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Impaired wound healing in diabetic patients is the leading cause of diabetes‐associated hospitalizations and approximately 50% of lower limb amputations. This is due to multiple factors, including elevated glucose, sustained hypoxia, and cell dysfunction. Previously, diabetic wounds were found to contain excessive levels of the matricellular protein thrombospondin‐2 (TSP2) and genetic ablation of TSP2 in diabetic mice or treatment of wounds with a hydrogel derived from TSP2‐null mouse skin improved healing. Previously, TSP2 has been shown to be repressed by hypoxia, but in the present study we observed sustained hypoxia and overlapping TSP2 deposition in diabetic wounds. We determined this observation was due to the insufficient HIF‐1α activation verified by western blot and immunofluorescent analysis of wound tissues and in vitro hypoxia experiments. Application of Dimethyloxalylglycine (DMOG), which can stabilize HIF‐1α, inhibited TSP2 expression in diabetic fibroblasts in hypoxic conditions. Therefore, we prepared DMOG‐containing TSP2KO hydrogel and applied it to the wounds of diabetic mice. In comparison to empty TSP2KO hydrogel or DMOG treatment, we observed improved wound healing associated with a reduction of TSP2, reduced hypoxia, and increased neovascularization. Overall, our findings shed light on the intricate interplay between hyperglycemia, hypoxia, and TSP2 in the complex environment of diabetic wounds. [ABSTRACT FROM AUTHOR]

The search for novel endometrial cancer diagnostic biomarkers is pertinent. The purpose of this study was to determine if IL-4, IL-7, IL-9, IL-10, NT, TSP-2, and NRP1 could be used as novel, helpful markers for the detection of endometrial cancer. Ninety-three women diagnosed with endometrial cancer (EC) and sixty-six patients with noncancerous endometrial lesions (NCEL) were included in this study. ELISA was used to measure the concentrations of the proteins tested. Median serum levels of IL-4, IL-7, IL-9, NT, and NRP1 were significantly higher in the EC group compared with NCEL. The cut-off level of IL-4 was set at 802.26 pg/mL with a sensitivity of 83.87% and a specificity of 50% (AUC = 0.7, p = 0.000023). The cut-off level of IL-7 was set at 133.63 ng/L with a sensitivity of 96.77% and a specificity of 75.76% (AUC = 0.91, p < 0.000001). The cut-off level of IL-9 was set at 228.79 pg/mL with a sensitivity of 69.89% and a specificity of 81.82% (AUC = 0.8, p < 0.000001). The cut-off level of NT was set at 275.43 pmol/L with a sensitivity of 94.62% and a specificity of 59.09% (AUC = 0.83, p < 0.000001). The cut-off level of NRP1 was set at 30.37 ng/mL with a sensitivity of 81.72% and a specificity of 57.58% (AUC = 0.71, p = 0.000004). This study suggests the clinical utility of IL-4, IL-7, IL-9, NT, and NRP1 in the diagnosis of endometrial cancer. Nevertheless, these biomarkers may also have prognostic or predictive value, which should be tested in future studies. [ABSTRACT FROM AUTHOR]

Background: Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder, the etiology of which has not been clearly determined yet. There is increasing evidence that synaptic and dendritic changes are involved in the etiology of ASD. The aim of this study is to determine whether serum Thrombospondin-1 and Thrombospondin-2 differ between ASD patients and healthy controls. This study also investigates possible correlations between clinical symptomatology of ASD and serum Thrombospondin-1 and Thrombospondin-2 levels. Method: A total of 44 children with ASD and 21 healthy controls under 6 years of age were included in the study. Symptom severity and behavioral problems among children with ASD were evaluated by using Childhood Autism Rating Scale and Abnormal Behavior Checklist. Serum levels of Thrombospondin-1 and Thrombospondin-2 were measured by using commercial enzyme-linked immunosorbent assay kits. Result: No statistically significant differences were found between the two groups in terms of serum Thrombospondin-1 and Thrombospondin-2 levels. In addition, no correlation was determined between Thrombospondin-2 levels and clinical symptomatology and severity of ASD. However, the Thrombospondin-1 level was found to negatively correlated with the total score of Childhood Autism Rating Scale, inappropriate speech and stereotype subscale scores of Aberrant Behavior Checklist scale. Conclusion: Thrombospondin-1 might have a potential role in the etiopathogenesis of ASD. Further studies are required to clearly elucidate the association between Trombospondin-1 and ASD. [ABSTRACT FROM AUTHOR]

Abstract Background and aims Stroke is the leading cause of adult-onset disability. Although clinical factors influence stroke outcome, there is a significant variability among individuals that may be attributed to genetics and epigenetics, including DNA methylation (DNAm). We aimed to study the association between DNAm and stroke prognosis. Methods and results To that aim, we conducted a two-phase study (discovery-replication and meta-analysis) in Caucasian patients with ischemic stroke from two independent centers (BasicMar [discovery, N = 316] and St. Pau [replication, N = 92]). Functional outcome was assessed using the modified Rankin Scale (mRS) at three months after stroke, being poor outcome defined as mRS > 2. DNAm was determined using the 450K and EPIC BeadChips in whole-blood samples collected within the first 24 h. We searched for differentially methylated positions (DMPs) in 370,344 CpGs, and candidates below p-value

Background and aims: Stroke is the leading cause of adult-onset disability. Although clinical factors influence stroke outcome, there is a significant variability among individuals that may be attributed to genetics and epigenetics, including DNA methylation (DNAm). We aimed to study the association between DNAm and stroke prognosis. Methods and results: To that aim, we conducted a two-phase study (discovery-replication and meta-analysis) in Caucasian patients with ischemic stroke from two independent centers (BasicMar [discovery, N = 316] and St. Pau [replication, N = 92]). Functional outcome was assessed using the modified Rankin Scale (mRS) at three months after stroke, being poor outcome defined as mRS > 2. DNAm was determined using the 450K and EPIC BeadChips in whole-blood samples collected within the first 24 h. We searched for differentially methylated positions (DMPs) in 370,344 CpGs, and candidates below p-value < 10–5 were subsequently tested in the replication cohort. We then meta-analyzed DMP results from both cohorts and used them to identify differentially methylated regions (DMRs). After doing the epigenome-wide association study, we found 29 DMPs at p-value < 10–5 and one of them was replicated: cg24391982, annotated to thrombospondin-2 (THBS2) gene (p-valuediscovery = 1.54·10–6; p-valuereplication = 9.17·10–4; p-valuemeta-analysis = 6.39·10–9). Besides, four DMRs were identified in patients with poor outcome annotated to zinc finger protein 57 homolog (ZFP57), Arachidonate 12-Lipoxygenase 12S Type (ALOX12), ABI Family Member 3 (ABI3) and Allantoicase (ALLC) genes (p-value < 1·10–9 in all cases). Discussion: Patients with poor outcome showed a DMP at THBS2 and four DMRs annotated to ZFP57, ALOX12, ABI3 and ALLC genes. This suggests an association between stroke outcome and DNAm, which may help identify new stroke recovery mechanisms. [ABSTRACT FROM AUTHOR]

