The angiostatic activity of interferon-inducible protein-10/CXCL10 in human melanoma depends on binding to CXCR3 but not to glycosaminoglycan.

Human interferon-inducible protein 10 (IP-10; HGMW-approved gene symbol CXCL10) is an ELR(-) CXC chemokine that contains binding domains for both the chemokine receptor CXCR3 and glycosaminoglycans. IP-10 has been recently demonstrated to be a potent angiostatic protein in vivo. Whether IP-10 exerts its angiostatic function through binding to CXCR3, glycosaminoglycans, or both, is not clear. To clarify this issue, we created expression constructs for mutants of IP-10 that exhibit partial (IP-10C) or total (IP-10C22) loss of binding to CXCR3 or loss of binding to glycosaminoglycans (IP-10H and IP-10C22H). The A375 human melanoma cell line was transfected with these expression vectors, and stable clones were selected and inoculated subcutaneously into nude mice. As expected, tumor cells secreting wild-type IP-10 showed remarkable reduction in tumor growth compared to control vector-transfected tumor cells. Surprisingly, mutation of IP-10 resulting in partial loss of receptor binding (IP-10C), or loss of GAG binding (IP-10H), did not significantly alter the ability to inhibit tumor growth. This tumor growth inhibition was associated with a reduction in microvessel density, leading to the observed increase in both tumor cell apoptosis and necrosis. In contrast, expression of the IP-10C22 mutant failed to inhibit melanoma tumor growth. These data suggest that CXCR3 receptor binding, but not glycosaminoglycan binding, is essential for the tumor angiostatic activity of IP-10. We conclude that the arginine 22 amino acid residue of IP-10 is essential for both CXCR3 binding and angiostasis.     

Inhibition of MRP4 prevents and reverses pulmonary hypertension in mice

Multidrug resistance-associated protein 4 (MRP4, also known as Abcc4) regulates intracellular levels of cAMP and cGMP in arterial SMCs. Here, we report our studies of the role of MRP4 in the development and progression of pulmonary arterial hypertension (PAH), a severe vascular disease characterized by chronically elevated pulmonary artery pressure and accompanied by remodeling of the small pulmonary arteries as a prelude to right heart failure and premature death. MRP4 expression was increased in pulmonary arteries from patients with idiopathic PAH as well as in WT mice exposed to hypoxic conditions. Consistent with a pathogenic role for MRP4 in PAH, WT mice exposed to hypoxia for 3 weeks showed reversal of hypoxic pulmonary hypertension (PH) following oral administration of the MRP4 inhibitor MK571, and Mrp4-/- mice were protected from hypoxic PH. Inhibition of MRP4 in vitro was accompanied by increased intracellular cAMP and cGMP levels and PKA and PKG activities, implicating cyclic nucleotide-related signaling pathways in the mechanism underlying the protective effects of MRP4 inhibition. Our data suggest that MRP4 could represent a potential target for therapeutic intervention in PAH.     

TLR4在博莱霉素诱导的肺纤维化小鼠模型肺组织中的表达

目的探讨Toll样受体4(TLR4)在博来霉素诱导的肺纤维化小鼠模型肺组织中的表达。方法将60只小鼠随机分为两组:对照组(气管内注入生理盐水)和纤维化组(气管内注入博来霉素5 mg/kg)。处理后用实时定量PCR和免疫蛋白印迹法分别在7、14、21 d观察肺组织中TLR4m RNA和蛋白质的表达。此外,通过HE染色判断肺纤维化的程度。所有数据均用均数±标准差(sx±)表示,两组之间比较采用t检验,多组之间比较采用方差分析。结果 14、21 d纤维化组TLR4 m RNA表达明显高于对照组(P<0.05),且在第21天达到高峰。与对照组相比,纤维化组TLR4蛋白表达增加,21 d达高峰。结论在博来霉素诱导的肺纤维化小鼠模型中,TLR4的表达与炎症和肺纤维化均密切相关。     

Doxycycline attenuated pulmonary fibrosis induced by bleomycin in mice

The administration of doxycycline prior to bleomycin in mice attenuated pulmonary fibrosis. Bronchoalveolar neutrophil influx and gelatinase activity, but not caseinolytic activity, were attenuated by doxycycline. Established fibrosis was not affected by doxycycline. Thus, doxycycline might be useful for slowing down pulmonary fibrosis by biological activity other than antibacterial activity.     

