Objective The goal of this study is to investigate the role and mechanism of endoplasmic reticulum stress and apoptosis regulated by thrombospondin 1(TSP1)in human renal tubular epithelial cells(HK-2 cells).Methods HK...Objective The goal of this study is to investigate the role and mechanism of endoplasmic reticulum stress and apoptosis regulated by thrombospondin 1(TSP1)in human renal tubular epithelial cells(HK-2 cells).Methods HK-2 cells were exposed to high concentrations of glucose(HG).The endoplasmic reticulum stress inhibitor 4-phenylbutyric acid(4-PBA)was administered by transfecting TSP1 or an empty vector to explore the mechanism of the endoplasmic reticulum response regulated by TSP1 and stress in renal cell apoptosis.The effects of TSP1 and 4-PBA on the proliferation and apoptosis of HK-2 cells under HG conditions were assessed using Cell counting kit-8 and flow cytometry.Western blotting was used to detect the apoptosis-and endoplasmic reticulum stress-related protein expression regulated by TSP1 and 4-PBA.Results HG treatment induced high cell apoptosis,abundantly expressed TSP1 level and restrained viability in HK-2 cells.Overexpression of TSP1 significantly inhibited the proliferation of and facilitated apoptosis of HK-2 cells under HG conditions.Administration of endoplasmic reticulum stress inhibitor 4-PBA after overexpression of TSP1 antagonized the inhibitory proliferation and promoted apoptosis rate in HG-triggered HK-2 cells induced by TSP1 overexpression.4-PBA treatment significantly hindered the expression of endoplasmic reticulum stress markers,such as PERK,ATF4,ATF6,p-eIF2α,IRE1,CHOP and XBP1,suggesting that the administration of 4-PBA was successful.Conclusion Overexpression of TSP1 activated endoplasmic reticulum stress by regulating the ATF6-CHOP axis.TSP1 restrained cell proliferation,and promoted apoptosis and endoplasmic reticulum stress by activating the ATF6-CHOP axis.展开更多
AIM: To evaluate the efficacy of the improvedthrombospondin mimetic peptide ABT-898 in a murine model of ulcerative colitis. METHODS: The dextran sodium sulfate(DSS) was used for the induction of colitis in both TSP-1...AIM: To evaluate the efficacy of the improvedthrombospondin mimetic peptide ABT-898 in a murine model of ulcerative colitis. METHODS: The dextran sodium sulfate(DSS) was used for the induction of colitis in both TSP-1 deficient(TSP-1-/-) and wild type(WT) mice during 7 d. While mice were receiving the DSS dissolved in the drinking water, the ABT-898 peptide was dissolved in sterile 5% glucose solution and delivered using mini pumps subcutaneously implanted. Plasma samples were analyzed for interleukin(IL)-6 by ELISA assay and colonic tissues were harvested, fixed and processed for histological evaluation. Immunohistochemistry using antibodies for the detection of CD31 and MECA in endothelial cells was performed. Inflammation was graded in colonic sections and the number of microvessels in each lesion was assessed. Activation of signal transducer and activator of transcription 3(STAT3) in colonic samples was quantified by immunohistochemistry and Western blotting using antibodies against total STAT3 and phosphorylated STAT3(p STAT3)(Ser727).RESULTS: Treatment with ABT-898 considerably diminished the inflammatory response in WT and TSP-1-/- mice(P < 0.0001 in both groups vs control). Identification of blood vessels highlighted by CD31/MECA immunohistochemistry, showed significantly reduced vessel counts in colitic lesions of WT and TSP-1-/- mice treated with ABT898(TSP-1-/- controls/TSP-1-/- treated, P = 0.0002; WT controls/WT treated, P = 0.0005). Consistently, IL-6 was significantly diminished in plasma samples of TSP-1-/- and WT treated with the peptide when compared to the control mice(P = 0.0002 and P = 0.0148, respectively). p STAT3 positive cells were quantified in WT and TSP-1-/- treated with ABT-898. A significant decrease in positive cells for p STAT3 was observed in treated mice(TSP-1-/- controls/TSP-1-/- treated, P = 0.0089; WT/WT treated, P = 0.0110). These results were confirmedby Western blotting analyses showing lower levels of p STAT3 in colitic lesions from mice treated with the peptide ABT-898.CONCLUSION: These findings indicate that the new peptide ABT-898 ameliorates inflammation and angiogenesis and might be a therapeutic alternative in IBD and inflammatory diseases.展开更多
Here, we review research on the mechanisms underlying the ability of thrombospondin to promote synaptogenesis and examine its role in central nervous system diseases and drug actions. Thrombospondin secreted by glial ...Here, we review research on the mechanisms underlying the ability of thrombospondin to promote synaptogenesis and examine its role in central nervous system diseases and drug actions. Thrombospondin secreted by glial cells plays a critical role in synaptogenesis and maintains synapse stability. Thrombospondin regulates synaptogenesis through receptor a26-1 and neuroligin 1, and promotes the proliferation and differentiation of neural progenitor cells. It also participates in synaptic remodeling following injury and in the action of some nervous system drugs.展开更多
BACKGROUND Osteoarthritis(OA),a chronic age-related disease characterized by the slowly progressive destruction of articular cartilage,is one of the leading causes of disability.As a new strategy for treatment of OA,m...BACKGROUND Osteoarthritis(OA),a chronic age-related disease characterized by the slowly progressive destruction of articular cartilage,is one of the leading causes of disability.As a new strategy for treatment of OA,mesenchymal stem cells(MSCs)have the potential for articular cartilage regeneration.Meanwhile,thrombospondin 2(TSP2)promotes the chondrogenic differentiation of MSCs.AIM To investigate whether TSP2 induces chondrogenic differentiation of human adipose-derived MSCs(hADMSCs)and potentiates the therapeutic effects of hADMSCs in OA rabbits.METHODS We investigated the chondrogenic potential of TSP2 in hADMSCs by analyzing the expression of chondrogenic markers as well as NOTCH signaling genes in normal and TSP2 small interfering RNA(siRNA)-treated stem cells.Anterior cruciate ligament transection surgery was performed in male New Zealand white rabbits,and 8 wk later,hADMSCs(1.7×10^6 or 1.7×10^7 cells)were injected into the injured knees alone or in combination with intra-articular injection of TSP2(100 ng/knee)at 2-d intervals.OA progression was monitored by gross,radiological,and histological examinations.RESULTS In hADMSC culture,treatment with TSP2 increased the expression of chondrogenic markers(SOX9 and collagen Ⅱ)as well as NOTCH signaling genes(JAGGED1 and NOTCH3),which were inhibited by TSP2 siRNA treatment.In vivo,OA rabbits treated with hADMSCs or TSP2 alone exhibited lower degree of cartilage degeneration,osteophyte formation,and extracellular matrix loss 8 wk after cell transplantation.Notably,such cartilage damage was further alleviated by the combination of hADMSCs and TSP2.In addition,synovial inflammatory cytokines,especially tumor-necrosis factor-α,markedly decreased following the combination treatment.CONCLUSION The results indicate that TSP2 enhances chondrogenic differentiation of hADMSCs via JAGGED1/NOTCH3 signaling,and that combination therapy with hADMSCs and TSP2 exerts synergistic effects in the cartilage regeneration of OA joints.展开更多
