Haem is associated with thrombosis in neonates and infants undergoing cardiac surgery for congenital heart disease.

BACKGROUND: Haem levels are associated with thrombosis in a variety of diseases, as well as being a contributing cause of thrombotic events in animal models. MATERIALS AND METHODS: We retrospectively analyzed samples from 39 children who underwent cardiac surgery with cardiopulmonary bypass, including 15 children who developed a postoperative thrombosis and 24 controls. RESULTS: Patients who developed thrombosis postoperatively had statistically significant higher average haem levels over time (presurgery to 12 h postsurgery) compared to patients who did not develop thrombosis. CONCLUSION: Higher cell-free total haem levels are associated with a higher risk of thrombosis in a paediatric cardiac surgical cohort.

A review of the available clinical therapies for vulvodynia management and new data implicating proinflammatory mediators in pain elicitation.

Localised provoked vulvodynia (LPV) is a common, chronic, and disabling condition: patients experience profound pain and a diminished quality of life. The aetiologic origins of vulvodynia are poorly understood, yet recent evidence suggests a link to site-specific inflammatory responses. Fibroblasts isolated from the vestibule of LPV patients are sensitive to proinflammatory stimuli and copiously produce pain-associated proinflammatory mediators (IL-6 and PGE2 ). Although LPV is a multifactorial disorder, understanding vulvar inflammation and targeting the inflammatory response should lead to treatment advances, especially for patients exhibiting signs of inflammation. NFκB (already targeted clinically) or other inflammatory components may be suitable therapeutic targets. TWEETABLE ABSTRACT: Vulvodynia is a poorly understood, prevalent, and serious women's health issue requiring better understanding to improve therapy.

Ionizing radiation induces myofibroblast differentiation via lactate dehydrogenase.

Pulmonary fibrosis is a common and dose-limiting side-effect of ionizing radiation used to treat cancers of the thoracic region. Few effective therapies are available for this disease. Pulmonary fibrosis is characterized by an accumulation of myofibroblasts and excess deposition of extracellular matrix proteins. Although prior studies have reported that ionizing radiation induces fibroblast to myofibroblast differentiation and collagen production, the mechanism remains unclear. Transforming growth factor-ß (TGF-ß) is a key profibrotic cytokine that drives myofibroblast differentiation and extracellular matrix production. However, its activation and precise role in radiation-induced fibrosis are poorly understood. Recently, we reported that lactate activates latent TGF-ß through a pH-dependent mechanism. Here, we wanted to test the hypothesis that ionizing radiation leads to excessive lactate production via expression of the enzyme lactate dehydrogenase-A (LDHA) to promote myofibroblast differentiation. We found that LDHA expression is increased in human and animal lung tissue exposed to ionizing radiation. We demonstrate that ionizing radiation induces LDHA, lactate production, and extracellular acidification in primary human lung fibroblasts in a dose-dependent manner. We also demonstrate that genetic and pharmacologic inhibition of LDHA protects against radiation-induced myofibroblast differentiation. Furthermore, LDHA inhibition protects from radiation-induced activation of TGF-ß. We propose a profibrotic feed forward loop, in which radiation induces LDHA expression and lactate production, which can lead to further activation of TGF-ß to drive the fibrotic process. These studies support the concept of LDHA as an important therapeutic target in radiation-induced pulmonary fibrosis.

Electrophilic PPARγ ligands inhibit corneal fibroblast to myofibroblast differentiation in vitro: a potentially novel therapy for corneal scarring.

