Anti-inflammatory effect of P2Y1 receptor blocker MRS2179 in a rat model of traumatic brain injury.

The aim of the current study was to determine the effects of cerebral contusion injury with purinergic adenosine triphosphate Y1 (P2Y1) receptor blockers on postinjury inflammatory responses. Adenosine triphosphate (ATP) is released into the extracellular space in several in vivo models, including traumatic brain injury. Released ATP triggers neuroinflammation via activation of microglial cells. P2Y1 receptor blockers were reported to suppress extracellular ATP elevation in several disease models through inhibition of cellular ATP release. In addition to the beneficial effects of inflammation, excess inflammatory reactions cause secondary damage and aggravate outcomes. Here, we assessed the effect of the selective P2Y1 receptor blocker MRS2179 on its potential to prevent posttraumatic inflammation in a rat cerebral contusion model. Cerebral contusion injury was induced in the rat cerebral cortex. Either MRS2179 or artificial cerebral spinal fluid as a control was administered in situ into the center of contused tissue via a subcutaneously implanted osmotic pump. Galectin 3, a marker of microglia and proinflammatory cytokines, was measured 1, 3 and 7 days following injury. Another group of rats was assessed for behavioral performance up to 28 days after injury, including the beam walk test, neurological response test and plus maze test. The Galectin 3 levels in the cortex around the contusion cavity and in the cortex far from the contusion cavity were significantly suppressed by MRS2179 administration on postinjury Days 1 and 3 (p < 0.05). However, administration of MRS2179 failed to improve behavioral outcome. Administration of MRS2179 successfully suppressed microglial activation in a traumatic brain injury model, which will be a potent treatment option in the future. Further study is required to conclude its therapeutic effects.

Intercellular mediators in bone remodeling regulation in the experimental renal pathology / Mediadores intercelulares de la regulación de la remodelación ósea en un modelo experimental de patología renal

Bone metabolism disorders are characterized by an imbalance of bone resorption and formation in the bone remodeling process. Glucocorticoids that are used to treat kidney diseases exacerbate these disorders. P-selectin and galectin-3 are molecules involved in the sclerotic process in kidney, whereas bone resorption is regulated by the interaction between the nuclear factor activator kappa b receptor (RANK), its ligand (RANKL) and the RANKL decoy receptor osteoprotegerin (OPG). The aim of this study was to investigate the cellular and molecular mechanisms of disruption of bone remodeling regulation processes, reflected by intercellular mediators (RANKL, OPG, P-selectin and galectin-3) in chronic kidney disease experimental model treated with glucocorticoids. Rats were divided into four groups of 10 animals each. The first group, the control group, included intact animals. The second group consisted of rats with impaired bone remodeling resulting from chronic kidney disease (experimental group (CKD). The third group was a group of animals with impaired bone remodeling due to exposure to glucocorticoids (experimental group (GCs)). The fourth group consisted of rats with impaired bone remodeling in chronic kidney disease, followed by exposure to glucocorticoids (experimental group (CKD + GCs)). The effects of CKD and glucocorticoid were evaluated biochemically, histologically and by measuring bone density. An enzymelinked immunoassay was used to measure intercellular mediator levels in the serum. The bone density in the experimental groups was reduced compared to the control group. RANKL levels in animals of three experimental groups were higher than in intact animals. Serum levels of OPG were higher in CKD and GCs groups than in intact animals. At the same time, in the animals' blood serum of the CKD + GCs group, the levels of OPG were lower, than those in animals from the control group. The levels of galectin-3 in the serum of the experimental groups GCs and CKD + GCs were lower than in intact animals. The serum levels of galectin-3 in animals of the CKD group were higher than those in animals from the control group. The levels of P-selectin were lower in the serum of the GCs group than in intact animals. At the same time, the levels of P-selectin were higher in the CKD and CKD + GCs groups, than those in animals from the control group. In conclusion, the study of the complex system of bone remodeling regulation, which includes many factors and their interactions, may lead to the development of new methods for treating patients with chronic kidney disease in order to prevent osteoporosis in the future. (AU)