In this study, a combination of growth factors was used to induce bone marrow mesenchymal stem cells differentiation into neuron-like cells, in a broader attempt to observe the role of thrombospondin 1 in synapse form...In this study, a combination of growth factors was used to induce bone marrow mesenchymal stem cells differentiation into neuron-like cells, in a broader attempt to observe the role of thrombospondin 1 in synapse formation. Results showed that there was no significant difference in the differentiation rate of neuron-like cells between bone marrow mesenchymal stem cells with thrombospondin induction and those without. However, the cell shape was more complex and the neurites were dendritic, with unipolar, bipolar or multipolar morphologies, after induction with thrombospondin 1. The induced cells were similar in morphology to normal neurites. Immunohistochemical staining showed that the number of positive cells for postsynaptic density protein 95 and synaptophysin 1 protein was significantly increased after induction with thrombospondin 1. These findings indicate that thrombospondin 1 promotes synapse formation in neuron-like cells that are differentiated from bone marrow mesenchymal stem cells.展开更多
The expression of angiopoietin- 1 （Ang- 1） and thrombospondin- 1 （TSP- 1） in 5/6 subtotal nephrectomy （STN） rats model, and its correlation to the renal microvasculature injury were investigated. Rat 5/6 STN mod...The expression of angiopoietin- 1 （Ang- 1） and thrombospondin- 1 （TSP- 1） in 5/6 subtotal nephrectomy （STN） rats model, and its correlation to the renal microvasculature injury were investigated. Rat 5/6 STN model was established in adult male SD rats, and the sham-operated group and 5/6 STN group were set up. The renal function and histopathological changes were examined at the 1st, 2nd, 4th, 8th and 12th week after operation. The expression orAng-1, TSP-1 and CD31 in renal tissues was detected by using immunohistochemistry. From 2nd to 8th week after operation, Ang-1 was significantly expressed in glomeruli of rats with STN. Ang-1 staining in glomeruli of STN group was increased significantly as compared with that in sham-operated group at 4th and 8th week after operation, and subsequently decreased after the 12th week. The expression of TSP-1 was increased significantly in STN group. As compared with sham-operated group, the CD31 expression was significantly down-regulated from the 2nd week. The expression of Ang-1 mRNA was detected by using RT-PCR at the same time points. The expression of Ang-1 mRNA in renal tissue of rats with STN was significantly up-regulated at the 2nd, 4th and 8th week after operation as compared with that in STN group at other time points or in sham-operated group at the same time points, while decreased evidently at the 12th week as compared with that in sham-operated group. It is concluded that there are changes in the mRNA expression of Ang-1, and the significant up-regulation of the expression of TSP-1 in renal tissue of rats with STN, which may be involved in the remnant renal microvasculature injury.展开更多
BACKGROUND Formation of intraperitoneal adhesions is one of the major complications after abdominal surgery, which may lead to bowel obstruction. Thrombospondin 1(TSP-1) is an extracellular matrix modulating glycoprot...BACKGROUND Formation of intraperitoneal adhesions is one of the major complications after abdominal surgery, which may lead to bowel obstruction. Thrombospondin 1(TSP-1) is an extracellular matrix modulating glycoprotein during tissue regeneration and collagen deposition.AIM To evaluated the therapeutic potential of overexpressed TSP-1 in suppressing pelvic adhesion formations in rat models.METHODS Pelvic adhesion was induced in anesthetized rats by laparotomy cecal abrasion.The animals were randomly assigned to treatment of local application with Seprafilm(an antiadhesive bioresorbable membrane) or adenoviral vectors encoding mouse TSP-1(AdTSP-1) on the surfaces of the injured cecum. The severity of the peritoneal adhesions was evaluated by blinded observers 14 d later.RESULTS Compared with control(no treatment) group, the application of Sperafilm significantly reduced the formation of adhesion band, and local administration of AdTSP-1 on the injured cecum the also attenuated the severity of peritoneal adhesion score. However, systemic delivery of AdTSP-1 did not affect the formation of adhesion.CONCLUSION We conclude that therapeutic approaches in inducing regional overexpression of TSP-1 may serve as alternative treatment strategies for preventing postoperative peritoneal adhesion.展开更多
Chronic heart failure（CHF）remains a leading cause of morbidity and mortality.In the current study,we aimed to evaluate the predictive value of circulating fhrombospondin-2（TSP-2）for cumulative survival in patients...Chronic heart failure（CHF）remains a leading cause of morbidity and mortality.In the current study,we aimed to evaluate the predictive value of circulating fhrombospondin-2（TSP-2）for cumulative survival in patients with ischemic CHF due to coronary artery disease（CAD）.The results showed that during a median follow-up of2.18 years,21 participants died and 106 subjects were hospitalized repeatedly.The median circulating levels of TSP-2 in patients who survived and those who died were 0.63 ng/mL（95%CI=0.55-0.64 ng/mL）and 1.03 ng/mL（95%CI=0.97-1.07 ng/mL）（P〈0.001）.Circulating TSP-2 independently predicted all-cause mortality（OR=1.27;95%CI=1.08-1.59;P=0.002）,CHF-related death（OR=1.16;95%CI=1.02-1.50;P〈0.001）,and also CHF-related rehospitalization（OR=1.12;95%CI=1.07-1.25;P〈0.001）.In conclusion,among CAD patients with symptomatic CHF,increased circulating TSP-2 is correlated with increased 3-year CHF-related death,all-cause mortality,and risk for recurrent hospitalization.展开更多
The redistribution of platelet membrane glycoprotein IV (GPIV) and the release of intracellular Q-granule thrombospondin (TSP) were examined and the inhibition of 5-thromboglobulin (&TG) and platelet factor 4 (PF4...The redistribution of platelet membrane glycoprotein IV (GPIV) and the release of intracellular Q-granule thrombospondin (TSP) were examined and the inhibition of 5-thromboglobulin (&TG) and platelet factor 4 (PF4) in patients with chronic myelogenous leukemia (CML) was observed and quantitation of β-TG and PF4 in sera was conducted. GPIV in inactive platelet from CML was 36080±17010 molecules/platelet as compared with 13190±4810 from the controls (P<0,01), No abnormality was found in the distribution of platelet membrane GPIb and GPIIb/III.(P>0. 05). The GPIV redistribution on active platelet membrane induced thrombin (1U/ml) from CML and healthy donors was 44320132310 and 228001 12700 molecules/platelet respectively (P<0. 01 ). The difference in the release of intracellular Q-granule TSP between CML and the control group was not found (P>0.05). There was no direct correlation between GPIV expression and TSP binding after platelet activation. The high leveIs of β-TG and PF4 in sera inhibited release of intracellular a-granule TSP in vitro. These results indicate that the abnormality of platelet membrane GPIV is a common marker in CML, therefore the specific increase of platelet GPIV in patients with CML may be a useful tool for the diagnosis and monitoring of the platelet dysfunction. The release of interna1 TSP pools is hindered by either β-TG or PF4 in sera.展开更多
Objective： The thrombospondin-4 （TSP-4） gene G29926C （A387P） polymorphism was recently reported to be associated with an increased risk of MI （myocardial infarction） in American population. However, several sub...Objective： The thrombospondin-4 （TSP-4） gene G29926C （A387P） polymorphism was recently reported to be associated with an increased risk of MI （myocardial infarction） in American population. However, several subsequent studies produced controversial findings. The aim of this study was to explore the possible association between TSP-4 A387P polymorphism and ACS （acute coronary syndrome） in Chinese Han population. Methods：A case-control study including 412 patients with ACS and 337 controls free from CAD （coronary artery disease） was conducted. TSP-4 A387P polymorphism was determined by PCR （polymerase chain reaction） and RFLP （restriction fragment length polymorphism） analysis. Results：Slightly decreased frequency of GC genotype was observed in patients with ACS, compared with controls（5.3% vs. 7.1%）, but the difference did not reach statistical significance （P = 0.31 ）. Similarly, the prevalence of C allele was 2.7% and 3.6% for ACS and control groups, respectively （P = 0.32）. None of homozygote was detected for C allele. Further analyses in subjects subgrouped according to sex and age also showed no association of TSP-4 A387P polymorphism with ACS. Furthermore, after adjustment for conventional risk factors by multiple logistic regression analysis, the carrier prevalence of C allele did not differ significantly between ACS and control groups （OR = 0.85; 95% CI：0.45-1.59; P = 0.60）. Conclusion：The present study suggested that the TSP-4 A387P variant showed a low prevalence compared with western populations and failed to associate with an altered risk of ACS in Chinese Han population. The findings further supplement experimental data for TSP-4 gene study of coronary disease.展开更多
