Role of thrombospondin-1 in high-salt-induced mesenteric artery endothelial impairment in rats

The matrix glycoprotein thrombospondin-1 (THBS1) modulates nitric oxide (NO) signaling in endothelial cells. A high-salt diet induces deficiencies of NO production and bioavailability, thereby leading to endothelial dysfunction. In this study we investigated the changes of THBS1 expression and its pathological role in the dysfunction of mesenteric artery endothelial cells (MAECs) induced by a high-salt diet. Wild-type rats, and wild-type and Thbs1-/- mice were fed chow containing 8% w/w NaCl for 4 weeks. We showed that a high salt diet significantly increased THBS1 expression and secretion in plasma and MAECs, and damaged endothelium-dependent vasodilation of mesenteric resistance arteries in wild-type animals, but not in Thbs1-/- mice. In rat MAECs, we demonstrated that a high salt environment (10-40 mM) dose-dependently increased THBS1 expression accompanied by suppressed endothelial nitric oxide synthase (eNOS) and phospho-eNOS S1177 production as well as NO release. Blockade of transforming growth factor-β1 (TGF-β1) activity by a TGF-β1 inhibitor SB 431542 reversed THBS1 up-regulation, rescued the eNOS decrease, enhanced phospho-eNOS S1177 expression, and inhibited Smad4 translocation to the nucleus. By conducting dual-luciferase reporter experiments in HEK293T cells, we demonstrated that Smad4, a transcription promoter, upregulated Thbs1 transcription. We conclude that THBS1 contributes to endothelial dysfunction in a high-salt environment and may be a potential target for treatment of high-salt-induced endothelium dysfunction.

PP2A Affects Angiogenesis via Its Interaction with a Novel Phosphorylation Site of TSP1

Alterations in angiogenic properties play a pivotal role in the manifestation and onset of various pathologies, including vascular diseases and cancer. Thrombospondin-1 (TSP1) protein is one of the master regulators of angiogenesis. This study unveils a novel aspect of TSP1 regulation through reversible phosphorylation. The silencing of the B55α regulatory subunit of protein phosphatase 2A (PP2A) in endothelial cells led to a significant decrease in TSP1 expression. Direct interaction between TSP1 and PP2A-B55α was confirmed via various methods. Truncated TSP1 constructs were employed to identify the phosphorylation site and the responsible kinase, ultimately pinpointing PKC as the enzyme phosphorylating TSP1 on Ser93. The biological effects of B55α-TSP1 interaction were also analyzed. B55α silencing not only counteracted the increase in TSP1 expression during wound closure but also prolonged wound closure time. Although B55α silenced cells initiated tube-like structures earlier than control cells, their spheroid formation was disrupted, leading to disintegration. Cells transfected with phosphomimic TSP1 S93D exhibited smaller spheroids and reduced effectiveness in tube formation, revealing insights into the effects of TSP1 phosphorylation on angiogenic properties. In this paper, we introduce a new regulatory mechanism of angiogenesis by reversible phosphorylation on TSP1 S93 by PKC and PP2A B55α.

Splenocytes with fucosylation deficiency promote T cell proliferation and differentiation through thrombospondin-1 downregulation

Fucosylation plays a critical role in cell-to-cell interactions and disease progression. However, the effects of fucosylation on splenocytes and their interactions with T cells remain unclear. In this study, we aimed to explore the transcriptome profiles of splenocytes deficient in fucosyltransferase (FUT) 1, an enzyme that mediates fucosylation, and investigate their impact on the proliferation and differentiation of T cells. We analysed and compared the transcriptomes of splenocytes isolated from Fut1 knockout (KO) mice and those from wild-type (WT) mice using RNA-seq. Additionally, we examined the effects of Fut1 KO splenocytes on CD4 T cell proliferation and differentiation, in comparison to WT splenocytes, and elucidated the mechanisms involved. The comparative analysis of transcriptomes between Fut1 KO and WT splenocytes revealed that thrombospondin-1, among the genes related to immune response and inflammation, was the most highly downregulated gene in Fut1 KO splenocytes. The reduced expression of thrombospondin-1 was further confirmed using qRT-PCR and flow cytometry. In coculture experiments, Fut1 KO splenocytes promoted the proliferation of CD4 T cells and drove their differentiation toward Th1 and Th17 cells, compared with WT splenocytes. Moreover, the levels of IL-2, IFN-γ and IL-17 were increased, while IL-10 was decreased, in T cells cocultured with Fut1 KO splenocytes compared with those with WT splenocytes. These effects of Fut1 KO splenocytes on T cells were reversed when thrombospondin-1 was replenished. Taken together, our results demonstrate that splenocytes with Fut1 deficiency promote CD4 T cell proliferation and Th1/Th17 differentiation at least in part through thrombospondin-1 downregulation.

Effects of adipose-derived mesenchymal stem cell conditioned medium on human tenocytes exposed to high glucose

Introduction

Diabetic tendinopathy is a common invalidating and challenging disease that may be treated using stem cells. However, the effects of adipose-derived mesenchymal stem cell conditioned medium (ASC-CM) in diabetic tendinopathy have never been explored.

Objectives

The present study evaluated the effects of ASC-CM on morphology, cell viability, structure, and scratch wound closure of human tenocytes (HTNC) exposed to high glucose (HG).

Design

Experimental study.

Methods

HTNC were exposed to HG (25 mM) for 7, 14 and 21 days with or without ASC-CM for the last 24 h. CM was collected from 4 × 105 ASCs, centrifuged for 10 min at 200 g and sterilized with 0.22 μm syringe filter.

Results

At 7 days, HG-HTNC had decreased cell viability [72 ± 2%, p < 0.01 versus normal glucose (NG)] compared to NG-HTNC (90 ± 5%). A further decrement was detected after 14 and 21 days (60 ± 4% and 60 ± 5%, both, p < 0.01 versus NG and p < 0.01 versus HG7). While NG-HTNC evidenced a normal fibroblast cell-like elongated morphology, HG-HTNC showed increased cell roundness. In contrast, HG-HTNC exposed to ASC-CM showed a significant increase in cell viability, an improved cell morphology and higher scratch wound closure at all HG time points. Moreover, the exposure to ASC-CM significantly increased thrombospondin 1 and transforming growth factor beta 1 (TGF-β1) content in HG-HTNC. The TGF-β1 elevation was paralleled by higher Collagen I and Vascular Endothelial Growth Factor in HG-HTNC.

Conclusion

ASC-CM may restore the natural morphology, cell viability and structure of HTNC, promoting their scratch wound closure through TGF-β1 increase.

A pilot study on the relationship between thrombospondin-1 (THBS1) and transforming growth factor beta1 (TGFβ1) in the bovine placenta during early mid-pregnancy as well as parturition with normally released and retained placenta

During pregnancy, it is necessary to create appropriate conditions for the development of the placenta and the fetus. However, during parturition, the placenta must be separated and subsequently removed as soon as possible to not expose the female to the possibility of infection. In this study, the relationship between thrombospondin-1 (THBS1) and transforming growth factor beta1 (TGFβ1) concentrations was described during bovine pregnancy (second, fourth, and sixth months; n = 3/each month), at normal parturition (NR) and parturition with fetal membrane retention (R). The presence of THBS1 and TGFβ1 was confirmed in bovine placental tissues of both maternal and fetal parts. Enzyme-linked immunosorbent assay showed statistically significant differences (p < 0.05) in THBS1 concentrations (pg/mg protein) between examined parturient samples (maternal part: 5.76 ± 1.61 in R vs. 2.26 ± 1.58 in NR; fetal part: 2.62 ± 1.94 in R vs. 1.70 ± 0.23 in NR). TGFβ1 concentrations (pg/mg protein) were significantly lower (p < 0.05) in the retained fetal membranes compared to the released fetal membranes in the maternal part of the placenta (26.22 ± 7.53 in NR vs. 17.80 ± 5.01 in R). The participation of THBS1 in the activation of TGFβ1 in parturient bovine placental tissues leading to the normal release of fetal membranes may be suggested.

Dupuytren's Disease Is Mediated by Insufficient TGF-β1 Release and Degradation

Dupuytren's disease (DD) is a fibroproliferative disorder affecting the palmar fascia, causing functional restrictions of the hand and thereby limiting patients' daily lives. The disturbed and excessive myofibroblastogenesis, causing DD, is mainly induced by transforming growth factor (TGF)-β1. But, the extent to which impaired TGF-β1 release or TGF-β signal degradation is involved in pathologically altered myofibroblastogenesis in DD has been barely examined. Therefore, the complex in which TGF-β1 is secreted in the extracellular matrix to elicit its biological activity, and proteins such as plasmin, integrins, and matrix metalloproteinases (MMPs), which are involved in the TGF-β1 activation, were herein analyzed in DD-fibroblasts (DD-FBs). Additionally, TGF-β signal degradation via caveolin-1 was examined with 5-fluoruracil (5-FU) in detail. Gene expression analysis was performed via Western blot, PCR, and immunofluorescence analyses. As a surrogate parameter for disturbed myofibroblastogenesis, 𝛼-smooth-muscle-actin (𝛼-SMA) expression was evaluated. It was demonstrated that latency-associated peptide (LAP)-TGF-β and latent TGF-β-binding protein (LTBP)-1 involved in TGF-β-complex building were significantly upregulated in DD. Plasmin a serinprotease responsible for the TGF-β release was significantly downregulated. The application of exogenous plasmin was able to inhibit disturbed myofibroblastogenesis, as measured via 𝛼-SMA expression. Furthermore, a reduced TGF-β1 degradation was also involved in the pathological phenotype of DD, because caveolin-1 expression was significantly downregulated, and if rescued, myofibroblastogenesis was also inhibited. Therefore, our study demonstrates that a deficient release and degradation of TGF-β1 are important players in the pathological phenotype of DD and should be addressed in future research studies to improve DD therapy or other related fibrotic conditions.

