The role of thrombospondin-1 in apoptosis

Deep learning untangles the resistance mechanism of p53 reactivator in lung cancer cells

Tumor suppressor p53 plays a pivotal role in suppressing cancer, so various drugs has been suggested to upregulate its function. However, drug resistance is still the biggest hurdle to be overcome. To address this, we developed a deep learning model called AnoDAN (anomalous gene detection using generative adversarial networks and graph neural networks for overcoming drug resistance) that unravels the hidden resistance mechanisms and identifies a combinatorial target to overcome the resistance. Our findings reveal that the TGF-β signaling pathway, alongside the p53 signaling pathway, mediates the resistance, with THBS1 serving as a core regulatory target in both pathways. Experimental validation in lung cancer cells confirms the effects of THBS1 on responsiveness to a p53 reactivator. We further discovered the positive feedback loop between THBS1 and the TGF-β pathway as the main source of resistance. This study enhances our understanding of p53 regulation and offers insights into overcoming drug resistance.

Thinking small to win big? A critical review on the potential application of extracellular vesicles for biomarker discovery and new therapeutic approaches in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is an extremely deadly form of cancer, with limited progress in 5-year survival rates despite significant research efforts. The main challenges in treating PDAC include difficulties in early detection, and resistance to current therapeutic approaches due to aggressive molecular and microenvironment features. These challenges emphasize the importance of identifying clinically validated biomarkers for early detection and clinical management. Extracellular vesicles (EVs), particularly exosomes, have emerged as crucial mediators of intercellular communication by transporting molecular cargo. Recent research has unveiled their role in initiation, metastasis, and chemoresistance of PDAC. Consequently, utilizing EVs in liquid biopsies holds promise for the identification of biomarkers for early detection, prognosis, and monitoring of drug efficacy. However, numerous limitations, including challenges in isolation and characterization of homogeneous EVs populations, as well as the absence of standardized protocols, can affect the reliability of studies involving EVs as biomarkers, underscoring the necessity for a prudent approach. EVs have also garnered considerable attention as a promising drug delivery system and novel therapy for tumors. The loading of biomolecules or chemical drugs into exosomes and their subsequent delivery to target cells can effectively impede tumor progression. Nevertheless, there are obstacles that must be overcome to ensure the accuracy and efficacy of therapies relying on EVs for the treatment of tumors. In this review, we examine both recent advancements and remaining obstacles, exploring the potential of utilizing EVs in biomarker discovery as well as for the development of drug delivery vehicles.

Bidirectional Communication Between the Brain and Other Organs: The Role of Extracellular Vesicles

A number of substances released by the brain under physiological and pathological conditions exert effects on other organs. In turn, substances produced primarily by organs such as bone marrow, adipose tissue, or the heart may have an impact on the metabolism and function and metabolism of the healthy and diseased brain. Despite a mounting amount of evidence supports such bidirectional communication between the brain and other organs, research on the function of molecular mediators carried by extracellular vesicles (EVs) is in the early stages. In addition to being able to target or reach practically any organ, EVs have the ability to cross the blood-brain barrier to transport a range of substances (lipids, peptides, proteins, and nucleic acids) to recipient cells, exerting biological effects. Here, we review the function of EVs in bidirectional communication between the brain and other organs. In a small number of cases, the role has been explicitly proven; yet, in most cases, it relies on indirect evidence from EVs in cell culture or animal models. There is a dearth of research currently available on the function of EVs-carrying mediators in the bidirectional communication between the brain and bone marrow, adipose tissue, liver, heart, lungs, and gut. Therefore, more studies are needed to determine how EVs facilitate communication between the brain and other organs.

Follicular fluid extracellular vesicle miRNAs and ovarian aging

The decrease in the reproductive potential due to aging occurs as a gradual decline in the quantity and quality of the ovarian reserve, a phenomenon associated with risk of miscarriage, pregnancy loss, low ovarian stimulation, and oocyte abnormalities, such as chromosomal aneuploidies. Numerous studies have shown that the fertility potential of older women is decreased by changes to the cellular composition of the follicles. Additionally, a unique method of cellular communication has been identified which involves the release of extracellular vesicles (EVs) in various body fluids including follicular fluid (FF). The changing composition of EVs especially non-coding RNAs, such as miRNAs has been documented across a broad range of cell types during aging. Accordingly, alterations of miRNA cargo within FF-derived EVs due to increased age may serve as a potential predictor of oocyte quality. In this review we examine the relationship between FF EV miRNAs and ovarian aging.

Neuroendocrine, Inflammatory, and Extracellular Vesicle Responses During the Navy Special Warfare Screener Selection Course

BACKGROUND

Military operational stress is known to increase adrenal hormones and inflammatory cytokines, while decreasing hormones associated with the anabolic milieu and neuroendocrine system. Less is known about the role of extracellular vesicles (EVs), a form of cell-to-cell communication, in military operational stress and their relationship to circulating hormones.

PURPOSE

To characterize the neuroendocrine, cytokine, and EV response to an intense, 24-h selection course known as the Naval Special Warfare (NSW) Screener and identify associations between EVs and cytokines.

METHODS

Blood samples were collected the morning of and following the NSW Screener in 29 men (18 - 26 years). Samples were analyzed for concentrations of cortisol, insulin-like growth factor I (IGF-I), neuropeptide-Y (NPY), brain-derived neurotrophic factor (BDNF), α-klotho, tumor necrosis factor- α (TNFα), and interleukins (IL) -1β, -6, and -10. EVs stained with markers associated with exosomes (CD63), microvesicles (VAMP3), and apoptotic bodies (THSD1) were characterized using imaging flow cytometry and vesicle flow cytometry.

RESULTS

The selection event induced significant changes in circulating BDNF (-43.2%), IGF-I (-24.56%), TNFα (+17.7%), IL-6 (+13.6%), accompanied by increases in intensities of THSD1⁺ and VAMP3⁺ EVs (all p<0.05). Higher concentrations of IL-1β and IL-10 were positively associated with THSD1⁺ EVs (p<0.05).

CONCLUSION

Military operational stress altered the EV profile. Surface markers associated with apoptotic bodies were positively correlated with an inflammatory response. Future studies should consider a multi-omics assessment of EV cargo to discern canonical pathways that may be mediated by EVs during military stress.

