Metabolic regulator ERRγ governs gastric stem cell differentiation into acid-secreting parietal cells

Parietal cells (PCs) produce gastric acid to kill pathogens and aid digestion. Dysregulated PC census is common in disease, yet how PCs differentiate is unclear. Here, we identify the PC progenitors arising from isthmal stem cells, using mouse models and human gastric cells, and show that they preferentially express cell-metabolism regulator and orphan nuclear receptor Estrogen-related receptor gamma (Esrrg, encoding ERRγ). Esrrg expression facilitated the tracking of stepwise molecular, cellular, and ultrastructural stages of PC differentiation. EsrrgP2ACreERT2 lineage tracing revealed that Esrrg expression commits progenitors to differentiate into mature PCs. scRNA-seq indicated the earliest Esrrg+ PC progenitors preferentially express SMAD4 and SP1 transcriptional targets and the GTPases regulating acid-secretion signal transduction. As progenitors matured, ERRγ-dependent metabolic transcripts predominated. Organoid and mouse studies validated the requirement of ERRγ for PC differentiation. Our work chronicles stem cell differentiation along a single lineage in vivo and suggests ERRγ as a therapeutic target for PC-related disorders.

CADHERIN-11 regulation of myeloid phagocytes and autoimmune inflammation in murine lupus

BACKGROUND AND OBJECTIVE

Understanding the regulation of efferocytosis by myeloid phagocytes is important in identifying novel targets in systemic lupus erythematosus (SLE). Cadherin-11 (CDH11), a cell adhesion molecule, is implicated in inflammatory arthritis and fibrosis and recently been shown to regulate macrophage phagocytosis. The extent and mechanism of this regulation is unknown. Our objective was to examine the extent to which CDH11 regulates myeloid phagocytes and contributes to autoimmunity and tissue inflammation.

METHODS

We analyzed efferocytosis in macrophages and dendritic cells (DCs) from WT and Cdh11-/- mice and investigated the mechanisms in vitro. We investigated the role of CDH11 in disease development in vivo using the pristane induced lupus model. To translate the clinical relevance of CDH11 in human disease, we measured serum CDH11 levels in two independent pediatric SLE (pSLE) cohorts and healthy controls.

RESULTS

Using bone marrow derived macrophages (BMDMs) and DCs (BMDCs), we found impaired efferocytosis in phagocytes from Cdh11-/- mice, mediated by downregulated efferocytosis receptor expression and RhoGTPase activation. Specifically, loss of CDH11 downregulated Mertk expression and Rac1 activation in BMDMs, and integrin αVβ3 expression and Cdc42 activation in BMDCs, highlighting distinct pathways. In vivo, Cdh11-/- mice displayed defective efferocytosis and increased accumulation of apoptotic debris in pristane-induced lupus. Further, Cdh11-/- mice had enhanced systemic inflammation and autoimmune inflammation with increased anti-dsDNA autoantibodies, splenomegaly, type I interferons, and inflammatory cytokines. Paradoxically, at the tissue level, Cdh11-/- mice were protected against glomerulonephritis, indicating a dual role in murine lupus. Finally, SLE patients had increased serum CDH11 compared to controls.

CONCLUSION

This study highlights a novel role of CDH11 in regulating myeloid cells and efferocytosis and its potential as a contributor to development in autoimmunity murine lupus. Despite the increase in autoimmunity, Cdh11-/- mice developed decreased tissue inflammation and damage.