Accurate diagnosis of prostate cancer by combining Proclarix with magnetic resonance imaging

OBJECTIVES

To assess of the clinical performance of Proclarix® (a novel Conformité Européenne [CE]-marked biomarker test aiding in the identification of clinically significant prostate cancer [csPCa]) alone or in combination with multiparametric magnetic resonance imaging (mpMRI) to predict csPCa (International Society of Urological Pathology Grade Group ≥2).

PATIENTS AND METHODS

The study included blood samples from 721 men undergoing mpMRI followed by biopsy at University College London, London, and Vall d'Hebron University Hospital, Barcelona. Samples were tested blindly. The Proclarix-MRI model combining prostate volume, Proclarix and mpMRI results was trained using the UCL cohort (n = 159) and validated in the Vall d'Hebron cohort (n = 562). Its diagnostic performance was established in correlation to biopsy outcome and compared to available clinical parameters and risk calculators.

RESULTS

Clinical performance of the Proclarix-MRI model in the validation cohort did not significantly differ from the training cohort and resulted in a sensitivity for csPCa of 90%, 90% negative predictive value and 66% positive predictive value. The Proclarix-MRI score's specificity (68%) was significantly (P < 0.001) better than the MRI-European Randomized study of Screening for Prostate Cancer risk score (51%), Proclarix (27%) or mpMRI (28%) alone. In addition, Proclarix by itself was found to be useful in the MRI Prostate Imaging-Reporting and Data System (PI-RADS) score 3 subgroup by outperforming prostate-specific antigen density in terms of specificity (25% vs 13%, P = 0.004) at 100% sensitivity.

CONCLUSION

When combined with mpMRI and prostate volume, Proclarix reliably predicted csPCa and ruled out men with no or indolent cancer. A large reduction of two thirds of unneeded biopsies was achieved. Proclarix can further be used with high confidence to reliably detect csPCa in men with an indeterminate PI-RADS score 3 mpMRI. Despite these encouraging results, further validation is needed.

Thrombospondin-1, CD47, and SIRPα Display Cell-Specific Molecular Signatures in Human Islets and Pancreata

BACKGROUND

Thrombospondin-1 (TSP1) is a secreted protein minimally expressed in health but increased in disease and age. TSP1 binds to the cell membrane receptor CD47, which itself engages signal regulatory protein α (SIRPα) and the latter creates a checkpoint for immune activation. Individuals with cancer administered checkpoint blocking molecules developed insulin-dependent diabetes. Relevant to this, CD47 blocking antibodies and SIRPα fusion proteins are in clinical trials. We characterized the molecular signature of TSP1, CD47, and SIRPα in human islets and pancreata.

METHODS

Fresh islets and pancreatic tissue from non-diabetic individuals were obtained. The expression of THBS1, CD47, and SIRPA was determined using single-cell mRNA sequencing, immunofluorescence microscopy, Western blot, and flow cytometry. Islets were exposed to diabetes-affiliated inflammatory cytokines and changes in protein expression determined.

RESULTS

CD47 mRNA was expressed in all islet cell types. THBS1 mRNA was restricted primarily to endothelial and mesenchymal cells, while SIRPA mRNA was found mostly in macrophages. Immunofluorescence staining showed CD47 protein expressed by beta cells and present in the exocrine pancreas. TSP1 and SIRPα proteins were not seen in islets or the exocrine pancreas. Western blot and flow cytometry confirmed immunofluorescent expression patterns. Importantly, human islets produced substantial quantities of secreted TSP1.

CONCLUSIONS

Human pancreatic exocrine and endocrine tissue expressed CD47 whereas fresh islets displayed cell surface CD47 and secreted TSP1 at baseline and in inflammation. These findings suggest unexpected effects on islets from agents that intersect TSP1-CD47-SIRPα.

CD47-Dependent Regulation of Immune Checkpoint Gene Expression and MYCN mRNA Splicing in Murine CD8 and Jurkat T Cells

Elevated expression of CD47 in some cancers is associated with poor survival related to its function as an innate immune checkpoint when expressed on tumor cells. In contrast, elevated CD47 expression in cutaneous melanomas is associated with improved survival. Previous studies implicated protective functions of CD47 expressed by immune cells in the melanoma tumor microenvironment. RNA sequencing analysis of responses induced by CD3 and CD28 engagement on wild type and CD47-deficient Jurkat T lymphoblast cells identified additional regulators of T cell function that were also CD47-dependent in mouse CD8 T cells. MYCN mRNA expression was upregulated in CD47-deficient cells but downregulated in CD47-deficient cells following activation. CD47 also regulated alternative splicing that produces two N-MYC isoforms. The CD47 ligand thrombospondin-1 inhibited expression of these MYCN mRNA isoforms, as well as induction of the oncogenic decoy MYCN opposite strand (MYCNOS) RNA during T cell activation. Analysis of mRNA expression data for melanomas in The Cancer Genome Atlas identified a significant coexpression of MYCN with CD47 and known regulators of CD8 T cell function. Thrombospondin-1 inhibited the induction of TIGIT, CD40LG, and MCL1 mRNAs following T cell activation in vitro. Increased mRNA expression of these T cell transcripts and MYCN in melanomas was associated with improved overall survival.

Pterostilbene supresses inflammation-induced melanoma metastasis by impeding neutrophil elastase-mediated thrombospondin-1 degradation

Objective

Chronic inflammation plays a fatal role in tumor metastasis. Pterostilbene (PTE) is a natural dimethylated analogue of resveratrol with anticancer and anti-inflammatory activities. This study aimed to investigate the inhibitory effect of PTE on inflammation-associated metastasis and explore the underlying mechanisms.

Methods

Lipopolysaccharide (LPS)-induced lung inflammation and melanoma metastasis models were established in mice. After PTE treatment for four weeks, the organ index, histological changes, proinflammatory cytokines, and the expression and activity of neutrophil elastase (NE), a biomarker of neutrophil influx in the lungs, were analysed. Additionally, direct effects of PTE on NE-induced B16 cell migration were explored in wound healing and Transwell assays, and the expression of thrombospondin-1 (TSP-1) and epithelial-mesenchymal transition (EMT) markers were also detected.

Results

PTE obviously attenuated the LPS-induced metastasis of circulatory B16 cells to lungs by reducing the number of metastatic nodules on the lung surfaces and the lung weight/body weight ratio. PTE treatment also significantly reduced LPS-activated increase levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in the lungs of tumor-bearing mice. In addition, increased expression and enzyme activity of NE and decreased expression of TSP-1 were observed, and these were blocked by PTE. In vitro, PTE at concentrations without cytotoxicity also markedly suppressed NE-triggered B16 cell migration, prevented NE-induced TSP-1 proteolysis and reversed the expression of vimentin, N-cadherin and E-cadherin.

Conclusion

PTE could block inflammation-enhanced tumor metastasis, and the underlying mechanism might be associated with the inhibition of NE-mediated TSP-1 degradation.

The matricellular protein thrombospondin-1 in lung inflammation and injury

Matricellular proteins comprise a diverse group of molecular entities secreted into the extracellular space. They interact with the extracellular matrix (ECM), integrins, and other cell-surface receptors, and can alter matrix strength, cell attachment to the matrix, and cell-cell adhesion. A founding member of this group is thrombospondin-1 (TSP-1), a high molecular-mass homotrimeric glycoprotein. Given the importance of the matrix and ECM remodeling in the lung following injury, TSP-1 has been implicated in a number of lung pathologies. This review examines the role of TSP-1 as a damage controller in the context of lung inflammation, injury resolution, and repair in noninfectious and infectious models. This review also discusses the potential role of TSP-1 in human diseases as it relates to lung inflammation and injury.

The Effect of Activated FXIII, a Transglutaminase, on Vascular Smooth Muscle Cells

Plasma factor XIII (pFXIII) is a heterotetramer of FXIII-A and FXIII-B subunits. The cellular form (cFXIII), a dimer of FXIII-A, is present in a number of cell types. Activated FXIII (FXIIIa), a transglutaminase, plays an important role in clot stabilization, wound healing, angiogenesis and maintenance of pregnancy. It has a direct effect on vascular endothelial cells and fibroblasts, which have been implicated in the development of atherosclerotic plaques. Our aim was to explore the effect of FXIIIa on human aortic smooth muscle cells (HAoSMCs), another major cell type in the atherosclerotic plaque. Osteoblastic transformation induced by Pi and Ca²⁺ failed to elicit the expression of cFXIII in HAoSMCs. EZ4U, CCK-8 and CytoSelect Wound Healing assays were used to investigate cell proliferation and migration. The Sircol Collagen Assay Kit was used to monitor collagen secretion. Thrombospondin-1 (TSP-1) levels were measured by ELISA. Cell-associated TSP-1 was detected by the immunofluorescence technique. The TSP-1 mRNA level was estimated by RT-qPCR. Activated recombinant cFXIII (rFXIIIa) increased cell proliferation and collagen secretion. In parallel, a 67% decrease in TSP-1 concentration in the medium and a 2.5-fold increase in cells were observed. TSP-1 mRNA did not change significantly. These effects of FXIIIa might contribute to the pathogenesis of atherosclerotic plaques.

Who with suspected prostate cancer can benefit from Proclarix after multiparametric magnetic resonance imaging?