Las enfermedades metabólicas óseas se caracterizan por un desequilibrio en el proceso de remodelación ósea en los que participan mediadores tales como receptor del activador del factor nuclear- kappa- b (RANK), su ligando (RANKL) y la osteoprotegerina (OPG). Los glucocorticoides, recuentemente empleados en el tratamiento de la enfermedad renal crónica, exacerban este desequilibrio. En la enfermedad esclerótica renal, las moléculas de adhesión celular P-selectina and galectina-3 tienen un rol fundamental. El objetivo de esta trabajo fue estudiar las alteraciones en los mediadores de la remodelación ósea (RANKL, OPG, P-selectina and galectina-3) en un modelo de enfermedad renal crónica con tratamiento glucocorticoideo. Ratas Wistar hembras fueron divididos en 4 grupos: control (C); enfermedad renal crónica con afección de la remodelación ósea (ERC); animales con afección de la remodelación ósea expuestos a glucocorticoides (GC); enfermedad renal crónica con afección de la remodelación ósea tratados con glucocorticoides (ERC+GC). Los efectos de la ERC y los GC fueron evaluados bioquímicamente, histológicamente y por medición de la densidad ósea. RANKL, OPG, Pselectina and galectina-3 se cuantificaron en muestras de sangre venosa empleando enzimoinmuno análisis. En los 3 grupos experimentales la densidad ósea se evidenció reducida y los niveles séricos de RANKL elevados respecto al grupo control. Los niveles de OPG en los grupos ERC y GC fueron superiores mientras que en el grupo ERC+GC menores respecto a los animales controles. Galectina 3 plasmática en GC y ERC+GC se encontró reducida y aumentada en los animales ERC, en comparación con los animales controles. La concentración sérica de P-selectina sérica fue mayor en los grupos ERC y ERC+GC, y menor en los animales GC respecto a los niveles plasmáticos de los animales intactos. El avance del conocimiento sobre la regulación de la remodelación ósea a través de la interacción de mediadores sistémicos, en un futuro, puede conducir al desarrollo de nuevas estrategias terapéuticas para la prevención de la osteoporosis en pacientes con enfermedad renal crónica. (AU)

Comparative effects of atorvastatin 80 mg and rosuvastatin 40 mg on the levels of serum endocan, chemerin, and galectin-3 in patients with acute myocardial infarction.

OBJECTIVE: Endocan, chemerin, and galectin-3 are discrete biomarkers associated with cardiovascular diseases and acting through different pathophysiological pathways. The aim of this study is to investigate and compare the effects of high doses of atorvastatin and rosuvastatin on serum endocan, chemerin, and galectin-3 levels in patients with acute myocardial infarction (AMI). METHODS: Sixty-three patients with AMI were randomized to receive atorvastatin (80 mg/day) or rosuvastatin (40 mg/day) after percutaneous revascularization. Serum levels of endocan, chemerin, and galectin-3 were evaluated at baseline and after 4-week therapy. RESULTS: Endocan levels were not decreased statistically significantly with atorvastatin 80 mg, but rosuvastatin 40 mg markedly decreased the levels of endocan according to baseline [from 110.27 (86.03-143.69) pg/mL to 99.22 (78.30-122.87) pg/mL with atorvastatin 80 mg and from 110.73 (77.28-165.22) pg/mL to 93.40 (70.48-115.13) pg/mL with rosuvastatin 40 mg, p=0.242 for atorvastatin 80 mg and p=0.014 for rosuvastatin 40 mg]. Chemerin levels significantly decreased in both groups according to baseline [from 264.90 (196.00-525.95) ng/mL to 135.00 (105.95-225.65) ng/mL with atorvastatin 80 mg and from 309.95 (168.87-701.27) ng/mL to 121.25 (86.60-212.65) ng/mL with rosuvastatin 40 mg, p<0.001, respectively, for both groups]. Galectin-3 levels did not change markedly with atorvastatin 80 mg, but they decreased with rosuvastatin 40 mg [from 17.00 (13.10-22.25) ng/mL to 19.30 (15.25-23.45) ng/mL with atorvastatin 80 mg, p=0.721, and from 18.25 (12.82-23.82) ng/mL to 16.60 (10.60-20.15) ng/mL with rosuvastatin 40 mg, p=0.074]. There were no significant between-group differences in terms of absolute and percentage changes of endocan, chemerin, and galectin-3 at 4 weeks. CONCLUSION: We reported that both statins similarly decreased the endocan levels, whereas rosuvastatin seems to have more prominent effects on the reduction of the chemerin and galectin-3 levels in patients with AMI.

Astragalus polysaccharides (PG2) Enhances the M1 Polarization of Macrophages, Functional Maturation of Dendritic Cells, and T Cell-Mediated Anticancer Immune Responses in Patients with Lung Cancer.