Purpose: To investigate the expression of thrombospondin 1 (TSP-1) in retinal pigment epithelium (RPE) and choroidal neovascular membranes (CNVMs) from patients with age-related macular degeneration (AMD). Methods: Ti...Purpose: To investigate the expression of thrombospondin 1 (TSP-1) in retinal pigment epithelium (RPE) and choroidal neovascular membranes (CNVMs) from patients with age-related macular degeneration (AMD). Methods: Tissue sections from normal human fetal and adult eyes and surgically removed CNVMs were immunostained for TSP-1 localization. Polymerase chain reaction and Western blotting were used to analyze TSP-1 mRNA and protein from human RPE cells, respectively. TSP-1 in the supernatant of cultured RPE cells and eye explants were measured using enzyme-linked immunosorbent assay. MTT assay was used to evaluate the RPE survival after TSP-1 treatment. Results: The strongest immunostaining for TSP-1 was observed in the RPE monolayer around drusen in early AMD. The intensity of TSP-1 staining in normal eye sections was much weaker than that of early AMD and CNVM. TSP-1 mRNA was positive in cultured fetal and adult RPE cells. There was increasing secretion of TSP-1 into the supernatant of cultured RPE and eye explants. The specific band of TSP-1 was identified by Western blot. No significant inhibition of RPE survival was found with the exposure to TSP-1. Conclusions: TSP-1 expression in drusen and CNVM was upregulated and associated with RPE monolayer. TSP-1 may be a natural negative regulator for choroidal neovascularization.展开更多
Background: Thrombospondin-1</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">(TSP1) is associated with atherosclerosis in animals wi...Background: Thrombospondin-1</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">(TSP1) is associated with atherosclerosis in animals with diabetes mellitus (DM)</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">but the precise role of TSP-1 in human atherosclerosis remains unknown. Objectives: To investigate serum thrombospondin1 level in patients with coronary artery disease with and without type 2 DM and its relationship to coronary artery scoring systems. Methods: The study comprised 180 patients recruited from those underwent coronary angiography for suspected coronary artery disease (CAD) was approved by Institutional Review Board and Institutional Ethical Committee for Human Research of menoufia university hospital. They were divided according to presence of CAD and type 2 DM into 4 groups</span><span style="font-family:Verdana;">:</span><span style="font-family:Verdana;"> Group I (n = 44 patients): Non diabetic subjects without CAD, Group II (n = 40 patients): Diabetic patients without CAD, Group III (n = 49 patients): Non diabetic patients with CAD and Group IV (n = 47 patients): Diabetic patients with CAD. Serum level of TSP-1 was measured in all groups and coronary artery scoring analysis was done. Results: Serum TSP-1 levels were higher in patients with CAD and DM than in other groups (P</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;"><</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">0.01) while the levels of serum TSP-1 in diabetic patients without CAD and non-diabetic patients with CAD didn</span><span style="font-family:Verdana;">’</span><span style="font-family:Verdana;">t show significant difference. Plasma TSP-1 levels were higher in patients with DM than those in patients without DM (582.95 ± 55.70 ng/mL vs. 516.91 ± 64.56 ng/ml, </span><span style="font-family:Verdana;">P </span><span style="font-family:Verdana;"><</span><span style="font-size:10pt;font-family:""></span><span style="font-family:Verdana;">0.001). Plasma levels of TSP-1 were higher in patients with CAD than those in patients without CAD (569.54 ± 68.16 ng/mL vs. 525.17 ± 61.77 ng/ml, </span><span style="font-family:Verdana;">P </span><span style="font-family:Verdana;"><</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">0.001). Patients with CAD and DM (group IV) had significantly higher severity score and vessel score than those with CAD only (group III) (9.13 ± 3.40, 2.49 ± 0.69 vs. 7.37 ± 3.16, 2.02</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">0.80 ng/ml, </span><span style="font-family:Verdana;">P </span><span style="font-family:Verdana;"><</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">0.05). Patients with three vessel disease had the highest serum TSP-1 level (581.32 ± 61.30 ng/ml) when compared to patients with one or two vessel disease. The highest diagnostic performance of serum TSP-1 level in prediction of coronary artery disease was more pronounced in presence of DM while the least diagnostic performance of serum TSP-1 was detected in absence of DM. Univariate logistic regression analysis of different variables for prediction of CAD showed that TSP-1 level was one of the independent predictor</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> of CAD (OR 1.016, CI 1.010 </span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;"> 1.023, </span><span style="font-family:Verdana;">P</span><span style="font-family:Verdana;"> < 0.001). Conclusion: Serum TSP-1 level is higher in patients with CAD with and without type 2 DM and its level is an independent predictor of CAD, but the diagnostic performance of serum TSP-1 level in prediction of CAD is more pronounced in presence of type 2 DM.展开更多
Thrombospondin 1 and 2(TSP1 and TSP2)are critical regulators of extracellular matrix(ECM)interactions,influencing cell differentiation and tissue repair.Recent discoveries from our laboratory and others highlight the ...Thrombospondin 1 and 2(TSP1 and TSP2)are critical regulators of extracellular matrix(ECM)interactions,influencing cell differentiation and tissue repair.Recent discoveries from our laboratory and others highlight the importance of altered ECM alignment in influencing aberrant mesenchymal progenitor cell(MPC)differentiation and subsequent ectopic bone formation in trauma-induced heterotopic ossification(HO).However,the key regulators of this MPC to ECM interaction have yet to be elucidated.This study uncovers the role of matricellular TSP1 and TSP2 in MPC/ECM interaction as well as HO formation and progression.Using single-cell RNA sequencing,spatial transcriptomics,and in vivo models,we found that TSP1 is upregulated in tissue remodeling macrophages and MPCs at the injury site,while TSP2 is restricted to MPCs surrounding the HO anlagen.TSP1/2 double knockout(DKO)mice exhibited significantly reduced HO volume and disrupted ECM alignment.These findings highlight the crucial roles of TSP1 and TSP2 in musculoskeletal injury repair as well as HO formation and progression,supporting the potential to therapeutically target TSP1 and TSP2 to prevent HO.展开更多
