Glycosaminoglycan-binding cytokines as tumor markers

Low TYROBP expression predicts poor prognosis in multiple myeloma

BACKGROUND

Multiple myeloma (MM) is the second most common refractory hematologic cancer. Searching for new targets and prognostic markers for MM is significant.

METHODS

GSE39754, GSE6477 and GSE24080 were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) in MM versus healthy people from GSE39754 and GSE6477 were screened using limma package, and MM-related module genes were chosen with the use of Weighted gene co-expression network analysis (WGCNA), and the two were intersected using ggVennDiagram for obtaining MM-related DEGs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were carried out. Then, protein-protein interactions (PPI) analysis in String database was used to obtain hub genes, while prognosis was analyzed by survival package in GSE24080. Receiver operating characteristic (ROC) curve was adopted for evaluating diagnostic value of hub genes. Besides, univariable/multivariable Cox regression were employed to screen independent prognostic biomarkers. Gene set enrichment analysis (GSEA) was used to find possible mechanism. Finally, western-blotting and reverse transcription-polymerase chain reaction (RT-PCR) verify TYROBP expression within MM and healthy people. We performed cell adhesion and transwell assays for investigating TYROBP function in MM cell adhesion and migration.

RESULTS

Through differential analyses, 92 MM-related DEGs were obtained. 10 hub genes were identified by PPI and CytoHubba. Their diagnostic and prognostic significance was analyzed. Down-regulation of genes like TYROBP, ELANE, MNDA, and MPO related to dismal MM prognosis. Upon univariable/multivariable Cox regression, TYROBP independently predicted MM prognosis. GSEA pathway was enriched, indicating that TYROBP expression affected MM development via cell adhesion molecular pathway. Upon Western-blotting and RT-PCR assays, TYROBP expression among MM patients decreased relative to healthy donors. Cell adhesion and transwell migration assays revealed increased MM cell adhesion and decreased migration upon TYROBP up-regulation.

CONCLUSION

In summary, TYROBP is a potential prognostic marker for MM.

Update on the Role of the Endothelial Glycocalyx in Angiogenesis and Vascular Inflammation

The endothelial glycocalyx is a negatively charged, carbohydrate-rich structure that arises from the luminal surface of the vascular endothelium and is comprised of proteoglycans, glycoproteins, and glycolipids. The glycocalyx, which sits at the interface between the endothelium and the blood, is involved in a wide array of physiological and pathophysiological processes, including as a mechanotransducer and as a regulator of inflammation. Most recently, components of the glycocalyx have been shown to play a key role in controlling angiogenesis. In this review, we briefly summarize the structure and function of the endothelial glycocalyx. We focus on its role and functions in vascular inflammation and angiogenesis and discuss the important unanswered questions in this field.

Low Molecular Weight Heparins (LMWH) and Implications along Pregnancy: a Focus on the Placenta

Low molecular weight heparins (LMWH) have been largely studied for their use during pregnancy. The biology and the pharmacology of these molecules are well known and may be summarized in three main mechanisms of action: anti-coagulant, anti-inflammatory, and immunomodulant. The clinical implications of these drugs during pregnancy are mainly related to their action on the placenta, because of the presence of specific molecular and cellular targets, particularly at the trophoblast-endometrial interface. As well as for the prevention and treatment of thromboembolism, LMWH have been largely investigated for the improvement of embryo implantation and for the prevention of placenta-related complications such as preeclampsia, fetal growth restriction, and intrauterine fetal death. However, data on this topic are still unclear. The present review discusses the biological features, the mechanisms of action, and the possible contribution of LMWH to the success of placentation along pregnancy, pointing out the need for future basic science and clinical researches in this important field with the final aim to improve clinical practice in high-risk pregnancies.

Construction and Comprehensive Analysis of a ceRNA Network to Reveal Potential Novel Biomarkers for Triple-Negative Breast Cancer

Background

Triple-negative breast cancer (TNBC) is the most common and aggressive type of breast cancer with an unfavourable outcome worldwide. Novel therapeutic targets are urgently required to explore this malignancy. This study explored the ceRNA network and the important genes for predicting the therapeutic targets.

Methods

It identified the differentially expressed genes of mRNAs, lncRNAs and miRNAs between TNBC and non-TNBC samples in four cohorts (TCGA, GSE38959, GSE45827 and GSE65194) to explore the novel therapeutic targets for TNBC. Downstream analyses, including functional enrichment analysis, ceRNA network, protein–protein interaction and survival analysis, were then conducted by bioinformatics analysis. Finally, the potential core protein of the ceRNA network in TNBC was validated by immunohistochemistry.