Background and Aim: The development of new blood vessels involves the stimulation of growth, migration, and stabilization, which is influenced by various stimulating and inhibiting factors such as Thrombospondin-2 (TSP-2) and transforming growth factor-beta (TGF-β). This study aimed to compare the effect of eight weeks of different aerobic training methods on the expression of TSP-2 and TGF-β genes in subcutaneous adipose tissue of rats. Materials and Methods: The study conducted an experimental research on 32 male Wistar rats to investigate the effects of different training protocols on gene expression. The rats were divided into four groups (n=8): scheme, high-intensity training (HIT), moderate-intensity training (MIT), and high-intensity interval training (HIIT). The training protocols involved treadmill running for eight weeks, with varying intensities and durations for each group. Gene expression was measured by RT-PCR method. The data were analyzed with one-way ANOVA and Tukey's tests at a significance level of p≤0.05. Results: The results of the study show that all three training methods led to a significant reduction in TGF-β expression compared to the scheme group. However, no significant difference was observed between training methods. It was also found that only the HIT and MIT methods caused a significant decrease in TSP-2 expression compared to the scheme group, and that HIT could significantly reduce the expression of TSP-2 compared to the HIIT protocol. Conclusion: In conclusion, it is suggested that aerobic exercises, particularly HIT with specific intensity and duration, may be effective in improving blood supply to fat tissue and subsequently reducing fat mass through their impact on the expression of angiostatic genes. [ABSTRACT FROM AUTHOR]

Aim of the study: Metabolic-associated fatty liver disease (MAFLD) requires close monitoring due to its increased incidence and progression to fibrosis, cirrhosis and even hepatocellular carcinoma. The search for non-invasive markers to diagnose liver fibrosis is ongoing. The aim of our study was to evaluate the serum levels of growth differentiation factor-15 (GDF-15), thrombospondin-2 (TSP2), pentraxin 3 (PTX3) and angiopoietin-like protein 8 (ANGPTL8) in children with MAFLD. Material and methods: Fifty-six overweight/obese children with suspected liver disease were included in this prospective study. MAFLD was diagnosed according to the latest consensus. Vibration-controlled transient elastography (TE) was performed to detect clinically significant liver fibrosis. Serum concentrations of GDF-15, TSP2, PTX3 and ANGPTL8 were measured by enzyme-linked immunosorbent assay (ELISA). Results: Liver steatosis was diagnosed in abdominal ultrasound in 31 (55.36%) overweight/obese patients who were classified as the MAFLD group. Aspartate aminotransferase (AST)/platelet ratio (APRI) and liver stiffness measurement (LSM) values and TSP2 concentrations showed significantly higher values in patients in MAFLD than in the non-MAFLD group. TSP2 was significantly positively correlated with alanine transaminase (ALT), AST, g-glutamyltransferase (GGT) and APRI in the study group. The receiver operating characteristics (ROC) analysis showed that the area under the curve (AUC) of LSM, APRI and serum TSP2 was significant for predicting MAFLD in obese children. In the multivariable regression model, LSM was the only significant parameter associated with the diagnosis of MAFLD in children. Conclusions: TSP2 may be a potential biomarker of hepatocyte injury in pediatric patients with MAFLD. None of the examined biomarkers were found to be effective non-invasive markers of liver fibrosis in children. [ABSTRACT FROM AUTHOR]

Roles of thrombospondin-1 (TSP-1) and thrombospondin-2 (TSP-2) in tissue repair and inflammation are well-documented, but the association of their serum expressions with the pathogenesis of COVID-19 remains unclear. We investigate the roles of TSP-1 and TSP-2 in COVID-19.

Abstract Objective Thrombospondin-2 (TSP-2) is a multifunctional matricellular glycoprotein correlated with glucose homeostasis, insulin sensitivity, and estimated glomerular filtration rate. Investigation of the association of TSP-2 with type 2 diabetes mellitus (T2DM) and the potential diagnostic value of serum TSP-2 for detecting early diabetic kidney disease (DKD) is needed. Research design and methods An enzyme-linked immunosorbent assay was used for detection serum TSP-2 levels in 494 Chinese T2DM subjects. The protein expression of TSP-2 in the kidney and other tissues were tested by western blotting. Results Serum TSP-2 levels in T2DM subjects were significantly higher than in healthy individuals. Serum TSP-2 correlated positively with triglycerides, serum uric acid, creatinine, platelets, and urinary albumin-to-creatinine ratio (UACR), but negatively with estimated glomerular filtration rate, after adjusting for age, sex, and T2DM duration. Logistic regression analysis demonstrated an independent association between serum TSP-2 and early DKD. Furthermore, the high UACR identified at risk of early DKD increased significantly from 0.78 (95%CI 0.73–0.83) to 0.82 (95%CI 0.77–0.86, p

Abstract Background Circulating thrombospondin-2 (TSP2) levels were associated with the development of heart failure (HF) in recent studies. However, these studies included only a minority of patients with type 2 diabetes, which is associated with an increased HF risk. As hyperglycemia induces TSP2 expression and its tissue expression increases in type 2 diabetes, we investigated the prospective association of circulating TSP2 with incident HF hospitalization (HHF), and its associations with longitudinal changes of echocardiographic parameters in type 2 diabetes. Methods Baseline serum TSP2 levels were measured in 4949 patients with type 2 diabetes to determine its association with incident HHF using multivariable Cox regression analysis. In the echocardiographic study, baseline serum TSP2 levels were measured in another 146 patients with type 2 diabetes but without cardiovascular diseases who underwent detailed transthoracic echocardiography at baseline and after 1 year. Results Over a median follow-up of 7.8 years, 330 of 4949 patients (6.7%) developed incident HHF. Baseline serum TSP2 levels were independently associated with the development of HHF (HR 1.31, 95%CI 1.06–1.62, p = 0.014) after adjustments for baseline conventional cardiovascular risk factors, atrial fibrillation, estimated glomerular filtration rate, albuminuria and high-sensitivity C-reactive protein level, use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, loop-diuretics, aspirin, insulin, metformin and sodium-glucose co-transporter 2 inhibitors. Moreover, baseline serum TSP2 levels were independently associated with increase in average E/e’ and left atrial volume index (p = 0.04 and

