Thrombin and TNF-alpha/IL-1beta synergistically induce fibroblast-mediated collagen gel degradation

Comprehensive Analysis to Identify Rh Family C Glycoprotein (RHCG) as the Causative Gene for Psoriasis and Search for Alternative Treatment Modalities

Background

Psoriasis is a complex autoimmune disease. Frequent interactions between epidermal and immune cells are likely to be responsible for the strong heterogeneity of psoriasis. Therefore, our work aims to build on current knowledge and further search for new molecular mechanisms related to psoriasis pathogenesis in order to develop new targeted drugs.

Methods

Data from psoriasis samples were obtained from the Gene Expression Omnibus (GEO) database, and batch effects were corrected using the "Combat" algorithm in the "SVA" package. Functional annotation of differential genes in psoriasis was performed by Gene set enrichment analysis (GSEA). Core functional modules were identified using the Multiscale Embedded Gene Co-Expression Network Analysis (MEGENA) algorithm for selection from the differential gene interaction network. The expression and potential function of Rh Family C Glycoprotein (RHCG) was predicted in single cell data by the "Seurat" package and validated in psoriasis samples by multiplex immunofluorescence. In addition, the regulatory function of HOP Homeobox (HOPX) on RHCG in keratinocytes was confirmed using RNA interference. Using immune infiltration analysis, RHCG and DC cells were analyzed for their association. Finally, the molecular mechanisms of treatment of psoriasis using Tripterygii Radix (TR) and Cinnamomi Ramulus (CR) were explored through network pharmacology and experimental validation.

Results

Immune response (represented by C1_2) and collagen matrix formation (represented by C1_3) were identified as two important pathogenic factors in psoriasis and helped to define new biological subtypes of psoriasis. One important psoriasis hub gene, RHCG, was obtained and found to be closely associated with keratinocyte differentiation as well as DC cell maturation. And RHCG was regulated by HOPX in keratinocytes. In addition, the mechanism of action of CR and TR in the treatment of psoriasis was tentatively confirmed to be related to TRPV3, NFKB2, and YAP1.

Conclusions

Our study identifies a new causal disease gene (RHCG) and offers potential alternatives for the treatment of psoriasis.

Hypoxia-induced Fascin-1 upregulation is regulated by Akt/Rac1 axis and enhances malignant properties of liver cancer cells via mediating actin cytoskeleton rearrangement and Hippo/YAP activation

In solid tumors, hypoxia facilitates malignant progression of cancer cells by triggering epithelial-mesenchymal transition (EMT) and cancer stemness. Fascin-1, an actin-bundling protein, takes part in the formation of many actin-based cellular structures. In the present study, we explored the potential functions of hypoxia-induced upregulation of Fascin-1 in liver cancer. Transcriptome RNA-sequencing was conducted to identify hypoxia-related genes. The potential functions of Fascin-1 were evaluated by western blot, transwell migration and invasion assays, sphere-formation assay, tumor xenograft growth, gelatin zymography analysis, immunofluorescence, cell viability assay, soft agar assay, and flow cytometry. We found that Fascin-1 was upregulated by hypoxia in liver cancer cell lines, elevated in liver cancer patients and correlated with larger tumor size, lymph node metastasis, distant metastasis, and shorter overall survival. Knockdown of Fascin-1 suppressed migration, invasion, EMT, stemness, and tumor xenograft growth of liver cancer cells under both normoxia and hypoxia conditions, while forced Fascin-1 expression showed opposite effects. Moreover, hypoxia-induced upregulation of Fascin-1 was regulated by the Akt/Rac1 signaling, and inhibition of Akt/Rac1 signaling by EHop-016 and MK-2206 restrained migration, invasion, EMT, and stemness of liver cancer cells under hypoxia. Furthermore, Fascin-1 knockdown suppressed MMP-2 and MMP-9 expression, impaired actin cytoskeleton rearrangement, inactivated Hippo/YAP signaling, and increased Sorafenib sensitivity in liver cancer cells. Our study provided a novel insight of Fascin-1 in regulating migration, invasion, EMT, and stemness of liver cancer cells under normoxia and hypoxia conditions.

Single Nucleotide Polymorphisms from CSF2, FLT1, TFPI and TLR9 Genes Are Associated with Prelabor Rupture of Membranes

A prelabor rupture of membranes (PROM) and its subtypes, preterm PROM (pPROM) and term PROM (tPROM), are associated with disturbances in the hemostatic system and angiogenesis. This study was designed to demonstrate the role of single nucleotide polymorphisms (SNPs), localized in CSF2 (rs25881), FLT1 (rs722503), TFPI (C-399T) and TLR9 (rs352140) genes, in PROM. A population of 360 women with singleton pregnancy consisted of 180 PROM cases and 180 healthy controls. A single-SNP analysis showed a similar distribution of genotypes in the studied polymorphisms between the PROM or the pPROM women and the healthy controls. Double-SNP TT variants for CSF2 and FLT1 polymorphisms, CC variants for TLR9 and TFPI SNPs, TTC for CSF2, FLT1 and TLR9 polymorphisms, TTT for FLT1, TLR9 and TFPI SNPs and CCCC and TTTC complex variants for all tested SNPs correlated with an increased risk of PROM after adjusting for APTT, PLT parameters and/or pregnancy disorders. The TCT variants for the CSF2, FLT1 and TLR9 SNPs and the CCTC for the CSF2, FLT1, TLR9 and TFPI polymorphisms correlated with a reduced risk of PROM when corrected by PLT and APTT, respectively. We concluded that the polymorphisms of genes, involved in hemostasis and angiogenesis, contributed to PROM.