Results

A total of 1,045 lncRNAs and 28 miRNAs were differentially expressed in the TCGA TNBC samples, and the intersections of 282 mRNAs (176 upregulations and 106 downregulations) between the GEO and TCGA databases were identified. A ceRNA network composed of 7 lncRNAs, 62 mRNAs, 12 miRNAs and 244 edges specific to TNBC was established. The functional assay showed dysregulated genes, and GO, DO and KEGG enrichment analysis were performed. Survival analysis showed that mRNA LIFR and lncRNA AC124312.3 were significantly correlated with the overall survival of patients with TNBC in the TCGA databases (P < 0.05). Finally, the LIFR protein was validated, and immunohistochemical results showed the upregulated expression of LIFR in TNBC tissues.

Conclusion

Thus, our study presents an enhanced understanding of the ceRNA network in TNBC, where the key gene LIFR may be a new promising potential therapeutic target for patients with TNBC.

In vitro antitumor and anti-angiogenic activities of a shrimp chondroitin sulfate

Thrombin triggers cellular responses that are crucial for development and progression of cancer, such as proliferation, migration, oncogene expression and angiogenesis. Thus, biomolecules capable of inhibiting this protease have become targets in cancer research. The present work describes the in vitro antitumor properties of a chondroitin sulfate with anti-thrombin activity, isolated from the Litopenaeus vannamei shrimp (sCS). Although the compound was unable to induce cytotoxicity or cell death and/or cell cycle changes after 24 h incubation, it showed a long-term antiproliferative effect, reducing the tumor colony formation of melanoma cells by 75% at 100 μg/mL concentration and inhibiting the anchorage-independent colony formation. sCS reduced 66% of melanoma cell migration in the wound healing assay and 70% in the transwell assay. The compound also decreased melanin and TNF-α content of melanoma cells by 52% and 75% respectively. Anti-angiogenic experiments showed that sCS promoted 100% reduction of tubular structure formation at 100 μg/mL. These results are in accordance with the sCS-mediated in vitro expression of genes related to melanoma development (Cx-43, MAPK, RhoA, PAFR, NFKB1 and VEGFA). These findings bring a new insight to CS molecules in cancer biology that can contribute to ongoing studies for new approaches in designing anti-tumor therapy.

The role of heparin/heparan sulphate in the IFN-γ-led Arena

IFN-γ (Interferon-gamma) is a pleiotropic cytokine. It is often involved in a variety of physiological processes by binding to the cell surface transmembrane receptor (IFN-γR) to initiate a series of signalling pathways that transmit external signals from cell surface receptors to the cell nucleus. Heparan sulphate (HS), a highly sulphated linear polysaccharide, is ubiquitous on the mammalian cell surface and extracellular matrix. Electrostatic interactions can be generated between the highly sulphated HS region and specific basic amino acid residues in the IFN-γ structure, thereby detaining IFN-γ on the cell surface, and the concentration of IFN-γ on the cell surface is thus, changed. IFN-γ retained on the cell surface will optimize the binding of IFN-γ to the transmembrane receptor resulting in high efficiency signalling. Heparin is a glycosaminoglycan with a structure similar to HS. The structural similarity provides a basis for modelling exogenous heparin dependence for interference with IFN-γ function. This model can be summarized as follows: First, the competitive binding effect; heparin bound to cytokines by competing with membrane-associated HS, causes a decrease in cytokine concentration on the cell surface. Second, the principle of priority occupancy; heparin can occupy the receptor binding site on cytokines, partially preventing the IFN-γ-IFN-γR interaction. These two models interfere with IFN-γ signal transmission. To decipher the mechanism by which heparin influences IFN-γ activity, studies of the structure-activity relationship are in progress. This paper summarizes research progress on the IFN-γ signalling pathway, heparin interference with IFN-γ activity and the structure-activity relationship between heparin and IFN-γ.

Heparin: An essential drug for modern medicine

Heparin is a life-saving drug, which belongs to few clinically used drugs without defined molecular structures in modern medicine. Heparin is the mostly negatively charged biopolymer with a broad distributions in molecular weight, charge density, and biological activities. Heparin is mainly composed of repeating trisulfated disaccharide units, which is made by mast cells that are enriched in the intestines, lungs or livers of animals. Porcine intestines and bovine lungs are two mostly used sources for heparin isolation. Heparin is well known for its anticoagulant and antithrombotic pharmacological effects. The anticoagulant activity of heparin is attributable to a 3-O-sulfate and 6-O-sulfate containing pentasaccharide sequence or a minimum eight-repeating disaccharide units containing the pentasaccharide sequence that catalyzes the suicidal inactivation of factor Xa or thrombin by a serpin or serine protease inhibitor named antithrombin III, respectively. Thus, heparin is responsible for the simultaneous inhibition of both thrombin generation and thrombin activity in the blood circulation. Moreover, heparin has many pharmacological properties such as anti-inflammatory, anti-viral, anti-angiogenesis, anti-neoplastic, and anti-metastatic effects though high affinity interactions with a variety of proteases, protease inhibitors, chemokines, cytokines, growth factors, and their respective receptors. The one drug multiple molecular targeting properties make heparin a very special drug in that various clinical trials are still conducting worldwide even 100 years after its discovery. In this review, we will summarize the structure-function relationship and the molecular mechanisms of heparin. We will also provide an overview of different clinical and potential clinical applications of heparin.