BACKGROUND: Recently, we demonstrated that Astragalus polysaccharide (PG2), the active ingredient in dried roots of astragalus membranaceus, ameliorates cancer symptom clusters and improves quality of life (QoL) in patients with metastatic disease by modulating inflammatory cascade against the background roles of inflammatory cells, including macrophages, dendritic cells (DCs), and cytotoxic T lymphocytes (CTLs) in tumor initiation, metastasis, and progression. Nevertheless, the role of PG2 in the modulation of anticancer immunogenicity and therapeutic response remains relatively underexplored and unclear. PURPOSE: The present study investigates how and to what extent PG2 modulates cellular and biochemical components of the inflammatory cascade and enhances anticancer immunity, as well as the therapeutic implication of these bio-events in patients with lung cancer. METHODS AND RESULTS: Herein, we demonstrated that PG2 significantly increased the M1/M2 macrophage polarization ratio in non-small cell carcinoma (NSCLC) H441 and H1299 cells. This PG2-induced preferential pharmacologic up-regulation of tumoral M1 population in vitro positively correlated with the downregulation of tumor-promoting IL-6 and IL-10 expression in NSCLC cell-conditioned medium, with concomitant marked inhibition of cell proliferation, clonogenicity, and tumorsphere formation. Our ex vivo results, using clinical sample from our NSCLC cohort, demonstrated that PG2 also promoted the functional maturation of DCs with consequent enhancement of T cell-mediated anticancer immune responses. Consistent with the in vitro and ex vivo results, our in vivo studies showed that treatment with PG2 elicited significant time-dependent depletion of the tumor-associated M2 population, synergistically enhanced the anti-M2-based anticancer effect of cisplatin, and inhibited xenograft tumor growth in the NSCLC mice models. Moreover, in the presence of PG2, cisplatin-associated dyscrasia and weight-loss was markedly suppressed. CONCLUSION: These results do indicate a therapeutically-relevant role for PG2 in modulating the M1/M2 macrophage pool, facilitating DC maturation and synergistically enhancing the anticancer effect of conventional chemotherapeutic agent, cisplatin, thus laying the foundation for further exploration of the curative relevance of PG2 as surrogate immunotherapy and/or clinical feasibility of its use for maintenance therapy in patients with lung cancer.

Glycated serum albumin stimulates expression of endothelial cell specific molecule-1 in human umbilical vein endothelial cells: Implication in diabetes mediated endothelial dysfunction.

Pro-inflammatory conditions induced by products of protein glycation in diabetes substantially enhance the risk of endothelial dysfunction and related vascular complications. Endothelial cell specific molecule-1 (ESM-1) or endocan has been demonstrated as a potential biomarker in cancer and sepsis. Its role in diabetes-induced pathologies remains unknown. The expression of ESM-1 gene is under cytokine regulation, indicating its role in endothelium-dependent pathological disorders. In this study, we investigated the effect of advanced glycated human serum albumin (AGE-HSA) on the production of ESM-1. We show that AGE-HSA exerts a modulating role on the expression of ESM-1 in human umbilical vein endothelial cells. It up-regulates expression of ESM-1 protein in a dose-dependent manner which correlates with its messenger RNA (mRNA) transcription. RAGE and galectin-3, both AGE receptors, show antagonistic action on its expression. While gene silencing of RAGE has down-regulatory effect, that of galectin-3 has up-regulatory effect on AGE-induced expression of ESM-1. Inhibition of MAPKKK and JNK pathways did not alter the expression. In contrast, phosphatidylinositol 3 kinase (PI3K) inhibition significantly up-regulated ESM-1 expression. In conclusion, these results suggest that AGE-induced activation of human umbilical vein endothelial cells promotes formation of endocan which is an endothelial dysfunction marker and may be related to vascular disease in diabetes.

Galectin-3, a biomarker linking oxidative stress and inflammation with the clinical outcomes of patients with atherothrombosis.