Proclarix is a new blood-based test to assess the likelihood of clinically significant prostate cancer (csPCa) defined as >2 grade group. In this study, we analyzed whether Proclarix and PSA density (PSAD) could improve the selection of candidates for prostate biopsy after multiparametric magnetic resonance imaging (mpMRI). Proclarix and PSAD were assessed in 567 consecutive men with suspected PCa in whom pre-biopsy 3 Tesla mpMRI, scoring with Prostate Imaging-Report and Data System (PI-RADS) v.2, and guided and/or systematic biopsies were performed. Proclarix and PSAD thresholds having csPCa sensitivity over 90% were found at 10% and 0.07 ng/(mL*cm³), respectively. Among 100 men with negative mpMRI (PI-RADS <3), csPCa was detected in 6 cases, which would have been undetected if systematic biopsies were avoided. However, Proclarix suggested performing a biopsy on 70% of men with negative mpMRI. In contrast, PSAD only detected 50% of csPCa and required 71% of prostate biopsies. In 169 men with PI-RADS 3, Proclarix avoided 21.3% of prostate biopsies and detected all 25 cases of csPCa, while PSAD avoided 26.3% of biopsies, but missed 16% of csPCa. In 190 men with PI-RADS 4 and 108 with PI-RADS 5, Proclarix avoided 12.1% and 5.6% of prostate biopsies, but missed 4.8% and 1% of csPCa, respectively. PSAD avoided 18.4% and 9.3% of biopsies, but missed 11.4% and 4.2% csPCa, respectively. We conclude that Proclarix outperformed PSAD in the selection of candidates for prostate biopsy, especially in men with PI-RADS <3.

Thrombospondin-1 induced programmed death-ligand 1-mediated immunosuppression by activating the STAT3 pathway in osteosarcoma

Thrombospondin‐1 (TSP1) is generally assumed to suppress the growth of osteosarcoma through inhibiting angiogenesis; however, it is unclear whether TSP1 could affect the antitumor immunity against osteosarcoma. We aimed to explore the immune‐related tumor‐promoting effects of TSP1 and decipher its underlying mechanism. First, we identified that TSP1 regulated programmed death‐ligand 1 (PD‐L1) expression, which was related to the CD8⁺ T cells anergy in osteosarcoma cells. The exact role of PD‐L1 in the immunosuppressive effect of TSP1 was then further confirmed by the addition of the PD‐L1 neutralizing Ab. With the addition of PD‐L1 neutralizing Abs during cocultivation, the inhibition of CD8⁺ T cells was abolished to a certain extent. Further mechanistic investigations showed that TSP1‐induced PD‐L1 upregulation was achieved by activation of the signal transducer and activator of transcription 3 (STAT3) pathway. In vivo experiments also indicated that TSP1 overexpression could promote the growth of primary lesions, whereas TSP1 knockdown effectively inhibits the growth of the primary lesion as well as lung metastasis by restoring the antitumor immunity. Thrombospondin‐1 knockdown combined with PD‐L1 neutralizing Ab achieved a more pronounced antitumor effect. Taken together, our study showed that TSP1 upregulates PD‐L1 by activating the STAT3 pathway and, therefore, impairs the antitumor immunity against osteosarcoma.

Laminin alpha-3 and thrombospondin-1 differently regulate the survival and differentiation of hepatocytes and hepatic stem cells from neonatal mice

The aim of this study was to search and identify the extracellular matrix/adhesion molecules potentially regulating liver regeneration. By using pathway-focused PCR array, we investigated the dynamic changes in the expression of extracellular matrix and adhesion molecules in normal livers or cholestatic livers following partial hepatectomy in adult mice. To confirm the data from PCR array, we further evaluated how laminin alpha-3 and thrombospondin-1 mediate the survival and differentiation of matured hepatocytes and immature hepatic stem cells by using primarily isolated liver cells from neonatal mice. According to the different changes in the expression of extracellular matrix and adhesion molecules between normal livers and cholestatic livers, we could find a number of potential molecules involved in liver regeneration. Our in vitro evaluations indicated that laminin alpha-3 significantly increased the number of liver cells (P<0.01 vs. Control) but decreased the proportion of claudin-3-positive hepatic stem cells (P<0.05 vs. Control). In contrast, thrombospondin-1 significantly reduced cell apoptosis (P<0.05 vs. Control) and maintained the proportion of claudin-3-positive hepatic stem cells. Otherwise, the combination of laminin alpha-3 and thrombospondin-1 increased the proliferation of liver cells. Based on our data, laminin alpha-3 and trombospondin-1 differently regulate the survival and differentiation of hepatocytes and hepatic stem cells, but relevant mechanisms are required to be elucidated by further study.

Dual Role of Thrombospondin-1 in Flow-Induced Remodeling

(1) Background: Chronic increases in blood flow, as in cardiovascular diseases, induce outward arterial remodeling. Thrombospondin-1 (TSP-1) is known to interact with matrix proteins and immune cell-surface receptors, but its contribution to flow-mediated remodeling in the microcirculation remains unknown. (2) Methods: Mesenteric arteries were ligated in vivo to generate high- (HF) and normal-flow (NF) arteries in wild-type (WT) and TSP-1-deleted mice (TSP-1-/-). After 7 days, arteries were isolated and studied ex vivo. (3) Results: Chronic increases in blood flow induced outward remodeling in WT mice (increasing diameter from 221 ± 10 to 280 ± 10 µm with 75 mmHg intraluminal pressure) without significant effect in TSP-1-/- (296 ± 18 to 303 ± 14 µm), neutropenic or adoptive bone marrow transfer mice. Four days after ligature, pro inflammatory gene expression levels (CD68, Cox2, Gp91phox, p47phox and p22phox) increased in WT HF arteries but not in TSP-1-/- mice. Perivascular neutrophil accumulation at day 4 was significantly lower in TSP-1-/- than in WT mice. (4) Conclusions: TSP-1 origin is important; indeed, circulating TSP-1 participates in vasodilation, whereas both circulating and tissue TSP-1 are involved in arterial wall thickness and diameter expansion.

Exosomes derived from LPS-stimulated human thymic mesenchymal stromal cells enhance inflammation via thrombospondin-1

Inflammatory response mediated by immune cells is either directly or indirectly regulated by mesenchymal stromal cells (MSCs). Accumulating evidence suggests that thrombospondin-1 (TSP-1) is highly expressed in response to inflammation. In this work, we isolated and identified human thymic mesenchymal stromal cells (tMSCs) and detected the expression of TSP-1. We found that tMSCs expressed TSP-1 and Poly (I:C) or LPS treatment promoted the expression of TSP-1. Further, we isolated and identified exosomes originating from tMSCs (MEXs). Notably, exosomes derived from LPS-pretreated tMSCs (MEXs^LPS) promoted the polarization of macrophages to M1-like phenotype and IL-6, TNF-α secretion as well as the pro-inflammatory differentiation of CD4⁺T cells into Th17 cells. Upon silencing the expression of TSP-1 in tMSCs, the pro-inflammatory effects of MEXs^LPS were suppressed. Therefore, these findings uncovered TSP-1 as the principal factor in MEXs^LPS pro-inflammatory regulation.

MiR-18a-5p acts as a novel serum biomarker for venous malformation and promotes angiogenesis by regulating the thrombospondin-1/P53 signaling axis

Venous malformation (VM) is a kind of congenital vascular anomaly with high recurrence, and screening for VM lacks an efficient, inexpensive and noninvasive approach now. Serum miRNAs with stable structures are expected to become new postoperative and postablative monitoring biomarkers. Thus, we identified a prognostic serum miR-18a-5p and validated its function in VM. Notably, higher expression level of miR-18a-5p was detected in VM patients than in healthy individuals. We found that miR-18a-5p plays a promotive role in human umbilical vein endothelial cells in vitro. In addition, immunohistochemistry (IHC) results showed a distinct increase of vessels in miR-18a-5p mimics group and a decrease of vessels in inhibitors group compared to the control group in a murine VM model. Furthermore, thrombospondin-1 (TSP1), a potential miR-18a-5p-binding protein, was identified via RNA-seq, luciferase reporter and RNA immunoprecipitation (RIP) assays. Moreover, miR-18a-5p regulated the activation of P53 signaling pathway constituents and consequently led to the regulation of proliferation, migration, invasion and angiogenesis. These results provide a strong theoretical basis for further investigations into pathological mechanism of VM and may provide novel and noninvasive biomarker for VM diagnosis and monitoring.

Plasminogen deficiency causes reduced angiogenesis and behavioral recovery after stroke in mice

Plasminogen is involved in the process of angiogenesis; however, the underlying mechanism is unclear. Here, we investigated the potential contribution of plasmin/plasminogen in mediating angiogenesis and thereby contributing to functional recovery post-stroke. Wild-type plasminogen naive (Plg^+/+) mice and plasminogen knockout (Plg^-/-) mice were subjected to unilateral permanent middle cerebral artery occlusion (MCAo). Blood vessels were labeled with FITC-dextran. Functional outcomes, and cerebral vessel density were compared between Plg^+/+ and Plg^-/- mice at different time points after stroke. We found that Plg^-/- mice exhibited significantly reduced functional recovery, associated with significantly decreased vessel density in the peri-infarct area in the ipsilesional cortex compared with Plg^+/+ mice. In vitro, cerebral endothelial cells harvested from Plg^-/- mice exhibited significantly reduced angiogenesis assessed using tube formation assay, and migration, as evaluated using Scratch assays, compared to endothelial cells harvested from Plg^+/+ mice. In addition, using Western blots, expression of thrombospondin (TSP)-1 and TSP-2 were increased after MCAo in the Plg^-/- group compared to Plg^+/+ mice, especially in the ipsilesional side of brain. Taken together, our data suggest that plasmin/plasminogen down-regulates the expression level of TSP-1 and TSP-2, and thereby promotes angiogenesis in the peri-ischemic brain tissue, which contributes to functional recovery after ischemic stroke.