A role for the NLRC4 inflammasome in premature rupture of membrane

PROM is one of the common complications of perinatal period, which seriously threatens the mother and newborn. The purpose of this study was to identify the role of NLRC4 inflammasomes in this process and their underlying mechanisms. We performed high-throughput RNA sequencing of fetal membrane tissue from 3 normal pregnant women and 3 term-premature rupture of fetal membrane (TPROM) patients who met the inclusion criteria, and found that NLRC4 was significantly up-regulated in TPROM patients. An observational study of TPROM patients (PROM group, n = 30) and normal pregnant women (control group, n = 30) was performed at the Xuzhou Maternal and Child Health Hospital affiliated to Xuzhou Medical University from May 2018 to May 2019. The expression of genes involved in inflammasome complex including NLRC1, NLRC3, AIM2, NLRC4, ASC, caspase-1, IL-6, IL-18 and IL-1βwas determined via real-time PCR, immunohistochemistry and immunofluorescence. Measurement of NLRC4 level in serum was conducted by ELISA assay. The results showed that the NLRC4, ASC, caspase-1, IL-1β and IL-18 levels in fetal membrane, placental tissues and maternal serum were markedly higher in the PROM group than that in the control group. In conclusion, NLRC4 is a markedly up-regulated gene in TPROM fetal membrane tissue, suggesting that NLRC4 is involved in the occurrence and development of TPROM; NLRC4 levels in maternal blood serum are closely related to TPROM and have the potential to assist doctors in predicting and diagnosing PROM.

Straight to the heart: Pleiotropic antiarrhythmic actions of oral anticoagulants

Mechanistic understanding of atrial fibrillation (AF) pathophysiology and the complex bidirectional relationship with thromboembolic risk remains limited. Oral anticoagulation is a mainstay of AF management. An emerging concept is that anticoagulants may themselves have potential pleiotropic disease-modifying effects. We here review the available evidence for hemostasis-independent actions of the oral anticoagulants on electrical and structural remodeling, and the inflammatory component of the vulnerable substrate.

Glycine improves the remodeling process of tenocytes in vitro

Tendinitis changes the biochemical and morphological properties of the tendon, promoting an increase of activity of metalloproteinases and disorganization of collagen bundles. Tenocytes, the primary cells in tendon, are scattered throughout the collagenic fibers, and are responsible of tendon remodeling and tissue repair in pathological condition. In vivo, glycine, component of the typical Gly-X-Y collagen tripeptide, showed beneficial effects in biochemical and biomechanical properties of Achilles tendon with tendinitis. In this study, we analyzed the effect of glycine in tenocytes subjected to inflammation. Tenocytes from Achilles tendon of rats were treated with TNF-α (10 ng/mL) with and without previous treatment with glycine (20 mM). Cell proliferation and migration were evaluated, as well as the expression of matrix molecules such as glycosaminoglycans, metalloproteinases (MMPs), TIMPs, and collagen I. Glycine can revert the inflammation due to the action of TNF-α by controlling the MMPs quantity and activity. These data indicated that the molecules involved to remodeling process of extracellular matrix are modulated both by TNF-α and the availability of collagen precursors; in fact, this study indicates the glycine can be useful for treatment of inflammation and for modulating tenocytes metabolism in tendons.

Role of corneal collagen fibrils in corneal disorders and related pathological conditions

The cornea is a soft tissue located at the front of the eye with the principal function of transmitting and refracting light rays to precisely sense visual information. Corneal shape, refraction, and stromal stiffness are to a large part determined by corneal fibrils, the arrangements of which define the corneal cells and their functional behaviour. However, the modality and alignment of native corneal collagen lamellae are altered in various corneal pathological states such as infection, injury, keratoconus, corneal scar formation, and keratoprosthesis. Furthermore, corneal recuperation after corneal pathological change is dependent on the balance of corneal collagen degradation and contraction. A thorough understanding of the characteristics of corneal collagen is thus necessary to develop viable therapies using the outcome of strategies using engineered corneas. In this review, we discuss the composition and distribution of corneal collagens as well as their degradation and contraction, and address the current status of corneal tissue engineering and the progress of corneal cross-linking.

The physiology of fetal membrane weakening and rupture: Insights gained from the determination of physical properties revisited

Rupture of the fetal membranes (FM) is precipitated by stretch forces acting upon biochemically mediated, pre-weakened tissue. Term FM develop a para-cervical weak zone, characterized by collagen remodeling and apoptosis, within which FM rupture is thought to initiate. Preterm FM also have a weak region but are stronger overall than term FM. Inflammation/infection and decidual bleeding/abruption are strongly associated with preterm premature FM rupture (pPROM), but the specific mechanisms causing FM weakening-rupture in pPROM are unknown. There are no animal models for study of FM weakening and rupture. Over a decade ago we developed equipment and methodology to test human FM strength and incorporated it into a FM explant system to create an in-vitro human FM weakening model system. Within this model TNF (modeling inflammation) and Thrombin (modeling bleeding) both weaken human FM with concomitant up regulation of MMP9 and cellular apoptosis, mimicking the characteristics of the spontaneous FM rupture site. The model has been enhanced so that test agents can be applied directionally to the choriodecidual side of the FM explant consistent with the in-vivo situation. With this enhanced system we have demonstrated that the pathways involving inflammation/TNF and bleeding/Thrombin induced FM weakening overlap. Furthermore GM-CSF production was demonstrated to be a critical common intermediate step in both the TNF and the Thrombin induced FM weakening pathways. This model system has also been used to test potential inhibitors of FM weakening and therefore pPROM. The dietary supplement α-lipoic acid and progestogens (P4, MPA and 17α-hydroxyprogesterone) have been shown to inhibit both TNF and Thrombin induced FM weakening. The progestogens act at multiple points by inhibiting both GM-CSF production and GM-CSF action. The use of a combined biomechanical/biochemical in-vitro human FM weakening model system has allowed the pathways of fetal membrane weakening to be delineated, and agents that may be of clinical use in inhibiting these pathways to be tested.

