficient mice models to investigate the effects of low iron diet (<0 mg iron carbonyl/kg), high iron diet (25,000 mg iron carbonyl/kg) on atherosclerosis in vivo. As exhibited, we observed that CD68 was significant enriched by high iron diet in apoE-deficient mice. In addition, transforming growth factor β, tumor necrosis factor α, interleukin 6 (IL-6), IL-23, IL-10, and IL-1β levels were also greatly induced by high iron diet. Then, we found that the iron load promoted the inflammation response in macrophages. Moreover, macrophage polarization is a process by which macrophage can express various functional programs in activating macrophages. Here, we observed that iron-load macrophages were polarized toward a proinflammatory macrophage phenotype. The polarization of M1 macrophage was promoted by ferric ammonium citrate (FAC) in bone marrow derived macrophages (BMDMs). Furthermore, ECAR and cellular OCR in BMDM with or without FAC was examined. As shown, BMDM indicated with 50 μM FAC showed a significant increase in basic state and maximal ECAR in contrast to the control group. However, there was no significant difference in OCR. This indicated that the glycolysis was involved in the polarization of M1 macrophage triggered by iron-load. In conclusion, we indicated that the iron load exacerbates the progression of atherosclerosis via inducing inflammation and enhancing glycolysis in macrophages.     

The density of extracellular matrix proteins regulates inflammation and insulin signaling in adipocytes

Cells can not only sense the type of extracellular matrix (ECM) protein that is present in the microenvironment, but they can also sense its density. Here, we investigated the effects of ECM protein density on adipokine secretion and insulin signaling in adipocytes. To this end, 3T3-L1 adipocytes were cultured on the surface of polyacrylamide gels that were coated with gradient densities of a collagen type I and fibronectin mixture. We found that high density ECM causes a decrease in insulin signaling and adiponectin secretion, whereas the secretion of monocyte chemoattractant protein-1 (MCP-1) was increased via the activation of nuclear factor-κB (NF-κB). These results indicate that the density of the ECM directly regulates the inflammatory response and insulin sensitivity of adipocytes.

Structured summary

MINT-7992217: Irs1 (uniprotkb:P35569) physically interacts (MI:0915) with phosphatidylinositol 3-kinase 85 kDa regulatory subunit alpha (uniprotkb:P26450) by anti bait coimmunoprecipitation (MI:0006)     

The interplay of fibroblasts,the extracellular matrix,and inflammation in scar formation

Various forms of fibrosis, comprising tissue thickening and scarring, are involved in 40% of deaths across the world. Since the discovery of scarless functional healing in fetuses prior to a certain stage of development, scientists have attempted to replicate scarless wound healing in adults with little success. While the extracellular matrix (ECM), fibroblasts, and inflammatory mediators have been historically investigated as separate branches of biology, it has become increasingly necessary to consider them as parts of a complex and tightly regulated system that becomes dysregulated in fibrosis. With this new paradigm, revisiting fetal scarless wound healing provides a unique opportunity to better understand how this highly regulated system operates mechanistically. In the following review, we navigate the four stages of wound healing (hemostasis, inflammation, repair, and remodeling) against the backdrop of adult versus fetal wound healing, while also exploring the relationships between the ECM, effector cells, and signaling molecules. We conclude by singling out recent findings that offer promising leads to alter the dynamics between the ECM, fibroblasts, and inflammation to promote scarless healing. One factor that promises to be significant is fibroblast heterogeneity and how certain fibroblast subpopulations might be predisposed to scarless healing. Altogether, reconsidering fetal wound healing by examining the interplay of the various factors contributing to fibrosis provides new research directions that will hopefully help us better understand and address fibroproliferative diseases, such as idiopathic pulmonary fibrosis, liver cirrhosis, systemic sclerosis, progressive kidney disease, and cardiovascular fibrosis.     

Bradykinin and des-Arg10-kallidin enhance the adhesion of polymorphonuclear leukocytes to extracellular matrix proteins and endothelial cells

Abstract

Bradykinin-related peptides (kinins) are well known to contribute to leukocyte recruitment to inflammatory foci; however, a role of these universal pro-inflammatory mediators in the first step of this process, i.e. the leukocyte adhesion to endothelial cells, is not well understood. In this work we found that bradykinin and des-Arg¹⁰-kallidin enhance the adhesion of polymorphonuclear bloods cells (PMN) to fibrinogen and fibronectin. Also, the PMN adherence to endothelial cells of HMEC-1 line strongly increased after stimulation by kinins, particularly des-Arg¹⁰-kallidin, or when PMN were co-stimulated with bradykinin and interleukin-1β. These effects were attenuated after PMN treatment with a specific inhibitor of carboxypeptidases, which convert kinins to their des-Arg metabolites. The kinin peptides were also able to change the Mac-1 integrin expression on the PMN surface. These results suggest a regulatory effect of kinins on leukocyte adhesion to endothelial wall, providing new aspects of the leukocyte infiltration into inflamed tissues.