Background Researchers have recently demonstrated that thrombospondin-1 （TSP-1） has an important function in regulating neovascularization. Whether it inhibits or accelerates neovascularization, however, is still co...Background Researchers have recently demonstrated that thrombospondin-1 （TSP-1） has an important function in regulating neovascularization. Whether it inhibits or accelerates neovascularization, however, is still controversial. We found few reports about the correlation between TSP-1 and vascularization in mucoepidermoid carcinoma. In this research, the distribution and expression of TSP-1 in mucoepidermoid carcinoma were investigated. We also analyzed （1） the correlation between the expression of TSP-1 and microvessel density （MVD）, as an indicator of neovascularization activity, and （2） the effect of TSP-1 on neovascularization and tumor growth in the subcutaneous xenotransplanted model of mucoepidermoid carcinoma. Method （1） The sites and intensity of expression of TSP-1 and the MVD were analyzed in 45 cases of mucoepidermoid carcinoma after surgery by the method of streptavidin-peroxidase （SP） immunohistochemistry; and （2） recombinant human thrombospondin-1 （rhTSP-1） was injected twice a week for five consecutive weeks around the tumor in the subcutaneous xenotransplanted tumor model of mucoepidermoid carcinoma in nude mice. Each week, the tumor size was measured, in order to draw the growth curve of the xenotransplanted tumor model of mucoepidermoid carcinoma, and MVD was measured. Results （1） The positive expression of TSP-1 protein was 57.78% （26/45）. Most positive staining for TSP-1 was found in the cytoplasm of the cancer cells, while some staining occurred in the extracellular matrix. The mean MVD in 45 cases of m ucoepidermoid carcinoma was 58.17±19.77 per 100 visual fields. Tumors with a high expression of TSP-1 showed a low MVD value, and the TSP-1 immunocompetence and microvessel density showed a significant negative correlation （rs=-0.947, P 〈0.001）. （2） The xenotransplanted tumors with the injection doses of 1.25, 0.75 and 0.25 ug/ml respectively were 36.97%, 53.36% and 73.61% of the size of the control group （（451±92）, （651±113）, （898±86） and （1220±157） mm^3 respectively, F=-53.167, P 〈0.001）, and their weights were respectively 35.14%, 51.35% and 70.27% of the control group （（1.3±0.5）, （1.9±0.5）, （2.6±0.3）, and （3.7±0.7） g respectively, F=-62.669, P 〈0.001）. Their MVDs were 25.00%, 45.93%, and 72.20% respectively of the control group and concentration dependent （15.43±3.45, 28.35±4.24, 44.57±3.35 and 61.73±5.43 per 100 visual fields respectively, F=54.582, P 〈0.001）. Conclusions The TSP-1 has a higher expression in mucoepidermoid carcinoma and the expression has a significant negative correlation with neovascularization. The TSP-1 inhibits neovascularization and tumor growth, and it might be a new biological therapy for treatment of patients with mucoepidermoid carcinoma.展开更多
Previously, we demonstrated that macrophages from thrombospondin 1 （TSP1）-deficient mice have a reduced inflammatory phenotype, suggesting that TSP1 plays a role in macrophage activation. In this study, we determine...Previously, we demonstrated that macrophages from thrombospondin 1 （TSP1）-deficient mice have a reduced inflammatory phenotype, suggesting that TSP1 plays a role in macrophage activation. In this study, we determined how TSP1 regulates macrophage function. We found that recombinant or purified piatelet human TSP1 treatment stimulated tumor-necrosis factor （TNF）-α expression in bone marrow-derived macrophages in a time- and dose-dependent manner. Toll-like receptor 4 （TLR4） expression （at the mRNA and protein levels） and nuclear factor-kappaB （NF-KB） activity were also stimulated by TSP1 treatment. The TSPl-mediated increase in TNF-a production was abolished in TLR4-deficient macrophages, suggesting that TSP1 activates macrophages through a TLR4-dependent pathway. TSP1 also stimulated TLR4 activation in macrophages in vivo. Furthermore, TSPl-mediated macrophage activation was attenuated by using a peptide or an antibody to block the association between TSP1 and CD36. Taken together, these data suggest that the stimulation of the macrophage TLR4 pathway by TSP1 is partially mediated by the interaction of TSP1 with its receptor, CD36.展开更多
Background Erythropoietin （EPO） functions as a tissue-protective cytokine in addition to its crucial hormonal role in red cell production and neuron protection. This study aimed to determine the neuron protective ef...Background Erythropoietin （EPO） functions as a tissue-protective cytokine in addition to its crucial hormonal role in red cell production and neuron protection. This study aimed to determine the neuron protective effect of erythropoietin on experimental rats enduring spinal cord injury （SCI） by assessing thrombospondin-1 （TSP-1） level and transforming growth factor-β （TGF-β） in the development of a rat model of SCI. Methods Sixty Sprague-Dawley rats were randomly assigned to three groups： sham operation control group, SCI group and EPO treatment group. By using a weight-drop contusion SCI model, the rats in the SCI group and EPO treatment group were sacrificed at 24 hours and 7 days subsequently. The Basso, Beattie, and Bresnahan （BBB） scores were examined for locomotor function. Pathological changes were observed after HE staining. The expressions of thrombospondin-2 （TSP-1） and TGF-β were determined by immunohistochemical staining and Western blotting. Results Slighter locomotor dysfunction was discovered and it was recovered abruptly as higher BBB scores were found in the EPO treatment group than in the SCI group （P 〈0.01）. Pathologically, progressive disruption of the dorsal white matter and regeneration of a few neurons were also observed in SCI rats. TSP-1 and TGF-β expression increased at 24 hours and 7 days after SCI in the injured segment, and it was higher in the SCI group than in the EPO treatment group. Spinal cord samples from the animals demonstrated a TSP-1 optical density of 112.2±6.8 and TSP-1 positive cells of 5.7±1.3 respectively. After injury, the TSP-1 optical density and cell number increased to 287.2±14.3/mm^2 and 23.2±2.6/mm^2 at 24 hours and to 232.1±13.2/mm^2 and 15.2±2.3/mm^2 at 7 days respectively. When EPO treated rats compared with the SCI rats, the TSP-1 optical density and cell number decreased to 213.1 ±11.6/mm^2 and 11.9±1.6/mm^2 at 24 hours and to 189.9±10.5/mm^2 and 9.3±1.5/mm^2 at 7 days, respectively （P 〈0.01）. In the SCI rats, the TGF-β optical density and positive neuron number were 291.4±15.2/mm^2 and 28.8±4.9/mm^2 at 24 hours and 259.1±12.3/mm^2 and 23.9±4.1/mm^2 at 7 days respectively. They decreased in the EPO treated rats to 222.8±11.9/mm^2 and 13.7±2.1/mm^2 at 24 hours and to 196.5±9.7/mm^2 and 8.7±2.2/mm^2 at 7 days （P 〈0.01）. Conclusions Increased expression of TSP-1 and TGF-β can be found in the injured segment of the spinal cord at 24 hours and 7 days after injury. EPO treatment can effectively prevent pathological alterations from severe spinal cord injury by reduced expression of TSP-1 and TGF-β.展开更多
Thrombospondins （TSPs） are a family of multidomain extracellular matrix glycoproteins, which consist offive members at present, TSP-1, -2, -3, -4 and TSP-5. TSP-1, which is synthesized and secreted by activated plat...Thrombospondins （TSPs） are a family of multidomain extracellular matrix glycoproteins, which consist offive members at present, TSP-1, -2, -3, -4 and TSP-5. TSP-1, which is synthesized and secreted by activated platelets and a variety of cell types including endothelial cells, macrophages, monotypes, fibroblasts, tumor cells and vascular smooth muscular cells, is the best characterized family member./ TSP-1 participates in a wide range of biological responses, including platelet activation and aggregation, vascular smooth muscular cell proliferation and migration, endothelial cell apoptosis and angiogenesis.l-3 TSP-1 may be involved in the pathogenesis of atherosclerosis and coronary artery disease （CAD）/myocardial infarction （MI）.4-7展开更多
基金This study was supported by a grant from Chinese Society of Nephrology(No.14050430580).