A critical component of corneal scarring is the TGFß-induced differentiation of corneal keratocytes into myofibroblasts. Inhibitors of this differentiation are potentially therapeutic for corneal scarring. In this study, we tested the relative effectiveness and mechanisms of action of two electrophilic peroxisome proliferator-activated receptor gamma (PPARγ) ligands: cyano-3,12-dioxolean-1,9-dien-28-oic acid-methyl ester (CDDO-Me) and 15-deoxy-Δ(-12,14)-prostaglandin J(2) (15d-PGJ(2)) for inhibiting TGFß-induced myofibroblast differentiation in vitro. TGFß was used to induce myofibroblast differentiation in cultured, primary human corneal fibroblasts. CDDO-Me and 15d-PGJ(2) were added to cultures to test their ability to inhibit this process. Myofibroblast differentiation was assessed by measuring the expression of myofibroblast-specific proteins (αSMA, collagen I, and fibronectin) and mRNA (αSMA and collagen III). The role of PPARγ in the inhibition of myofibroblast differentiation by these agents was tested in genetically and pharmacologically manipulated cells. Finally, we assayed the importance of electrophilicity in the actions of these agents on TGFß-induced αSMA expression via Western blotting and immunofluorescence. Both electrophilic PPARγ ligands (CDDO-Me and 15d-PGJ(2)) potently inhibited TGFß-induced myofibroblast differentiation, but PPARγ was only partially required for inhibition of myofibroblast differentiation by either agent. Electrophilic PPARγ ligands were able to inhibit myofibroblast differentiation more potently than non-electrophilic PPARγ ligands, suggesting an important role of electrophilicity in this process. CDDO-Me and 15d-PGJ(2) are strong inhibitors of TGFß-induced corneal fibroblast to myofibroblast differentiation in vitro, suggesting this class of agents as potential novel therapies for corneal scarring warranting further study in pre-clinical animal models.

Release of biologically active CD154 during collection and storage of platelet concentrates prepared for transfusion.

BACKGROUND: Millions of platelet transfusions are given each year. Transfusion reactions occur in as many as 30% of patients receiving unmodified platelet transfusions. The cause of some transfusion reactions remains unclear. The current paradigm suggests that platelet concentrates (PC) contain proinflammatory mediators that are released by white blood cells during collection, processing and storage. CD154 (CD40 ligand, CD40L) is a potent inflammatory mediator, normally sequestered inside the resting platelet, that is known to translocate to the platelet membrane and be shed into plasma in response to agonist activation. We hypothesized that platelet-soluble CD154 (sCD154) is 'spontaneously' released by transfused platelets and plays a major role in transfusion reactions. OBJECTIVES: To determine the time course and biological properties of CD154 translocation and release during collection and storage of platelets for transfusion. METHODS: We measured surface and sCD154 in platelets prepared by the platelet-rich plasma method or apheresis by fluorescence-activated cell sorting and enzyme-linked immunosorbent assay, respectively. The specific biological activity of platelet sCD154 was assayed by stimulation of the CD154/CD40 pathway in known CD40-positive cells with PC-derived supernatants. RESULTS AND CONCLUSIONS: We demonstrate that PCs prepared for transfusion have high levels of membrane-bound CD154 and sCD154, with maximum levels being seen 72 h after platelet collection. Importantly, we show that platelet-derived sCD154 potently stimulates CD40-positive cells. We propose that platelet-derived CD154 is a key 'cytokine' responsible for adverse reactions associated with platelet transfusions. Improved methods of platelet collection and/or storage, which limit CD154 expression, could reduce the risks of transfusion reaction.

Effects of pioglitazone on fasting and postprandial levels of lipid and hemostatic variables in overweight non-diabetic patients with coronary artery disease.

OBJECTIVES: To evaluate the effects of pioglitazone on insulin sensitivity and levels of biomarkers associated with thrombotic risk in overweight and obese, non-diabetic subjects with coronary artery disease. BACKGROUND: Little information is available regarding the effects of thiazolidinediones in the absence of diabetes. Further, although postprandial hyperlipemia is a risk factor for cardiovascular diseases, there is limited information about the postprandial effects. METHODS: Twenty overweight and obese, non-diabetic patients with coronary artery disease were enrolled in a randomized, placebo-controlled, double-blind study. Subjects were on atorvastatin for the duration of the study and received either placebo or pioglitazone (45 mg day(-1)) for 12 weeks and then crossed over to the alternative therapy for an additional 12 weeks. Insulin sensitivity, fasting and postprandial levels of lipid, hemostatic, and inflammatory variables were measured, and endothelial function was assessed. RESULTS: Insulin sensitivity improved from 0.03 micromol kg(-1) x min pM(-1) on placebo to 0.04 on pioglitazone (P = 0.0002), and there were decreases in fasting levels of factor (F) VII:C (102 +/- 17% to 92 +/- 18%, P = 0.001), FVII:Ag (68 +/- 12% to 60 +/- 14%, P = 0.01) and in von Willebrand factor (VWF) (174 +/- 94% to 142 +/- 69%, P = 0.01). Pioglitazone lowered postprandial levels of FVII:Ag, FVII:C, plasminogen activator inhibitor-1, VWF, and triglycerides, and increased high-density lipoproteins (+9%, P = 0.02). CONCLUSIONS: Pioglitazone improves insulin sensitivity and favorably modifies fasting and postprandial lipid, hemostatic and inflammatory markers of the metabolic syndrome in overweight and obese non-diabetic patients with coronary artery disease.