Objective: Thrombospondin-2 (TSP-2) is a multifunctional matricellular glycoprotein correlated with glucose homeostasis, insulin sensitivity, and estimated glomerular filtration rate. Investigation of the association of TSP-2 with type 2 diabetes mellitus (T2DM) and the potential diagnostic value of serum TSP-2 for detecting early diabetic kidney disease (DKD) is needed. Research design and methods: An enzyme-linked immunosorbent assay was used for detection serum TSP-2 levels in 494 Chinese T2DM subjects. The protein expression of TSP-2 in the kidney and other tissues were tested by western blotting. Results: Serum TSP-2 levels in T2DM subjects were significantly higher than in healthy individuals. Serum TSP-2 correlated positively with triglycerides, serum uric acid, creatinine, platelets, and urinary albumin-to-creatinine ratio (UACR), but negatively with estimated glomerular filtration rate, after adjusting for age, sex, and T2DM duration. Logistic regression analysis demonstrated an independent association between serum TSP-2 and early DKD. Furthermore, the high UACR identified at risk of early DKD increased significantly from 0.78 (95%CI 0.73–0.83) to 0.82 (95%CI 0.77–0.86, p < 0.001) when added to a clinical model consisting of TSP-2 and age. In db/db mice, serum TSP-2 levels were elevated. TSP-2 expression was markedly increased in the kidney tissue compared with that in db/m and m/m mice. Furthermore, serum TSP-2 expression correlated well with UACR in mice. Conclusions: TSP-2 is a novel glycoprotein associated with early DKD in patients with T2DM. The paradoxical increase of serum TSP-2 in T2DM individuals may be due to a compensatory response to chronic inflammatory and renal vascular endothelial growth, warranting further investigation. [ABSTRACT FROM AUTHOR]

Thrombospondin-2 (Tsp2), a glycoprotein in the extracellular matrix, plays a critical role in the maintenance of vascular homeostasis. However, its role in the pathogenesis of cardiovascular disorders such as intimal hyperplasia is not fully elucidated. This study, therefore, aims to explore the effect of Tsp2 on intimal hyperplasia and its associated underlying mechanisms. Intimal hyperplasia (IH) was established using a modified wire-mediated femoral artery injury model. Immunofluorescence and qPCR identified upregulated Tsp2 expression in the injured femoral artery compared with the uninjured femoral artery. Similarly, TSP2 expression was also increased in human samples from the atherosclerotic femoral artery and colocalized with vascular smooth muscle cells (VSMCs). Compared with the wild-type littermates, Tsp2 knockout mice displayed a mitigated IH in the injured femoral artery, as demonstrated by a decreased neointimal area and intimal/median ratio. Primary mouse VSMCs were cultured to explore the mechanism by which Tsp2 influenced IH in vitro. PDGF-stimulated VSMCs presented an elevated Tsp2 expression and enhanced migration and proliferation. However, Tsp2 knockdown by siRNA blocked the increased migration and proliferation of VSMCs. Further analysis identified an association between Notch3 and IH when the intracellular domain of Notch3 (Nicd3) was upregulated in PDGF-stimulated VSMCs and femoral arteries with IH in human tissues. Along with the overexpression and downregulation of Tsp2, the Nicd3 expression was also up and downregulated accordingly. Tsp2 was associated with IH and may serve as a therapeutic target for IH. Downregulation of Tsp2 could mitigate the progression of IH by modulating the proliferation and migration of VSMCs. [ABSTRACT FROM AUTHOR]

Abstract Background Thrombospondin-2 (THBS2) is a versatile glycoprotein that regulates numerous biological functions, including the apoptosis-proliferation balance in endothelial cells, and it has been linked to tumor angiogenesis. However, the exact role of THBS2 in human cancer remains unknown. This study aimed to determine THBS2 expression in a pan-cancer analysis and its association with pan-cancer prognosis and to further identify its possible roles in tumor immunity and the extracellular matrix (ECM). Methods Data on THBS2 expression in cancers and normal tissues were downloaded from the Genotype-Tissue Expression portal and UCSC Xena visual exploration tool and analyzed using the ONCOMINE database, Perl programming language, and Gene Expression Profiling and Interactive Analyses vision 2 webserver. In addition, survival prognosis was analyzed using the survival, survminer, limma, and forestplot packages in R v. 4.0.3.Immune and matrix components were also analyzed using R v. 4.0.3. Most importantly, we partially validated the role and mechanism of THBS2 in pancreatic and gastric cancers in vitro using PANC1 and BGC-823 cell lines. Results THBS2 was significantly overexpressed in 17 of the 33 investigated cancers and linked to a poor prognosis in pan-cancer survival analysis. High THBS2 expression was an independent unfavorable prognostic factor in kidney renal papillary cell, mesothelioma, and stomach and pancreatic adenocarcinomas. Immune infiltration and THBS2 expression were also related. THBS2 expression has been linked to immune and stromal scores and immune checkpoint markers in various cancers. The protein–protein interaction network revealed that THBS2 is associated with multiple ECM and immune proteins. THBS2 knockdown decreased the expression of CD47 and matrix metallopeptidase 2 (MMP-2) as well as the proliferation, migration, and invasion of PANC1 and BGC-823 cells in vitro. Conclusions Our findings suggested that THBS2 might promote cancer progression by remodeling the tumor microenvironment, affecting CD47-mediated signaling pathways, activating the pro-tumor functions of a disintegrin and metalloproteinase with thrombospondin motifs, and enhancing MMP-2 expression. Furthermore, it functions as a bridge between the ECM and immune infiltration in cancer and serves as a potential prognostic biomarker for several cancers, especially pancreatic and gastric adenocarcinomas.