文摘Objective The goal of this study is to investigate the role and mechanism of endoplasmic reticulum stress and apoptosis regulated by thrombospondin 1(TSP1)in human renal tubular epithelial cells(HK-2 cells).Methods HK-2 cells were exposed to high concentrations of glucose(HG).The endoplasmic reticulum stress inhibitor 4-phenylbutyric acid(4-PBA)was administered by transfecting TSP1 or an empty vector to explore the mechanism of the endoplasmic reticulum response regulated by TSP1 and stress in renal cell apoptosis.The effects of TSP1 and 4-PBA on the proliferation and apoptosis of HK-2 cells under HG conditions were assessed using Cell counting kit-8 and flow cytometry.Western blotting was used to detect the apoptosis-and endoplasmic reticulum stress-related protein expression regulated by TSP1 and 4-PBA.Results HG treatment induced high cell apoptosis,abundantly expressed TSP1 level and restrained viability in HK-2 cells.Overexpression of TSP1 significantly inhibited the proliferation of and facilitated apoptosis of HK-2 cells under HG conditions.Administration of endoplasmic reticulum stress inhibitor 4-PBA after overexpression of TSP1 antagonized the inhibitory proliferation and promoted apoptosis rate in HG-triggered HK-2 cells induced by TSP1 overexpression.4-PBA treatment significantly hindered the expression of endoplasmic reticulum stress markers,such as PERK,ATF4,ATF6,p-eIF2α,IRE1,CHOP and XBP1,suggesting that the administration of 4-PBA was successful.Conclusion Overexpression of TSP1 activated endoplasmic reticulum stress by regulating the ATF6-CHOP axis.TSP1 restrained cell proliferation,and promoted apoptosis and endoplasmic reticulum stress by activating the ATF6-CHOP axis.
基金Supported by National Institutes of Health(AREA),No.R15 DK067901-02the Howard Hughes Medical Institute,No.52006328Wilkes Mentoring funds and institutional funds from Wilkes University and TCMC
文摘AIM: To evaluate the efficacy of the improvedthrombospondin mimetic peptide ABT-898 in a murine model of ulcerative colitis. METHODS: The dextran sodium sulfate(DSS) was used for the induction of colitis in both TSP-1 deficient(TSP-1-/-) and wild type(WT) mice during 7 d. While mice were receiving the DSS dissolved in the drinking water, the ABT-898 peptide was dissolved in sterile 5% glucose solution and delivered using mini pumps subcutaneously implanted. Plasma samples were analyzed for interleukin(IL)-6 by ELISA assay and colonic tissues were harvested, fixed and processed for histological evaluation. Immunohistochemistry using antibodies for the detection of CD31 and MECA in endothelial cells was performed. Inflammation was graded in colonic sections and the number of microvessels in each lesion was assessed. Activation of signal transducer and activator of transcription 3(STAT3) in colonic samples was quantified by immunohistochemistry and Western blotting using antibodies against total STAT3 and phosphorylated STAT3(p STAT3)(Ser727).RESULTS: Treatment with ABT-898 considerably diminished the inflammatory response in WT and TSP-1-/- mice(P < 0.0001 in both groups vs control). Identification of blood vessels highlighted by CD31/MECA immunohistochemistry, showed significantly reduced vessel counts in colitic lesions of WT and TSP-1-/- mice treated with ABT898(TSP-1-/- controls/TSP-1-/- treated, P = 0.0002; WT controls/WT treated, P = 0.0005). Consistently, IL-6 was significantly diminished in plasma samples of TSP-1-/- and WT treated with the peptide when compared to the control mice(P = 0.0002 and P = 0.0148, respectively). p STAT3 positive cells were quantified in WT and TSP-1-/- treated with ABT-898. A significant decrease in positive cells for p STAT3 was observed in treated mice(TSP-1-/- controls/TSP-1-/- treated, P = 0.0089; WT/WT treated, P = 0.0110). These results were confirmedby Western blotting analyses showing lower levels of p STAT3 in colitic lesions from mice treated with the peptide ABT-898.CONCLUSION: These findings indicate that the new peptide ABT-898 ameliorates inflammation and angiogenesis and might be a therapeutic alternative in IBD and inflammatory diseases.
基金supported by the Natural Science Foundation of Guangdong Province,No.S2011010004096the Medical Scientific Research Foundation of Guangdong Province,No.A2010431 A2009477
文摘Here, we review research on the mechanisms underlying the ability of thrombospondin to promote synaptogenesis and examine its role in central nervous system diseases and drug actions. Thrombospondin secreted by glial cells plays a critical role in synaptogenesis and maintains synapse stability. Thrombospondin regulates synaptogenesis through receptor a26-1 and neuroligin 1, and promotes the proliferation and differentiation of neural progenitor cells. It also participates in synaptic remodeling following injury and in the action of some nervous system drugs.
基金Supported by Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Science and ICT to Y.B.K.,No.2017R1A2A2A05069417
文摘BACKGROUND Osteoarthritis(OA),a chronic age-related disease characterized by the slowly progressive destruction of articular cartilage,is one of the leading causes of disability.As a new strategy for treatment of OA,mesenchymal stem cells(MSCs)have the potential for articular cartilage regeneration.Meanwhile,thrombospondin 2(TSP2)promotes the chondrogenic differentiation of MSCs.AIM To investigate whether TSP2 induces chondrogenic differentiation of human adipose-derived MSCs(hADMSCs)and potentiates the therapeutic effects of hADMSCs in OA rabbits.METHODS We investigated the chondrogenic potential of TSP2 in hADMSCs by analyzing the expression of chondrogenic markers as well as NOTCH signaling genes in normal and TSP2 small interfering RNA(siRNA)-treated stem cells.Anterior cruciate ligament transection surgery was performed in male New Zealand white rabbits,and 8 wk later,hADMSCs(1.7×10^6 or 1.7×10^7 cells)were injected into the injured knees alone or in combination with intra-articular injection of TSP2(100 ng/knee)at 2-d intervals.OA progression was monitored by gross,radiological,and histological examinations.RESULTS In hADMSC culture,treatment with TSP2 increased the expression of chondrogenic markers(SOX9 and collagen Ⅱ)as well as NOTCH signaling genes(JAGGED1 and NOTCH3),which were inhibited by TSP2 siRNA treatment.In vivo,OA rabbits treated with hADMSCs or TSP2 alone exhibited lower degree of cartilage degeneration,osteophyte formation,and extracellular matrix loss 8 wk after cell transplantation.Notably,such cartilage damage was further alleviated by the combination of hADMSCs and TSP2.In addition,synovial inflammatory cytokines,especially tumor-necrosis factor-α,markedly decreased following the combination treatment.CONCLUSION The results indicate that TSP2 enhances chondrogenic differentiation of hADMSCs via JAGGED1/NOTCH3 signaling,and that combination therapy with hADMSCs and TSP2 exerts synergistic effects in the cartilage regeneration of OA joints.