Midkine and pleiotrophin concentrations in needle biopsies of breast and lung masses

BACKGROUND/OBJECTIVE

Midkine (MDK) and pleiotrophin (PTN) are two closely related heparin-binding growth factors which are overexpressed in a wide variety of human cancers. We hypothesized that the concentrations of these factors in washout of biopsy needles would be higher in breast and lung cancer than in benign lesions.

METHODS

Seventy subjects underwent pre-operative core needle biopsies of 78 breast masses (16 malignancies). In 11 subjects, fine needle aspiration was performed ex vivo on 7 non-small cell lung cancers and 11 normal lung specimens within surgically excised lung tissue. The biopsy needle was washed with buffer for immunoassay.

RESULTS

The MDK/DNA and the PTN/DNA ratio in most of the malignant breast masses were similar to the ratios in benign masses except one lobular carcinoma in situ (24-fold higher PTN/DNA ratio than the average benign mass). The MDK/DNA and PTN/DNA ratio were similar in most malignant and normal lung tissue except one squamous cell carcinoma (38-fold higher MDK/DNA ratio than the average of normal lung tissue).

CONCLUSIONS

Both MDK and PTN are readily measurable in washout of needle biopsy samples from breast and lung masses and levels are highly elevated only in a specific subset of these malignancies.

A Multivariate Mixture Model to Estimate the Accuracy of Glycosaminoglycan Identifications Made by Tandem Mass Spectrometry (MS/MS) and Database Search

We present a statistical model to estimate the accuracy of derivatized heparin and heparan sulfate (HS) glycosaminoglycan (GAG) assignments to tandem mass (MS/MS) spectra made by the first published database search application, GAG-ID. Employing a multivariate expectation-maximization algorithm, this statistical model distinguishes correct from ambiguous and incorrect database search results when computing the probability that heparin/HS GAG assignments to spectra are correct based upon database search scores. Using GAG-ID search results for spectra generated from a defined mixture of 21 synthesized tetrasaccharide sequences as well as seven spectra of longer defined oligosaccharides, we demonstrate that the computed probabilities are accurate and have high power to discriminate between correctly, ambiguously, and incorrectly assigned heparin/HS GAGs. This analysis makes it possible to filter large MS/MS database search results with predictable false identification error rates.

Pharmacology of Heparin and Related Drugs

Heparin has been recognized as a valuable anticoagulant and antithrombotic for several decades and is still widely used in clinical practice for a variety of indications. The anticoagulant activity of heparin is mainly attributable to the action of a specific pentasaccharide sequence that acts in concert with antithrombin, a plasma coagulation factor inhibitor. This observation has led to the development of synthetic heparin mimetics for clinical use. However, it is increasingly recognized that heparin has many other pharmacological properties, including but not limited to antiviral, anti-inflammatory, and antimetastatic actions. Many of these activities are independent of its anticoagulant activity, although the mechanisms of these other activities are currently less well defined. Nonetheless, heparin is being exploited for clinical uses beyond anticoagulation and developed for a wide range of clinical disorders. This article provides a "state of the art" review of our current understanding of the pharmacology of heparin and related drugs and an overview of the status of development of such drugs.

Changes in composition and sulfation patterns of glycoaminoglycans in renal cell carcinoma