Utility of extracellular vesicles as a potential biological indicator of physiological resilience during military operational stress

Extracellular vesicles (EVs) transport biological content between cells to mediate physiological processes. The association between EVs and resilience, the ability to cope with stress, is unknown. Using unbiased machine learning approaches, we aimed to identify a biological profile of resilience. Twenty servicemen (27.8 ± 5.9 years) completed the Connor Davidson Resilience (CD‐RISC) questionnaire and were exposed to daily physical and cognitive exertion with 48‐hr sleep and caloric restriction. Blood samples from baseline and the second day of stress were analyzed for neuroendocrine biomarkers impacted by military stress. EVs were isolated from plasma and stained with antibodies associated with exosomes (CD63), microvesicles (VAMP3), and apoptotic bodies (THSD1). Individuals were separated into high (n = 10, CD‐RISC > 90) and low (n = 10, CD‐RISC < 79) resilience. EV features were stratified by size, then down‐selected using regression trees and compared between groups. Diagnostic accuracy was assessed using receiver operating characteristic curves. Compared to low resilience, high resilience demonstrated a greater increase in variability of THSD1 local bright spot intensities among large‐sized EVs in response to stress (p = 0.002, Hedges’ g = 1.59). Among medium‐sized EVs, high resilience exhibited a greater decrease in side scatter intensity (p = 0.014, Hedges’ g = 1.17). Both features demonstrated high to moderate diagnostic accuracy for high resilience (AUC = 0.90 and 0.79). In contrast, neuroendocrine biomarker concentrations were similar between groups. The increase in variability among THSD1 + EVs in high, but not low, resilient individuals following stress may suggest high resilience is accompanied by stress‐triggered apoptotic adaptations to the environment that are not detected in neuroendocrine biomarkers.

Recent Advances in the Label-Free Characterization of Exosomes for Cancer Liquid Biopsy: From Scattering and Spectroscopy to Nanoindentation and Nanodevices

Exosomes (EXOs) are nano-sized vesicles secreted by most cell types. They are abundant in bio-fluids and harbor specific molecular constituents from their parental cells. Due to these characteristics, EXOs have a great potential in cancer diagnostics for liquid biopsy and personalized medicine. Despite this unique potential, EXOs are not yet widely applied in clinical settings, with two main factors hindering their translational process in diagnostics. Firstly, conventional extraction methods are time-consuming, require large sample volumes and expensive equipment, and often do not provide high-purity samples. Secondly, characterization methods have some limitations, because they are often qualitative, need extensive labeling or complex sampling procedures that can induce artifacts. In this context, novel label-free approaches are rapidly emerging, and are holding potential to revolutionize EXO diagnostics. These methods include the use of nanodevices for EXO purification, and vibrational spectroscopies, scattering, and nanoindentation for characterization. In this progress report, we summarize recent key advances in label-free techniques for EXO purification and characterization. We point out that these methods contribute to reducing costs and processing times, provide complementary information compared to the conventional characterization techniques, and enhance flexibility, thus favoring the discovery of novel and unexplored EXO-based biomarkers. In this process, the impact of nanotechnology is systematically highlighted, showing how the effectiveness of these techniques can be enhanced using nanomaterials, such as plasmonic nanoparticles and nanostructured surfaces, which enable the exploitation of advanced physical phenomena occurring at the nanoscale level.

Thrombospondin-1/CD47 signaling modulates transmembrane cation conductance, survival, and deformability of human red blood cells

BACKGROUND

Thrombospondin-1 (TSP-1), a Ca²⁺-binding trimeric glycoprotein secreted by multiple cell types, has been implicated in the pathophysiology of several clinical conditions. Signaling involving TSP-1, through its cognate receptor CD47, orchestrates a wide array of cellular functions including cytoskeletal organization, migration, cell-cell interaction, cell proliferation, autophagy, and apoptosis. In the present study, we investigated the impact of TSP-1/CD47 signaling on Ca²⁺ dynamics, survival, and deformability of human red blood cells (RBCs).

METHODS

Whole-cell patch-clamp was employed to examine transmembrane cation conductance. RBC intracellular Ca²⁺ levels and multiple indices of RBC cell death were determined using cytofluorometry analysis. RBC morphology and microvesiculation were examined using imaging flow cytometry. RBC deformability was measured using laser-assisted optical rotational cell analyzer.

RESULTS

Exposure of RBCs to recombinant human TSP-1 significantly increased RBC intracellular Ca²⁺ levels. As judged by electrophysiology experiments, TSP-1 treatment elicited an amiloride-sensitive inward current alluding to a possible Ca²⁺ influx via non-selective cation channels. Exogenous TSP-1 promoted microparticle shedding as well as enhancing Ca²⁺- and nitric oxide-mediated RBC cell death. Monoclonal (mouse IgG1) antibody-mediated CD47 ligation using 1F7 recapitulated the cell death-inducing effects of TSP-1. Furthermore, TSP-1 treatment altered RBC cell shape and stiffness (maximum elongation index).

CONCLUSIONS

Taken together, our data unravel a new role for TSP-1/CD47 signaling in mediating Ca²⁺ influx into RBCs, a mechanism potentially contributing to their dysfunction in a variety of systemic diseases. Video abstract.

Extracellular Vesicles: Recent Developments in Aging and Reproductive Diseases

Extracellular vesicles (EVs), present in cell culture media and several body fluids, play a prominent role in intercellular communication under physiological and pathological conditions. We performed a systematic literature search to review evidence regarding the existence, composition, and release of different EVs, as well as the biomarkers, cargos, and separation methods. We also reviewed the potential of EVs to transport cargos and alter the function and phenotype of recipient cells associated with aging and reproductive diseases, including polycystic ovary syndrome and endometriosis. In aging, EVs promote inflammatory reactions and offsetting the occurrence of aging. In the polycystic ovary syndrome and endometriosis, EVs and their cargos are involved in the occurrence of diseases, therapeutic strategies, and perform as non-invasive biomarkers. As the study of EVs is still in the early stages, it is not surprising that most of the current literature only describes their possible roles.

Circular RNA circ_0020123 promotes non-small cell lung cancer progression by sponging miR-590-5p to regulate THBS2

Background

The incidence and death rate of non-small cell lung cancer (NSCLC) in China ranks the first among the malignant tumors. Circular RNA (circRNA) was reported to be involved in the progression of NSCLC. Our study aimed to investigate the underlying mechanism of circ_0020123 in NSCLC progression.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of circ_0020123, miR-590-5p and Thrombospondin 2 (THBS2) in NSCLC tissues and cells. Cell proliferation and migration were examined by Cell Counting Kit-8 (CCK-8) assay and Transwell assay, respectively. Flow cytometry assay was used to detect the apoptosis of NSCLC cells. The protein levels of Ki-67, matrix metalloprotein-9 (MMP-9), Cleaved-caspase9 (Cleaved-casp9) and THBS2 were detected by Western blot. The targets of circ_0020123 and miR-590-5p were predicted by starBase 3.0 and TargetScan, and then confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. The animal experiment showed the effect of circ_0020123 on tumor growth in vivo.