基金supported by the Natural Science Foundation of Guangdong Province, No. S2011010004096the Medical Scientific Research Foundation of Guangdong Province, No. A2010431 A2009477
文摘In this study, a combination of growth factors was used to induce bone marrow mesenchymal stem cells differentiation into neuron-like cells, in a broader attempt to observe the role of thrombospondin 1 in synapse formation. Results showed that there was no significant difference in the differentiation rate of neuron-like cells between bone marrow mesenchymal stem cells with thrombospondin induction and those without. However, the cell shape was more complex and the neurites were dendritic, with unipolar, bipolar or multipolar morphologies, after induction with thrombospondin 1. The induced cells were similar in morphology to normal neurites. Immunohistochemical staining showed that the number of positive cells for postsynaptic density protein 95 and synaptophysin 1 protein was significantly increased after induction with thrombospondin 1. These findings indicate that thrombospondin 1 promotes synapse formation in neuron-like cells that are differentiated from bone marrow mesenchymal stem cells.
文摘The expression of angiopoietin- 1 （Ang- 1） and thrombospondin- 1 （TSP- 1） in 5/6 subtotal nephrectomy （STN） rats model, and its correlation to the renal microvasculature injury were investigated. Rat 5/6 STN model was established in adult male SD rats, and the sham-operated group and 5/6 STN group were set up. The renal function and histopathological changes were examined at the 1st, 2nd, 4th, 8th and 12th week after operation. The expression orAng-1, TSP-1 and CD31 in renal tissues was detected by using immunohistochemistry. From 2nd to 8th week after operation, Ang-1 was significantly expressed in glomeruli of rats with STN. Ang-1 staining in glomeruli of STN group was increased significantly as compared with that in sham-operated group at 4th and 8th week after operation, and subsequently decreased after the 12th week. The expression of TSP-1 was increased significantly in STN group. As compared with sham-operated group, the CD31 expression was significantly down-regulated from the 2nd week. The expression of Ang-1 mRNA was detected by using RT-PCR at the same time points. The expression of Ang-1 mRNA in renal tissue of rats with STN was significantly up-regulated at the 2nd, 4th and 8th week after operation as compared with that in STN group at other time points or in sham-operated group at the same time points, while decreased evidently at the 12th week as compared with that in sham-operated group. It is concluded that there are changes in the mRNA expression of Ang-1, and the significant up-regulation of the expression of TSP-1 in renal tissue of rats with STN, which may be involved in the remnant renal microvasculature injury.
文摘BACKGROUND Formation of intraperitoneal adhesions is one of the major complications after abdominal surgery, which may lead to bowel obstruction. Thrombospondin 1(TSP-1) is an extracellular matrix modulating glycoprotein during tissue regeneration and collagen deposition.AIM To evaluated the therapeutic potential of overexpressed TSP-1 in suppressing pelvic adhesion formations in rat models.METHODS Pelvic adhesion was induced in anesthetized rats by laparotomy cecal abrasion.The animals were randomly assigned to treatment of local application with Seprafilm(an antiadhesive bioresorbable membrane) or adenoviral vectors encoding mouse TSP-1(AdTSP-1) on the surfaces of the injured cecum. The severity of the peritoneal adhesions was evaluated by blinded observers 14 d later.RESULTS Compared with control(no treatment) group, the application of Sperafilm significantly reduced the formation of adhesion band, and local administration of AdTSP-1 on the injured cecum the also attenuated the severity of peritoneal adhesion score. However, systemic delivery of AdTSP-1 did not affect the formation of adhesion.CONCLUSION We conclude that therapeutic approaches in inducing regional overexpression of TSP-1 may serve as alternative treatment strategies for preventing postoperative peritoneal adhesion.
文摘Chronic heart failure（CHF）remains a leading cause of morbidity and mortality.In the current study,we aimed to evaluate the predictive value of circulating fhrombospondin-2（TSP-2）for cumulative survival in patients with ischemic CHF due to coronary artery disease（CAD）.The results showed that during a median follow-up of2.18 years,21 participants died and 106 subjects were hospitalized repeatedly.The median circulating levels of TSP-2 in patients who survived and those who died were 0.63 ng/mL（95%CI=0.55-0.64 ng/mL）and 1.03 ng/mL（95%CI=0.97-1.07 ng/mL）（P〈0.001）.Circulating TSP-2 independently predicted all-cause mortality（OR=1.27;95%CI=1.08-1.59;P=0.002）,CHF-related death（OR=1.16;95%CI=1.02-1.50;P〈0.001）,and also CHF-related rehospitalization（OR=1.12;95%CI=1.07-1.25;P〈0.001）.In conclusion,among CAD patients with symptomatic CHF,increased circulating TSP-2 is correlated with increased 3-year CHF-related death,all-cause mortality,and risk for recurrent hospitalization.
文摘The redistribution of platelet membrane glycoprotein IV (GPIV) and the release of intracellular Q-granule thrombospondin (TSP) were examined and the inhibition of 5-thromboglobulin (&TG) and platelet factor 4 (PF4) in patients with chronic myelogenous leukemia (CML) was observed and quantitation of β-TG and PF4 in sera was conducted. GPIV in inactive platelet from CML was 36080±17010 molecules/platelet as compared with 13190±4810 from the controls (P<0,01), No abnormality was found in the distribution of platelet membrane GPIb and GPIIb/III.(P>0. 05). The GPIV redistribution on active platelet membrane induced thrombin (1U/ml) from CML and healthy donors was 44320132310 and 228001 12700 molecules/platelet respectively (P<0. 01 ). The difference in the release of intracellular Q-granule TSP between CML and the control group was not found (P>0.05). There was no direct correlation between GPIV expression and TSP binding after platelet activation. The high leveIs of β-TG and PF4 in sera inhibited release of intracellular a-granule TSP in vitro. These results indicate that the abnormality of platelet membrane GPIV is a common marker in CML, therefore the specific increase of platelet GPIV in patients with CML may be a useful tool for the diagnosis and monitoring of the platelet dysfunction. The release of interna1 TSP pools is hindered by either β-TG or PF4 in sera.