Glycosaminoglycans (GAGs) are heterogeneous, linear, highly charged, anionic polysaccharides consisting of repeating disaccharides units. GAGs have some biological significance in cancer progression (invasion and metastasis) and cell signaling. In different cancer types, GAGs undergo specific structural changes. In the present study, in depth investigation of changes in sulfation pattern and composition of GAGs, heparan sulfate (HS)/heparin (HP), chondroitin sulfate (CS)/dermatan sulfate and hyaluronan (HA) in normal renal tissue (NRT) and renal cell carcinoma tissue (RCCT) were evaluated. The statistical evaluation showed that alteration of the HS (HSNRT = 415.1 ± 115.3; HSRCCT = 277.5 ± 134.3), and CS (CSNRT = 35.3 ± 12.3; CSRCCT = 166.7 ± 108.8) amounts (in ng/mg dry tissue) were statistically significant (p < 0.05). Sulfation pattern in NRT and RCCT was evaluated to reveal disaccharide profiles. Statistical analyses showed that RCCT samples contain significantly increased amounts (in units of ng/mg dry tissue) of 4SCS (NRT = 25.7 ± 9.4; RCCT = 117.1 ± 73.9), SECS (NRT = 0.7 ± 0.3; RCCT = 4.7 ± 4.5), 6SCS (NRT = 6.1 ± 2.7; RCCT = 39.4 ± 34.7) and significantly decreased amounts (in units of ng/mg dry tissue) of NS6SHS (RCCT = 28.6 ± 6.5, RCCT = 10.2 ± 8.0), NS2SHS (RCCT = 44.2 ± 13.8; RCCT = 27.2 ± 15.0), NSHS (NRT = 68.4 ± 15.8; RCCT = 50.4 ± 21.2), 2S6SHS (NRT = 1.0 ± 0.4; RCCT = 0.4 ± 0.3), and 6SHS (NRT = 60.6 ± 17.5; RCCT = 24.9 ± 12.3). If these changes in GAGs are proven to be specific and sensitive, they may serve as potential biomarkers in RCC. Our findings are likely to help us to show the direction for further investigations to be able to bring different diagnostic and prognostic approaches in renal tumors.

GAG-ID: Heparan Sulfate (HS) and Heparin Glycosaminoglycan High-Throughput Identification Software

Heparin and heparan sulfate are very large linear polysaccharides that undergo a complex variety of modifications and are known to play important roles in human development, cell-cell communication and disease. Sequencing of highly sulfated glycosaminoglycan oligosaccharides like heparin and heparan sulfate by liquid chromatography-tandem mass spectrometry (LC-MS/MS) remains challenging because of the presence of multiple isomeric sequences in a complex mixture of oligosaccharides, the difficulties in separation of these isomers, and the facile loss of sulfates in MS/MS. We have previously introduced a method for structural sequencing of heparin/heparan sulfate oligosaccharides involving chemical derivatizations that replace labile sulfates with stable acetyl groups. This chemical derivatization scheme allows the use of reversed phase LC for high-resolution separation and MS/MS for sequencing of isomeric heparan sulfate oligosaccharides. However, because of the large number of analytes present in complex mixtures of heparin/HS oligosaccharides, the resulting LC-MS/MS data sets are large and cannot be annotated with existing glycomics software because of the specifically designed chemical derivatization strategy. We have developed a tool, called GAG-ID, to automate the interpretation of derivatized heparin/heparan sulfate LC-MS/MS data based on a modified multivariate hypergeometric distribution to weight the annotation of more intense peaks. The software is tested on a LC-MS/MS data set collected from a mixture of 21 synthesized heparan sulfate tetrasaccharides. By testing the discrimination of scoring with this system, we show that stratifying peaks into different intensity classes benefits the discrimination of scoring, and GAG-ID is able to properly assign all 21 synthetic tetrasaccharides in a defined mixture from a single LC-MS/MS run.

Acidolysis-based component mapping of glycosaminoglycans by reversed-phase high-performance liquid chromatography with off-line electrospray ionization-tandem mass spectrometry: evidence and tags to distinguish different glycosaminoglycans

Diverse monosaccharide analysis methods have been established for a long time, but few methods are available for a complete monosaccharide analysis of glycosaminoglycans (GAGs) and certain acidolysis-resistant components derived from GAGs. In this report, a reversed-phase high-performance liquid chromatography (RP-HPLC) method with pre-column 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization was established for a complete monosaccharide analysis of GAGs. Good separation of glucosamine/mannosamine (GlcN/ManN) and glucuronic acid/iduronic acid (GlcA/IdoA) was achieved. This method can also be applied to analyze the acidolysis-resistant disaccharides derived from GAGs, and the sequences of these disaccharides were confirmed by electrospray ionization-collision-induced dissociation-tandem mass spectrometry (ESI-CID-MS/MS). These unique disaccharides could be used as markers to distinguish heparin/heparan sulfate (HP/HS), chondroitin sulfate/dermatan sulfate (CS/DS), and hyaluronic acid (HA).

Heparin and related drugs: beyond anticoagulant activity

Heparin has been widely used as an anticoagulant for more than 80 years. However, there is now considerable evidence that heparin also possesses anti-inflammatory activity, both experimentally and clinically. Importantly in many instances, the anti-inflammatory actions of heparin are independent of anticoagulant activity raising the possibility of developing novel drugs based on heparin that retain the anti-inflammatory activity. Heparin exhibits anti-inflammatory activities via a variety of mechanisms including neutralization of cationic mediators, inhibition of adhesion molecules, and the inhibition of heparanase, all involved in leukocyte recruitment into tissues. It is anticipated that furthering our understanding of the anti-inflammatory actions of heparin will lead to the development of novel anti-inflammatory drugs for a variety of clinical indications.

