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The protozoan parasite, Trypanosoma cruzi, causes severe morbidity and mortality in afflicted individuals. Approximately 30% of T. cruzi infected individuals present with cardiac pathology. The invasive forms of the parasite are carried in the vascular system to infect other cells of the body. During transportation, the molecular mechanisms by which the parasite signals and interact with host endothelial cells (EC) especially heart endothelium is currently unknown. The parasite increases host thrombospondin-1 (TSP1) expression and activates the Wnt/β-catenin and hippo signaling pathways during the early phase of infection. The links between TSP1 and activation of the signaling pathways and their impact on parasite infectivity during the early phase of infection remain unknown. To elucidate the significance of TSP1 function in YAP/β-catenin colocalization and how they impact parasite infectivity during the early phase of infection, we challenged mouse heart endothelial cells (MHEC) from wild type (WT) and TSP1 knockout mice with T. cruzi and evaluated Wnt signaling, YAP/β-catenin crosstalk, and how they affect parasite infection. We found that in the absence of TSP1, the parasite induced the expression of Wnt-5a to a maximum at 2 h (1.73±0.13), P< 0.001 and enhanced the level of phosphorylated glycogen synthase kinase 3β at the same time point (2.99±0.24), P<0.001. In WT MHEC, the levels of Wnt-5a were toned down and the level of p-GSK-3β was lowest at 2 h (0.47±0.06), P< 0.01 compared to uninfected control. This was accompanied by a continuous significant increase in the nuclear colocalization of β-catenin/YAP in TSP1 KO MHEC with a maximum Pearson correlation coefficient of (0.67±0.02), P< 0.05 at 6 h. In WT MHEC, the nuclear colocalization of β-catenin/YAP remained steady and showed a reduction at 6 h (0.29±0.007), P< 0.05. These results indicate that TSP1 plays an important role in regulating β-catenin/YAP colocalization during the early phase of T. cruzi infection. Importantly, dysregulation of this crosstalk by pre-incubation of WT MHEC with a β-catenin inhibitor, endo-IWR 1, dramatically reduced the level of infection of WT MHEC. Parasite infectivity of inhibitor treated WT MHEC was similar to the level of infection of TSP1 KO MHEC. These results indicate that the β-catenin pathway induced by the parasite and regulated by TSP1 during the early phase of T. cruzi infection is an important potential therapeutic target, which can be explored for the prophylactic prevention of T. cruzi infection. Author summary: Trypanosoma cruzi, the causative agent of Chagas disease, is now considered a global health threat in all industrialized regions of the world. About 30% of infected individuals will develop cardiac pathology. The molecular mechanisms by which the parasite signals and infect host cells to cause pathology remain to be elucidated. We showed that host thrombospondin-1 (TSP1) is essential for T. cruzi infection since cells deficient in TSP1 are poorly infected by the parasite. In this study, we challenged mouse heart endothelial cells from wild type and TSP1 KO mice and evaluated the importance of TSP1 in Wnt/β-catenin signaling, β-catenin/YAP colocalization and how it can be exploited to regulate parasite infectivity. The parasite activated Wnt/β-catenin signaling pathway and nuclear β-catenin/YAP colocalization. In TSP1 KO MHEC (absence of TSP1), the parasite induced a continuous increase in nuclear translocation and colocalization of β-catenin/YAP. These results suggest that during the early phase of T. cruzi infection, TSP1 regulates β-catenin/YAP interaction. Inhibition of the Wnt/β-catenin pathway in WT MHEC led to a significant reduction of parasite infectivity. The level of parasite infection of the pretreated WT cells was as low as that of TSP1 KO MHEC. Our studies show that the β-catenin pathway is an important therapeutic target for T. cruzi infection. [ABSTRACT FROM AUTHOR]

Acquired thrombocytopenic thrombotic purpura (aTTP) is an autoantibody-mediated disease against the enzyme A Disintegrin and Metalloprotease domain with ThromboSpondin-1 type motif 13, which until now has been treated with plasma exchange (PEX) and corticosteroids. A 29-year-old female patient, who presented with aTTP in the context of pregnancy, has developed multiple relapses after treatment with PEX, corticosteroids, and rituximab. Recently, caplacizumab, a nanobody against von Willebrand factor, has been approved for the treatment of aTTP. In our patient, caplacizumab achieved better disease control, with a lower platelet count restoration time, days of PEX and hospitalization duration, as compared to standard therapy, reproducing the results of clinical trials. Caplacizumab represents a significant advance in the treatment of aTTP, especially in cases of recurrent relapses. [ABSTRACT FROM AUTHOR]

Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death in women worldwide. Recent advances in the field of immuno-oncology demonstrate the beneficial immunostimulatory effects of the induction of immunogenic cell death (ICD). ICD increases tumor infiltration by T cells and is associated with improved prognosis in patients affected by triple negative breast cancer (TNBC) with residual disease. The aim of this study was to evaluate the antitumoral effect of PKHB1, a thrombospondin-1 peptide mimic, against breast cancer cells, and the immunogenicity of the cell death induced by PKHB1 in vitro, ex vivo, and in vivo. Our results showed that PKHB1 induces mitochondrial alterations, ROS production, intracellular Ca2+ accumulation, as well calciumdependent cell death in breast cancer cells, including triple negative subtypes. PKHB1 has antitumor effect in vivo leading to a reduction of tumor volume and weight and promotes intratumoral CD8 + T cell infiltration. Furthermore, in vitro, PKHB1 induces calreticulin (CALR), HSP70, and HSP90 exposure and release of ATP and HMGB1. Additionally, the killed cells obtained after treatment with PKHB1 (PKHB1-KC) induced dendritic cell maturation, and T cell antitumor responses, ex vivo. Moreover, PKHB1-KC in vivo were able to induce an antitumor response against breast cancer cells in a prophylactic application, whereas in a therapeutic setting, PKHB1-KC induced tumor regression; both applications induced a long-term antitumor response. Altogether our data shows that PKHB1, a thrombospondin-1 peptide mimic, has in vivo antitumor effect and induce immune system activation through immunogenic cell death induction in breast cancer cells. [ABSTRACT FROM AUTHOR]