文摘Objective： The thrombospondin-4 （TSP-4） gene G29926C （A387P） polymorphism was recently reported to be associated with an increased risk of MI （myocardial infarction） in American population. However, several subsequent studies produced controversial findings. The aim of this study was to explore the possible association between TSP-4 A387P polymorphism and ACS （acute coronary syndrome） in Chinese Han population. Methods：A case-control study including 412 patients with ACS and 337 controls free from CAD （coronary artery disease） was conducted. TSP-4 A387P polymorphism was determined by PCR （polymerase chain reaction） and RFLP （restriction fragment length polymorphism） analysis. Results：Slightly decreased frequency of GC genotype was observed in patients with ACS, compared with controls（5.3% vs. 7.1%）, but the difference did not reach statistical significance （P = 0.31 ）. Similarly, the prevalence of C allele was 2.7% and 3.6% for ACS and control groups, respectively （P = 0.32）. None of homozygote was detected for C allele. Further analyses in subjects subgrouped according to sex and age also showed no association of TSP-4 A387P polymorphism with ACS. Furthermore, after adjustment for conventional risk factors by multiple logistic regression analysis, the carrier prevalence of C allele did not differ significantly between ACS and control groups （OR = 0.85; 95% CI：0.45-1.59; P = 0.60）. Conclusion：The present study suggested that the TSP-4 A387P variant showed a low prevalence compared with western populations and failed to associate with an altered risk of ACS in Chinese Han population. The findings further supplement experimental data for TSP-4 gene study of coronary disease.
文摘Purpose: To investigate the expression of thrombospondin 1 (TSP-1) in retinal pigment epithelium (RPE) and choroidal neovascular membranes (CNVMs) from patients with age-related macular degeneration (AMD). Methods: Tissue sections from normal human fetal and adult eyes and surgically removed CNVMs were immunostained for TSP-1 localization. Polymerase chain reaction and Western blotting were used to analyze TSP-1 mRNA and protein from human RPE cells, respectively. TSP-1 in the supernatant of cultured RPE cells and eye explants were measured using enzyme-linked immunosorbent assay. MTT assay was used to evaluate the RPE survival after TSP-1 treatment. Results: The strongest immunostaining for TSP-1 was observed in the RPE monolayer around drusen in early AMD. The intensity of TSP-1 staining in normal eye sections was much weaker than that of early AMD and CNVM. TSP-1 mRNA was positive in cultured fetal and adult RPE cells. There was increasing secretion of TSP-1 into the supernatant of cultured RPE and eye explants. The specific band of TSP-1 was identified by Western blot. No significant inhibition of RPE survival was found with the exposure to TSP-1. Conclusions: TSP-1 expression in drusen and CNVM was upregulated and associated with RPE monolayer. TSP-1 may be a natural negative regulator for choroidal neovascularization.
文摘Background: Thrombospondin-1</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">(TSP1) is associated with atherosclerosis in animals with diabetes mellitus (DM)</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">but the precise role of TSP-1 in human atherosclerosis remains unknown. Objectives: To investigate serum thrombospondin1 level in patients with coronary artery disease with and without type 2 DM and its relationship to coronary artery scoring systems. Methods: The study comprised 180 patients recruited from those underwent coronary angiography for suspected coronary artery disease (CAD) was approved by Institutional Review Board and Institutional Ethical Committee for Human Research of menoufia university hospital. They were divided according to presence of CAD and type 2 DM into 4 groups</span><span style="font-family:Verdana;">:</span><span style="font-family:Verdana;"> Group I (n = 44 patients): Non diabetic subjects without CAD, Group II (n = 40 patients): Diabetic patients without CAD, Group III (n = 49 patients): Non diabetic patients with CAD and Group IV (n = 47 patients): Diabetic patients with CAD. Serum level of TSP-1 was measured in all groups and coronary artery scoring analysis was done. Results: Serum TSP-1 levels were higher in patients with CAD and DM than in other groups (P</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;"><</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">0.01) while the levels of serum TSP-1 in diabetic patients without CAD and non-diabetic patients with CAD didn</span><span style="font-family:Verdana;">’</span><span style="font-family:Verdana;">t show significant difference. Plasma TSP-1 levels were higher in patients with DM than those in patients without DM (582.95 ± 55.70 ng/mL vs. 516.91 ± 64.56 ng/ml, </span><span style="font-family:Verdana;">P </span><span style="font-family:Verdana;"><</span><span style="font-size:10pt;font-family:""></span><span style="font-family:Verdana;">0.001). Plasma levels of TSP-1 were higher in patients with CAD than those in patients without CAD (569.54 ± 68.16 ng/mL vs. 525.17 ± 61.77 ng/ml, </span><span style="font-family:Verdana;">P </span><span style="font-family:Verdana;"><</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">0.001). Patients with CAD and DM (group IV) had significantly higher severity score and vessel score than those with CAD only (group III) (9.13 ± 3.40, 2.49 ± 0.69 vs. 7.37 ± 3.16, 2.02</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">±</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">0.80 ng/ml, </span><span style="font-family:Verdana;">P </span><span style="font-family:Verdana;"><</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">0.05). Patients with three vessel disease had the highest serum TSP-1 level (581.32 ± 61.30 ng/ml) when compared to patients with one or two vessel disease. The highest diagnostic performance of serum TSP-1 level in prediction of coronary artery disease was more pronounced in presence of DM while the least diagnostic performance of serum TSP-1 was detected in absence of DM. Univariate logistic regression analysis of different variables for prediction of CAD showed that TSP-1 level was one of the independent predictor</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> of CAD (OR 1.016, CI 1.010 </span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;"> 1.023, </span><span style="font-family:Verdana;">P</span><span style="font-family:Verdana;"> < 0.001). Conclusion: Serum TSP-1 level is higher in patients with CAD with and without type 2 DM and its level is an independent predictor of CAD, but the diagnostic performance of serum TSP-1 level in prediction of CAD is more pronounced in presence of type 2 DM.
基金support from the Department of Defense grant HT9425-23-1-0327the National Institutes of Health R01AR078324。
文摘Thrombospondin 1 and 2(TSP1 and TSP2)are critical regulators of extracellular matrix(ECM)interactions,influencing cell differentiation and tissue repair.Recent discoveries from our laboratory and others highlight the importance of altered ECM alignment in influencing aberrant mesenchymal progenitor cell(MPC)differentiation and subsequent ectopic bone formation in trauma-induced heterotopic ossification(HO).However,the key regulators of this MPC to ECM interaction have yet to be elucidated.This study uncovers the role of matricellular TSP1 and TSP2 in MPC/ECM interaction as well as HO formation and progression.Using single-cell RNA sequencing,spatial transcriptomics,and in vivo models,we found that TSP1 is upregulated in tissue remodeling macrophages and MPCs at the injury site,while TSP2 is restricted to MPCs surrounding the HO anlagen.TSP1/2 double knockout(DKO)mice exhibited significantly reduced HO volume and disrupted ECM alignment.These findings highlight the crucial roles of TSP1 and TSP2 in musculoskeletal injury repair as well as HO formation and progression,supporting the potential to therapeutically target TSP1 and TSP2 to prevent HO.
基金This study was supported by the NatiOnal Natural Science Foundation of China （No. 0040305401042）.Acknowledgements： We would like to thank Steven Pan and Mary Meyer for the assistance in polishing the paper. Their innovative suggestions and advice contributed significantly to the final version of the paper.