In the mouse, two distinct populations of Leydig cells arise during testis development. Fetal Leydig cells arise from a stem cell population and produce T required for masculinization. It is debated whether they persist in the adult testis. A second adult Leydig stem cell population gives rise to progenitor-immature-mature adult type Leydig cells that produce T in response to LH to maintain spermatogenesis. In testis of adult null male mice lacking either only LH (Lhb−/−) or LHR (Lhr−/−), mature Leydig cells are absent but fetal Leydig cells persist. Thus, it is not clear whether other ligands signal via LHRs in Lhb null mice or LH signals via other receptors in the absence of LHR in Lhr null mice. Moreover, it is not clear whether truncated LHR isoforms generated from the same Lhr gene promoter encode functionally relevant LH receptors. To determine the in vivo roles of LH-LHR signaling pathway in the Leydig cell lineage, we generated double null mutant mice lacking both LH Ligand and all forms of LHR. Phenotypic analysis indicated testis morpho-histological characteristics are identical among double null and single mutants which all showed poorly developed interstitium with a reduction in Leydig cell number and absence of late stage spermatids. Gene expression analyses confirmed that the majority of the T biosynthesis pathway enzyme-encoding mRNAs expressed in Leydig cells were all suppressed. Expression of thrombospondin-2, a fetal Leydig cell marker gene was upregulated in single and double null mutants indicating that fetal Leydig cells originate and develop independent of LH-LHR signaling pathway in vivo. Serum and intratesticular T levels were similarly suppressed in single and double mutants. Consequently, expression of AR-regulated genes in Sertoli and germ cells were similarly affected in single and double mutants without any evidence of any additive effect in the combined absence of both LH and LHR. Our studies unequivocally provide genetic evidence that in the mouse testis, fetal Leydig cells do not require LH-LHR signaling pathway and a one-to-one LH ligand-LHR signaling pathway exists in vivo to regulate adult Leydig cell lineage and spermatogenesis. [ABSTRACT FROM AUTHOR]

Background: Circulating thrombospondin-2 (TSP2) levels were associated with the development of heart failure (HF) in recent studies. However, these studies included only a minority of patients with type 2 diabetes, which is associated with an increased HF risk. As hyperglycemia induces TSP2 expression and its tissue expression increases in type 2 diabetes, we investigated the prospective association of circulating TSP2 with incident HF hospitalization (HHF), and its associations with longitudinal changes of echocardiographic parameters in type 2 diabetes. Methods: Baseline serum TSP2 levels were measured in 4949 patients with type 2 diabetes to determine its association with incident HHF using multivariable Cox regression analysis. In the echocardiographic study, baseline serum TSP2 levels were measured in another 146 patients with type 2 diabetes but without cardiovascular diseases who underwent detailed transthoracic echocardiography at baseline and after 1 year. Results: Over a median follow-up of 7.8 years, 330 of 4949 patients (6.7%) developed incident HHF. Baseline serum TSP2 levels were independently associated with the development of HHF (HR 1.31, 95%CI 1.06–1.62, p = 0.014) after adjustments for baseline conventional cardiovascular risk factors, atrial fibrillation, estimated glomerular filtration rate, albuminuria and high-sensitivity C-reactive protein level, use of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, loop-diuretics, aspirin, insulin, metformin and sodium-glucose co-transporter 2 inhibitors. Moreover, baseline serum TSP2 levels were independently associated with increase in average E/e' and left atrial volume index (p = 0.04 and < 0.01, respectively). Conclusion: Serum TSP2 levels were independently associated with both incident HHF and deterioration in diastolic function in type 2 diabetes. Trial registration: Not Applicable [ABSTRACT FROM AUTHOR]

Context: Metabolic associated fatty liver disease (MAFLD) is the hepatic manifestation of obesity-related metabolic syndrome (MetS). Noninvasive biomarkers for monitoring the progression and severity of these metabolic comorbidities are needed. Objectives: To investigate the associations of serum thrombospondin-2 (TSP2) with MetS and MAFLD severity, and the potential diagnostic value of serum TSP2 for identifying at-risk metabolic associated steatohepatitis (MASH). Methods: Blood samples, clinical data, and liver biopsies were collected from consecutively recruited 252 individuals with morbid obesity receiving bariatric surgery. Histopathology samples of liver biopsies were examined in a blinded fashion by 3 independent pathologists. Serum TSP2 levels were measured by enzyme-linked immunosorbent assay. Results: Serum TSP2 levels were significantly elevated in MetS (1.58 [1.07-2.20] ng/mL) compared with non-MetS (1.28 [0.84-1.73] ng/mL; P = .006) in obese patients and positively correlated with increasing number of the MetS components, fasting glucose, glycated hemoglobin, fasting insulin, C-peptide, and homeostatic model assessment of insulin resistance after adjustment of conventional confounders. Serum TSP2 levels differentiated MASH (1.74 [1.32-3.09] ng/mL) from the other non-MASH less severe groups: normal liver (1.41 [1.04-1.63] ng/mL), simple steatosis (1.45 [0.89-1.92] ng/mL), and borderline MASH (1.30 [0.99-2.17] ng/mL) (P < .05). Elevated serum TSP2 was positively associated with the severity of hepatic steatosis, inflammation, fibrosis, and abnormal liver function independent of age, sex and adiposity. Furthermore, high serum TSP2 identified at-risk MASH with area under the operating curve of 0.84 (95% CI 0.70-0.98). Conclusion: Serum TSP2 is closely associated with severity and progression of MetS and MAFLD, and is a promising noninvasive biomarker for differentiating MASH from benign steatosis and identifying at-risk MASH patients among individuals with obesity. [ABSTRACT FROM AUTHOR]

Background: Thrombospondin-2 (THBS2) is a versatile glycoprotein that regulates numerous biological functions, including the apoptosis-proliferation balance in endothelial cells, and it has been linked to tumor angiogenesis. However, the exact role of THBS2 in human cancer remains unknown. This study aimed to determine THBS2 expression in a pan-cancer analysis and its association with pan-cancer prognosis and to further identify its possible roles in tumor immunity and the extracellular matrix (ECM). Methods: Data on THBS2 expression in cancers and normal tissues were downloaded from the Genotype-Tissue Expression portal and UCSC Xena visual exploration tool and analyzed using the ONCOMINE database, Perl programming language, and Gene Expression Profiling and Interactive Analyses vision 2 webserver. In addition, survival prognosis was analyzed using the survival, survminer, limma, and forestplot packages in R v. 4.0.3.Immune and matrix components were also analyzed using R v. 4.0.3. Most importantly, we partially validated the role and mechanism of THBS2 in pancreatic and gastric cancers in vitro using PANC1 and BGC-823 cell lines. Results: THBS2 was significantly overexpressed in 17 of the 33 investigated cancers and linked to a poor prognosis in pan-cancer survival analysis. High THBS2 expression was an independent unfavorable prognostic factor in kidney renal papillary cell, mesothelioma, and stomach and pancreatic adenocarcinomas. Immune infiltration and THBS2 expression were also related. THBS2 expression has been linked to immune and stromal scores and immune checkpoint markers in various cancers. The protein–protein interaction network revealed that THBS2 is associated with multiple ECM and immune proteins. THBS2 knockdown decreased the expression of CD47 and matrix metallopeptidase 2 (MMP-2) as well as the proliferation, migration, and invasion of PANC1 and BGC-823 cells in vitro. Conclusions: Our findings suggested that THBS2 might promote cancer progression by remodeling the tumor microenvironment, affecting CD47-mediated signaling pathways, activating the pro-tumor functions of a disintegrin and metalloproteinase with thrombospondin motifs, and enhancing MMP-2 expression. Furthermore, it functions as a bridge between the ECM and immune infiltration in cancer and serves as a potential prognostic biomarker for several cancers, especially pancreatic and gastric adenocarcinomas. [ABSTRACT FROM AUTHOR]