Results

The expression of circ_0020123 was upregulated in NSCLC tissues and cells. Functionally, circ_0020123 downregulation inhibited the proliferation and migration and promoted the apoptosis of NSCLC cells. Interestingly, circ_0020123 directly targeted miR-590-5p, and inhibition of miR-590-5p reversed the knockdown effects of circ_0020123 on NSCLC cells. More importantly, THBS2 was a target of miR-590-5p, and THBS2 overexpression reversed the effects of circ_0020123 knockdown on cell proliferation, migration and apoptosis in NSCLC cells. Finally, suppression of circ_0020123 inhibited tumor growth in vivo through miR-590-5p/THBS2 axis.

Conclusion

Circular RNA circ_0020123 regulated THBS2 by sponging miR-590-5p to promote cell proliferation and migration and inhibit cell apoptosis in NSCLC cells.

Non-Exosomal and Exosomal Circulatory MicroRNAs: Which Are More Valid as Biomarkers?

MicroRNAs (miRNAs) are a group of small non-coding RNAs with approximately 19–25 nucleotides that are involved in regulating a range of developmental and physiological processes. Non-exosomal circulating and exosomal miRNAs have also been proposed to be useful in diagnostics as biomarkers for diseases and different types of cancer. In this review, the quantity of miRNAs and of reliable experimental data analyses of miRNAs that come from exosomal and non-exosomal sources are discussed from the perspective of their use as biomarkers for cancer and other diseases, including viral infections, nervous system disorders, cardiovascular disorders, and diabetes. We summarize other research findings regarding the use of miRNA from these two sources as biomarkers in diagnostics and clinical use. The challenges in using miRNA from these two sources in cancer and disease diagnostics are evaluated and discussed. Validation of specific miRNA signatures as biomarkers is a critical milestone in diagnostics.

A population-based study identifies an association of THBS2 with intervertebral disc degeneration

OBJECTIVE

To clarify the genetic mechanisms underlying intervertebral disc degeneration (IDD), we examined the associations between single-nucleotide polymorphisms (SNPs) and indicated as coefficient of interaction term (IDD) in a general population in Japan.

METHODS

This was a cross-sectional study. In 1,605 participants, C2-3 to L5/S1 in the total spine magnetic resonance imaging (MRI) were evaluated using the Pfirrmann's scoring system. Disc scores of 4 and 5 were defined as IDD. Eight SNPs in eight genes associated with IDD were examined at each disc level, considering the non-genetic risk factors of age, sex, and body mass index (BMI).

RESULTS

The highest odds ratio was found for rs9406328 in the THBS2 gene at disc level T12-L1 (OR 1.27, 95%CI 1.05 to 1.53), and this association was strengthened after adjustment for age using logistic regression (OR 1.37, 95%CI 1.12 to 1.67). Among participants aged <50 years and 50-59, the average IDD score in those with 2 risk alleles of rs9406328 was markedly higher than in those with 0 or 1 risk allele, and the difference is much wider than the elderly participants. It indicates the genetic effect of rs9406328 is stronger in the younger age groups. Finally, multiple linear regression analyses of the association between rs9406328 and IDD, adjusted for age, sex, and BMI at each disc level, showed a statistical interaction between age and the number of risk alleles at C7-T1, T3-4 and T4-T5 as well as T12-L1.

CONCLUSION

CONCLUSION: The association between rs9406328 in THBS2 and IDD was replicated. The contributions of genetic and environmental factors to IDD differed by disc level.

Exosomes and their implications in central nervous system tumor biology

Exosomes are 20-100 nm cellular derived vesicles that upon discovery, were thought to be a form of cellular recycling of intracellular contents. More recently, these vesicles are under investigation for their purported significant roles in intercellular communication in both healthy and diseased states. Herein, we focus on the secretion of exosomes associated with glioblastoma, as most exosome studies on brain tumors have been performed in this tumor type. However, we included exosomes secreted from other forms of brain tumors for comparison as available. Exosomes contain intracellular content that can be transferred to other cells in the tumor or to cells of the immune system and endothelial cells. These recipient cells may subsequently take on oncogenic properties, including therapeutic resistance, cancer progression, and angiogenesis. Genetic components (DNA, RNA and miRNA) of the cell of origin may be included in the secreted exosomes. The presence of genetic material in the exosomes could serve as a biomarker for mutations in tumors, potentially leading to novel treatment strategies. In the last decade, exosomes have been identified as having a major impact on multiple aspects of medicine and tumor biology, and appear to be primed for a critical position in cancer diagnosis, prognosis, and treatment.

Extracellular Vesicles in Human Reproduction in Health and Disease

Extensive evidence suggests that the release of membrane-enclosed compartments, more commonly known as extracellular vesicles (EVs), is a potent newly identified mechanism of cell-to-cell communication both in normal physiology and in pathological conditions. This review presents evidence about the formation and release of different EVs, their definitive markers and cargo content in reproductive physiological processes, and their capacity to convey information between cells through the transfer of functional protein and genetic information to alter phenotype and function of recipient cells associated with reproductive biology. In the male reproductive tract, epididymosomes and prostasomes participate in regulating sperm motility activation, capacitation, and acrosome reaction. In the female reproductive tract, follicular fluid, oviduct/tube, and uterine cavity EVs are considered as vehicles to carry information during oocyte maturation, fertilization, and embryo-maternal crosstalk. EVs via their cargo might be also involved in the triggering, maintenance, and progression of reproductive- and obstetric-related pathologies such as endometriosis, polycystic ovarian syndrome, preeclampsia, gestational diabetes, and erectile dysfunction. In this review, we provide current knowledge on the present and future use of EVs not only as biomarkers, but also as therapeutic targeting agents, mainly as vectors for drug or compound delivery into target cells and tissues.

Tumor-Derived Apoptotic Vesicles: With Death They Do Part

Tumor cells release lipid particles known as extracellular vesicles (EV) that contribute to cancer metastasis, to the immune response, and to thrombosis. When tumors are exposed to radiation or chemotherapy, apoptotic vesicles (ApoVs) are released in abundance as the plasma membrane delaminates from the cytoskeleton. Recent studies have suggested that ApoVs are distinct from the EVs released from living cells, such as exosomes or microvesicles. Depending on their treatment conditions, tumor-released ApoV have been suggested to either enhance or suppress anti-cancer immunity. In addition, tumor-derived ApoV possess procoagulant activity that could increase the thrombotic state in cancer patients undergoing chemotherapy or radiotherapy. Since ApoVs are one of the least appreciated type of EVs, we focus in this review on the distinctive characterization of tumor ApoVs and their proposed mechanistic effects on cancer immunity, coagulation, and metastasis.

Exosomes: new molecular targets of diseases

Extracellular vesicles (EVs) comprise apoptotic bodies, microvesicles and exosomes, and they perform as key regulators in cell-to-cell communication in normal as well as diseased states. EVs contain natural cargo molecules, such as miRNA, mRNA and proteins, and transfer these functional cargos to neighboring cells or more distant cells through circulation. These functionally active molecules then affect distinct signaling cascades. The message conveyed to the recipient cells is dependent upon the composition of the EV, which is determined by the parent cell and the EV biogenesis. Because of their properties such as increased stability in circulation, biocompatibility, low immunogenicity and toxicity, EVs have drawn attention as attractive delivery systems for therapeutics. This review focuses on the functional use of exosomes in therapy and the potential advantages and challenges in using exosomes for therapeutic purposes.