Bleomycin-induced pulmonary fibrosis in fibrinogen-null mice

Mice deleted for the plasminogen activator inhibitor-1 (PAI-1) gene are relatively protected from developing pulmonary fibrosis induced by bleomycin. We hypothesized that PAI-1 deficiency reduces fibrosis by promoting plasminogen activation and accelerating the clearance of fibrin matrices that accumulate within the damaged lung. In support of this hypothesis, we found that the lungs of PAI-1(-/-) mice accumulated less fibrin after injury than wild-type mice, due in part to enhanced fibrinolytic activity. To further substantiate the importance of fibrin removal as the mechanism by which PAI-1 deficiency limited bleomycin-induced fibrosis, bleomycin was administered to mice deficient in the gene for the Aalpha-chain of fibrinogen (fib). Contrary to our expectation, fib(-/-) mice developed pulmonary fibrosis to a degree similar to fib(+/-) littermate controls, which have a plasma fibrinogen level that is 70% of that of wild-type mice. Although elimination of fibrin from the lung was not in itself protective, the beneficial effect of PAI-1 deficiency was still associated with proteolytic activity of the plasminogen activation system. In particular, inhibition of plasmin activation and/or activity by tranexamic acid reversed both the accelerated fibrin clearance and the protective effect of PAI-1 deficiency. We conclude that protection from fibrosis by PAI-1 deficiency is dependent upon increased proteolytic activity of the plasminogen activation system; however, complete removal of fibrin is not sufficient to protect the lung.     

Delayed wound repair and impaired angiogenesis in mice lacking syndecan-4

The syndecans make up a family of transmembrane heparan sulfate proteoglycans that act as coreceptors with integrins and growth factor tyrosine kinase receptors. Syndecan-4 is upregulated in skin dermis after wounding, and, in cultured fibroblasts adherent to the ECM protein fibronectin, this proteoglycan signals cooperatively with beta1 integrins. In this study, we generated mice in which the syndecan-4 gene was disrupted by homologous recombination in embryonic stem cells to test the hypothesis that syndecan-4 contributes to wound repair. Mice heterozygous or homozygous for the disrupted syndecan-4 gene are viable, fertile, and macroscopically indistinguishable from wild-type littermates. Compared with wild-type littermates, mice heterozygous or homozygous for the disrupted gene have statistically significant delayed healing of skin wounds and impaired angiogenesis in the granulation tissue. These results indicate that syndecan-4 is an important cell-surface receptor in wound healing and angiogenesis and that syndecan-4 is haplo-insufficient in these processes.     

Suplatast tosilate prevents bleomycin-induced pulmonary fibrosis in mice

Increasing evidence suggests that the development of pulmonary fibrosis is a T helper (Th) 2-mediated process. Suplatast tosilate is a Th2 cytokine inhibitor that is widely used as an asthma controller in Japan. Therefore, we hypothesized that suplatast tosilate might have an inhibitory effect on the development of pulmonary fibrosis. To investigate this effect, suplatast tosilate was administered to mice after the intratracheal instillation of bleomycin (BLM). The effect of suplatast tosilate was studied by analysis of bronchoalveolar lavage (BAL) fluid and a hydroxyproline assay. We found that the treatment of mice with suplatast tosilate significantly reduced the degree of pulmonary fibrosis. Because a significantly elevated Th2 response was not detected in the C57BL/6 mice after BLM administration, the effect of suplatast tosilate on Th2 cytokines could not be demonstrated. Interestingly, however, the up-regulation of the monocyte chemoattractant protein (MCP)-1 levels in the BAL fluid was found to be suppressed. Following these results, we also demonstrated that suplatast tosilate effectively inhibited the production of MCP-1 in alveolar macrophages (AMs). These findings suggest that suplatast tosilate has both anti-inflammatory and antifibrotic effects, which were associated with a suppressed MCP-1 expression in AMs. Thus, suplatast tosilate, which is already widely used in Japan, may warrant further consideration as a potentially useful treatment for pulmonary fibrosis.     

Inhibition of leukocyte elastase, polymorphonuclear chemoinvasion, and inflammation-triggered pulmonary fibrosis by a 4-alkyliden-beta-lactam with a galloyl moiety

beta-Lactams, a well known class of antibiotics, have been investigated as inhibitors of the disruptive protease released by inflammatory cells, leukocyte elastase (LE). We have synthesized a new beta-lactam with an N-linked galloyl moiety, the latter identified as strategic in conferring anti-LE properties to some flavonols. This N-galloyl-derivative beta-lactam inhibits the LE activity with a K(i) of 0.7 microM, whereas it exerts weak activity against cathepsin G and protease-3 (IC(50) > 100 microM), and matrix metalloproteinase (MMP)-2 and MMP-9. Without affecting chemotactic response and viability of polymorphonuclear (PMN) leukocytes, the compound efficiently restrains their chemoinvasion (IC(50) of 1-2 microM) blocking the LE-triggered activation of pro-MMP-9, instrumental to extravasation. Daily i.p. injection of compound enhances resolution in a pulmonary inflammation model, significantly reducing consequent fibrosis. These results indicate that the new beta-lactam is a potent anti-inflammatory compound with therapeutic potential.     