Purpose Distal cholangiocarcinoma and pancreatic ductal adenocarcinoma are malignancies with poor prognoses that can be difficult to distinguish preoperatively. Thrombospondin-2 has been proposed as a novel diagnostic biomarker for early pancreatic ductal adenocarcinoma. The aim of the present study was to evaluate thrombospondin-2 as a diagnostic and prognostic biomarker in combination with current biomarker CA 19-9 for distal cholangiocarcinoma and pancreatic ductal adenocarcinoma. Methods Thrombospondin-2 was measured in prospectively collected serum samples from patients who underwent surgery with a histopathological diagnosis of distal cholangiocarcinoma (N = 51), pancreatic ductal adenocarcinoma (N = 52) and benign pancreatic diseases (N = 27) as well as healthy blood donors (N = 52) using an enzyme-linked immunosorbent assay. Results Thrombospondin-2 levels (ng/ml) were similar in distal cholangiocarcinoma 55 (41–77) and pancreatic ductal adenocarcinoma 48 (35–80) (P = 0.221). Thrombospondin-2 + CA 19-9 had an area under the curve of 0.92 (95% CI 0.88–0.97) in differentiating distal cholangiocarcinoma and pancreatic ductal adenocarcinoma from healthy donors which was superior to CA 19-9 alone (P < 0.001). The diagnostic value of adding thrombospondin-2 to CA 19-9 was larger in early disease stages. Thrombospondin-2 did not provide additional value to CA 19-9 in differentiating the benign disease group; however, heterogeneity was notable in the benign cohort. Three of five patients with autoimmune pancreatitis patients had greatly elevated thrombospondin-2 levels. Thrombospondin-2 levels had no correlation with prognoses. Conclusions Serum thrombospondin-2 in combination with CA 19-9 has potential as a biomarker for distal cholangiocarcinoma and pancreatic cancer. [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]

Objectives: Bone marrow‐derived cells (BMDCs), especially mesenchymal stem cells (MSCs), may be involved in the development of Helicobacter pylori‐associated gastric cancer (GC) in mice, but the specific mechanism remains unclear, and evidence from human studies is lacking. Materials and Methods: To verify the role of BM‐MSCs in H pylori‐associated GC, green fluorescent protein (GFP)‐labelled BM‐MSCs were transplanted into the subserosal layers of the stomach in a mouse model of chronic H pylori infection. Three months post‐transplantation, the mice were sacrificed, and the gastric tissues were subjected to histopathological and immunofluorescence analyses. In addition, we performed fluorescence in situ hybridization (FISH) and immunofluorescence analyses of gastric tissue from a female patient with H pylori infection and a history of acute myeloid leukaemia who received a BM transplant from a male donor. Results: In mice with chronic H pylori infection, GFP‐labelled BM‐MSCs migrated from the serous layer to the mucosal layer and promoted GC progression. The BM‐MSCs differentiated into pan‐cytokeratin‐positive epithelial cells and α‐smooth muscle actin‐positive cancer‐associated fibroblasts (CAFs) by secreting the protein thrombospondin‐2. FISH analysis of gastric tissue from the female patient revealed Y‐chromosome‐positive cells. Immunofluorescence analyses further confirmed that Y‐chromosome‐positive cells showed positive BM‐MSCs marker. These results suggested that allogeneic BMDCs, including BM‐MSCs, can migrate to the stomach under chronic H pylori infection. Conclusions: Taken together, these findings imply that BM‐MSCs participate in the development of chronic H pylori‐associated GC by differentiating into both gastric epithelial cells and CAFs. [ABSTRACT FROM AUTHOR]

• Distribution of serum thrombospondin-2 in general population and cancer patients in China have not been reported. • The concentrations of serum THBS2 in general population were not associated with sex and age. • The expression levels of serum THBS2 displayed an obvious heterogeneity among various cancers. • Ovarian cancer patients detected with low THBS2 expression may be more prone to develop metastasis. Distribution of serum thrombospondin-2 in general population and cancer patients in China have not been reported. This study evaluated the expression level of serum thrombospondin-2 in general population and various cancer patients, the 95% confidence interval was used for the derivation of reference range. The comparison of the expression levels in controls for age and gender was performed. The associations between candidate biomarkers (thrombospondin-2 [THBS2]) expression and tumor metastasis status were also explored. 125 healthy controls and 193 various cancer patients were enrolled. The mean ± SD in serum THBS2 levels in general population was 42.37 ± 12.24 ng/ml, there was no significant sex and age difference, the reference range is 18.37–66.36 ng/ml. Most cancer patients present a decreased serum THBS2 level except hepatoma and lymphoma which most patients showed a relatively high level of THBS2. There was no statistical difference of serum THBS2 level between metastasis and non-metastasis group in breast, lung, cervical, colorectal cancer, nasopharyngeal carcinoma and hepatoma (P > 0.05) while a significant negative correlation was observed in ovarian cancer (P = 0.0209). The distribution of serum THBS2 displayed an obvious heterogeneity among various cancers comparing to health controls, ovarian cancer patients detected with low THBS2 expression may be more prone to develop metastasis in China. [ABSTRACT FROM AUTHOR]

Introduction: Mobility disability is a powerful indicator of poor health in older adults. The biological and pathophysiological mechanism underlying the development of mobility disability remains unknown. This study conducted a data‐driven discovery phase investigation to identify plasma proteins that predict the incidence of mobility disability in community‐dwelling older adults without mobility disability at baseline. Methods: We investigated 660 women and men, aged 71.9 ± 6.0 (60–94) years, who participated in the Invecchiare in Chianti, "Aging in the Chianti Area" study and completed the 400‐m walk at fast pace (400‐m walk) at enrollment. Median follow‐up time was 8.57 [interquartile, 3.20–9.08] years. SOMAscan technology was used to measure 1,301 plasma proteins at enrollment. The incident of mobility disability was defined as inability to complete the 400‐m walk. Protein‐specific Cox proportional hazard model was adjusted for sex, age, and other important covariates. Results: Plasma levels of 75 proteins predicted mobility disability (p <.05). Significant proteins were enriched for the KEGG "PI3K‐Akt signaling," "phagosomes," and "cytokine–cytokine receptor interaction" pathways. After multiple comparison adjustment, plasma cathepsin S (CTSS; hazard ratio [HR] 1.33, 95% CI: 1.17, 1.51, q = 0.007), growth/differentiation factor 15 (GDF15; HR: 1.45, 95% CI: 1.23, 1.72, q = 0.007), and thrombospondin‐2 (THBS2; HR: 1.44, 95% CI: 1.22, 1.69, q = 0.007) remained significantly associated with high risk of losing mobility. Conclusion: CTSS, GDF15, and THBS2 are novel blood biomarkers associated with new mobility disability in community‐dwelling individuals. Overall, our analysis suggests that cellular senescence and inflammation should be targeted for prevention of mobility disability. [ABSTRACT FROM AUTHOR]