Role of extracellular vesicles in glioma progression

The role of extracellular vesicles in cancer biology has emerged as a focus of the study of great importance and has been shown to directly influence tumour development in several cancers including brain tumours, such as gliomas. Gliomas are the most aggressive brain tumours, and in the last time, a considerable effort has been made to understand their biology. Studies focus in the signalling pathways involved in the processes of angiogenesis, viability, drug resistance and immune response evasion, as well as gliomas ability to infiltrate healthy tissue, a phenomenon regulated by the migratory and invasive capacity of the cells within a tumour. In this review, we summarize the different types and classifications of extracellular vesicles, their intravesicular content, and their role in the regulation of tumour progression processes in glioma.

The Roles of Thrombospondins in Hemorrhagic Stroke

Hemorrhagic stroke is a devastating cerebrovascular disease with significant morbidity and mortality worldwide. Thrombospondins (TSPs), as matricellular proteins, belong to the TSP family which is comprised of five members. All TSPs modulate a variety of cellular functions by binding to various receptors. Recently, TSPs gained attention in the area of hemorrhagic stroke, especially TSP-1. TSP-1 participates in angiogenesis, the inflammatory response, apoptosis, and fibrosis after hemorrhagic stroke through binding to various molecules including but not limited to CD36, CD47, and TGF-β. In this review, we will discuss the roles of TSPs in hemorrhagic stroke and focus primarily on TSP-1.

Plasma thrombospondin-1 and clinical outcomes in traumatic brain injury

OBJECTIVE

Thrombospondin-1 (TSP-1) acts as an anti-angiogenic factor, and its expression in rat brain is upregulated after intracerebral hemorrhage. The current study was designed to investigate the change of plasma TSP-1 levels and assess the prognostic predictive effect of plasma TSP-1 level and it is associated with head trauma severity in the patients with severe traumatic brain injury (STBI).

MATERIALS AND METHODS

The plasma TSP-1 levels of 134 patients and 134 healthy controls were measured using enzyme-linked immunosorbent assay. The relationships between plasma TSP-1 levels and trauma severity reflected by Glasgow Coma Scale (GCS) scores as well as between plasma TSP-1 levels and short-term and long-term clinical outcomes were analyzed using multivariate analysis.

RESULTS

Plasma TSP-1 levels were statistically significantly higher in patients than in healthy controls. The multivariate analysis demonstrated close association of TSP-1 with GCS scores and also identified TSP-1 as an independent predictor for 1-week mortality, 6-month mortality, and 6-month unfavorable outcome. Plasma TSP-1 levels had high prognostic predictive value based on receiver operating characteristic curve. The difference between its prognostic predictive value and GCS scores was not statistically significant.

CONCLUSIONS

Plasma TSP-1 levels are elevated and are highly associated with head trauma severity and short-term and long-term outcomes of STBI. TSP-1 may be a good prognostic biomarker of STBI.

Predictive value of thrombospondin-1 for outcomes in patients with acute ischemic stroke

BACKGROUND

Thrombospondin-1 is a potent regulator of angiogenesis. The expression of cerebral thrombospondin-1 is promoted in a rat model of intracerebral hemorrhage. The current study was designed to investigate the change of plasma thrombospondin-1 concentrations and assess the prognostic value of plasma thrombospondin-1 concentrations for long-term mortality and functional outcome of ischemic stroke patients.

METHODS

This study included 192 patients and 150 healthy controls. The plasma thrombospondin-1 concentrations were measured using enzyme-linked immunosorbent assay. An unfavorable outcome was defined as a modified Rankin Scale score >3. The relationships between plasma thrombospondin-1 concentrations and 6-month clinical outcomes were analyzed using multivariate analysis.

RESULTS

Compared with healthy controls, plasma thrombospondin-1 concentrations were statistically significantly elevated in patients. Using multivariate analysis, thrombospondin-1 emerged as an independent predictor for 6-month mortality, 6-month unfavorable outcome and 6-month overall survival. Plasma thrombospondin-1 concentrations possessed high predictive values under receiver operating characteristic curve. Their predictive values were similar to those of National Institutes of Health Stroke Scale scores.

CONCLUSIONS

Plasma thrombospondin-1 concentrations are elevated obviously and are highly associated with long-term outcome of ischemic stroke.

Thrombospondin-1 induces differential response in human corneal and conjunctival epithelial cells lines under in vitro inflammatory and apoptotic conditions

Recently, thrombospondin-1 (TSP-1) has been reported to be critical for maintaining a healthy ocular surface. The purpose of the study was to characterize the expression of TSP-1 and of its receptors CD36 and CD47 in corneal and conjunctival epithelial cells and determine the effect of exogenous TSP-1 treatment on these cells, following the induction of inflammation- and apoptosis-related changes. The expression of TSP-1, CD36 and CD47 by corneal and conjunctival cell lines was firstly characterized by ELISA, immunofluorescence analysis, Western blotting and reverse transcription polymerase chain reaction (RT-PCR). Benzalkonium chloride (BAC) exposure for 5 or 15 min was used as pro-inflammatory and pro-apoptotic stimulus for corneal or conjunctival epithelial cells, respectively. To analyze inflammation and apoptosis-related changes, IL-6 and TGF-β2 secretion determined by ELISA was used as inflammatory markers, while activated caspase-3/7 levels and cell viability, determined by CellEvent™ Caspase-3/7 Green Detection Reagent and XTT cytotoxicity assay, respectively, were used as apoptotic markers. Changes in CD36 and CD47 mRNA expression were quantified by real time RT-PCR. Corneal epithelial cells secreted and expressed higher protein levels of TSP-1 than conjunctival epithelial cells, although TSP-1 mRNA expression levels were similar and had lower CD36 and CD47, both at protein and mRNA levels. Both cell lines responded to exogenous TSP-1 treatment increasing CD36 at protein and mRNA levels. Blocking experiments revealed a predominance of TSP-1/CD47 rather than TSP-1/CD36 interactions to up-regulate CD36 levels in conjunctival epithelial cells, but not in corneal epithelial cells. BAC exposure increased IL-6 secretion and caspase-3/7 levels and decreased cell viability in both, corneal and conjunctival epithelial cells. Moreover, BAC exposure increased latent TGF-β2 levels in conjunctival epithelial cells. Interestingly, CD36 mRNA expression was down-regulated after BAC exposure in both cell lines. Exogenous TSP-1 treatment reduced TGF-β2 up-regulated levels by BAC exposure in conjunctival epithelial cells and less pronounced reduced IL-6 in BAC-exposed corneal epithelial cells. The effect on CD36 and CD47 regulation was less pronounced or even opposite depending on the inflammation- and apoptosis-related markers tested. Our results show evidence of the capacity of corneal and conjunctival epithelial cells to respond to TSP-1 via CD36 or CD47. Experimental simulation of inflammation- and apoptosis-related conditions changed the effects differentially elicited by TSP-1 on corneal and conjunctival epithelial cells, suggesting an unexpected and relevant contribution of TSP-1 on ocular surface homeostasis regulation.