Inhibition of platelet-derived growth factor signaling attenuates pulmonary fibrosis

Pulmonary fibrosis is the consequence of a variety of diseases with no satisfying treatment option. Therapy-induced fibrosis also limits the efficacy of chemotherapy and radiotherapy in numerous cancers. Here, we studied the potential of platelet-derived growth factor (PDGF) receptor tyrosine kinase inhibitors (RTKIs) to attenuate radiation-induced pulmonary fibrosis. Thoraces of C57BL/6 mice were irradiated (20 Gy), and mice were treated with three distinct PDGF RTKIs (SU9518, SU11657, or Imatinib). Irradiation was found to induce severe lung fibrosis resulting in dramatically reduced mouse survival. Treatment with PDGF RTKIs markedly attenuated the development of pulmonary fibrosis in excellent correlation with clinical, histological, and computed tomography results. Importantly, RTKIs also prolonged the life span of irradiated mice. We found that radiation up-regulated expression of PDGF (A-D) isoforms leading to phosphorylation of PDGF receptor, which was strongly inhibited by RTKIs. Our findings suggest a pivotal role of PDGF signaling in the pathogenesis of pulmonary fibrosis and indicate that inhibition of fibrogenesis, rather than inflammation, is critical to antifibrotic treatment. This study points the way to a potential new approach for treating idiopathic or therapy-related forms of lung fibrosis.     

Tetrathiomolybdate therapy protects against bleomycin-induced pulmonary fibrosis in mice

Tetrathiomolybdate (TM), a drug developed for the treatment of Wilson's disease, produces an antiangiogenic effect by reducing systemic copper levels. Several angiogenic cytokines appear to depend on normal levels of copper for activity. In both animal tumor models and in cancer patients, TM therapy has proved effective in inhibiting the growth of tumors. We have hypothesized that the activities of fibrotic and inflammatory cytokines are also subject to modulation by the availability of copper in a manner similar to angiogenic cytokines. As a first step in evaluating whether TM plays a therapeutic role in diseases of inflammation and fibrosis, we studied the effects of TM on a murine model of bleomycin-induced pulmonary fibrosis. Oral TM therapy resulted in dose-dependent reduction in serum ceruloplasmin, a surrogate marker of systemic copper levels. Significant decreases in systemic copper levels were associated with marked reduction in lung fibrosis as determined on the basis of histopathologic findings and a biochemical measure of fibrosis. The protection afforded by TM was also reflected in significantly reduced bleomycin-induced body-weight loss. In the next phase of this work, we will seek to determine the mechanisms by which TM brings about this therapeutic benefit.     

Blocking follistatin-like 1 attenuates bleomycin-induced pulmonary fibrosis in mice