Maresin 1 induces a novel pro-resolving phenotype in human platelets.

Essentials Specialized proresolving mediators (SPMs) promote the resolution of inflammation. This study sought to investigate the effects of SPMs on human platelet function. The SPM, Maresin 1, enhanced hemostatic, but suppressed inflammatory functions of platelets. SPMs uniquely regulate platelet function and may represent a new class of antiplatelet agents. SUMMARY: Background Antiplatelet therapy is a cornerstone of modern medical practice and is routinely employed to reduce the likelihood of myocardial infarction, thrombosis and stroke. However, current antiplatelet therapies, such as aspirin, often have adverse side-effects, including increased risk of bleeding, and some patients are relatively 'aspirin-resistant'. Platelets are intimately involved in hemostasis and inflammation, and clinical consequences are associated with excessive or insufficient platelet activation. Objectives A major unmet need in the field of hematology is the development of new agents that safely prevent unwanted platelet activation in patients with underlying cardiovascular disease, while minimizing the risk of bleeding. Here, we investigate the potential of endogenously produced, specialized pro-resolving mediators (SPMs) as novel antiplatelet agents. SPMs are a recently discovered class of lipid-derived molecules that drive the resolution of inflammation without being overtly immunosuppressive. Methods Human platelets were treated with lipoxin A4, resolvin D1, resolvin D2, 17-HDHA or maresin 1 for 15 min, then were subjected to platelet function tests, including spreading, aggregation and inflammatory mediator release. Results We show for the first time that human platelets express the SPM receptors, GPR32 and ALX. Furthermore, our data demonstrate that maresin 1 differentially regulates platelet hemostatic function by enhancing platelet aggregation and spreading, while suppressing release of proinflammatory and prothrombotic mediators. Conclusions These data support the concept that SPMs differentially regulate platelet function and may represent a novel class of antiplatelet agents. SPMs also may play an important role in the resolution of inflammation in cardiovascular diseases.

Differential presentation of tolerogenic immunoglobulin in vivo by macrophages and by a lymphoid dendritic cell-like tumor line.

Previous work indicated that macrophages and a lymphoid dendritic cell-like tumor line, P388AD.2, possessed a differential ability to present a haptenated immunoglobulin (tolerogen) in vitro. Macrophages presented fluorescein-conjugated sheep gamma globulin (FL-SGG) and elicited B-cell unresponsiveness. In contrast, P388AD.2 presented this normally tolerogenic signal as an immunogenic one and induced augmented anti-hapten antibody responses. The objective of the present study was to determine whether differential tolerogen presentation could occur in vivo using defined accessory cells pulsed with FL-SGG. Interestingly, the intravenous (IV) injection of FL-SGG-pulsed thioglycollate-elicited macrophages, which secreted prostaglandin E2, induced hapten-specific B-cell unresponsiveness in syngeneic recipients. One thousand times as much FL-SGG in soluble form was required to produce the same degree of unresponsiveness. In contrast to macrophage-elicited negative signalling, non-prostaglandin secreting P388AD.2, when pulsed with FL-SGG, induced hapten-specific responses 2-3 times control values. Moreover, as few as 2 x 10(4) FL-SGG-pulsed P388AD.2 induced significant augmentation of the anti-FL antibody response. The presentation of FL-SGG in an immunogenic fashion by P388AD.2 was rapid and long lasting since increased responses were demonstrated as early as 1 day or as long as 21 days after IV injection. P388AD.2 were not simply acting as a passive carrier, nor permitting host presentation of FL-SGG, since there were requirements for P388AD.2 viability, and for syngeneic recipients in order to generate augmented anti-FL antibody responses. Moreover, inappropriate presentation of FL-SGG by P388AD.2 injected into allogeneic recipients did not elicit positive or negative signalling. In order to demonstrate that the ability of P388AD.2 to present FL-SGG in an immunogenic fashion was not simply a property of all tumor cells, the P388D1 cell line was pulsed with FL-SGG and injected. Neither tolerance nor augmentation was induced. Overall these results demonstrate that the type of antigen-presenting cell which introduces the immune system to an immunoglobulin tolerogen is critical to the induction of B-cell unresponsiveness or priming.