CD47 has established roles in the immune system for regulating macrophage phagocytosis and lymphocyte activation, with growing evidence of its cell-intrinsic regulatory roles in natural killer and CD8+ T cells. CD47 limits antigen-dependent cytotoxic activities of human and murine CD8+ T cells, but its role in T cell activation kinetics remains unclear. Using in vitro and in vivo models, we show here that CD47 differentially regulates CD8+ T cell responses to short-versus long-term activation. Although CD47 was not required for T cell development in mice and early activation in vitro, short-term stimuli elevated pathogen-reactive gene expression and enhanced proliferation and the effector phenotypes of Cd47-deficient relative to Cd47-sufficient CD8+ T cells. In contrast, persistent TCR stimulation limited the effector phenotypes of Cd47-/- CD8+ T cells and enhanced their apoptosis signature. CD8+ T cell expansion and activation in vivo induced by acute lymphocytic choriomeningitis virus (LCMV) infection did not differ in the absence of CD47. However, the frequency and effector phenotypes of Cd47-/- CD8+ T cells were constrained in chronic LCMV-infected as well as in mice bearing B16 melanoma tumors. Therefore, CD47 regulates CD8+ T cell activation, proliferation, and fitness in a context-dependent manner. [ABSTRACT FROM AUTHOR]

Primary open-angle glaucoma (POAG) is a complex heterogeneous disease. While several POAG genes have been identified, a high proportion of estimated heritability remains unexplained. Elevated intraocular pressure (IOP) is a leading POAG risk factor and dysfunctional extracellular matrix (ECM) in the trabecular meshwork (TM) contributes to elevated IOP. In this study, we sought to identify missense variants in ECM genes that correlate with ocular hypertensive POAG. Whole-genome sequencing was used to identify genetic variants in five members of a large POAG family (n = 68) with elevated IOP. The remaining family members were screened by Sanger sequencing. Unrelated normal (NTM) and glaucomatous (GTM) cells were sequenced for the identified variants. The ECM protein levels were determined by Western immunoblotting and confocal and electron microscopy investigated ECM ultrastructural organization. Three ECM gene variants were significantly associated with POAG or elevated IOP in a large POAG pedigree. These included rs2228262 (N700S; thrombospondin-1 (THBS1, TSP1)), rs112913396 (D563 G; collagen type VI, alpha 3 (COL6A3)) and rs34759087 (E987K; laminin subunit beta 2 (LAMB2)). Screening of unrelated TM cells (n = 27) showed higher prevalence of the THBS1 variant but not the LAMB2 variant, in GTM cells (39%) than NTM cells (11%). The rare COL6A3 variant was not detected. TSP1 protein was upregulated and COL6A3 was down-regulated in TM cells with N700S subject to mechanical stretch, an in vitro method that mimics elevated IOP. Immunofluorescence showed increased TSP1 immunostaining in cell strains with N700S compared to wild-type TM cells. Ultrastructural studies showed ECM disorganization and altered collagen type VI distribution in GTM versus NTM cells. Our results suggest that missense variants in ECM genes may not cause catastrophic changes to the TM, but over many years, subtle changes in ECM may accumulate and cause structural disorganization of the outflow resistance leading to elevated IOP in POAG patients. [ABSTRACT FROM AUTHOR]

Tumor vasculature is structurally abnormal, with anatomical deformities, reduced pericyte coverage and low tissue perfusion. As a result of this vascular dysfunction, tumors are often hypoxic, which is associated with an aggressive tumor phenotype, and reduced delivery of therapeutic compounds to the tumor. We have previously shown that a peptide containing the thrombospondin-1 type I repeats (3TSR) specifically targets tumor vessels and induces vascular normalization in a mouse model of epithelial ovarian cancer (EOC). However, due to its small size, 3TSR is rapidly cleared from circulation. We now introduce a novel construct with the 3TSR peptide fused to the C-terminus of each of the two heavy chains of the Fc region of human IgG1 (Fc3TSR). We hypothesize that Fc3TSR will have greater anti-tumor activity in vitro and in vivo compared to the native compound. Fc3TSR was evaluated in vitro using proliferation and apoptosis assays to investigate differences in efficacy compared to native 3TSR. In light of the multivalency of Fc3TSR, we also investigate whether it induces greater clustering of its functional receptor, CD36. We also compare the compounds in vivo using an orthotopic, syngeneic mouse model of advanced stage EOC. The impact of the two compounds on changes to tumor vasculature morphology was also investigated. Fc3TSR significantly decreased the viability and proliferative potential of EOC cells and endothelial cells in vitro compared to native 3TSR. High-resolution imaging followed by image correlation spectroscopy demonstrated enhanced clustering of the CD36 receptor in cells treated with Fc3TSR. This was associated with enhanced downstream signaling and greater in vitro and in vivo cellular responses. Fc3TSR induced greater vascular normalization and disease regression compared to native 3TSR in an orthotopic, syngeneic mouse model of advanced stage ovarian cancer. The development of Fc3TSR which is greater in size, stable in circulation and enhances receptor activation compared to 3TSR, facilitates its translational potential as a therapy in the treatment of metastatic advanced stage ovarian cancer. • Addition of a Fc IgG generates a construct with a ½ life of approximately 8 days in serum. • Fc3TSR has significantly enhanced anti-tumor activity in vitro , compared to native 3TSR. • Fc-induced clustering of the CD36 receptor mediates the enhanced efficacy of Fc3TSR. • Fc3TSR normalizes ovarian tumor vasculature. • Fc3TSR induces potent regression of advanced stage epithelial ovarian cancer in an orthotopic, syngeneic mouse model. [ABSTRACT FROM AUTHOR]