Background: Minimally invasive diagnostic biomarkers for patients with pancreatic ductal adenocarcinoma (PDAC) and distal cholangiocarcinoma (dCCA) are warranted to facilitate accurate diagnosis. This study identified diagnostic plasma proteins based on proteomics of tumor secretome. Materials and Methods: Secretome of tumor and normal tissue was collected after resection of PDAC and dCCA. Differentially expressed proteins were measured by mass spectrometry. Selected candidate biomarkers and carbohydrate antigen 19‐9 (CA19‐9) were validated by enzyme‐linked immunosorbent assay in plasma from patients with PDAC (n = 82), dCCA (n = 29), benign disease (BD; n = 30), and healthy donors (HDs; n = 50). Areas under the curve (AUCs) of receiver operator characteristic curves were calculated to determine the discriminative power. Results: In tumor secretome, 696 discriminatory proteins were identified, including 21 candidate biomarkers. Thrombospondin‐2 (THBS2) emerged as promising biomarker. Abundance of THBS2 in plasma from patients with cancer was significantly higher compared to HDs (p <.001, AUC = 0.844). Combined expression of THBS2 and CA19‐9 yielded the optimal discriminatory capacity (AUC = 0.952), similarly for early‐ and late‐stage disease (AUC = 0.971 and AUC = 0.911). Remarkably, this combination demonstrated a power similar to CA19‐9 to discriminate cancer from BD (AUC = 0.764), and THBS2 provided an additive value in patients with high expression levels of bilirubin. Conclusion: Our proteome approach identified a promising set of candidate biomarkers. The combined plasma expression of THBS2/CA19‐9 is able to accurately distinguish patients with PDAC or dCCA from HD and BD. Implications for Practice: The combined plasma expression of thrombospondin‐2 and carbohydrate antigen 19‐9 is able to accurately diagnose patients with pancreatic cancer and distal cholangiocarcinoma. This will facilitate minimally invasive diagnosis for these patients by distinguishing them from healthy individuals and benign diseases. This article identifies diagnostic plasma proteins to distinguish patients with pancreatic ductal adenocarcinoma and distal cholangiocarcinoma from benign disease and health donors and evaluates these new markers for additive value with CA19‐9 at different disease stages. [ABSTRACT FROM AUTHOR]

Introduction: Epilepsy is a common chronic disease characterized by repetitive convulsions related to sudden, abnormal discharges of neurons that unfavorably influence neurobiological, cognitive, psychological, and social abilities. Although some treatment choices, including medical and surgical procedures, exist, there are refractory cases as well. Our aim was to explain the role of thrombospondin-2 (TSP), a glycoprotein produced by astrocytes in the central nervous system, in refractory epilepsy. Method: In this prospective study, 82 children (<18 years old) -regardless of their sex-that attended Bezmialem Vakıf University Hospital between August 2023 and January 2024 were included and classified into three groups: an epilepsy group (n=34) whose convulsions were under control with 1 drug, a refractory epilepsy group (n=28) that still had convulsions despite using two or more drugs, and a healthy group (n=20) that had no chronic disease. Children who had any chronic disease other than epilepsy or any lesion detected in cranial MR were excluded. TSP-2 levels in serum samples were analyzed using a commercial ELISA kits and compared between each group using the Kruskal-Wallis H test. Results: Mean age was 2.17±0.66 in epilepsy group, 2.02±0.80 in refractory epilepsy group and 2.15±0.43 in control group. There was no significant difference between the mean ages of the groups (p=0.55). The mean TSP-2 level was 2.73±0.75 in epilepsy group, 2.31±0.73 in refractory epilepsy group and 1.77±0.80 in control group. There was a statistically significant difference between the TSP-2 levels of the groups (p<0.001). Conclusion: The TSP-2 levels of both epilepsy and refractory epilepsy patients were increased, whereas the mean TSP-2 levels of the epilepsy group were higher than those of the refractory epilepsy group. Further studies are essential to confirm our results. [ABSTRACT FROM AUTHOR]

Abstract Background Thrombospondin-2 (TSP-2) is a secreted matricellular glycoprotein that is found to mediate cell-to-extracellular matrix attachment and participates in many physiological and pathological processes. The expression profile of TSP-2 on tumors is controversial, and it up-regulates in some cancers, whereas it down-regulates in others, suggesting that the functional role of TSP-2 on tumors is still uncertain. Methods The expression of TSP-2 on prostate cancer progression was determined in the tissue array by the immunohistochemistry. The molecular mechanism of TSP-2 on prostate cancer (PCa) metastasis was investigated through pharmaceutical inhibitors, siRNAs, and miRNAs analyses. The role of TSP-2 on PCa metastasis in vivo was verified through xenograft in vivo imaging system. Results Based on the gene expression omnibus database and immunohistochemistry, we found that TSP-2 increased with the progression of PCa, especially in metastatic PCa and is correlated with the matrix metalloproteinase-2 (MMP-2) expression. Additionally, through binding to CD36 and integrin ανβ3, TSP-2 increased cell migration and MMP-2 expression. With inhibition of p38, ERK, and JNK, the TSP-2-induced cell migration and MMP-2 expression were abolished, indicating that the TSP-2’s effect on PCa is MAPK dependent. Moreover, the microRNA-376c (miR-376c) was significantly decreased by the TSP-2 treatment. Furthermore, the TSP-2-induced MMP-2 expression and the subsequent cell motility were suppressed upon miR-376c mimic stimulation. On the other hand, the animal studies revealed that the bone metastasis was abolished when TSP-2 was stably knocked down in PCa cells. Conclusions Taken together, our results indicate that TSP-2 enhances the migration of PCa cells by increasing MMP-2 expression through down-regulation of miR-376c expression. Therefore, TSP-2 may represent a promising new target for treating PCa.