文摘Background Researchers have recently demonstrated that thrombospondin-1 （TSP-1） has an important function in regulating neovascularization. Whether it inhibits or accelerates neovascularization, however, is still controversial. We found few reports about the correlation between TSP-1 and vascularization in mucoepidermoid carcinoma. In this research, the distribution and expression of TSP-1 in mucoepidermoid carcinoma were investigated. We also analyzed （1） the correlation between the expression of TSP-1 and microvessel density （MVD）, as an indicator of neovascularization activity, and （2） the effect of TSP-1 on neovascularization and tumor growth in the subcutaneous xenotransplanted model of mucoepidermoid carcinoma. Method （1） The sites and intensity of expression of TSP-1 and the MVD were analyzed in 45 cases of mucoepidermoid carcinoma after surgery by the method of streptavidin-peroxidase （SP） immunohistochemistry; and （2） recombinant human thrombospondin-1 （rhTSP-1） was injected twice a week for five consecutive weeks around the tumor in the subcutaneous xenotransplanted tumor model of mucoepidermoid carcinoma in nude mice. Each week, the tumor size was measured, in order to draw the growth curve of the xenotransplanted tumor model of mucoepidermoid carcinoma, and MVD was measured. Results （1） The positive expression of TSP-1 protein was 57.78% （26/45）. Most positive staining for TSP-1 was found in the cytoplasm of the cancer cells, while some staining occurred in the extracellular matrix. The mean MVD in 45 cases of m ucoepidermoid carcinoma was 58.17±19.77 per 100 visual fields. Tumors with a high expression of TSP-1 showed a low MVD value, and the TSP-1 immunocompetence and microvessel density showed a significant negative correlation （rs=-0.947, P 〈0.001）. （2） The xenotransplanted tumors with the injection doses of 1.25, 0.75 and 0.25 ug/ml respectively were 36.97%, 53.36% and 73.61% of the size of the control group （（451±92）, （651±113）, （898±86） and （1220±157） mm^3 respectively, F=-53.167, P 〈0.001）, and their weights were respectively 35.14%, 51.35% and 70.27% of the control group （（1.3±0.5）, （1.9±0.5）, （2.6±0.3）, and （3.7±0.7） g respectively, F=-62.669, P 〈0.001）. Their MVDs were 25.00%, 45.93%, and 72.20% respectively of the control group and concentration dependent （15.43±3.45, 28.35±4.24, 44.57±3.35 and 61.73±5.43 per 100 visual fields respectively, F=54.582, P 〈0.001）. Conclusions The TSP-1 has a higher expression in mucoepidermoid carcinoma and the expression has a significant negative correlation with neovascularization. The TSP-1 inhibits neovascularization and tumor growth, and it might be a new biological therapy for treatment of patients with mucoepidermoid carcinoma.
文摘Previously, we demonstrated that macrophages from thrombospondin 1 （TSP1）-deficient mice have a reduced inflammatory phenotype, suggesting that TSP1 plays a role in macrophage activation. In this study, we determined how TSP1 regulates macrophage function. We found that recombinant or purified piatelet human TSP1 treatment stimulated tumor-necrosis factor （TNF）-α expression in bone marrow-derived macrophages in a time- and dose-dependent manner. Toll-like receptor 4 （TLR4） expression （at the mRNA and protein levels） and nuclear factor-kappaB （NF-KB） activity were also stimulated by TSP1 treatment. The TSPl-mediated increase in TNF-a production was abolished in TLR4-deficient macrophages, suggesting that TSP1 activates macrophages through a TLR4-dependent pathway. TSP1 also stimulated TLR4 activation in macrophages in vivo. Furthermore, TSPl-mediated macrophage activation was attenuated by using a peptide or an antibody to block the association between TSP1 and CD36. Taken together, these data suggest that the stimulation of the macrophage TLR4 pathway by TSP1 is partially mediated by the interaction of TSP1 with its receptor, CD36.
基金This study was supported by grants from the Major Science Research Program of Zhejiang Province （No. 2006C23029）, Medical Science Foundation of Zhejiang Province （No. 2005HN007） and Zhejiang Provincial Program for the Cultivation of High-level Innovative Health Talents.
文摘Background Erythropoietin （EPO） functions as a tissue-protective cytokine in addition to its crucial hormonal role in red cell production and neuron protection. This study aimed to determine the neuron protective effect of erythropoietin on experimental rats enduring spinal cord injury （SCI） by assessing thrombospondin-1 （TSP-1） level and transforming growth factor-β （TGF-β） in the development of a rat model of SCI. Methods Sixty Sprague-Dawley rats were randomly assigned to three groups： sham operation control group, SCI group and EPO treatment group. By using a weight-drop contusion SCI model, the rats in the SCI group and EPO treatment group were sacrificed at 24 hours and 7 days subsequently. The Basso, Beattie, and Bresnahan （BBB） scores were examined for locomotor function. Pathological changes were observed after HE staining. The expressions of thrombospondin-2 （TSP-1） and TGF-β were determined by immunohistochemical staining and Western blotting. Results Slighter locomotor dysfunction was discovered and it was recovered abruptly as higher BBB scores were found in the EPO treatment group than in the SCI group （P 〈0.01）. Pathologically, progressive disruption of the dorsal white matter and regeneration of a few neurons were also observed in SCI rats. TSP-1 and TGF-β expression increased at 24 hours and 7 days after SCI in the injured segment, and it was higher in the SCI group than in the EPO treatment group. Spinal cord samples from the animals demonstrated a TSP-1 optical density of 112.2±6.8 and TSP-1 positive cells of 5.7±1.3 respectively. After injury, the TSP-1 optical density and cell number increased to 287.2±14.3/mm^2 and 23.2±2.6/mm^2 at 24 hours and to 232.1±13.2/mm^2 and 15.2±2.3/mm^2 at 7 days respectively. When EPO treated rats compared with the SCI rats, the TSP-1 optical density and cell number decreased to 213.1 ±11.6/mm^2 and 11.9±1.6/mm^2 at 24 hours and to 189.9±10.5/mm^2 and 9.3±1.5/mm^2 at 7 days, respectively （P 〈0.01）. In the SCI rats, the TGF-β optical density and positive neuron number were 291.4±15.2/mm^2 and 28.8±4.9/mm^2 at 24 hours and 259.1±12.3/mm^2 and 23.9±4.1/mm^2 at 7 days respectively. They decreased in the EPO treated rats to 222.8±11.9/mm^2 and 13.7±2.1/mm^2 at 24 hours and to 196.5±9.7/mm^2 and 8.7±2.2/mm^2 at 7 days （P 〈0.01）. Conclusions Increased expression of TSP-1 and TGF-β can be found in the injured segment of the spinal cord at 24 hours and 7 days after injury. EPO treatment can effectively prevent pathological alterations from severe spinal cord injury by reduced expression of TSP-1 and TGF-β.
文摘Thrombospondins （TSPs） are a family of multidomain extracellular matrix glycoproteins, which consist offive members at present, TSP-1, -2, -3, -4 and TSP-5. TSP-1, which is synthesized and secreted by activated platelets and a variety of cell types including endothelial cells, macrophages, monotypes, fibroblasts, tumor cells and vascular smooth muscular cells, is the best characterized family member./ TSP-1 participates in a wide range of biological responses, including platelet activation and aggregation, vascular smooth muscular cell proliferation and migration, endothelial cell apoptosis and angiogenesis.l-3 TSP-1 may be involved in the pathogenesis of atherosclerosis and coronary artery disease （CAD）/myocardial infarction （MI）.4-7