Lysyl hydroxylase 1 (LH1) deficiency promotes angiotensin II (Ang II)-induced dissecting abdominal aortic aneurysm

Rationale: The progressive disruption of extracellular matrix (ECM) proteins, particularly early elastin fragmentation followed by abnormalities in collagen fibril organization, are key pathological processes that contribute to dissecting abdominal aortic aneurysm (AAA) pathogenesis. Lysyl hydroxylase 1 (LH1) is essential for type I/III collagen intermolecular crosslinking and stabilization. However, its function in dissecting AAA has not been explored. Here, we investigated whether LH1 is significantly implicated in dissecting AAA progression and therapeutic intervention. Methods and Results: Sixteen-week-old male LH1-deficient and wild-type (WT) mice on the C57Bl/6NCrl background were infused with angiotensin II (Ang II, 1000 ng/kg per minute) via subcutaneously implanted osmotic pumps for 4 weeks. Ang II increased LH1 levels in the abdominal aortas of WT mice, whereas mice lacking LH1 developed dissecting AAA. To evaluate the related mechanism, we performed whole-transcriptomic analysis, which demonstrated that LH1 deficiency aggravated gene transcription alterations; in particular, the expression of thrombospondin-1 was markedly upregulated in the aortas of LH1-deficient mice. Furthermore, targeting thrombospondin-1 with TAX2 strongly inhibited the proinflammatory process, matrix metalloproteinase (MMP) activity and vascular smooth muscle cells (VSMCs) apoptosis, ultimately decreasing the incidence of dissecting AAA. Restoration of LH1 protein expression in LH1-deficient mice by intraperitoneal injection of an adeno-associated virus normalized thrombospondin-1 levels, subsequently alleviating dissecting AAA formation and preserving aortic structure and function. Consistently, in human AAA specimens, decreased LH1 expression was associated with increased thrombospondin-1 levels. Conclusions: LH1 deficiency contributes to dissecting AAA pathogenesis, at least in part, by upregulating thrombospondin-1 expression, which subsequently enables proinflammatory processes, MMP activation and VSMCs apoptosis. Our study provides evidence that LH1 is a potential critical therapeutic target for AAA.

Differential expression of microRNAs in human endometrium after implantation of an intrauterine contraceptive device containing copper

Intrauterine devices containing copper placement will release a large amount of Cu2+ into the uterine fluid, leading to local endometrial damage and inflammation, which is considered to be one of the causes of abnormal uterine bleeding. Studies have shown that the metabolism and function of metal ions are related to the regulation of microRNA. The aims of this study were to investigate changes in endometrial microRNA levels after implantation of an intrauterine device containing copper and to preliminarily explore the signalling pathways involved in abnormal uterine bleeding. The subjects were fertile women, aged 25-35, without major obstetrics and gynaecology diseases. Human endometrial tissues were collected before implantation or removal of the intrauterine device containing copper. High-throughput microRNA sequencing was performed on human endometrial tissues, and real-time quantitative PCR, western blotting and immunohistochemistry were used to detect the expression of relevant genes. MicroRNA sequencing results showed that 72 miRNAs were differentially expressed in the endometrial tissue after the insertion of the intrauterine device containing copper. Implantation of an intrauterine device containing copper implantation can up-regulate the expression of miR-144-3p in endometrial tissue, and therefore, decreases the mRNA and protein expression levels of genes related to endometrial injury and tissue repair, including the MT/NF-κB/MMP damage pathway and the THBS-1/TGF-β/SMAD3 repair pathway. In this study, the molecular mechanisms of abnormal uterine bleeding due to an intrauterine device containing copper were preliminarily investigated. The information will be beneficial for the clinical treatment of abnormal uterine bleeding caused by intrauterine device.

Hypertensive Patients Exhibit Enhanced Thrombospondin-1 Levels at High-Altitude

Thrombospondin-1 (THBS1) levels elevate under hypoxia and have relevance in several cardiovascular disorders. The association of THBS1 with endothelial dysfunction implies its important role in hypertension. To establish the hypothesis, we screened patients with hypertension and their respective controls from the two different environmental regions. Cohort 1 was composed of Ladakhis, residing at 3500 m above sea level (ASL), whereas Cohort 2 was composed of north-Indians residing at ~200 m ASL. Clinical parameters and circulating THBS1 levels were correlated in the case–control groups of the two populations. THBS1 levels were significantly elevated in hypertension patients of both cohorts; however, the levels were distinctly enhanced in the hypertensive patients of HA as compared to normoxia (p < 0.002). The observation was supported by the receiver operating curve analysis with an area under curve of 0.7007 (0.627–0.774) demonstrating the discriminatory effect of hypobaric hypoxia on the levels as compared to normoxia (p < 0.011). Significant correlation of THBS1 and mean arterial pressure was observed with upraised positive correlations in the hypertensive highlanders as compared to the hypertensive patients from sea-level. The prevalence of differential distribution of THBS1 and CD47 genes variants, their interactions, and association with the THBS1 levels were also determined. Genotype-interactions between THBS1 rs2228263 and CD47 rs9879947 were relevant and the regression analysis highlighted the association of risk genotype-interactions with increased THBS1 levels in hypertension. Genetic studies of additional thrombospondin pathway-related genes suggest the complex role of THBS1 in the presence of its family members and the related receptor molecules at HA.

Decreased Thrombospondin-1 and Bone Morphogenetic Protein-4 Serum Levels as Potential Indices of Advanced Stage Lung Cancer

Introduction: Lung cancer belongs to the most common carcinoma worldwide and is the leading cause of cancer-related death. Bone morphogenetic protein-4 (BMP-4) is extracellular signaling molecule involved in many important processes, including cell proliferation and mobility, apoptosis and angiogenesis. Thrombospondin-1 (TSP-1) belongs to the extracellular matrix proteins. It participates in the cell-to-cell and cell-to-matrix interactions and thus plays important role in tumor microenvironment for cancer development and metastasis formation. Aim: To investigate serum levels of TSP-1 and BMP-4 together with BMP-4 polymorphism in lung cancer patients. Material and Methods: A total of 111 patients (76 men) with newly diagnosed lung cancer, including 102 patients with non-small cell lung cancer and 9 patients with small-cell lung cancer. Advanced stage of lung cancer was diagnosed in 99 (89%) of patients: stage IV—in 48, stage IIIB—in 33, stage IIIA—in 18 patients; there were six patients with stage II and six patients with stage I. The control group consisted of 61 healthy persons. In all the subjects, serum levels of BMP-4 and TSP-1 were measured by ELISA. With a Real-Time PCR system genotyping of BMP-4 was performed. Results: BMP-4 and TSP-1 serum levels were significantly lower in the patients with lung cancer than in the controls (TSP-1:10,109.2 ± 9581 ng/mL vs. 11,415.09 ± 9781 ng/mL, p < 0.05; BMP-4: 138.35 ± 62.59 pg/mL vs. 226.68 ± 135.86 pg/mL p < 0.001). In lung cancer patients TSP-1 levels were lower in advanced stages (9282.07 ± 4900.78 ng/mL in the stages III-IV vs. 16,933.60 ± 6299.02 ng/mL in the stages I-II, p < 0.05) and in the patients with than without lymph nodes involvement (10,000.13 ± 9021.41 ng/mL vs. 18,497.75 ± 12,548.25 ng/mL, p = 0.01). There was no correlation between TSP-1 and BMP-4 serum levels. BMP-4 gene polymorphism did not influence the results of the study. Conclusion: Decreased levels of TSP-1 and BMP-4 may serve as potential indices of lung cancer, with additional importance of low TSP-1 level as a marker of advanced stage of the disease.

A unique esophageal extracellular matrix proteome alters normal fibroblast function in severe eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic TH2 disorder complicated by tissue fibrosis and loss of esophageal luminal patency. The fibrostenotic esophagus does not respond well to therapy, but profibrotic therapeutic targets are largely unclear.

OBJECTIVE

Our aim was to utilize proteomics and primary cells as a novel approach to determine relevant profibrotic factors.

METHODS

We utilized primary esophageal EoE and normal fibroblasts, their derivative extracellular matrixes (ECMs), an approach of fibroblast culture on autologous versus nonautologous ECM, and proteomics to elucidate EoE ECM proteins that dysregulate cellular function.

RESULTS

We cultured esophageal fibroblasts from normal esophagi and esophagi from patients with severe EoE on autologous versus nonautologous ECM. The EoE ECM proteome shifted normal esophageal fibroblast protein expression. Proteomic analysis demonstrated that thrombospondin-1 is detected only in the EoE ECM, is central in the EoE ECM protein-protein interactome, is found at significantly elevated levels in biopsy specimens from patients with active EoE, and induces fibroblast collagen I production.

CONCLUSION

Fibroblasts from patients with EoE secrete a unique ECM proteome that reflects their in vivo state and induces collagen I and α-smooth muscle actin protein expression from normal fibroblasts. Thrombospondin-1 is a previously unappreciated profibrotic molecule in EoE.

Thrombospondin-1 mediates Rho-kinase inhibitor-induced increase in outflow-facility

Rho‐kinase (ROCK) inhibitors, a novel class of anti‐glaucoma agents, act by increasing the aqueous humor outflow through the conventional trabecular meshwork pathway. However, the downstream signaling consequences of the ROCK inhibitor are not completely understood. Our data show that Y39983, a selective ROCK inhibitor, could induce filamentous actin remodeling, reduced cell motility (as measured by cell migration), and transepithelial resistance in primary human TM (hTM) cells. After 2 days Y39983 treatment of hTM cells, a proteomic study identified 20 proteins whose expression was significantly altered. Pathway analysis of those proteins revealed the involvement of the p53 pathway, integrin signaling pathway, and cytoskeletal pathway regulation by Rho GTPase. Thrombospondin‐1 (TSP1), a matricellular protein that is increased in glaucoma patients, was downregulated fivefold following Y39983 treatment. More importantly, both TSP1 antagonist leucine–serine–lysine–leucine (LSKL) and small interfering RNA (siRNA) reduced TSP1 gene and protein expressions as well as hTM cell migration. In the presence of Y39983, no further inhibition of cell migration resulted after LSKL and TSP1 siRNA knockdown. Likewise, LSKL triggered a dose‐dependent increase in outflow facility in ex vivo mouse eyes, to a similar extent as Y39983 (83.8% increase by Y39983 vs. 71.2% increase by LSKL at 50 µM). There were no additive effects with simultaneous treatment with LSKL and Y39983, supporting the notion that the effects of ROCK inhibition were mediated by TSP1.