BACKGROUND: Galectin-3 (Gal-3) participates in different mechanisms involved in atherothrombosis, such as inflammation, proliferation, or macrophage chemotaxis. Thus, there have been committed intensive efforts to elucidate the function of Gal-3 in cardiovascular (CV) diseases. The role of Gal-3 as a circulating biomarker has been demonstrated in patients with heart failure, but its importance as a biomarker in atherothrombosis is still unknown. METHODS AND RESULTS: Because Gal-3 is involved in monocyte-to-macrophage transition, we used fresh isolated monocytes and the in vitro model of macrophage differentiation of THP-1 cells stimulated with phorbol myristate acetate (PMA). Gal-3 release is increased by PMA in human monocytes and macrophages, a process involving exosomes and regulated by reactive oxygen species/NADPH oxidase activity. In asymptomatic subjects (n=199), Gal-3 plasma levels are correlated with NADPH oxidase activity in peripheral blood mononuclear cells (r=0.476; P<0.001) and carotid intima-media thickness (r=0.438; P<0.001), a surrogate marker of atherosclerosis. Accordingly, Gal-3 plasma concentrations are increased in patients with carotid atherosclerosis (n=158), compared to control subjects (n=115; 14.3 [10.7 to 16.9] vs. 10.4 [8.6 to 12.5] ng/mL; P<0.001). Finally, on a 5-year follow-up study in patients with peripheral artery disease, Gal-3 concentrations are significantly and independently associated with an increased risk for CV mortality (hazard ratio=2.24, 95% confidence interval: 1.06 to 4.73, P<0.05). CONCLUSIONS: Gal-3 extracellular levels could reflect key underlying mechanisms involved in atherosclerosis etiology, development, and plaque rupture, such as inflammation, infiltration of circulating cells and oxidative stress. Moreover, circulating Gal-3 concentrations are associated with clinical outcomes in patients with atherothrombosis.

Galectin-3: its role in asthma and potential as an anti-inflammatory target.

Galectins constitute an evolutionary conserved family that bind to ß-galactosides. Increasing evidence shows that galectins are involved in many fundamental biological processes such as cellular communication, inflammation, differentiation and apoptosis. Changes in galectin-3 (Gal-3) expression are commonly seen in cancer and pre-cancerous conditions, and Gal-3 may be involved in the regulation of diverse cancer cell activities that contribute to tumourigenesis, cancer progression and metastasis. In addition, Gal-3 is a pro-inflammatory regulator in rheumatoid arthritis. Gal-3 has been shown to be involved in many aspects in allergic inflammation, such as eosinophil recruitment, airway remodeling, development of a Th2 phenotype as well as increased expression of inflammatory mediators. In an in vivo model it was shown that bronchoalveolar lavage (BAL) fluid from ovalbumin-challenged mice contained significantly higher levels of Gal-3 compared to control mice. The molecular mechanisms of Gal-3 in human asthma have not been fully elucidated. This review will focus on what is known about the Gal-3 and its role in the pathophysiological mechanisms of asthma to evaluate the potential of Gal-3 as a biomarker and therapeutic target of asthma.

Involvement of galectin-3 in cadmium-induced cardiac toxicity.

OBJECTIVE: Accumulation of the wide spread environmental toxin cadmium (Cd) in tissues results in toxicity. Heart is one of the most effected tissues. Cd exposure induces inflammation in effected tissues. The present study was focused to evaluate roles of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) in Cd toxicity and their relationships with galectin-3 levels. METHODS: In this experimental study, male Wistar rats were divided randomly to control and experimental groups. Experimental group was exposed to Cd at the dose of 15 ppm for 8 weeks (n=10/group). Inflammatory status in hearts was evaluated with measurement of tissue TNF-α and IL-6 levels. Histopathological examination of heart was carried out by light microscopy. Heart tissue caspase-3 level was used to identify apoptosis. Tissue galectin-3 level was evaluated by ELISA. Statistical difference between groups was evaluated by unpaired Student t-test, correlation was analyzed by Pearson's test. RESULTS: Heart sizes were increased after Cd toxicity. A significant increase in galectin-3 tissue levels was seen after Cd toxicity, this was accompanied with a significant increase in the TNF-α (control: 402±39, Cd: 793±26 pg/g tissue, p<0.001) and IL-6 (control: 150±78, Cd: 325±65 pg/g tissue, p<0.001) levels. Histopathological examination under light microscope suggested a combination of ongoing necrosis and apoptosis. Increased caspase-3 levels were measured after Cd toxicity (control: 12±2, Cd: 18±3 pmol/µg/min, p<0.001). CONCLUSION: Chronic Cd administration induces inflammation and apoptosis in rat hearts. Cadmium causes increased galectin-3 production from heart tissue. The formation of TNF-α due to Cd exposure may likely trigger this mechanism.

The role of galectin-3 in cancer drug resistance.