A molecular analysis of PGE receptor (EP) expression on normal and transformed B lymphocytes: coexpression of EP1, EP2, EP3beta and EP4.

The E-series prostaglandins (PGEs) are complex lipid regulators of B lymphocyte function. They inhibit the growth of certain B lymphoma lines. We report that heterogeneity with respect to PGE-induced growth inhibition correlates with the maturation state of the B cell lines. Specifically, the pre-B cell line 70Z/3 and the immature lymphoma CH31 are extremely sensitive to PGE2. To a lesser degree, other immature lymphomas (CH33, ECH408.1 and WEHI-231) are sensitive to PGE2. More mature lymphomas (BAL-17, CH12 and CH27) and fully differentiated myelomas (J558 and MOPC-315) are insensitive to PGE2. It is unknown what subtype of PGE receptor(s) (EPs) are expressed by B lymphocytes. It is also unknown if modulation of EP receptor expression could account for the differences in the sensitivity of these B cell lines to PGE2. To investigate these issues, reverse transcriptase polymerase chain reaction, Northern blot and DNA sequencing analyses were employed to obtain a definitive EP receptor subtype profile for these B cell lines, and for normal splenic B lymphocytes. Both normal and transformed B lymphocytes express mRNA encoding EP1, EP3beta and EP4 subtypes of PGE receptors. The B lineage cells do not express EP3alpha nor EP3gamma mRNA. The B cell lines are clonal, indicating that EP1, EP3beta and EP4 mRNA are coexpressed. Surprisingly, quantitative differences in basal EP1, EP3beta and EP4 expression were not observed between B cell lines despite their differing susceptibilities to PGE-induced growth inhibition. Conversely, the polyclonal activator LPS selectively upregulates EP4 mRNA expression in the mature B cell line CH12, but not in the LPS-sensitive pre-B cell line, 70Z/3. The activator LPS does not affect EP1 nor EP3beta mRNA expression. Treatment with dbcAMP, an analog of cAMP, mimics PGE-induced growth inhibition indicating that Gs-coupled EP2 and/or EP4 receptors mediate this inhibitory signal. Indeed, EP2 agonists mimic PGE2-induced growth inhibition unlike IP, EP1 and EP3-selective agonists. These data indicate that EP2 receptors are sufficient for mediating PGE-induced growth inhibition of susceptible B lineage cells.

Human thyroid fibroblasts exhibit a distinctive phenotype in culture: characteristic ganglioside profile and functional CD40 expression.

Fibroblasts from different regions of the human body exhibit substantial phenotypic diversity, some of which relates to the capacity for cross-talk with cells of the immune system. We examine, for the first time, thyroid fibroblast biology in culture. Thyroid explants were placed in culture, and fibroblasts were outgrown and serially passaged. These fibroblasts take on a morphology in culture resembling cells from other anatomic regions. When treated with PGE2, they assume a stellate morphology similar to that of prostanoid-treated orbital fibroblasts. The ganglioside profile exhibited by these cells is distinct from that observed previously in orbital and dermal fibroblasts. They uniformly express Thy-1, a surface glycoprotein. Messenger RNA encoding CD40, a surface receptor found on bone marrow-derived cells, and CD40 protein were expressed constitutively at low levels. Interferon-gamma (500 U/ml) treatment for 48-72 h resulted in high levels of surface HLA-DR and CD40 display. When CD40 is engaged with CD40 ligand (CD40L), nuclear factor-kappaB binding activity is up-regulated as is interleukin (IL)-6 and IL-8 expression. IL-1beta treatment up-regulates the expression of IL-1alpha, IL-1beta, and PGE2. These observations suggest that thyroid fibroblasts possess the molecular machinery necessary for cross-talk with immunocompetent cells such as lymphocytes and mast cells through the CD40/CD40L complex, as well as through classic cytokine networks, and to participate potentially in the inflammatory response of the thyroid gland.