Progressive tissue fibrosis is a cause of major morbidity and mortality. Pulmonary fibrosis is an epithelial-mesenchymal disorder in which TGF-β1 plays a central role in pathogenesis. Here we show that follistatin-like 1 (FSTL1) differentially regulates TGF-β and bone morphogenetic protein signaling, leading to epithelial injury and fibroblast activation. Haplodeletion of Fstl1 in mice or blockage of FSTL1 with a neutralizing antibody in mice reduced bleomycin-induced fibrosis in vivo. Fstl1 is induced in response to lung injury and promotes the accumulation of myofibroblasts and subsequent fibrosis. These data suggest that Fstl1 may serve as a novel therapeutic target for treatment of progressive lung fibrosis.Progressive tissue fibrosis is an increasing cause of morbidity and mortality worldwide with limited therapeutic options. Idiopathic pulmonary fibrosis (IPF), a particularly severe form of lung fibrosis, is a chronic, progressive, and often fatal interstitial lung disease of unknown etiology with a mean survival of 2–3 yr from diagnosis (ATS/ERS, 2000; Olson et al., 2007). The hallmark of IPF is the unremitting extracellular matrix (ECM) deposition with minimal associated inflammation (Noble and Homer, 2004; Wilson and Wynn, 2009). Although evidence suggests that lung fibrosis is an epithelial-mesenchymal disorder (Selman and Pardo, 2002; Chapman, 2011), the mechanisms by which injured epithelium activates fibroblasts/myofibroblasts are unclear. Epithelial apoptosis pathways are activated in the lungs of patients with acute lung injury, in part by activation of signaling pathways such as Fas ligand–Fas and TGF-β (Hagimoto et al., 2002). In addition, the injured alveolar epithelial cells (AECs) may also be abnormally activated with phenotypic changes (King et al., 2011; Kage and Borok, 2012; Yang et al., 2013). The signals required for this activation are unknown. A recent study suggests that injured kidney epithelial cells produce an increased number of TGF-β–containing exosomes to activate fibroblasts (Borges et al., 2013). We hypothesized that injured pulmonary epithelial cells may activate mesenchymal cells by releasing soluble factors to promote a fibrogenic microenvironment.Both TGF-β (Sime et al., 1997; Gauldie et al., 2007) and bone morphogenetic protein (BMP) signaling pathways (Costello et al., 2010) play a role in the initiation and progression of fibrosis. They regulate both epithelial cell injury and fibroblast proliferation and transdifferentiation into myofibroblasts at the injury site (Leask and Abraham, 2004; Selman et al., 2008; Goodwin and Jenkins, 2009). BMP4 antagonists have been implicated in fibrotic disorders of multiple organs including lung (Dolan et al., 2003; Patella et al., 2006; Costello et al., 2010). The precise mechanisms of TGF-β superfamily members in regulating lung fibrogenesis in specific cell types are largely unclear.Follistatin-like 1 (FSTL1), initially identified as a TGF-β–inducible gene (Shibanuma et al., 1993), encodes a small secreted glycoprotein belonging to a group of matricellular proteins. We recently reported that Fstl1 acts as a BMP4 antagonist to play a key role in lung development (Geng et al., 2011). The role of FSTL1 in lung fibrosis has not been investigated. In this study, we have interrogated the role of FSTL1-regulated TGF-β/BMP signaling in different cell types during lung injury and fibrosis. We report that FSTL1 mediates epithelial-mesenchymal communication at the cellular level. We found that FSTL1 modulated TGF-β but not BMP signaling, leading to fibroblast activation. We provide evidence that targeting FSTL1 may offer a novel therapeutic approach for patients with progressive tissue fibrosis.     

格列卫对博莱霉素致小鼠肺纤维化的干预作用

目的 观察酪氨酸激酶抑制剂格列卫对小鼠肺纤维化的干预作用，并探讨其作用机制。方法 120只C57BL／6小鼠被随机分为对照组、模型组、地塞米松组和格列卫组，每组30只。采用气管穿刺注入博莱霉素制备肺纤维化小鼠模型。分别于制模后7、14和21d处死动物，观察各组肺组织病理学变化、肺系数、肺组织羟脯氨酸（HYP）含量及血小板源性生长因子-BB（PDGF—BB）的表达。结果 与对照组比较，模型组动物术后不同时间点肺系数明显增加（P均〈0．05），肺泡炎分级和肺纤维化程度均明显增加（P均〈0．01），肺组织HYP含量明显升高（P均〈0．05），且随术后时间延长不断增加；而PDGF—BB含量也明显高于对照组（P均〈0．05），但随术后时间延长逐渐恢复降低。与模型组比较，格列卫组与地塞米松组的肺泡炎分级和肺纤维化程度均明显减轻，HYP含量和肺组织PDGF—BB表达均降低（P〈0．05或P〈0．01）；格列卫组上述各指标较地塞米松组稍好转；但两组间各指标比较差异均无显著性（P均〉0．05）。结论 格列卫能明显抑制博莱霉素诱导的小鼠肺纤维化过程。     

Anti-tumor immunity in mismatch repair-deficient colorectal cancers requires type I IFN–driven CCL5 and CXCL10

Colorectal cancers (CRCs) deficient in DNA mismatch repair (dMMR) contain abundant CD8⁺ tumor-infiltrating lymphocytes (TILs) responding to the abundant neoantigens from their unstable genomes. Priming of such tumor-targeted TILs first requires recruitment of CD8⁺ T cells into the tumors, implying that this is an essential prerequisite of successful dMMR anti-tumor immunity. We have discovered that selective recruitment and activation of systemic CD8⁺ T cells into dMMR CRCs strictly depend on overexpression of CCL5 and CXCL10 due to endogenous activation of cGAS/STING and type I IFN signaling by damaged DNA. TIL infiltration into orthotopic dMMR CRCs is neoantigen-independent and followed by induction of a resident memory-like phenotype key to the anti-tumor response. CCL5 and CXCL10 could be up-regulated by common chemotherapies in all CRCs, indicating that facilitating CD8⁺ T cell recruitment underlies their efficacy. Induction of CCL5 and CXCL10 thus represents a tractable therapeutic strategy to induce TIL recruitment into CRCs, where local priming can be maximized even in neoantigen-poor CRCs.     