MCPIP1 mediates silica-induced cell migration in human pulmonary fibroblasts

Silicosis is a systemic disease caused by inhaling silicon dioxide (SiO2). Phagocytosis of SiO2 in the lungs initiates an inflammatory cascade that results in fibroblast proliferation and migration followed by fibrosis. According to previous data from our laboratory, monocyte chemotactic protein-1 (MCP-1) plays a critical role in fibroblast proliferation and migration in conventional two-dimensional (2D) monolayer cultures. The present study aimed to explore the downstream cascade of MCP-1 in both 2D and three-dimensional (3D) cell culture models of silicosis. Experiments using primary cultured adult human pulmonary fibroblasts (HPF-a) demonstrated the following: 1) SiO2 treatment induces expression of MCP-1-induced protein (MCPIP1) in a time- and dose-dependent manner in both 2D and 3D cultures; 2) the MAPK and phosphatidylinositol-3-kinase (PI3K)/Akt pathways are involved in SiO2-induced MCPIP1 expression; and 3) MCPIP1 induction mediates the SiO2-induced increase in cell migration in both 2D and 3D cultures. The effect of MCP-1 in silicosis occurs mainly through MCPIP1, which, in turn, mediates the observed SiO2-induced increase in pulmonary fibroblast migration. However, the time frame for MCPIP1 induction differed between 2D and 3D cultures, indicating that, compared with conventional 2D cell culture systems, 3D culture may be useful for analyses of fibroblast physiology under conditions that more closely resemble in vivo environments. Our study determined the link between fibroblast-derived MCPIP1 and SiO2-induced cell migration, and this finding provides novel evidence of the potential of MCPIP1 in the development of novel therapeutic strategies for silicosis.

Thrombin decreases expression of the glutamate transporter GLAST and inhibits glutamate uptake in primary cortical astrocytes via the Rho kinase pathway

Astrocyte glutamate transporters GLAST and GLT1 play a key role in regulating neuronal excitation and their levels are altered in patients with epilepsy, and after traumatic brain injury. The mechanisms which regulate their expression are not well understood. We tested the hypothesis that exposure of astrocytes to high levels of thrombin, as may occur after a compromise of the blood-brain barrier, would reduce astrocyte glutamate transporter levels. In isolated rat cortical astrocytes we examined the effects of thrombin on the expression and function of glutamate transporters, and the signaling pathways involved in these responses by using Western blotting and selective inhibitors. Thrombin induced a selective decrease in the expression of GLAST but not GLT1, with a corresponding decrease in the capacity of astrocytes to take up glutamate. Activation of the thrombin receptor PAR-1 with an activating peptide induced a similar decrease in the expression of GLAST and compromise of glutamate uptake. The downregulation of GLAST induced by thrombin was mediated by the mitogen activated protein kinases p38 MAPK, ERK and JNK, but inhibition of these kinases did not prevent the decrease in glutamate uptake induced by thrombin. In contrast, inhibition of the Rho kinase pathway using the specific inhibitor, Y27632, suppressed both the decrease in the expression of GLAST and the decrease in glutamate uptake induced by thrombin. In hippocampal astrocyte cultures, thrombin caused a decrease in both GLAST and GLT1. In tissue resected from brains of children with intractable epilepsy, we found a decrease in the integrity of the blood-brain barrier along with a reduction in immunoreactivity for both transporters which was associated with an increase in cleaved thrombin and reactive astrogliosis. The in vitro results suggest a specific mechanism by which thrombin may lead to a compromise of astrocyte function and enhanced synaptic excitability after the blood-brain barrier is compromised. The human in vivo results provide indirect support evidence linking the compromise of the blood-brain barrier to thrombin-induced reduction in glutamate transporter expression and an increase in neuronal excitation.

MiR-29a reduces TIMP-1 production by dermal fibroblasts via targeting TGF-β activated kinase 1 binding protein 1, implications for systemic sclerosis

Background

Systemic sclerosis (SSc) is an autoimmune connective tissue disease characterised by skin and internal organs fibrosis due to accumulation of extra cellular matrix (ECM) proteins. Tissue inhibitor of metalloproteinases 1 (TIMP-1) plays a key role in ECM deposition.

Aim

To investigate the role of miR-29a in regulation of TAB1-mediated TIMP-1 production in dermal fibroblasts in systemic sclerosis.