A structural analysis of glycosaminoglycans from lethal and nonlethal breast cancer tissues: toward a novel class of theragnostics for personalized medicine in oncology?

Cancer is one of the leading noncommunicable diseases that vastly impacts both developed and developing countries. Truly innovative diagnostics that inform disease susceptibility, prognosis, and/or response to treatment (theragnostics) are seriously needed for global public health and personalized medicine for patients with cancer. This study examined the structure and content of glycosaminoglycans (GAGs) in lethal and nonlethal breast cancer tissues from six patients. The glycosaminoglycan content isolated from tissue containing lethal cancer tumors was approximately twice that of other tissues. Molecular weight analysis showed that glycosaminoglycans from cancerous tissue had a longer weight average chain length by an average of five disaccharide units, an increase of approximately 15%. Dissacharide analysis found differences in sulfation patterns between cancerous and normal tissues, as well as sulfation differences in GAG chains isolated from patients with lethal and nonlethal cancer. Specifically, cancerous tissue showed an increase in sulfation at the "6S" position of CS chains and an increase in the levels of the HS disaccharide NSCS. Patients with lethal cancer showed a decrease in HS sulfation, with lower levels of "6S" and higher levels of the unsulfated "0S" disaccharide. Although these findings come from a limited sample size, they indicate that structural changes in GAGs exist between cancerous and noncancerous tissues and between tissues from patients with highly metastatic cancer and cancer that was successfully treated by chemotherapy. Based on these findings, we hypothesize that (1) there are putative changes in the body's construction of GAGs as tissue becomes cancerous; (2) there may be innate structural person-to-person variations in GAG composition that facilitate the metastasis of tumors in some patients when they develop cancer.

Midkine acts as proangiogenic cytokine in hypoxia-induced angiogenesis

The cytokine midkine (MK) promotes tumor growth mainly by inducing angiogenesis. Here, we identified the source of MK in the vascular system under hypoxic conditions and demonstrated the relevance of MK during ischemia of normal tissue. Hypoxia increased MK protein expression in human polymorphonuclear neutrophils (PMN), monocytes, and human umbilical vein endothelial cells (HUVEC) compared with normoxia. Immunoelectron microscopy showed elevated cell surface expression of MK in PMN and monocytes during hypoxia. However, only HUVEC released significant amounts of soluble MK during hypoxia compared with normoxia (301 ± 81 pg/ml vs. 158 ± 45 pg/ml; P < 0.05). Exogenous MK induced neovascularization in a chorioallantoic membrane (CAM) assay compared with negative control as measured by counting the number of branching points per visual field (1,074 ± 54 vs. 211 ± 70; P < 0.05). In a hind limb ischemia model, the angiogenic response was almost completely absent in MK-deficient mice, whereas control animals showed a profound angiogenic response measured as proliferating endothelial cells per visual field (45 ± 30 vs. 169 ± 34; P < 0.01). These unanticipated results identified endothelial cells as the source of soluble MK in the vascular system during hypoxia and defined MK as a pivotal player of angiogenesis during ischemia in nonmalignant tissue.

Exploiting enzyme specificities in digestions of chondroitin sulfates A and C: production of well-defined hexasaccharides

Interactions between proteins and glycosaminoglycans (GAGs) of the extracellular matrix are important to the regulation of cellular processes including growth, differentiation and migration. Understanding these processes can benefit greatly from the study of protein-GAG interactions using GAG oligosaccharides of well-defined structure. Materials for such studies have, however, been difficult to obtain because of challenges in synthetic approaches and the extreme structural heterogeneity in GAG polymers. Here, it is demonstrated that diversity in structures of oligosaccharides derived by limited enzymatic digestion of materials from natural sources can be greatly curtailed by a proper selection of combinations of source materials and digestive enzymes, a process aided by an improved understanding of the specificities of certain commercial preparations of hydrolases and lyases. Separation of well-defined oligosaccharides can then be accomplished by size-exclusion chromatography followed by strong anion-exchange chromatography. We focus here on two types of chondroitin sulfate (CS) as starting material (CS-A, and CS-C) and the use of three digestive enzymes with varying specificities (testicular hyaluronidase and bacterial chondroitinases ABC and C). Analysis using nuclear magnetic resonance and mass spectrometry focuses on isolated CS disaccharides and hexasaccharides. In all, 15 CS hexasaccharides have been isolated and characterized. These serve as useful contributions to growing libraries of well-defined GAG oligosaccharides that can be used in further biophysical assays.