Mechanisms driving fasting-induced protection from genotoxic injury in the small intestine

Genotoxic agents such as doxorubicin (DXR) can cause damage to the intestines that can be ameliorated by fasting. How fasting is protective and the optimal timing of fasting and refeeding remain unclear. Here, our analysis of fasting/refeeding-induced global intestinal transcriptional changes revealed metabolic shifts and implicated the cellular energetic hub mechanistic target of rapamycin complex 1 (mTORC1) in protecting from DXR-induced DNA damage. Our analysis of specific transcripts and proteins in intestinal tissue and tissue extracts showed that fasting followed by refeeding at the time of DXR administration reduced damage and caused a spike in mTORC1 activity. However, continued fasting after DXR prevented the mTORC1 spike and damage reduction. Surprisingly, the mTORC1 inhibitor, rapamycin, did not block fasting/refeeding-induced reduction in DNA damage, suggesting that increased mTORC1 is dispensable for protection against the initial DNA damage response. In Ddit4-/- mice [DDIT4 (DNA-damage-inducible transcript 4) functions to regulate mTORC1 activity], fasting reduced DNA damage and increased intestinal crypt viability vs. ad libitum-fed Ddit4-/- mice. Fasted/refed Ddit4-/- mice maintained body weight, with increased crypt proliferation by 5 days post-DXR, whereas ad libitum-fed Ddit4-/- mice continued to lose weight and displayed limited crypt proliferation. Genes encoding epithelial stem cell and DNA repair proteins were elevated in DXR-injured, fasted vs. ad libitum Ddit4-/- intestines. Thus, fasting strongly reduced intestinal damage when normal dynamic regulation of mTORC1 was lost. Overall, the results confirm that fasting protects the intestines against DXR and suggests that fasting works by pleiotropic - including both mTORC1-dependent and independent - mechanisms across the temporally dynamic injury response.NEW & NOTEWORTHY New findings are 1) DNA damage reduction following a 24-h fast depends on the timing of postfast refeeding in relation to chemotherapy initiation; 2) fasting/refeeding-induced upregulation of mTORC1 activity is not required for early (6 h) protection against DXR-induced DNA damage; and 3) fasting increases expression of intestinal stem cell and DNA damage repair genes, even when mTORC1 is dysregulated, highlighting fasting's crucial role in regulating mTORC1-dependent and independent mechanisms in the dynamic recovery process.

Thermal Disorder in Finite-Length Carbon Nanowire

Enhancement in chemisorption is one of the active research areas in carbon materials. To remedy the thermally degraded chemisorption occurring at high temperatures, we report a comprehensive study of kink structures in free-standing monoatomic carbon nanowires upon heating. Our Monte Carlo simulation considers multi-monoatomic carbon chains laterally interacting by van der Waals forces. Our study reveals that carbon nanowires maintain their linearity regardless of chain length at low temperatures, but this is not the case at high temperatures. Disordered kink structure is observed in short carbon chains, especially above the Peierls transition temperature. A severe kink structure may increase the possibility of attaching negatively charged atoms, thereby contributing to the development of next-generation materials for chemisorption at high temperatures. We have also provided an important indication that any physical property of the finite-length carbon chain predicted by ab initio calculation should reconsider the atomic rearrangement due to thermal instability at high temperatures.

Cadherin-11 and Its Role in Tissue Fibrosis

Fibrosis is the excessive deposition of extracellular matrix that results from chronic inflammation and injury, leading to the loss of tissue integrity and function. Cadherins are important adhesion molecules that classically mediate calcium-dependent cell-to-cell adhesion and play important roles in tissue development and cellular migration but likely have functions beyond these important roles. Cadherin-11 (CDH11), a member of the cadherin family, has been implicated in several pathological processes including cancer. More recent evidence suggests that CDH11 is a central mediator of tissue fibrosis. CDH11 expression is increased in patients with fibrotic diseases such as idiopathic pulmonary fibrosis and systemic sclerosis. CDH11 expression is increased in mouse models of lung, skin, liver, cardiac, renal, and intestinal fibrosis. Targeting CDH11 in murine models of fibrosis clearly demonstrates that CDH11 is a common mediator of fibrosis across multiple tissues. Insight into potential mechanisms at the cellular and molecular level is emerging. In this review, we present the evolving evidence for the involvement of CDH11 in tissue fibrosis. We also discuss some of the proposed mechanisms and highlight the potential of CDH11 as a common therapeutic target and biomarker in different fibrotic pathologies.