Methods

Healthy control (HC) and SSc fibroblasts were cultured from skin biopsies. The expression of TIMP-1, MMP-1 and TGF-β activated kinase 1 binding protein 1 (TAB1) was measured following miR-29a transfection using ELISA, qRT-PCR, and Western Blotting. The functional effect of miR-29a on dermal fibroblasts was assessed in collagen gel assay. In addition, HeLa cells were transfected with 3′UTR of TAB1 plasmid cloned downstream of firefly luciferase gene to assess TAB1 activity. HC fibroblasts and HeLa cells were also transfected with Target protectors in order to block the endogenous miR-29a activity.

Results

We found that TAB1 is a novel target gene of miR-29a, also regulating downstream TIMP-1 production. TAB1 is involved in TGF-β signal transduction, a key cytokine triggering TIMP-1 production. To confirm that TAB1 is a bona fide target gene of miR-29a, we used a TAB1 3′UTR luciferase assay and Target protector system. We showed that miR-29a not only reduced TIMP-1 secretion via TAB1 repression, but also increased functional MMP-1 production resulting in collagen degradation. Blocking TAB1 activity by pharmacological inhibition or TAB1 knockdown resulted in TIMP-1 reduction, confirming TAB1-dependent TIMP-1 regulation. Enhanced expression of miR-29a was able to reverse the profibrotic phenotype of SSc fibroblasts via downregulation of collagen and TIMP-1.

Conclusions

miR-29a repressed TAB1-mediated TIMP-1 production in dermal fibroblasts, demonstrating that miR-29a may be a therapeutic target in SSc.

Intervention of transforming pulmonary fibrosis with NF-κB p65 antisense oligonucleotide

OBJECTIVE

NF-κB, especially p65 subunit, plays important role in the process of pulmonary fibrosis. In this study, we transformed fibroblast into myofibroblast induced by bleomycin, and then studied the effects of NF-κB p65 antisense oligonucleotide on pulmonary fibrosis in mouse model.

METHODS

Pulmonary fibrosis was induced by bleomycin in C57BL/6 mouse (modeling group). The NF-κB antisense oligonucleotide was injected intravenously into mouse 6 hours before inducing (test group), we performed broncho-alveolar lavage and blood collecting through cardiac puncture. Bronchoalveolar Lavage Fluid (BALF) and serum from normal C57BL/6 mouse (control group) were collected for comparison. Immunohistochemistry staining of the NF-κB and α-SMA on lung tissues and cultured cells were carried out in each group, respectively.

RESULTS

The expression level of NF-κB and α-SMA were both consistently higher in modeling group when compared with control group (P < 0.05). Meanwhile, they were reduced significantly through the intervention of NF-κB p65 antisense oligonucleotide in the test group (P < 0.05). More importantly, the expression of NF-κB was positively correlated with α-SMA.

CONCLUSION

our study suggests the potential in prevention of bleomycin-induced pulmonary fibrosis with NF-κB p65 antisense oligonucleotide.

The application of the starfish hatching enzyme for the improvement of scar and keloid based on the fibroblast-populated collagen lattice

Various bioactivities of the starfish hatching enzyme (HE) including collagen gel contraction, MMPs activity, hydroxyproline release, and gene regulation based on the fibroblast-populated collagen lattice (FPCL) in three-dimensional medium were investigated for the improvement of scar and keloid. The starfish HE significantly inhibited the collagen gel contraction over 2 days of culture. MMP-2 and MMP-9 activities were also identified by gelatin zymography and RT-PCR products with both HE and collagenase treatments, which resulted in the high amount of hydroxyproline release. The HE treatment on the FPCL significantly inhibited the fibroblast proliferation at 3 days of culture. The LPS-induced NO level and iNOS mRNA expression at low concentrations of HE presented a certain ability to inflammatory response. The COX-2 mRNA from the FPCL indicated no significant inflammation-mediated activity at 5 μg/mL of HE, whereas the cytokines of TNF-α and IL-1β were significantly higher than those of the control. Hence, the starfish hatching enzyme can regulate the fibroblast-populated collagen gel conditions by the contraction, MMP production, inflammatory gene expression, etc. Therefore, the starfish HE could be a potential cosmeceutical to heal the scar and keloid tissue.

Hemostasis and alterations of the central nervous system

Modulation of coagulation has been successfully applied to ischemic disorders of the central nervous system (CNS). Some components of the coagulation system have been identified in the CNS, yet with limited exception their functions have not been clearly defined. Little is known about how events within the cerebral tissues affect hemostasis. Nonetheless, the interaction between cerebral cells and vascular hemostasis and the possibility that endogenous coagulation factors can participate in functions within the neurovascular unit provide intriguing possibilities for deeper insight into CNS functions and the potential for treatment of CNS injuries. Here, we consider the expression of coagulation factors in the CNS, the coagulopathy associated with focal cerebral ischemia (and its relationship to hemorrhagic transformation), the use of recombinant tissue plasminogen activator (rt-PA) in ischemic stroke and its study in animal models, the impact of rt-PA on neuron and CNS structure and function, and matrix protease generation and matrix degradation and hemostasis. Interwoven among these topics is evidence for interactions of coagulation factors with and within the CNS. How activation of hemostasis occurs in the cerebral tissues and how the brain responds are difficult questions that offer many research possibilities.

Effect of budesonide on fibroblast-mediated collagen gel contraction and degradation

Background

The balance between production and degradation of extracellular matrix is crucial in maintaining normal tissue structure. This study was designed to investigate the effect of budesonide on fibroblast-mediated tissue repair and remodeling.