[Correlation of serum ADAMTS13 and TSP1 levels with myocardial injury and prognosis in patients with acute coronary syndrome]

OBJECTIVE

To investigate serum levels of von Willebrand factor lytic protease (ADAMTS13) and thrombospondin-1 (TSP1) in patients with different types of acute coronary syndrome (ACS) and their correlation with the patients' clinical prognosis.

OBJECTIVE

According to their disease history, results of angiography and clinical biochemical tests, a total of 405 patients undergoing coronary angiography, were divided into unstable angina (UAP) group (n=215), acute myocardial infarction (AMI) group (n=96), and angiographically normal group (n=94). Serum ADAMTS13 and TSP1 levels were detected in all the patients, who were followed up for 15 months to evaluate the occurrence of long-term major cardiac adverse events (MACE).

OBJECTIVE

Serum ADAMTS13 level was significantly lower and TSP1 level was significantly higher in AMI group and UAP group than in the normal group (P < 0.001). Serum ADAMTS13 and TSP1 levels were negative correlated in ACS patients (R=-0.577, P < 0.001). The patients experiencing MACE had significantly different serum TSP1 level from those without MACE (P < 0.05). Cox proportion regression model analysis showed that TSP1 was a risk factor affecting the occurrence of MACE in ACS patients; Kaplan-Meier survival analysis showed that the patients with high levels of TSP1 had a higher incidence of longterm MACE than those with low TSP1 levels.

OBJECTIVE

A lowered serum ADAMTS13 level and an elevated TSP1 level can support the diagnosis of ACS. An elevated TSP1 level may serve as an indicator for predicting the risk of MACE in patients with ACS.

Thrombospondin 1-induced exosomal proteins attenuate hypoxia-induced paraptosis in corneal epithelial cells and promote wound healing

Thrombospondin-1 (TSP1) is involved in corneal wound healing caused by chemical injury. Herein, we examined the effects of TSP1 on hypoxia-induced damages and wound-healing activity in human corneal epithelial (HCE) cells. Exosomal protein expression was determined using liquid chromatography-tandem mass spectrometry, and HCE cell migration and motility were examined through wound-healing assay and time-lapse microscopy. Reestablishment of cell junctions by TSP1 was assessed through confocal microscopy and 3D image reconstruction. Our results show that CoCl₂ -induced hypoxia promoted HCE cell death by paraptosis. TSP1 protected these cells against paraptosis by attenuating mitochondrial membrane potential depletion, swelling and dilation of endoplasmic reticulum and mitochondria, and mitochondrial fission. Exosomes isolated from HCE cells treated with TSP1 contained wound healing-associated proteins that were taken up by HCE cells to promote tissue remodeling and repair. TSP1 protected HCE cells against hypoxia-induced damages and inhibited paraptosis progression by promoting cell migration, cell-cell adhesion, and extracellular matrix remodeling. These findings indicate that TSP1 ameliorates hypoxia-induced paraptosis in HCE cells and promotes wound healing and remodeling by regulating exosomal protein expression. TSP1 may, therefore, play important roles in the treatment of hypoxia-associated corneal diseases.

Age-Dependent Control of Collagen-Dependent Platelet Responses by Thrombospondin-1-Comparative Analysis of Platelets from Neonates, Children, Adolescents, and Adults

Platelet function is developmentally regulated. Healthy neonates do not spontaneously bleed, but their platelets are hypo-reactive to several agonists. The mechanisms underlying immature platelet function in neonates are incompletely understood. This critical issue remains challenging for the establishment of age-specific reference ranges. In this study, we evaluated platelet reactivity of five pediatric age categories, ranging from healthy full-term neonates up to adolescents (11–18 years) in comparison to healthy adults (>18 years) by flow cytometry. We confirmed that platelet hypo-reactivity detected by fibrinogen binding, P-selectin, and CD63 surface expression was most pronounced in neonates compared to other pediatric age groups. However, maturation of platelet responsiveness varied with age, agonist, and activation marker. In contrast to TRAP and ADP, collagen-induced platelet activation was nearly absent in neonates. Granule secretion markedly remained impaired at least up to 10 years of age compared to adults. We show for the first time that neonatal platelets are deficient in thrombospondin-1, and exogenous platelet-derived thrombospondin-1 allows platelet responsiveness to collagen. Platelets from all pediatric age groups normally responded to the C-terminal thrombospondin-1 peptide RFYVVMWK. Thus, thrombospondin-1 deficiency of neonatal platelets might contribute to the relatively impaired response to collagen, and platelet-derived thrombospondin-1 may control distinct collagen-induced platelet responses.

Thrombospondin-1 Restricts Interleukin-36γ-Mediated Neutrophilic Inflammation during Pseudomonas aeruginosa Pulmonary Infection

Interleukin-36γ (IL-36γ), a member of the IL-1 cytokine superfamily, amplifies lung inflammation and impairs host defense during acute pulmonary Pseudomonas aeruginosa infection. To be fully active, IL-36γ is cleaved at its N-terminal region by proteases such as neutrophil elastase (NE) and cathepsin S (CatS). However, it remains unclear whether limiting extracellular proteolysis restrains the inflammatory cascade triggered by IL-36γ during P. aeruginosa infection. Thrombospondin-1 (TSP-1) is a matricellular protein with inhibitory activity against NE and the pathogen-secreted Pseudomonas elastase LasB-both proteases implicated in amplifying inflammation. We hypothesized that TSP-1 tempers the inflammatory response during lung P. aeruginosa infection by inhibiting the proteolytic environment required for IL-36γ activation. Compared to wild-type (WT) mice, TSP-1-deficient (Thbs1-/-) mice exhibited a hyperinflammatory response in the lungs during P. aeruginosa infection, with increased cytokine production and an unrestrained extracellular proteolytic environment characterized by higher free NE and LasB, but not CatS activity. LasB cleaved IL-36γ proximally to M19 at a cleavage site distinct from those generated by NE and CatS, which cleave IL-36γ proximally to Y16 and S18, respectively. N-terminal truncation experiments in silico predicted that the M19 and the S18 isoforms bind the IL-36R complex almost identically. IL-36γ neutralization ameliorated the hyperinflammatory response and improved lung immunity in Thbs1-/- mice during P. aeruginosa infection. Moreover, administration of cleaved IL-36γ induced cytokine production and neutrophil recruitment and activation that was accentuated in Thbs1-/- mice lungs. Collectively, our data show that TSP-1 regulates lung neutrophilic inflammation and facilitates host defense by restraining the extracellular proteolytic environment required for IL-36γ activation.IMPORTANCEPseudomonas aeruginosa pulmonary infection can lead to exaggerated neutrophilic inflammation and tissue destruction, yet host factors that regulate the neutrophilic response are not fully known. IL-36γ is a proinflammatory cytokine that dramatically increases in bioactivity following N-terminal processing by proteases. Here, we demonstrate that thrombospondin-1, a host matricellular protein, limits N-terminal processing of IL-36γ by neutrophil elastase and the Pseudomonas aeruginosa-secreted protease LasB. Thrombospondin-1-deficient mice (Thbs1-/-) exhibit a hyperinflammatory response following infection. Whereas IL-36γ neutralization reduces inflammatory cytokine production, limits neutrophil activation, and improves host defense in Thbs1-/- mice, cleaved IL-36γ administration amplifies neutrophilic inflammation in Thbs1-/- mice. Our findings indicate that thrombospondin-1 guards against feed-forward neutrophilic inflammation mediated by IL-36γ in the lung by restraining the extracellular proteolytic environment.

Astrocyte-mediated purinergic signaling is upregulated in a mouse model of Fragile X syndrome

Fragile X syndrome (FXS) is the leading monogenic cause of intellectual disability and autism spectrum disorders. With increasing investigation into the molecular mechanisms underlying FXS, there is growing evidence that perturbations in glial signaling are widely associated with neurological pathology. Purinergic signaling, which utilizes nucleoside triphosphates as signaling molecules, provides one of the most ubiquitous signaling systems for glial-neuronal and glial-glial crosstalk. Here, we sought to identify whether purinergic signaling is dysregulated within the FXS mouse cortex, and whether this dysregulation contributes to aberrant intercellular communication. In primary astrocyte cultures derived from the Fmr1 knockout (KO) mouse model of FXS, we found that application of exogenous ATP and UTP evoked elevated intracellular calcium responses compared to wildtype levels. Accordingly, purinergic P2Y₂ and P2Y₆ receptor expression was increased in Fmr1 KO astrocytes both in vitro and in acutely dissociated tissue, while P2Y antagonism via suramin prevented intracellular calcium elevations, suggesting a role for these receptors in aberrant FXS astrocyte activation. To investigate the impact of elevated purinergic signaling on astrocyte-mediated synaptogenesis, we quantified synaptogenic protein TSP-1, known to be regulated by P2Y activation. TSP-1 secretion and expression were both heightened in Fmr1 KO vs wildtype astrocytes following UTP application, while naïve TSP-1 cortical expression was also transiently elevated in vivo, indicating increased potential for excitatory TSP-1-mediated synaptogenesis in the FXS cortex. Together, our results demonstrate novel and significant purinergic signaling elevations in Fmr1 KO astrocytes, which may serve as a potential therapeutic target to mitigate the signaling aberrations observed in FXS.