The aim of the study was to investigate the possible role of coagulation factor XIII (FXIII) plasma activity and its gene (F13A1) Val34Leu variant as well as thrombospondin-2 gene (THBS2) T/G 3′UTR and thrombospondin-4 gene (THBS4) Ala387Pro variants in the development of myocardial infarction (MI) in young patients. The studied group consisted of 158 patients aged < 50 years with MI, and the control groups consisted of 150 healthy people aged < 50 years and 202 patients suffering from MI aged ≥ 50 years. Factor XIII activity was measured by photometric assay; genetic variants were determined using the restriction fragment length polymorphism (RFLP) method. FXIII activity was significantly higher in the young MI group compared with young healthy controls and the MI ≥ 50 group (126.2 U/dl vs. 109.6 U/dl, p < 0.0001; 126.2 U/dl vs. 119.8 U/dl, p = 0.01, respectively). FXIII activity did not correlate with F13A1 gene variants. F13A1, THBS2 and THBS4 genotypes were equally distributed in all studied groups. There was also no statistically significant differences in the prevalence of the extended CC/TT/GG haplotype of F13A1/THBS2/THBS4 variants between the young MI group and the young healthy control group and between the young MI group and the MI aged ≥ 50 group. In conclusion, our study revealed that increased FXIII activity is associated with an increased risk of MI in young patients. None of studied single genetic variants—F13A1 Val34Leu, THBS2 T/G 3′UTR and THBS4 Ala387Pro—and the extended CC/TT/GG haplotype of F13A1/THBS2/THBS4 genes was associated with MI in young age. [ABSTRACT FROM AUTHOR]

Cervical cancer pathogenesis is regulated by numerous factors, including microRNAs. MicroRNA 1246 (miR-1246) has been shown to serve a role in cervical cancer tumorigenesis. However, the mechanisms through which miR-1246 exerts its oncogenic effects are largely unknown. The aim of the current study was to evaluate the effects of lentivirus-mediated miR-1246 knockdown on the biological characteristics and behavior of cervical cancer cells, and to identify the downstream signaling pathways affected by miR-1246 knockdown. Short hairpins inhibiting miR-1246 were synthesized and cloned into a recombinant lentiviral vector (LV-miR-1246-Inh), which was then used to infect SiHa cervical cancer cells. The effects of LV-miR-1246-Inh infection on cell invasion, proliferation and apoptosis were evaluated by Transwell assay, Cell Counting Kit-8 assay and flow cytometry, respectively. Thrombospondin-2 (THBS2), matrix metalloproteinase 2 (MMP2), MMP9 and extracellular matrix (ECM) component expression levels were evaluated, and the growth of xenograft tumors formed following injection of SiHa cells with knockdown of miR-1246 was assessed. miR-1246 downregulation in SiHa cells decreased proliferation, induced apoptosis and upregulated THBS2 expression. Furthermore, MMP2 and MMP9 levels were downregulated, whereas components of the ECM were upregulated subsequent to miR-1246 knockdown, indicating that this miRNA regulates cervical cancer cell pathogenesis via the THBS2/MMP/ECM pathway. Notably, SiHa cells with miR-1246 downregulation had a markedly decreased ability to form tumors in vivo. These results suggest that miR-1246 functions during cervical cancer pathogenesis and tumor formation via the THBS2/MMP/ECM signaling pathway. These findings support the future use of miR-1246 suppression in the treatment of cervical cancer. [ABSTRACT FROM AUTHOR]

Aims: Recently, cancer-derived exosomes were shown to have pro-metastasis function in cancer, but the mechanism remains unclear. Angiogenesis is essential for tumor progression and is a great promising therapeutic target for advanced cervical cancer. Here, we investigated the role of cervical cancer cell-secreted exosomal miR-221-3p in tumor angiogenesis. Methods and results: miR-221-3p was found to be closely correlated with microvascular density in cervical squamous cell carcinoma (CSCC) by evaluating the microvascular density with immunohistochemistry and miR-221-3p expression with in situ hybridization in clinical specimens. Using the groups of CSCC cell lines (SiHa and C33A) with miR-221-3p overexpression and silencing, the CSCC exosomes were characterized by electron microscopy, western blotting, and fluorescence microscopy. The enrichment of miR-221-3p in CSCC exosomes and its transfer into human umbilical vein endothelial cells (HUVECs) were confirmed by qRT-PCR. CSCC exosomal miR-221-3p promoted angiogenesis in vitro in Matrigel tube formation assay, spheroid sprouting assay, migration assay, and wound healing assay. Then, exosome intratumoral injection indicated that CSCC exosomal miR-221-3p promoted tumor growth in vivo. Thrombospondin-2 (THBS2) was bioinformatically predicted to be a direct target of miR-221-3p, and this was verified by using the in vitro and in vivo experiments described above. Additionally, overexpression of THBS2 in HUVECs rescued the angiogenic function of miR-221-3p. Conclusions: Our results suggest that CSCC exosomes transport miR-221-3p from cancer cells to vessel endothelial cells and promote angiogenesis by downregulating THBS2. Therefore, CSCC-derived exosomal miR-221-3p could be a possible novel diagnostic biomarker and therapeutic target for CSCC progression. [ABSTRACT FROM AUTHOR]

Thrombospondin-2 (TSP-2) is highly expressed in hypertensive heart. Interstitial fibrosis is frequently observed in hypertensive heart, and it is a characteristic feature of heart failure with preserved ejection fraction (HFpEF). We tested here the hypothesis that high TSP-2 serum levels reflect disease severity and can predict poor prognosis of patients with HFpEF. Serum TSP-2 levels were measured by ELISA in 150 patients with HFpEF. HFpEF was defined as left ventricular ejection fraction ≥50 %, B-type natriuretic peptide (BNP) ≥100 pg/ml or E/e′ ≥15. The endpoints were mortality rate, HF-related hospitalization, stroke and non-fatal myocardial infarction. The median serum TSP-2 level was 19.2 (14.4-26.0) ng/ml. Serum TSP-2 levels were associated with the New York Heart Association (NYHA) functional class. Circulating levels of BNP and high-sensitivity troponin T were positively correlated with serum TSP-2 levels. Kaplan-Meier survival curve showed high risk of adverse cardiovascular events in the high TSP-2 group (>median value), and that the combination of high TSP-2 and high BNP (≥100 pg/ml) was associated with the worst event-free survival rate. Multivariate Cox proportional hazard analysis identified TSP-2 as independent predictor of risk of death and cardiovascular events. Circulating TSP-2 correlates with disease severity in patients with HFpEF. TSP-2 is a potentially useful predictor of future adverse cardiovascular events in patients with HFpEF. [ABSTRACT FROM AUTHOR]

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 thrombospondin-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 of 2.18 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. [ABSTRACT FROM AUTHOR]