Methods

Using human fetal lung fibroblasts in a three-dimensional collagen gel culture system, we investigated the effect of budesonide (1-1000 nM) on collagen gel contraction and degradation in the presence or absence of Inflammatory cytokines (interleukin-1β and tumor necrosis factor α; 5 ng/mL each) and, in order to activate latent proteases, serine protease trypsin 0.25 μg/mL. The effects of budesonide on metalloproteinase production and activation were also investigated.

Results

Inflammatory cytokines significantly inhibited collagen gel contraction mediated by lung fibroblasts. Budesonide counteracted the effect of cytokines in a concentration-dependent manner (to 50%, P< 0.01). Budesonide 100 nM almost completely inhibited the release and mRNA expression of metalloproteinase-1, metalloproteinase-3, and metalloproteinase-9 induced by the cytokines (P< 0.05). Exposure to the cytokines plus trypsin increased collagen degradation and conversion of the metalloproteinases to lower molecular weight forms corresponding to their active forms. Budesonide blocked both enhanced collagen degradation (P< 0.01) and suppressed trypsin-mediated conversion of cytokine-induced metalloproteinase-9 and metalloproteinase-3 to lower molecular weight forms. Similar effects were observed with dexamethasone 1 μM, suggesting a class effect.

Conclusion

These findings demonstrate that budesonide directly modulates contraction of collagen gels and can decrease collagen degradation under Inflammatory conditions. The mechanism of this effect is through suppressing gene expression, release, and activation of metalloproteinases. By modulating the release and activity of metalloproteinases, inhaled budesonide may be able to modify airway tissue repair and remodeling.

Pin1 protein regulates Smad protein signaling and pulmonary fibrosis

Interstitial pulmonary fibrosis is caused by the excess production of extracellular matrix (ECM) by Fb in response to TGF-β1. Here, we show that the peptidyl-prolyl isomerase Pin1 modulates the production of many pro- and antifibrogenic cytokines and ECM. After acute, bleomycin injury, Pin1(-/-) mice showed reduced, pulmonary expression of collagens, tissue inhibitors of metalloproteinases, and fibrogenic cytokines but increased matrix metalloproteinases, compared with WT mice, despite similar levels of inflammation. In primary fibroblasts, Pin1 was required for TGF-β-induced phosphorylation, nuclear translocation, and transcriptional activity of Smad3. In Pin1(-/-) cells, inhibitory Smad6 was found in the cytoplasm rather than nucleus. Smad6 knockdown in Pin1(-/-) fibroblasts restored TGF-β-induced Smad3 activation, translocation, and target gene expression. Therefore, Pin1 is essential for normal Smad6 function and ECM production in response to injury or TGF-β and thus may be an attractive therapeutic target to prevent excess scarring in diverse lung diseases.

TFPI-2 silencing increases tumour progression and promotes metalloproteinase 1 and 3 induction through tumour-stromal cell interactions

Tissue factor pathway inhibitor-2 (TFPI-2) is a potent inhibitor of plasmin which activates matrix metalloproteinases (MMPs) involved in degradation of the extracellular matrix. Its secretion in the tumour microenvironment makes TFPI-2 a potential inhibitor of tumour invasion and metastasis. As demonstrated in aggressive cancers, TFPI-2 is frequently down-regulated in cancer cells, but the mechanisms involved in the inhibition of tumour progression remained unclear. We showed in this study that stable TFPI-2 down-regulation in the National Cancer Institute (NCI)-H460 non-small cell lung cancer cell line using specific micro interfering micro-interfering RNA promoted tumour progression in a nude mice orthotopic model that resulted in an increase in cell invasion. Moreover, TFPI-2 down-regulation enhanced cell adhesion to collagen IV and laminin via an increase in α₁ integrin on cell surface, and increased MMP expression (mainly MMP-1 and -3) contributing to cancer cell invasion through basement membrane components. This study also reveals for the first time that pulmonary fibroblasts incubated with conditioned media from TFPI-2 silencing cancer cells exhibited increased expression of MMPs, particularly MMP-1, -3 and -7, that are likely involved in lung cancer cell invasion through the surrounding stromal tissue, thus enhancing formation of metastases.

Regulated expressions of MMP-2, -9 by diterpenoids from Euphorbia formosana Hayata

Two new abietane type diterpenoids, namely seco-helioscopinolide (1) and 3b,7b-dihydroxy-ent-abieta-8,13-diene-12,16-olide (2) were isolated from the aerial parts of Euphorbia formosana Hayata together with helioscopinolide A (3), helioscopinolide B (4), helioscopinolide C (5) and ent-(5b,8a,9b,10a,12a)-12-hydroxyatis-16-ene-3,14-dione (6). The structures of compounds 1-6 were elucidated by analyzing their spectroscopic data and comparison with the literature. Further biological tests by gelatin zymographic analysis revealed that 3-5 significantly up-regulated the expressions and activation of MMP-2 and -9 in human fibrosarcoma cell line HT1080.