Variations in the Profiles of Vascular-Related Factors Among Different Sub-Types of Polycystic Ovarian Syndrome in Northern China

Recently, a growing body of evidence has suggested that abnormal ovarian angiogenesis, secondary to the imbalance between various angiogenic markers, is involved in the pathogenesis of PCOS, and this has led to the use of various interventions (such as Diane-35) to restore the normal ovarian angiogenesis. Therefore, we conducted the current investigation to determine the role of such markers (endothelial growth factor (VEGF), endostatin (ES), and thrombospondin-1 (TSP-1)) in the pathogenesis of PCOS along with the associated changes in ovarian blood flow in patients with PCOS compared to healthy controls, both before and after a course of oral contraception. A total of 381 patients with PCOS and 98 healthy females of childbearing age were recruited from July 2014 to June 2017 at the Reproductive Center of the Second Affiliated Hospital of Harbin Medical University. The serum levels of VEGF, ES, and TSP-1 were determined by enzyme-linked immunosorbent assay, while ovarian perfusion was measured by the pulsatility index (PI) and resistance index (RI) by using transvaginal color Doppler ultrasound. Repeated analyses were carried out after 3 months of Diane-35 treatment. Post-treatment serum levels of luteinizing hormone (LH)/follicle stimulating hormone (FSH) ratio of patients with PCOS decreased significantly (P <0.05). The RI values of most PCOS patients increased after treatment (P<0.05), while PI was significantly increased in all patients (P<0.05). However, variable changes in the serum levels of TSP-1, VEGF, and ES after treatment were observed. Serum VEGF levels showed a negative correlation with serum LH/FSH ratio, T concentration, and ES (P <0.05), while ES levels were negatively correlated with serum T concentrations only (P<0.05). The markers of angiogenesis (VEGF, ES, and TSP-1) were expressed differently among PCOS patients, who also responded differently to the same course of Diane-35 treatment. This field still warrants further investigation to reach a more definitive conclusion.

Syndecan-4 promotes vascular beds formation in tissue engineered liver via thrombospondin 1

Instantaneous blood coagulation after bioengineered liver transplantation is a major issue, and the key process in its prevention is the construction of the endothelial vascular bed on biomimetic scaffolds. However, the specific molecules involved in the regulation of the vascular bed formation remain unclear. Syndecan-4 is a type I transmembrane glycoprotein commonly expressed in the human body; its receptor has been reported as critical for optimal cell adhesion and initiation of intracellular signaling, indicating its promising application in vascular bed formation. In the current study, bioinformatics analysis and in vitro experiments were performed to evaluate whether syndecan-4 promoted endothelial cell migration and functional activation. Exogenous syndecan-4-overexpressing endothelial cells were perfused into the decellularized liver scaffold, which was assessed by Masson’s trichrome staining. Western blotting and qRT-PCR were used to evaluate the effects of syndecan-4 on the thrombospondin 1 (THBS1) stability. We found that syndecan-4 promoted the adhesion of vascular endothelial cells and facilitated cell migration and angiogenesis. Furthermore, syndecan-4 overexpression resulted in a well-aligned endothelium on the decellularized liver scaffolds. Mechanistically, syndecan-4 destabilized THBS1 at the protein level. Therefore, our data revealed that syndecan-4 promoted the biological activity of endothelial cells on the bionic liver vascular bed through THBS1. These findings provide scientific evidences for solving transient blood coagulation after bionic liver transplantation.

Plasmin-Induced Activation of Human Platelets Is Modulated by Thrombospondin-1, Bona Fide Misfolded Proteins and Thiol Isomerases

Inflammatory processes are triggered by the fibrinolytic enzyme plasmin. Tissue-type plasminogen activator, which cleaves plasminogen to plasmin, can be activated by the cross-β-structure of misfolded proteins. Misfolded protein aggregates also represent substrates for plasmin, promoting their degradation, and are potent platelet agonists. However, the regulation of plasmin-mediated platelet activation by misfolded proteins and vice versa is incompletely understood. In this study, we hypothesize that plasmin acts as potent agonist of human platelets in vitro after short-term incubation at room temperature, and that the response to thrombospondin-1 and the bona fide misfolded proteins Eap and SCN^--denatured IgG interfere with plasmin, thereby modulating platelet activation. Plasmin dose-dependently induced CD62P surface expression on, and binding of fibrinogen to, human platelets in the absence/presence of plasma and in citrated whole blood, as analyzed by flow cytometry. Thrombospondin-1 pre-incubated with plasmin enhanced these plasmin-induced platelet responses at low concentration and diminished them at higher dose. Platelet fibrinogen binding was dose-dependently induced by the C-terminal thrombospondin-1 peptide RFYVVMWK, Eap or NaSCN-treated IgG, but diminished in the presence of plasmin. Blocking enzymatically catalyzed thiol-isomerization decreased plasmin-induced platelet responses, suggesting that plasmin activates platelets in a thiol-dependent manner. Thrombospondin-1, depending on the concentration, may act as cofactor or inhibitor of plasmin-induced platelet activation, and plasmin blocks platelet activation induced by misfolded proteins and vice versa, which might be of clinical relevance.

miR-195 reduces age-related blood-brain barrier leakage caused by thrombospondin-1-mediated selective autophagy

Blood–brain barrier (BBB) disruption contributes to neurodegenerative diseases. Loss of tight junction (TJ) proteins in cerebral endothelial cells (ECs) is a leading cause of BBB breakdown. We recently reported that miR‐195 provides vasoprotection, which urges us to explore the role of miR‐195 in BBB integrity. Here, we found cerebral miR‐195 levels decreased with age, and BBB leakage was significantly increased in miR‐195 knockout mice. Furthermore, exosomes from miR‐195‐enriched astrocytes increased endothelial TJ proteins and improved BBB integrity. To decipher how miR‐195 promoted BBB integrity, we first demonstrated that TJ proteins were metabolized via autophagic–lysosomal pathway and the autophagic adaptor p62 was necessary to promote TJ protein degradation in cerebral ECs. Next, proteomic analysis of exosomes revealed miR‐195‐suppressed thrombospondin‐1 (TSP1) as a major contributor to BBB disruption. Moreover, TSP1 was demonstrated to activate selective autophagy of TJ proteins by increasing the formation of claudin‐5‐p62 and ZO1‐p62 complexes in cerebral ECs while TSP1 impaired general autophagy. Delivering TSP1 antibody into the circulation showed dose‐dependent reduction of BBB leakage by 20%–40% in 25‐month‐old mice. Intravenous or intracerebroventricular injection of miR‐195 rescued TSP1‐induced BBB leakage. Dementia patients with BBB damage had higher levels of serum TSP1 compared to those without BBB damage (p = 0.0015), while the normal subjects had the lowest TSP1 (p < 0.0001). Taken together, the study implies that TSP1‐regulated selective autophagy facilitates the degradation of TJ proteins and weakens BBB integrity. An adequate level of miR‐195 can suppress the autophagy–lysosome pathway via a reduction of TSP1, which may be important for maintaining BBB function.

Protection against light-induced retinal degeneration via dual anti-inflammatory and anti-angiogenic functions of thrombospondin-1

BACKGROUND AND PURPOSE

Retinal photodamage is a high-risk factor for age-related macular degeneration (AMD), the leading cause of irreversible blindness worldwide. However, both the pathogenesis and effective therapies for retinal photodamage are still unclear and debated.

EXPERIMENTAL APPROACH

The anti-inflammatory effects of thrombospondin-1 on blue light-induced inflammation in ARPE-19 cells and in retinal inflammation were evaluated. Furthermore, the anti-angiogenic effects of thrombospondin-1 on human microvascular endothelial cells (hMEC-1 cells) and a laser-induced choroidal neovascularisation (CNV) mouse model were evaluated. in vitro experiments, including western blotting, immunocytochemistry, migration assays and tube formation assays, as well as in vivo experiments, including immunofluorescence, visual electrophysiology, spectral-domain optical coherence tomography, and fluorescein angiography, were employed to evaluate the anti-inflammatory and anti-angiogenic effects of thrombospondin-1.

KEY RESULTS

Specific effects of blue light-induced retinal inflammation and pathological angiogenesis were reflected by up-regulation of pro-inflammatory factors and activation of angiogenic responses, predominantly regulated by the NF-κB and VEGFR2 pathways respectively. During the blue light-induced pathological progress, THBS-1 derived from retinal pigment epithelium down-regulated proteomics and biological assays. Thrombospondin-1 treatment also suppressed inflammatory infiltration and neovascular leakage. The protective effect of Thrombospondin-1 was additionally demonstrated by a substantial rescue of visual function. Mechanistically, thrombospondin-1 reversed blue light-induced retinal inflammation and angiogenesis by blocking the activated NF-κB and VEGFR2 pathways, respectively.

CONCLUSION AND IMPLICATIONS

Thrombospondin-1, with dual anti-inflammatory and anti-neovascularisation properties, is a promising agent for protection against blue light-induced retinal damage and retinal degenerative disorders which are pathologically associated with inflammatory and angiogenic progress.

Lysophosphatidic acid induces thrombospondin-1 production in primary cultured rat cortical astrocytes

Lysophosphatidic acid (LPA), a brain membrane-derived lipid mediator, plays important roles including neural development, function, and behavior. In the present study, the effects of LPA on astrocyte-derived synaptogenesis factor thrombospondins (TSPs) production were examined by real-time PCR and western blotting, and the mechanism underlying this event was examined by pharmacological approaches in primary cultured rat cortical astrocytes. Treatment of astrocytes with LPA increased TSP-1 mRNA, and TSP-2 mRNA, but not TSP-4 mRNA expression. TSP-1 protein expression and release were also increased by LPA. LPA-induced TSP-1 production were inhibited by AM966 a LPA₁ receptor antagonist, and Ki16425, LPA_1/3 receptors antagonist, but not by H2L5146303, LPA₂ receptor antagonist. Pertussis toxin, Gi/o inhibitor, but not YM-254890, Gq inhibitor, and NF499, Gs inhibitor, inhibited LPA-induced TSP-1 production, indicating that LPA increases TSP-1 production through Gi/o-coupled LPA₁ and LPA₃ receptors. LPA treatment increased phosphorylation of extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinase (JNK). LPA-induced TSP-1 mRNA expression was inhibited by U0126, MAPK/ERK kinase (MEK) inhibitor, but not SB202190, p38 MAPK inhibitor, or SP600125, JNK inhibitor. However, LPA-induced TSP-1 protein expression was diminished with inhibition of all three MAPKs, indicating that these signaling molecules are involved in TSP-1 protein production. Treatment with antidepressants, which bind to astrocytic LPA₁ receptors, increased TSP-1 mRNA and protein production. The current findings show that LPA/LPA_1/3 receptors signaling increases TSP-1 production in astrocytes, which could be important in the pathogenesis of affective disorders and could potentially be a target for the treatment of affective disorders.