Cadherin-11 Regulates Macrophage Development and Function

Cadherin-11 (CDH11) is a cell-cell adhesion protein that has previously been reported to play an important role in the pathogenesis of pulmonary fibrosis. It is expressed on macrophages in the fibrotic lung. However, the role of CDH11 on macrophage biology has not yet been studied. We show using immunophenotypic analyses that Cdh11^-/- mice have fewer recruited monocyte-derived macrophages and Ly6C^hi monocytes in the lungs compared to wild-type mice in the intraperitoneal bleomycin-induced pulmonary fibrosis model. Additionally, fewer Ly6C^hi monocytes were detected in the bone marrow and peripheral blood of naive Cdh11^-/- mice. Given that macrophages are derived from monocytes, we investigated the precursors of the monocyte/macrophage lineage in the bone marrow. We found increased numbers of CMPs and reduced numbers of GMPs and MPs/cMoPs in Cdh11^-/- mice compared to wild-type mice, suggesting decreased differentiation towards the myeloid lineage in Cdh11^-/- mice. Furthermore, we show using bone marrow cells that loss of CDH11 impaired monocyte to macrophage differentiation. We also demonstrate that CDH11 deficiency repressed the M2 program and impaired the phagocytic function of bone marrow-derived macrophages. Overall, our findings demonstrate a role for CDH11 in macrophage development, M2 polarization, and phagocytic function.

Cadherin-11 contributes to liver fibrosis induced by carbon tetrachloride

Background and aims

Liver fibrosis is characterized by the excessive deposition of extracellular matrix (ECM) leading to impaired function and cirrhosis. Previous reports support a role for cadherin-11 (CDH11) in regulating the development of dermal and pulmonary fibrosis. In the current report, the extent to which CDH11 modulates the development of liver fibrosis induced by carbon tetrachloride (CCL₄) was assessed.

Methods

Wild type (WT) and CDH11 deficient (CDH11^-/-) mice were treated with CCl₄ or vehicle control for 8 weeks to induce liver fibrosis. Liver fibrosis was assessed by histology, collagen content, and RTPCR of fibrotic mediators.

Results

Livers from WT mice treated with CCl₄ had increased levels of CDH11 which localized to injured hepatocytes, hepatic stellate cells, and macrophages. Interestingly, CDH11^-/- mice had decreased histological evidence of liver fibrosis, collagen deposition, α-smooth muscle actin (α-SMA) accumulation, and mRNA levels of fibrotic mediators such as Col1-α1, Snail, TGF-β and IL-6.

Conclusions

These data demonstrate that CDH11 is increased during liver fibrosis, is an important regulator of liver fibrosis induced by CCL₄ and suggest that CDH11 may be a potential therapeutic target for liver fibrosis.

Control of the ductile and brittle behavior of titanium alloys in diamond cutting by applying a magnetic field

As a result of extensive investigations into deformation mechanisms of titanium alloys, it has been found that ductile and brittle behavior occurs during diamond cutting of the alloys. Other than implementing ductile regime machining for improving machining performances, in this study, an application of magnetic field in diamond cutting is proposed to enhance the machining performances in both ductile and brittle deformations in diamond cutting of titanium alloys. Results from the experiments showed that under the influence of a magnetic field, the cutting heat at the tool/titanium interface decreased, and surface damages induced from the brittle deformation were remarkably suppressed. The surface quality of both ductile and brittle deformation areas was enhanced in a presence of the magnetic field, which the surface profiles were less distortive with fewer cracks and defects in brittle deformation regions, and the cutting forces at the transition point became less fluctuant and much smoother. This study contributes enhancements of machining performances in ductile and brittle machining in diamond cutting of titanium alloys, increasing the precise level of machined components made with titanium alloys.

Role of STAT3 in skin fibrosis and transforming growth factor beta signalling

Objective

SSc is an autoimmune disease characterized by progressive fibrosis of the skin and internal organs. IL-6 and related cytokines that signal through STAT3 have been implicated in the pathogenesis of SSc and mouse models of fibrosis. The aim of this study was to investigate the efficacy of inhibiting STAT3 in the development of fibrosis in two mouse models of skin fibrosis.