The effects of thrombin and cytokines upon the biomechanics and remodeling of isolated amnion membrane, in vitro

Abruption-induced thrombin generation and inflammation/infection induced cytokine production have both been associated with fetal membrane (FM) weakening and preterm premature rupture of the fetal membranes (PPROM). Using our in vitro model system we have demonstrated that thrombin, and separately the cytokines, tumor necrosis factor-alpha (TNFα) and interleukin-1-beta (IL-1β), remodel and weaken full thickness FM. Additionally, we have reported that the anti-oxidant and NFκB inhibitor, alpha-lipoic acid (LA), blocks these thrombin and cytokine induced effects. The purpose of these studies was to determine whether thrombin and cytokines directly weaken the amnion membrane (AM), the major load-bearing component of FM. Isolated AM or full thickness FM fragments from unlabored Cesarean deliveries were incubated with thrombin, TNFα, or IL-1β, for 48 h. Rupture strength (breaking force) of each fragment was thereafter determined using our published methodology. Biochemical evidence of remodeling and apoptosis; immunoreactive Matrix Metalloproteinase 9 (MMP9), Tissue Inhibitor of Matrix Metalloproteinase 3 (TIMP3) and cleaved poly (ADP-ribose) polymerase (C-PARP) levels in tissue extracts, were determined by western blot and densitometry. Thrombin induced a dose-dependent weakening of isolated AM (P < 0.001) coupled with dose dependent increases in PARP cleavage, and reciprocal increases and decreases, respectively, in MMP9 and TIMP3 protein (all P < 0.01). Thrombin receptor activating peptide-6 (TRAP) also weakened isolated AM. Neither TNFα nor IL-1β weakened isolated AM. However, both cytokines weakened AM when it was incubated together with the choriodecidua as part of full thickness FM (P < 0.001). Cytokine-conditioned choriodecidua medium also weakened isolated AM (P < 0.001). Under conditions in which cytokines weakened the AM, the changes in MMP9, TIMP3 and PARP cleavage were consistent with those seen after thrombin incubation. LA blocked the FM weakening and remodeling effects. In summary, thrombin weakens AM directly whereas cytokines weaken AM indirectly by causing the release of soluble intermediates from the choriodecidua.

The P2Y(2) nucleotide receptor mediates tissue factor expression in human coronary artery endothelial cells

The discovery of the role of P2Y(12) receptor in platelet aggregation leads to a new anti-thrombotic drug Plavix; however, little is known about non-platelet P2Y receptors in thrombosis. This study tested the hypothesis that endothelial P2Y receptor(s) mediates up-regulation of tissue factor (TF), the initiator of coagulation cascade. Stimulation of human coronary artery endothelial cells (HCAEC) by UTP/ATP increased the mRNA level of TF but not of its counterpart-tissue factor pathway inhibitor, which was accompanied by up-regulation of TF protein and cell surface activity. RT-PCR revealed a selective expression of P2Y(2) and P2Y(11) receptors in HCAEC. Consistent with this, TF up-regulation was inhibited by suramin or by siRNA silencing of P2Y(2) receptor, but not by NF-157, a P2Y(11)-selective antagonist, suggesting a role for the P2Y(2) receptor. In addition, P2Y(2) receptor activated ERK1/2, JNK, and p38 MAPK pathways without affecting the positive NF-κB and negative AKT regulatory pathways of TF expression. Furthermore, TF up-regulation was abolished or partially suppressed by inhibition of p38 or JNK but not ERK1/2. Interestingly, blockade of the PLC/Ca(2+) pathway did not affect P2Y(2) receptor activation of p38, JNK, and TF induction. However, blockade of Src kinase reduced phosphorylation of p38 but not JNK, eliminating TF induction. In contrast, inhibition of Rho kinase reduced phosphorylation of JNK but not p38, decreasing TF expression. These findings demonstrate that P2Y(2) receptor mediates TF expression in HCAEC through new mechanisms involving Src/p38 and Rho/JNK pathways, possibly contributing to a pro-thrombotic status after vascular injury.

Transforming growth factor-β1 suppresses the up-regulation of matrix metalloproteinase-2 by lung fibroblasts in response to tumor necrosis factor-α

Exposed to inflammatory factors or cytokines, fibroblasts appear to play additional roles beyond the deposition of extracellular matrix. It has been reported that tumor necrosis factor-α (TNF-α) induces the production of matrix metalloproteinase-2 (MMP-2) and transforming growth factor-β1 (TGF-β1) in fibroblasts. In this study, we demonstrated that the active MMP-2 secreted by lung fibroblasts reached the peak level at 12 hours after TNF-α treatment, whereas, by adding anti-TGF-β1 antibody in the culture medium, the MMP-2 production in response to TNF-α was maintained at high levels after 24 hours of treatment. We also confirmed that TNF-α induced up-regulation of active TGF-β1 and exogenous TGF-β1 induced down-regulation of MMP-2 synthesis in lung fibroblasts. Moreover, an increased MMP-2 level was observed in a rat model with pulmonary inflammation and fibrosis induced by bleomycin-A5. This revealed that MMP-2 in the lung reached the peak level when TNF-α reached the peak level at the 7th day, and then MMP-2 decreased along with an increase in the TGF-β1 level. Taken together, our results demonstrate that TNF-α induced an increase of MMP-2 and TGF-β1 in lung fibroblasts, and the TGF-β1 attenuated the up-regulation of MMP-2. This suggests that MMP-2 secreted from fibroblasts modulated by TNF-α/TGF-β1 might play an important role in pulmonary inflammation and fibrosis.