We hypothesized that carbon monoxide (CO) establishes an inflammatory cycle mediated by microparticles (MPs). Mice exposed to a CO protocol (1000 ​ppm for 40 ​min and then 3000 ​ppm for 20 ​min) that causes neuroinflammation exhibit NF-κB activation in astrocytes leading to generation of MPs expressing thrombospondin-1(TSP-1) that collect in deep cervical lymph nodes draining the brain glymphatic system. TSP-1 bearing MPs gain access to the blood stream where they activate neutrophils to generate a new family of MPs, and also stimulate endothelial cells as documented by leakage of intravenous 2000 ​kDa dextran. At the brain microvasculature, neutrophil and MPs sequestration, and myeloperoxidase activity result in elevations of the p65 subunit of NF-κB, serine 536 phosphorylated p65, CD36, and loss of astrocyte aquaporin-4 that persist for at least 7 days. Knock-out mice lacking the CD36 membrane receptor are resistant to all CO inflammatory changes. Events triggered by CO are recapitulated in naïve wild type mice injected with cervical node MPs from CO-exposed mice, but not control mice. All MPs-mediated events are inhibited with a NF-κB inhibitor, a myeloperoxidase inhibitor, or anti-TSP-1 antibodies. We conclude that astrocyte-derived MPs expressing TSP-1 establish a feed-forward neuroinflammatory cycle involving endothelial CD36-to-astrocyte NF-κB crosstalk. As there is currently no treatment for CO-induced neurological sequelae, these findings pose several possible sites for therapeutic interventions.

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. [ABSTRACT FROM AUTHOR]

Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disease in reproductive women, and the endocrine levels are also affected by diseases. The aim of this study was to determine the effect of thrombospondin-1 (TSP-1) on PCOS rat model. We established the PCOS rat model, the serum hormones including TSP-1 expression were determined and morphological characteristics were investigated to evaluate the model. These above endocrine and morphological features were investigated again to evaluate the effect of TSP-1 treatment. In the PCOS model group, the serum hormones change (higher luteinizing hormone, testosterone and estrogen) and decreased TSP-1 expression levels were found compared with the control group. Besides, the morphological characteristics of PCOS were also observed in the model group. After TSP-1 treatment, the higher TSP-1, ANGPT2, PDGFB and PDGFD expression levels, the lower LH and T levels, decreased vessel density as well as VEGFA and ANGPT1 expression levels were found compared with the control group, and the ovary morphological changes were also observed in the TSP-1 experimental group. TSP-1 delivery system might be an alternative therapy for PCOS treatment. [ABSTRACT FROM AUTHOR]

Objectives: Atrial remodeling is the main developmental cause of atrial arrhythmias (AA), which may induce atrial fibrillation, atrial flutter, atrial tachycardia, and frequent premature atrial beats in acute myocardial infarction (AMI) patients. Thrombospondin-1 (TSP-1) has been shown to play an important role in inflammatory and fibrotic processes, but its role in atrial arrhythmias is not well described. The purpose of this study was to investigate the role of TSP-1 in AMI patients with atrial arrhythmias.Methods: A total of 219 patients with AMI who underwent percutaneous coronary intervention and with no previous arrhythmias were included. TSP-1 were analyzed in plasma samples. Patients were classified into 2 groups, namely, with and without AA during the acute phase of MI. Continuous electrocardiographic monitoring was used for AA diagnosis in hospital.Results: Twenty-four patients developed AA. Patients with AA had higher TSP-1 levels (29.01 ± 25.87 μg/mL vs 18.36 ± 10.89 μg/mL, p < 0.001) than those without AA. AA patients also tended to be elderly (65.25 ± 9.98 years vs 57.47 ± 10.78 years, p < 0.001), had higher Hs-CRP (39.74 ± 43.50 mg/L vs 12.22 ± 19.25 mg/L, p < 0.001) and worse heart function. TSP-1 (OR 1.033; 95% CI 1.003-1.065, p = 0.034), Hs-CRP (OR 1.023; 95% CI 1.006-1.041, p = 0.008), age (OR 1.067; 95% CI 1.004-1.135, p = 0.038) and LVDd (OR 1.142; 95% CI 1.018-1.282, p = 0.024) emerged as independent risk factors for AA in AMI patients.Conclusion: TSP-1 is a potential novel indicator of atrial arrhythmias during AMI. [ABSTRACT FROM AUTHOR]

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 (MEXsLPS) 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 MEXsLPS were suppressed. Therefore, these findings uncovered TSP-1 as the principal factor in MEXsLPS pro-inflammatory regulation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose: Conjunctival squamous cell carcinoma (SCC) is primarily treated with surgical resection. SCC has various stages, and local recurrence is common. The purpose of this study was to investigate thrombospondin-1 expression and its association with prognosis. Methods: In this retrospective study, a gene expression array along with immunohistochemistry were performed for the evaluation of thrombospondin-1 expression, localization, as well as Ki67 labeling cell indices in carcinoma in situ (Tis) and advanced conjunctival SCC (Tadv). The presence or absence and intensity of cytoplasmic and nuclear staining in tumor cells were also divided into groups with a score of 0–3 and semi-quantitatively analyzed to investigate intracellular staining patterns. The association between thrombospondin-1 expression and tumor progression in a series of 31 conjunctival SCCs was further investigated. Results: All 31 patients in the cohort (100%) were East Asian. A simple comparison between Tis and Tadv demonstrated significant differences in expressions of 45 genes, including thrombospondin-1 (p < 0.01). In this cohort, 30/31 tumors were positive (96%) for thrombospondin-1. Furthermore, thrombospondin-1 intracellular staining pattern analysis scores were 2.12 and 0.96 for nuclear and cytoplasmic staining, respectively, with a significant difference observed between Tis and Tadv (p < 0.01). Alteration of the Ki67 labeling index was significantly correlated with that of the thrombospondin-1 cytoplasmic score (p = 0.030). Furthermore, univariate Cox regression analysis showed a significant correlation between thrombospondin-1 staining and progression-free survival (p = 0.026) and final orbital exenteration (p = 0.019). Conclusions: The present results demonstrated that thrombospondin-1 is a potential molecular target in the pathology of conjunctival SCC, in addition to serving as a prognostic factor. [ABSTRACT FROM AUTHOR]

Abstract 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.