Non-anticoagulant effects of heparin: an overview

Heparin has long been known to possess biological effects that are unrelated to its anticoagulant activity. In particular, much emphasis has been placed upon heparin, or novel agents based upon the heparin template, as potential anti-inflammatory agents. Moreover, heparin has been reported to possess clinical benefit in humans, including in chronic inflammatory diseases and cancer, that are over and above the expected effects on blood coagulation and which in many cases are entirely separable from this role. This chapter aims to provide an overview of the non-anticoagulant effects that have been ascribed to heparin, from those involving the binding and inhibition of specific mediators involved in the inflammatory process to effects in whole system models of disease, with reference to the effects of heparin that have been reported to date in human diseases.

Lactoferrin, a key molecule in immune and inflammatory processes

Lactoferrin (Lf) belongs to the family of antimicrobial molecules that constitute the principal defense line of nonvertebrate organisms. In human immunity, their roles are considerably extended, and actually exceed mere direct antimicrobial properties. As a result, Lf is involved in both innate and adaptive immunities where its modulating effects not only help the host fight against microbes but also protect the host against harmful effects of inflammation. Such beneficial effects have been noticed in studies using dietary Lf, without the experimenters always explaining the exact modes of action of Lf. Effects on mucosal and systemic immunities are indeed often observed, which make the roles of Lf tricky to decipher. It is now known that the immunomodulatory properties of Lf are due to its ability to interact with numerous cellular and molecular targets. At the cellular level, Lf modulates the migration, maturation, and functions of immune cells. At the molecular level, in addition to iron binding, interactions of Lf with a plethora of compounds, either soluble or cell-surface molecules, account for its modulatory properties. This paper reviews our current understanding of the mechanisms that explain the regulatory properties of Lf in immune and inflammatory processes.

Midkine: a promising molecule for drug development to treat diseases of the central nervous system

Midkine (MK) is a heparin-binding cytokine, and promotes growth, survival, migration and other activities of target cells. After describing the general properties of MK, this review focuses on MK and MK inhibitors as therapeutics for diseases in the central nervous system. MK is strongly expressed during embryogenesis especially at the midgestation period, but is expressed only at restricted sites in adults. MK expression is induced upon tissue injury such as ischemic brain damage. Since exogenously administered MK or the gene transfer of MK suppresses neuronal cell death in experimental systems, MK has the potential to treat cerebral infarction. MK might become important also in the treatment of neurodegenerative diseases such as Alzheimer's disease. MK is involved in inflammatory diseases by enhancing migration of leukocytes, inducing chemokine production and suppressing regulatory T cells. Since an aptamer to MK suppresses experimental autoimmune encephalitis, MK inhibitors are promising for the treatment of multiple sclerosis. MK is overexpressed in most malignant tumors including glioblastoma, and is involved in tumor invasion. MK inhibitors may be of value in the treatment of glioblastoma. Furthermore, an oncolytic adenovirus, whose replication is under the control of the MK promoter, inhibits the growth of glioblastoma xenografts. MK inhibitors under development include antibodies, aptamers, glycosaminoglycans, peptides and low molecular weight compounds. siRNA and antisense oligoDNA have proved effective against malignant tumors and inflammatory diseases in experimental systems. Practical information concerning the development of MK and MK inhibitors as therapeutics is described in the final part of the review.

Heparin characterization: challenges and solutions

Although heparin is an important and widely prescribed pharmaceutical anticoagulant, its high degree of sequence microheterogeneity and size polydispersity make molecular-level characterization challenging. Unlike nucleic acids and proteins that are biosynthesized through template-driven assembly processes, heparin and the related glycosaminoglycan heparan sulfate are actively remodeled during biosynthesis through a series of enzymatic reactions that lead to variable levels of O- and N-sulfonation and uronic acid epimers. As summarized in this review, heparin sequence information is determined through a bottom-up approach that relies on depolymerization reactions, size- and charge-based separations, and sensitive mass spectrometric and nuclear magnetic resonance experiments to determine the structural identity of component oligosaccharides. The structure-elucidation process, along with its challenges and opportunities for future analytical improvements, is reviewed and illustrated for a heparin-derived hexasaccharide.