Methods

Biopsy samples of skin from SSc patients and healthy control subjects were used to determine the expression pattern of phosphotyrosyl (pY705)-STAT3. C188-9, a small molecule inhibitor of STAT3, was used to treat fibrosis in the bleomycin-induced fibrosis model and Tsk-1 mice. In vitro studies were performed to determine the extent to which STAT3 regulates the fibrotic phenotype of dermal fibroblasts.

Results

Increased STAT3 and pY705-STAT3 was observed in SSc skin biopsies and in both mouse models of SSc. STAT3 inhibition with C188-9 resulted in attenuated skin fibrosis, myofibroblast accumulation, pro-fibrotic gene expression and collagen deposition in both mouse models of skin fibrosis. C188-9 decreased in vitro dermal fibroblast production of fibrotic genes induced by IL-6 trans-signalling and TGF-β. Finally, TGF-β induced phosphotyrosylation of STAT3 in a SMAD3-dependent manner.

Conclusion

STAT3 inhibition decreases dermal fibrosis in two models of SSc. STAT3 regulates dermal fibroblasts function in vitro and can be activated by TGF-β. These data suggest that STAT3 is a potential therapeutic target for dermal fibrosis in diseases such as SSc.

Abstract A098: Whole blood assay for rapid detection of AR-v7 in metastatic castration-resistant prostate cancer: No correlation with response to androgen-axis targeting agents

Background: The expression of AR-v7 in circulating tumor cells (CTCs) of mCRPC patients potentially confers treatment resistance to AR-axis targeting agents, though recent data from the ARMOR3-SV study as well as other publications challenge this hypothesis. Due to the potential barriers of developing a reliable CTC platform, our aim was to develop a rapid assay for AR-v7 detection in patient whole blood samples.

Method: We created and optimized a whole blood quantitative real-time polymerase chain reaction assay to correlate outcomes of patients on AR-axis targeting agents with expression of AR-v7. The expression of AR-v7 mRNA in whole blood from 47 patients with mCRPC was obtained prior to commencing therapy. Each sample was run in triplicate; positivity was defined as at least two replicates reaching cycle threshold within a standard deviation between cycles of ≤ 0.25. Gene expression was correlated with PSA response rate using Fisher’s exact test.

Results: In our cohort, 10 of 47 patients (21%) were AR-v7+. Of patients commencing abiraterone or enzalutamide (37/47 patients, 79%), we observed similar response rates in the AR-v7+ (4/7) patients, compared to the AR-v7 (20/30) patients (57% vs. 66%, P=0.63; Fisher’s exact test). In two patients, early onset of acquired resistance was associated with conversion from AR-v7 to AR-v7+. AR-v7 was not detected in any of the 13 normal male controls.

Conclusion: We developed a specific assay for AR-v7 detection in whole blood from mCRPC patients. Similar PSA response rates were seen in AR-v7+ and AR-v7 patients, inconsistent with literature characterizing AR-v7 as a predictive biomarker, but in support of ARMOR3-SV data demonstrating moderate response rates to an AR-axis targeting agent in AR-v7+ patients. Future directions will include cohort expansion, interrogation of other AR variants, and examination of other clinically meaningful endpoints.

Citation Format: Sarah To, Edmond Kwan, Heidi Fettke, Maria Docanto, Nicole Ng, Andrew Mant, Phillip Parente, Carmel Pezaro, Lisa Horvath, Lisa Graham, Tilman Todenhofer, Arun Azad. Whole blood assay for rapid detection of AR-v7 in metastatic castration-resistant prostate cancer: No correlation with response to androgen-axis targeting agents [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr A098.