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.

Abstract Background Hepatocellular carcinoma (HCC) is the most frequent primary liver cancer associated with a high mortality. Long non-coding RNAs (lncRNAs) have recently emerged as regulators in the development and progression of several cancers, and therefore represent an opportunity to uncover new targets for therapy. In the present study, we aimed to investigate the potential effect of lncRNA BZRAP1-AS1 on the angiogenesis of HCC. Methods Microarray-based data analysis was initially employed to screen genes and lncRNAs that are differentially expressed in HCC and the candidate BZRAP1-AS1 was identified as a hit. The expression of BZRAP1-AS1 and thrombospondin-1 (THBS1) in HCC tissues and cells were then determined using RT-qPCR. The gene methylation level was measured by methylation-specific PCR (MSP) and bisulfite sequencing PCR (BSP) assays. Next, the interactions between BZRAP1-AS1, DNA methyltransferase 3B (DNMT3b), and THBS1 were assessed by RIP, RNA pull-down and ChIP assays. Finally, the roles of BZRAP1-AS1, DNMT3b and THBS1 in angiogenesis in vitro as well as tumorigenesis in vivo were evaluated by a battery of the gain- and loss-of function experiments. Results BZRAP1-AS1 was identified as a highly expressed lncRNA in HCC tissues and cells. Down-regulation of BZRAP1-AS1 in HCC cells inhibited HUVEC proliferation, migration and angiogenesis. By interacting with DNMT3b, BZRAP1-AS1 induced methylation of the THBS1 promoter and inhibited the transcription of THBS1, resulting in promoted angiogenesis of HUVECs. Moreover, silencing of BZRAP1-AS1 repressed the angiogenesis as well as the tumor growth of HCC in vivo via up-regulating THBS1. Conclusion This study provides evidence that angiogenesis in HCC is hindered by silencing of BZRAP1-AS1. Thus, BZRAP1-AS1 may be a promising marker for the treatment of HCC.

PurposePolycystic ovary syndrome (PCOS) is a gynecological endocrine disorder that is characterized by disturbances in ovarian blood flow and angiogenesis. The aim of this study was to determine the association of vascular endothelial growth factor (VEGF) and thrombospondin-1 (TSP-1) serum levels with the body mass index (BMI) in patients with PCOS compared with healthy subjects.MethodsThe study was conducted with 80 subjects in 3 PCOS groups, including normal weight, overweight, and obese PCOS groups, and a control group of healthy subjects (n=20). The participants in all groups completed a questionnaire comprising sociodemographic and obstetric questions. The PCOS diagnosis in the study subjects was confirmed based on the Rotterdam criteria, BMI was determined according to the World Health Organization guidelines, and the lipid accumulation product index was calculated for all groups. Venous blood samples were collected from all participants after fasting to measure the serum levels of fasting blood glucose (FBG), lipids, insulin, VEGF, TSP-1, and leptin.ResultsOur findings showed that the serum VEGF level was significantly higher in the normal BMI PCOS group than that in the control group (P=0.03), and the TSP-1 level was significantly lower in the obese PCOS group than that in the control group (P=0.04).ConclusionsOur study demonstrated that alterations in VEGF and TSP-1 concentrations are dependent on BMI. Because abnormal ovarian angiogenesis is considered to be the main feature of PCOS, the study of ovarian angiogenic imbalance is proposed as a new tool for PCOS diagnosis and management.

• The abnormal morphological and functional properties of the tumor vasculature are a major hindrance to the distribution and efficacy of antineoplastic therapies. • This study describes the ability of a domain of the matricellular protein thrombospondin-1 (TSP-1) to remodel the tumor vasculature, restrain tumor growth, and boost drug delivery and efficacy. • These findings indicate a new role for TSP-1 in tumor vessel remodeling and open new perspectives for the development of TSP-1-based therapies. The disorganized and inefficient tumor vasculature is a major obstacle to the delivery and efficacy of antineoplastic treatments. Antiangiogenic agents can normalize the tumor vessels, improving vessel function and boosting the distribution and activity of chemotherapy. The type III repeats (T3R) domain of thrombospondin-1 contains different potential antiangiogenic sequences. We therefore hypothesized that it might affect the tumor vasculature. Ectopic expression of the T3R domain by the tumor cells or by the host, or administration of recombinant T3R, delayed the in vivo growth of experimental tumors. Tumors presented marked reorganization of the vasculature, with abundant but smaller vessels, associated with substantially less necrosis. Mechanistically, the use of truncated forms of the domain, containing different active sequences, pointed to the FGF2/FGFR/ERK axis as a target for T3R activity. Along with reduced necrosis, the expression of T3R promoted tumor distribution of chemotherapy (paclitaxel), with a higher drug concentration and more homogeneous distribution, as assessed by HPLC and MALDI imaging mass spectrometry. T3R-expressing tumors were more responsive to paclitaxel and cisplatin. This study shows that together with its known role as a canonical inhibitor of angiogenesis, thrombospondin-1 can also remodel tumor blood vessels, affecting the morphological and functional properties of the tumor vasculature. The ability of T3R to reduce tumor growth and improve the response to chemotherapy opens new perspectives for therapeutic strategies based on T3R to be used in combination therapies. [ABSTRACT FROM AUTHOR]