Inhibition of pulmonary metastasis in mice by all-trans retinoic acid incorporated in cationic liposomes.

The purpose of this study was to investigate whether all-trans retinoic acid (ATRA), an active metabolite of retinal, incorporated in cationic liposomes composed of 1,2 dioleoyl-3-trimethylammonium propane (DOTAP)/cholesterol could inhibit established metastatic lung tumors by delivery to the pulmonary tumor site after intravenous injection. After intravenous injection in mice, the highest lung accumulation of [(3)H]ATRA was observed by the DOTAP/cholesterol liposomes formulation, while other formulations including [(3)H]ATRA dissolved in serum or [(3)H]ATRA incorporated in distearoyl-l-phosphatidylcholine (DSPC)/cholesterol liposomes produced little accumulation in the lung. In mice used as a model of lung cancer metastasis, ATRA incorporated in DOTAP/cholesterol liposomes, injected intravenously, reduced the number of tumor nodules compared with free ATRA or ATRA incorporated in DSPC/cholesterol liposomes. These results suggest that ATRA incorporated in cationic liposomes would be an effective strategy for differentiation therapy of lung cancer metastasis.     

雷公藤内酯醇抑制小鼠肾小球系膜细胞表达CXCL10的实验研究

目的探讨雷公藤内酯醇(triptolide,TPL)对γ干扰素(interferon-γ,IFN-γ)诱导的小鼠肾小球系膜细胞(SV40MES13)表达趋化因子CXCL10 m RNA的影响及其可能机制。方法将对数生长期SV40MES13随机分为空白组、刺激组、干预组,用不同浓度的IFN-γ(0U/ml~2000U/ml)刺激细胞不同时间(0h~48h)后,观察细胞表达CXCL10 m RNA的变化;用CCK-8法检测不同浓度(2ng/ml~20ng/ml)TPL对SV40MES13生存率的影响,选用细胞生存率大于90%的TPL用于后续实验,观察TPL对SV40MES13表达CXCL10 m RNA的影响;选用JAK/STAT信号通路特异性抑制剂AG490干预细胞,探讨IFN-γ是否通过JAK/STAT信号通路诱导CXCL10表达;收集以上细胞,用Real-Time PCR技术检测各组CXCL10 m RNA表达水平。结果 IFN-γ能诱导SV40MES13表达CXCL10 m RNA,并呈时间、剂量依赖性;AG490具有抑制IFN-γ诱导的SV40MES13表达CXCL10 m RNA;TPL具有抑制IFN-γ诱导的SV40MES13表达CXCL10 m RNA的作用。结论 IFN-γ可能通过激活JAK/STAT信号通路,诱导SV40MES13表达CXCL10 m RNA;TPL具有抑制IFN-γ诱导的SV40MES13表达CXCL10的作用。     

CXCL8, CXCL9, and CXCL10 serum levels increase in syphilitic patients with seroresistance

BackgroundRecently, the rise of syphilitic seroresistance brings great confusion to the clinical diagnosis and treatment of syphilis, and no clear diagnostic marker has been found to distinguish syphilitic seroresistance from other progression of syphilis. This study evaluated the serum chemokines levels of CCL2, CXCL8, CXCL9, and CXCL10 and its correlation with blood routine, coagulation, and biochemical indexes in seroresistant syphilitic patients.MethodSerum levels of chemokines were quantitatively determined by Flow Cytometric Bead Array (CBA). The results expressed in pg/ml. Clinical parameters were detected and analyzed according to the clinical laboratory standards. A correlation analysis was subsequently performed.ResultsThe seroresistant syphilitic patients increased significantly serum chemokines levels of CXCL8 (***p < 0.001), CXCL9 (***p < 0.001), and CXCL10 (**p < 0.01) when compared to noninfected individuals, but the CCL2 was not statistically significant, and serum CXCL8 shows a strong association with platelets (r = 0.51, **p = 0.004) and serum CXCL10 was significantly positively related to INR levels (r = 0.49, **p = 0.007).ConclusionIncreasing serum abnormalities in CXCL8, CXCL9, and CXCL10 level combining with platelets of peripheral blood and plasmatic INR in syphilis patients may be helpful for the diagnosis of serofast state.