Macrophages and the regulation of pulmonary fibrosis by Cadherin-11

Pulmonary fibrosis is a chronic lung disease characterized by excessive deposition of extracellular matrix proteins by myofibroblasts leading to remodeling of the lung architecture. Alveolar macrophages play a key role in the development of pulmonary fibrosis and it has generally been associated with the polarization of these cells towards a profibrotic phenotype. Studies have shown the expression of the cell adhesion molecule Cadherin-11 (Cdh11) in alveolar macrophages from patients with pulmonary fibrosis and mice given bleomycin, and Cdh11-deficient mice are protected from bleomycin-induced pulmonary fibrosis suggesting an important role for Cdh11 in the pathogenesis of pulmonary fibrosis. In order to understand the role of Cdh11 in the development of pulmonary fibrosis, our study focuses on macrophages and aims to characterize the function and phenotype of Cdh11-deficient macrophages. We show that Cdh11-deficient mice have reduced numbers of tissue-resident alveolar macrophages compared to the wild type control mice and when given bleomycin, these mice have reduced numbers of CD11b+ monocyte-derived alveolar macrophages. Using BMDMs derived from Cdh11-deficient mice, we show that Cdh11-deficient macrophages have decreased expression of the alternative activation markers Arg1, Ym1, and CD206, and reduced secretion of TGF-β1, suggesting a reduced fibrotic phenotype. Furthermore, we show decreased phagocytosis, proliferation, and migration by Cdh11-deficient macrophages. These data suggest that Cdh11 may alter fibrotic responses by regulating the number and function of alveolar macrophages that are recruited to the lung.

Ductile and brittle transition behavior of titanium alloys in ultra-precision machining

Titanium alloys are extensively applied in biomedical industries due to their excellent material properties. However, they are recognized as difficult to cut materials due to their low thermal conductivity, which induces a complexity to their deformation mechanisms and restricts precise productions. This paper presents a new observation about the removal regime of titanium alloys. The experimental results, including the chip formation, thrust force signal and surface profile, showed that there was a critical cutting distance to achieve better surface integrity of machined surface. The machined areas with better surface roughness were located before the clear transition point, defining as the ductile to brittle transition. The machined area at the brittle region displayed the fracture deformation which showed cracks on the surface edge. The relationship between depth of cut and the ductile to brittle transaction behavior of titanium alloys in ultra-precision machining(UPM) was also revealed in this study, it showed that the ductile to brittle transaction behavior of titanium alloys occurred mainly at relatively small depth of cut. The study firstly defines the ductile to brittle transition behavior of titanium alloys in UPM, contributing the information of ductile machining as an optimal machining condition for precise productions of titanium alloys.

Whole blood AR-V7 and AR-V9 mRNA expression and treatment response in metastatic castrate-resistant prostate cancer (mCRPC)

252

Background: Androgen receptor splice variant (AR-V) expression has previously been regarded as a negative predictive biomarker for response to abiraterone and enzalutamide in mCRPC patients. However, recent data questions this association. We designed a whole blood assay to detect AR-V7 and AR-V9, the two most abundantly expressed AR-Vs, and correlated expression with clinical outcomes in patients commencing abiraterone or enzalutamide. Methods: We developed a quantitative real-time polymerase chain reaction assay to detect AR-V7 and AR-V9 from whole blood collected in PAXgene tubes. The assay was applied to samples prospectively collected from 37 mCRPC patients prior to commencing abiraterone or enzalutamide, and at treatment cessation. Patients positive for either AR-V7 or AR-V9 were defined as AR-V-positive, and AR-V-negative if neither variant was detected. AR-V expression was correlated with PSA response rate (chi-square test) and PSA progression-free survival (PSA-PFS) (log-rank test). Assay sensitivity was determined by serially diluting RNA from VCaP prostate cancer cells (known to express AR-V7) to establish a lower limit of detection. Results: The median follow-up was 7.29 months (IQR 4.21-10.55); 9 of 37 patients (24%) were AR-V-positive. We observed similar response rates in AR-V-positive (6/9) and AR-V-negative (18/28) patients (66% vs. 64%, p = 0.896). PSA-PFS did not differ significantly between groups (9.2 months vs. not reached, p = 0.355). Two patients converted from AR-V-negative to AR-V-positive (PSA-PFS 3.35 and 0.60 months respectively), and one patient remained AR-V-positive at baseline and end-of-treatment sampling. The lower limit of detection for AR-V7 was 0.1%, and AR-V7/V9 was not detected in any of the 13 normal male controls. Conclusions: We developed a sensitive and specific whole blood assay for AR-V7 and AR-V9 detection in patients with mCRPC. Neither PSA response rates nor PSA-PFS differed significantly between AR-V-positive and AR-V-negative patients. These data support recent literature questioning the role of AR-V expression as a negative predictive biomarker in mCRPC patients receiving abiraterone or enzalutamide.