Functions and transcriptional regulation of thrombospondins and their interrelationship with fibroblast growth factor-2 in bovine luteal cells

Previously, we showed luteal stage-specific regulation of angiogenesis-modulating factors by prostaglandin F2 alpha (PGF2alpha). Fibroblast growth factor 2 (FGF2) and thrombospondins (THBSs) exhibited the most divergent profile of induction by PGF2alpha. We therefore examined the transcriptional regulation and roles of THBSs in luteal cells and studied their interaction with FGF2. THBSs and their receptors exhibited cell-specific expression: THBS1 was the predominant form in luteal endothelial cells (LEC), whereas luteinized granulosa cells (LGC) expressed mostly THBS2. CD36 was confined to LGC, but CD47 did not exhibit preferential expression between LEC and LGC. THBS1 and THBS2 were both stimulated in vitro by PGF2a and its analog in LGC. In contrast, luteinizing signals (LH and insulin) decreased the expression of THBS1, THBS2, and CD36. Importantly, LH increased FGF2 expression, suggesting that THBSs and FGF2 are conversely regulated. We found that FGF2 inhibited THBS1 and vice versa, and that THBS1 treatment decreased FGF2 expression, suggesting reciprocal inhibition. In agreement, ablation of THBS1 by specific small interference RNAs elevated FGF2 levels. THBS1 reduced LEC numbers and promoted apoptosis by activation of caspase-3. In contrast, FGF2 reduced basal and THBS1-induced caspase-3 levels. Consistent with these findings, small interference RNA silencing of THBS1 in luteal cells reduced the levels of active caspase-3 and improved the survival of cells when challenged with staurosporine. Taken together, these studies suggest that THBSs are suppressed during luteinization but are induced by PGF2alpha in luteolysis. THBS1 has antiangiogenic, proapoptotic properties; these, together with its ability to inhibit FGF2 expression and activity, can promote luteolysis.

A caspase-3 'death-switch' in colorectal cancer cells for induced and synchronous tumor apoptosis in vitro and in vivo facilitates the development of minimally invasive cell death biomarkers

Novel anticancer drugs targeting key apoptosis regulators have been developed and are undergoing clinical trials. Pharmacodynamic biomarkers to define the optimum dose of drug that provokes tumor apoptosis are in demand; acquisition of longitudinal tumor biopsies is a significant challenge and minimally invasive biomarkers are required. Considering this, we have developed and validated a preclinical 'death-switch' model for the discovery of secreted biomarkers of tumour apoptosis using in vitro proteomics and in vivo evaluation of the novel imaging probe [(18)F]ML-10 for non-invasive detection of apoptosis using positron emission tomography (PET). The 'death-switch' is a constitutively active mutant caspase-3 that is robustly induced by doxycycline to drive synchronous apoptosis in human colorectal cancer cells in vitro or grown as tumor xenografts. Death-switch induction caused caspase-dependent apoptosis between 3 and 24 hours in vitro and regression of 'death-switched' xenografts occurred within 24 h correlating with the percentage of apoptotic cells in tumor and levels of an established cell death biomarker (cleaved cytokeratin-18) in the blood. We sought to define secreted biomarkers of tumor apoptosis from cultured cells using Discovery Isobaric Tag proteomics, which may provide candidates to validate in blood. Early after caspase-3 activation, levels of normally secreted proteins were decreased (e.g. Gelsolin and Midkine) and proteins including CD44 and High Mobility Group protein B1 (HMGB1) that were released into cell culture media in vitro were also identified in the bloodstream of mice bearing death-switched tumors. We also exemplify the utility of the death-switch model for the validation of apoptotic imaging probes using [(18)F]ML-10, a PET tracer currently in clinical trials. Results showed increased tracer uptake of [(18)F]ML-10 in tumours undergoing apoptosis, compared with matched tumour controls imaged in the same animal. Overall, the death-switch model represents a robust and versatile tool for the discovery and validation of apoptosis biomarkers.

Biogenesis of extracellular vesicles (EV): exosomes, microvesicles, retrovirus-like vesicles, and apoptotic bodies

Recent studies suggest both normal and cancerous cells secrete vesicles into the extracellular space. These extracellular vesicles (EVs) contain materials that mirror the genetic and proteomic content of the secreting cell. The identification of cancer-specific material in EVs isolated from the biofluids (e.g., serum, cerebrospinal fluid, urine) of cancer patients suggests EVs as an attractive platform for biomarker development. It is important to recognize that the EVs derived from clinical samples are likely highly heterogeneous in make-up and arose from diverse sets of biologic processes. This article aims to review the biologic processes that give rise to various types of EVs, including exosomes, microvesicles, retrovirus like particles, and apoptotic bodies. Clinical pertinence of these EVs to neuro-oncology will also be discussed.

Genetic polymorphisms associated with intervertebral disc degeneration

BACKGROUND CONTEXT

Disc degeneration (DD) is a multifaceted chronic process that alters the structure and function of the intervertebral discs and can lead to painful conditions. The pathophysiology of degeneration is not well understood, but previous studies suggest that certain genetic polymorphisms may be important contributing factors leading to an increased risk of DD.

PURPOSE

To review the genetic factors in DD with a focus on polymorphisms and their putative role in the pathophysiology of degeneration. Elucidating the genetic components that are associated with degeneration could provide insights into the mechanism of the process. Furthermore, defining these relationships and eventually using them in a clinical setting may allow an identification and early intervention for those who are at a high risk for painful DD.

STUDY DESIGN

Literature review.

METHODS

This literature review focused on the studies concerning genetic polymorphisms and their associations with DD.

RESULTS

Genetic polymorphisms in 20 genes have been analyzed in association with DD, including vitamin D receptor, growth differentiation factor 5 (GDF5), aggrecan, collagen Types I, IX, and XI, fibronectin, hyaluronan and proteoglycan link protein 1 (HAPLN1), thrombospondin, cartilage intermediate layer protein (CILP), asporin, MMP1, 2, and 3, parkinson protein 2, E3 ubiquitin protein ligase (PARK2), proteosome subunit β type 9 (PSMB9), tissue inhibitor of metalloproteinase (TIMP), cyclooxygenase-2 (COX2), and IL1α, IL1β, and IL6. Each genetic polymorphism codes for a protein that has a functional role in the pathogenesis of DD.