Effect of Age and Acute Exercise on Circulating Angioregulatory Factors

The balance of angiogenic factors, including vascular endothelial growth factor (VEGF), and angiostatic factors, like thrombospondin-1 (TSP-1) and endostatin, controls striated muscle angiogenic responses to exercise training. The effect of age on circulating levels of these factors following a bout of exercise is unclear. The authors hypothesized that older adults would have lower circulating VEGF but higher TSP-1 and endostatin after exercise compared with young adults. Ten young and nine older participants cycled for 45 min at 60% estimated HRmax. Serum [VEGF], [TSP-1], and [endostatin] obtained before (PREX), immediately after (POSTX0), and 3 hr after (POSTX3) exercise were analyzed. [VEGF] increased in older adults only from PREX to POSTX0 (p < .05). [TSP-1] increased in both age groups (p < .05). There was no effect of age or exercise on [endostatin]. In conclusion, immediately after exercise, both groups had a similar increase in [TSP-1], but [VEGF] increased in older adults only.

microRNA-221 Inhibits Latent TGF-β1 Activation through Targeting Thrombospondin-1 to Attenuate Kidney Failure-Induced Cardiac Fibrosis

Kidney failure (KF) is associated with cardiac fibrosis and significantly increased mortality in heart failure. Thrombospondin-1 (TSP1), a key regulator of latent transforming growth factor-β1 (L-TGF-β1) activation, is a predicted target of miR-221. We hypothesized miR-221 attenuates severe KF-associated cardiac fibrosis via targeting of Thbs1 with subsequent inhibition of L-TGF-β1 activation. Rat cardiac fibroblasts (cFB) were isolated and transfected with microRNA-221 (miR-221) mimics or mimic control (miR-221 and MC) with or without exposure to L-TGF-β1. We demonstrate miR-221 downregulates Thbs1 via direct 3′ untranslated region (3′ UTR) targeting with consequent inhibition of L-TGF-β1 activation in cFB as proven by the significant reduction of myofibroblast activation, collagen secretion, TGF-β1 signaling, TSP1 secretion, and TGF-β1 bioactivity measured by Pai1 promoter reporter. The 5/6 nephrectomy (Nx) model of cardiac fibrosis was used to test the in vivo therapeutic efficacy of miR-221 (i.v. 1 mg/kg ×3). miR-221 significantly inhibited Nx-induced upregulation of TSP1 and p-SMAD3 in the heart at day-7 and reduced cardiac fibrosis (picro-sirius), improved cardiac function (±dP/dt), and improved 8-week survival rate (60% versus 36%; p = 0.038). miR-221 mimic treatment improved survival and reduced cardiac fibrosis in a model of severe KF. miR-221 is a therapeutic target to address cardiac fibrosis originating from renal disease and other causes.

Aging-associated changes in CD47 arrangement and interaction with thrombospondin-1 on red blood cells visualized by super-resolution imaging

CD47 serves as a ligand for signaling regulatory protein α (SIRPα) and as a receptor for thrombospondin-1 (TSP-1). Although CD47, TSP-1, and SIRPα are thought to be involved in the clearance of aged red blood cells (RBCs), aging-associated changes in the expression and interaction of these molecules on RBCs have been elusive. Using direct stochastic optical reconstruction microscopy (dSTORM)-based imaging and quantitative analysis, we can report that CD47 molecules on young RBCs reside as nanoclusters with little binding to TSP-1, suggesting a minimal role for TSP-1/CD47 signaling in normal RBCs. On aged RBCs, CD47 molecules decreased in number but formed bigger and denser clusters, with increased ability to bind TSP-1. Exposure of aged RBCs to TSP-1 resulted in a further increase in the size of CD47 clusters via a lipid raft-dependent mechanism. Furthermore, CD47 cluster formation was dramatically inhibited on thbs1-/- mouse RBCs and associated with a significantly prolonged RBC lifespan. These results indicate that the strength of CD47 binding to its ligand TSP-1 is predominantly determined by the distribution pattern and not the amount of CD47 molecules on RBCs, and offer direct evidence for the role of TSP-1 in phagocytosis of aged RBCs. This study provides clear nanoscale pictures of aging-associated changes in CD47 distribution and TSP-1/CD47 interaction on the cell surface, and insights into the molecular basis for how these molecules coordinate to remove aged RBCs.

CD47 Promotes Age-Associated Deterioration in Angiogenesis, Blood Flow and Glucose Homeostasis

The aged population is currently at its highest level in human history and is expected to increase further in the coming years. In humans, aging is accompanied by impaired angiogenesis, diminished blood flow and altered metabolism, among others. A cellular mechanism that impinges upon these manifestations of aging can be a suitable target for therapeutic intervention. Here we identify cell surface receptor CD47 as a novel age-sensitive driver of vascular and metabolic dysfunction. With the natural aging process, CD47 and its ligand thrombospondin-1 were increased, concurrent with a reduction of self-renewal transcription factors OCT4, SOX2, KLF4 and cMYC (OSKM) in arteries from aged wild-type mice and older human subjects compared to younger controls. These perturbations were prevented in arteries from aged CD47-null mice. Arterial endothelial cells isolated from aged wild-type mice displayed cellular exhaustion with decreased proliferation, migration and tube formation compared to cells from aged CD47-null mice. CD47 suppressed ex vivo sprouting, in vivo angiogenesis and skeletal muscle blood flow in aged wild-type mice. Treatment of arteries from older humans with a CD47 blocking antibody mitigated the age-related deterioration in angiogenesis. Finally, aged CD47-null mice were resistant to age- and diet-associated weight gain, glucose intolerance and insulin desensitization. These results indicate that the CD47-mediated signaling maladapts during aging to broadly impair endothelial self-renewal, angiogenesis, perfusion and glucose homeostasis. Our findings provide a strong rationale for therapeutically targeting CD47 to minimize these dysfunctions during aging.

Thrombospondin-1 in maladaptive aging responses: a concept whose time has come

Numerous age-dependent alterations at the molecular, cellular, tissue and organ systems levels underlie the pathophysiology of aging. Herein, the focus is upon the secreted protein thrombospondin-1 (TSP1) as a promoter of aging and age-related diseases. TSP1 has several physiological functions in youth, including promoting neural synapse formation, mediating responses to ischemic and genotoxic stress, minimizing hemorrhage, limiting angiogenesis, and supporting wound healing. These acute functions of TSP1 generally require only transient expression of the protein. However, accumulating basic and clinical data reinforce the view that chronic diseases of aging are associated with accumulation of TSP1 in the extracellular matrix, which is a significant maladaptive contributor to the aging process. Identification of the relevant cell types that chronically produce and respond to TSP1 and the molecular mechanisms that mediate the resulting maladaptive responses could direct the development of therapeutic agents to delay or revert age-associated maladies.

Matrix mechanotransduction mediated by thrombospondin-1/integrin/YAP in the vascular remodeling

The extracellular matrix (ECM) initiates mechanical cues that activate intracellular signaling through matrix-cell interactions. In blood vessels, additional mechanical cues derived from the pulsatile blood flow and pressure play a pivotal role in homeostasis and disease development. Currently, the nature of the cues from the ECM and their interaction with the mechanical microenvironment in large blood vessels to maintain the integrity of the vessel wall are not fully understood. Here, we identified the matricellular protein thrombospondin-1 (Thbs1) as an extracellular mediator of matrix mechanotransduction that acts via integrin αvβ1 to establish focal adhesions and promotes nuclear shuttling of Yes-associated protein (YAP) in response to high strain of cyclic stretch. Thbs1-mediated YAP activation depends on the small GTPase Rap2 and Hippo pathway and is not influenced by alteration of actin fibers. Deletion of Thbs1 in mice inhibited Thbs1/integrin β1/YAP signaling, leading to maladaptive remodeling of the aorta in response to pressure overload and inhibition of neointima formation upon carotid artery ligation, exerting context-dependent effects on the vessel wall. We thus propose a mechanism of matrix mechanotransduction centered on Thbs1, connecting mechanical stimuli to YAP signaling during vascular remodeling in vivo.

Exercise and insulin-like growth factor 1 supplementation improve angiogenesis and angiogenic cytokines in a rat model of diabetes-induced neuropathy

NEW FINDINGS

What is the central question of this study? Do changes in levels of angiogenesis-related mediators [vascular endothelial growth factor-A (VEGF-A), thrombospondin-1 (TSP-1) and nuclear factor-κB (NF-κB)] in the sciatic nerve mediate diabetic neuropathy in the streptozotocin-induced type 1 diabetic male rat? Can exercise and insulin-like growth factor 1 (IGF-I) treatment improve the diabetes-related decrease in angiogenesis in sciatic nerve in these animals? What is the main finding and its importance? Levels of VEGF-A, TSP-1 and NF-κB change in the sciatic nerve of diabetic rats and might mediate diabetic neuropathy. Treatment with IGF-I and exercise could increase angiogenesis in the diabetic rats by increasing VEGF-A and decreasing TSP-1 and NF-κB expression in the sciatic nerve.