Abstract 2537: MicroRNA targeting anti-apoptotic and G2/M pathways as therapeutic targets for castration resistant prostate cancer

Prostate cancer (PC) is one of the most common cancers in men. Unfortunately, limited treatment options currently exist for those who have developed advanced castration-resistant PC (CRPC). G-1 is a GPER1/GPR30 agonist, and a promising candidate for CRPC therapy. G-1 is effective in halting the growth of CR tumors but not those grown in intact hosts. These findings suggest GPER1 is a therapeutic target for CRPC. We found that G-1, through activation of GPER1, inhibited growth of CRPC cells via cell-cycle arrest at the G2-M phase, probably leading to mitotic catastrophy. However, the exact mode of action of G-1 was not known. To better understand the pathways involved in G-1 action, we conducted a genome-wide mRNA-seq and miRNA-seq study on G-1 treated xenografts. We identified a panel of novel G-1-associated tumor suppressive miRNAs and genes. Moreover, Ingenuity Pathway Analysis revealed that the G-1 differentially regulated genes are involved in “Cellular Growth and Proliferation”, “endocrine function” and “Cancer” pathways. We validated the expression of the key miRNA (miR-34c, miR-10b, miR-138 and miR218) and genes in G-1 treated castration resistant xenografts and cell lines (C4-2 and 22Rv1). Furthermore, we have shown the tumor suppressor function of these miRNA in cell survival, migration, and invasion. The predicted target genes were next examined for decreased expression by qRT-PCR. We confirmed decreased expression of some of the downstream targets, which consist of genes involved in cell cycle regulation (CCNA and CCND, CDK1, CDK4, PLK1), cell survival (Bcl2, Survivin), cell migration/F-actin formation (LASP, PCDH7, ITGA9, ROBO1, SLIT1) and G2/M checkpoint (CDK1, PLK1, BCL-2 Survivin). Thus these miRNAs - miR-34c, miR-10b, miR-138 and miR218 - are ideal candidates for therapy of CRPC.

Citation Format: Pheruza Tarapore, Sarah To, Bin Ouyang, Yuet-Kin Leung, Ana Cheong, Shuk-mei Ho. MicroRNA targeting anti-apoptotic and G2/M pathways as therapeutic targets for castration resistant prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2537. doi:10.1158/1538-7445.AM2017-2537

Bisphenol A and its analogues disrupt centrosome cycle and microtubule dynamics in prostate cancer