Background: Thrombospondin-2 (TSP2) is a matricellular protein with tissue expression induced by hyperglycaemia. TSP2 has been implicated in non-diabetic renal injury in preclinical studies and high circulating levels were associated with worse kidney function in cross-sectional clinical studies. Therefore, we investigated the prospective associations of circulating TSP2 level with kidney function decline and the trajectories of estimated glomerular filtration rate (eGFR) in type 2 diabetes., Methods: Baseline serum TSP2 level was measured in 5471 patients with type 2 diabetes to evaluate its association with incident eGFR decline, defined as ≥ 40% sustained eGFR decline, using multivariable Cox regression analysis. Among participants with relatively preserved kidney function (Baseline eGFR ≥ 60 ml/min/1.73m2), joint latent class modelling was employed to identify three different eGFR trajectories. Their associations with baseline serum TSP2 was evaluated using multinomial logistic regression analysis. The predictive performance of serum TSP2 level was examined using time-dependent c-statistics and calibration statistics., Results: Over a median follow-up of 8.8 years, 1083 patients (19.8%) developed eGFR decline. Baseline serum TSP2 level was independently associated with incident eGFR decline (HR 1.21, 95%CI 1.07-1.37, P = 0.002). With internal validation, incorporating serum TSP2 to a model of clinical risk factors including albuminuria led to significant improvement in c-statistics from 83.9 to 84.4 (P < 0.001). Among patients with eGFR ≥ 60 ml/min/1.73m2, baseline serum TSP2 level was independently associated with a rapidly declining eGFR trajectory (HR 1.63, 95%CI 1.26-2.10, P < 0.001)., Conclusion: Serum TSP2 level was independently associated with incident eGFR decline, particularly a rapidly declining trajectory, in type 2 diabetes., (© The Author(s) 2023. Published by Oxford University Press on behalf of the ERA.)

Thrombospondin-2 (Tsp2), a glycoprotein in the extracellular matrix, plays a critical role in the maintenance of vascular homeostasis. However, its role in the pathogenesis of cardiovascular disorders such as intimal hyperplasia is not fully elucidated. This study, therefore, aims to explore the effect of Tsp2 on intimal hyperplasia and its associated underlying mechanisms. Intimal hyperplasia (IH) was established using a modified wire-mediated femoral artery injury model. Immunofluorescence and qPCR identified upregulated Tsp2 expression in the injured femoral artery compared with the uninjured femoral artery. Similarly, TSP2 expression was also increased in human samples from the atherosclerotic femoral artery and colocalized with vascular smooth muscle cells (VSMCs). Compared with the wild-type littermates, Tsp2 knockout mice displayed a mitigated IH in the injured femoral artery, as demonstrated by a decreased neointimal area and intimal/median ratio. Primary mouse VSMCs were cultured to explore the mechanism by which Tsp2 influenced IH in vitro. PDGF-stimulated VSMCs presented an elevated Tsp2 expression and enhanced migration and proliferation. However, Tsp2 knockdown by siRNA blocked the increased migration and proliferation of VSMCs. Further analysis identified an association between Notch3 and IH when the intracellular domain of Notch3 (Nicd3) was upregulated in PDGF-stimulated VSMCs and femoral arteries with IH in human tissues. Along with the overexpression and downregulation of Tsp2, the Nicd3 expression was also up and downregulated accordingly. Tsp2 was associated with IH and may serve as a therapeutic target for IH. Downregulation of Tsp2 could mitigate the progression of IH by modulating the proliferation and migration of VSMCs., (© 2023 Federation of American Societies for Experimental Biology.)

Previous studies have shown that mesenchymal stem cell (MSC)-based therapies have varying efficacies for the treatment of various diseases, including cartilage defects. In this study, we demonstrated that the chondrogenic differentiation potential of human umbilical cord blood-derived MSCs (hUCB-MSCs) obtained from different individual donors varies, and we investigated the molecular basis for this variation. Microarray gene expression analysis identified thrombospondin-2 ( TSP2) as a candidate gene underlying the interindividual variation in the chondrogenic differentiation potential of hUCB-MSCs. To assess the association between TSP-2 and the differentiation potential, we evaluated chondrogenic differentiation of hUCB-MSCs treated with TSP2 siRNA. In addition, we studied the effect of supplementing exogenous recombinant TSP-2 on TSP2 siRNA-treated hUCB-MSCs. We found that TSP-2 autocrinally promoted chondrogenic differentiation of hUCB-MSCs via the Notch signaling pathway, which was confirmed in MSCs from other sources such as bone marrow and adipose tissue. Interestingly, we observed that TSP-2 attenuated hypertrophy, which inevitably occurs during chondrogenic differentiation of hUCB-MSCs. Our findings indicated that the variable chondrogenic differentiation potential of MSCs obtained from different donors is influenced by the TSP-2 level in the differentiating cells. Thus, the TSP-2 level can be used as a marker to select MSCs with superior chondrogenic differentiation potential for use in cartilage regeneration therapy. S tem C ells 2015;33:3291-3303 [ABSTRACT FROM AUTHOR]

Thrombospondin-2 (TSP2) is a matricellular protein component of the bone extracellular matrix. Long bones of adult TSP2-deficient mice have increased endosteal bone thickness due to expansion of the osteoblast progenitor cell pool, and these cells display deficits in osteoblastic potential. Here, we investigated the effects of TSP2 deficiency on whole bone geometric and mechanical properties in growing 6-wk-old male and female wild-type and TSP2-knockout (KO) mice. Microcomputed tomography and mechanical testing were conducted on femora and L2 vertebrae to assess morphology and whole bone mechanical properties. In a second series of experiments, femoral diaphyses were harvested from wild-type and TSP2-KO mice. Detergent-soluble type I collagen content was determined by Western blot of right femora. Total collagen content was determined by hydroxyproline analysis of left femora. In a third series of experiments, cortical bone was dissected from the anterior and posterior aspects of the femoral middiaphysis and imaged by transmission electron microscopy to visualize collagen fibrils. Microcomputed tomography revealed minimal structural effects of TSP2 deficiency. TSP2 deficiency imparted a brittle phenotype on cortical bone. Femoral tissue mineral density was not affected by TSP2 deficiency. Instead, transmission electron microscopy revealed less intensely stained collagen fibrils with altered morphology in the extracellular matrix assembled by osteoblasts on the anterior surface of TSP2-KO femora. Femoral diaphyseal bone displayed comparable amounts of total collagen, but the TSP2-KO bones had higher levels of detergent-extractable type I collagen. Together, our data suggest that TSP2 is required for optimal collagen fibrillogenesis in bone and thereby contributes to normal skeletal tissue quality. [ABSTRACT FROM AUTHOR]