CONCLUSIONS

There are known associations between several genetic polymorphisms and DD. Of the 20 genes analyzed, polymorphisms in vitamin D receptor, aggrecan, Type IX collagen, asporin, MMP3, IL1, and IL6 show the most promise as functional variants. Genetic studies are crucial for understanding the mechanism of the degeneration. This genetic information could eventually be used as a predictive model for determining a patient's risk for symptomatic DD.

Chronic delivery of a thrombospondin-1 mimetic decreases skeletal muscle capillarity in mice

Angiogenesis is an essential process for normal skeletal muscle function. There is a growing body of evidence suggesting that thrombospondin-1 (TSP-1), a potent antiangiogenic protein in tumorigenesis, is an important regulator of both physiological and pathological skeletal muscle angiogenesis. We tested the hypothesis that chronic exposure to a TSP-1 mimetic (ABT-510), which targets the CD36 TSP-1 receptor, would decrease skeletal muscle capillarity as well as alter the balance between positive and negative angiogenic proteins under basal conditions. Osmotic minipumps with either ABT-510 or vehicle (5% dextrose) were implanted subcutaneously in the subscapular region of C57/BL6 mice for 14 days. When compared to the vehicle treated mice, the ABT-510 group had a 20% decrease in capillarity in the superficial region of the gastrocnemius (GA), 11% decrease in the plantaris (PLT), and a 35% decrease in the soleus (SOL). ABT-510 also decreased muscle protein expression of vascular endothelial growth factor (VEGF) in both the GA (-140%) and SOL (-62%); however there was no change in VEGF in the PLT. Serum VEGF was not altered in ABT-510 treated animals. Endogenous TSP-1 protein expression in all muscles remained unaltered. Tunnel staining revealed no difference in muscle apoptosis between ABT-510 and vehicle treated groups. These data provide evidence that the anti-angiogenic effects of TSP-1 are mediated, at least in part, via the CD36 receptor. It also suggests that under physiologic conditions the TSP-1/CD36 axis plays a role in regulating basal skeletal muscle microvessel density.

Thrombospondin-1-derived 4N1K peptide expression is negatively associated with malignant aggressiveness and prognosis in urothelial carcinoma of the upper urinary tract

Background

Thrombospondin (TSP) is a multi-functional protein that appears to have dual roles in cancer, that is, either as a promoter or a suppressor. 4N1K is a TSP-derived peptide that has been reported to be associated with neovascularity, cell survival, and invasion. There is a little information regarding its pathological roles in human cancer tissues. Our aim was to clarify clinical significance and prognostic value of 4N1K expression in patients with urothelial carcinoma of the upper urinary tract (UC-UUT).

Methods

We investigated 4N1K expression in 97 surgically excised, non-metastasized UC-UUT specimens and five normal tissues via immunohistochemistry. Microvessel density (MVD), lymph vessel density (LVD), cancer cell proliferation (PI), apoptotic index (AI), and matrix metalloproteinase (MMP)-9 expression was also determined. The relationships 4N1K expression and pT stage, grade, and prognosis were analysed. In addition, correlations with these cancer-related and TSP-related factors were also investigated.

Results

Strong and moderate 4N1K expression was found in normal urothelial tissues. Of the 97 specimens, 45 patients were positive for 4N1K expression, which was primarily located in the interstitial areas of the cancer tissue. 4N1K expression was negatively associated with pT stage (p = 0.003) and grade (p = 0.002). Survival analyses revealed that 4N1K is a predictor of metastasis-free (p = 0.036) and cause-specific survival (p = 0.009). 4N1K expression was closely associated with malignant behaviour, specifically MVD (p = 0.001), AI (p = 0.013), and MMP-9 expression (p = 0.036), but not PI and LVD, as determined via multivariate analysis models.

Conclusions

4N1K expression appears to be associated with cancer cell progression and survival in UC-UUT patients via the regulation of angiogenesis, apoptosis, and MMP-9 expression. There is a possibility that the 4N1K-peptide may be a useful marker and novel therapeutic target in patients with UC-UUT.

Circulating levels of thrombospondin-1 are decreased in HELLP syndrome

BACKGROUND

Preeclampsia is characterised by an imbalance of circulating pro- and anti-angiogenic factors. The syndrome of haemolysis, elevated liver enzymes and low platelet count (HELLP) develops mostly on the ground of preeclampsia, and one of its important features is the severe disturbance of the coagulation system, intravascular coagulopathy. Thrombospondin-1 (TSP-1) is derived from the endothelium and platelets, and exerts potent pro-thrombotic and anti-angiogenic effects. Our aim was to determine, whether its circulating levels are altered in preeclampsia and in HELLP syndrome.

METHODS

We enrolled 45 pregnant women with early-, 43 with late-onset preeclampsia, 21 with HELLP-syndrome, 45 with uncomplicated pregnancy and 20 non-pregnant controls in our case-control study. TSP-1 levels were determined by enzyme-linked immunosorbent assay.

RESULTS

Circulating TSP-1 levels were lower in HELLP syndrome compared to all other study groups, while they were unaltered in preeclampsia compared to the control groups. There was a significant positive linear correlation between TSP-1 levels and platelet count in HELLP syndrome. In patients with more severe HELLP syndrome, TSP-1 levels were significantly lower compared to women suffering from a milder form of HELLP syndrome.

CONCLUSIONS

Circulating thrombospondin-1 levels are decreased in HELLP syndrome and they seem to reflect disease severity, lower levels representing a more severe state. Nevertheless, despite its potent anti-angiogenic effect, our results suggest that circulating TSP-1 does not play a significant role in the pathogenesis of preeclampsia.

Thrombospondin-1-deficient mice are not protected from bleomycin-induced pulmonary fibrosis

Thrombospondin-1 (TSP-1) is an extracellular protein critical to normal lung homeostasis, and is reported to activate latent transforming growth factor-β (TGF-β). Because active TGF-β is causally involved in lung fibrosis after bleomycin challenge, alterations in TSP-1 may be relevant to pulmonary fibrosis. We sought to determine the effects of TSP-1 deficiency on the susceptibility to bleomycin-induced pulmonary fibrosis in a murine model. Age-matched and sex-matched C57BL/6 wild-type (WT) and TSP-1-deficient mice were treated twice weekly for 4 weeks with intraperitoneal bleomycin (0.035 U/g) or PBS, and were allowed to rest 1 week before being killed. Their lungs were inflated with PBS, fixed in formalin, paraffin-embedded, and sectioned. A certified veterinary pathologist blindly scored each slide for inflammation and fibrosis. Lungs were homogenized to obtain RNA and protein for the real-time RT-PCR analysis of connective tissue growth factor (CTGF) and collagen I, and for Western blotting to detect phospho-Smad2, or total Smad2/3, respectively. In response to bleomycin treatment, measures of fibrosis and inflammation, along with CTGF and collagen I mRNA concentrations, were increased in TSP-1-deficient mice compared with WT mice. Notably, Smad 2/3 signaling was of equal strength in WT and TSP-1 knockout mice treated with bleomycin, suggesting that TSP-1 is not required for the activation of TGF-β. These results demonstrate that TSP-1 deficiency does not protect mice from systemic bleomycin challenge, and that TSP-1 deficiency is associated with increased expression of lung collagen and CTGF.