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, LPA1/3 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/LPA1/3 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. [ABSTRACT FROM AUTHOR]

Thrombospondin-1 (TSP1) is the prototypical member of a family of secreted proteins that modulate cell behavior by engaging with molecules in the extracellular matrix and with receptors on the cell surface. CD47 is widely displayed on many, if not all, cell types and is a high-affinity TSP1 receptor. CD47 is a marker of self that limits innate immune cell activities, a feature recently exploited to enhance cancer immunotherapy. Another major role for CD47 in health and disease is to mediate TSP1 signaling. TSP1 acting through CD47 contributes to mitochondrial, metabolic, and endocrine dysfunction. Studies in animal models found that elevated TSP1 expression, acting in part through CD47, causes mitochondrial and metabolic dysfunction. Clinical studies established that abnormal TSP1 expression positively correlates with obesity, fatty liver disease, and diabetes. The unabated increase in these conditions worldwide and the availability of CD47 targeting drugs justify a closer look into how TSP1 and CD47 disrupt metabolic balance and the potential for therapeutic intervention. [ABSTRACT FROM AUTHOR]

Post-surgery liver failure is a serious complication for patients after extended partial hepatectomies (ePHx). Previously, we demonstrated in the pig model that transplantation of mesenchymal stromal cells (MSC) improved circulatory maintenance and supported multi-organ functions after 70% liver resection. Mechanisms behind the beneficial MSC effects remained unknown. Here we performed 70% liver resection in pigs with and without MSC treatment, and animals were monitored for 24 h post surgery. Gene expression profiles were determined in the lung and liver. Bioinformatics analysis predicted organ-independent MSC targets, importantly a role for thrombospondin-1 linked to transforming growth factor-β (TGF-β) and downstream signaling towards providing epithelial plasticity and epithelial-mesenchymal transition (EMT). This prediction was supported histologically and mechanistically, the latter with primary hepatocyte cell cultures. MSC attenuated the surgery-induced increase of tissue damage, of thrombospondin-1 and TGF-β, as well as of epithelial plasticity in both the liver and lung. This suggests that MSC ameliorated surgery-induced hepatocellular stress and EMT, thus supporting epithelial integrity and facilitating regeneration. MSC-derived soluble factor(s) did not directly interfere with intracellular TGF-β signaling, but inhibited thrombospondin-1 secretion from thrombocytes and non-parenchymal liver cells, therewith obviously reducing the availability of active TGF-β. [ABSTRACT FROM AUTHOR]

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Adamts9 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 9) is one of a few metalloproteinases structurally conserved from C. elegans to humans and is indispensable in germ cell migration in invertebrates. However, adamts9′s roles in germ cell migration in vertebrates has not been examined. In the present study, we found zygotic expression of adamts9 started around the germ ring stage and reached peak levels at 3 days post fertilization (dpf) in zebrafish. The migration of primordial germ cells (PGC) was completed within 24 hours (h) in wildtype siblings, while a delay in PGC migration was found at 15 and 24-h post-fertilization (hpf) in the Adamts9 knockout (KO). However, the delayed PGC migration in Adamts9 KO disappeared at 48 hpf. Our study suggests a conserved function of Adamts9 in germ cell migration among invertebrates and vertebrates. In addition, our results also suggest that Adamts9 is not essential for germ cell migration as reported in C. elegans, possibly due to expansion of Adamts family members and compensatory roles from other metalloproteinases in vertebrates. Further studies are required in order to elucidate the functions and mechanisms of metalloproteinases in germ cell migration and gonad formation in vertebrates. [ABSTRACT FROM AUTHOR]

Thrombospondin (TSP) proteins have been shown to impact T-cell adhesion, migration, differentiation, and apoptosis. Thrombospondin-1 (TSP-1) is specifically upregulated in several inflammatory diseases and can effectively promote lipopolysaccharide- (LPS-) induced inflammation. In contrast, thrombospondin-2 (TSP-2) has been associated with activation of "anti-inflammatory" T-regulatory cells (Tregs). In this study, we investigated the effects of both TSP-1 and TSP-2 overexpression on macrophage polarization and activation in vitro and in vivo. We analyzed the effects of TSP-1 and TSP-2 on inflammation, vascular endothelial permeability, edema, ultrastructural morphology, and apoptosis in lung tissues of an ARDS mouse model and cultured macrophages. Our results demonstrated that TSP-2 overexpression effectively attenuated LPS-induced ARDS in vivo and promoted M2 macrophage phenotype polarization in vitro. Furthermore, TSP-2 played a role in regulating pulmonary vascular barrier leakage by activating the PI3K/Akt pathway. Overall, our findings indicate that TSP-2 can modulate inflammation and could therefore be a potential therapeutic target against LPS-induced ARDS. [ABSTRACT FROM AUTHOR]

Inappropriate endometrial stromal decidualization has been implied as an important reason of many pregnancy-related complications, such as unexplained recurrent spontaneous abortion, preeclampsia, and intrauterine growth restriction. Here, we observed that thrombospondin-1, an adhesive glycoprotein, was significantly downregulated in endometrial decidual cells from patients with unexplained recurrent spontaneous abortion. The immortalized human endometrial stromal cell line was used to investigate the possible THBS1-mediated regulation of decidualization. In vitro experiments found that the expression level of THBS1 increased with the normal decidualization process. Knockdown of THBS1 could decrease the expression levels of prolactin and insulin-like growth factor binding protein-1, two acknowledged human decidualization markers, whereas THBS1 overexpression could reverse these effects. The RNA sequencing results demonstrated that the extracellular regulated protein kinases signaling pathway was potentially affected by the knockdown of THBS1. We further confirmed that the regulation of THBS1 on decidualization was achieved through the ERK signaling pathway by the treatment of inhibitors. Moreover, knockdown of THBS1 in pregnant mice could impair decidualization and result in an increased fetus resorption rate. Altogether, our study demonstrated a crucial role of THBS1 in the pathophysiological process of unexplained recurrent spontaneous abortion and provided some new insights into the research of pregnancy-related complications., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