Serglycin-independent release of active mast cell proteases in response to Toxoplasma gondii infection

Earlier studies identified serglycin proteoglycan and its heparin chains to be important for storage and activity of mast cell proteases. However, the importance of serglycin for secretion and activity of mast cell proteases in response to parasite infection has been poorly investigated. To address this issue, we studied the effects on mast cell proteases in serglycin-deficient and wild type mice after peritoneal infection with the obligate intracellular parasite Toxoplasma gondii. In line with previous results, we found severely reduced levels of cell-bound mast cell proteases in both noninfected and infected serglycin-deficient mice. However, serglycin-deficient mice secreted mast cell proteases at wild type levels at the site of infection, and enzymatic activities associated with mast cell proteases were equally up-regulated in wild type and serglycin-deficient mice 48 h after infection. In both wild type and serglycin-deficient mice, parasite infection resulted in highly increased extracellular levels of glycosaminoglycans, including hyaluronan and chondroitin sulfate A, suggesting a role of these substances in the general defense mechanism. In contrast, heparan sulfate/heparin was almost undetectable in serglycin-deficient mice, and in wild type mice, it was mainly confined to the cellular fraction and was not increased upon infection. Furthermore, the heparan sulfate/heparin population was less sulfated in serglycin-deficient than in wild type mice indicative for the absence of heparin, which supports that heparin production is dependent on the serglycin core protein. Together, our results suggest that serglycin proteoglycan is dispensable for normal secretion and activity of mast cell proteases in response to peritoneal infection with T. gondii.

Syndecan-1 knock-down in decidualized human endometrial stromal cells leads to significant changes in cytokine and angiogenic factor expression patterns

BACKGROUND

Successful embryonic implantation depends on a synchronized embryo-maternal dialogue. Chemokines, such as chemokine ligand 1 (CXCL1), play essential roles in the maternal reproductive tract leading to morphological changes during decidualization, mediating maternal acceptance towards the semi-allograft embryo and induction of angiogenesis. Chemokine binding to their classical G-protein coupled receptors is essentially supported by the syndecan (Sdc) family of heparan sulfate proteoglycans. The aim of this study was to identify the involvement of Sdc-1 at the embryo-maternal interface regarding changes of the chemokine and angiogenic profile of the decidua during the process of decidualization and implantation in human endometrium.

METHODS

A stable Sdc-1 knock-down was generated in the immortalized human endometrial stromal cell line St-T1 and was named KdS1. The ability of KdS1 to decidualize was proven by Insulin-like growth factor binding 1 (IGFBP1) and prolactin (PRL) confirmation on mRNA level before further experiments were carried out. Dot blot protein analyses of decidualized knock-down cells vs non-transfected controls were performed. In order to imitate embryonic implantation, decidualized KdS1 were then incubated with IL-1beta, an embryo secretion product, vs controls. Statistical analyses were performed applying the Student's t-test with p < 0.05, p < 0.02 and p < 0.01 and one way post-hoc ANOVA test with p < 0.05 as cut-offs for statistical significance.

RESULTS

The induction of the Sdc-1 knock-down revealed significant changes in cytokine and angiogenic factor expression profiles of dKdS1 vs decidualized controls. Incubation with embryonic IL-1beta altered the expression patterns of KdS1 chemokines and angiogenic factors towards inflammatory-associated molecules and factors involved in matrix regulation.

CONCLUSIONS

Sdc-1 knock-down in human endometrial stroma cells led to fulminant changes regarding cytokine and angiogenic factor expression profiles upon decidualization and imitation of embryonic contact. Sdc-1 appears to play an important role as a co-receptor and storage factor for many cytokines and angiogenic factors during decidualization and implantation period, supporting proper implantation and angiogenesis by regulation of chemokine and angiogenic factor secretion in favour of the implanting embryo.

Characterization of glycosaminoglycans by 15N NMR spectroscopy and in vivo isotopic labeling

Characterization of glycosaminoglycans (GAGs), including chondroitin sulfate (CS), dermatan sulfate (DS), and heparan sulfate (HS), is important in developing an understanding of cellular function and in assuring quality of preparations destined for biomedical applications. While use of (1)H and (13)C NMR spectroscopy has become common in characterization of these materials, spectra are complex and difficult to interpret when a more heterogeneous GAG type or a mixture of several types is present. Herein a method based on (1)H-(15)N two-dimensional NMR experiments is described. The (15)N- and (1)H-chemical shifts of amide signals from (15)N-containing acetylgalactosamines in CSs are shown to be quite sensitive to the sites of sulfation (4-, 6-, or 4,6-) and easily distinguishable from those of DS. The amide signals from residual (15)N-containing acetylglucosamines in HS are shown to be diagnostic of the presence of these GAG components as well. Most data were collected at natural abundance of (15)N despite its low percentage. However enrichment of the (15)N-content in GAGs using metabolic incorporation from (15)N-glutamine added to cell culture media is also demonstrated and used to distinguish metabolic states in different cell types.