Thrombospondin-1 null mice are resistant to hypoxia-induced pulmonary hypertension

BACKGROUND AND OBJECTIVE

Chronic hypoxia induces pulmonary hypertension in mice. Smooth muscle cell hyperplasia and medial thickening characterize the vasculature of these animals. Thrombospondin-1 null (TSP-1(-/-)) mice spontaneously develop pulmonary smooth muscle cell hyperplasia and medial thickening. In addition, TSP-1 produced by the pulmonary endothelium inhibits pulmonary artery smooth muscle cell growth. Based on these observations we sought to describe the pulmonary vascular changes in TSP-1(-/-) mice exposed to chronic hypoxia.

METHODS

We exposed TSP-1(-/-) and wild type (WT) mice to a fraction of inspired oxygen (FiO2) of 0.1 for up to six weeks. Pulmonary vascular remodeling was evaluated using tissue morphometrics. Additionally, right ventricle systolic pressures (RVSP) and right ventricular hypertrophy by right ventricle/left ventricle + septum ratios (RV/LV+S) were measured to evaluate pulmonary hypertensive changes. Finally, acute pulmonary vasoconstriction response in both TSP-1(-/-) and WT mice was evaluated by acute hypoxia and U-46619 (a prostaglandin F2 analog) response.

RESULTS

In hypoxia, TSP-1(-/-) mice had significantly lower RVSP, RV/LV+S ratios and less pulmonary vascular remodeling when compared to WT mice. TSP-1(-/-) mice also had significantly lower RVSP in response to acute pulmonary vasoconstriction challenges than their WT counterparts.

CONCLUSION

TSP-1(-/-) mice had diminished pulmonary vasoconstriction response and were less responsive to hypoxia-induced pulmonary hypertension than their wild type counterparts. This observation suggests that TSP-1 could play an active role in the pathogenesis of pulmonary hypertension associated with hypoxia.

The C-terminal CD47/IAP-binding domain of thrombospondin-1 prevents camptothecin- and doxorubicin-induced apoptosis in human thyroid carcinoma cells

Camptothecin and doxorubicin belong to a family of anticancer drugs that exert cytotoxic effects by triggering apoptosis in various cell types. However there have only been few investigations showing that matricellular proteins like thrombospondin-1 (TSP-1) could be involved in the underlying mechanism of this cytotoxicity. In this report, using Hoechst reagent staining, reactive oxygen species production and caspase-3 activity measurement, we determined that both camptothecin and doxorubicin induced apoptosis in human thyroid carcinoma cells (FTC-133). On the one hand, we demonstrated that camptothecin and doxorubicin inhibited TSP-1 expression mainly occurring at the transcriptional level. On the other hand, drug-induced apoptosis determined by western blot analysis for PARP cleavage and caspase-3 activity measurement, was significantly decreased in presence of exogenous TSP-1. In order to identify the sequence responsible for this effect, we used the CD47/IAP-binding peptide 4N1 (RFYVVMWK), derived from the C-terminal domain of TSP-1, and known to play a role in apoptosis. Thus, in presence of 4N1, camptothecin and doxorubicin-induced pro-apoptotic activity was considerably inhibited. These findings suggest that induction of apoptosis by camptothecin or doxorubicin in FTC-133 cells is greatly dependent by a down-regulation of TSP-1 expression and shed new light on a possible role for TSP-1 in drug resistance.

Thrombospondin-1 C-terminal-derived peptide protects thyroid cells from ceramide-induced apoptosis through the adenylyl cyclase pathway

Thrombospondin-1, a multi-modular matrix protein is able to interact with a variety of matrix proteins and cell-surface receptors. Thus it is multifunctional. In this work, we examined the role of thrombospondin-1 in ceramide-induced thyroid apoptosis. We focused on the VVM containing sequence localized in the C-terminal domain of the molecule. Primary cultured thyroid cells synthesize thrombospondin-1 depending on their morphological organization. As it leads thyrocytes to organize into monolayers before inducing apoptosis ceramide can modulate this organization. Here, we established that C(2)-ceramide treatment decreased thrombospondin-1 expression by interfering with the adenylyl cyclase pathway, thus leading to apoptosis. Furthermore, we demonstrated that the thrombospondin-1-derived peptide 4N1 (RFYVVMWK) abolished ceramide-induced thyroid cell death by preventing intracellular cAMP levels from dropping. Finally, we reported that 4N1-mediated inhibition of ceramide-induced apoptosis was consistently associated with a down-regulation of the caspase-3 processing. Integrin-associated protein receptor (IAP or CD47) was identified as a molecular relay mediating the observed 4N1 effects. Taken together, our results shed light for the first time on anti-apoptotic activities of the thrombospondin-1-derived peptide 4N1 and provide new information on how thrombospondin-1 may control apoptosis of non-tumoral cells.

Testicular Gene Expression Profiling following Prepubertal Rat Mono-(2-ethylhexyl) Phthalate Exposure Suggests a Common Initial Genetic Response at Fetal and Prepubertal Ages

Phthalate chemical plasticizers can damage the fetal and postnatal mammalian testis, but several aspects of the injury mechanism remain unknown. Using a genome-wide microarray, the profile of testicular gene expression changes was examined following exposure of postnatal day 28 rats to a single, high dose (1000 mg/kg) of mono-(2-ethylhexyl) phthalate (MEHP). By microarray analysis, approximately 1675 nonredundant genes exhibited significant expression changes; the vast majority were observed at 12 h. Among the 36 genes significantly altered up to the 3-h time point, prominent functional categories were secreted, transcription, and signaling factors. Using quantitative PCR (qPCR), the dose-response of 24 genes was determined after a single MEHP exposure of 10, 100, or 1000 mg/kg. Increasing 114-fold by 12 h at 1000 mg/kg, Thbs1 (thrombospondin 1) showed the highest level of gene induction. The vast majority of genes analyzed by qPCR exhibited significant expression alterations at the lowest dose level. Interestingly, a unique, dose-dependent expression pattern was observed for the transcription factor Nr0b1, steroidogenic genes (Cyp17a1 and StAR), and a cholesterol metabolism gene (Dhcr7). For these genes, the direction of expression change at 10 or 100 mg/kg was opposite that observed at 1000 mg/kg. Gene profiling data at 1000 mg/kg MEHP were phenotypically anchored to increased germ cell apoptosis (6 and 12 h) and an interstitial neutrophil infiltrate (12 h). At 10 or 100 mg/kg MEHP, no testicular morphological changes were detected, but a significant increase in germ cell apoptosis was seen at 6 h. Finally, comparison of the prepubertal MEHP microarray data to similar data from fetal dibutyl phthalate (DBP) exposure showed conservation in both the identities of testicular genes altered and the direction of expression changes. For example, 60% of the genes altered within 3 h of prepubertal MEHP exposure also were changed following acute fetal DBP exposure, and the direction of expression change was highly preserved. These data demonstrate that similar genetic targets are altered following fetal and prepubertal phthalate exposure, suggesting that the initial mechanism of fetal and prepubertal phthalate-induced testicular injury is shared.