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

AIM: To evaluate whether the level of thrombospondin-1 (TSP-1) in aqueous humor can predict the prognosis of trabeculectomy in patients with primary angle-closure glaucoma (PACG). METHODS: This case-control study involved 26 patients with PACG who experienced a failed trabeculectomy (case group) and 78 age- and sex-matched patients with PACG who underwent successful trabeculectomy (control group). Aqueous humor was collected at the time of trabeculectomy and tested for TSP-1 and TGF-β2 levels with an enzyme-linked immunosorbent assay method. Logistic regression modeling was used to assess the risk factors for failed trabeculectomy. RESULTS: The mean TSP-1 aqueous concentrations were significantly higher in the case group (20.67±9.79 ng/mL) than the control group (5.17±2.29 ng/mL) (P

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

C1q/TNF-related protein 9 (CTRP9) is implicated in diverse cardiovascular diseases, but its role in viral myocarditis (VMC) is not well explored. This study is aimed at investigating the role and potential mechanism of CTRP9 in VMC. Herein, we found that the peripheral blood collected from children with VMC had lower CTRP9 levels than that from children who had recovered from VMC. H9c2 cardiomyocytes treated with coxsackievirus B3 (CVB3) were applied to establish a VMC model in vitro, and the expression of CTRP9 was significantly decreased in CVB3-induced H9c2 cells. The overexpression of CTRP9 attenuated CVB3-induced apoptosis, inflammation, and fibrosis reactions in H9c2 cells by promoting cell proliferation, reducing the cell apoptosis rate, and inhibiting inflammatory cytokine levels and fibrosis-related gene expression. Moreover, we found that thrombospondin 1 (THBS1) levels were increased in children with VMC, and CTRP9 negatively regulated THBS1 expression by interacting with THBS1. The downregulation of THBS1 inhibited CVB3-induced apoptosis, inflammation, and fibrosis in H9c2 cells. In addition, our mechanistic investigation indicated that the overexpression of THBS1 impaired the inhibitory effect of CTRP9 on CVB3-induced H9c2 cells. The results further revealed that the CVB3-induced NF-κB and TGF-β1/Smad2/3 signaling pathways of H9c2 cells were blocked by CTRP9 yet activated by THBS1. In conclusion, CTRP9 protected H9c2 cells from CVB3-induced injury via the NF-κB and TGF-β1/Smad2/3 signaling pathways by modulating THBS1. [ABSTRACT FROM AUTHOR]

T Cell Motility-How Is It Regulated? Lipoprotein receptor-related protein 1, thrombospondin-1, chemokine receptors, integrins, adhesion, motility. [Extracted from the article]

It is now admitted that in addition to acquired resistance, the tumor microenvironment contributes to the development of chemo-resistance and malignant progression. In a previous study, we showed that Dox induced apoptosis in FTC-133 cells by trigging JNK pathway. This process was accompanied by a decrease of thrombospondin-1 (TSP-1) expression. Moreover, exogenous TSP-1 or its C-terminal-derived peptide interact with receptor CD47 and are able to protect FTC-133 cells against Dox-induced apoptosis. Here, we investigated the involvement of TSP-1/CD47 interaction in a context of acquired multidrug resistance in FTC-133 cells. To that end, we established a Dox-resistant cell line (FTC-133R cells) which developed a resistance against Dox-induced apoptosis. Cell viability was evaluated by Uptiblue assay, nuclear Dox was measured by microspectrofluorimetry, caspase activity was measured by fluorescence of cleaved caspase-3 substrate, gene expression was evaluated by RT-PCR and protein expression was examined by western-blot. Our results showed that FTC-133R overexpressed the P-gp and were 15-fold resistant to Dox. JNK phosphorylation and Dox-induced apoptosis were reduced in FTC-133R cells. Expression of CD47 was increased in FTC-133R cells but TSP-1 expression presented similar levels in two cell lines. VPL restored Dox nuclear uptake and FTC-133R cell sensitivity to apoptosis and induced a decrease in CD47 mRNA expression. Moreover, knockdown of CD47 in FTC-133R cells induced an increase in JNK activation and sensitized FTC-133R cells to Dox. Our data suggest that CD47 is able to contribute to the protection of FTC-133R cells against Dox-induced apoptosis and/or to potentiate the acquired Dox resistance. [ABSTRACT FROM AUTHOR]

Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy that can have high mortality rates without prompt treatment. Standard treatment is urgent plasma exchange (PLEX), which leads to disease remission in the vast majority of patients. Deficiency of ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) alone is not sufficient to cause the clinical manifestations characteristic of TTP. We present a case of acquired TTP, where spontaneous recovery was observed prior to initiation of any TTP-specific therapy. A 73-year-old asymptomatic female presented with new-onset mild haemolytic anaemia and thrombocytopenia. Further testing revealed a significantly reduced ADAMTS13 activity level and an ADAMTS13 inhibitor, concerning for acquired TTP. On reassessment, the patient's haematologic parameters had been corrected prior to initiation of therapy. During subsequent follow-up three months later, she developed acute worsening thrombocytopenia indicative of relapsed, acute TTP. The patient was then successfully managed with PLEX and rituximab and achieved a sustained remission. TTP is a haematologic emergency that requires urgent therapy to reduce morbidity and mortality. However, it is well documented that individuals with hereditary TTP and a proportion with acquired TTP in clinical remission can have low or nearly absent ADAMTS13 activity levels without evidence of microangiopathic haemolytic anaemia (MAHA) or thrombotic manifestations. Our patient represents a unique case of confirmed ADAMTS13 deficiency due to a documented inhibitor, leading to mild haemolytic anaemia and thrombocytopenia both of which recovered spontaneously. We propose that this scenario could represent a 'subclinical' TTP state that precedes the development of clinically significant disease. [ABSTRACT FROM AUTHOR]