ABSTRACT

Diabetic neuropathy is a severe complication of diabetes that affects 40-50% of diabetic people in the world. The aim of this study was to characterize alterations in angiogenesis and related molecular mediators in the sciatic nerve in diabetic conditions alone or in diabetes in combination with exercise and/or administration of insulin-like growth factor 1 (IGF-I). Forty male Wistar rats were assigned into one of five groups, namely control, diabetes, diabetes + exercise, diabetes + IGF-I and diabetes + exercise + IGF-I. Type 1 diabetes was induced by i.p. injection of streptozotocin (60 mg kg^-1 ). After 30 days of treatment with exercise or IGF-I alone or in combination, diabetic neuropathy was evaluated with a hotplate, glycated haemoglobin was measured, angiogenesis was determined by immunostaining for PECAM-1/CD31, and expressions of vascular endothelial growth factor-A (VEGF-A), thrombospondin-1 (TSP-1) and nuclear factor-κB (NF-κB) were determined by enzyme-linked immunosorbent assay.After 4 weeks, the diabetes group showed a significant decrease in capillary density and VEGF-A levels, but a significant increase in glycated haemoglobin in blood, TSP-1 and NF-κB levels in the sciatic nerve compared with the control group, and these effects were ameliorated by exercise and IGF-I. However, simultaneous treatment of diabetic rats with IGF-I and exercise did not have any synergistic effects. These findings indicate that diabetes-induced neuropathy may be associated, in part, with decreased angiogenesis mediated by overproduction of TSP-1 and NF-κB, in addition to reduced production of VEGF-A. The findings also showed that exercise and IGF-I can reduce neuropathy, followed by increased angiogenesis, by changes in TSP-1, NF-κB and VEGF-A production levels.

THBS1 (thrombospondin-1)

Thrombospondins are encoded in vertebrates by a family of 5 THBS genes. THBS1 is infrequently mutated in most cancers, but its expression is positively regulated by several tumor suppressor genes and negatively regulated by activated oncogenes and promoter hypermethylation. Consequently, thrombospondin-1 expression is frequently lost during oncogenesis and is correlated with a poor prognosis for some cancers. Thrombospondin-1 is a secreted protein that acts in the tumor microenvironment to inhibit angiogenesis, regulate antitumor immunity, stimulate tumor cell migration, and regulate the activities of extracellular proteases and growth factors. Differential effects of thrombospondin-1 on the sensitivity of normal versus malignant cells to ischemic and genotoxic stress also regulate the responses to tumors to therapeutic radiation and chemotherapy.

TSP-1 as a novel biological marker of tumor vasculature normalization in colon carcinoma induced by Endostar

Blood vessels in tumors often exhibit abnormal morphology and function, which promotes the growth, metastasis and resistance of tumors to conventional therapies. Therefore, vascular normalization is an emerging strategy to enhance the effectiveness of radiotherapy and chemotherapy when used in combination; however, there is a lack of evidence regarding the optimal schedule for the co-administration of anti-angiogenic and chemotherapeutic drugs. Scheduling treatment is important as the period for normalization is transient, also known as the ‘time window’; however, no biomarker has been identified to detect this window. In the present study, recombinant human endostatin (rhES) was employed as an anti-angiogenic agent in xenograft tumor tissue in mice. Following rhES or control (saline) treatment, the density and integrity of tumor vessels were detected by immunofluorescence staining for cluster of differentiation 31 and α-smooth muscle actin; the level of hypoxia in tumor tissue was examined by immunohistochemistry with pimonidazole; the necrotic area was evaluated by hematoxylin and eosin staining; and the level of thrombospondin-1 (TSP-1) in plasma was tested by ELISA. The Cell Counting Kit-8 assay was also used to evaluate the effect of rhES on the proliferation of colon carcinoma SW620 cells. A ‘time window’ normalized vasculature was determined between day 4 and 6 following rhES treatment, and accompanied by a decrease in hypoxia in tumor tissue. Decreasing plasma TSP-1 levels were consistent with changes in vascular morphology and hypoxia, which exhibited features of normalization. In addition, rhES had no effect on the proliferation of SW620 cells, suggesting that the reduction in TSP-1 was associated with increased oxygen content during vascular normalization, rather than inhibited cell proliferation. In conclusion, TSP-1 may be a potential biomarker for predicting the normalization window of colon cancer vessels.

Evaluation of thrombospondin-1 gene polymorphisms in corneal allograft rejection in Asian Indian patients

Purpose:

To evaluate the frequency and the association of Thrombospondin 1 (THBS1) gene single nucleotide polymorphisms (SNPs) in Asian Indian patients with optical full thickness corneal grafting surgery.

Methods:

Prospective case–control analysis of optical penetrating keratoplasty patients with and without immune rejection and controls for genotyping of 3 THBS1 gene SNPs (rs1478604 A>G; rs2228261 C>T; rs2228262 A>G) by Amplification Refractory Mutation System-Polymerase Chain Reaction (ARMS PCR).

Results:

Among 58 patients [45 with immune allograft rejection (DNA isolation was possible in 38 samples) and 13 without immune corneal allograft rejection] and 65 controls, allele frequencies observed for rs1478604 (A>G) are A: 69.7% and 72.6%, G: 30.2% and 27.3%; for rs2228261 (C>T) are T: 70.2% and 62.3%, C: 29.7% and 37.6%; and for rs2228262 (A>G) A: 97.4% and 98.4%; G 2.5% and 1.5% respectively. Genotype frequencies were rs1478604 (A>G) AA: 57.8% and 59.3%, AG 23.6% and 26.5%; GG 18.4% and 14%; for rs2228261 (C>T) TT: 40.5% and 33.8%, TC: 59% and 56.9%, CC: 0% and 9.2%; for rs2228262 (A>G) AA: 94.8% and 96.8%, AG: 5.1% and 3.1% in rejection and controls respectively. The allele and genotype frequency for the 3 described THSB1 SNPs did not show any difference between the corneal graft immune rejection patients and controls.

Conclusion:

Asian Indian population evaluated for THBS1 gene SNPs by ARMS PCR genotyping in Asian Indian population did not show any genetic association to immune rejection occurrence in our study.

CD47 blockade alleviates acute rejection of allogeneic mouse liver transplantation by reducing ischemia/reperfusion injury

Despite advances in immunosuppressive therapies, acute rejection response is still a serious concern especially in the early phase after liver transplantation. This study aimed to evaluate whether blocking the TSP1-CD47 signaling pathway could attenuate the acute rejection after liver transplantation. An allogeneic mouse orthotopic liver transplantation model (Balb/c→C3H) with prolonged cold ischemic phase was used to induce severe IRI and lethal acute rejection. CD47mAb or isotype matched-control IgG_2a was administered to donor liver during graft perfusion. Recipients were sacrificed at 1d, 3d, 5d and 7d after reperfusion. Blood samples were collected to evaluate serum alanine aminotransferase, total bilirubin, HMGB-1,TNF-α, IL-2 and INF-γ level. Flow cytometric analysis was used to detect the strength of innate and adaptive immune response. Liver tissue was obtained for HE, TUNEL staining and F4/80 immumohistochemical staining. Moreover, we conducted a mixed lymphocyte reaction treated with IgG_2a or CD47mAb. Mice in CD47mAb-treated group demonstrated improved survival and significantly lower increase in Suzuki score, apoptosis index, acute rejection index, serum alanine aminotransferase, total bilirubin, HMGB-1, TNF-α, IL-2, INF-γ level and the degree of Kupffer cells' activation especially in the early phase of acute rejection. In addition, Pearson's correlation analysis confirmed significant correlation between Suzuki score/ALT and acute rejection index. The in vitro inhibition assay showed that CD47 blockade couldn't directly inhibit recipient lymphocyte proliferation. Based on the evidence that TSP1-CD47 signaling blockade with CD47mAb could alleviate acute rejection by reducing the extent of IRI after liver transplantation indirectly, this study provided a basis for new interventions and management methods to support better transplant outcomes.

Decreased serum levels of thrombospondin-1 in female depressed patients

Aim

Thrombospondin‐1 (TSP‐1) is an astrocyte‐derived synaptogenesis‐related factor. It was previously reported to be increased by chronic treatment of electroconvulsive seizure, a model of electroconvulsive therapy (ECT), in rat hippocampus. The aim of this study was to examine whether serum levels of TSP‐1 are associated with depression and ECT.

Methods

Serum TSP‐1 levels of major depressive disorder (MDD) patients (n = 36) and age‐ and gender‐matched healthy controls (n = 36) were measured by TSP‐1 ELISA. MDD patients were diagnosed according to the Diagnostics and Statistical Manual of Mental Disorders‐IV‐TR and underwent ECT. MDD patients were also analyzed for serum TSP‐1 levels pre‐ and post‐ECT. Evaluation of symptoms was obtained using the Hamilton Rating Scale for Depression.

Results

Serum TSP‐1 levels showed significant decreases specific to female MDD patients. However, TSP‐1 did not change pre‐ and post‐ECT, did not correlate with symptoms, nor was not affected by the dose of antidepressants.

Conclusion

Serum TSP‐1 is a possible female‐specific factor that reflects depressive trait, but not state.

The aim of this study was to examine whether serum levels of TSP‐1 are associated with depression and ECT. As a result, serum TSP‐1 levels showed significant decreases specific to female depressed patients. However, TSP‐1 did not change pre‐ and post‐ECT. In conclusion, serum TSP‐1 is a possible female‐specific factor that reflects depressive trait, but not state.

Metabolomic Analysis Reveals Unique Biochemical Signatures Associated with Protection from Radiation Induced Lung Injury by Lack of cd47 Receptor Gene Expression

The goal of this study was to interrogate biochemical profiles manifested in mouse lung tissue originating from wild type (WT) and cd47 null mice with the aim of revealing the in vivo role of CD47 in the metabolic response to ionizing radiation, especially changes related to the known association of CD47 deficiency with increased tissue viability and survival. For this objective, we performed global metabolomic analysis in mouse lung tissue collected from (C57Bl/6 background) WT and cd47 null mice with and without exposure to 7.6 Gy whole body radiation. Principal component analysis and hierarchical clustering revealed a consistent separation between genotypes following radiation exposure. Random forest analysis also revealed a unique biochemical signature in WT and cd47 null mice following treatment. Our data show that cd47 null irradiated lung tissue activates a unique set of metabolic pathways that facilitate the handling of reactive oxygen species, lipid metabolism, nucleotide metabolism and nutrient metabolites which may be regulated by microbial processing. Given that cd47 has pleiotropic effects on responses to ionizing radiation, we not only propose this receptor as a therapeutic target but postulate that the biomarkers regulated in this study associated with radioprotection are potential mitigators of radiation-associated pathologies, including the onset of pulmonary disease.