Transcriptional Program Associated with IFN-αResponse of Renal Cell Carcinoma

Metastatic renal cell carcinoma (RCC) is refractory to therapy; however, 10%-20% of patients respond favorably with interferon-alpha (IFN-alpha) treatment. To understand the molecular basis of response to IFN-alpha therapy, we performed global gene expression analysis of sensitive and resistant RCC cell lines in the absence and in the presence of IFN-alpha, using high-density oligonucleotide arrays to detect differentially expressed genes. In the absence of IFN-alpha, no significant differences in gene expression were observed between six sensitive and six resistant cell lines. Gene expression analysis following a time course of IFN-alpha2b treatment in one sensitive (SK-RC-17) and one resistant (SK-RC-12) cell line revealed that 484 and 354 transcripts, respectively, were modulated. A considerable number of these transcripts were similarly modulated between the two cell types that included several known targets of IFN signaling associated with antiviral and immunomodulatory activity. A further analysis of gene expression pattern in response to IFN revealed that several transcripts associated with proapoptotic function were upregulated in the sensitive cells. In the resistant cells, transcripts associated with cell survival and proliferation were induced, and key apoptotic molecules were suppressed. This study suggests that the IFN-alpha response of individual RCC tumors is determined by the expression pattern of genes in the apoptosis vs. survival and proliferation pathways rather than by alterations in expression of one or more individual genes.

Radiographic progression of lumbar spine disc degeneration is influenced by variation at inflammatory genes: a candidate SNP association study in the Chingford cohort

STUDY DESIGN

A candidate gene association study in a longitudinal cohort.

OBJECTIVE

To investigate the association between polymorphisms at 25 candidate genes and progression of individual radiographic features of lumbar disc degeneration (LDD).

SUMMARY OF BACKGROUND DATA

LDD is characterized radiographically by the presence of osteophytes and disc space narrowing and is known to have a genetic component. Because of the high prevalence of radiographic features, progression may be a more useful phenotype clinically to study than prevalence itself.

METHODS

We tested the effect on radiographic progression of LDD of polymorphisms in 25 genes, 24 of which had been previously tested with regards to knee osteoarthritis. The progression traits used were the change in radiographic grade over 9 years in osteophytes, disc space narrowing, and summary Kellgren-Lawrence grade. Lumbar spine radiographs (L1-L5) at baseline and at follow-up were read for 720 women genotyped at the 25 genes participating in the Chingford study.

RESULTS

Polymorphisms in MMP3, TIMP1, and COX2, which encode molecules involved in inflammatory pathways, were associated with radiographic progression of LDD. The strongest associations observed (statistically significant after correcting for multiple comparisons) were between COX2 and change in osteophyte grade (P < 0.001) and Kellgren-Lawrence grade (P < 2 x 10(-5)), and between the genes for vitamin D receptor (P < 0.002) and a thrombospondin (THSD2) (P < 0.002) and change in osteophyte grade.

CONCLUSIONS

Our results suggest a role for genes regulating inflammatory pathways in the radiographic progression of spine degeneration. This could prove a fruitful area for future therapeutics for the spine and other joints.

Suppression of tumor cell invasion by cyclooxygenase inhibitors is mediated by thrombospondin-1 via the early growth response geneEgr-1

Cyclooxygenase (COX) inhibitors have antitumorigenic activity and increase the expression of the early growth response gene Egr-1, a tumor suppressor gene and transcription factor. In this study, we have investigated the gene regulatory and anti-invasive activity of two traditional nonsteroidal anti-inflammatory drugs (NSAID), sulindac sulfide and indomethacin. These compounds inhibited tumor cell invasion and induced Egr-1 expression in lung adenocarcinoma A549 cells. Overexpression of Egr-1 reduced cellular invasion in the Matrigel system, whereas suppression of Egr-1 by small interference RNA (siRNA) attenuated the inhibition of Matrigel invasion by these compounds, indicating that Egr-1 is responsible for the decrease in invasion reported following treatment with NSAIDs. Egr-1-overexpressing cells were analyzed for genes involved in invasion and metastasis. Thrombospondin-1 (TSP-1) an antiangiogenic and anti-invasion protein was up-regulated by Egr-1 overexpression, which was confirmed following treatment with sulindac sulfide. Furthermore, the induction of TSP-1 by sulindac sulfide was blocked by Egr-1 siRNA. When TSP-1 was sequestered by the addition of anti-TSP-1 antibody, the inhibition of invasion by sulindac sulfide was attenuated, indicating that TSP-1 is involved in the inhibition of invasion by NSAIDs. We used the Min mouse model to determine if sulindac sulfide would increase Egr-1 and TSP-1 in vivo, because this model is widely used to study the effects of NSAIDs on tumor formation. Treatment of Min mice with concentrations of sulindac sulfide that inhibit tumor formation increased the expression of Egr-1 and TSP-1 in colonic tissues and in the polyps of these mice. This is the first report suggesting that COX inhibitors suppress tumor cell invasion via TSP-1, which occurs downstream of Egr-1.

TAIL1: an isthmin-like gene, containing type 1 thrombospondin-repeat and AMOP domain, mapped to ARVD1 critical region

Isthmins represent a novel family of vertebrate secreted proteins containing one copy of the thrombospondin type 1 repeat (TSR), which in mammals is shared by several proteins with diverse biological functions, including cell adhesion, angiogenesis, and patterning of developing nervous system. We have determined the genomic organization of human TAIL1 (thrombospondin and AMOP containing isthmin-like 1), a novel isthmin-like gene encoding a protein that contains a TSR and a C-terminal AMOP domain (adhesion-associated domain in MUC4 and other proteins), characteristic of extracellular proteins involved in adhesion processes. TAIL1 gene encompasses more than 24.4 kb. Analysis of the DNA sequence surrounding the putative transcriptional start region revealed a TATA-less promoter located in a CpG island. Several consensus binding sites for the transcription factors Sp1 and MZF-1 were identified in this promoter region. In humans, TAIL1 gene is located on chromosome 14q24.3 within ARVD1 (arrhythmogenic right ventricular dysplasia/cardiomyopathy, type 1) critical region; preliminary evidence suggests that it is expressed in several tissues, showing multiple alternative splicing.