Nonsurgical bleeding is the most frequent complication of left ventricular assist device (LVAD) support. Supraphysiologic shear rates generated in LVAD causes impaired platelet aggregation, which increases the risk of bleeding. The effect of shear rate on the formation size of platelet aggregates has never been reported experimentally, although platelet aggregation size can be considered to be directly relevant to bleeding complications. Therefore, this study investigated the impact of shear rate and exposure time on the formation size of platelet aggregates, which is vital in predicting bleeding in patients with an LVAD. Human platelet‐poor plasma (containing von Willebrand factor, vWF) and fluorochrome‐labeled platelets were subjected to a range of shear rates (0‐10 000 s−1) for 0, 5, 10, and 15 minutes using a custom‐built blood‐shearing device. Formed sizes of platelet aggregates under a range of shear‐controlled environment were visualized and measured using microscopy. The loss of high molecular weight (HMW) vWF multimers was quantified using gel electrophoresis and immunoblotting. An inhibition study was also performed to investigate the reduction in platelet aggregation size and HMW vWF multimers caused by either mechanical shear or enzymatic (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13—ADAMTS13, the von Willebrand factor protease) mechanism under low and high shear conditions (360 and 10 000 s−1). We found that the average size of platelet aggregates formed under physiological shear rates of 360‐3000 s−1 (200‐300 μm2) was significantly larger compared to those sheared at >6000 s−1 (50‐100 μm2). Furthermore, HMW vWF multimers were reduced with increased shear rates. The inhibition study revealed that the reduction in platelet aggregation size and HWM vWF multimers were mainly associated with ADAMTS13. In conclusion, the threshold of shear rate must not exceed >6000 s−1 in order to maintain the optimal size of platelet aggregates to "plug off" the injury site and stop bleeding. [ABSTRACT FROM AUTHOR]

Membranous nephropathy (MN) is an immune complex mediated disease. Although limited to the kidney, in up to 20% of patients MN is associated with other autoimmune, infectious or malignant diseases. The initial pathogenetic event in what is still considered "primary" MN is the binding of circulating autoantibodies to proteins (autoantigens) expressed in glomerular podocytes. This antibody binding leads to the formation of immune complexes in the glomerular basement membrane. There is clinical and experimental evidence that these immune deposits lead to the activation of the complement system. Experimental studies in the MN model of Heymann's nephritis show that the terminal membrane attack complex (MAC) of the complement system induces a disturbance of the glomerular filtration barrier and leads to proteinuria, the clinical hallmark of MN. After the discovery of the phospholipase A 2 receptor 1 and thrombospondin type 1 domain containing protein 7A as endogenous antigens, it is assumed that IgG4 antibodies directed against these proteins induce MN in over 85% of patients with primary MN. As a result, the role of complement in the pathogenesis of MN needs to be defined in light of these developments. In this review we describe the current knowledge on the function of the complement system in primary MN and discuss the open questions, which have to be solved for a better understanding of the potential role of complement in the pathophysiology of primary MN. [ABSTRACT FROM AUTHOR]

Both neutrophil extracellular traps (NETs) and von Willebrand factor (VWF) are essential for thrombosis and inflammation. During these processes, a complex series of events, including endothelial activation, NET formation, VWF secretion, and blood cell adhesion, aggregation and activation, occurs in an ordered manner in the vasculature. The adhesive activity of VWF multimers is regulated by a specific metalloprotease ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motifs, member 13). Increasing evidence indicates that the interaction between NETs and VWF contributes to arterial and venous thrombosis as well as inflammation. Furthermore, contents released from activated neutrophils or NETs induce the reduction of ADAMTS13 activity, which may occur in both thrombotic microangiopathies (TMAs) and acute ischemic stroke (AIS). Recently, NET is considered as a driver of endothelial damage and immunothrombosis in COVID-19. In addition, the levels of VWF and ADAMTS13 can predict the mortality of COVID-19. In this review, we summarize the biological characteristics and interactions of NETs, VWF, and ADAMTS13, and discuss their roles in TMAs, AIS, and COVID-19. Targeting the NET-VWF axis may be a novel therapeutic strategy for inflammation-associated TMAs, AIS, and COVID-19. [ABSTRACT FROM AUTHOR]

• TGF-β signalling pathway in ovary controls the release of FSH by activin follistatin ratio. • In Kidney, TGF-β signalling pathway regulates apoptosis, cell growth and differentiation. • In PCOS, increased follistatin levels interferes with the TGF-β pathway. • In FSGS, the TGF-β pathway is upregulated through elevated TSP1 level. • The excess androgen produced in PCOS damages kidney podocytes leading to TSP1 hypersecretion. Research on polycystic ovarian syndrome (PCOS) remains intense due to its evolving impact on metabolism, reproduction and cardiovascular function. Changes in metabolic pathways can also significantly impact renal function including the development of Focal Segmental Glomerulosclerosis (FSGS), one of the most highly investigated renal diseases. In FSGS, scarring of the glomerulus vascular tuft damages the kidneys. Onset of FSGS may either be congenital or due to other disorders that affect the metabolism and normal kidney function. Both PCOS and FSGS appear to be associated with Transforming Growth Factor-β (TGF-β) signalling. Over-expression of TGF-β may be due to the activation of the thrombospondin 1 (TSP1) gene, which increases the probability of developing renal disorders. Higher androgen levels in PCOS may also cause podocyte damage thus directly impacting development of FSGS. This article reviews the role of TGF-β's in PCOS and FSGS and explores the inter-relationship between these two disorders. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Human adipose tissue derived mesenchymal stem cells (hAD-MSC S) with suppressive immunogenicity, homing to injury, inflammatory, and cancer sites can be suitable for gene therapy. PiggyBac (PB) is a type of transposon vector applied in mammalian systems and could overcome some limitations of other transposon and viral vectors. In this study, the therapeutic potential hAD-MSCs expressing thrombospondin-1 (TSP-1) is assessed through tail vein injection in C57BL/6 models bearing melanoma mice. Twenty days after injection, antiangiogenic effects and number of activated T. cells are assessed by Immunohistochemistry (IHC) method. Apoptosis value is analyzed by tunnel assay. Mice survival and numbers of nodules in mice lungs also are assessed. By western blotting, value of TSP-1, Bax and Bcl2 expression are assessed. The result revealed that hAD-MSCs. TSP-1 can inhibit angiogenesis and induce apoptosis and activated T. cells in a significant manner in C57BL/6 mice models bearing melanoma. Survival also significantly increased and number of nodules decreased, value of Bax and TSP-1 expression increased and value of Bcl2 expression decreased. In conclusion, our result showed that hAD-MSC. TSP-1 can be applied as an effective delivery vehicle in lung metastatic melanoma therapy. [ABSTRACT FROM AUTHOR]