Humans are increasingly exposed to structural analogues of bisphenol A (BPA), as BPA is being replaced by these compounds in BPA-free consumer products. We have previously shown that chronic and developmental exposure to BPA is associated with increased prostate cancer (PCa) risk in human and animal models. Here, we examine whether exposure of PCa cells (LNCaP, C4-2) to low-dose BPA and its structural analogues (BPS, BPF, BPAF, TBBPA, DMBPA and TMBPA) affects centrosome amplification (CA), a hallmark of cancer initiation and progression. We found that exposure to BPA, BPS, DMBPA and TBBPA, in descending order, increased the number of cells with CA, in a non-monotonic dose-response manner. Furthermore, cells treated with BPA and their analogues initiated centrosome duplication at 8 h after release from serum starvation, significantly earlier in G-1 phase than control cells. This response was attended by earlier release of nucleophosmin from unduplicated centrosomes. BPA-exposed cells exhibited increased expression of cyclin-dependent kinase CDK6 and decreased expression of CDK inhibitors (p21^Waf1/CIP1 and p27^KIP1). Using specific antagonists for estrogen/androgen receptors, CA in the presence of BPA or its analogues was likely to be mediated via ESR1 signaling. Change in microtubule dynamics was observed on exposure to these analogues, which, for BPA, was accompanied by increased expression of centrosome-associated protein CEP350 Similar to BPA, chronic treatment of cells with DMBPA, but not other analogues, resulted in the enhancement of anchorage-independent growth. We thus conclude that selected BPA analogues, similar to BPA, disrupt centrosome function and microtubule organization, with DMBPA displaying the broadest spectrum of cancer-promoting effects.

STAT-3 contributes to pulmonary fibrosis through epithelial injury and fibroblast-myofibroblast differentiation

Lung fibrosis is the hallmark of the interstitial lung diseases. Alveolar epithelial cell (AEC) injury is a key step that contributes to a profibrotic microenvironment. Fibroblasts and myofibroblasts subsequently accumulate and deposit excessive extracellular matrix. In addition to TGF-β, the IL-6 family of cytokines, which signal through STAT-3, may also contribute to lung fibrosis. In the current manuscript, the extent to which STAT-3 inhibition decreases lung fibrosis is investigated. Phosphorylated STAT-3 was elevated in lung biopsies from patients with idiopathic pulmonary fibrosis and bleomycin (BLM)-induced fibrotic murine lungs. C-188-9, a small molecule STAT-3 inhibitor, decreased pulmonary fibrosis in the intraperitoneal BLM model as assessed by arterial oxygen saturation (control, 84.4 ± 1.3%; C-188-9, 94.4 ± 0.8%), histology (Ashcroft score: untreated, 5.4 ± 0.25; C-188-9, 3.3 ± 0.14), and attenuated fibrotic markers such as diminished α-smooth muscle actin, reduced collagen deposition. In addition, C-188-9 decreased the expression of epithelial injury markers, including hypoxia-inducible factor-1α (HIF-1α) and plasminogen activator inhibitor-1 (PAI-1). In vitro studies show that inhibition of STAT-3 decreased IL-6- and TGF-β-induced expression of multiple genes, including HIF-1α and PAI-1, in AECs. Furthermore, C-188-9 decreased fibroblast-to-myofibroblast differentiation. Finally, TGF-β stimulation of lung fibroblasts resulted in SMAD2/SMAD3-dependent phosphorylation of STAT-3. These findings demonstrate that STAT-3 contributes to the development of lung fibrosis and suggest that STAT-3 may be a therapeutic target in pulmonary fibrosis.

PI16 is expressed by a subset of human memory Treg with enhanced migration to CCL17 and CCL20

The peptidase inhibitor PI16 was shown previously by microarray analysis to be over-expressed by CD4-positive/CD25-positive Treg compared with CD4-positive/CD25-negative Th cells. Using a monoclonal antibody to the human PI16 protein, we found that PI16-positive Treg have a memory (CD45RO-positive) phenotype and express higher levels of FOXP3 than PI16-negative Treg. PI16-positive Treg are functional in suppressor assays in vitro with potency similar to PI16-negative Treg. Further phenotyping of the PI16-positive Treg revealed that the chemokine receptors CCR4 and CCR6 are expressed by more of the PI16-positive/CD45RO-positive Treg compared with PI16-negative/CD45RO-positive Treg or Th cells. PI16-positive Treg showed enhanced in vitro migration towards the inflammatory chemokines CCL17 and CCL20, suggesting they can migrate to sites of inflammation. We conclude that PI16 identifies a novel distinct subset of functional memory Treg which can migrate to sites of inflammation and regulate the pro-inflammatory response at those sites.