Coagulation and autoimmunity in scleroderma interstitial lung disease

OBJECTIVES

Interstitial lung disease in systemic sclerosis (SSc-ILD) is often an irreversible and progressive fibrosing process that now is the leading cause of scleroderma-related deaths. In this review we present our current understanding of the role played by coagulation and particularly by thrombin in autoimmune-mediated tissue injury and fibrosis, mainly as it relates to SSc-ILD.

METHODS

We used PubMed to search for articles published up to October 2010 for keywords referring to autoimmunity, coagulation, pulmonary fibrosis, and scleroderma.

RESULTS

SSc-ILD is an autoimmune disease associated with lymphocyte activation and release of various cytokines and growth factors. The production of autoantibodies is a central feature in SSc. Activation of the coagulation cascade with release of thrombin is 1 of the earliest events following tissue injury. Thrombin contributes to autoimmune responses by activating of pathogenic Th2 lymphocyte profile in SSc. Thrombin also modulates tissue repair responses, stimulates transformation of epithelial cells, endothelial cells, and fibroblasts into myofibroblast phenotype, and induces secretion of several pro-immune and profibrotic factors, which serve as antigens for pathogenic autoantibodies production in SSc-ILD.

CONCLUSIONS

The identification of links between autoimmunity and coagulation would provide new insights into the pathogenesis of pulmonary fibrosis associated with autoimmune diseases and further acknowledge the importance of thrombin in the development of SSc-ILD.

Alpha-lipoic acid inhibits thrombin-induced fetal membrane weakening in vitro

Cytokine-mediated inflammation and abruption-induced thrombin generation are separately implicated in matrix metalloproteinase (MMP)-mediated weakening of fetal membranes (FM) leading to preterm premature rupture of the fetal membranes (PPROM). At term, FM of both labored vaginal and unlabored Cesarean deliveries exhibit a weak zone overlying the cervix exhibiting ECM remodeling characterized by increased MMP9 protein and activity. We have reproduced these biochemical changes as well as FM weakening in vitro using tumor necrosis factor-alpha (TNF) and interleukin (IL)-1β, inflammatory cytokines implicated in PPROM. Additionally, we have reported that the antioxidant and NFκB inhibitor alpha-lipoic Acid (LA) blocks these TNF-induced effects. We now present the first direct evidence that thrombin also can induce FM weakening in vitro, and LA treatment inhibits this thrombin-induced-weakening. Full thickness FM fragments from unlabored Cesarean deliveries were incubated with increasing doses of thrombin (0-100 u/ml) for 48 h. Fragments were then strength tested (breaking force and work to rupture) using our published methodology. MMP3 and 9 levels in tissue extracts were determined by Western blot and densitometry. To determine the effect of LA, FM fragments were incubated with control medium or 10 u/ml thrombin, with or without 0.25 mM LA. Strength testing and MMP induction were determined. Thrombin induced a dose-dependent decrease in FM strength (42% baseline rupture force and 45% work to rupture) coupled with a dose-dependent increase in MMP3 and 9 expression (all p < 0.001). Treatment of FM with 0.25 mM LA completely inhibited thrombin-induced FM weakening and MMP expression (all p < 0.001). Thrombin treatment of cultured FM induces mechanical weakening and increased MMP3 and 9. Treatment of FM with LA inhibits these thrombin-induced effects. We speculate LA may prove clinically useful in prevention of PPROM associated with abruption.

The effect of the pro-inflammatory cytokine tumor necrosis factor-alpha on human joint capsule myofibroblasts

Introduction

Previous studies have shown that the number of myoblastically differentiated fibroblasts known as myofibroblasts (MFs) is significantly increased in stiff joint capsules, indicating their crucial role in the pathogenesis of post-traumatic joint stiffness. Although the mode of MFs' function has been well defined for different diseases associated with tissue fibrosis, the underlying mechanisms of their regulation in the pathogenesis of post-traumatic joint capsule contracture are largely unknown.

Methods

In this study, we examined the impact of the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α) on cellular functions of human joint capsule MFs. MFs were challenged with different concentrations of TNF-α with or without both its specifically inactivating antibody infliximab (IFX) and cyclooxygenase-2 (COX2) inhibitor diclofenac. Cell proliferation, gene expression of both alpha-smooth muscle actin (α-SMA) and collagen type I, the synthesis of prostaglandin derivates E₂, F_1A, and F_2A, as well as the ability to contract the extracellular matrix were assayed in monolayers and in a three-dimensional collagen gel contraction model. The α-SMA and COX2 protein expressions were evaluated by immunofluorescence staining and Western blot analysis.

Results

The results indicate that TNF-α promotes cell viability and proliferation of MFs, but significantly inhibits the contraction of the extracellular matrix in a dose-dependent manner. This effect was associated with downregulation of α-SMA and collagen type I by TNF-α application. Furthermore, we found a significant time-dependent upregulation of prostaglandin E₂ synthesis upon TNF-α treatment. The effect of TNF-α on COX2-positive MFs could be specifically prevented by IFX and partially reduced by the COX2 inhibitor diclofenac.

Conclusions

Our results provide evidence that TNF-α specifically modulates the function of MFs through regulation of prostaglandin E₂ synthesis and therefore may play a crucial role in the pathogenesis of joint capsule contractures.