Prolificacy of most local goat breeds in China is low. Jining Grey goat is one of the most prolific goat breeds in China, it is an important goat breed for the rural economy. ASMT (acetylserotonin O‐methyltransferase) and ADAMTS1 (ADAM metallopeptidase with thrombospondin type 1 motif) are essential for animal reproduction. Single nucleotide polymorphisms (SNPs) of ASMT and ADAMTS1 genes in the highly prolific breed (Jining Grey goats), medium prolific breed (Boer goats and Guizhou White goats) and low prolific breeds (Angora goats, Liaoning Cashmere goats and Inner Mongolia Cashmere goats) were detected by polymerase chain reaction‐restriction fragment length polymorphism and sequencing. Two SNPs (g.158122T>C, g.158700G>A) of ASMT gene and two SNPs (g.7979798A>G, g.7979477C>T) of ADAMTS1 gene were identified. For g.158122T>C of ASMT gene, further analysis revealed that genotype TC or CC had 0.66 (p < 0.05) or 0.75 (p < 0.05) kids more than those with genotype TT in Jining Grey goats. No significant difference (p > 0.05) was found in litter size between TC and CC genotypes. The SNP (g.158122T>C) caused a p.Tyr298His change and this SNP mutation resulted in changes in protein binding sites and macromolecule‐binding sites. The improvement in reproductive performance may be due to changes in the structure of ASMT protein. For g.7979477C>T of ADAMTS1 gene, Jining Grey does with genotype CT or TT had 0.82 (p < 0.05) or 0.86 (p < 0.05) more kids than those with genotype CC. No significant difference (p > 0.05) was found in litter size between CT or TT genotypes. These results preliminarily indicated that C allele (g.158122T>C) of ASMT gene and T allele (g.7979477C>T) of ADAMTS1 gene are potential molecular markers which could improve litter size of Jining Grey goats and be used in goat breeding. [ABSTRACT FROM AUTHOR]

Thrombospondin type I domain‐containing 7A (THSD7A), is a specific autoantigen of adult idiopathic membranous nephropathy (IMN), whose circulating antibody (THSD7A‐AB) represents a promising biomarker for diagnosis of IMN. The objective of this meta‐analysis is to investigate the diagnostic efficiency of THSD7A‐AB for IMN. After rigorous data extraction, quality assessment, and data analysis, 10 articles (4545 patients) are included. For IMN, the summary sensitivity is 4% (2–7%), and the specificity is 99% (98–100%). The summary positive likelihood ratio (PLR) and negative likelihood ratio (NLR) are 5.40 (2.40–11.90) and 0.97 (0.95–0.99), respectively. The diagnostic odds ratio (DOR) is 6.00 (2.00–12.00). The area under the summary receiver operating characteristic curve (AUC) is 0.78 (0.74–0.81). For M‐type phospholipase A2 receptor (PLA2R)‐negative IMN, the summary sensitivity is 8% (6–10%), specificity is 100% (99–100%). The summary PLR and NLR are 15.80 (5.70–44.00) and 0.93 (0.91–0.95), respectively. The DOR is 17.00 (6.00–48.00). The AUC is 0.99 (0.98–1.00). THSD7A‐AB has higher diagnostic value in PLA2R‐negative patients than in IMN patients. These results suggest that THSD7A‐AB could possibly be applied as an auxiliary non‐invasive diagnostic method for PLA2R‐negative IMN. [ABSTRACT FROM AUTHOR]

Aims Transforming growth factor-β (TGF-β) signalling is required for chronic hypoxia-induced pulmonary hypertension (PH). The activation of TGF-β by thrombospondin-1 (TSP-1) contributes to the pathogenesis of hypoxia-induced PH. However, neither the cellular source of pathologic TSP-1 nor the downstream signalling pathway that link activated TGF-β to PH have been determined. In this study, we hypothesized that circulating monocytes, which are recruited to become interstitial macrophages (IMs), are the major source of TSP-1 in hypoxia-exposed mice, and TSP-1 activates TGF-β with increased Rho-kinase signalling, causing vasoconstriction. Methods and results Flow cytometry revealed that a specific subset of IMs is the major source of pathologic TSP-1 in hypoxia. Intravenous depletion and parabiosis experiments demonstrated that these cells are circulating prior to recruitment into the interstitium. Rho-kinase-mediated vasoconstriction was a major downstream target of active TGF-β. Thbs1 deficient bone marrow (BM) protected against hypoxic-PH by blocking TGF-β activation and Rho-kinase-mediated vasoconstriction. Conclusion In hypoxia-challenged mice, BM derived and circulating monocytes are recruited to become IMs which express TSP-1, resulting in TGF-β activation and Rho-kinase-mediated vasoconstriction. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]