Use of EBSD to study electropulsing induced reverse phase transformations in a Zn-Al alloy (ZA22)

Multi-phase identification and phase transformations in electropulsing treated Zn-Al based alloy wire specimens were studied using electron back-scattered diffraction, back-scattered scanning electron microscopy and X-ray diffraction techniques. By using electron back-scattered diffraction, two phases: η'(S) and η'(T) with a small difference of about 1% in lattice parameters (c(0)/a(0) ) were identified, based on the determined lattice parameters of the phases, and the reverse eutectoid phase transformations: η'(T) +ɛ'(T) +α'(T) →η'(S) and ɛ+α→T'+η were successfully detected. Electron back-scattered diffraction appeared to be an effective technique for studying complex electropulsing induced phase transformations.

Epigenetic Control of Estrogen Synthesis in Human Preadipocytes and Breast Cancer Cells

Estrogen plays a significant role in the development and progression of breast cancer (BC). Cytochrome aromatase p450, encoded by the gene CYP19, is the key enzyme catalyzing the synthesis of estrogens from androgens. In post-menopausal women, adipose tissue becomes the major site for estrogen production and an increase in CYP19 expression in mammary adipose is strongly linked to the hormone-dependent progression of BC. Therefore, understanding CYP19 regulation in BC is critical for the development of therapeutic measures. Previous studies of CYP19 regulation in BC have mainly focussed on hormone-induced regulation of transcription via upstream tissue- and promoter-specific regulatory regions. While this is clearly important, it is increasingly evident that epigenetic regulation of expression, such as DNA methylation, is also a common factor in the progression of cancers. The aim of this study was to investigate whether CYP19 expression is under epigenetic regulation and to determine if such mechanisms contribute to the tissue- and promoter-specific expression of CYP19 observed in BC.CYP19 transcripts in cancer-free primary human breast adipose fibroblasts (BAFs) stimulated with cytokines and glucocorticoids (e.g. TNFα and dexamethasone) are derived from the distal promoter 1.4, whereas breast tumour-derived factors (e.g. prostaglandin E2) induce a regulatory switch to proximal promoters 1.3 and II. DNA from BAFs maintained under these two conditions was treated with sodium bisulfite allowing for methylation analysis of CpG dinucleotides. Methylation mapping revealed a stochastic heterogeneous level of methylation among 9 CpG sites (promoter 1.4) and 11 CpG sites (promoters 1.3 and II) in untreated BAFs.No correlation was observed between promoter methylation and promoter activation after response to stimuli. However, treatment of BAFs with 5-aza-2'-deoxycytidine, a DNA methylation inhibitor, increased total CYP19 mRNA expression up to 40-fold, primarily via promoter 1.4 thorugh up-regulation of trans-acting factors, suggesting CYP19 is under tonic inhibition by methylation in BAFs. Similar results were also obtained in four BC cell lines. Ongoing work has elucidated trans-acting factors of CYP19 epigenetically silenced in BAFs. These studies uncover a new layer of complexity in the regulation of aromatase expression in BC and may identify new targets for epigenetic therapy, including DNA methylation inhibitors. These findings will translate to BC by determining the methylation state of CYP19 in clinical BC specimens, and by correlation with clinicopathological parameters such as steroid receptor status, grade and stage.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1147.

Use of EBSD to identify phases in interdendrite region of a cast Zn-Al-based alloy (ZA27)

Electron backscattered Kikuchi diffraction methodology was used to identify phases in the interdendrite region of an alloy ZA27. Two Zn-rich hexagonal close-packed structure phases eta and epsilon phases were distinguished using predetermined lattice parameters of the phases. In relation to studies of scanning electron microscopy and X-ray diffraction, electron backscattered diffraction results revealed that the Al-rich precipitates of the alpha phase were from decomposition of the eta'(T), and the four-phase transformation: alpha+epsilon--> T'+eta, had occurred in the epsilon phase after ageing at 150 degrees C for 8 h.