Roles and regulation of Thy-1, a context-dependent modulator of cell phenotype

Thy-1 or CD90 is a glycophosphatidylinositol-linked glycoprotein expressed on the surface of neurons, thymocytes, subsets of fibroblasts, endothelial cells, mesangial cells and some hematopoietic cells. Thy-1 is evolutionarily conserved, developmentally regulated, and often has dramatic effects on cell phenotype; however, the effects vary between and in some cases within cell types and tissues, and between similar tissues in different species, indicating that the biological role of Thy-1 is context-dependent. Thy-1 exists in soluble form in some body fluids; however, the mechanisms of its shedding are unknown. In addition, Thy-1 expression can be regulated by epigenetic silencing. Because Thy-1 modulates many basic cellular processes and is involved in the pathogenesis of a number of diseases, it is important to better understand its regulation.

Use of a three-dimensional cell culture model to study airway smooth muscle-mast cell interactions in airway remodeling

Increased airway smooth muscle (ASM) mass and infiltration by mast cells are key features of airway remodeling in asthma. We describe a model to investigate the relationship between ASM, the extracellular matrix, mast cells, and airway remodeling. ASM cells were cultured in a three-dimensional (3-D) collagen I gel (3-D culture) alone or with mast cells. Immunocytochemistry and Western blotting of ASM in 3-D cultures revealed a spindle-shaped morphology and significantly lower alpha-smooth muscle actin and vimentin expression than in ASM cultured in monolayers on collagen type I or plastic (2-D culture). In 3-D cultures, basal ASM proliferation, examined by Ki67 immunocytochemistry, was reduced to 33 +/- 7% (P < 0.05) of that in 2-D cultures. The presence of mast cells in cocultures increased ASM proliferation by 1.8-fold (P < 0.05). Gelatin zymography revealed more active matrix metalloproteinase (MMP)-2 in 3-D than in 2-D culture supernatants over 7 days. Functional MMP activity was examined by gel contraction. The spontaneous gel contraction over 7 days was significantly inhibited by the MMP inhibitor ilomastat. Mast cell coculture enhanced ASM gel contraction by 22 +/- 16% (not significant). Our model shows that ASM has different morphology, with lower contractile protein expression and basal proliferation in 3-D culture. Compared with standard techniques, ASM synthetic function, as shown by MMP production and activity, is sustained over longer periods. The presence of mast cells in the 3-D model enhanced ASM proliferation and MMP production. Airway remodeling in asthma may be more accurately modeled by our system than by standard culture systems.

MMP dependence of fibroblast contraction and collagen production induced by human mast cell activation in a three-dimensional collagen lattice

Mast cell-fibroblast interactions may contribute to fibrosis in asthma and other disease states. Fibroblast contraction is known to be stimulated by coculture with the human mast cell line, HMC-1, or by mast cell-derived agents. Matrix metalloproteinases (MMPs) can also mediate contraction, but the MMP-dependence of mast cell-induced fibroblast contractility is not established, and the consequences of mast cell activation within the coculture system have not been fully explored. We demonstrate that activation of primary human mast cells (pHMC) with IgE receptor cross-linking, or activation of HMC-1 with C5a, enhanced contractility of human lung fibroblasts in a three-dimensional collagen lattice system. This enhanced contractility was inhibited by the pan-MMP antagonist, batimastat, and was transferrable in the conditioned medium of activated mast cells. Exogenously added MMPs promoted gel contraction by mediating the proteolytic activation of latent transforming growth factor-beta (TGF-beta). Consistent with this, fibroblast contraction induced by mast cell activation was enhanced by addition of excess latent TGF-beta to the cultures. Batimastat inhibited this response, suggesting that MMPs capable of activating latent TGF-beta were released following mast cell activation in coculture with fibroblasts. Collagen production was also stimulated by activated mast cells in an MMP-dependent manner. MMP-2 and MMP-3 content of the gels increased in the presence of activated mast cells, and inhibition of these enzymes blocked the contractile response. These findings demonstrate the MMP dependence of mast cell-induced fibroblast contraction and collagen production.

Dendritic cell-derived interferon-gamma-induced protein mediates tumor necrosis factor-alpha stimulation of human lung fibroblasts

Lung fibroblast plays a pivotal role in lung repair and remodeling, and also contributes to lung inflammation. The present study investigated differential protein profiling of normal human lung fibroblasts stimulated with tumor necrosis factor (TNF)-alpha. Total proteins from lung fibroblasts were separated by 2-DE, and differentially expressed proteins were identified by MALDI-TOF MS. TNF-alpha was found for the first time to alter the expression levels of myxovirus resistance protein A, interferon-stimulated gene 15, plasminogen activator inhibitor-2, lysyl hydroxylase 2 (isoform a), and prolyl 4-hydroxylase (alpha subunit) in human lung fibroblasts. In particular, dendritic cell-derived interferon-gamma-induced protein (DCIP) was upregulated by TNF-alpha in lung fibroblasts and its biological function is at present unknown. We found that TNF-alpha-induced DCIP expression was dependent on the transcription factor interferon regulatory factor-1. DCIP-selective antisense oligodeoxynucleotide inhibited the expression of TNF-alpha-responsive gene targets including vascular cell adhesion molecule-1, intercellular adhesion molecule-1, IL-6, IL-8, IP-10, and thymic stromal lymphopoietin. In a lipopolysaccharide-induced acute lung injury mouse model, DCIP mRNA level was elevated together with that of TNF-alpha. We have demonstrated for the first time that DCIP is upregulated by TNF-alpha and also mediates TNF-alpha stimulation of human lung fibroblasts. Further studies on the role of DCIP in airway inflammation and remodeling are warranted.