The galectins comprise a family of 14 members of beta-galactoside-binding proteins, characterized by their affinity for beta-galactosides and by a conserved sequence in the carbohydrate recognition domain that bind to the carbohydrate portion of cell surface glycoproteins or glycolipids. Galectin-3, a 31kDa gene product, is a multifunctional oncogenic protein which regulates cell growth, cell adhesion, cell proliferation, angiogenesis, and apoptosis. Recent studies have revealed that galectin-3 demonstrates anti-apoptotic effects which contribute to cell survival in several types of cancer cells. Intracellular galectin-3 in particular, which contains the NWGR anti-death motif of the Bcl-2 family, inhibits cell apoptosis induced by chemotherapeutic agent such as cisplatin and etoposide in some types of cancer cells. We have also reported that nuclear export of phosphorylated galectin-3 regulates its anti-apoptotic activity in response to chemotherapeutic drugs. Here, we will describe the role of galectin-3 as an anti-apoptotic factor in response to chemotherapeutic drugs and will discuss recent data on its molecular mechanism that contribute to drug resistance. We suggest that targeting galectin-3 could improve the efficacy of anticancer drug chemotherapy in several types of cancer.

Galectin-3 in macrophage-like cells exposed to immunomodulatory drugs.

During the last few decades, the effects of immunomodulatory drugs on numerous molecules and biological processes have been widely studied. Nevertheless, the relationship between immunomodulatory drugs and lectin expression/function is still to be elucidated. In this study, we used THP-1-derived macrophages to investigate the effects of non-steroidal anti-inflammatory drugs (aspirin and indomethacin) and glucocorticoids (hydrocortisone and dexamethasone) on galectin-3, a multifunctional beta-galactoside binding lectin, which in general acts as a strong pro-inflammatory signal. The results showed that all immunomodulatory drugs applied in clinically relevant doses affect both the gene (LGALS3) and protein expression level of galectin-3. The provoked changes on protein level are qualitatively and quantitatively different comparing to the effects on galectin-3 mRNA level, and depend on the differentiation state of the cell, drug type and applied concentration as well as on time of the exposure. Our data revealed galectin-3 as a new target molecule of immunomodulatory drugs, thus suggesting an additional pathway of their action on immune response.

Cross-reactivities between date palm (Phoenix dactylifera L.) polypeptides and foods implicated in the oral allergy syndrome.

BACKGROUND: Date fruit and pollen antigens share a number of cross-reactive epitopes. Date pollen has been shown to cross-react with antigens from Artemisia, cultivated rye (Secale cereale), Timothy grass (Phleum pratense), Sydney golden wattle (Acacia longifolia) and Bermuda grass (Cynodon dactylon) pollen. The present study was carried out to examine any cross-reactivities between date palm polypeptides and antigens of some common foods and vegetables that have been implicated in the oral allergy syndrome (OAS). Because most of such cross-reactivities in other allergens are attributable to the presence of carbohydrate chains and profilin, their role was also investigated. METHODS: Fresh extracts of 20 common fruits and vegetables were prepared. Putative date profilins were isolated by affinity chromatography using a poly L-proline column. Date fruit extracts were digested by various endoglycosidases and the immunoglobulin (Ig)E binding of the postdigest products was assessed in immunoblots. Rabbit antisera to whole date fruit extracts, Timothy grass profilin and putative date profilins, as well as human sera from date sensitive individuals were used in immunoblotting, ELISA and in inhibition experiments. RESULTS: IgG, ELISA and immunoblot results with the different rabbit antisera and date-sensitive atopic sera showed several antigenic cross-reactivities and similar cross-reactivities were seen with birch, date and timothy grass profilins. IgE, ELISA and immunoblot experiments with pooled date sensitive human sera showed a range of cross-reactivities with some food extracts. A number of the IgE cross-reactivities could be inhibited after preabsorption of pooled sera with date extracts. Sixty-six percent of individual date hypersensitive human sera bound IgE in putative date fruit profilin and their pooled sera bound IgE in birch pollen profilin. IgE-binding of the endoglycosidase digested date fruit extracts to atopic serum pool was restricted to only a very low molecular weight band of 6.5-8 kDa. CONCLUSION: These results indicate that date palm polypeptides share cross-reactive IgG and IgE epitopes with a number of foods implicated in the oral allergy syndrome, bind to birch and Timothy grass profilins and bind IgE through glycosyl residues. The clinical relevance of these cross-reactivities needs to be further elucidated.