Cd40 expression in uterine tissues: a key regulator of cytokine expression by fibroblasts.

CD40 is a cell surface receptor initially discovered on cells of the hemopoietic lineage. Its primary role on immune cells is to enhance their activation and hence their production of cytokines and immunomodulatory molecules. Recently, CD40 has also been detected on human fibroblasts. An emerging view of the fibroblast is that it is far more than a structural cell, being capable of intimate interaction with cells of the immune system. In fibroblasts from several tissues, the engagement of CD40 with its ligand (CD40L) resulted in the secretion of proinflammatory molecules such as interleukin-6 (IL-6) and IL-8. Currently, there are few data about the presence of the CD40-CD40L system in female reproductive tissues. This study investigates the expression of CD40 by human endometrium, myometrium, and cervix both in situ and in tissue explant-derived fibroblasts. CD40 was detected mainly in the perivascular region of endometrium, myometrium, and cervix. Light staining for CD40 was observed in stromal elements. Additionally, the basal epithelium of cervix expressed CD40. Fibroblastic cells derived from all three sources express low levels of CD40, and this is up-regulated with interferon-gamma treatment (500 U/mL; 72 h). When activated with interferon-gamma and CD40L, the fibroblasts secreted increased amounts of IL-6, IL-8, and MCP-1. These data suggest that the CD40-CD40L system may provide a link between the resident structural cells of these reproductive tissues and the infiltrating immune cells or activated platelets that may express CD40L. The possible interaction of CD40 with CD40L may be particularly important during events such as menstruation and cervical ripening, where up-regulation of the proinflammatory molecules IL-6 and IL-8 is viewed as critical for these processes. In addition, dysregulation of this system may be a contributory factor to problems such as menstrual dysfunction and preterm labor.

Evidence for cellular heterogeneity in primary cultures of human orbital fibroblasts.

Orbital fibroblasts in culture display phenotypic attributes that distinguish them from fibroblasts derived from other anatomical regions. The current studies were conducted to define potential cellular heterogeneity among orbital fibroblasts with regard to 1) differential expression of Thy-1, a 25-kilodalton glycoprotein associated with cell signaling; 2) cells undergoing a change in shape in response to prostaglandin E2 (PGE2); and 3) differences in morphology and Thy-1 expression between single cell-derived clonal fibroblast strains. On the basis of flow cytometric analysis using an anti-Thy-1 monoclonal antibody, 65% of intact orbital fibroblasts expressed surface Thy-1 (n = 5; range, 54-71%). In contrast, greater than 95% of the fibroblasts present in the five dermal strains tested were Thy-1 positive. A total of six strains of orbital fibroblasts were assessed for their shape change response to a 4-h treatment with PGE2 (100 nmol/L). A mean of 37% of the fibroblasts present in each culture responded to PGE2 (range, 22-50%). In contrast, only 1% of dermal fibroblasts exhibited any change in morphology. Three separate clones were generated from a single parent strain of Graves' orbital fibroblasts. These clones consisted of homogeneous appearing cells; however, substantial clone to clone differences in morphology were stably expressed for several population doublings. Thy-1 was expressed uniformly in cells of two clones, whereas the third was Thy-1 negative. Factor VIII and smooth muscle-specific alpha-actin were undetectable in any of the orbital or dermal cultures examined. Thus, Thy-1 expression is uniform in fibroblasts from certain anatomical regions such as the skin and heterogeneous in cells derived from human lung and orbit. These findings suggest that human orbital connective tissue may have a complexity not previously appreciated.

Synthesis of interleukin-1 receptor antagonist by Thy-1+ and Thy-1- murine lung fibroblast subsets.