ZC3H12A (MCPIP1): molecular characteristics and clinical implications

BACKGROUND

ZC3H12A is a gene whose absence is related to autoimmune disorders and to other phenotypical alterations.

METHODS

A comprehensive review of the structure, molecular functions and regulation of ZC3H12A gene and its protein MCPIP1 is done in order to understand their clinical implications.

RESULTS

ZC3H12A, at 1p34.3, has 9860bp, six exons and 61 described SNPs. Eleven are non-synonymous thus leading to changes in MCPIP1, the protein encoded by ZC3H12A. MCPIP1 is induced by MCP-1 and IL-1 whose signals are transduced through the NF-kβ and MAPkinase pathways. This protein acts as an RNAse by degrading chemokine transcripts such as IL-1 as well as its own mRNA and as a transcription factor by reducing the expression of other chemokines induced by NF-kβ such as MCP-1. It also up-regulates genes involved in several differentiation processes and apoptosis. Therefore, ZC3H12A is an equilibrium gatekeeper that not only regulates its own inducers but also controls the regulation by degrading its own mRNA.

CONCLUSION

Understanding ZC3H12A gives a comprehensive panorama that promises to improve our understanding of processes in which this gene is involved including autoimmune, infectious and cardiovascular diseases.

Midkine, a heparin-binding cytokine with multiple roles in development, repair and diseases

Midkine is a heparin-binding cytokine or a growth factor with a molecular weight of 13 kDa. Midkine binds to oversulfated structures in heparan sulfate and chondroitin sulfate. The midkine receptor is a molecular complex containing proteoglycans. Midkine promotes migration, survival and other activities of target cells. Midkine has about 50% sequence identity with pleiotrophin. Mice deficient in both factors exhibit severe abnormalities including female infertility. In adults, midkine is expressed in damaged tissues and involved in the reparative process. It is also involved in inflammatory reactions by promoting the migration of leukocytes, induction of chemokines and suppression of regulatory T cells. Midkine is expressed in a variety of malignant tumors and promotes their growth and invasion. Midkine appears to be helpful for the treatment of injuries in the heart, brain, spinal cord and retina. Midkine inhibitors are expected to be effective in the treatment of malignancies, rheumatoid arthritis, multiple sclerosis, renal diseases, restenosis, hypertension and adhesion after surgery.

Utilization of gene profiling and proteomics to determine mineral pathogenicity in a human mesothelial cell line (LP9/TERT-1)

Identifying and understanding the early molecular events that underscore mineral pathogenicity using in vitro screening tests is imperative, especially given the large number of synthetic and natural fibers and particles being introduced into the environment. The purpose of the work described here was to examine the ability of gene profiling (Affymetrix microarrays) to predict the pathogenicity of various materials in a human mesothelial cell line (LP9/TERT-1) exposed to equal surface area concentrations (15 x 10(6) or 75 x 10(6) microm(2)/cm(2)) of crocidolite asbestos, nonfibrous talc, fine titanium dioxide (TiO(2)), or glass beads for 8 or 24 h. Since crocidolite asbestos caused the greatest number of alterations in gene expression, multiplex analysis (Bio-Plex) of proteins released from LP9/TERT-1 cells exposed to crocidolite asbestos was also assessed to reveal if this approach might also be explored in future assays comparing various mineral types. To verify that LP9/TERT-1 cells were more sensitive than other cell types to asbestos, human ovarian epithelial cells (IOSE) were also utilized in microarray studies. Upon assessing changes in gene expression via microarrays, principal component analysis (PCA) of these data was used to identify patterns of differential gene expression. PCA of microarray data confirmed that LP9/TERT-1 cells were more responsive than IOSE cells to crocidolite asbestos or nonfibrous talc, and that crocidolite asbestos elicited greater responses in both cell types when compared to nonfibrous talc, TiO(2), or glass beads. Bio-Plex analysis demonstrated that asbestos caused an increase in interleukin-13 (IL-13), basic fibroblast growth factor (bFGF), granulocyte colony-stimulating factor (G-CSF), and vascular endothelial growth factor (VEGF). These responses were generally dose-dependent (bFGF and G-CSF only) and tumor necrosis factor (TNF)-alpha independent (except for G-CSF). Thus, microarray and Bio-Plex analyses are valuable in determining early molecular responses to fibers/particles and may directly contribute to understanding the etiology of diseases caused by them. The number and magnitude of changes in gene expression or "profiles" of secreted proteins may serve as valuable metrics for determining the potential pathogenicity of various mineral types. Hence, alterations in gene expression and cytokine/chemokine changes induced by crocidolite asbestos in LP9/TERT-1 cells may be indicative of its increased potential to cause mesothelioma in comparison to the other nonfibrous materials examined.