IL-1 is a key cytokine that promotes pulmonary inflammation and fibrosis, as a result of its ability to stimulate lung fibroblast proliferation and collagen synthesis, two hallmarks of fibrosis. The IL-1 receptor antagonist (IL-1Ra) is an important natural inhibitor of IL-1-mediated functions. In models of pulmonary fibrosis induced by chemotherapeutic agents or noxious particles, administration of IL-1Ra significantly ameliorates lung fibrosis. Lung tissue undergoing an inflammatory response shows elevations in IL-1Ra, although it is not clear which pulmonary cells are responsible for the IL-1Ra synthesis. The purpose of this research was to determine whether Thy-1+ and Thy-1- subsets of mouse lung fibroblasts were capable of synthesizing IL-1Ra. In this report, it is demonstrated for the first time that lung fibroblasts are capable of synthesizing IL-1Ra. Both Thy-1+ and Thy-1- parental lines and clones constitutively express IL-1Ra mRNA. Quantitation of IL-1Ra protein indicates that Thy-1+ and Thy-1- fibroblasts secrete similar levels of secreted but not intracellular IL-1Ra. Thy-1- fibroblasts accumulate higher levels of IL-1Ra intracellularly. Moreover, fibroblast-conditioned supernatants containing IL-1Ra significantly suppress the mitogenic response of a T cell clone, D10G4.1, to concanavalin A and IL-1 beta. Overall, our observations indicate that Thy-1+ and Thy-1- fibroblasts release IL-1Ra and possess an IL-1-specific inhibitory activity in their supernatants. In vivo, fibroblast-derived IL-1Ra may serve to regulate IL-1-mediated effects in an autocrine and/or paracrine fashion to maintain homeostasis in the pulmonary interstitium.

A method for the isolation of autoreactive B cells.

A technique was developed to isolate a population of autoreactive B cells from both normal and autoimmune-prone mice. Modifications of the procedure of Haas and Layton (1975) permitted coupling the nucleoside guanosine (GU) to gelatin and subsequently coating this matrix onto tissue culture dishes. After incubation on GU-gelatin, B lymphocytes specific for GU could be isolated. Specificity was demonstrated by rosetting techniques as well as by inhibition of binding to GU-gelatin by GU-containing conjugates. Isolated GU+ B cells were triggerable with GU-Brucella abortus antigen as well as LPS, to secrete anti-GU antibody in a direct plaque assay. The DNA-binding activity of the antibody was assessed using hapten inhibition of anti-GU PFC. Both native (N) DNA as well as denatured (D) DNA inhibited plaque formation. DNA-binding ability of secreted anti-GU antibody was also demonstrated by plaque formation using D-DNA-coated erythrocytes as target cells. Isolated GU+ B cells that are triggerable with antigen will be important in investigating growth, triggering and tolerance defects in a specific population of autoreactive B cells. In addition autoreactive B cells can now be compared to nonautoreactive hapten-specific lymphocytes. These properties as well as others can now be studied in controlled systems free from the regulatory effects of murine T or accessory cells.

The relationship of CD5+ B lymphocytes to macrophages: insights from normal biphenotypic B/macrophage cells.

For decades, numerous investigators have reported derivation of macrophage-like cells from CD5(+) pre-B cell lymphomas. Recently, it has become clear that biphenotypic CD5(+) B/macrophage cells are not a spurious result of malignancy. Indeed, the existence of normal biphenotypic cells with CD5(+) B lymphocyte and macrophage characteristics has been demonstrated in the mouse. This review considers normal B/macrophage cell function in an evolutionary context where a primitive, flexible cell type could perform dual roles in adaptive and innate immunity.

The CD40-CD40 ligand system: a potential therapeutic target in atherosclerosis.

Atherosclerosis is a leading cause of cardiovascular disease in the westernized world. This review highlights emerging evidence linking atherosclerosis to the CD40-CD40 ligand (CD154) pathway. Recently, atherosclerosis has been associated with chronic inflammation, linking it to the immune system. This novel viewpoint may serve as an additional target for therapeutic intervention. CD40 and CD154 are highly expressed in atherosclerotic human plaques. Recent data from preclinical animal models of atherosclerosis show that disruption of the CD40-CD154 pathway can prevent atherosclerotic progression and may reverse established lesions. Blockade of the CD40-CD154 pathway by biologicals or small molecules may prove valuable in the treatment of atherosclerosis.

PPAR-gamma-mediated regulation of normal and malignant B lineage cells.

Prostaglandins of the E-series stimulate B lymphocytes by enhancing immunoglobulin-class switching and antibody production. Little is known about whether or not other prostaglandins affect B lineage cells and perhaps counterbalance the stimulatory effects of PGE2. PGD2 is a major product of cyclooxygenase in bone marrow and in macrophages, suggesting a role for this lipid product in immunological responses. PGD2 undergoes dehydration to the biologically active prostaglandin 15-deoxy-delta 12,14-PGJ2 (15d-PGJ2) that binds to the nuclear receptor known as peroxisome proliferator-activated receptor gamma (PPAR-gamma). We found that normal mouse B cells and a variety of B lymphoma cells (e.g., 70Z/3, WEHI-231, CH12, and J558) express PPAR-gamma mRNA and the 67-kDa PPAR-gamma protein. 15d-PGJ2 had a dose-dependent antiproliferative/cytotoxic effect on normal and malignant B cells, as shown by 3H-thymidine and MTT assays. Only PPAR-gamma agonists (i.e., thiazolidinediones) mimicked the effect of 15d-PGJ2 on B lineage cells, indicating that the mechanism by which 15d-PGJ2 negatively affects B lineage cells involves PPAR-gamma. The mechanism whereby PPAR-gamma agonists induced cytotoxicity is via apoptosis, as shown by Annexin V assay. PPAR-gamma agonists may serve as a counterbalance to the stimulating effects of PGE2, which promotes B-cell differentiation. The use of prostaglandins, such as 15d-PGJ2, and synthetic PPAR-gamma agonists to induce apoptosis in B lineage cells may lead to the development of therapies for fatal PGE2-resistant B lymphomas.

CD40 expression in human thyroid tissue: evidence for involvement of multiple cell types in autoimmune and neoplastic diseases.

CD40, a member of the tumor necrosis factor-alpha (TNF-alpha) receptor family of surface molecules, is expressed by a variety of cell types. It is a crucial activational molecule displayed by lymphocytes and other bone marrow-derived cells and recently has also been found on nonlymphoid cells such as fibroblasts, endothelia, and epithelial cells in culture. While its role in lymphocyte signaling and activation has been examined in great detail, the function of CD40 expression on nonlymphoid cells, especially in vivo, is not yet understood. Most of the studies thus far have been conducted in cell culture. In this article, we report that several cell types resident in thyroid tissue in vivo can display CD40 under pathological conditions. Sections from a total of 46 different cases were examined immunohistochemically and included nodular hyperplasia, chronic lymphocytic thyroiditis, diffuse hyperplasia, follicular neoplasia, papillary carcinoma, and medullary carcinoma. Thyroid epithelial cells, lymphocytes, macrophages, endothelial cells, and spindle-shape fibroblast-like cells were found to stain positively in the context of inflammation. The staining pattern observed in all cell types was entirely membranous. In general, epithelial staining was limited to that adjacent to lymphocytic infiltration except in 5 of 17 cases of neoplasia and in diffuse hyperplasia. Moreover, we were able to detect CD40 mRNA by reverse transcriptase-polymerase chain reaction (RT-PCR) in human thyroid tissue. These results constitute convincing evidence for expression of CD40 in nonlymphocytic elements of the human thyroid gland. Our findings suggest a potentially important pathway that might be of relevance to the pathogenesis of thyroid diseases. They imply the potential participation of the CD40/CD40 ligand bridge in the cross-talk between resident thyroid cells and bone marrow-derived cells recruited to the thyroid.

The Second International Scientific Symposium on Tea & Human Health, September 14th, 1998.

It is fascinating to reflect that tea, the world's most widely consumed beverage next to water, began in Chinese antiquity not as a beverage but as a medicine. Several millennia later, modern scientific research is confirming that such ancient intuition has relevance to contemporary health concerns including cancer, heart disease, and antibiotic-resistant bacteria. The timeliness of this message as the 20th century concludes could not be better. The importance of a balanced diet has been recognized and studied throughout this century. The concept that we are what we eat has become a part of popular culture. If tea's health message, which future scientific research will continue to articulate, is creatively presented and embraces the romantic image that tea affords the industry, there is every reason to expect a rebirth and reinvigoration of this ancient beverage as a new millennium commences.